| Doc. no. | -N3011=09-0201 | +Doc. no. | +D3181=10-0171 |
| Date: | -2009-11-08 | +Date: | +2010-11-29 |
| Project: | -Programming Language C++ | +Project: | +Programming Language C++ |
| Reply to: | -Howard Hinnant <howard.hinnant@gmail.com> | +Reply to: | +Alisdair Meredith <lwgchair@gmail.com> |
Revised 2010-11-29 at 10:11:56 UTC
Reference ISO/IEC IS 14882:2003(E)
Also see:
@@ -49,8 +49,8 @@ del {background-color:#FFA0A0}The purpose of this document is to record the status of issues - which have come before the Library Working Group (LWG) of the ANSI - (J16) and ISO (WG21) C++ Standards Committee. Issues represent + which have come before the Library Working Group (LWG) of the INCITS PL22.16 + and ISO WG21 C++ Standards Committee. Issues represent potential defects in the ISO/IEC IS 14882:2003(E) document.
@@ -64,7 +64,7 @@ del {background-color:#FFA0A0}The issues in these lists are not necessarily formal ISO Defect Reports (DR's). While some issues will eventually be elevated to official Defect Report status, other issues will be disposed of in - other ways. See Issue Status.
+ other ways. See Issue Status.Prior to Revision 14, library issues lists existed in two slightly different versions; a Committee Version and a Public @@ -153,6 +153,168 @@ ownership of it.
A Proposed Resolution for a deferred issue is still not be + construed as the view of LWG. Comments on the current state of + discussions are often given at the end of open issues in an italic + font. Such comments are for information only and should not be given + undue importance.
+Dup - The LWG has reached consensus that the issue is a duplicate of another issue, and will not be further dealt with. A Rationale identifies the duplicated issue's @@ -1086,7 +1260,13 @@ format, DR - (Defect Report) - The full J16 +
Resolved - The LWG has reached consensus + that the issue is a defect in the Standard, but the resolution adopted to + resolve the issue came via some other mechanism than this issue in the + list - typically by applying a formal paper, occasionally as a side effect + of consolidating several interacting issue resolutions into a single issue.
+ +DR - (Defect Report) - The full WG21/PL22.16 committee has voted to forward the issue to the Project Editor to be processed as a Potential Defect Report. The Project Editor reviews the issue, and then forwards it to the WG21 Convenor, who returns it @@ -1095,12 +1275,12 @@ format, TC1 - (Technical Corrigenda 1) - The full - WG21 committee has voted to accept the Defect Report's Proposed + WG21/PL22.16 committee has voted to accept the Defect Report's Proposed Resolution as a Technical Corrigenda. Action on this issue is thus complete and no further action is possible under ISO rules.
CD1 - (Committee Draft 2008) - The full - WG21 committee has voted to accept the Defect Report's Proposed + WG21/PL22.16 committee has voted to accept the Defect Report's Proposed Resolution into the Fall 2008 Committee Draft.
TRDec - (Decimal TR defect) - The @@ -1110,7 +1290,7 @@ format, WP - (Working Paper) - The proposed resolution has not been accepted as a Technical Corrigendum, but - the full WG21 committee has voted to apply the Defect Report's Proposed + the full WG21/PL22.16 committee has voted to apply the Defect Report's Proposed Resolution to the working paper.
Tentatively - This is a status qualifier. The issue has @@ -1144,12849 +1324,10 @@ format, 296. Missing descriptions and requirements of pair operators -
Section: 20.3.4 [pairs] Status: Ready - Submitter: Martin Sebor Opened: 2001-01-14 Last modified: 2009-10-26
-View other active issues in [pairs].
-View all other issues in [pairs].
-View all issues with Ready status.
-Discussion:
-The synopsis of the header <utility> in 20.3 [utility] -lists the complete set of equality and relational operators for pair -but the section describing the template and the operators only describes -operator==() and operator<(), and it fails to mention -any requirements on the template arguments. The remaining operators are -not mentioned at all. -
- -[ -2009-09-27 Alisdair reopens. -]
- - --- --The issue is a lack of wording specifying the semantics of std::pair -relational operators. The rationale is that this is covered by -catch-all wording in the relops component, and that as relops directly -precedes pair in the document this is an easy connection to make. -
- --Reading the current working paper I make two observations: -
- --
- -- -relops no longer immediately precedes pair in the order of -specification. However, even if it did, there is a lot of pair -specification itself between the (apparently) unrelated relops and the -relational operators for pair. (The catch-all still requires -operator== and operator< to be specified -explicitly) -
- -- -No other library component relies on the catch-all clause. The following -all explicitly document all six relational operators, usually in a -manner that could have deferred to the relops clause. -
-- -tuple -unique_ptr -duration -time_point -basic_string -queue -stack -move_iterator -reverse_iterator -regex submatch -thread::id --The container components provide their own (equivalent) definition in -23.2.1 [container.requirements.general] Table 90 -- Container -requirements and do so do not defer to relops. -
- --Shared_ptr explicitly documents operator!= and does -not supply the other 3 missing operators -(>,>=,<=) so does not meet the -reqirements of the relops clause. -
- --Weak_ptr only supports operator< so would not be -covered by relops. -
- --At the very least I would request a note pointing to the relops clause -we rely on to provide this definition. If this route is taken, I would -recommend reducing many of the above listed clauses to a similar note -rather than providing redundant specification. -
- --My preference would be to supply the 4 missing specifications consistent -with the rest of the library. -
- -
[ -2009-10-11 Daniel opens 1233 which deals with the same issue as -it pertains to unique_ptr. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready -- - - -
Proposed resolution:
--After p20 20.3.4 [pairs] add: -
- -- - -template <class T1, class T2> -bool operator!=(const pair<T1,T2>& x, const pair<T1,T2>& y); -- --Returns: !(x==y) -- -template <class T1, class T2> -bool operator> (const pair<T1,T2>& x, const pair<T1,T2>& y); -- --Returns: y < x -- -template <class T1, class T2> -bool operator>=(const pair<T1,T2>& x, const pair<T1,T2>& y); -- --Returns: !(x < y) -- -template <class T1, class T2> -bool operator<=(const pair<T1,T2>& x, const pair<T1,T2>& y); -- --Returns: !(y < x) --
Rationale:
-20.3.1 [operators] paragraph 10 already specifies the semantics. -That paragraph says that, if declarations of operator!=, operator>, -operator<=, and operator>= appear without definitions, they are -defined as specified in 20.3.1 [operators]. There should be no user -confusion, since that paragraph happens to immediately precede the -specification of pair.
- - - - - -Section: 24.2.4 [bidirectional.iterators], 24.2.5 [random.access.iterators] Status: Open - Submitter: John Potter Opened: 2001-01-22 Last modified: 2009-10-26
-View all other issues in [bidirectional.iterators].
-View all issues with Open status.
-Discussion:
--In section 24.2.4 [bidirectional.iterators], -Table 75 gives the return type of *r-- as convertible to T. This is -not consistent with Table 74 which gives the return type of *r++ as -T&. *r++ = t is valid while *r-- = t is invalid. -
- --In section 24.2.5 [random.access.iterators], -Table 76 gives the return type of a[n] as convertible to T. This is -not consistent with the semantics of *(a + n) which returns T& by -Table 74. *(a + n) = t is valid while a[n] = t is invalid. -
- --Discussion from the Copenhagen meeting: the first part is -uncontroversial. The second part, operator[] for Random Access -Iterators, requires more thought. There are reasonable arguments on -both sides. Return by value from operator[] enables some potentially -useful iterators, e.g. a random access "iota iterator" (a.k.a -"counting iterator" or "int iterator"). There isn't any obvious way -to do this with return-by-reference, since the reference would be to a -temporary. On the other hand, reverse_iterator takes an -arbitrary Random Access Iterator as template argument, and its -operator[] returns by reference. If we decided that the return type -in Table 76 was correct, we would have to change -reverse_iterator. This change would probably affect user -code. -
- --History: the contradiction between reverse_iterator and the -Random Access Iterator requirements has been present from an early -stage. In both the STL proposal adopted by the committee -(N0527==94-0140) and the STL technical report (HPL-95-11 (R.1), by -Stepanov and Lee), the Random Access Iterator requirements say that -operator[]'s return value is "convertible to T". In N0527 -reverse_iterator's operator[] returns by value, but in HPL-95-11 -(R.1), and in the STL implementation that HP released to the public, -reverse_iterator's operator[] returns by reference. In 1995, the -standard was amended to reflect the contents of HPL-95-11 (R.1). The -original intent for operator[] is unclear. -
- --In the long term it may be desirable to add more fine-grained -iterator requirements, so that access method and traversal strategy -can be decoupled. (See "Improved Iterator Categories and -Requirements", N1297 = 01-0011, by Jeremy Siek.) Any decisions -about issue 299 should keep this possibility in mind. -
- -Further discussion: I propose a compromise between John Potter's -resolution, which requires T& as the return type of -a[n], and the current wording, which requires convertible to -T. The compromise is to keep the convertible to T -for the return type of the expression a[n], but to also add -a[n] = t as a valid expression. This compromise "saves" the -common case uses of random access iterators, while at the same time -allowing iterators such as counting iterator and caching file -iterators to remain random access iterators (iterators where the -lifetime of the object returned by operator*() is tied to the -lifetime of the iterator). -
- --Note that the compromise resolution necessitates a change to -reverse_iterator. It would need to use a proxy to support -a[n] = t. -
- --Note also there is one kind of mutable random access iterator that -will no longer meet the new requirements. Currently, iterators that -return an r-value from operator[] meet the requirements for a -mutable random access iterartor, even though the expression a[n] = -t will only modify a temporary that goes away. With this proposed -resolution, a[n] = t will be required to have the same -operational semantics as *(a + n) = t. -
- -[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-09-18 Alisdair adds: -]
- - --- --Why can't we write through the reference returned from operator[] on a -random access iterator? -
- --Recommended solution: -
- --In table Table 104 -- Random access iterator requirements, replace -
- --a[n] : convertible to-const T &-T& if X is mutable, otherwise convertible to const T& -
[ -2009-10 Santa Cruz: -]
- - --Leave Open. Alisdair to spearhead a paper on revivification. -- - - -
Proposed resolution:
- --In section 24.1.4 [lib.bidirectdional.iterators], change the return -type in table 75 from "convertible to T" to -T&. -
- --In section 24.1.5 [lib.random.access.iterators], change the -operational semantics for a[n] to " the r-value of -a[n] is equivalent to the r-value of *(a + -n)". Add a new row in the table for the expression a[n] = t -with a return type of convertible to T and operational semantics of -*(a + n) = t. -
- -[Lillehammer: Real problem, but should be addressed as part of - iterator redesign]
- - - - -Rationale:
-[ -San Francisco: -]
- - --Solved by -N2758. -- - - - - - - -
Section: 27.7.2.4 [ostream::sentry] Status: Open - Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2009-10-20
-View all other issues in [ostream::sentry].
-View all issues with Open status.
-Discussion:
--17.4.4.8, p3 prohibits library dtors from throwing exceptions. -
--27.6.2.3, p4 says this about the ostream::sentry dtor: -
--4- If ((os.flags() & ios_base::unitbuf) && !uncaught_exception()) - is true, calls os.flush(). --
-27.6.2.6, p7 that describes ostream::flush() says: -
--7- If rdbuf() is not a null pointer, calls rdbuf()->pubsync(). - If that function returns ?-1 calls setstate(badbit) (which - may throw ios_base::failure (27.4.4.3)). --
-That seems like a defect, since both pubsync() and setstate() can -throw an exception. -
-[ -The contradiction is real. Clause 17 says destructors may never -throw exceptions, and clause 27 specifies a destructor that does -throw. In principle we might change either one. We're leaning -toward changing clause 17: putting in an "unless otherwise specified" -clause, and then putting in a footnote saying the sentry destructor -is the only one that can throw. PJP suggests specifying that -sentry::~sentry() should internally catch any exceptions it might cause. -]
- - -[ -See 418 and 622 for related issues. -]
- - -[ -2009-07 Frankfurt -]
- - --- --Move to Review. Add "Throws: nothing" to the specification of ostream::sentry::~sentry(). -
-
[ -2009-10-13 Daniel adds: -]
- - --The proposed resolution of 835 is written to match the outcome -of this issue. -- -
[ -2009 Santa Cruz: -]
- - --Move to Open. Our intent is to solve this issue with 835. -- - - -
Proposed resolution:
--Add after 27.7.2.4 [ostream::sentry] p17: -
- --- - - - - -~sentry(); ------17- If ((os.flags() & ios_base::unitbuf) && !uncaught_exception()) -is true, calls os.flush(). -
- --Throws: Nothing. -
-
Section: 24.2 [iterator.requirements] Status: Open - Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2009-11-03
-View other active issues in [iterator.requirements].
-View all other issues in [iterator.requirements].
-View all issues with Open status.
-Discussion:
--I've been discussing iterator semantics with Dave Abrahams, and a -surprise has popped up. I don't think this has been discussed before. -
- --X [iterator.concepts] says that the only operation that can be performed on "singular" -iterator values is to assign a non-singular value to them. (It -doesn't say they can be destroyed, and that's probably a defect.) -Some implementations have taken this to imply that there is no need -to initialize the data member of a reverse_iterator<> in the default -constructor. As a result, code like -
--std::vector<std::reverse_iterator<char*> > v(7); - v.reserve(1000); -
-invokes undefined behavior, because it must default-initialize the -vector elements, and then copy them to other storage. Of course many -other vector operations on these adapters are also left undefined, -and which those are is not reliably deducible from the standard. -
- --I don't think that 24.1 was meant to make standard-library iterator -types unsafe. Rather, it was meant to restrict what operations may -be performed by functions which take general user- and standard -iterators as arguments, so that raw pointers would qualify as -iterators. However, this is not clear in the text, others have come -to the opposite conclusion. -
- --One question is whether the standard iterator adaptors have defined -copy semantics. Another is whether they have defined destructor -semantics: is -
- { std::vector<std::reverse_iterator<char*> > v(7); }
--undefined too? -
- --Note this is not a question of whether algorithms are allowed to -rely on copy semantics for arbitrary iterators, just whether the -types we actually supply support those operations. I believe the -resolution must be expressed in terms of the semantics of the -adapter's argument type. It should make clear that, e.g., the -reverse_iterator<T> constructor is actually required to execute -T(), and so copying is defined if the result of T() is copyable. -
- --Issue 235, which defines reverse_iterator's default -constructor more precisely, has some relevance to this issue. -However, it is not the whole story. -
- --The issue was whether -
- reverse_iterator() { }
--is allowed, vs. -
- reverse_iterator() : current() { }
--The difference is when T is char*, where the first leaves the member -uninitialized, and possibly equal to an existing pointer value, or -(on some targets) may result in a hardware trap when copied. -
- --8.5 paragraph 5 seems to make clear that the second is required to -satisfy DR 235, at least for non-class Iterator argument -types. -
- --But that only takes care of reverse_iterator, and doesn't establish -a policy for all iterators. (The reverse iterator adapter was just -an example.) In particular, does my function -
- template <typename Iterator>
- void f() { std::vector<Iterator> v(7); }
--evoke undefined behavior for some conforming iterator definitions? -I think it does, now, because vector<> will destroy those singular -iterator values, and that's explicitly disallowed. -
- --24.1 shouldn't give blanket permission to copy all singular iterators, -because then pointers wouldn't qualify as iterators. However, it -should allow copying of that subset of singular iterator values that -are default-initialized, and it should explicitly allow destroying any -iterator value, singular or not, default-initialized or not. -
- - -[ -We don't want to require all singular iterators to be copyable, -because that is not the case for pointers. However, default -construction may be a special case. Issue: is it really default -construction we want to talk about, or is it something like value -initialization? We need to check with core to see whether default -constructed pointers are required to be copyable; if not, it would be -wrong to impose so strict a requirement for iterators. -]
- - -[ -2009-05-10 Alisdair provided wording. -]
- - --The comments regarding destroying singular iterators have already been -resolved. That just leaves copying (with moving implied). -- -
[ -2009-07 Frankfurt -]
- - --- --This is related to LWG 1012. -
--Note that there is a bug in the proposed resolution to LWG 1012. The -change to [reverse.iter.con] should be modified so that the word -"default" in the second sentence of the Effects clause is replaced by -"value." -
--We believe that the proposed fix to LWG 1012 (now corrected) is -sufficient to solve the problem for reverse_iterator. However, Alisdair -pointed out that LWG 1012 does not solve the general problem for authors -of iterator adaptors. -
--There are some problems with the proposed resolution. The phrase "safely -copyable" is not a term of art. Also, it mentions a -DefaultConstructible? concept. -
--Move to Review after Alisdair updates the wording. -
-
[ -2009-07-31 Alisdair revised wording: -]
- - -[ -2009-08-17 Alisdair and Daniel collaborate on slightly revised wording. -This issue depends upon 724 -]
- - -[ -2009-10-14 Daniel adds: -]
- - --There is a clear dependency on 1213, because the term "singular", -which is used as part of the resolution, is not properly defined yet. -- -
[ -2009-10 Santa Cruz: -]
- - --Moved to Open. Alisdair will provide improved wording to make -this have "value semantics" and otherwise behave like a valid iterator. -- - - -
Proposed resolution:
--Add a new paragrpah to Iterator concepts 24.2 [iterator.requirements] after para 5 (the one describing -singular iterators) -
--- - - - - - --Just as a regular pointer to an array guarantees that there is a pointer -value pointing past the last element of the array, so for any iterator -type there is an iterator value that points past the last element of a -corresponding container. These values are called past-the-end values. -Values of an iterator i for which the expression *i is defined are called -dereferenceable. The library never assumes that past-the-end values are -dereferenceable. Iterators can also have singular values that are not -associated with any container. [Example: After the declaration of an -uninitialized pointer x (as with int* x;), x must always be assumed to -have a singular value of a pointer. — end example] Results of most -expressions are undefined for singular values; the only exceptions are -destroying an iterator that holds a singular value and the assignment of -a non-singular value to an iterator that holds a singular value. In this -case the singular value is overwritten the same way as any other value. -Dereferenceable values are always non-singular. -
--After value-initialization, any iterator that satisfies the -DefaultConstructible requirements ([defaultconstructible]) shall not introduce undefined behaviour -when used as the -source of a copy or move operation, even if it would -otherwise be singular. [Note: This guarantee is not offered for -default-initialization (8.5 [dcl.init]), although the distinction only -matters for types with trivial default constructors such as pointers. — -end note] -
- - -
Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: Open - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-10-26
-View other active issues in [facet.num.get.virtuals].
-View all other issues in [facet.num.get.virtuals].
-View all issues with Open status.
-Discussion:
--The requirements specified in Stage 2 and reiterated in the rationale -of DR 221 (and echoed again in DR 303) specify that num_get<charT>:: -do_get() compares characters on the stream against the widened elements -of "012...abc...ABCX+-" -
- --An implementation is required to allow programs to instantiate the num_get -template on any charT that satisfies the requirements on a user-defined -character type. These requirements do not include the ability of the -character type to be equality comparable (the char_traits template must -be used to perform tests for equality). Hence, the num_get template cannot -be implemented to support any arbitrary character type. The num_get template -must either make the assumption that the character type is equality-comparable -(as some popular implementations do), or it may use char_traits<charT> to do -the comparisons (some other popular implementations do that). This diversity -of approaches makes it difficult to write portable programs that attempt to -instantiate the num_get template on user-defined types. -
- -[Kona: the heart of the problem is that we're theoretically - supposed to use traits classes for all fundamental character - operations like assignment and comparison, but facets don't have - traits parameters. This is a fundamental design flaw and it - appears all over the place, not just in this one place. It's not - clear what the correct solution is, but a thorough review of facets - and traits is in order. The LWG considered and rejected the - possibility of changing numeric facets to use narrowing instead of - widening. This may be a good idea for other reasons (see issue - 459), but it doesn't solve the problem raised by this - issue. Whether we use widen or narrow the num_get facet - still has no idea which traits class the user wants to use for - the comparison, because only streams, not facets, are passed traits - classes. The standard does not require that two different - traits classes with the same char_type must necessarily - have the same behavior.]
- - -Informally, one possibility: require that some of the basic -character operations, such as eq, lt, -and assign, must behave the same way for all traits classes -with the same char_type. If we accept that limitation on -traits classes, then the facet could reasonably be required to -use char_traits<charT>.
- -[ -2009-07 Frankfurt -]
- - --- --There was general agreement that the standard only needs to specify the -behavior when the character type is char or wchar_t. -
--Beman: we don't need to worry about C++1x because there is a non-zero -possibility that we would have a replacement facility for iostreams that -would solve these problems. -
--We need to change the following sentence in [locale.category], paragraph -6 to specify that C is char and wchar_t: -
--"A template formal parameter with name C represents the set of all -possible specializations on a parameter that satisfies the requirements -for a character on which any member of the iostream components can be -instantiated." -
--We also need to specify in 27 that the basic character operations, such -as eq, lt, and assign use std::char_traits. -
--Daniel volunteered to provide wording. -
-
[ -2009-09-19 Daniel provided wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Leave as Open. Alisdair and/or Tom will provide wording based on discussions. -We want to clearly state that streams and locales work just on char -and wchar_t (except where otherwise specified). -- - - -
Proposed resolution:
--Change 22.3.1.1.1 [locale.category]/6: -
- --[..] A template formal parameter with name C represents the set of all possible -specializations on a char or wchar_t parameter-that satisfies -the requirements for a character on which any of the iostream components -can be instantiated. [..] -
-Add the following sentence to the end of 22.4.2 [category.numeric]/2: -
- --[..] These specializations refer to [..], and also for the ctype<> facet to -perform character classification. Implementations are encouraged -but not required to use the char_traits<charT> functions for all -comparisons and assignments of characters of type charT that do -not belong to the set of required specializations. --
-Change 22.4.2.1.2 [facet.num.get.virtuals]/3: -
- --- --Stage 2: If in==end then stage 2 terminates. Otherwise a charT is taken -from in and local variables are initialized as if by -
- -- -char_type ct = *in; -using tr = char_traits<char_type>; -const char_type* pos = tr::find(atoms, sizeof(src) - 1, ct); -char c = src[find(atoms, atoms + sizeof(src) - 1, ct) - atoms- pos ? pos - atoms : sizeof(src) - 1]; -if (tr::eq(ct,ct ==use_facet<numpunct<charT>(loc).decimal_point())) - c = '.'; -bool discard = - tr::eq(ct,ct ==use_facet<numpunct<charT>(loc).thousands_sep()) - && use_facet<numpunct<charT> >(loc).grouping().length() != 0; --where the values src and atoms are defined as if by: [..] -
-
-[Remark of the author: I considered to replace the initialization -"char_type ct = *in;" -by the sequence "char_type ct; tr::assign(ct, *in);", but decided -against it, because -it is a copy-initialization context, not an assignment] -
--Add the following sentence to the end of 22.4.5 [category.time]/1: -
- --[..] Their members use [..] , to determine formatting details. -Implementations are encouraged but not required to use the -char_traits<charT> functions for all comparisons and assignments -of characters of type charT that do -not belong to the set of required specializations. --
-Change 22.4.5.1.1 [locale.time.get.members]/8 bullet 4: -
- --Add the following sentence to the end of 22.4.6 [category.monetary]/2: -
- --Their members use [..] to determine formatting details. -Implementations are encouraged but not required to use the -char_traits<charT> functions for all comparisons and assignments -of characters of type charT that do -not belong to the set of required specializations. --
-Change 22.4.6.1.2 [locale.money.get.virtuals]/4: -
- ----[..] The value units is produced as if by: -
- --for (int i = 0; i < n; ++i) - buf2[i] = src[char_traits<charT>::find(atoms,atoms+sizeof(src), buf1[i]) - atoms]; -buf2[n] = 0; -sscanf(buf2, "%Lf", &units); -
-Change 22.4.6.2.2 [locale.money.put.virtuals]/1: -
- --[..] for character buffers buf1 and buf2. If for the first -character c -in digits or buf2-is equal to -ct.widen('-')char_traits<charT>::eq(c, -ct.widen('-')) == true, [..] -
-Add a footnote to the first sentence of 27.7.1.2.2 [istream.formatted.arithmetic]/1: -
- ----As in the case of the inserters, these extractors depend on the locale's -num_get<> (22.4.2.1) object to perform parsing the input stream -data.(footnote) [..] -
- -- -footnote) If the traits of the input stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -
-
-Add a footnote to the second sentence of 27.7.2.6.2 [ostream.inserters.arithmetic]/1: -
- ----Effects: The classes num_get<> and -num_put<> handle locale-dependent numeric formatting and -parsing. These inserter functions use the imbued locale value to perform -numeric formatting.(footnote) [..] -
- -- -footnote) If the traits of the output stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -
-
-Add a footnote after the first sentence of 27.7.4 [ext.manip]/4: -
- ----Returns: An object of unspecified type such that if in is an object of type -basic_istream<charT, traits> then the expression in >> get_money(mon, intl) -behaves as if it called f(in, mon, intl), where the function f is defined -as:(footnote) [..] -
- -- -footnote) If the traits of the input stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -
-
-Add a footnote after the first sentence of 27.7.4 [ext.manip]/5: -
- ----Returns: An object of unspecified type such that if out is an object of type -basic_ostream<charT, traits> then the expression out << put_money(mon, intl) -behaves as a formatted input function that calls f(out, mon, intl), where the -function f is defined as:(footnote) [..] -
- -- -footnote) If the traits of the output stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -
-
-13) Add a footnote after the first sentence of 27.7.4 [ext.manip]/8: -
- ----Returns: An object of unspecified type such that if in is an -object of type basic_istream<charT, traits> then the expression -in >>get_time(tmb, fmt) behaves as if it called f(in, tmb, fmt), -where the function f is defined as:(footnote) [..] -
- -- -footnote) If the traits of the input stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -
-
-Add a footnote after the first sentence of 27.7.4 [ext.manip]/10: -
- ----Returns: An object of unspecified type such that if out is an object of type -basic_ostream<charT, traits> then the expression out <<put_time(tmb, fmt) -behaves as if it called f(out, tmb, fmt), where the function f is defined -as:(footnote) [..] -
- -- -footnote) If the traits of the output stream has different semantics for lt(), -eq(), and assign() than char_traits<char_type>, this may give surprising -results. - -
-
Section: 26.6.2.4 [valarray.sub] Status: Open - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-11-04
-View all issues with Open status.
-Discussion:
--The standard fails to specify the behavior of valarray::operator[](slice) -and other valarray subset operations when they are passed an "invalid" -slice object, i.e., either a slice that doesn't make sense at all (e.g., -slice (0, 1, 0) or one that doesn't specify a valid subset of the valarray -object (e.g., slice (2, 1, 1) for a valarray of size 1). -
-[Kona: the LWG believes that invalid slices should invoke - undefined behavior. Valarrays are supposed to be designed for high - performance, so we don't want to require specific checking. We - need wording to express this decision.]
- - -[ -Bellevue: -]
- - --Please note that the standard also fails to specify the behavior of -slice_array and gslice_array in the valid case. Bill Plauger will -endeavor to provide revised wording for slice_array and gslice_array. -- -
[ -post-Bellevue: Bill provided wording. -]
- - -[ -2009-07 Frankfurt -]
- - --- --Move to Ready. -
-
[ -2009-11-04 Pete opens: -]
- - --The resolution to LWG issue 430 has not been applied --- there have been -changes to the underlying text, and the resolution needs to be reworked. -- - - -
Proposed resolution:
--Insert after 26.6.2.4 [valarray.sub], paragraph 1: -
- --- - - - - --The member operator is overloaded to provide several ways to select -sequences -of elements from among those controlled by *this. The first group of five -member operators work in conjunction with various overloads of operator= -(and other assigning operators) to allow selective replacement (slicing) of -the controlled sequence. The selected elements must exist. -
--The first member operator selects element off. For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -v0[3] = 'A'; -// v0 == valarray<char>("abcAefghijklmnop", 16) --The second member operator selects those elements of the controlled sequence -designated by slicearr. For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -valarray<char> v1("ABCDE", 5); -v0[slice(2, 5, 3)] = v1; -// v0 == valarray<char>("abAdeBghCjkDmnEp", 16) --The third member operator selects those elements of the controlled sequence -designated by gslicearr. For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -valarray<char> v1("ABCDEF", 6); -const size_t lv[] = {2, 3}; -const size_t dv[] = {7, 2}; -const valarray<size_t> len(lv, 2), str(dv, 2); -v0[gslice(3, len, str)] = v1; -// v0 == valarray<char>("abcAeBgCijDlEnFp", 16) --The fourth member operator selects those elements of the controlled sequence -designated by boolarr. For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -valarray<char> v1("ABC", 3); -const bool vb[] = {false, false, true, true, false, true}; -v0[valarray<bool>(vb, 6)] = v1; -// v0 == valarray<char>("abABeCghijklmnop", 16) --The fifth member operator selects those elements of the controlled sequence -designated by indarr. For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -valarray<char> v1("ABCDE", 5); -const size_t vi[] = {7, 5, 2, 3, 8}; -v0[valarray<size_t>(vi, 5)] = v1; -// v0 == valarray<char>("abCDeBgAEjklmnop", 16) --The second group of five member operators each construct an object that -represents the value(s) selected. The selected elements must exist. -
- --The sixth member operator returns the value of element off. For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -// v0[3] returns 'd' --The seventh member operator returns an object of class valarray<Ty> -containing those elements of the controlled sequence designated by slicearr. -For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -// v0[slice(2, 5, 3)] returns valarray<char>("cfilo", 5) --The eighth member operator selects those elements of the controlled sequence -designated by gslicearr. For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -const size_t lv[] = {2, 3}; -const size_t dv[] = {7, 2}; -const valarray<size_t> len(lv, 2), str(dv, 2); -// v0[gslice(3, len, str)] returns -// valarray<char>("dfhkmo", 6) --The ninth member operator selects those elements of the controlled sequence -designated by boolarr. For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -const bool vb[] = {false, false, true, true, false, true}; -// v0[valarray<bool>(vb, 6)] returns -// valarray<char>("cdf", 3) --The last member operator selects those elements of the controlled sequence -designated by indarr. For example: -
- -- -valarray<char> v0("abcdefghijklmnop", 16); -const size_t vi[] = {7, 5, 2, 3, 8}; -// v0[valarray<size_t>(vi, 5)] returns -// valarray<char>("hfcdi", 5) -
Section: 24.2 [iterator.requirements], 23.2 [container.requirements] Status: Open - Submitter: Andy Koenig Opened: 2003-12-16 Last modified: 2009-11-03
-View other active issues in [iterator.requirements].
-View all other issues in [iterator.requirements].
-View all issues with Open status.
-Discussion:
--What requirements does the standard place on equality comparisons between -iterators that refer to elements of different containers. For example, if -v1 and v2 are empty vectors, is v1.end() == v2.end() allowed to yield true? -Is it allowed to throw an exception? -
- --The standard appears to be silent on both questions. -
-[Sydney: The intention is that comparing two iterators from -different containers is undefined, but it's not clear if we say that, -or even whether it's something we should be saying in clause 23 or in -clause 24. Intuitively we might want to say that equality is defined -only if one iterator is reachable from another, but figuring out how -to say it in any sensible way is a bit tricky: reachability is defined -in terms of equality, so we can't also define equality in terms of -reachability. -]
- - -[ -2009-07 Frankfurt -]
- - --Daniel volunteered to work on this. -- -
[ -2009-09-20 Daniel provided wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Leave as Open. Alisdair has volunteered to refine the wording. -- - - -
Proposed resolution:
--Insert a new paragraph between 24.2 [iterator.requirements]/7+8: -
- --- - - - - - --[..] The result of the application of functions in the library to invalid -ranges is undefined. -
- -The result of directly or indirectly evaluating any comparison function -or the binary - operator with two iterator values as arguments that -were obtained -from two different ranges r1 and r2 (including their past-the-end values) which -are not subranges of one common range is undefined, unless explicitly -described otherwise. -
- -
Section: 18.8.1 [exception] Status: Ready - Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2009-10-26
-View all issues with Ready status.
-Discussion:
- -[lib.exception] specifies the following:
-exception (const exception&) throw(); - exception& operator= (const exception&) throw(); - - -4- Effects: Copies an exception object. - -5- Notes: The effects of calling what() after assignment - are implementation-defined. -- -
-First, does the Note only apply to the assignment operator? If so, -what are the effects of calling what() on a copy of an object? Is -the returned pointer supposed to point to an identical copy of -the NTBS returned by what() called on the original object or not? -
- --Second, is this Note intended to extend to all the derived classes -in section 19? I.e., does the standard provide any guarantee for -the effects of what() called on a copy of any of the derived class -described in section 19? -
- --Finally, if the answer to the first question is no, I believe it -constitutes a defect since throwing an exception object typically -implies invoking the copy ctor on the object. If the answer is yes, -then I believe the standard ought to be clarified to spell out -exactly what the effects are on the copy (i.e., after the copy -ctor was called). -
- -[Redmond: Yes, this is fuzzy. The issue of derived classes is - fuzzy too.]
- - -[ -Batavia: Howard provided wording. -]
- - -[ -Bellevue: -]
- - --- --Eric concerned this is unimplementable, due to nothrow guarantees. -Suggested implementation would involve reference counting. -
--Is the implied reference counting subtle enough to call out a note on -implementation? Probably not. -
--If reference counting required, could we tighten specification further -to require same pointer value? Probably an overspecification, especially -if exception classes defer evalutation of final string to calls to -what(). -
--Remember issue moved open and not resolved at Batavia, but cannot -remember who objected to canvas a disenting opinion - please speak up if -you disagree while reading these minutes! -
--Move to Ready as we are accepting words unmodified. -
-
[ -Sophia Antipolis: -]
- - --The issue was pulled from Ready. It needs to make clear that only homogenous copying -is intended to be supported, not coping from a derived to a base. -- -
[ -Batavia (2009-05): -]
- --- --Howard supplied the following replacement wording -for paragraph 7 of the proposed resolution: -
---7- Postcondition: what() shall return the same NTBS - as would be obtained by using static_cast - to cast the rhs to the same types as the lhs - and then calling what() on that possibly sliced object. ---Pete asks what "the same NTBS" means. -
-
[ -2009-07-30 Niels adds: -]
- - --Further discussion in the thread starting with c++std-lib-24512. -- -
[ -2009-09-24 Niels provided updated wording: -]
- - --- --I think the resolution should at least guarantee -that the result of what() is independent of whether the compiler does -copy-elision. And for any class derived from std::excepion that has a -constructor that allows specifying a what_arg, it should make sure that -the text of a user-provided what_arg is preserved, when the object is -copied. Note that all the implementations I've tested already appear to -satisfy the proposed resolution, including MSVC 2008 SP1, Apache -stdcxx-4.2.1, GCC 4.1.2, GCC 4.3.2, and CodeGear C++ 6.13. -
--The proposed resolution was updated with help from Daniel Krügler; -the update aims to clarify that the proposed postcondition only -applies to homogeneous copying. -
-
[ -2009-10 Santa Cruz: -]
- - --Moved to Ready after inserting "publicly accessible" in two places. -- - - -
Proposed resolution:
- --Change 18.8.1 [exception] to: -
- --- - - - - ---1- The class exception defines the base class for the types of -objects thrown as exceptions by C++ standard library components, and -certain expressions, to report errors detected during program execution. -
--Each standard library class T that derives from class -exception shall have a publicly accessible copy constructor and a publicly accessible copy assignment -operator that do not exit with an exception. These member functions -shall preserve the following postcondition: If two objects lhs -and rhs both have dynamic type T, and lhs is a -copy of rhs, then strcmp(lhs.what(), -rhs.what()) == 0. -
-- ... -
- -exception(const exception& rhs) throw(); -exception& operator=(const exception& rhs) throw();- --- ---4- Effects: Copies an exception object. -
--
--5- Remarks: The effects of calling what() after assignment -are implementation-defined.---5- Postcondition: - If *this - and rhs both have dynamic type exception - then strcmp(what(), rhs.what()) == 0. -
- -
Section: 22.4.1.1 [locale.ctype] Status: Ready - Submitter: Martin Sebor Opened: 2004-07-01 Last modified: 2009-10-21
-View all issues with Ready status.
-Discussion:
--Most ctype member functions come in two forms: one that operates -on a single character at a time and another form that operates -on a range of characters. Both forms are typically described by -a single Effects and/or Returns clause. -
--The Returns clause of each of the single-character non-virtual forms -suggests that the function calls the corresponding single character -virtual function, and that the array form calls the corresponding -virtual array form. Neither of the two forms of each virtual member -function is required to be implemented in terms of the other. -
--There are three problems: -
--1. One is that while the standard does suggest that each non-virtual -member function calls the corresponding form of the virtual function, -it doesn't actually explicitly require it. -
--Implementations that cache results from some of the virtual member -functions for some or all values of their arguments might want to -call the array form from the non-array form the first time to fill -the cache and avoid any or most subsequent virtual calls. Programs -that rely on each form of the virtual function being called from -the corresponding non-virtual function will see unexpected behavior -when using such implementations. -
--2. The second problem is that either form of each of the virtual -functions can be overridden by a user-defined function in a derived -class to return a value that is different from the one produced by -the virtual function of the alternate form that has not been -overriden. -
--Thus, it might be possible for, say, ctype::widen(c) to return one -value, while for ctype::widen(&c, &c + 1, &wc) to set -wc to another value. This is almost certainly not intended. Both -forms of every function should be required to return the same result -for the same character, otherwise the same program using an -implementation that calls one form of the functions will behave -differently than when using another implementation that calls the -other form of the function "under the hood." -
--3. The last problem is that the standard text fails to specify whether -one form of any of the virtual functions is permitted to be implemented -in terms of the other form or not, and if so, whether it is required -or permitted to call the overridden virtual function or not. -
--Thus, a program that overrides one of the virtual functions so that -it calls the other form which then calls the base member might end -up in an infinite loop if the called form of the base implementation -of the function in turn calls the other form. -
--Lillehammer: Part of this isn't a real problem. We already talk about -caching. 22.1.1/6 But part is a real problem. ctype virtuals may call -each other, so users don't know which ones to override to avoid avoid -infinite loops.
- -This is a problem for all facet virtuals, not just ctype virtuals, -so we probably want a blanket statement in clause 22 for all -facets. The LWG is leaning toward a blanket prohibition, that a -facet's virtuals may never call each other. We might want to do that -in clause 27 too, for that matter. A review is necessary. Bill will -provide wording.
- -[ -2009-07 Frankfurt, Howard provided wording directed by consensus. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Add paragraph 3 to 22.4 [locale.categories]: -
- ---3- Within this clause it is unspecified if one virtual function calls another -virtual function. -- - - -
Rationale:
--We are explicitly not addressing bullet -item #2, thus giving implementors more latitude. Users will have to -override both virtual functions, not just one. -
- - - - -Section: 24.2.2 [output.iterators] Status: Ready - Submitter: Chris Jefferson Opened: 2004-10-13 Last modified: 2009-10-26
-View all other issues in [output.iterators].
-View all issues with Ready status.
-Discussion:
--The note on 24.1.2 Output iterators insufficiently limits what can be -performed on output iterators. While it requires that each iterator is -progressed through only once and that each iterator is written to only -once, it does not require the following things:
- -Note: Here it is assumed that x is an output iterator of type X which -has not yet been assigned to.
- -a) That each value of the output iterator is written to: -The standard allows: -++x; ++x; ++x; -
- --b) That assignments to the output iterator are made in order -X a(x); ++a; *a=1; *x=2; is allowed -
- --c) Chains of output iterators cannot be constructed: -X a(x); ++a; X b(a); ++b; X c(b); ++c; is allowed, and under the current -wording (I believe) x,a,b,c could be written to in any order. -
- -I do not believe this was the intension of the standard?
-[Lillehammer: Real issue. There are lots of constraints we - intended but didn't specify. Should be solved as part of iterator - redesign.]
- - -[ -2009-07 Frankfurt -]
- - --Bill provided wording according to consensus. -- -
[ -2009-07-21 Alisdair requests change from Review to Open. See thread starting -with c++std-lib-24459 for discussion. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Modified wording. Set to Review. -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready after looking at again in a larger group in Santa Cruz. -- - - -
Proposed resolution:
--Change Table 101 — Output iterator requirements in 24.2.2 [output.iterators]: -
--- - - - - --
-Table 101 — Output iterator requirements -- - -Expression -Return type -Operational semantics -Assertion/note pre-/post-condition -- - --X(a) - -- - -- - --a = t is equivalent to X(a) = t. note: a destructor is assumed. - -- - --X u(a); -
-X u = a; -- - -- - -- - -- - --*r = o - --result is not used - -- - -- -Post: r is not required to be dereferenceable. r is incrementable. - - -- - --++r - --X& - -- - --&r == &++r - -Post: r is dereferenceable, unless otherwise specified. r is not required to be incrementable. - - -- - --r++ - --convertible to const X& - --{X tmp = r; -
++r;
return tmp;} -- -Post: r is dereferenceable, unless otherwise specified. r is not required to be incrementable. - - -- - --*r++ = o; - --result is not used - -- - -- - -
Section: 26.7.3 [partial.sum] Status: Ready - Submitter: Marc Schoolderman Opened: 2006-02-06 Last modified: 2009-10-24
-View all issues with Ready status.
-Discussion:
--There are some problems in the definition of partial_sum and -adjacent_difference in 26.4 [lib.numeric.ops] -
- --Unlike accumulate and inner_product, these functions are not -parametrized on a "type T", instead, 26.4.3 [lib.partial.sum] simply -specifies the effects clause as; -
- -- --Assigns to every element referred to by iterator i in the range -[result,result + (last - first)) a value correspondingly equal to -
--((...(* first + *( first + 1)) + ...) + *( first + ( i - result ))) -
-And similarly for BinaryOperation. Using just this definition, it seems -logical to expect that: -
- - -char i_array[4] = { 100, 100, 100, 100 };
-int o_array[4];
-
-std::partial_sum(i_array, i_array+4, o_array);
--Is equivalent to -
- -int o_array[4] = { 100, 100+100, 100+100+100, 100+100+100+100 };
--i.e. 100, 200, 300, 400, with addition happening in the result type, -int. -
- --Yet all implementations I have tested produce 100, -56, 44, -112, -because they are using an accumulator of the InputIterator's -value_type, which in this case is char, not int. -
- --The issue becomes more noticeable when the result of the expression *i + -*(i+1) or binary_op(*i, *i-1) can't be converted to the -value_type. In a contrived example: -
- -enum not_int { x = 1, y = 2 };
-...
-not_int e_array[4] = { x, x, y, y };
-std::partial_sum(e_array, e_array+4, o_array);
--Is it the intent that the operations happen in the input type, or in -the result type? -
- --If the intent is that operations happen in the result type, something -like this should be added to the "Requires" clause of 26.4.3/4 -[lib.partial.sum]: -
- -- --The type of *i + *(i+1) or binary_op(*i, *(i+1)) shall meet the -requirements of CopyConstructible (20.1.3) and Assignable -(23.1) types. -
-(As also required for T in 26.4.1 [lib.accumulate] and 26.4.2 -[lib.inner.product].) -
- --The "auto initializer" feature proposed in -N1894 -is not required to -implement partial_sum this way. The 'narrowing' behaviour can still be -obtained by using the std::plus<> function object. -
- --If the intent is that operations happen in the input type, then -something like this should be added instead; -
- -- --The type of *first shall meet the requirements of -CopyConstructible (20.1.3) and Assignable (23.1) types. -The result of *i + *(i+1) or binary_op(*i, *(i+1)) shall be -convertible to this type. -
-The 'widening' behaviour can then be obtained by writing a custom proxy -iterator, which is somewhat involved. -
- --In both cases, the semantics should probably be clarified. -
- --26.4.4 [lib.adjacent.difference] is similarly underspecified, although -all implementations seem to perform operations in the 'result' type: -
- -unsigned char i_array[4] = { 4, 3, 2, 1 };
-int o_array[4];
-
-std::adjacent_difference(i_array, i_array+4, o_array);
--o_array is 4, -1, -1, -1 as expected, not 4, 255, 255, 255. -
- --In any case, adjacent_difference doesn't mention the requirements on the -value_type; it can be brought in line with the rest of 26.4 -[lib.numeric.ops] by adding the following to 26.4.4/2 -[lib.adjacent.difference]: -
- ---The type of *first shall meet the requirements of -CopyConstructible (20.1.3) and Assignable (23.1) types." -
[ -Berlin: Giving output iterator's value_types very controversial. Suggestion of -adding signatures to allow user to specify "accumulator". -]
- - -[ -Bellevue: -]
- - --The intent of the algorithms is to perform their calculations using the type of the input iterator. -Proposed wording provided. -- -
[ -Sophia Antipolis: -]
- - --We did not agree that the proposed resolution was correct. For example, -when the arguments are types (float*, float*, double*), the -highest-quality solution would use double as the type of the -accumulator. If the intent of the wording is to require that the type of -the accumulator must be the input_iterator's value_type, the wording -should specify it. -- -
[ -2009-05-09 Alisdair adds: -]
- - --- --Now that we have the facility, the 'best' accumulator type could probably be -deduced as: -
--std::common_type<InIter::value_type, OutIter::reference>::type --This type would then have additional requirements of constructability and -incrementability/assignability. -
--If this extracting an accumulator type from a pair/set of iterators (with -additional requirements on that type) is a problem for multiple functions, -it might be worth extracting into a SharedAccumulator concept or similar. -
--I'll go no further in writing up wording now, until the group gives a -clearer indication of preferred direction. -
-
[ -2009-07 Frankfurt -]
- - --The proposed resolution isn't quite right. For example, "the type of -*first" should be changed to "iterator::value_type" or similar. Daniel -volunteered to correct the wording. -- -
[ -2009-07-29 Daniel corrected wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
- - - --Change 26.7.3 [partial.sum]/1 as indicated: -
- ----Effects: Let VT be InputIterator's value type. For a nonempty range, -initializes an accumulator acc of type VT with *first and performs -*result = acc. For every iterator i in [first + 1, last) in order, acc is then -modified by acc = acc + *i or acc = binary_op(acc, *i) and is assigned -to *(result + (i - first)).
- -Assigns to every element referred to by -iterator i in the range [result,result + (last - first)) a value -correspondingly -equal to-- --((...(*first + *(first + 1)) + ...) + *(first + (i - result))) -- -
-or ---binary_op(binary_op(..., - binary_op(*first, *(first + 1)),...), *(first + (i - result))) -
-Change 26.7.3 [partial.sum]/3 as indicated: -
- --Complexity: Exactly max((last - first) - 1, 0) -applications -of-binary_opthe binary operation. -
-Change 26.7.3 [partial.sum]/4 as indicated: -
- --Requires: VT shall be constructible from the type of *first, the result of -acc + *i or binary_op(acc, *i) shall be implicitly convertible to VT, and -the result of the expression acc shall be writable to the result -output iterator. In the ranges [first,last] and -[result,result + (last - first)] [..] --
-Change 26.7.4 [adjacent.difference]/1 as indicated: -
- ----Effects: Let VT be InputIterator's value type. For a nonempty range, -initializes an accumulator acc of type VT with *first and performs -*result = acc. For every iterator i in [first + 1, last) in order, -initializes a -value val of type VT with *i, assigns the result of val - acc or -binary_op(val, acc) -to *(result + (i - first)) and modifies acc = std::move(val). -
- -Assigns to every element referred to by iterator i in the range -[result + 1, -result + (last - first)) a value correspondingly equal to-- --*(first + (i - result)) - *(first + (i - result) - 1) -- -
-or -- --binary_op(*(first + (i - result)), *(first + (i - result) - 1)). --
-result gets the value of *first.-
-Change 26.7.4 [adjacent.difference]/2 as indicated: -
- --Requires: VT shall be MoveAssignable ([moveassignable]) -and shall be -constructible from the type of *first. The result -of the expression acc and the result of the expression val - acc or -binary_op(val, acc) -shall be writable to the result output iterator. In the ranges -[first,last] [..] --
-Change 26.7.4 [adjacent.difference]/5 as indicated: -
- --Complexity: Exactly max((last - first) - 1, 0) -applications -of-binary_opthe binary operation. -
Section: 25.4 [alg.sorting] Status: Review - Submitter: Martin Sebor Opened: 2006-02-05 Last modified: 2009-10-25
-View all other issues in [alg.sorting].
-View all issues with Review status.
-Discussion:
--In 25, p8 we allow BinaryPredicates to return a type that's convertible -to bool but need not actually be bool. That allows predicates to return -things like proxies and requires that implementations be careful about -what kinds of expressions they use the result of the predicate in (e.g., -the expression in if (!pred(a, b)) need not be well-formed since the -negation operator may be inaccessible or return a type that's not -convertible to bool). -
--Here's the text for reference: -
-- -- ...if an algorithm takes BinaryPredicate binary_pred as its argument - and first1 and first2 as its iterator arguments, it should work - correctly in the construct if (binary_pred(*first1, first2)){...}. -
-In 25.3, p2 we require that the Compare function object return true -of false, which would seem to preclude such proxies. The relevant text -is here: -
-- -- Compare is used as a function object which returns true if the first - argument is less than the second, and false otherwise... -
[ -Portland: Jack to define "convertible to bool" such that short circuiting isn't -destroyed. -]
- - -[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Review once wording received. Stefanus to send proposed wording. -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Review once wording received. Stefanus to send proposed wording. -- -
[ -2009-10-24 Stefanus supplied wording. -]
- - --Move to Review once wording received. Stefanus to send proposed wording. -Current proposed wording proposed here: -- - - ----I think we could fix this by rewording 25.3, p2 to read somthing like: -
----2- Compare is
used as a function object which returns -true if the first argumenta BinaryPredicate. The -return value of the function call operator applied to an object of type -Compare, when converted to type bool, yields true -if the first argument of the call is less than the second, and -false otherwise. Compare comp is used throughout for -algorithms assuming an ordering relation. It is assumed that comp -will not apply any non-constant function through the dereferenced iterator. -
Proposed resolution:
--Change 25.4 [alg.sorting] p2: -
--Compare is used as a function object. The return value of -the function call operator applied to an object of type Compare, when -converted to type bool, yields true if the first argument of the -call- - -which returns true if the first argument-is less than the second, and false otherwise. Compare -comp is used throughout for algorithms assuming an ordering -relation. It is assumed that comp will not apply any -non-constant function through the dereferenced iterator. -
Rationale:
-[ -San Francisco: -]
- - --Solved by -(N2774). -- - - - - - -
Section: 20.2.1 [utility.arg.requirements] Status: Open - Submitter: Niels Dekker Opened: 2006-11-02 Last modified: 2009-11-08
-View other active issues in [utility.arg.requirements].
-View all other issues in [utility.arg.requirements].
-View all issues with Open status.
-Discussion:
--It seems undesirable to define the Swappable requirement in terms of -CopyConstructible and Assignable requirements. And likewise, once the -MoveConstructible and MoveAssignable requirements (N1860) have made it -into the Working Draft, it seems undesirable to define the Swappable -requirement in terms of those requirements. Instead, it appears -preferable to have the Swappable requirement defined exclusively in -terms of the existence of an appropriate swap function. -
--Section 20.1.4 [lib.swappable] of the current Working Draft (N2009) -says: -
---The Swappable requirement is met by satisfying one or more of the -following conditions:
--
-- -T is Swappable if T satisfies the CopyConstructible requirements -(20.1.3) and the Assignable requirements (23.1); -
-- -T is Swappable if a namespace scope function named swap exists in the -same namespace as the definition of T, such that the expression -swap(t,u) is valid and has the semantics described in Table 33. -
-
-I can think of three disadvantages of this definition: -
--If a client's type T satisfies the first condition (T is both -CopyConstructible and Assignable), the client cannot stop T from -satisfying the Swappable requirement without stopping T from -satisfying the first condition. -
--A client might want to stop T from satisfying the Swappable -requirement, because swapping by means of copy construction and -assignment might throw an exception, and she might find a throwing -swap unacceptable for her type. On the other hand, she might not feel -the need to fully implement her own swap function for this type. In -this case she would want to be able to simply prevent algorithms that -would swap objects of type T from being used, e.g., by declaring a -swap function for T, and leaving this function purposely undefined. -This would trigger a link error, if an attempt would be made to use -such an algorithm for this type. For most standard library -implementations, this practice would indeed have the effect of -stopping T from satisfying the Swappable requirement. -
--A client's type T that does not satisfy the first condition can not be -made Swappable by providing a specialization of std::swap for T. -
--While I'm aware about the fact that people have mixed feelings about -providing a specialization of std::swap, it is well-defined to do so. -It sounds rather counter-intuitive to say that T is not Swappable, if -it has a valid and semantically correct specialization of std::swap. -Also in practice, providing such a specialization will have the same -effect as satisfying the Swappable requirement. -
--For a client's type T that satisfies both conditions of the Swappable -requirement, it is not specified which of the two conditions prevails. -After reading section 20.1.4 [lib.swappable], one might wonder whether -objects of T will be swapped by doing copy construction and -assignments, or by calling the swap function of T. -
--I'm aware that the intention of the Draft is to prefer calling the -swap function of T over doing copy construction and assignments. Still -in my opinion, it would be better to make this clear in the wording of -the definition of Swappable. -
--I would like to have the Swappable requirement defined in such a way -that the following code fragment will correctly swap two objects of a -type T, if and only if T is Swappable: -
-using std::swap; - swap(t, u); // t and u are of type T. --
-This is also the way Scott Meyers recommends calling a swap function, -in Effective C++, Third Edition, item 25. -
--Most aspects of this issue have been dealt with in a discussion on -comp.std.c++ about the Swappable requirement, from 13 September to 4 -October 2006, including valuable input by David Abrahams, Pete Becker, -Greg Herlihy, Howard Hinnant and others. -
- -[ -San Francisco: -]
- - --Recommend NAD. Solved by -N2774. -- -
[ -2009-07 Frankfurt -]
- - --Moved to Open. Waiting for non-concepts draft. -- -
[ -2009-11-08 Howard adds: -]
- - --This issue is very closely related to 742. -- - -
Proposed resolution:
--Change section 20.1.4 [lib.swappable] as follows: -
-- - - - - --The Swappable requirement is met by satisfying -
-one or more of the following conditions:-the following condition:- -
-- -
-T is Swappable if T satisfies the CopyConstructible requirements -(20.1.3) and the Assignable requirements (23.1);-- -
--T is Swappable if a namespace scope function named swap exists in the -same namespace as the definition of T, such that the expression -swap(t,u) is valid and has the semantics described in Table 33. --T is Swappable if an unqualified function call swap(t,u) is valid -within the namespace std, and has the semantics described in Table 33. -
Section: 17 [library] Status: Open - Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2009-10-20
-View other active issues in [library].
-View all other issues in [library].
-View all issues with Open status.
-Duplicate of: 895
-Discussion:
-
-
-Many member functions of basic_string are overloaded,
-with some of the overloads taking a string argument,
-others value_type*, others size_type, and
-others still iterators. Often, the requirements on one of
-the overloads are expressed in the form of Effects,
-Throws, and in the Working Paper
-(N2134)
-also Remark clauses, while those on the rest of the overloads
-via a reference to this overload and using a Returns clause.
-
-The difference between the two forms of specification is that per -17.5.1.4 [structure.specifications], p3, an Effects clause specifies -"actions performed by the functions," i.e., its observable -effects, while a Returns clause is "a description of the -return value(s) of a function" that does not impose any -requirements on the function's observable effects. -
- --Since only Notes are explicitly defined to be informative and -all other paragraphs are explicitly defined to be normative, like -Effects and Returns, the new Remark clauses also -impose normative requirements. -
- -
-So by this strict reading of the standard there are some member
-functions of basic_string that are required to throw an
-exception under some conditions or use specific traits members while
-many other otherwise equivalent overloads, while obliged to return the
-same values, aren't required to follow the exact same requirements
-with regards to the observable effects.
-
-Here's an example of this problem that was precipitated by the change -from informative Notes to normative Remarks (presumably made to -address 424): -
- -
-In the Working Paper, find(string, size_type) contains a
-Remark clause (which is just a Note in the current
-standard) requiring it to use traits::eq().
-
-find(const charT *s, size_type pos) is specified to
-return find(string(s), pos) by a Returns clause
-and so it is not required to use traits::eq(). However,
-the Working Paper has replaced the original informative Note
-about the function using traits::length() with a
-normative requirement in the form of a Remark. Calling
-traits::length() may be suboptimal, for example when the
-argument is a very long array whose initial substring doesn't appear
-anywhere in *this.
-
-Here's another similar example, one that existed even prior to the -introduction of Remarks: -
- -
- insert(size_type pos, string, size_type, size_type) is
-required to throw out_of_range if pos >
-size().
-
-insert(size_type pos, string str) is specified to return
-insert(pos, str, 0, npos) by a Returns clause and
-so its effects when pos > size() are strictly speaking
-unspecified.
-
- -
-I believe a careful review of the current Effects and -Returns clauses is needed in order to identify all such -problematic cases. In addition, a review of the Working Paper should -be done to make sure that the newly introduced normative Remark -clauses do not impose any undesirable normative requirements in place -of the original informative Notes. - - -[ -Batavia: Alan and Pete to work. -]
- - -[ -Bellevue: Marked as NAD Editorial. -]
- - -[ -Post-Sophia Antipolis: -Martin indicates there is still work to be done on this issue. -Reopened. -]
- - -[ -Batavia (2009-05): -]
- --Tom proposes we say that, unless specified otherwise, -it is always the caller's responsibility to verify that supplied arguments -meet the called function's requirements. -If further semantics are specified -(e.g., that the function throws under certain conditions), -then it is up to the implementer to check those conditions. -Alan feels strongly that our current use of Requires in this context -is confusing, especially now that requires is a new keyword. -- -
[ -2009-07 Frankfurt -]
- - --Move to Tentatively NAD. -- -
[ -2009 Santa Cruz: -]
- - --Move to Open. Martin will work on proposed wording. -- - - -
Proposed resolution:
--
- - - - - -Section: 25 [algorithms] Status: Review - Submitter: James Kanze Opened: 2007-01-31 Last modified: 2009-10-24
-View other active issues in [algorithms].
-View all other issues in [algorithms].
-View all issues with Review status.
-Discussion:
--The general requirements for BinaryPredicate (in 25 [algorithms]/8) contradict the implied specific requirements for -some functions. In particular, it says that: -
- -- --[...] if an algorithm takes BinaryPredicate binary_pred -as its argument and first1 and first2 as its -iterator arguments, it should work correctly in the construct if -(binary_pred (*first1 , *first2 )){...}. -BinaryPredicate always takes the first iterator type as its -first argument, that is, in those cases when T value is -part of the signature, it should work correctly in the context of if -(binary_pred (*first1 , value)){...}. -
-In the description of upper_bound (25.4.3.2 [upper.bound]/2), however, the use is described as -"!comp(value, e)", where e is an -element of the sequence (a result of dereferencing -*first). -
- --In the description of lexicographical_compare, we have both -"*first1 < *first2" and "*first2 -< *first1" (which presumably implies "comp( -*first1, *first2 )" and "comp( *first2, -*first1 )". -
- -[ -Toronto: Moved to Open. ConceptGCC seems to get lower_bound -and upper_bound to work withoutt these changes. -]
- - -[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Review. The small problem with the "iterator type" -will be fixed. The cited functions (lower_bound, uppwer_bound, -equal_range) don't actually use BinaryPredicate , and where it is used, -it is consistent with [algorithm]/8, so the main complaint of the issue -is moot. -- - - -
Proposed resolution:
--Logically, the BinaryPredicate is used as an ordering -relationship, with the semantics of "less than". Depending on the -function, it may be used to determine equality, or any of the inequality -relationships; doing this requires being able to use it with either -parameter first. I would thus suggest that the requirement be: -
- -- --[...] BinaryPredicate always takes the first iterator -value_type as one of its arguments, it is unspecified which. If -an algorithm takes BinaryPredicate binary_pred as its -argument and first1 and first2 as its -iterator arguments, it should work correctly both in the construct -if (binary_pred (*first1 , *first2 )){...} and -if (binary_pred (*first2, *first1)){...}. In -those cases when T value is part of the signature, it -should work correctly in the context of if (binary_pred -(*first1 , value)){...} and of if (binary_pred -(value, *first1)){...}. [Note: if the two -types are not identical, and neither is convertable to the other, this -may require that the BinaryPredicate be a functional object -with two overloaded operator()() functions. --end note] -
-Alternatively, one could specify an order for each function. IMHO, this -would be more work for the committee, more work for the implementors, -and of no real advantage for the user: some functions, such as -lexicographical_compare or equal_range, will still require both -functions, and it seems like a much easier rule to teach that both -functions are always required, rather than to have a complicated list of -when you only need one, and which one. -
- - -Rationale:
-[ -post San Francisco: -]
- - --Solved by -N2759. -- - - - - - -
Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: Ready - Submitter: John Salmon Opened: 2007-04-20 Last modified: 2009-10-21
-View other active issues in [facet.num.put.virtuals].
-View all other issues in [facet.num.put.virtuals].
-View all issues with Ready status.
-Discussion:
--I am trying to understand how TR1 supports hex float (%a) output. -
--As far as I can tell, it does so via the following: -
--8.15 Additions to header <locale> [tr.c99.locale] -
--In subclause 22.4.2.2.2 [facet.num.put.virtuals], Table 58 Floating-point conversions, after -the line: -floatfield == ios_base::scientific %E -
--add the two lines: -
--floatfield == ios_base::fixed | ios_base::scientific && !uppercase %a -floatfield == ios_base::fixed | ios_base::scientific %A 2 -
-[Note: The additional requirements on print and scan functions, later -in this clause, ensure that the print functions generate hexadecimal -floating-point fields with a %a or %A conversion specifier, and that -the scan functions match hexadecimal floating-point fields with a %g -conversion specifier. end note] -
--Following the thread, in 22.4.2.2.2 [facet.num.put.virtuals], we find: -
--For conversion from a floating-point type, if (flags & fixed) != 0 or -if str.precision() > 0, then str.precision() is specified in the -conversion specification. -
--This would seem to imply that when floatfield == fixed|scientific, the -precision of the conversion specifier is to be taken from -str.precision(). Is this really what's intended? I sincerely hope -that I'm either missing something or this is an oversight. Please -tell me that the committee did not intend to mandate that hex floats -(and doubles) should by default be printed as if by %.6a. -
- -[ -Howard: I think the fundamental issue we overlooked was that with %f, -%e, %g, the default precision was always 6. With %a the default -precision is not 6, it is infinity. So for the first time, we need to -distinguish between the default value of precision, and the precision -value 6. -]
- - -[ -2009-07 Frankfurt -]
- - --- --Leave this open for Robert and Daniel to work on. -
--Straw poll: Disposition? -
--
-- Default is %.6a (i.e. NAD): 2
-- Always %a (no precision): 6
-- precision(-1) == %a: 3
--Daniel and Robert have direction to write up wording for the "always %a" solution. -
- -[ -2009-07-15 Robert provided wording. -]
- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Change 22.4.2.2.2 [facet.num.put.virtuals], Stage 1, under p5 (near the end -of Stage 1): -
- --For conversion from a floating-point type, str.precision() is specified -as precision in the conversion specification -if floatfield != (ios_base::fixed | ios_base::scientific), else no -precision is specified. -- - - -
[ -Kona (2007): Robert volunteers to propose wording. -]
- - - - - -Section: 23.5 [unord] Status: Review - Submitter: Howard Hinnant Opened: 2007-05-05 Last modified: 2009-10-29
-View all other issues in [unord].
-View all issues with Review status.
-Discussion:
--Move semantics are missing from the unordered containers. The proposed -resolution below adds move-support consistent with -N1858 -and the current working draft. -
- --The current proposed resolution simply lists the requirements for each function. -These might better be hoisted into the requirements table for unordered associative containers. -Futhermore a mild reorganization of the container requirements could well be in order. -This defect report is purposefully ignoring these larger issues and just focusing -on getting the unordered containers "moved". -
- -[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-10-17 Removed rvalue-swaps from wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Review. Alisdair will review proposed wording. -- -
[ -2009-10-29 Daniel updates wording. -]
- - - - -Proposed resolution:
- -unordered_map
- --Change 23.5.1 [unord.map]: -
- -class unordered_map
-{
- ...
- unordered_map(const unordered_map&);
- unordered_map(unordered_map&&);
- ~unordered_map();
- unordered_map& operator=(const unordered_map&);
- unordered_map& operator=(unordered_map&&);
- ...
- // modifiers
- std::pair<iterator, bool> insert(const value_type& obj);
- template <class P> pair<iterator, bool> insert(P&& obj);
- iterator insert(const_iterator hint, const value_type& obj);
- template <class P> iterator insert(const_iterator hint, P&& obj);
- ...
- mapped_type& operator[](const key_type& k);
- mapped_type& operator[](key_type&& k);
- ...
-};
-
--Add to 23.5.1.1 [unord.map.cnstr]: -
- --- -template <class InputIterator> - unordered_map(InputIterator f, InputIterator l, - size_type n = implementation-defined, - const hasher& hf = hasher(), - const key_equal& eql = key_equal(), - const allocator_type& a = allocator_type()); -- --- -Requires: If the iterator's dereference operator returns an -lvalue or a const rvalue pair<key_type, mapped_type>, -then both key_type and mapped_type shall be -CopyConstructible. - -
-Add to 23.5.1.2 [unord.map.elem]: -
- -- -- -mapped_type& operator[](const key_type& k);- --- -...
--Requires: key_type shall be CopyConstructible -and mapped_type shall be DefaultConstructible. -
-mapped_type& operator[](key_type&& k);- --- --Effects: If the unordered_map does not already contain an -element whose key is equivalent to k , inserts the value -std::pair<const key_type, mapped_type>(std::move(k), mapped_type()). -
- --Requires: mapped_type shall be DefaultConstructible. -
- --Returns: A reference to x.second, where x is the -(unique) element whose key is equivalent to k. -
- -
-Add new section [unord.map.modifiers]: -
- --- -pair<iterator, bool> insert(const value_type& x); -template <class P> pair<iterator, bool> insert(P&& x); -iterator insert(const_iterator hint, const value_type& x); -template <class P> iterator insert(const_iterator hint, P&& x); -template <class InputIterator> - void insert(InputIterator first, InputIterator last); -- --- --Requires: Those signatures taking a const value_type& parameter -requires both the key_type and the mapped_type to be -CopyConstructible. - If P is instantiated as a reference -type, then the argument x is copied from. Otherwise x -is considered to be an rvalue as it is converted to value_type -and inserted into the unordered_map. Specifically, in such -cases CopyConstructible is not required for key_type or -mapped_type unless the conversion from P specifically -requires it (e.g. if P is a tuple<const key_type, -mapped_type>, then key_type must be -CopyConstructible). -
- --The signature taking InputIterator -parameters requires CopyConstructible of both -key_type and mapped_type if the dereferenced -InputIterator returns an lvalue or const rvalue -value_type. -
- -
unordered_multimap
- --Change 23.5.2 [unord.multimap]: -
- -class unordered_multimap
-{
- ...
- unordered_multimap(const unordered_multimap&);
- unordered_multimap(unordered_multimap&&);
- ~unordered_multimap();
- unordered_multimap& operator=(const unordered_multimap&);
- unordered_multimap& operator=(unordered_multimap&&);
- ...
- // modifiers
- iterator insert(const value_type& obj);
- template <class P> iterator insert(P&& obj);
- iterator insert(const_iterator hint, const value_type& obj);
- template <class P> iterator insert(const_iterator hint, P&& obj);
- ...
-};
-
--Add to 23.5.2.1 [unord.multimap.cnstr]: -
- --- -template <class InputIterator> - unordered_multimap(InputIterator f, InputIterator l, - size_type n = implementation-defined, - const hasher& hf = hasher(), - const key_equal& eql = key_equal(), - const allocator_type& a = allocator_type()); -- --- -Requires: If the iterator's dereference operator returns an -lvalue or a const rvalue pair<key_type, mapped_type>, -then both key_type and mapped_type shall be -CopyConstructible. - -
-Add new section [unord.multimap.modifiers]: -
- --- -iterator insert(const value_type& x); -template <class P> iterator insert(P&& x); -iterator insert(const_iterator hint, const value_type& x); -template <class P> iterator insert(const_iterator hint, P&& x); -template <class InputIterator> - void insert(InputIterator first, InputIterator last); -- --- --Requires: Those signatures taking a const value_type& parameter -requires both the key_type and the mapped_type to be -CopyConstructible. -If P is instantiated as a reference -type, then the argument x is copied from. Otherwise x -is considered to be an rvalue as it is converted to value_type -and inserted into the unordered_multimap. Specifically, in such -cases CopyConstructible is not required for key_type or -mapped_type unless the conversion from P specifically -requires it (e.g. if P is a tuple<const key_type, -mapped_type>, then key_type must be -CopyConstructible). -
- --The signature taking InputIterator -parameters requires CopyConstructible of both -key_type and mapped_type if the dereferenced -InputIterator returns an lvalue or const rvalue -value_type. -
-
unordered_set
- --Change 23.5.3 [unord.set]: -
- -class unordered_set
-{
- ...
- unordered_set(const unordered_set&);
- unordered_set(unordered_set&&);
- ~unordered_set();
- unordered_set& operator=(const unordered_set&);
- unordered_set& operator=(unordered_set&&);
- ...
- // modifiers
- std::pair<iterator, bool> insert(const value_type& obj);
- pair<iterator, bool> insert(value_type&& obj);
- iterator insert(const_iterator hint, const value_type& obj);
- iterator insert(const_iterator hint, value_type&& obj);
- ...
-};
--Add to 23.5.3.1 [unord.set.cnstr]: -
- --- -template <class InputIterator> - unordered_set(InputIterator f, InputIterator l, - size_type n = implementation-defined, - const hasher& hf = hasher(), - const key_equal& eql = key_equal(), - const allocator_type& a = allocator_type()); -- --- -Requires: If the iterator's dereference operator returns an -lvalue or a const rvalue value_type, then the -value_type shall be CopyConstructible. - -
-Add new section [unord.set.modifiers]: -
- --- -pair<iterator, bool> insert(const value_type& x); -pair<iterator, bool> insert(value_type&& x); -iterator insert(const_iterator hint, const value_type& x); -iterator insert(const_iterator hint, value_type&& x); -template <class InputIterator> - void insert(InputIterator first, InputIterator last); -- -- -- --Requires: Those signatures taking a const -value_type& parameter requires the value_type to -be CopyConstructible. -
- --The signature taking InputIterator parameters requires -CopyConstructible of value_type if the dereferenced -InputIterator returns an lvalue or const rvalue -value_type. -
- -
unordered_multiset
- --Change 23.5.4 [unord.multiset]: -
- -class unordered_multiset
-{
- ...
- unordered_multiset(const unordered_multiset&);
- unordered_multiset(unordered_multiset&&);
- ~unordered_multiset();
- unordered_multiset& operator=(const unordered_multiset&);
- unordered_multiset& operator=(unordered_multiset&&);
- ...
- // modifiers
- iterator insert(const value_type& obj);
- iterator insert(value_type&& obj);
- iterator insert(const_iterator hint, const value_type& obj);
- iterator insert(const_iterator hint, value_type&& obj);
- ...
-};
-
--Add to 23.5.4.1 [unord.multiset.cnstr]: -
- --- -template <class InputIterator> - unordered_multiset(InputIterator f, InputIterator l, - size_type n = implementation-defined, - const hasher& hf = hasher(), - const key_equal& eql = key_equal(), - const allocator_type& a = allocator_type()); -- --- -Requires: If the iterator's dereference operator returns an -lvalue or a const rvalue value_type, then the -value_type shall be CopyConstructible. - -
-Add new section [unord.multiset.modifiers]: -
- --- - - -iterator insert(const value_type& x); -iterator insert(value_type&& x); -iterator insert(const_iterator hint, const value_type& x); -iterator insert(const_iterator hint, value_type&& x); -template <class InputIterator> - void insert(InputIterator first, InputIterator last); -- -- -- --Requires: Those signatures taking a const -value_type& parameter requires the value_type to -be CopyConstructible. -
- --The signature taking InputIterator parameters requires -CopyConstructible of value_type if the dereferenced -InputIterator returns an lvalue or const rvalue -value_type. -
- -
[ -Voted to WP in Bellevue. -]
- - -[ -post Bellevue, Pete notes: -]
- - --- --Please remind people who are reviewing issues to check that the text -modifications match the current draft. Issue 676, for example, adds two -overloads for unordered_map::insert taking a hint. One takes a -const_iterator and returns a const_iterator, and the other takes an -iterator and returns an iterator. This was correct at the time the issue -was written, but was changed in Toronto so there is only one hint -overload, taking a const_iterator and returning an iterator. -
--This issue is not ready. In addition to the relatively minor signature -problem I mentioned earlier, it puts requirements in the wrong places. -Instead of duplicating requirements throughout the template -specifications, it should put them in the front matter that talks about -requirements for unordered containers in general. This presentation -problem is editorial, but I'm not willing to do the extensive rewrite -that it requires. Please put it back into Open status. -
-
Rationale:
-[ -San Francisco: -]
- - --Solved by -N2776. -- - - - - - -
Section: 23.2 [container.requirements] Status: Open - Submitter: Howard Hinnant Opened: 2007-05-20 Last modified: 2009-10-20
-View other active issues in [container.requirements].
-View all other issues in [container.requirements].
-View all issues with Open status.
-Discussion:
--The move-related changes inadvertently overwrote the intent of 276. -Issue 276 removed the requirement of CopyAssignable from -most of the member functions of node-based containers. But the move-related changes -unnecessarily introduced the MoveAssignable requirement for those members which used to -require CopyAssignable. -
- --We also discussed (c++std-lib-18722) the possibility of dropping MoveAssignable -from some of the sequence requirements. Additionally the in-place construction -work may further reduce requirements. For purposes of an easy reference, here are the -minimum sequence requirements as I currently understand them. Those items in requirements -table in the working draft which do not appear below have been purposefully omitted for -brevity as they do not have any requirements of this nature. Some items which do not -have any requirements of this nature are included below just to confirm that they were -not omitted by mistake. -
- -| X u(a) | value_type must be CopyConstructible |
| X u(rv) | array and containers with a propagate_never allocator require value_type to be MoveConstructible |
| a = u | Sequences require value_type to be CopyConstructible and CopyAssignable. - Associative containers require value_type to be CopyConstructible. |
| a = rv | array requires value_type to be MoveAssignable. - Sequences and Associative containers with propagate_never and propagate_on_copy_construction allocators require value_type to be MoveConstructible. |
| swap(a,u) | array and containers with propagate_never and - propagate_on_copy_construction allocators require value_type to be Swappable. |
-
- -| X(n) | value_type must be DefaultConstructible |
| X(n, t) | value_type must be CopyConstructible |
| X(i, j) | If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the value_type must be MoveConstructible. |
| a.insert(p, t) | The value_type must be CopyConstructible. - The sequences vector and deque also require the value_type to be CopyAssignable. |
| a.insert(p, rv) | The value_type must be MoveConstructible. - The sequences vector and deque also require the value_type to be MoveAssignable. |
| a.insert(p, n, t) | The value_type must be CopyConstructible. - The sequences vector and deque also require the value_type to be CopyAssignable. |
| a.insert(p, i, j) | If the iterators return an lvalue the value_type must be CopyConstructible. - The sequences vector and deque also require the value_type to be CopyAssignable when the iterators return an lvalue. - If the iterators return an rvalue the value_type must be MoveConstructible. - The sequences vector and deque also require the value_type to be MoveAssignable when the iterators return an rvalue. |
| a.erase(p) | The sequences vector and deque require the value_type to be MoveAssignable. |
| a.erase(q1, q2) | The sequences vector and deque require the value_type to be MoveAssignable. |
| a.clear() | |
| a.assign(i, j) | If the iterators return an lvalue the value_type must be CopyConstructible and CopyAssignable. - If the iterators return an rvalue the value_type must be MoveConstructible and MoveAssignable. |
| a.assign(n, t) | The value_type must be CopyConstructible and CopyAssignable. |
| a.resize(n) | The value_type must be DefaultConstructible. - The sequence vector also requires the value_type to be MoveConstructible. |
| a.resize(n, t) | The value_type must be CopyConstructible. |
-
- -| a.front() | |
| a.back() | |
| a.push_front(t) | The value_type must be CopyConstructible. |
| a.push_front(rv) | The value_type must be MoveConstructible. |
| a.push_back(t) | The value_type must be CopyConstructible. |
| a.push_back(rv) | The value_type must be MoveConstructible. |
| a.pop_front() | |
| a.pop_back() | |
| a[n] | |
| a.at[n] |
-
- -| X(i, j) | If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the value_type must be MoveConstructible. |
| a_uniq.insert(t) | The value_type must be CopyConstructible. |
| a_uniq.insert(rv) | The key_type and the mapped_type (if it exists) must be MoveConstructible. |
| a_eq.insert(t) | The value_type must be CopyConstructible. |
| a_eq.insert(rv) | The key_type and the mapped_type (if it exists) must be MoveConstructible. |
| a.insert(p, t) | The value_type must be CopyConstructible. |
| a.insert(p, rv) | The key_type and the mapped_type (if it exists) must be MoveConstructible. |
| a.insert(i, j) | If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the key_type and the mapped_type (if it exists) must be MoveConstructible.. |
-
- -| X(i, j, n, hf, eq) | If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the value_type must be MoveConstructible. |
| a_uniq.insert(t) | The value_type must be CopyConstructible. |
| a_uniq.insert(rv) | The key_type and the mapped_type (if it exists) must be MoveConstructible. |
| a_eq.insert(t) | The value_type must be CopyConstructible. |
| a_eq.insert(rv) | The key_type and the mapped_type (if it exists) must be MoveConstructible. |
| a.insert(p, t) | The value_type must be CopyConstructible. |
| a.insert(p, rv) | The key_type and the mapped_type (if it exists) must be MoveConstructible. |
| a.insert(i, j) | If the iterators return an lvalue the value_type must be CopyConstructible. - If the iterators return an rvalue the key_type and the mapped_type (if it exists) must be MoveConstructible.. |
-
- -| map[lvalue-key] | The key_type must be CopyConstructible. - The mapped_type must be DefaultConstructible and MoveConstructible. |
| map[rvalue-key] | The key_type must be MoveConstructible. - The mapped_type must be DefaultConstructible and MoveConstructible. |
[ -Kona (2007): Howard and Alan to update requirements table in issue with emplace signatures. -]
- - -[ -Bellevue: This should be handled as part of the concepts work. -]
- - -[ -2009-07-20 Reopened by Howard: -]
- - --- --This is one of the issues that was "solved by concepts" and is now no longer solved. -
- --In a nutshell, concepts adopted the "minimum requirements" philosophy outlined -in the discussion of this issue, and enforced it. My strong suggestion is that -we translate the concepts specification into documentation for the containers. -
- --What this means for vendors is that they will have to implement container members -being careful to only use those characteristics of a type that the concepts specification -formally allowed. Note that I am not talking about enable_if'ing -everything. I am simply suggesting that (for example) we tell the vendor he can't call T's -copy constructor or move constructor within the emplace member function, etc. -
- --What this means for customers is that they will be able to use types within C++03 -containers which are sometimes not CopyConstructible, and sometimes not even -MoveConstructible, etc. -
-
[ -2009-10 Santa Cruz: -]
- - --Leave open. Howard to provide wording. -- - - -
Proposed resolution:
- - - -Rationale:
-[ -post San Francisco: -]
- - --Solved by -N2776. -- - - - - - -
Section: 20.2.1 [utility.arg.requirements] Status: Open - Submitter: Pablo Halpern Opened: 2007-09-12 Last modified: 2009-10-23
-View other active issues in [utility.arg.requirements].
-View all other issues in [utility.arg.requirements].
-View all issues with Open status.
-Discussion:
--The DefaultConstructible requirement is referenced in -several places in the August 2007 working draft -N2369, -but is not defined anywhere. -
- -[ -Bellevue: -]
- - --- --Walking into the default/value-initialization mess... -
--Why two lines? Because we need both expressions to be valid. -
--AJM not sure what the phrase "default constructed" means. This is -unfortunate, as the phrase is already used 24 times in the library! -
--Example: const int would not accept first line, but will accept the second. -
--This is an issue that must be solved by concepts, but we might need to solve it independantly first. -
--It seems that the requirements are the syntax in the proposed first -column is valid, but not clear what semantics we need. -
--A table where there is no post-condition seems odd, but appears to sum up our position best. -
--At a minimum an object is declared and is destuctible. -
--Move to open, as no-one happy to produce wording on the fly. -
-
[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-08-17 Daniel adds "[defaultconstructible]" to table title. 408 -depends upon this issue. -]
- - -[ -2009-08-18 Alisdair adds: -]
- - --- --Looking at the proposed table in this issue, it really needs two rows: -
- --- --
-Table 33: DefaultConstructible requirements [defaultconstructible] -- - -expression post-condition -- - -T t; t is default-initialized. -- -T{} Object of type T is value-initialized. --Note I am using the new brace-initialization syntax that is unambiguous -in all use cases (no most vexing parse.) -
-
[ -2009-10-03 Daniel adds: -]
- - --- --The suggested definition T{} describing it as -value-initialization is wrong, because it belongs to list-initialization -which would - as the current rules are - always prefer a -initializer-list constructor over a default-constructor. I don't -consider this as an appropriate definition of -DefaultConstructible. My primary suggestion is to ask core, -whether the special case T{} (which also easily leads to -ambiguity situations for more than one initializer-list in a class) -would always prefer a default-constructor - if any - before considering -an initializer-list constructor or to provide another syntax form to -prefer value-initialization over list-initialization. If that fails I -would fall back to suggest to use the expression T() instead of -T{} with all it's disadvantages for the meaning of the -expression -
- --T t(); -
[ -2009-10 Santa Cruz: -]
- - --Leave Open. Core is looking to make Alisdair's proposed -resolution correct. -- - - -
Proposed resolution:
--In section 20.2.1 [utility.arg.requirements], before table 33, add the -following table: -
- -Table 33: DefaultConstructible requirements [defaultconstructible]
- -|
- expression - |
-
- post-condition - |
-
|
- T
- t; |
-
- T - is default constructed. - |
-
Rationale:
-[ -San Francisco: -]
- --We believe concepts will solve this problem -(N2774). -- - - - - -
Section: 28.11.4 [re.alg.replace] Status: Open - Submitter: Stephan T. Lavavej Opened: 2007-09-22 Last modified: 2009-10-23
-View other active issues in [re.alg.replace].
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-Discussion:
--Two overloads of regex_replace() are currently provided: -
- -- -template <class OutputIterator, class BidirectionalIterator, - class traits, class charT> - OutputIterator - regex_replace(OutputIterator out, - BidirectionalIterator first, BidirectionalIterator last, - const basic_regex<charT, traits>& e, - const basic_string<charT>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - -template <class traits, class charT> - basic_string<charT> - regex_replace(const basic_string<charT>& s, - const basic_regex<charT, traits>& e, - const basic_string<charT>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); -
The absence of const charT * overloads prevents ordinary-looking code from compiling, such as:
- -const string s("kitten");
-const regex r("en");
-cout << regex_replace(s, r, "y") << endl;
--The compiler error message will be something like "could not deduce -template argument for 'const std::basic_string<_Elem> &' from 'const -char[1]'". -
- --Users expect that anything taking a basic_string<charT> can also take a -const charT *. In their own code, when they write a function taking -std::string (or std::wstring), they can pass a const char * (or const -wchar_t *), thanks to basic_string's implicit constructor. Because the -regex algorithms are templated on charT, they can't rely on -basic_string's implicit constructor (as the compiler error message -indicates, template argument deduction fails first). -
- --If a user figures out what the compiler error message means, workarounds -are available - but they are all verbose. Explicit template arguments -could be given to regex_replace(), allowing basic_string's implicit -constructor to be invoked - but charT is the last template argument, not -the first, so this would be extremely verbose. Therefore, constructing -a basic_string from each C string is the simplest workaround. -
-[ -Sophia Antipolis: -]
- - --We note that Boost already has these overloads. However, the proposed -wording is provided only for 28.11.4 [re.alg.replace]; wording is needed for the synopsis -as well. We also note that this has impact on match_results::format, -which may require further overloads. -- -
[ -2009-07 Frankfurt: -]
- - --Daniel to tweak for us. -- -
[ -2009-07-25 Daniel tweaks both this issue and 727. -]
- - --- --This is solved by the proposed resolution of 727. -
-
[ -2009-10 Santa Cruz: -]
- - --Leave Open. Though we believe this is solved by the proposed resolution -to 727. -- - - -
Proposed resolution:
- --Provide additional overloads for regex_replace(): one additional -overload of the iterator-based form (taking const charT* fmt), and three -additional overloads of the convenience form (one taking const charT* -str, another taking const charT* fmt, and the third taking both const -charT* str and const charT* fmt). 28.11.4 [re.alg.replace]: -
- --- - - - - - -template <class OutputIterator, class BidirectionalIterator, - class traits, class charT> - OutputIterator - regex_replace(OutputIterator out, - BidirectionalIterator first, BidirectionalIterator last, - const basic_regex<charT, traits>& e, - const basic_string<charT>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - -template <class OutputIterator, class BidirectionalIterator, - class traits, class charT> - OutputIterator - regex_replace(OutputIterator out, - BidirectionalIterator first, BidirectionalIterator last, - const basic_regex<charT, traits>& e, - const charT* fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); --...
-template <class traits, class charT> - basic_string<charT> - regex_replace(const basic_string<charT>& s, - const basic_regex<charT, traits>& e, - const basic_string<charT>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - -template <class traits, class charT> - basic_string<charT> - regex_replace(const basic_string<charT>& s, - const basic_regex<charT, traits>& e, - const charT* fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - -template <class traits, class charT> - basic_string<charT> - regex_replace(const charT* s, - const basic_regex<charT, traits>& e, - const basic_string<charT>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - -template <class traits, class charT> - basic_string<charT> - regex_replace(const charT* s, - const basic_regex<charT, traits>& e, - const charT* fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); --
Section: 28.11.4 [re.alg.replace] Status: Review - Submitter: Stephan T. Lavavej Opened: 2007-09-22 Last modified: 2009-10-23
-View other active issues in [re.alg.replace].
-View all other issues in [re.alg.replace].
-View all issues with Review status.
-Discussion:
--regex_match() and regex_search() take const basic_string<charT, ST, -SA>&. regex_replace() takes const basic_string<charT>&. This prevents -regex_replace() from accepting basic_strings with custom traits and -allocators. -
- --Overloads of regex_replace() taking basic_string should be additionally -templated on class ST, class SA and take const basic_string<charT, ST, -SA>&. Consistency with regex_match() and regex_search() would place -class ST, class SA as the first template arguments; compatibility with -existing code using TR1 and giving explicit template arguments to -regex_replace() would place class ST, class SA as the last template -arguments. -
- -[ -Batavia (2009-05): -]
- --- --Bill comments, "We need to look at the depth of this change." -
--Pete remarks that we are here dealing with a convenience function -that saves a user from calling the iterato-based overload. -
--Move to Open. -
-
[ -2009-07 Frankfurt: -]
- - --Howard to ask Stephan Lavavej to provide wording. -- -
[ -2009-07-17 Stephan provided wording. -]
- - -[ -2009-07-25 Daniel tweaks both this issue and 726. -]
- - --- --One relevant part of the proposed resolution below suggests -to add a new overload of the format member function in the -match_results class template that accepts two character pointers -defining the begin and end of a format range. A more general -approach could have proposed a pair of iterators instead, but -the used pair of char pointers reflects existing practice. If the -committee strongly favors an iterator-based signature, this -could be simply changed. I think that the minimum requirement -should be a BidirectionalIterator, but current implementations -take advantage (at least partially) of the RandomAccessIterator -sub interface of the char pointers. -
- -Suggested Resolution:
- -[Moved into the proposed resloution]
- - - -
[ -2009-07-30 Stephan agrees with Daniel's wording. Howard places Daniel's wording -in the Proposed Resolution. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Review. Chair is anxious to move this to Ready in Pittsburgh. -- - - -
Proposed resolution:
- --Change 28.4 [re.syn] as indicated: -
- --// 28.11.4, function template regex_replace: -template <class OutputIterator, class BidirectionalIterator, - class traits, class charT, class ST, class SA> - OutputIterator - regex_replace(OutputIterator out, - BidirectionalIterator first, BidirectionalIterator last, - const basic_regex<charT, traits>& e, - const basic_string<charT, ST, SA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - - -template <class OutputIterator, class BidirectionalIterator, - class traits, class charT> - OutputIterator - regex_replace(OutputIterator out, - BidirectionalIterator first, BidirectionalIterator last, - const basic_regex<charT, traits>& e, - const charT* fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - - -template <class traits, class charT, class ST, class SA, - class FST, class FSA> - basic_string<charT, ST, SA> - regex_replace(const basic_string<charT, ST, SA>& s, - const basic_regex<charT, traits>& e, - const basic_string<charT, FST, FSA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - - -template <class traits, class charT, class ST, class SA> - basic_string<charT, ST, SA> - regex_replace(const basic_string<charT, ST, SA>& s, - const basic_regex<charT, traits>& e, - const charT* fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - - - -template <class traits, class charT, class ST, class SA> - basic_string<charT> - regex_replace(const charT* s, - const basic_regex<charT, traits>& e, - const basic_string<charT, ST, SA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - - - -template <class traits, class charT> - basic_string<charT> - regex_replace(const charT* s, - const basic_regex<charT, traits>& e, - const charT* fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - -
-Change 28.10 [re.results]/3, class template match_results as -indicated: -
- ---template <class OutputIter> - OutputIter - format(OutputIter out, - const char_type* fmt_first, const char_type* fmt_last, - regex_constants::match_flag_type flags = - regex_constants::format_default) const; - - -template <class OutputIter, class ST, class SA> - OutputIter - format(OutputIter out, - conststring_typebasic_string<char_type, ST, SA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::format_default) const; - -template <class ST, class SA> -string_typebasic_string<char_type, ST, SA> - format(conststring_typebasic_string<char_type, ST, SA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::format_default) const; - - -string_type -format(const char_type* fmt, - regex_constants::match_flag_type flags = - regex_constants::format_default) const; - -
-Insert at the very beginning of 28.10.4 [re.results.form] the following: -
- ---template <class OutputIter> - OutputIter - format(OutputIter out, - const char_type* fmt_first, const char_type* fmt_last, - regex_constants::match_flag_type flags = - regex_constants::format_default) const; - --- ---1 Requires: The type OutputIter shall satisfy the requirements for an -Output Iterator (24.2.2 [output.iterators]). -
- --2 Effects: Copies the character sequence [fmt_first,fmt_last) to -OutputIter out. Replaces each -format specifier or escape sequence in the copied range with either -the character(s) it represents -or the sequence of characters within *this to which it refers. The -bitmasks specified in flags -determines what format specifiers and escape sequences are recognized. -
- --3 Returns: out. -
-
-Change 28.10.4 [re.results.form], before p. 1 until p. 3 (according to -previous numbering) -as indicated: -
- --template <class OutputIter, class ST, class SA> - OutputIter - format(OutputIter out, - const- -string_typebasic_string<char_type, ST, SA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::format_default) const; ----
- -Requires: The type OutputIter shall satisfy the requirements for -an Output Iterator (24.2.3).--
- -Effects: Copies the character sequence [fmt.begin(),fmt.end()) to -OutputIter out. Replaces each -format specifier or escape sequence in fmt with either the -character(s) it represents or the sequence of -characters within *this to which it refers. The bitmasks specified in -flags determines what format -specifiers and escape sequences are recognized.--Returns:
-outformat(out, fmt.data(), fmt.data() + -fmt.size(), flags). -
-Change 28.10.4 [re.results.form], before p. 4 until p. 4 (according to -previous numbering) as indicated: -
- --template <class ST, class SA> -- -string_typebasic_string<char_type, ST, SA> - format(conststring_typebasic_string<char_type, ST, SA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::format_default) const; ----Effects:
- -Returns a copy of the string fmt. Replaces each format -specifier or escape sequence -in fmt with either the character(s) it represents or the sequence of -characters within *this to which -it refers. The bitmasks specified in flags determines what format -specifiers and escape sequences are -recognized.Constructs an empty string result of type -basic_string<char_type, ST, SA>, -and calls format(back_inserter(result), fmt, flags). --Returns: result -
-
-At the end of 28.10.4 [re.results.form] insert as indicated: -
- -- --string_type - format(const char_type* fmt, - regex_constants::match_flag_type flags = - regex_constants::format_default) const; -- ----Effects: Constructs an empty string result of type string_type, and calls -format(back_inserter(result), fmt, fmt + -char_traits<char_type>::length(fmt), flags). -
--Returns: result -
-
-Change 28.11.4 [re.alg.replace] before p. 1 as indicated: -
- --template <class OutputIterator, class BidirectionalIterator, - class traits, class charT, class ST, class SA> - OutputIterator - regex_replace(OutputIterator out, - BidirectionalIterator first, BidirectionalIterator last, - const basic_regex<charT, traits>& e, - const basic_string<charT, ST, SA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - - -template <class OutputIterator, class BidirectionalIterator, - class traits, class charT> - OutputIterator - regex_replace(OutputIterator out, - BidirectionalIterator first, BidirectionalIterator last, - const basic_regex<charT, traits>& e, - const charT* fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); -- --Effects: [..]. If any matches are found then, for each such match, if !(flags & - regex_constants::format_no_copy) calls std::copy(m.prefix().first, -m.prefix().second, - out), and then calls m.format(out, fmt, flags) for the first -form of the function - and m.format(out, fmt, fmt + char_traits<charT>::length(fmt), flags) -for the second - form. [..]. --
-Change 28.11.4 [re.alg.replace] before p. 3 as indicated: -
- --template <class traits, class charT, class ST, class SA, - class FST, class FSA> - basic_string<charT, ST, SA> - regex_replace(const basic_string<charT, ST, SA>& s, - const basic_regex<charT, traits>& e, - const basic_string<charT, FST, FSA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - - -template <class traits, class charT, class ST, class SA> - basic_string<charT, ST, SA> - regex_replace(const basic_string<charT, ST, SA>& s, - const basic_regex<charT, traits>& e, - const charT* fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); -- --Effects: Constructs an empty string result of type basic_string<charT, -ST, SA>, calls regex_replace(back_inserter(result), s.begin(), s.end(), -e, fmt, flags), and then returns result. --
-At the end of 28.11.4 [re.alg.replace] add the following new prototype description: -
- ---template <class traits, class charT, class ST, class SA> - basic_string<charT> - regex_replace(const charT* s, - const basic_regex<charT, traits>& e, - const basic_string<charT, ST, SA>& fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); - - - -template <class traits, class charT> - basic_string<charT> - regex_replace(const charT* s, - const basic_regex<charT, traits>& e, - const charT* fmt, - regex_constants::match_flag_type flags = - regex_constants::match_default); -- -- -Effects: Constructs an empty string result of type basic_string<charT>, -calls regex_replace(back_inserter(result), s, s + -char_traits<charT>::length(s), -e, fmt, flags), and then returns result. - --
Section: 20.2.1 [utility.arg.requirements] Status: Open - Submitter: Howard Hinnant Opened: 2007-10-10 Last modified: 2009-11-08
-View other active issues in [utility.arg.requirements].
-View all other issues in [utility.arg.requirements].
-View all issues with Open status.
-Discussion:
--This issue was split from 672. 672 now just -deals with changing the requirements of T in the Swappable -requirement from CopyConstructible and CopyAssignable to -MoveConstructible and MoveAssignable. -
- --This issue seeks to widen the Swappable requirement to support proxy iterators. Here -is example code: -
- -namespace Mine {
-
-template <class T>
-struct proxy {...};
-
-template <class T>
-struct proxied_iterator
-{
- typedef T value_type;
- typedef proxy<T> reference;
- reference operator*() const;
- ...
-};
-
-struct A
-{
- // heavy type, has an optimized swap, maybe isn't even copyable or movable, just swappable
- void swap(A&);
- ...
-};
-
-void swap(A&, A&);
-void swap(proxy<A>, A&);
-void swap(A&, proxy<A>);
-void swap(proxy<A>, proxy<A>);
-
-} // Mine
-
-...
-
-Mine::proxied_iterator<Mine::A> i(...)
-Mine::A a;
-swap(*i1, a);
--The key point to note in the above code is that in the call to swap, *i1 -and a are different types (currently types can only be Swappable with the -same type). A secondary point is that to support proxies, one must be able to pass rvalues -to swap. But note that I am not stating that the general purpose std::swap -should accept rvalues! Only that overloaded swaps, as in the example above, be allowed -to take rvalues. -
- --That is, no standard library code needs to change. We simply need to have a more flexible -definition of Swappable. -
- -[ -Bellevue: -]
- - --- --While we believe Concepts work will define a swappable concept, we -should still resolve this issue if possible to give guidance to the -Concepts work. -
--Would an ambiguous swap function in two namespaces found by ADL break -this wording? Suggest that the phrase "valid expression" means such a -pair of types would still not be swappable. -
--Motivation is proxy-iterators, but facility is considerably more -general. Are we happy going so far? -
--We think this wording is probably correct and probably an improvement on -what's there in the WP. On the other hand, what's already there in the -WP is awfully complicated. Why do we need the two bullet points? They're -too implementation-centric. They don't add anything to the semantics of -what swap() means, which is there in the post-condition. What's wrong -with saying that types are swappable if you can call swap() and it -satisfies the semantics of swapping? -
-
[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Leave as Open. Dave to provide wording. -- -
[ -2009-11-08 Howard adds: -]
- - --Updated wording to sync with -N3000. -Also this issue is very closely related to 594. -- - - -
Proposed resolution:
--Change 20.2.1 [utility.arg.requirements]: -
- -- -- - - ---1- The template definitions in the C++ Standard Library refer to various -named requirements whose details are set out in tables 31-38. In these -tables, T and V are
- -is atypes to be supplied by a C++ program -instantiating a template; a, b, and c are -values of type const T; s and t are modifiable -lvalues of type T; u is a value of type (possibly -const) T;andrv is a non-const -rvalue of type T; w is a value of type T; and v is a value of type V. --
-Table 37: Swappable requirements [swappable] -- expression Return type Post-condition - swap( sw,tv)void -tw has the value originally -held byuv, and -uv has the value originally held -bytw- - -The Swappable requirement is met by satisfying one or more of the following conditions: -
--
-- -T is Swappable if T and V are -the same type and T satisfies the -MoveConstructible requirements (Table -33) and the -MoveAssignable requirements (Table -35); -
-- -T is Swappable with V if a namespace scope function named -swap exists in the same namespace as the definition of -T or V, such that the expression -swap(
-sw,tv) is valid and has the -semantics described in this table. -- -T is Swappable if T is an array type whose -element type is Swappable. -
-
Rationale:
-[ -post San Francisco: -]
- - --Solved by -N2758. -- - - - - - -
Section: 23 [containers] Status: Open - Submitter: Alisdair Meredith Opened: 2008-01-14 Last modified: 2009-10-31
-View other active issues in [containers].
-View all other issues in [containers].
-View all issues with Open status.
-Discussion:
--It appears most containers declare but do not define a member-swap -function. -
- --This is unfortunate, as all overload the swap algorithm to call the -member-swap function! -(required for swappable guarantees [Table 37] and Container Requirements -[Table 87]) -
- --Note in particular that Table 87 gives semantics of a.swap(b) as swap(a,b), -yet for all containers we define swap(a,b) to call a.swap(b) - a circular -definition. -
- --A quick survey of clause 23 shows that the following containers provide a -definition for member-swap: -
- -- -array -queue -stack -vector -
-Whereas the following declare it, but do not define the semantics: -
- -- -deque -list -map -multimap -multiset -priority_queue -set -unordered_map -unordered_multi_map -unordered_multi_set -unordered_set -
-Suggested resolution: -
--Provide a definition for each of the affected containers... -- -
[ -Bellevue: -]
- - --Move to Open and ask Alisdair to provide wording. -- -
[ -2009-07 Frankfurt: -]
- - --Daniel to provide wording. -N2590 -is no longer applicable. -- -
[ -2009-07-28 Daniel provided wording. -]
- - --- --
-- -It assumes that the proposed resolution for 883 is applied, -which breaks the circularity of definition between member -swap and free swap. -
- -- -It uses the notation of the pre-concept allocator trait -allocator_propagation_map, which might be renamed after the -next refactoring phase of generalized allocators. -
- -- -It requires that compare objects, key equal functions and -hash functions in containers are swapped via unqualified free -swap according to 594. -
-
[ -2009-09-30 Daniel adds: -]
- - --The outcome of this issue should be considered with the outcome of 1198 both in style and in content (e.g. bullet 9 suggests to -define the semantic of void -priority_queue::swap(priority_queue&) in terms of the member -swap of the container). -- -
[ -2009-10 Santa Cruz: -]
- - --Looked at, but took no action on as it overlaps too much with -N2982. -Waiting for a new draft WP. -- -
[ -2009-10 Santa Cruz: -]
- - --Leave as open. Pablo to provide wording. -- -
[ -2009-10-26 Pablo updated wording. Here is the wording he replaced: -]
- - --- --
- -- -
- --Add a new Throws clause just after X [allocator.propagation.map]/5: -
- --static void swap(Alloc& a, Alloc& b); -----Effects: [..] -
- --Throws: Nothing. -
-[ -This exception requirement is added, such that it's combination with the -general container requirements of -N2723 -[container.requirements.general]/9 -make it unambiguously clear that the following descriptions of "swaps the -allocators" have the following meaning: (a) This swap is done by calling -allocator_propagation_map<allocator_type>::swap and (b) This allocator -swap does never propagate an exception -]
- -- -
- --Change 23.2.4.1 [associative.reqmts.except]/3 as indicated: -
- --For associative containers, no swap function throws an exception unless that -exception is thrown by the-copy constructor or copy assignment -operator-swap of the container's Pred objects(if any). -- -
- --Change 23.2.5.1 [unord.req.except]/3 as indicated: -
- --For unordered associative containers, no swap function throws an -exception unless -that exception is thrown by the-copy constructor or copy -assignment operator-swap of the container's Hash or Pred objects, -respectively(if any). -- -
- --Insert a new paragraph just after 23.3 [sequences]/1: -
- --In addition to being available via inclusion of the <algorithm> header, -the swap function templates in 25.3.3 [alg.swap] are also available when the -header <queue> is included. -- -[ -There is a new issue in process that will suggest a minimum header for swap -and move. If this one is provided, this text can be removed and the header -dependency should be added to <queue> -]
- - -- -
- --Add one further clause at the end of 23.3.1.2 [array.special]: -
-[This part is added, because otherwise array::swap would otherwise -contradict the -general contract of 23.2.1 [container.requirements.general] p. 10 b. 5]
- - --Throws: Nothing, unless one of the element-wise swap calls throws -an exception. --- -
- --
-- -
- --In 23.3.2 [deque], class template deque synopsis change as indicated: -
--void swap(deque<T,Alloc>&); -- -
--At the end of 23.3.2.3 [deque.modifiers] add as indicated: -
- --void swap(deque& x); -----Effects: Exchanges the contents and swaps the allocators of *this -with that of x. -
--Complexity: Constant time. -
-- -
- --
-- -
- --In 23.3.3 [forwardlist], class template forward_list synposis change as indicated: -
- --void swap(forward_list<T,Allocator>&); -- -
--At the end of 23.3.3.4 [forwardlist.modifiers] add as indicated: -
- --void swap(forward_list& x); -----Effects: Exchanges the contents and swaps the allocators of *this -with that of x. -
--Complexity: Constant time. -
-- -
- --
-- -
- --In 23.3.4 [list], class template list synopsis change as indicated: -
- --void swap(list<T,Allocator>&); -- -
--At the end of 23.3.4.3 [list.modifiers] add as indicated: -
- --void swap(list& x); -- ----Effects: Exchanges the contents and swaps the allocators of *this -with that of x. -
- --Complexity: Constant time. -
-- -
- --At the end of 23.3.5.2.2 [priqueue.members] add a new prototype description: -
- --void swap(priority_queue& q); -----Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -
- -[ -This requirement is added to ensure that even a user defined swap -which is found by -ADL for Compare satisfies the Swappable requirements -]
- - --Effects: this->c.swap(q.c); swap(this->comp, q.comp); -
--Throws: What and if c.swap(q.c) and swap(comp, q.comp) throws. -
-[ -This part is added, because otherwise priority_queue::swap would otherwise -contradict the general contract of 23.2.1 [container.requirements.general] p. 10 b. 5 -]
- -- -
- --
-- -
- --In 23.3.6 [vector], class template vector synopsis change as indicated: -
- --void swap(vector<T,Allocator>&); -- -
--Change 23.3.6.2 [vector.capacity]/8 as indicated: -
- --void swap(vector- -<T,Allocator>& x); --Effects: Exchanges the contents and capacity() and swaps the -allocators -of *this with that of x. --- -
- --Insert a new paragraph just before 23.4 [associative]/1: -
- --In addition to being available via inclusion of the <algorithm> header, -the swap function templates in 25.3.3 [alg.swap] are also available when any of the -headers <map> or <set> are included. --- -
- --
-- -
- --In 23.4.1 [map], class template map synopsis change as indicated: -
- --void swap(map<Key,T,Compare,Allocator>&); -- -
--At the end of 23.4.1.3 [map.modifiers] add as indicated: -
- --void swap(map& x); -- ----Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -
- -[ -This requirement is added to ensure that even a user defined swap -which is found by ADL for Compare satisfies the Swappable -requirements -]
- - --Effects: Exchanges the contents and swaps the allocators of *this -with that of x, followed by an unqualified swap of the comparison objects -of *this and x. -
- --Complexity: Constant time -
-- -
- --
-- -
- --In 23.4.2 [multimap], class template multimap synopsis change as indicated: -
- --void swap(multimap<Key,T,Compare,Allocator>&); -- -
--At the end of 23.4.2.2 [multimap.modifiers] add as indicated: -
- --void swap(multimap& x); -- ----Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -
--Effects: Exchanges the contents and swaps the allocators of *this -with that of x, followed by an unqualified swap of the comparison objects -of *this and x. -
--Complexity: Constant time -
-- -
- --
-- -
- --In 23.4.3 [set], class template set synopsis change as indicated: -
- --void swap(set<Key,Compare,Allocator>&); -- -
--After section 23.4.3.1 [set.cons] add a new section set modifiers - [set.modifiers] -and add the following paragraphs: -
- --void swap(set& x); -- ----Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -
- --Effects: Exchanges the contents and swaps the allocators of *this -with that of x, followed by an unqualified swap of the comparison objects -of *this and x. -
- --Complexity: Constant time -
-- -
- --
-- -
- --In 23.4.4 [multiset], class template multiset synosis, change as indicated: -
- --void swap(multiset<Key,Compare,Allocator>&); -- -
--After section 23.4.4.1 [multiset.cons] add a new section multiset modifiers - [multiset.modifiers] and add the following paragraphs: -
- --void swap(multiset& x); -- ----Requires: Compare shall satisfy the Swappable requirements -( [swappable]). -
- --Effects: Exchanges the contents and swaps the allocators of *this -with that of x, followed by an unqualified swap of the comparison objects -of *this and x. -
- --Complexity: Constant time -
-- -
- --Insert a new paragraph just before 23.5 [unord]/1: -
- --In addition to being available via inclusion of the <algorithm> header, -the swap function templates in 25.3.3 [alg.swap] are also available when any of the -headers <unordered_map> or <unordered_set> are included. -- -- -
- --After section 23.5.1.2 [unord.map.elem] add a new section unordered_map -modifiers [unord.map.modifiers] and add the following paragraphs: -
- --void swap(unordered_map& x); -- ----Requires: Hash and Pred shall satisfy the Swappable requirements -( [swappable]). -
- -[ -This requirement is added to ensure that even a user defined swap -which is found by ADL for Hash and Pred satisfies the Swappable -requirements -]
- - --Effects: Exchanges the contents and hash policy and swaps the -allocators of *this -with that of x, followed by an unqualified swap of the Pred objects -and an unqualified swap of the Hash objects of *this and x. -
- --Complexity: Constant time -
-- -
- --After section 23.5.2.1 [unord.multimap.cnstr] add a new section -unordered_multimap -modifiers [unord.multimap.modifiers] and add the following paragraphs: -
- --void swap(unordered_multimap& x); -- ----Requires: Hash and Pred shall satisfy the Swappable requirements -( [swappable]). -
- --Effects: Exchanges the contents and hash policy and swaps the -allocators of *this -with that of x, followed by an unqualified swap of the Pred objects -and an unqualified swap of the Hash objects of *this and x -
--Complexity: Constant time -
-- -
- --After section 23.5.3.1 [unord.set.cnstr] add a new section -unordered_set modifiers - [unord.set.modifiers] and add the following paragraphs: -
- --void swap(unordered_set& x); -- ----Requires: Hash and Pred shall satisfy the Swappable requirements -( [swappable]). -
- --Effects: Exchanges the contents and hash policy and swaps the -allocators of *this -with that of x, followed by an unqualified swap of the Pred objects -and an unqualified swap of the Hash objects of *this and x -
- --Complexity: Constant time -
-- -
- --After section 23.5.4.1 [unord.multiset.cnstr] add a new section -unordered_multiset -modifiers [unord.multiset.modifiers] and add the following paragraphs: -
- --void swap(unordered_multiset& x); -- ----Requires: Hash and Pred shall satisfy the Swappable requirements -( [swappable]). -
- --Effects: Exchanges the contents and hash policy and swaps the -allocators of *this -with that of x, followed by an unqualified swap of the Pred objects -and an unqualified swap of the Hash objects of *this and x -
--Complexity: Constant time -
-
[ -2009-10-30 Pablo and Daniel updated wording. -]
- - - - -Proposed resolution:
- -[ -This resolution is based on the September 2009 WP, -N2960, -except that it -assumes that -N2982 -and issues 883 and 1232 have already been applied. Note in -particular that Table 91 in -N2960 -is refered to as Table 90 because -N2982 -removed the old Table 90. This resolution also addresses issue 431. -]
- --In 23.2.1 [container.requirements.general], replace the a.swap(b) row in table 90, -"container requirements" (was table 91 before the application of N2982 to the -WP): -
----
-- -- a.swap(b)- void- - swap(a,b)Exchange the contents of a and b.(Note A) -- -- swap(a,b)- void- - a.swap(b)(Note A) -
-Modify the notes immediately following Table 90 in -23.2.1 [container.requirements.general] as follows (The wording below is after the -application of N2982 to N2960. The editor might also want to combine Notes -A and B into one.): -
---Notes: the algorithms
swap(),equal() and lexicographical_compare() -are defined in Clause 25. Those entries marked "(Note A)" or "(Note B)" -shouldhave linear complexity for array and constant -complexity for all other standard containers. -
-In 23.2.1 [container.requirements.general], after paragraph 9, add: -
---The expression
a.swap(b), for containersa-andbof a standard container type other thanarray, -exchanges the values ofaandbwithout invoking any -move, copy, or swap operations on the individual container elements. -AnyCompare,Pred, orHashfunction -objects belonging toaandbshall satisfy -theSwappablerequirements and are exchanged by unqualified calls -to non-memberswap. If -allocator_traits<allocator_type>::propagate_on_container_swap::value -== true, then the allocators ofaandbare -also exchanged using an unqualified call to non-memberswap. -Otherwise, the behavior is undefined unlessa.get_allocator() == -b.get_allocator(). Each iterator refering to an element in one -container before the swap shall refer to the same element in the other -container after the swap. It is unspecified whether an iterator with -valuea.end()before the swap will have -valueb.end()after the swap. In addition to being available via -inclusion of the<utility>header, theswap-function template in 25.3.3 [alg.swap] is also available within the definition of -every standard container'sswapfunction. -
[ -Note to the editor: Paragraph 2 starts with a sentence fragment, -clearly from an editing or source-control error. -]
- --Modify 23.2.4.1 [associative.reqmts.except] as follows: -
----23.2.4.1 Exception safety guarantees 23.2.4.1 [associative.reqmts.except] -
--For associative containers, no
-clear()function throws an -exception.erase(k)does not throw an exception unless that -exception is thrown by the -container'sobject (if any). -PredCompare-For associative containers, if an exception is thrown by any operation from -within an
-insert()function inserting a single element, -theinsert()function has no effect. --For associative containers, no
swapfunction throws an exception -unless that exception is thrown by thecopy constructor -or copy assignment operatorswap of the -container'sobject (if any). -PredCompare
-Modify 23.2.5.1 [unord.req.except], paragraph 3 as follows: -
---For unordered associative containers, no
swapfunction throws an -exception unless that exception is thrown by thecopy constructor or copy -assignment operatorswap of the container'sHash-orPredobject (if any). -
-Modify section 23.3.1.2 [array.special]: -
----array specialized algorithms 23.3.1.2 [array.special] -
--
-template <class T, size_t N> void swap(array<T,N>& x,array<T,N>& y);----Effects:
--swap_ranges(x.begin(), x.end(), y.begin() );x.swap(y);
-Add a new section after 23.3.1.5 [array.fill] (Note to the editor: array::fill make use -of a concept requirement that must be removed or changed to text.): -
--- --array::swap [array.swap] -
--
-void swap(array& y);----Effects:
-swap_ranges(this->begin(), this->end(), y.begin() );--Throws: Nothing unless one of the element-wise swap calls throws an -exception. -
--[Note: Unlike other containers'
-swapfunctions, -array::swaptakes linear, not constant, time, may exit via an -exception, and does not cause iterators to become associated with the other -container. — end note] -
-Insert a new paragraph just after 23.3.5 [container.adaptors]/1: -
-- - - - - - - - - - - - --For container adaptors, no
swapfunction throws an exception -unless that exception is thrown by the swap of the -adaptor'sContainerorCompareobject (if any). -
Section: 25.4.4 [alg.merge] Status: Review - Submitter: Daniel Krügler Opened: 2008-01-25 Last modified: 2009-10-22
-View all issues with Review status.
-Discussion:
--Though issue 283 has fixed many open issues, it seems that some are still open: -
- --Both 25.3.4 [lib.alg.merge] in 14882:2003 and 25.4.4 [alg.merge] in N2461 -have no Requires element and the Effects element contains some requirements, -which is probably editorial. Worse is that: -
- -[ -Post Summit Alisdair adds: -]
- - --- --Suggest: -
--(where last is equal to next(result, distance(first1, last1) + -distance(first2, last2)), such that resulting range will be sorted in -non-decreasing order; that is, for every iterator i in [result,last) other -than result, the condition *i < *prev(i) or, respectively, comp(*i, -*prev(i)) will be false. -- --Note that this might still not be technically accurate in the case of -InputIterators, depending on other resolutions working their way through the -system (1011). -
-
[ -Post Summit Daniel adds: -]
- - --If we want to use prev and next here (Note: merge -is sufficiently satisfied with InputIterator) we should instead *add* more to -25 [algorithms]/6, but I can currently not propose any good wording for this. -- -
[ -Batavia (2009-05): -]
- --- --Pete points out the existing wording in [algorithms]/4 -that permits the use of + in algorithm specifications. -
--Alisdair points out that that wording may not apply to input iterators. -
--Move to Review. -
-
[ -2009-07 Frankfurt: -]
- - --Move to Ready. -- -
[ -2009-08-23 Daniel reopens: -]
- - --- --The proposed wording must be rephrased, because the part -
- --for every iterator i in [result,last) other than result, the condition -*i < *(i - 1) or, respectively, comp(*i, *(i - 1)) will be false" -- --isn't meaningful, because the range [result,last) is that of a pure -OutputIterator, which is not readable in general. -
- -[Howard: Proposed wording updated by Daniel, status moved from Ready to Review.]
- -
[ -2009-10 Santa Cruz: -]
- - --- - - --Matt has some different words to propose. Those words have been moved into -the proposed wording section, and the original proposed wording now appears -here: -
----In 25.4.4 [alg.merge] replace p.1+ 2: -
- ----Effects:
- -MergesCopies all the elements of the -two sorted ranges -[first1,last1) and [first2,last2) into the range [result,result + -(last1 - first1) + (last2 - first2)) -, such that resulting range will be sorted in non-decreasing -order; that is for every -pair of iterators i and j of either input ranges, where *i was copied -to the output range -before *j was copied to the output range, the condition *j < *i or, -respectively, comp(*j, *i) -will be false. --Requires:The resulting range shall not overlap with either -of the original ranges. -
-The list will be sorted in non-decreasing order according to the -ordering defined by -comp; that is, for every iterator i in [first,last) other than first, -the condition *i < *(i - 1) or -comp(*i, *(i - 1)) will be false.-
Proposed resolution:
-
-Effects: Merges two sorted ranges [first1,last1) and
-[first2,last2) into the range [result, result + (last1 -
-first1) + (last2 - first2)).
-
-Effects: Copies all the elements of the two sorted ranges -[first1,last1) and [first2,last2) into the range -[result, result_last), where result_last is result -+ (last1 - first1) + (last2 - first2), such that the resulting -range satisfies is_sorted(result, result_last) or -is_sorted(result, result_last, comp), respectively. -
- -
-Requires: The resulting range shall not overlap with
-either of the original ranges. The list will be sorted in
-non-decreasing order according to the ordering defined by comp;
-that is, for every iterator i in [first,last) other
-than first, the condition *i < *(i - 1) or
-comp(*i, *(i - 1)) will be false.
-
Section: 20.5 [tuple] Status: Open - Submitter: Lawrence Crowl Opened: 2008-02-18 Last modified: 2009-10-23
-View all other issues in [tuple].
-View all issues with Open status.
-Discussion:
--Classes with trivial special member functions are inherently more -efficient than classes without such functions. This efficiency is -particularly pronounced on modern ABIs that can pass small classes -in registers. Examples include value classes such as complex numbers -and floating-point intervals. Perhaps more important, though, are -classes that are simple collections, like pair and tuple. When the -parameter types of these classes are trivial, the pairs and tuples -themselves can be trivial, leading to substantial performance wins. -
--The current working draft make specification of trivial functions -(where possible) much easer through defaulted and deleted functions. -As long as the semantics of defaulted and deleted functions match -the intended semantics, specification of defaulted and deleted -functions will yield more efficient programs. -
--There are at least two cases where specification of an explicitly -defaulted function may be desirable. -
--First, the std::pair template has a non-trivial default constructor, -which prevents static initialization of the pair even when the -types are statically initializable. Changing the definition to -
- -- -pair() = default; -
-would enable such initialization. Unfortunately, the change is -not semantically neutral in that the current definition effectively -forces value initialization whereas the change would not value -initialize in some contexts. -
- --** Does the committee confirm that forced value initialization -was the intent? If not, does the committee wish to change the -behavior of std::pair in C++0x? -
--Second, the same default constructor issue applies to std::tuple. -Furthermore, the tuple copy constructor is current non-trivial, -which effectively prevents passing it in registers. To enable -passing tuples in registers, the copy constructor should be -make explicitly defaulted. The new declarations are: -
- -- -tuple() = default; -tuple(const tuple&) = default; -
-This changes is not implementation neutral. In particular, it -prevents implementations based on pointers to the parameter -types. It does however, permit implementations using the -parameter types as bases. -
--** How does the committee wish to trade implementation -efficiency versus implementation flexibility? -
- -[ -Bellevue: -]
- - --- --General agreement; the first half of the issue is NAD. -
--Before voting on the second half, it was agreed that a "Strongly Favor" -vote meant support for trivial tuples (assuming usual requirements met), -even at the expense of other desired qualities. A "Weakly Favor" vote -meant support only if not at the expense of other desired qualities. -
--Concensus: Go forward, but not at expense of other desired qualities. -
--It was agreed to Alisdair should fold this work in with his other -pair/tuple action items, above, and that issue 801 should be "open", but -tabled until Alisdair's proposals are disposed of. -
-
[ -2009-05-27 Daniel adds: -]
- - --This is partly solved by 1117. -- -
[ -2009-07 Frankfurt: -]
- - --Wait for dust to settle from fixing exception safety problem -with rvalue refs. -- -
[ -2009-07-20 Alisdair adds: -]
- - --- --Basically, this issue is what should we do with the default constructor -for pairs and tuples of trivial types. The motivation of the issue was -to force static initialization rather than dynamic initialization, and -was rejected in the case of pair as it would change the meaning of -existing programs. The advice was "do the best we can" for tuple -without changing existing meaning. -
- --Frankfurt seems to simply wait and see the resolution on no-throw move -constructors, which (I believe) is only tangentially related to this -issue, but as good as any to defer until Santa Cruz. -
- --Looking again now, I think constant (static) initialization for pair can -be salvaged by making the default construct constexpr. I have a -clarification from Core that this is intended to work, even if the -constructor is not trivial/constexpr, so long as no temporaries are -implied in the process (even if elided). -
-
[ -2009-10 Santa Cruz: -]
- - --Leave as open. Alisdair to provide wording. -- - - -
Proposed resolution:
--
- - - - - -Section: 20.3.4 [pairs] Status: Open - Submitter: Doug Gregor Opened: 2008-03-14 Last modified: 2009-10-23
-View other active issues in [pairs].
-View all other issues in [pairs].
-View all issues with Open status.
-Discussion:
-#include <utility>
-
-int main()
-{
- std::pair<char *, char *> p (0,0);
-}
--I just got a bug report about that, because it's valid C++03, but not -C++0x. The important realization, for me, is that the emplace -proposal---which made push_back variadic, causing the push_back(0) -issue---didn't cause this break in backward compatibility. The break -actually happened when we added this pair constructor as part of adding -rvalue references into the language, long before variadic templates or -emplace came along: -
- -- -template<class U, class V> pair(U&& x, V&& y); -
-Now, concepts will address this issue by constraining that pair -constructor to only U's and V's that can properly construct "first" and -"second", e.g. (from -N2322): -
- -- -template<class U , class V > -requires Constructible<T1, U&&> && Constructible<T2, V&&> -pair(U&& x , V&& y ); -
[ -San Francisco: -]
- - --- --Suggested to resolve using pass-by-value for that case. -
--Side question: Should pair interoperate with tuples? Can construct a -tuple of a pair, but not a pair from a two-element tuple. -
--Related to 885. -
-
[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Leave as open. Howard to provide wording. -- - - -
Proposed resolution:
--
- - -Rationale:
-[ -San Francisco: -]
- - --Solved by -N2770. -- - - - - - - -
Section: 20.7.15.2.4 [func.wrap.func.inv] Status: Open - Submitter: Alisdair Meredith Opened: 2008-03-16 Last modified: 2009-10-23
-View all issues with Open status.
-Discussion:
--std::function and reference_closure should use "perfect forwarding" as -described in the rvalue core proposal. -
- -[ -Sophia Antipolis: -]
- - --According to Doug Gregor, as far as std::function is concerned, perfect -forwarding can not be obtained because of type erasure. Not everyone -agreed with this diagnosis of forwarding. -- -
[ -2009-05-01 Howard adds: -]
- - --- --Sebastian Gesemann brought to my attention that the CopyConstructible -requirement on function's ArgTypes... is an unnecessary -restriction. -
- -- -template<Returnable R, CopyConstructible... ArgTypes> -class function<R(ArgTypes...)> -... --On further investigation, this complaint seemed to be the same -issue as this one. I believe the reason CopyConstructible was put -on ArgTypes in the first place was because of the nature of the -invoke member: -
- -- -template<class R, class ...ArgTypes> -R -function<R(ArgTypes...)>::operator()(ArgTypes... arg) const -{ - if (f_ == 0) - throw bad_function_call(); - return (*f_)(arg...); -} --However now with rvalue-refs, "by value" no longer implies CopyConstructible -(as Sebastian correctly points out). If rvalue arguments are supplied, MoveConstructible -is sufficient. Furthermore, the constraint need not be applied in function -if I understand correctly. Rather the client must apply the proper constraints -at the call site. Therefore, at the very least, I recommend that CopyConstructible -be removed from the template class function. -
- --Furthermore we need to mandate that the invoker is coded as: -
- -- -template<class R, class ...ArgTypes> -R -function<R(ArgTypes...)>::operator()(ArgTypes... arg) const -{ - if (f_ == 0) - throw bad_function_call(); - return (*f_)(std::forward<ArgTypes>(arg)...); -} --Note that ArgTypes&& (the "perfect forwarding signature") is not -appropriate here as this is not a deduced context for ArgTypes. Instead -the client's arguments must implicitly convert to the non-deduced ArgType -type. Catching these arguments by value makes sense to enable decay. -
- --Next forward is used to move the ArgTypes as efficiently as -possible, and also with minimum requirements (not CopyConstructible) -to the type-erased functor. For object types, this will be a move. For -reference type ArgTypes, this will be a copy. The end result must be -that the following is a valid program: -
- -- -#include <functional> -#include <memory> -#include <cassert> - -std::unique_ptr<int> -f(std::unique_ptr<int> p, int& i) -{ - ++i; - return std::move(p); -} - -int main() -{ - int i = 2; - std::function<std::unique_ptr<int>(std::unique_ptr<int>, - int&> g(f); - std::unique_ptr<int> p = g(std::unique_ptr<int>(new int(1)), i); - assert(*p == 1); - assert(i == 3); -} -[ -Tested in pre-concepts rvalue-ref-enabled compiler. -]
- - --In the example above, the first ArgType is unique_ptr<int> -and the second ArgType is int&. Both must work! -
- -
[ -2009-05-27 Daniel adds: -]
- - --- --in the 2009-05-01 comment of above mentioned issue Howard -
- --
-- -Recommends to replace the CopyConstructible requirement by a -MoveConstructible requirement -
-- -Says: "Furthermore, the constraint need not be applied in function if I -understand correctly. Rather the client must apply the proper constraints -at the call site" -
--I'm fine with (a), but I think comment (b) is incorrect, at least in the -sense I read these sentences. Let's look at Howard's example code: -
- -- -function<R(ArgTypes...)>::operator()(ArgTypes... arg) const -{ - if (f_ == 0) - throw bad_function_call(); - return (*f_)(std::forward<ArgTypes>(arg)...); -} --In the constrained scope of this operator() overload the expression -"(*f_)(std::forward<ArgTypes>(arg)...)" must be valid. How can it -do so, if ArgTypes aren't at least MoveConstructible? -
-
[ -2009-07 Frankfurt: -]
- - --Leave this open and wait until concepts are removed from the Working -Draft so that we know how to write the proposed resolution in terms of -diffs to otherwise stable text. -- -
[ -2009-10 Santa Cruz: -]
- - --Leave as open. Howard to provide wording. Howard welcomes any help. -- - - -
Proposed resolution:
--
- - - - - -Section: 20.7.11.1.3 [func.bind.bind] Status: Ready - Submitter: Stephan T. Lavavej Opened: 2008-02-08 Last modified: 2009-11-07
-View other active issues in [func.bind.bind].
-View all other issues in [func.bind.bind].
-View all issues with Ready status.
-Discussion:
--Library Issue 527 notes that bind(f, t1, ..., tN) -should be nofail when f, t1, ..., tN have nofail copy ctors. -
--However, no guarantees are provided for the copy ctor of the functor -returned by bind(). (It's guaranteed to have a copy ctor, which can -throw implementation-defined exceptions: bind() returns a forwarding -call wrapper, TR1 3.6.3/2. A forwarding call wrapper is a call wrapper, -TR1 3.3/4. Every call wrapper shall be CopyConstructible, TR1 3.3/4. -Everything without an exception-specification may throw -implementation-defined exceptions unless otherwise specified, C++03 -17.4.4.8/3.) -
--Should the nofail guarantee requested by Library Issue 527 be extended -to cover both calling bind() and copying the returned functor? -
- -[ -Howard adds: -]
- - --tuple construction should probably have a similar guarantee. -- -
[ -San Francisco: -]
- - --Howard to provide wording. -- -
[ -Post Summit, Anthony provided wording. -]
- - -[ -Batavia (2009-05): -]
- --Part of all of this issue appears to be rendered moot -by the proposed resolution to issue 817 (q.v.). -We recommend the issues be considered simultaneously -(or possibly even merged) -to ensure there is no overlap. -Move to Open, and likewise for issue 817. -- -
[ -2009-07 Frankfurt: -]
- - --Related to 817 (see below). Leave Open. -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. Decoupling from issue 817. -- - - -
Proposed resolution:
--Add a new sentence to the end of paragraphs 2 and 4 of 20.7.11.1.3 [func.bind.bind]: -
- --- - - - - ---2- Returns: A forwarding call wrapper g with a weak result type (20.6.2). The effect of g(u1, u2, -..., uM) shall be INVOKE(f, v1, v2, ..., vN, Callable<F cv,V1, V2, ..., VN>::result_type), where cv -represents the cv-qualifiers of g and the values and types of the bound arguments -v1, v2, ..., vN are determined as specified below. -The copy constructor and move constructor of the forwarding call wrapper shall throw an -exception if and only if the corresponding constructor of F or any of the types -in BoundArgs... throw an exception. -
-...
---5- Returns: A forwarding call wrapper g with a nested type result_type defined as a synonym -for R. The effect of g(u1, u2, ..., uM) shall be INVOKE(f, v1, v2, ..., vN, R), where the -values and types of the bound arguments v1, v2, ..., vN are determined as specified below. -The copy constructor and move constructor of the forwarding call wrapper shall throw an -exception if and only if the corresponding constructor of F or any of the types -in BoundArgs... throw an exception. -
- -
Section: 20.7.11.1.3 [func.bind.bind] Status: Open - Submitter: Howard Hinnant Opened: 2008-03-17 Last modified: 2009-11-08
-View other active issues in [func.bind.bind].
-View all other issues in [func.bind.bind].
-View all issues with Open status.
-Discussion:
-Addresses US 72, JP 38 and DE 21
- --The functor returned by bind() should have a move constructor that -requires only move construction of its contained functor and bound arguments. -That way move-only functors can be passed to objects such as thread. -
--This issue is related to issue 816. -
- --US 72: -
- --bind should support move-only functors and bound arguments. -- -
-JP 38: -
- --- --add the move requirement for bind's return type. -
--For example, assume following th1 and th2, -
- -- -void f(vector<int> v) { } - -vector<int> v{ ... }; -thread th1([v]{ f(v); }); -thread th2(bind(f, v)); --When function object are set to thread, v is moved to th1's lambda -expression in a Move Constructor of lambda expression because th1's lambda -expression has a Move Constructor. But bind of th2's -return type doesn't have the requirement of Move, so it may not -moved but copied. -
--Add the requirement of move to get rid of this useless copy. -
--And also, add the MoveConstructible as well as CopyConstructible. -
-
-DE 21 -
- --The specification for bind claims twice that "the values and types for -the bound arguments v1, v2, ..., vN are determined as specified below". -No such specification appears to exist. -- -
[ -San Francisco: -]
- - --Howard to provide wording. -- -
[ -Post Summit Alisdair and Howard provided wording. -]
- - --- --Several issues are being combined in this resolution. They are all touching the -same words so this is an attempt to keep one issue from stepping on another, and -a place to see the complete solution in one place. -
- --
-- -bind needs to be "moved". -
-- -20.7.11.1.3 [func.bind.bind]/p3, p6 and p7 were accidently removed from N2798. -
-- -Issue 929 argues for a way to pass by && for -efficiency but retain the decaying behavior of pass by value for the -thread constructor. That same solution is applicable here. -
-
[ -Batavia (2009-05): -]
- --- --We were going to recommend moving this issue to Tentatively Ready -until we noticed potential overlap with issue 816 (q.v.). -
--Move to Open, -and recommend both issues be considered together -(and possibly merged). -
-
[ -2009-07 Frankfurt: -]
- - --The proposed resolution uses concepts. Leave Open. -- -
[ -2009-10 Santa Cruz: -]
- - --Leave as Open. Howard to provide deconceptified wording. -- -
[ -2009-11-07 Howard updates wording. -]
- - - - -Proposed resolution:
--Change 20.7 [function.objects] p2: -
- -- -template<class Fn, class...TypesBoundArgs> - unspecified bind(Fn&&,TypesBoundArgs&&...); -template<class R, class Fn, class...TypesBoundArgs> - unspecified bind(Fn&&,TypesBoundArgs&&...); -
-Change 20.7.11.1.3 [func.bind.bind]: -
- --- - - - - - --Within this clause: -
- --
- -- -Let FD be a synonym for the type decay<F>::type. -
-- -Let fd be an lvalue of type FD constructed from -std::forward<F>(f). -
-- -Let Ti be a synonym for the ith type in the -parameter pack BoundArgs. -
-- -Let TiD be a synonym for the type decay<Ti>::type. -
-- -Let ti be the ith argument in bound_args. -
-- -Let tid be an lvalue of type TiD constructed from -std::forward<Ti>(ti). -
-template<class F, class... BoundArgs> - unspecified bind(F&& f, BoundArgs&&... bound_args); -- --- ---1- Requires: -is_constructible<FD, F>::value -shall be true. -is_constructible<TiD, Ti>::value -shall be true. -
-F and each Ti in -BoundArgs shall be CopyConstructible.-INVOKE(fd, w1, w2, ..., wN) (20.7.2 [func.require]) shall be a valid expression for some values -w1, w2, ..., wN, where N == sizeof...(bound_args). ---2- Returns: A forwarding call wrapper g with a weak -result type (20.7.2 [func.require]). The effect of g(u1, u2, -..., uM) shall be INVOKE(fd, v1, v2, ..., vN, -result_of<FD cv (V1, V2, ..., VN)>::type), where -cv represents the cv-qualifiers of g and the -values and types of the bound arguments v1, v2, ..., vN are -determined as specified below. -The copy constructor and move constructor of the forwarding call wrapper shall throw an -exception if and only if the corresponding constructor of FD or any of the types -TiD throw an exception. -
---3- Throws: Nothing unless the
-copy-constructionorof -Ffd or of one of the values -tidtypes in the BoundArgs... pack -expansionthrows an exception. -- -Remarks: The unspecified return type shall be -MoveConstructible. If all of FD and TiD are -CopyConstructible then the unspecified return type shall -be CopyConstructible. [Note: This implies that all of -FD and TiD shall be MoveConstructible — -end note] - -
-template<class R, class F, class... BoundArgs> - unspecified bind(F&& f, BoundArgs&&... bound_args); -- --- ---4- Requires: -is_constructible<FD, F>::value -shall be true. -is_constructible<TiD, Ti>::value -shall be true. -
-F and each Ti in -BoundArgs shall be CopyConstructible.-INVOKE(fd, w1, -w2, ..., wN) shall be a valid expression for some values w1, w2, -..., wN, where N == sizeof...(bound_args). ---5- Returns: A forwarding call wrapper g with a nested -type result_type defined as a synonym for R. The -effect of g(u1, u2, ..., uM) shall be INVOKE(fd, v1, -v2, ..., vN, R), where the values and types of the bound arguments -v1, v2, ..., vN are determined as specified below. -The copy constructor and move constructor of the forwarding call wrapper shall throw an -exception if and only if the corresponding constructor of FD or any of the types -TiD throw an exception. -
---6- Throws: Nothing unless the
-copy-constructionorof -Ffd or of one of the values -tidtypes in the BoundArgs... pack -expansionthrows an exception. -- -Remarks: The unspecified return type shall be -MoveConstructible. If all of FD and TiD are -CopyConstructible then the unspecified return type shall -be CopyConstructible. [Note: This implies that all of -FD and TiD shall be MoveConstructible — -end note] - -
---7- The values of the bound arguments v1, v2, ..., vN and -their corresponding types V1, V2, ..., VN depend on the types -TiD derived from -
- -of the corresponding argument ti in bound_args of type -Ti in BoundArgs in-the call to bind and the -cv-qualifiers cv of the call wrapper g as -follows: --
- -- -if
-tiTiDis ofhas -type reference_wrapper<T> the argument is -tid.get() and its type Vi is -T&; -- -if the value of -std::is_bind_expression<TiD>::value is -true the argument is tid(u1, u2, ..., uM) -and its type Vi is result_of<TiD cv -(U1&, U2&, ..., UM&)>::type; -
-- -if the value j of -std::is_placeholder<TiD>::value is not zero -the argument is std::forward<Uj>(uj) and its type -Vi is Uj&&; -
-- -otherwise the value is tid and its type Vi -is TiD cv &. -
-
Section: 18.8.6 [except.nested] Status: Open - Submitter: Alisdair Meredith Opened: 2008-03-25 Last modified: 2009-10-23
-View other active issues in [except.nested].
-View all other issues in [except.nested].
-View all issues with Open status.
-Discussion:
--Looking at the wording I submitted for rethrow_if_nested, I don't think I -got it quite right. -
- --The current wording says: -
- --- -template <class E> void rethrow_if_nested(const E& e); -----Effects: Calls e.rethrow_nested() only if e -is publicly derived from nested_exception. -
-
-This is trying to be a bit subtle, by requiring e (not E) to be publicly -derived from nested_exception the idea is that a dynamic_cast would be -required to be sure. Unfortunately, if e is dynamically but not statically -derived from nested_exception, e.rethrow_nested() is ill-formed. -
- -[ -San Francisco: -]
- - --Alisdair was volunteered to provide wording. -- -
[ -2009-10 Santa Cruz: -]
- - --Leave as Open. Alisdair to provide wording. -- - - -
Proposed resolution:
- - - - - -Section: 20.8.14.2 [unique.ptr.single] Status: Open - Submitter: Daniel Krügler Opened: 2008-05-14 Last modified: 2009-10-26
-View other active issues in [unique.ptr.single].
-View all other issues in [unique.ptr.single].
-View all issues with Open status.
-Discussion:
--Issue 673 (including recent updates by 821) proposes a useful -extension point for unique_ptr by granting support for an optional -deleter_type::pointer to act as pointer-like replacement for element_type* -(In the following: pointer). -
--Unfortunately no requirements are specified for the type pointer which has -impact on at least two key features of unique_ptr: -
- --Unique_ptr specification makes great efforts to require that essentially *all* -operations cannot throw and therefore adds proper wording to the affected -operations of the deleter as well. If user-provided pointer-emulating types -("smart pointers") will be allowed, either *all* throw-nothing clauses have to -be replaced by weaker "An exception is thrown only if pointer's {op} throws -an exception"-clauses or it has to be said explicitly that all used -operations of -pointer are required *not* to throw. I understand the main focus of unique_ptr -to be as near as possible to the advantages of native pointers which cannot -fail and thus strongly favor the second choice. Also, the alternative position -would make it much harder to write safe and simple template code for -unique_ptr. Additionally, I assume that a general statement need to be given -that all of the expressions of pointer used to define semantics are required to -be well-formed and well-defined (also as back-end for 762). -
- -[ -Sophia Antipolis: -]
- - --- --Howard: We maybe need a core concept PointerLike, but we don't need the -arithmetic (see shared_ptr vs. vector<T>::iterator. -
--Howard will go through and enumerate the individual requirements wrt. pointer for each member function. -
-
[ -2009-07 Frankfurt: -]
- - --Move to Ready. -- -
[ -2009-10-15 Alisdair pulls from Ready: -]
- - --- --I hate to pull an issue out of Ready status, but I don't think 834 is -fully baked yet. -
- --For reference the proposed resolution is to add the following words: -
- --unique_ptr<T, D>::pointer's operations shall be -well-formed, shall have well defined behavior, and shall not throw -exceptions. -- --This leaves me with a big question : which operations? -
- --Are all pointer operations required to be nothrow, including operations -that have nothing to do with interactions with unique_ptr? This was -much simpler with concepts where we could point to operations within a -certain concept, and so nail down the interactions. -
-
[ -2009-10-15 Daniel adds: -]
- - --I volunteer to prepare a more fine-grained solution, but I would like -to ask for feedback that helps me doing so. If this question is asked -early in the meeting I might be able to fix it within the week, but I -cannot promise that now. -- -
[ -2009-10 Santa Cruz: -]
- - --Leave in open. Daniel to provide wording as already suggested. -- - - - -
Proposed resolution:
--Add the following sentence just at the end of the newly proposed -20.8.14.2 [unique.ptr.single]/p. 3: -
- --unique_ptr<T, D>::pointer's operations shall be well-formed, shall have well -defined behavior, and shall not throw exceptions. -- - - - - -
Section: 27.5.4.2 [basic.ios.members] Status: Open - Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2009-10-20
-View other active issues in [basic.ios.members].
-View all other issues in [basic.ios.members].
-View all issues with Open status.
-Discussion:
-- -The fix for -issue 581, -now integrated into the working paper, overlooks a couple of minor -problems. - -
-
-
-First, being an unformatted function once again, flush()
-is required to create a sentry object whose constructor must, among
-other things, flush the tied stream. When two streams are tied
-together, either directly or through another intermediate stream
-object, flushing one will also cause a call to flush() on
-the other tied stream(s) and vice versa, ad infinitum. The program
-below demonstrates the problem.
-
-
-
-Second, as Bo Persson notes in his
-comp.lang.c++.moderated post,
-for streams with the unitbuf flag set such
-as std::stderr, the destructor of the sentry object will
-again call flush(). This seems to create an infinite
-recursion for std::cerr << std::flush;
-
-
- #include <iostream>
-
-int main ()
-{
- std::cout.tie (&std::cerr);
- std::cerr.tie (&std::cout);
- std::cout << "cout\n";
- std::cerr << "cerr\n";
-}
-
-
-
-[ -Batavia (2009-05): -]
- --We agree with the proposed resolution. -Move to Review. -- -
[ -2009-05-26 Daniel adds: -]
- - --- --I think that the most recently suggested change in -27.7.2.4 [ostream::sentry] need some further word-smithing. As -written, it would make the behavior undefined, if under -conditions when pubsync() should be called, but when -in this scenario os.rdbuf() returns 0. -
--This case is explicitly handled in flush() and needs to be -taken care of. My suggested fix is: -
- --If ((os.flags() & ios_base::unitbuf) && !uncaught_exception() -&& os.rdbuf() != 0) is true, calls- -os.flush()-os.rdbuf()->pubsync(). --Two secondary questions are: -
- --
-- -Should pubsync() be invoked in any case or shouldn't a -base requirement for this trial be that os.good() == true -as required in the original flush() case? -
-- -Since uncaught_exception() is explicitly tested, shouldn't -a return value of -1 of pubsync() produce setstate(badbit) -(which may throw ios_base::failure)? -
-
[ -2009-07 Frankfurt: -]
- - --- --Daniel volunteered to modify the proposed resolution to address his two questions. -
--Move back to Open. -
-
[ -2009-07-26 Daniel provided wording. Moved to Review. -]
- - -[ -2009-10-13 Daniel adds: -]
- - --This proposed wording is written to match the outcome -of 397. -- -
[ -2009 Santa Cruz: -]
- - --Move to Open. Martin to propose updated wording that will also resolve -issue 397 consistently. -- - - -
Proposed resolution:
-[ -based on -N2960 -numbering -]
- - --Just before 27.5.4.2 [basic.ios.members]/2 insert a new paragraph: -
- --Requires: If (tiestr != 0) is true, tiestr must not be reachable -by traversing the linked list of tied stream objects starting from -tiestr->tie(). --
-Change 27.7.2.4 [ostream::sentry]/4 as indicated: -
- --If ((os.flags() & ios_base::unitbuf) && !uncaught_exception()&& -os.good()) is true, calls-os.flush()-os.rdbuf()->pubsync(). If that function returns -1 sets -badbit in os.rdstate() without propagating an exception. -
money_base::space and
- money_base::none on money_get
- Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: Ready - Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2009-10-21
-View all other issues in [locale.money.get.virtuals].
-View all issues with Ready status.
-Duplicate of: 670
-Discussion:
- -- -In paragraph 2, 22.4.6.1.2 [locale.money.get.virtuals] specifies the following: - -
-- -Where-spaceornoneappears in the format -pattern, except at the end, optional white space (as recognized -byct.is) is consumed after any required space. - -
- -This requirement can be (and has been) interpreted two mutually -exclusive ways by different readers. One possible interpretation -is that: - -
----
-- - -where
-money_base::spaceappears in the format, at least -one space is required, and - -- - -where
-money_base::noneappears in the format, space is -allowed but not required. - -
- -The other is that: - -
-- -where either- -money_base::spaceormoney_base::noneappears in the format, white space is optional. - -
[ -San Francisco: -]
- - --Martin will revise the proposed resolution. -- -
[ -2009-07 Frankfurt: -]
- - --- --There is a noun missing from the proposed resolution. It's not clear -that the last sentence would be helpful, even if the word were not -missing: -
--In either case, any required MISSINGWORD followed by all optional whitespace (as recognized by ct.is()) is consumed. ---Strike this sentence and move to Review. -
- -[ -Howard: done. -]
- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
-- -I propose to change the text to make it clear that the first -interpretation is intended, that is, to make following change to -22.4.6.1.2 [locale.money.get.virtuals], p2: - -
- -- -When- - - - -money_base::space-ormoney_base::noneappears as the last -element in the format pattern,except at the end, optional -white space (as recognized byno white space is consumed. Otherwise, -wherect.is) is consumed after -any required space.money_base::spaceappears in any of the initial -elements of the format pattern, at least one white space character is -required. Wheremoney_base::noneappears in any of the -initial elements of the format pattern, white space is allowed but not -required. -If(str.flags() & str.showbase)isfalse, ... - -
Section: 20.8.14.1.1 [unique.ptr.dltr.dflt] Status: Ready - Submitter: Howard Hinnant Opened: 2008-06-18 Last modified: 2009-10-21
-View all issues with Ready status.
-Discussion:
--No relationship between U and T in the converting constructor for default_delete template. -
--Requirements: U* is convertible to T* and has_virtual_destructor<T>; -the latter should also become a concept. -
--Rules out cross-casting. -
--The requirements for unique_ptr conversions should be the same as those on the deleter. -
- -[ -Howard adds 2008-11-26: -]
- - --- --I believe we need to be careful to not outlaw the following use case, and -I believe the current proposed wording -(requires Convertible<U*, T*> && HasVirtualDestructor<T>) does so: -
- -- -#include <memory> - -int main() -{ - std::unique_ptr<int> p1(new int(1)); - std::unique_ptr<const int> p2(move(p1)); - int i = *p2; -// *p2 = i; // should not compile -} --I've removed "&& HasVirtualDestructor<T>" from the -requires clause in the proposed wording. -
- -
[ -Post Summit: -]
- - --- --Alisdair: This issue has to stay in review pending a paper constraining -unique_ptr. -
--Consensus: We agree with the resolution, but unique_ptr needs -to be constrained, too. -
--Recommend Keep in Review. -
-
[ -Batavia (2009-05): -]
- --Keep in Review status for the reasons cited. -- -
[ -2009-07 Frankfurt: -]
- - --- --The proposed resolution uses concepts. Howard needs to rewrite the -proposed resolution. -
--Move back to Open. -
-
[ -2009-07-26 Howard provided rewritten proposed wording and moved to Review. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Add after 20.8.14.1.1 [unique.ptr.dltr.dflt], p1: -
- -- - - - - - -template <class U> default_delete(const default_delete<U>& other); ------1- Effects: ... -
--Remarks: This constructor shall participate in overload resolution -if and only if U* is implicitly convertible to T*. -
-
Section: 26 [numerics] Status: Ready - Submitter: Lawrence Crowl Opened: 2008-06-23 Last modified: 2009-10-23
-View all other issues in [numerics].
-View all issues with Ready status.
-Discussion:
--There are a number of functions that affect the floating point state. -These function need to be thread-safe, but I'm unsure of the right -approach in the standard, as we inherit them from C. -
- -[ -San Francisco: -]
- - --- --Nick: I think we already say that these functions do not introduce data -races; see 17.6.5.6/20 -
--Pete: there's more to it than not introducing data races; are these -states maintained per thread? -
--Howard: 21.5/14 says that strtok and strerror are not required to avoid -data races, and 20.9/2 says the same about asctime, gmtime, ctime, and -gmtime. -
--Nick: POSIX has a list of not-safe functions. All other functions are -implicitly thread safe. -
--Lawrence is to form a group between meetings to attack this issue. Nick -and Tom volunteered to work with Lawrence. -
--Move to Open. -
-
[ -Post Summit: -]
- - --- --Hans: Sane oses seem ok. Sensible thing is implementable and makes sense. -
--Nick: Default wording seems to cover this? Hole in POSIX, these -functions need to be added to list of thread-unsafe functions. -
--Lawrence: Not sufficient, not "thread-safe" per our definition, but -think of state as a thread-local variable. Need something like "these -functions only affect state in the current thread." -
--Hans: Suggest the following wording: "The floating point environment is -maintained per-thread." -
--Walter: Any other examples of state being thread safe that are not -already covered elsewhere? -
--Have thread unsafe functions paper which needs to be updated. Should -just fold in 26.3 [cfenv] functions. -
--Recommend Open. Lawrence instead suggests leaving it open until we have -suitable wording that may or may not include the thread local -commentary. -
-
[ -2009-09-23 Hans provided wording. -]
- - --If I understand the history correctly, Nick, as the Posix liaison, -should probably get a veto on this, since I think it came from Posix (?) -via WG14 and should probably really be addressed there (?). But I think -we are basically in agreement that there is no other sane way to do -this, and hence we don't have to worry too much about stepping on toes. -As far as I can tell, this same issue also exists in the latest Posix -standard (?). -- -
[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
--Add at the end of 26.3.1 [cfenv.syn]: -
- --- - - - - --2 The header defines all functions, types, and macros the same as C99 7.6. -
- --A separate floating point environment shall be maintained for each -thread. Each function accesses the environment corresponding to its -calling thread. -
-
Section: 23.2 [container.requirements] Status: Open - Submitter: Daniel Krügler Opened: 2008-06-24 Last modified: 2009-10-24
-View other active issues in [container.requirements].
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-Discussion:
--Table 89, Container requirements, defines operator== in terms of the container -member function size() and the algorithm std::equal: -
- --== is an equivalence relation. a.size() == b.size() && -equal(a.begin(), a.end(), b.begin() -- -
-The new container forward_list does not provide a size member function -by design but does provide operator== and operator!= without specifying it's semantic. -
--Other parts of the (sequence) container requirements do also depend on -size(), e.g. empty() -or clear(), but this issue explicitly attempts to solve the missing -EqualityComparable specification, -because of the special design choices of forward_list. -
--I propose to apply one of the following resolutions, which are described as: -
- --Both proposal choices are discussed, the preferred choice of the author is -to apply (A). -
- -[ -San Francisco: -]
- - --- --There's an Option C: change the requirements table to use distance(). -
--LWG found Option C acceptable. -
--Martin will draft the wording for Option C. -
-
[ -post San Francisco: -]
- - --Martin provided wording for Option C. -- -
[ -2009-07 Frankfurt -]
- - --- --Other operational semantics (see, for example, Tables 82 and 83) are -written in terms of a container's size() member. Daniel to update -proposed resolution C. -
-[ -Howard: Commented out options A and B. -]
- -
[ -2009-07-26 Daniel updated proposed resolution C. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Mark NAD Editorial. Addressed by -N2986. -- -
[ -2009-10 Santa Cruz: -]
- - --Reopened. -N2986 -was rejected in full committee on procedural grounds. -- - - -
Proposed resolution:
- - --Option (C): -
-- -- - - - - -[ -The changes are relative to -N2914 -but concept-free. -]
- - --
- - -- -
- --In 23.2.1 [container.requirements.general] change Table 80 -- Container requirements as indicated: -
- --
-- -
- --Change the text in the Assertion/note column in the row for "X u;" -as follows: -
- --post: u.-size() == 0empty() == true -- -
- --Change the text in the Assertion/note column in the row for "X();" -as follows: -
- --X().-size() == 0empty() == true -- -
- --Change the text in the Operational Semantics column in the row for -"a == b" as follows: -
--== is an equivalence relation. --a.size()distance(a.begin(), a.end()) == -b.size()distance(b.begin(), b.end()) && -equal(a.begin(), a.end(), b.begin()) -- -
- --Change the text in the Operational Semantics column in the row for -"a.size()" as follows: -
- ---a.end() - a.begin()distance(a.begin(), a.end()) -- -
- --Change the text in the Operational Semantics column in the row for -"a.max_size()" as follows: -
- ---size()distance(begin(), end()) of the largest -possible container -- -
--Change the text in the Operational Semantics column in the row for -"a.empty()" as follows: -
- ---a.size() == 0a.begin() == a.end() -- -
- --In 23.2.1 [container.requirements.general] change Table 82 -- Allocator-aware container requirements as indicated: -
- --
-- -
- --Change the text in the Assertion/note column in the row for "X() / -X u;" as follows: -
- --Requires: A is DefaultConstructible post:-u.size() == -0u.empty() == true, get_allocator() == A() -- -
--Change the text in the Assertion/note column in the row for "X(m) / -X u(m);" as follows: -
- --post:-u.size() == 0u.empty() == true, -get_allocator() == m -- -
- --In 23.2.3 [sequence.reqmts] change Table 83 -- Sequence container requirements as indicated: -
- --
-- -
- --Change the text in the Assertion/note column in the row for "X(n, -t) / X a(n, t)" as follows: -
- --post:-size()distance(begin(), end()) == n [..] -- -
- --Change the text in the Assertion/note column in the row for "X(i, -j) / X a(i, j)" as follows: -
- --[..] post:-size() == distance between i and -jdistance(begin(), end()) == distance(i, j) [..] -- -
--Change the text in the Assertion/note column in the row for -"a.clear()" as follows: -
--a.erase(a.begin(), a.end()) post: --size() == 0a.empty() == true -- -
- --In 23.2.4 [associative.reqmts] change Table 85 -- Associative container requirements as indicated: -
- -[ -Not every occurrence of size() was replaced, because all current -associative containers -have a size. The following changes ensure consistency regarding the -semantics of "erase" -for all tables and adds some missing objects -]
- - --
-- -
- --Change the text in the Complexity column in the row for -"a.insert(i, j)" as follows: -
--N log(a.size() + N)-(N is the distance from i to -j)where N == distance(i, j) -- -
- --Change the text in the Complexity column in the row for -"a.erase(k)" as follows: -
--log(a.size()) + a.count(k) --- -
- --Change the text in the Complexity column in the row for -"a.erase(q1, q2)" as follows: -
- --log(a.size()) + N where N-is the distance from q1 -to q2- == distance(q1, q2). -- -
- --Change the text in the Assertion/note column in the row for -"a.clear()" as follows: -
- --a.erase(a.begin(),a.end()) post:-size() == -0a.empty() == true -- -
- --Change the text in the Complexity column in the row for "a.clear()" -as follows: -
- --linear in a.size() --- -
--Change the text in the Complexity column in the row for -"a.count(k)" as follows: -
- --log(a.size()) + a.count(k) --- -
--In 23.2.5 [unord.req] change Table 87 -- Unordered associative container requirements as indicated: -
-[ -The same rational as for Table 85 applies here -]
- - --
-- -
--Change the text in the Assertion/note column in the row for -"a.clear()" as follows: -
- --[..] Post: a.-size() == 0empty() == true -
Section: 25.3.6 [alg.fill], 25.3.7 [alg.generate] Status: Ready - Submitter: Daniel Krügler Opened: 2008-07-13 Last modified: 2009-10-23
-View all issues with Ready status.
-Discussion:
--In regard to library defect 488 I found some more algorithms which -unnecessarily throw away information. These are typically algorithms, -which sequentially write into an OutputIterator, but do not return the -final value of this output iterator. These cases are: -
- -template<class OutputIterator, class Size, class T> -void fill_n(OutputIterator first, Size n, const T& value);
template<class OutputIterator, class Size, class Generator> -void generate_n(OutputIterator first, Size n, Generator gen);
-In both cases the minimum requirements on the iterator are -OutputIterator, which means according to the requirements of -24.2.2 [output.iterators]/2 that only single-pass iterations are guaranteed. -So, if users of fill_n and generate_n have *only* an OutputIterator -available, they have no chance to continue pushing further values -into it, which seems to be a severe limitation to me. -
- -[ -Post Summit Daniel "conceptualized" the wording. -]
- - -[ -Batavia (2009-05): -]
- --- --Alisdair likes the idea, but has concerns about the specific wording -about the returns clauses. -
--Alan notes this is a feature request. -
--Bill notes we have made similar changes to other algorithms. -
--Move to Open. -
-
[ -2009-07 Frankfurt -]
- - --We have a consensus for moving forward on this issue, but Daniel needs -to deconceptify it. -- -
[ -2009-07-25 Daniel provided non-concepts wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
- --Replace the current declaration of fill_n in 25 [algorithms]/2, header -<algorithm> synopsis and in 25.3.6 [alg.fill] by -
- -- -template<class OutputIterator, class Size, class T> -voidOutputIterator fill_n(OutputIterator first, Size n, const T& value); -
-Just after the effects clause add a new returns clause saying: -
- --Returns: For fill_n and positive n, returns first + n. Otherwise -returns first for fill_n. --
-Replace the current declaration of generate_n in 25 [algorithms]/2, -header <algorithm> synopsis and in 25.3.7 [alg.generate] by -
- -- -template<class OutputIterator, class Size, class Generator> -voidOutputIterator generate_n(OutputIterator first, Size n, Generator gen); -
-Just after the effects clause add a new returns clause saying: -
- --For generate_n and positive n, returns first + n. Otherwise -returns first for generate_n. --
Section: 23 [containers] Status: Ready - Submitter: Alberto Ganesh Barbati Opened: 2008-07-22 Last modified: 2009-10-20
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-Discussion:
--The term "default constructed" is often used in wording that predates -the introduction of the concept of value-initialization. In a few such -places the concept of value-initialization is more correct than the -current wording (for example when the type involved can be a built-in) -so a replacement is in order. Two of such places are already covered by -issue 867. This issue deliberately addresses the hopefully -non-controversial changes in the attempt of being approved more quickly. -A few other occurrences (for example in std::tuple, -std::reverse_iterator and std::move_iterator) are left to separate -issues. For std::reverse_iterator, see also issue 408. This issue is -related with issue 724. -
- -[ -San Francisco: -]
- - --- --The list provided in the proposed resolution is not complete. James -Dennett will review the library and provide a complete list and will -double-check the vocabulary. -
--This issue relates to Issue 886 tuple construction -
-
[ -2009-07 Frankfurt -]
- - --- --The proposed resolution is incomplete. -
--Move to Tentatively NAD Future. Howard will contact Ganesh for wording. -If wording is forthcoming, Howard will move it back to Review. -
-
[ -2009-07-18 Ganesh updated the proposed wording. -]
- - --- --Howard: Moved back to Review. Note that 20.2.1 [utility.arg.requirements] -refers to a section that is not in the current working paper, but does refer to -a section that we expect to reappear after the de-concepts merge. This was a -point of confusion we did not recognize when we reviewed this issue in Frankfurt. -
--Howard: Ganesh also includes a survey of places in the WP surveyed for changes -of this nature and purposefully not treated: -
- --- --Places where changes are not being -proposed -
--In the following paragraphs, we are not proposing changes because -it's not clear whether we actually prefer value-initialization over -default-initialization (now partially covered by 1012): -
--
-- -
20.8.14.2.1 [unique.ptr.single.ctor] para 3 e 7
- -
24.5.1.3.1 [reverse.iter.cons] para 1
- -
24.5.3.3.1 [move.iter.op.const] para 1
In the following paragraphs, the expression "default -constructed" need not be changed, because the relevant type does -not depend on a template parameter and has a user-provided -constructor:
--
-- -
[func.referenceclosure.invoke] para 12, type: - reference_closure
- -
30.3.1.2 [thread.thread.constr] para 30, type: thread
- -
30.3.1.5 [thread.thread.member] para 52, type: thread_id
- -
30.3.2 [thread.thread.this], para 1, type: thread_id
[ -2009-08-18 Daniel adds: -]
- - --- --I have no objections against the currently suggested changes, but I -also cross-checked -with the list regarding intentionally excluded changes, and from this -I miss the discussion -of -
- --
- -- -
- --21.4.1 [string.require]/2: -
- --"[..] The Allocator object used shall be a copy of the Allocator> -object passed to the basic_string object's -constructor or, if the constructor does not take an Allocator -argument, a copy of a default-constructed -Allocator object." --- -
- --N2723, -X [rand.req.eng], Table 109, expression "T()": -
--Pre-/post-condition: "Creates an engine with the same initial state as -all other default-constructed engines of type X." -- --as well as in 26.5.5 [rand.predef]/1-9 (N2914), 26.5.7.1 [rand.util.seedseq]/3, 27.7.1.1.1 [istream.cons]/3, 27.7.2.2 [ostream.cons]/9 (N2914), 28.13 [re.grammar]/2, 30.3.1.4 [thread.thread.assign]/1 (N2914), -
-[ -Candidates for the "the expression "default constructed" need not be -changed" list -]
- - --I'm fine, if these would be added to the intentionally exclusion list, -but mentioning them makes it -easier for other potential reviewers to decide on the relevance or -not-relevance of them for this issue. -
-- -
- --I suggest to remove the reference of [func.referenceclosure.invoke] -in the "it's not clear" list, because -this component does no longer exist. -
-- -
--I also suggest to add a short comment that all paragraphs in the -resolution whether they refer to N2723 or to N2914 numbering, because e.g. "Change 23.3.2.1 [deque.cons] para 5" is an N2723 coordinate, while "Change 23.3.2.2 [deque.capacity] para 1" is an N2914 coordinate. Even better would be to use one default document -for the numbering (probably N2914) and mention special cases (e.g. "Change 20.2.1 [utility.arg.requirements] para 2" as referring to N2723 numbering). -
-
[ -2009-08-18 Alisdair adds: -]
- - --- --I strongly believe the term "default constructed" should not appear in -the library clauses unless we very clearly define a meaning for it, and -I am not sure what that would be. -
- --In those cases where we do not want to replace "default constructed" -with "vale initialized" we should be using "default initialized". If we -have a term that could mean either, we reduce portability of programs. -
- --I have not done an exhaustive review to clarify if that is a vendor -freedom we have reason to support (e.g. value-init in debug, -default-init in release) so I may yet be convinced that LWG has reason -to define this new term of art, but generally C++ initialization is -confusing enough without supporting further ill-defined terms. -
-
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Change 20.2.1 [utility.arg.requirements] para 2: -
- --In general, a default constructor is -not required. Certain container class member function signatures -specify- -the default constructorT() -as a default argument. T() shall be a well-defined expression (8.5) -if one of those signatures is called using the default argument -(8.3.6). -
-Change 23.3.2.1 [deque.cons] para 5: -
- --Effects: Constructs a deque with n -- -default constructedvalue-initialized -elements. -
-Change 23.3.2.2 [deque.capacity] para 1: -
- --Effects: If sz < size(), equivalent -to erase(begin() + sz, end());. If size() < sz, appends sz - -size()- -default -constructedvalue-initialized -elements to the sequence. -
-Change 23.3.3.1 [forwardlist.cons] para 5: -
- --Effects: Constructs a forward_list object with n- -default -constructedvalue-initialized -elements. -
-Change 23.3.3.4 [forwardlist.modifiers] para 21: -
- --Effects: [...] For the first signature -the inserted elements are- -default -constructedvalue-initialized, -and for the second signature they are copies of c. -
-Change 23.3.4.1 [list.cons] para 5: -
- --Effects: Constructs a list with n- -default -constructedvalue-initialized -elements. -
-Change 23.3.4.2 [list.capacity] para 15: -
- --Effects: If sz < size(), equivalent -to list<T>::iterator it = begin(); advance(it, sz); erase(it, -end());. If size() < sz, appends sz - size()- -default -constructedvalue-initialized -elements to the sequence. -
-Change 23.3.6.1 [vector.cons] para 3: -
- --Effects: Constructs a vector with n -- -default constructedvalue-initialized -elements. -
-Change 23.3.6.2 [vector.capacity] para 24: -
- --Effects: If sz < size(), equivalent -to erase(begin() + sz, end());. If size() < sz, appends sz - -size()- - - - - - -default -constructedvalue-initialized -elements to the sequence. -
Section: 23.2.5 [unord.req] Status: Open - Submitter: Daniel Krügler Opened: 2008-08-17 Last modified: 2009-10-20
-View other active issues in [unord.req].
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-Discussion:
--Good ol' associative containers allow both function pointers and -function objects as feasible -comparators, as described in 23.2.4 [associative.reqmts]/2: -
- --Each associative container is parameterized on Key and an ordering -relation Compare that -induces a strict weak ordering (25.3) on elements of Key. [..]. The -object of type Compare is -called the comparison object of a container. This comparison object -may be a pointer to -function or an object of a type with an appropriate function call operator.[..] -- -
-The corresponding wording for unordered containers is not so clear, -but I read it to disallow -function pointers for the hasher and I miss a clear statement for the -equality predicate, see -23.2.5 [unord.req]/3+4+5: -
- --- --Each unordered associative container is parameterized by Key, by a -function object Hash that -acts as a hash function for values of type Key, and by a binary -predicate Pred that induces an -equivalence relation on values of type Key.[..] -
--A hash function is a function object that takes a single argument of -type Key and returns a -value of type std::size_t. -
--Two values k1 and k2 of type Key are considered equal if the -container's equality function object -returns true when passed those values.[..] -
-
-and table 97 says in the column "assertion...post-condition" for the -expression X::hasher: -
- --Hash shall be a unary function object type such that the expression -hf(k) has type std::size_t. -- -
-Note that 20.7 [function.objects]/1 defines as "Function objects are -objects with an operator() defined.[..]" -
--Does this restriction exist by design or is it an oversight? If an -oversight, I suggest that to apply -the following -
- -[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Ask Daniel to provide proposed wording that: makes it explicit that -function pointers are function objects at the beginning of 20.7 [function.objects]; fixes the "requirements" for typedefs in -20.7.5 [refwrap] to instead state that the function objects -defined in that clause have these typedefs, but not that these typedefs -are requirements on function objects; remove the wording that explicitly -calls out that associative container comparators may be function -pointers. -- - - -
Proposed resolution:
--In 23.2.5 [unord.req]/3, just after the second sentence which is written as -
- --Additionally, unordered_map and unordered_multimap associate an -arbitrary mapped type T with the Key. -- -
-add one further sentence: -
- --Both Hash and Pred may be pointers to function or objects of a type -with an appropriate function call operator. -- -
-[Note1: Since the detailed requirements for Pred and Hash are given in -p.4 and p.5, it an alternative resolution -would be to insert a new paragraph just after p.5, which contains the -above proposed sentence] -
--[Note2: I do not propose a change of above quoted element in table 97, -because the mis-usage of the -notion of "function object" seems already present in the standard at -several places, even if it includes -function pointers, see e.g. 25 [algorithms]/7. The important point is -that in those places a statement is -given that the actually used symbol, like "Predicate" applies for -function pointers as well] -
- - -Rationale:
-[ -San Francisco: -]
- - --This is fixed by -N2776. -- - - - - - -
Section: 26.7.5 [numeric.iota] Status: Ready - Submitter: Daniel Krügler Opened: 2008-08-20 Last modified: 2009-10-22
-View all issues with Ready status.
-Discussion:
--According to the recent WP -N2691, -26.7.5 [numeric.iota]/1, the requires clause -of std::iota says: -
- --T shall meet the requirements of CopyConstructible and Assignable types, and -shall be convertible to ForwardIterator's value type.[..] -- -
-Neither CopyConstructible nor Assignable is needed, instead MoveConstructible -seems to be the correct choice. I guess the current wording resulted as an -artifact from comparing it with similar numerical algorithms like accumulate. -
- --Note: If this function will be conceptualized, the here proposed -MoveConstructible -requirement can be removed, because this is an implied requirement of -function arguments, see -N2710/[temp.req.impl]/3, last bullet. -
- -[ -post San Francisco: -]
- - --Issue pulled by author prior to review. -- -
[ -2009-07-30 Daniel reopened: -]
- - --with the absence of concepts, this issue (closed) is valid again and I -suggest to reopen it. -I also revised by proposed resolution based on N2723 wording: -- -
[ -2009-10 Santa Cruz: -]
- - --Change 'convertible' to 'assignable', Move To Ready. -- - - -
Proposed resolution:
--Change the first sentence of 26.7.5 [numeric.iota]/1: -
- --Requires: T shall- - - - - - - - -meet the requirements of CopyConstructible and -Assignable types, and shallbe -assignable to ForwardIterator's value type. [..] -
Section: 24.5.3.3.12 [move.iter.op.index] Status: Ready - Submitter: Doug Gregor Opened: 2008-08-21 Last modified: 2009-10-23
-View all issues with Ready status.
-Discussion:
--move_iterator's operator[] is declared as: -
- -- -reference operator[](difference_type n) const; -
-This has the same problem that reverse_iterator's operator[] used to -have: if the underlying iterator's operator[] returns a proxy, the -implicit conversion to value_type&& could end up referencing a temporary -that has already been destroyed. This is essentially the same issue that -we dealt with for reverse_iterator in DR 386. -
- -[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-08-15 Howard adds: -]
- - --I recommend closing this as a duplicate of 1051 which addresses -this issue for both move_iterator and reverse_iterator. -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. Note that if 1051 is reopened, it may yield a -better resolution, but 1051 is currently marked NAD. -- - - -
Proposed resolution:
--In 24.5.3.1 [move.iterator] and 24.5.3.3.12 [move.iter.op.index], change the declaration of -move_iterator's operator[] to: -
- -- - - -referenceunspecified operator[](difference_type n) const; -
Rationale:
-[ -San Francisco: -]
- - --NAD Editorial, see -N2777. -- - - - -
Section: 20.3.4 [pairs] Status: Open - Submitter: Alisdair Meredith Opened: 2008-09-15 Last modified: 2009-07-17
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-Discussion:
-- -20.2.3 pairs -Missing assignemnt operator: -template<class U , class V> - requires CopyAssignable<T1, U> && CopyAssignable<T2, V> - pair& operator=(pair<U , V> const & p ); -
-Well, that's interesting. This assignment operator isn't in the -current working paper, either. Perhaps we deemed it acceptable to -build a temporary of type pair from pair<U, V>, then move-assign -from that temporary? -
--It sounds more like an issue waiting to be opened, unless you want to plug -it now. As written we risk moving from lvalues. -
- -[ -San Francisco: -]
- - --- --Would be NAD if better ctors fixed it. -
--Related to 811. -
-
[ -post San Francisco: -]
- - --Possibly NAD Editorial, solved by -N2770. -- -
[ -2009-05-25 Alisdair adds: -]
- - --Issue 885 was something I reported while reviewing the library concepts -documents ahead of San Francisco. The missing operator was added as part of -the paper adopted at that meeting -(N2770) -and I can confirm this operator is -present in the current working paper. I recommend NAD. -- -
[ -2009-07 Frankfurt -]
- - --We agree with the intent, but we need to wait for the dust to settle on concepts. -- - - -
Proposed resolution:
--
- - - - - -Section: 30.5.1 [thread.condition.condvar] Status: Open - Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2009-10-26
-View other active issues in [thread.condition.condvar].
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-Discussion:
--The Posix/C++ working group has identified an inconsistency between -Posix and the C++ working draft in that Posix requires the clock to be -identified at creation, whereas C++ permits identifying the clock at the -call to wait. The latter cannot be implemented with the former. -
- -[ -San Francisco: -]
- - --- --Howard recommends NAD with the following explanation: -
- --The intent of the current wording is for the condtion_variable::wait_until -be able to handle user-defined clocks as well as clocks the system knows about. -This can be done by providing overloads for the known clocks, and another -overload for unknown clocks which synchs to a known clock before waiting. -For example: -
- -- -template <class Duration> -bool -condition_variable::wait_until(unique_lock<mutex>& lock, - const chrono::time_point<chrono::system_clock, Duration>& abs_time) -{ - using namespace chrono; - nanoseconds d = __round_up<nanoseconds>(abs_time.time_since_epoch()); - __do_timed_wait(lock.mutex()->native_handle(), time_point<system_clock, nanoseconds>(d)); - return system_clock::now() < abs_time; -} - -template <class Clock, class Duration> -bool -condition_variable::wait_until(unique_lock<mutex>& lock, - const chrono::time_point<Clock, Duration>& abs_time) -{ - using namespace chrono; - system_clock::time_point s_entry = system_clock::now(); - typename Clock::time_point c_entry = Clock::now(); - nanoseconds dn = __round_up<nanoseconds>(abs_time.time_since_epoch() - - c_entry.time_since_epoch()); - __do_timed_wait(lock.mutex()->native_handle(), s_entry + dn); - return Clock::now() < abs_time; -} --In the above example, system_clock is the only clock which the underlying -condition variable knows how to deal with. One overload just passes that clock -through. The second overload (approximately) converts the unknown clock into -a system_clock time_point prior to passing it down to the native -condition variable. -
- --On Posix systems vendors are free to add implementation defined constructors which -take a clock. That clock can be stored in the condition_variable, and converted -to (or not as necessary) as shown above. -
- --If an implementation defined constructor takes a clock (for example), then part -of the semantics for that implementation defined ctor might include that a -wait_until using a clock other than the one constructed with results -in an error (exceptional condition) instead of a conversion to the stored clock. -Such a design is up to the vendor as once an implementation defined ctor is used, -the vendor is free to specifiy the behavior of waits and/or notifies however -he pleases (when the cv is constructed in an implementation defined manner). -
-
[ -Post Summit: -]
- - --- --"POSIX people will review the proposed NAD resolution at their upcoming NY -meeting. -
- --See the minutes at: http://wiki.dinkumware.com/twiki/bin/view/Posix/POSIX-CppBindingWorkingGroupNewYork2009. -
-
[ -2009-07 Frankfurt -]
- - --Move to NAD. -- -
[ -2009-07-18 Detlef reopens the issue: -]
- - --- --On Friday afternoon in Frankfurt is was decided that 887 is NAD. -This decision was mainly based on a sample implementation presented -by Howard that implemented one clock on top of another. -Unfortunately this implementation doesn't work for the probably most -important case where a system has a monotonic clock and a real-time -clock (or "wall time" clock): -
--If the underlying "system_clock" is a monotonic clock, and -the program waits on the real-time clock, and the real-time clock -is set forward, the wait will unblock too late. -
- --If the underlying "system_clock" is a real-time clock, and the -program waits on the monotonic clock, and the real-time clock -is set back, the wait again will unblock too late. -
- --Sorry that I didn't remember this on Friday, but it was Friday -afternoon after a busy week... -
- --So as the decision was made on a wrong asumption, I propose to re-open -the issue. -
-
[ -2009-07-26 Howard adds: -]
- - --- --Detlef correctly argues that condition_variable::wait_until could -return "too late" in the context of clocks being adjusted during the wait. I agree -with his logic. But I disagree that this makes this interface unimplementable -on POSIX. -
- --The POSIX spec also does not guarantee that pthread_cond_timedwait does -not return "too late" when clocks are readjusted during the wait. Indeed, the -POSIX specification lacks any requirements at all concerning how soon -pthread_cond_timedwait returns after a time out. This is evidently a -QOI issue by the POSIX standard. Here is a quote of the most relevant normative -text concerning pthread_cond_timedwait found -here. -
- --The pthread_cond_timedwait() function shall be equivalent to -pthread_cond_wait(), except that an error is returned if the absolute -time specified by abstime passes (that is, system time equals or exceeds -abstime) before the condition cond is signaled or broadcasted, or if the -absolute time specified by abstime has already been passed at the time -of the call. -- --I.e. the POSIX specification speaks of the error code returned in case of a time -out, but not on the timeliness of that return. -
- --Might this simply be an oversight, or minor defect in the POSIX specification? -
- --I do not believe so. This same section goes on to say in non-normative -text: -
- --For cases when the system clock is advanced discontinuously by an -operator, it is expected that implementations process any timed wait -expiring at an intervening time as if that time had actually occurred. -- --Here is non-normative wording encouraging the implementation to ignore an advancing -underlying clock and subsequently causing an early (spurious) return. There is -no wording at all which addresses Detlef's example of a "late return". With -pthread_cond_timedwait this would be caused by setting the system clock -backwards. It seems reasonable to assume, based on the wording that is already -in the POSIX spec, that again, the discontinuously changed clock would be ignored -by pthread_cond_timedwait. -
- --A noteworthy difference between pthread_cond_timedwait and -condition_variable::wait_until is that the POSIX spec appears to -say that ETIMEDOUT should be returned if pthread_cond_timedwait -returns because of timeout signal, whether or not the system clock was discontinuously -advanced during the wait. In contrast condition_variable::wait_until -always returns: -
- -- -Clock::now() < abs_time --That is, the C++ spec requires that the clock be rechecked (detecting discontinuous -adjustments during the wait) at the time of return. condition_variable::wait_until -may indeed return early or late. But regardless it will return a value -reflecting timeout status at the time of return (even if clocks have been adjusted). -Of course the clock may be adjusted after the return value is computed but before the client has -a chance to read the result of the return. Thus there are no iron-clad guarantees -here. -
- --condition_variable::wait_until (and pthread_cond_timedwait) -is little more than a convenience function for making sure -condition_variable::wait doesn't hang for an unreasonable amount of -time (where the client gets to define "unreasonable"). I do not think it -is in anyone's interest to try to make it into anything more than that. -
- --I maintain that this is a useful and flexible specification in the spirit of -C++, and is implementable on POSIX. The implementation technique described above -is a reasonable approach. There may also be higher quality approaches. This -specification, like the POSIX specification, gives a wide latitude for QOI. -
- --I continue to recommend NAD, but would not object to a clarifying note regarding -the behavior of condition_variable::wait_until. At the moment, I do -not have good wording for such a note, but welcome suggestions. -
- -
[ -2009-09-30: See N2969. -]
- - -[ -2009-10 Santa Cruz: -]
- - --The LWG is in favor of Detlef to supply revision which adopts Option 2 from -N2969 -but is modified by saying that system_clock must be available for wait_until. -- - - -
Proposed resolution:
--
- - - - - -Section: 30.3.1.1 [thread.thread.id] Status: Ready - Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2009-10-22
-View all other issues in [thread.thread.id].
-View all issues with Ready status.
-Discussion:
- -Addresses UK 324
- --The thread::id type supports the full set of comparison operators. This -is substantially more than is required for the associative containers that -justified them. Please place an issue against the threads library. -
- -[ -San Francisco: -]
- - --- --Would depend on proposed extension to POSIX, or non-standard extension. -What about hash? POSIX discussing op. POSIX not known to be considering -support needed for hash, op. -
--Group expresses support for putting ids in both unordered and ordered containers. -
-
[ -post San Francisco: -]
- - --- --Howard: It turns out the current working paper -N2723 -already has hash<thread::id> -(20.7 [function.objects], 20.7.16 [unord.hash]). We simply -overlooked it in the meeting. It is a good thing we voted in favor of it -(again). :-) -
--Recommend NAD. -
- -
[ -Post Summit: -]
- - --Recommend to close as NAD. For POSIX, see if we need to add a function to -convert pthread_t to integer. -- -
[ -Post Summit, Alisdair adds: -]
- - --- --The recommendation for LWG-889/UK-324 is NAD, already specified. -
--It is not clear to me that the specification is complete. -
--In particular, the synopsis of <functional> in 20.7 [function.objects] does not mention hash< thread::id -> nor hash< error_code >, although their -existence is implied by 20.7.16 [unord.hash], p1. -
--I am fairly uncomfortable putting the declaration for the -thread_id specialization into <functional> as -id is a nested class inside std::thread, so it implies -that <functional> would require the definition of the -thread class template in order to forward declared -thread::id and form this specialization. -
--It seems better to me that the dependency goes the other way around -(<thread> will more typically make use of -<functional> than vice-versa) and the -hash<thread::id> specialization be declared in the -<thread> header. -
--I think hash<error_code> could go into either -<system_error> or <functional> and have no -immediate preference either way. However, it should clearly appear in -the synopsis of one of these two. -
--Recommend moving 889 back to open, and tying in a reference to UK-324. -
-
[ -Batavia (2009-05): -]
- --Howard observes that thread::id need not be a nested class; -it could be a typedef for a more visible type. -- -
[ -2009-05-24 Alisdair adds: -]
- --I do not believe this is correct. thread::id is explicitly documents as a -nested class, rather than as an unspecified typedef analogous to an -iterator. If the intent is that this is not implemented as a nested class -(under the as-if freedoms) then this is a novel form of standardese. -- -
[ -2009-07 Frankfurt -]
- - --Decided we want to move hash specialization for thread_id to the thread -header. Alisdair to provide wording. -- -
[ -2009-07-28 Alisdair provided wording, moved to Review. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Add a strike for hash<thread::id>. Move to Ready -- - - -
Proposed resolution:
- --Remove the following prototype from the synopsis in -20.7 [function.objects]: -
- -- --template <> struct hash<std::thread::id>; -
-Add to 30.3 [thread.threads], p1 Header <thread> synopsis: -
- -- -template <class T> struct hash; -template <> struct hash<thread::id>; -
-Add template specialization below class definition in 30.3.1.1 [thread.thread.id] -
- -template <>
-struct hash<thread::id> : public unary_function<thread::id, size_t> {
- size_t operator()(thread::id val) const;
-};
--Extend note in p2 30.3.1.1 [thread.thread.id] with second sentence: -
- --[Note: Relational operators allow thread::id objects to be used -as keys in associative containers. -hash template specialization allow thread::id objects to be used as keys -in unordered containers. -— end note] -- -
-Add new paragraph to end of 30.3.1.1 [thread.thread.id] -
- -- - - - - -template <> struct hash<thread::id>; ---An explicit specializations of the class template hash (20.7.16 [unord.hash]) -shall be provided for the values of type thread::id -suitable for use as keys in unordered associative containers (23.5 [unord]). --
Section: 30.3.1.2 [thread.thread.constr], 30.4.5.2 [thread.once.callonce] Status: Open - Submitter: Peter Dimov Opened: 2008-09-15 Last modified: 2009-10-24
-View other active issues in [thread.thread.constr].
-View all other issues in [thread.thread.constr].
-View all issues with Open status.
-Discussion:
--I notice that the vararg overloads of std::thread and std::call_once -(N2723 30.3.1.2 [thread.thread.constr] and 30.4.5.2 [thread.once.callonce]) are no longer specified in terms of -std::bind; instead, some of the std::bind wording has been inlined into -the specification. -
--There are two problems with this. -
--First, the specification (and implementation) in terms of std::bind allows, for example: -
- -- -std::thread th( f, 1, std::bind( g ) ); -
-which executes f( 1, g() ) in a thread. This can be useful. The -"inlined" formulation changes it to execute f( 1, bind(g) ) in a thread. -
--Second, assuming that we don't want the above, the specification has copied the wording -
- --INVOKE(func, w1, w2, ..., wN) (20.6.2) shall be a valid -expression for some values w1, w2, ..., wN -- -
-but this is not needed since we know that our argument list is args; it should simply be -
- --INVOKE(func, args...) (20.6.2) shall be a valid expression -- -
[ -Summit: -]
- - --Move to open. -- -
[ -Post Summit Anthony provided proposed wording. -]
- - -[ -2009-07 Frankfurt -]
- - --Leave Open. Await decision for thread variadic constructor. -- -
[ -2009-10 Santa Cruz: -]
- - --See proposed wording for 929 for this, for the formulation -on how to solve this. 929 modifies the thread constructor to -have "pass by value" behavior with pass by reference efficiency through the use -of the decay trait. This same formula would be useful for call_once. -- - - -
Proposed resolution:
--Change paragraph 4 of 30.3.1.2 [thread.thread.constr] to: -
- --- -template <class F> explicit thread(F f); -template <class F, class ...Args> thread(F&& f, Args&&... args); ----4- Requires: F and each Ti in Args -shall be CopyConstructible if an lvalue and otherwise -MoveConstructible. INVOKE(f,-w1, w2, ..., wNargs...) -(20.6.2) shall be a valid expressionfor some values w1, w2, ..., -wN, where N == sizeof...(Args). -
-Change paragraph 1 of 30.4.5.2 [thread.once.callonce] to: -
- -- - - - - -template<class Callable, class ...Args> - void call_once(once_flag& flag, Callable func, Args&&... args); ----1- Requires: The template parameters Callable> and each -Ti in Args shall be CopyConstructible if an -lvalue and otherwise MoveConstructible. INVOKE(func, --w1, w2, ..., wNargs...) (20.6.2) shall be a -valid expressionfor some values w1, w2, ..., wN, where -N == sizeof...(Args). -
Section: 30.4.1.1 [thread.mutex.class] Status: Ready - Submitter: Peter Dimov Opened: 2008-09-15 Last modified: 2009-10-22
-View all other issues in [thread.mutex.class].
-View all issues with Ready status.
-Duplicate of: 905
-Discussion:
--30.4.1.1 [thread.mutex.class]/27 (in -N2723) -says that the behavior is undefined if: -
--I don't believe that this is right. Calling lock() or try_lock() on a -locked mutex is well defined in the general case. try_lock() is required -to fail and return false. lock() is required to either throw an -exception (and is allowed to do so if it detects deadlock) or to block -until the mutex is free. These general requirements apply regardless of -the current owner of the mutex; they should apply even if it's owned by -the current thread. -
--Making double lock() undefined behavior probably can be justified (even -though I'd still disagree with the justification), but try_lock() on a -locked mutex must fail. -
- -[ -Summit: -]
- --- --Move to open. Proposed resolution: -
--
-- -In 30.4.1 [thread.mutex.requirements] paragraph 12, change the error -condition for resource_deadlock_would_occur to: "if the implementation -detects that a deadlock would occur" -
-- -Strike 30.4.1.1 [thread.mutex.class] paragraph 3 bullet 2 "a thread that owns a mutex object -calls lock() or try_lock() on that object, or" -
-
[ -2009-07 Frankfurt -]
- - --Move to Review. Alisdair to provide note. -- -
[ -2009-07-31 Alisdair provided note. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
--In 30.4.1 [thread.mutex.requirements] paragraph 12 change: -
- --- --
-- ...
-- -resource_deadlock_would_occur -- if the
-current thread already owns the mutex and is able -to detect itimplementation detects that a deadlock would occur. -- ...
-
-Strike 30.4.1.1 [thread.mutex.class] paragraph 3 bullet 2: -
--- ---3- The behavior of a program is undefined if: -
--
-- ...
-- -
-a thread that owns a mutex object calls lock() or try_lock() on that object, or-- ...
-
-Add the following note after p3 30.4.1.1 [thread.mutex.class] -
- --[Note: a program may deadlock if the thread that owns a mutex -object calls lock() or try_lock() on that object. If the program can -detect the deadlock, a resource_deadlock_would_occur error condition may -be observed. — end note] -- - - - - - -
Section: 20.8.15.2 [util.smartptr.shared] Status: Open - Submitter: Hans Boehm Opened: 2008-09-16 Last modified: 2009-10-25
-View all other issues in [util.smartptr.shared].
-View all issues with Open status.
-Discussion:
--It is unclear whether shared_ptr is thread-safe in the sense that -multiple threads may simultaneously copy a shared_ptr. However this -is a critical piece of information for the client, and it has significant -impact on usability for many applications. (Detlef Vollman thinks it -is currently clear that it is not thread-safe. Hans Boehm thinks -it currently requires thread safety, since the use_count is not an -explicit field, and constructors and assignment take a const reference -to an existing shared_ptr.) -
- --Pro thread-safety: -
--Many multi-threaded usages are impossible. A thread-safe version can -be used to destroy an object when the last thread drops it, something -that is often required, and for which we have no other easy mechanism. -
--Against thread-safety: -
--The thread-safe version is well-known to be far more expensive, even -if used by a single thread. Many applications, including all single-threaded -ones, do not care. -
- -[ -San Francisco: -]
- - --- --Beman: this is a complicated issue, and would like to move this to Open -and await comment from Peter Dimov; we need very careful and complete -rationale for any decision we make; let's go slow -
--Detlef: I think that shared_ptr should not be thread-safe. -
--Hans: When you create a thread with a lambda, it in some cases makes it -very difficult for the lambda to reference anything in the heap. It's -currently ambiguous as to whether you can use a shared_ptr to get at an -object. -
--Leave in Open. Detlef will submit an alternative proposed resolution -that makes shared_ptr explicitly unsafe. -
--A third option is to support both threadsafe and non-safe share_ptrs, -and to let the programmer decide which behavior they want. -
- --Beman: Peter, do you support the PR? -
- --Peter: -
--- --Yes, I support the proposed resolution, and I certainly oppose any -attempts to make shared_ptr thread-unsafe. -
--I'd mildly prefer if -
--[Note: This is true in spite of that fact that such functions often -modify use_count() --end note] ---is changed to -
--[Note: This is true in spite of that fact that such functions often -cause a change in use_count() --end note] ---(or something along these lines) to emphasise that use_count() is not, -conceptually, a variable, but a return value. -
-
[ -2009-07 Frankfurt -]
- - --- --Vote: Do we want one thread-safe shared pointer or two? If two, one -would allow concurrent construction and destruction of shared pointers, -and one would not be thread-safe. If one, then it would be thread-safe. -
--No concensus on that vote. -
--Hans to improve wording in consultation with Pete. Leave Open. -
-
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. Ask Editor to clear up wording a little when integrating to -make it clear that the portion after the first comma only applies for -the presence of data races. -- -
[ -2009-10-24 Hans adds: -]
- - --- - - --I think we need to pull 896 back from ready, unfortunately. My wording -doesn't say the right thing. -
- --I suspect we really want to say something along the lines of: -
- --For purposes of determining the presence of a data race, member -functions access and modify only the shared_ptr and -weak_ptr objects themselves and not objects they refer to. -Changes in use_count() do not reflect modifications that can -introduce data races. -- --But I think this needs further discussion by experts to make sure this -is right. -
- --Detlef and I agree continue to disagree on the resolution, but I think -we agree that it would be good to try to expedite this so that it can be -in CD2, since it's likely to generate NB comments no matter what we do. -And lack of clarity of intent is probably the worst option. I think it -would be good to look at this between meetings. -
-
Proposed resolution:
--Make it explicitly thread-safe, in this weak sense, as I believe was intended: -
--Insert in 20.8.15.2 [util.smartptr.shared], before p5: -
----For purposes of determining the presence of a data race, -member functions do not modify const shared_ptr and -const weak_ptr arguments, nor any objects they -refer to. [Note: This is true in spite of that fact that such functions often -cause a change in use_count() --end note] -
-
-On looking at the text, I'm not sure we need a similar disclaimer -anywhere else, since nothing else has the problem with the modified -use_count(). I think Howard arrived at a similar conclusion. -
- - - - - -Section: 27.9.1.8 [ifstream.assign] Status: Open - Submitter: Niels Dekker Opened: 2008-09-20 Last modified: 2009-10-20
-View all issues with Open status.
-Discussion:
--It -appears that we have an issue similar to issue 675 regarding the move-assignment of -stream types. For example, when assigning to an std::ifstream, -ifstream1, it seems preferable to close the file originally held by -ifstream1: -
- -- -ifstream1 = std::move(ifstream2); -
-The current Draft -(N2723) -specifies that the move-assignment of -stream types like ifstream has the same effect as a swap: -
- --- --Assign and swap 27.9.1.8 [ifstream.assign] -
-basic_ifstream& operator=(basic_ifstream&& rhs); ---Effects: swap(rhs). --
[ -Batavia (2009-05): -]
- --- --Howard agrees with the analysis and the direction proposed. -
--Move to Open pending specific wording to be supplied by Howard. -
-
[ -2009-07 Frankfurt: -]
- - --Howard is going to write wording. -- -
[ -2009-07-26 Howard provided wording. -]
- - -[ -2009-09-13 Niels adds: -]
- - --Note: The proposed change of 27.9.1.3 [filebuf.assign]/1 depends on the -resolution of LWG 1204, which allows implementations to assume that -*this and rhs refer to different objects. -- -
[ -2009 Santa Cruz: -]
- - --Leave as Open. Too closely related to 911 to move on at this time. -- - - -
Proposed resolution:
- --Change 27.8.1.2 [stringbuf.assign]/1: -
- -- -basic_stringbuf& operator=(basic_stringbuf&& rhs); ----1- Effects:-swap(rhs).-After the move assignment *this reflects the same observable -state it would have if it had been move constructed from rhs -(27.8.1.1 [stringbuf.cons]). - -
-Change 27.8.2.2 [istringstream.assign]/1: -
- -- -basic_istringstream& operator=(basic_istringstream&& rhs); ----1- Effects:-swap(rhs).-Move assigns the base and members of *this with the respective -base and members of rhs. - -
-Change 27.8.3.2 [ostringstream.assign]/1: -
- -- -basic_ostringstream& operator=(basic_ostringstream&& rhs); ----1- Effects:-swap(rhs).-Move assigns the base and members of *this with the respective -base and members of rhs. - -
-Change 27.8.5.1 [stringstream.assign]/1: -
- -- -basic_stringstream& operator=(basic_stringstream&& rhs); ----1- Effects:-swap(rhs).-Move assigns the base and members of *this with the respective -base and members of rhs. - -
-Change 27.9.1.3 [filebuf.assign]/1: -
- -- -basic_filebuf& operator=(basic_filebuf&& rhs); ----1- Effects:-swap(rhs).-Begins by calling this->close(). -After the move assignment *this reflects the same observable -state it would have if it had been move constructed from rhs -(27.9.1.2 [filebuf.cons]). - -
-Change 27.9.1.8 [ifstream.assign]/1: -
- -- -basic_ifstream& operator=(basic_ifstream&& rhs); ----1- Effects:-swap(rhs).-Move assigns the base and members of *this with the respective -base and members of rhs. -
-Change 27.9.1.12 [ofstream.assign]/1: -
- -- -basic_ofstream& operator=(basic_ofstream&& rhs); ----1- Effects:-swap(rhs).-Move assigns the base and members of *this with the respective -base and members of rhs. -
-Change 27.9.1.16 [fstream.assign]/1: -
- -- - - - - - -basic_fstream& operator=(basic_fstream&& rhs); ----1- Effects:-swap(rhs).-Move assigns the base and members of *this with the respective -base and members of rhs. -
Section: 20.2.1 [utility.arg.requirements] Status: Open - Submitter: Alberto Ganesh Barbati Opened: 2008-09-29 Last modified: 2009-11-03
-View other active issues in [utility.arg.requirements].
-View all other issues in [utility.arg.requirements].
-View all issues with Open status.
-Discussion:
-Addresses UK 150
- --The description of the effect of operator= in the MoveAssignable -concept, given in paragraph 7 is: -
- -- -result_type T::operator=(T&& rv); // inherited from HasAssign<T, T&&> -- --Postconditions: the constructed T object is equivalent to the value of -rv before the assignment. [Note: there is no -requirement on the value of rv after the assignment. --end note] --
-The sentence contains a typo (what is the "constructed T object"?) -probably due to a cut&paste from MoveConstructible. Moreover, the -discussion of LWG issue 675 shows that the postcondition is too generic -and might not reflect the user expectations. An implementation of the -move assignment that just calls swap() would always fulfill the -postcondition as stated, but might have surprising side-effects in case -the source rvalue refers to an object that is not going to be -immediately destroyed. See LWG issue 900 for another example. Due to -the sometimes intangible nature of the "user expectation", it seems -difficult to have precise normative wording that could cover all cases -without introducing unnecessary restrictions. However a non-normative -clarification could be a very helpful warning sign that swapping is not -always the correct thing to do. -
- -[ -2009-05-09 Alisdair adds: -]
- - --- --Issue 910 is exactly the reason BSI advanced the Editorial comment UK-150. -
--The post-conditions after assignment are at a minimum that the object -referenced by rv must be safely destructible, and the transaction should not -leak resources. Ideally it should be possible to simply assign rv a new -valid state after the call without invoking undefined behaviour, but any -other use of the referenced object would depend upon additional guarantees -made by that type. -
-
[ -2009-05-09 Howard adds: -]
- - --- --The intent of the rvalue reference work is that the moved from rv is -a valid object. Not one in a singular state. If, for example, the moved from -object is a vector, one should be able to do anything on that moved-from -vector that you can do with any other vector. However you would -first have to query it to find out what its current state is. E.g. it might have capacity, -it might not. It might have a non-zero size, it might not. But regardless, -you can push_back on to it if you want. -
- --That being said, most standard code is now conceptized. That is, the concepts -list the only operations that can be done with templated types - whether or not -the values have been moved from. -
- --Here is user-written code which must be allowed to be legal: -
-- -#include <vector> -#include <cstdio> - -template <class Allocator> -void -inspect(std::vector<double, Allocator>&& v) -{ - std::vector<double, Allocator> result(move(v)); - std::printf("moved from vector has %u size and %u capacity\n", v.size(), v.capacity()); - std::printf("The contents of the vector are:\n"); - typedef typename std::vector<double, Allocator>::iterator I; - for (I i = v.begin(), e = v.end(); i != e; ++i) - printf("%f\n", *i); -} - -int main() -{ - std::vector<double> v1(100, 5.5); - inspect(move(v1)); -} --The above program does not treat the moved-from vector as singular. It -only treats it as a vector with an unknown value. -
--I believe the current proposed wording is consistent with my view on this. -
-
[ -Batavia (2009-05): -]
- --We agree that the proposed resolution -is an improvement over the current wording. -- -
[ -2009-07 Frankfurt: -]
- - --Need to look at again without concepts. -- -
[ -2009-07 Frankfurt: -]
- - --Walter will consult with Dave and Doug. -- -
[ -2009-10 Santa Cruz: -]
- - --We believe this is handled by the resolution to issue 1204, -but there is to much going on in this area to be sure. Defer for now. -- - - -
Proposed resolution:
--In [concept.copymove], replace the postcondition in paragraph 7 with: -
- --Postconditions: *this is equivalent to the value of rv before the -assignment. [Note: there is no requirement on the value of rv after the -assignment, but the -effect should be unsurprising to the user even in case rv is not -immediately destroyed. This may require that resources previously owned -by *this are released instead of transferred to rv. -- end note] -- - - - - -
Section: 27.7.1 [input.streams], 27.7.2 [output.streams] Status: Open - Submitter: Alberto Ganesh Barbati Opened: 2008-09-29 Last modified: 2009-10-20
-View all issues with Open status.
-Discussion:
--Class template basic_istream, basic_ostream and basic_iostream -implements public move constructors, move assignment operators and swap -method and free functions. This might induce both the user and the -compiler to think that those types are MoveConstructible, MoveAssignable -and Swappable. However, those class templates fail to fulfill the user -expectations. For example: -
- -std::ostream os(std::ofstream("file.txt"));
-assert(os.rdbuf() == 0); // buffer object is not moved to os, file.txt has been closed
-
-std::vector<std::ostream> v;
-v.push_back(std::ofstream("file.txt"));
-v.reserve(100); // causes reallocation
-assert(v[0].rdbuf() == 0); // file.txt has been closed!
-
-std::ostream&& os1 = std::ofstream("file1.txt");
-os1 = std::ofstream("file2.txt");
-os1 << "hello, world"; // still writes to file1.txt, not to file2.txt!
-
-std::ostream&& os1 = std::ofstream("file1.txt");
-std::ostream&& os2 = std::ofstream("file2.txt");
-std::swap(os1, os2);
-os1 << "hello, world"; // writes to file1.txt, not to file2.txt!
--This is because the move constructor, the move assignment operator and -swap are all implemented through calls to std::basic_ios member -functions move() and swap() that do not move nor swap the controlled -stream buffers. That can't happen because the stream buffers may have -different types. -
- --Notice that for basic_streambuf, the member function swap() is -protected. I believe that is correct and all of basic_istream, -basic_ostream, basic_iostream should do the same as the move ctor, move -assignment operator and swap member function are needed by the derived -fstreams and stringstreams template. The free swap functions for -basic_(i|o|io)stream templates should be removed for the same reason. -
- -[ -Batavia (2009-05): -]
- --- --We note that the rvalue swap functions have already been removed. -
--Bill is unsure about making the affected functions protected; -he believes they may need to be public. -
--We are also unsure about removing the lvalue swap functions as proposed. -
--Move to Open. -
-
[ -2009-07 Frankfurt: -]
- - --- --It's not clear that the use case is compelling. -
--Howard: This needs to be implemented and tested. -
-
[ -2009-07-26 Howard adds: -]
- - --- --I started out thinking I would recommend NAD for this one. I've turned around -to agree with the proposed resolution (which I've updated to the current draft). -I did not fully understand Ganesh's rationale, and attempt to describe my -improved understanding below. -
- --The move constructor, move assignment operator, and swap function are different -for basic_istream, basic_ostream and basic_iostream -than other classes. A timely conversation with Daniel reminded me of this long -forgotten fact. These members are sufficiently different that they would be -extremely confusing to use in general, but they are very much needed for derived -clients. -
- --
- -- -The move constructor moves everything but the rdbuf pointer. -
-- -The move assignment operator moves everything but the rdbuf pointer. -
-- -The swap function swaps everything but the rdbuf pointer. -
--The reason for this behavior is that for the std-derived classes (stringstreams, -filestreams), the rdbuf pointer points back into the class itself -(self referencing). It can't be swapped or moved. But this fact isn't born out -at the stream level. Rather it is born out at the fstream/sstream -level. And the lower levels just need to deal with that fact by not messing around -with the rdbuf pointer which is stored down at the lower levels. -
- --In a nutshell, it is very confusing for all of those who are not so intimately -related with streams that they've implemented them. And it is even fairly -confusing for some of those who have (including myself). I do not think it is -safe to swap or move istreams or ostreams because this will -(by necessary design) separate stream state from streambuffer state. Derived -classes (such as fstream and stringstream must be used to -keep the stream state and stream buffer consistently packaged as one unit during -a move or swap. -
- --I've implemented this proposal and am living with it day to day. -
- -
[ -2009 Santa Cruz: -]
- - --Leave Open. Pablo expected to propose alternative wording which would rename -move construction, move assignment and swap, and may or may not make them -protected. This will impact issue 900. -- - - -
Proposed resolution:
--27.7.1.1 [istream]: make the following member functions protected: -
- -- -basic_istream(basic_istream&& rhs); -basic_istream& operator=(basic_istream&& rhs); -void swap(basic_istream& rhs); -
-Ditto: remove the swap free function signature -
- -- -// swap: -template <class charT, class traits> - void swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);-
-27.7.1.1.2 [istream.assign]: remove paragraph 4 -
- -- --template <class charT, class traits> - void swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);---Effects: x.swap(y).-
-27.7.1.5 [iostreamclass]: make the following member function protected: -
- -- -basic_iostream(basic_iostream&& rhs); -basic_iostream& operator=(basic_iostream&& rhs); -void swap(basic_iostream& rhs); -
-Ditto: remove the swap free function signature -
- -- -template <class charT, class traits> - void swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);-
-27.7.1.5.3 [iostream.assign]: remove paragraph 3 -
- -- --template <class charT, class traits> - void swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);---Effects: x.swap(y).-
-27.7.2.1 [ostream]: make the following member function protected: -
- -- -basic_ostream(basic_ostream&& rhs); -basic_ostream& operator=(basic_ostream&& rhs); -void swap(basic_ostream& rhs); -
-Ditto: remove the swap free function signature -
- -- -// swap: -template <class charT, class traits> - void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);-
-27.7.2.3 [ostream.assign]: remove paragraph 4 -
- -- - - - - - --template <class charT, class traits> - void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);---Effects: x.swap(y).-
Section: 25.4.7 [alg.min.max] Status: Open - Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2009-10-23
-View all other issues in [alg.min.max].
-View all issues with Open status.
-Discussion:
--It seems that the proposed changes for -N2772 -were not clear enough in -this point: -
- --25.4.7 [alg.min.max], before p.23 + p.24 + before p. 27 + p. 28 say that the return -type of the minmax overloads with an initializer_list is -pair<const T&, const T&>, -which is inconsistent with the decision for the other min/max overloads which take -a initializer_list as argument and return a T, not a const T&. -Doing otherwise for minmax would easily lead to unexpected life-time -problems by using minmax instead of min and max separately. -- -
[ -Batavia (2009-05): -]
- --We agree with the proposed resolution. -Move to Tentatively Ready. -- -
[ -2009-07 Frankfurt -]
- - --Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -- -
[ -2009-08-18 Daniel adds: -]
- - --Recommend NAD since the proposed changes have already been performed -as part of editorial work of -N2914. -- -
[ -2009-10 Santa Cruz: -]
- - --Can't find initializer_list form of minmax anymore, only variadic -version. Seems like we had an editing clash with concepts. Leave Open, -at least until editorial issues resolved. Bring this to Editor's -attention. -- - - -
Proposed resolution:
--In 25 [algorithms]/2, header <algorithm> synopsis change as indicated: -
- --template<classLessThanComparable T> -requires CopyConstructible<T> -pair<constT&,constT&> -minmax(initializer_list<T> t); - -template<class T,classStrictWeakOrder<auto, T> Compare> -requires CopyConstructible<T> -pair<constT&,constT&> -minmax(initializer_list<T> t, Compare comp); -
-In 25.4.7 [alg.min.max] change as indicated (Begin: Just before p.20): -
--template<-classLessThanComparable T> - requires CopyConstructible<T> - pair<constT&,constT&> - minmax(initializer_list<T> t); --- --
--20- Requires: T is LessThanComparable and -CopyConstructible.---21- Returns: pair<
-constT&,const -T&>(x, y) where x is the -smallest value and y the largest value in the initializer_list. -[..]
-template<class T,- -classStrictWeakOrder<auto, T> Compare> - requires CopyConstructible<T> - pair<constT&,constT&> - minmax(initializer_list<T> t, Compare comp); ----
--24- Requires: type T is LessThanComparable and CopyConstructible.---25- Returns: pair<
-constT&,const -T&>(x, y) where x is the -smallest value and y largest value in the initializer_list. -
Section: 20.7.14 [func.memfn] Status: Ready - Submitter: Bronek Kozicki Opened: 2008-10-06 Last modified: 2009-10-23
-View all other issues in [func.memfn].
-View all issues with Ready status.
-Duplicate of: 1230
-Discussion:
--Daniel Krügler wrote: -
- --- --Shouldn't above list be completed for &- and &&-qualified -member functions This would cause to add: -
-- -template<Returnable R, class T, CopyConstructible... Args> -unspecified mem_fn(R (T::* pm)(Args...) &); -template<Returnable R, class T, CopyConstructible... Args> -unspecified mem_fn(R (T::* pm)(Args...) const &); -template<Returnable R, class T, CopyConstructible... Args> -unspecified mem_fn(R (T::* pm)(Args...) volatile &); -template<Returnable R, class T, CopyConstructible... Args> -unspecified mem_fn(R (T::* pm)(Args...) const volatile &); -template<Returnable R, class T, CopyConstructible... Args> -unspecified mem_fn(R (T::* pm)(Args...) &&); -template<Returnable R, class T, CopyConstructible... Args> -unspecified mem_fn(R (T::* pm)(Args...) const &&); -template<Returnable R, class T, CopyConstructible... Args> -unspecified mem_fn(R (T::* pm)(Args...) volatile &&); -template<Returnable R, class T, CopyConstructible... Args> -unspecified mem_fn(R (T::* pm)(Args...) const volatile &&); -
-yes, absolutely. Thanks for spotting this. Without this change mem_fn -cannot be initialized from pointer to ref-qualified member function. I -believe semantics of such function pointer is well defined. -
- -[ -Post Summit Daniel provided wording. -]
- - -[ -Batavia (2009-05): -]
- --- --We need to think about whether we really want to go down the proposed path -of combinatorial explosion. -Perhaps a Note would suffice. -
--We would really like to have an implementation before proceeding. -
--Move to Open, and recommend this be deferred until after the next -Committee Draft has been issued. -
-
[ -2009-10-10 Daniel updated wording to post-concepts. -]
- - --1230 has a similar proposed resolution -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Change 20.7 [function.objects]/2, header -<functional> synopsis as follows: -
- --// 20.7.14, member function adaptors: -template<class R, class T> unspecified mem_fn(R T::*); - -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...)); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile); - -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) &); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const &); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile &); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile &); - -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) &&); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const &&); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile &&); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile &&); -
-Change the prototype list of 20.7.14 [func.memfn] as follows [NB: The -following text, most notably p.2 and p.3 which -discuss influence of the cv-qualification on the definition of the -base class's first template parameter remains -unchanged. ]: -
- --template<class R, class T> unspecified mem_fn(R T::* pm); - -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...)); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile); - -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) &); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const &); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile &); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile &); - -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) &&); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const &&); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile &&); -template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile &&); -
-Remove 20.7.14 [func.memfn]/5: -
- ---Remarks: Implementations may implement mem_fn as a set of -overloaded function templates.-
Section: 20.4.1 [ratio.ratio] Status: Ready - Submitter: Pablo Halpern Opened: 2008-10-07 Last modified: 2009-10-21
-View all other issues in [ratio.ratio].
-View all issues with Ready status.
-Discussion:
--The compile-time functions that operate on ratio<N,D> require the -cumbersome and error-prone "evaluation" of a type member using a -meta-programming style that predates the invention of template aliases. -Thus, multiplying three ratios a, b, and c requires the expression: -
- -- -ratio_multiply<a, ratio_multiply<b, c>::type>::type -
-The simpler expression: -
- -- -ratio_multiply<a, ratio_multiply<b, c>> -
-Could be used by if template aliases were employed in the definitions. -
- -[ -Post Summit: -]
- - --- --Jens: not a complete proposed resolution: "would need to make similar change" -
--Consensus: We agree with the direction of the issue. -
--Recommend Open. -
-
[ -2009-05-11 Daniel adds: -]
- - --- --Personally I'm not in favor for the addition of: -
--typedef ratio type; --For a reader of the -standard it's usage or purpose is unclear. I haven't seen similar examples -of attempts to satisfy non-feature complete compilers. -
-
[ -2009-05-11 Pablo adds: -]
- - --- --The addition of type to the ratio template allows the previous style -(i.e., in the prototype implementations) to remain valid and permits the -use of transitional library implementations for C++03 compilers. I do -not feel strongly about its inclusion, however, and leave it up to the -reviewers to decide. -
-
[ -Batavia (2009-05): -]
- --Bill asks for additional discussion in the issue -that spells out more details of the implementation. -Howard points us to issue 948 -which has at least most of the requested details. -Tom is strongly in favor of overflow-checking at compile time. -Pete points out that there is no change of functionality implied. -We agree with the proposed resolution, -but recommend moving the issue to Review -to allow time to improve the discussion if needed. -- -
[ -2009-07-21 Alisdair adds: -]
- - --See 1121 for a potentially incompatible proposal. -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
- - --In 20.4 [ratio]/3 change as indicated: -
- --// ratio arithmetic -template <class R1, class R2>structusing ratio_add = see below; -template <class R1, class R2>structusing ratio_subtract = see below; -template <class R1, class R2>structusing ratio_multiply = see below; -template <class R1, class R2>structusing ratio_divide = see below; -
-In 20.4.1 [ratio.ratio], change as indicated: -
-namespace std {
- template <intmax_t N, intmax_t D = 1>
- class ratio {
- public:
- typedef ratio type;
- static const intmax_t num;
- static const intmax_t den;
- };
-}
--In 20.4.2 [ratio.arithmetic] change as indicated: -
- --template <class R1, class R2>- -structusing ratio_add = see below{ - typedef see below type; -}; ----1 The
-nested typedeftype ratio_add<R1, R2> -shall be a synonym for ratio<T1, T2> -where T1 has the value R1::num * R2::den + R2::num * R1::den and T2 -has the value R1::den * R2::den. -
-template <class R1, class R2>-structusing ratio_subtract = see below{ - typedef see below type; -}; ----2 The
-nested typedeftype ratio_subtract<R1, R2> -shall be a synonym for ratio<T1, T2> -where T1 has the value R1::num * R2::den - R2::num * R1::den and T2 -has the value R1::den * R2::den. -
-template <class R1, class R2>-structusing ratio_multiply = see below{ - typedef see below type; -}; ----3 The
-nested typedeftype ratio_multiply<R1, R2> -shall be a synonym for ratio<T1, T2> -where T1 has the value R1::num * R2::num and T2 has the value R1::den * R2::den. -
-template <class R1, class R2>-structusing ratio_divide = see below{ - typedef see below type; -}; ----4 The
-nested typedeftype ratio_divide<R1, R2> -shall be a synonym for ratio<T1, T2> -where T1 has the value R1::num * R2::den and T2 has the value R1::den * R2::num. -
-In 20.9.3.1 [time.duration.cons]/4 change as indicated: -
----Requires: treat_as_floating_point<rep>::value shall be true or -ratio_divide<Period2, period>::
-type::den shall be 1.[..] -
-In 20.9.3.7 [time.duration.cast]/2 change as indicated: -
----Returns: Let CF be ratio_divide<Period, typename -ToDuration::period>
-::type, and [..] -
Section: 30.3.1.2 [thread.thread.constr] Status: Review - Submitter: Anthony Williams Opened: 2008-10-23 Last modified: 2009-10-25
-View other active issues in [thread.thread.constr].
-View all other issues in [thread.thread.constr].
-View all issues with Review status.
-Discussion:
- -Addresses UK 323
- --The thread constructor for starting a new thread with a function and -arguments is overly constrained by the signature requiring rvalue -references for func and args and the CopyConstructible requirements -for the elements of args. The use of an rvalue reference for the -function restricts the potential use of a plain function name, since -the type of the bound parameter will be deduced to be a function -reference and decay to pointer-to-function will not happen. This -therefore complicates the implementation in order to handle a simple -case. Furthermore, the use of rvalue references for args prevents the -array to pointer decay. Since arrays are not CopyConstructible or even -MoveConstructible, this essentially prevents the passing of arrays as -parameters. In particular it prevents the passing of string literals. -Consequently a simple case such as -
- -- -void f(const char*); -std::thread t(f,"hello"); -
-is ill-formed since the type of the string literal is const char[6]. -
- --By changing the signature to take all parameters by value we can -eliminate the CopyConstructible requirement and permit the use of -arrays, as the parameter passing semantics will cause the necessary -array-to-pointer decay. They will also cause the function name to -decay to a pointer to function and allow the implementation to handle -functions and function objects identically. -
- --The new signature of the thread constructor for a function and -arguments is thus: -
- -- -template<typename F,typename... Args> -thread(F,Args... args); -
-Since the parameter pack Args can be empty, the single-parameter -constructor that takes just a function by value is now redundant. -
- -[ -Howard adds: -]
- - --- --I agree with everything Anthony says in this issue. However I believe we -can optimize in such a way as to get the pass-by-value behavior with the -pass-by-rvalue-ref performance. The performance difference is that the latter -removes a move when passing in an lvalue. -
- --This circumstance is very analogous to make_pair (20.3.4 [pairs]) -where we started with passing by const reference, changed to pass by value to -get pointer decay, and then changed to pass by rvalue reference, but modified with -decay<T> to retain the pass-by-value behavior. If we were to -apply the same solution here it would look like: -
- -- --template <class F> explicit thread(F f);-template <class F, class ...Args> thread(F&& f, Args&&... args); -----4- Requires: F and each Ti in Args shall be
-CopyConstructible -if an lvalue and otherwiseMoveConstructible. -INVOKE(f, w1, w2, ..., wN) (20.7.2 [func.require]) shall be a valid expression for -some values w1, w2, ... , wN, where N == sizeof...(Args). ---5- Effects: Constructs an object of type thread -
-and executes INVOKE(f, t1, t2, ..., tN) in a new -thread of execution, where t1, t2, ..., tN are the values in args.... -Constructs -the following objects in memory which is accessible to a new thread of execution -as if: --typename decay<F>::type g(std::forward<F>(f)); -tuple<typename decay<Args>::type...> w(std::forward<Args>(args)...); --The new thread of -execution executes INVOKE(g, wi...) where the wi... refers -to the elements stored in the tuple w. -Any return value from g is ignored. -
-If f terminates with an uncaught exception, std::terminate() shall be called.-If the evaluation of INVOKE(g, wi...) terminates -with an uncaught exception, std::terminate() shall be called [Note: -std::terminate() could be called before entering g. -- end note]. Any -exception thrown before the evaluation of INVOKE has started shall be -catchable in the calling thread. --Text referring to when terminate() is called was contributed by Ganesh. -
- -
[ -Batavia (2009-05): -]
- --We agree with the proposed resolution, -but would like the final sentence to be reworded -since "catchable" is not a term of art (and is used nowhere else). -- -
[ -2009-07 Frankfurt: -]
- - --- --This is linked to -N2901. -
--Howard to open a separate issue to remove (1176). -
--In Frankfurt there is no consensus for removing the variadic constructor. -
-
[ -2009-10 Santa Cruz: -]
- - --We want to move forward with this issue. If we later take it out via 1176 -then that's ok too. Needs small group to improve wording. -- -
[ -2009-10 Santa Cruz: -]
- - --- - --Stefanus provided revised wording. Moved to Review Here is the original wording: -
----Modify the class definition of std::thread in 30.3.1 [thread.thread.class] to remove the -following signature: -
- -- -template<class F> explicit thread(F f);-template<class F, class ... Args> explicit thread(F&& f, Args&& ... args); --Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with -the single constructor as above. Replace paragraph 4 - 6 with the -following: -
- --- ---4- Requires: F and each Ti in Args shall be
-CopyConstructible -if an lvalue and otherwiseMoveConstructible. -INVOKE(f, w1, w2, ..., wN) (20.7.2 [func.require]) shall be a valid expression for -some values w1, w2, ... , wN, where N == sizeof...(Args). ---5- Effects: Constructs an object of type thread -
-and executes INVOKE(f, t1, t2, ..., tN) in a new -thread of execution, where t1, t2, ..., tN are the values in args.... -Constructs -the following objects: --typename decay<F>::type g(std::forward<F>(f)); -tuple<typename decay<Args>::type...> w(std::forward<Args>(args)...); --and executes INVOKE(g, wi...) in a new thread of execution. -These objects shall be destroyed when the new thread of execution completes. -Any return value from g is ignored. -
-If f terminates with an uncaught exception, std::terminate() shall be called.-If the evaluation of INVOKE(g, wi...) terminates -with an uncaught exception, std::terminate() shall be called [Note: -std::terminate() could be called before entering g. -- end note]. Any -exception thrown before the evaluation of INVOKE has started shall be -catchable in the calling thread. ---6- Synchronization: The invocation of the constructor happens before the -invocation of
-fg. -
Proposed resolution:
--Modify the class definition of std::thread in 30.3.1 [thread.thread.class] to remove the -following signature: -
- -- -template<class F> explicit thread(F f);-template<class F, class ... Args> explicit thread(F&& f, Args&& ... args); -
-Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with -the single constructor as above. Replace paragraph 4 - 6 with the -following: -
- --- - - - - - ---4- Requires: F and each Ti in Args -shall be
- -CopyConstructible if an lvalue and -otherwiseMoveConstructible. INVOKE(f, w1, w2, -..., wN) (20.7.2 [func.require]) shall be a valid expression -for some values w1, w2, ... , wN, where N == -sizeof...(Args). ---5- Effects: Constructs an object of type thread
- -and executes -INVOKE(f, t1, t2, ..., tN) in a new thread of execution, where -t1, t2, ..., tN are the values in args.... -Given a function as follows: -Any return -value from f is ignored. If f terminates with an -uncaught exception, std::terminate() shall be called.-- --template<typename T> typename decay<T>::type decay_copy(T&& v) - { return std::forward<T>(v); } --The new thread of execution executes INVOKE(decay_copy(f), -decay_copy(args)...) with the calls to decay_copy() being evaluated in -the constructing thread. Any return value from this invocation is -ignored. [Note: this implies any exceptions not thrown from the -invocation of the copy of f will be thrown in the constructing thread, -not the new thread. — end note]. -
- ---6- Synchronization: The invocation of the constructor happens before the -invocation of copy of f. -
-
Section: 20.8.14.2.1 [unique.ptr.single.ctor] Status: Ready - Submitter: Howard Hinnant Opened: 2008-11-26 Last modified: 2009-10-22
-View other active issues in [unique.ptr.single.ctor].
-View all other issues in [unique.ptr.single.ctor].
-View all issues with Ready status.
-Discussion:
- -Addresses US 79
- --20.8.14.2.1 [unique.ptr.single.ctor]/5 no longer requires for D -not to be a pointer type. I believe this restriction was accidently removed -when we relaxed the completeness reuqirements on T. The restriction -needs to be put back in. Otherwise we have a run time failure that could -have been caught at compile time: -
- -{
-unique_ptr<int, void(*)(void*)> p1(malloc(sizeof(int))); // should not compile
-} // p1.~unique_ptr() dereferences a null function pointer
-unique_ptr<int, void(*)(void*)> p2(malloc(sizeof(int)), free); // ok
-[ -Post Summit: -]
- - --Recommend Tentatively Ready. -- -
[ -2009-07 Frankfurt -]
- - --Moved from Tentatively Ready to Open only because the wording needs to be -improved for enable_if type constraining, possibly following Robert's -formula. -- -
[ -2009-07 Frankfurt: -]
- - --- --We need to consider whether some requirements in the Requires paragraphs -of [unique.ptr] should instead be Remarks. -
--Leave Open. Howard to provide wording, and possibly demonstrate how this -can be implemented using enable_if. -
-
[ -2009-07-27 Howard adds: -]
- - --- --The two constructors to which this issue applies are not easily constrained -with enable_if as they are not templated: -
- -- -unique_ptr(); -explicit unique_ptr(pointer p); --To "SFINAE" these constructors away would take heroic effort such as specializing -the entire unique_ptr class template on pointer deleter types. There -is insufficient motivation for such heroics. Here is the expected and -reasonable implementation for these constructors: -
- -- -unique_ptr() - : ptr_(pointer()) - { - static_assert(!is_pointer<deleter_type>::value, - "unique_ptr constructed with null function pointer deleter"); - } -explicit unique_ptr(pointer p) - : ptr_(p) - { - static_assert(!is_pointer<deleter_type>::value, - "unique_ptr constructed with null function pointer deleter"); - } --I.e. just use static_assert to verify that the constructor is not -instantiated with a function pointer for a deleter. The compiler will automatically -take care of issuing a diagnostic if the deleter is a reference type (uninitialized -reference error). -
- --In keeping with our discussions in Frankfurt, I'm moving this requirement on -the implementation from the Requires paragraph to a Remarks paragraph. -
- -
[ -2009-08-17 Daniel adds: -]
- - --- --It is insufficient to require a diagnostic. This doesn't imply an -ill-formed program -as of 1.3.3 [defns.diagnostic] (a typical alternative would be a compiler -warning), but -exactly that seems to be the intend. I suggest to use the following -remark instead: -
- --Remarks: The program shall be ill-formed if this constructor is -instantiated when D is a pointer type or reference type. -- --Via the general standard rules of 1.4 [intro.compliance] the "diagnostic -required" is implied. -
- -
[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
--Change the description of the default constructor in 20.8.14.2.1 [unique.ptr.single.ctor]: -
- -- -unique_ptr(); ------1- Requires: D shall be default constructible, and that construction -shall not throw an exception.
-D shall -not be a reference type or pointer type (diagnostic required).-...
--Remarks: The program shall be ill-formed if this constructor is -instantiated when D is a pointer type or reference type. - -
-
-Add after 20.8.14.2.1 [unique.ptr.single.ctor]/8: -
- -- - - - - -unique_ptr(pointer p); ----...
--Remarks: The program shall be ill-formed if this constructor is -instantiated when D is a pointer type or reference type. - -
-
Section: 20.3.3 [forward] Status: Ready - Submitter: Alisdair Meredith Opened: 2008-12-11 Last modified: 2009-10-29
-View all other issues in [forward].
-View all issues with Ready status.
-Discussion:
--std::identity takes an argument of type T const & -and returns a result of T const &. -
--Unfortunately, this signature will accept a value of type other than T that -is convertible-to-T, and then return a reference to the dead temporary. The -constraint in the concepts version simply protects against returning -reference-to-void. -
--Solutions: -
----i/ Return-by-value, potentially slicing bases and rejecting non-copyable -types -
--ii/ Provide an additional overload: -
--template< typename T > -template operator( U & ) = delete; --This seems closer on intent, but moves beyond the original motivation for -the operator, which is compatibility with existing (non-standard) -implementations. -
--iii/ Remove the operator() overload. This restores the original definition -of the identity, although now effectively a type_trait rather than part of -the perfect forwarding protocol. -
--iv/ Remove std::identity completely; its original reason to exist is -replaced with the IdentityOf concept. -
-
-My own preference is somewhere between (ii) and (iii) - although I stumbled -over the issue with a specific application hoping for resolution (i)! -
- -[ -Batavia (2009-05): -]
- --- --We dislike options i and iii, and option ii seems like overkill. -If we remove it (option iv), implementers can still provide it under a -different name. -
--Move to Open pending wording (from Alisdair) for option iv. -
-
[ -2009-05-23 Alisdair provided wording for option iv. -]
- - -[ -2009-07-20 Alisdair adds: -]
- - --- --I'm not sure why this issue was not discussed at Frankfurt (or I missed -the discussion) but the rationale is now fundamentally flawed. With the -removal of concepts, std::identity again becomes an important library -type so we cannot simply remove it. -
--At that point, we need to pick one of the other suggested resolutions, -but have no guidance at the moment. -
-
[ -2009-07-20 Howard adds: -]
- - --- --I believe the rationale for not addressing this issue in Frankfurt was that it did -not address a national body comment. -
--I also believe that removal of identity is still a practical option as -my latest reformulation of forward, which is due to comments suggested -at Summit, no longer uses identity. :-) -
- -- -template <class T, class U, - class = typename enable_if - < - !is_lvalue_reference<T>::value || - is_lvalue_reference<T>::value && - is_lvalue_reference<U>::value - >::type, - class = typename enable_if - < - is_same<typename remove_all<T>::type, - typename remove_all<U>::type>::value - >::type> -inline -T&& -forward(U&& t) -{ - return static_cast<T&&>(t); - -} -- -[ -The above code assumes acceptance of 1120 for the definition of -remove_all. This is just to make the syntax a little more palatable. -Without this trait the above is still very implementable. -]
- - --Paper with rationale is on the way ... really, I promise this time! ;-) -
-
[ -2009-07-30 Daniel adds: See 823 for an alternative resolution. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. Howard will update proposed wording to reflect current draft. -- - - -
Proposed resolution:
--Strike from 20.3 [utility]: -
- -- -template <class T> struct identity;-
-Remove from 20.3.3 [forward]: -
- --- - - - - - --template <class T> struct identity { - typedef T type; - - const T& operator()(const T& x) const; -};- -const T& operator()(const T& x) const;----2- Returns: x-
Section: 24.4.4 [iterator.operations] Status: Ready - Submitter: Thomas Opened: 2008-12-14 Last modified: 2009-10-22
-View other active issues in [iterator.operations].
-View all other issues in [iterator.operations].
-View all issues with Ready status.
-Discussion:
- -Addresses UK 270
- --Regarding the std::distance - function, 24.4.4 [iterator.operations] -/ 4 says: -
--Returns the -number of increments or decrements needed to get from first to last. --
-This sentence is completely silent about the sign of the return value. -24.4.4 [iterator.operations] / 1 gives more information about the -underlying operations, but -again no inferences about the sign can be made. -Strictly speaking, that is taking that sentence literally, I think this -sentence even implies a positive return value in all cases, as the -number of increments or decrements is clearly a ratio scale variable, -with a natural zero bound. -
--Practically speaking, my implementations did what common sense and -knowledge based on pointer arithmetic forecasts, namely a positive sign -for increments (that is, going from first to last by operator++), and a -negative sign for decrements (going from first to last by operator--). -
--Here are my two questions: -
--First, is that paragraph supposed to be interpreted in the way what I -called 'common sense', that is negative sign for decrements ? I am -fairly sure that's the supposed behavior, but a double-check here in -this group can't hurt. -
--Second, is the present wording (2003 standard version - no idea about -the draft for the upcoming standard) worth an edit to make it a bit more -sensible, to mention the sign of the return value explicitly ? -
- -[ -Daniel adds: -]
- - --- --My first thought was that resolution 204 would already cover the -issue report, but it seems that current normative wording is in -contradiction to that resolution: -
- --Referring to -N2798, -24.4.4 [iterator.operations]/ p.4 says: -
- --Effects: Returns the number of increments or decrements needed to get -from first to last. -- --IMO the part " or decrements" is in contradiction to p. 5 which says -
- --Requires: last shall be reachable from first. -- --because "reachable" is defined in X [iterator.concepts]/7 as -
- --An iterator j is called reachable from an iterator i if and only if -there is a finite -sequence of applications of the expression ++i that makes i == j.[..] -- --Here is wording that would be consistent with this definition of "reachable": -
- --Change 24.4.4 [iterator.operations] p4 as follows: -
- --Effects: Returns the number of increments- -or decrements-needed to get from first to last. -
-Thomas adds more discussion and an alternative view point -here. -
- -[ -Summit: -]
- - --The proposed wording below was verbally agreed to. Howard provided. -- -
[ -Batavia (2009-05): -]
- --- --Pete reports that a recent similar change has been made -for the advance() function. -
--We agree with the proposed resolution. -Move to Tentatively Ready. -
-
[ -2009-07 Frankfurt -]
- - --Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -- -
[ -2009-07 Frankfurt: -]
- - --Leave Open pending arrival of a post-Concepts WD. -- -
[ -2009-10-14 Daniel provided de-conceptified wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready, replacing the Effects clause in the proposed wording with -"If InputIterator meets the requirements of random access iterator then -returns (last - first), otherwise returns the number of increments -needed to get from first to list.". -- - - -
Proposed resolution:
--Change 24.2.5 [random.access.iterators], Table 105 as indicated [This change is not -essential but it simplifies the specification] for the row with -expression "b - a" -and the column Operational semantics: -
- --(a < b) ?distance(a,b) -: -distance(b,a)-
-Change 24.4.4 [iterator.operations]/4+5 as indicated: -
- --template<class InputIterator> - typename iterator_traits<InputIterator>::difference_type - distance(InputIterator first, InputIterator last); -----4 Effects: If InputIterator meets the requirements -of random access iterator then returns (last - first), -otherwise
- -Rreturns the number of increments -or decrementsneeded to get from first to -last. --5 Requires: If InputIterator meets the requirements -of random access iterator then last shall be reachable from -first or first shall be reachable from last, -otherwise last shall be reachable from first. -
-
Section: 20.8.14.2.1 [unique.ptr.single.ctor] Status: Ready - Submitter: Howard Hinnant Opened: 2009-01-07 Last modified: 2009-10-21
-View other active issues in [unique.ptr.single.ctor].
-View all other issues in [unique.ptr.single.ctor].
-View all issues with Ready status.
-Discussion:
--unique_ptr's of array type should not convert to -unique_ptr's which do not have an array type. -
- -struct Deleter
-{
- void operator()(void*) {}
-};
-
-int main()
-{
- unique_ptr<int[], Deleter> s;
- unique_ptr<int, Deleter> s2(std::move(s)); // should not compile
-}
-[ -Post Summit: -]
- - --- --Walter: Does the "diagnostic required" apply to both arms of the "and"? -
--Tom Plum: suggest to break into several sentences -
--Walter: suggest "comma" before the "and" in both places -
--Recommend Review. -
-
[ -Batavia (2009-05): -]
- --The post-Summit comments have been applied to the proposed resolution. -We now agree with the proposed resolution. -Move to Tentatively Ready. -- -
[ -2009-07 Frankfurt -]
- - --Moved from Tentatively Ready to Open only because the wording needs to be -improved for enable_if type constraining, possibly following Robert's -formula. -- -
[ -2009-08-01 Howard updates wording and sets to Review. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Change 20.8.14.2.1 [unique.ptr.single.ctor]: -
- --- -template <class U, class E> unique_ptr(unique_ptr<U, E>&& u); ------20- Requires: If D is not a reference type, -construction of the deleter D from an rvalue of type E -shall be well formed and shall not throw an exception.
- -If D is -a reference type, then E shall be the same type as D -(diagnostic required). unique_ptr<U, E>::pointer shall be -implicitly convertible to pointer. [Note: These requirements -imply that T and U are complete types. — end note]--Remarks: If D is -a reference type, then E shall be the same type as D, else this -constructor shall not participate in overload resolution. unique_ptr<U, E>::pointer shall be -implicitly convertible to pointer, else this -constructor shall not participate in overload resolution. U shall not be -an array type, else this -constructor shall not participate in overload resolution. [Note: These requirements -imply that T and U are complete types. — end note] -
- -
-Change 20.8.14.2.3 [unique.ptr.single.asgn]: -
- --- - - - - - -template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u); ------6- Requires: Assignment of the deleter D from an rvalue -D shall not throw an exception.
- -unique_ptr<U, -E>::pointer shall be implicitly convertible to pointer. -[Note: These requirements imply that T and U -are complete types. — end note]--Remarks: unique_ptr<U, -E>::pointer shall be implicitly convertible to pointer, else this -operator shall not participate in overload resolution. -U shall not be an array type, else this -operator shall not participate in overload resolution. -[Note: These requirements imply that T and U -are complete types. — end note] -
- -
Section: 20.9.2.1 [time.traits.is_fp] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-23
-View all issues with Open status.
-Discussion:
- --Related to 953. -
- --20.9.2.1 [time.traits.is_fp] says that the type Rep "is -assumed to be ... a class emulating an integral type." What are the -requirements for such a type? -
-[ -2009-05-10 Howard adds: -]
- - --IntegralLike. -- -
[ -Batavia (2009-05): -]
- --- --As with issue 953, -we recommend this issue be addressed in the context of providing concepts for the entire thread header. -
--We look forward to proposed wording. -
--Move to Open. -
-
[ -2009-08-01 Howard adds: -]
- - --- --I have surveyed all clauses of 20.9.2.2 [time.traits.duration_values], -20.9.2.3 [time.traits.specializations] and 20.9.3 [time.duration]. -I can not find any clause which involves the use of a duration::rep type -where the requirements on the rep type are not clearly spelled out. -These requirements were carefully crafted to allow any arithmetic type, or -any user-defined type emulating an arithmetic type. -
- --Indeed, treat_as_floating_point -becomes completely superfluous if duration::rep can never be a class type. -
- --There will be some Rep types which will not meet the requirements of -every duration operation. This is no different than the fact -that vector<T> can easily be used for types T which are -not DefaultConstructible, even though some members of vector<T> -require T to be DefaultConstructible. This is why the requirements -on Rep are specified for each operation individually. -
- --In 20.9.2.1 [time.traits.is_fp] p1: -
- -- -template <class Rep> struct treat_as_floating_point - : is_floating_point<Rep> { }; -- --The duration template uses the treat_as_floating_point trait to help -determine if a duration object can be converted to another duration -with a different tick period. If treat_as_floating_point<Rep>::value is -true, then Rep is a floating-point type and implicit conversions are -allowed among durations. Otherwise, the implicit convertibility depends -on the tick periods of the durations. If Rep is a class type which -emulates a floating-point type, the author of Rep can specialize -treat_as_floating_point so that duration will treat this Rep as if it -were a floating-point type. Otherwise Rep is assumed to be an integral -type or a class emulating an integral type. ---The phrases "a class type which emulates a floating-point type" and -"a class emulating an integral type" are clarifying phrases which refer to -the summation of all the requirements on the Rep type specified in -detail elsewhere (and should not be repeated here). -
- --This specification has been implemented, now multiple times, and the experience -has been favorable. The current specification clearly specifies the requirements -at each point of use (though I'd be happy to fix any place I may have missed, -but none has been pointed out). -
- --I am amenable to improved wording of this paragraph (and any others), but do not have any -suggestions for improved wording at this time. I am strongly opposed to -changes which would significantly alter the semantics of the -specification under 20.9 [time] without firmly grounded and -documented rationale, example implementation, testing, and user -experience which relates a positive experience. -
- --I recommend NAD unless someone wants to produce some clarifying wording. -
-
[ -2009-10 Santa Cruz: -]
- - --Stefanus to provide wording to turn this into a note. -- - - -
Proposed resolution:
--
- - - - - -Section: 20.9.1 [time.clock.req] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-23
-View other active issues in [time.clock.req].
-View all other issues in [time.clock.req].
-View all issues with Open status.
-Discussion:
- --Related to 951. -
- --20.9.1 [time.clock.req] says that a clock's rep member is "an -arithmetic type or a class emulating an arithmetic type." What are the -requirements for such a type? -
- -[ -2009-05-10 Howard adds: -]
- - --This wording was aimed directly at the ArithmeticLike concept. -- -
[ -Batavia (2009-05): -]
- --- --We recommend this issue be addressed in the context of providing concepts -for the entire thread header. -
--May resolve for now by specifying arithmetic types, -and in future change to ArithmeticLike. -However, Alisdair believes this is not feasible. -
--Bill disagrees. -
--We look forward to proposed wording. Move to Open. -
-
[ -2009-08-01 Howard adds: -]
- - --See commented dated 2009-08-01 in 951. -- -
[ -2009-10 Santa Cruz: -]
- - --Stefanus to provide wording to turn this into a note. -- - - -
Proposed resolution:
--
- - - - - -Section: 20.9.1 [time.clock.req] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-21
-View other active issues in [time.clock.req].
-View all other issues in [time.clock.req].
-View all issues with Ready status.
-Discussion:
--Table 55 -- Clock Requirements (in 20.9.1 [time.clock.req]) -
- -[ -2009-05-10 Howard adds: -]
- - --"epoch" is purposefully not defined beyond the common English -definition. The C standard -also chose not to define epoch, though POSIX did. I believe it is a strength -of the C standard that epoch is not defined. When it is known that two time_points -refer to the same epoch, then a definition of the epoch is not needed to compare -the two time_points, or subtract them. -
--A time_point and a Clock implicitly refer to an (unspecified) epoch. -The time_point represents an offset (duration) from an epoch. -
--The sentence: -
--Different clocks -may share a time_point -definition if it is valid to -compare their time_points by -comparing their respective -durations. -- -
-is redundant and could be removed. I believe the sentence which follows the above: -
- --C1 and C2 shall refer to the same epoch. -- -
-is sufficient. If two clocks share the same epoch, then by definition, comparing -their time_points is valid. -
--This should probably instead be worded: -
--An instantiation of ratio. --
[ -Batavia (2009-05): -]
- --- --Re (a): It is not clear to us whether "epoch" is a term of art. -
--Re (b), (c), and (d): We agree with Howard's comments, -and would consider adding to (c) a static constexpr requirement. -
--Move to Open pending proposed wording. -
-
[ -2009-05-25 Daniel adds: -]
- - --In regards to (d) I suggest to say "a specialization of ratio" instead of -"An instantiation of ratio". This seems to be the better matching standard -core language term for this kind of entity. -- -
[ -2009-05-25 Ganesh adds: -]
- - --- --Regarding (a), I found this paper on the ISO website using the term "epoch" consistently with the current wording: -
- - --which is part of ISO/IEC 18026 "Information technology -- Spatial Reference Model (SRM)". -
-
[ -2009-08-01 Howard: Moved to Reivew as the wording requested in Batavia has been provided. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Change 20.9.1 [time.clock.req] p1: -
---1- A clock is a bundle consisting of a native duration, a native time_point, and a function now() to get the -current time_point. The origin of the clock's time_point is referred to as the clock's epoch as defined in -section 6.3 of ISO/IEC 18026. -A clock shall meet the requirements in Table 45. --
-Remove the sentence from the time_point row of the table "Clock Requirements": -
-| -C1::time_point - | --chrono::time_point<C1> or chrono::time_point<C2, C1::duration> - | -
-The native time_point type of the clock.
- |
-
-Change the row starting with C1::period of the table "Clock Requirements": -
-| -C1::period - | --a specialization of ratio - | --The tick period of the clock in seconds. - | -
Section: 20.9.1 [time.clock.req] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-24
-View other active issues in [time.clock.req].
-View all other issues in [time.clock.req].
-View all issues with Open status.
-Discussion:
--20.9.1 [time.clock.req] uses the word "native" in several places, -but doesn't define it. What is a "native duration"? -
- -[ -2009-05-10 Howard adds: -]
- - --The standard uses "native" in several places without defining it (e.g. -2.14.3 [lex.ccon]). It is meant to mean "that which is defined -by the facility", or something along those lines. In this case it refers -to the nested time_point and duration types of the clock. -Better wording is welcome. -- -
[ -Batavia (2009-05): -]
- --Move to Open pending proposed wording from Pete. -- -
[ -2009-10-23 Pete provides wording: -]
- - - -Proposed resolution:
--Remove every occurrence of "native" in 20.9.1 [time.clock.req]. -
- --Add the following sentence at the end of 20.9.1 [time.clock.req]/1: -
- --A clock is a bundle consisting of a- - - - - -nativeduration, anative-time_point, and a function now() to get the current time_point. A clock -shall meet the requirements in Table 55. -The duration and time_point types have the natural size and resolution -suggested by the architecture of the execution environment. -
Section: 20.9.5.1 [time.clock.system] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-21
-View all other issues in [time.clock.system].
-View all issues with Ready status.
-Discussion:
--20.9.5.1 [time.clock.system]: to_time_t is overspecified. It -requires truncation, but should allow rounding. For example, suppose a -system has a clock that gives times in milliseconds, but time() rounds -those times to the nearest second. Then system_clock can't use any -resolution finer than one second, because if it did, truncating times -between half a second and a full second would produce the wrong time_t -value. -
- -[ -Post Summit Anthony Williams provided proposed wording. -]
- - -[ -Batavia (2009-05): -]
- --Move to Review pending input from Howard. and other stakeholders. -- -
[ -2009-05-23 Howard adds: -]
- - --I am in favor of the wording provided by Anthony. -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--In 20.9.5.1 [time.clock.system] replace paragraphs 3 and 4 with: -
- --- - - - - -time_t to_time_t(const time_point& t); ----3- Returns: A time_t object that represents the same -point in time as t when both values are- -truncated-restricted to the coarser of the precisions of -time_t and time_point. It is implementation -defined whether values are rounded or truncated to the required -precision. -time_point from_time_t(time_t t); ----4- Returns: A time_point object that represents the -same point in time as t when both values are-truncated-restricted to the -coarser of the precisions of time_t and time_point. -It is implementation defined whether values are -rounded or truncated to the required precision. -
Section: 30.5.1 [thread.condition.condvar] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26
-View other active issues in [thread.condition.condvar].
-View all other issues in [thread.condition.condvar].
-View all issues with Open status.
-Discussion:
--30.5.1 [thread.condition.condvar]: condition_variable::wait_for -is required to compute the absolute time by adding the duration value to -chrono::monotonic_clock::now(), but monotonic_clock is not required to -exist. -
- -[ -Summit: -]
- - --Move to open. Associate with LWG 859 and any other monotonic-clock -related issues. -- -
[ -2009-08-01 Howard adds: -]
- - --I believe that 859 (currently Ready) addresses this issue, and -that this issue should be marked NAD, solved by 859 (assuming -it moves to WP). -- -
[ -2009-10 Santa Cruz: -]
- - --Leave open, but expect to be fixed by N2969 revision that Detlef is writing. -- - - -
Proposed resolution:
--
- - - - - -Section: 30.4.1 [thread.mutex.requirements] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26
-View other active issues in [thread.mutex.requirements].
-View all other issues in [thread.mutex.requirements].
-View all issues with Ready status.
-Discussion:
--30.4.1 [thread.mutex.requirements]: paragraph 4 is entitled -"Error conditions", but according to 17.5.1.4 [structure.specifications], "Error -conditions:" specifies "the error conditions for error codes reported by -the function." It's not clear what this should mean when there is no -function in sight. -
- -[ -Summit: -]
- - --Move to open. -- -
[ -Beman provided proposed wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. Fix the proposed wording with "functions of type Mutex" --> "functions of Mutex type" -- - - -
Proposed resolution:
--Change 30.4.1 [thread.mutex.requirements] Mutex requirements, -paragraph 4 as indicated: -
- --- - - - - ---4-
-Error conditions:-The error conditions for error codes, if any, reported by member -functions of Mutex type shall be: --
-- -not_enough_memory -- if there is not enough memory to construct -the mutex object. -
-- -resource_unavailable_try_again -- if any native handle type -manipulated is not available. -
-- -operation_not_permitted -- if the thread does not have the -necessary permission to change the state of the mutex object. -
-- -device_or_resource_busy -- if any native handle type -manipulated is already locked. -
-- -invalid_argument -- if any native handle type manipulated as -part of mutex construction is incorrect. -
-
Section: 30.4.3.2.2 [thread.lock.unique.locking] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-22
-View other active issues in [thread.lock.unique.locking].
-View all other issues in [thread.lock.unique.locking].
-View all issues with Ready status.
-Discussion:
--30.4.3.2.2 [thread.lock.unique.locking]: unique_lock::lock is -required to throw an object of type std::system_error "when the -postcondition cannot be achieved." The postcondition is owns == true, -and this is trivial to achieve. Presumably, the requirement is intended -to mean something more than that. -
- -[ -Summit: -]
- --Move to open. -- -
[ -Beman has volunteered to provide proposed wording. -]
- - -[ -2009-07-21 Beman added wording to address 30.2.2 [thread.req.exception] -in response to the Frankfurt notes in 859. -]
- - -[ -2009-09-25 Beman: minor update to wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
- -Change Exceptions 30.2.2 [thread.req.exception] as indicated:
--- -Some functions described in this Clause are specified to throw exceptions of -type
-system_error(19.5.5). Such exceptions shall be thrown if -any of the Error conditions are detected or a call to an operating -system or other underlying API results in an error that prevents the library -function fromsatisfying its postconditions or from returning a meaningful -valuemeeting its specifications. Failure to -allocate storage shall be reported as described in -17.6.4.11 [res.on.exception.handling].
Change thread assignment 30.3.1.5 [thread.thread.member], join(), -paragraph 8 as indicated:
--- -Throws:
- -std::system_errorwhenthe postconditions cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change thread assignment 30.3.1.5 [thread.thread.member], detach(), paragraph -13 as indicated:
-- -- -Throws:
- -std::system_errorwhenthe effects or -postconditions cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change Mutex requirements 30.4.1 [thread.mutex.requirements], paragraph -11, as indicated:
-- --Throws:
-std::system_errorwhenthe effects or -postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 3, as indicated:
-- --Throws:
-std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 8, as indicated:
-- --Throws:
-std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 13, as indicated:
-- --Throws:
-std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 18, as indicated:
-- --Throws:
-std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], -paragraph 22, as indicated:
-- --Throws:
-std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change Function call_once 30.4.5.2 [thread.once.callonce], paragraph 4, as -indicated
---Throws:
-std::system_errorwhenthe effects cannot be achievedan exception is required (30.2.2 [thread.req.exception]), - or any exception thrown byfunc.
Change Class condition_variable 30.5.1 [thread.condition.condvar], -paragraph 12, as indicated:
-- --Throws:
-std::system_errorwhenthe effects or -postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change Class condition_variable 30.5.1 [thread.condition.condvar], -paragraph 19, as indicated:
-- --Throws:
-std::system_errorwhenthe effects or -postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], -paragraph 10, as indicated:
-- --Throws:
-std::system_errorwhenthe effects or -postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], -paragraph 16, as indicated:
-- -- -Throws:
-std::system_errorwhenthe returned value, effects, or -postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been -applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as -indicated:
--- -template <class Rep, class Period> -bool wait_for(unique_lock<mutex>& lock, - const chrono::duration<Rep, Period>& rel_time);-...- -Throws:
-std::system_errorwhenthe effects or -postcondition cannot be achievedan exception is required ([thread.req.exception]).
Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been -applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as -indicated:
--- -template <class Rep, class Period, class Predicate> - bool wait_for(unique_lock<mutex>& lock, - const chrono::duration<Rep, Period>& rel_time, - Predicate pred);-...- -Throws:
-std::system_errorwhenthe effects or -postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been -applied to the working paper, change 30.5.2 [thread.condition.condvarany] as -indicated:
--- -template <class Lock, class Rep, class Period> - bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);-...- -Throws:
-std::system_errorwhenthe returned value, effects or -postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been -applied to the working paper, change 30.5.2 [thread.condition.condvarany] as -indicated:
--- - - - - - -template <class Lock, class Rep, class Period, class Predicate> - bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);-...- -Throws:
-std::system_errorwhenthe returned value, effects or -postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
Section: 30.3.1.5 [thread.thread.member] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26
-View other active issues in [thread.thread.member].
-View all other issues in [thread.thread.member].
-View all issues with Ready status.
-Discussion:
--30.3.1.5 [thread.thread.member]: thread::detach is required to -throw an exception if the thread is "not a detachable thread". -"Detachable" is never defined. -
- -[ -Howard adds: -]
- - --Due to a mistake on my part, 3 proposed resolutions appeared at approximately -the same time. They are all three noted below in the discussion. -- -
[ -Summit, proposed resolution: -]
- - --- --In 30.3.1.5 [thread.thread.member] change: -
- -- -void detach(); ---- -...
--14- Error conditions:
--
-- no_such_process -- if the thread is not
-avalidthread.- invalid_argument -- if the thread is not
-a detachablejoinablethread.
[ -Post Summit, Jonathan Wakely adds: -]
- - --- --A thread is detachable if it is joinable. As we've defined joinable, -we can just use that. -
--This corresponds to the pthreads specification, where pthread_detach -fails if the thread is not joinable: -
--EINVAL: The implementation has detected that the value specified by -thread does not refer to a joinable thread. ---Jonathan recommends this proposed wording: -
----In 30.3.1.5 [thread.thread.member] change: -
- --void detach(); ---- -...
--14- Error conditions:
--
-- ...
-- invalid_argument -- not a
-detachablejoinable thread.
[ -Post Summit, Anthony Williams adds: -]
- - --- --This is covered by the precondition that joinable() be true. -
--Anthony recommends this proposed wording: -
- --- --In 30.3.1.5 [thread.thread.member] change: -
- -- -void detach(); ---- -...
--14- Error conditions:
--
-- ...
-- -
invalid_argument -- not a detachable thread.
[ -2009-10 Santa Cruz: -]
- - --Mark as Ready with proposed resolution from Summit. -- - - -
Proposed resolution:
- --In 30.3.1.5 [thread.thread.member] change: -
- -- - - - - -void detach(); ---- -...
--14- Error conditions:
--
-- no_such_process -- if the thread is not
-avalidthread.- invalid_argument -- if the thread is not
-a detachablejoinablethread.
Section: 30.5.2 [thread.condition.condvarany] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26
-View other active issues in [thread.condition.condvarany].
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29View all other issues in [thread.condition.condvarany].
View all issues with Open status.
Discussion:
@@ -14031,6 +1372,27 @@ non-POSIX platforms, but such complaints would not surprise me if they surfaced. Leave open. Benjamin to provide wording. +[ +2010 Pittsburgh: +]
+ + ++++We don't have throw clauses for condition variables. +
++This issue may be dependent on LWG 1268. +
++Leave open. Detlef will coordinate with Benjamin. +
++Consider merging LWG 964, 966, and 1268 into a +single paper. +
+
Proposed resolution:
@@ -14042,8 +1404,7 @@ Leave open. Benjamin to provide wording.Section: 30.5.1 [thread.condition.condvar] Status: Open - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26
-View other active issues in [thread.condition.condvar].
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29View all other issues in [thread.condition.condvar].
View all issues with Open status.
Discussion:
@@ -14138,6 +1499,94 @@ cannot be achieved. Leave open, Detlef to provide improved wording. +[ +2009-11-18 Anthony adds: +]
+ + +++ ++condition_variable::wait takes a unique_lock<mutex>. We +know whether or not a unique_lock owns a lock, through use of its +owns_lock() member. +
+ ++I would like to propose the following resolution: +
+ ++++Modify the first sentence of 30.5.1 [thread.condition.condvar] p9: +
+ ++ +void wait(unique_lock<mutex>& lock); +++9 Precondition:+lock is locked by the calling thread+lock.owns_lock() is true, and either +...
++Replace 30.5.1 [thread.condition.condvar] p11-13 with: +
+ ++void wait(unique_lock<mutex>& lock); ++++...
++11 Postcondition:
+ +lock is locked by the calling +threadlock.owns_lock() is true. ++12 Throws: std::system_error
+ +when the effects or +postcondition cannot be achievedif the implementation detects that +the preconditions are not met or the effects cannot be achieved. Any exception +thrown by lock.lock() or lock.unlock(). ++13 Error Conditions: The error conditions are implementation +defined. +
+ ++
+ +- +
+equivalent error condition from lock.lock() or lock.unlock(). +
[ +2010 Pittsburgh: +]
+ + ++++There are heavy conflicts with adopted papers. +
++This issue is dependent on LWG 1268. +
++Leave open pending outstanding edits to the working draft. Detlef will provide +wording. +
++Possibly related to 964. +
+ +
Proposed resolution:
@@ -14161,7 +1610,7 @@ equivalent error condition from lock.lock() or lock.unlock().-Throws: It's implementation-defined whether a std::system_error +Throws: It is implementation-defined whether a std::system_error with implementation-defined error condition is thrown if the precondition is not met.
@@ -14172,597 +1621,10 @@ precondition is not met. -Section: 30.3.1.2 [thread.thread.constr] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-22
-View other active issues in [thread.thread.constr].
-View all other issues in [thread.thread.constr].
-View all issues with Ready status.
-Discussion:
--the error handling for the constructor for condition_variable -distinguishes lack of memory from lack of other resources, but the error -handling for the thread constructor does not. Is this difference -intentional? -
- -[ -Beman has volunteered to provide proposed wording. -]
- - -[ -2009-09-25 Beman provided proposed wording. -]
- - --The proposed resolution assumes 962 has been accepted and -its proposed resolution applied to the working paper. -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
- - -Change Mutex requirements 30.4.1 [thread.mutex.requirements], -paragraph 4, as indicated:
-- -- -Error conditions:
-- ---
-- - -
not_enough_memory— if there is not enough memory to construct -the mutex object.- - -
resource_unavailable_try_again— if any native handle type -manipulated is not available.- - -
operation_not_permitted— if the thread does not have the -necessary permission to change the state of the mutex object.- - -
device_or_resource_busy— if any native handle type -manipulated is already locked.- -
invalid_argument— if any native handle type manipulated as -part of mutex construction is incorrect.
Change Class condition_variable 30.5.1 [thread.condition.condvar], -default constructor, as indicated:
--- - - - - --
condition_variable();--Effects: Constructs an object of type
-condition_variable.Throws:
-std::system_errorwhen an exception is required (30.2.2 [thread.req.exception]).Error conditions:
----
-- -
not_enough_memory— if a memory limitation prevents - initialization.- -
resource_unavailable_try_again— if some non-memory - resource limitation prevents initialization.- -
device_or_resource_busy— if attempting to initialize a - previously-initialized but as of yet undestroyedcondition_variable.
Section: 30.4.1 [thread.mutex.requirements] Status: Ready - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-22
-View other active issues in [thread.mutex.requirements].
-View all other issues in [thread.mutex.requirements].
-View all issues with Ready status.
-Discussion:
--30.4.1 [thread.mutex.requirements]: several functions are -required to throw exceptions "if the thread does not have the necessary -permission ...". "The necessary permission" is not defined. -
- -[ -Summit: -]
- --Move to open. -- - -
[ -Beman has volunteered to provide proposed wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Moved to Ready with minor word-smithing in the example. -- - - -
Proposed resolution:
- - -Change Exceptions 30.2.2 [thread.req.exception] as indicated:
--- -Some functions described in this Clause are -specified to throw exceptions of type
- -system_error(19.5.5). Such exceptions -shall be thrown if any of the Error conditions are detected or a call to an operating system or other underlying API -results in an error that prevents the library function from meeting its specifications. -[Note: See 17.6.4.11 [res.on.exception.handling] for exceptions thrown to report -storage allocation failures. —end -note][Example:
- -- -- -Consider a function in this clause that is specified to throw exceptions of type
- --system_errorand specifies Error conditions that include-operation_not_permittedfor a thread that does not have the privilege to -perform the operation. Assume that, during the execution of this function, anerrno-ofEPERMis reported by a POSIX API call used by the -implementation. Since POSIX specifies anerrnoofEPERM-when "the caller does not have the privilege to perform the operation", -the implementation mapsEPERMto anerror_condition-ofoperation_not_permitted(19.5 [syserr]) and an exception of type-system_erroris thrown.—end example]
- -Editorial note: For the sake of exposition, -the existing text above is shown with the changes proposed in issues 962 and 967. The -proposed additional example is independent of whether or not the 962 and 967 -proposed resolutions are accepted.
- -
Change Mutex requirements 30.4.1 [thread.mutex.requirements], -paragraph 4, as indicated:
- -- -- -—
- -operation_not_permitted— if the thread does not have the -necessary permission to change the state of the mutex objectprivilege to perform the operation.
Change Mutex requirements 30.4.1 [thread.mutex.requirements], -paragraph 12, as indicated:
- -- -- - - - - - -—
- -operation_not_permitted— if the thread does not have the -necessary permission to change the state of the mutexprivilege to perform the operation.
Section: 20.9.3.1 [time.duration.cons] Status: Ready - Submitter: Howard Hinnant Opened: 2009-01-21 Last modified: 2009-10-26
-View all issues with Ready status.
-Discussion:
--The following code should not compile because it involves implicit truncation -errors (against the design philosophy of the duration library). -
- -- -duration<double> d(3.5); -duration<int> i = d; // implicit truncation, should not compile -
-This intent was codified in the example implementation which drove this proposal -but I failed to accurately translate the code into the specification in this -regard. -
- -[ -Batavia (2009-05): -]
- --- --We agree with the proposed resolution. -
--Move to Tentatively Ready. -
-
[ -2009-07 Frankfurt -]
- - --Moved from Tentatively Ready to Open only because the wording needs to be -improved for enable_if type constraining, possibly following Robert's -formula. -- -
[ -2009-08-01 Howard adds: -]
- - --Addressed by 1177. -- -
[ -2009-10 Santa Cruz: -]
- - --Not completely addressed by 1177. Move to Ready. -- - - -
Proposed resolution:
--Change 20.9.3.1 [time.duration.cons], p4: -
- --- - - - - -template <class Rep2, class Period2> - duration(const duration<Rep2, Period2>& d); ----4- Requires: treat_as_floating_point<rep>::value -shall be true or both ratio_divide<Period2, -period>::type::den shall be 1 -and treat_as_floating_point<Rep2>::value -shall be false. -Diagnostic required. -[Note: This requirement prevents implicit truncation error when -converting between integral-based duration types. Such a -construction could easily lead to confusion about the value of the -duration. -- end note] --
Section: 20.7.16 [unord.hash] Status: Ready - Submitter: Alisdair Meredith Opened: 2009-02-02 Last modified: 2009-10-27
-View other active issues in [unord.hash].
-View all other issues in [unord.hash].
-View all issues with Ready status.
-Discussion:
-Addresses UK 208
--I don't see an open issue on supporting std::hash for smart pointers -(unique_ptr and shared_ptr at least). -
--It seems reasonable to at least expect support for the smart -pointers, especially as they support comparison for use in ordered -associative containers. -
- -[ -Batavia (2009-05): -]
- --- --Howard points out that the client can always supply a custom hash function. -
--Alisdair replies that the smart pointer classes are highly likely -to be frequently used as hash keys. -
--Bill would prefer to be conservative. -
--Alisdair mentions that this issue may also be viewed as a subissue or -duplicate of issue 1025. -
--Move to Open, and recommend the issue be deferred until after the next -Committee Draft is issued. -
-
[ -2009-05-31 Peter adds: -]
- - --- --Howard points out that the client can always supply a custom hash function. ---Not entirely true. The client cannot supply the function that hashes the -address of the control block (the equivalent of the old operator<, now -proudly carrying the awkward name of 'owner_before'). Only the -implementation can do that, not necessarily via specializing hash<>, of -course. -
--This hash function makes sense in certain situations for shared_ptr -(when one needs to switch from set/map using ownership ordering to -unordered_set/map) and is the only hash function that makes sense for -weak_ptr. -
-
[ -2009-07-28 Alisdair provides wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Add the following declarations to the synopsis of <memory> -in 20.8 [memory] -
- -- -// 20.8.10.X hash support -template <class T> struct hash; -template <class T, class D> struct hash<unique_ptr<T,D>>; -template <class T> struct hash<shared_ptr<T>>; -
-Add a new subclause 20.8.10.X hash support -
- --- - - - - --20.8.10.X hash support [util.smartptr.hash] -
- -template <class T, class D> struct hash<unique_ptr<T,D>>; -- --A partial specialization of the class template hash (20.7.16 [unord.hash]) shall be provided for instances of the -unique_ptr template suitable for use as a key in unordered -associative containers (23.5 [unord]) if and only if there is a -hash specialization available for the type D::pointer. -For an object p of type unqiue_ptr<T,D> the -hash shall evaluate to the same value as hash<typename -D::pointer>{}(p.get()). -- -template <class T> struct hash<shared_ptr<T>>; -- --A partial specialization of the class template hash (20.7.16 [unord.hash]) -shall be provided for instances of the shared_ptr template -suitable for use as a key in unordered associative containers -(23.5 [unord]). For an object p of type shared_ptr<T> -the hash shall evaluate -to the same value as hash<T*>{}(p.get()). --
Section: 20.8.14.2 [unique.ptr.single] Status: Ready - Submitter: Howard Hinnant Opened: 2009-02-10 Last modified: 2009-10-21
-View other active issues in [unique.ptr.single].
-View all other issues in [unique.ptr.single].
-View all issues with Ready status.
-Discussion:
--Dave brought to my attention that when a unique_ptr has a non-const reference -type deleter, move constructing from it, even when the unique_ptr containing -the reference is an rvalue, could have surprising results: -
- -- -D d(some-state); -unique_ptr<A, D&> p(new A, d); -unique_ptr<A, D> p2 = std::move(p); -// has d's state changed here? -
-I agree with him. It is the unique_ptr that is the rvalue, not the -deleter. When the deleter is a reference type, the unique_ptr should -respect the "lvalueness" of the deleter. -
- --Thanks Dave. -
- -[ -Batavia (2009-05): -]
- --Seems correct, but complicated enough that we recommend moving to Review. -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Change 20.8.14.2.1 [unique.ptr.single.ctor], p20-21 -
- --- -template <class U, class E> unique_ptr(unique_ptr<U, E>&& u); -- -- ----20- Requires: If
- -DE is not a reference type, -construction of the deleter D from an rvalue of type E -shall be well formed and shall not throw an exception. - -Otherwise E is a reference type and construction of the deleter -D from an lvalue of type E shall be well formed and -shall not throw an exception. - -If D is -a reference type, then E shall be the same type as D -(diagnostic required). unique_ptr<U, E>::pointer shall be -implicitly convertible to pointer. [Note: These -requirements imply that T and U are complete types. --- end note] ---21- Effects: Constructs a unique_ptr which owns the -pointer which u owns (if any). If the deleter -E is not a reference type,
- -itthis -deleter is move constructed from u's deleter, otherwise -the referencethis deleter is copy constructed -from u.'s deleter. After the construction, u no longer -owns a pointer. [Note: The deleter constructor can be implemented -with std::forward<DE>. -- end -note] -
-Change 20.8.14.2.3 [unique.ptr.single.asgn], p1-3 -
- --- -unique_ptr& operator=(unique_ptr&& u); --- ----1- Requires: If the deleter D is not a reference type, -
- -Aassignment of the deleter D from an rvalue D shall not throw an exception. - -Otherwise the deleter D is a reference type, -and assignment of the deleter D from an lvalue D shall not throw an exception. ---2- Effects: reset(u.release()) followed by -an
- -moveassignment fromu's deleter to this deleter-std::forward<D>(u.get_deleter()). ---3- Postconditions: This unique_ptr now owns the pointer -which u owned, and u no longer owns it.
-[Note: If -D is a reference type, then the referenced lvalue deleters are -move assigned. -- end note]-
-Change 20.8.14.2.3 [unique.ptr.single.asgn], p6-7 -
- --- - - - - -template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u); --- ---Requires: If the deleter E is not a reference type, -
- -Aassignment of the deleter D from an rvalue -DE shall not throw an exception. - -Otherwise the deleter E is a reference type, -and assignment of the deleter D from an lvalue E shall not throw an exception. -unique_ptr<U, E>::pointer shall be implicitly convertible to pointer. -[Note: These requirements imply that T and U> -are complete types. -- end note] --Effects: reset(u.release()) followed by -an
- -moveassignment fromu's deleter to this deleter-std::forward<E>(u.get_deleter()). -If either -D or E is a reference type, then the referenced lvalue -deleter participates in the move assignment.-
Section: 23.2.1 [container.requirements.general] Status: Open - Submitter: Rani Sharoni Opened: 2009-02-12 Last modified: 2009-10-20
+ Submitter: Rani Sharoni Opened: 2009-02-12 Last modified: 2010-10-29View other active issues in [container.requirements.general].
View all other issues in [container.requirements.general].
View all issues with Open status.
@@ -14903,17 +1765,53 @@ Should wait to get direction from Dave/Rani (N2983). +[ +2010-03-28 Daniel updated wording to sync with N3092. +]
+ + ++++The suggested change of 23.3.2.3 [deque.modifiers]/2 should be removed, +because the current wording does say more general things: +
+ ++2 Remarks: If an exception is thrown other than by the copy constructor, +move constructor, assignment operator, or move assignment operator of T +there are no effects. If an exception is thrown by the move constructor of a +non-CopyConstructible T, the effects are unspecified. ++ ++The suggested change of 23.4.1.2 [vector.capacity]/2 should be removed, +because the current wording does say more general things: +
+ ++2 Effects: A directive that informs a vector of a planned change +in size, so that it can manage the storage allocation accordingly. After +reserve(), capacity() is greater or equal to the argument of +reserve if reallocation happens; and equal to the previous value of +capacity() otherwise. Reallocation happens at this point if and only if +the current capacity is less than the argument of reserve(). If an +exception is thrown other than by the move constructor of a +non-CopyConstructible type, there are no effects. ++ +
Proposed resolution:
-23.2.1 [container.requirements.general] paragraph 10 add footnote: +23.2.1 [container.requirements.general] paragraph 11 add footnote:
--10- Unless otherwise specified (see 23.1.4.1, 23.1.5.1, 23.2.2.3, and +-11- Unless otherwise specified (see 23.1.4.1, 23.1.5.1, 23.2.2.3, and 23.2.6.4) all container types defined in this Clause meet the following additional requirements:
@@ -14965,29 +1863,11 @@ the move constructor of T.
-23.3.2.3 [deque.modifiers] change paragraph 6 to say: +23.4.1.2 [vector.capacity] paragraph 2 change to say:
--6- Throws: Nothing unless an exception is thrown by the copy -constructor, move constructor or assignment operator of T. -- -
-23.3.6.2 [vector.capacity] remove paragraph 2 -
- --- --2- Requires: If value_type has a move constructor, -that constructor shall not throw any exceptions.-
-23.3.6.2 [vector.capacity] paragraph 3 change to say: -
- ---3- Effects: A directive that informs a vector +-2- Effects: A directive that informs a vector of a planned change in size, so that it can manage the storage allocation accordingly. After reserve(), capacity() is greater or equal to the argument of reserve @@ -15000,7 +1880,7 @@ unless the exception is thrown by the contained object move constructor.
-23.3.6.2 [vector.capacity] paragraph 12 change to say: +23.4.1.2 [vector.capacity] paragraph 12 change to say:
@@ -15011,7 +1891,7 @@ the contained object move constructor.
-23.3.6.4 [vector.modifiers] change paragraph 1 to say: +23.4.1.4 [vector.modifiers] change paragraph 1 to say:
@@ -15022,5663 +1902,6 @@ or emplace_back() function, that function has no effect unless the exception is thrown by the move constructor of T.-
-23.3.6.4 [vector.modifiers] change paragraph 2 to say: -
- ---2- Remarks: Causes reallocation if the new size is greater than -the old capacity. If no reallocation happens, all the iterators and -references before the insertion point remain valid. If an exception is -thrown other than by the copy constructor, move constructor -or assignment operator of T or by any InputIterator -operation there are no effects. -- -
-23.3.6.4 [vector.modifiers] change paragraph 6 to say: -
- ---6- Throws: Nothing unless an exception is thrown by the copy -constructor, move constructor or assignment operator of T. -- - - - - - -
Section: 20.7.5 [refwrap] Status: Tentatively Ready - Submitter: Howard Hinnant Opened: 2009-02-18 Last modified: 2009-10-26
-View all other issues in [refwrap].
-View all issues with Tentatively Ready status.
-Discussion:
--The synopsis in 20.7.5 [refwrap] says: -
- -- -template <ObjectType T> class reference_wrapper -... -
-And then paragraph 3 says: -
- --- --The template instantiation reference_wrapper<T> shall be -derived from std::unary_function<T1, R> only if the type -T is any of the following: -
- --
-- -a function type or a pointer to function type taking one argument of -type T1 and returning R -
-
-But function types are not ObjectTypes. -
- --Paragraph 4 contains the same contradiction. -
- -[ -Post Summit: -]
- - --- --Jens: restricted reference to ObjectType -
--Recommend Review. -
-
[ -Post Summit, Peter adds: -]
- - --- --In https://svn.boost.org/trac/boost/ticket/1846 -however Eric Niebler makes the very reasonable point that reference_wrapper<F>, -where F is a function type, represents a reference to a function, -a legitimate entity. So boost::ref was changed to allow it. -
--https://svn.boost.org/trac/boost/browser/trunk/libs/bind/test/ref_fn_test.cpp -
--Therefore, I believe an alternative proposed resolution for issue 987 could simply -allow reference_wrapper to be used with function types. -
-
[ -Post Summit, Howard adds: -]
- - --- - - --I agree with Peter (and Eric). I got this one wrong on my first try. Here -is code that demonstrates how easy (and useful) it is to instantiate -reference_wrapper with a function type: -
- -- -#include <functional> - -template <class F> -void test(F f); - -void f() {} - -int main() -{ - test(std::ref(f)); -} --Output (link time error shows type of reference_wrapper instantiated -with function type): -
- -- -Undefined symbols: - "void test<std::reference_wrapper<void ()()> >(std::reference_wrapper<void ()()>)",... --I've taken the liberty of changing the proposed wording to allow function types -and set to Open. I'll also freely admit that I'm not positive ReferentType -is the correct concept. -
- -
[ -Batavia (2009-05): -]
- --- --Howard observed that FunctionType, -a concept not (yet?) in the Working Paper, -is likely the correct constraint to be applied. -However, the proposed resolution provides an adequate approximation. -
--Move to Review. -
-
[ -2009-05-23 Alisdair adds: -]
- - --- --By constraining to PointeeType we rule out the ability for T to be a -reference, and call in reference-collapsing. I'm not sure if this is -correct and intended, but would like to be sure the case was considered. -
--Is dis-allowing reference types and the -implied reference collapsing the intended result? -
-
[ -2009-07 Frankfurt -]
- - --Moved from Review to Open only because the wording needs to be -tweaked for concepts removal. -- -
[ -2009-10-14 Daniel provided de-conceptified wording. -]
- - -[ -2009-10 post-Santa Cruz: -]
- - --Move to Tentatively Ready. -- - - -
Proposed resolution:
--Change 20.7.5 [refwrap]/1 as indicated: -
- --reference_wrapper<T> is a CopyConstructible and -CopyAssignable wrapper around a -reference to an object or function of type T. -- - - - - -
Rationale:
--a) The occurrence of T& in the function signature auto-implies -std::ReferentType, -this is due to [temp.req.impl]/4 bullet 4 -
--b) The occurrence of the constrained template reference_wrapper<T> in -the remaining -signatures lets kick in [temp.req.impl]/4 bullet 1 and adds *all* requirements of -this template. But we need to add at least *one* requirement (and it -was an arbitrary, -but natural decision to require std::PointeeType here) to *activate* -this. If we hadn't done -this, we were in unconstrained mode! -
- - - - - -Section: 17 [library] Status: Open - Submitter: David Abrahams Opened: 2009-03-06 Last modified: 2009-05-23
-View other active issues in [library].
-View all other issues in [library].
-View all issues with Open status.
-Discussion:
--There are lots of places in the standard where we talk about "the move -constructor" but where we mean "the move operation," i.e. T( move( x ) ). -
--We also don't account for whether that operation modifies x or not, and -we need to. -
- -[ -Batavia (2009-05): -]
- --Move to Open, pending proposed wording from Dave for further -review. -- - -
Proposed resolution:
--
- - - - - -Section: 20.8.13 [specialized.algorithms] Status: Tentatively Ready - Submitter: Peter Dimov Opened: 2009-03-09 Last modified: 2009-10-26
-View all other issues in [specialized.algorithms].
-View all issues with Tentatively Ready status.
-Discussion:
--The same fix (reference 987) may be applied to addressof, which is also constrained to -ObjectType. (That was why boost::ref didn't work with functions - it -tried to apply boost::addressof and the reinterpret_cast<char&> -implementation of addressof failed.) -
- - - -[ -Batavia (2009-05): -]
- --- --We agree. -
--Move to Tentatively Ready. -
-
[ -2009-07 Frankfurt -]
- - --Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -- -
[ -2009-10-10 Daniel updates wording to concept-free. -]
- - -[ -2009-10 post-Santa Cruz: -]
- - --Move to Tentatively Ready. -- - - -
Proposed resolution:
-[ -The resolution assumes that addressof is reintroduced as described in -n2946 -]
- - --In 20.8.13 [specialized.algorithms] change as described: -
- -- - - - -template <class T> T* addressof(T& r); ---Returns: The actual address of the object or function -referenced by r, even in the -presence of an overloaded operator&. --
Rationale:
--a) The occurrence of T& in the function signature auto-implies -std::ReferentType, -this is due to [temp.req.impl]/4 bullet 4 -
- - - - - -Section: 18.8.6 [except.nested] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-22
-View other active issues in [except.nested].
-View all other issues in [except.nested].
-View all issues with Open status.
-Discussion:
- -Addresses JP 31
- --It is difficult to understand in which case nested_exception is applied. -
- -[ -Summit: -]
- - --Alisdair will add an example in an update to -N2619. -- -
[ -2009-10 Santa Cruz: -]
- - --It doesn't appear that N2619 really addresses this. Alisdair to propose wording. -- - - -
Proposed resolution:
- - - - - -Section: 24.4.4 [iterator.operations] Status: Ready - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-22
-View other active issues in [iterator.operations].
-View all other issues in [iterator.operations].
-View all issues with Ready status.
-Discussion:
- -Addresses UK 271
- --next/prev return an incremented iterator without changing the value of -the original iterator. However, even this may invalidate an -InputIterator. A ForwardIterator is required to guarantee the -'multipass' property. -
- -[ -Batavia (2009-05): -]
- --We agree with the proposed resolution. -Move to Tentatively Ready. -- -
[ -2009-07 Frankfurt -]
- - --Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -- -
[ -2009-10-14 Daniel provided de-conceptified wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
- - --Change header <iterator> synopsis 24.3 [iterator.synopsis] as indicated: -
- --// 24.4.4, iterator operations: -... -template <classInputForwardIterator> -InputForwardIterator - next(InputForwardIterator x, typename std::iterator_traits<InputForwardIterator>::difference_type n = 1); -
-Change 24.4.4 [iterator.operations] before p.6 as indicated: -
- --template <classInputForwardIterator> -InputForwardIterator - next(InputForwardIterator x, typename std::iterator_traits<InputForwardIterator>::difference_type n = 1); -
Section: 20.8.15.5 [util.smartptr.shared.atomic] Status: Ready - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-23
-View all issues with Ready status.
-Discussion:
- -Addresses JP 44
- --The 1st parameter p and 2nd parameter v is now -shared_ptr<T>*. -
--It should be shared_ptr<T>&, or if these are -shared_ptr<T>* then add the "p shall not be a -null pointer" at the requires. -
- -[ -Summit: -]
- - --Agree. All of the functions need a requirement that p (or -v) is a pointer to a valid object. -- -
[ -2009-07 post-Frankfurt: -]
- - --- --Lawrence explained that these signatures match the regular atomics. The -regular atomics must not use references because these signatures are -shared with C. The decision to pass shared_ptrs by pointer rather than -by reference was deliberate and was motivated by the principle of least -surprise. -
--Lawrence to write wording that requires that the pointers not be null. -
-
[ -2009-09-20 Lawrence provided wording: -]
- - --- --The parameter types for atomic shared pointer access -were deliberately chosen to be pointers -to match the corresponding parameters of the atomics chapter. -Those in turn were deliberately chosen -to match C functions, -which do not have reference parameters. -
--We adopt the second suggestion, -to require that such pointers not be null. -
-
[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
-
-In section "shared_ptr atomic access"
-20.8.15.5 [util.smartptr.shared.atomic], add to each function the
-following clause.
-
- - - - - --Requires:
pshall not be null. -
Section: 30.3.1.5 [thread.thread.member] Status: Open - Submitter: Alberto Ganesh Barbati Opened: 2009-03-12 Last modified: 2009-05-23
-View other active issues in [thread.thread.member].
-View all other issues in [thread.thread.member].
-View all issues with Open status.
-Discussion:
- --While looking at thread::join() I think I spotted a couple of -possible defects in the specifications. I could not find a previous -issue or NB comment about that, but I might have missed it. -
- --The postconditions clause for thread::join() is: -
- --Postconditions: If join() throws an exception, the value -returned by get_id() is unchanged. Otherwise, get_id() == id(). -- -
-and the throws clause is: -
- --Throws: std::system_error when the postconditions cannot be achieved. -- -
-Now... how could the postconditions not be achieved? -It's just a matter of resetting the value of get_id() or leave it -unchanged! I bet we can always do that. Moreover, it's a chicken-and-egg -problem: in order to decide whether to throw or not I depend on the -postconditions, but the postconditions are different in the two cases. -
- --I believe the throws clause should be: -
- --Throws: std::system_error when the effects or postconditions -cannot be achieved. -- -
-as it is in detach(), or, even better, as the postcondition is -trivially satisfiable and to remove the circular dependency: -
- - --Throws: std::system_error if the effects cannot be achieved. -- -
-Problem is that... ehm... join() has no "Effects" clause. Is that intentional? -
- -[ -See the thread starting at c++std-lib-23204 for more discussion. -]
- - -[ -Batavia (2009-05): -]
- --- - --Pete believes there may be some more general language (in frontmatter) -that can address this and related issues such as 962. -
--Move to Open. -
-
Proposed resolution:
- - - - - -Section: 23.2.1 [container.requirements.general] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-20
-View other active issues in [container.requirements.general].
-View all other issues in [container.requirements.general].
-View all issues with Open status.
-Discussion:
- -Addresses UK 222
- --It is not clear what purpose the Requirement tables serve in the -Containers clause. Are they the definition of a library Container? Or -simply a conventient shorthand to factor common semantics into a single -place, simplifying the description of each subsequent container? This -becomes an issue for 'containers' like array, which does not meet the -default-construct-to-empty requirement, or forward_list which does not -support the size operation. Are these components no longer containers? -Does that mean the remaining requirements don't apply? Or are these -contradictions that need fixing, despite being a clear design decision? -
- --Recommend: -
- --Clarify all the tables in 23.2 [container.requirements] are -there as a convenience for documentation, rather than a strict set of -requirements. Containers should be allowed to relax specific -requirements if they call attention to them in their documentation. The -introductory text for array should be expanded to mention a -default constructed array is not empty, and -forward_list introduction should mention it does not provide -the required size operation as it cannot be implemented -efficiently. -
- -[ -Summit: -]
- - --Agree in principle. -- -
[ -2009-07 post-Frankfurt: -]
- - --We agree in principle, but we have a timetable. This group feels that -the issue should be closed as NAD unless a proposed resolution is -submitted prior to the March 2010 meeting. -- -
[ -2009-10 Santa Cruz: -]
- - --Looked at this and still intend to close as NAD in March -2010 unless there is proposed wording that we like. -- - - -
Proposed resolution:
- - - - - -Section: 24.5.1.3.5 [reverse.iter.opref] Status: Ready - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-22
-View all issues with Ready status.
-Discussion:
- -Addresses UK 281
- --The current specification for return value for reverse_iterator::operator-> -will always be a true pointer type, but reverse_iterator supports proxy -iterators where the pointer type may be some kind of 'smart pointer'. -
- -[ -Summit: -]
- - --- --move_iterator avoids this problem by returning a value of the wrapped -Iterator type. -study group formed to come up with a suggested resolution. -
--move_iterator solution shown in proposed wording. -
-
[ -2009-07 post-Frankfurt: -]
- - --Howard to deconceptize. Move to Review after that happens. -- -
[ -2009-08-01 Howard deconceptized: -]
- - --- -
[ -2009-10 Santa Cruz: -]
- - --- - - --We can't think of any reason we can't just define reverse -iterator's pointer types to be the same as the underlying iterator's -pointer type, and get it by calling the right arrow directly. -
--Here is the proposed wording that was replaced: -
-- -template <class Iterator> -class reverse_iterator { - ... - typedeftypename iterator_traits<Iterator>::pointerpointer; --Change 24.5.1.3.5 [reverse.iter.opref]: -
- --pointer operator->() const; ---Returns: ---&(operator*());-this->tmp = current; ---this->tmp; -return this->tmp; -
Proposed resolution:
--Change 24.5.1.3.5 [reverse.iter.opref]: -
- -- - - - - - - - - -pointer operator->() const; ---Returns: ---&(operator*());-deref_tmp = current; ---deref_tmp; -return deref_tmp::operator->(); -
Section: 26.5 [rand] Status: Tentatively NAD - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-11-03
-View all other issues in [rand].
-View all issues with Tentatively NAD status.
-Discussion:
- --Both the concepts RandomNumberEngine and RandomNumberDistribution have -requirements to be InputStreamable and OutputStreamable. -
--I have no problems leaving the WP in an inconsistent state on the best-faith -assumption these concepts will be provided later, however disagree with the -proposers that these constraints are not separable, orthogonal to the basic -concepts of generating random number distributions. -
--These constraints should be dropped, and applied to specific algorithms as -needed. -
--If a more refined concept (certainly deemed useful by the proposers) is -proposed there is no objection, but the basic concept should not require -persistence via streaming. -
- -[ -Batavia (2009-05): -]
- --Move to Open. -- -
[ -2009-05-31 Alisdair adds: -]
- - --- --Working on constraining the stream iterators, I have a few more observations -to make on the concepts proposed while constraining the random number -facility. -
--While I still believe the concerns are orthogonal, I don't believe the -existing constraints go far enough either! The goal we want to achieve is -not that a RandomNumberEngine / RandomNumberDistribution supports the stream -operators, but that it is Serializable. I.e. there is a relationship -between the insert and extract operations that guarantees to restore the -state of the original object. This implies a coupling of the concepts -together in a broader concept (Serializable) with at least one axiom to -assert the semantics. -
--One problem is that istream and ostream may be fundamentally different -types, although we can hook a relation if we are prepared to drop down to -the char type and char_traits template parameters. Doing so ties us to a -form of serialization that demands implementation via the std iostreams -framework, which seems overly prescriptive. I believe the goal is generally -to support serialization without regard to how it is expressed - although -this is getting even more inventive in terms of concepts we do not have -today. -
-
[ -2009-11-03 Alisdair adds: -]
- - --- --I can't find the record in the wiki minutes, but it was agreed at both -Frankfurt and Santa Cruz that this issue is NAD. -
--The agreement in SC was that I would provide you with the rationale (see -below) to include when moving to NAD. -
-
[ -2009-11-03 Howard adds: -]
- - --Moved to Tentatively NAD after 5 positive votes on c++std-lib. -- - -
Proposed resolution:
- - -Rationale:
--The issue suggests a more refined concept should be used if we want to -require streaming, to separate concerns from the basic -RandomNumberEngine behaviour. In Frankfurt it was observed -that RandomNumberEngine is that more refined concept, -and the basic concept used in the framework is -UniformRandomNumberGenerator, which it refines. -
- --We concur, and expect this to have no repurcussions re-writing this -clause now concepts are removed. -
- - - - - -Section: 26.5.6 [rand.device] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-18 Last modified: 2009-10-26
-View all other issues in [rand.device].
-View all issues with Open status.
-Discussion:
- --class random_device should be movable. -
- -[ -Batavia (2009-05): -]
- --Move to Open, and recommend this issue be deferred until after the next -Committee Draft is issued. -- -
[ -2009-10 post-Santa Cruz: -]
- - --Leave open. Walter to provide drafting as part of his planned paper. -- - - -
Proposed resolution:
- - - - - -Section: 26.5.7.1 [rand.util.seedseq] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-18 Last modified: 2009-10-26
-View all other issues in [rand.util.seedseq].
-View all issues with Open status.
-Discussion:
- --class seed_seq should support efficient move operations. -
- -[ -Batavia (2009-05): -]
- --Move to Open, and recommend this issue be deferred until after the next -Committee Draft is issued. -- -
[ -2009-10 post-Santa Cruz: -]
- - --Leave open. Walter to provide drafting as part of his planned paper. -- - - -
Proposed resolution:
- - - - - -Section: 20.7.11.1.1 [func.bind.isbind] Status: Tentatively Ready - Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2009-10-26
-View all issues with Tentatively Ready status.
-Discussion:
- --Class template is_bind_expression 20.7.11.1.1 [func.bind.isbind]: -
- -namespace std {
- template<class T> struct is_bind_expression {
- static const bool value = see below;
- };
-}
--is_bind_expression should derive from std::integral_constant<bool> like -other similar trait types. -
- -[ -Daniel adds: -]
- --We need the same thing for the trait is_placeholder as well. --
[ -2009-03-22 Daniel provided wording. -]
- - -[ -Batavia (2009-05): -]
- --- --We recommend this be deferred until after the next Committee Draft is issued. -
--Move to Open. -
-
[ -2009-05-31 Peter adds: -]
- - --- --I am opposed to the proposed resolution and to the premise of the issue -in general. The traits's default definitions should NOT derive from -integral_constant, because this is harmful, as it misleads people into -thinking that is_bind_expression<E> always derives from -integral_constant, whereas it may not. -
--is_bind_expression and is_placeholder allow user -specializations, and in fact, this is their primary purpose. Such user -specializations may not derive from integral_constant, and the -places where is_bind_expression and is_placeholder are -used intentionally do not require such derivation. -
--The long-term approach here is to switch to -BindExpression<E> and Placeholder<P> -explicit concepts, of course, but until that happens, I say leave them -alone. -
-
[ -2009-10 post-Santa Cruz: -]
- - --Move to Tentatively Ready. We are comfortable with requiring user specializations -to derive from integral_constant. -- - - -
Proposed resolution:
--In 20.7.11.1.1 [func.bind.isbind] change as indicated: -
-namespace std {
- template<class T> struct is_bind_expression : integral_constant<bool, see below> { };{
- static const bool value = see below;
- };
-}
--In 20.7.11.1.1 [func.bind.isbind]/2 change as indicated: -
---static const bool value;---2--true if T is a type returned from bind, false otherwise.- If T is a type returned from bind, is_bind_expression<T> shall -be publicly derived from - integral_constant<bool, true>, otherwise it shall be -publicly derived from - integral_constant<bool, false>. -
-In 20.7.11.1.2 [func.bind.isplace] change as indicated: -
-namespace std {
- template<class T> struct is_placeholder : integral_constant<int, see below> { };{
- static const int value = see below;
- };
-}
--In 20.7.11.1.2 [func.bind.isplace]/2 change as indicated: -
---static const int value;---2--value is J if T is the type of std::placeholders::_J, 0 otherwise.- If T is the type of std::placeholders::_J, is_placeholder<T> -shall be publicly - derived from integral_constant<int, J> otherwise it shall -be publicly derived - from integral_constant<int, 0>. -
Section: 20.7.10 [negators] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-20 Last modified: 2009-10-26
-View all issues with Open status.
-Discussion:
--The class templates unary/binary_negate need constraining and move support. -
--Ideally these classes would be deprecated, allowing unary/binary_function to -also be deprecated. However, until a generic negate adaptor is introduced -that can negate any Callable type, they must be supported so should be -constrained. Likewise, they should be movable, and support adopting a -move-only predicate type. -
--In order to preserve ABI compatibility, new rvalue overloads are supplied in -preference to changing the existing pass-by-const-ref to pass-by-value. -
--Do not consider the issue of forwarding mutable lvalues at this point, -although remain open to another issue on the topic. -
- -[ -2009-05-01 Daniel adds: -]
- --- --IMO the currently proposed resolution needs some updates -because it is ill-formed at several places: -
- --
-- -
--In concept AdaptableUnaryFunction change -
--typename X::result_type; -typename X::argument_type; --to -
--Returnable result_type = typename X::result_type; -typename argument_type = typename X::argument_type; --[The replacement "Returnable result_type" instead of "typename -result_type" is non-editorial, but maybe you prefer that as well] -
-- -
- --In concept AdaptableBinaryFunction change -
--typename X::result_type; -typename X::first_argument_type; -typename X::second_argument_type; --to -
--Returnable result_type = typename X::result_type; -typename first_argument_type = typename X::first_argument_type; -typename second_argument_type = typename X::second_argument_type; --[The replacement "Returnable result_type" instead of "typename -result_type" is non-editorial, but maybe you prefer that as well.] -
-- -
--In class unary/binary_function -
--
-- -I suggest to change "ReturnType" to "Returnable" in both cases. -
-- -I think you want to replace the remaining occurrences of "Predicate" by "P" -(in both classes in copy/move from a predicate) -
-- -
--I think you need to change the proposed signatures of not1 and not2, because -they would still remain unconstrained: To make them constrained at least a -single requirement needs to be added to enable requirement implication. This -could be done via a dummy ("requires True<true>") or just explicit as follows: -
--
-- -
--template <AdaptableUnaryFunction P> -requires Predicate< P, P::argument_type> -unary_negate<P> not1(const P&& pred); -template <AdaptableUnaryFunction P> -requires Predicate< P, P::argument_type > -unary_negate<P> not1(P&& pred); ----3- Returns: unary_negate<P>(pred). ---[Don't we want a move call for the second overload as in -
--unary_negate<P>(std::move(pred)) --in the Returns clause ?] -
-- -
-template <AdaptableBinaryFunction P> -requires Predicate< P, P::first_argument_type, P::second_argument_type > -binary_negate<P> not2(const P& pred); -template <AdaptableBinaryFunction P> -requires Predicate< P, P::first_argument_type, P::second_argument_type > -binary_negate<P> not2(P&& pred); ----5- Returns: binary_negate<P>(pred). -
--[Don't we want a move call for the second overload as in -
--binary_negate<P>(std::move(pred)) --in the Returns clause ?] -
-
[ -Batavia (2009-05): -]
- --- --There is concern that complicating the solution -to preserve the ABI seems unnecessary, -since we're not in general preserving the ABI. -
--We would prefer a separate paper consolidating all Clause 20 -issues that are for the purpose of providing constrained versions -of the existing facilities. -
--Move to Open. -
-
[ -2009-10 post-Santa Cruz: -]
- - --Leave open pending the potential move constructor paper. Note that -we consider the "constraining" part NAD Concepts. -- - - -
Proposed resolution:
--Add new concepts where appropriate:: -
- -auto concept AdaptableUnaryFunction< typename X > {
- typename X::result_type;
- typename X::argument_type;
-}
-
-auto concept AdaptableBinaryFunction< typename X > {
- typename X::result_type;
- typename X::first_argument_type;
- typename X::second_argument_type;
-}
--Revise as follows: -
- --Base 20.7.3 [base] (Only change is constrained Result) -
- --- ---1- The following classes are provided to simplify the typedefs of the -argument and result types: -
-namespace std { - template <class Arg,classReturnType Result> - struct unary_function { - typedef Arg argument_type; - typedef Result result_type; - }; - - template <class Arg1, class Arg2,classReturnType Result> - struct binary_function { - typedef Arg1 first_argument_type; - typedef Arg2 second_argument_type; - typedef Result result_type; - }; -} -
-Negators 20.7.10 [negators]: -
- --- - - - - - ---1- Negators not1 and not2 take a unary and a binary predicate, -respectively, and return their complements (5.3.1). -
- -template <-classAdaptableUnaryFunction Predicate> - requires Predicate< P, P::argument_type > - class unary_negate - : public unary_function<typenamePredicate::argument_type,bool> { - public: - unary_negate(const unary_negate & ) = default; - unary_negate(unary_negate && ); - - requires CopyConstructible< P > - explicit unary_negate(const Predicate& pred); - requires MoveConstructible< P > - explicit unary_negate(Predicate && pred); - - bool operator()(consttypenamePredicate::argument_type& x) const; - }; ---2 operator() returns !pred(x). -- -template <class Predicate> - unary_negate<Predicate> not1(const Predicate& pred); -template <class Predicate> - unary_negate<Predicate> not1(Predicate&& pred); ----3- Returns: unary_negate<Predicate>(pred). -- -template <-classAdaptableBinaryFunction Predicate> - requires Predicate< P, P::first_argument_type, P::second_argument_type > - class binary_negate - : public binary_function<typenamePredicate::first_argument_type, -typenamePredicate::second_argument_type, bool> { - public: - biary_negate(const binary_negate & ) = default; - binary_negate(binary_negate && ); - - requires CopyConstructible< P > - explicit binary_negate(const Predicate& pred); - requires MoveConstructible< P > - explicit binary_negate(const Predicate& pred); - - bool operator()(consttypenamePredicate::first_argument_type& x, - consttypenamePredicate::second_argument_type& y) const; - }; ---4- operator() returns !pred(x,y). -- -template <class Predicate> - binary_negate<Predicate> not2(const Predicate& pred); -template <class Predicate> - binary_negate<Predicate> not2(Predicate&& pred); -- ---5- Returns: binary_negate<Predicate>(pred). --
RandomAccessIterator's operator- has nonsensical effects clauseSection: 24.2.5 [random.access.iterators] Status: Ready - Submitter: Doug Gregor Opened: 2009-03-20 Last modified: 2009-10-23
-View all other issues in [random.access.iterators].
-View all issues with Ready status.
-Discussion:
-Addresses UK 265
- -UK-265:
--This effects clause is nonesense. It looks more like an axiom stating -equivalence, and certainly an effects clause cannot change the state of -two arguments passed by const reference -
- -[ -2009-09-18 Alisdair adds: -]
- - --- --For random access iterators, the definitions of (b-a) and -(a<b) are circular: -
- --From table Table 104 -- Random access iterator requirements: -
- --b - a :==> (a < b) ? distance(a,b) : -distance(b,a) - -a < b :==> b - a > 0 -
[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
- -Modify 24.2.5 [random.access.iterators]p7-9 as follows:
- -- - - - - -difference_type operator-(const X& a, const X& b); ---
-- Precondition: there exists a value
-nof -difference_typesuch thata == b + n.- -
Effects:b == a + (b - a)- Returns:
-(a < b) ? distance(a,b) : - -distance(b,a)n
Section: 30 [thread] Status: Open - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-10-23
-View all other issues in [thread].
-View all issues with Open status.
-Discussion:
-Addresses JP 76
- --A description for "Throws: Nothing." are not unified. -
- --At the part without throw, "Throws: Nothing." should be described. -
- --Add "Throws: Nothing." to the following. -
- -[ -Summit: -]
- --Pass on to editor. -- -
[ -Post Summit: Editor declares this non-editorial. -]
- - -[ -2009-08-01 Howard provided wording: -]
- - -- -- --The definition of "Throws: Nothing." that I added is probably going to -be controversial, but I beg you to consider it seriously. -
- --- --In C++ there are three "flow control" options for a function: -
- --
- -The above list can be abbreviated with: - -- -It can return, either with a value, or with void. -
-- -It can call a function which never returns, such as std::exit or -std::terminate. -
-- -It can throw an exception. -
--
- -- Returns.
-- Ends program.
-- Throws exception.
--In general a function can have the behavior of any of these 3, or any combination -of any of these three, depending upon run time data. -
- --
- -- R
-- E
-- T
-- RE
-- RT
-- ET
-- RET
--A function with no throw spec, and no documentation, is in general a RET -function. It may return, it may end the program, or it may throw. When we -specify a function with an empty throw spec: -
- -- -void f() throw(); --We are saying that f() is an RE function: It may return or end -the program, but it will not throw. -
- --I posit that there are very few places in the library half of the standard -where we intend for functions to be able to end the program (call terminate). -And none of those places where we do say terminate could be called, -do we currently say "Throws: Nothing.". -
- --I believe that if we define "Throws: Nothing." to mean R, -we will both clarify many, many places in the standard, and give us a -good rationale for choosing between "Throws: Nothing." (R) -and throw() (RE) in the future. Indeed, this may give us motivation -to change several throw()s to "Throws: Nothing.". -
--I did not add the following changes as JP 76 requested as I believe we want to -allow these functions to throw: -
- --- --Add a paragraph under 30.4.3.1 [thread.lock.guard] p4: -
- -- -explicit lock_guard(mutex_type& m); -- --Throws: Nothing. -
--Add a paragraph under 30.4.3.2.1 [thread.lock.unique.cons] p6: -
- -- -explicit unique_lock(mutex_type& m); -- --Throws: Nothing. -
--Add a paragraph under 30.5.2 [thread.condition.condvarany] p19, p21 and p25: -
- -- -template <class Lock, class Rep, class Period> - bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time); -- --Throws: Nothing. -
-- -template <class Lock, class Duration, class Predicate> - bool wait_until(Lock& lock, const chrono::time_point<Clock, Duration>& rel_time, Predicate pred); -- --Throws: Nothing. -
-- -template <class Lock, class Rep, class Period, class Predicate> - bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred); -- --Throws: Nothing. -
-
[ -2009-10 Santa Cruz: -]
- - --Defer pending further developments with exception restriction annotations. -- - - -
Proposed resolution:
--Add a paragraph after 17.5.1.4 [structure.specifications] p4: -
- --- ---3- Descriptions of function semantics contain the following elements -(as appropriate):158 -
--
- -- ...
-- -Throws: any exceptions thrown by the function, and the conditions -that would cause the exception -
-- ...
---4- For non-reserved replacement and handler functions, ... -
- --A "Throws: Nothing." element indicates that the function shall -return ordinarily, and not exit via an exception. This element also -indicates that the function shall return. [Note: This -differs from an empty throw specification which may cause a function to -call unexpected and subsequently terminate. — -end note] -
-
-Add a paragraph under 30.3.1.6 [thread.thread.static] p1: -
- -- -unsigned hardware_concurrency(); -- ---1- Returns: ... -
- --Throws: Nothing. -
-
-Add a paragraph under 30.5.1 [thread.condition.condvar] p7 and p8: -
- --- --[Informational, not to be incluced in the WP: The POSIX spec allows only: -
--
- -- [EINVAL]
-- The value cond does not refer to an initialized condition variable. — end informational]
-void notify_one(); -- ---7- Effects: ... -
- --Throws: Nothing. -
-
- - -void notify_all(); -- ---8- Effects: ... -
- --Throws: Nothing. -
-
-Add a paragraph under 30.5.2 [thread.condition.condvarany] p6 and p7: -
- --- -void notify_one(); -- ---6- Effects: ... -
- --Throws: Nothing. -
-
- - - - - - - -void notify_all(); -- ---7- Effects: ... -
- --Throws: Nothing. -
-
Section: 30.6.10 [futures.task] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-03-22 Last modified: 2009-10-26
-View all issues with Tentatively Ready status.
-Discussion:
--Class template packaged_task in 30.6.10 [futures.task] shows a member swap -declaration, but misses to -document it's effects (No prototype provided). Further on this class -misses to provide a non-member -swap. -
- -[ -Batavia (2009-05): -]
- --- --Alisdair notes that paragraph 2 of the proposed resolution has already been -applied in the current Working Draft. -
--We note a pending future-related paper by Detlef; -we would like to wait for this paper before proceeding. -
--Move to Open. -
-
[ -2009-05-24 Daniel removed part 2 of the proposed resolution. -]
- - -[ -2009-10 post-Santa Cruz: -]
- - --Move to Tentatively Ready, removing bullet 3 from the proposed -resolution but keeping the other two bullets. -- - - -
Proposed resolution:
--In 30.6.10 [futures.task], immediately after the definition of class -template packaged_task add: -
---template<class R, class... Argtypes> -void swap(packaged_task<R(ArgTypes...)>&, packaged_task<R(ArgTypes...)>&); - -
-At the end of 30.6.10 [futures.task] (after p. 20), add add the following -prototype description: -
- ---template<class R, class... Argtypes> -void swap(packaged_task<R(ArgTypes...)>& x, packaged_task<R(ArgTypes...)>& y); -----Effects: x.swap(y) -
--Throws: Nothing. -
-
Section: 25.3.12 [alg.random.shuffle] Status: Open - Submitter: Alisdair Meredith Opened: 2009-03-22 Last modified: 2009-10-26
-View all other issues in [alg.random.shuffle].
-View all issues with Open status.
-Discussion:
- --There are a couple of issues with the declaration of the random_shuffle -algorithm accepting a random number engine. -
- -[ -2009-05-02 Daniel adds: -]
- - --- --this issue completes adding necessary requirement to the -third new random_shuffle overload. The current suggestion is: -
- -- -template<RandomAccessIterator Iter, UniformRandomNumberGenerator Rand> -requires ShuffleIterator<Iter> -void random_shuffle(Iter first, Iter last, Rand&& g); --IMO this is still insufficient and I suggest to add the requirement -
--Convertible<Rand::result_type, Iter::difference_type> --to the list (as the two other overloads already have). -
- --Rationale: -
- --- --Its true that this third overload is somewhat different from the remaining -two. Nevertheless we know from UniformRandomNumberGenerator, that -it's result_type is an integral type and that it satisfies -UnsignedIntegralLike<result_type>. -
--To realize it's designated task, the algorithm has to invoke the -Callable aspect of g and needs to perform some algebra involving -it's min()/max() limits to compute another index value that -at this point is converted into Iter::difference_type. This is so, -because 24.2.5 [random.access.iterators] uses this type as argument -of it's algebraic operators. Alternatively consider the equivalent -iterator algorithms in 24.4.4 [iterator.operations] with the same result. -
--This argument leads us to the conclusion that we also need -Convertible<Rand::result_type, Iter::difference_type> here. -
-
[ -Batavia (2009-05): -]
- --- --Alisdair notes that point (ii) has already been addressed. -
--We agree with the proposed resolution to point (i) -with Daniel's added requirement. -
--Move to Review. -
-
[ -2009-06-05 Daniel updated proposed wording as recommended in Batavia. -]
- - -[ -2009-07-28 Alisdair adds: -]
- - --Revert to Open, with a note there is consensus on direction but the -wording needs updating to reflect removal of concepts. -- -
[ -2009-10 post-Santa Cruz: -]
- - --Leave Open, Walter to work on it. -- - - -
Proposed resolution:
--Change in [algorithms.syn] and 25.3.12 [alg.random.shuffle]: -
- -- - - - - - -concept UniformRandomNumberGenerator<typename Rand> { }-template<RandomAccessIterator Iter, UniformRandomNumberGenerator Rand> - requires ShuffleIterator<Iter> && - Convertible<Rand::result_type, Iter::difference_type> - void random_shuffle(Iter first, Iter last, Rand&& g); -
Section: 27.5.4.3 [iostate.flags] Status: Ready - Submitter: P.J. Plauger Opened: 2009-03-24 Last modified: 2009-10-20
-View all other issues in [iostate.flags].
-View all issues with Ready status.
-Discussion:
-Addresses JP 65 and JP 66
- --Switch from "unspecified-bool-type" to "explicit operator bool() const". -
- --Replace operator unspecified-bool-type() const;" with explicit operator bool() const; -
- -[ -Batavia (2009-05): -]
- --We agree with the proposed resolution. -Move to Review. -- -
[ -2009 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
--Change the synopis in 27.5.4 [ios]: -
- -- -explicit operatorunspecified-bool-typebool() const; -
-Change 27.5.4.3 [iostate.flags]: -
- -- - - - - - - -explicit operator- -unspecified-bool-typebool() const; -----1- Returns: !fail()
-If fail() then a value that will evaluate -false in a boolean context; otherwise a value that will evaluate true in -a boolean context. The value type returned shall not be convertible to -int.--
-[Note: This conversion can be used in contexts where a bool is expected -(e.g., an if condition); however, implicit conversions (e.g., -to int) that can occur with bool are not allowed, -eliminating some sources of user error. One possible implementation -choice for this type is pointer-to-member. -- end note]-
Section: 17.6.3.10 [res.on.objects] Status: Ready - Submitter: Beman Dawes Opened: 2009-03-27 Last modified: 2009-10-21
-View all issues with Ready status.
-Discussion:
--N2775, -Small library thread-safety revisions, among other changes, removed a note from -17.6.3.10 [res.on.objects] that read: -
- --[Note: This prohibition against concurrent non-const access means that -modifying an object of a standard library type shared between threads -without using a locking mechanism may result in a data race. --end note.] -- -
-That resulted in wording which is technically correct but can only be -understood by reading the lengthy and complex 17.6.4.8 [res.on.data.races] -Data race avoidance. This has the effect of making -17.6.3.10 [res.on.objects] unclear, and has already resulted in a query -to the LWG reflector. See c++std-lib-23194. -
- -[ -Batavia (2009-05): -]
- --- --The proposed wording seems to need a bit of tweaking -("really bad idea" isn't quite up to standardese). -We would like feedback -as to whether the original Note's removal was intentional. -
--Change the phrase "is a really bad idea" -to "risks undefined behavior" and -move to Review status. -
-
[ -2009-10 Santa Cruz: -]
- - --Note: Change to read: "Modifying...", Delete 'thus', move to Ready -- - - -
Proposed resolution:
--Change 17.6.3.10 [res.on.objects] as indicated: -
- --- - - - - --The behavior of a program is undefined if calls to standard library -functions from different threads may introduce a data race. The -conditions under which this may occur are specified in 17.6.4.7. -
--[Note: Modifying an object of a standard library type shared between -threads risks undefined behavior unless objects of the type are explicitly -specified as being sharable without data races or the user supplies a -locking mechanism. --end note] -
-
Section: 18.2 [support.types] Status: Ready - Submitter: Jens Maurer Opened: 2009-04-03 Last modified: 2009-10-21
-View all other issues in [support.types].
-View all issues with Ready status.
-Discussion:
-Addresses DE 18
- --Freestanding implementations do not (necessarily) have - support for multiple threads (see 1.10 [intro.multithread]). - Applications and libraries may want to optimize for the - absence of threads. I therefore propose a preprocessor - macro to indicate whether multiple threads can occur. -
- --There is ample prior implementation experience for this - feature with various spellings of the macro name. For - example, gcc implicitly defines _REENTRANT - if multi-threading support is selected on the compiler - command-line. -
- --While this is submitted as a library issue, it may be more - appropriate to add the macro in 16.8 cpp.predefined in the - core language. -
- --See also -N2693. -
- -[ -Batavia (2009-05): -]
- --- --We agree with the issue, and believe it is properly a library issue. -
--We prefer that the macro be conditionally defined -as part of the <thread> header. -
--Move to Review. -
-
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Insert a new subsection before 18.2 [support.types], entitled -"Feature Macros" (support.macros): -
--- - - - - - --The standard library defines the following macros; no explicit -prior inclusion of any header file is necessary. -
----
-- __STDCPP_THREADS
-- -The macro __STDCPP_THREADS shall be defined if and only if a - program can have more than one thread of execution (1.10 [intro.multithread]). -If the macro is defined, it shall have the same - value as the predefined macro __cplusplus (16.8 [cpp.predefined]). -
-
Section: 20.8.15.6 [util.dynamic.safety] Status: Ready - Submitter: Jens Maurer Opened: 2009-04-03 Last modified: 2009-10-23
-View all other issues in [util.dynamic.safety].
-View all issues with Ready status.
-Discussion:
-Addresses DE 18
- -- In 20.8.15.6 [util.dynamic.safety], get_pointer_safety() purports -to define behavior for - non-safely derived pointers (3.7.4.3 [basic.stc.dynamic.safety]). However, - the cited core-language section in paragraph 4 specifies undefined behavior - for the use of such pointer values. This seems an unfortunate near-contradiction. - I suggest to specify the term relaxed pointer safety in - the core language section and refer to it from the library description. - This issue deals with the library part, the corresponding core issue (c++std-core-13940) - deals with the core modifications. -
- --See also -N2693. -
- -[ -Batavia (2009-05): -]
- --- --We recommend if this issue is to be moved, -the issue be moved concurrently with the cited Core issue. -
--We agree with the intent of the proposed resolution. -We would like input from garbage collection specialists. -
--Move to Open. -
-
[ -2009-10 Santa Cruz: -]
- - --The core issue is 853 and is in Ready status. -- - - -
Proposed resolution:
--In 20.8.15.6 [util.dynamic.safety] p16, replace the description of -get_pointer_safety() with: -
- --- - - - - --pointer_safety get_pointer_safety(); -
----
-Returns: an enumeration value indicating the implementation's treatment -of pointers that are not safely derived (3.7.4.3). Returns -pointer_safety::relaxed if pointers that are not safely derived will be -treated the same as pointers that are safely derived for the duration of -the program. Returns pointer_safety::preferred if pointers that are not -safely derived will be treated the same as pointers that are safely -derived for the duration of the program but allows the implementation to -hint that it could be desirable to avoid dereferencing pointers that are -not safely derived as described. [Example: pointer_safety::preferred -might be returned to detect if a leak detector is running to avoid -spurious leak reports. -- end note] Returns pointer_safety::strict if -pointers that are not safely derived might be treated differently than -pointers that are safely derived.--Returns: Returns pointer_safety::strict if the implementation has - strict pointer safety (3.7.4.3 [basic.stc.dynamic.safety]). It is - implementation-defined whether get_pointer_safety returns - pointer_safety::relaxed or pointer_safety::preferred if the - implementation has relaxed pointer safety - (3.7.4.3 [basic.stc.dynamic.safety]).Footnote -
- --Throws: nothing -
- --Footnote) pointer_safety::preferred might be returned to indicate to the - program that a leak detector is running so that the program can avoid - spurious leak reports. - -
- -
Section: 17 [library] Status: Tentatively NAD - Submitter: David Abrahams Opened: 2009-03-21 Last modified: 2009-10-26
-View other active issues in [library].
-View all other issues in [library].
-View all issues with Tentatively NAD status.
-Discussion:
--Notes -
--- --[2009-03-21 Sat] p. 535 at the top we need MoveConstructible V1, -MoveConstructible V2 (where V1,V2 are defined on 539). Also make_tuple -on 550 -
- --- --CD-1 reads: -
- -- -template <MoveConstructible T1, MoveConstructible T2> -pair<V1, V2> make_pair(T1&&, T2&&); --Actually I'm guessing we need something like MoveConstructible<V1,T1>, -i.e. "V1 can be constructed from an rvalue of type T1." -
- --Ditto for make_tuple -
--[2009-03-21 Sat] p1183 thread ctor, and in general, we need a way to -talk about "copiable from generalized rvalue ref argument" for cases -where we're going to forward and copy. -
---- This issue may well be quite large. Language in para 4 about "if - an lvalue" is wrong because types aren't expressions. -
- --- --Maybe we should define the term "move" so we can just say in the -effects, "f is moved into the newly-created thread" or something, and -agree (and ideally document) that saying "f is moved" implies -
- -- -F x(move(f)) --is required to work. That would cover both ctors at once. -
-- p1199, call_once has all the same issues. -
--[2009-03-21 Sat] p869 InputIterator pointer type should not be required -to be convertible to const value_type*, rather it needs to have a -operator-> of its own that can be used for the value type. -
- --This one is serious and unrelated to the move issue. -- --[2009-03-21 Sat] p818 stack has the same problem with default ctor. -
--[2009-03-21 Sat] p816 priority_queue has the same sorts of problems as queue, only more so -
--requires MoveConstructible<Cont> - explicit priority_queue(const Compare& x = Compare(), Cont&& = Cont()); --- Don't require MoveConstructible when default constructing Cont. - Also missing semantics for move ctor. -
-- [2009-03-21 Sat] Why are Allocators required to be CopyConstructible as - opposed to MoveConstructible? -
-- [2009-03-21 Sat] p813 queue needs a separate default ctor (Cont needn't - be MoveConstructible). No documented semantics for move c'tor. Or - *any* of its 7 ctors! -
-- [2009-03-21 Sat] std::array should have constructors for C++0x, - consequently must consider move construction. -
- -[ -2009-05-01 Daniel adds: -]
- - --This could be done as part of 1035, which already handles -deviation of std::array from container tables. -- -- [2009-03-21 Sat] p622 all messed up. -
--- -- para 8 "implementation-defined" is the wrong term; should be "see - below" or something. -
-- para 12 "will be selected" doesn't make any sense because we're not - talking about actual arg types. -
-- paras 9-13 need to be totally rewritten for concepts. -
-- [2009-03-21 Sat] Null pointer comparisons (p587) have all become - unconstrained. Need to fix that -
-- [2009-03-21 Sat] mem_fun_t etc. definition doesn't match declaration. - We think CopyConstructible is the right reqt. -
-- make_pair needs Constructible<V1, T1&&> requirements! -
-- make_tuple needs something similar -
-- tuple bug in synopsis: -
-- -template <class... UTypes> - requires Constructible<Types, const UTypes&>... - template <class... UTypes> - requires Constructible<Types, RvalueOf<UTypes>::type>... --- Note: removal of MoveConstructible requirements in std::function makes - these routines unconstrained! -
-[ -2009-05-02 Daniel adds: -]
- - --This part of the issue is already covered by 1077. -- -- these unique_ptr constructors are broken [ I think this is covered in "p622 all messed up" ] -
--unique_ptr(pointer p, implementation-defined d); - unique_ptr(pointer p, implementation-defined d); -- multimap range constructor should not have MoveConstructible<value_type> requirement. -
-- same with insert(..., P&&); multiset has the same issue, as do - unordered_multiset and unordered_multimap. Review these! -- -
[ -Batavia (2009-05): -]
- --Move to Open, pending proposed wording from Dave for further review. -- -
[ -2009-10 post-Santa Cruz: -]
- - --Tentatively NAD. We are not sure what has been addressed and what hasn't. -Recommend closing unless someone sorts this out into something more readable. -- - - -
Proposed resolution:
--
- - - - - -Section: 20.8.14.2.1 [unique.ptr.single.ctor] Status: Ready - Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2009-10-21
-View other active issues in [unique.ptr.single.ctor].
-View all other issues in [unique.ptr.single.ctor].
-View all issues with Ready status.
-Discussion:
--Message c++std-lib-23182 led to a discussion in which several people -expressed interest in being able to convert an auto_ptr to a -unique_ptr without the need to call release. Below is -wording to accomplish this. -
- -[ -Batavia (2009-05): -]
- --- --Pete believes it not a good idea to separate parts of a class's definition. -Therefore, if we do this, -it should be part of unique-ptr's specification. -
--Alisdair believes the lvalue overload may be not necessary. -
--Marc believes it is more than just sugar, -as it does ease the transition to unique-ptr. -
--We agree with the resolution as presented. -Move to Tentatively Ready. -
-
[ -2009-07 Frankfurt -]
- - --Moved from Tentatively Ready to Open only because the wording needs to be -tweaked for concepts removal. -- -
[ -2009-08-01 Howard deconceptifies wording: -]
- - --I also moved the change from D.10 [depr.auto.ptr] -to 20.8.14.2 [unique.ptr.single] per the Editor's request -in Batavia (as long as I was making changes anyway). Set back -to Review. -- -
[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Add to 20.8.14.2 [unique.ptr.single]: -
- -template <class T, class D>
-class unique_ptr
-{
-public:
- template <class U>
- unique_ptr(auto_ptr<U>& u);
- template <class U>
- unique_ptr(auto_ptr<U>&& u);
-};
--Add to 20.8.14.2.1 [unique.ptr.single.ctor]: -
- -- - - - - - -template <class U> - unique_ptr(auto_ptr<U>& u); -template <class U> - unique_ptr(auto_ptr<U>&& u); -----Effects: Constructs a unique_ptr with u.release(). -
- --Postconditions: get() == the value u.get() had before -the construciton, modulo any required offset adjustments resulting from the cast from -U* to T*. u.get() == nullptr. -
- --Throws: nothing. -
- --Remarks: U* shall be implicitly convertible to T* and -D shall be the same type as default_delete<T>, else these -constructors shall not participate in overload resolution. -
-
Section: 27.5.4.2 [basic.ios.members] Status: Ready - Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2009-10-20
-View other active issues in [basic.ios.members].
-View all other issues in [basic.ios.members].
-View all issues with Ready status.
-Discussion:
--With the rvalue reference changes in -N2844 -basic_ios::move no longer has the most convenient signature: -
- -- -void move(basic_ios&& rhs); -
-This signature should be changed to accept lvalues. It does not need to be -overloaded to accept rvalues. This is a special case that only derived clients -will see. The generic move still needs to accept rvalues. -
- -[ -Batavia (2009-05): -]
- --- --Tom prefers, on general principles, to provide both overloads. -Alisdair agrees. -
--Howard points out that there is no backward compatibility issue -as this is new to C++0X. -
--We agree that both overloads should be provided, -and Howard will provide the additional wording. -Move to Open. -
-
[ -2009-05-23 Howard adds: -]
- - --Added overload, moved to Review. -- -
[ -2009 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Add a signature to the existing prototype in the synopsis of 27.5.4 [ios] -and in 27.5.4.2 [basic.ios.members]: -
- -- - - - - -void move(basic_ios& rhs); -void move(basic_ios&& rhs); -
Section: 30.6.7 [future.shared_future] Status: Open - Submitter: Thomas J. Gritzan Opened: 2009-04-03 Last modified: 2009-05-23
-View all other issues in [future.shared_future].
-View all issues with Open status.
-Discussion:
--It is not clear, if multiple threads are waiting in a -shared_future::get() call, if each will rethrow the stored exception. -
--Paragraph 9 reads: -
--Throws: the stored exception, if an exception was stored and not -retrieved before. --
-The "not retrieved before" suggests that only one exception is thrown, -but one exception for each call to get() is needed, and multiple calls -to get() even on the same shared_future object seem to be allowed. -
--I suggest removing "and not retrieved before" from the Throws paragraph. -I recommend adding a note that explains that multiple calls on get() are -allowed, and each call would result in an exception if an exception was -stored. -
- -[ -Batavia (2009-05): -]
- --- - --We note there is a pending paper by Detlef -on such future-related issues; -we would like to wait for his paper before proceeding. -
--Alisdair suggests we may want language to clarify that this -get() function can be called from several threads -with no need for explicit locking. -
--Move to Open. -
-
Proposed resolution:
--Change 30.6.7 [future.shared_future]: -
- -- - - - - - -const R& shared_future::get() const; -R& shared_future<R&>::get() const; -void shared_future<void>::get() const; ----...
---9- Throws: the stored exception, if an exception was stored
-and not retrieved before. - -[Note: Multiple calls on get() are -allowed, and each call would result in an exception if an exception was -stored. — end note] - -
Section: 30.2.2 [thread.req.exception] Status: Tentatively Ready - Submitter: Christopher Kohlhoff Opened: 2009-04-25 Last modified: 2009-10-26
-View all issues with Tentatively Ready status.
-Discussion:
--The current formulation of 30.2.2 [thread.req.exception]/2 reads: -
--The error_category of the error_code reported by such an -exception's code() member function is as specified in the error -condition Clause. --
-This constraint on the code's associated error_categor means an -implementation must perform a mapping from the system-generated -error to a generic_category() error code. The problems with this -include: -
- --The original error produced by the operating system is lost. -
--The latter was one of Peter Dimov's main objections (in a private -email discussion) to the original error_code-only design, and led to -the creation of error_condition in the first place. Specifically, -error_code and error_condition are intended to perform the following -roles: -
--Any mapping determining correspondence of the returned error code to -the conditions listed in the error condition clause falls under the -"latitude" granted to implementors in 19.5.1.5 [syserr.errcat.objects]. -(Although obviously their latitude is restricted a little by the -need to match the right error condition when returning an error code -from a library function.) -
--It is important that this error_code/error_condition usage is done -correctly for the thread library since it is likely to set the -pattern for future TR libraries that interact with the operating -system. -
- -[ -Batavia (2009-05): -]
- --Move to Open, and recommend the issue be deferred until after the next -Committee Draft is issued. -- -
[ -2009-10 post-Santa Cruz: -]
- - --Move to Tentatively Ready. -- - - -
Proposed resolution:
--Change 30.2.2 [thread.req.exception]/2: -
- --- - - - - - ---2-
-The error_category (19.5.1.1) of the error_code reported by -such an exception's code() member function -is as specified in the error condition Clause.- -The error_code reported by such an exception's code() member -function shall compare equal to one of the conditions specified in -the function's error condition Clause. [Example: When the thread -constructor fails: - -- --ec.category() == implementation-defined // probably system_category -ec == errc::resource_unavailable_try_again // holds true --— end example] -
- -
Section: 25.2.4 [alg.foreach] Status: Open - Submitter: Alisdair Meredith Opened: 2009-04-29 Last modified: 2009-10-27
-View all other issues in [alg.foreach].
-View all issues with Open status.
-Discussion:
--Quoting working paper for reference (25.2.4 [alg.foreach]): -
- --- -template<InputIterator Iter, Callable<auto, Iter::reference> Function> - requires CopyConstructible<Function> - Function for_each(Iter first, Iter last, Function f); -----1 Effects: Applies f to the result of dereferencing every iterator in the - range [first,last), starting from first and proceeding to last - 1. -
--2 Returns: f. -
--3 Complexity: Applies f exactly last - first times. -
-
-P2 implies the passed object f should be invoked at each stage, rather than -some copy of f. This is important if the return value is to usefully -accumulate changes. So the requirements are an object of type Function can -be passed-by-value, invoked multiple times, and then return by value. In -this case, MoveConstructible is sufficient. This would open support for -move-only functors, which might become important in concurrent code as you -can assume there are no other references (copies) of a move-only type and so -freely use them concurrently without additional locks. -
- -[ -See further discussion starting with c++std-lib-23686. -]
- - -[ -Batavia (2009-05): -]
- --- --Pete suggests we may want to look at this in a broader context -involving other algorithms. -We should also consider the implications of parallelism. -
--Move to Open, and recommend the issue be deferred until after the next -Committee Draft is issued. -
-
[ -2009-10-14 Daniel de-conceptified the proposed resolution. -]
- - --- --The note in 25.1 [algorithms.general]/9 already says the right thing: -
--Unless otherwise specified, algorithms that take function objects -as arguments are permitted to copy those function objects freely. ---So we only need to ensure that the wording for for_each is sufficiently -clear, which is the intend of the following rewording. -
-
[ -2009-10-15 Daniel proposes: -]
- - --- --
-- -
--Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]): -
----Requires: Function shall be MoveConstructible -( [moveconstructible]), CopyConstructible is not required. -
-- -
--Change 25.2.4 [alg.foreach]/2 as indicated: -
- --Returns: std::move(f). --
[ -2009-10 post-Santa Cruz: -]
- - --Move to Tentatively Ready, using Daniel's wording without the portion -saying "CopyConstructible is not required". -- -
[ -2009-10-27 Daniel adds: -]
- - --- - - --I see that during the Santa Cruz meeting the originally proposed addition -
- --, CopyConstructible is not required. -- --was removed. I don't think that this removal was a good idea. The combination -of 25.1 [algorithms.general]/9 -
- --[Note: Unless otherwise specified, algorithms that take function objects -as arguments are permitted to copy those function objects freely.[..] -- --with the fact that CopyConstructible is a refinement MoveConstructible -makes it necessary that such an explicit statement is given. Even the -existence of the usage of std::move in the Returns clause doesn't -help much, because this would still be well-formed for a CopyConstructible -without move constructor. Let me add that the originally proposed -addition reflects current practice in the standard, e.g. 25.3.9 [alg.unique]/5 -usages a similar terminology. -
- --For similar wording need in case for auto_ptr see 973. -
- -[ -Howard: Moved from Tentatively Ready to Open. -]
- -
Proposed resolution:
--Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]): -
----Requires: Function shall be MoveConstructible -( [moveconstructible]). -
-
-Change 25.2.4 [alg.foreach]/2 as indicated: -
- --Returns: std::move(f). --
Section: 20.3.7 [template.bitset] Status: Tentatively NAD Future - Submitter: Alisdair Meredith Opened: 2009-05-06 Last modified: 2009-10-26
-View other active issues in [template.bitset].
-View all other issues in [template.bitset].
-View all issues with Tentatively NAD Future status.
-Discussion:
--Std::bitset is a homogeneous container-like sequence of bits, yet it does -not model the Range concept so cannot be used with the new for-loop syntax. -It is the only such type in the library that does NOT support the new for -loop. -
--The obvious reason is that bitset does not support iterators. -
--At least two reasonable solutions are available: -
--The latter will still need some kind of iterator-like adapter for bitset, -but gives implementers greater freedom on the details. E.g. begin/end return -some type that simply invokes operator[] on the object it wraps, and -increments its index on operator++. A vendor can settle for InputIterator -support, rather than wrapping up a full RandomAccessIterator. -
--I have a mild preference for option (ii) as I think it is less work to -specify at this stage of the process, although (i) is probably more useful -in the long run. -
--Hmm, my wording looks a little woolly, as it does not say what the element -type of the range is. Do I get a range of bool, bitset<N>::reference, or -something else entirely? -
--I guess most users will assume the behaviour of reference, but expect to -work with bool. Bool is OK for read-only traversal, but you really need to -take a reference to a bitset::reference if you want to write back. -
- -[ -Batavia (2009-05): -]
- --Move to Open. -We further recommend this be deferred until after the next Committee Draft. -- -
[ -2009-05-25 Alisdair adds: -]
- - --- --I just stumbled over the Range concept_map for valarray and this should -probably set the precedent on how to write the wording. -
- -[ -Howard: I've replaced the proposed wording with Alisdair's suggestion. -]
- - -
[ -2009-07-24 Daniel modifies the proposed wording for non-concepts. -]
- - -[ -2009-10 post-Santa Cruz: -]
- - --Mark as Tentatively NAD Future due to the loss of concepts. -- - - -
Proposed resolution:
--Modify the section 20.3.7 [template.bitset] <bitset> synopsis by adding -the following at the end of the synopsis: -
---// XX.X.X bitset range access [bitset.range] -template<size_t N> unspecified-1 begin(bitset<N>&); -template<size_t N> unspecified-2 begin(const bitset<N>&); -template<size_t N> unspecified-1 end(bitset<N>&); -template<size_t N> unspecified-2 end(const bitset<N>&); - -
-Add a new section "bitset range access" [bitset.range] -after the current section 20.3.7.3 [bitset.operators] with the following series of -paragraphs: -
---- -1. In the begin and end function templates that follow, unspecified-1 -is a type that meets the requirements of a mutable random access -iterator (24.2.5 [random.access.iterators]) whose value_type is bool and -whose reference type is bitset<N>::reference. -unspecified-2 is a type that meets the requirements of a constant -random access iterator (24.2.5 [random.access.iterators]) whose value_type -is bool and whose reference type is bool. - -
--template<size_t N> unspecified-1 begin(bitset<N>&); -template<size_t N> unspecified-2 begin(const bitset<N>&); - ---2. Returns: an iterator referencing the first bit in the bitset. -- --template<size_t N> unspecified-1 end(bitset<N>&); -template<size_t N> unspecified-2 end(const bitset<N>&); -- --3. Returns: an iterator referencing one past the last bit in the -bitset. --
Section: 20.3.7 [template.bitset] Status: Tentatively Ready - Submitter: Alisdair Meredith Opened: 2009-05-09 Last modified: 2009-10-26
-View other active issues in [template.bitset].
-View all other issues in [template.bitset].
-View all issues with Tentatively Ready status.
-Discussion:
--In 853 our resolution is changing the signature by adding two -defaulting arguments to 3 calls. In principle, this means that ABI breakage -is not an issue, while API is preserved. -
--With that observation, it would be very nice to use the new ability to -supply default template parameters to function templates to collapse all 3 -signatures into 1. In that spirit, this issue offers an alternative resolution -than that of 853. -
- -[ -Batavia (2009-05): -]
- --Move to Open, -and look at the issue again after 853 has been accepted. -We further recommend this be deferred until after the next Committee Draft. -- -
[ -2009-10 post-Santa Cruz: -]
- - --Move to Tentatively Ready. -- - - -
Proposed resolution:
- --In 20.3.7 [template.bitset]/1 (class bitset) ammend: -
-template <class charT = char,
- class traits = char_traits<charT>,
- class Allocator = allocator<charT>>
- basic_string<charT, traits, Allocator>
- to_string(charT zero = charT('0'), charT one = charT('1')) const;
-template <class charT, class traits>
- basic_string<charT, traits, allocator<charT> > to_string() const;
-template <class charT>
- basic_string<charT, char_traits<charT>, allocator<charT> > to_string() const;
-basic_string<char, char_traits<char>, allocator<char> > to_string() const;
--In 20.3.7.2 [bitset.members] prior to p35 ammend: -
-template <class charT = char,
- class traits = char_traits<charT>,
- class Allocator = allocator<charT>>
- basic_string<charT, traits, Allocator>
- to_string(charT zero = charT('0'), charT one = charT('1')) const;
-Section: 20.6 [meta] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-05-12 Last modified: 2009-10-26
-View all other issues in [meta].
-View all issues with Tentatively Ready status.
-Discussion:
- - - --The current wording in 20.6.1 [meta.rqmts] is still unclear concerning -it's requirements on the type traits classes regarding ambiguities. -Specifically it's unclear -
- -[ -Batavia (2009-05): -]
- --- --Alisdair would prefer to factor some of the repeated text, -but modulo a corner case or two, -he believes the proposed wording is otherwise substantially correct. -
--Move to Open. -
-
[ -2009-10 post-Santa Cruz: -]
- - --Move to Tentatively Ready. -- - - -
Proposed resolution:
-[ -The usage of the notion of a BaseCharacteristic below -might be -useful in other places - e.g. to define the base class relation in -20.7.5 [refwrap], 20.7.14 [func.memfn], or 20.7.15.2 [func.wrap.func]. -In this case it's definition should probably -be moved to Clause 17 -]
- - --Change 20.6.1 [meta.rqmts]/1 as indicated: -
--[..] It shall be DefaultConstructible, CopyConstructible, and publicly -and unambiguously derived, directly or indirectly, from -its BaseCharacteristic, which is a specialization of the -template integral_constant (20.6.3), with the arguments to the template -integral_constant determined by the requirements for the particular -property being described. The member names of the -BaseCharacteristic shall be unhidden and unambiguously -available in the UnaryTypeTrait. --
-Change 20.6.1 [meta.rqmts]/2 as indicated: -
--[..] It shall be DefaultConstructible, CopyConstructible, and publicly -and unambiguously derived, directly or indirectly, from --an instanceits BaseCharacteristic, which is a -specialization of the template integral_constant (20.6.3), with -the arguments to the template integral_constant determined by the -requirements for the particular relationship being described. The -member names of the BaseCharacteristic shall be unhidden -and unambiguously available in the BinaryTypeTrait. -
-Change 20.6.4 [meta.unary]/2 as indicated: -
--Each of these templates shall be a UnaryTypeTrait (20.6.1), --publicly derived directly or indirectly from true_type if the -corresponding condition is true, otherwise from false_type-where its BaseCharacteristic shall be true_type if the -corresponding condition is true, otherwise false_type. -
-Change 20.6.5 [meta.rel]/2 as indicated: -
- --Each of these templates shall be a BinaryTypeTrait (20.6.1), --publicly derived directly or indirectly from true_type if the -corresponding condition is true, otherwise from false_type-where its BaseCharacteristic shall be true_type if the -corresponding condition is true, otherwise false_type. -
Section: C.2 [diff.library] Status: Tentatively NAD Editorial - Submitter: Miles Zhao Opened: 2009-05-23 Last modified: 2009-10-26
-View all other issues in [diff.library].
-View all issues with Tentatively NAD Editorial status.
-Discussion:
--In "Table 122 -- Standard macros" of C.2 [diff.library], which lists the 56 macros -inherited from C library, va_copy seems to be missing. But in -"Table 21 -- Header <cstdarg> synopsis" (18.10 [support.runtime]), there is. -
- -[ -2009-10 post-Santa Cruz: -]
- - --Mark as Tentatively NAD Editorial, if Pete disagrees, Howard -will move to Tentatively Ready -- - - -
Proposed resolution:
--Add va_copy to Table 122 -- Standard macros in C.2 [diff.library]. -
- - - - - -Section: 20.5.2.5 [tuple.helper] Status: Open - Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2009-10-26
-View other active issues in [tuple.helper].
-View all other issues in [tuple.helper].
-View all issues with Open status.
-Discussion:
--The APIs tuple_size and tuple_element do not support -cv-qualified tuples, pairs or arrays. -
--The most generic solution would be to supply partial specializations once -for each cv-type in the tuple header. However, requiring this header for -cv-qualified pairs/arrays seems unhelpful. The BSI editorial -suggestion (UK-198/US-69, -N2533) -to merge tuple into <utility> would help with pair, -but not array. That might be resolved by making a dependency between the -<array> header and <utility>, or simply recognising -the dependency be fulfilled in a Remark. -
- -[ -2009-05-24 Daniel adds: -]
- - --- --All tuple_size templates with a base class need to derive publicly, e.g. -
- -- -template <IdentityOf T> class tuple_size< const T > : - public tuple_size<T> {}; --The same applies to the tuple_element class hierarchies. -
--What is actually meant with the comment -
--this solution relies on 'metafunction forwarding' to inherit the -nested typename type ---? -
--I ask, because all base classes are currently unconstrained and their -instantiation is invalid in the constrained context of the tuple_element partial -template specializations. -
-
[ -2009-05-24 Alisdair adds: -]
- - --- --I think a better solution might be to ask Pete editorially to change all -declarations of tupling APIs to use the struct specifier instead of class. -
--"metafunction forwarding" refers to the MPL metafunction protocol, where a -metafunction result is declared as a nested typedef with the name "type", -allowing metafunctions to be chained by means of inheritance. It is a -neater syntax than repeatedly declaring a typedef, and inheritance syntax is -slightly nicer when it comes to additional typename keywords. -
--The constrained template with an unconstrained base is a good observation -though. -
-
[ -2009-10 post-Santa Cruz: -]
- - --Move to Open, Alisdair to provide wording. Once wording is -provided, Howard will move to Review. -- - - -
Proposed resolution:
--Add to 20.5.1 [tuple.general] p2 (Header <tuple> synopsis) -
- -// 20.5.2.3, tuple helper classes:
-template <IdentityOf T> class tuple_size; // undefined
-template <IdentityOf T> class tuple_size< const T > : tuple_size<T> {};
-template <IdentityOf T> class tuple_size< volatile T > : tuple_size<T> {};
-template <IdentityOf T> class tuple_size< const volatile T > : tuple_size<T> {};
-
-template <VariableType... Types> class tuple_size<tuple<Types...> >;
-
-template <size_t I, IdentityOf T> class tuple_element; // undefined
-template <size_t I, IdentityOf T> class tuple_element<I, const T>;
-template <size_t I, IdentityOf T> class tuple_element<I, volatile T>;
-template <size_t I, IdentityOf T> class tuple_element<I, const volatile T>;
-
-template <size_t I, VariableType... Types>
- requires True<(I < sizeof...(Types))> class tuple_element<I, tuple<Types...> >;
--Add to 20.5.2.5 [tuple.helper] -
-[ -(note that this solution relies on 'metafunction forwarding' to inherit the -nested typename type) -]
- - -template <class... Types>
-class tuple_size<tuple<Types...> >
- : public integral_constant<size_t, sizeof...(Types)> { };
-
-template <size_t I, class... Types>
-requires True<(I < sizeof...(Types))>
-class tuple_element<I, tuple<Types...> > {
-public:
- typedef TI type;
-};
-
-template <size_t I, IdentityOf T>
- class tuple_element<I, const T> : add_const<tuple_element<I,T>> {};
-
-template <size_t I, IdentityOf T>
- class tuple_element<I, volatile T> : add_volatile<tuple_element<I,T>> {};
-
-template <size_t I, IdentityOf T>
- class tuple_element<I, const volatile T> : add_cv<tuple_element<I,T>> {};
-Section: 20.5.2.5 [tuple.helper] Status: Open - Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2009-10-26
-View other active issues in [tuple.helper].
-View all other issues in [tuple.helper].
-View all issues with Open status.
-Discussion:
--The tuple query APIs tuple_size and -tuple_element do not support references-to-tuples. This can be -annoying when a template deduced a parameter type to be a reference, -which must be explicitly stripped with remove_reference before calling -these APIs. -
--I am not proposing a resolution at this point, as there is a -combinatorial explosion with lvalue/rvalue references and -cv-qualification (see previous issue) that suggests some higher -refactoring is in order. This might be something to kick back over to -Core/Evolution. -
--Note that we have the same problem in numeric_limits. -
- -[ -2009-10 post-Santa Cruz: -]
- - --Move to Open. Alisdair to provide wording. -- - - -
Proposed resolution:
- - - - - -Section: 20.4.2 [ratio.arithmetic] Status: Tentatively NAD Future - Submitter: Alisdair Meredith Opened: 2009-05-25 Last modified: 2009-11-02
-View all other issues in [ratio.arithmetic].
-View all issues with Tentatively NAD Future status.
-Discussion:
--Both add and multiply could sensibly be called with more than two arguments. -The variadic template facility makes such declarations simple, and is likely -to be frequently wrapped by end users if we do not supply the variant -ourselves. -
--We deliberately ignore divide at this point as it is not transitive. -Likewise, subtract places special meaning on the first argument so I do not -suggest extending that immediately. Both could be supported with analogous -wording to that for add/multiply below. -
--Note that the proposed resolution is potentially incompatible with that -proposed for 921, although the addition of the typedef to ratio would be -equally useful. -
- -[ -2009-10-30 Alisdair adds: -]
- - --- --The consensus of the group when we reviewed this in Santa Cruz was that -921 would proceed to Ready as planned, and the -multi-paramater add/multiply templates should be renamed as -ratio_sum and ratio_product to avoid the problem -mixing template aliases with partial specializations. -
- --It was also suggested to close this issue as NAD Future as it does not -correspond directly to any NB comment. NBs are free to submit a -specific comment (and re-open) in CD2 though. -
- --Walter Brown also had concerns on better directing the order of -evaluation to avoid overflows if we do proceed for 0x rather than TR1, -so wording may not be complete yet. -
- -[ -Alisdair updates wording. -]
- - -
[ -2009-10-30 Howard: -]
- - --Moved to Tentatively NAD Future after 5 positive votes on c++std-lib. -- - - -
Proposed resolution:
- --Add the following type traits to p3 20.4 [ratio] -
- -- -// ratio arithmetic -template <class R1, class R2> struct ratio_add; -template <class R1, class R2> struct ratio_subtract; -template <class R1, class R2> struct ratio_multiply; -template <class R1, class R2> struct ratio_divide; -template <class R1, class ... RList> struct ratio_sum; -template <class R1, class ... RList> struct ratio_product; -
-after 20.4.2 [ratio.arithmetic] p1: add -
- -- -template <class R1, class ... RList> struct ratio_sum; // declared, never defined - -template <class R1> struct ratio_sum<R1> : R1 {}; -- --Requires: R1 is a specialization of class template ratio -- -template <class R1, class R2, class ... RList> - struct ratio_sum<R1, R2, RList...> - : ratio_add< R1, ratio_sum<R2, RList...>> { -}; -- --Requires: R1 and each element in parmater pack -RList is a specialization of class template ratio --
-after 20.4.2 [ratio.arithmetic] p3: add -
- -- - - - - - - - -template <class R1, class ... RList> struct ratio_product; // declared, never defined - -template <class R1> struct ratio_product<R1> : R1 {}; -- --Requires: R1 is a specialization of class template ratio -- -template <class R1, class R2, class ... RList> - struct ratio_sum<R1, R2, RList...> - : ratio_add< R1, ratio_product<R2, RList...>> { -}; -- --Requires: R1 and each element in parmater pack -RList is a specialization of class template ratio --
Section: 27.5.2.1.6 [ios::Init] Status: Ready - Submitter: James Kanze Opened: 2009-05-14 Last modified: 2009-10-20
-View all other issues in [ios::Init].
-View all issues with Ready status.
-Discussion:
--As currently formulated, the standard doesn't require that there -is ever a flush of cout, etc. (This implies, for example, that -the classical hello, world program may have no output.) In the -current draft -(N2798), -there is a requirement that the objects -be constructed before main, and before the dynamic -initialization of any non-local objects defined after the -inclusion of <iostream> in the same translation unit. The only -requirement that I can find concerning flushing, however, is in -27.5.2.1.6 [ios::Init], where the destructor of the last -std::ios_base::Init object flushes. But there is, as far as I -can see, no guarantee that such an object ever exists. -
--Also, the wording in [iostreams.objects] says that: -
--The objects -are constructed and the associations are established at some -time prior to or during the first time an object of class -ios_base::Init is constructed, and in any case before the body -of main begins execution. --
-In 27.5.2.1.6 [ios::Init], however, as an -effect of the constructor, it says that -
--If init_cnt is zero, -the function stores the value one in init_cnt, then constructs -and initializes the objects cin, cout, cerr, clog -wcin, wcout, wcerr, and wclog" -- -
-which seems to forbid earlier -construction. -
- --(Note that with these changes, the exposition only "static -int init_cnt" in ios_base::Init can be dropped.) -
--Of course, a determined programmer can still inhibit the -flush with things like: -
--new std::ios_base::Init ; // never deleted -
-or (in a function): -
--std::ios_base::Init ensureConstruction ; -// ... -exit( EXIT_SUCCESS ) ; -
-Perhaps some words somewhere to the effect that all -std::ios_base::Init objects should have static lifetime -would be in order. -
- -[ -2009 Santa Cruz: -]
- - --Moved to Ready. Some editorial changes are expected (in addition to the -proposed wording) to remove init_cnt from Init. -- - - -
Proposed resolution:
--Change 27.4 [iostream.objects]/2: -
- ---2- The objects are constructed and the associations are established at -some time prior to or during the first time an object of class -ios_base::Init is constructed, and in any case before the body -of main begins execution.292 The objects are not destroyed -during program execution.293 -- -If a translation unit includes -<iostream> or explicitly constructs an -ios_base::Init object, these stream objects shall be -constructed before dynamic initialization of non-local objects defined -later in that translation unit.-The results of including <iostream> in a translation -unit shall be as if <iostream> defined an instance of -ios_base::Init with static lifetime. Similarly, the entire -program shall behave as if there were at least one instance of -ios_base::Init with static lifetime. -
-Change 27.5.2.1.6 [ios::Init]/3: -
- --- -Init(); ----3- Effects: Constructs an object of class Init. --If init_cnt is zero, the function stores the value one in -init_cnt, then constructs and initializes the objects -cin, cout, cerr, clog (27.4.1), -wcin, wcout, wcerr, and wclog -(27.4.2). In any case, the function then adds one to the value stored in -init_cnt.-Constructs and initializes the objects cin, cout, -cerr, clog, wcin, wcout, -wcerr and wclog if they have not already been -constructed and initialized. -
-Change 27.5.2.1.6 [ios::Init]/4: -
- --- - - - - - -~Init(); ----4- Effects: Destroys an object of class Init. --The function subtracts one from the value stored in init_cnt and, -if the resulting stored value is one,-If there are no other instances of the class still in -existance, -calls cout.flush(), -cerr.flush(), clog.flush(), wcout.flush(), -wcerr.flush(), wclog.flush(). -
Section: 24.6.2.2 [ostream.iterator.ops] Status: New - Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2009-05-30
-View all issues with New status.
-Discussion:
--ostream_iterator has not been updated to support moveable types, in a -similar manner to the insert iterators. -Note that this is not a problem for ostreambuf_iterator, as the types it is -restricted to dealing with do not support extra-efficient moving. -
- - -Proposed resolution:
--Add second operator= overload to class template ostream_iterator -in 24.6.2 [ostream.iterator], para 2: -
- -- -ostream_iterator<T,charT,traits>& operator=(const T& value); -ostream_iterator<T,charT,traits>& operator=(T&& value); -
-Add a new paragraph: in 24.6.2.2 [ostream.iterator.ops]: -
- --- - - - - - -ostream_iterator& operator=(T&& value); ------2- Effects: -
--*out_stream << std::move(value); -if(delim != 0) - *out_stream << delim; -return (*this); -
Section: 24.6.3.5 [istreambuf.iterator::equal] Status: Tentatively Ready - Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2009-11-02
-View all other issues in [istreambuf.iterator::equal].
-View all issues with Tentatively Ready status.
-Discussion:
--The equal member function of istreambuf_iterator is -declared const, but takes its argument by non-const reference. -
--This is not compatible with the operator== free function overload, which is -defined in terms of calling equal yet takes both arguments by reference to -const. -
- -[ -The proposed wording is consistent with 110 with status TC1. -]
- - -[ -2009-11-02 Howard adds: -]
- - --Set to Tentatively Ready after 5 positive votes on c++std-lib. -- - - -
Proposed resolution:
-
-Ammend in both:
-24.6.3 [istreambuf.iterator]
-24.6.3.5 [istreambuf.iterator::equal]
-
- - - - - - -bool equal(const istreambuf_iterator& b) const; -
Section: 18.8.5 [propagation] Status: Review - Submitter: Peter Dimov Opened: 2009-05-13 Last modified: 2009-10-20
-View other active issues in [propagation].
-View all other issues in [propagation].
-View all issues with Review status.
-Discussion:
--The naming of std::copy_exception misleads almost everyone -(experts included!) to think that it is the function that copies an -exception_ptr: -
- -- -exception_ptr p1 = current_exception(); -exception_ptr p2 = copy_exception( p1 ); -
-But this is not at all what it does. The above actually creates an -exception_ptr p2 that contains a copy of p1, not of -the exception to which p1 refers! -
--This is, of course, all my fault; in my defence, I used copy_exception -because I was unable to think of a better name. -
--But I believe that, based on what we've seen so far, any other name would be better. -
--Therefore, I propose copy_exception to be renamed to -create_exception: -
- -- -template<class E> exception_ptr create_exception(E e); -
-with the following explanatory paragraph after it: -
- --Creates an exception_ptr that refers to a copy of e. -- -
[ -2009-05-13 Daniel adds: -]
- - --- --What about -
--make_exception_ptr --in similarity to make_pair and make_tuple, make_error_code and -make_error_condition, or make_shared? Or, if a stronger symmetry to -current_exception is preferred: -
- --make_exception --We have not a single create_* function in the library, it was always -make_* used. -
-
[ -2009-05-13 Peter adds: -]
- - --make_exception_ptr works for me. -- -
[ -2009-06-02 Thomas J. Gritzan adds: -]
- - --- --To avoid surprises and unwanted recursion, how about making a call to -std::make_exception_ptr with an exception_ptr illegal? -
--It might work like this: -
--template<class E> -exception_ptr make_exception_ptr(E e); -template<> -exception_ptr make_exception_ptr<exception_ptr>(exception_ptr e) = delete; -
[ -2009 Santa Cruz: -]
- - --Move to Review for the time being. The subgroup thinks this is a good -idea, but doesn't want to break compatibility unnecessarily if someone -is already shipping this. Let's talk to Benjamin and PJP tomorrow to -make sure neither objects. -- - - -
Proposed resolution:
--Change 18.8.5 [propagation]: -
- --- - - - - - -template<class E> exception_ptr- -copy_exceptionmake_exception_ptr(E e); --- ---11- Effects: Creates an exception_ptr that refers -to a copy of e, as if -
- -- -try { - throw e; -} catch(...) { - return current_exception(); -} -...
-
Section: 20.6.4.3 [meta.unary.prop] Status: New - Submitter: Niels Dekker Opened: 2009-06-01 Last modified: 2009-06-02
-View other active issues in [meta.unary.prop].
-View all other issues in [meta.unary.prop].
-View all issues with New status.
-Discussion:
--The alignment_of template is no longer necessary, now that the -core language will provide alignof. Scott Meyers raised this -issue at comp.std.c++, -C++0x: alignof vs. alignment_of, -May 21, 2009. In a reply, Daniel Krügler pointed out that -alignof was added to the working paper after -alignment_of. So it appears that alignment_of is only -part of the current Working Draft -(N2857) -because it is in TR1. -
--Having both alignof and alignment_of would cause -unwanted confusion. In general, I think TR1 functionality should not be -brought into C++0x if it is entirely redundant with other C++0x language -or library features. -
- - -Proposed resolution:
--Remove from Header <type_traits> synopsis 20.6.2 [meta.type.synop]: -
-- -template <class T> struct alignment_of;-
-Remove the first row of Table 34 ("Type property queries"), from -Type properties 20.6.4.3 [meta.unary.prop]: -
--- --
-Table 34 -- Type property queries -- -- template <class T> struct alignment_of;- alignof(T).
-Precondition: T shall be a complete type, a reference -type, or an array of unknown bound, but shall not be a function type or -(possibly cv-qualified) void.-
-Change text in Table 41 ("Other transformations"), from Other -transformations 20.6.7 [meta.trans.other], as follows: -
--- - - - - --
-Table 41 -- Other transformations -... -- Align shall be equal to - -alignment_of<T>::value- alignof(T) - for some type T or to default-alignment. -... -
Section: 23.3.3.5 [forwardlist.ops], 23.3.4.4 [list.ops] Status: New - Submitter: Alisdair Meredith Opened: 2009-05-09 Last modified: 2009-10-27
-View all other issues in [forwardlist.ops].
-View all issues with New status.
-Discussion:
--IIUC, -N2844 -means that lvalues will no longer bind to rvalue references. -Therefore, the current specification of list::splice (list -operations 23.3.4.4 [list.ops]) will be a breaking change of behaviour for existing -programs. That is because we changed the signature to swallow via an rvalue -reference rather than the lvalue reference used in 03. -
--Retaining this form would be safer, requiring an explicit move when splicing -from lvalues. However, this will break existing programs. -We have the same problem with forward_list, although without the risk of -breaking programs so here it might be viewed as a positive feature. -
--The problem signatures: -
-- -Possible resolutions: - -void splice_after(const_iterator position, forward_list<T,Alloc>&& x); -void splice_after(const_iterator position, forward_list<T,Alloc>&& x, - const_iterator i); -void splice_after(const_iterator position, forward_list<T,Alloc>&& x, - const_iterator first, const_iterator last); - -void splice(const_iterator position, list<T,Alloc>&& x); -void splice(const_iterator position, list<T,Alloc>&& x, - const_iterator i); -void splice(const_iterator position, list<T,Alloc>&& x, - const_iterator first, const_iterator last); -
-Option A. Add an additional (non-const) lvalue-reference -overload in each case -
--Option B. Change rvalue reference back to (non-const) -lvalue-reference overload in each case -
--Option C. Add an additional (non-const) lvalue-reference -overload in just the std::list cases -
--I think (B) would be very unfortunate, I really like the forward_list -behaviour in (C) but feel (A) is needed for consistency. -
--My actual preference would be NAD, ship with this as a breaking change as it -is a more explicit interface. I don't think that will fly though! -
- --See the thread starting with c++std-lib-23725 for more discussion. -
- -[ -2009-10-27 Christopher Jefferson provides proposed wording for Option C. -]
- - - -Proposed resolution:
--In 23.3.4 [list] -
- --Add lvalue overloads before rvalue ones: -
- -- -void splice(const_iterator position, list<T,Allocator>& x); -void splice(const_iterator position, list<T,Allocator>&& x); -void splice(const_iterator position, list<T,Allocator>& x, const_iterator i); -void splice(const_iterator position, list<T,Allocator>&& x, const_iterator i); -void splice(const_iterator position, list<T,Allocator>& x, - const_iterator first, const_iterator last); -void splice(const_iterator position, list<T,Allocator>&& x, - const_iterator first, const_iterator last); -
-In 23.3.4.4 [list.ops], similarly add lvalue overload before each rvalue one: -
--(After paragraph 2) -
- -- -void splice(const_iterator position, list<T,Allocator>& x); -void splice(const_iterator position, list<T,Allocator>&& x); -
-(After paragraph 6) -
- -- -void splice(const_iterator position, list<T,Allocator>& x, const_iterator i); -void splice(const_iterator position, list<T,Allocator>&& x, const_iterator i); -
-(After paragraph 10) -
- -- - - - - - -void splice(const_iterator position, list<T,Allocator>& x, - const_iterator first, const_iterator last); -void splice(const_iterator position, list<T,Allocator>&& x, - const_iterator first, const_iterator last); -
Section: 18.4.2 [stdinth], 26.3.2 [fenv], 26.8 [c.math], 26.4.11 [cmplxh] Status: Ready - Submitter: Robert Klarer Opened: 2009-05-26 Last modified: 2009-10-20
-View all issues with Ready status.
-Discussion:
--This is probably editorial. -
--The following items should be removed from the draft, because they're -redundant with Annex D, and they arguably make some *.h headers -non-deprecated: -
--18.4.2 [stdinth] (regarding <stdint.h>) -
--26.3.2 [fenv] (regarding <fenv.h> -
--Line 3 of 26.8 [c.math] (regarding <tgmath.h>) -
--26.4.11 [cmplxh] (regarding <complex.h>, though the note in this subclause is not redundant) -
- -[ -2009-06-10 Ganesh adds: -]
- - --While searching for stdint in the CD, I found that <stdint.h> is also -mentioned in 3.9.1 [basic.fundamental] /5. It guess it should refer to -<cstdint> instead. -- -
[ -2009 Santa Cruz: -]
- - --Real issue. Maybe just editorial, maybe not. Move to Ready. -- - - -
Proposed resolution:
--Remove the section 18.4.2 [stdinth]. -
--Remove the section 26.3.2 [fenv]. -
--Remove 26.8 [c.math], p3: -
- ----3- The header <tgmath.h> effectively includes the headers <complex.h> -and <math.h>.-
-Remove the section 26.4.11 [cmplxh]. -
- - - - - -Section: 18.8.5 [propagation] Status: Ready - Submitter: Daniel Krügler Opened: 2007-06-06 Last modified: 2009-10-20
-View other active issues in [propagation].
-View all other issues in [propagation].
-View all issues with Ready status.
-Discussion:
--As of -N2857 -18.8.5 [propagation]/5, the implementation-defined type -exception_ptr does provide the following ways to check whether -it is a null value: -
-void f(std::exception_ptr p) {
- p == nullptr;
- p == 0;
- p == exception_ptr();
-}
--This is rather cumbersome way of checking for the null value -and I suggest to require support for evaluation in a boolean -context like so: -
- -void g(std::exception_ptr p) {
- if (p) {}
- !p;
-}
-[ -2009 Santa Cruz: -]
- - --Move to Ready. Note to editor: considering putting in a cross-reference -to 4 [conv], paragraph 3, which defines the phrase -"contextually converted to bool". -- - - -
Proposed resolution:
--In section 18.8.5 [propagation] insert a new paragraph between p.5 and p.6: -
- -- -An object e of type exception_ptr can be contextually converted to bool. -The effect shall be as if e != exception_ptr() had been evaluated in place -of e. There shall be no implicit conversion to arithmetic type, to -enumeration type or to pointer type. - -- - - - - -
Section: 18.8.6 [except.nested] Status: Ready - Submitter: Daniel Krügler Opened: 2007-06-06 Last modified: 2009-10-20
-View other active issues in [except.nested].
-View all other issues in [except.nested].
-View all issues with Ready status.
-Discussion:
--It was recently mentioned in a newsgroup article -http://groups.google.de/group/comp.std.c++/msg/f82022aff68edf3d -that the specification of the member function rethrow_nested() of the -class nested_exception is incomplete, specifically it remains unclear -what happens, if member nested_ptr() returns a null value. In -18.8.6 [except.nested] we find only the following paragraph related to that: -
--void rethrow_nested() const; // [[noreturn]] ----4- Throws: the stored exception captured by this nested_exception object. --
-This is a problem, because it is possible to create an object of -nested_exception with exactly such a state, e.g. -
-#include <exception>
-#include <iostream>
-
-int main() try {
- std::nested_exception e; // OK, calls current_exception() and stores it's null value
- e.rethrow_nested(); // ?
- std::cout << "A" << std::endl;
-}
-catch(...) {
- std::cout << "B" << std::endl;
-}
--I suggest to follow the proposal of the reporter, namely to invoke -terminate() if nested_ptr() return a null value of exception_ptr instead -of relying on the fallback position of undefined behavior. This would -be consistent to the behavior of a throw; statement when no -exception is being handled. -
- -[ -2009 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Change around 18.8.6 [except.nested]/4 as indicated: -
--- - - - - ---4- Throws: the stored exception captured by this nested_exception -object, if nested_ptr() != nullptr -
--- Remarks: If nested_ptr() == nullptr, terminate() -shall be called. -
-
Section: 26.4.9 [cmplx.over] Status: New - Submitter: Marc Steinbach Opened: 2009-06-11 Last modified: 2009-06-27
-View all other issues in [cmplx.over].
-View all issues with New status.
-Discussion:
--In clause 1, the Working Draft -(N2857) -specifies overloads of the -functions -
--arg, conj, imag, norm, proj, real -
-for non-complex arithmetic types (float, double, -long double, and integers). -The only requirement (clause 2) specifies effective type promotion of arguments. -
--I strongly suggest to add the following requirement on the return types: -
--All the specified overloads must return real (i.e., non-complex) values, -specifically, the nested value_type of effectively promoted arguments. -- -
-(This has no effect on arg, imag, norm, real: -they are real-valued anyway.) -
-Rationale:
--Mathematically, conj() and proj(), like the transcendental functions, are -complex-valued in general but map the (extended) real line to itself. -In fact, both functions act as identity on the reals. -A typical user will expect conj() and proj() to preserve this essential -mathematical property in the same way as exp(), sin(), etc. -A typical use of conj(), e.g., is the generic scalar product of n-vectors: -
- -template<typename T>
-inline T
-scalar_product(size_t n, T const* x, T const* y) {
- T result = 0;
- for (size_t i = 0; i < n; ++i)
- result += x[i] * std::conj(y[i]);
- return result;
-}
--This will work equally well for real and complex floating-point types T if -conj() returns T. It will not work with real types if conj() -returns complex values. -
--Instead, the implementation of scalar_product becomes either less efficient -and less useful (if a complex result is always returned), or unnecessarily -complicated (if overloaded versions with proper return types are defined). -In the second case, the real-argument overload of conj() cannot be used. -In fact, it must be avoided. -
--Overloaded conj() and proj() are principally needed in generic programming. -All such use cases will benefit from the proposed return type requirement, -in a similar way as the scalar_product example. -The requirement will not harm use cases where a complex return value -is expected, because of implicit conversion to complex. -Without the proposed return type guarantee, I find overloaded versions -of conj() and proj() not only useless but actually troublesome. -
- - - -Proposed resolution:
--Insert a new paragraph after 26.4.9 [cmplx.over]/2: -
- -- -All of the specified overloads shall have a return type which is the nested value_type of -the effectively promoted arguments. - -- - - - - -
Section: 21.4.8.1 [string::op+] Status: Tentatively Ready - Submitter: Alisdair Meredith Opened: 2009-06-12 Last modified: 2009-11-05
-View all issues with Tentatively Ready status.
-Discussion:
--Many of the basic_string operator+ overloads return an rvalue-reference. Is -that really intended? -
--I'm considering it might be a mild performance tweak to avoid making -un-necessary copies of a cheaply movable type, but it opens risk to dangling -references in code like: -
- -auto && s = string{"x"} + string{y};
--and I'm not sure about: -
- -auto s = string{"x"} + string{y};
-[ -2009-10-11 Howard updated Returns: clause for each of these. -]
- - -[ -2009-11-05 Howard adds: -]
- - --Moved to Tentatively Ready after 5 positive votes on c++std-lib. -- - -
Proposed resolution:
--Strike the && from the return type in the following function -signatures: -
- --- - - - - - --21.3 [string.classes] p2 Header Synopsis -
- -- -template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>&&- operator+(basic_string<charT,traits,Allocator>&& lhs, - const basic_string<charT,traits,Allocator>& rhs); - -template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>&&- operator+(const basic_string<charT,traits,Allocator>& lhs, - basic_string<charT,traits,Allocator>&& rhs); - -template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>&&- operator+(basic_string<charT,traits,Allocator>&& lhs, - basic_string<charT,traits,Allocator>&& rhs); - - -template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>&&- operator+(const charT* lhs, - basic_string<charT,traits,Allocator>&& rhs); - -template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>&&- operator+(charT lhs, basic_string<charT,traits,Allocator>&& rhs); - -template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>&&- operator+(basic_string<charT,traits,Allocator>&& lhs, - const charT* rhs); - -template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>&&- operator+(basic_string<charT,traits,Allocator>&& lhs, charT rhs); --21.4.8.1 [string::op+] -
- -- -template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>-&&- operator+(basic_string<charT,traits,Allocator>&& lhs, - const basic_string<charT,traits,Allocator>& rhs); --Returns: std::move(lhs.append(rhs)) --template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>-&&- operator+(const basic_string<charT,traits,Allocator>& lhs, - basic_string<charT,traits,Allocator>&& rhs); --Returns: std::move(rhs.insert(0, lhs)) --template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>-&&- operator+(basic_string<charT,traits,Allocator>&& lhs, - basic_string<charT,traits,Allocator>&& rhs); --Returns: std::move(lhs.append(rhs)) [Note: Or equivalently -std::move(rhs.insert(0, lhs)) — end note] --template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>-&&- operator+(const charT* lhs, - basic_string<charT,traits,Allocator>&& rhs); --Returns: std::move(rhs.insert(0, lhs)). --template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>-&&- operator+(charT lhs, basic_string<charT,traits,Allocator>&& rhs); --Returns: std::move(rhs.insert(0, 1, lhs)). --template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>-&&- operator+(basic_string<charT,traits,Allocator>&& lhs, - const charT* rhs); --Returns: std::move(lhs.append(rhs)). --template<class charT, class traits, class Allocator> - basic_string<charT,traits,Allocator>-&&- operator+(basic_string<charT,traits,Allocator>&& lhs, charT rhs); --Returns: std::move(lhs.append(1, rhs)). --
Section: 18.5 [support.start.term] Status: Ready - Submitter: LWG Opened: 2009-06-16 Last modified: 2009-10-20
-View all other issues in [support.start.term].
-View all issues with Ready status.
-Discussion:
- -Addresses UK 187
- --The term "thread safe" is not defined nor used in this context -anywhere else in the standard. -
- -Suggested action:
--Clarify the meaning of "thread safe". -
- -[ -2009 Santa Cruz: -]
- - --- - - --The "thread safe" language has already been change in the WP. It was -changed to "happen before", but the current WP text is still a little -incomplete: "happen before" is binary, but the current WP text only -mentions one thing. -
--Move to Ready. -
-
Proposed resolution:
--For the following functions in 18.5 [support.start.term]. -
-- --extern "C" int at_quick_exit(void (*f)(void)); -extern "C++" int at_quick_exit(void (*f)(void)); -
-Edit paragraph 10 as follows. -The intent is -to provide the other half of the happens before relation; -to note indeterminate ordering; -and to clean up some formatting. -
-- --Effects: -The
at_quick_exit()functions -register the function pointed to byf-to be called without arguments whenquick_exitis called. -It is unspecified whether a call toat_quick_exit()-that does nothappen-beforehappen before (1.10) -all calls toquick_exit-will succeed. -[Note: -theat_quick_exit()functions -shall not introduce a data race (17.6.4.7). -exitnote-—end note] - -[Note: -The order of registration may be indeterminate -ifat_quick_exitwas called from more than one thread. -—end note] - -[Note: Theat_quick_exitregistrations -are distinct from theatexitregistrations, -and applications may need to call both registration functions -with the same argument. -—end note] -
-For the following function. -
-- --void quick_exit [[noreturn]] (int status) -
-Edit paragraph 13 as follows. -The intent is to note that thread-local variables may be different. -
-- - - - - --Effects: -Functions registered by calls to
at_quick_exit-are called in the reverse order of their registration, -except that a function shall be called -after any previously registered functions -that had already been called at the time it was registered. -Objects shall not be destroyed as a result of callingquick_exit. -If control leaves a registered function called byquick_exit-because the function does not provide a handler for a thrown exception, -terminate()shall be called. - -[Note: -Functions registered by one thread may be called by any thread, -and hence should not rely on the identity of thread-storage-duration objects. -—end note] - -After calling registered functions, -quick_exitshall call_Exit(status). -[Note: -The standard file buffers are not flushed. -See: ISO C 7.20.4.4. -—end note] -
Section: 17 [library] Status: Open - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-20
-View other active issues in [library].
-View all other issues in [library].
-View all issues with Open status.
-Discussion:
-Addresses US 63
- -Description
-The behavior of the library in the presence of threads - is incompletely specified.
-For example, if thread 1 assigns to X, then writes data - to file f, which is read by thread 2, and then accesses - variable X, is thread 2 guaranteed to be able to see the - value assigned to X by thread 1? In other words, does the - write of the data "happen before" the read?
-Another example: does simultaneous access using operator - at() to different characters in the same non-const string - really introduce a data race?
-Suggestion
-Notes
17 SG: should go to threads group; misclassified in document -
- -Concurrency SG: Create an issue. Hans will look into it.
- -[ -2009 Santa Cruz: -]
- - --Move to "Open". Hans and the rest of the concurrency working group will -study this. We can't make progress without a thorough review and a -paper. -- - - -
Proposed resolution:
- - - - - -Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: Tentatively Ready - Submitter: Seungbeom Kim Opened: 2009-06-27 Last modified: 2009-10-28
-View other active issues in [facet.num.put.virtuals].
-View all other issues in [facet.num.put.virtuals].
-View all issues with Tentatively Ready status.
-Discussion:
--In Table 73 -- Floating-point conversions, 22.4.2.2.2 [facet.num.put.virtuals], -in -N2914, -we have the following entries: -
-| State | stdio equivalent | -
|---|---|
| floatfield == ios_base::fixed | ios_base::scientific && !uppercase | -%a | -
| floatfield == ios_base::fixed | ios_base::scientific | -%A | -
-These expressions are supposed to mean: -
- --floatfield == (ios_base::fixed | ios_base::scientific) && !uppercase -floatfield == (ios_base::fixed | ios_base::scientific) -
-but technically parsed as: -
--((floatfield == ios_base::fixed) | ios_base::scientific) && (!uppercase) -((floatfield == ios_base::fixed) | ios_base::scientific) -
-and should be corrected with additional parentheses, as shown above. -
- -[ -2009-10-28 Howard: -]
- - --Moved to Tentatively Ready after 5 positive votes on c++std-lib. -- - - -
Proposed resolution:
--Change Table 83 — Floating-point conversions in 22.4.2.2.2 [facet.num.put.virtuals]: -
- -| State | stdio equivalent | -
|---|---|
| floatfield == (ios_base::fixed | ios_base::scientific) && !uppercase | -%a | -
| floatfield == (ios_base::fixed | ios_base::scientific) | -%A | -
Section: 17 [library], 30 [thread], D [depr] Status: Open - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-20
-View other active issues in [library].
-View all other issues in [library].
-View all issues with Open status.
-Discussion:
- -Addresses DE 2
- -Description
-Marking a constructor with explicit has semantics - even for a constructor with zero or several parameters: - Such a constructor cannot be used with list-initialization - in a copy-initialization context, see 13.3.1.7 [over.match.list]. The - standard library apparently has not been reviewed for - marking non-single-parameter constructors as explicit.
-Suggestion
-Consider marking zero-parameter and multi-parameter - constructors explicit in classes that have at least one - constructor marked explicit and that do not have an - initializer-list constructor.
- -Notes
-Robert Klarer to address this one.
- -[ -2009 Santa Cruz: -]
- - --Move to "Open". Robert Klarer has promised to provide wording. -- - - -
Proposed resolution:
- - - - - -Section: 26.4 [complex.numbers] Status: New - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-26
-View all other issues in [complex.numbers].
-View all issues with New status.
-Discussion:
- -Addresses FR 35
- -Description
-Instantiations of the class - template complex<> have to be allowed for integral - types, to reflect existing practice and ISO standards - (LIA-III).
- -Suggestion
- -[ -2009-10-26 Proposed wording in -N3002. -]
- - - - -Proposed resolution:
-Adopt -N3002. - - - - - -Section: 17.5.2.1.2 [enumerated.types], 17.5.2.1.3 [bitmask.types] Status: Open - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-27
-View all issues with Open status.
-Discussion:
- -Addresses UK 165
- -Description
-Constraints on - bitmask and enumeration types were supposed to be tightened - up as part of the motivation for the constexpr feature - - see paper - N2235 - for details
-Suggestion
-Adopt wording in line with the motivation - described in - N2235
-Notes
-Robert Klarer to review
- -[ -2009 Santa Cruz: -]
- - --Move to Open. Ping Robert Klarer to provide wording, using N2235 as -guidance. -- - - -
Proposed resolution:
- - - - - -Section: 17.6.3.2.1 [namespace.std] Status: Ready - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-21
-View all issues with Ready status.
-Discussion:
- -Addresses UK 175
- -Description
-Local types can - now be used to instantiate templates, but don't have - external linkage.
-Suggestion
-Remove the reference to external linkage.
- -Notes
-We accept the proposed solution. Martin will draft an issue.
- -[ -2009-07-28 Alisdair provided wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
--17.6.3.2.1 [namespace.std] -
--Strike "of external linkage" in p1 and p2: -
- --- - - - - - ---1- The behavior of a C++ program is undefined if it adds declarations or -definitions to namespace std or to a namespace within namespace std -unless otherwise specified. A program may add a concept map for any -standard library concept or a template specialization for any standard -library template to namespace std only if the declaration depends on a -user-defined type
- -of external linkageand the specialization meets the -standard library requirements for the original template and is not -explicitly prohibited.179 ---2- The behavior of a C++ program is undefined if it declares -
--
-- -an explicit specialization of any member function of a standard library -class template, or -
-- -an explicit specialization of any member function template of a standard -library class or class template, or -
-- -an explicit or partial specialization of any member class template of a -standard library class or class template. -
--A program may explicitly instantiate a template defined in the standard -library only if the declaration depends on the name of a user-defined -type
-of external linkageand the instantiation meets the standard -library requirements for the original template. -
Section: 30.2.4 [thread.req.timing] Status: Tentatively Ready - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-31
-View all issues with Tentatively Ready status.
-Discussion:
- -Addresses UK 322, US 96
- -Description
-Not all systems - can provide a monotonic clock. How are they expected to - treat a _for function?
-Suggestion
-Add at least a note explaining the intent - for systems that do not support a monotonic clock.
- -Notes
-Create an issue, together with UK 96. Note that the specification as is - already allows a non-monotonic clock due to the word “should” rather than - “shall”. If this wording is kept, a footnote should be added to make the - meaning clear.
- -[ 2009-06-29 Beman provided a proposed resolution. ]
- -[ -2009-10-31 Howard adds: -]
- - --Set to Tentatively Ready after 5 positive votes on c++std-lib. -- - - -
Proposed resolution:
- -Change Timing specifications 30.2.4 [thread.req.timing] as indicated:
- -The member functions whose names end in _for take an argument that
-specifies a relative time. Implementations
-should are encouraged but not required to use a
-monotonic clock to measure time for these functions.
Section: 30.4.3.2.2 [thread.lock.unique.locking] Status: New - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-07-04
-View other active issues in [thread.lock.unique.locking].
-View all other issues in [thread.lock.unique.locking].
-View all issues with New status.
-Discussion:
- -Addresses UK 327, UK 328
- -UK 327 Description
-Not clear what - the specification for error condition - resource_deadlock_would_occur means. It is perfectly - possible for this thread to own the mutex without setting - owns to true on this specific lock object. It is also - possible for lock operations to succeed even if the thread - does own the mutex, if the mutex is recursive. Likewise, if - the mutex is not recursive and the mutex has been locked - externally, it is not always possible to know that this - error condition should be raised, depending on the host - operating system facilities. It is possible that 'i.e.' was - supposed to be 'e.g.' and that suggests that recursive - locks are not allowed. That makes sense, as the - exposition-only member owns is boolean and not a integer to - count recursive locks.
- -UK 327 Suggestion
-Add a precondition !owns. Change the 'i.e.' - in the error condition to be 'e.g.' to allow for this - condition to propogate deadlock detection by the host OS.
-UK 327 Notes
-Create an issue. Assigned to Lawrence Crowl. Note: not sure what try_lock - means for recursive locks when you are the owner. POSIX has language on - this, which should ideally be followed. Proposed fix is not quite right, for - example, try_lock should have different wording from lock.
- -UK 328 Description
- -There is a missing precondition that owns - is true, or an if(owns) test is missing from the effect - clause
-UK 328 Suggestion
-Add a - precondition that owns == true. Add an error condition to - detect a violation, rather than yield undefined behaviour.
-UK 328 Notes
-Handle in same issue as UK 327. Also uncertain that the proposed resolution - is the correct one.
- - - - -Proposed resolution:
@@ -20686,11 +1909,10 @@ monotonic clock to measure time for these functions.Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: New - Submitter: Cosmin Truta Opened: 2009-07-04 Last modified: 2009-07-07
-View other active issues in [facet.num.get.virtuals].
+Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: Open + Submitter: Cosmin Truta Opened: 2009-07-04 Last modified: 2010-10-23
View all other issues in [facet.num.get.virtuals].
-View all issues with New status.
+View all issues with Open status.
Discussion:
As specified in the latest draft, @@ -20741,6 +1963,44 @@ closely follow the behavior of all of its underlying C functions.
+ +[ +2010 Rapperswil: +]
+ + ++Some concern that this is changing the specification for an existing C++03 function, but it was pointed out that this was underspecified as resolved by issue 23. This is clean-up for that issue in turn. + +Some concern that we are trying to solve the same problem in both clause 22 and 27. + +Bill: There's a change here as to whether val is stored to in an error case. + +Pablo: Don't think this changes whether val is stored to or not, but changes the value that is stored. + +Bill: Remembers having skirmishes with customers and testers as to whether val is stored to, and the resolution was not to store in error cases. + +Howard: Believes since C++03 we made a change to always store in overflow. + +Everyone took some time to review the issue. + +Pablo: C++98 definitely did not store any value during an error condition. + +Dietmar: Depends on the question of what is considered an error, and whether overflow is an error or not, which was the crux of LWG 23. + +Pablo: Yes, but given the "zero, if the conversion function fails to convert the entire field", we are requiring every error condition to store. + +Bill: When did this happen? + +Alisdair: One of the last two or three meetings. + +Dietmar: To store a value in case of failure is a very bad idea. + +Move to Open, needs more study. ++ + +
Proposed resolution:
@@ -20796,287 +2056,13 @@ field represents a value outside the range of representable values, -
Section: 21.1 [strings.general] Status: New - Submitter: Beman Dawes Opened: 2009-06-22 Last modified: 2009-11-04
-View all issues with New status.
-Discussion:
- -Addresses UK 218
- -Prior to the introduction of constant expressions into the library, -basic_string elements had to be POD types, and thus had to be both trivially -copyable and standard-layout. This ensured that they could be memcpy'ed and -would be compatible with other libraries and languages, particularly the C -language and its library.
--N2349, -Constant Expressions in the Standard Library Revision 2, changed the -requirement in 21/1 from "POD type" to "literal type". That change had the -effect of removing the trivially copyable and standard-layout requirements from -basic_string elements.
-This means that basic_string elements no longer are guaranteed to be -memcpy'able, and are no longer guaranteed to be standard-layout types:
---3.9/p2 and 3.9/p3 both make it clear that a "trivially copyable type" is - required for memcpy to be guaranteed to work.
-Literal types (3.9p12) may have a non-trivial copy assignment operator, and - that violates the trivially copyable requirements given in 9/p 6, bullet item - 2.
-Literal types (3.9p12) have no standard-layout requirement, either.
-
This situation probably arose because the wording for "Constant Expressions -in the Standard Library" was in process at the same time the C++ POD -deconstruction wording was in process.
-Since trivially copyable types meet the C++0x requirements for literal types, -and thus work with constant expressions, it seems an easy fix to revert the -basic_string element wording to its original state.
- -[ - 2009-07-28 Alisdair adds: - ]
- - --When looking for any resolution for this issue, consider the definition of -"character container type" in 17.3.4 [defns.character.container]. This -does require the character type to be a POD, and this term is used in a -number of places through clause 21 and 28. This suggests the PODness -constraint remains, but is much more subtle than before. Meanwhile, I -suspect the change from POD type to literal type was intentional with -the assumption that trivially copyable types with -non-trivial-but-constexpr constructors should serve as well. I don't -believe the current wording offers the right guarantees for either of -the above designs. -- -
[ -2009-11-04 Howard modifies proposed wording to disallow array types as -char-like types. -]
- - - - -Proposed resolution:
- -Change General 21.1 [strings.general] as indicated:
--- - - - - - -This Clause describes components for manipulating sequences of any -
-literalnon-array POD (3.9) type. In this Clause -such types are called char-like types, and objects of char-like -types are called char-like objects or simply -characters.
Section: 20.9.3 [time.duration] Status: Open - Submitter: Alisdair Meredith Opened: 2009-07-06 Last modified: 2009-10-31
-View other active issues in [time.duration].
-View all other issues in [time.duration].
-View all issues with Open status.
-Discussion:
--The duration types in 20.9.3 [time.duration] are exactly the sort of type -that should be "literal types" in the new standard. Likewise, -arithmetic operations on durations should be declared constexpr. -
- -[ -2009-09-21 Daniel adds: -]
- - --An alternative (and possibly preferable solution for potentially -heap-allocating big_int representation types) would be to ask the core -language to allow references to const literal types as feasible -arguments for constexpr functions. -- -
[ -2009-10-30 Alisdair adds: -]
- - --- - - --I suggest this issue moves from New to Open. -
- --Half of this issue was dealt with in paper -n2994 -on constexpr constructors. -
- --The other half (duration arithmetic) is on hold pending Core support for -const & in constexpr functions. -
- -
Proposed resolution:
--Add constexpr to declaration of following functions and constructors: -
--p1 20.9 [time] -
- ----Header <chrono> synopsis -
- -[Draughting note - observe switch to pass-by-value to support constexpr]
- - -// duration arithmetic -template <class Rep1, class Period1, class Rep2, class Period2> - typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type - constexpr operator+(- -constduration<Rep1, Period1>&lhs,constduration<Rep2, Period2>&rhs); -template <class Rep1, class Period1, class Rep2, class Period2> - typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type - constexpr operator-(constduration<Rep1, Period1>&lhs,constduration<Rep2, Period2>&rhs); -template <class Rep1, class Period, class Rep2> - duration<typename common_type<Rep1, Rep2>::type, Period> - constexpr operator*(constduration<Rep1, Period>&d,constRep2&s); -template <class Rep1, class Period, class Rep2> - duration<typename common_type<Rep1, Rep2>::type, Period> - constexpr operator*(constRep1&s,constduration<Rep2, Period>&d); -template <class Rep1, class Period, class Rep2> - duration<typename common_type<Rep1, Rep2>::type, Period> - constexpr operator/(constduration<Rep1, Period>&d,constRep2&s); -template <class Rep1, class Period1, class Rep2, class Period2> - typename common_type<Rep1, Rep2>::type - constexpr operator/(constduration<Rep1, Period1>&lhs,constduration<Rep2, Period2>&rhs); - -// duration comparisons -template <class Rep1, class Period1, class Rep2, class Period2> - constexpr bool operator==(constduration<Rep1, Period1>&lhs,constduration<Rep2, Period2>&rhs); -template <class Rep1, class Period1, class Rep2, class Period2> - constexpr bool operator!=(constduration<Rep1, Period1>&lhs,constduration<Rep2, Period2>&rhs); -template <class Rep1, class Period1, class Rep2, class Period2> - constexpr bool operator< (constduration<Rep1, Period1>&lhs,constduration<Rep2, Period2>&rhs); -template <class Rep1, class Period1, class Rep2, class Period2> - constexpr bool operator<=(constduration<Rep1, Period1>&lhs,constduration<Rep2, Period2>&rhs); -template <class Rep1, class Period1, class Rep2, class Period2> - constexpr bool operator> (constduration<Rep1, Period1>&lhs,constduration<Rep2, Period2>&rhs); -template <class Rep1, class Period1, class Rep2, class Period2> - constexpr bool operator>=(constduration<Rep1, Period1>&lhs,constduration<Rep2, Period2>&rhs); - -// duration_cast -template <class ToDuration, class Rep, class Period> - constexpr ToDuration duration_cast(constduration<Rep, Period>&d); --20.9.3 [time.duration] -
- -template <class Rep, class Period = ratio<1>> -class duration { - .... -public: - // 20.9.3.1, construct/copy/destroy: - constexpr duration() = default; - - template <class Rep2> - constexpr explicit duration(const Rep2& r); - template <class Rep2, class Period2> - constexpr duration(const duration<Rep2, Period2>& d); - - constexpr duration(const duration&) = default; - - // 20.9.3.2, observer: - constexpr rep count() const; - - // 20.9.3.3, arithmetic: - constexpr duration operator+() const; - constexpr duration operator-() const; - ... - -}; --
[ -Note - this edit already seems assumed by definition of the duration static members zero/min/max. -They cannot meaningfully be constexpr without this change. -]
- - - - - - -Section: 17 [library] Status: Open - Submitter: David Abrahams Opened: 2009-07-14 Last modified: 2009-10-20
-View other active issues in [library].
-View all other issues in [library].
-View all issues with Open status.
-Discussion:
--Issue: The CopyConstructible requirements are wishy-washy. It requires -that the copy is "equivalent" to the original, but "equivalent" is never -defined. -
--I believe this to be an example of a more general lack of rigor around -copy and assignment, although I haven't done the research to dig up all -the instances. -
--It's a problem because if you don't know what CopyConstructible means, -you also don't know what it means to copy a pair of CopyConstructible -types. It doesn't prevent us from writing code, but it is a hole in our -ability to understand the meaning of copy. -
--Furthermore, I'm pretty sure that vector's copy constructor doesn't -require the elements to be EqualityComparable, so that table is actually -referring to some ill-defined notion of equivalence when it uses ==. -
- -[ -2009 Santa Cruz: -]
- - --Move to "Open". Dave is right that this is a big issue. Paper D2987 -("Defining Move Special Member Functions", Bjarne Stroustrup and -Lawrence Crowl) touches on this but does not solve it. This issue is -discussed in Elements of Programming. -- - - -
Proposed resolution:
- - - - -Section: 23.2.5 [unord.req] Status: New - Submitter: Pablo Halpern Opened: 2009-07-17 Last modified: 2009-07-19
+Section: 23.2.5 [unord.req] Status: Open + Submitter: Pablo Halpern Opened: 2009-07-17 Last modified: 2010-10-23
View other active issues in [unord.req].
View all other issues in [unord.req].
-View all issues with New status.
+View all issues with Open status.
Discussion:
When I look at the unordered_* constructors, I think the complexity is poorly @@ -21102,2610 +2088,19 @@ The number of calls to key_equal::operator() is proportional to -
Proposed resolution:
--
- - - - - -Section: 30.3.1.2 [thread.thread.constr] Status: New - Submitter: Howard Hinnant Opened: 2009-07-18 Last modified: 2009-07-18
-View other active issues in [thread.thread.constr].
-View all other issues in [thread.thread.constr].
-View all issues with New status.
-Discussion:
--The variadic thread constructor is causing controversy, e.g. -N2901. -This issue has been created as a placeholder for this course of action. -
- -- -template <class F, class ...Args> thread(F&& f, Args&&... args); -
-See 929 for wording which specifies an rvalue-ref signature but -with "decay behavior", but using variadics. -
- - -Proposed resolution:
--
- - - - - -Section: 20.9.3 [time.duration] Status: Ready - Submitter: Howard Hinnant Opened: 2009-07-18 Last modified: 2009-10-26
-View other active issues in [time.duration].
-View all other issues in [time.duration].
-View all issues with Ready status.
-Discussion:
--"diagnostic required" has been used (by me) for code words meaning "use -enable_if to constrain templated functions. This needs to be -improved by referring to the function signature as not participating in -the overload set, and moving this wording to a Remarks paragraph. -
-[ -2009-10 Santa Cruz: +2010 Rapperswil: ]
-Moved to Ready. -+Concern that the current wording may require O(1) where that cannot be delivered. We need to look at both the clause 23 requirements tables and the constructor description of each unodered container to be sure. +Howard suggests NAD Editorial as we updated the container requirement tables since this issue was written. +Daniel offers to look deeper, and hopefully produce wording addressing any outstanding concerns at the next meeting. -
Proposed resolution:
-[ -This proposed resolution addresses 947 and 974. -]
- - --Change 20.9.3.1 [time.duration.cons]: -
- ---template <class Rep2> - explicit duration(const Rep2& r); ---- --
-Requires:Remarks: -Rep2 shall be implicitly convertible to rep and --
-- -treat_as_floating_point<rep>::value shall be true or -
-- -treat_as_floating_point<Rep2>::value shall be false. -
--
-Diagnostic requiredIf these constraints are not met, this -constructor shall not participate in overload resolution. [Example: -- -duration<int, milli> d(3); // OK -duration<int, milli> d(3.5); // error --— end example] -
- --Effects: Constructs an object of type duration. -
- --Postcondition: count() == static_cast<rep>(r). -
- -template <class Rep2, class Period2> - duration(const duration<Rep2, Period2>& d); ---- - --
- -Requires:Remarks: treat_as_floating_point<rep>::value shall be true or -ratio_divide<Period2, period>::type::den shall be 1. Diagnostic -required, else this constructor shall not participate in overload -resolution. [Note: This requirement prevents implicit truncation error -when converting between integral-based duration types. Such a -construction could easily lead to confusion about the value of the -duration. — end note] [Example: -- -duration<int, milli> ms(3); -duration<int, micro> us = ms; // OK -duration<int, milli> ms2 = us; // error --— end example] -
- --Effects: Constructs an object of type duration, constructing -rep_ from -duration_cast<duration>(d).count(). -
- -
-Change the following paragraphs in 20.9.3.5 [time.duration.nonmember]: -
- ---template <class Rep1, class Period, class Rep2> - duration<typename common_type<Rep1, Rep2>::type, Period> - operator*(const duration<Rep1, Period>& d, const Rep2& s); ---- -RequiresRemarks: Rep2 shall be implicitly convertible to -CR(Rep1, Rep2), else this signature shall not participate in -overload resolution.Diagnostic required.-template <class Rep1, class Period, class Rep2> - duration<typename common_type<Rep1, Rep2>::type, Period> - operator*(const Rep1& s, const duration<Rep2, Period>& d); ---- -RequiresRemarks: Rep1 shall be implicitly convertible to -CR(Rep1, Rep2), else this signature shall not participate in -overload resolution.Diagnostic required.-template <class Rep1, class Period, class Rep2> - duration<typename common_type<Rep1, Rep2>::type, Period> - operator/(const duration<Rep1, Period>& d, const Rep2& s); ---- -RequiresRemarks: Rep2 shall be implicitly convertible to -CR(Rep1, Rep2) and Rep2 shall not be an instantiation of -duration, else this signature shall not participate in -overload resolution.Diagnostic required.-template <class Rep1, class Period, class Rep2> - duration<typename common_type<Rep1, Rep2>::type, Period> - operator%(const duration<Rep1, Period>& d, const Rep2& s); ---- -RequiresRemarks: Rep2 shall be implicitly convertible to -CR(Rep1, Rep2) and Rep2 shall not be an instantiation of -duration, else this signature shall not participate in -overload resolution.Diagnostic required.-
-Change the following paragraphs in 20.9.3.7 [time.duration.cast]: -
- --template <class ToDuration, class Rep, class Period> - ToDuration duration_cast(const duration<Rep, Period>& d); -- ---RequiresRemarks: ToDuration shall be an instantiation of -duration, else this signature shall not participate in -overload resolution.Diagnostic required.-
-Change the following paragraphs in 20.9.4.7 [time.point.cast]: -
- --template <class ToDuration, class Clock, class Duration> - time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t); -- ---RequiresRemarks: ToDuration shall be an instantiation of -duration, else this signature shall not participate in -overload resolution.Diagnostic required.-
Section: 28.9.1 [re.submatch.members] Status: New - Submitter: Daniel Krügler Opened: 2009-07-25 Last modified: 2009-07-26
-View all issues with New status.
-Discussion:
--The definition of class template sub_match is strongly dependent -on the type basic_string<value_type>, both in interface and effects, -but does not provide a corresponding typedef string_type, as e.g. -class match_results does, which looks like an oversight to me that -should be fixed. -
- - -Proposed resolution:
- --In the class template sub_match synopsis 28.9 [re.submatch]/1 -change as indicated: -
- -template <class BidirectionalIterator>
-class sub_match : public std::pair<BidirectionalIterator, BidirectionalIterator> {
-public:
- typedef typename iterator_traits<BidirectionalIterator>::value_type value_type;
- typedef typename iterator_traits<BidirectionalIterator>::difference_type difference_type;
- typedef BidirectionalIterator iterator;
- typedef basic_string<value_type> string_type;
-
- bool matched;
-
- difference_type length() const;
- operator basic_string<value_type>string_type() const;
- basic_string<value_type>string_type str() const;
- int compare(const sub_match& s) const;
- int compare(const basic_string<value_type>string_type& s) const;
- int compare(const value_type* s) const;
-};
--In 28.9.1 [re.submatch.members]/2 change as indicated: -
- --operator- -basic_string<value_type>string_type() const; --Returns: matched ?-basic_string<value_type>-string_type(first, second) :basic_string<value_type>-string_type(). -
-In 28.9.1 [re.submatch.members]/3 change as indicated: -
- --- -basic_string<value_type>string_type str() const; --Returns: matched ?-basic_string<value_type>-string_type(first, second) :basic_string<value_type>-string_type(). -
Section: 28.9.2 [re.submatch.op] Status: New - Submitter: Daniel Krügler Opened: 2009-07-25 Last modified: 2009-07-28
-View all other issues in [re.submatch.op].
-View all issues with New status.
-Discussion:
--Several heterogeneous comparison operators of class template -sub_match are specified by return clauses that are not valid -in general. E.g. 28.9.2 [re.submatch.op]/7: -
- -- -template <class BiIter, class ST, class SA> -bool operator==( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); ---Returns: lhs == rhs.str(). --
-The returns clause would be ill-formed for all cases where -ST != std::char_traits<iterator_traits<BiIter>::value_type> -or SA != std::allocator<iterator_traits<BiIter>::value_type>. -
--The generic character of the comparison was intended, so -there are basically two approaches to fix the problem: The -first one would define the semantics of the comparison -using the traits class ST (The semantic of basic_string::compare -is defined in terms of the compare function of the corresponding -traits class), the second one would define the semantics of the -comparison using the traits class -
- -- -std::char_traits<iterator_traits<BiIter>::value_type> -
-which is essentially identical to -
- -- -std::char_traits<sub_match<BiIter>::value_type> -
-I suggest to follow the second approach, because -this emphasizes the central role of the sub_match -object as part of the comparison and would also -make sure that a sub_match comparison using some -basic_string<char_t, ..> always is equivalent to -a corresponding comparison with a string literal -because of the existence of further overloads (beginning -from 28.9.2 [re.submatch.op]/19). If users really want to -take advantage of their own traits::compare, they can -simply write a corresponding compare function that -does so. -
- - -Proposed resolution:
--In 28.9.2 [re.submatch.op] change as indicated: -
- --If 1180 is accepted: -
- --- -template <class BiIter, class ST, class SA> - bool operator==( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); ---7 Returns:- -lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) == -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator!=( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --8 Returns:- -lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) != -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator<( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --9 Returns:- -lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) < -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator>( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --10 Returns:- -lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) > -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator>=( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --11 Returns:- -lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) >= -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator<=( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --12 Returns:- -lhstypename -sub_match<BiIter>::string_type(lhs.begin(), lhs.end()) <= -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator==(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --13 Returns: lhs.str() ==- -rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator!=(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --14 Returns: lhs.str() !=- -rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator<(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --15 Returns: lhs.str() <- -rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator>(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --16 Returns: lhs.str() >- -rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator>=(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --17 Returns: lhs.str() >=- -rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator<=(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --18 Returns: lhs.str() <=-rhstypename -sub_match<BiIter>::string_type(rhs.begin(), rhs.end()). -
-If 1180 is not accepted: -
- --- -template <class BiIter, class ST, class SA> - bool operator==( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); ---7 Returns:- -lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) == -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator!=( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --8 Returns:- -lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) != -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator<( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --9 Returns:- -lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) < -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator>( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --10 Returns:- -lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) > -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator>=( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --11 Returns:- -lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) >= -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator<=( - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, - const sub_match<BiIter>& rhs); -- --12 Returns:- -lhsbasic_string<typename -sub_match<BiIter>::value_type>(lhs.begin(), lhs.end()) <= -rhs.str(). -template <class BiIter, class ST, class SA> - bool operator==(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --13 Returns: lhs.str() ==- -rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator!=(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --14 Returns: lhs.str() !=- -rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator<(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --15 Returns: lhs.str() <- -rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator>(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --16 Returns: lhs.str() >- -rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator>=(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --17 Returns: lhs.str() >=- -rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -template <class BiIter, class ST, class SA> - bool operator<=(const sub_match<BiIter>& lhs, - const basic_string< - typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); -- --18 Returns: lhs.str() <=-rhsbasic_string<typename -sub_match<BiIter>::value_type>(rhs.begin(), rhs.end()). -
Section: 20.7.16 [unord.hash] Status: New - Submitter: Alisdair Meredith Opened: 2009-07-28 Last modified: 2009-09-21
-View other active issues in [unord.hash].
-View all other issues in [unord.hash].
-View all issues with New status.
-Discussion:
--The implied library dependencies created by spelling out all the hash -template specializations in the <functional> synopsis are unfortunate. -The potential coupling is greatly reduced if the hash specialization is -declared in the appropriate header for each library type, as it is much -simpler to forward declare the primary template and provide a single -specialization than it is to implement a hash function for a string or -vector without providing a definition for the whole string/vector -template in order to access the necessary bits. -
- --Note that the proposed resolution purely involves moving the -declarations of a few specializations, it specifically does not make any -changes to 20.7.16 [unord.hash]. -
- -[ -2009-09-15 Daniel adds: -]
- - ---
-I suggest to add to the current existing -proposed resolution the following items. -
- --Add to the very first strike-list of the currently suggested resolution -the following lines: -
- --template <> struct hash<std::error_code>;-template <> struct hash<std::thread::id>;-
-Add the following declarations to 19.5 [syserr], header -<system_error> synopsis after // 19.5.4: -
- ---// 19.5.x hash support -template <class T> struct hash; -template <> struct hash<error_code>; - -
-Add a new clause 19.5.X (probably after 19.5.4): -
- ----19.5.X Hash support [syserr.hash] -
- --template <> struct hash<error_code>; -- --An explicit specialization of the class template hash (20.7.16 [unord.hash]) -shall be provided -for the type error_code suitable for using this type as key in -unordered associative -containers (23.5 [unord]). --
-Add the following declarations to 30.3.1.1 [thread.thread.id] just after the -declaration of -the comparison operators: -
- ---template <class T> struct hash; -template <> struct hash<thread::id>; -
-Add a new paragraph at the end of 30.3.1.1 [thread.thread.id]: -
- ----template <> struct hash<thread::id>; -- --An explicit specialization of the class template hash (20.7.16 [unord.hash]) -shall be provided -for the type thread::id suitable for using this type as key in -unordered associative -containers (23.5 [unord]). --
Proposed resolution:
--Strike the following specializations declared in the <functional> -synopsis p2 20.7 [function.objects] -
- -- -template <> struct hash<std::string>;-template <> struct hash<std::u16string>;-template <> struct hash<std::u32string>;-template <> struct hash<std::wstring>;- -template <class Allocator> struct hash<std::vector<bool, Allocator> >;-template <std::size_t N> struct hash<std::bitset<N> >;-
-Add the following declarations to the synopsis of <string> in -21.3 [string.classes] -
- -- -// 21.4.x hash support -template <class T> struct hash; -template <> struct hash<string>; -template <> struct hash<u16string>; -template <> struct hash<u32string>; -template <> struct hash<wstring>; -
-Add a new clause 21.4.X -
- --- --21.4.X Hash support [basic.string.hash] -
- -template <> struct hash<string>; -template <> struct hash<u16string>; -template <> struct hash<u32string>; -template <> struct hash<wstring>; -- --Explicit specializations of the class template hash (20.7.16 [unord.hash]) -shall be provided for the types string, u16string, -u32string and wstring suitable for using these types as keys in -unordered associative containers (23.5 [unord]). --
-Add the following declarations to the synopsis of <vector> in -23.3 [sequences] -
- -- --// 21.4.x hash support -template <class T> struct hash; -template <class Allocator> struct hash<vector<bool, Allocator>>; -
-Add a new paragraph to the end of 23.3.7 [vector.bool] -
- -- -template <class Allocator> struct hash<vector<bool, Allocator>>; ---A partial specialization of the class template hash (20.7.16 [unord.hash]) -shall be provided for vectors of boolean values suitable for use as a key -in unordered associative containers (23.5 [unord]). --
-Add the following declarations to the synopsis of <bitset> -in 20.3.7 [template.bitset] -
- -- --// 20.3.6.X hash support -template <class T> struct hash; -template <size_t N> struct hash<bitset<N> >; -
-Add a new subclause 20.3.6.X [bitset.hash] -
- --- - - - - - --20.3.6.X bitset hash support [bitset.hash] -
- -template <size_t N> struct hash<bitset<N> >; -- --A partial specialization of the class template hash -(20.7.16 [unord.hash]) shall be provided for bitsets suitable for use as a key in -unordered associative containers (23.5 [unord]). --
Section: 27.5.4.2 [basic.ios.members] Status: Open - Submitter: Daniel Krügler Opened: 2009-07-28 Last modified: 2009-10-22
-View other active issues in [basic.ios.members].
-View all other issues in [basic.ios.members].
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-Discussion:
--The protected member function set_rdbuf had been added during the -process of adding move and swap semantics to IO classes. A relevant -property of this function is described by it's effects in -27.5.4.2 [basic.ios.members]/19: -
- --Effects: Associates the basic_streambuf object pointed to by sb with -this stream without calling clear(). -- -
-This means that implementors of or those who derive from existing IO classes -could cause an internal state where the stream buffer could be 0, but the -IO class has the state good(). This would break several currently existing -implementations which rely on the fact that setting a stream buffer via the -currently only ways, i.e. either by calling -
- -- -void init(basic_streambuf<charT,traits>* sb); -
-or by calling -
- -- -basic_streambuf<charT,traits>* rdbuf(basic_streambuf<charT,traits>* sb); -
-to set rdstate() to badbit, if the buffer is 0. This has the effect that many -internal functions can simply check rdstate() instead of rdbuf() for being 0. -
- --I therefore suggest that a requirement is added for callers of set_rdbuf to -set a non-0 value. -
- -[ -2009-10 Santa Cruz: -]
- - --Moved to Open. Martin volunteers to provide new wording, where -set_rdbuf() sets the badbit but does not cause an -exception to be thrown like a call to clear() would. -- -
[ -2009-10-20 Martin provides wording: -]
- - - - -Proposed resolution:
--Change 27.5.4.2 [basic.ios.members] around p. 19 as indicated: -
- -- - -void set_rdbuf(basic_streambuf<charT, traits>* sb); -- ---- -
-Effects: Associates the basic_streambuf object pointed -to by sb with this stream without calling clear(). -Postconditions: rdbuf() == sb. --Effects: As if: -
- -- --iostate state = rdstate(); -try { rdbuf(sb); } -catch(ios_base::failure) { - if (0 == (state & ios_base::badbit)) - unsetf(badbit); -} --Throws: Nothing. -
- -
Rationale:
-We need to be able to call set_rdbuf() on stream objects -for which (rdbuf() == 0) holds without causing ios_base::failure to -be thrown. We also don't want badbit to be set as a result of -setting rdbuf() to 0 if it wasn't set before the call. This changed -Effects clause maintains the current behavior (as of N2914) without -requiring that sb be non-null. - - - - - -Section: 24.2 [iterator.requirements] Status: New - Submitter: Alisdair Meredith Opened: 2009-07-31 Last modified: 2009-07-31
-View other active issues in [iterator.requirements].
-View all other issues in [iterator.requirements].
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-Discussion:
--(wording relative to -N2723 -pending new working paper) -
- --According to p3 24.2 [iterator.requirements], Forward iterators, -Bidirectional iterators and Random Access iterators all satisfy the -requirements for an Output iterator: -
- --XXX iterators satisfy all the requirements of the input and output iterators -and can be used whenever either kind is specified ... -- -
-Meanwhile, p4 goes on to contradict this: -
- --Besides its category, a forward, bidirectional, or random access -iterator can also be mutable or constant... -- -
-... Constant iterators do not satisfy the requirements for output iterators -- -
-The latter seems to be the overriding concern, as the iterator tag -hierarchy does not define forward_iterator_tag as multiply derived from -both input_iterator_tag and output_iterator_tag. -
- --The work on concepts for iterators showed us that output iterator really -is fundamentally a second dimension to the iterator categories, rather -than part of the linear input -> forward -> bidirectional -> -random-access sequence. It would be good to clear up these words to -reflect that, and separately list output iterator requirements in the -requires clauses for the appropriate algorithms and operations. -
- - -Proposed resolution:
- - - - - -Section: 23.3.5.3 [stack] Status: Tentatively NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-07-31 Last modified: 2009-11-02
-Discussion:
--The library template forward_list could easily model the idea of a -stack, where the operations work on the front of the list rather than -the back. However, the standard library stack adaptor cannot support -this. -
- --It would be relatively easy to write a partial specialization for stack -to support forward_list, but that opens the question of which header to -place it in. A much better solution would be to add a concept_map for -the StackLikeContainer concept to the <forward_list> header and then -everything just works, including a user's own further uses in a -stack-like context. -
- --Therefore while I am submitting the issue now so that it is on record, I -strongly recommend we resolve as "NAD Concepts" as any non-concepts -based solution will be inferior to the final goal, and the feature is -not so compelling it must be supported ahead of the concepts-based -library. -
- -[ -2009-11-02 Howard adds: -]
- - --Moved to Tentatively NAD Concepts after 5 positive votes on c++std-lib. -- - -
Proposed resolution:
- - - - - -Section: 20.6.7 [meta.trans.other] Status: New - Submitter: Jason Merrill Opened: 2009-08-07 Last modified: 2009-08-22
-View all other issues in [meta.trans.other].
-View all issues with New status.
-Discussion:
--I notice that std::decay is specified to strip the cv-quals from -anything but an array or pointer. This seems incorrect for values of -class type, since class rvalues can have cv-qualified type (3.10 [basic.lval]/9). -
- -[ -2009-08-09 Howard adds: -]
- - --See the thread starting with c++std-lib-24568 for further discussion. And -here is a convenience link to the -original proposal. -Also see the closely related issue 705. -- - -
Proposed resolution:
- --Add a note to decay in 20.6.7 [meta.trans.other]: -
- --[Note: This behavior is similar to the lvalue-to-rvalue (4.1), -array-to-pointer (4.2), and function-to-pointer (4.3) conversions -applied when an lvalue expression is used as an rvalue, but also strips -cv-qualifiers from class types in order to more closely model by-value -argument passing. — end note] -- - - - - - - - -
Section: 23.2.5 [unord.req], 23.5 [unord] Status: New - Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2009-08-11
-View other active issues in [unord.req].
-View all other issues in [unord.req].
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-Discussion:
--Unordered associative containers have a notion of a maximum load factor: -when the number of elements grows large enough, the containers -automatically perform a rehash so that the number of elements per bucket -stays below a user-specified bound. This ensures that the hash table's -performance characteristics don't change dramatically as the size -increases. -
- --For similar reasons, Google has found it useful to specify a minimum -load factor: when the number of elements shrinks by a large enough, the -containers automatically perform a rehash so that the number of elements -per bucket stays above a user-specified bound. This is useful for two -reasons. First, it prevents wasting a lot of memory when an unordered -associative container grows temporarily. Second, it prevents amortized -iteration time from being arbitrarily large; consider the case of a hash -table with a billion buckets and only one element. (This was discussed -even before TR1 was published; it was TR issue 6.13, which the LWG -closed as NAD on the grounds that it was a known design feature. -However, the LWG did not consider the approach of a minimum load -factor.) -
- --The only interesting question is when shrinking is allowed. In principle -the cleanest solution would be shrinking on erase, just as we grow on -insert. However, that would be a usability problem; it would break a -number of common idioms involving erase. Instead, Google's hash tables -only shrink on insert and rehash. -
- --The proposed resolution allows, but does not require, shrinking in -rehash, mostly because a postcondition for rehash that involves the -minimum load factor would be fairly complicated. (It would probably have -to involve a number of special cases and it would probably have to -mention yet another parameter, a minimum bucket count.) -
- --The current behavior is equivalent to a minimum load factor of 0. If we -specify that 0 is the default, this change will have no impact on -backward compatibility. -
- - -Proposed resolution:
--Add two new rows, and change rehash's postcondition in the unordered -associative container requirements table in 23.2.5 [unord.req]: -
- --- --
-Table 87 — Unordered associative container requirements -(in addition to container) - -- -Expression Return type Assertion/note pre-/post-condition -Complexity -- - --a.min_load_factor() - --float - --Returns a non-negative number that the container attempts to keep the -load factor greater than or equal to. The container automatically -decreases the number of buckets as necessary to keep the load factor -above this number. - --constant - -- -a.min_load_factor(z) -void -Pre: z shall be non-negative. Changes the container's minimum -load factor, using z as a hint. [Footnote: the minimum -load factor should be significantly smaller than the maximum. -If z is too large, the implementation may reduce it to a more sensible value.] - --constant - -- -a.rehash(n) -void --Post: a.bucket_count() >= n, and a.size() <= a.bucket_count() -* a.max_load_factor(). [Footnote: It is intentional that the -postcondition does not mention the minimum load factor. -This member function is primarily intended for cases where the user knows -that the container's size will increase soon, in which case the container's -load factor will temporarily fall below a.min_load_factor().] - --a.bucket_cout > a.size() / a.max_load_factor() and a.bucket_count() ->= n. ---Average case linear in a.size(), worst case quadratic. - -
-Add a footnote to 23.2.5 [unord.req] p12: -
- --- --The insert members shall not affect the validity of references to -container elements, but may invalidate all iterators to the container. -The erase members shall invalidate only iterators and references to the -erased elements. -
- --[A consequence of these requirements is that while insert may change the -number of buckets, erase may not. The number of buckets may be reduced -on calls to insert or rehash.] --
-Change paragraph 13: -
- --The insert members shall not affect the validity of iterators if -- -(N+n) < z * Bzmin * B <= (N+n) <= zmax * B, -where N is the number of elements in -the container prior to the insert operation, n is the number of -elements inserted, B is the container's bucket count, -zmin is the container's minimum load factor, -and zmax is the container's maximum load factor. -
-Add to the unordered_map class synopsis in section 23.5.1 [unord.map], -the unordered_multimap class synopsis -in 23.5.2 [unord.multimap], the unordered_set class synopsis in -23.5.3 [unord.set], and the unordered_multiset class synopsis -in 23.5.4 [unord.multiset]: -
- -- --float min_load_factor() const; -void min_load_factor(float z); -
-In 23.5.1.1 [unord.map.cnstr], 23.5.2.1 [unord.multimap.cnstr], 23.5.3.1 [unord.set.cnstr], and -23.5.4.1 [unord.multiset.cnstr], change: -
- --... max_load_factor() returns 1.0 and -min_load_factor() returns 0. -- - - - - -
Section: 23.2.5 [unord.req], 23.5 [unord] Status: Tentatively Ready - Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2009-10-28
-View other active issues in [unord.req].
-View all other issues in [unord.req].
-View all issues with Tentatively Ready status.
-Discussion:
--Consider a typical use case: I create an unordered_map and then start -adding elements to it one at a time. I know that it will eventually need -to store a few million elements, so, for performance reasons, I would -like to reserve enough capacity that none of the calls to insert will -trigger a rehash. -
- --Unfortunately, the existing interface makes this awkward. The user -naturally sees the problem in terms of the number of elements, but the -interface presents it as buckets. If m is the map and n is the expected -number of elements, this operation is written m.rehash(n / -m.max_load_factor()) — not very novice friendly. -
- -[ -2009-09-30 Daniel adds: -]
- - --I recommend to replace "resize" by a different name like -"reserve", because that would better match the intended -use-case. Rational: Any existing resize function has the on-success -post-condition that the provided size is equal to size(), which -is not satisfied for the proposal. Reserve seems to fit the purpose of -the actual renaming suggestion. -- -
[ -2009-10-28 Ganesh summarizes alternative resolutions and expresses a -strong preference for the second (and opposition to the first): -]
- - --- --
-- -
--In the unordered associative container requirements (23.2.5 [unord.req]), -remove the row for -rehash and replace it with: -
- --- --
-Table 87 — Unordered associative container requirements -(in addition to container) - -- -Expression Return type Assertion/note pre-/post-condition -Complexity -- -a. -rehashreserve(n)void --Post: a.bucket_count > max(a.size(), n) -/ a.max_load_factor() -and a.bucket_count() ->= n. --Average case linear in a.size(), worst case quadratic. - --Make the corresponding change in the class synopses in 23.5.1 -[unord.map], 23.5.2 [unord.multimap], 23.5.3 [unord.set], and 23.5.4 -[unord.multiset]. -
-- - -
--In 23.2.5 [unord.req]/9, table 98, append a new row after the last one: -
- --- --
-Table 87 — Unordered associative container requirements -(in addition to container) - -- -Expression Return type Assertion/note pre-/post-condition -Complexity -- -a.rehash(n) -void --Post: a.bucket_count > a.size() -/ a.max_load_factor() and a.bucket_count() ->= n. - --Average case linear in a.size(), worst case quadratic. - -- --a.reserve(n) - --void - --Same as a.rehash(ceil(n / a.max_load_factor())) - --Average case linear in a.size(), worst case quadratic. - --In 23.5.1 [unord.map]/3 in the definition of class template unordered_map, in -23.5.2 [unord.multimap]/3 in the definition of class template unordered_multimap, in -23.5.3 [unord.set]/3 in the definition of class template unordered_set and in -23.5.4 [unord.multiset]/3 in the definition of class template unordered_multiset, add the -following line after member function rehash(): -
- -- -void reserve(size_type n); -
[ -2009-10-28 Howard: -]
- - --- - --Moved to Tentatively Ready after 5 votes in favor of Ganesh's option 2 above. -The original proposed wording now appears here: -
- ----Informally: instead of providing rehash(n) provide resize(n), with the -semantics "make the container a good size for n elements". -
- --In the unordered associative container requirements (23.2.5 [unord.req]), -remove the row for -rehash and replace it with: -
- --- --
-Table 87 — Unordered associative container requirements -(in addition to container) - -- -Expression Return type Assertion/note pre-/post-condition -Complexity -- -a. -rehashresize(n)void --Post: a.bucket_count > max(a.size(), n) -/ a.max_load_factor() -and a.bucket_count() ->= n. --Average case linear in a.size(), worst case quadratic. - -Make the corresponding change in the class synopses in 23.5.1 -[unord.map], 23.5.2 [unord.multimap], 23.5.3 [unord.set], and 23.5.4 -[unord.multiset]. -
- -
Proposed resolution:
--In 23.2.5 [unord.req]/9, table 98, append a new row after the last one: -
- --- --
-Table 87 — Unordered associative container requirements -(in addition to container) - -- -Expression Return type Assertion/note pre-/post-condition -Complexity -- -a.rehash(n) -void --Post: a.bucket_count > a.size() -/ a.max_load_factor() and a.bucket_count() ->= n. - --Average case linear in a.size(), worst case quadratic. - -- --a.reserve(n) - --void - --Same as a.rehash(ceil(n / a.max_load_factor())) - --Average case linear in a.size(), worst case quadratic. - -
-In 23.5.1 [unord.map]/3 in the definition of class template unordered_map, in -23.5.2 [unord.multimap]/3 in the definition of class template unordered_multimap, in -23.5.3 [unord.set]/3 in the definition of class template unordered_set and in -23.5.4 [unord.multiset]/3 in the definition of class template unordered_multiset, add the -following line after member function rehash(): -
- -- - - - - -void reserve(size_type n); -
Section: 23.2.5 [unord.req], 23.5 [unord] Status: New - Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2009-08-11
-View other active issues in [unord.req].
-View all other issues in [unord.req].
-View all issues with New status.
-Discussion:
--The unordered associative container requirements table specifies that -a.set_max_load_factor(z) has return type void. However, there is a -useful piece of information to return: the previous value. Users who -don't need it can always ignore it. -
- - -Proposed resolution:
--In the unordered associative container requirements table, change: -
- --- --
-Table 87 — Unordered associative container requirements -(in addition to container) - -- - -Expression Return type Assertion/note pre-/post-condition -Complexity -- -a.max_load_factor(z) -- voidfloatPre: z shall be positive. Changes the container's maximum - -loadload factor, using z as a hint. -Returns: the previous value of -a.max_load_factor(). --constant - --
-Change the return type of set_max_load_factor -in the class synopses in 23.5.1 [unord.map], 23.5.2 [unord.multimap], 23.5.3 [unord.set], -and 23.5.4 [unord.multiset]. -
- --If issue 1188 is also accepted, make the same changes for -min_load_factor. -
- - - - - -Section: 20.5.2.6 [tuple.elem] Status: Open - Submitter: Alisdair Meredith Opened: 2009-08-18 Last modified: 2009-10-31
-View all issues with Open status.
-Discussion:
--The tuple get API should respect rvalues. This would allow for moving a -single element out of a tuple-like type. -
- -[ -2009-10-30 Alisdair adds: -]
- - --- - - --The issue of rvalue overloads of get for tuple-like types was briefly -discussed in Santa Cruz. -
- --The feedback was this would be welcome, but we need full wording for the -other types (pair and array) before advancing. -
- --I suggest the issue moves to Open from New as it has been considered, -feedback given, and it has not (yet) been rejected as NAD. -
-
Proposed resolution:
--Add the following signature to p2 20.5.1 [tuple.general] -
- -- --template <size_t I, class ... Types> -typename tuple_element<I, tuple<Types...> >::type&& get(tuple<Types...> &&); -
-And again to 20.5.2.6 [tuple.elem]. -
- -- --template <size_t I, class ... Types> -typename tuple_element<I, tuple<Types...> >::type&& get(tuple<Types...>&& t); -- ----Effects: Equivalent to return std::forward<typename tuple_element<I, tuple<Types...> >::type&&>(get<I>(t)); -
- - --[Note: If a T in Types is some reference type X&, -the return type is X&, not X&&. -However, if the element type is non-reference type T, -the return type is T&&. — end note] -
- -
-Add the following signature to p1 20.3 [utility] -
- -- --template <size_t I, class T1, class T2> -typename tuple_element<I, pair<T1,T2> >::type&& get(pair<T1, T2>&&); -
-And to p5 20.3.5 [pair.astuple] -
- -- --template <size_t I, class T1, class T2> -typename tuple_element<I, pair<T1,T2> >::type&& get(pair<T1, T2>&& p); -- --- --Returns: If I == 0 returns std::forward<T1&&>(p.first); -if I == 1 -returns std::forward<T2&&>(p.second); otherwise the program is ill-formed. -
- --Throws: Nothing. -
- -
-Add the following signature to 23.3 [sequences] <array> synopsis -
- -- -template <size_t I, class T, size_t N> -T&& get(array<T,N> &&); -
-And after p8 23.3.1.7 [array.tuple] -
- -- - - - - - -template <size_t I, class T, size_t N> -T&& get(array<T,N> && a); -- --Effects: Equivalent to return std::move(get<I>(a)); --
Section: 21.4.3 [string.iterators] Status: Tentatively Ready - Submitter: Jonathan Wakely Opened: 2009-08-14 Last modified: 2009-10-29
-View all issues with Tentatively Ready status.
-Discussion:
--Unlike the containers in clause 23, basic_string has definitions for -begin() and end(), but these have not been updated to include cbegin, -cend, crbegin and crend. -
- -[ -2009-10-28 Howard: -]
- - --Moved to Tentatively NAD after 5 positive votes on c++std-lib. Added -rationale. -- -
[ -2009-10-28 Alisdair disagrees: -]
- - --- --I'm going to have to speak up as the dissenting voice. -
- --I agree the issue could be handled editorially, and that would be my -preference if Pete feels this is appropriate. Failing that, I really -think this issue should be accepted and moved to ready. The other -begin/end functions all have a semantic definition for this template, -and it is confusing if a small few are missing. -
- --I agree that an alternative would be to strike all the definitions for -begin/end/rbegin/rend and defer completely to the requirements tables in -clause 23. I think that might be confusing without a forward reference -though, as those tables are defined in a *later* clause than the -basic_string template itself. If someone wants to pursue this I would -support it, but recommend it as a separate issue. -
- --So my preference is strongly to move Ready over NAD, and a stronger -preference for NAD Editorial if Pete is happy to make these changes. -
- -
[ -2009-10-29 Howard: -]
- - --Moved to Tentatively Ready after 5 positive votes on c++std-lib. Removed -rationale to mark it NAD. :-) -- - - -
Proposed resolution:
--Add to 21.4.3 [string.iterators] -
- -- - - - - -iterator begin(); -const_iterator begin() const; -const_iterator cbegin() const; -- -...
- -iterator end(); -const_iterator end() const; -const_iterator cend() const; -- -...
- -reverse_iterator rbegin(); -const_reverse_iterator rbegin() const; -const_reverse_iterator crbegin() const; -- -...
- -reverse_iterator rend(); -const_reverse_iterator rend() const; -const_reverse_iterator crend() const; -- -
Section: 20.8.14.1 [unique.ptr.dltr] Status: New - Submitter: Daniel Krügler Opened: 2009-08-18 Last modified: 2009-08-22
-View all issues with New status.
-Discussion:
--According to the general rules of 17.6.3.8 [res.on.functions]/2 b 5 the effects -are undefined, if an incomplete type is used to instantiate a library template. But neither in -20.8.14.1 [unique.ptr.dltr] nor -in any other place of the standard such explicit allowance is given. -Since this template is intended to be instantiated with incomplete -types, this must -be fixed. -
- - -Proposed resolution:
--Add two new paragraphs directly to 20.8.14.1 [unique.ptr.dltr] (before -20.8.14.1.1 [unique.ptr.dltr.dflt]) with the following -content: -
- --- - - - - --The class template default_delete serves as the default deleter (destruction policy) for -the class template unique_ptr. -
- --The template parameter T of default_delete may be an incomplete type. -
-
Section: 23.3.5 [container.adaptors] Status: Ready - Submitter: Howard Hinnant Opened: 2009-08-20 Last modified: 2009-10-20
-View other active issues in [container.adaptors].
-View all other issues in [container.adaptors].
-View all issues with Ready status.
-Discussion:
--23.3.5.1.1 [queue.defn] has the following queue constructor: -
- -- -template <class Alloc> explicit queue(const Alloc&); -
-This will be implemented like so: -
- -template <class Alloc> explicit queue(const Alloc& a) : c(a) {}
--The issue is that Alloc can be anything that a container will construct -from, for example an int. Is this intended to compile? -
- -- -queue<int> q(5); -
-Before the addition of this constructor, queue<int>(5) would not compile. -I ask, not because this crashes, but because it is new and appears to be -unintended. We do not want to be in a position of accidently introducing this -"feature" in C++0X and later attempting to remove it. -
- --I've picked on queue. priority_queue and stack have -the same issue. Is it useful to create a priority_queue of 5 -identical elements? -
- -[ -Daniel, Howard and Pablo collaborated on the proposed wording. -]
- - -[ -2009-10 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
- -[ -This resolution includes a semi-editorial clean up, giving definitions to members -which in some cases weren't defined since C++98. -This resolution also offers editorially different wording for 976, -and it also provides wording for 1196. -]
- - --Change container.adaptors, p1: -
- --The container adaptors each take a Container template parameter, and -each constructor takes a Container reference argument. This container is -copied into the Container member of each adaptor. If the container takes -an allocator, then a compatible allocator may be passed in to the -adaptor's constructor. Otherwise, normal copy or move construction is -used for the container argument.- -[Note: it is not necessary for an -implementation to distinguish between the one-argument constructor that -takes a Container and the one- argument constructor that takes an -allocator_type. Both forms use their argument to construct an instance -of the container. — end note]-
-Change queue.defn, p1: -
- -template <class T, class Container = deque<T> >
-class queue {
-public:
- typedef typename Container::value_type value_type;
- typedef typename Container::reference reference;
- typedef typename Container::const_reference const_reference;
- typedef typename Container::size_type size_type;
- typedef Container container_type;
-protected:
- Container c;
-
-public:
- explicit queue(const Container&);
- explicit queue(Container&& = Container());
- queue(queue&& q); : c(std::move(q.c)) {}
- template <class Alloc> explicit queue(const Alloc&);
- template <class Alloc> queue(const Container&, const Alloc&);
- template <class Alloc> queue(Container&&, const Alloc&);
- template <class Alloc> queue(queue&&, const Alloc&);
- queue& operator=(queue&& q); { c = std::move(q.c); return *this; }
-
- bool empty() const { return c.empty(); }
- ...
-};
--Add a new section after 23.3.5.1.1 [queue.defn], [queue.cons]: -
- --- -queue constructors [queue.cons]
- -explicit queue(const Container& cont); -- -- -- --Effects: Initializes c with cont. -
- -explicit queue(Container&& cont = Container()); -- -- -- --Effects: Initializes c with std::move(cont). -
- -queue(queue&& q) -- -- -- --Effects: Initializes c with std::move(q.c). -
- --For each of the following constructors, -if uses_allocator<container_type, Alloc>::value is false, -then the constructor shall not participate in overload resolution. -
- -template <class Alloc> - explicit queue(const Alloc& a); -- -- -- --Effects: Initializes c with a. -
- -template <class Alloc> - queue(const container_type& cont, const Alloc& a); -- -- -- --Effects: Initializes c with cont as the first -argument and a as the second argument. -
- -template <class Alloc> - queue(container_type&& cont, const Alloc& a); -- -- -- --Effects: Initializes c with std::move(cont) as the -first argument and a as the second argument. -
- -template <class Alloc> - queue(queue&& q, const Alloc& a); -- -- -- --Effects: Initializes c with std::move(q.c) as the -first argument and a as the second argument. -
- -queue& operator=(queue&& q); -- -- -- - - --Effects: Assigns c with std::move(q.c). -
- --Returns: *this. -
- -
-Add to 23.3.5.2.1 [priqueue.cons]: -
- -- -- - - - -priority_queue(priority_queue&& q); -- -- -- --Effects: Initializes c with std::move(q.c) and -initializes comp with std::move(q.comp). -
- --For each of the following constructors, -if uses_allocator<container_type, Alloc>::value is false, -then the constructor shall not participate in overload resolution. -
- -template <class Alloc> - explicit priority_queue(const Alloc& a); -- -- -- --Effects: Initializes c with a and value-initializes comp. -
- -template <class Alloc> - priority_queue(const Compare& compare, const Alloc& a); -- -- -- --Effects: Initializes c with a and initializes comp -with compare. -
- -template <class Alloc> - priority_queue(const Compare& compare, const Container& cont, const Alloc& a); -- -- -- --Effects: Initializes c with cont as the first argument -and a as the second argument, -and initializes comp with compare. -
- -template <class Alloc> - priority_queue(const Compare& compare, Container&& cont, const Alloc& a); -- -- -- --Effects: Initializes c with std::move(cont) as -the first argument and a as the second argument, -and initializes comp with compare. -
- -template <class Alloc> - priority_queue(priority_queue&& q, const Alloc& a); -- -- -- --Effects: Initializes c with std::move(q.c) as the -first argument and a as the second argument, -and initializes comp with std::move(q.comp). -
- -priority_queue& operator=(priority_queue&& q); -- -- -- --Effects: Assigns c with std::move(q.c) and -assigns comp with std::move(q.comp). -
- --Returns: *this. -
- -
-Change 23.3.5.3.1 [stack.defn]: -
- -template <class T, class Container = deque<T> >
-class stack {
-public:
- typedef typename Container::value_type value_type;
- typedef typename Container::reference reference;
- typedef typename Container::const_reference const_reference;
- typedef typename Container::size_type size_type;
- typedef Container container_type;
-protected:
- Container c;
-
-public:
- explicit stack(const Container&);
- explicit stack(Container&& = Container());
- stack(stack&& s);
- template <class Alloc> explicit stack(const Alloc&);
- template <class Alloc> stack(const Container&, const Alloc&);
- template <class Alloc> stack(Container&&, const Alloc&);
- template <class Alloc> stack(stack&&, const Alloc&);
- stack& operator=(stack&& s);
-
- bool empty() const { return c.empty(); }
- ...
-};
--Add a new section after 23.3.5.3.1 [stack.defn], [stack.cons]: -
- --- - - - - - -stack constructors [stack.cons]
- -stack(stack&& s); -- -- -- --Effects: Initializes c with std::move(s.c). -
- --For each of the following constructors, -if uses_allocator<container_type, Alloc>::value is false, -then the constructor shall not participate in overload resolution. -
- -template <class Alloc> - explicit stack(const Alloc& a); -- -- -- --Effects: Initializes c with a. -
- -template <class Alloc> - stack(const container_type& cont, const Alloc& a); -- -- -- --Effects: Initializes c with cont as the -first argument and a as the second argument. -
- -template <class Alloc> - stack(container_type&& cont, const Alloc& a); -- -- -- --Effects: Initializes c with std::move(cont) as the -first argument and a as the second argument. -
- -template <class Alloc> - stack(stack&& s, const Alloc& a); -- -- -- --Effects: Initializes c with std::move(s.c) as the -first argument and a as the second argument. -
- -stack& operator=(stack&& s); -- -- -- --Effects: Assigns c with std::move(s.c). -
- --Returns: *this. -
- -
Section: 23.2.5 [unord.req] Status: New - Submitter: Howard Hinnant Opened: 2009-08-24 Last modified: 2009-09-03
-View other active issues in [unord.req].
-View all other issues in [unord.req].
-View all issues with New status.
-Discussion:
--Table 97 "Unordered associative container requirements" in -23.2.5 [unord.req] says: -
- --- --
-Table 97 — Unordered associative container requirements -(in addition to container) - -- - -Expression -Return type -Assertion/note pre-/post-condition -Complexity -- - -b.bucket(k) -size_type -Returns the index of the bucket in which elements with keys -equivalent to k would be found, -if any such element existed. -Post: the return value shall be -in the range [0, -b.bucket_count()). -Constant -
-What should b.bucket(k) return if b.bucket_count() == 0? -
- --I believe allowing b.bucket_count() == 0 is important. It is a -very reasonable post-condition of the default constructor, or of a moved-from -container. -
- --I can think of several reasonable results from b.bucket(k) when -b.bucket_count() == 0: -
- -[ -2009-08-26 Daniel adds: -]
- - --@@ -23718,1897 +2113,12 @@ b.bucket_count()), otherwise 0. --A forth choice would be to add the pre-condition "b.bucket_count() != 0" -and thus imply undefined behavior if this is violated. -
- -[ -Howard: I like this option too, added to the list. -]
- - --Further on here my own favorite solution (rationale see below): -
- -Suggested resolution:
- --[Rationale: I suggest to follow choice (1). The main reason is -that all associative container functions which take a key argument, -are basically free of pre-conditions and non-disrupting, therefore -excluding choices (3) and (4). Option (2) seems a bit unexpected -to me. It would be more natural, if several similar functions -would exist which would also justify the existence of a symbolic -constant like npos for this situation. The value 0 is both simple -and consistent, it has exactly the same role as a past-the-end -iterator value. A typical use-case is: -
- -- -size_type pos = m.bucket(key); -if (pos != m.bucket_count()) { - ... -} else { - ... -} -— end Rationale]
- --- Change Table 97 in 23.2.5 [unord.req] as follows (Row b.bucket(k), Column "Assertion/..."): -
- --- +Move to Open.-
-Table 97 — Unordered associative container requirements -(in addition to container) - -- - -Expression -Return type -Assertion/note pre-/post-condition -Complexity -- - -b.bucket(k) -size_type -Returns the index of the bucket in which elements with keys -equivalent to k would be found, -if any such element existed. -Post: if b.bucket_count() != 0, the return value shall be -in the range [0, -b.bucket_count()), otherwise 0. -Constant -
Section: 23.3.5 [container.adaptors] Status: New - Submitter: Pablo Halpern Opened: 2009-08-26 Last modified: 2009-09-30
-View other active issues in [container.adaptors].
-View all other issues in [container.adaptors].
-View all issues with New status.
-Discussion:
--Under 23.3.5 [container.adaptors] of -N2914 -the member function of swap of queue and stack call: -
- -- -swap(c, q.c); -
-But under 23.3.5 [container.adaptors] of -N2723 -these members are specified to call: -
- -- -c.swap(q.c); -
-Neither draft specifies the semantics of member swap for -priority_queue though it is declared. -
- --Although the distinction between member swap and non-member -swap is not important when these adaptors are adapting standard -containers, it may be important for user-defined containers. -
--We (Pablo and Howard) feel that -it is more likely for a user-defined container to support a namespace scope -swap than a member swap, and therefore these adaptors -should use the container's namespace scope swap. -
- -[ -2009-09-30 Daniel adds: -]
- - --The outcome of this issue should be considered with the outcome of 774 both in style and in content (e.g. 774 bullet 9 -suggests to define the semantic of void -priority_queue::swap(priority_queue&) in terms of the member -swap of the container). -- - - -
Proposed resolution:
-[ -Changes written with respect to -N2723. -]
- - --Change 23.3.5.1.1 [queue.defn]: -
- -template <class T, class Container = deque<T> >
-class queue {
- ...
- void swap(queue&& q) { using std::swap;
- c.swap(c, q.c); }
- ...
-};
--Change 23.3.5.2 [priority.queue]: -
- -template <class T, class Container = vector<T>,
- class Compare = less<typename Container::value_type> >
-class priority_queue {
- ...
- void swap(priority_queue&& q); { using std::swap;
- swap(c, q.c);
- swap(comp, q.comp); }
- ...
-};
--Change 23.3.5.3.1 [stack.defn]: -
- -template <class T, class Container = deque<T> >
-class stack {
- ...
- void swap(stack&& s) { using std::swap;
- c.swap(c, s.c); }
- ...
-};
-Section: 23.3.5 [container.adaptors] Status: New - Submitter: Pablo Halpern Opened: 2009-08-26 Last modified: 2009-08-31
-View other active issues in [container.adaptors].
-View all other issues in [container.adaptors].
-View all issues with New status.
-Discussion:
--queue has a constructor: -
- -- -template <class Alloc> - queue(queue&&, const Alloc&); -
-but it is missing a corresponding constructor: -
- -- -template <class Alloc> - queue(const queue&, const Alloc&); -
-The same is true of priority_queue, and stack. This -"extended copy constructor" is needed for consistency and to ensure that the -user of a container adaptor can always specify the allocator for his adaptor. -
- - - -Proposed resolution:
-[ -This resolution has been harmonized with the proposed resolution to issue -1194 -]
- - -Change 23.3.5.1.1 [queue.defn], p1:
- -template <class T, class Container = deque<T> >
-class queue {
-public:
- typedef typename Container::value_type value_type;
- typedef typename Container::reference reference;
- typedef typename Container::const_reference const_reference;
- typedef typename Container::size_type size_type;
- typedef Container container_type;
-protected:
- Container c;
-
-public:
- explicit queue(const Container&);
- explicit queue(Container&& = Container());
- queue(queue&& q);
-
- template <class Alloc> explicit queue(const Alloc&);
- template <class Alloc> queue(const Container&, const Alloc&);
- template <class Alloc> queue(Container&&, const Alloc&);
- template <class Alloc> queue(const queue&, const Alloc&);
- template <class Alloc> queue(queue&&, const Alloc&);
- queue& operator=(queue&& q);
-
- bool empty() const { return c.empty(); }
- ...
-};
--To the new section [queue.cons], introduced -in 1194, add: -
- -- -- -template <class Alloc> - queue(const queue& q, const Alloc& a); -- -- --Effects: Initializes c with q.c as the -first argument and a as the second argument. -
Change 23.3.5.2 [priority.queue] as follows (I've an included an editorial change to - move the poorly-placed move-assignment operator):
- -template <class T, class Container = vector<T>,
- class Compare = less<typename Container::value_type> >
-class priority_queue {
-public:
- typedef typename Container::value_type value_type;
- typedef typename Container::reference reference;
- typedef typename Container::const_reference const_reference;
- typedef typename Container::size_type size_type;
- typedef Container container_type;
-protected:
- Container c;
- Compare comp;
-
-public:
- priority_queue(const Compare& x, const Container&);
- explicit priority_queue(const Compare& x = Compare(), Container&& = Container());
- template <class InputIterator>
- priority_queue(InputIterator first, InputIterator last,
- const Compare& x, const Container&);
- template <class InputIterator>
- priority_queue(InputIterator first, InputIterator last,
- const Compare& x = Compare(), Container&& = Container());
- priority_queue(priority_queue&&);
- priority_queue& operator=(priority_queue&&);
- template <class Alloc> explicit priority_queue(const Alloc&);
- template <class Alloc> priority_queue(const Compare&, const Alloc&);
- template <class Alloc> priority_queue(const Compare&,
- const Container&, const Alloc&);
- template <class Alloc> priority_queue(const Compare&,
- Container&&, const Alloc&);
- template <class Alloc> priority_queue(const priority_queue&, const Alloc&);
- template <class Alloc> priority_queue(priority_queue&&, const Alloc&);
-
- priority_queue& operator=(priority_queue&&);
- ...
-};
--Add to 23.3.5.2.1 [priqueue.cons]: -
- -- -- -template <class Alloc> - explicit priority_queue(const priority_queue& q, const Alloc& a); -- -- --Effects: Initializes c with q.c as the -first argument and a as the second argument, -and initializes comp with q.comp. -
-Change 23.3.5.3.1 [stack.defn]: -
- -template <class T, class Container = deque<T> >
-class stack {
-public:
- typedef typename Container::value_type value_type;
- typedef typename Container::reference reference;
- typedef typename Container::const_reference const_reference;
- typedef typename Container::size_type size_type;
- typedef Container container_type;
-protected:
- Container c;
-
-public:
- explicit stack(const Container&);
- explicit stack(Container&& = Container());
- stack(stack&& s);
-
- template <class Alloc> explicit stack(const Alloc&);
- template <class Alloc> stack(const Container&, const Alloc&);
- template <class Alloc> stack(Container&&, const Alloc&);
- template <class Alloc> stack(const stack&, const Alloc&);
- template <class Alloc> stack(stack&&, const Alloc&);
- stack& operator=(stack&& s);
-
- bool empty() const { return c.empty(); }
- ...
-};
--To the new section [stack.cons], introduced -in 1194, add: -
- -- -- - - - - - -template <class Alloc> - stack(const stack& s, const Alloc& a); -- ---Effects: Initializes c with s.c as the -first argument and a as the second argument. -
Section: 21.2.2 [char.traits.typedefs] Status: New - Submitter: Sean Hunt Opened: 2009-09-03 Last modified: 2009-10-28
-View all other issues in [char.traits.typedefs].
-View all issues with New status.
-Discussion:
--The footnote for int_type in 21.2.2 [char.traits.typedefs] says that -
- --If eof() -can be held in char_type then some iostreams implementations may give -surprising results. -- -
-This implies that int_type should be a superset of -char_type. However, the requirements for char16_t and char32_t define -int_type to be equal to int_least16_t and int_least32_t respectively. -int_least16_t is likely to be the same size as char_16_t, which may lead -to surprising behavior, even if eof() is not a valid UTF-16 code unit. -The standard should not prescribe surprising behavior, especially -without saying what it is (it's apparently not undefined, just -surprising). The same applies for 32-bit types. -
- --I personally recommend that behavior be undefined if eof() is a member -of char_type, and another type be chosen for int_type (my personal -favorite has always been a struct {bool eof; char_type c;}). -Alternatively, the exact results of such a situation should be defined, -at least so far that I/O could be conducted on these types as long as -the code units remain valid. Note that the argument that no one streams -char16_t or char32_t is not really valid as it would be perfectly -reasonable to use a basic_stringstream in conjunction with UTF character -types. -
- -[ -2009-10-28 Ganesh provides two possible resolutions and expresses a preference -for the second: -]
- - --- - - --
-- -
--Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with: -
- --The member eof() shall return- -an implementation-defined -constant that cannot appear as a valid UTF-16 code unit-UINT_LEAST16_MAX [Note: this value is guaranteed to -be a permanently reserved UCS-2 code position if UINT_LEAST16_MAX == -0xFFFF and it's not a UCS-2 code position otherwise — end -note]. --Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with: -
- --The member eof() shall return-an implementation-defined constant that -cannot appear as a Unicode code point- -UINT_LEAST32_MAX [Note: this value is guaranteed to be a -permanently reserved UCS-4 code position if UINT_LEAST32_MAX == -0xFFFFFFFF and it's not a UCS-4 code position otherwise — end -note]. -- -
--In 21.2.3.2 [char.traits.specializations.char16_t], in the -definition of char_traits<char16_t> replace the definition of nested -typedef int_type with: -
- -- -namespace std { - template<> struct char_traits<char16_t> { - typedef char16_t char_type; - typedefuint_least16_tuint_fast16_t int_type; - ... --Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with: -
- --The member eof() shall return- -an implementation-defined -constant that cannot appear as a valid UTF-16 code unit-UINT_FAST16_MAX [Note: this value is guaranteed to -be a permanently reserved UCS-2 code position if UINT_FAST16_MAX == -0xFFFF and it's not a UCS-2 code position otherwise — end -note]. --In 21.2.3.3 [char.traits.specializations.char32_t], in the -definition of char_traits<char32_t> replace the definition of nested -typedef int_type with: -
- -- -namespace std { - template<> struct char_traits<char32_t> { - typedef char32_t char_type; - typedefuint_least32_tuint_fast32_t int_type; - ... --Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with: -
- --The member eof() shall return-an implementation-defined constant that -cannot appear as a Unicode code point- -UINT_FAST32_MAX [Note: this value is guaranteed to be a -permanently reserved UCS-4 code position if UINT_FAST32_MAX == -0xFFFFFFFF and it's not a UCS-4 code position otherwise — end -note]. -
Proposed resolution:
--
- - - - - -Section: 20.5.2.4 [tuple.creation], 20.3.4 [pairs] Status: Tentatively NAD Future - Submitter: Alisdair Meredith Opened: 2009-09-05 Last modified: 2009-10-26
-View all issues with Tentatively NAD Future status.
-Discussion:
--Spotting a recent thread on the boost lists regarding collapsing -optional representations in optional<optional<T>> instances, I wonder if -we have some of the same issues with make_tuple, and now make_pair? -
- --Essentially, if my generic code in my own library is handed a -reference_wrapper by a user, and my library in turn delegates some logic -to make_pair or make_tuple, then I am going to end up with a pair/tuple -holding a real reference rather than the intended reference wrapper. -
- --There are two things as a library author I can do at this point: -
- --(There may be some metaprogramming approaches my library can use to wrap -the make_tuple call, but all will be significantly more complex than -simply implementing a simplified make_tuple.) -
- --Now I don't propose we lose this library facility, I think unwrapping -references will be the common behaviour. However, we might want to -consider adding another overload that does nothing special with -ref-wrappers. Note that we already have a second overload of make_tuple -in the library, called tie. -
- -[ -2009-09-30 Daniel adds: -]
- - --- --I suggest to change the currently proposed paragraph for -make_simple_pair -
- -- -template<typename... Types> - pair<typename decay<Types>::type...> make_simple_pair(Types&&... t); -----
-Type requirements: sizeof...(Types) == 2.-Remarks: The program shall be ill-formed, if -sizeof...(Types) != 2. --... -
--or alternatively (but with a slightly different semantic): -
- --- --Remarks: If sizeof...(Types) != 2, this function shall not -participate in overload resolution. ---to follow a currently introduced style and because the library does -not have yet a specific "Type requirements" element. If such thing -would be considered as useful this should be done as a separate -issue. Given the increasing complexity of either of these wordings -it might be preferable to use the normal two-argument-declaration -style again in either of the following ways: -
- --
- -- -
-template<class T1, class T2> -pair<typename decay<T1>::type, typename decay<T2>::type> -make_simple_pair(T1&& t1, T2&& t2); --- -
-template<class T1, class T2> -pair<V1, V2> make_simple_pair(T1&& t1, T2&& t2); ---Let V1 be typename decay<T1>::type and V2 be -typename decay<T2>::type. --
[ -2009-10 post-Santa Cruz: -]
- - --Mark as Tentatively NAD Future. -- - - -
Proposed resolution:
--Add the following function to 20.3.4 [pairs] and signature in -appropriate synopses: -
- -- -template<typename... Types> - pair<typename decay<Types>::type...> make_simple_pair(Types&&... t); -----Type requirements: sizeof...(Types) == 2. -
--Returns: pair<typename decay<Types>::type...>(std::forward<Types>(t)...). -
-
[ -Draughting note: I chose a variadic representation similar to make_tuple -rather than naming both types as it is easier to read through the -clutter of metaprogramming this way. Given there are exactly two -elements, the committee may prefer to draught with two explicit template -type parameters instead -]
- - --Add the following function to 20.5.2.4 [tuple.creation] and -signature in appropriate synopses: -
- -- - - - - -template<typename... Types> - tuple<typename decay<Types>::type...> make_simple_tuple(Types&&... t); -----Returns: tuple<typename decay<Types>::type...>(std::forward<Types>(t)...). -
-
Section: 20.6.3 [meta.help] Status: New - Submitter: Alisdair Meredith Opened: 2009-09-05 Last modified: 2009-09-06
-View all other issues in [meta.help].
-View all issues with New status.
-Discussion:
--The specification of integral_constant has been inherited -essentially unchanged from TR1: -
- -template <class T, T v>
-struct integral_constant {
- static const T value = v;
- typedef T value_type;
- typedef integral_constant<T,v> type;
-};
--In light of 0x language changes there are several things we might -consider changing, notably the form of specification for value. -
- --The current form requires a static data member have storage allocated -for it, where we could now implement without this using the new enum -syntax: -
- -template <class T, T v>
-struct integral_constant {
- enum : T { value = v };
- typedef T value_type;
- typedef integral_constant type;
-};
--The effective difference between these two implementation is: -
- --Also note the editorial change to drop the explicit qualification of -integral_constant in the typedef type. This makes it quite clear we -mean the current instantiation, and cannot be mistaken for a recursive -metaprogram. -
- --Even if we don't mandate this implementation, it would be nice to give -vendors freedom under QoI to choose their preferred representation. -
- --The other side of this issue is if we choose to retain the static -constant form. In that case we should go further and insist on -constexpr, much like we did throughout numeric_limits: -
- -template <class T, T v>
-struct integral_constant {
- static constexpr T value = v;
- typedef T value_type;
- typedef integral_constant type;
-};
--[Footnote] It turns out constexpr is part of the Tentatively Ready -resolution for 1019. I don't want to interfere with that issue, but -would like a new issue to consider if the fixed-base enum implementation -should be allowed. -
- -[ -2009-09-05 Daniel adds: -]
- - --- - - --I think that the suggested resolution is incomplete and -may have some possible unwanted side-effects. To understand -why, note that integral_constant is completely specified -by code in 20.6.3 [meta.help]. While this is usually considered -as a good thing, let me give a possible user-defined -specialization that would break given the suggested changes: -
- -- -enum NodeColor { Red, Black }; - -std::integral_constant<NodeColor, Red> red; --The reason why that breaks is due to the fact that -current core language rules does only allow integral -types as enum-bases, see 7.2 [dcl.enum]/2. -
- --So, I think that we cannot leave the implementation the -freedom to decide which way they would like to provide -the implementation, because that is easily user-visible -(I don't speak of addresses, but of instantiation errors), -therefore if applied, this should be either specified or -wording must be added that gives a note about this -freedom of implementation. -
- --Another possible disadvantage seems to me that user-expectations -are easy to disappoint if they see a failure -of the test -
- -- -assert(typeid(std::integral_constant<int, 0>::value) == typeid(int)); --or of -
- -- -static_assert(std::is_same<decltype(std::integral_constant<int, 0>::value), const int>::value, "Bad library"); -
Proposed resolution:
- - - - - -Section: 17.6.3.9 [res.on.arguments] Status: Ready - Submitter: Howard Hinnant Opened: 2009-09-12 Last modified: 2009-10-20
-View all issues with Ready status.
-Discussion:
--When a library function binds an rvalue reference parameter to an argument, the -library must be able to assume that the bound argument is a temporary, and not -a moved-from lvalue. The reason for this is that the library function must be -able to modify that argument without concern that such modifications will corrupt -the logic of the calling code. For example: -
- -template <class T, class A>
-void
-vector<T, A>::push_back(value_type&& v)
-{
- // This function should move from v, potentially modifying
- // the object v is bound to.
-}
--If v is truly bound to a temporary, then push_back has the -only reference to this temporary in the entire program. Thus any -modifications will be invisible to the rest of the program. -
- --If the client supplies std::move(x) to push_back, the onus is -on the client to ensure that the value of x is no longer important to -the logic of his program after this statement. I.e. the client is making a statement -that push_back may treat x as a temporary. -
- --The above statement is the very foundation upon which move semantics is based. -- -
-The standard is currently lacking a global statement to this effect. I propose -the following addition to 17.6.3.9 [res.on.arguments]: -
- --- --Each of the following statements applies to all arguments to functions -defined in the C++ standard library, unless explicitly stated otherwise. -
--
- -- -If an argument to a function has an invalid value (such as a value -outside the domain of the function, or a pointer invalid for its -intended use), the behavior is undefined. -
-- -If a function argument is described as being an array, the pointer -actually passed to the function shall have a value such that all address -computations and accesses to objects (that would be valid if the pointer -did point to the first element of such an array) are in fact valid. -
-- -If a function argument binds to an rvalue reference parameter, the C++ -standard library may assume that this parameter is a unique reference -to this argument. If the parameter is a generic parameter of the -form T&&, and an lvalue of type A is bound, -then the binding is considered to be to an lvalue reference -(14.9.2.1 [temp.deduct.call]) and thus not covered by this clause. -[Note: -If a program casts an lvalue to an rvalue while passing that lvalue to -a library function (e.g. move(x)), then the program is effectively -asking the library to treat that lvalue as a temporary. The library is at -liberty to optimize away aliasing checks which might be needed if the argument -were an lvalue. -— end note] -
-
-Such a global statement will eliminate the need for piecemeal statements such as -23.2.1 [container.requirements.general]/13: -
- --An object bound to an rvalue reference parameter of a member function of -a container shall not be an element of that container; no diagnostic -required. -- -
-Additionally this clarifies that move assignment operators need not perform the -traditional if (this != &rhs) test commonly found (and needed) in -copy assignment operators. -
- -[ -2009-09-13 Niels adds: -]
- - --Note: This resolution supports the change of 27.9.1.3 [filebuf.assign]/1, -proposed by LWG 900. -- -
[ -2009 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Add a bullet to 17.6.3.9 [res.on.arguments]: -
- --- --Each of the following statements applies to all arguments to functions -defined in the C++ standard library, unless explicitly stated otherwise. -
--
-- -If an argument to a function has an invalid value (such as a value -outside the domain of the function, or a pointer invalid for its -intended use), the behavior is undefined. -
-- -If a function argument is described as being an array, the pointer -actually passed to the function shall have a value such that all address -computations and accesses to objects (that would be valid if the pointer -did point to the first element of such an array) are in fact valid. -
-- -If a function argument binds to an rvalue reference parameter, the C++ -standard library may assume that this parameter is a unique reference -to this argument. If the parameter is a generic parameter of the -form T&&, and an lvalue of type A is bound, -then the binding is considered to be to an lvalue reference -(14.9.2.1 [temp.deduct.call]) and thus not covered by this clause. -[Note: -If a program casts an lvalue to an rvalue while passing that lvalue to -a library function (e.g. move(x)), then the program is effectively -asking the library to treat that lvalue as a temporary. The library is at -liberty to optimize away aliasing checks which might be needed if the argument -were an lvalue. -— end note] -
-
-Delete 23.2.1 [container.requirements.general]/13: -
- -- - - - - - --An object bound to an rvalue reference parameter of a member function of -a container shall not be an element of that container; no diagnostic -required. -
Section: 25 [algorithms] Status: New - Submitter: Alisdair Meredith Opened: 2009-09-13 Last modified: 2009-09-13
-View other active issues in [algorithms].
-View all other issues in [algorithms].
-View all issues with New status.
-Discussion:
--There are a number of algorithms whose result might depend on the -handling of an empty range. In some cases the result is not clear, -while in others it would help readers to clearly mention the result -rather than require some subtle intuition of the supplied wording. -
- --25.2.1 [alg.all_of] -
- --Returns: true if pred(*i) is true for every -iterator i in the range [first,last), ... -- -
-What does this mean if the range is empty? -
- --I believe that we intend this to be true and suggest a -non-normative note to clarify: -
- --Add to p1 25.2.1 [alg.all_of]: -
- --[Note: Returns true if [first,last) is empty. -— end note] -- -
-25.2.3 [alg.none_of] -
- --Returns: true if pred(*i) is false for every -iterator i in the range [first,last), ... -- -
-What does this mean if the range empty? -
- --I believe that we intend this to be true and suggest a -non-normative note to clarify: -
- --Add to p1 25.2.3 [alg.none_of]: -
- --[Note: Returns true if [first,last) is empty. -— end note] -- -
-25.2.2 [alg.any_of] -
- --The specification for an empty range is actually fairly clear in this -case, but a note wouldn't hurt and would be consistent with proposals -for all_of/none_of algorithms. -
- --Add to p1 25.2.2 [alg.any_of]: -
- --[Note: Returns false if [first,last) is empty. -— end note] -- -
-25.2.6 [alg.find.end] -
- --what does this mean if [first2,last2) is empty? -
- --I believe the wording suggests the algorithm should return -last1 in this case, but am not 100% sure. Is this in fact the -correct result anyway? Surely an empty range should always match and the -naive expected result would be first1? -
- --My proposed wording is a note to clarify the current semantic: -
- --Add to p2 25.2.6 [alg.find.end]: -
- --[Note: Returns last1 if [first2,last2) is -empty. — end note] -- -
-I would prefer a normative wording treating empty ranges specially, but -do not believe we can change semantics at this point in the process, -unless existing implementations actually yield this result: -
- --Alternative wording: (NOT a note) -
--Add to p2 25.2.6 [alg.find.end]: -
--Returns first1 if [first2,last2) is empty. -- -
-25.2.7 [alg.find.first.of] -
- --The phrasing seems precise when [first2, last2) is empty, but a small -note to confirm the reader's understanding might still help. -
- --Add to p2 25.2.7 [alg.find.first.of] -
--[Note: Returns last1 if [first2,last2) is -empty. — end note] -- -
-25.2.12 [alg.search] -
- --What is the expected result if [first2, last2) is empty? -
- --I believe the wording suggests the algorithm should return last1 in this -case, but am not 100% sure. Is this in fact the correct result anyway? -Surely an empty range should always match and the naive expected result -would be first1? -
- --My proposed wording is a note to clarify the current semantic: -
- --Add to p2 25.2.12 [alg.search]: -
- --[Note: Returns last1 if [first2,last2) is -empty. — end note] -- -
-Again, I would prefer a normative wording treating empty ranges -specially, but do not believe we can change semantics at this point in -the process, unless existing implementations actually yield this result: -
- --Alternative wording: (NOT a note) -
--Add to p2 25.2.12 [alg.search]: -
- --Returns first1 if [first2,last2) is empty. -- -
-25.3.13 [alg.partitions] -
- --Is an empty range partitioned or not? -
- --Proposed wording: -
- --Add to p1 25.3.13 [alg.partitions]: -
- --[Note: Returns true if [first,last) is empty. -— end note] -- -
-25.4.5.1 [includes] -
- --Returns: true if every element in the range -[first2,last2) is contained in the range -[first1,last1). ... -- -
-I really don't know what this means if [first2,last2) is empty. -I could loosely guess that this implies empty ranges always match, and -my proposed wording is to clarify exactly that: -
- --Add to p1 25.4.5.1 [includes]: -
- --[Note: Returns true if [first2,last2) is empty. -— end note] -- -
-25.4.6.2 [pop.heap] -
- --The effects clause is invalid if the range [first,last) is empty, unlike -all the other heap alogorithms. The should be called out in the -requirements. -
- --Proposed wording: -
--Revise p2 25.4.6.2 [pop.heap] -
- --Requires: The range [first,last) shall be a valid -non-empty heap. -- -
-[Editorial] Reverse order of 25.4.6.2 [pop.heap] p1 and p2. -
- --25.4.7 [alg.min.max] -
- --minmax_element does not clearly specify behaviour for an empty -range in the same way that min_element and max_element do. -
- --Add to p31 25.4.7 [alg.min.max]: -
- --Returns make_pair(first, first) if first == last. -- -
-25.4.8 [alg.lex.comparison] -
- --The wording here seems quite clear, especially with the sample algorithm -implementation. A note is recommended purely for consistency with the -rest of these issue resolutions: -
- --Add to p1 25.4.8 [alg.lex.comparison]: -
- --[Note: An empty sequence is lexicographically less than any other -non-empty sequence, but not to another empty sequence. — end note] -- - -
Proposed resolution:
--Add to p1 25.2.1 [alg.all_of]: -
--[Note: Returns true if [first,last) is empty. -— end note] -- -
-Add to p1 25.2.2 [alg.any_of]: -
--[Note: Returns false if [first,last) is empty. -— end note] -- -
-Add to p1 25.2.3 [alg.none_of]: -
--[Note: Returns true if [first,last) is empty. -— end note] -- -
-Add to p2 25.2.6 [alg.find.end]: -
--[Note: Returns last1 if [first2,last2) is -empty. — end note] -- -
-Add to p2 25.2.7 [alg.find.first.of] -
--[Note: Returns last1 if [first2,last2) is -empty. — end note] -- -
-Add to p2 25.2.12 [alg.search]: -
--[Note: Returns last1 if [first2,last2) is -empty. — end note] -- -
-Add to p1 25.3.13 [alg.partitions]: -
--[Note: Returns true if [first,last) is empty. -— end note] -- -
-Add to p1 25.4.5.1 [includes]: -
--[Note: Returns true if [first2,last2) is empty. -— end note] -- -
-Revise p2 25.4.6.2 [pop.heap] -
--Requires: The range [first,last) shall be a valid -non-empty heap. -- -
-[Editorial] -
--Reverse order of 25.4.6.2 [pop.heap] p1 and p2. -- -
-Add to p31 25.4.7 [alg.min.max]: -
--Returns make_pair(first, first) if first == last. -- -
-Add to p1 25.4.8 [alg.lex.comparison]: -
--[Note: An empty sequence is lexicographically less than any other -non-empty sequence, but not less than another empty sequence. — -end note] -- - - - - - -
Section: 25.3.2 [alg.move] Status: New - Submitter: Howard Hinnant Opened: 2009-09-13 Last modified: 2009-09-13
-View all issues with New status.
-Discussion:
--25.3.2 [alg.move], p6 says: -
- --- -template<class BidirectionalIterator1, class BidirectionalIterator2> - BidirectionalIterator2 - move_backward(BidirectionalIterator1 first, - BidirectionalIterator1 last, - BidirectionalIterator2 result); ----...
--Requires: result shall not be in the range -[first,last). -
-
-This is essentially an "off-by-one" error. -
- --When result == last, which -is allowed by this specification, then the range [first, last) -is being move assigned into the range [first, last). The move -(forward) algorithm doesn't allow self move assignment, and neither should -move_backward. So last should be included in the range which -result can not be in. -
- --Conversely, when result == first, which is not allowed by this -specification, then the range [first, last) -is being move assigned into the range [first - (last-first), first). -I.e. into a non-overlapping range. Therefore first should -not be included in the range which result can not be in. -
- --The same argument applies to copy_backward though copy assigning elements -to themselves (result == last) should be harmless (though is disallowed -by copy). -
- - - -Proposed resolution:
--Change 25.3.2 [alg.move], p6: -
- --- -template<class BidirectionalIterator1, class BidirectionalIterator2> - BidirectionalIterator2 - move_backward(BidirectionalIterator1 first, - BidirectionalIterator1 last, - BidirectionalIterator2 result); ----...
--Requires: result shall not be in the range -
-[(first,last]). -
-Change 25.3.1 [alg.copy], p13: -
- --- - - - - -template<class BidirectionalIterator1, class BidirectionalIterator2> - BidirectionalIterator2 - copy_backward(BidirectionalIterator1 first, - BidirectionalIterator1 last, - BidirectionalIterator2 result); ----...
--Requires: result shall not be in the range -
-[(first,last]). -
Section: 23.3.4.4 [list.ops] Status: New - Submitter: Loďc Joly Opened: 2009-09-13 Last modified: 2009-09-19
-View other active issues in [list.ops].
-View all other issues in [list.ops].
-View all issues with New status.
-Discussion:
--It looks to me like some operations of std::list -(sort, reverse, remove, unique & -merge) do not specify the validity of iterators, pointers & -references to elements of the list after those operations. Is it implied -by some other text in the standard? -
- --I believe sort & reverse do not invalidating -anything, remove & unique only invalidates what -refers to erased elements, merge does not invalidate anything -(with the same precision as splice for elements who changed of -container). Are those assumptions correct ? -
- - -Proposed resolution:
- - - - - -Section: 26.6.2.1 [valarray.cons] Status: Tentatively Ready - Submitter: Howard Hinnant Opened: 2009-09-23 Last modified: 2009-10-29
-View all other issues in [valarray.cons].
-View all issues with Tentatively Ready status.
-Discussion:
--26.6.2.1 [valarray.cons] says: -
- --- -valarray(initializer_list<T> il); ---Effects: Same as valarray(il.begin(), il.end()). --
-But there is no valarray constructor taking two const T*. -
- -[ -2009-10-29 Howard: -]
- - --Moved to Tentatively Ready after 6 positive votes on c++std-lib. -- - -
Proposed resolution:
--Change 26.6.2.1 [valarray.cons]: -
- --- - - - - -valarray(initializer_list<T> il); ---Effects: Same as valarray(il.begin(), il.-endsize()). -
Section: 28.10.1 [re.results.const] Status: New - Submitter: Stephan T. Lavavej Opened: 2009-09-15 Last modified: 2009-09-21
-View all issues with New status.
-Discussion:
--In Working Draft -N2914, -match_results lacks a move constructor and move -assignment operator. Because it owns dynamically allocated memory, it -should be moveable. -
- --As far as I can tell, this isn't tracked by an active issue yet; Library -Issue 723 doesn't talk about match_results. -
- -[ -2009-09-21 Daniel provided wording. -]
- - - -Proposed resolution:
--Add the following member declarations to 28.10 [re.results]/3: -
- --// 28.10.1, construct/copy/destroy: -explicit match_results(const Allocator& a = Allocator()); -match_results(const match_results& m); -match_results(match_results&& m); -match_results& operator=(const match_results& m); -match_results& operator=(match_results&& m); -~match_results(); -
-Add the following new prototype descriptions to 28.10.1 [re.results.const] -using the table numbering of -N2723: -
- ---match_results(const match_results& m); -- --4 Effects: Constructs an object of class match_results, as a -copy of m. -- -match_results(match_results&& m); -- --- --5 Effects: Move-constructs an object of class match_results -from m satisfying the same postconditions as Table 132. Additionally -the stored Allocator value is move constructed from m.get_allocator(). -After the initialization of *this sets m to an unspecified but valid -state. -
- --6 Throws: Nothing if the allocator's move constructor throws nothing. -
-match_results& operator=(const match_results& m); -- --7 Effects: Assigns m to *this. The postconditions of this function are -indicated in Table 132. -- -match_results& operator=(match_results&& m); -- ----8 Effects: Move-assigns m to *this. The postconditions of this -function are indicated in Table 132. After the assignment, m is in -a valid but unspecified state. -
- --9 Throws: Nothing. -
-
Section: 24.2 [iterator.requirements] Status: New - Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2009-09-19
-View other active issues in [iterator.requirements].
-View all other issues in [iterator.requirements].
-View all issues with New status.
-Discussion:
--p6 Iterator requirements 24.2 [iterator.requirements] -
- --An iterator j is called reachable from an iterator i if and only if -there is a finite sequence of applications of the expression ++i that -makes i == j. If j is reachable from i, they refer to the same -container. -- -
-A good example would be stream iterators, which do not refer to a -container. Typically, the end iterator from a range of stream iterators -will compare equal for many such ranges. I suggest striking the second -sentence. -
- --An alternative wording might be: -
- --If j is reachable from i, and both i and -j are dereferencable iterators, then they refer to the same -range. -- - -
Proposed resolution:
--Change 24.2 [iterator.requirements], p6: -
- --An iterator j is called reachable from an iterator -i if and only if there is a finite sequence of applications of -the expression ++i that makes i == j.- - - - - -If -j is reachable from i, they refer to the same -container.-
Section: 24.5.3.1 [move.iterator] Status: Open - Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2009-10-26
-View all other issues in [move.iterator].
-View all issues with Open status.
-Discussion:
--I contend that while we can support both bidirectional and random access -traversal, the category of a move iterator should never be better than -input_iterator_tag. -
- --The contentious point is that you cannot truly have a multipass property -when values are moved from a range. This is contentious if you view a -moved-from object as still holding a valid value within the range. -
- --The second reason comes from the Forward Iterator requirements table: -
- --- --Forward iterators 24.2.3 [forward.iterators] -
- --Table 102 -- Forward iterator requirements -
- --For expression *a the return type is: -"T& if X is mutable, otherwise const T&" --
-There is a similar constraint on a->m. -
- --There is no support for rvalue references, nor do I believe their should -be. Again, opinions may vary but either this table or the definition of -move_iterator need updating. -
- --Note: this requirement probably need updating anyway if we wish to -support proxy iterators but I am waiting to see a new working paper -before filing that issue. -
- -[ -2009-10 post-Santa Cruz: -]
- - --Move to Open. Howard to put his rationale mentioned above into the issue -as a note. -- -
[ -2009-10-26 Howard adds: -]
- - --- - - --vector::insert(pos, iter, iter) is significantly more effcient when -iter is a random access iterator, as compared to when it is an -input iterator. -
- --When iter is an input iterator, the best algorithm -is to append the inserted range to the end of the vector using -push_back. This may involve several reallocations before the input -range is exhausted. After the append, then one can use std::rotate -to place the inserted range into the correct position in the vector. -
- --But when iter is a random access iterator, the best algorithm -is to first compute the size of the range to be inserted (last - first), -do a buffer reallocation if necessary, scoot existing elements in the vector -down to make the "hole", and then insert the new elements directly to their correct -place. -
- --The insert-with-random-access-iterators algorithm is considerably more efficient -than the insert-with-input-iterators algorithm -- --Now consider: -
- -- -vector<A> v; -// ... build up a large vector of A ... -vector<A> temp; -// ... build up a large temporary vector of A to later be inserted ... -typedef move_iterator<vector<A>::iterator> MI; -// Now insert the temporary elements: -v.insert(v.begin() + N, MI(temp.begin()), MI(temp.end())); --A major motivation for using move_iterator in the above example is the -expectation that A is cheap to move but expensive to copy. I.e. the -customer is looking for high performance. If we allow vector::insert -to subtract two MI's to get the distance between them, the customer enjoys -substantially better performance, compared to if we say that vector::insert -can not subtract two MI's. -
- --I can find no rationale for not giving this performance boost to our customers. -Therefore I am strongly against restricting move_iterator to the -input_iterator_tag category. -
- --I believe that the requirement that forward -iterators have a dereference that returns an lvalue reference to cause unacceptable -pessimization. For example vector<bool>::iterator also does not return -a bool& on dereference. Yet I am not aware of a single vendor that -is willing to ship vector<bool>::iterator as an input iterator. -Everyone classifies it as a random access iterator. Not only does this not -cause any problems, it prevents significant performance problems. -
- -
Proposed resolution:
--Class template move_iterator 24.5.3.1 [move.iterator] -
- -namespace std {
-template <class Iterator>
-class move_iterator {
-public:
- ...
- typedef typename iterator_traits<Iterator>::iterator_category input_iterator_tag iterator_category;
-Section: 24.2 [iterator.requirements] Status: New - Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2009-09-19
-View other active issues in [iterator.requirements].
-View all other issues in [iterator.requirements].
-View all issues with New status.
-Discussion:
-Forward iterator and bidirectional iterator place different -requirements on the result of post-increment/decrement operator. The -same form should be used in each case. -
- --Merging row from: -
- -- - -Table 102 -- Forward iterator requirements -Table 103 -- Bidirectional iterator requirements - - r++ : convertible to const X& - r-- : convertible to const X& - - *r++ : T& if X is mutable, otherwise const T& - *r-- : convertible to T -
Proposed resolution:
- - - - -Section: 24.2 [iterator.requirements] Status: New - Submitter: Daniel Krügler Opened: 2009-09-19 Last modified: 2009-09-19
-View other active issues in [iterator.requirements].
+Section: 24.2 [iterator.requirements] Status: Deferred + Submitter: Daniel Krügler Opened: 2009-09-19 Last modified: 2010-11-14
View all other issues in [iterator.requirements].
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+View all issues with Deferred status.
Discussion:
The terms valid iterator and singular aren't @@ -25673,7 +2183,7 @@ it must still be equality-comparable and in general be a readable value.
Second, the standard doesn't clearly say whether a past-the-end value is -a valid iterator or not. E.g. 20.8.13 [specialized.algorithms]/1 says: +a valid iterator or not. E.g. 20.9.8 [specialized.algorithms]/1 says:
@@ -25703,7 +2213,7 @@ we find:+11 Returns: a pointer to the allocated memory. [Note: if n == 0, the return -value is unspecified. —end note] +value is unspecified. —end note]@@ -25727,8 +2237,27 @@ is unspecified, it could be a null pointer. Does that mean that programmers need to check the pointer value for a null value before calling deallocate?
+[ +2010-11-09 Daniel comments: +]
+ + ++A later paper is in preparation. +
+ +[ +2010 Batavia: +]
+ + ++Doesn't need to be resolved for Ox +
+Proposed resolution:
+Consider to await the paper. @@ -25736,11 +2265,11 @@ need to check the pointer value for a null value before calling deallocate?
1214. Insufficient/inconsistent key immutability requirements for associative containers
-Section: 23.2.4 [associative.reqmts] Status: New - Submitter: Daniel Krügler Opened: 2009-09-20 Last modified: 2009-09-20
+Section: 23.2.4 [associative.reqmts] Status: Deferred + Submitter: Daniel Krügler Opened: 2009-09-20 Last modified: 2010-11-14
View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
-View all issues with New status.
+View all issues with Deferred status.
Discussion:
Scott Meyers' mentions on a recent posting on c.s.c++ @@ -25791,8 +2320,152 @@ containers.
[ +2010-03-27 Daniel provides wording. +]
+ + ++This update attempts to provide normative wording that harmonizes the key and +function object constraints of associative and unordered containers. ++ +
[ +2010 Batavia: +]
+ + ++We're uncomfortable with the first agenda item, and we can live with the second agenda +item being applied before or after Madrid. +
+Proposed resolution:
++Change 23.2.4 [associative.reqmts]/2 as indicated: [This ensures that +associative containers make better clear what this "arbitrary" type is, as the +unordered containers do in 23.2.5 [unord.req]/3] +
+ ++2 Each associative container is parameterized on Key and an ordering +relation Compare that induces a strict weak ordering (25.4) on elements +of Key. In addition, map and multimap associate an +arbitrary mapped type+typeT with the +Key. The object of type Compare is called the comparison +object of a container. +
+Change 23.2.4 [associative.reqmts]/5 as indicated: [This removes the +too strong requirement that keys must not be changed at all and brings this line +in sync with 23.2.5 [unord.req]/7. We take care about the real +constraints by the remaining suggested changes. The rationale provided by LWG +103 didn't really argue why that addition is necessary, and I +believe the remaining additions make it clear that any user changes have strong +restrictions]: +
+ ++5 For set and multiset the value type is the same as the key +type. For map and multimap it is equal to pair<const +Key, T>.+Keys in an associative container are immutable.+
+Change 23.2.5 [unord.req]/3+4 as indicated: [The current sentence of +p.4 has doesn't say something really new and this whole subclause misses to +define the concepts of the container-specific hasher object and predicate +object. We introduce the term key equality predicate which is +already used in the requirements table. This change does not really correct part +of this issue, but is recommended to better clarify the nomenclature and the +difference between the function objects and the function object types, +which is important, because both can potentially be stateful.] +
+ ++++3 Each unordered associative container is parameterized by Key, by a +function object type Hash that meets the Hash requirements +(20.2.4) and acts as a hash function for argument values of type Key, +and by a binary predicate Pred that induces an equivalence relation on +values of type Key. Additionally, unordered_map and +unordered_multimap associate an arbitrary mapped type +T with the Key. +
+ ++4 The container's object of type Hash - denoted by +hash - is called the hash function of the container. +The container's object of type Pred - denoted by +pred - is called the key equality predicate of the +container.
+A hash function is a function object that takes a single +argument of type Key and returns a value of type +std::size_t. +
+Change 23.2.5 [unord.req]/5 as indicated: [This adds a similar +safe-guard as the last sentence of 23.2.4 [associative.reqmts]/3] +
+ ++5 Two values k1 and k2 of type Key are considered +equivalent if the container's key equality +predicate+key_equal function objectreturns +true when passed those values. If k1 and k2 are +equivalent, the container's hash function shall return the same value +for both. [Note: thus, when an unordered associative container is +instantiated with a non-default Pred parameter it usually needs a +non-default Hash parameter as well. — end note] For +any two keys k1 and k2 in the same container, calling +pred(k1, k2) shall always return the same value. For any key k +in a container, calling hash(k) shall always return the same +value. +
+After 23.2.5 [unord.req]/7 add the following new paragraph: [This +ensures the same level of compile-time protection that we already require for +associative containers. It is necessary for similar reasons, because any change +in the stored key which would change it's equality relation to others or would +change it's hash value such that it would no longer fall in the same bucket, +would break the container invariants] +
+ ++++7 For unordered_set and unordered_multiset the value type is +the same as the key type. For unordered_map and +unordered_multimap it is std::pair<const Key, T>. +
++For unordered containers where the value type is the same as the key type, +both iterator and const_iterator are constant iterators. It is +unspecified whether or not iterator and const_iterator are the +same type. [Note: iterator and const_iterator have +identical semantics in this case, and iterator is convertible to +const_iterator. Users can avoid violating the One Definition Rule by +always using const_iterator in their function parameter lists. — +end note] +
+
Section: 23.3.4.4 [list.ops] Status: New - Submitter: Pablo Halpern Opened: 2009-09-24 Last modified: 2009-09-24
-View other active issues in [list.ops].
+Section: 23.3.4.4 [list.ops] Status: Tentatively Ready + Submitter: Pablo Halpern Opened: 2009-09-24 Last modified: 2010-11-13
View all other issues in [list.ops].
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+View all issues with Tentatively Ready status.
Discussion:
In Bellevue (I think), we passed @@ -25863,1848 +2535,11 @@ exception is thrown other than by a comparison there are no effects. -
Section: 18.8.6 [except.nested] Status: Ready - Submitter: Pete Becker Opened: 2009-09-25 Last modified: 2009-10-20
-View other active issues in [except.nested].
-View all other issues in [except.nested].
-View all issues with Ready status.
-Discussion:
--LWG 1066 adds [[noreturn]] to a bunch of things. -It doesn't add it to rethrow_nested(), which seems like an obvious -candidate. I've made the changes indicated in the issue, and haven't -changed rethrow_nested(). -
- -[ -2009 Santa Cruz: -]
- - --Move to Ready. -- - - -
Proposed resolution:
--Add [[noreturn]] to rethrow_nested() in 18.8.6 [except.nested]. -
- - - - - -Section: 30.4.1 [thread.mutex.requirements] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30
-View other active issues in [thread.mutex.requirements].
-View all other issues in [thread.mutex.requirements].
-View all issues with New status.
-Discussion:
--If an object *o contains a mutex mu and a -correctly-maintained reference count c, is the following code -safe? -
- -o->mu.lock();
-bool del = (--(o->c) == 0);
-o->mu.unlock();
-if (del) { delete o; }
--If the implementation of mutex::unlock() can touch the mutex's -memory after the moment it becomes free, this wouldn't be safe, and -"Construction and destruction of an object of a Mutex type need not be -thread-safe" 30.4.1 [thread.mutex.requirements] may imply that -it's not safe. Still, it's useful to allow mutexes to guard reference -counts, and if it's not allowed, users are likely to write bugs. -
- - -Proposed resolution:
--
- - - - - -Section: 30.4.3.2.2 [thread.lock.unique.locking] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30
-View other active issues in [thread.lock.unique.locking].
-View all other issues in [thread.lock.unique.locking].
-View all issues with New status.
-Discussion:
--unique_lock::lock and friends raise -"resource_deadlock_would_occur -- if the current thread already -owns the mutex (i.e., on entry, owns is true)." 1) -The current thread owning a mutex is not the same as any particular -unique_lock::owns being true. 2) There's no need to -raise this exception for a recursive_mutex if owns is -false. 3) If owns is true, we need to raise some -exception or the unique_lock will lose track of whether to unlock itself -on destruction, but "deadlock" isn't it. For (3), s/bool owns/int -ownership_level/ would fix it. -
- - -Proposed resolution:
- - - - - -Section: 30.5 [thread.condition] Status: Tentatively Ready - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-11-06
-View other active issues in [thread.condition].
-View all other issues in [thread.condition].
-View all issues with Tentatively Ready status.
-Discussion:
--"Class condition_variable provides a condition variable that can only -wait on an object of type unique_lock" should say "...object of type -unique_lock<mutex>" -
- -[ -2009-11-06 Howard adds: -]
- - --Moved to Tentatively Ready after 5 positive votes on c++std-lib. -- - - -
Proposed resolution:
--Change 30.5 [thread.condition], p1: -
- --Condition variables provide synchronization primitives used to block a -thread until notified by some other thread that some condition is met or -until a system time is reached. Class condition_variable -provides a condition variable that can only wait on an object of type -unique_lock<mutex>, allowing maximum -efficiency on some platforms. Class condition_variable_any -provides a general condition variable that can wait on objects of -user-supplied lock types. -- - - - - -
Section: 30.5.1 [thread.condition.condvar] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30
-View other active issues in [thread.condition.condvar].
-View all other issues in [thread.condition.condvar].
-View all issues with New status.
-Discussion:
--30.5.1 [thread.condition.condvar] says: -
- --- -~condition_variable(); ---Precondition: There shall be no thread blocked on *this. -[Note: That is, all threads shall have been notified; they may -subsequently block on the lock specified in the wait. Beware that -destroying a condition_variable object while the corresponding -predicate is false is likely to lead to undefined behavior. -— end note] --
-The text hasn't introduced the notion of a "corresponding predicate" -yet. -
- - -Proposed resolution:
- - - - - -Section: 30.5 [thread.condition] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30
-View other active issues in [thread.condition].
-View all other issues in [thread.condition].
-View all issues with New status.
-Discussion:
--30.5.1 [thread.condition.condvar] says: -
- --- -void wait(unique_lock<mutex>& lock); ----...
--Effects: -
--
-- ...
-- -If the function exits via an exception, lock.unlock() shall be -called prior to exiting the function scope. -
-
-Should that be lock.lock()? -
- - -Proposed resolution:
- --Change 30.5.1 [thread.condition.condvar] p10: -
- --- -void wait(unique_lock<mutex>& lock); ----...
--Effects: -
--
-- ...
-- -If the function exits via an exception, lock.
-unlock() shall be -called prior to exiting the function scope. -
-And make a similar change in p16, and in 30.5.2 [thread.condition.condvarany], -p8 and p13. -
- - - - - - -Section: 30.5.2 [thread.condition.condvarany] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30
-View other active issues in [thread.condition.condvarany].
-View all other issues in [thread.condition.condvarany].
-View all issues with New status.
-Discussion:
--For condition_variable_any, must all lock arguments to concurrent wait calls -"match" in some way, similar to the requirement in -30.5.1 [thread.condition.condvar] that lock.mutex() returns the same -value for each of the lock arguments supplied by all concurrently -waiting threads (via wait or timed_wait)? -
- - - -Proposed resolution:
- - - - - -Section: 30.5.2 [thread.condition.condvarany] Status: New - Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2009-09-30
-View other active issues in [thread.condition.condvarany].
-View all other issues in [thread.condition.condvarany].
-View all issues with New status.
-Discussion:
--For condition_variable_any, are recursive mutexes allowed? (I think "no") -
- - - -Proposed resolution:
- - - - - -Section: 20.7.4 [func.ret] Status: New - Submitter: Sebastian Gesemann Opened: 2009-10-05 Last modified: 2009-10-17
-View all other issues in [func.ret].
-View all issues with New status.
-Discussion:
--I think the text about std::result_of could be a little more precise. -Quoting from -N2960... -
- --- --20.7.4 [func.ret] Function object return types -
- -template<class> class result_of; - -template<class Fn, class... ArgTypes> -class result_of<Fn(ArgTypes...)> { -public: - typedef see below type; -}; -- --Given an rvalue fn of type Fn and values t1, t2, -..., tN of types T1, T2, ... TN in ArgTypes -respectivly, the type member is the result type of the -expression fn(t1,t2,...,tN). the values ti are lvalues -when the corresponding type Ti is an lvalue-reference type, and -rvalues otherwise. -
-
-This text doesn't seem to consider lvalue reference types for Fn. -Also, it's not clear whether this class template can be used for -"SFINAE" like std::enable_if. Example: -
- -template<typename Fn, typename... Args>
-typename std::result_of<Fn(Args...)>::type
-apply(Fn && fn, Args && ...args)
-{
- // Fn may be an lvalue reference, too
- return std::forward<Fn>(fn)(std::forward<Args>(args)...);
-}
--Either std::result_of<...> can be instantiated and simply may not have -a typedef "type" (-->SFINAE) or instantiating the class template for -some type combinations will be a "hard" compile-time error. -
- - -Proposed resolution:
- -[ -These changes will require compiler support -]
- - --Change 20.7.4 [func.ret]: -
- -- -template<class> class result_of; // undefined - -template<class Fn, class... ArgTypes> -class result_of<Fn(ArgTypes...)> { -public: -- -typedefsee belowtype;-}; -- -
-Given an rvalue fn of type Fn and values t1, t2, -..., tN of types T1, T2, ... TN in ArgTypes -respectivly, the type member is the result type of the -expression fn(t1,t2,...,tN). the values ti are lvalues -when the corresponding type Ti is an lvalue-reference type, and -rvalues otherwise. --The class template result_of shall meet the requirements of a -TransformationTrait: Given the types Fn, T1, T2, ..., TN every -template specialization result_of<Fn(T1,T2,...,TN)> shall define the -member typedef type equivalent to decltype(RE) if and only if -the expression RE -
- -- --value<Fn>() ( value<T1>(), value<T2>(), ... value<TN>() ) --would be well-formed. Otherwise, there shall be no member typedef -type defined. -
- -
[ -The value<> helper function is a utility Daniel Krügler -proposed in -N2958. -]
- - - - - - -Section: 30.6.2 [futures.errors] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-10-05 Last modified: 2009-10-27
-View all issues with Tentatively Ready status.
-Discussion:
--Defect issue 890 overlooked to adapt the future_category from -30.6.1 [futures.overview] and 30.6.2 [futures.errors]: -
- -- -extern const error_category* const future_category; -
-which should be similarly transformed into function form. -
- -[ -2009-10-27 Howard: -]
- - --Moved to Tentatively Ready after 5 positive votes on c++std-lib. -- - - -
Proposed resolution:
--Change in 30.6.1 [futures.overview], header <future> synopsis: -
- --externconst error_category&* constfuture_category(); -
-Change in 30.6.2 [futures.errors]: -
- --- -externconst error_category&* constfuture_category(); --- --
-1- future_category shall point to a statically initialized object -of a type derived from class error_category.--1- Returns: A reference to an object of a type -derived from class error_category. -
-constexpr error_code make_error_code(future_errc e); -- --3 Returns: error_code(static_cast<int>(e), -- -*future_category()). -constexpr error_code make_error_condition(future_errc e); -- --4 Returns: error_condition(static_cast<int>(e), --*future_category()). -
Section: 20.3.7 [template.bitset] Status: Ready - Submitter: Bo Persson Opened: 2009-10-05 Last modified: 2009-10-26
-View other active issues in [template.bitset].
-View all other issues in [template.bitset].
-View all issues with Ready status.
-Discussion:
--The resolutions to some library defect reports, like 1178 -requires that #includes in each synopsis should be taken -literally. This means that the <bitset> header now -must include <stdexcept>, even though none of the -exceptions are mentioned in the <bitset> header. -
--Many other classes are required to throw exceptions like -invalid_argument and out_of_range, without explicitly -including <stdexcept> in their synopsis. It is totally -possible for implementations to throw the needed exceptions from utility -functions, whose implementations are not visible in the headers. -
--I propose that <stdexcept> is removed from the -<bitset> header. -
- -[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
--Change 20.3.7 [template.bitset]: -
- -- - - - - -#include <cstddef> // for size_t -#include <string> -#include <stdexcept> // for invalid_argument,-// out_of_range, overflow_error-#include <iosfwd> // for istream, ostream -namespace std { -... -
Section: 20.6.4.3 [meta.unary.prop] Status: Open - Submitter: Alisdair Meredith Opened: 2009-10-07 Last modified: 2009-10-26
-View other active issues in [meta.unary.prop].
-View all other issues in [meta.unary.prop].
-View all issues with Open status.
-Discussion:
--According to p1 20.6.2 [meta.type.synop]: -
- --The behavior of a program that adds specializations for any of the class -templates defined in this subclause is undefined unless otherwise -specified. -- -
-I believe we should 'otherwise specify' for the nothrow traits, are -these are exactly the use cases where the end user actually has more -information than the compiler. -
- -[ -2009-10 Santa Cruz: -]
- - --Moved to Open. Definitely need to give the users the ability to ensure -that the traits give the right answers. Unsure we want to give them the -ability to say this in more than one way. Believes the noexcept proposal -already gives this. -- - - -
Proposed resolution:
--Add the following comment: -
- --user specialization permitted to derive from std::true_type when the -operation is known not to throw. -- -
-to the following traits in 20.6.4.3 [meta.unary.prop] Table 43 Type -property predicates. -
- -[ -This may require a new Comments column -]
- - -- - - - - -has_nothrow_default_constructor -has_nothrow_copy_constructor -has_nothrow_assign -
Section: 20.8.15.3.5 [util.smartptr.weak.obs] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-10-10 Last modified: 2009-11-06
-View all issues with Tentatively Ready status.
-Discussion:
--The -n2637 -paper suggested several updates of the ordering semantics of -shared_ptr -and weak_ptr, among those the explicit comparison operators of weak_ptr were -removed/deleted, instead a corresponding functor owner_less was added. -The problem -is that -n2637 -did not clearly enough specify, how the previous wording -parts describing -the comparison semantics of weak_ptr should be removed. -
- -[ -2009-11-06 Howard adds: -]
- - --Moved to Tentatively Ready after 5 positive votes on c++std-lib. -- - - -
Proposed resolution:
--Change 20.8.15.3 [util.smartptr.weak]/2 as described, the intention is to fix -the now no longer valid -requirement that weak_ptr is LessComparable [Note the deleted comma]: -
- --Specializations of weak_ptr shall be CopyConstructible-,-and CopyAssignable, -and LessThanComparable,allowing their use in standard containers. -
-In 20.8.15.3.5 [util.smartptr.weak.obs] remove the paragraphs 9-11 including prototype: -
- ---template<class T, class U> bool operator<(const weak_ptr<T>& a, const weak_ptr<U>& b);- --
-Returns: an unspecified value such that--
- -- -
-operator< is a strict weak ordering as described in 25.4;-- -
-under the equivalence relation defined by operator<, !(a -< b) && !(b < a), two weak_ptr instances are -equivalent if and only if they share ownership or are both empty.--
- -Throws: nothing.--
-[Note: Allows weak_ptr objects to be used as keys in associative -containers. — end note]-
Section: 20.8 [memory] Status: Tentatively NAD Editorial - Submitter: Daniel Krügler Opened: 2009-10-11 Last modified: 2009-11-04
-View all other issues in [memory].
-View all issues with Tentatively NAD Editorial status.
-Discussion:
--Related to 296. Some unique_ptr signatures are missing -from the synopsis in 20.8 [memory]. -
- -[ -2009-11-04 Howard adds: -]
- - --Moved to Tentatively NAD Editorial. The editor has adopted the fix. -- - -
Proposed resolution:
--Add in 20.8 [memory], Header <memory> synopsis -missing declarations as shown below: -
- -- - - - - -// 20.8.11 Class unique_ptr: -template <class X> class default_delete; -template<class T> struct default_delete<T[]>; -template <class X, class D = default_delete<T>> class unique_ptr; -template<class T, class D> class unique_ptr<T[], D>; - -template<class T, class D> void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y); - -template<class T1, class D1, class T2, class D2> -bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); -template<class T1, class D1, class T2, class D2> -bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); -template<class T1, class D1, class T2, class D2> -bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); -template<class T1, class D1, class T2, class D2> -bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); -template<class T1, class D1, class T2, class D2> -bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); -template<class T1, class D1, class T2, class D2> -bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); -
Section: 23.2.3 [sequence.reqmts] Status: New - Submitter: Matt Austern Opened: 2009-10-09 Last modified: 2009-10-13
-View other active issues in [sequence.reqmts].
-View all other issues in [sequence.reqmts].
-View all issues with New status.
-Discussion:
--On g++ 4.2.4 (x86_64-linux-gnu), the following file gives a compile -error: -
- -#include <vector>
-void foo() { std::vector<int*> v(500l, NULL); }
--Is this supposed to work? -
- --The issue: if NULL happens to be defined as 0l, this is an invocation of -the constructor with two arguments of the same integral type. -23.2.3 [sequence.reqmts]/11 says that this will behave as if the the -overloaded constructor -
- -- -X(size_type, const value_type& = value_type(), - const allocator_type& = allocator_type()) -
-were called instead, with the arguments -static_cast<size_type>(first), last and -alloc, respectively. However, it does not say whether this -actually means invoking that constructor with the exact textual form of -the arguments as supplied by the user, or whether the standard permits -an implementation to invoke that constructor with variables of the same -type and value as what the user passed in. In most cases this is a -distinction without a difference. In this particular case it does make a -difference, since one of those things is a null pointer constant and the -other is not. -
- --Note that an implementation based on forwarding functions will use the -latter interpretation. -
- - -Proposed resolution:
- - - - - -Section: 19.5 [syserr] Status: Ready - Submitter: Daniel Krügler Opened: 2009-10-14 Last modified: 2009-10-26
-View all other issues in [syserr].
-View all issues with Ready status.
-Discussion:
--I'm just reflecting on the now SFINAE-constrained constructors -and assignment operators of error_code and error_condition: -
--These are the only library components that are pro-actively -announcing that they are using std::enable_if as constraining tool, -which has IMO several disadvantages: -
- --With the availability of template default arguments and -decltype, using enable_if in C++0x standard library, seems -unnecessary restricting implementation freedom. E.g. there -should be not need for a useless specification of a dummy -default function argument, which only confuses the reader. -A more reasonable implementation could e.g. be -
- -- -template <class ErrorCodeEnum - class = typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type> -error_code(ErrorCodeEnum e); -
-As currently specified, the function signatures are so unreadable, -that errors quite easily happen, see e.g. 1229. -
--We have a lot of constrained functions in other places, that -now have a standard phrase that is easily understandable: -
- --Remarks: This constructor/function shall participate in overload -resolution if and only if X. -- -
-where X describes the condition. Why should these components deviate? -
--If enable_if would not be explicitly specified, the standard library -is much better prepared for the future. It would also be possible, that -libraries with partial support for not-yet-standard-concepts could provide -a much better diagnostic as is possible with enable_if. This again -would allow for experimental concept implementations in the wild, -which as a result would make concept standardization a much more -natural thing, similar to the way as templates were standardized -in C++. -
- --In summary: I consider it as a library defect that error_code and -error_condition explicitly require a dependency to enable_if and -do limit implementation freedom and I volunteer to prepare a -corresponding resolution. -
-[ -2009-10-18 Beman adds: -]
- - --I support this proposed resolution, and thank Daniel for writing it up. -- -
[ -2009-10 Santa Cruz: -]
- - --Moved to Ready. -- - - -
Proposed resolution:
-[ -Should this resolution be accepted, I recommend to resolve 1229 as NAD -]
- - --In 19.5.2.1 [syserr.errcode.overview]/1, class error_code, -change as indicated: -
- --// 19.5.2.2 constructors: -error_code(); -error_code(int val, const error_category& cat); -template <class ErrorCodeEnum> - error_code(ErrorCodeEnum e, - typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type * = 0); - -// 19.5.2.3 modifiers: -void assign(int val, const error_category& cat); -template <class ErrorCodeEnum> -typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::typeerror_code& - operator=(ErrorCodeEnum e); -void clear(); -
-Change 19.5.2.2 [syserr.errcode.constructors] around the prototype before p. 7: -
- --template <class ErrorCodeEnum> -error_code(ErrorCodeEnum e-, - typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type * = 0); ----Remarks: This constructor shall not participate in overload -resolution, unless -is_error_code_enum<ErrorCodeEnum>::value == true. -
-
-Change 19.5.2.3 [syserr.errcode.modifiers] around the prototype before p. 3: -
- --template <class ErrorCodeEnum> -- -typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::typeerror_code& - operator=(ErrorCodeEnum e); --Remarks: This operator shall not participate in overload resolution, unless -is_error_code_enum<ErrorCodeEnum>::value == true. --
-In 19.5.3.1 [syserr.errcondition.overview]/1, class error_condition, change -as indicated: -
- --// 19.5.3.2 constructors: -error_condition(); -error_condition(int val, const error_category& cat); -template <class ErrorConditionEnum> - error_condition(ErrorConditionEnum e, - typename enable_if<is_error_condition_enum<ErrorConditionEnum>::type* = 0); - -// 19.5.3.3 modifiers: -void assign(int val, const error_category& cat); -template<typenameclass ErrorConditionEnum> -typename enable_if<is_error_condition_enum<ErrorConditionEnum>, error_code>::typeerror_condition & - operator=( ErrorConditionEnum e ); -void clear(); -
-Change 19.5.3.2 [syserr.errcondition.constructors] around the -prototype before p. 7: -
- --template <class ErrorConditionEnum> - error_condition(ErrorConditionEnum e-, - typename enable_if<is_error_condition_enum<ErrorConditionEnum>::value>::type* = 0); --Remarks: This constructor shall not participate in overload -resolution, unless -is_error_condition_enum<ErrorConditionEnum>::value == true. --
-Change 19.5.3.3 [syserr.errcondition.modifiers] around the -prototype before p. 3: -
- -- -template <class ErrorConditionEnum> -- -typename enable_if<is_error_condition_enum<ErrorConditionEnum>::value>::typeerror_condition& - operator=(ErrorConditionEnum e); ----Remarks: This operator shall not participate in overload resolution, unless -is_error_condition_enum<ErrorConditionEnum>::value == true. -
- --Postcondition: *this == make_error_condition(e). -
- --Returns: *this -
-
Section: 25 [algorithms] Status: Tentatively NAD Future - Submitter: Alisdair Meredith Opened: 2009-10-15 Last modified: 2009-11-03
-View other active issues in [algorithms].
-View all other issues in [algorithms].
-View all issues with Tentatively NAD Future status.
-Discussion:
--The library has many algorithms that take a source range represented by -a pair of iterators, and the start of some second sequence given by a -single iterator. Internally, these algorithms will produce undefined -behaviour if the second 'range' is not as large as the input range, but -none of the algorithms spell this out in Requires clauses, and there is -no catch-all wording to cover this in clause 17 or the front matter of -25. -
- --There was an attempt to provide such wording in paper -n2944 -but this -seems incidental to the focus of the paper, and getting the wording of -this issue right seems substantially more difficult than the simple -approach taken in that paper. Such wording will be removed from an -updated paper, and hopefully tracked via the LWG issues list instead. -
- --It seems there are several classes of problems here and finding wording -to solve all in one paragraph could be too much. I suspect we need -several overlapping requirements that should cover the desired range of -behaviours. -
- --Motivating examples: -
- --A good initial example is the swap_ranges algorithm. Here there is a -clear requirement that first2 refers to the start of a valid range at -least as long as the range [first1, last1). n2944 tries to solve this -by positing a hypothetical last2 iterator that is implied by the -signature, and requires distance(first2,last2) < distance(first1,last1). - This mostly works, although I am uncomfortable assuming that last2 is -clearly defined and well known without any description of how to obtain -it (and I have no idea how to write that). -
- --A second motivating example might be the copy algorithm. Specifically, -let us image a call like: -
- -- -copy(istream_iterator<int>(is),istream_iterator(),ostream_iterator<int>(os)); -
-In this case, our input iterators are literally simple InputIterators, -and the destination is a simple OutputIterator. In neither case am I -happy referring to std::distance, in fact it is not possible for the -ostream_iterator at all as it does not meet the requirements. However, -any wording we provide must cover both cases. Perhaps we might deduce -last2 == ostream_iterator<int>{}, but that might not always be valid for -user-defined iterator types. I can well imagine an 'infinite range' -that writes to /dev/null and has no meaningful last2. -
- --The motivating example in n2944 is std::equal, and that seems to fall somewhere between the -two. -
- --Outlying examples might be partition_copy that takes two output -iterators, and the _n algorithms where a range is specified by a -specific number of iterations, rather than traditional iterator pair. -We should also not accidentally apply inappropriate constraints to -std::rotate which takes a third iterator that is not intended to be a -separate range at all. -
- --I suspect we want some wording similar to: -
- --For algorithms that operate on ranges where the end iterator of the -second range is not specified, the second range shall contain at least -as many elements as the first. -- -
-I don't think this quite captures the intent yet though. I am not sure -if 'range' is the right term here rather than sequence. More awkwardly, -I am not convinced we can describe an Output sequence such as produce by -an ostream_iterator as "containing elements", at least not as a -precondition to the call before they have been written. -
- --Another idea was to describe require that the trailing iterator support -at least distance(input range) applications of operator++ and may be -written through the same number of times if a mutable/output iterator. -
- --We might also consider handling the case of an output range vs. an input -range in separate paragraphs, if that simplifies how we describe some of -these constraints. -
- -[ -2009-11-03 Howard adds: -]
- - --Moved to Tentatively NAD Future after 5 positive votes on c++std-lib. -- - -
Proposed resolution:
- - - - - -Section: 20.6.4.3 [meta.unary.prop] Status: Tentatively NAD Editorial - Submitter: David Abrahams Opened: 2009-10-16 Last modified: 2009-10-26
-View other active issues in [meta.unary.prop].
-View all other issues in [meta.unary.prop].
-View all issues with Tentatively NAD Editorial status.
-Discussion:
--Table 43 defines a number of traits that yield true for arrays of class -types with the trait's property, but not arrays of other types with that -property. For example, has_trivial_default_constructor: -
- --T is a trivial type (3.9) or a class type with a trivial default -constructor (12.1) or an array of such a class type. -- -
[ -2009-10 post-Santa Cruz: -]
- - --- - - --An array of a trivial type is a trivial type. -
--Mark as Tentatively NAD Editorial. The wording is OK as is, -since an array of a trivial type is a trivial type, but the wording as -proposed might be clearer. -
-
Proposed resolution:
--Change all the traits in question following this pattern: -
- --T is a trivial type (3.9) or a class type with a trivial default - constructor (12.1), or an array of such a- -classtype. -
-i.e., add a comma and delete a "class." -
- - - - - -Section: 20.7.15.2 [func.wrap.func] Status: New - Submitter: Daniel Krügler Opened: 2009-10-18 Last modified: 2009-10-19
-View all other issues in [func.wrap.func].
-View all issues with New status.
-Discussion:
--The class template std::function contains the following member -declarations: -
- -- -// deleted overloads close possible hole in the type system -template<class R2, class... ArgTypes2> - bool operator==(const function<R2(ArgTypes2...)>&) = delete; -template<class R2, class... ArgTypes2> - bool operator!=(const function<R2(ArgTypes2...)>&) = delete; -
-The leading comment here is part of the history of std::function, which -was introduced with N1402. -During that time no explicit conversion functions existed, and the -"safe-bool" idiom (based on pointers-to-member) was a popular -technique. The only disadvantage of this idiom was that given two -objects f1 and f2 of type std::function the expression -
- -- -f1 == f2; -
-was well-formed, just because the built-in operator== for pointer to member -was considered after a single user-defined conversion. To fix this, an -overload set of undefined comparison functions was added, -such that overload resolution would prefer those ending up in a linkage error. -The new language facility of deleted functions provided a much better -diagnostic mechanism to fix this issue. -
- --The central point of this issue is, that with the replacement of the -safe-bool idiom by explicit conversion to bool the original "hole in the -type system" does no longer exist and therefore the comment is wrong and -the superfluous function definitions should be removed as well. An -explicit conversion function is considered in direct-initialization -situations only, which indirectly contain the so-called "contextual -conversion to bool" (4 [conv]/3). These conversions are not considered for -== or != as defined by the core language. -
- - -Proposed resolution:
--In 20.7.15.2 [func.wrap.func]/1, class function change as indicated: -
- -- - - - - -// 20.7.15.2.3, function capacity: -explicit operator bool() const; - -// deleted overloads close possible hole in the type system-template<class R2, class... ArgTypes2>-bool operator==(const function<R2(ArgTypes2...)>&) = delete;-template<class R2, class... ArgTypes2>-bool operator!=(const function<R2(ArgTypes2...)>&) = delete;-
Section: 25.3.9 [alg.unique] Status: Tentatively Ready - Submitter: Daniel Krügler Opened: 2009-10-17 Last modified: 2009-10-31
-View all other issues in [alg.unique].
-View all issues with Tentatively Ready status.
-Discussion:
--A lot of fixes were silently applied during concept-time and we should -not lose them again. The Requires clause of 25.3.9 [alg.unique]/5 -doesn't mention that == and the predicate need to satisfy an -EquivalenceRelation, as it is correctly said for -unique. This was intentionally fixed during conceptification, -were we had: -
- -- -template<InputIterator InIter, class OutIter> - requires OutputIterator<OutIter, RvalueOf<InIter::value_type>::type> - && EqualityComparable<InIter::value_type> - && HasAssign<InIter::value_type, InIter::reference> - && Constructible<InIter::value_type, InIter::reference> - OutIter unique_copy(InIter first, InIter last, OutIter result); - -template<InputIterator InIter, class OutIter, - EquivalenceRelation<auto, InIter::value_type> Pred> - requires OutputIterator<OutIter, RvalueOf<InIter::value_type>::type> - && HasAssign<InIter::value_type, InIter::reference> - && Constructible<InIter::value_type, InIter::reference> - && CopyConstructible<Pred> - OutIter unique_copy(InIter first, InIter last, OutIter result, Pred pred); -
-Note that EqualityComparable implied an equivalence relation. -
- -[ -N.B. adjacent_find was also specified to require -EquivalenceRelation, but that was considered as a defect in -concepts, see 1000 -]
- - -[ -2009-10-31 Howard adds: -]
- - --Moved to Tentatively Ready after 5 positive votes on c++std-lib. -- - - -
Proposed resolution:
--Change 25.3.9 [alg.unique]/5 as indicated: -
- -- - - - - -template<class InputIterator, class OutputIterator> - OutputIterator - unique_copy(InputIterator first, InputIterator last, OutputIterator result); - -template<class InputIterator, class OutputIterator, class BinaryPredicate> - OutputIterator - unique_copy(InputIterator first, InputIterator last, - OutputIterator result, BinaryPredicate pred); ---Requires: The comparison function shall be an equivalence -relation. The ranges [first,last) and -[result,result+(last-first)) shall not overlap. The expression -*result = *first shall be valid. If neither -InputIterator nor OutputIterator meets the -requirements of forward iterator then the value type of -InputIterator shall be CopyConstructible (34) and -CopyAssignable (table 36). Otherwise CopyConstructible -is not required. --
Section: 30.6 [futures] Status: New - Submitter: Detlef Vollmann Opened: 2009-10-22 Last modified: 2009-10-23
-View all other issues in [futures].
-View all issues with New status.
-Discussion:
--With the addition of async(), a future might be -associated with a function that is not running in a different thread but -is stored to by run synchronously on the get() call. It's not -clear what the wait() functions should do in this case. -
- --Suggested resolution: -
- --Throw an exception. -
- - -Proposed resolution:
- - - - - -Section: 20.7.16 [unord.hash] Status: New - Submitter: Paolo Carlini Opened: 2009-10-22 Last modified: 2009-10-25
-View other active issues in [unord.hash].
-View all other issues in [unord.hash].
-View all issues with New status.
-Discussion:
--In 20.7.16 [unord.hash], operator() is specified as -taking the argument by value. Moreover, it is said that operator() shall -not throw exceptions. -
- --However, for the specializations for class types, like string, wstring, -etc, the former requirement seems suboptimal from the performance point -of view (a specific PR has been filed about this in the GCC Bugzilla) -and, together with the latter requirement, hard if not impossible to -fulfill. It looks like pass by const reference should be allowed in such -cases. -
- - -Proposed resolution:
--Add to 20.7.16 [unord.hash]/2: -
- --- - - - - -namespace std { - template <class T> - struct hash : public std::unary_function<T, std::size_t> { - std::size_t operator()(T val) const; - }; -} -- --The return value of operator() is unspecified, except that -equal arguments shall yield the same result. operator() shall -not throw exceptions. It is also unspecified whether -operator() of std::hash specializations for class -types takes its argument by value or const reference. -
-
Section: 23.3.6.2 [vector.capacity] Status: New - Submitter: David Abrahams Opened: 2009-10-24 Last modified: 2009-10-25
-View all other issues in [vector.capacity].
-View all issues with New status.
-Discussion:
--If v is a vector, I think repeated calls to -v.resize( v.size() + 1 ) should be amortized O(1), but it's not -clear that's true from the text of the standard: -
- -- -void resize(size_type sz); ---Effects: If sz < size(), equivalent to erase(begin() + sz, end());. If -size() < sz, appends sz - size() default constructed elements to the -sequence. --
-Seems to me if we used push_back instead of appends, we might be giving -the guarantee I'd like. Thoughts? -
- - -Proposed resolution:
--In 23.3.6.2 [vector.capacity]/10, change -
- -- - - - - - -void resize(size_type sz); ---Effects: If sz < size(), equivalent to erase(begin() + sz, end());. If -size() < sz,-appends sz - size() default constructed elements to the -sequence-equivalent to sz - size() consecutive evaluations of push_back(T()). -
Section: D.10.1 [auto.ptr] Status: Review - Submitter: Alisdair Meredith Opened: 2009-10-24 Last modified: 2009-11-06
-View all other issues in [auto.ptr].
-View all issues with Review status.
-Discussion:
--This issue is extracted as the ongoing point-of-interest from earlier -issue 463. -
- --auto_ptr is overspecified as the auto_ptr_ref -implementation detail is formally specified, and the technique is -observable so workarounds for compiler defects can cause a working -implementation of the primary auto_ptr template become -non-conforming. -
- --auto_ptr_ref is a documentation aid to describe a possible -mechanism to implement the class. It should be marked exposition only, -as per similar classes, e.g., istreambuf_iterator::proxy -
- -[ -2009-10-25 Daniel adds: -]
- - --- --I wonder, whether the revised wording shouldn't be as straight as -for istream_buf by adding one further sentence: -
- --An implementation is permitted to provide equivalent functionality without -providing a class with this name. --
[ -2009-11-06 Alisdair adds Daniel's suggestion to the proposed wording. -]
- - -[ -2009-11-06 Howard moves issue to Review. -]
- - - - -Proposed resolution:
--Add the term "exposition only" in the following two places: -
- --Ammend D.10.1 [auto.ptr]p2: -
- --- - - - - --The exposition only class
- -Ttemplate auto_ptr_ref -holds a reference to an auto_ptr. It is used by the -auto_ptr conversions to allow auto_ptr objects to be -passed to and returned from functions. -An implementation is permitted to provide equivalent functionality -without providing a class with this name. --namespace std { - template <class Y> struct auto_ptr_ref { }; // exposition only -
Section: 27.5.4.1 [basic.ios.cons] Status: New - Submitter: Martin Sebor Opened: 2009-10-25 Last modified: 2009-10-26
-View all other issues in [basic.ios.cons].
-View all issues with New status.
-Discussion:
--The basic_ios default ctor is required to leave the objects members -uninitialized (see below). The paragraph says the object must be -initialized by calling basic_ios::init() before it's destroyed by -I can't find a requirement that it be initialized before calling -any of the class other member functions. Am I not looking in the -right place or that an issue? -
- -[ -2009-10-25 Daniel adds: -]
- - --- - - --I agree, that your wording makes that clearer, but suggest to write -
- --... calling basic_ios::init- -()before ... --Doing so, I recommend to adapt that of ios_base(); as well, where -we have: -
- --Effects: Each ios_base member has an indeterminate value -after construction. These members shall be initialized by calling -basic_ios::init. If an ios_base object is destroyed -before these initializations have taken place, the behavior is -undefined. --
Proposed resolution:
--Change 27.5.2.7 [ios.base.cons] p1: -
- -- -ios_base(); ---Effects: Each ios_base member has an indeterminate value -after construction.-TheseThe object's members shall be initialized by calling -basic_ios::init before the object's first use or before - it is destroyed, whichever comes first; otherwise the behavior - is undefined..If an ios_base object is destroyed -before these initializations have taken place, the behavior is -undefined.-
-Change 27.5.4.1 [basic.ios.cons] p2: -
- -- - - - - -basic_ios(); ---Effects: Constructs an object of class basic_ios -(27.5.2.7) leaving its member objects uninitialized. The object shall be -initialized by calling-its-basic_ios::init before its first -use or before it is destroyed, whichever comes first; otherwise the -behavior is undefined.member function. If it is destroyed -before it has been initialized the behavior is undefined.-
Section: 20.3.7 [template.bitset] Status: New - Submitter: Martin Sebor Opened: 2009-10-29 Last modified: 2009-10-29
-View other active issues in [template.bitset].
-View all other issues in [template.bitset].
-View all issues with New status.
-Discussion:
--Issue 1227 — <bitset> synopsis overspecified makes the observation -that std::bitset, and in fact the whole library, may be implemented -without needing to #include <stdexcept> in any library header. The -proposed resolution removes the #include <stdexcept> directive from -the header. -
- --I'd like to add that the <bitset> header (as well as the rest of -the library) has also been implemented without #including the -<cstddef> header in any library header. In the case of std::bitset, -the template is fully usable (i.e., it may be instantiated and all -its member functions may be used) without ever mentioning size_t. -In addition, just like no library header except for <bitset> -#includes <stdexcept> in its synopsis, no header but <bitset> -#includes <cstddef> either. -
- --Thus I suggest that the #include <cstddef> directive be similarly -removed from the synopsis of <bitset>. -
- - -Proposed resolution:
--Change 20.3.7 [template.bitset]: -
- -- - - - - -#include <cstddef> // for size_t-#include <string> -#include <iosfwd> // for istream, ostream -namespace std { -... -
Section: 27.8.1.1 [stringbuf.cons] Status: New - Submitter: Martin Sebor Opened: 2009-10-29 Last modified: 2009-10-29
-View all other issues in [stringbuf.cons].
-View all issues with New status.
-Discussion:
--I just came across issue 1204 -- Global permission to move, which -seems to address the concern raised by the example in c++std-lib-25030. -
--IIUC, the example violates the permission to assume that arguments -bound to rvalue references are unnamed temporaries granted to -implementations by the resolution of issue 1204 - Global permission -to move. -
- --I.e., the ostringstream(ostringstream &&rhs) ctor can leave the rhs -pointers pointing to the newly constructed object's buffer just as -long as the dtor doesn't change or invalidate the buffer. The caller -may not make any assumptions about rhs after the move beyond it being -safe to destroy or reassign. -
- --So unless I misunderstood something, I still think the basic_stringbuf -move ctor is overspecified. Specifically, I think the third sentence -in the Effects clause and the last 6 bullets in the Postconditions -clause can, and IMO should, be stricken. -
- - -Proposed resolution:
--Strike from 27.8.1.1 [stringbuf.cons]: -
- -- - - - - -basic_stringbuf(basic_stringbuf&& rhs); -----Effects: Move constructs from the rvalue rhs. It is -implementation-defined whether the sequence pointers in *this -(eback(), gptr(), egptr(), pbase(), -pptr(), epptr()) obtain the values which rhs -had.
- -Whether they do or not, *this and rhs reference -separate buffers (if any at all) after the construction.The openmode, -locale and any other state of rhs is also copied. --Postconditions: Let rhs_p refer to the state of -rhs just prior to this construction and let rhs_a -referto the state of rhs just after this construction. -
--
-- -str() == rhs_p.str() -
-- -gptr() - eback() == rhs_p.gptr() - rhs_p.eback() -
-- -egptr() - eback() == rhs_p.egptr() - rhs_p.eback() -
-- -pptr() - pbase() == rhs_p.pptr() - rhs_p.pbase() -
-- -epptr() - pbase() == rhs_p.epptr() - rhs_p.pbase() -
-- -
-if (eback()) eback() != rhs_a.eback() -- -
-if (gptr()) gptr() != rhs_a.gptr() -- -
-if (egptr()) egptr() != rhs_a.egptr() -- -
-if (pbase()) pbase() != rhs_a.pbase() -- -
-if (pptr()) pptr() != rhs_a.pptr() -- -
-if (epptr()) epptr() != rhs_a.epptr() -
Section: 22.3.3.2.3 [conversions.buffer] Status: New - Submitter: Bo Persson Opened: 2009-10-21 Last modified: 2009-10-31
-View all issues with New status.
+Section: 22.3.3.2.3 [conversions.buffer] Status: Open + Submitter: Bo Persson Opened: 2009-10-21 Last modified: 2010-11-13
+View all issues with Open status.
Discussion:
The synopisis for wbuffer_convert 22.3.3.2.3 [conversions.buffer]/2 contains @@ -27737,6 +2572,15 @@ From what I can see, it might be hard to implement be the same type.
+[ +Batavia 2010: +]
+ + ++Howard to draft wording, move to Review. Run it by Bill. Need to move this in Madrid. +
+Proposed resolution:
@@ -27746,11 +2590,11 @@ be the same type.Section: 23.2.4 [associative.reqmts] Status: New - Submitter: Boris Dušek Opened: 2009-10-24 Last modified: 2009-10-31
+Section: 23.2.4 [associative.reqmts] Status: Tentatively Ready + Submitter: Boris Dušek Opened: 2009-10-24 Last modified: 2010-11-13
View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
-View all issues with New status.
+View all issues with Tentatively Ready status.
Discussion:
In the latest published draft @@ -27767,282 +2611,1141 @@ since both modify the container. For the sake of consistency, in 23.2.4 [associa that modify it).
- -Proposed resolution:
--
- - - - - -Section: 23.3.7 [vector.bool] Status: New - Submitter: Christopher Jefferson Opened: 2009-11-01 Last modified: 2009-11-01
-View all other issues in [vector.bool].
-View all issues with New status.
-Discussion:
--The effects of vector<bool>::flip has the line: -
- --It is unspecified whether the function has any effect on allocated but -unused bits. -- -
-While this is technically true, it is misleading, as any member function -in any standard container may change unused but allocated memory. Users -can never observe such changes as it would also be undefined behaviour -to read such memory. -
- - -Proposed resolution:
--Strike second sentence from the definition of vector<bool>::flip(), -23.3.7 [vector.bool], paragraph 5. -
- --Effects: Replaces each element in the container with its complement. -- - - - - -It is unspecified whether the function has any effect on allocated -but unused bits.-
Section: 20.3 [utility] Status: New - Submitter: Daniel Krügler Opened: 2009-11-03 Last modified: 2009-11-04
-View all issues with New status.
-Discussion:
--During the Santa Cruz meeting it was decided to split off the provision -of the library utility value() proposed in N2979 -from the concrete request of the -UK 300 -comment. -The provision of a new library component that allows the production of -values in unevaluated expressions is considered as important -to realize constrained templates in C++0x where concepts are not -available. -
- --The following proposed resolution is an improvement over that suggested in -N2958, -because the proposed component can now be defined without loss of -general usefulness and any use by user-code will make the program ill-formed. -A possible prototype implementation that satisfies the core language -requirements -can be written as: -
- -template<class T>
- struct declval_protector {
- static const bool stop = false;
- static typename std::add_rvalue_reference<T>::type delegate(); // undefined
- };
-
-template<class T>
-typename std::add_rvalue_reference<T>::type declval() {
- static_assert(declval_protector<T>::stop, "declval() must not be used!");
- return declval_protector<T>::delegate();
-}
--Further-on the earlier suggested name value() has been changed to declval() -after discussions with committee members. -
- --Finally the suggestion shown below demonstrates that it can simplify -existing standard wording by directly using it in the library -specification, and that it also improves an overlooked corner case for -common_type by adding support for cv void. -
- - -Proposed resolution:
[ -The following edit assumes that the earlier component identity -has been removed as part of applying the solution of 939, -N2951, -and -N2984. -Note that the proposal does not depend on this application, -but it just simplifies the editorial representation +2009-11-18 Chris provided wording. ]
++This suggested wording covers both the issue discussed, and a number of other +identical issues (namely insert being discussed without emplace). I'm happy to +go back and split and introduce a new issue if appropriate, but I think the +changes are fairly mechanical and obvious. ++ +
[ +2010-01-23 Daniel Krügler and J. Daniel García updated wording to +make the use of hint consistent with insert. +]
+ + + + +Proposed resolution:
++Modify bullet 1 of 23.2.1 [container.requirements.general], p10: +
+ ++10 Unless otherwise specified (see 23.2.4.1, 23.2.5.1, 23.3.2.3, and 23.3.6.4) +all container types defined in this Clause meet the following additional +requirements: +
+ ++Modify 23.2.4 [associative.reqmts], p4: +
+ ++4 An associative container supports unique keys if it may contain at most +one element for each key. Otherwise, it supports equivalent keys. The +set and map classes support unique keys; the multiset +and multimap classes support equivalent keys. For multiset and +multimap, insert, emplace, and +erase preserve the relative ordering of equivalent elements. ++ +
+Modify Table 96 — Associative container requirements in 23.2.4 [associative.reqmts]: +
+ +++ ++
+Table 96 — Associative container requirements (in addition to container) ++ + +Expression +Return type +Assertion/note +
pre-/post-conditionComplexity ++ + ++ ... + + +a_eq.emplace(args) +iterator +inserts a T object t constructed with +std::forward<Args>(args)... and returns the iterator pointing to +the newly inserted element. If a range containing elements equivalent to +t exists in a_eq, t is inserted at the end of that +range. +logarithmic ++ + +a.emplace_hint(p, args) +iterator +equivalent to a.emplace(std::forward<Args>(args)...). Return +value is an iterator pointing to the element with the key equivalent to the +newly inserted element. +The const_iterator p is a hint pointing to +where the search should start.The element is inserted as close as +possible to the position just prior to p.Implementations +are permitted to ignore the hint.logarithmic in general, but amortized constant if the element is inserted +right +afterbefore p+ + ++ ...
+Modify 23.2.4 [associative.reqmts], p8: +
+ ++8 The insert and emplace members shall not affect +the validity of iterators and references to the container, and the +erase members shall invalidate only iterators and references to the +erased elements. ++ +
+Modify 23.2.4.1 [associative.reqmts.except], p2: +
+ ++2 For associative containers, if an exception is thrown by any operation from +within an insert() or emplace() function inserting +a single element, the+ +insert() functioninsertion +has no effect. +
+Modify 23.2.5 [unord.req], p6, p12 and p13: +
+ +++ ++6 An unordered associative container supports unique keys if it may +contain at most one element for each key. Otherwise, it supports equivalent +keys. unordered_set and unordered_map support unique keys. +unordered_multiset and unordered_multimap support equivalent +keys. In containers that support equivalent keys, elements with equivalent keys +are adjacent to each other. For unordered_multiset and +unordered_multimap, insert, emplace, and +erase preserve the relative ordering of equivalent elements. +
+ ++12 The insert and emplace members shall not affect +the validity of references to container elements, but may invalidate all +iterators to the container. The erase members shall invalidate only iterators +and references to the erased elements. +
+ ++13 The insert and emplace members shall not affect +the validity of iterators if (N+n) < z * B, where N is the +number of elements in the container prior to the insert operation, n is +the number of elements inserted, B is the container's bucket count, and +z is the container's maximum load factor. +
+
+Modify 23.2.5.1 [unord.req.except], p2: +
+ ++2 For unordered associative containers, if an exception is thrown by any +operation other than the container's hash function from within an +insert() or emplace() function inserting a single +element, the+ + + + + +insert()insertion +functionhas no effect. +
Section: X [base] Status: Ready + Submitter: Alberto Ganesh Barbati Opened: 2009-11-30 Last modified: 2010-11-13
+View all other issues in [base].
+View all issues with Ready status.
+Discussion:
++A program should not be allowed to add specialization of class templates +unary_function and binary_function, in force of 17.6.3.2.1 [namespace.std]/1. +If a program were allowed to specialize these templates, the library could no +longer rely on them to provide the intended typedefs or there might be other +undesired interactions. +
+ +[ +2010-03-27 Daniel adds: +]
+ + ++Accepting issue 1290 would resolve this issue as NAD editorial. ++ +
[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3145 would resolve this issue as NAD editorial. ++ +
[ +2010 Batavia: Solved by N3198 +]
+ + ++Previous proposed resolution: +
+Change paragraph X [base]/1 as follows: +
+ ++1 The following+ + + + + +classesclass templates are provided to +simplify the typedefs of the argument and result types:. A +program shall not declare specializations of these templates. +
Proposed resolution:
+Addressed by paper D3198. + + + + + +Section: 20.9.9.4 [unique.ptr.special] Status: Open + Submitter: Daniel Krügler Opened: 2009-12-23 Last modified: 2010-11-13
+View all issues with Open status.
+Discussion:
++The comparison functions of unique_ptr currently directly delegate to +the underlying comparison functions of unique_ptr<T, D>::pointer. +This is disadvantageous, because this would not guarantee to induce a total +ordering for native pointers and it is hard to define a total order for mixed +types anyway. +
++The currently suggested resolution for shared_ptr comparison as of +1262 uses a normalization strategy: They perform the comparison on +the composite pointer type (5.9 [expr.rel]). This is not +exactly possible for unique_ptr in the presence of user-defined +pointer-like types but the existing definition of std::duration +comparison as of 20.11.3.6 [time.duration.comparisons] via +common_type of both argument types demonstrates a solution of this +problem. The approach can be seen as the general way to define a composite +pointer type and this is the approach which is used for here suggested +wording change. +
++For consistency reasons I would have preferred the same normalization strategy +for == and !=, but Howard convinced me not to do so (now). +
+ +[ +2010-11-03 Daniel comments and adjustes the currently proposed wording changes: +]
+ + ++Issue 1401 is remotely related. Bullet A of its proposed resolution +provides an alternative solution for issue discussed here and addresses NB comment GB-99. +Additionally I updated the below suggested wording in regard to the following: +It is an unncessary requirement that the below defined effective composite pointer-like +type CT satisfies the LessThanComparable requirements. All what is +needed is, that the function object type less<CT> induces a strict +weak ordering on the pointer values. +
+ + +Proposed resolution:
+ ++Change 20.9.9.4 [unique.ptr.special]/4-7 as indicated: [The implicit +requirements and remarks imposed on the last three operators are the same as for +the first one due to the normative "equivalent to" usage within a Requires +element, see 17.5.1.4 [structure.specifications]/4. The effects of this +change are that all real pointers wrapped in a unique_ptr will order +like shared_ptr does.] +
+ ++ + + + + + +template <class T1, class D1, class T2, class D2> + bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ +++ ++? Requires: Let CT be common_type<unique_ptr<T1, +D1>::pointer, unique_ptr<T2, D2>::pointer>::type. Then +the specialization less<CT> shall be a function object type ([function.objects]) +that induces a strict weak ordering ([alg.sorting]) on the pointer values. +
+ ++4 Returns: less<CT>()(x.get(), y.get())
+ +x.get() +< y.get(). ++? Remarks: If unique_ptr<T1, D1>::pointer is not +implicitly convertible to CT or unique_ptr<T2, +D2>::pointer is not implicitly convertible to CT, the program +is ill-formed. +
+template <class T1, class D1, class T2, class D2> + bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ ++5 Effects: Equivalent to return !(y < x) ++ +Returns: x.get() <= y.get(). +template <class T1, class D1, class T2, class D2> + bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ ++6 Effects: Equivalent to return (y < x) ++ +Returns: x.get() > y.get(). +template <class T1, class D1, class T2, class D2> + bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ ++7 Effects: Equivalent to return !(x < y) ++Returns: x.get() >= y.get(). +
Section: 23.3.3.5 [forwardlist.ops] Status: Tentatively Ready + Submitter: Howard Hinnant Opened: 2010-02-05 Last modified: 2010-11-13
+View all other issues in [forwardlist.ops].
+View all issues with Tentatively Ready status.
+Discussion:
++We've moved 1133 to Tentatively Ready and I'm fine with that. +
+ ++1133 adds lvalue-references to the splice signatures for list. So now +list can splice from lvalue and rvalue lists (which was the intent of the +original move papers btw). During the discussion of this issue it was mentioned +that if we want to give the same treatment to forward_list, that should be a +separate issue. +
+ ++This is that separate issue. +
+ ++Consider the following case where you want to splice elements from one place in +a forward_list to another. Currently this must be coded like so: +
+ ++ +fl.splice_after(to_here, std::move(fl), from1, from2); +
+This looks pretty shocking to me. I would expect to be able to code instead: +
+ ++ +fl.splice_after(to_here, fl, from1, from2); +
+but we currently don't allow it. +
+ ++When I say move(fl), I consider that as saying that I don't care about +the value of fl any more (until I assign it a new value). But in the +above example, this simply isn't true. I do care about the value of fl +after the move, and I'm not assigning it a new value. I'm merely permuting its +current value. +
+ ++I propose adding forward_list& overloads to the 3 +splice_after members. For consistency's sake (principal of least +surprise) I'm also proposing to overload merge this way as well. +
+ + +Proposed resolution:
++Add to the synopsis of 23.3.3 [forwardlist]: +
+ +template <class T, class Allocator = allocator<T> >
+class forward_list {
+public:
+ ...
+ void splice_after(const_iterator p, forward_list& x);
+ void splice_after(const_iterator p, forward_list&& x);
+ void splice_after(const_iterator p, forward_list& x, const_iterator i);
+ void splice_after(const_iterator p, forward_list&& x, const_iterator i);
+ void splice_after(const_iterator p, forward_list& x,
+ const_iterator first, const_iterator last);
+ void splice_after(const_iterator p, forward_list&& x,
+ const_iterator first, const_iterator last);
+ ...
+ void merge(forward_list& x);
+ void merge(forward_list&& x);
+ template <class Compare> void merge(forward_list& x, Compare comp);
+ template <class Compare> void merge(forward_list&& x, Compare comp);
+ ...
+};
++Add to the signatures of 23.3.3.5 [forwardlist.ops]: +
+ +++ + + + + + +void splice_after(const_iterator p, forward_list& x); +void splice_after(const_iterator p, forward_list&& x); ++++ +1 ...
+void splice_after(const_iterator p, forward_list& x, const_iterator i); +void splice_after(const_iterator p, forward_list&& x, const_iterator i); ++++ +5 ...
+void splice_after(const_iterator p, forward_list& x, + const_iterator first, const_iterator last); +void splice_after(const_iterator p, forward_list&& x, + const_iterator first, const_iterator last); ++++ +9 ...
+void merge(forward_list& x); +void merge(forward_list&& x); +template <class Compare> void merge(forward_list& x, Compare comp); +template <class Compare> void merge(forward_list&& x, Compare comp); ++++ +18 ...
+
Section: 20.9.4.1 [allocator.traits.types] Status: Ready + Submitter: Pete Becker Opened: 2010-02-11 Last modified: 2010-11-12
+View all issues with Ready status.
+Duplicate of: 1375
+Discussion:
+Addresses US-87
++N2982 +says that containers should have a nested typedef that defines their +reference_type as value_type&; the previous +standard deferred to the allocator to define its +reference_type, and containers simply passed the allocator's +typedef on. This change is a mistake. Allocators should define both a +pointer type and a reference type. That's essential +for their original purpose, which was to make different memory models +transparent. If an allocator defines a pointer type that isn't +compatible with a normal pointer it also has to define a corresponding +reference type. For example (and please forgive a Windows-ism), +if an allocator's pointer is T __far*, then it's +reference has to be T __far&. Otherwise everything +crashes (under the hood, references are pointers and have to have the +same memory access mechanics). Extensions such as this for more general +memory models were explicitly encouraged by C++03, and the allocator's +pointer and reference typedefs were the hooks for such +extensions. Removing the allocator's reference and +const_reference typedefs makes those extensions unimplementable +and breaks existing implementations that rely on those hooks. +
+ +[ +2010-02-25 Alisdair adds: +]
+ + +++ ++vector<bool>::reference is a nested class, and not a typedef. It +should be removed from the list of containers when this change is made. +
+ ++In general, I am unfcomfortable placing this reference requirement on each +container, as I would prefer to require: +
+ ++ +is_same<Container::reference, Container::iterator::reference> ++This distinction is important, if we intend to support proxy iterators. The +iterator paper in the pre-Pittsburgh mailing +(N3046) +does not make this proposal, but organises clause 24 in such a way this +will be much easier to specify. +
+ ++The changes to clause 20 remain important for all the reasons Pete highlights. +
+
[ +2010 Batavia +]
+ + ++Removed vector from list of templates that should be adjusted. +
+ + +Proposed resolution:
-Change 20.3 [utility], header <utility> synopsis -as indicated: +Add the following two rows to Table 40, Allocator requirements:
--// 20.3.2, forward/move: -template <class T, class U> T&& forward(U&& u);; -template <class T> typename remove_reference<T>::type&& move(T&&); - -// 20.3.3, declval: -template <class T> typename add_rvalue_reference<T>::type declval(); // for unused context -
-Immediately after the current section 20.3.3 [forward] insert a -new section: -
--20.3.3 Function template declval [declval] -
--The library provides the function template declval to simplify -the definition of expressions in -unevaluated and unused contexts (3.2 [basic.def.odr], 5 [expr]). The -template parameter T of declval may -be an incomplete type. -
- -template <class T> typename add_rvalue_reference<T>::type declval(); // for unused context --
--Remarks: If this function is used according to 3.2 [basic.def.odr], -the program shall be ill-formed. -
++
Table 40 — Allocator requirements ++ + ++Expression + --[Example: -
++Return type + -+-template<class To, class From> -decltype(static_cast<To>(declval<From>())) convert(From&&); -+Assertion/note -
pre-/post-condition +- -declares a function template convert, which does only participate in -overloading, if the type From can be -explicitly casted to type To — end example] -
++Default + + ++ + +X::reference + ++ + + + T& ++ + +X::const_reference + ++ + + + const T& +
-This bullet just makes clear that after applying N2984, the changes in 20.6.4.3 [meta.unary.prop], before -table Type property queries should not use declval, -because the well-formedness requirement of the specification of -is_constructible would become more complicated, because we -would need to make sure that the expression CE is checked in an -unevaluated context. +2. Change the following two rows in Table 40:
+ ++++
+Table 40 — Allocator requirements ++ + ++Expression + + ++Return type + + ++Assertion/note + +
pre-/post-condition ++Default + + ++ + +*p + ++ + T&X::reference+ + + + + +*q + ++ + const T&X::const_reference+ + +
-Also 20.6.5 [meta.rel]/4 is not modified similar to the previous bullet, -because with -the stricter requirements of not using declval() the well-formedness condition -would be harder to specify. The following changes are only editorial ones (e.g. -the removal of the duplicate declaration of create()): +Add the following typedef declarations to allocator_traits 20.9.4 [allocator.traits]: +
+ +template <class Alloc> struct allocator_traits {
+ ...
+ typedef see below reference;
+ typedef see below const_reference;
+ ...
++Add the following descriptions to 20.9.4.1 [allocator.traits.types]:
--Given the following function prototype: -
+typedef see below reference;++Type: Alloc::reference if such a type exists; otherwise, +value_type&. +-- -template <class T> - typename add_rvalue_reference<T>::type create(); --the predicate condition for a template specialization -is_convertible<From, To> shall be satisfied if and only -if the return expression in the following code would be well-formed, -including any -im
- -mplicit conversions to the return type of the function: -+template <class T> -typename add_rvalue_reference<T>::type create();-To test() { - return create<From>(); -} -typedef see below const reference;++Type: Alloc::const_reference if such a type exists; otherwise, +const value_type&. +
-Change the entry in column "Comments" for common_type in Table 51 — -Other transformations (20.6.7 [meta.trans.other]): +Add the following typdef declarations to scoped_allocator_adaptor 20.10 [allocator.adaptor]: +
+ +template <class OuterAlloc, class... InnerAllocs>
+class scoped_allocator_adaptor : public OuterAlloc {
+ ...
+ typedef typename OuterTraits::reference reference;
+ typedef typename OuterTraits::const_reference const_reference;
+ ...
++Change the nested typedefs reference and +const_reference to: +
+ ++ +typedef typename allocator_traits<Allocator>::reference reference; +typedef typename allocator_traits<Allocator>::const_reference const_reference; +
+for each of the following class templates: +
+ ++deque 23.3.2 [deque]+
+forward_list 23.3.3 [forwardlist]
+list 23.3.4 [list]
+queue 23.5.1.1 [queue.defn]
+priority_queue 23.5.2 [priority.queue]
+stack 23.5.3.1 [stack.defn]
+vector<bool> 23.4.2 [vector.bool]
+map 23.6.1 [map]
+multimap 23.6.2 [multimap]
+set 23.6.3 [set]
+multiset 23.6.4 [multiset]
+unordered_map 23.7.1 [unord.map]
+unordered_multimap 23.7.2 [unord.multimap]
+unordered_set 23.7.3 [unord.set]
+unordered_multiset 23.7.4 [unord.multiset]
+basic_string 21.4 [basic.string]
+match_results 28.10 [re.results] +
Section: 24.3 [iterator.synopsis] Status: Tentatively NAD Future + Submitter: Alisdair Meredith Opened: 2010-02-16 Last modified: 2010-11-13
+Discussion:
++The iter_swap function template appears in the +<algorithm> header, yet its main use is in building further +algorithms, not calling existing ones. The main clients are implementers of data +structures and their iterators, so it seems most appropriate to place the +template in the <iterator> header instead. +
+ ++Note that this is not an issue for implementers of the standard library, as they +rarely use the standard headers directly, designing a more fine-grained set of +headers for their own internal use. This option is not available to customers +of the standard library. +
+ ++Note that we cannot remove iter_swap from <algorithm> +without breaking code, but there is no reason we cannot offer the same +declaration via two standard headers. Alternatively, require +<algorithm> to #include <iterator>, but +introducing the dependency on the iterator adaptors seems un-necessary.
[ -NB: This wording change extends the type domain of common_type for cv -void => cv void transformations and thus makes common_type usable for -all binary type combinations that are supported by is_convertible ]
++Discussed possibly moving to <utility> but don't like that. Some not seeing this +as a defect, and want to keep it in <algorithm>. No one seems to feel strongly +about moving to <iterator>. +
+ + +Proposed resolution:
+ ++Add the declaration of iter_swap to the <iterator> +header synopsis (24.3 [iterator.synopsis]), with a note that it is +documented in clause 25 [algorithms]. +
+ ++ + + + + + +... +template <class T, size_t N> T* end(T (&array)[N]); + +// documented in 25 [algorithms] +template<class ForwardIterator1, class ForwardIterator2> + void iter_swap(ForwardIterator1 a, ForwardIterator2 b); +
Section: 23.2 [container.requirements] Status: Deferred + Submitter: Nicolai Josuttis Opened: 2010-03-10 Last modified: 2010-11-15
+View all other issues in [container.requirements].
+View all issues with Deferred status.
+Discussion:
++Abstract: +
++In general, it seems that in a couple of places container behavior is +not described in requirement tables although it is a general behavior. +
+ ++History: +
+ ++Issue 676 added move semantics to unordered containers. +For the added insert functions the Editor requested to put their +semantic description into a requirements table rather than describing +them for each container individually. The text however was taken from +the associative containers, where we also have the semantics for each +container described. Also, 1034 is to some extend +requesting a clarification of the requirement tables and it turned out +that in other places we have the same problem (e.g. we have no general +requirement for type pointer and const_pointer although each container +has them with issue 1306). +
+ ++From my personal list of functions in requirement tables +and containers, the following types/functions are missing in +requirement tables: +
+ ++all copy constructors, copy constructors with allocator, + assignment operators, and insert operators + with move semantics for associative and unordered containers +
++ContType c1(c2&&) +ContType c1(c2&&,alloc) +c1 = c2&& +c.insert(val&&) +c.insert(pos,val&&) +
+As a special case, we lack the following requirements for all sequence +containers BUT array (so special wording or a new container category is +required): +
+ ++constructor with only a size argument +
++ContType c(num) +
+copy constructor with allocator and move semantics +
++ContType c1(c2&&,alloc) +
+all constructors that insert multiple elements with additional allocator +
++ContType c(num, val,alloc) +ContType c(beg, end,alloc) +ContType c(initlist,alloc) +
+all resize functiuons: +
++c.resize(num) +c.resize(num,val) +
+Note that we also might have to add additional requirements on other +places for sequence containers because having an allocator requires +additional statements for the treatment of the allocators. E.g. swap for +containers with allocators is not specified in any requirement table. +
+ ++And finally, if we have the requirements in the requirements tables, we +can remove the corresponding descriptions for the individual container. +However, note that sequence container requirements have NO complexity +column, so that we still need container specific descriptions for the +functions listed there. +
+ +[ +2010 Batavia +]
+ ++While there is consensus that further cleaning up the container requirement +tables would be a good thing, there is no feeling that this must +be done in time for 0x. The issue remains open, but Deferred. +
+ + + + +Proposed resolution:
+ + + + + +Section: 20.2.4 [hash.requirements] Status: Ready + Submitter: Daniel Krügler Opened: 2010-03-26 Last modified: 2010-11-14
+View all issues with Ready status.
+Discussion:
++The currently added Hash requirements demand in Table 40 — Hash +requirements [hash]: +
+-The member typedef type shall be defined as set out below. All -types in the parameter pack T shall be complete or -(possibly cv-qualified) void. A program may specialize -this trait if at least one template parameter in the specialization is a -user-defined type. [Note: Such specializations are needed when -only explicit conversions are desired among the template arguments. -— end note] ++ ++ +
+Table 40 — Hash requirements [hash] + ++ + +Expression +Return type +Requirement ++ + +h(k) +size_t +Shall not throw exceptions. [..] +
+While it surely is a generally accepted idea that hash function objects +should not throw exceptions, this basic constraint for such a fundamental +requirement set does neither match the current library policy nor real world +cases: +
+ ++The new definition goes beyond the original hash requirements as specified +by SGI library in regard to the exception requirement: +
++http://www.sgi.com/tech/stl/HashFunction.html ++
+Even though the majority of all known move, swap, and hash functions won't throw +and in some cases must not throw, it seems like unnecessary +over-constraining the definition of a Hash functor not to propagate exceptions +in any case and it contradicts the general principle of C++ to impose such a +requirement for this kind of fundamental requirement. +
+ +[ +2010-11-11 Daniel asks the working group whether they would prefer a replacement +for the second bullet of the proposed resolution (a result of discussing this +with Alberto) of the form: +]
+ + ++Add to 20.8.15 [unord.hash]/1 a new bullet: +
+ +++ + + ++1 The unordered associative containers defined in Clause 23.5 use +specializations of the class template hash +as the default hash function. For all object types Key for which there +exists a specialization hash<Key>, the +instantiation hash<Key> shall: +
++
+- +satisfy the Hash requirements (20.2.4), with Key as the +function call argument type, the DefaultConstructible requirements +(33), the CopyAssignable requirements (37), +
+- +be swappable (20.2.2) for lvalues, +
+- +provide two nested types result_type and argument_type which +shall be synonyms for size_t and Key, respectively, +
+- +satisfy the requirement that if k1 == k2 is true, h(k1) == +h(k2) is also true, where h is an object of type +hash<Key> and k1 and k2 are objects of type +Key,
+.+- +satisfy the requirement noexcept(h(k)) == true, where h is an object +of type hash<Key> and k is an object of type Key, unless +hash<Key> is a user-defined specialization that depends on at least one user-defined type. +
+
[Batavia: Closed as NAD Future, then reopened. See the wiki for Tuesday.]
+ + +Proposed resolution:
++Change Table 40 — Hash requirements [hash] as indicated: +
+ +++ +
Table 40 — Hash requirements [hash] + ++ + +Expression +Return type +Requirement ++ + +h(k) +size_t ++ Shall not throw exceptions.[..]
-Change 20.6.7 [meta.trans.other]/3 as indicated: -
- -[ -NB: This wording change is more than an editorial simplification of -the definition of common_type: It also extends its usefulness for cv -void types as outlined above -]
- - ---The nested typedef common_type::type shall be defined as follows: +Add to 20.8.15 [unord.hash]/1 a new bullet:
+-[..] +1 The unordered associative containers defined in Clause 23.5 use +specializations of the class template hash +as the default hash function. For all object types Key for which there +exists a specialization hash<Key>, the +instantiation hash<Key> shall:
-template <class T, class U> -struct common_type<T, U> { --private: - static T&& __t(); - static U&& __u(); -public:- typedef decltype(true ?__tdeclval<T>() :__udeclval<U>()) type; -}; -+
- +satisfy the Hash requirements (20.2.4), with Key as the +function call argument type, the DefaultConstructible requirements +(33), the CopyAssignable requirements (37), +
+- +be swappable (20.2.2) for lvalues, +
+- +provide two nested types result_type and argument_type which +shall be synonyms for size_t and Key, respectively, +
+- +satisfy the requirement that if k1 == k2 is true, h(k1) == +h(k2) is also true, where h is an object of type +hash<Key> and k1 and k2 are objects of type +Key,
+.+- +satisfy the requirement that the expression h(k), where h +is an object of type hash<Key> and k is an object of +type Key, shall not throw an exception, unless +hash<Key> is a user-defined specialization that depends on at +least one user-defined type. +
+
Section: 20.8.15.3 [util.smartptr.weak] Status: New - Submitter: Daniel Krügler Opened: 2009-11-04 Last modified: 2009-11-04
-View all issues with New status.
+Section: 17 [library] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-31
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Open status.
Discussion:
+Addresses GB-61
-Additional to the necessary cleanup of the description of the the -weak_ptr component from 20.8.15.3 [util.smartptr.weak] -described in 1231 it turns out that the currently deleted -comparison functions of weak_ptr are not needed at all: There -is no safe-bool conversion from weak_ptr, and it won't silently -chose a conversion to shared_ptr. +All library types should have non-throwing move +constructors and move-assignment operators unless +wrapping a type with a potentially throwing move operation. +When such a type is a class-template, these +operations should have a conditional noexcept +specification. +
++There are many other places where a noexcept +specification may be considered, but the move operations +are a special case that must be called out, to effectively +support the move_if_noexcept function template.
- -Proposed resolution:
--Change 20.8.15.3 [util.smartptr.weak]/1 as indicated: -
- -namespace std {
-template<class T> class weak_ptr {
-public:
-...
- // comparisons
- template<class Y> bool operator<(weak_ptr<Y> const&) const = delete;
- template<class Y> bool operator<=(weak_ptr<Y> const&) const = delete;
- template<class Y> bool operator>(weak_ptr<Y> const&) const = delete;
- template<class Y> bool operator>=(weak_ptr<Y> const&) const = delete;
-};
-...
-concept_mapSection: 27.5 [iostreams.base] Status: New - Submitter: Beman Dawes Opened: 2009-11-04 Last modified: 2009-11-04
-View all other issues in [iostreams.base].
-View all issues with New status.
-Discussion:
--The current WP still contains a concept_map. -
- - -Proposed resolution:
--Change Iostreams base classes 27.5 [iostreams.base], Header <ios> synopsis, -as indicated: -
- -- - - - - - -concept_map ErrorCodeEnum<io_errc> { };-template <> struct is_error_code_enum<io_errc> : true_type { } -error_code make_error_code(io_errc e); -error_condition make_error_condition(io_errc e); -const error_category& iostream_category(); -
Section: 20.7.15.2.2 [func.wrap.func.mod] Status: New - Submitter: Daniel Krügler Opened: 2009-11-05 Last modified: 2009-11-05
-View all issues with New status.
-Discussion:
--As of 20.7.15.2.2 [func.wrap.func.mod]/2+ we have the following -prototype description: -
- -- -template<class F, Allocator Alloc> - requires Callable<F, ArgTypes...> - && Convertible<Callable<F, ArgTypes...>::result_type, R> - void assign(F, const Alloc&); ---Effects: function(f, a).swap(*this) --
-Two things: First the concept debris needs to be removed, second and -much more importantly, the effects clause is now impossible to satisfy, -because there is no constructor that would match the parameter sequence -(FunctionObject, Allocator) [plus the fact that no -f and no a is part of the signature]. The most -probable candidate is -
- -- -template<class F, class A> function(allocator_arg_t, const A&, F); -
-and the effects clause needs to be adapted to use this signature. -
- - -Proposed resolution:
--Change in 20.7.15.2.2 [func.wrap.func.mod] the complete prototype description as -indicated -
[ -Question to -the editor: Shouldn't there a paragraph number in front of the Effects clause? +Resolution proposed by ballot comment: +]
+ ++Review every class and class template in the +library. If noexcept move constructor/assignment +operators can be implicitly declared, then they +should be implicitly declared, or explicitly +defaulted. Otherwise, a move constructor/moveassingment +operator with a noexcept exception +specification should be provided. +
+ +[ +2010-10-31 Daniel comments: ]
-+template<class F, Allocator Alloc> - requires Callable<F, ArgTypes...> - && Convertible<Callable<F, ArgTypes...>::result_type, R> - void assign(F, const Alloc&);-template<class F, class A> void assign(F f, const A& a); --3 Effects: function(+The proposed resolution of n3157 +would satisfy this request.f, aallocator_arg, a, -f).swap(*this) -
Proposed resolution:
+See n3157 + +Section: 23.2.3 [sequence.reqmts] Status: New - Submitter: Sean Hunt Opened: 2009-11-05 Last modified: 2009-11-06
-View other active issues in [sequence.reqmts].
-View all other issues in [sequence.reqmts].
-View all issues with New status.
+Section: 17 [library] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-25
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Open status.
Discussion:
+Addresses GB-64
-According to 23.2.3 [sequence.reqmts], X(il) is -equivalent to X(il.begin(), il.end()). Should it instead be -equivalent to X(move_iterator(il.begin()), -move_iterator(il.end())) so that needless copies are not made? This -doesn't seem ideal either - it may make more sense to provide two -overloads for the constructor, one for move and one for copy. +There are a number of unspecified types used throughout +the library, such as the container iterators. Many of these +unspecified types have restrictions or expectations on +their behaviour in terms of exceptions. Are they permitted +or required to use exception specifications, more +specifically the new noexcept specification? For example, +if vector<T>::iterator is implemented as a native pointer, +all its operations will have an (effective) noexcept +specification. If the implementation uses a class type to +implement this iterator, is it permitted or required to +support that same guarantee? +
+ +[ +Resolution proposed by ballot comment +]
+ ++Clearly state the requirements for exception +specifications on all unspecified library types. For +example, all container iterator operations should +be conditionally noexcept, with the condition +matching the same operation applied to the +allocator's pointer_type, a certain subset of which +are already required not to throw.
Proposed resolution:
--
Section: 20.6.4.3 [meta.unary.prop] Status: New - Submitter: Peter Dimov Opened: 2009-11-07 Last modified: 2009-11-08
-View other active issues in [meta.unary.prop].
-View all other issues in [meta.unary.prop].
-View all issues with New status.
+Section: 17 [library] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-25
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Open status.
Discussion:
+Addresses GB-65
-The specification of is_constructible<T,Args...> in -N3000 -uses +Nothrowing swap operations are key to many C++ idioms, +notably the common copy/swap idiom to provide the +strong exception safety guarantee.
-+static_cast<T>(create<Args>()...) -
[ +Resolution proposed by ballot comment +]
-for the one-argument case, but static_cast also permits -unwanted conversions such as void* to T* and -Base* to Derived*. +Where possible, all library types should provide a +swap operation with an exception specification +guaranteeing no exception shall propagate. +Where noexcept(true) cannot be guaranteed to +not terminate the program, and the swap in +questions is a template, an exception specification +with the appropriate conditional expression could +be specified. +
+ + +Proposed resolution:
+ + + + + +Section: 17 [library] Status: Open + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-14
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Open status.
+Discussion:
+Addresses CH-18
++The general approach on moving is that a library object +after moving out is in a "valid but unspecified state". But +this is stated at the single object specifications, which is +error prone (especially if the move operations are implicit) +and unnecessary duplication. +
+ +[ +Resolution propsed by ballot comment +]
+ ++Consider putting a general statement to the same +effect into clause 17. +
+ +[2010-11-05 Beman provides exact wording. +The wording was inspired by Dave Abrahams' +message c++std-lib-28958, and refined with help from Alisdair, Daniel, and Howard. +]
+ + + + +Proposed resolution:
+Add a new definition to 17.3 Definitions [definitions]:
+ +++ +17.3.24 [defns.valid.unspecified]
+
+ valid but unspecified state
+ an object state that is not specified except that the object's invariants are met, and operations + on the object perform as specified, + subject only to the operation's normal preconditions.+ [Example: If an object x of type std::vector<int> is in a valid but + unspecified state, x.empty() can be called unconditionally, and + x.front() can be called provided x.empty() returns + false. --end example]
+
Change Table 34 - MoveConstructible requirements [moveconstructible] as + indicated:
+++ ++
[ Note: rv remains a valid object. Its state is + unspecified --end note ]
+ Postcondition: rv is in a valid but + unspecified state ([defns.valid.unspecified]).
Change Table 36 - MoveAssignable requirements [moveassignable] as + indicated:
+++ ++
[ Note: rv remains a valid object. Its state is + unspecified --end note ]
+ Postcondition: rv is in a valid but + unspecified state ([defns.valid.unspecified]).
No change in the half-dozen or so places in the standard library that + use "valid but unspecified state" directly, and no change in the many places + that require MoveCostructible or MoveAssignable, + since MoveCostructible and MoveAssignable will now + normatively require "valid but unspecified state".
+ + + + + + +Section: 17.6.1.3 [compliance] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-29
+View all other issues in [compliance].
+View all issues with Open status.
+Discussion:
+Addresses GB-55
++The <thread> header uses duration types, found in the +<chrono> header, and which rely on the ratio types +declared in the <ratio> header. +
+ +[ +Extracts from lengthy Rapperswil discussion: +]
+ ++There is a concern that this issue is a misunderstanding of the actual +requirements of a free-standing implementation to support the <thread> +header. In general, a free-standanding implementation will provide an empty +header, specifically so that a user can test for the absence of the +_ _ STDCPP_THREADS _ _ macro. This idiom as used as there is no portable way to test for the lack of a header. +
++At this point, it was suggested the NB comment is trying to solve the wrong problem, and that _ _ STDCPP_THREADS _ _ should be a pre-defined macro in clause 16 that can be tested before including <thread>. That would remove the need to add additional headers to the free-standanding requirements. +
++It is worth noting that Japan requested <ratio> as a free-standing header in their CD1 comments. No-one seemed keen to require clocks of a free-standing implementation though. +
+ +Detlef volunteers to look at a way to redraft 17.6.1.3 p3.
+ +[ +Original resolution proposed by NB comment: +]
+ + +++ + + ++Add the <chrono> and <ratio> headers to the +freestanding requirements. +
++It might be necessary to address scaled-down +expectations of clock support in a freestanding +environment, much like <thread>. +
+
Proposed resolution:
+ + + + + +Section: 18.8.5 [propagation] Status: Open + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-24
+View other active issues in [propagation].
+View all other issues in [propagation].
+View all issues with Open status.
+Discussion:
+Addresses CH-19
++It is not clear how exception_ptr is synchronized. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Make clear that accessing in different threads +multiple exception_ptr objects that all refer to the +same exception introduce a race. +
+ + + +Proposed resolution:
+ + + + + +Section: 18.8.5 [propagation] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
+View other active issues in [propagation].
+View all other issues in [propagation].
+View all issues with Open status.
+Discussion:
+Addresses GB-74
++One idea for the exception_ptr type was that a reference-counted +implementation could simply 'reactivate' the same +exception object in the context of a call to +rethrow_exception. Such an implementation would allow +the same exception object to be active in multiple threads +(such as when multiple threads join on a shared_future) +and introduce potential data races in any exception +handler that catches exceptions by reference - notably +existing library code written before this capability was +added. rethrow_exception should always make a copy +of the target exception object.
Proposed resolution:
-Change 20.6.4.3 [meta.unary.prop], p6: +Add the following to 18.8.5, [propogation]
++Throws: a copy of the exception object to which p refers. ++ + + + + + +
Section: 19 [diagnostics] Status: Tentatively NAD + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
+View all issues with Tentatively NAD status.
+Discussion:
+Addresses GB-75
++None of the exception types defined in clause 19 are +allowed to throw an exception on copy or move +operations, but there is no clear specification that the +operations have an exception specification to prove it. +Note that the implicitly declared constructors, taking the +exception specification from their base class (ultimately +std::exception) will implicitly generate a noexcept +exception specification if all of their data members +similarly declare noexcept operations. As the +representation is unspecified, we cannot assume nonthrowing +operations unless we explicitly state this as a +constraint on the implementation. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Add a global guarantee that all exception types +defined in clause 19 that rely on implicitly declared +operations have a non-throwing exception +specification on those operations. +
+ +[ +2010 Batavia: +]
+ ++This is addressed by the current words in 18.8.1 [exception], p2 +
++Each standard library class T that derives from class exception +shall have a publicly accessible copy constructor and a publicly accessible copy +assignment operator that do not exit with an exception. ++ + + +
Proposed resolution:
+ + + + + +Section: 20.2.1 [utility.arg.requirements] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [utility.arg.requirements].
+View all issues with Open status.
+Discussion:
+Addresses US-85
++20.2.1 Table 34 "MoveConstructible requirements" says +"Note: rv remains a valid object. Its state is unspecified". +Some components give stronger guarantees. For +example, moved-from shared_ptrs are guaranteed empty +(20.9.11.2.1/25). +In general, what the standard really should say (preferably +as a global blanket statement) is that moved-from objects +can be destroyed and can be the destination of an +assignment. Anything else is radioactive. For example, +containers can be "emptier than empty". This needs to be +explicit and required generally. +
++Note: The last time that one of us mentioned "emptier +than empty" (i.e. containers missing sentinel nodes, etc.) +the objection was that containers can store sentinel nodes +inside themselves in order to avoid dynamically allocating +them. This is unacceptable because +
++(a) it forces existing implementations (i.e. Dinkumware's, Microsoft's, +IBM's, etc.) to change for no good reason (i.e. permitting more +operations on moved-from objects), and +
++(b) it invalidates end-iterators when swapping containers. (The Working +Paper currently permits end-iterator invalidation, which we +consider to be wrong, but that's a separate argument. In +any event, mandating end-iterator invalidation is very +different from permitting it.) +
+ +[ +Resolution proposed in ballot comment +]
+ ++State as a general requirement that moved-from +objects can be destroyed and can be the +destination of an assignment. Any other use is +undefined behavior. +
+ + +Proposed resolution:
+ + + + + +Section: 20.4.2.4 [tuple.creation] Status: Ready + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
+View all other issues in [tuple.creation].
+View all issues with Ready status.
+Discussion:
+Addresses GB-88
++The tuple_cat template consists of four overloads and that +can concatenate only two tuples. A single variadic +signature that can concatenate an arbitrary number of +tuples would be preferred. +
+ +[ +Resolution proposed by ballot comment: +]
++Adopt a simplified form of the proposal in n2975, +restricted to tuples and neither requiring nor outlawing support for other tuple-like types. ++ +
[ +2010 Rapperswil: Alisdair to provide wording. +]
+ + +[ +2010-11-06: Daniel comments and proposes some alternative wording: +]
+ +
-the predicate condition for a template specialization
-is_constructible<T, Args> shall be satisfied, if and only
-if the following expression CE variable
-definition would be well-formed:
+There are some problems in the wording: First, even though the result type tuple<see below>
+implies it, the specification of the contained tuple element types is missing. Second, the term "tuple
+protocol" is not defined anywhere and I see no reason why this normative wording should not be a non-normative
+note. We could at least give a better approximation, maybe "tuple-like protocol" as indicated from header
+<utility> synopsis. Further, it seems to me that the effects need to contain a combination of std::forward
+with the call of get. Finally I suggest to replace the requirements Move/CopyConstructible
+by proper usage of is_constructible, as indicated by n3140.
[ +2010 Batavia +]
+
-if sizeof...(Args) == 0 1, the expression:
+Moved to Ready with Daniel's improved wording.
static_cast<T>(create<Args>()...)-T t; + + +Proposed resolution:
+Note: This alternate proposed resolution works only if 1191 has been accepted.
+ ++
+
+ + + + + + + +- Change 20.4.1 [tuple.general] p. 2, header <tuple> synopsis, as indicated: +
-namespace std { + +... + +// 20.4.2.4, tuple creation functions: +const unspecified ignore; + +template <class... Types> + tuple<VTypes...> make_tuple(Types&&...); + template <class... Types> + tuple<ATypes...> forward_as_tuple(Types&&...); + +template<class... Types> + tuple<Types&...> tie(Types&...); + +template <class... TTypes, class... UTypes> + tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>&, const tuple<UTypes...>&); +template <class... TTypes, class... UTypes> + tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&&, const tuple<UTypes...>&); +template <class... TTypes, class... UTypes> + tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>&, tuple<UTypes...>&&); +template <class... TTypes, class... UTypes> + tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&&, tuple<UTypes...>&&);+template <class... Tuples> + tuple<CTypes...> tuple_cat(Tuples&&...); + +... +- +
- Change 20.4.2.4 [tuple.creation] as indicated: +
++++template <class... TTypes, class... UTypes> + tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>& t, const tuple<UTypes...>& u);++8 Requires: All the types in TTypes shall be CopyConstructible (Table 35). All the types in +UTypes shall be CopyConstructible (Table 35). +++9 Returns: A tuple object constructed by copy constructing its first sizeof...(TTypes) elements +from the corresponding elements of t and copy constructing its last sizeof...(UTypes) elements from the +corresponding elements of u. ++template <class... TTypes, class... UTypes> + tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&& t, const tuple<UTypes...>& u);++10 Requires: All the types in TTypes shall be MoveConstructible (Table 34). All the types in +UTypes shall be CopyConstructible (Table 35). +++11 Returns: A tuple object constructed by move constructing its first sizeof...(TTypes) elements +from the corresponding elements of t and copy constructing its last sizeof...(UTypes) elements from the +corresponding elements of u. ++template <class... TTypes, class... UTypes> + tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>& t, tuple<UTypes...>&& u);++12 Requires: All the types in TTypes shall be CopyConstructible (Table 35). All the types in +UTypes shall be MoveConstructible (Table 34). +++13 Returns: A tuple object constructed by copy constructing its first sizeof...(TTypes) elements +from the corresponding elements of t and move constructing its last sizeof...(UTypes) elements from the +corresponding elements of u. ++template <class... TTypes, class... UTypes> + tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&& t, tuple<UTypes...>&& u);++14 Requires: All the types in TTypes shall be MoveConstructible (Table 34). All the types in +UTypes shall be MoveConstructible (Table 34). +++15 Returns: A tuple object constructed by move constructing its first sizeof...(TTypes) elements +from the corresponding elements of t and move constructing its last sizeof...(UTypes) elements from the +corresponding elements of u. +template <class... Tuples> + tuple<CTypes...> tuple_cat(Tuples&&... tpls); +++8 Let Ti be the ith type in Tuples, Ui be remove_reference<Ti>::type, +and tpi be the ith parameter in the function parameter pack tpls, where all +indexing is zero-based in the following paragraphs of this sub-clause [tuple.creation]. +++9 Requires: For all i, Ui shall be the type cvi tuple<Argsi...>, +where cvi is the (possibly empty) ith cv-qualifier-seq, and +Argsi is the parameter pack representing the element types in Ui. Let Aik be the +kith type in Argsi, then for all Aik the following +requirements shall be satisfied: If Ti is deduced as an lvalue reference type, then +is_constructible<Aik, cvi Aik&>::value == true, otherwise +is_constructible<Aik, cvi Aik&&>::value == true. +++10 Remarks: The types in CTypes shall be equal to the ordered sequence of the expanded types +Args0..., Args1..., Argsn-1..., where n equals +sizeof...(Tuples). Let ei... be the ith ordered +sequence of tuple elements of the result tuple object corresponding to the type sequence +Argsi. +++11 Returns: A tuple object constructed by initializing +the kith type element eik in ei... +with get<ki>(std::forward<Ti>(tpi)) +for each valid ki and each element group ei in order. +++12 [Note: An implementation may support additional types in the parameter pack Tuples, such as +pair and array that support the tuple-like protocol. -- end note] ++
+1396. [FCD] regex should support allocators
+Section: 28.8 [re.regex] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-07
+View all other issues in [re.regex].
+View all issues with Open status.
+Duplicate of: 1451
+Discussion:
+Addresses US-104, US-141
-otherwise
-the expression: +std::basic_regex should have an allocator for all the +reasons that a std::string does. For example, I can use +boost::interprocess to put a string or vector +in shared memory, but not a regex.T t(create<Args>()...); + +[ +Resolution proposed by ballot comment +]
+ ++Add allocators to regexes +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3171 would solve this issue. ++ + + +Proposed resolution:
+See n3171. + + + + + +
+1401. [FCD] unique_ptr<T> == nullptr
+Section: 20.9 [memory] Status: Ready + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
+View all other issues in [memory].
+View all issues with Ready status.
+Discussion:
+Addresses GB-99
++One reason that the unique_ptr constructor taking a +nullptr_t argument is not explicit is to allow conversion +of nullptr to unique_ptr in contexts like equality +comparison. Unfortunately operator== for unique_ptr is a +little more clever than that, deducing template parameters for both +arguments. This means that nullptr does not get deduced +as unique_ptr type, and there are no other comparison +functions to match. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Add the following signatures to 20.9 [memory] p.1, <memory> +header synopsis: ++ ++template<typename T, typename D> +bool operator==(const unique_ptr<T, D> & lhs, nullptr_t); +template<typename T, typename D> +bool operator==(nullptr_t, const unique_ptr<T, D> & rhs); +template<typename T, typename D> +bool operator!=(const unique_ptr<T, D> & lhs, nullptr_t); +template<typename T, typename D> +bool operator!=(nullptr_t, const unique_ptr<T, D> & rhs);[ +2010-11-02 Daniel comments and provides a proposed resolution: +]
+ + ++The same problem applies to shared_ptr as well: In both cases there are no +conversions considered because the comparison functions are templates. I agree with +the direction of the proposed resolution, but I believe it would be very surprising +and inconsistent, if given a smart pointer object p, the expression +p == nullptr would be provided, but not p < nullptr and the +other relational operators. According to 5.9 [expr.rel] they are defined +if null pointer values meet other pointer values, even though the result is unspecified +for all except some trivial ones. But null pointer values are nothing special here: +The Library already defines the relational operators for both unique_ptr and +shared_ptr and the outcome of comparing non-null pointer values will be equally +unspecified. If the idea of supporting nullptr_t arguments for relational +operators is not what the committee prefers, I suggest at least to consider to remove +the existing relational operators for both unique_ptr and shared_ptr +for consistency. But that would not be my preferred resolution of this issue. ++ ++The number of overloads triple the current number, but I think it is much clearer to +provide them explicitly instead of adding wording that attempts to say that "sufficient overloads" are +provided. The following proposal makes the declarations explicit. +
+Additionally, the proposal adds the missing declarations for some shared_ptr +comparison functions for consistency. +
[ +2010-11-03 Daniel adds: +]
+ + ++Issue 1297 is remotely related. The following proposed resolution splits +this bullet into sub-bullets A and B. Sub-bullet A would +also solve 1297, but sub-bullet B would not. +
+A further remark in regard to the proposed semantics of the ordering of nullptr +against other pointer(-like) values: One might think that the following definition might +be superior because of simplicity: + +
+ +The underlying idea behind this approach is the assumption that nullptr corresponds +to the least ordinal pointer value. But this assertion does not hold for all supported +architectures, therefore this approach was not followed because it would lead to +the inconsistency, that the following assertion could fire: + +template<class T> +bool operator<(const shared_ptr<T>& a, nullptr_t); +template<class T> +bool operator>(nullptr_t, const shared_ptr<T>& a); ++Returns: false. ++ + + +shared_ptr<int> p(new int); +shared_ptr<int> null; +bool v1 = p < nullptr; +bool v2 = p < null; +assert(v1 == v2); +Proposed resolution:
+Wording changes are against N3126. ++
+
+ + + + + +- Change 20.9 [memory] p. 1, header <memory> synopsis as indicated. +noexcept specifications are only added, where the guarantee exists, that the function +shall no throw an exception (as replacement of "Throws: Nothing". This needs +to be harmonized with the result of the noexcept proposals: +
++namespace std { + [..] + // 20.9.10 Class unique_ptr: + template <class T> class default_delete; + template <class T> class default_delete<T[]>; + template <class T, class D = default_delete<T>> class unique_ptr; + template <class T, class D> class unique_ptr<T[], D>; + + template <class T1, class D1, class T2, class D2> + bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + + template <class T, class D> + bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept; + template <class T, class D> + bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept; + template <class T, class D> + bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept; + template <class T, class D> + bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept; + template <class T, class D> + bool operator<(const unique_ptr<T, D>& x, nullptr_t); + template <class T, class D> + bool operator<(nullptr_t, const unique_ptr<T, D>& x); + template <class T, class D> + bool operator<=(const unique_ptr<T, D>& x, nullptr_t); + template <class T, class D> + bool operator<=(nullptr_t, const unique_ptr<T, D>& x); + template <class T, class D> + bool operator>(const unique_ptr<T, D>& x, nullptr_t); + template <class T, class D> + bool operator>(nullptr_t, const unique_ptr<T, D>& x); + template <class T, class D> + bool operator>=(const unique_ptr<T, D>& x, nullptr_t); + template <class T, class D> + bool operator>=(nullptr_t, const unique_ptr<T, D>& x); + + // 20.9.11.1, Class bad_weak_ptr: + class bad_weak_ptr; + + // 20.9.11.2, Class template shared_ptr: + template<class T> class shared_ptr; + + // 20.9.11.2.7, shared_ptr comparisons: + template<class T, class U> + bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b); + template<class T, class U> + bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b); + template<class T, class U> + bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b); + template<class T, class U> + bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b); + template<class T, class U> + bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b); + template<class T, class U> + bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b); + + template<class T> + bool operator==(shared_ptr<T> const& a, nullptr_t) noexcept; + template<class T> + bool operator==(nullptr_t, shared_ptr<T> const& a) noexcept; + template<class T> + bool operator!=(shared_ptr<T> const& a, nullptr_t) noexcept; + template<class T> + bool operator!=(nullptr_t, shared_ptr<T> const& a) noexcept; + template<class T> + bool operator<(shared_ptr<T> const& a, nullptr_t) noexcept; + template<class T> + bool operator<(nullptr_t, shared_ptr<T> const& a) noexcept; + template>class T> + bool operator>(shared_ptr<T> const& a, nullptr_t) noexcept; + template>class T> + bool operator>(nullptr_t, shared_ptr<T> const& a) noexcept; + template<class T> + bool operator<=(shared_ptr<T> const& a, nullptr_t) noexcept; + template<class T> + bool operator<=(nullptr_t, shared_ptr<T> const& a) noexcept; + template>class T> + bool operator>=(shared_ptr<T> const& a, nullptr_t) noexcept; + template>class T> + bool operator>=(nullptr_t, shared_ptr<T> const& a) noexcept; + + [..] +} +- Change the synopsis just after 20.9.9 [unique.ptr] p. 6 as indicated: +
++namespace std { + [..] + + template <class T1, class D1, class T2, class D2> + bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + template <class T1, class D1, class T2, class D2> + bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); + + template <class T, class D> + bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept; + template <class T, class D> + bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept; + template <class T, class D> + bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept; + template <class T, class D> + bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept; + template <class T, class D> + bool operator<(const unique_ptr<T, D>& x, nullptr_t); + template <class T, class D> + bool operator<(nullptr_t, const unique_ptr<T, D>& x); + template <class T, class D> + bool operator<=(const unique_ptr<T, D>& x, nullptr_t); + template <class T, class D> + bool operator<=(nullptr_t, const unique_ptr<T, D>& x); + template <class T, class D> + bool operator>(const unique_ptr<T, D>& x, nullptr_t); + template <class T, class D> + bool operator>(nullptr_t, const unique_ptr<T, D>& x); + template <class T, class D> + bool operator>=(const unique_ptr<T, D>& x, nullptr_t); + template <class T, class D> + bool operator>=(nullptr_t, const unique_ptr<T, D>& x); + +} +- This bullet splits into two sub-bullets A and B as mentioned in the discussion comment: +
++
+- Change 20.9.9.4 [unique.ptr.special]/4-7 as indicated and add a series of prototype +descriptions: +
++ +template <class T1, class D1, class T2, class D2> + bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ +++ ++? Requires: Let CT be common_type<unique_ptr<T1, +D1>::pointer, unique_ptr<T2, D2>::pointer>::type. Then +the specialization less<CT> shall be a function object type ([function.objects]) +that induces a strict weak ordering ([alg.sorting]) on the pointer values. +
+ ++4 Returns: less<CT>()(x.get(), y.get())
+ +x.get() +< y.get(). ++? Remarks: If unique_ptr<T1, D1>::pointer is not +implicitly convertible to CT or unique_ptr<T2, +D2>::pointer is not implicitly convertible to CT, the program +is ill-formed. +
+template <class T1, class D1, class T2, class D2> + bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ ++5 Returns: !(y < x)+ +x.get() <= y.get(). +template <class T1, class D1, class T2, class D2> + bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ ++6 Returns: (y < x)+ +x.get() > y.get(). +template <class T1, class D1, class T2, class D2> + bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ ++7 Returns: !(x < y)+x.get() >= y.get(). ++ +template <class T, class D> +bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept; +template <class T, class D> +bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept; ++? Returns: !x. ++ +template <class T, class D> +bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept; +template <class T, class D> +bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept; ++? Returns: (bool) x. ++ +template <class T, class D> +bool operator<(const unique_ptr<T, D>& x, nullptr_t); +template <class T, class D> +bool operator>(nullptr_t, const unique_ptr<T, D>& x); +++? Requires: The specialization less<unique_ptr<T, D>::pointer> +shall be a function object type ([function.objects]) that induces a strict weak ordering ([alg.sorting]) +on the pointer values. +++? Returns: less<unique_ptr<T, D>::pointer>()(x.get(), nullptr). ++ +template <class T, class D> +bool operator<(nullptr_t, const unique_ptr<T, D>& x); +template <class T, class D> +bool operator>(const unique_ptr<T, D>& x, nullptr_t); +++? Requires: The specialization less<unique_ptr<T, D>::pointer> +shall be a function object type ([function.objects]) that induces a strict weak ordering ([alg.sorting]) +on the pointer values. +++? Returns: less<unique_ptr<T, D>::pointer>()(nullptr, x.get()). ++ +template <class T, class D> +bool operator<=(const unique_ptr<T, D>& x, nullptr_t); +template <class T, class D> +bool operator>=(nullptr_t, const unique_ptr<T, D>& x); ++? Returns: !(nullptr < x). ++ +template <class T, class D> +bool operator<=(nullptr_t, const unique_ptr<T, D>& x); +template <class T, class D> +bool operator>=(const unique_ptr<T, D>& x, nullptr_t); ++? Returns: !(x < nullptr). +- +Add the following series of prototype specifications at the very end of 20.9.9.4 [unique.ptr.special]. +Intentionally, the relational operators are defined individually, because there is no guarantee that +from x.get() < nullptr follows the relation nullptr > x.get(): +
++ +template <class T, class D> +bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept; +template <class T, class D> +bool operator==(nullptr_t, const unique_ptr<T, D>& x) noexcept; ++? Returns: !x. ++ +template <class T, class D> +bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept; +template <class T, class D> +bool operator!=(nullptr_t, const unique_ptr<T, D>& x) noexcept; ++? Returns: (bool) x. ++ +template <class T, class D> +bool operator<(const unique_ptr<T, D>& x, nullptr_t); ++? Returns: x.get() < nullptr. ++ +template <class T, class D> +bool operator<(nullptr_t, const unique_ptr<T, D>& x); ++? Returns: nullptr < x.get(). ++ +template <class T, class D> +bool operator<=(const unique_ptr<T, D>& x, nullptr_t); ++? Returns: x.get() <= nullptr. ++ +template <class T, class D> +bool operator<=(nullptr_t, const unique_ptr<T, D>& x); ++? Returns: nullptr <= x.get(). ++ +template <class T, class D> +bool operator>(const unique_ptr<T, D>& x, nullptr_t); ++? Returns: x.get() > nullptr. ++ +template <class T, class D> +bool operator>(nullptr_t, const unique_ptr<T, D>& x); ++? Returns: nullptr > x.get(). ++ +template <class T, class D> +bool operator>=(const unique_ptr<T, D>& x, nullptr_t); ++? Returns: x.get() >= nullptr. ++template <class T, class D> +bool operator>=(nullptr_t, const unique_ptr<T, D>& x); ++? Returns: nullptr >= x.get(). +- Change 20.9.10.2 [util.smartptr.shared] p. 1, class template shared_ptr +synopsis as indicated. For consistency reasons the remaining normal relation +operators are added as well: +
++namespace std { + [..] + // 20.9.11.2.7, shared_ptr comparisons: + template<class T, class U> + bool operator==(const shared_ptr<T>& a, const shared_ptr<U>& b); + template<class T, class U> + bool operator!=(const shared_ptr<T>& a, const shared_ptr<U>& b); + template<class T, class U> + bool operator<(const shared_ptr<T>& a, const shared_ptr<U>& b); + template<class T, class U> + bool operator>(const shared_ptr<T>& a, const shared_ptr<U>& b) noexcept; + template<class T, class U> + bool operator<=(const shared_ptr<T>& a, const shared_ptr<U>& b) noexcept; + template<class T, class U> + bool operator>=(const shared_ptr<T>& a, const shared_ptr<U>& b) noexcept; + + template<class T> + bool operator==(const shared_ptr<T>& a, nullptr_t) noexcept; + template<class T> + bool operator==(nullptr_t, const shared_ptr<T>& a) noexcept; + template<class T> + bool operator!=(const shared_ptr<T>& a, nullptr_t) noexcept; + template<class T> + bool operator!=(nullptr_t, const shared_ptr<T>& a) noexcept; + template<class T> + bool operator<(const shared_ptr<T>& a, nullptr_t) noexcept; + template<class T> + bool operator<(nullptr_t, const shared_ptr<T>& a) noexcept; + template>class T> + bool operator>(const shared_ptr<T>& a, nullptr_t) noexcept; + template>class T> + bool operator>(nullptr_t, const shared_ptr<T>& a) noexcept; + template<class T> + bool operator<=(const shared_ptr<T>& a, nullptr_t) noexcept; + template<class T> + bool operator<=(nullptr_t, const shared_ptr<T>& a) noexcept; + template>class T> + bool operator>=(const shared_ptr<T>& a, nullptr_t) noexcept; + template>class T> + bool operator>=(nullptr_t, const shared_ptr<T>& a) noexcept; + + [..] +} +- Add the following series of prototype specifications at the very end of 20.9.10.2.7 [util.smartptr.shared.cmp]. +For mixed comparison the general "generation" rule of 20.3.1 [operators] p. 10 does not apply, +therefore all of them are defined. Below wording takes advantage of the simplified definition of the +composite pointer type if one partner is a null pointer constant: +
++ +template<class T> +bool operator==(const shared_ptr<T>& a, nullptr_t) noexcept; +template<class T> +bool operator==(nullptr_t, const shared_ptr<T>& a) noexcept; ++? Returns: !a. ++ +template<class T> +bool operator!=(const shared_ptr<T>& a, nullptr_t) noexcept; +template<class T> +bool operator!=(nullptr_t, const shared_ptr<T>& a) noexcept; ++? Returns: (bool) a. ++ +template<class T> +bool operator<(const shared_ptr<T>& a, nullptr_t) noexcept; +template<class T> +bool operator>(nullptr_t, const shared_ptr<T>& a) noexcept; ++? Returns: less<T*>()(a.get(), nullptr). ++ +template<class T> +bool operator<(nullptr_t, const shared_ptr<T>& a) noexcept; +template<class T> +bool operator>(const shared_ptr<T>& a, nullptr_t) noexcept; ++? Returns: less<T*>()(nullptr, a.get()). ++ +template<class T> +bool operator<=(const shared_ptr<T>& a, nullptr_t) noexcept; +template<class T> +bool operator>=(nullptr_t, const shared_ptr<T>& a) noexcept; ++? Returns: !(nullptr < a). ++ +template<class T> +bool operator<=(nullptr_t, const shared_ptr<T>& a) noexcept; +template<class T> +bool operator>=(const shared_ptr<T>& a, nullptr_t) noexcept; ++? Returns: !(a < nullptr). +
+1408. [FCD] Allow recycling of pointers after undeclare_no_pointers
+Section: 20.9.11 [util.dynamic.safety] Status: Ready + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
+View all other issues in [util.dynamic.safety].
+View all issues with Ready status.
+Discussion:
+Addresses GB-103
++The precondition to calling declare_no_pointers is that no +bytes in the range "have been previously registered" with +this call. As written, this precondition includes bytes in +ranges, even after they have been explicitly unregistered +with a later call to undeclare_no_pointers. +
+ + +Proposed resolution:
++Update 20.9.11 [util.dynamic.safety] p.9: +
++ + + + + +void declare_no_pointers(char *p, size_t n); ++9 Requires: No bytes in the specified rangehave been +previously registeredare currently registered with declare_no_pointers(). +If the specified range is in an allocated object, then it must be entirely within a single allocated object. +The object must be live until the corresponding undeclare_no_pointers() call. [..] +
+1413. [FCD] Specify whether high_resolution_clock is a distinct type or a typedef
+Section: 20.11.5.3 [time.clock.hires] Status: Tentatively NAD + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-14
+View all issues with Tentatively NAD status.
+Discussion:
+Addresses US-112
++What it means for high_resolution_clock to be a synonym +is undefined. If it may or may not be a typedef, then +certain classes of programs become unportable. +
+ +[ +Resolution proposed in ballot comment +]
+ ++Require that it be a distinct class type. +
+ +[ +2010 Batavia +]
+ ++This is not a defect. Threre are a number of places in the standard where +we allow implentations to choose their preferred technique, the most obvious +example being the iterator/const_iterator types of set. +
++Typically, this means it is not portable to declare function overloads that differ +only in their use of these types. +
+ + + +Proposed resolution:
+ + + + + +
+1418. [FCD] Effects of resize(size()) on a deque
+Section: 23.3.2.2 [deque.capacity] Status: Ready + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
+View all other issues in [deque.capacity].
+View all issues with Ready status.
+Discussion:
+Addresses GB-113
++There is no mention of what happens if sz==size(). While +it obviously does nothing I feel a standard needs to say +this explicitely. +
+ + +[ +2010 Batavia +]
+ ++Accepted with a simplified resolution turning one of the < +comparisons into <=. +
+ +Proposed resolution:
+Ammend [deque.capacity]
+++void resize(size_type sz);
++Effects: If sz <= size(), equivalent to erase(begin() + +sz, end());. If size() < sz, appends sz - size()
+ + + + + +default +constructedvalue initialized elements to the sequence. +
+1420. [FCD] Effects of resize(size()) on a list
+Section: 23.3.4.2 [list.capacity] Status: Ready + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
+View all other issues in [list.capacity].
+View all issues with Ready status.
+Discussion:
+Addresses GB-115
++There is no mention of what happens if sz==size(). While +it obviously does nothing I feel a standard needs to say +this explicitely. +
+ +[ +Resolution proposed in ballot comment +]
+ ++Express the semantics as pseudo-code similarly +to the way it is done for the copying overload that +follows (in p3). Include an else clause that does +nothing and covers the sz==size() case. +
+ +[ +2010 Batavia +]
+ ++Accepted with a simplified resolution turning one of the < +comparisons into <=. +
+ + + + +Proposed resolution:
++Ammend [list.capacity] p1: +
+++ + + + + + +void resize(size_type sz);
++Effects: If sz <= size(), equivalent to list<T>::iterator +it = begin(); advance(it, sz); erase(it, end());. If +size() < sz, appends sz - size()+default constructed+value initialized elements to the sequence. +
+1421. [FCD] Accidental move-only library types due to new core language rules
+Section: 23.5 [container.adaptors] Status: Open + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-10-26
+View all other issues in [container.adaptors].
+View all issues with Open status.
+Duplicate of: 1350
+Discussion:
+ +Addresses DE-22, CH-15
++With the final acceptance of move operations as special +members and introduction of corresponding suppression +rules of implicitly generated copy operations the some +library types that were copyable in C++03 are no longer +copyable (only movable) in C++03, among them queue, +priority_queue, and stack. +
+ +[ +2010-10-26: Daniel comments: +]
+ + ++Accepting n3112 should fix this. +
+ + + +Proposed resolution:
+See n3112 + + + + + +
+1438. [FCD] No definition for base()
+Section: 26.5.4.1 [rand.adapt.disc] Status: Ready + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [rand.adapt.disc].
+View all issues with Ready status.
+Discussion:
+Addresses US-126
+ +Each adaptor has a member function called base() which has no definition. + +[ +Resolution proposed by ballot comment: +]
+ ++Give it the obvious definition. ++ +[ +2010-11-03 Daniel comments and provides a proposed resolution: +]
+ + +The following proposal adds noexcept specifiers to the declarations of +the base() functions as replacement for a "Throws: Nothing" element. +
+ +[ +2010 Batavia: The working group reviewed this issue, and recommended to add the following to the Proposed Resolution. +
+After further review, the working group concurred with the Proposed Resolution. +] + + +
- +Append to paragraph 1 of [rand.req.adapt] (or at the Editor's discretion insert as a new paragraph following that paragraph): +The expression a.base() shall be valid and shall return a const reference to a's base engine. +
+[Batavia: waiting for WEB to review wording]
+ + + + +Proposed resolution:
++
+ + + + + +- +Add the following sentence to the end of 26.5.1.5 [rand.req.adapt]/1: +
++A random number engine adaptor (commonly shortened to adaptor) a of type A is a +random number engine that takes values produced by some other random number engine, and applies an algorithm to +those values in order to deliver a sequence of values with different randomness properties. An engine b +of type B adapted in this way is termed a base engine in this context. The expression +a.base() shall be valid and shall return a const reference to a's base engine. ++- Change in [rand.adapt.disc]/3, class template discard_block_engine synopsis, the following declaration: +
++// property functions +const Engine& base() const noexcept; +- Add the following new prototype description at the end of sub-clause 26.5.4.1 [rand.adapt.disc]: +
+++const Engine& base() const noexcept; +++? Returns: e. ++- Change in [rand.adapt.ibits]/4, class template independent_bits_engine synopsis, the following declaration: +
++// property functions +const Engine& base() const noexcept; +- Add the following new prototype description at the end of sub-clause 26.5.4.2 [rand.adapt.ibits]: +
+++const Engine& base() const noexcept; +++? Returns: e. ++- Change in 26.5.4.3 [rand.adapt.shuf]/3, class template shuffle_order_engine synopsis, the following declaration: +
++// property functions +const Engine& base() const noexcept; +- Add the following new prototype description at the end of sub-clause 26.5.4.3 [rand.adapt.shuf]: +
+++const Engine& base() const noexcept; +++? Returns: e. ++
+1448. [FCD] Concerns about basic_stringbuf::str(basic_string) postconditions
+Section: 27.8.1.3 [stringbuf.members] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
+View all issues with Open status.
+Discussion:
+Addresses GB-124
+ ++N3092 27.8.1.3 [stringbuf.members] contains this textcspecifying the postconditions of +basic_stringbuf::str(basic_string): +
++Postconditions: If mode & ios_base::out is true, +pbase() points to the first underlying character and epptr() >= +pbase() + s.size() holds; in addition, if mode & ios_base::in +is true, pptr() == pbase() + s.data() holds, otherwise +pptr() == pbase() is true. [...] +++Firstly, there's a simple mistake: It should be pbase() + s.length(), +not pbase() + s.data(). +
++Secondly, it doesn't match existing implementations. As far as I can tell, +GCC 4.5 does not test for mode & ios_base::in in the second part +of that sentence, but for mode & (ios_base::app | ios_base_ate), +and Visual C++ 9 for mode & ios_base::app. Besides, the wording of +the C++0x draft doesn't make any sense to me. I suggest changing the second part +of the sentence to one of the following: +
++Replace ios_base::in with (ios_base::ate | ios_base::app), +but this would require Visual C++ to change (replacing only with +ios_base::ate would require GCC to change, and would make +ios_base::app completely useless with stringstreams): +
++in addition, if mode & (ios_base::ate | ios_base::app) is true, +pptr() == pbase() + s.length() holds, otherwise pptr() == pbase() +is true. +
++Leave pptr() unspecified if mode & ios_base::app, but not +mode & ios_base::ate (implementations already differ in this case, and it +is always possible to use ios_base::ate to get the effect of appending, so it +is not necessary to require any implementation to change): +
++in addition, if mode & ios_base::ate is true, +pptr() == pbase() + s.length() holds, if neither mode & ios_base::ate +nor mode & ios_base::app is true, pptr() == pbase() holds, +otherwise pptr() >= pbase() && pptr() <= pbase() + s.length() +(which of the values in this range is unspecified). +
++Slightly stricter: +
++in addition, if mode & ios_base::ate is true, +pptr() == pbase() + s.length() holds, if neither +mode & ios_base::ate nor mode & ios_base::app is true, +pptr() == pbase() holds, otherwise pptr() == pbase() || pptr() == pbase() + s.length() +(which of these two values is unspecified). A small table might help to better explain the three cases. +BTW, at the end of the postconditions is this text: "egptr() == eback() + s.size() hold". +Is there a perference for basic_string::length or basic_string::size? It doesn't really +matter, but it looks a bit inconsistent. +
+ + +Proposed resolution:
+ + + + + +
+1450. [FCD] Contradiction in regex_constants
+Section: 28.5.2 [re.matchflag] Status: Deferred + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-13
+View all issues with Deferred status.
+Discussion:
+Addresses GB-127
+ +The Bitmask Type requirements in 17.5.2.1.3 [bitmask.types] p.3 say that +all elements on a bitmask type have distinct values, but +28.5.2 [re.matchflag] defines regex_constants::match_default and +regex_constants::format_default as elements of the +bitmask type regex_constants::match_flag_type, both with +value 0. This is a contradiction. + +[ +Resolution proposed by ballot comment: +]
+ ++One of the bitmask elements should be removed +from the declaration and should be defined +separately, in the same manner as +ios_base::adjustfield, ios_base::basefield and +ios_base::floatfield are defined by 27.5.2.1.2 [ios::fmtflags] p.2 +and Table 120. These are constants of a bitmask +type, but are not distinct elements, they have +more than one value set in the bitmask. +regex_constants::format_default should be +specified as a constant with the same value as +regex_constants::match_default. ++ +[ +2010-10-31 Daniel comments: +]
+ ++Strictly speaking, a bitmask type cannot have any element of value 0 at all, because +any such value would contradict the requirement expressed in 17.5.2.1.3 [bitmask.types] p. 3: +
+for any pair Ci and Cj, Ci & Ci is nonzero ++So, actually both regex_constants::match_default and +regex_constants::format_default are only constants of the type +regex_constants::match_flag_type, and no bitmask elements. + + +[ +2010-11-03 Daniel comments and provides a proposed resolution: +]
+ + +The proposed resolution is written against N3126 and considered as a further improvement +of the fixes suggested by n3110. +
+ + +Proposed resolution:
+Add the following sentence to 28.5.2 [re.matchflag] paragraph 1: ++1 The type regex_constants::match_flag_type is an implementation-defined bitmask type (17.5.2.1.3). +Matching a regular expression against a sequence of characters [first,last) proceeds according to the +rules of the grammar specified for the regular expression object, modified according to the effects listed in +Table 136 for any bitmask elements set. Type regex_constants::match_flag_type also defines the +constants regex_constants::match_default and regex_constants::format_default. ++ + + + + +
+1452. [FCD] "target sequence" is not defined
+Section: 28.10.4 [re.results.acc] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-01
+View all other issues in [re.results.acc].
+View all issues with Open status.
+Discussion:
+Addresses GB-125
+ +The term "target sequence" is not defined (28.10.4 [re.results.acc] p. 2). + +[ +Resolution proposed by ballot comment: +]
+ ++Replace "target sequence" with "string being searched/matched" +
+ +[ +2010-11-01 Daniel comments: +]
+ ++The proposed resolution looks incomplete to me, there are more normative +usages of the term target sequence in clause 28, e.g. +28.12.2 [re.tokiter] p. 7. +
+ + + +Proposed resolution:
+Wording changes are against N3126. They are intended not to conflict with the wording changes +suggested by n3158. ++Change 28.10.4 [re.results.acc] p. 2 as indicated: +
+ + + + + +difference_type position(size_type sub = 0) const; ++2 Returns: The distance from the start of thetarget sequencestring being matched to (*this)[sub].first. +
+1456. [FCD] Missing fixed-size atomic_ typedefs
+Section: 29 [atomics] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-29
+View other active issues in [atomics].
+View all other issues in [atomics].
+View all issues with Open status.
+Discussion:
+Addresses GB-129
+ +Table 143 lists the typedefs for various atomic types +corresponding to the various standard integer typedefs, +such as atomic_int_least8_t for int_least8_t, and +atomic_uint_fast64_t for uint_fast64_t. However, there are +no atomic typedefs corresponding to the fixed-size +standard typedefs int8_t, int16_t, and so forth. + +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3164 would solve this issue. ++ + + +Proposed resolution:
+Add the following entries to table 143: + +++ + + + + ++
+Table 143 — Atomics for standard typedef types ++ +atomic typedef name +<cstdint> typedef name ++ +... +... ++ +atomic_uintmax_t +uintmax_t ++ +atomic_int8_t +int8_t (optional) ++ +atomic_int16_t +int16_t (optional) ++ +atomic_int32_t +int32_t (optional) ++ +atomic_int64_t +int64_t (optional) ++ +atomic_uint8_t +uint8_t (optional) ++ +atomic_uint16_t +uint16_t (optional) ++ +atomic_uint32_t +uint32_t (optional) ++ +atomic_uint64_t +uint64_t (optional) +
+1457. [FCD] Splitting lock-free properties
+Section: 29.2 [atomics.syn] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-26
+View all issues with Open status.
+Discussion:
+Addresses GB-130
+ +The synopsis for the <atomic> header lists the macros +ATOMIC_INTEGRAL_LOCK_FREE and ATOMIC_ADDRESS_LOCK_FREE. ++The ATOMIC_INTEGRAL_LOCK_FREE macro has been replaced with a set of macros +for each integral type, as listed in 29.4 [atomics.lockfree]. +
+ + +[ +2010-10-26: Daniel adds: +]
+ + ++The proposed resolution below is against the FCD working draft. After application +of the editorial issues US-144 +and US-146 the remaining difference +against the working draft is the usage of implementation-defined instead of unspecified, effectively +resulting in this delta: + +
+ + +// 29.4, lock-free property +#define ATOMIC_CHAR_LOCK_FREEunspecifiedimplementation-defined +#define ATOMIC_CHAR16_T_LOCK_FREEunspecifiedimplementation-defined +#define ATOMIC_CHAR32_T_LOCK_FREEunspecifiedimplementation-defined +#define ATOMIC_WCHAR_T_LOCK_FREEunspecifiedimplementation-defined +#define ATOMIC_SHORT_LOCK_FREEunspecifiedimplementation-defined +#define ATOMIC_INT_LOCK_FREEunspecifiedimplementation-defined +#define ATOMIC_LONG_LOCK_FREEunspecifiedimplementation-defined +#define ATOMIC_LLONG_LOCK_FREEunspecifiedimplementation-defined +#define ATOMIC_ADDRESS_LOCK_FREE unspecified ++It is my understanding that the intended wording should be unspecified as for ATOMIC_ADDRESS_LOCK_FREE +but if this is right, we need to use the same wording in 29.4 [atomics.lockfree], which consequently uses +the term implementation-defined. I recommend to keep 29.2 [atomics.syn] as it currently is and to +fix 29.4 [atomics.lockfree] instead as indicated (against N3126): +
++New proposed resolution: +
++Change 29.4 [atomics.lockfree] as indicated: +
+ +#define ATOMIC_CHAR_LOCK_FREEimplementation-definedunspecified +#define ATOMIC_CHAR16_T_LOCK_FREEimplementation-definedunspecified +#define ATOMIC_CHAR32_T_LOCK_FREEimplementation-definedunspecified +#define ATOMIC_WCHAR_T_LOCK_FREEimplementation-definedunspecified +#define ATOMIC_SHORT_LOCK_FREEimplementation-definedunspecified +#define ATOMIC_INT_LOCK_FREEimplementation-definedunspecified +#define ATOMIC_LONG_LOCK_FREEimplementation-definedunspecified +#define ATOMIC_LLONG_LOCK_FREEimplementation-definedunspecified +#define ATOMIC_ADDRESS_LOCK_FREEimplementation-definedunspecified +Proposed resolution:
+Against FCD, N3092: ++In [atomics.syn], header <atomic> synopsis replace as indicated: +
++ + + + + + +// 29.4, lock-free property +#define ATOMIC_INTEGRAL_LOCK_FREE unspecified+#define ATOMIC_CHAR_LOCK_FREE implementation-defined +#define ATOMIC_CHAR16_T_LOCK_FREE implementation-defined +#define ATOMIC_CHAR32_T_LOCK_FREE implementation-defined +#define ATOMIC_WCHAR_T_LOCK_FREE implementation-defined +#define ATOMIC_SHORT_LOCK_FREE implementation-defined +#define ATOMIC_INT_LOCK_FREE implementation-defined +#define ATOMIC_LONG_LOCK_FREE implementation-defined +#define ATOMIC_LLONG_LOCK_FREE implementation-defined +#define ATOMIC_ADDRESS_LOCK_FREE unspecified +
+1459. [FCD] Overlapping evaluations are allowed
+Section: 29.3 [atomics.order] Status: Open + Submitter: Canada Opened: 2010-08-25 Last modified: 2010-10-29
+View all other issues in [atomics.order].
+View all issues with Open status.
+Duplicate of: 1458
+Discussion:
+Addresses CA-21, GB-131
+ +29.4 [atomics.lockfree] p.8 states: ++An atomic store shall only store a value that has +been computed from constants and program input values +by a finite sequence of program evaluations, such +that each evaluation observes the values of variables +as computed by the last prior assignment in the +sequence. +++... but 1.9 [intro.execution] p.13 states: +
++If A is not sequenced before B and B is not +sequenced before A, then A and B are unsequenced. +[ Note: The execution of unsequenced +evaluations can overlap. — end note ] +++Overlapping executions can make it impossible to +construct the sequence described in 29.4 [atomics.lockfree] p.8. We are not +sure of the intention here and do not offer a suggestion for +change, but note that 29.4 [atomics.lockfree] p.8 is the condition that prevents +out-of-thin-air reads. +
++For an example, suppose we have a function invocation +f(e1,e2). The evaluations of e1 and e2 can overlap. +Suppose that the evaluation of e1 writes y and reads x +whereas the evaluation of e2 reads y and writes x, with +reads-from edges as below (all this is within a single +thread). +
e1 e2 +Wrlx y-- --Wrlx x + rf\ /rf + X + / \ +Rrlx x<- ->Rrlx y ++This seems like it should be allowed, but there seems to +be no way to produce a sequence of evaluations with the +property above. + +In more detail, here the two evaluations, e1 and e2, are +being executed as the arguments of a function and are +consequently not sequenced-before each other. In +practice we'd expect that they could overlap (as allowed +by 1.9 [intro.execution] p.13), with the two writes taking effect before the two +reads. However, if we have to construct a linear order of +evaluations, as in 29.4 [atomics.lockfree] p.8, then the execution above is not +permited. Is that really intended? + +[ +Resolution proposed by ballot comment +]
+ ++Please clarify. +
+ + +Proposed resolution:
+ + + + + +
+1460. [FCD] Missing lock-free property for type bool should be added
+Section: 29.4 [atomics.lockfree] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [atomics.lockfree].
+View all issues with Open status.
+Discussion:
+Addresses US-154
+ +There is no ATOMIC_BOOL_LOCK_FREE macro. + + +Proposed resolution:
+Add ATOMIC_BOOL_LOCK_FREE to 29.4 [atomics.lockfree] and to 29.2 [atomics.syn]: ++
+ + + + + + +[..] +#define ATOMIC_BOOL_LOCK_FREE unspecified +#define ATOMIC_CHAR_LOCK_FREE unspecified +#define ATOMIC_CHAR16_T_LOCK_FREE unspecified +#define ATOMIC_CHAR32_T_LOCK_FREE unspecified +[..] +
+1461. [FCD] Rename all ATOMIC_* macros as STD_ATOMIC_*
+Section: 29 [atomics] Status: Open + Submitter: Canada Opened: 2010-08-25 Last modified: 2010-10-26
+View other active issues in [atomics].
+View all other issues in [atomics].
+View all issues with Open status.
+Discussion:
+Addresses CA-1
+ +All ATOMIC_... macros should be prefixed with STD_ as +in STD_ATOMIC_... to indicate they are STD macros as +other standard macros. The rationale that they all seem too long seems weak. + + +Proposed resolution:
++
+ + + + + +- Change sub-clause 29.2 [atomics.syn] as indicated: +
++
+ +[..] +// 29.4, lock-free property +#define STD_ATOMIC_CHAR_LOCK_FREE unspecified +#define STD_ATOMIC_CHAR16_T_LOCK_FREE unspecified +#define STD_ATOMIC_CHAR32_T_LOCK_FREE unspecified +#define STD_ATOMIC_WCHAR_T_LOCK_FREE unspecified +#define STD_ATOMIC_SHORT_LOCK_FREE unspecified +#define STD_ATOMIC_INT_LOCK_FREE unspecified +#define STD_ATOMIC_LONG_LOCK_FREE unspecified +#define STD_ATOMIC_LLONG_LOCK_FREE unspecified +#define STD_ATOMIC_ADDRESS_LOCK_FREE unspecified + +// 29.6, operations on atomic types +#define STD_ATOMIC_VAR_INIT(value) see below +[..] +- +Change 29.4 [atomics.lockfree] p. 1 as indicated: +
++#define STD_ATOMIC_CHAR_LOCK_FREE implementation-defined +#define STD_ATOMIC_CHAR16_T_LOCK_FREE implementation-defined +#define STD_ATOMIC_CHAR32_T_LOCK_FREE implementation-defined +#define STD_ATOMIC_WCHAR_T_LOCK_FREE implementation-defined +#define STD_ATOMIC_SHORT_LOCK_FREE implementation-defined +#define STD_ATOMIC_INT_LOCK_FREE implementation-defined +#define STD_ATOMIC_LONG_LOCK_FREE implementation-defined +#define STD_ATOMIC_LLONG_LOCK_FREE implementation-defined +#define STD_ATOMIC_ADDRESS_LOCK_FREE implementation-defined ++1 The STD_ATOMIC_..._LOCK_FREE macros indicate the lock-free property of the corresponding atomic types, [..] +- +Change 29.6 [atomics.types.operations] p. 5 as indicated: +
++#define STD_ATOMIC_VAR_INIT(value) see below ++5 Remarks: A macro that expands to a token sequence suitable for initializing an atomic variable of +a type that is initializion-compatible with value. Concurrent access to the variable being initialized, +even via an atomic operation, constitutes a data race. [ Example: ++— end example ] +atomic_int v = STD_ATOMIC_VAR_INIT(5); +- +Change 29.7 [atomics.flag] p. 1+4 as indicated: +
++namespace std { + [..] + #define STD_ATOMIC_FLAG_INIT see below +} ++[..] +4 The macro STD_ATOMIC_FLAG_INIT shall be defined in such a way that it can be used to initialize an object of +type atomic_flag to the clear state. For a static-duration object, that initialization shall be static. It is +unspecified whether an unitialized atomic_flag object has an initial state of set or clear. [ Example: ++— end example ] +atomic_flag guard = STD_ATOMIC_FLAG_INIT; +
+1474. [FCD] weak compare-and-exchange confusion
+Section: 29.6 [atomics.types.operations] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [atomics.types.operations].
+View all other issues in [atomics.types.operations].
+View all issues with Open status.
+Duplicate of: 1470, 1475, 1476, 1477
+Discussion:
+ + + +Addresses US-175, US-165, CH-23, GB-135
+ +29.6 [atomics.types.operations] p. 23: The first sentence is grammatically incorrect. + +[ +2010-10-28 Daniel adds: +]
+ ++Proposed resolution of duplicate issue 1475: +
+Change 29.6 [atomics.types.operations] p. 23 as indicated: ++23 Remark:+ + +The weak compare-and-exchange operations may fail spuriously, that is, return false while +leaving the contents of memory pointed to by expected before the operation is the same that same +as that of the object and the same as that of expected after the operationThe weak +compare-and-exchange operations may fail spuriously, that is, return false while leaving the contents of memory +pointed to by expected unchanged.. [ Note: This spurious failure enables implementation of +compare-and-exchange on a broader class of machines, e.g., loadlocked store-conditional machines. A consequence of +spurious failure is that nearly all uses of weak compare-and-exchange will be in a loop. ++When a compare-and-exchange is in a loop, the weak version will yield better performance on some +platforms. When a weak compare-and-exchange would require a loop and a strong one would not, the +strong one is preferable. — end note ] +
Proposed resolution:
+Change 29.6 [atomics.types.operations] p. 23 as indicated: ++23 Remark:+ + + + + +The weak compare-and-exchange operations may fail spuriously, that is, return false while +leaving the contents of memory pointed to by expected before the operation is the same that same +as that of the object and the same as that of expected after the operationThe weak +compare-and-exchange operations may fail spuriously. That is, it may return false while leaving the contents of +memory pointed to by expected the same as it was before the operation. [ Note: This spurious +failure enables implementation of compare-and-exchange on a broader class of machines, e.g., loadlocked +store-conditional machines. A consequence of spurious failure is that nearly all uses of weak +compare-and-exchange will be in a loop. ++When a compare-and-exchange is in a loop, the weak version will yield better performance on some +platforms. When a weak compare-and-exchange would require a loop and a strong one would not, the +strong one is preferable. — end note ] +
+1478. [FCD] Clarify race conditions in atomics initialization
+Section: 29.6 [atomics.types.operations] Status: Open + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-29
+View other active issues in [atomics.types.operations].
+View all other issues in [atomics.types.operations].
+View all issues with Open status.
+Discussion:
+Addresses GB-136
+ +GB requests normative clarification in 29.6 [atomics.types.operations] p.4 that +concurrent access constitutes a race, as already done on p.6 and p.7. + +[ +Resolution proposed in ballot comment: +]
+ + ++Initialisation of atomics: ++ + ++We believe the intent is that for any atomics there is a distinguished +initialisation write, but that this need not happens-before all the +other operations on that atomic - specifically so that the +initialisation write might be non-atomic and hence give rise to a data +race, and hence undefined behaviour, in examples such as this (from +Hans): +
+(where na is nonatomic and rlx is relaxed). We suspect also that no +other mixed atomic/nonatomic access to the same location is intended +to be permitted. Either way, a note would probably help. +atomic<atomic<int> *> p +f() | +{ atomic<int>x; | W_na x + p.store(&x,mo_rlx); | W_rlx p=&x +} | +Proposed resolution:
+ + + + + +
+1479. [FCD] Fence functions should be extern "C"
+Section: 29.8 [atomics.fences] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [atomics.fences].
+View all other issues in [atomics.fences].
+View all issues with Open status.
+Discussion:
+Addresses US-179
+ +The fence functions (29.8 [atomics.fences] p.5 + p.6) should be extern "C", for C compatibility. + + +Proposed resolution:
++
+ + + + + +- Change 29.2 [atomics.syn], header <atomic> synopsis as indicated: +
++namespace std { + [..] + // 29.8, fences + extern "C" void atomic_thread_fence(memory_order); + extern "C" void atomic_signal_fence(memory_order); +} +- Change 29.8 [atomics.fences], p. 5 and p. 6 as indicated: +
++extern "C" void atomic_thread_fence(memory_order); ++5 Effects: depending on the value of order, this operation: [..] ++extern "C" void atomic_signal_fence(memory_order); ++6 Effects: equivalent to atomic_thread_fence(order), except that synchronizes with relationships are +established only between a thread and a signal handler executed in the same thread. +
+1480. [FCD] Atomic fences don't have synchronizes with relation
+Section: 29.8 [atomics.fences] Status: Review + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-14
+View other active issues in [atomics.fences].
+View all other issues in [atomics.fences].
+View all issues with Review status.
+Discussion:
+Addresses GB-137
+ +Thread fence not only establish synchronizes with relationships, +there are semantics of fences that are expressed not in +terms of synchronizes with relationships (for example see 29.3 [atomics.order] p.5). +These semantics also need to apply to the use of +atomic_signal_fence in a restricted way. + +[Batavia: Concurrency group discussed issue, and is OK with the proposed resolution.]
+ + + +Proposed resolution:
+Change 29.8 [atomics.fences] p. 6 as indicated: ++ + + + + +void atomic_signal_fence(memory_order); ++6 Effects: equivalent to atomic_thread_fence(order), except thatsynchronizes +with relationshipsthe resulting ordering constraints are established only between a +thread and a signal handler executed in the same thread. +
+1485. [FCD] Unclear thread::id specification
+Section: 30.3.1.1 [thread.thread.id] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-23
+View all other issues in [thread.thread.id].
+View all issues with Open status.
+Discussion:
+Addresses US-184
+ +It is unclear when a thread::id ceases to be meaningful. +The sentence "The library may reuse the value of a +thread::id of a terminated thread that can no longer be +joined." implies that some terminated threads can be +joined. It says nothing about detached threads. + +[ +Resolution proposed by ballot comment: +]
+ ++Require a unique thread::id for every thread that is +(1) detached and not terminated or (2) has an associated std::thread +object. ++ +[ +2010-11-22 Howard Hinnant observes +]
+ + + ++A thread can either be running or terminated. Additionally a thread can be joined, detached, or neither. These combine into the five possible states shown in this table: +
+ ++
++ +Running Terminated ++ +Neither joined nor detached shall not reuse id shall not reuse id ++ +detached shall not reuse id may reuse id ++ +joined impossible state may reuse id ++Only if a thread is neither joined nor detached can it be joined. Or said differently, if a thread has already been joined or detached, then it can not be joined. The sentence: +
+The library may reuse the value of a thread::id of a terminated thread that can no longer be joined. ++precisely defines the two states shown in the above table where a thread::id may be reused. + ++The following program illustrates all of the possibilities: +
++ +#include <mutex> +#include <thread> +#include <iostream> +#include <chrono> + +std::mutex mut; + +void f() +{ + std::lock_guard<std::mutex> _(mut); + std::cout << "f id = " << std::this_thread::get_id() << " terminating\n"; +} + +void g() +{ + std::lock_guard<std::mutex> _(mut); + std::cout << "g id = " << std::this_thread::get_id() << " terminating\n"; +} + +int main() +{ + std::cout << "main id = " << std::this_thread::get_id() << "\n"; + std::thread t1(f); + std::thread(g).detach(); + std::this_thread::sleep_for(std::chrono::seconds(1)); + std::cout << "g's thread::id can be reused here because g has terminated and is detached.\n"; + std::cout << "f's thread::id can't be reused here because f has terminated but is still joinable.\n"; + std::cout << "f id = " << t1.get_id() << "\n"; + t1.join(); + std::cout << "f's thread::id can be reused here because f has terminated and is joined.\n"; + std::cout << "f id = " << t1.get_id() << "\n"; +} + +main id = 0x7fff71197ca0 +f id = 0x100381000 terminating +g id = 0x100581000 terminating +g's thread::id can be reused here because g has terminated and is detached. +f's thread::id can't be reused here because f has terminated but is still joinable. +f id = 0x100381000 +f's thread::id can be reused here because f has terminated and is joined. +f id = 0x0 +Proposed resolution:
+ + + + + +
+1486. [FCD] Value of this_thread::get_id() underspecified for detached thread
+Section: 30.3.2 [thread.thread.this] Status: Open + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-23
+View other active issues in [thread.thread.this].
+View all other issues in [thread.thread.this].
+View all issues with Open status.
+Discussion:
+Addresses CH-24
+ +What would be the value this_thread::get_id() when called from a detached thread? + +[ +Resolution proposed by ballot comment: +]
+ ++Add some text to clarify that get_id() still returns +the same value even after detaching. +
+ +[ +2010-11-22 Howard Hinnant observes +]
+ + ++30.3.2 [thread.thread.this]/1 contains the following sentence describing this_thread::get_id(): +
+ ++... No other thread of execution shall have this id and this thread of execution shall always have this id. ++ +I don't object to adding "even if detached" to this sentence, but it seems unnecessary to me. "Always" means always. + + +Proposed resolution:
+ + + + + +
+1487. [FCD] Clock related operations exception specifications conflict
+Section: 30.3.2 [thread.thread.this] Status: Open + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-01
+View other active issues in [thread.thread.this].
+View all other issues in [thread.thread.this].
+View all issues with Open status.
+Discussion:
+Addresses CH-25
+ +Clock related operations are currently not required not to +throw. So "Throws: Nothing." is not always true. + +[ +Resolution proposed by ballot comment: +]
+ ++Either require clock related operations not to throw +(in 20.10) or change the Throws clauses in 30.3.2. +Also possibly add a note that abs_time in the past +or negative rel_time is allowed. ++ + + +Proposed resolution:
+ + + + + +
+1494. [FCD] Term "are serialized" not defined
+Section: 30.4.4.2 [thread.once.callonce] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all issues with Open status.
+Discussion:
+Addresses US-190
+ +The term "are serialized" is never defined (30.4.4.2 [thread.once.callonce] p. 2). + +[ +Resolution proposed by ballot comment: +]
+ ++Remove the sentence with "are serialized" from +paragraph 2. Add "Calls to call_once on the same +once_flag object shall not introduce data races +(17.6.4.8)." to paragraph 3. +
+ +[ +2010-11-01 Daniel translates NB comment into wording +]
+ + + + +Proposed resolution:
+Change 30.4.4.2 [thread.once.callonce] p.2+3 as indicated: ++ + + + + +template<class Callable, class ...Args> +void call_once(once_flag& flag, Callable&& func, Args&&... args); ++[..] ++2 Effects:
Calls to call_once on the same once_flag object are serialized.+If there has been a prior effective call to call_once on the same once_flag object, +the call to call_once returns without invoking func. If there has been no prior +effective call to call_once on the same once_flag object, +INVOKE(decay_copy( std::forward<Callable>(func)), decay_copy(std::forward<Args>(args))...) +is executed. The call to call_once is effective if and only if +INVOKE(decay_copy( std::forward<Callable>(func)), decay_copy(std::forward<Args>(args))...) +returns without throwing an exception. If an exception is thrown it is propagated to the caller. ++3 Synchronization: The completion of an effective call to call_once on a once_flag +object synchronizes with (1.10) all subsequent calls to call_once on the same once_flag object. +Calls to call_once on the same once_flag object shall not introduce data races ([res.on.data.races]). +
+1497. [FCD] lock() postcondition can not be generally achieved
+Section: 30.5 [thread.condition] Status: Tentatively Ready + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-08
+View all other issues in [thread.condition].
+View all issues with Tentatively Ready status.
+Discussion:
+Addresses CH-30
+ +If lock.lock() throws an exception, the postcondition can not be generally achieved. + +[ +Resolution proposed by ballot comment: +]
+ ++Either state that the postcondition might not be achieved, depending on the error condition, or +state that terminate() is called in this case. ++ +[ +2010-08-13 Peter Sommerlad comments and provides wording +]
+ + ++30.5.1 [thread.condition.condvar], 30.5.2 [thread.condition.condvarany] ++ + ++p. 13, last bullet, and corresponding paragraphs in all wait functions +
+Problem:
+Condition variable wait might fail, because the lock cannot be acquired when notified. +CH-30 says: "If lock.lock() throws an exception, the postcondition can not be generally achieved." +CH-30 proposes: "Either state that the postcondition might not be achieved, depending on the error +condition, or state that terminate() is called in this case." ++The discussion in Rapperswil concluded that calling terminate() might be too drastic in +this case and a corresponding exception should be thrown/passed on and one should use a lock type +that allows querying its status, which unique_lock allows for std::condition_variable +
+We also had some additional observations while discussing in Rapperswil: +
+
+and add the following proposed solution: +- in 30.5.1 [thread.condition.condvar] wait with predicate and wait_until with +predicate lack the precondition, postcondition and Error conditions sections. the lack of the precondition +would allow to call pred() without holding the lock. +
+- in 30.5.1 [thread.condition.condvar] wait_until and wait_for and +30.5.2 [thread.condition.condvarany] wait_for still specify an +error condition for a violated precondition. This should be removed. +
+Proposed resolution:
++
+ + + + + +- Change 30.5.1 [thread.condition.condvar] as indicated: +
+ ++void wait(unique_lock<mutex>& lock); ++12 Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either ++[..] ++
- no other thread is waiting on this condition_variable object or +
+- lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait or timed_wait) threads.
+14 Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. ++[..] ++template <class Predicate> +void wait(unique_lock<mutex>& lock, Predicate pred); ++?? Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either +++
+- no other thread is waiting on this condition_variable object or +
+- lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait or timed_wait) threads. +
++17 Effects: ++ ++while (!pred()) + wait(lock); ++?? Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. +++?? Throws: std::system_error when an exception is required (30.2.2). +++?? Error conditions: ++ ++
+- equivalent error condition from lock.lock() or lock.unlock(). +
++template <class Clock, class Duration> +cv_status wait_until(unique_lock<mutex>& lock, + const chrono::time_point<Clock, Duration>& abs_time); ++18 Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either ++[..] ++
+- no other thread is waiting on this condition_variable object or +
+- lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait, wait_for, or wait_until) threads. +
++20 Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. ++[..] ++23 Error conditions: +++
+- +
operation_not_permitted — if the thread does not own the lock.+- equivalent error condition from lock.lock() or lock.unlock(). +
++template <class Rep, class Period> +cv_status wait_for(unique_lock<mutex>& lock, + const chrono::duration<Rep, Period>& rel_time); ++24 Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either ++[..] ++
+- no other thread is waiting on this condition_variable object or +
+- lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait, wait_for, or wait_until) threads. +
++27 Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. ++[..] ++29 Error conditions: +++
+- +
operation_not_permitted — if the thread does not own the lock.+- equivalent error condition from lock.lock() or lock.unlock(). +
++template <class Clock, class Duration, class Predicate> +bool wait_until(unique_lock<mutex>& lock, + const chrono::time_point<Clock, Duration>& abs_time, + Predicate pred); ++?? Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either +++
+- no other thread is waiting on this condition_variable object or +
+- lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait or timed_wait) threads. +
++30 Effects: +++while (!pred()) + if (wait_until(lock, abs_time) == cv_status::timeout) + return pred(); +return true; ++31 Returns: pred() ++ ++?? Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. ++ ++32 [ Note: The returned value indicates whether the predicate evaluates to true regardless of whether the +timeout was triggered. — end note ] ++ ++?? Throws: std::system_error when an exception is required (30.2.2). +++?? Error conditions: ++ ++
+- equivalent error condition from lock.lock() or lock.unlock(). +
++template <class Rep, class Period, class Predicate> +bool wait_for(unique_lock<mutex>& lock, + const chrono::duration<Rep, Period>& rel_time, + Predicate pred); ++33 Requires: lock.owns_lock() is true and lock.mutex() is locked by the calling thread, and either ++[..] ++
+- no other thread is waiting on this condition_variable object or +
+- lock.mutex() returns the same value for each of the lock arguments supplied by all concurrently +waiting (via wait, wait_for, or wait_until) threads. +
++36 Postcondition: lock.owns_lock() is true and lock.mutex() is locked by the calling thread. ++[..] ++40 Error conditions: ++ ++
+- +
operation_not_permitted — if the thread does not own the lock.+- equivalent error condition from lock.lock() or lock.unlock(). +
+- Change 30.5.2 [thread.condition.condvarany] as indicated: +
+ ++[..] +
+template <class Lock, class Predicate> +void wait(Lock& lock, Predicate pred); ++[Note: if any of the wait functions exits with an exception it is indeterminate if the Lock is held. +One can use a Lock type that allows to query that, such as the unique_lock wrapper. — end note] +++14 Effects: ++ +[..] ++while (!pred()) + wait(lock); ++34 Error conditions: +++
+- +
operation_not_permitted — if the thread does not own the lock.+- equivalent error condition from lock.lock() or lock.unlock(). +
+
+1502. [FCD] Specification of [futures.state]
+Section: 30.6.4 [futures.state] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [futures.state].
+View all other issues in [futures.state].
+View all issues with Open status.
+Discussion:
+Addresses US-195
+ +The intent and meaning of the paragraph is not apparent. + + +Proposed resolution:
+ + + + + +
+1503. [FCD] "associated asynchronous state" must go
+Section: 30.6.4 [futures.state] Status: Open + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-01
+View other active issues in [futures.state].
+View all other issues in [futures.state].
+View all issues with Open status.
+Discussion:
+Addresses CH-35
+ +The term "associated asynchronous state" is long, ugly +and misleading terminology. When introduced we agreed +upon that we should come up with a better name. Here it +is: "liaison state". Since the state is hidden and provides +synchronization of a future with its corresponding promise, +we believe "liaison state" is a much better and shorter +name (liaison ~ (typically hidden) relationship) + +[ +Resolution proposed by ballot comment: +]
+ ++Change all occurrences of "associated +asynchronous state" to "liaison state". ++ + +Proposed resolution:
+ + + + + +
+1504. [FCD] Term "are serialized" is not defined
+Section: 30.6.5 [futures.promise] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [futures.promise].
+View all other issues in [futures.promise].
+View all issues with Open status.
+Discussion:
+Addresses US-196
+ +The term "are serialized" is not defined (30.6.5 [futures.promise] p. 21, 25). + +[ +Resolution proposed by ballot comment: +]
+ ++Replace "are serialized" with "shall not introduce a data race (17.6.4.8)". ++ +[ +2010-11-02 Daniel translates proposal into proper wording changes +]
+ + + +Proposed resolution:
++
+ + + + + +- Change 30.6.5 [futures.promise] p. 21 as indicated: +
++21 Synchronization: calls to set_value and set_exception on a single +promise object+are serializedshall not introduce a data race ([res.on.data.races]). +[ Note: and they synchronize and serialize with other functions through the referred associated asynchronous +state. — end note ] +- Change 30.6.5 [futures.promise] p. 25 as indicated: +
++25 Synchronization: calls to set_value and set_exception on a single +promise object+are serializedshall not introduce a data race ([res.on.data.races]). +[ Note: and they synchronize and serialize with other functions through the referred associated asynchronous +state. — end note ] +
+1505. [FCD] Synchronization between +promise::set_value and future::get
+Section: 30.6.5 [futures.promise] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [futures.promise].
+View all other issues in [futures.promise].
+View all issues with Open status.
+Discussion:
+Addresses US-197
+ +There is no defined synchronization between +promise::set_value and future::get (30.6.5 [futures.promise] p. 21, 25). + +[ +Resolution proposed by ballot comment: +]
+ ++Replace "[Note: and they synchronize and +serialize with other functions through the referred +associated asynchronous state. --end note]" with +the normative "They synchronize with (1.10) any +operation on a future object with the same +associated asynchronous state marked ready." ++ +[ +2010-11-02 Daniel translates proposal into proper wording changes +]
+ + + +Proposed resolution:
++
+ + + + + +- Change 30.6.5 [futures.promise] p. 21 as indicated: +
++21 Synchronization: calls to set_value and set_exception on a single +promise object are serialized. ++[ Note: and they synchronize and serialize with other functions through the referred associated asynchronous +state. — end note ]They synchronize with ([intro.multithread]) any +operation on a future object with the same associated asynchronous state marked ready. +- Change 30.6.5 [futures.promise] p. 25 as indicated: +
++25 Synchronization: calls to set_value and set_exception on a single +promise object are serialized. ++[ Note: and they synchronize and serialize with other functions through the referred associated asynchronous +state. — end note ]They synchronize with ([intro.multithread]) any +operation on a future object with the same associated asynchronous state marked ready. +
+1507. [FCD] promise::XXX_at_thread_exit functions have no +synchronization requirements
+Section: 30.6.5 [futures.promise] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [futures.promise].
+View all other issues in [futures.promise].
+View all issues with Open status.
+Discussion:
+Addresses US-199
+ +promise::XXX_at_thread_exit functions have no +synchronization requirements. Specifying synchronization +for these member functions requires coordinating with the +words in 30.6.5/21 and 25, which give synchronization +requirements for promise::set_value and +promise::set_exception (30.6.5 [futures.promise] p. 26 ff., p. 29 ff.). + +[ +Resolution proposed by ballot comment: +]
+ ++Change 30.6.5/21 to mention +set_value_at_thread_exit and +set_exception_at_thread_exit; with this text, +replace 30.6.5/25 and add two new paragraphs, +after 30.6.5/28 and 30.6.5/31. ++ + +Proposed resolution:
+ + + + + +
+1514. [FCD] packaged_task constructors need review
+Section: 30.6.10.1 [futures.task.members] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [futures.task.members].
+View all other issues in [futures.task.members].
+View all issues with Open status.
+Discussion:
+Addresses US-207
+ +The constructor that takes R(*)(ArgTypes...) is not +needed; the constructor that takes a callable type works +for this argument type. More generally, the constructors +for packaged_task should parallel those for function. + +[ +US-207 Suggested Resolution: +]
+ + ++Review the constructors for packaged_task and +provide the same ones as function, except where +inappropriate. ++ +[ +2010-10-22 Howard provides wording, as requested by the LWG in Rapperswil. +]
+ + + + +Proposed resolution:
+Alter the list of constructors in both [futures.task] and in [futures.task.members] as indicated: + +++ + + + + ++template <class F> +explicit packaged_task(F f); +template <class F, class Allocator> +explicit packaged_task(allocator_arg_t, const Allocator& a, F f); +explicit packaged_task(R(*f)(ArgTypes...));+template <class F> +explicit packaged_task(F&& f); +template <class F, class Allocator> +explicit packaged_task(allocator_arg_t, const Allocator& a, F&& f); +
+1515. [FCD] packaged_task::make_ready_at_thread_exit has no +synchronization requirements
+Section: 30.6.10.1 [futures.task.members] Status: Open + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [futures.task.members].
+View all other issues in [futures.task.members].
+View all issues with Open status.
+Discussion:
+Addresses US-208
+ ++packaged_task::make_ready_at_thread_exit has no +synchronization requirements. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Figure out what the synchronization requirements +should be and write them. +
+ + + +Proposed resolution:
+ + + + + +
+1521. Requirements on internal pointer representations in containers
+Section: 23.2.1 [container.requirements.general] Status: New + Submitter: Mike Spertus Opened: 2010-10-16 Last modified: 2010-11-04
+View other active issues in [container.requirements.general].
+View all other issues in [container.requirements.general].
+View all issues with New status.
+Discussion:
+Addresses US-104, US-141
+ ++The standard doesn't say that containers should use abstract pointer +types internally. Both Howard and Pablo agree that this is the intent. +Further, it is necessary for containers to be stored, for example, in +shared memory with an interprocess allocator (the type of scenario that +allocators are intended to support). +
++In spite of the (possible) agreement on intent, it is necessary to make +this explicit: +
++An implementations may like to store the result of dereferencing the +pointer (which is a raw reference) as an optimization, but that prevents +the data structure from being put in shared memory, etc. In fact, a +container could store raw references to the allocator, which would be a +little weird but conforming as long as it has one by-value copy. +Furthermore, pointers to locales, ctypes, etc. may be there, which also +prevents the data structure from being put in shared memory, so we +should make explicit that a container does not store raw pointers or +references at all. +
+ +[ +Pre-batavia +]
+ ++This issue is being opened as part of the response to NB comments US-104/141. +See paper N3171 +in the pre-Batavia mailing. +
+ + + +Proposed resolution:
++Add to the end of 23.2.1 [container.requirements.general] p. 8: +
++[..] In all container types defined in this Clause, the member get_allocator() returns +a copy of the allocator used to construct the container or, if that allocator has been replaced, +a copy of the most recent replacement. The container may not store internal objects whose +types are of the form T * or T & except insofar as they are part of the +item type or members. ++ + + + + +
+1523. [FCD] noexcept for Clause 29
+Section: 29 [atomics] Status: New + Submitter: Hans Boehm Opened: 2010-11-13 Last modified: 2010-11-14
+View other active issues in [atomics].
+View all other issues in [atomics].
+View all issues with New status.
+Discussion:
+Addresses GB-63 for Clause 29
+ +Clause 29 does not specify noexcept for any of the atomic operations. +It probably should, though that's not completely clear. +In particular, atomics may want to throw in implementations that support transactional memory. +
+ + +Proposed resolution:
++
+ + + + + +
+2000. Missing definition of packaged_task specialization of uses_allocator
+Section: 30.6.10.2 [futures.task.nonmembers] Status: Tentatively Ready + Submitter: Howard Hinnant Opened: 2010-08-29 Last modified: 2010-11-13
+View all issues with Tentatively Ready status.
+Discussion:
++[futures.task.nonmembers]/3 says: +
+ +This is a declaration, but should be a definition. + + + +template <class R, class Alloc> + struct uses_allocator<packaged_task<R>, Alloc>; +Proposed resolution:
++Change [futures.task.nonmembers]/3: +
+ ++ + + + + +template <class R, class Alloc> + struct uses_allocator<packaged_task<R>, Alloc>;+ : true_type {}; +
+2001. Class template basic_regex uses non existent string_type
+Section: 28.8.3 [re.regex.assign] Status: Open + Submitter: Volker Lukas Opened: 2010-10-21 Last modified: 2010-11-13
+View all issues with Open status.
+Discussion:
++In working draft N3126, subclause 28.8.3 [re.regex.assign], paragraphs 12, 13 and 19, +the name string_type is used. This is presumably a typedef for basic_string<value_type>, where +value_type is the character type used by basic_regex. The basic_regex +template however defines no such typedef, and neither does the <regex> +header or the <initializer_list> header included by <regex>. +
+ +[ +2010-11-03 Daniel comments and suggests alternative wording: +]
+ ++The proposed resolution needs to use basic_string<charT> instead of basic_string<char> ++ +Proposed Resolution:
+ +Make the following changes to [re.regex.assign]:+ +
++ +basic_regex& assign(const charT* ptr, flag_type f = regex_constants::ECMAScript); +++12 Returns: assign(+ +string_typebasic_string<charT>(ptr), f). +basic_regex& assign(const charT* ptr, size_t len, + flag_type f = regex_constants::ECMAScript); +++13 Returns: assign(+ +string_typebasic_string<charT>(ptr, len), f). +[..] + +template <class InputIterator> + basic_regex& assign(InputIterator first, InputIterator last, + flag_type f = regex_constants::ECMAScript); ++ ++18 Requires: The type InputIterator shall satisfy the requirements for an Input Iterator (24.2.3). ++ ++19 Returns: assign(+ +string_typebasic_string<charT>(first, last), f). +[ +2010 Batavia +]
+ + ++Unsure if we should just give basic_regex a string_type typedef. Looking for when string_type was +introduced into regex. Howard to draft wording for typedef typename traits::string_type string_type, then move to Review. +
+ + +Proposed resolution:
++Make the following changes to [re.regex.assign]:
+ ++ ++ + + + + + +basic_regex& assign(const charT* ptr, flag_type f = regex_constants::ECMAScript); +++12 Returns: assign(+ +string_typebasic_string<char>(ptr), f). +basic_regex& assign(const charT* ptr, size_t len, + flag_type f = regex_constants::ECMAScript); +++13 Returns: assign(+ +string_typebasic_string<char>(ptr, len), f). +[..] + +template <class InputIterator> + basic_regex& assign(InputIterator first, InputIterator last, + flag_type f = regex_constants::ECMAScript); ++ ++18 Requires: The type InputIterator shall satisfy the requirements for an Input Iterator (24.2.3). ++ ++19 Returns: assign(+ +string_typebasic_string<char>(first, last), f). +
+2003. String exception inconsistency in erase.
+Section: 21.4.1 [string.require] Status: Open + Submitter: JoseĚ Daniel GarciĚa SaĚnchez Opened: 2010-10-21 Last modified: 2010-11-13
+View all other issues in [string.require].
+View all issues with Open status.
+Discussion:
++Clause 21.4.1 [string.require]p3 states: +
++No erase() or pop_back() member function shall throw +any exceptions. +++However in 21.4.6.5 [string::erase] p2 the first version of erase has +
++Throws: out_of_range if pos > size(). ++ + + +Proposed resolution:
++Update [string.require]p/3: +
++3 No+ + + + + +erase() orpop_back() member function +shall throw any exceptions. +
+2004. duration::operator* has template parameters in funny order
+Section: 20.11.3.5 [time.duration.nonmember] Status: Tentatively Ready + Submitter: P.J. Plauger Opened: 2010-10-14 Last modified: 2010-11-13
+View all other issues in [time.duration.nonmember].
+View all issues with Tentatively Ready status.
+Discussion:
++In [time] and [time.duration.nonmember] we have: +
++template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + operator*(const Rep1& s, const duration<Rep2, Period>& d); ++Everywhere else, we always have <rep, period> in that order for a given +type. But here, we have Period and Rep2 in reverse order for +<Rep2, Period>. This is probably of little importance, since the +template parameters are seldom spelled out for a function like this. But changing it +now will eliminate a potential source of future errors and confusion. +
+ + +Proposed resolution:
++Change the signature in [time] and [time.duration.nonmember] to: +
++ + + + + +template <class Rep1, classPeriodRep2, classRep2Period> + duration<typename common_type<Rep1, Rep2>::type, Period> + operator*(const Rep1& s, const duration<Rep2, Period>& d); +
+2005. unordered_map::insert(T&&) protection should apply to map too
+Section: 23.6.1.3 [map.modifiers], 23.6.2.2 [multimap.modifiers] Status: Open + Submitter: P.J. Plauger Opened: 2010-10-14 Last modified: 2010-11-13
+View all issues with Open status.
+Discussion:
++In [unord.map.modifiers], the signature: +
+now has an added Remarks paragraph: + +template <class P> + pair<iterator, bool> insert(P&& obj); ++Remarks: This signature shall not participate in overload resolution unless P +is implicitly convertible to value_type. +++The same is true for unordered_multimap. +
++But neither map nor multimap have this constraint, even though it is a +Good Thing(TM) in those cases as well. +
+ +[ +The submitter suggests: Add the same Remarks clause to [map.modifiers] and [multimap.modifiers]. +]
+ + +[ +2010-10-29 Daniel comments: +]
+ + ++I believe both paragraphs need more cleanup: First, the current Requires element conflict with the Remark; +second, it seems to me that the whole single Requires element is intended to be split into a Requires +and an Effects element; third, the reference to tuple is incorrect (noticed by Paolo Carlini); +fourth, it refers to some non-existing InputIterator parameter relevant for a completely different +overload; sixth, the return type of the overload with hint is wrong. +The following proposed resolution tries to solve these issues as well and uses similar wording as for +the corresponding unordered containers. Unfortunately it has some redundancy over Table 99, but I did +not remove the specification because of the more general template parameter P - the Table 99 +requirements apply only for an argument identical to value_type. +
+ ++Proposed resolution: +
+ ++
+
+ + +- Change 23.6.1.3 [map.modifiers] around p. 1 as indicated: +
++template <class P> pair<iterator, bool> insert(P&& x); +template <class P>pair<iterator, bool>insert(const_iterator position, P&& x); ++1 Requires:P shall be convertible tovalue_type is constructible +from std::forward<P>(x).. ++
If P is instantiated as a reference type, then the argument x is copied from. Otherwise x is considered +to be an rvalue as it is converted to value_type and inserted into the map. Specifically, in +such cases CopyConstructible is not required of key_type or mapped_type unless the conversion +from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, then key_type +must be CopyConstructible). The signature taking InputIterator parameters does not require +CopyConstructible of either key_type or mapped_type if the dereferenced InputIterator returns a +non-const rvalue pair<key_type,mapped_type>. Otherwise CopyConstructible is required for both +key_type and mapped_type.
+? Effects: Inserts x converted to value_type if and only if there is no element in the container with +key equivalent to the key of value_type(x). For the second form, the iterator position is a hint pointing to where the +search should start. ++? Returns: For the first form, the bool component of the returned pair object indicates whether the +insertion took place and the iterator component - or for the second form the returned iterator - points to the element with key equivalent +to the key of value_type(x). +
+? Complexity: Logarithmic in general, but amortized constant if x is inserted right before position. +
+? Remarks: These signatures shall not participate in overload resolution unless P +is implicitly convertible to value_type. +
- Change 23.6.2.2 [multimap.modifiers] around p. 1 as indicated: +
++template <class P> iterator insert(P&& x); +template <class P> iterator insert(const_iterator position, P&& x); ++1 Requires:P shall be convertible tovalue_type is constructible from +std::forward<P>(x). ++
If P is instantiated as a reference type, then the argument x is copied from. Otherwise +x is considered to be an rvalue as it is converted to value_type and inserted into the map. +Specifically, in such cases CopyConstructible is not required of key_type or mapped_type +unless the conversion from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, +then key_type must be CopyConstructible). The signature taking InputIterator parameters +does not require CopyConstructible of either key_type or mapped_type if the dereferenced +InputIterator returns a non-const rvalue pair<key_type, mapped_type>. Otherwise CopyConstructible +is required for both key_type and mapped_type.
+? Effects: Inserts x converted to value_type. For the second form, the iterator position +is a hint pointing to where the search should start. ++? Returns: An iterator that points to the element with key equivalent to the key of value_type(x). +
+? Complexity: Logarithmic in general, but amortized constant if x is inserted right before position. +
+? Remarks: These signatures shall not participate in overload resolution unless P +is implicitly convertible to value_type. +
[ +2010 Batavia: +]
+ + ++We need is_convertible, not is_constructible, both in ordered and unordered containers. +
+ + + +Proposed resolution:
++
+ + + + + +- Add a new Remarks element after 23.6.1.3 [map.modifiers] p. 1: +
++template <class P> pair<iterator, bool> insert(P&& x); +template <class P> pair<iterator, bool> insert(const_iterator position, P&& x); ++1 Requires: P shall be convertible to value_type. ++If P is instantiated as a reference type, then the argument x is copied from. Otherwise x is considered +to be an rvalue as it is converted to value_type and inserted into the map. Specifically, in +such cases CopyConstructible is not required of key_type or mapped_type unless the conversion +from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, then key_type +must be CopyConstructible). The signature taking InputIterator parameters does not require +CopyConstructible of either key_type or mapped_type if the dereferenced InputIterator returns a +non-const rvalue pair<key_type,mapped_type>. Otherwise CopyConstructible is required for both +key_type and mapped_type. +
+? Remarks: These signatures shall not participate in overload resolution unless P +is implicitly convertible to value_type. +
- Change 23.6.2.2 [multimap.modifiers] around p. 1 as indicated: +
++template <class P> iterator insert(P&& x); +template <class P> iterator insert(const_iterator position, P&& x); ++1 Requires: P shall be convertible to value_type. ++If P is instantiated as a reference type, then the argument x is copied from. Otherwise +x is considered to be an rvalue as it is converted to value_type and inserted into the map. +Specifically, in such cases CopyConstructible is not required of key_type or mapped_type +unless the conversion from P specifically requires it (e.g., if P is a tuple<const key_type, mapped_type>, +then key_type must be CopyConstructible). The signature taking InputIterator parameters +does not require CopyConstructible of either key_type or mapped_type if the dereferenced +InputIterator returns a non-const rvalue pair<key_type, mapped_type>. Otherwise CopyConstructible +is required for both key_type and mapped_type. +
+? Remarks: These signatures shall not participate in overload resolution unless P +is implicitly convertible to value_type. +
+2006. emplace broken for associative containers
+Section: 23.2.5 [unord.req] Status: Tentatively NAD + Submitter: Pablo Halpern Opened: 2010-10-18 Last modified: 2010-11-13
+View other active issues in [unord.req].
+View all other issues in [unord.req].
+View all issues with Tentatively NAD status.
+Discussion:
++The current definition of emplace(args) for associative containers as +described in Table 99 is: +
++ ++Requires: T shall be constructible from args. +
++Effects: Inserts a T object t constructed with +std::forward<Args>(args)... if and only if there is no element +in the container with key equivalent to the key of t. The bool +component of the returned pair is true if and only if the +insertion takes place, and the iterator component of the pair +points to the element with key equivalent to the key of t. +
++There is similar language in Table 100 for unordered associative containers. +
++The first issue is editorial: T should be value_type throughout +both tables. +
++The major issue is that, if the container is map, multimap, +unordered_map, or unordered_multimap, then the only way to +construct an object of value_type is to supply exactly two arguments +for Key and Value, a pair<Key,Value>, or a +piecewise_construct_t followed by two tuples. The original +emplace() proposal would have allowed you to specify a Key +value followed by any number of constructor arguments for Value. +When we removed the variadic constructor to pair, this ability went +away. I don't think that was deliberate. +
++Fixing this is non-trivial, I think. I think that emplace() for map +and multimap need several overloads: one for each overloaded constructor in +pair<Key,Value>, and one for the emplace(Key, valueargs...) case. +And it probably needs some SFINAE meta-programming to ensure that the last case +doesn't override any of the other ones. Alternatively, one could say that +there are exactly two cases: emplace(args) where pair<Key,Value> +is constructible from args, and emplace(args) where Key is +constructible form the first arg and Value is constructible from the +rest. +
++Alternatively, the status quo is to use piecewise_construct_t if you want to +construct an object. +
+ +[ +2010 Batavia: +]
+ + ++N3178 was looked at in session and moved to NAD. +
+ + +Proposed resolution:
+ + + + + +
+2007. Incorrect specification of return value for map<>::at()
+Section: 23.6.1.2 [map.access] Status: Tentatively Ready + Submitter: Matt Austern Opened: 2010-11-01 Last modified: 2010-11-13
+View all other issues in [map.access].
+View all issues with Tentatively Ready status.
+Discussion:
++In [map.access]/9, the Returns clause for map<Key, T>::at(x) says +that it returns "a reference to the element whose key is equivalent to x." That can't be right. +The signature for at() says that its return type is T, but the elements +of map<Key, T> have type pair<const K, T>. (I checked [unord.map.elem] +and found that its specification of at() is correct. This is a problem for map only.) +
+ + +Proposed resolution:
++Change the wording in [map.access]/9 so it's identical to what we already say for operator[], +which is unambiguous and correct. +
++Returns: A reference to the+ + + + + +element whose key is equivalentmapped_type +corresponding to x in *this. +
+2008. Conflicting Error Conditions for packaged_task::operator()
+Section: 30.6.10.1 [futures.task.members] Status: New + Submitter: Pete Becker Opened: 2010-06-21 Last modified: 2010-11-07
+View other active issues in [futures.task.members].
+View all other issues in [futures.task.members].
+View all issues with New status.
+Discussion:
++The Throws clause for packaged_task::operator() says that it throws "a +future_error exception object if there is no associated asynchronous +state or the stored task has already been invoked." However, the Error +Conditions clause does not define an error condition when the stored task has +already been invoked, only when the associated state is already ready (i.e. the +invocation has completed). +
+ + +Proposed resolution:
++Change the first bullet item in 30.6.10.1 [futures.task.members] /22: +
+ ++ + + + + +void operator()(ArgTypes... args); +++++20 ... +
++21 ... +
++22 Error conditions: +
++
+- +promise_already_satisfied if
+the associated asynchronous state is +already readyoperator() has already been called. +- +no_state if *this has no associated asynchronous state. +
+
+2009. Reporting out-of-bound values on numeric string conversions
+Section: 21.5 [string.conversions] Status: Review + Submitter: Alisdair Meredith Opened: 2010-07-19 Last modified: 2010-11-13
+View all other issues in [string.conversions].
+View all issues with Review status.
+Discussion:
++The functions (w)stoi and (w)stof +are specified in terms of calling C library APIs for potentially wider +types. The integer and floating-point versions have subtly different +behaviour when reading values that are too large to convert. The +floating point case will throw out_of_bound if the read value +is too large to convert to the wider type used in the implementation, +but behaviour is undefined if the converted value cannot narrow to a +float. The integer case will throw out_of_bounds if the +converted value cannot be represented in the narrower type, but throws +invalid_argument, rather than out_of_bounds, if the +conversion to the wider type fails due to overflow. +
+ ++Suggest that the Throws clause for both specifications should be +consistent, supporting the same set of fail-modes with the matching set +of exceptions. +
+ + + +Proposed resolution:
++21.5p3 [string.conversions] +
+ ++ +int stoi(const string& str, size_t *idx = 0, int base = 10); +long stol(const string& str, size_t *idx = 0, int base = 10); +unsigned long stoul(const string& str, size_t *idx = 0, int base = 10); +long long stoll(const string& str, size_t *idx = 0, int base = 10); +unsigned long long stoull(const string& str, size_t *idx = 0, int base = 10); ++ ++++... +
++3 Throws: invalid_argument if strtol, +strtoul, strtoll, or strtoull reports that no +conversion could be performed. Throws out_of_range if +strtol, strtoul, strtoll or +strtoull sets errno to ERANGE, or if +the converted value is outside the range of representable values for the +return type. +
++21.5p6 [string.conversions] +
+ ++ + + + + + +float stof(const string& str, size_t *idx = 0); +double stod(const string& str, size_t *idx = 0); +long double stold(const string& str, size_t *idx = 0); ++ ++++... +
++6 Throws: invalid_argument if strtod or +strtold reports that no conversion could be performed. Throws +out_of_range if strtod or strtold sets +errno to ERANGE or if the converted value is +outside the range of representable values for the return type. +
+
+2010. is_* traits for binding operations can't be meaningfully specialized
+Section: 20.8.10.1.1 [func.bind.isbind] Status: Open + Submitter: Sean Hunt Opened: 2010-07-19 Last modified: 2010-11-16
+View all other issues in [func.bind.isbind].
+View all issues with Open status.
+Discussion:
++20.8.10.1.1 [func.bind.isbind] says for is_bind_expression: +
+ ++Users may specialize this template to indicate that a type should be +treated as a subexpression in a bind call. ++ ++But it also says: +
+ ++If T is a type returned from bind, +is_bind_expression<T> shall be publicly derived from +integral_constant<bool, true>, otherwise from +integral_constant<bool, false>. ++ ++This means that while the user is free to specialize, any specialization +would have to be false to avoid violating the second +requirement. A similar problem exists for is_placeholder. +
+ + +[ +2010 Batavia (post meeting session) +]
+ ++Alisdair recognises this is clearly a bug introduced by some wording he +wrote, the sole purpose of this metafunction is as a customization point +for users to write their own bind-expression types that participate +in the standard library bind protocol. The consensus was that this +should be fixed in Madrid, moved to Open. +
+ +Proposed resolution:
+ + + + + +
+2011. unexpected output required of strings
+Section: 21.4.8.9 [string.io] Status: Open + Submitter: James Kanze Opened: 2010-07-23 Last modified: 2010-11-16
+View all other issues in [string.io].
+View all issues with Open status.
+Discussion:
++What should the following code output? +
+ ++ +#include <string> +#include <iostream> +#include <iomanip> + +int +main() +{ + std::string test("0X1Y2Z"); + std::cout.fill('*'); + std::cout.setf(std::ios::internal, std::ios::adjustfield); + std::cout << std::setw(8) << test << std::endl; +} ++I would expect "**0X1Y2Z", and this is what the compilers I have access +to (VC++, g++ and Sun CC) do. But according to the standard, it should be +"0X**1Y2Z": +
+ ++21.4.8.9 [string.io]/5: +
+ ++ +template<class charT, class traits, class Allocator> + basic_ostream<charT, traits>& + operator<<(basic_ostream<charT, traits>& os, const basic_string<charT,traits,Allocator>& str); ++Effects: Behaves as a formatted output function (27.7.2.6.1 [ostream.formatted.reqmts]). After constructing a sentry +object, if this object returns true when converted to a value of type +bool, determines padding as described in 22.4.2.2.2 [facet.num.put.virtuals], then inserts the resulting sequence of +characters seq as if by calling os.rdbuf()->sputn(seq, n), where +n is the larger of os.width() and str.size(); then +calls os.width(0). +++22.4.2.2.2 [facet.num.put.virtuals]/5: +
+ +++ ++[...] +
+ ++Stage 3: A local variable is initialized as +
+ ++ +fmtflags adjustfield= (flags & (ios_base::adjustfield)); ++The location of any padding is determined according to Table 88. +
+ ++If str.width() is nonzero and the number of charT's in the +sequence after stage 2 is less than str.width(), then enough fill +characters are added to the sequence at the position indicated for padding to +bring the length of the sequence to str.width(). str.width(0) +is called. +
+ ++
+ +Table 88 — Fill padding ++ + +State +Location ++ + +adjustfield == ios_base::left +pad after ++ + +adjustfield == ios_base::right +pad before ++ + +adjustfield == internal and a sign occurs in the representation +pad after the sign ++ + +adjustfield == internal and representation after stage 1 began with 0x or 0X +pad after x or X ++ +otherwise +pad before ++Although it's not 100% clear what "the sequence after stage 2" should mean here, +when there is no stage 2, the only reasonable assumption is that it is the +contents of the string being output. In the above code, the string being output +is "0X1Y2Z", which starts with "0X", so the padding should be +inserted "after x or X", and not before the string. I believe that this is a +defect in the standard, and not in the three compilers I tried. +
+ + + + +[ +2010 Batavia (post meeting session) +]
+ ++Consensus that all known implementations are consistent, and disagree with the +standard. Preference is to fix the standard before implementations start trying +to conform to the current spec, as the current implementations have the preferred +form. Howard volunteered to drught for Madrid, move to Open. +
+ +Proposed resolution:
+ + + + + +
+2012. Associative maps should insert pair, not tuple
+Section: 23.6 [associative] Status: New + Submitter: Paolo Carlini Opened: 2010-10-29 Last modified: 2010-11-07
+View all other issues in [associative].
+View all issues with New status.
+Discussion:
++I'm seeing something strange in the paragraphs 23.6.1.3 [map.modifiers] and 23.6.2.2 [multimap.modifiers]: +they both talk about tuple<const key_type, mapped_type> but I think they +should be talking about pair<const key_type, mapped_type> because, among +other reasons, a tuple is not convertible to a pair. If I replace tuple +with pair everything makes sense to me. + +The proposed resolution is obvious. +
+ +[ +2010-11-07 Daniel comments +]
+ + ++This is by far not the only necessary fix within both sub-clauses. For details see the 2010-10-29 comment in +2005. +
+ + +Proposed resolution:
+Apply the resolution proposed by the 2010-10-29 comment in 2005. + + + + + +
+2013. Do library implementers have the freedom to add constexpr?
+Section: 17.6.4.6 [constexpr.functions] Status: New + Submitter: Matt Austern Opened: 2010-11-12 Last modified: 2010-11-13
+View all issues with New status.
+Discussion:
+Suppose that a particular function is not tagged as constexpr in the standard, +but that, in some particular implementation, it is possible to write it within +the constexpr constraints. If an implementer tags such a function as constexpr, +is that a violation of the standard or is it a conforming extension?
+ +There are two questions to consider. First, is this allowed under the +as-if rule? Second, if it does not fall under as-if, is there +(and should there be) any special license granted to implementers +to do this anyway, sort of the way we allow elision of copy constructors +even though it is detectable by users?
+ +I believe that this does not fall under "as-if", so implementers +probably don't have that freedom today. I suggest changing the WP +to grant it. Even if we decide otherwise, however, I suggest that +we make it explicit.
+ + + +Proposed resolution:
+In 17.6.4.6 [constexpr.functions], change paragraph 1 to:
+ ++This standard explicitly requires that certain standard library functions +are constexpr [dcl.constexpr]. +Additionally, an implementation may declare any function to be constexpr +if that function's definition satisfies the necessary constraints. +Within any header that provides any non-defining declarations of constexpr +functions or constructors an implementation shall provide corresponding definitions. ++ + + + + + +
+2014. More restrictions on macro names
+Section: 17.6.3.3.1 [macro.names] Status: New + Submitter: Alberto Ganesh Barbati Opened: 2010-11-16 Last modified: 2010-11-17
+View all other issues in [macro.names].
+View all issues with New status.
+Discussion:
+A program is currently forbidden to use keywords as macro names. This restriction should be strengthened to include all identifiers +that could be used by the library as attribute-tokens (for example noreturn, which is used by header <cstdlib>) +and the special identifiers introduced recently for override control (these are not currently used in the library public interface, +but could potentially be used by the implementation or in future revisions of the library). + + + +Proposed resolution:
+Modify 17.6.3.3.1 [macro.names] paragraph 2 as follows:
+ ++A translation unit shall not #define or #undef names lexically identical to keywords, to the identifiers +listed in Table X [Identifiers with special meaning] or to the attribute-tokens described in clause 7.6 [dcl.attr]. ++ + + + + + +
+2015. Incorrect pre-conditions for some type traits
+Section: 20.7.4 [meta.unary] Status: New + Submitter: Nikolay Ivchenkov Opened: 2010-11-08 Last modified: 2010-11-17
+View all other issues in [meta.unary].
+View all issues with New status.
+Discussion:
+According to N3126 ‑ 3.9/9, + +"Scalar types, trivial class types (Clause 9), arrays of such types +and cv‑qualified versions of these types (3.9.3) are collectively +called trivial types."
+ +Thus, an array (possibly of unknown bound) can be trivial type, non‑trivial type, +or an array type whose triviality cannot be determined because its element type is incomplete.
+ +According to N3126 ‑ Table 45, preconditions for std::is_trivial are +defined as follows:
+ +"T shall be a complete type, (possibly cv-qualified) void, +or an array of unknown bound"
+ +It seems that "an array of unknown bound" should be changed to "an +array of unknown bound of a complete element type". Preconditions for +some other templates (e.g., std::is_trivially_copyable, +std::is_standard_layout, std::is_pod, and std::is_literal_type) should +be changed similarly.
+ +On the other hand, some preconditions look too restrictive. For +example, std::is_empty and std::is_polymorphic might accept any +incomplete non-class type.
+ + +Proposed resolution:
+ + + + + +
+2016. Allocators must be no-throw swappable
+Section: 20.2.5 [allocator.requirements] Status: New + Submitter: Daniel Krügler Opened: 2010-11-17 Last modified: 2010-11-23
+View all other issues in [allocator.requirements].
+View all issues with New status.
+Discussion:
+During the Batavia meeting it turned out that there is a definition +hole for types satisfying the Allocators requirements: The problem +became obvious when it was discussed whether all swap functions +of Containers with internal data handles can be safely tagged +with noexcept or not. While it is correct that the implicit +swap function of an allocator is required to be a no-throw +operation (because move/copy-constructors and assignment operators are +required to be no-throw functions), there are no such requirements +for specialized swap overloads for a particular allocator. + +But this requirement is essential because the Containers are +required to support swappable Allocators, when the value +allocator_traits<>::propagate_on_container_swap evaluates +to true. + + +Proposed resolution:
+ + + + + +
+2017. std::reference_wrapper makes incorrect usage of std::result_of
+Section: 20.8.4 [refwrap] Status: New + Submitter: Nikolay Ivchenkov Opened: 2010-11-15 Last modified: 2010-11-23
+View all other issues in [refwrap].
+View all issues with New status.
+Discussion:
+std::reference_wrapper's function call operator uses wrong +type encoding for rvalue-arguments. An rvalue-argument of type T must +be encoded as T&&, not as just T. + ++ +Lets consider the function template f1 (which is similar to +std::reference_wrapper's function call operator). In the invocation +(1) F is deduced as 'Functor' and Types is deduced as type sequence +which consists of one type 'std::string const'. After the substitution +we have the following equivalent: + +#include <functional> +#include <iostream> +#include <string> +#include <type_traits> +#include <utility> + +template <class F, class... Types> + typename std::result_of<F (Types...)>::type + f1(F f, Types&&... params) +{ + return f(std::forward<Types...>(params...)); +} + +template <class F, class... Types> + typename std::result_of<F (Types&&...) + f2(F f, Types&&... params) +{ + return f(std::forward<Types...>(params...)); +} + +struct Functor +{ + template <class T> + T&& operator()(T&& t) const + { + return static_cast<T&&>(t); + } +}; + +int main() +{ + typedef std::string const Str; + std::cout << f1(Functor(), Str("1")) << std::endl; // (1) + std::cout << f2(Functor(), Str("2")) << std::endl; // (2) +} ++ +The top-level cv-qualifier in the parameter type of 'F (std::string const)' is removed, so we have + +template <> + std::result_of<F (std::string const)>::type + f1<Functor, std::string const>(Functor f, std::string const && params) +{ + return f(std::forward<const std::string>(params)); +} ++ +Let r be an rvalue of type 'std::string' and cr be an rvalue of type +'std::string const'. The expression Str("1") is cr. The corresponding +return type for the invocation + +template <> + std::result_of<F (std::string)>::type + f1<Functor, std::string const>(Functor f, std::string const && params) +{ + return f(std::forward<const std::string>(params)); +} ++ +is 'std::string &&'. The corresponding return type for the invocation + + +Functor().operator()(r) ++ +is 'std::string const &&'. +Functor().operator()(cr) ++std::result_of<Functor (std::string)>::type is the same type as the +corresponding return type for the invocation Functor().operator()(r), +i.e. it is 'std::string &&'. As a consequence, we have wrong reference +binding in the return statement in f1. +
+Now lets consider the invocation (2) of the function template f2. When +the template arguments are substituted we have the following equivalent: + +
+ +std::result_of<F (std::string const &&)>::type is the same type as +'std::string const &&'. This is correct result. +template <> + std::result_of<F (std::string const &&)>::type + f2<Functor, std::string const>(Functor f, std::string const && params) +{ + return f(std::forward<const std::string>(params)); +} +Proposed resolution:
+ + + + + +
+2018. regex_traits::isctype Returns clause is wrong
+Section: 28.7 [re.traits] Status: New + Submitter: Jonathan Wakely Opened: 2010-11-16 Last modified: 2010-11-23
+View all other issues in [re.traits].
+View all issues with New status.
+Discussion:
+28.7 [re.traits] p12 says:
+++ +returns true if f bitwise or’ed with the result of calling +lookup_classname with an iterator pair that designates the character +sequence "w" is not equal to 0 and c == ’_’
+If the bitmask value corresponding to "w" has a non-zero value (which +it must do) then the bitwise or with any value is also non-zero, and +so isctype('_', f) returns true for any f. Obviously this is wrong, +since '_' is not in every ctype category.
+ +There's a similar problem with the following phrases discussing the +"blank" char class. +
+ + +Proposed resolution:
+Replace the Returns clause with a description in terms of ctype +categories, rather than pseudocode in terms of bitwise operations. +(full replacement wording to follow) + +
+ + + + + +
+2019. isblank not supported by std::locale
+Section: 22.3.3.1 [classification] Status: New + Submitter: Jonathan Wakely Opened: 2010-11-16 Last modified: 2010-11-23
+View all issues with New status.
+Discussion:
+C99 added isblank and iswblank to <locale.h> but <locale> does not +provide any equivalent.
+ + +Proposed resolution:
+Add to 22.3.3.1 [classification] synopsis:
+++ +template <class charT> bool isgraph (charT c, const locale& loc); +template <class charT> bool isblank (charT c, const locale& loc); ++Add to 22.4.1 [category.ctype] synopsis:
+ +++ + + diff --git a/libstdc++-v3/doc/html/ext/lwg-closed.html b/libstdc++-v3/doc/html/ext/lwg-closed.html index 7839575d728..c0848eb90e2 100644 --- a/libstdc++-v3/doc/html/ext/lwg-closed.html +++ b/libstdc++-v3/doc/html/ext/lwg-closed.html @@ -1,43 +1,43 @@ - - - - - + + +static const mask xdigit = 1 << 8; +static const mask blank = 1 << 9; +static const mask alnum = alpha | digit; +static const mask graph = alnum | punct; ++C++ Standard Library Closed Issues List - + +-
- Doc. no. -N3013=09-0203 +Doc. no. +D3183=10-0173 - Date: -2009-11-08 +Date: +2010-11-29 - Project: -Programming Language C++ +Project: +Programming Language C++ - Reply to: -Howard Hinnant <howard.hinnant@gmail.com> +Reply to: +Alisdair Meredith <lwgchair@gmail.com> C++ Standard Library Closed Issues List (Revision R68)
+C++ Standard Library Closed Issues List (Revision D73)
+Revised 2010-11-29 at 10:11:56 UTC
Reference ISO/IEC IS 14882:2003(E)
Also see:
@@ -59,6 +59,168 @@ del {background-color:#FFA0A0}Revision History
+
@@ -121,11 +283,11 @@ del {background-color:#FFA0A0}- D73: Batavia meeting preview
++
+- Summary:
++
- 80 open issues, down by 126.
+- 1459 closed issues, up by 145.
+- 1539 issues total, up by 19.
+- Details:
++
- Added the following 11 New issues: 1521, 1523, 2008, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019.
+- Added the following 5 Open issues: 2001, 2003, 2005, 2010, 2011.
+- Added the following Resolved issue: 2002.
+- Added the following Review issue: 2009.
+- Added the following Tentatively NAD issue: 2006.
+- Added the following 3 Tentatively Ready issues: 2000, 2004, 2007.
+- Added the following WP issue: 1522.
+- Changed the following 3 issues from New to Deferred: 1213, 1214, 1330.
+- Changed the following issue from Open to Deferred: 1450.
+- Changed the following 14 issues from Open to Dup: 1350, 1351, 1352, 1375, 1411, 1443, 1451, 1454, 1458, 1463, 1470, 1475, 1476, 1477.
+- Changed the following issue from New to NAD: 1331.
+- Changed the following 8 issues from Open to NAD: 579, 1359, 1361, 1373, 1376, 1398, 1446, 1473.
+- Changed the following 2 issues from Tentatively NAD to NAD: 1190, 1200.
+- Changed the following issue from WP to NAD: 822.
+- Changed the following 11 issues from Open to NAD Editorial: 1395, 1442, 1471, 1472, 1489, 1495, 1496, 1509, 1510, 1511, 1512.
+- Changed the following issue from Review to NAD Editorial: 1281.
+- Changed the following issue from New to NAD Future: 1289.
+- Changed the following 6 issues from Open to NAD Future: 1406, 1422, 1484, 1488, 1493, 1499.
+- Changed the following 2 issues from Tentatively NAD Future to NAD Future: 1173, 1188.
+- Changed the following 2 issues from New to Open: 1252, 1297.
+- Changed the following 3 issues from New to Ready: 1279, 1318, 1332.
+- Changed the following 6 issues from Open to Ready: 1385, 1401, 1408, 1418, 1420, 1438.
+- Changed the following 42 issues from NAD Editorial to Resolved: 353, 431, 482, 525, 594, 625, 635, 658, 697, 719, 742, 786, 815, 816, 823, 827, 834, 884, 932, 947, 950, 953, 983, 1054, 1055, 1075, 1100, 1116, 1117, 1122, 1135, 1151, 1174, 1258, 1260, 1283, 1293, 1307, 1321, 1394, 1405, 1407.
+- Changed the following 5 issues from New to Resolved: 1290, 1322, 1324, 1326, 1328.
+- Changed the following 46 issues from Open to Resolved: 801, 1268, 1327, 1344, 1346, 1347, 1355, 1356, 1357, 1365, 1366, 1377, 1378, 1379, 1380, 1382, 1383, 1389, 1390, 1391, 1392, 1393, 1397, 1409, 1410, 1412, 1445, 1447, 1453, 1455, 1462, 1464, 1465, 1466, 1467, 1468, 1469, 1481, 1482, 1490, 1491, 1492, 1498, 1501, 1508, 1513.
+- Changed the following issue from Open to Review: 1480.
+- Changed the following 2 issues from Open to Tentatively NAD: 1371, 1413.
+- Changed the following issue from New to Tentatively NAD Future: 1320.
+- Changed the following 3 issues from New to Tentatively Ready: 1215, 1253, 1310.
+- Changed the following issue from Open to Tentatively Ready: 1497.
+- Changed the following 24 issues from NAD Editorial to WP: 1360, 1363, 1367, 1372, 1381, 1384, 1386, 1387, 1388, 1399, 1400, 1402, 1403, 1416, 1417, 1423, 1424, 1425, 1426, 1427, 1429, 1430, 1431, 1441.
+- Changed the following issue from New to WP: 1294.
+- Changed the following 10 issues from Open to WP: 1354, 1362, 1368, 1370, 1428, 1435, 1436, 1437, 1439, 1440.
+- Changed the following 2 issues from Ready to WP: 868, 951.
+- Changed the following 33 issues from Tentatively Ready to WP: 956, 1118, 1171, 1181, 1183, 1191, 1198, 1207, 1234, 1240, 1249, 1292, 1295, 1316, 1319, 1323, 1325, 1333, 1334, 1335, 1337, 1338, 1339, 1340, 1404, 1414, 1432, 1449, 1516, 1517, 1518, 1519, 1520.
+- R72: +2010-10-18 pre-Batavia mailing. +
++
+- Summary:
++
- 206 open issues, up by 141.
+- 1314 closed issues, up by 36.
+- 1520 issues total, up by 177.
+- Details:
++
- Added the following Dup issues: 1433, 1444.
+- Added the following NAD Editorial issues: 1360, 1363, 1367, 1372, 1381, 1384, 1386, 1387, 1388, 1394, 1399, 1400, 1402, 1403, 1405, 1407, 1415, 1416, 1417, 1419, 1423, 1424, 1425, 1426, 1427, 1429, 1430, 1431, 1434, 1441, 1483, 1500, 1506.
+- Added the following Open issues: 1344, 1345, 1346, 1347, 1348, 1349, 1350, 1351, 1352, 1353, 1354, 1355, 1356, 1357, 1358, 1359, 1361, 1362, 1364, 1365, 1366, 1368, 1369, 1370, 1371, 1373, 1374, 1375, 1376, 1377, 1378, 1379, 1380, 1382, 1383, 1385, 1389, 1390, 1391, 1392, 1393, 1395, 1396, 1397, 1398, 1401, 1406, 1408, 1409, 1410, 1411, 1412, 1413, 1418, 1420, 1421, 1422, 1428, 1435, 1436, 1437, 1438, 1439, 1440, 1442, 1443, 1445, 1446, 1447, 1448, 1450, 1451, 1452, 1453, 1454, 1455, 1456, 1457, 1458, 1459, 1460, 1461, 1462, 1463, 1464, 1465, 1466, 1467, 1468, 1469, 1470, 1471, 1472, 1473, 1474, 1475, 1476, 1477, 1478, 1479, 1480, 1481, 1482, 1484, 1485, 1486, 1487, 1488, 1489, 1490, 1491, 1492, 1493, 1494, 1495, 1496, 1497, 1498, 1499, 1501, 1502, 1503, 1504, 1505, 1507, 1508, 1509, 1510, 1511, 1512, 1513, 1514, 1515.
+- Added the following Tentatively Ready issues: 1404, 1414, 1432, 1449, 1516, 1517, 1518, 1519, 1520.
+- Changed the following issues from New to NAD Editorial: 1260.
+- Changed the following issues from New to Tentatively Ready: 1181, 1240, 1249, 1292, 1295, 1316, 1319, 1323, 1325, 1333, 1334, 1335, 1337, 1338, 1339, 1340.
+- Changed the following issues from Open to Tentatively Ready: 956, 1118, 1183, 1234.
+- R71: +2010-08-25 post-Rapperswil mailing. +
++
+- Summary:
++
- 65 open issues, up by 2.
+- 1278 closed issues, up by 7.
+- 1343 issues total, up by 9.
+- Details:
++
- Added the following New issues: 1335, 2008, 1337, 1338, 1339, 1340, 2009, 2010, 2011.
+- Changed the following issues from Open to NAD: 996, 1119.
+- Changed the following issues from Open to NAD Concepts: 1076.
+- Changed the following issues from Open to NAD Editorial: 953.
+- Changed the following issues from New to Open: 1169, 1175.
+- Changed the following issues from Open to Ready: 951.
+- Changed the following issues from Review to Ready: 868.
+- Changed the following issues from New to Tentatively NAD: 1190, 1200.
+- Changed the following issues from New to Tentatively NAD Future: 1188.
+- Changed the following issues from Open to Tentatively NAD Future: 1173.
+- Changed the following issues from New to Tentatively Ready: 1198.
+- Changed the following issues from Open to Tentatively Ready: 1171, 1191, 1207.
+- Changed the following issues from Ready to WP: 1187, 1206, 1278.
+- R70: +2010-03-26 post-Pittsburgh mailing. +
++
+- Summary:
++
- 63 open issues, down by 203.
+- 1271 closed issues, up by 219.
+- 1334 issues total, up by 16.
+- Details:
++
- Added the following NAD Editorial issues: 1321, 1329.
+- Added the following New issues: 1319, 1320, 1322, 1323, 1324, 1325, 1326, 1328, 1330, 1331, 1332, 1333, 1334.
+- Added the following Open issues: 1327.
+- Changed the following issues from Tentatively Dup to Dup: 1219.
+- Changed the following issues from New to NAD: 1302, 1308, 1313, 1314.
+- Changed the following issues from Open to NAD: 887, 1008, 1068, 1069, 1153, 1156, 1228.
+- Changed the following issues from Tentatively NAD to NAD: 631, 726, 959, 1056, 1099, 1125, 1176, 1202, 1223, 1224, 1246, 1251, 1259, 1263, 1265, 1296.
+- Changed the following issues from Tentatively NAD Concepts to NAD Concepts: 910, 1186.
+- Changed the following issues from New to NAD Editorial: 1185, 1210, 1212, 1225, 1244, 1266, 1269, 1272, 1275, 1291, 1305, 1307, 1311.
+- Changed the following issues from Open to NAD Editorial: 299, 397, 408, 446, 594, 625, 742, 834, 915, 1093, 1151, 1211, 1248.
+- Changed the following issues from Ready to NAD Editorial: 485, 932, 940, 950, 983, 1100, 1135.
+- Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 815, 816, 889, 1106, 1115, 1233, 1239, 1258, 1283, 1301.
+- Changed the following issues from Tentatively Ready to NAD Editorial: 1090, 1226, 1273, 1274, 1293, 1300, 1304, 1315.
+- Changed the following issues from New to NAD Future: 1154, 1317.
+- Changed the following issues from Ready to NAD Future: 1052.
+- Changed the following issues from Tentatively NAD Future to NAD Future: 1112, 1121, 1201, 1238, 1282.
+- Changed the following issues from New to Open: 1234, 1268.
+- Changed the following issues from Tentatively Ready to Open: 579.
+- Changed the following issues from New to Ready: 1187, 1206, 1278.
+- Changed the following issues from New to Review: 1281.
+- Changed the following issues from Ready to Review: 868.
+- Changed the following issues from New to WP: 1159.
+- Changed the following issues from Open to WP: 427, 430, 774, 819, 835, 861, 885, 896, 900, 911, 1079.
+- Changed the following issues from Ready to WP: 296, 471, 473, 539, 671, 836, 854, 860, 865, 871, 872, 920, 921, 939, 954, 957, 960, 962, 963, 967, 968, 974, 1011, 1030, 1094, 1095, 1097, 1098, 1104, 1123, 1134, 1136, 1144, 1157, 1194, 1204, 1216, 1227, 1237.
+- Changed the following issues from Tentatively Ready to WP: 556, 676, 704, 724, 727, 780, 811, 817, 870, 891, 893, 929, 978, 987, 999, 1033, 1034, 1071, 1089, 1108, 1110, 1113, 1114, 1126, 1130, 1131, 1133, 1137, 1138, 1152, 1158, 1170, 1177, 1180, 1182, 1189, 1192, 1193, 1195, 1197, 1199, 1205, 1208, 1209, 1218, 1220, 1221, 1222, 1231, 1241, 1245, 1247, 1250, 1254, 1255, 1256, 1257, 1261, 1262, 1264, 1267, 1270, 1271, 1276, 1277, 1280, 1284, 1285, 1286, 1287, 1288, 1298, 1299, 1303, 1306, 1309, 1312.
+- R69: +2010-02-12 pre-Pittsburgh mailing. +
+
+- Summary:
++
- 266 open issues, up by 61.
+- 1052 closed issues, down by 3.
+- 1318 issues total, up by 58.
+- Details:
++
- Added the following New issues: 1266, 1268, 1269, 1272, 1275, 1278, 1279, 1281, 1289, 1290, 1291, 1292, 1294, 1295, 1297, 1302, 1305, 1307, 1308, 1310, 1311, 1313, 1314, 1316, 1317, 1318.
+- Added the following Tentatively NAD issues: 1263, 1265, 1296.
+- Added the following Tentatively NAD Editorial issues: 1283, 1301.
+- Added the following Tentatively NAD Future issues: 1282.
+- Added the following Tentatively Ready issues: 1261, 1262, 1264, 1267, 1270, 1271, 1273, 1274, 1276, 1277, 1280, 1284, 1285, 1286, 1287, 1288, 1293, 1298, 1299, 1300, 1303, 1304, 1306, 1309, 1312, 1315.
+- Changed the following issues from NAD to NAD Editorial: 101.
+- Changed the following issues from NAD Future to Open: 1248.
+- Changed the following issues from New to Open: 1207.
+- Changed the following issues from Ready to Open: 1079.
+- Changed the following issues from New to Tentatively Dup: 1219.
+- Changed the following issues from New to Tentatively NAD: 1125, 1176, 1202, 1223, 1224, 1246, 1251, 1259.
+- Changed the following issues from Open to Tentatively NAD: 726, 959.
+- Changed the following issues from Review to Tentatively NAD: 631.
+- Changed the following issues from Open to Tentatively NAD Concepts: 910.
+- Changed the following issues from New to Tentatively NAD Editorial: 1258.
+- Changed the following issues from Open to Tentatively NAD Editorial: 815, 1106.
+- Changed the following issues from Ready to Tentatively NAD Editorial: 816, 889.
+- Changed the following issues from NAD to Tentatively Ready: 579.
+- Changed the following issues from NAD Editorial to Tentatively Ready: 1195.
+- Changed the following issues from New to Tentatively Ready: 1131, 1133, 1137, 1170, 1180, 1182, 1193, 1197, 1199, 1205, 1209, 1218, 1221, 1222, 1245, 1250, 1254, 1255, 1256, 1257.
+- Changed the following issues from Open to Tentatively Ready: 704, 724, 811, 817, 870, 891, 1033, 1034, 1089, 1110.
+- Changed the following issues from Ready to Tentatively Ready: 893, 978, 1177.
+- Changed the following issues from Review to Tentatively Ready: 556, 676, 727, 780, 929, 1130, 1247.
+- Changed the following issues from Pending WP to WP: 970.
+- R68: 2009-11-06 post-Santa Cruz mailing.
@@ -72,42 +234,42 @@ del {background-color:#FFA0A0}
- Added the following NAD issues: 1229, 1236, 1243.
- Added the following NAD Editorial issues: 1232.
- Added the following NAD Future issues: 1235, 1242, 1248.
-- Added the following New issues: 1218, 1219, 1221, 1222, 1223, 1224, 1225, 1234, 1240, 1244, 1245, 1246, 1249, 1250, 1251, 1252, 1253, 1254, 1255, 1256, 1257, 1258, 1259, 1260.
-- Added the following Open issues: 1228.
-- Added the following Ready issues: 1227, 1237.
-- Added the following Review issues: 1247.
-- Added the following Tentatively NAD Editorial issues: 1233, 1239.
-- Added the following Tentatively NAD Future issues: 1238.
-- Added the following Tentatively Ready issues: 1220, 1226, 1231, 1241.
+- Added the following New issues: 1218, 1219, 1221, 1222, 1223, 1224, 1225, 1234, 1240, 1244, 1245, 1246, 1249, 1250, 1251, 1252, 1253, 1254, 1255, 1256, 1257, 1258, 1259, 1260.
+- Added the following Open issues: 1228.
+- Added the following Ready issues: 1227, 1237.
+- Added the following Review issues: 1247.
+- Added the following Tentatively NAD Editorial issues: 1233, 1239.
+- Added the following Tentatively NAD Future issues: 1238.
+- Added the following Tentatively Ready issues: 1220, 1226, 1231, 1241.
- Changed the following issues from New to NAD: 1132, 1148.
- Changed the following issues from Open to NAD: 96, 458, 463, 916, 917, 919, 955, 977, 1009, 1020, 1035, 1042, 1051, 1064.
- Changed the following issues from Review to NAD: 668, 930, 1091, 1102.
- Changed the following issues from Tentatively NAD to NAD: 588, 617, 971.
- Changed the following issues from Tentatively NAD Future to NAD: 1062.
- Changed the following issues from NAD Concepts to NAD Editorial: 1143.
-- Changed the following issues from New to NAD Editorial: 1116, 1117, 1122, 1129, 1145, 1146, 1147, 1155, 1166, 1172, 1174, 1179, 1195, 1196.
-- Changed the following issues from Open to NAD Editorial: 431, 580, 635, 719, 823, 827, 879, 880, 908, 923, 924, 926, 944, 947, 958, 1046, 1048, 1054, 1055, 1075, 1088, 1160, 1161, 1162, 1163, 1165.
+- Changed the following issues from New to NAD Editorial: 1116, 1117, 1122, 1129, 1145, 1146, 1147, 1155, 1166, 1172, 1174, 1179, 1195, 1196.
+- Changed the following issues from Open to NAD Editorial: 431, 580, 635, 719, 823, 827, 879, 880, 908, 923, 924, 926, 944, 947, 958, 1046, 1048, 1054, 1055, 1075, 1088, 1160, 1161, 1162, 1163, 1165.
- Changed the following issues from Review to NAD Editorial: 828, 897, 976, 1043, 1047, 1049, 1050.
- Changed the following issues from New to NAD Future: 1120, 1150, 1184, 1203, 1217.
- Changed the following issues from Open to NAD Future: 484, 532, 851, 933, 935, 936, 961, 1041, 1053.
- Changed the following issues from Tentatively NAD Future to NAD Future: 1031.
-- Changed the following issues from New to Open: 1118, 1119, 1151, 1153, 1156, 1171, 1173, 1183, 1191, 1211.
-- Changed the following issues from Ready to Open: 430, 834.
-- Changed the following issues from Review to Open: 397, 408, 835.
-- Changed the following issues from Tentatively NAD to Open: 625.
-- Changed the following issues from New to Ready: 1123, 1134, 1135, 1136, 1144, 1177, 1194, 1204, 1216.
-- Changed the following issues from Open to Ready: 296, 471, 485, 539, 816, 860, 865, 872, 920, 932, 939, 940, 960, 963, 974, 978, 1011, 1030, 1079, 1098.
-- Changed the following issues from Review to Ready: 473, 671, 836, 854, 868, 871, 889, 893, 921, 950, 954, 957, 962, 967, 968, 983, 1052, 1094, 1095, 1097, 1100, 1104, 1157.
-- Changed the following issues from New to Review: 1130.
-- Changed the following issues from Open to Review: 556, 631, 676, 727, 929.
-- Changed the following issues from Open to Tentatively NAD: 1056, 1099.
-- Changed the following issues from New to Tentatively NAD Concepts: 1186.
-- Changed the following issues from New to Tentatively NAD Editorial: 1115.
-- Changed the following issues from New to Tentatively NAD Future: 1121, 1201.
-- Changed the following issues from Open to Tentatively NAD Future: 1112.
-- Changed the following issues from New to Tentatively Ready: 1126, 1138, 1152, 1158, 1189, 1192, 1208.
-- Changed the following issues from Open to Tentatively Ready: 987, 999, 1071, 1090, 1108, 1113, 1114.
-- Changed the following issues from Ready to WP: 149, 419, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 822, 838, 847, 857, 859, 876, 881, 883, 886, 934, 1004, 1178.
+- Changed the following issues from New to Open: 1118, 1119, 1151, 1153, 1156, 1171, 1173, 1183, 1191, 1211.
+- Changed the following issues from Ready to Open: 430, 834.
+- Changed the following issues from Review to Open: 397, 408, 835.
+- Changed the following issues from Tentatively NAD to Open: 625.
+- Changed the following issues from New to Ready: 1123, 1134, 1135, 1136, 1144, 1177, 1194, 1204, 1216.
+- Changed the following issues from Open to Ready: 296, 471, 485, 539, 816, 860, 865, 872, 920, 932, 939, 940, 960, 963, 974, 978, 1011, 1030, 1079, 1098.
+- Changed the following issues from Review to Ready: 473, 671, 836, 854, 868, 871, 889, 893, 921, 950, 954, 957, 962, 967, 968, 983, 1052, 1094, 1095, 1097, 1100, 1104, 1157.
+- Changed the following issues from New to Review: 1130.
+- Changed the following issues from Open to Review: 556, 631, 676, 727, 929.
+- Changed the following issues from Open to Tentatively NAD: 1056, 1099.
+- Changed the following issues from New to Tentatively NAD Concepts: 1186.
+- Changed the following issues from New to Tentatively NAD Editorial: 1115.
+- Changed the following issues from New to Tentatively NAD Future: 1121, 1201.
+- Changed the following issues from Open to Tentatively NAD Future: 1112.
+- Changed the following issues from New to Tentatively Ready: 1126, 1138, 1152, 1158, 1189, 1192, 1208.
+- Changed the following issues from Open to Tentatively Ready: 987, 999, 1071, 1090, 1108, 1113, 1114.
+- Changed the following issues from Ready to WP: 149, 419, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 822, 838, 847, 857, 859, 876, 881, 883, 886, 934, 1004, 1178.
- Changed the following issues from Tentatively Ready to WP: 1012, 1019.
- 1217 issues total, up by 31.
Section: D.10.1.3 [auto.ptr.conv] Status: NAD - Submitter: Nathan Myers Opened: 1997-12-04 Last modified: 2006-12-29
+Section: D.12.1.3 [auto.ptr.conv] Status: NAD + Submitter: Nathan Myers Opened: 1997-12-04 Last modified: 2010-10-29
View all issues with NAD status.
Discussion:
Paragraph 1 in "Effects", says "Calls @@ -952,7 +1114,7 @@ exists.)
Proposed resolution:
-Change 20.6.4.3 [meta.unary.prop] paragraph 1 Effects from +
Change 20.7.4.3 [meta.unary.prop] paragraph 1 Effects from "Calls p->release()" to "Calls p.release()".
@@ -967,7 +1129,7 @@ exists.)Section: 21.4 [basic.string] Status: NAD - Submitter: Beman Dawes Opened: 1997-11-16 Last modified: 2006-12-27
+ Submitter: Beman Dawes Opened: 1997-11-16 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with NAD status.
Discussion:
@@ -991,7 +1153,7 @@ from implementation defined.Section: 27.5.3 [fpos] Status: NAD - Submitter: Matt Austern Opened: 1997-12-15 Last modified: 2006-12-27
+ Submitter: Matt Austern Opened: 1997-12-15 Last modified: 2010-10-29View all other issues in [fpos].
View all issues with NAD status.
Discussion:
@@ -1017,7 +1179,7 @@ and that the above summary is what the Standard in effect says.Section: 22.4.1.5 [locale.codecvt.byname] Status: Dup - Submitter: Matt Austern Opened: 1998-01-14 Last modified: 2006-12-30
+ Submitter: Matt Austern Opened: 1998-01-14 Last modified: 2010-10-29View all other issues in [locale.codecvt.byname].
View all issues with Dup status.
Duplicate of: 19
@@ -1040,8 +1202,8 @@ intended here.Section: 20.2.2 [allocator.requirements] Status: NAD - Submitter: Angelika Langer Opened: 1998-02-23 Last modified: 2006-12-30
+Section: 20.2.5 [allocator.requirements] Status: NAD + Submitter: Angelika Langer Opened: 1998-02-23 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with NAD status.
Discussion:
@@ -1066,7 +1228,7 @@ clear. See 23.2 [container.requirements], paragraph 8.Section: 22.4.1.5 [locale.codecvt.byname] Status: Dup - Submitter: Brendan Kehoe Opened: 1998-06-01 Last modified: 2006-12-30
+ Submitter: Brendan Kehoe Opened: 1998-06-01 Last modified: 2010-10-29View all other issues in [locale.codecvt.byname].
View all issues with Dup status.
Duplicate of: 33
@@ -1083,14 +1245,12 @@ clear. See 23.2 [container.requirements], paragraph 8.Section: 27.8.3 [ostringstream] Status: NAD - Submitter: Matthias Mueller Opened: 1998-05-27 Last modified: 2006-12-27
+ Submitter: Matthias Mueller Opened: 1998-05-27 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
In a comp.lang.c++.moderated Matthias Mueller wrote:
-"We are not sure how to interpret the CD2 (see 27.3 -[iostream.forward], 27.8.3.1 [ostringstream.cons], 27.8.1.1 -[stringbuf.cons]) +
"We are not sure how to interpret the CD2 (see 27.3 [iostream.forward], 27.8.3.1 [ostringstream.cons], 27.8.1.1 [stringbuf.cons]) with respect to the question as to what the correct initial positions of the write and read pointers of a stringstream should be."
@@ -1118,7 +1278,7 @@ behavior is known to be different from strstreams.Section: 27.7.1.2.3 [istream::extractors] Status: NAD - Submitter: Matt Austern Opened: 1998-07-01 Last modified: 2006-12-27
+ Submitter: Matt Austern Opened: 1998-07-01 Last modified: 2010-10-29View all other issues in [istream::extractors].
View all issues with NAD status.
Discussion:
@@ -1142,8 +1302,8 @@ this is the intent of the LWG.Section: D.8.1.3 [depr.strstreambuf.virtuals] Status: NAD - Submitter: Matt Austern Opened: 1998-08-18 Last modified: 2006-12-27
+Section: D.9.1.3 [depr.strstreambuf.virtuals] Status: NAD + Submitter: Matt Austern Opened: 1998-08-18 Last modified: 2010-10-29
View all other issues in [depr.strstreambuf.virtuals].
View all issues with NAD status.
Discussion:
@@ -1169,7 +1329,7 @@ to invest effort in this deprecated feature.Section: 21.4.8.9 [string.io] Status: Dup - Submitter: Steve Clamage Opened: 1998-07-09 Last modified: 2006-12-30
+ Submitter: Steve Clamage Opened: 1998-07-09 Last modified: 2010-10-29View all other issues in [string.io].
View all issues with Dup status.
Duplicate of: 25
@@ -1208,7 +1368,7 @@ parameters whatsoever.Section: 22.4.1.4 [locale.codecvt] Status: Dup - Submitter: Nathan Myers Opened: 1998-08-24 Last modified: 2006-12-30
+ Submitter: Nathan Myers Opened: 1998-08-24 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with Dup status.
Duplicate of: 24
@@ -1228,7 +1388,7 @@ contexts above.Section: 27.9.1 [fstreams] Status: NAD - Submitter: Matt Austern Opened: 1998-08-27 Last modified: 2006-12-27
+ Submitter: Matt Austern Opened: 1998-08-27 Last modified: 2010-10-29View all other issues in [fstreams].
View all issues with NAD status.
Discussion:
@@ -1248,7 +1408,7 @@ meaningless.Section: 26.6.2.3 [valarray.access] Status: Dup - Submitter: Levente Farkas Opened: 1998-09-09 Last modified: 2007-10-11
+ Submitter: Levente Farkas Opened: 1998-09-09 Last modified: 2010-10-29View all other issues in [valarray.access].
View all issues with Dup status.
Duplicate of: 389
@@ -1287,7 +1447,7 @@ otherwise possible.Section: 26.6.5 [template.slice.array], 26.6.7 [template.gslice.array], 26.6.8 [template.mask.array], 26.6.9 [template.indirect.array] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-29
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [template.slice.array].
View all issues with NAD status.
Discussion:
@@ -1314,7 +1474,7 @@ otherwise possible.Section: 23.2.4 [associative.reqmts] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2007-01-15
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with NAD status.
@@ -1342,7 +1502,7 @@ issue.Section: 21.4.5 [string.access] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-27
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
If I try
@@ -1374,7 +1534,7 @@ defect in the Standard as such .Section: 21 [strings] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-27
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [strings].
View all issues with NAD status.
Discussion:
@@ -1393,7 +1553,7 @@ requires them to be the same.Section: 21.4.6.8 [string::swap] Status: Dup - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-30
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [string::swap].
View all issues with Dup status.
Duplicate of: 5
@@ -1418,7 +1578,7 @@ exception)Section: 21.4.6.4 [string::insert], 21.4.6.2 [string::append] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-27
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [string::insert].
View all issues with NAD status.
Discussion:
@@ -1443,7 +1603,7 @@ serious to constitute a defect.Section: 21.4.6.4 [string::insert], 21.4.6.6 [string::replace] Status: Dup - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-30
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [string::insert].
View all issues with Dup status.
Duplicate of: 83
@@ -1465,7 +1625,7 @@ of issue 93. Incomplete Valarray Subset DefinitionsSection: 26.6 [numarray] Status: NAD - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2006-12-29
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [numarray].
View all issues with NAD status.
Discussion:
@@ -1502,7 +1662,7 @@ creates a temporary objects, which could be avoided without the cast.Section: 17.6.4 [conforming] Status: NAD - Submitter: Matt Austern Opened: 1998-01-22 Last modified: 2006-12-27
+ Submitter: Matt Austern Opened: 1998-01-22 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
Is it a permitted extension for library implementors to add template parameters to @@ -1546,7 +1706,7 @@ may be provided by a non-Standard implementation class:
Proposed resolution:
-Add a new subclause [presumably 17.4.4.9] following 17.6.4.11 [res.on.exception.handling]:
+Add a new subclause [presumably 17.4.4.9] following 17.6.4.12 [res.on.exception.handling]:
17.4.4.9 Template Parameters
A specialization of a @@ -1591,7 +1751,7 @@ of standard library class templates.
95. Members added by the implementation
Section: 17.6.4.5 [member.functions] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
In 17.3.4.4/2 vs 17.3.4.7/0 there is a hole; an implementation could add virtual @@ -1629,8 +1789,8 @@ illegal. See 17.6.4.5 [member.functions] paragraph 2.
96. Vector<bool> is not a container
-Section: 23.3.6 [vector] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2009-10-26
+Section: 23.4.1 [vector] Status: NAD + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29
View all other issues in [vector].
View all issues with NAD status.
Discussion:
@@ -1820,8 +1980,7 @@ tractable. Therefore we are closing.
97. Insert inconsistent definition
Section: 23 [containers] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27
-View other active issues in [containers].
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View all other issues in [containers].
View all issues with NAD status.
Discussion:
@@ -1841,7 +2000,7 @@ the design, for better or for worse.
99. Reverse_iterator comparisons completely wrong
Section: 24.5.1.3.13 [reverse.iter.op==] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
The <, >, <=, >= comparison operator are wrong: they @@ -1863,7 +2022,7 @@ exactly what the Standard says.
100. Insert iterators/ostream_iterators overconstrained
Section: 24.5.2 [insert.iterators], 24.6.4 [ostreambuf.iterator] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View all other issues in [insert.iterators].
View all issues with NAD status.
Discussion:
@@ -1884,13 +2043,26 @@ incorrect code to work, rather than the other way around.
101. No way to free storage for vector and deque
-Section: 23.3.6 [vector], 23.3.1 [array] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2007-02-19
+Section: 23.4.1 [vector], 23.3.1 [array] Status: NAD Editorial + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29
View all other issues in [vector].
-View all issues with NAD status.
+View all issues with NAD Editorial status.
Discussion:
Reserve can not free storage, unlike string::reserve
+[ +2010-02-13 Alisdair adds: +]
+ + +++ ++This issue has been revisited and addressed (755, 850). This issues should be reclassified to NAD Editorial to reflect +this action. +
+Rationale:
This is not a defect in the Standard. The LWG has considered this @@ -1911,7 +2083,7 @@ expressed in a single line of code (where v is
102. Bug in insert range in associative containers
Section: 23.2.4 [associative.reqmts] Status: Dup - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-30
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with Dup status.
@@ -1936,7 +2108,7 @@ container is O(1)!
104. Description of basic_string::operator[] is unclear
Section: 21.4.4 [string.capacity] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-27
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View all other issues in [string.capacity].
View all issues with NAD status.
Discussion:
@@ -1959,7 +2131,7 @@ the Standard.
105. fstream ctors argument types desired
Section: 27.9 [file.streams] Status: Dup - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2008-01-05
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View all issues with Dup status.
Duplicate of: 454
Discussion:
@@ -1982,7 +2154,7 @@ interesting extension for the next Standard.
107. Valarray constructor is strange
Section: 26.6.2 [template.valarray] Status: NAD - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2006-12-29
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View all other issues in [template.valarray].
View all issues with NAD status.
Discussion:
@@ -2012,7 +2184,7 @@ perhaps other cases.
111. istreambuf_iterator::equal overspecified, inefficient
Section: 24.6.3.5 [istreambuf.iterator::equal] Status: NAD - Submitter: Nathan Myers Opened: 1998-10-15 Last modified: 2009-07-14
+ Submitter: Nathan Myers Opened: 1998-10-15 Last modified: 2010-10-29View all other issues in [istreambuf.iterator::equal].
View all issues with NAD status.
Discussion:
@@ -2050,7 +2222,7 @@ Post Summit Daniel adds: Recommend NAD. The proposed wording would violate the axioms of concept requirement EqualityComparable axioms as part of concept InputIterator and more specifically it would violate the explicit wording of -24.2.1 [input.iterators]/7: +24.2.3 [input.iterators]/7:@@ -2104,7 +2276,7 @@ would no longer treat it as an empty range.
113. Missing/extra iostream sync semantics
Section: 27.7.1.1 [istream], 27.7.1.3 [istream.unformatted] Status: NAD - Submitter: Steve Clamage Opened: 1998-10-13 Last modified: 2006-12-27
+ Submitter: Steve Clamage Opened: 1998-10-13 Last modified: 2010-10-29View all other issues in [istream].
View all issues with NAD status.
Discussion:
@@ -2142,9 +2314,8 @@ desired functionality.
116. bitset cannot be constructed with a const char*
-Section: 20.3.7 [template.bitset] Status: Dup - Submitter: Judy Ward Opened: 1998-11-06 Last modified: 2008-03-14
-View other active issues in [template.bitset].
+Section: 20.5 [template.bitset] Status: Dup + Submitter: Judy Ward Opened: 1998-11-06 Last modified: 2010-10-29
View all other issues in [template.bitset].
View all issues with Dup status.
Duplicate of: 778
@@ -2188,13 +2359,13 @@ longer work.Proposed resolution:
-Add to 20.3.7 [template.bitset] a bitset constructor declaration
+Add to 20.5 [template.bitset] a bitset constructor declaration
-explicit bitset(const char*);and in Section 20.3.7.1 [bitset.cons] add:
+and in Section 20.5.1 [bitset.cons] add:
explicit bitset(const char* str);@@ -2216,7 +2387,7 @@ extension.
121. Detailed definition for ctype<wchar_t> specialization
Section: 22.3.1.1.1 [locale.category] Status: NAD - Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2006-12-27
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29View all other issues in [locale.category].
View all issues with NAD status.
Discussion:
@@ -2251,7 +2422,7 @@ ctype<wchar_t> specialization.
128. Need open_mode() function for file stream, string streams, file buffers, and string buffers
Section: 27.8 [string.streams], 27.9 [file.streams] Status: NAD - Submitter: Angelika Langer Opened: 1999-02-22 Last modified: 2009-07-14
+ Submitter: Angelika Langer Opened: 1999-02-22 Last modified: 2010-10-29View all other issues in [string.streams].
View all issues with NAD status.
Discussion:
@@ -2326,8 +2497,7 @@ retained for future reference.
131. list::splice throws nothing
Section: 23.3.4.4 [list.ops] Status: NAD - Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2007-02-19
-View other active issues in [list.ops].
+ Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29View all other issues in [list.ops].
View all issues with NAD status.
Discussion:
@@ -2345,7 +2515,7 @@ beyond max_size()?
135. basic_iostream doubly initialized
Section: 27.7.1.5.1 [iostream.cons] Status: NAD - Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2006-12-27
+ Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
-1- Effects Constructs an object of class basic_iostream, assigning @@ -2377,7 +2547,7 @@ standard.
138. Class ctype_byname<char> redundant and misleading
Section: 22.4.1.4 [locale.codecvt] Status: NAD - Submitter: Angelika Langer Opened: 1999-03-18 Last modified: 2009-07-14
+ Submitter: Angelika Langer Opened: 1999-03-18 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with NAD status.
Discussion:
@@ -2432,10 +2602,10 @@ not in the specialization. See issue 140. map<Key, T>::value_type does not satisfy the assignable requirement -Section: 23.4.1 [map] Status: NAD Editorial - Submitter: Mark Mitchell Opened: 1999-04-14 Last modified: 2008-03-14
+Section: 23.6.1 [map] Status: NAD Editorial + Submitter: Mark Mitchell Opened: 1999-04-14 Last modified: 2010-10-29
View all other issues in [map].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
23.2 [container.requirements]
@@ -2448,7 +2618,7 @@ not in the specialization. See issue 143. C .h header wording unclear -Section: D.6 [depr.c.headers] Status: NAD - Submitter: Christophe de Dinechin Opened: 1999-05-04 Last modified: 2006-12-27
+Section: D.7 [depr.c.headers] Status: NAD + Submitter: Christophe de Dinechin Opened: 1999-05-04 Last modified: 2010-10-29
View all issues with NAD status.
Discussion:
[depr.c.headers] paragraph 2 reads:
@@ -2561,7 +2731,7 @@ int main() {Proposed resolution:
-Replace D.6 [depr.c.headers] paragraph 2 with:
+Replace D.7 [depr.c.headers] paragraph 2 with:
@@ -2588,7 +2758,7 @@ write code that depends on Koenig lookup of C library functions.@@ -9085,7 +9717,7 @@ be considered as an active user-support for this transition.
145. adjustfield lacks default value
Section: 27.5.4.1 [basic.ios.cons] Status: NAD - Submitter: Angelika Langer Opened: 1999-05-12 Last modified: 2006-12-27
+ Submitter: Angelika Langer Opened: 1999-05-12 Last modified: 2010-10-29View all other issues in [basic.ios.cons].
View all issues with NAD status.
Discussion:
@@ -2622,7 +2792,7 @@ set. Consider Arabic or Hebrew, for example. See 22.4.2.2.2 [facet.num.put.virtu
157. Meaningless error handling for pword() and iword()
Section: 27.5.2.5 [ios.base.storage] Status: Dup - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2007-01-15
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [ios.base.storage].
View all issues with Dup status.
Duplicate of: 41
@@ -2646,7 +2816,7 @@ character type used...
162. Really "formatted input functions"?
Section: 27.7.1.2.3 [istream::extractors] Status: Dup - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2007-01-15
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [istream::extractors].
View all issues with Dup status.
Duplicate of: 60
@@ -2656,9 +2826,7 @@ defined in the paragraphs 1 to 5 to be "Formatted input function" but since these functions are defined in a section labeled "Formatted input functions" it is unclear to me whether these operators are considered formatted input functions which -have to conform to the "common requirements" from 27.7.1.2.1 -[istream.formatted.reqmts]: If this is the case, all manipulators, not -just +have to conform to the "common requirements" from 27.7.1.2.1 [istream.formatted.reqmts]: If this is the case, all manipulators, not just ws, would skip whitespace unless noskipws is set (... but setting noskipws using the manipulator syntax would also skip whitespace :-) @@ -2676,15 +2844,13 @@ output
163. Return of gcount() after a call to gcount
Section: 27.7.1.3 [istream.unformatted] Status: Dup - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2007-01-15
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with Dup status.
Duplicate of: 60
Discussion:
It is not clear which functions are to be considered unformatted -input functions. As written, it seems that all functions in 27.7.1.3 -[istream.unformatted] are unformatted input functions. However, it does -not +input functions. As written, it seems that all functions in 27.7.1.3 [istream.unformatted] are unformatted input functions. However, it does not really make much sense to construct a sentry object for gcount(), sync(), ... Also it is unclear what happens to the gcount() if eg. gcount(), @@ -2711,7 +2877,7 @@ clarification should be used.
166. Really "formatted output functions"?
Section: 27.7.2.6.3 [ostream.inserters] Status: Dup - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2007-01-15
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all issues with Dup status.
Duplicate of: 60
Discussion:
@@ -2732,7 +2898,7 @@ for output instead of input.
177. Complex operators cannot be explicitly instantiated
Section: 26.4.6 [complex.ops] Status: NAD - Submitter: Judy Ward Opened: 1999-07-02 Last modified: 2006-12-27
+ Submitter: Judy Ward Opened: 1999-07-02 Last modified: 2010-10-29View all other issues in [complex.ops].
View all issues with NAD status.
Discussion:
@@ -2789,7 +2955,7 @@ syntax.
178. Should clog and cerr initially be tied to cout?
Section: 27.4.1 [narrow.stream.objects] Status: NAD - Submitter: Judy Ward Opened: 1999-07-02 Last modified: 2006-12-27
+ Submitter: Judy Ward Opened: 1999-07-02 Last modified: 2010-10-29View all other issues in [narrow.stream.objects].
View all issues with NAD status.
Discussion:
@@ -2822,7 +2988,7 @@ ios_base::init to basic_ios::init().)
188. valarray helpers missing augmented assignment operators
Section: 26.6.2.6 [valarray.cassign] Status: NAD - Submitter: Gabriel Dos Reis Opened: 1999-08-15 Last modified: 2008-03-11
+ Submitter: Gabriel Dos Reis Opened: 1999-08-15 Last modified: 2010-10-29View all other issues in [valarray.cassign].
View all issues with NAD status.
Discussion:
@@ -2860,7 +3026,7 @@ operators.
190. min() and max() functions should be std::binary_functions
Section: 25.4.7 [alg.min.max] Status: NAD - Submitter: Mark Rintoul Opened: 1999-08-26 Last modified: 2009-07-14
+ Submitter: Mark Rintoul Opened: 1999-08-26 Last modified: 2010-10-29View all other issues in [alg.min.max].
View all issues with NAD status.
Discussion:
@@ -2904,7 +3070,7 @@ function objects.
191. Unclear complexity for algorithms such as binary search
Section: 25.4.3 [alg.binary.search] Status: NAD - Submitter: Nico Josuttis Opened: 1999-10-10 Last modified: 2006-12-27
+ Submitter: Nico Josuttis Opened: 1999-10-10 Last modified: 2010-10-29View all other issues in [alg.binary.search].
View all issues with NAD status.
Discussion:
@@ -2933,7 +3099,7 @@ iterators.
192. a.insert(p,t) is inefficient and overconstrained
Section: 23.2.4 [associative.reqmts] Status: NAD - Submitter: Ed Brey Opened: 1999-06-06 Last modified: 2006-12-30
+ Submitter: Ed Brey Opened: 1999-06-06 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with NAD status.
@@ -3021,7 +3187,7 @@ both before p and after p, and don't want to change this behavior.
194. rdbuf() functions poorly specified
Section: 27.5.4 [ios] Status: NAD - Submitter: Steve Clamage Opened: 1999-09-07 Last modified: 2006-12-27
+ Submitter: Steve Clamage Opened: 1999-09-07 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
In classic iostreams, base class ios had an rdbuf function that returned a @@ -3074,7 +3240,7 @@ class rdbuf() always returns the original streambuf, whereas the base
196. Placement new example has alignment problems
Section: 18.6.1.3 [new.delete.placement] Status: Dup - Submitter: Herb Sutter Opened: 1998-12-15 Last modified: 2006-12-30
+ Submitter: Herb Sutter Opened: 1998-12-15 Last modified: 2010-10-29View all other issues in [new.delete.placement].
View all issues with Dup status.
Duplicate of: 114
@@ -3103,8 +3269,8 @@ class rdbuf() always returns the original streambuf, whereas the base
197. max_size() underspecified
-Section: 20.2.2 [allocator.requirements], 23.2 [container.requirements] Status: NAD - Submitter: Andy Sawyer Opened: 1999-10-21 Last modified: 2006-12-30
+Section: 20.2.5 [allocator.requirements], 23.2 [container.requirements] Status: NAD + Submitter: Andy Sawyer Opened: 1999-10-21 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with NAD status.
Discussion:
@@ -3160,7 +3326,7 @@ called.
203. basic_istream::sentry::sentry() is uninstantiable with ctype<user-defined type>
Section: 27.7.1.1.3 [istream::sentry] Status: NAD - Submitter: Matt McClure and Dietmar Kühl Opened: 2000-01-01 Last modified: 2007-01-15
+ Submitter: Matt McClure and Dietmar Kühl Opened: 2000-01-01 Last modified: 2010-10-29View all other issues in [istream::sentry].
View all issues with NAD status.
Discussion:
@@ -3219,8 +3385,7 @@ and is not a defect.
204. distance(first, last) when "last" is before "first"
Section: 24.4.4 [iterator.operations] Status: NAD - Submitter: Rintala Matti Opened: 2000-01-28 Last modified: 2008-09-30
-View other active issues in [iterator.operations].
+ Submitter: Rintala Matti Opened: 2000-01-28 Last modified: 2010-10-29View all other issues in [iterator.operations].
View all issues with NAD status.
Discussion:
@@ -3264,7 +3429,7 @@ the standard.
205. numeric_limits unclear on how to determine floating point types
Section: 18.3.1.2 [numeric.limits.members] Status: NAD - Submitter: Steve Cleary Opened: 2000-01-28 Last modified: 2006-12-27
+ Submitter: Steve Cleary Opened: 2000-01-28 Last modified: 2010-10-29View all other issues in [numeric.limits.members].
View all issues with NAD status.
Discussion:
@@ -3296,7 +3461,7 @@ floating point type.
207. ctype<char> members return clause incomplete
Section: 22.4.1.3.2 [facet.ctype.char.members] Status: Dup - Submitter: Robert Klarer Opened: 1999-11-02 Last modified: 2006-12-30
+ Submitter: Robert Klarer Opened: 1999-11-02 Last modified: 2010-10-29View all other issues in [facet.ctype.char.members].
View all issues with Dup status.
Duplicate of: 153
@@ -3339,7 +3504,7 @@ paragraphs.
213. Math function overloads ambiguous
Section: 26.8 [c.math] Status: NAD - Submitter: Nico Josuttis Opened: 2000-02-26 Last modified: 2006-12-29
+ Submitter: Nico Josuttis Opened: 2000-02-26 Last modified: 2010-10-29View all other issues in [c.math].
View all issues with NAD status.
Discussion:
@@ -3365,7 +3530,7 @@ or write floating point expressions as arguments.
215. Can a map's key_type be const?
Section: 23.2.4 [associative.reqmts] Status: NAD - Submitter: Judy Ward Opened: 2000-02-29 Last modified: 2006-12-27
+ Submitter: Judy Ward Opened: 2000-02-29 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with NAD status.
@@ -3398,7 +3563,7 @@ too.
216. setbase manipulator description flawed
Section: 27.7.3 [std.manip] Status: Dup - Submitter: Hyman Rosen Opened: 2000-02-29 Last modified: 2006-12-30
+ Submitter: Hyman Rosen Opened: 2000-02-29 Last modified: 2010-10-29View all other issues in [std.manip].
View all issues with Dup status.
Duplicate of: 193
@@ -3449,7 +3614,7 @@ occurs additional places in the section, all requiring fixes.]
218. Algorithms do not use binary predicate objects for default comparisons
Section: 25.4 [alg.sorting] Status: NAD - Submitter: Pablo Halpern Opened: 2000-03-06 Last modified: 2006-12-27
+ Submitter: Pablo Halpern Opened: 2000-03-06 Last modified: 2010-10-29View all other issues in [alg.sorting].
View all issues with NAD status.
Discussion:
@@ -3485,7 +3650,7 @@ operator<.
219. find algorithm missing version that takes a binary predicate argument
Section: 25.2.5 [alg.find] Status: NAD - Submitter: Pablo Halpern Opened: 2000-03-06 Last modified: 2009-07-14
+ Submitter: Pablo Halpern Opened: 2000-03-06 Last modified: 2010-10-29View all other issues in [alg.find].
View all issues with NAD status.
Discussion:
@@ -3556,7 +3721,7 @@ bind_2nd".
236. ctype<char>::is() member modifies facet
Section: 22.4.1.3.2 [facet.ctype.char.members] Status: Dup - Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2007-01-15
+ Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2010-10-29View all other issues in [facet.ctype.char.members].
View all issues with Dup status.
Duplicate of: 28
@@ -3590,7 +3755,7 @@ ie. the do_is() method as described in 22.4.1.1.2 [locale.ctype.virtual
244. Must find's third argument be CopyConstructible?
Section: 25.2.5 [alg.find] Status: NAD - Submitter: Andrew Koenig Opened: 2000-05-02 Last modified: 2006-12-27
+ Submitter: Andrew Koenig Opened: 2000-05-02 Last modified: 2010-10-29View all other issues in [alg.find].
View all issues with NAD status.
Discussion:
@@ -3631,7 +3796,7 @@ might reasonably pass an argument that is not Copy Constructible.
245. Which operations on istream_iterator trigger input operations?
Section: 24.6.1 [istream.iterator] Status: NAD - Submitter: Andrew Koenig Opened: 2000-05-02 Last modified: 2006-12-27
+ Submitter: Andrew Koenig Opened: 2000-05-02 Last modified: 2010-10-29View all other issues in [istream.iterator].
View all issues with NAD status.
Discussion:
@@ -3664,7 +3829,7 @@ how many times find may invoke operator++.
246. a.insert(p,t) is incorrectly specified
Section: 23.2.4 [associative.reqmts] Status: Dup - Submitter: Mark Rodgers Opened: 2000-05-19 Last modified: 2007-01-15
+ Submitter: Mark Rodgers Opened: 2000-05-19 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with Dup status.
@@ -3752,8 +3917,8 @@ Change the words "right after" to "immediately before".
249. Return Type of auto_ptr::operator=
-Section: D.10.1 [auto.ptr] Status: NAD - Submitter: Joseph Gottman Opened: 2000-06-30 Last modified: 2006-12-29
+Section: D.12.1 [auto.ptr] Status: NAD + Submitter: Joseph Gottman Opened: 2000-06-30 Last modified: 2010-10-29
View all other issues in [auto.ptr].
View all issues with NAD status.
Discussion:
@@ -3794,10 +3959,10 @@ code.
255. Why do basic_streambuf<>::pbump() and gbump() take an int?
-Section: 27.6.2 [streambuf] Status: NAD Future - Submitter: Martin Sebor Opened: 2000-08-12 Last modified: 2009-07-14
+Section: 27.6.2 [streambuf] Status: NAD Future + Submitter: Martin Sebor Opened: 2000-08-12 Last modified: 2010-10-29
View all other issues in [streambuf].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
The basic_streambuf members gbump() and pbump() are specified to take an @@ -3899,8 +4064,8 @@ signature.
257. STL functional object and iterator inheritance.
-Section: 20.7.3 [base], 24.4.2 [iterator.basic] Status: NAD - Submitter: Robert Dick Opened: 2000-08-17 Last modified: 2006-12-29
+Section: X [base], 24.4.2 [iterator.basic] Status: NAD + Submitter: Robert Dick Opened: 2000-08-17 Last modified: 2010-10-29
View all other issues in [base].
View all issues with NAD status.
Discussion:
@@ -3983,8 +4148,8 @@ want to pass temporaries as traits or tag types in generic code.
267. interaction of strstreambuf::overflow() and seekoff()
-Section: D.8.1.3 [depr.strstreambuf.virtuals] Status: NAD - Submitter: Martin Sebor Opened: 2000-10-05 Last modified: 2007-01-15
+Section: D.9.1.3 [depr.strstreambuf.virtuals] Status: NAD + Submitter: Martin Sebor Opened: 2000-10-05 Last modified: 2010-10-29
View all other issues in [depr.strstreambuf.virtuals].
View all issues with NAD status.
Discussion:
@@ -4047,7 +4212,7 @@ behavior of the program is undefined.Proposed resolution:
-Change the last sentence of D.8.1 [depr.strstreambuf] paragraph 4 from
+Change the last sentence of D.9.1 [depr.strstreambuf] paragraph 4 from
@@ -7579,10 +8232,10 @@ basic_filebuf.Otherwise, seeklow equals gbeg and seekhigh is either pend, if @@ -4088,7 +4253,7 @@ corner cases in a deprecated feature.
269. cstdarg and unnamed parameters
Section: 18.8 [support.exception] Status: NAD - Submitter: J. Stephen Adamczyk Opened: 2000-10-10 Last modified: 2006-12-27
+ Submitter: J. Stephen Adamczyk Opened: 2000-10-10 Last modified: 2010-10-29View all other issues in [support.exception].
View all issues with NAD status.
Discussion:
@@ -4148,8 +4313,8 @@ necessary.
277. Normative encouragement in allocator requirements unclear
-Section: 20.2.2 [allocator.requirements] Status: NAD - Submitter: Matt Austern Opened: 2000-11-07 Last modified: 2006-12-30
+Section: 20.2.5 [allocator.requirements] Status: NAD + Submitter: Matt Austern Opened: 2000-11-07 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with NAD status.
Discussion:
@@ -4183,8 +4348,7 @@ even if it is misunderstood.
279. const and non-const iterators should have equivalent typedefs
Section: 23.2 [container.requirements] Status: NAD - Submitter: Steve Cleary Opened: 2000-11-27 Last modified: 2006-12-27
-View other active issues in [container.requirements].
+ Submitter: Steve Cleary Opened: 2000-11-27 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with NAD status.
Discussion:
@@ -4252,7 +4416,7 @@ have the same value type, but that is a new issue. (Issue 287. conflicting ios_base fmtflagsSection: 27.5.2.2 [fmtflags.state] Status: NAD - Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2006-12-27
+ Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2010-10-29View all other issues in [fmtflags.state].
View all issues with NAD status.
Discussion:
@@ -4303,11 +4467,10 @@ ios_base::dec. adjustfield, basefield, and floatfield are each multi-bit fields. It is possible to set multiple bits within each of those fields. (For example, dec and -oct). These fields are used by locale facets. The LWG +oct). These fields are used by locale facets. The LWG reviewed the way in which each of those three fields is used, and believes that in each case the behavior is well defined for any -possible combination of bits. See for example Table 58, in 22.4.2.2.2 -[facet.num.put.virtuals], noting the requirement in paragraph 6 of that +possible combination of bits. See for example Table 58, in 22.4.2.2.2 [facet.num.put.virtuals], noting the requirement in paragraph 6 of that section.@@ -4322,7 +4485,7 @@ version of setf, to avoid unexpected behavior.
289. <cmath> requirements missing C float and long double versions
Section: 26.8 [c.math] Status: NAD - Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2007-01-15
+ Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2010-10-29View all other issues in [c.math].
View all issues with NAD status.
Discussion:
@@ -4393,7 +4556,7 @@ never referred to by the C++ standard.
290. Requirements to for_each and its function object
Section: 25.2.4 [alg.foreach] Status: NAD - Submitter: Angelika Langer Opened: 2001-01-03 Last modified: 2009-07-14
+ Submitter: Angelika Langer Opened: 2001-01-03 Last modified: 2010-10-29View all other issues in [alg.foreach].
View all issues with NAD status.
Discussion:
@@ -4456,7 +4619,7 @@ of the library.
293. Order of execution in transform algorithm
Section: 25.3.4 [alg.transform] Status: NAD - Submitter: Angelika Langer Opened: 2001-01-04 Last modified: 2007-01-15
+ Submitter: Angelika Langer Opened: 2001-01-04 Last modified: 2010-10-29View all other issues in [alg.transform].
View all issues with NAD status.
Discussion:
@@ -4522,10 +4685,191 @@ wrapping it in an Input Iterator adaptor. +
+299. Incorrect return types for iterator dereference
+Section: 24.2.6 [bidirectional.iterators], 24.2.7 [random.access.iterators] Status: NAD Editorial + Submitter: John Potter Opened: 2001-01-22 Last modified: 2010-10-29
+View all other issues in [bidirectional.iterators].
+View all issues with NAD Editorial status.
+Discussion:
++In section 24.2.6 [bidirectional.iterators], +Table 75 gives the return type of *r-- as convertible to T. This is +not consistent with Table 74 which gives the return type of *r++ as +T&. *r++ = t is valid while *r-- = t is invalid. +
+ ++In section 24.2.7 [random.access.iterators], +Table 76 gives the return type of a[n] as convertible to T. This is +not consistent with the semantics of *(a + n) which returns T& by +Table 74. *(a + n) = t is valid while a[n] = t is invalid. +
+ ++Discussion from the Copenhagen meeting: the first part is +uncontroversial. The second part, operator[] for Random Access +Iterators, requires more thought. There are reasonable arguments on +both sides. Return by value from operator[] enables some potentially +useful iterators, e.g. a random access "iota iterator" (a.k.a +"counting iterator" or "int iterator"). There isn't any obvious way +to do this with return-by-reference, since the reference would be to a +temporary. On the other hand, reverse_iterator takes an +arbitrary Random Access Iterator as template argument, and its +operator[] returns by reference. If we decided that the return type +in Table 76 was correct, we would have to change +reverse_iterator. This change would probably affect user +code. +
+ ++History: the contradiction between reverse_iterator and the +Random Access Iterator requirements has been present from an early +stage. In both the STL proposal adopted by the committee +(N0527==94-0140) and the STL technical report (HPL-95-11 (R.1), by +Stepanov and Lee), the Random Access Iterator requirements say that +operator[]'s return value is "convertible to T". In N0527 +reverse_iterator's operator[] returns by value, but in HPL-95-11 +(R.1), and in the STL implementation that HP released to the public, +reverse_iterator's operator[] returns by reference. In 1995, the +standard was amended to reflect the contents of HPL-95-11 (R.1). The +original intent for operator[] is unclear. +
+ ++In the long term it may be desirable to add more fine-grained +iterator requirements, so that access method and traversal strategy +can be decoupled. (See "Improved Iterator Categories and +Requirements", N1297 = 01-0011, by Jeremy Siek.) Any decisions +about issue 299 should keep this possibility in mind. +
+ +Further discussion: I propose a compromise between John Potter's +resolution, which requires T& as the return type of +a[n], and the current wording, which requires convertible to +T. The compromise is to keep the convertible to T +for the return type of the expression a[n], but to also add +a[n] = t as a valid expression. This compromise "saves" the +common case uses of random access iterators, while at the same time +allowing iterators such as counting iterator and caching file +iterators to remain random access iterators (iterators where the +lifetime of the object returned by operator*() is tied to the +lifetime of the iterator). +
+ ++Note that the compromise resolution necessitates a change to +reverse_iterator. It would need to use a proxy to support +a[n] = t. +
+ ++Note also there is one kind of mutable random access iterator that +will no longer meet the new requirements. Currently, iterators that +return an r-value from operator[] meet the requirements for a +mutable random access iterartor, even though the expression a[n] = +t will only modify a temporary that goes away. With this proposed +resolution, a[n] = t will be required to have the same +operational semantics as *(a + n) = t. +
+ +[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-09-18 Alisdair adds: +]
+ + +++ ++Why can't we write through the reference returned from operator[] on a +random access iterator? +
+ ++Recommended solution: +
+ ++In table Table 104 -- Random access iterator requirements, replace +
+ ++a[n] : convertible to+const T &+T& if X is mutable, otherwise convertible to const T& +[ +2009-10 Santa Cruz: +]
+ + ++Leave Open. Alisdair to spearhead a paper on revivification. ++ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3066. +
+ + +Proposed resolution:
+ ++In section 24.1.4 [lib.bidirectdional.iterators], change the return +type in table 75 from "convertible to T" to +T&. +
+ ++In section 24.1.5 [lib.random.access.iterators], change the +operational semantics for a[n] to " the r-value of +a[n] is equivalent to the r-value of *(a + +n)". Add a new row in the table for the expression a[n] = t +with a return type of convertible to T and operational semantics of +*(a + n) = t. +
+ +[Lillehammer: Real problem, but should be addressed as part of + iterator redesign]
+ + + + +Rationale:
+[ +San Francisco: +]
+ + ++Solved by +N2758. ++ + + + + + +
302. Need error indication from codecvt<>::do_length
Section: 22.4.1.5 [locale.codecvt.byname] Status: NAD - Submitter: Gregory Bumgardner Opened: 2001-01-25 Last modified: 2006-12-27
+ Submitter: Gregory Bumgardner Opened: 2001-01-25 Last modified: 2010-10-29View all other issues in [locale.codecvt.byname].
View all issues with NAD status.
Discussion:
@@ -4596,7 +4940,7 @@ external characters, it stops.
304. Must *a return an lvalue when a is an input iterator?
Section: X [iterator.concepts] Status: NAD - Submitter: Dave Abrahams Opened: 2001-02-05 Last modified: 2008-09-30
+ Submitter: Dave Abrahams Opened: 2001-02-05 Last modified: 2010-10-29View all other issues in [iterator.concepts].
View all issues with NAD status.
Discussion:
@@ -4641,7 +4985,7 @@ buffered somewhere to make a legal input iterator.
309. Does sentry catch exceptions?
Section: 27.7 [iostream.format] Status: NAD - Submitter: Martin Sebor Opened: 2001-03-19 Last modified: 2009-07-14
+ Submitter: Martin Sebor Opened: 2001-03-19 Last modified: 2010-10-29View all other issues in [iostream.format].
View all issues with NAD status.
Discussion:
@@ -4964,7 +5308,7 @@ reopened, agreed with the rationale.
313. set_terminate and set_unexpected question
Section: 18.8.3.3 [terminate] Status: NAD - Submitter: Judy Ward Opened: 2001-04-03 Last modified: 2006-12-27
+ Submitter: Judy Ward Opened: 2001-04-03 Last modified: 2010-10-29View all other issues in [terminate].
View all issues with NAD status.
Discussion:
@@ -5014,7 +5358,7 @@ to call itself.
314. Is the stack unwound when terminate() is called?
Section: 18.8.3.3 [terminate] Status: NAD - Submitter: Detlef Vollmann Opened: 2001-04-11 Last modified: 2007-01-15
+ Submitter: Detlef Vollmann Opened: 2001-04-11 Last modified: 2010-10-29View all other issues in [terminate].
View all issues with NAD status.
Discussion:
@@ -5061,7 +5405,7 @@ about when terminate() is called; it merely specifies which
323. abs() overloads in different headers
Section: 26.8 [c.math] Status: NAD - Submitter: Dave Abrahams Opened: 2001-06-04 Last modified: 2008-03-12
+ Submitter: Dave Abrahams Opened: 2001-06-04 Last modified: 2010-10-29View all other issues in [c.math].
View all issues with NAD status.
Discussion:
@@ -5140,7 +5484,7 @@ The situation is not sufficiently severe to warrant a change.
326. Missing typedef in moneypunct_byname
Section: 22.4.6.4 [locale.moneypunct.byname] Status: NAD - Submitter: Martin Sebor Opened: 2001-07-05 Last modified: 2006-12-27
+ Submitter: Martin Sebor Opened: 2001-07-05 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
The definition of the moneypunct facet contains the typedefs char_type @@ -5165,7 +5509,7 @@ the typedef, because it is inherited from the base class.
330. Misleading "exposition only" value in class locale definition
Section: 22.3.1 [locale] Status: NAD - Submitter: Martin Sebor Opened: 2001-07-15 Last modified: 2006-12-27
+ Submitter: Martin Sebor Opened: 2001-07-15 Last modified: 2010-10-29View all other issues in [locale].
View all issues with NAD status.
Discussion:
@@ -5215,7 +5559,7 @@ any other choice would be.
332. Consider adding increment and decrement operators to std::fpos< T >
Section: 27.5.3 [fpos] Status: NAD - Submitter: PremAnand M. Rao Opened: 2001-08-27 Last modified: 2006-12-27
+ Submitter: PremAnand M. Rao Opened: 2001-08-27 Last modified: 2010-10-29View all other issues in [fpos].
View all issues with NAD status.
Discussion:
@@ -5257,7 +5601,7 @@ report. Additionally, nobody saw a clear need for this extension;
342. seek and eofbit
Section: 27.7.1.3 [istream.unformatted] Status: NAD - Submitter: Howard Hinnant Opened: 2001-10-09 Last modified: 2009-07-14
+ Submitter: Howard Hinnant Opened: 2001-10-09 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with NAD status.
Discussion:
@@ -5386,7 +5730,7 @@ In case of failure, the function calls setstate(failbit)
343. Unspecified library header dependencies
Section: 17 [library] Status: NAD - Submitter: Martin Sebor Opened: 2001-10-09 Last modified: 2009-07-28
+ Submitter: Martin Sebor Opened: 2001-10-09 Last modified: 2010-10-29View other active issues in [library].
View all other issues in [library].
View all issues with NAD status.
@@ -5634,7 +5978,7 @@ Hinnant: It's time we dealt with this issue for C++0X. Reopened.
344. grouping + showbase
Section: 22.4.2 [category.numeric] Status: NAD - Submitter: Howard Hinnant Opened: 2001-10-13 Last modified: 2007-01-15
+ Submitter: Howard Hinnant Opened: 2001-10-13 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -5677,9 +6021,8 @@ consensus in the LWG for action.
348. Minor issue with std::pair operator<
-Section: 20.3.4 [pairs] Status: Dup - Submitter: Andy Sawyer Opened: 2001-10-23 Last modified: 2008-01-05
-View other active issues in [pairs].
+Section: 20.3.5 [pairs] Status: Dup + Submitter: Andy Sawyer Opened: 2001-10-23 Last modified: 2010-10-29
View all other issues in [pairs].
View all issues with Dup status.
Duplicate of: 532
@@ -5693,7 +6036,7 @@ operator< on any pair type which contains a pointer.Proposed resolution:
-In 20.3.4 [pairs] paragraph 6, replace:
+In 20.3.5 [pairs] paragraph 6, replace:
Returns: x.first < y.first || (!(y.first < x.first) && x.second < y.second).@@ -5726,8 +6069,8 @@ operator< on any pair type which contains a pointer.
350. allocator<>::address
-Section: 20.8.8.1 [allocator.members], 20.2.2 [allocator.requirements], 17.6.1.1 [contents] Status: Dup - Submitter: Nathan Myers Opened: 2001-10-25 Last modified: 2007-10-11
+Section: 20.9.5.1 [allocator.members], 20.2.5 [allocator.requirements], 17.6.1.1 [contents] Status: Dup + Submitter: Nathan Myers Opened: 2001-10-25 Last modified: 2010-10-29
View all other issues in [allocator.members].
View all issues with Dup status.
Duplicate of: 634
@@ -5811,15 +6154,15 @@ exhibiting a problem.
351. unary_negate and binary_negate: struct or class?
-Section: 20.7 [function.objects] Status: NAD Editorial - Submitter: Dale Riley Opened: 2001-11-12 Last modified: 2007-04-24
+Section: 20.8 [function.objects] Status: NAD Editorial + Submitter: Dale Riley Opened: 2001-11-12 Last modified: 2010-10-29
View all other issues in [function.objects].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
-In 20.7 [function.objects] the header <functional> synopsis declares +In 20.8 [function.objects] the header <functional> synopsis declares the unary_negate and binary_negate function objects as struct. -However in 20.7.10 [negators] the unary_negate and binary_negate +However in 20.8.9 [negators] the unary_negate and binary_negate function objects are defined as class. Given the context, they are not "basic function objects" like negate, so this is either a typo or an editorial oversight. @@ -5830,7 +6173,7 @@ an editorial oversight.
Proposed resolution:
-Change the synopsis to reflect the useage in 20.7.10 [negators]
+Change the synopsis to reflect the useage in 20.8.9 [negators]
[Curaçao: Since the language permits "struct", the LWG views this as NAD. They suggest, however, that the Project Editor @@ -5842,66 +6185,10 @@ might wish to make the change as editorial.]
-
-353. std::pair missing template assignment
-Section: 20.3.4 [pairs] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2001-12-02 Last modified: 2008-01-05
-View other active issues in [pairs].
-View all other issues in [pairs].
-View all issues with NAD Editorial status.
-Discussion:
--The class template std::pair defines a template ctor (20.2.2, p4) but -no template assignment operator. This may lead to inefficient code since -assigning an object of pair<C, D> to pair<A, B> -where the types C and D are distinct from but convertible to -A and B, respectively, results in a call to the template copy -ctor to construct an unnamed temporary of type pair<A, B> -followed by an ordinary (perhaps implicitly defined) assignment operator, -instead of just a straight assignment. -
- - -Proposed resolution:
--Add the following declaration to the definition of std::pair: -
-template<class U, class V> - pair& operator=(const pair<U, V> &p); ---And also add a paragraph describing the effects of the function template to the -end of 20.2.2: -
-template<class U, class V> - pair& operator=(const pair<U, V> &p); --- Effects: first = p.first; - second = p.second; - Returns: *this -
- -[Curaçao: There is no indication this is was anything other than -a design decision, and thus NAD. May be appropriate for a future -standard.]
- - -[ -Pre Bellevue: It was recognized that this was taken care of by -N1856, -and thus moved from NAD Future to NAD Editorial. -]
- - - - - -
356. Meaning of ctype_base::mask enumerators
Section: 22.4.1 [category.ctype] Status: NAD - Submitter: Matt Austern Opened: 2002-01-23 Last modified: 2006-12-27
+ Submitter: Matt Austern Opened: 2002-01-23 Last modified: 2010-10-29View all other issues in [category.ctype].
View all issues with NAD status.
Discussion:
@@ -6055,10 +6342,10 @@ to see which interpretation is being used.
357. <cmath> float functions cannot return HUGE_VAL
-Section: 26.8 [c.math] Status: NAD Editorial - Submitter: Ray Lischner Opened: 2002-02-26 Last modified: 2007-04-24
+Section: 26.8 [c.math] Status: NAD Editorial + Submitter: Ray Lischner Opened: 2002-02-26 Last modified: 2010-10-29
View all other issues in [c.math].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
The float versions of the math functions have no meaningful value to return @@ -6117,8 +6404,7 @@ discussion concur.
361. num_get<>::do_get (..., void*&) checks grouping
Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: NAD - Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2007-01-15
-View other active issues in [facet.num.put.virtuals].
+ Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2010-10-29View all other issues in [facet.num.put.virtuals].
View all issues with NAD status.
Discussion:
@@ -6172,7 +6458,7 @@ Change the first sentence of 22.2.2.2.2, p12 from
366. Excessive const-qualification
Section: 27 [input.output] Status: NAD - Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2006-12-27
+ Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2010-10-29View all other issues in [input.output].
View all issues with NAD status.
Discussion:
@@ -6296,7 +6582,7 @@ those terms, does not appear in the standard.]
367. remove_copy/remove_copy_if and Input Iterators
Section: 25.3.8 [alg.remove] Status: NAD - Submitter: Anthony Williams Opened: 2002-05-13 Last modified: 2006-12-27
+ Submitter: Anthony Williams Opened: 2002-05-13 Last modified: 2010-10-29View all other issues in [alg.remove].
View all issues with NAD status.
Discussion:
@@ -6332,9 +6618,10 @@ constructible. Otherwise copy constructible is not required." to
368. basic_string::replace has two "Throws" paragraphs
-Section: 21.4.6.6 [string::replace] Status: NAD Editorial - Submitter: Beman Dawes Opened: 2002-06-03 Last modified: 2007-04-24
-View all issues with NAD Editorial status.
+Section: 21.4.6.6 [string::replace] Status: NAD Editorial + Submitter: Beman Dawes Opened: 2002-06-03 Last modified: 2010-10-29
+View all other issues in [string::replace].
+View all issues with NAD Editorial status.
Discussion:
21.4.6.6 [string::replace] basic_string::replace, second @@ -6364,13 +6651,13 @@ part of the "Effects" paragraph.
372. Inconsistent description of stdlib exceptions
-Section: 17.6.4.11 [res.on.exception.handling], 18.7.1 [type.info] Status: NAD - Submitter: Randy Maddox Opened: 2002-07-22 Last modified: 2006-12-27
+Section: 17.6.4.12 [res.on.exception.handling], 18.7.1 [type.info] Status: NAD + Submitter: Randy Maddox Opened: 2002-07-22 Last modified: 2010-10-29
View all other issues in [res.on.exception.handling].
View all issues with NAD status.
Discussion:
-Paragraph 3 under clause 17.6.4.11 [res.on.exception.handling], Restrictions on +
Paragraph 3 under clause 17.6.4.12 [res.on.exception.handling], Restrictions on Exception Handling, states that "Any other functions defined in the C++ Standard Library that do not have an exception-specification may throw implementation-defined exceptions unless otherwise specified." @@ -6405,7 +6692,7 @@ Standard library components ...".
374. moneypunct::frac_digits returns int not unsigned
Section: 22.4.6.3.1 [locale.moneypunct.members], 22.4.6.3.2 [locale.moneypunct.virtuals] Status: NAD - Submitter: Ray Lischner Opened: 2002-08-08 Last modified: 2006-12-27
+ Submitter: Ray Lischner Opened: 2002-08-08 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -6438,7 +6725,7 @@ checks.
377. basic_string::insert and length_error
Section: 21.4.6.4 [string::insert] Status: NAD - Submitter: Ray Lischner Opened: 2002-08-16 Last modified: 2006-12-27
+ Submitter: Ray Lischner Opened: 2002-08-16 Last modified: 2010-10-29View all other issues in [string::insert].
View all issues with NAD status.
Discussion:
@@ -6464,7 +6751,7 @@ needed.
378. locale immutability and locale::operator=()
Section: 22.3.1 [locale] Status: Dup - Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2006-12-30
+ Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2010-10-29View all other issues in [locale].
View all issues with Dup status.
Duplicate of: 31
@@ -6513,7 +6800,7 @@ out of scope?
382. codecvt do_in/out result
Section: 22.4.1.4 [locale.codecvt] Status: NAD - Submitter: Martin Sebor Opened: 2002-08-30 Last modified: 2009-07-14
+ Submitter: Martin Sebor Opened: 2002-08-30 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with NAD status.
Discussion:
@@ -6653,7 +6940,7 @@ NAD without prejudice. Will reopen if proposed resolution is supplied.
385. Does call by value imply the CopyConstructible requirement?
Section: 17 [library] Status: NAD - Submitter: Matt Austern Opened: 2002-10-23 Last modified: 2007-04-18
+ Submitter: Matt Austern Opened: 2002-10-23 Last modified: 2010-10-29View other active issues in [library].
View all other issues in [library].
View all issues with NAD status.
@@ -6732,7 +7019,7 @@ then precisely describe and enforce the precise requirements.
388. Use of complex as a key in associative containers
Section: 26.4 [complex.numbers] Status: NAD - Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2008-02-27
+ Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2010-10-29View all other issues in [complex.numbers].
View all issues with NAD status.
Discussion:
@@ -6803,11 +7090,10 @@ provide their own comparison function object.
390. CopyConstructible requirements too strict
-Section: 20.2.1 [utility.arg.requirements] Status: NAD Editorial - Submitter: Doug Gregor Opened: 2002-10-24 Last modified: 2008-03-14
-View other active issues in [utility.arg.requirements].
+Section: 20.2.1 [utility.arg.requirements] Status: NAD Editorial + Submitter: Doug Gregor Opened: 2002-10-24 Last modified: 2010-10-29
View all other issues in [utility.arg.requirements].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
The CopyConstructible requirements in Table 30 state that for an @@ -6871,14 +7157,14 @@ that &t and &u return the address of t and u, respectively.
392. 'equivalence' for input iterators
-Section: 24.2.1 [input.iterators] Status: NAD - Submitter: Corwin Joy Opened: 2002-12-11 Last modified: 2006-12-27
+Section: 24.2.3 [input.iterators] Status: NAD + Submitter: Corwin Joy Opened: 2002-12-11 Last modified: 2010-10-29
View all other issues in [input.iterators].
View all issues with NAD status.
Discussion:
-In section 24.2.1 [input.iterators] table 72 - +In section 24.2.3 [input.iterators] table 72 - 'Input Iterator Requirements' we have as a postcondition of *a: "If a==b and (a, b) is in the domain of == then *a is equivalent to *b".
@@ -6936,10 +7222,10 @@ of input iterators.
393. do_in/do_out operation on state unclear
-Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: NAD Editorial - Submitter: Alberto Barbati Opened: 2002-12-24 Last modified: 2008-07-02
+Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: NAD Editorial + Submitter: Alberto Barbati Opened: 2002-12-24 Last modified: 2010-10-29
View all other issues in [locale.codecvt.virtuals].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
this DR follows the discussion on the previous thread "codecvt::do_in @@ -6999,7 +7285,7 @@ correct. Proposed Disposition: NAD, Editorial
394. behavior of formatted output on failure
Section: 27.7.2.6.1 [ostream.formatted.reqmts] Status: NAD - Submitter: Martin Sebor Opened: 2002-12-27 Last modified: 2009-07-14
+ Submitter: Martin Sebor Opened: 2002-12-27 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -7110,10 +7396,129 @@ NAD. This issue is already fixed. +
+397. ostream::sentry dtor throws exceptions
+Section: 27.7.2.4 [ostream::sentry] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2010-10-29
+View all other issues in [ostream::sentry].
+View all issues with NAD Editorial status.
+Discussion:
++17.4.4.8, p3 prohibits library dtors from throwing exceptions. +
++27.6.2.3, p4 says this about the ostream::sentry dtor: +
+-4- If ((os.flags() & ios_base::unitbuf) && !uncaught_exception()) + is true, calls os.flush(). +++27.6.2.6, p7 that describes ostream::flush() says: +
+-7- If rdbuf() is not a null pointer, calls rdbuf()->pubsync(). + If that function returns ?-1 calls setstate(badbit) (which + may throw ios_base::failure (27.4.4.3)). +++That seems like a defect, since both pubsync() and setstate() can +throw an exception. +
+[ +The contradiction is real. Clause 17 says destructors may never +throw exceptions, and clause 27 specifies a destructor that does +throw. In principle we might change either one. We're leaning +toward changing clause 17: putting in an "unless otherwise specified" +clause, and then putting in a footnote saying the sentry destructor +is the only one that can throw. PJP suggests specifying that +sentry::~sentry() should internally catch any exceptions it might cause. +]
+ + +[ +See 418 and 622 for related issues. +]
+ + +[ +2009-07 Frankfurt +]
+ + +++ ++Move to Review. Add "Throws: nothing" to the specification of ostream::sentry::~sentry(). +
+[ +2009-10-13 Daniel adds: +]
+ + ++The proposed resolution of 835 is written to match the outcome +of this issue. ++ +[ +2009 Santa Cruz: +]
+ + ++Move to Open. Our intent is to solve this issue with 835. ++ +[ +2010-03-06 Martin updates wording. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. ++ + + +Rationale:
++Solved by 835. +
+ + +Proposed resolution:
++Add after 27.7.2.4 [ostream::sentry] p17: +
+ +++ + + + +~sentry(); +++++-17- If (os.flags() & ios_base::unitbuf) +is true, calls os.flush(). +
+ ++Throws: Nothing. +
+
398. effects of end-of-file on unformatted input functions
Section: 27.7.2.4 [ostream::sentry] Status: NAD - Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2009-07-14
+ Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2010-10-29View all other issues in [ostream::sentry].
View all issues with NAD status.
Discussion:
@@ -7225,7 +7630,7 @@ Moved to NAD. See 27.7.1.1 [istream] p3.
399. volations of unformatted input function requirements
Section: 27.7.1.3 [istream.unformatted] Status: NAD - Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2006-12-27
+ Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with NAD status.
Discussion:
@@ -7269,10 +7674,261 @@ can use alternative signatures that don't call widen. +
+408. Is vector<reverse_iterator<char*> > forbidden?
+Section: 24.2 [iterator.requirements] Status: NAD Editorial + Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2010-10-29
+View all other issues in [iterator.requirements].
+View all issues with NAD Editorial status.
+Discussion:
++I've been discussing iterator semantics with Dave Abrahams, and a +surprise has popped up. I don't think this has been discussed before. +
+ ++X [iterator.concepts] says that the only operation that can be performed on "singular" +iterator values is to assign a non-singular value to them. (It +doesn't say they can be destroyed, and that's probably a defect.) +Some implementations have taken this to imply that there is no need +to initialize the data member of a reverse_iterator<> in the default +constructor. As a result, code like +
++std::vector<std::reverse_iterator<char*> > v(7); + v.reserve(1000); ++invokes undefined behavior, because it must default-initialize the +vector elements, and then copy them to other storage. Of course many +other vector operations on these adapters are also left undefined, +and which those are is not reliably deducible from the standard. +
+ ++I don't think that 24.1 was meant to make standard-library iterator +types unsafe. Rather, it was meant to restrict what operations may +be performed by functions which take general user- and standard +iterators as arguments, so that raw pointers would qualify as +iterators. However, this is not clear in the text, others have come +to the opposite conclusion. +
+ ++One question is whether the standard iterator adaptors have defined +copy semantics. Another is whether they have defined destructor +semantics: is +
++{ std::vector<std::reverse_iterator<char*> > v(7); } ++undefined too? +
+ ++Note this is not a question of whether algorithms are allowed to +rely on copy semantics for arbitrary iterators, just whether the +types we actually supply support those operations. I believe the +resolution must be expressed in terms of the semantics of the +adapter's argument type. It should make clear that, e.g., the +reverse_iterator<T> constructor is actually required to execute +T(), and so copying is defined if the result of T() is copyable. +
+ ++Issue 235, which defines reverse_iterator's default +constructor more precisely, has some relevance to this issue. +However, it is not the whole story. +
+ ++The issue was whether +
++reverse_iterator() { } ++is allowed, vs. +
++ +reverse_iterator() : current() { } ++The difference is when T is char*, where the first leaves the member +uninitialized, and possibly equal to an existing pointer value, or +(on some targets) may result in a hardware trap when copied. +
+ ++8.5 paragraph 5 seems to make clear that the second is required to +satisfy DR 235, at least for non-class Iterator argument +types. +
+ ++But that only takes care of reverse_iterator, and doesn't establish +a policy for all iterators. (The reverse iterator adapter was just +an example.) In particular, does my function +
++template <typename Iterator> + void f() { std::vector<Iterator> v(7); } ++evoke undefined behavior for some conforming iterator definitions? +I think it does, now, because vector<> will destroy those singular +iterator values, and that's explicitly disallowed. +
+ ++24.1 shouldn't give blanket permission to copy all singular iterators, +because then pointers wouldn't qualify as iterators. However, it +should allow copying of that subset of singular iterator values that +are default-initialized, and it should explicitly allow destroying any +iterator value, singular or not, default-initialized or not. +
+ + +[ +We don't want to require all singular iterators to be copyable, +because that is not the case for pointers. However, default +construction may be a special case. Issue: is it really default +construction we want to talk about, or is it something like value +initialization? We need to check with core to see whether default +constructed pointers are required to be copyable; if not, it would be +wrong to impose so strict a requirement for iterators. +]
+ + +[ +2009-05-10 Alisdair provided wording. +]
+ + ++The comments regarding destroying singular iterators have already been +resolved. That just leaves copying (with moving implied). ++ +[ +2009-07 Frankfurt +]
+ + +++ ++This is related to LWG 1012. +
++Note that there is a bug in the proposed resolution to LWG 1012. The +change to [reverse.iter.con] should be modified so that the word +"default" in the second sentence of the Effects clause is replaced by +"value." +
++We believe that the proposed fix to LWG 1012 (now corrected) is +sufficient to solve the problem for reverse_iterator. However, Alisdair +pointed out that LWG 1012 does not solve the general problem for authors +of iterator adaptors. +
++There are some problems with the proposed resolution. The phrase "safely +copyable" is not a term of art. Also, it mentions a +DefaultConstructible? concept. +
++Move to Review after Alisdair updates the wording. +
+[ +2009-07-31 Alisdair revised wording: +]
+ + +[ +2009-08-17 Alisdair and Daniel collaborate on slightly revised wording. +This issue depends upon 724 +]
+ + +[ +2009-10-14 Daniel adds: +]
+ + ++There is a clear dependency on 1213, because the term "singular", +which is used as part of the resolution, is not properly defined yet. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Open. Alisdair will provide improved wording to make +this have "value semantics" and otherwise behave like a valid iterator. ++ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3066. +
+ + +Proposed resolution:
++Add a new paragrpah to Iterator concepts 24.2 [iterator.requirements] after para 5 (the one describing +singular iterators) +
+++ + + + + ++Just as a regular pointer to an array guarantees that there is a pointer +value pointing past the last element of the array, so for any iterator +type there is an iterator value that points past the last element of a +corresponding container. These values are called past-the-end values. +Values of an iterator i for which the expression *i is defined are called +dereferenceable. The library never assumes that past-the-end values are +dereferenceable. Iterators can also have singular values that are not +associated with any container. [Example: After the declaration of an +uninitialized pointer x (as with int* x;), x must always be assumed to +have a singular value of a pointer. — end example] Results of most +expressions are undefined for singular values; the only exceptions are +destroying an iterator that holds a singular value and the assignment of +a non-singular value to an iterator that holds a singular value. In this +case the singular value is overwritten the same way as any other value. +Dereferenceable values are always non-singular. +
++After value-initialization, any iterator that satisfies the +DefaultConstructible requirements ([defaultconstructible]) shall not introduce undefined behaviour +when used as the +source of a copy or move operation, even if it would +otherwise be singular. [Note: This guarantee is not offered for +default-initialization (8.5 [dcl.init]), although the distinction only +matters for types with trivial default constructors such as pointers. — +end note] +
+ + +
417. what does ctype::do_widen() return on failure
Section: 22.4.1.1.2 [locale.ctype.virtuals] Status: NAD - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-14
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all other issues in [locale.ctype.virtuals].
View all issues with NAD status.
Discussion:
@@ -7317,7 +7973,7 @@ implementation is required to provide, for the basic character set.
418. exceptions thrown during iostream cleanup
Section: 27.5.2.1.6 [ios::Init] Status: NAD - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-14
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all other issues in [ios::Init].
View all issues with NAD status.
Discussion:
@@ -7347,7 +8003,7 @@ object throws.[ -See 397 and 622 for related issues. +See 397 and 622 for related issues. ]
@@ -7370,7 +8026,7 @@ Moved to NAD, no consensus for change.
421. is basic_streambuf copy-constructible?
Section: 27.6.2.1 [streambuf.cons] Status: NAD - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-14
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all other issues in [streambuf.cons].
View all issues with NAD status.
Discussion:
@@ -7488,16 +8144,13 @@ Constructs an independent copy of sb as if with sb.str(), and with the openmode getloc() == sb.getloc() -Note: The only requirement on epptr() is that it point beyond the -initialized range if an output sequence exists. There is no requirement -that epptr() - pbase() == sb.epptr() - sb.pbase(). +
+Note: The only requirement on epptr() is that it point beyond the initialized range if an output sequence exists. There is no requirement that epptr() - pbase() == sb.epptr() - sb.pbase().
basic_stringbuf& operator=(const basic_stringbuf& sb);-After assignment the basic_stringbuf has the same state as if it -were initially copy constructed from sb, except that the -basic_stringbuf is allowed to retain any excess capacity it might have, -which may in turn effect the value of epptr(). +
+After assignment the basic_stringbuf has the same state as if it were initially copy constructed from sb, except that the basic_stringbuf is allowed to retain any excess capacity it might have, which may in turn effect the value of epptr().
423. effects of negative streamsize in iostreams
-Section: 27 [input.output] Status: NAD Future - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-14
+Section: 27 [input.output] Status: NAD Future + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
View all other issues in [input.output].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
@@ -7636,9 +8289,9 @@ ostream::write().
424. normative notes
-Section: 17.5.1.2 [structure.summary] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-07-13
-View all issues with NAD Editorial status.
+Section: 17.5.1.2 [structure.summary] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
@@ -7658,8 +8311,8 @@ is not so clear (see list 3). List 1 -- Examples of (presumably) normative Notes:
-20.8.8.1 [allocator.members], p3,
-20.8.8.1 [allocator.members], p10,
+20.9.5.1 [allocator.members], p3,
+20.9.5.1 [allocator.members], p10,
21.4.2 [string.cons], p11,
22.3.1.2 [locale.cons], p11,
23.3.2.3 [deque.modifiers], p2,
@@ -7748,7 +8401,7 @@ Move to NAD Editorial.
429. typo in basic_ios::clear(iostate)
Section: 27.5.4.3 [iostate.flags] Status: Dup - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2006-12-30
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all other issues in [iostate.flags].
View all issues with Dup status.
Duplicate of: 412
@@ -7787,119 +8440,10 @@ to -
-431. Swapping containers with unequal allocators
-Section: 20.2.2 [allocator.requirements], 25 [algorithms] Status: NAD Editorial - Submitter: Matt Austern Opened: 2003-09-20 Last modified: 2009-10-26
-View all other issues in [allocator.requirements].
-View all issues with NAD Editorial status.
-Discussion:
-Clause 20.2.2 [allocator.requirements] paragraph 4 says that implementations - are permitted to supply containers that are unable to cope with - allocator instances and that container implementations may assume - that all instances of an allocator type compare equal. We gave - implementers this latitude as a temporary hack, and eventually we - want to get rid of it. What happens when we're dealing with - allocators that don't compare equal? -
- -In particular: suppose that v1 and v2 are both - objects of type vector<int, my_alloc> and that - v1.get_allocator() != v2.get_allocator(). What happens if - we write v1.swap(v2)? Informally, three possibilities:
- -1. This operation is illegal. Perhaps we could say that an - implementation is required to check and to throw an exception, or - perhaps we could say it's undefined behavior.
-2. The operation performs a slow swap (i.e. using three - invocations of operator=, leaving each allocator with its - original container. This would be an O(N) operation.
-3. The operation swaps both the vectors' contents and their - allocators. This would be an O(1) operation. That is:
--- -my_alloc a1(...); - my_alloc a2(...); - assert(a1 != a2); - - vector<int, my_alloc> v1(a1); - vector<int, my_alloc> v2(a2); - assert(a1 == v1.get_allocator()); - assert(a2 == v2.get_allocator()); - - v1.swap(v2); - assert(a1 == v2.get_allocator()); - assert(a2 == v1.get_allocator()); --[Kona: This is part of a general problem. We need a paper - saying how to deal with unequal allocators in general.]
- - -[pre-Sydney: Howard argues for option 3 in -N1599. -]
- - -[ -2007-01-12, Howard: This issue will now tend to come up more often with move constructors -and move assignment operators. For containers, these members transfer resources (i.e. -the allocated memory) just like swap. -]
- - -[ -Batavia: There is agreement to overload the container swap on the allocator's Swappable -requirement using concepts. If the allocator supports Swappable, then container's swap will -swap allocators, else it will perform a "slow swap" using copy construction and copy assignment. -]
- - -[ -2009-04-28 Pablo adds: -]
- --Fixed in -N2525. -I argued for marking this Tentatively-Ready right after Bellevue, -but there was a concern that -N2525 -would break in the presence of the RVO. (That breakage had nothing to do with -swap, but never-the-less). I addressed that breakage in in -N2840 -(Summit) by means of a non-normative reference: - -- --[Note: in situations where the copy constructor for a container is elided, -this function is not called. The behavior in these cases is as if -select_on_container_copy_construction returned x — end note] -- -[ -2009-10 Santa Cruz: -]
- - --NAD Editorial. Addressed by -N2982. -- - - -Proposed resolution:
- - - - -
433. Contradiction in specification of unexpected()
-Section: 18.8.2.4 [unexpected] Status: NAD - Submitter: Vyatcheslav Sysoltsev Opened: 2003-09-29 Last modified: 2006-12-27
+Section: D.13.3 [unexpected] Status: NAD + Submitter: Vyatcheslav Sysoltsev Opened: 2003-09-29 Last modified: 2010-10-29
View all issues with NAD status.
Discussion:
@@ -7932,7 +8476,7 @@ ambiguity in understanding.
437. Formatted output of function pointers is confusing
Section: 27.7.2.6.2 [ostream.inserters.arithmetic] Status: NAD - Submitter: Ivan Godard Opened: 2003-10-24 Last modified: 2006-12-27
+ Submitter: Ivan Godard Opened: 2003-10-24 Last modified: 2010-10-29View all other issues in [ostream.inserters.arithmetic].
View all issues with NAD status.
Discussion:
@@ -7978,7 +8522,7 @@ conversions from C and the function pointer is converted to bool.
439. Should facets be copyable?
Section: 22.4 [locale.categories] Status: NAD - Submitter: Matt Austern Opened: 2003-11-02 Last modified: 2006-12-27
+ Submitter: Matt Austern Opened: 2003-11-02 Last modified: 2010-10-29View all other issues in [locale.categories].
View all issues with NAD status.
Discussion:
@@ -8034,7 +8578,7 @@ conversions from C and the function pointer is converted to bool.
440. Should std::complex use unqualified transcendentals?
Section: 26.4.8 [complex.transcendentals] Status: NAD - Submitter: Matt Austern Opened: 2003-11-05 Last modified: 2009-03-21
+ Submitter: Matt Austern Opened: 2003-11-05 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -8071,10 +8615,101 @@ are off.
+
+446. Iterator equality between different containers
+Section: 24.2 [iterator.requirements], 23.2 [container.requirements] Status: NAD Editorial + Submitter: Andy Koenig Opened: 2003-12-16 Last modified: 2010-10-29
+View all other issues in [iterator.requirements].
+View all issues with NAD Editorial status.
+Discussion:
++What requirements does the standard place on equality comparisons between +iterators that refer to elements of different containers. For example, if +v1 and v2 are empty vectors, is v1.end() == v2.end() allowed to yield true? +Is it allowed to throw an exception? +
+ ++The standard appears to be silent on both questions. +
+[Sydney: The intention is that comparing two iterators from +different containers is undefined, but it's not clear if we say that, +or even whether it's something we should be saying in clause 23 or in +clause 24. Intuitively we might want to say that equality is defined +only if one iterator is reachable from another, but figuring out how +to say it in any sensible way is a bit tricky: reachability is defined +in terms of equality, so we can't also define equality in terms of +reachability. +]
+ + +[ +2009-07 Frankfurt +]
+ + ++Daniel volunteered to work on this. ++ +[ +2009-09-20 Daniel provided wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Leave as Open. Alisdair has volunteered to refine the wording. ++ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3066. +
+ + +Proposed resolution:
++Insert a new paragraph between 24.2 [iterator.requirements]/7+8: +
+ +++ + + + + ++[..] The result of the application of functions in the library to invalid +ranges is undefined. +
+ +The result of directly or indirectly evaluating any comparison function +or the binary - operator with two iterator values as arguments that +were obtained +from two different ranges r1 and r2 (including their past-the-end values) which +are not subranges of one common range is undefined, unless explicitly +described otherwise. +
+ +
447. Wrong template argument for time facets
Section: 22.3.1.1.1 [locale.category] Status: Dup - Submitter: Pete Becker Opened: 2003-12-26 Last modified: 2007-01-15
+ Submitter: Pete Becker Opened: 2003-12-26 Last modified: 2010-10-29View all other issues in [locale.category].
View all issues with Dup status.
Duplicate of: 327
@@ -8109,8 +8744,8 @@ Change the second template argument to InputIterator.
450. set::find is inconsistent with associative container requirements
-Section: 23.4.3 [set] Status: Dup - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2009-05-01
+Section: 23.6.3 [set] Status: Dup + Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29
View all other issues in [set].
View all issues with Dup status.
Duplicate of: 214
@@ -8146,8 +8781,8 @@ table, in this regard.
451. Associative erase should return an iterator
-Section: 23.2.4 [associative.reqmts], 23.4 [associative] Status: Dup - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2009-05-01
+Section: 23.2.4 [associative.reqmts], 23.6 [associative] Status: Dup + Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29
View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with Dup status.
@@ -8184,7 +8819,7 @@ first element beyond the erased subrange.
452. locale::combine should be permitted to generate a named locale
Section: 22.3.1.3 [locale.members] Status: NAD - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2009-05-01
+ Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29View all other issues in [locale.members].
View all issues with NAD status.
Discussion:
@@ -8225,7 +8860,7 @@ standard facets.
454. basic_filebuf::open should accept wchar_t names
Section: 27.9.1.4 [filebuf.members] Status: NAD - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2009-05-01
+ Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29View all other issues in [filebuf.members].
View all issues with NAD status.
Duplicate of: 105
@@ -8416,8 +9051,8 @@ NAD.
458. 24.1.5 contains unintended limitation for operator-
-Section: 24.2.5 [random.access.iterators] Status: NAD - Submitter: Daniel Frey Opened: 2004-02-27 Last modified: 2009-10-26
+Section: 24.2.7 [random.access.iterators] Status: NAD + Submitter: Daniel Frey Opened: 2004-02-27 Last modified: 2010-10-29
View all other issues in [random.access.iterators].
View all issues with NAD status.
Discussion:
@@ -8445,7 +9080,7 @@ Post Summit Alisdair adds: This issue refers to a requirements table we have removed.-The issue might now relate to 24.2.5 [random.access.iterators] p5. +The issue might now relate to 24.2.7 [random.access.iterators] p5. However, the rationale in the issue already recognises that the difference_type must be signed, so this really looks NAD.
@@ -8515,8 +9150,7 @@ operational semantics for this column to:
459. Requirement for widening in stage 2 is overspecification
Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: NAD - Submitter: Martin Sebor Opened: 2004-03-16 Last modified: 2009-07-14
-View other active issues in [facet.num.get.virtuals].
+ Submitter: Martin Sebor Opened: 2004-03-16 Last modified: 2010-10-29View all other issues in [facet.num.get.virtuals].
View all issues with NAD status.
Discussion:
@@ -8563,13 +9197,11 @@ drastic. Existing implementations with the exception of libstdc++ currently already use narrow() so the impact of the change on programs would presumably be isolated to just a single implementation. Further, since narrow() is not required to translate alternate wide digit -representations such as those mentioned in issue 303 -to +representations such as those mentioned in issue 303 to their narrow equivalents (i.e., the portable source characters '0' through '9'), the change does not necessarily imply that these alternate digits would be treated as ordinary digits and accepted as -part of numbers during parsing. In fact, the requirement in 22.4.1.1.2 -[locale.ctype.virtuals], p13 forbids narrow() to translate an alternate +part of numbers during parsing. In fact, the requirement in 22.4.1.1.2 [locale.ctype.virtuals], p13 forbids narrow() to translate an alternate digit character, wc, to an ordinary digit in the basic source character set unless the expression (ctype<charT>::is(ctype_base::digit, wc) == true) holds. This in @@ -8617,7 +9249,7 @@ technique to perform the comparison:
462. Destroying objects with static storage duration
Section: 3.6.3 [basic.start.term], 18.4 [cstdint] Status: NAD - Submitter: Bill Plauger Opened: 2004-03-23 Last modified: 2008-02-25
+ Submitter: Bill Plauger Opened: 2004-03-23 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -8770,8 +9402,8 @@ Bill agrees issue is no longer serious, and accepts NAD.
463. auto_ptr usability issues
-Section: D.10.1 [auto.ptr] Status: NAD - Submitter: Rani Sharoni Opened: 2003-12-07 Last modified: 2009-10-26
+Section: D.12.1 [auto.ptr] Status: NAD + Submitter: Rani Sharoni Opened: 2003-12-07 Last modified: 2010-10-29
View all other issues in [auto.ptr].
View all issues with NAD status.
Discussion:
@@ -9074,7 +9706,7 @@ references auto_ptr_ref. This risk seems to indicate that a decision which would not touch the current spec of auto_ptr at all (but deprecating it) and instead recommending to use unique_ptr for new code instead might have the best -cost-benefit ratio. IMO the current solution of 1100 can +cost-benefit ratio. IMO the current solution of 1100 can be considered as an active user-support for this transition.-Mark as NAD. Alisdair will open a new issue (1247) with +Mark as NAD. Alisdair will open a new issue (1247) with proposed wording to handle auto_ptr_ref.@@ -9093,7 +9725,7 @@ proposed wording to handle auto_ptr_ref.Proposed resolution:
-Change the synopsis in D.10.1 [auto.ptr]: +Change the synopsis in D.12.1 [auto.ptr]:
namespace std { @@ -9147,11 +9779,11 @@ Change the synopsis in D.10.1 [auto.ptr]:-Remove D.10.1.3 [auto.ptr.conv]. +Remove D.12.1.3 [auto.ptr.conv].
-Change D.10.1 [auto.ptr], p3: +Change D.12.1 [auto.ptr], p3:
@@ -9175,7 +9807,7 @@ elements and thus instantiating a Standard Library container with an-Change D.10.1.1 [auto.ptr.cons], p5: +Change D.12.1.1 [auto.ptr.cons], p5:
@@ -9195,7 +9827,7 @@ Change D.10.1.1 [auto.ptr.cons], p5:-Change D.10.1.1 [auto.ptr.cons], p10: +Change D.12.1.1 [auto.ptr.cons], p10:
@@ -9223,7 +9855,7 @@ The expression delete get() is well formed.
466. basic_string ctor should prevent null pointer error
Section: 21.4.1 [string.require] Status: NAD - Submitter: Daniel Frey Opened: 2004-06-10 Last modified: 2009-07-14
+ Submitter: Daniel Frey Opened: 2004-06-10 Last modified: 2010-10-29View all other issues in [string.require].
View all issues with NAD status.
Discussion:
@@ -9311,8 +9943,7 @@ Add to the synopsis in 21.4 [basic.string]
470. accessing containers from their elements' special functions
Section: 23 [containers] Status: NAD - Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2007-04-18
-View other active issues in [containers].
+ Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29View all other issues in [containers].
View all issues with NAD status.
Discussion:
@@ -9365,7 +9996,7 @@ corner cases.
472. Missing "Returns" clause in std::equal_range
Section: 25.4.3.3 [equal.range] Status: Dup - Submitter: Prateek R Karandikar Opened: 2004-06-30 Last modified: 2006-12-30
+ Submitter: Prateek R Karandikar Opened: 2004-06-30 Last modified: 2010-10-29View all other issues in [equal.range].
View all issues with Dup status.
Duplicate of: 270
@@ -9388,8 +10019,8 @@ There is no "Returns:" clause for std::equal_range, which returns non-void.
476. Forward Iterator implied mutability
-Section: 24.2.3 [forward.iterators] Status: NAD - Submitter: Dave Abrahams Opened: 2004-07-09 Last modified: 2007-01-15
+Section: 24.2.5 [forward.iterators] Status: NAD + Submitter: Dave Abrahams Opened: 2004-07-09 Last modified: 2010-10-29
View all other issues in [forward.iterators].
View all issues with NAD status.
Discussion:
@@ -9428,8 +10059,8 @@ overhaul.)
477. Operator-> for const forward iterators
-Section: 24.2.3 [forward.iterators] Status: Dup - Submitter: Dave Abrahams Opened: 2004-07-11 Last modified: 2007-01-15
+Section: 24.2.5 [forward.iterators] Status: Dup + Submitter: Dave Abrahams Opened: 2004-07-11 Last modified: 2010-10-29
View all other issues in [forward.iterators].
View all issues with Dup status.
Duplicate of: 478
@@ -9482,8 +10113,7 @@ as the first line.
479. Container requirements and placement new
Section: 23.2 [container.requirements] Status: Dup - Submitter: Herb Sutter Opened: 2004-08-01 Last modified: 2007-04-18
-View other active issues in [container.requirements].
+ Submitter: Herb Sutter Opened: 2004-08-01 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with Dup status.
Duplicate of: 580
@@ -9530,8 +10160,8 @@ support that the eventual solution should make this code well formed.
480. unary_function and binary_function should have protected nonvirtual destructors
-Section: 20.7.3 [base] Status: NAD - Submitter: Joe Gottman Opened: 2004-08-19 Last modified: 2006-12-29
+Section: X [base] Status: NAD + Submitter: Joe Gottman Opened: 2004-08-19 Last modified: 2010-10-29
View all other issues in [base].
View all issues with NAD status.
Discussion:
@@ -9596,7 +10226,7 @@ nonvirtual destructors.
481. unique's effects on the range [result, last)
Section: 25.3.9 [alg.unique] Status: NAD - Submitter: Andrew Koenig Opened: 2004-08-30 Last modified: 2006-12-27
+ Submitter: Andrew Koenig Opened: 2004-08-30 Last modified: 2010-10-29View all other issues in [alg.unique].
View all issues with NAD status.
Discussion:
@@ -9630,53 +10260,10 @@ explicit, but it's hard to think that's a major problem. -
-482. Swapping pairs
-Section: 20.3.4 [pairs], 20.5 [tuple] Status: NAD Editorial - Submitter: Andrew Koenig Opened: 2004-09-14 Last modified: 2007-05-06
-View other active issues in [pairs].
-View all other issues in [pairs].
-View all issues with NAD Editorial status.
-Discussion:
-(Based on recent comp.std.c++ discussion)
- -Pair (and tuple) should specialize std::swap to work in terms of -std::swap on their components. For example, there's no obvious reason -why swapping two objects of type pair<vector<int>, -list<double> > should not take O(1).
- -[Lillehammer: We agree it should be swappable. Howard will - provide wording.]
- - -[ -Post Oxford: We got swap for pair but accidently -missed tuple. tuple::swap is being tracked by 522. -]
- - - - -Proposed resolution:
--Wording provided in -N1856. -
- -Rationale:
--Recommend NAD, fixed by -N1856. -
- - - - -
483. Heterogeneous equality and EqualityComparable
Section: 25.2 [alg.nonmodifying], 25.3 [alg.modifying.operations] Status: Dup - Submitter: Peter Dimov Opened: 2004-09-20 Last modified: 2007-01-15
+ Submitter: Peter Dimov Opened: 2004-09-20 Last modified: 2010-10-29View all issues with Dup status.
Duplicate of: 283
Discussion:
@@ -9780,10 +10367,10 @@ operator that takes a T, or a T may be convertible to the type of *i.
484. Convertible to T
-Section: 24.2.1 [input.iterators] Status: NAD Future - Submitter: Chris Jefferson Opened: 2004-09-16 Last modified: 2009-10-26
+Section: 24.2.3 [input.iterators] Status: NAD Future + Submitter: Chris Jefferson Opened: 2004-09-16 Last modified: 2010-10-29
View all other issues in [input.iterators].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
From comp.std.c++:
@@ -9866,10 +10453,217 @@ Solved by +
+485. output iterator insufficiently constrained
+Section: 24.2.4 [output.iterators] Status: NAD Editorial + Submitter: Chris Jefferson Opened: 2004-10-13 Last modified: 2010-10-29
+View all other issues in [output.iterators].
+View all issues with NAD Editorial status.
+Discussion:
++The note on 24.1.2 Output iterators insufficiently limits what can be +performed on output iterators. While it requires that each iterator is +progressed through only once and that each iterator is written to only +once, it does not require the following things:
+ +Note: Here it is assumed that x is an output iterator of type X which +has not yet been assigned to.
+ +a) That each value of the output iterator is written to: +The standard allows: +++x; ++x; ++x; +
+ ++b) That assignments to the output iterator are made in order +X a(x); ++a; *a=1; *x=2; is allowed +
+ ++c) Chains of output iterators cannot be constructed: +X a(x); ++a; X b(a); ++b; X c(b); ++c; is allowed, and under the current +wording (I believe) x,a,b,c could be written to in any order. +
+ +I do not believe this was the intension of the standard?
+[Lillehammer: Real issue. There are lots of constraints we + intended but didn't specify. Should be solved as part of iterator + redesign.]
+ + +[ +2009-07 Frankfurt +]
+ + ++Bill provided wording according to consensus. ++ +[ +2009-07-21 Alisdair requests change from Review to Open. See thread starting +with c++std-lib-24459 for discussion. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Modified wording. Set to Review. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready after looking at again in a larger group in Santa Cruz. ++ +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added below. ++ + + +Rationale:
++Solved by N3066. +
+ + +Proposed resolution:
++Change Table 101 — Output iterator requirements in 24.2.4 [output.iterators]: +
+++ + + + ++
+Table 101 — Output iterator requirements ++ + +Expression +Return type +Operational semantics +Assertion/note pre-/post-condition ++ + ++X(a) + ++ + ++ + ++a = t is equivalent to X(a) = t. note: a destructor is assumed. + ++ + ++X u(a); +
+X u = a; ++ + ++ + ++ + ++ + ++*r = o + ++result is not used + ++ + ++ +Post: r is not required to be dereferenceable. r is incrementable. + + ++ + ++++r + ++X& + ++ + ++&r == &++r + +Post: r is dereferenceable, unless otherwise specified. r is not required to be incrementable. + + ++ + ++r++ + ++convertible to const X& + ++{X tmp = r; +
++r;
return tmp;} ++ +Post: r is dereferenceable, unless otherwise specified. r is not required to be incrementable. + + ++ + ++*r++ = o; + ++result is not used + ++ + ++ + +
486. min/max CopyConstructible requirement is too strict
Section: 25.4.7 [alg.min.max] Status: Dup - Submitter: Dave Abrahams Opened: 2004-10-13 Last modified: 2006-12-30
+ Submitter: Dave Abrahams Opened: 2004-10-13 Last modified: 2010-10-29View all other issues in [alg.min.max].
View all issues with Dup status.
Duplicate of: 281
@@ -9891,8 +10685,8 @@ copy T.
487. Allocator::construct is too limiting
-Section: 20.2.2 [allocator.requirements] Status: NAD - Submitter: Dhruv Matani Opened: 2004-10-17 Last modified: 2006-12-30
+Section: 20.2.5 [allocator.requirements] Status: NAD + Submitter: Dhruv Matani Opened: 2004-10-17 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with NAD status.
Discussion:
@@ -9936,7 +10730,7 @@ be called! Doesn't that sound great?
489. std::remove / std::remove_if wrongly specified
Section: 25.3.8 [alg.remove] Status: NAD - Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2006-12-27
+ Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2010-10-29View all other issues in [alg.remove].
View all issues with NAD status.
Discussion:
@@ -10135,7 +10929,7 @@ ISO/IEC 14882:2003.
490. std::unique wrongly specified
Section: 25.3.9 [alg.unique] Status: NAD - Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2006-12-27
+ Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2010-10-29View all other issues in [alg.unique].
View all issues with NAD status.
Discussion:
@@ -10386,8 +11180,7 @@ change, so there is no real-world harm here.
491. std::list<>::unique incorrectly specified
Section: 23.3.4.4 [list.ops] Status: NAD - Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2007-02-19
-View other active issues in [list.ops].
+ Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2010-10-29View all other issues in [list.ops].
View all issues with NAD status.
Discussion:
@@ -10589,7 +11382,7 @@ harm.
492. Invalid iterator arithmetic expressions
Section: 17.5.1.4 [structure.specifications] Status: NAD - Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2009-07-15
+ Submitter: Thomas Mang Opened: 2004-12-12 Last modified: 2010-10-29View all other issues in [structure.specifications].
View all issues with NAD status.
Discussion:
@@ -10805,8 +11598,8 @@ it doesn't cover. Bill will provide wording.]
493. Undefined Expression in Input Iterator Note Title
-Section: 24.2.1 [input.iterators] Status: NAD - Submitter: Chris Jefferson Opened: 2004-12-13 Last modified: 2006-12-27
+Section: 24.2.3 [input.iterators] Status: NAD + Submitter: Chris Jefferson Opened: 2004-12-13 Last modified: 2010-10-29
View all other issues in [input.iterators].
View all issues with NAD status.
Discussion:
@@ -10846,7 +11639,7 @@ not guarantee the substitution property or referential transparency).
494. Wrong runtime complexity for associative container's insert and delete
Section: 23.2.4 [associative.reqmts] Status: NAD - Submitter: Hans B os Opened: 2004-12-19 Last modified: 2006-12-27
+ Submitter: Hans B os Opened: 2004-12-19 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with NAD status.
@@ -10904,9 +11697,9 @@ last) and insert(first, last).
499. Std. doesn't seem to require stable_sort() to be stable!
-Section: 25.4.1.2 [stable.sort] Status: NAD Editorial - Submitter: Prateek Karandikar Opened: 2005-04-12 Last modified: 2008-03-13
-View all issues with NAD Editorial status.
+Section: 25.4.1.2 [stable.sort] Status: NAD Editorial + Submitter: Prateek Karandikar Opened: 2005-04-12 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
17.3.1.1 Summary
@@ -10975,7 +11768,7 @@ This change has already been made.
500. do_length cannot be implemented correctly
Section: 22.4.1.5 [locale.codecvt.byname] Status: NAD - Submitter: Krzysztof Żelechowski Opened: 2005-05-24 Last modified: 2008-03-13
+ Submitter: Krzysztof Żelechowski Opened: 2005-05-24 Last modified: 2010-10-29View all other issues in [locale.codecvt.byname].
View all issues with NAD status.
Discussion:
@@ -10999,8 +11792,8 @@ Contradiction.
501. Proposal: strengthen guarantees of lib.comparisons
-Section: 20.7.3 [base] Status: NAD - Submitter: Me <anti_spam_email2003@yahoo.com> Opened: 2005-06-07 Last modified: 2008-03-13
+Section: X [base] Status: NAD + Submitter: Me <anti_spam_email2003@yahoo.com> Opened: 2005-06-07 Last modified: 2010-10-29
View all other issues in [base].
View all issues with NAD status.
Discussion:
@@ -11072,7 +11865,7 @@ to detect overlapping memory situations.
502. Proposition: Clarification of the interaction between a facet and an iterator
Section: 22.3.1.1.1 [locale.category] Status: NAD - Submitter: Christopher Conrade Zseleghovski Opened: 2005-06-07 Last modified: 2009-07-15
+ Submitter: Christopher Conrade Zseleghovski Opened: 2005-06-07 Last modified: 2010-10-29View all other issues in [locale.category].
View all issues with NAD status.
Discussion:
@@ -11133,7 +11926,7 @@ Bill.
503. more on locales
Section: 22.4 [locale.categories] Status: NAD - Submitter: P.J. Plauger Opened: 2005-06-20 Last modified: 2009-07-15
+ Submitter: P.J. Plauger Opened: 2005-06-20 Last modified: 2010-10-29View all other issues in [locale.categories].
View all issues with NAD status.
Discussion:
@@ -11259,10 +12052,10 @@ Move to NAD.
504. Integer types in pseudo-random number engine requirements
-Section: X [rand.req], TR1 5.1.1 [tr.rand.req] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+Section: 26.5.1 [rand.req], TR1 5.1.1 [tr.rand.req] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
View all other issues in [rand.req].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
In [tr.rand.req], Paragraph 2 states that "... s is a value of integral type, @@ -11329,7 +12122,7 @@ Portland: Subsumed by N2111.
506. Requirements of Distribution parameter for variate_generator
Section: 26.5 [rand], TR1 5.1.3 [tr.rand.var] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+ Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29View all other issues in [rand].
View all issues with NAD status.
Discussion:
@@ -11370,7 +12163,7 @@ Marc supports having min and max to satisfy generic programming interface.
509. Uniform_int template parameters
Section: 26.5.8.1 [rand.dist.uni], TR1 5.1.7.1 [tr.rand.dist.iunif] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+ Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29View all other issues in [rand.dist.uni].
View all issues with NAD status.
Discussion:
@@ -11411,7 +12204,7 @@ eliminated.
510. Input_type for bernoulli_distribution
Section: 26.5.8.2 [rand.dist.bern], TR1 5.1.7.2 [tr.rand.dist.bern] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+ Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -11442,7 +12235,7 @@ eliminated.
511. Input_type for binomial_distribution
Section: 26.5.8 [rand.dist], TR1 5.1.7.5 [tr.rand.dist.bin] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+ Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29View all other issues in [rand.dist].
View all issues with NAD status.
Discussion:
@@ -11531,10 +12324,10 @@ eliminated.
512. Seeding subtract_with_carry_01 from a single unsigned long
-Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
View all other issues in [rand.eng].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Paragraph 8 specifies the algorithm by which a subtract_with_carry_01 engine @@ -11574,7 +12367,7 @@ void seed(unsigned long value = 19780503) by case,
with a linear congruential generator lcg(i) having parameters mlcg = 2147483563, alcg = 40014, clcg = 0, and lcg(0) = value,-sets carry(-1) and x(-r) … x(-1) +sets carry(-1) and x(-r) … x(-1) as if executing@@ -11621,10 +12414,10 @@ Portland: Subsumed by N2111.@@ -11584,7 +12377,7 @@ seed(lcg);
to (lcg(1) · 2-w) mod 1 -… (lcg(r) · 2-w) mod 1, +… (lcg(r) · 2-w) mod 1, respectively. If x(-1) == 0, sets carry(-1) = 2-w, else sets carry(-1) = 0.
513. Size of state for subtract_with_carry_01
-Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
View all other issues in [rand.eng].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Paragraph 3 begins: @@ -11674,9 +12467,9 @@ Berlin: N1932 adopts the proposed NAD.
514. Size of state for subtract_with_carry
-Section: 26.5.3.3 [rand.eng.sub], TR1 5.1.4.3 [tr.rand.eng.sub] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
-View all issues with NAD Editorial status.
+Section: 26.5.3.3 [rand.eng.sub], TR1 5.1.4.3 [tr.rand.eng.sub] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
Paragraph 2 begins: @@ -11719,8 +12512,8 @@ Berlin: N1932 adopts the proposed NAD.
515. Random number engine traits
-Section: 26.5.1 [rand.synopsis], TR1 5.1.2 [tr.rand.synopsis] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+Section: 26.5.2 [rand.synopsis], TR1 5.1.2 [tr.rand.synopsis] Status: NAD + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
View all other issues in [rand.synopsis].
View all issues with NAD status.
Discussion:
@@ -11793,10 +12586,10 @@ covers this. Already in WP.
516. Seeding subtract_with_carry_01 using a generator
-Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+Section: 26.5.3 [rand.eng], TR1 5.1.4.4 [tr.rand.eng.sub1] Status: NAD Editorial + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
View all other issues in [rand.eng].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Paragraph 6 says: @@ -11831,8 +12624,8 @@ Portland: Subsumed by N2111.
517. Should include name in external representation
-Section: X [rand.req], TR1 5.1.1 [tr.rand.req] Status: NAD - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-03-13
+Section: 26.5.1 [rand.req], TR1 5.1.1 [tr.rand.req] Status: NAD + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
View all other issues in [rand.req].
View all issues with NAD status.
Discussion:
@@ -11869,10 +12662,10 @@ Berlin: N1932 considers this NAD. This is a QOI issue.
523. regex case-insensitive character ranges are unimplementable as specified
-Section: 28 [re] Status: NAD Future - Submitter: Eric Niebler Opened: 2005-07-01 Last modified: 2009-07-15
+Section: 28 [re] Status: NAD Future + Submitter: Eric Niebler Opened: 2005-07-01 Last modified: 2010-10-29
View all other issues in [re].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
A problem with TR1 regex is currently being discussed on the Boost @@ -12020,46 +12813,10 @@ Move to NAD Future. -
-525. type traits definitions not clear
-Section: 20.6.4 [meta.unary], TR1 4.5 [tr.meta.unary] Status: NAD Editorial - Submitter: Robert Klarer Opened: 2005-07-11 Last modified: 2008-03-13
-View all issues with NAD Editorial status.
-Discussion:
--It is not completely clear how the primary type traits deal with -cv-qualified types. And several of the secondary type traits -seem to be lacking a definition. -
- -[ -Berlin: Howard to provide wording. -]
- - - -Proposed resolution:
--Wording provided in N2028. -A -revision (N2157) -provides more detail for motivation. -
- - -Rationale:
-Solved by revision (N2157) -in the WP. - - - - -
526. Is it undefined if a function in the standard changes in parameters?
Section: 23.2.3 [sequence.reqmts] Status: NAD - Submitter: Chris Jefferson Opened: 2005-09-14 Last modified: 2008-03-13
-View other active issues in [sequence.reqmts].
+ Submitter: Chris Jefferson Opened: 2005-09-14 Last modified: 2010-10-29View all other issues in [sequence.reqmts].
View all issues with NAD status.
Discussion:
@@ -12208,8 +12965,8 @@ template insert functions from self referencing.
Section: 23.5 [unord], TR1 6.3.4 [tr.unord.unord] Status: NAD - Submitter: Paolo Carlini Opened: 2005-10-12 Last modified: 2008-03-13
+Section: 23.7 [unord], TR1 6.3.4 [tr.unord.unord] Status: NAD + Submitter: Paolo Carlini Opened: 2005-10-12 Last modified: 2010-10-29
View all other issues in [unord].
View all issues with NAD status.
Discussion:
@@ -12284,9 +13041,9 @@ chapter 17 wording.Section: 17.6.3.11 [res.on.required] Status: NAD Editorial - Submitter: David Abrahams Opened: 2005-10-25 Last modified: 2008-03-13
-View all issues with NAD Editorial status.
+Section: 17.6.3.11 [res.on.required] Status: NAD Editorial + Submitter: David Abrahams Opened: 2005-10-25 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
17.4.3.8/1 says: @@ -12378,10 +13135,10 @@ Alan provided the survey
Section: 20.5.2.7 [tuple.rel], TR1 6.1.3.5 [tr.tuple.rel] Status: NAD Future - Submitter: David Abrahams Opened: 2005-11-29 Last modified: 2009-10-24
+Section: 20.4.2.7 [tuple.rel], TR1 6.1.3.5 [tr.tuple.rel] Status: NAD Future + Submitter: David Abrahams Opened: 2005-11-29 Last modified: 2010-10-29
View all other issues in [tuple.rel].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Duplicate of: 348
Discussion:
@@ -12483,8 +13240,7 @@ Solved by
Section: 23.2 [container.requirements] Status: Dup - Submitter: Joaquín M López Muńoz Opened: 2005-12-17 Last modified: 2007-04-18
-View other active issues in [container.requirements].
+ Submitter: Joaquín M López Muńoz Opened: 2005-12-17 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with Dup status.
Duplicate of: 589
@@ -12554,10 +13310,10 @@ Berlin: Some support, not universal, for respecting the explicit qualifier.Section: C.2 [diff.library] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2005-11-25 Last modified: 2007-04-24
+Section: C.2 [diff.library] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2005-11-25 Last modified: 2010-10-29
View all other issues in [diff.library].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
According to C.2.2.3, p1, "the macro NULL, defined in any of <clocale>, @@ -12600,7 +13356,7 @@ Portland: Resolution is considered editorial. It will be incorporated into the
Section: TR1 5.1.1 [tr.rand.req] Status: NAD - Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2009-07-15
+ Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -12646,7 +13402,7 @@ Move to NAD.
Section: 26.5 [rand], TR1 5.1 [tr.rand] Status: NAD - Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2007-04-18
+ Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29View all other issues in [rand].
View all issues with NAD status.
Discussion:
@@ -12679,7 +13435,7 @@ Recommend NAD as the affected section is now gone and so the issue is moot.Section: 26.5.6 [rand.device], TR1 5.1.6 [tr.rand.device] Status: NAD - Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2007-10-18
+ Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29View all other issues in [rand.device].
View all issues with NAD status.
Discussion:
@@ -12721,10 +13477,10 @@ Adopt the proposed resolution inSection: 26.5.8 [rand.dist], TR1 5.1.7.5 [tr.rand.dist.bin] Status: NAD Editorial - Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2007-04-24
+Section: 26.5.8 [rand.dist], TR1 5.1.7.5 [tr.rand.dist.bin] Status: NAD Editorial + Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29
View all other issues in [rand.dist].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Paragraph 1 says that "A binomial distributon random distribution produces @@ -12750,10 +13506,10 @@ Portland: Subsumed by N2111.
Section: 18.4.1 [cstdint.syn], TR1 8.22.1 [tr.c99.cstdint.syn] Status: NAD Editorial - Submitter: Paolo Carlini Opened: 2006-01-30 Last modified: 2007-07-02
+Section: 18.4.1 [cstdint.syn], TR1 8.22.1 [tr.c99.cstdint.syn] Status: NAD Editorial + Submitter: Paolo Carlini Opened: 2006-01-30 Last modified: 2010-10-29
View all other issues in [cstdint.syn].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
In the synopsis, some types are identified as optional: int8_t, int16_t, @@ -12789,7 +13545,7 @@ Recommend NAD and fix as editorial with the proposed resolution.
Section: 18.3.1.5 [numeric.special] Status: NAD - Submitter: Howard Hinnant Opened: 2006-01-29 Last modified: 2007-01-15
+ Submitter: Howard Hinnant Opened: 2006-01-29 Last modified: 2010-10-29View all other issues in [numeric.special].
View all issues with NAD status.
Discussion:
@@ -12854,9 +13610,9 @@ value that will trap.Section: TR1 8.21 [tr.c99.boolh] Status: NAD Editorial - Submitter: Paolo Carlini Opened: 2006-02-02 Last modified: 2007-04-24
-View all issues with NAD Editorial status.
+Section: TR1 8.21 [tr.c99.boolh] Status: NAD Editorial + Submitter: Paolo Carlini Opened: 2006-02-02 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
This one, if nobody noticed it yet, seems really editorial: @@ -12885,10 +13641,10 @@ Redmond: Editorial.
Section: 18.4 [cstdint], TR1 8.22 [tr.c99.cstdint] Status: NAD Editorial - Submitter: Paolo Carlini Opened: 2006-02-06 Last modified: 2008-07-02
+Section: 18.4 [cstdint], TR1 8.22 [tr.c99.cstdint] Status: NAD Editorial + Submitter: Paolo Carlini Opened: 2006-02-06 Last modified: 2010-10-29
View all other issues in [cstdint].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
I'm seeing a problem with such overloads: when, _Longlong == intmax_t == @@ -12976,10 +13732,10 @@ may not be unique if intmax_t==_longlong.
Section: 24.2.1 [input.iterators] Status: NAD Editorial - Submitter: David Abrahams Opened: 2006-02-09 Last modified: 2007-04-24
+Section: 24.2.3 [input.iterators] Status: NAD Editorial + Submitter: David Abrahams Opened: 2006-02-09 Last modified: 2010-10-29
View all other issues in [input.iterators].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
@@ -13024,8 +13780,8 @@ Portland: Editorial.
560. User-defined allocators without default constructor
-Section: 20.2.2 [allocator.requirements] Status: NAD - Submitter: Sergey P. Derevyago Opened: 2006-02-17 Last modified: 2007-04-18
+Section: 20.2.5 [allocator.requirements] Status: NAD + Submitter: Sergey P. Derevyago Opened: 2006-02-17 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with NAD status.
Discussion:
@@ -13163,7 +13919,7 @@ semantics of copying the allocator from one of the strings (lhs when ther
568. log2 overloads missing
Section: TR1 8.16.4 [tr.c99.cmath.over] Status: NAD - Submitter: Paolo Carlini Opened: 2006-03-07 Last modified: 2009-07-13
+ Submitter: Paolo Carlini Opened: 2006-03-07 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -13196,7 +13952,7 @@ Add log2 to the list of functions in TR1 8.16.4 [tr.c99.cmath.over] p1.
569. Postcondition for basic_ios::clear(iostate) incorrectly stated
Section: 27.5.4.3 [iostate.flags] Status: Dup - Submitter: Seungbeom Kim Opened: 2006-03-10 Last modified: 2006-12-30
+ Submitter: Seungbeom Kim Opened: 2006-03-10 Last modified: 2010-10-29View all other issues in [iostate.flags].
View all issues with Dup status.
Duplicate of: 272
@@ -13235,7 +13991,7 @@ committee meant.
570. Request adding additional explicit specializations of char_traits
Section: 21.2 [char.traits] Status: NAD - Submitter: Jack Reeves Opened: 2006-04-06 Last modified: 2008-06-18
+ Submitter: Jack Reeves Opened: 2006-04-06 Last modified: 2010-10-29View all other issues in [char.traits].
View all issues with NAD status.
Discussion:
@@ -13301,10 +14057,10 @@ Nobody has submitted the requested paper, so we move to NAD, as suggested by the
571. Update C90 references to C99?
-Section: 1.2 [intro.refs] Status: NAD Editorial - Submitter: Beman Dawes Opened: 2006-04-08 Last modified: 2007-07-02
+Section: 1.2 [intro.refs] Status: NAD Editorial + Submitter: Beman Dawes Opened: 2006-04-08 Last modified: 2010-10-29
View all other issues in [intro.refs].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
1.2 Normative references [intro.refs] of the WP currently refers to ISO/IEC @@ -13338,7 +14094,7 @@ Recommend NAD, fixed editorially.
572. Oops, we gave 507 WP status
Section: 26.5 [rand], TR1 5.1 [tr.rand] Status: NAD - Submitter: Howard Hinnant Opened: 2006-04-11 Last modified: 2007-04-18
+ Submitter: Howard Hinnant Opened: 2006-04-11 Last modified: 2010-10-29View all other issues in [rand].
View all issues with NAD status.
Discussion:
@@ -13374,7 +14130,7 @@ is adopted.
573. C++0x file positioning should handle modern file sizes
Section: 27.5.3 [fpos] Status: NAD - Submitter: Beman Dawes Opened: 2006-04-12 Last modified: 2009-07-15
+ Submitter: Beman Dawes Opened: 2006-04-12 Last modified: 2010-10-29View all other issues in [fpos].
View all issues with NAD status.
Discussion:
@@ -13446,7 +14202,7 @@ Move to NAD.
579. erase(iterator) for unordered containers should not return an iterator
Section: 23.2.5 [unord.req] Status: NAD - Submitter: Joaquín M López Muńoz Opened: 2006-06-13 Last modified: 2008-03-12
+ Submitter: Joaquín M López Muńoz Opened: 2006-06-13 Last modified: 2010-11-29View other active issues in [unord.req].
View all other issues in [unord.req].
View all issues with NAD status.
@@ -13457,8 +14213,41 @@ See for full discussion. +[ +2009-12-11 Paolo opens: +]
-Proposed resolution:
+ ++I'm asking for DR 579 to be re-opened, basing on recent discussions on the +library reflector, see Message c++std-lib-26040 and replies. ++ +[ +2010-02-07 Paolo updates wording. +]
+ + ++As pointed out by Chris in c++std-lib-26040, that an +erase(unordered_container, iterator) returning an iterator can +easily implemented in user code, if needed; that actually returning an +iterator costs nothing for the overload taking two iterators, +thus that proposed change is only for consistency; that +forward_list::erase_after also returns void (for different +reasons, granted, but isn't that any "erase" function in the containers +uniformly returns an iterator); that, also in thread started by Chris' +message, Alberto pointed out that the proxy idea isn't a good one; that users +both of the GNU and Boost implementations are reporting serious performance +problems with the current version returning an iterator. ++ +[ +2010-02-07 Original wording saved here: +]
+ + +Option 1:
@@ -13498,34 +14287,89 @@ have some collateral effects when the expression a.erase(q) is used ins code. - - -Rationale:
--N2023 -was discussed in Portland and the consensus was that there appears to be -no need for either change proposed in the paper. The consensus opinion -was that since the iterator could serve as its own proxy, there appears -to be no need for the change. In general, "converts to" is undesirable -because it interferes with template matching. -
- --Post Toronto: There does not at this time appear to be consensus with the Portland consensus. -
+[ -Bellevue: +2010-03-27 Joaquín adds: ]
-The Bellevue review of this issue reached consensus with the Portland -consensus, in contravention of the Toronto non-consensus. Common -implementations have the iterator readily available, and most common -uses depend on the iterator being returned. +++Signature of iterator erase(const_iterator) should be changed to void +erase(const_iterator). If this is not viable an acceptable tradeoff +could be to make the return type of erase(const_iterator) +implementation defined. +
+ ++The standard should allow implementations of unordered associative +containers using either singly or doubly linked lists. +N2023 +proves that singly-linked lists implementations cannot provide the required +complexity for iterator erase(const_iterator). Thus, some action is +needed to allow both implementations. +
+ ++Option 1: Changing the required complexity from O(1) to O(log n). This option +merely masks a design flaw. Users are forcefully penalized for what they don't +use (the returned iterator). Besides, they would have to learn about the +pathological (yet very real) situations where using erase can lead to +quadratic performance. Two out of these three objections remain even if some +alternative member function like void quick_erase(const_iterator) is +thrown in to the interface. +
+ ++Some objections have been expressed to changing return type of erase to +void, arguing that it would break current existing practice with +standard library implementations based on doubly-linked lists, where the problem +does not occur. However implementations based on drafts should not block the +resolution of a serious design issue, more so when the issue will hurt future +users of C++, as it's happening already. +
+ ++Option 2: Make erase return type implementation defined. There's +a possible tradeoff with the objectors above consisting in changing the +signature to implementation defined erase(iterator), so that +returning an iterator is indeed a valid extension. To this it can be argued that +this would make implementantions returning an iterator look as somehow promoting +proprietary extensions: this in my opinion is not a valid argument since those +implementations are already extending the required interface by +providing bidirectional iterators (just forward iterators are required). +
[ +2010 Rapperswil: +]
+ + +++ + ++The issue was lengthy discussed and implementation experience was demonstrated that a non-void return +type is implementable for both single-linked and double-linked lists without loss of efficiency. +
+ ++By a 12-1-1-0 poll voted to keep the return type of erase as iterator instead of +void and a second 0-0-3-10 poll rejected the additional proposal to add a +quick_erase returning void, thus LWG decided for NAD. +
+Rationale:
+ ++No consensus for a change. +
+ + + +Proposed resolution:
@@ -13533,11 +14377,11 @@ uses depend on the iterator being returned.
580. unused allocator members
-Section: 23.2.1 [container.requirements.general] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2009-10-26
+Section: 23.2.1 [container.requirements.general] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2010-10-29
View other active issues in [container.requirements.general].
View all other issues in [container.requirements.general].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Duplicate of: 479
Discussion:
@@ -13695,7 +14539,7 @@ destroy temporaries.
[ -Howard: This same paragraph will need some work to accommodate 431. +Howard: This same paragraph will need some work to accommodate 431. ]
@@ -13710,8 +14554,8 @@ post Oxford: This would be rendered NAD Editorial by acceptance of
582. specialized algorithms and volatile storage
-Section: 20.8.13.2 [uninitialized.copy] Status: NAD - Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2009-07-15
+Section: 20.9.8.2 [uninitialized.copy] Status: NAD + Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2010-10-29
View all other issues in [uninitialized.copy].
View all issues with NAD status.
Discussion:
@@ -13762,7 +14606,7 @@ possible editorial change would be to put my previous sentence into a non-normative note.-Note that the three sections starting with 20.8.13.2 [uninitialized.copy] do not +Note that the three sections starting with 20.9.8.2 [uninitialized.copy] do not yet have concepts. Here's a first crack at the first one:
template <InputIterator InIter, OutputIterator OutIter> @@ -13933,7 +14777,7 @@ effect by means of function template overloading.
583. div() for unsigned integral types
Section: 26.8 [c.math] Status: NAD - Submitter: Beman Dawes Opened: 2006-06-15 Last modified: 2007-07-25
+ Submitter: Beman Dawes Opened: 2006-06-15 Last modified: 2010-10-29View all other issues in [c.math].
View all issues with NAD status.
Discussion:
@@ -13971,7 +14815,7 @@ behavior and thus does not need this treatment.
584. missing int pow(int,int) functionality
Section: 26.8 [c.math] Status: NAD - Submitter: Beman Dawes Opened: 2006-06-15 Last modified: 2007-07-25
+ Submitter: Beman Dawes Opened: 2006-06-15 Last modified: 2010-10-29View all other issues in [c.math].
View all issues with NAD status.
Discussion:
@@ -14001,7 +14845,7 @@ Toronto: We already have double pow(integral, integral) from 26.8 [c.math] p11.
585. facet error reporting
Section: 22.4 [locale.categories] Status: NAD - Submitter: Martin Sebor, Paolo Carlini Opened: 2006-06-22 Last modified: 2009-07-15
+ Submitter: Martin Sebor, Paolo Carlini Opened: 2006-06-22 Last modified: 2010-10-29View all other issues in [locale.categories].
View all issues with NAD status.
Discussion:
@@ -14131,9 +14975,9 @@ Proposed Disposition: Open
587. iststream ctor missing description
-Section: D.8.2.1 [depr.istrstream.cons] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2006-06-22 Last modified: 2007-05-11
-View all issues with NAD Editorial status.
+Section: D.9.2.1 [depr.istrstream.cons] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2006-06-22 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
@@ -14165,7 +15009,7 @@ post Oxford: Noted that it is already fixed in
588. requirements on zero sized tr1::arrays and other details
Section: 23.3.1 [array] Status: NAD - Submitter: Gennaro Prota Opened: 2006-07-18 Last modified: 2009-10-20
+ Submitter: Gennaro Prota Opened: 2006-07-18 Last modified: 2010-10-29View all other issues in [array].
View all issues with NAD status.
Discussion:
@@ -14321,7 +15165,7 @@ star bullet 3 ("it would be desiderable to have a static const data member..."):-It seems that tuple_size<array<T, N> >::value as of 23.3.1.7 [array.tuple] does +It seems that tuple_size<array<T, N> >::value as of 23.3.1.8 [array.tuple] does provide this functionality now.@@ -14370,10 +15214,10 @@ requirements? Alisdair will prepare a paper. Proposed Disposition: Open
590. Type traits implementation latitude should be removed for C++0x
-Section: 20.6 [meta], TR1 4.9 [tr.meta.req] Status: NAD Editorial - Submitter: Beman Dawes Opened: 2006-08-10 Last modified: 2007-05-11
+Section: 20.7 [meta], TR1 4.9 [tr.meta.req] Status: NAD Editorial + Submitter: Beman Dawes Opened: 2006-08-10 Last modified: 2010-10-29
View all other issues in [meta].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
20.4.9 [lib.meta.req], Implementation requirements, provides latitude for type @@ -14411,10 +15255,10 @@ current working draft.
591. Misleading "built-in
-Section: 18.3.1.2 [numeric.limits.members] Status: NAD Editorial - Submitter: whyglinux Opened: 2006-08-08 Last modified: 2007-07-02
+Section: 18.3.1.2 [numeric.limits.members] Status: NAD Editorial + Submitter: whyglinux Opened: 2006-08-08 Last modified: 2010-10-29
View all other issues in [numeric.limits.members].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
18.2.1.2 numeric_limits members [lib.numeric.limits.members] @@ -14480,10 +15324,10 @@ Recommend NAD / Editorial. The proposed resolution is accepted as editorial.
592. Incorrect treatment of rdbuf()->close() return type
-Section: 27.9.1.9 [ifstream.members] Status: NAD Editorial - Submitter: Christopher Kohlhoff Opened: 2006-08-17 Last modified: 2008-07-02
+Section: 27.9.1.9 [ifstream.members] Status: NAD Editorial + Submitter: Christopher Kohlhoff Opened: 2006-08-17 Last modified: 2010-10-29
View all other issues in [ifstream.members].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
I just spotted a minor problem in 27.8.1.7 @@ -14541,7 +15385,7 @@ Kona (2007): Proposed Disposition: NAD, Editorial
597. Decimal: The notion of 'promotion' cannot be emulated by user-defined types.
Section: TRDecimal 3.2 [trdec.types.types] Status: NAD - Submitter: Daveed Vandevoorde Opened: 2006-04-05 Last modified: 2009-07-15
+ Submitter: Daveed Vandevoorde Opened: 2006-04-05 Last modified: 2010-10-29View all other issues in [trdec.types.types].
View all issues with NAD status.
Discussion:
@@ -14588,10 +15432,8 @@ better than the other.Robert comments:
-In general, a library of arithmetic types cannot exactly emulate the -behavior of the intrinsic numeric types. There are several ways to tell -whether an implementation of the decimal types uses compiler -intrinisics or a library. For example: +
+In general, a library of arithmetic types cannot exactly emulate the behavior of the intrinsic numeric types. There are several ways to tell whether an implementation of the decimal types uses compiler intrinisics or a library. For example:
_Decimal32 d1; d1.operator+=(5); // If d1 is a builtin type, this won't compile. @@ -14602,20 +15444,13 @@ In preparing the decimal TR, we have three options:
- require that the decimal types be class types
- require that the decimal types be builtin types, like float and double
-- specify a library of class types, but allow enough implementor -latitude that a conforming implementation could instead provide builtin -types
+- specify a library of class types, but allow enough implementor latitude that a conforming implementation could instead provide builtin types
-We decided as a group to pursue option #3, but that approach implies -that implementations may not agree on the semantics of certain use -cases (first example, above), or on whether certain other cases are -well-formed (second example). Another potentially important problem is -that, under the present definition of POD, the decimal classes are not -POD types, but builtins will be. +We decided as a group to pursue option #3, but that approach implies that implementations may not agree on the semantics of certain use cases (first example, above), or on whether certain other cases are well-formed (second example). Another potentially important problem is that, under the present definition of POD, the decimal classes are not POD types, but builtins will be.
-Note that neither example above implies any problems with respect to -C-to-C++ compatibility, since neither example can be expressed in C. +
+Note that neither example above implies any problems with respect to C-to-C++ compatibility, since neither example can be expressed in C.
[ @@ -14646,16 +15481,15 @@ Move to NAD.
606. Decimal: allow narrowing conversions
Section: TRDecimal 3.2 [trdec.types.types] Status: NAD - Submitter: Martin Sebor Opened: 2006-06-15 Last modified: 2009-07-15
+ Submitter: Martin Sebor Opened: 2006-06-15 Last modified: 2010-10-29View all other issues in [trdec.types.types].
View all issues with NAD status.
Discussion:
In c++std-lib-17205, Martin writes:
-...was it a deliberate design choice to make narrowing -assignments ill-formed while permitting narrowing compound assignments? -For instance: +
+...was it a deliberate design choice to make narrowing assignments ill-formed while permitting narrowing compound assignments? For instance:
decimal32 d32; decimal64 d64; @@ -14666,10 +15500,8 @@ For instance:In c++std-lib-17229, Robert responds:
-It is a vestige of an old idea that I forgot to remove -from the paper. Narrowing assignments should be permitted. The bug is -that the converting constructors that cause narrowing should not be -explicit. Thanks for pointing this out. +
+It is a vestige of an old idea that I forgot to remove from the paper. Narrowing assignments should be permitted. The bug is that the converting constructors that cause narrowing should not be explicit. Thanks for pointing this out.
[ @@ -14721,7 +15553,7 @@ Redmond: We prefer explicit conversions for narrowing and implicit for widening.
614. std::string allocator requirements still inconsistent
Section: 21.4 [basic.string] Status: NAD - Submitter: Bo Persson Opened: 2006-12-05 Last modified: 2009-07-15
+ Submitter: Bo Persson Opened: 2006-12-05 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with NAD status.
Discussion:
@@ -14764,14 +15596,14 @@ rules (substr, operator+, etc.). Howard to supply wording. Bo adds: The new container constructor which takes only a size_type is not consistent with 23.2 [container.requirements], p9 which says in part: -++]All other constructors for these container types take an Allocator& argument (20.1.2), an allocator whose value type is the same as the container's value type. A copy of this argument is used for any memory allocation performed, by these constructors and by all member functions, during the lifetime of each container object. --] +[ @@ -14800,10 +15632,10 @@ Move to NAD.
615. Inconsistencies in Section 21.4
-Section: 21.6 [c.strings] Status: NAD Editorial - Submitter: Bo Persson Opened: 2006-12-11 Last modified: 2007-04-24
+Section: 21.7 [c.strings] Status: NAD Editorial + Submitter: Bo Persson Opened: 2006-12-11 Last modified: 2010-10-29
View all other issues in [c.strings].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
In the current draft N2134, 21.4/1 says @@ -14840,7 +15672,7 @@ Recommend NAD, editorial. Send to Pete.
617. std::array is a sequence that doesn't satisfy the sequence requirements?
Section: 23.3.1 [array] Status: NAD - Submitter: Bo Persson Opened: 2006-12-30 Last modified: 2009-10-20
+ Submitter: Bo Persson Opened: 2006-12-30 Last modified: 2010-10-29View all other issues in [array].
View all issues with NAD status.
Discussion:
@@ -14968,10 +15800,10 @@ what's specified about sequences. Move to NAD.
626. new Remark clauses not documented
-Section: 17.5.1.4 [structure.specifications] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2008-02-25
+Section: 17.5.1.4 [structure.specifications] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29
View all other issues in [structure.specifications].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
@@ -15010,7 +15842,7 @@ Bellevue: Already resolved in current working paper.
627. Low memory and exceptions
Section: 18.6.1.1 [new.delete.single] Status: NAD - Submitter: P.J. Plauger Opened: 2007-01-23 Last modified: 2008-02-25
+ Submitter: P.J. Plauger Opened: 2007-01-23 Last modified: 2010-10-29View all other issues in [new.delete.single].
View all issues with NAD status.
Discussion:
@@ -15041,11 +15873,159 @@ its resource limits", so no further escape hatch is necessary. +
+631. conflicting requirements for BinaryPredicate
+Section: 25 [algorithms] Status: NAD + Submitter: James Kanze Opened: 2007-01-31 Last modified: 2010-10-29
+View all other issues in [algorithms].
+View all issues with NAD status.
+Discussion:
++The general requirements for BinaryPredicate (in 25 [algorithms]/8) contradict the implied specific requirements for +some functions. In particular, it says that: +
+ ++ ++[...] if an algorithm takes BinaryPredicate binary_pred +as its argument and first1 and first2 as its +iterator arguments, it should work correctly in the construct if +(binary_pred (*first1 , *first2 )){...}. +BinaryPredicate always takes the first iterator type as its +first argument, that is, in those cases when T value is +part of the signature, it should work correctly in the context of if +(binary_pred (*first1 , value)){...}. +
+In the description of upper_bound (25.4.3.2 [upper.bound]/2), however, the use is described as +"!comp(value, e)", where e is an +element of the sequence (a result of dereferencing +*first). +
+ ++In the description of lexicographical_compare, we have both +"*first1 < *first2" and "*first2 +< *first1" (which presumably implies "comp( +*first1, *first2 )" and "comp( *first2, +*first1 )". +
+ ++Logically, the BinaryPredicate is used as an ordering +relationship, with the semantics of "less than". Depending on the +function, it may be used to determine equality, or any of the inequality +relationships; doing this requires being able to use it with either +parameter first. I would thus suggest that the requirement be: +
+ ++Alternatively, one could specify an order for each function. IMHO, this +would be more work for the committee, more work for the implementors, +and of no real advantage for the user: some functions, such as +lexicographical_compare or equal_range, will still require both +functions, and it seems like a much easier rule to teach that both +functions are always required, rather than to have a complicated list of +when you only need one, and which one. +
+ +[ +Toronto: Moved to Open. ConceptGCC seems to get lower_bound +and upper_bound to work withoutt these changes. +]
+ + +[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Review. The small problem with the "iterator type" +will be fixed. The cited functions (lower_bound, uppwer_bound, +equal_range) don't actually use BinaryPredicate , and where it is used, +it is consistent with [algorithm]/8, so the main complaint of the issue +is moot. ++ +[ +2010-01-16 Beman clarified wording. +]
+ + +[ +2010-01-31: Moved to Tentatively NAD after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + + +Rationale:
+[ +post San Francisco: +]
+ + +++ ++Solved by +N2759. +
++2010-01-31: The draft standard is well specified as is, and this specification +is desired. Issues 556 and 870 solve the remaining +unclearness regarding the meaning of BinaryPredicate. +
+ + + +Proposed resolution:
+Change 25 [algorithms] paragraph 8 as indicated:
+ ++ ++ + + + + ++8 The BinaryPredicate parameter is used whenever an algorithm expects a +function object that when applied to the result of dereferencing two +corresponding iterators or to dereferencing an iterator and type T when +T is part of the signature returns a value testable as true. +BinaryPredicate always takes the first iterator value_type as +one of its arguments; which argument is unspecified.
+ +In other words, +ifIf an algorithm takes BinaryPredicate binary_pred +as its argument and first1 and first2 as its iterator +arguments, it should work correctly both in the construct if +(binary_pred(*first1, *first2)){...} and if (binary_pred (*first2, +*first1)){...}.BinaryPredicate always takes the first +iterator type as its first argument, that is, inIn those cases +when T value is part of the signature, it should work correctly in the +context of if (binary_pred(*first1, value)){...} and of if +(binary_pred (value, *first1)){...}.binary_pred shall +not apply any non-constant function through the dereferenced iterators.+[Note: if the two types are not identical, and neither is +convertable to the other, this may require that the BinaryPredicate be +a functional object with two overloaded operator()() functions. +— end note] +
632. Time complexity of size() for std::set
Section: 23.2 [container.requirements] Status: NAD - Submitter: Lionel B Opened: 2007-02-01 Last modified: 2009-07-15
-View other active issues in [container.requirements].
+ Submitter: Lionel B Opened: 2007-02-01 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with NAD status.
Discussion:
@@ -15141,12 +16121,12 @@ Fixed by paper N2923.
633. Return clause mentions undefined "type()"
-Section: 20.7.15.2.5 [func.wrap.func.targ] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-02-03 Last modified: 2007-07-02
-View all issues with NAD Editorial status.
+Section: 20.8.14.2.5 [func.wrap.func.targ] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-02-03 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
-20.7.15.2.5 [func.wrap.func.targ], p4 says: +20.8.14.2.5 [func.wrap.func.targ], p4 says:
Returns: If type() == typeid(T), a pointer to the stored @@ -15162,7 +16142,7 @@ function type() in class template function nor in the global or
Assuming that type should have been target_type(), this description would lead to false results, if T = cv -void due to returns clause 20.7.15.2.5 [func.wrap.func.targ], p1. +void due to returns clause 20.8.14.2.5 [func.wrap.func.targ], p1. @@ -15170,7 +16150,7 @@ void due to returns clause 20.7.15.2.5 [func.wrap.func.targ], p1.Proposed resolution:
-Change 20.7.15.2.5 [func.wrap.func.targ], p4: +Change 20.8.14.2.5 [func.wrap.func.targ], p4:
@@ -15189,138 +16169,12 @@ Pete: Agreed. It's editorial, so I'll fix it. -
-635. domain of allocator::address
-Section: 20.2.2 [allocator.requirements] Status: NAD Editorial - Submitter: Howard Hinnant Opened: 2007-02-08 Last modified: 2009-10-26
-View all other issues in [allocator.requirements].
-View all issues with NAD Editorial status.
-Discussion:
--The table of allocator requirements in 20.2.2 [allocator.requirements] describes -allocator::address as: -
--a.address(r) -a.address(s) --where r and s are described as: -
-- --a value of type X::reference obtained by the expression *p. -
-and p is -
- -- --a value of type X::pointer, obtained by calling a1.allocate, -where a1 == a -
-This all implies that to get the address of some value of type T that -value must have been allocated by this allocator or a copy of it. -
- --However sometimes container code needs to compare the address of an external value of -type T with an internal value. For example list::remove(const T& t) -may want to compare the address of the external value t with that of a value -stored within the list. Similarly vector or deque insert may -want to make similar comparisons (to check for self-referencing calls). -
- --Mandating that allocator::address can only be called for values which the -allocator allocated seems overly restrictive. -
- -[ -post San Francisco: -]
- - --Pablo recommends NAD Editorial, solved by -N2768. -- -[ -2009-04-28 Pablo adds: -]
- - --Tentatively-ready NAD Editorial as fixed by -N2768. -- -[ -2009-07 Frankfurt -]
- - --Fixed by N2768. -- -[ -2009-07-28 Reopened by Alisdair. No longer solved by concepts. -]
- - -[ -2009-10 Santa Cruz: -]
- - --NAD Editorial. Addressed by -N2982. -- - - -Proposed resolution:
--Change 20.2.2 [allocator.requirements]: -
- --- --r : a value of type X::reference
-obtained by the expression *p. --s : a value of type X::const_reference
-obtained by the -expression *q or by conversion from a value r. -[ -post Oxford: This would be rendered NAD Editorial by acceptance of -N2257. -]
- - -[ -Kona (2007): This issue is section 8 of N2387. There was some discussion of it but -no resolution to this issue was recorded. Moved to Open. -]
- - - - - - -
636. 26.5.2.3 valarray::operator[]
-Section: 26.6.2.3 [valarray.access] Status: NAD Editorial - Submitter: Bo Persson Opened: 2007-02-11 Last modified: 2007-07-02
+Section: 26.6.2.3 [valarray.access] Status: NAD Editorial + Submitter: Bo Persson Opened: 2007-02-11 Last modified: 2010-10-29
View all other issues in [valarray.access].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
The signature of the const operator[] has been changed to return a const @@ -15346,10 +16200,10 @@ Pete recommends editorial fix.
637. [c.math]/10 inconsistent return values
-Section: 26.8 [c.math] Status: NAD Editorial - Submitter: Bo Persson Opened: 2007-02-13 Last modified: 2007-07-26
+Section: 26.8 [c.math] Status: NAD Editorial + Submitter: Bo Persson Opened: 2007-02-13 Last modified: 2010-10-29
View all other issues in [c.math].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
26.8 [c.math], paragraph 10 has long lists of added signatures for float and long double @@ -15384,7 +16238,7 @@ Change 26.8 [c.math], paragraph 10,
639. Still problems with exceptions during streambuf IO
Section: 27.7.1.2.3 [istream::extractors], 27.7.2.6.3 [ostream.inserters] Status: NAD - Submitter: Daniel Krügler Opened: 2007-02-17 Last modified: 2007-10-10
+ Submitter: Daniel Krügler Opened: 2007-02-17 Last modified: 2010-10-29View all other issues in [istream::extractors].
View all issues with NAD status.
Discussion:
@@ -15527,10 +16381,10 @@ input functions because that applies to the case in which badbit is set.
641. Editorial fix for 27.6.4 (N2134)
-Section: 27.7.4 [ext.manip] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-02-18 Last modified: 2007-07-02
+Section: 27.7.4 [ext.manip] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-02-18 Last modified: 2010-10-29
View all other issues in [ext.manip].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
The function f in para 4 (27.7.4 [ext.manip]) references an unknown strm @@ -15561,10 +16415,10 @@ Oxford: Editorial.
642. Invalidated fstream footnotes in N2134
-Section: 27.9.1.9 [ifstream.members], 27.9.1.13 [ofstream.members] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-02-20 Last modified: 2007-07-02
+Section: 27.9.1.9 [ifstream.members], 27.9.1.13 [ofstream.members] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-02-20 Last modified: 2010-10-29
View all other issues in [ifstream.members].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
The standard wording of N2134 has extended the 14882:2003(E) @@ -15631,13 +16485,13 @@ In 27.9.1.13 [ofstream.members], remove footnote:
644. Possible typos in 'function' description
-Section: 20.7.15.2 [func.wrap.func] Status: NAD - Submitter: Bo Persson Opened: 2007-02-25 Last modified: 2009-07-13
+Section: 20.8.14.2 [func.wrap.func] Status: NAD + Submitter: Bo Persson Opened: 2007-02-25 Last modified: 2010-10-29
View all other issues in [func.wrap.func].
View all issues with NAD status.
Discussion:
-20.7.15.2 [func.wrap.func] +20.8.14.2 [func.wrap.func]
The note in paragraph 2 refers to 'undefined void operators', while the @@ -15663,7 +16517,7 @@ type of these deleted functions to be?
I suggest harmonizing this issue with similar classes. E.g. in -20.8.15.3 [util.smartptr.weak] bool return values for +20.9.10.3 [util.smartptr.weak] bool return values for
template <class Y> bool operator<(weak_ptr<Y> const&) const = delete; template <class Y> bool operator<=(weak_ptr<Y> const&) const = delete; @@ -15701,19 +16555,19 @@ Move to NAD.Proposed resolution:
-Change 20.7.15.2 [func.wrap.func] +Change 20.8.14.2 [func.wrap.func]
... private: - // 20.7.15.2 [func.wrap.func], undefined operators: + // 20.8.14.2 [func.wrap.func], undefined operators: template<class Function2>boolvoid operator==(const function<Function2>&); template<class Function2>boolvoid operator!=(const function<Function2>&); };-Change 20.7.15.2 [func.wrap.func] +Change 20.8.14.2 [func.wrap.func]
template<class Function2>boolvoid operator==(const function<Function2>&); @@ -15726,10 +16580,10 @@ template<class Function2>boolvoid operator!=(const
645. Missing members in match_results
-Section: 28.10 [re.results] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-02-26 Last modified: 2008-03-12
+Section: 28.10 [re.results] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-02-26 Last modified: 2010-10-29
View all other issues in [re.results].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
According to the description given in 28.10 [re.results]/2 the class template @@ -15791,7 +16645,7 @@ const_iterator cend() const;
-In section 28.10.3 [re.results.acc] change: +In section 28.10.4 [re.results.acc] change:
@@ -15833,9 +16687,9 @@ Bellevue: Proposed wording now in the WP.
647. Inconsistent regex_search params
-Section: 28.11.3 [re.alg.search] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-02-26 Last modified: 2007-07-26
-View all issues with NAD Editorial status.
+Section: 28.11.3 [re.alg.search] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-02-26 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
28.11.3 [re.alg.search]/5 declares @@ -15893,9 +16747,9 @@ Applied to working paper while issue was still in New status.
648. regex_iterator c'tor needs clarification/editorial fix
-Section: 28.12.1.1 [re.regiter.cnstr] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-03-03 Last modified: 2007-07-02
-View all issues with NAD Editorial status.
+Section: 28.12.1.1 [re.regiter.cnstr] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-03-03 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
In 28.12.1.1 [re.regiter.cnstr]/2 the effects paragraph starts with: @@ -15947,10 +16801,10 @@ constructor sets *this to the end-of-sequence iterator.
649. Several typos in regex_token_iterator constructors
-Section: 28.12.2.1 [re.tokiter.cnstr] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-03-03 Last modified: 2007-07-02
+Section: 28.12.2.1 [re.tokiter.cnstr] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-03-03 Last modified: 2010-10-29
View all other issues in [re.tokiter.cnstr].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
In 28.12.2.1 [re.tokiter.cnstr]/1+2 both the constructor declaration @@ -16050,7 +16904,7 @@ constructor sets *this to an end-of-sequence iterator.
653. Library reserved names
Section: 1.2 [intro.refs] Status: NAD - Submitter: Alisdair Meredith Opened: 2007-03-08 Last modified: 2008-02-25
+ Submitter: Alisdair Meredith Opened: 2007-03-08 Last modified: 2010-10-29View all other issues in [intro.refs].
View all issues with NAD status.
Discussion:
@@ -16135,13 +16989,13 @@ Suggest a formal paper rather than a defect report is the correct way to proceed
656. Typo in subtract_with_carry_engine declaration
-Section: 26.5.1 [rand.synopsis] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-03-08 Last modified: 2007-07-02
+Section: 26.5.2 [rand.synopsis] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-03-08 Last modified: 2010-10-29
View all other issues in [rand.synopsis].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
-26.5.1 [rand.synopsis] the header <random> synopsis +26.5.2 [rand.synopsis] the header <random> synopsis contains an unreasonable closing curly brace inside the subtract_with_carry_engine declaration.
@@ -16149,7 +17003,7 @@ contains an unreasonable closing curly brace inside theProposed resolution:
-Change the current declaration in 26.5.1 [rand.synopsis] +Change the current declaration in 26.5.2 [rand.synopsis]
@@ -16781,7 +17580,7 @@ example]template <class UIntType, size_t w}, size_t s, size_t r> @@ -16168,7 +17022,7 @@ Pete: Recommends editorial.
657. unclear requirement about header inclusion
Section: 17.6.2.2 [using.headers] Status: NAD - Submitter: Gennaro Prota Opened: 2007-03-14 Last modified: 2007-10-10
+ Submitter: Gennaro Prota Opened: 2007-03-14 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -16261,62 +17115,10 @@ unlikely to be better than what's already in the standard. -
-658. Two unspecified function comparators in [function.objects]
-Section: 20.7 [function.objects] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-03-19 Last modified: 2007-08-05
-View all other issues in [function.objects].
-View all issues with NAD Editorial status.
-Discussion:
--The header <functional> synopsis in 20.7 [function.objects] -contains the following two free comparison operator templates -for the function class template -
- -- -template<class Function1, class Function2> -void operator==(const function<Function1>&, const function<Function2>&); -template<class Function1, class Function2> -void operator!=(const function<Function1>&, const function<Function2>&); --which are nowhere described. I assume that they are relicts before the -corresponding two private and undefined member templates in the function -template (see 20.7.15.2 [func.wrap.func] and [func.wrap.func.undef]) have been introduced. The original free -function templates should be removed, because using an undefined entity -would lead to an ODR violation of the user. -
- - -Proposed resolution:
--Remove the above mentioned two function templates from -the header <functional> synopsis (20.7 [function.objects]) -
- -- - - -template<class Function1, class Function2> -void operator==(const function<Function1>&, const function<Function2>&); -template<class Function1, class Function2> -void operator!=(const function<Function1>&, const function<Function2>&);-Rationale:
-Fixed by -N2292 -Standard Library Applications for Deleted Functions. - - - - -
662. Inconsistent handling of incorrectly-placed thousands separators
Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: NAD - Submitter: Cosmin Truta Opened: 2007-04-05 Last modified: 2007-07-25
-View other active issues in [facet.num.get.virtuals].
+ Submitter: Cosmin Truta Opened: 2007-04-05 Last modified: 2010-10-29View all other issues in [facet.num.get.virtuals].
View all issues with NAD status.
Discussion:
@@ -16443,7 +17245,7 @@ makes this resolution obsolete.
663. Complexity Requirements
Section: 17.5.1.4 [structure.specifications] Status: NAD - Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2009-05-01
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29View all other issues in [structure.specifications].
View all issues with NAD status.
Discussion:
@@ -16493,7 +17295,7 @@ identified, and big-O notation always involves constant factors.
667. money_get's widened minus sign
Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: NAD - Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2009-07-13
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29View all other issues in [locale.money.get.virtuals].
View all issues with NAD status.
Discussion:
@@ -16571,7 +17373,7 @@ Move to NAD.
668. money_get's empty minus sign
Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: NAD - Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2009-10-21
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29View all other issues in [locale.money.get.virtuals].
View all issues with NAD status.
Discussion:
@@ -16615,11 +17417,8 @@ Related to negative_sign of "" means "there is no way to +write a negative sign". The meaning requires the sentences of 22.4.6.1.2 [locale.money.get.virtuals] p3 following that quoted above to be taken into account: @@ -16770,7 +17569,7 @@ characters are matched, s is consumed up to and including those charact value of "()" and a currency symbol of "L", in "(100 L)" the entire string is consumed; but for a neg value of "-", in "-100 L", the string is consumed -through the second "0" (the space and "L" are not consumed). — end +through the second "0" (the space and "L" are not consumed). — end example]
669. Equivalent postive and negative signs in money_get
Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: NAD - Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2009-07-13
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29View all other issues in [locale.money.get.virtuals].
View all issues with NAD status.
Discussion:
@@ -16850,9 +17649,9 @@ We further recommend issue 670. money_base::pattern and spaceSection: 22.4.6.3 [locale.moneypunct] Status: Dup - Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2008-09-22
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29View all issues with Dup status.
-Duplicate of: 836
+Duplicate of: 836
Discussion:
22.4.6.3 [locale.moneypunct], para 2 says: @@ -16892,10 +17691,10 @@ whitespace characters on input.
683. regex_token_iterator summary error
-Section: 28.12.2 [re.tokiter] Status: NAD Editorial - Submitter: Eric Niebler Opened: 2007-06-02 Last modified: 2009-03-09
+Section: 28.12.2 [re.tokiter] Status: NAD Editorial + Submitter: Eric Niebler Opened: 2007-06-02 Last modified: 2010-10-29
View all other issues in [re.tokiter].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
28.12.2 [re.tokiter], p3 says: @@ -16941,10 +17740,10 @@ Yep, looks like a typo/administrative fix to me.
684. Unclear which members of match_results should be used in comparison
-Section: 28.10 [re.results] Status: NAD Editorial - Submitter: Nozomu Katoo Opened: 2007-05-27 Last modified: 2008-03-12
+Section: 28.10 [re.results] Status: NAD Editorial + Submitter: Nozomu Katoo Opened: 2007-05-27 Last modified: 2010-10-29
View all other issues in [re.results].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
In 28.4 [re.syn] of N2284, two template functions @@ -16989,7 +17788,7 @@ Kona (2007): Bill and Pete to add minor wording to that proposed in
Proposed resolution:
-Add a new section after 28.10.6 [re.results.swap], which reads: +Add a new section after 28.10.7 [re.results.swap], which reads:
28.10.7 match_results non-member functions. @@ -17042,13 +17841,13 @@ Bellevue: Proposed wording now in WP.
686. Unique_ptr and shared_ptr fail to specify non-convertibility to int for unspecified-bool-type
-Section: 20.8.14.2.4 [unique.ptr.single.observers], 20.8.15.2.5 [util.smartptr.shared.obs] Status: NAD - Submitter: Beman Dawes Opened: 2007-06-14 Last modified: 2008-02-27
+Section: 20.9.9.2.4 [unique.ptr.single.observers], 20.9.10.2.5 [util.smartptr.shared.obs] Status: NAD + Submitter: Beman Dawes Opened: 2007-06-14 Last modified: 2010-10-29
View all issues with NAD status.
Discussion:
The standard library uses the operator unspecified-bool-type() const idiom in -five places. In three of those places (20.7.15.2.3 [func.wrap.func.cap], function capacity +five places. In three of those places (20.8.14.2.3 [func.wrap.func.cap], function capacity for example) the returned value is constrained to disallow unintended conversions to int. The standardese is
@@ -17075,9 +17874,7 @@ makes it irrelevant.Proposed resolution:
To the Returns paragraph for operator unspecified-bool-type() -const -of 20.8.14.2.4 [unique.ptr.single.observers] paragraph 11 and -20.8.15.2.5 [util.smartptr.shared.obs] paragraph 16, add the sentence: +const of 20.9.9.2.4 [unique.ptr.single.observers] paragraph 11 and 20.9.10.2.5 [util.smartptr.shared.obs] paragraph 16, add the sentence:
@@ -23461,7 +24018,7 @@ array<double, 4>The return type shall not be convertible to int. @@ -17094,10 +17891,10 @@ Kona (2007): Uncertain if nullptr will address this issue.
690. abs(long long) should return long long
-Section: 26.8 [c.math] Status: NAD Editorial - Submitter: Niels Dekker Opened: 2007-06-10 Last modified: 2007-07-25
+Section: 26.8 [c.math] Status: NAD Editorial + Submitter: Niels Dekker Opened: 2007-06-10 Last modified: 2010-10-29
View all other issues in [c.math].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Quoting the latest draft (n2135), 26.8 [c.math]: @@ -17131,72 +17928,10 @@ Had already been fixed in the WP by the time the LWG reviewed this. -
-697. New <system_error> header leads to name clashes
-Section: 19.5 [syserr] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-06-24 Last modified: 2008-01-06
-View all other issues in [syserr].
-View all issues with NAD Editorial status.
-Discussion:
--The most recent state of -N2241 -as well as the current draft -N2284 -(section 19.5 [syserr], p.2) proposes a -new -enumeration type posix_errno immediatly in the namespace std. One of -the enumerators has the name invalid_argument, or fully qualified: -std::invalid_argument. This name clashes with the exception type -std::invalid_argument, see 19.2 [std.exceptions]/p.3. This clash makes -e.g. the following snippet invalid: -
- -- -#include <system_error> -#include <stdexcept> - -void foo() { throw std::invalid_argument("Don't call us - we call you!"); } --I propose that this enumeration type (and probably the remaining parts -of -<system_error> as well) should be moved into one additional inner -namespace, e.g. sys or system to reduce foreseeable future clashes -due -to the great number of members that std::posix_errno already contains -(Btw.: Why has the already proposed std::sys sub-namespace from -N2066 -been rejected?). A further clash candidate seems to be -std::protocol_error -(a reasonable name for an exception related to a std network library, -I guess). -
- --Another possible resolution would rely on the proposed strongly typed -enums, -as described in N2213. -But maybe the forbidden implicit conversion to integral types would -make -these enumerators less attractive in this special case? -
- - -Proposed resolution:
--Fixed by issue 7 of N2422. -
- - - - - -
701. assoc laguerre poly's
Section: TR1 5.2.1.1 [tr.num.sf.Lnm] Status: NAD - Submitter: Christopher Crawford Opened: 2007-06-30 Last modified: 2009-07-13
+ Submitter: Christopher Crawford Opened: 2007-06-30 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -17247,7 +17982,7 @@ Move to NAD.
702. Restriction in associated Legendre functions
Section: TR1 5.2.1.2 [tr.num.sf.Plm] Status: NAD - Submitter: Christopher Crawford Opened: 2007-06-30 Last modified: 2009-07-13
+ Submitter: Christopher Crawford Opened: 2007-06-30 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -17279,7 +18014,7 @@ Move to NAD.
707. null pointer constant for exception_ptr
Section: 18.8.5 [propagation] Status: NAD - Submitter: Jens Maurer Opened: 2007-07-20 Last modified: 2008-02-25
+ Submitter: Jens Maurer Opened: 2007-07-20 Last modified: 2010-10-29View other active issues in [propagation].
View all other issues in [propagation].
View all issues with NAD status.
@@ -17338,10 +18073,10 @@ implementation details.
708. Locales need to be per thread and updated for POSIX changes
-Section: 22 [localization] Status: NAD Future - Submitter: Peter Dimov Opened: 2007-07-28 Last modified: 2009-07-16
+Section: 22 [localization] Status: NAD Future + Submitter: Peter Dimov Opened: 2007-07-28 Last modified: 2010-10-29
View all other issues in [localization].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
The POSIX "Extended API Set Part 4," @@ -17379,7 +18114,7 @@ Kona (2007): Bill and Nick to provide wording.
[ San Francisco: Bill and Nick still intend to provide wording, but this is a part of the task to be addressed by the group that will look into -issue 860. +issue 860. ]
@@ -17410,10 +18145,10 @@ Move to NAD Future.
717. Incomplete valarray::operator[] specification in [valarray.access]
-Section: 26.6.2.3 [valarray.access] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-08-27 Last modified: 2008-09-22
+Section: 26.6.2.3 [valarray.access] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-08-27 Last modified: 2010-10-29
View all other issues in [valarray.access].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Since the return type of valarray's operator[] const overload has been @@ -17470,10 +18205,10 @@ of that array ends, whichever happens first.
718. basic_string is not a sequence
-Section: 21.4 [basic.string] Status: NAD Editorial - Submitter: Bo Persson Opened: 2007-08-18 Last modified: 2009-07-16
+Section: 21.4 [basic.string] Status: NAD Editorial + Submitter: Bo Persson Opened: 2007-08-18 Last modified: 2010-10-29
View all other issues in [basic.string].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Paragraph 21.4 [basic.string]/3 states: @@ -17541,142 +18276,10 @@ different, a string abstraction in its own right. -
-719. std::is_literal type traits should be provided
-Section: 20.6 [meta] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-08-25 Last modified: 2009-10-26
-View all other issues in [meta].
-View all issues with NAD Editorial status.
-Duplicate of: 750
-Discussion:
--Since the inclusion of constexpr in the standard draft N2369 we have -a new type category "literal", which is defined in 3.9 [basic.types]/p.11: -
- --- ---11- A type is a literal type if it is: -
--
-- a scalar type; or
-- -
a class type (clause 9) with
--
-- a trivial copy constructor,
-- a trivial destructor,
-- at least one constexpr constructor other than the copy constructor,
-- no virtual base classes, and
-- all non-static data members and base classes of literal types; or
-- an array of literal type.
--I strongly suggest that the standard provides a type traits for -literal types in 20.6.4.3 [meta.unary.prop] for several reasons: -
- --
- -- To keep the traits in sync with existing types.
-- I see many reasons for programmers to use this trait in template - code to provide optimized template definitions for these types, - see below.
-- A user-provided definition of this trait is practically impossible -to write portably.
--The special problem of reason (c) is that I don't see currently a -way to portably test the condition for literal class types: -
- --- - - --
-- at least one constexpr constructor other than the copy constructor,
-[ -Alisdair is considering preparing a paper listing a number of missing -type traits, and feels that it might be useful to handle them all -together rather than piecemeal. This would affect issue 719 and 750. -These two issues should move to OPEN pending AM paper on type traits. -]
- - -[ -2009-07 Frankfurt: -]
- - --Beman, Daniel, and Alisdair will work on a paper proposing new type traits. -- -[ -Addressed in N2947. -]
- - -[ -2009-10 Santa Cruz: -]
- - --NAD Editorial. Solved by -N2984. -- - - -Proposed resolution:
--In 20.6.2 [meta.type.synop] in the group "type properties", -just below the line -
- -- -template <class T> struct is_pod; --add a new one: -
- -- -template <class T> struct is_literal; --In 20.6.4.3 [meta.unary.prop], table Type Property Predicates, just -below the line for the is_pod property add a new line: -
- --
- - - - - -- -Template Condition Preconditions -- -template <class T> struct is_literal; -T is a literal type (3.9) -T shall be a complete type, an -array of unknown bound, or -(possibly cv-qualified) void. -
721. wstring_convert inconsistensies
Section: 22.3.3.2.2 [conversions.string] Status: NAD - Submitter: Bo Persson Opened: 2007-08-27 Last modified: 2009-07-16
+ Submitter: Bo Persson Opened: 2007-08-27 Last modified: 2010-10-29View all other issues in [conversions.string].
View all issues with NAD status.
Discussion:
@@ -17740,11 +18343,10 @@ Move to NAD.
725. Optional sequence container requirements column label
-Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial - Submitter: David Abrahams Opened: 2007-09-16 Last modified: 2008-09-22
-View other active issues in [sequence.reqmts].
+Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial + Submitter: David Abrahams Opened: 2007-09-16 Last modified: 2010-10-29
View all other issues in [sequence.reqmts].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Table 90: (Optional sequence container operations) states the @@ -17775,15 +18377,218 @@ Surely that's meant to be "operational semantics?" +
+726. Missing regex_replace() overloads
+Section: 28.11.4 [re.alg.replace] Status: NAD + Submitter: Stephan T. Lavavej Opened: 2007-09-22 Last modified: 2010-10-29
+View all other issues in [re.alg.replace].
+View all issues with NAD status.
+Discussion:
++Two overloads of regex_replace() are currently provided: +
+ ++ +template <class OutputIterator, class BidirectionalIterator, + class traits, class charT> + OutputIterator + regex_replace(OutputIterator out, + BidirectionalIterator first, BidirectionalIterator last, + const basic_regex<charT, traits>& e, + const basic_string<charT>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + +template <class traits, class charT> + basic_string<charT> + regex_replace(const basic_string<charT>& s, + const basic_regex<charT, traits>& e, + const basic_string<charT>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); ++
+ +- Overloads taking const charT * are provided for regex_match() and +regex_search(), but not regex_replace(). This is inconsistent.
+- +
+ +The absence of const charT * overloads prevents ordinary-looking code from compiling, such as:
+ ++ +const string s("kitten"); +const regex r("en"); +cout << regex_replace(s, r, "y") << endl; ++The compiler error message will be something like "could not deduce +template argument for 'const std::basic_string<_Elem> &' from 'const +char[1]'". +
+ ++Users expect that anything taking a basic_string<charT> can also take a +const charT *. In their own code, when they write a function taking +std::string (or std::wstring), they can pass a const char * (or const +wchar_t *), thanks to basic_string's implicit constructor. Because the +regex algorithms are templated on charT, they can't rely on +basic_string's implicit constructor (as the compiler error message +indicates, template argument deduction fails first). +
+ ++If a user figures out what the compiler error message means, workarounds +are available - but they are all verbose. Explicit template arguments +could be given to regex_replace(), allowing basic_string's implicit +constructor to be invoked - but charT is the last template argument, not +the first, so this would be extremely verbose. Therefore, constructing +a basic_string from each C string is the simplest workaround. +
+- +There is an efficiency consideration: constructing basic_strings can +impose performance costs that could be avoided by a library +implementation taking C strings and dealing with them directly. +(Currently, for replacement sources, C strings can be converted into +iterator pairs at the cost of verbosity, but for format strings, there +is no way to avoid constructing a basic_string.) +
+[ +Sophia Antipolis: +]
+ + ++We note that Boost already has these overloads. However, the proposed +wording is provided only for 28.11.4 [re.alg.replace]; wording is needed for the synopsis +as well. We also note that this has impact on match_results::format, +which may require further overloads. ++ +[ +2009-07 Frankfurt: +]
+ + ++Daniel to tweak for us. ++ +[ +2009-07-25 Daniel tweaks both this issue and 727. +]
+ + +++ ++This is solved by the proposed resolution of 727. +
+[ +2009-10 Santa Cruz: +]
+ + ++Leave Open. Though we believe this is solved by the proposed resolution +to 727. ++ +[ +2010-01-27 Moved to Tentatively NAD after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + +Rationale:
++Solved by 727. +
+ + +Proposed resolution:
+ ++Provide additional overloads for regex_replace(): one additional +overload of the iterator-based form (taking const charT* fmt), and three +additional overloads of the convenience form (one taking const charT* +str, another taking const charT* fmt, and the third taking both const +charT* str and const charT* fmt). 28.11.4 [re.alg.replace]: +
+ +++ + + + + +template <class OutputIterator, class BidirectionalIterator, + class traits, class charT> + OutputIterator + regex_replace(OutputIterator out, + BidirectionalIterator first, BidirectionalIterator last, + const basic_regex<charT, traits>& e, + const basic_string<charT>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + +template <class OutputIterator, class BidirectionalIterator, + class traits, class charT> + OutputIterator + regex_replace(OutputIterator out, + BidirectionalIterator first, BidirectionalIterator last, + const basic_regex<charT, traits>& e, + const charT* fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); ++...
+template <class traits, class charT> + basic_string<charT> + regex_replace(const basic_string<charT>& s, + const basic_regex<charT, traits>& e, + const basic_string<charT>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + +template <class traits, class charT> + basic_string<charT> + regex_replace(const basic_string<charT>& s, + const basic_regex<charT, traits>& e, + const charT* fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + +template <class traits, class charT> + basic_string<charT> + regex_replace(const charT* s, + const basic_regex<charT, traits>& e, + const basic_string<charT>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + +template <class traits, class charT> + basic_string<charT> + regex_replace(const charT* s, + const basic_regex<charT, traits>& e, + const charT* fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); ++
729. Problem in [rand.req.eng]/3
-Section: X [rand.req.eng] Status: NAD - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-02-27
+Section: 26.5.1.4 [rand.req.eng] Status: NAD + Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
View all other issues in [rand.req.eng].
View all issues with NAD status.
Discussion:
-The 3rd table row in X [rand.req.eng]/3 requires random number engines to accept any +The 3rd table row in 26.5.1.4 [rand.req.eng]/3 requires random number engines to accept any arithmetic type as a seed, which is then casted to the engine's result_type and subsequently used for seeding the state of the engine. The requirement stated as "Creates an engine with initial state determined by static_cast<X::result_type>(s)" forces random number engines @@ -17802,11 +18607,11 @@ implementation specific unsigned integer type."
-Additionally, the definition of s in X [rand.req.eng]/1 c) could be restricted to unsigned integer types. +Additionally, the definition of s in 26.5.1.4 [rand.req.eng]/1 c) could be restricted to unsigned integer types.
-Similarly, the type of the seed in X [rand.req.adapt]/3 e) could be left unspecified. +Similarly, the type of the seed in 26.5.1.5 [rand.req.adapt]/3 e) could be left unspecified.
@@ -17829,7 +18634,7 @@ regarding this issue: The descriptions of all engines and engine adaptors given in sections 26.5.3 [rand.eng] and 26.5.4 [rand.adapt] already specify the concrete types of the integer arguments for seeding. Hence, relaxing the general -requirement in X [rand.req.eng] would not affect portability and +requirement in 26.5.1.4 [rand.req.eng] would not affect portability and reproducibility of the standard library. Furthermore, it is not clear to me what exactly the guarantee "with initial state determined by static_cast<X::result_type>(s)" is useful for. On the other hand, @@ -17864,7 +18669,7 @@ Stephan Tolksdorf adds pre-Bellevue:
-Change row 3 of table 105 "Random number engine requirements" in X [rand.req.eng]/3 +Change row 3 of table 105 "Random number engine requirements" in 26.5.1.4 [rand.req.eng]/3
@@ -17873,7 +18678,7 @@ Creates an engine with initial state determined by-Similarly, change X [rand.req.adapt]/3 e) +Similarly, change 26.5.1.5 [rand.req.adapt]/3 e)
@@ -17890,8 +18695,8 @@ When X::X is invoked with@@ -18088,8 +18891,8 @@ Addressed byan X::result_typevalue <
730. Comment on [rand.req.adapt]/3 e)
-Section: X [rand.req.adapt] Status: NAD - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-02-27
+Section: 26.5.1.5 [rand.req.adapt] Status: NAD + Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
View all issues with NAD status.
Discussion:
@@ -17938,7 +18743,7 @@ for the proposed resolution.
731. proposal for a customizable seed_seq
Section: 26.5.7.1 [rand.util.seedseq] Status: NAD - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-02-27
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29View all other issues in [rand.util.seedseq].
View all issues with NAD status.
Discussion:
@@ -17983,7 +18788,7 @@ struct is_seed_seq<seed_seq> { static const bool value = true; }which users can supplement with further specializations.
-Change X [rand.req.eng]/1 d) to "q is an lvalue of a type that fulfils the SeedSeq requirements", and +Change 26.5.1.4 [rand.req.eng]/1 d) to "q is an lvalue of a type that fulfils the SeedSeq requirements", and modify the constructors and seed methods in 26.5.3 [rand.eng] appropriately (the actual implementation could be done using the SFINAE technique). @@ -18012,10 +18817,10 @@ for the proposed resolution.
732. Defect in [rand.dist.samp.genpdf]
-Section: X [rand.dist.samp.genpdf] Status: NAD Editorial - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2009-03-09
+Section: X [rand.dist.samp.genpdf] Status: NAD Editorial + Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
View all other issues in [rand.dist.samp.genpdf].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Duplicate of: 795
Discussion:
@@ -18061,10 +18866,8 @@ Objector proposes the following possible compromise positions:
rand.dist.samp.genpdf takes an number of points so that implementor need not guess. -replace rand.disk.samp.genpdf with an extension to either or both -of the discrete functions to take arguments that take a functor and -number of points in place of the list of probabilities. Reference -issues 793 and 794. + +replace rand.disk.samp.genpdf with an extension to either or both of the discrete functions to take arguments that take a functor and number of points in place of the list of probabilities. Reference issues 793 and 794.
733. Comment on [rand.req.dist]/9
-Section: X [rand.req.dist] Status: NAD - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-02-27
+Section: 26.5.1.6 [rand.req.dist] Status: NAD + Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
View all issues with NAD status.
Discussion:
@@ -18130,7 +18933,7 @@ for the proposed resolution.
735. Unfortunate naming
Section: 26.5.8.2.2 [rand.dist.bern.bin], 26.5.8.2.4 [rand.dist.bern.negbin] Status: NAD - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-02-27
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -18180,7 +18983,7 @@ for the proposed resolution.
736. Comment on [rand.dist.samp.discrete]
Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-02-27
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29View all other issues in [rand.dist.samp.discrete].
View all issues with NAD status.
Discussion:
@@ -18336,7 +19139,7 @@ as the weights . -- end note]
737. Comment on [rand.dist.samp.pconst]
Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-02-27
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29View all other issues in [rand.dist.samp.pconst].
View all issues with NAD status.
Discussion:
@@ -18465,9 +19268,10 @@ and change in para. 3
738. Editorial issue in [rand.adapt.disc]/3
-Section: 26.5.4.1 [rand.adapt.disc] Status: NAD Editorial - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-09-22
-View all issues with NAD Editorial status.
+Section: 26.5.4.1 [rand.adapt.disc] Status: NAD Editorial + Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29
+View all other issues in [rand.adapt.disc].
+View all issues with NAD Editorial status.
Discussion:
Since the template parameter p and r are of type size_t, the member n in the class @@ -18488,7 +19292,7 @@ for the proposed resolution.
739. Defect in [rand.util.canonical]/3
Section: 26.5.7.2 [rand.util.canonical] Status: NAD - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-02-27
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29View all other issues in [rand.util.canonical].
View all issues with NAD status.
Discussion:
@@ -18527,8 +19331,8 @@ for the proposed resolution.
741. Const-incorrect get_deleter function for shared_ptr
-Section: 20.8.15.2.11 [util.smartptr.getdeleter] Status: NAD - Submitter: Daniel Krügler Opened: 2007-09-27 Last modified: 2008-02-27
+Section: 20.9.10.2.11 [util.smartptr.getdeleter] Status: NAD + Submitter: Daniel Krügler Opened: 2007-09-27 Last modified: 2010-10-29
View all other issues in [util.smartptr.getdeleter].
View all issues with NAD status.
Discussion:
@@ -18538,7 +19342,7 @@ The following issue was raised by Alf P. Steinbach in c.l.c++.mod:According to the recent draft N2369, both the header memory synopsis -of 20.8 [memory] and 20.8.15.2.11 [util.smartptr.getdeleter] declare: +of 20.9 [memory] and 20.9.10.2.11 [util.smartptr.getdeleter] declare:
template<class D, class T> D* get_deleter(shared_ptr<T> const& p); @@ -18553,7 +19357,7 @@ the mutability of the owner (as seen for the both overloads of unique_ptr::get_deleter). Even the next similar counter-part of get_deleter - the two overloads of function::target in the class template function -synopsis 20.7.15.2 [func.wrap.func] or in 20.7.15.2.5 [func.wrap.func.targ] - do +synopsis 20.8.14.2 [func.wrap.func] or in 20.8.14.2.5 [func.wrap.func.targ] - do properly mirror the const-state of the owner. @@ -18561,7 +19365,7 @@ properly mirror the const-state of the owner.Replace the declarations of get_deleter in the header <memory> -synopsis of 20.8 [memory] and in 20.8.15.2.11 [util.smartptr.getdeleter] by one of the +synopsis of 20.9 [memory] and in 20.9.10.2.11 [util.smartptr.getdeleter] by one of the following alternatives (A) or (B):
@@ -18583,7 +19387,7 @@ Just remove the function. Alberto Ganesh Barbati adds: -+
- +
Replace it with two functions: @@ -18632,7 +19436,7 @@ Concern this is similar to confusing "pointer to const" with "a constant pointer
745. copy_exception API slices.
Section: 18.8.5 [propagation] Status: NAD - Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2008-02-25
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29View other active issues in [propagation].
View all other issues in [propagation].
View all issues with NAD status.
@@ -18674,9 +19478,8 @@ slicing involved.
747. We have 3 separate type traits to identify classes supporting no-throw operations
-Section: 20.6.4.3 [meta.unary.prop] Status: NAD - Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2009-07-16
-View other active issues in [meta.unary.prop].
+Section: 20.7.4.3 [meta.unary.prop] Status: NAD + Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
View all other issues in [meta.unary.prop].
View all issues with NAD status.
Discussion:
@@ -18763,9 +19566,8 @@ Move to NAD.
748. The is_abstract type trait is defined by reference to 10.4.
-Section: 20.6.4.3 [meta.unary.prop] Status: NAD - Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2009-05-01
-View other active issues in [meta.unary.prop].
+Section: 20.7.4.3 [meta.unary.prop] Status: NAD + Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
View all other issues in [meta.unary.prop].
View all issues with NAD status.
Discussion:
@@ -18801,11 +19603,11 @@ Core has clarified that the definition abstract is adequate. Issue withdrawn by
750. The current definition for is_convertible requires that the type be implicitly convertible, so explicit constructors are ignored.
-Section: 20.6.5 [meta.rel] Status: Dup - Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2009-09-13
+Section: 20.7.6 [meta.rel] Status: Dup + Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
View all other issues in [meta.rel].
View all issues with Dup status.
-Duplicate of: 719
+Duplicate of: 719
Discussion:
With the pending arrival of explicit conversion functions though, I'm @@ -18830,7 +19632,7 @@ These two issues should move to OPEN pending AM paper on type traits.
-Duplicate of 719 (for our purposes). +Duplicate of 719 (for our purposes).[ @@ -18849,8 +19651,8 @@ Addressed in 751. change pass-by-reference members of vector<bool> to pass-by-value? -
Section: 23.3.7 [vector.bool] Status: NAD - Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2009-07-16
+Section: 23.4.2 [vector.bool] Status: NAD + Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
View all other issues in [vector.bool].
View all issues with NAD status.
Discussion:
@@ -18931,10 +19733,10 @@ NAD. Insufficient motivation to make any changes.
754. Ambiguous return clause for std::uninitialized_copy
-Section: 20.8.13.2 [uninitialized.copy] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2007-10-15 Last modified: 2008-07-02
+Section: 20.9.8.2 [uninitialized.copy] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2007-10-15 Last modified: 2010-10-29
View all other issues in [uninitialized.copy].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
14882-2003, [lib.uninitialized.copy] is currently written as follows: @@ -18961,7 +19763,7 @@ NAD. Insufficient motivation to make any changes.
similarily for N2369, and its corresponding section -20.8.13.2 [uninitialized.copy]. +20.9.8.2 [uninitialized.copy].
@@ -19009,7 +19811,7 @@ for std::copy.
Proposed resolution:
-Change the wording of the return clause to say (20.8.13.2 [uninitialized.copy]): +Change the wording of the return clause to say (20.9.8.2 [uninitialized.copy]):
@@ -19035,11 +19837,10 @@ occur.
756. Container adaptors push
-Section: 23.3.5 [container.adaptors] Status: NAD Editorial - Submitter: Paolo Carlini Opened: 2007-10-31 Last modified: 2008-06-18
-View other active issues in [container.adaptors].
+Section: 23.5 [container.adaptors] Status: NAD Editorial + Submitter: Paolo Carlini Opened: 2007-10-31 Last modified: 2010-10-29
View all other issues in [container.adaptors].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
After n2369 we have a single push_back overload in the sequence containers, @@ -19065,7 +19866,7 @@ Related to 757. Typo in the synopsis of vector -
Section: 23.3.6 [vector] Status: NAD Editorial - Submitter: Paolo Carlini Opened: 2007-11-04 Last modified: 2008-07-02
+Section: 23.4.1 [vector] Status: NAD Editorial + Submitter: Paolo Carlini Opened: 2007-11-04 Last modified: 2010-10-29
View all other issues in [vector].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
-In the synopsis 23.3.6 [vector], there is the signature: +In the synopsis 23.4.1 [vector], there is the signature:
void insert(const_iterator position, size_type n, T&& x); @@ -19153,14 +19954,14 @@ instead of:-23.3.6.4 [vector.modifiers] is fine. +23.4.1.4 [vector.modifiers] is fine.
Proposed resolution:
-Change the synopsis in 23.3.6 [vector]: +Change the synopsis in 23.4.1 [vector]:
iterator insert(const_iterator position, const T& x); @@ -19175,11 +19976,10 @@ void insert(const_iterator position, size_type n, const T& x);
760. The emplace issue
-Section: 23.2 [container.requirements] Status: NAD Future - Submitter: Paolo Carlini Opened: 2007-11-11 Last modified: 2009-07-17
-View other active issues in [container.requirements].
+Section: 23.2 [container.requirements] Status: NAD Future + Submitter: Paolo Carlini Opened: 2007-11-11 Last modified: 2010-10-29
View all other issues in [container.requirements].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
In an emplace member function the function parameter pack may be bound @@ -19261,7 +20061,7 @@ elements of the container. No diagnostic required.
763. Renaming emplace() overloads
Section: 23.2.4 [associative.reqmts] Status: NAD - Submitter: Sylvain Pion Opened: 2007-12-04 Last modified: 2008-03-12
+ Submitter: Sylvain Pion Opened: 2007-12-04 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with NAD status.
@@ -19314,7 +20114,7 @@ For example to emplace_here, hint_emplace...
764. equal_range on unordered containers should return a pair of local_iterators
Section: 23.2.5 [unord.req] Status: NAD - Submitter: Joe Gottman Opened: 2007-11-29 Last modified: 2008-03-12
+ Submitter: Joe Gottman Opened: 2007-11-29 Last modified: 2010-10-29View other active issues in [unord.req].
View all other issues in [unord.req].
View all issues with NAD status.
@@ -19393,11 +20193,10 @@ Change the entry for equal_range in Table 93 (23.2.5 [unord.req]) as fo
767. Forwarding and backward compatibility
-Section: 23 [containers] Status: NAD Editorial - Submitter: Sylvain Pion Opened: 2007-12-28 Last modified: 2008-06-18
-View other active issues in [containers].
+Section: 23 [containers] Status: NAD Editorial + Submitter: Sylvain Pion Opened: 2007-12-28 Last modified: 2010-10-29
View all other issues in [containers].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Playing with g++'s C++0X mode, I noticed that the following @@ -19417,15 +20216,11 @@ int main() now fails with the following error message:
-.../include/c++/4.3.0/ext/new_allocator.h: In member -function 'void __gnu_cxx::new_allocator<_Tp>::construct(_Tp*, -_Args&& ...) [with _Args = int, _Tp = char*]': -.../include/c++/4.3.0/bits/stl_vector.h:707: instantiated from 'void -std::vector<_Tp, _Alloc>::push_back(_Args&& ...) [with -_Args = int, _Tp = char*, _Alloc = std::allocator<char*>]' -test.cpp:6: instantiated from here -.../include/c++/4.3.0/ext/new_allocator.h:114: error: invalid -conversion from 'int' to 'char*' ++.../include/c++/4.3.0/ext/new_allocator.h: In member function 'void __gnu_cxx::new_allocator<_Tp>::construct(_Tp*, _Args&& ...) [with _Args = int, _Tp = char*]': +.../include/c++/4.3.0/bits/stl_vector.h:707: instantiated from 'void std::vector<_Tp, _Alloc>::push_back(_Args&& ...) [with _Args = int, _Tp = char*, _Alloc = std::allocator<char*>]' +test.cpp:6: instantiated from here +.../include/c++/4.3.0/ext/new_allocator.h:114: error: invalid conversion from 'int' to 'char*'@@ -19624,7 +20419,7 @@ template <class... Args> requires Constructible<T, Args&&.
-Change the synopsis in 23.3.6 [vector]: +Change the synopsis in 23.4.1 [vector]:
void push_back(const T& x); @@ -19633,7 +20428,7 @@ template <class... Args> requires Constructible<T, Args&&.-Change 23.3.6.4 [vector.modifiers]: +Change 23.4.1.4 [vector.modifiers]:
void push_back(const T& x); @@ -19661,7 +20456,7 @@ If there is still an issue with pair, Howard should submit another issue.
773. issues with random
Section: 26.5.8.1 [rand.dist.uni] Status: NAD - Submitter: P.J. Plauger Opened: 2008-01-14 Last modified: 2008-02-27
+ Submitter: P.J. Plauger Opened: 2008-01-14 Last modified: 2010-10-29View all other issues in [rand.dist.uni].
View all issues with NAD status.
Discussion:
@@ -19704,8 +20499,8 @@ NAD. Withdrawn.
784. unique_lock::release
-Section: 30.4.3.2.3 [thread.lock.unique.mod] Status: NAD - Submitter: Constantine Sapuntzakis Opened: 2008-02-02 Last modified: 2008-02-27
+Section: 30.4.2.2.3 [thread.lock.unique.mod] Status: NAD + Submitter: Constantine Sapuntzakis Opened: 2008-02-02 Last modified: 2010-10-29
View all issues with NAD status.
Discussion:
@@ -19751,7 +20546,7 @@ changing. NAD
Proposed resolution:
-Change the synopsis in 30.4.3.2 [thread.lock.unique]: +Change the synopsis in 30.4.2.2 [thread.lock.unique]:
template <class Mutex> @@ -19765,7 +20560,7 @@ public:-Change 30.4.3.2.3 [thread.lock.unique.mod]: +Change 30.4.2.2.3 [thread.lock.unique.mod]:
mutex_type *releasedisown(); @@ -19778,7 +20573,7 @@ Change 30.4.3.2.3 [thread.lock.unique.mod]:
785. Random Number Requirements in TR1
Section: TR1 5.1.4.5 [tr.rand.eng.disc], TR1 5.1.4.6 [tr.rand.eng.xor] Status: NAD - Submitter: John Maddock Opened: 2008-01-15 Last modified: 2009-07-13
+ Submitter: John Maddock Opened: 2008-01-15 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -19811,10 +20606,8 @@ member, which will not accept an integer literal as an argument: something that So... is this a bug in TR1?
-This is a real issue BTW, since the Boost implementation does adhere -to the requirements of Table 16, while at least one commercial -implementation does not and follows a strict adherence to sections -5.1.4.5 and 5.1.4.6 instead. +
+This is a real issue BTW, since the Boost implementation does adhere to the requirements of Table 16, while at least one commercial implementation does not and follows a strict adherence to sections 5.1.4.5 and 5.1.4.6 instead.
[ @@ -19857,137 +20650,10 @@ NAD Recommended. -
-786. Thread library timed waits, UTC and monotonic clocks
-Section: 20.9 [time] Status: NAD Editorial - Submitter: Christopher Kohlhoff, Jeff Garland Opened: 2008-02-03 Last modified: 2008-09-30
-View all other issues in [time].
-View all issues with NAD Editorial status.
-Discussion:
--The draft C++0x thread library requires that the time points of type -system_time and returned by get_system_time() represent Coordinated -Universal Time (UTC) (section [datetime.system]). This can lead to -surprising behavior when a library user performs a duration-based wait, -such as condition_variable::timed_wait(). A complete explanation of the -problem may be found in the -Rationale for the Monotonic Clock -section in POSIX, but in summary: -
- --
- -- -Operations such as condition_variable::timed_wait() (and its POSIX -equivalent, pthread_cond_timedwait()) are specified using absolute times -to address the problem of spurious wakeups. -
- -- -The typical use of the timed wait operations is to perform a relative -wait. This may be achieved by first calculating an absolute time as the -sum of the current time and the desired duration. In fact, the C++0x -thread library includes duration-based overloads of -condition_variable::timed_wait() that behave as if by calling the -corresponding absolute time overload with a time point value of -get_system_time() + rel_time. -
- -- -A UTC clock may be affected by changes to the system time, such as -synchronization with an external source, leap seconds, or manual changes -to the clock. -
- -- -Should the clock change during a timed wait operation, the actual -duration of the wait will not be the expected length. For example, a -user may intend a timed wait of one second duration but, due to an -adjustment of the system clock backwards by a minute, the wait instead -takes 61 seconds. -
--POSIX solves the problem by introducing a new monotonic clock, which is -unaffected by changes to the system time. When a condition variable is -initialized, the user may specify whether the monotonic clock is to be -used. (It is worth noting that on POSIX systems it is not possible to -use condition_variable::native_handle() to access this facility, since -the desired clock type must be specified during construction of the -condition variable object.) -
- --In the context of the C++0x thread library, there are added dimensions -to the problem due to the need to support platforms other than POSIX: -
- --
- -- -Some environments (such as embedded systems) do not have a UTC clock, but do have a monotonic clock. -
- -- -Some environments do not have a monotonic clock, but do have a UTC clock. -
- -- -The Microsoft Windows API's synchronization functions use relative -timeouts based on an implied monotonic clock. A program that switches -from the Windows API to the C++0x thread library will now find itself -susceptible to clock changes. -
--One possible minimal solution: -
- --
- - - -- -Strike normative references to UTC and an epoch based on 1970-01-01. -
- -- -Make the semantics of system_time and get_system_time() -implementation-defined (i.e standard library implementors may choose the -appropriate underlying clock based on the capabilities of the target -platform). -
- -- -Add a non-normative note encouraging use of a monotonic clock. -
- -- -Remove system_time::seconds_since_epoch(). -
- -- -Change the constructor explicit system_time(time_t secs, nanoseconds ns -= 0) to explicit system_time(nanoseconds ns). -
-Proposed resolution:
--
- - -Rationale:
-Addressed by -N2661: A Foundation to Sleep On. - - - - -
790. xor_combine::seed not specified
Section: X [rand.adapt.xor] Status: NAD - Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2008-02-27
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29View all other issues in [rand.adapt.xor].
View all issues with NAD status.
Discussion:
@@ -20017,7 +20683,7 @@ Overcome by the previous proposal. NAD mooted by resolution of 791. piecewise_constant_distribution::densities has wrong nameSection: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD - Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2008-03-11
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29View all other issues in [rand.dist.samp.pconst].
View all issues with NAD status.
Discussion:
@@ -20087,10 +20753,10 @@ Change 26.5.8.5.2 [rand.dist.samp.pconst]/6:
793. discrete_distribution missing constructor
-Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD Editorial - Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2009-03-09
+Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD Editorial + Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
View all other issues in [rand.dist.samp.discrete].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
discrete_distribution should have a constructor like: @@ -20334,10 +21000,10 @@ Addressed by
794. piecewise_constant_distribution missing constructor
-Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD Editorial - Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2009-03-09
+Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD Editorial + Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29
View all other issues in [rand.dist.samp.pconst].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
piecewise_constant_distribution should have a constructor like: @@ -20609,7 +21275,7 @@ Addressed by
795. general_pdf_distribution should be dropped
Section: X [rand.dist.samp.genpdf] Status: Dup - Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2008-03-11
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29View all other issues in [rand.dist.samp.genpdf].
View all issues with Dup status.
Duplicate of: 732
@@ -20639,7 +21305,7 @@ This appears to be a duplicate of 796. ranlux48_base returns wrong valueSection: 26.5.5 [rand.predef] Status: NAD - Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2008-02-27
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29View all other issues in [rand.predef].
View all issues with NAD status.
Discussion:
@@ -20683,7 +21349,7 @@ object of type ranlux48_base shall produce the value
797. ranlux48 returns wrong value
Section: 26.5.5 [rand.predef] Status: NAD - Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2008-02-27
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29View all other issues in [rand.predef].
View all issues with NAD status.
Discussion:
@@ -20726,7 +21392,7 @@ object of type ranlux48 shall produce the value
799. [tr.rand.eng.mers] and [rand.eng.mers]
Section: 26.5.3.2 [rand.eng.mers], TR1 5.1.4.2 [tr.rand.eng.mers] Status: NAD - Submitter: Stephan Tolksdorf Opened: 2008-02-18 Last modified: 2008-03-11
+ Submitter: Stephan Tolksdorf Opened: 2008-02-18 Last modified: 2010-10-29View all other issues in [rand.eng.mers].
View all issues with NAD status.
Discussion:
@@ -20826,10 +21492,10 @@ The textual representation of xi consists of the values of
800. Issues in 26.4.7.1 [rand.util.seedseq](6)
-Section: 26.5.7.1 [rand.util.seedseq] Status: NAD Editorial - Submitter: Stephan Tolksdorf Opened: 2008-02-18 Last modified: 2009-03-09
+Section: 26.5.7.1 [rand.util.seedseq] Status: NAD Editorial + Submitter: Stephan Tolksdorf Opened: 2008-02-18 Last modified: 2010-10-29
View all other issues in [rand.util.seedseq].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
The for-loop in the algorithm specification has n iterations, where n is @@ -20912,7 +21578,7 @@ Addressed by
802. knuth_b returns wrong value
Section: 26.5.5 [rand.predef] Status: NAD - Submitter: P.J. Plauger Opened: 2008-02-20 Last modified: 2008-03-17
+ Submitter: P.J. Plauger Opened: 2008-02-20 Last modified: 2010-10-29View all other issues in [rand.predef].
View all issues with NAD status.
Discussion:
@@ -20949,10 +21615,10 @@ Bellevue: Submitter withdraws defect. "We got the wrong value for entirely the r
803. Simplification of seed_seq::seq_seq
-Section: 26.5.7.1 [rand.util.seedseq] Status: NAD Editorial - Submitter: Charles Karney Opened: 2008-02-22 Last modified: 2009-03-09
+Section: 26.5.7.1 [rand.util.seedseq] Status: NAD Editorial + Submitter: Charles Karney Opened: 2008-02-22 Last modified: 2010-10-29
View all other issues in [rand.util.seedseq].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
seed_seq(InputIterator begin, InputIterator end); constructs a seed_seq @@ -21200,9 +21866,9 @@ Addressed by
812. unsolicited multithreading considered harmful?
-Section: 25.4.1 [alg.sort] Status: NAD Editorial - Submitter: Paul McKenney Opened: 2008-02-27 Last modified: 2008-09-17
-View all issues with NAD Editorial status.
+Section: 25.4.1 [alg.sort] Status: NAD Editorial + Submitter: Paul McKenney Opened: 2008-02-27 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
Multi-threading is a good thing, but unsolicited multi-threading can @@ -21242,132 +21908,147 @@ This is already covered by 17.6.5.6/20 in N2723.
-823. identity<void> seems broken
-Section: 20.3.3 [forward] Status: NAD Editorial - Submitter: Walter Brown Opened: 2008-04-09 Last modified: 2009-10-23
-View all other issues in [forward].
-View all issues with NAD Editorial status.
+822. Object with explicit copy constructor no longer CopyConstructible
+Section: 20.2.1 [utility.arg.requirements] Status: NAD + Submitter: James Kanze Opened: 2008-04-01 Last modified: 2010-11-29
+View all other issues in [utility.arg.requirements].
+View all issues with NAD status.
Discussion:
-N2588 seems to have added an operator() member function to the -identity<> helper in 20.3.3 [forward]. I believe this change makes it no -longer possible to instantiate identity<void>, as it would require -forming a reference-to-void type as this operator()'s parameter type. +I just noticed that the following program is legal in C++03, but +is forbidden in the current draft:
++#include <vector> +#include <iostream> + +class Toto +{ +public: + Toto() {} + explicit Toto( Toto const& ) {} +} ; + +int +main() +{ + std::vector< Toto > v( 10 ) ; + return 0 ; +} +-Suggested resolution: Specialize identity<void> so as not to require -the member function's presence. +Is this change intentional? (And if so, what is the +justification? I wouldn't call such code good, but I don't see +any reason to break it unless we get something else in return.)
[ -Sophia Antipolis: +San Francisco: +]
+ + ++The subgroup that looked at this felt this was a good change, but it may +already be handled by incoming concepts (we're not sure). ++ +[ +Post Summit: ]
-Jens: suggests to add a requires clause to avoid specializing on void. +Alisdair: Proposed resolution kinda funky as these tables no longer +exist. Move from direct init to copy init. Clarify with Doug, recommends +NAD.
-Alisdair: also consider cv-qualified void. +Walter: Suggest NAD via introduction of concepts.
-Alberto provided proposed wording. +Recommend close as NAD.
[ -2009-07-30 Daniel reopens: +2009-07 Frankfurt: ]
--This issue became closed, because the ReferentType requirement -fixed the problem - this is no longer the case. In retrospective it seems -to be that the root of current issues around std::identity (823, 700, -939) -is that it was standardized as something very different (an unconditional -type mapper) than traditional usage indicated (a function object that should -derive from std::unary_function), as the SGI definition does. This issue could -be solved, if std::identity is removed (one proposal of 939), but until this -has been decided, this issue should remain open. An alternative for -removing it, would be, to do the following: -
- --
+Need to look at again without concepts.- -
- --Let identity stay as a real function object, which would -now properly -derive from unary_function: -
- --template <class T> struct identity : unary_function<T, T> { - const T& operator()(const T&) const; -}; -- -
--Invent (if needed) a generic type wrapper (corresponding to concept -IdentityOf), -e.g. identity_of, and move it's prototype description back to 20.3.3 [forward]: -
- -- -template <class T> struct identity_of { - typedef T type; -}; --and adapt the std::forward signature to use identity_of -instead of identity. -
-[ -2009-10 Santa Cruz: +2009-07 Frankfurt: ]
-Mark as NAD Editorial, fixed by 939. ++ ++Move to Ready with original proposed resolution. +
+[Howard: Original proposed resolution restored.]
+ +[ +2010-11 Batavia: +]
+ ++This issue was re-reviewed in relation to [another issue, number to follow], +and the verdict was reversed. Explicit copy and move constructors are rare +beasts, and the ripple effect of this fix was far more difficult to contain +than simply saying such types do not satisfy the MoveConstructible +and CopyConstructible requirements. +
+ +++In 20.2.1 [utility.arg.requirements] change Table 33: MoveConstructible requirements [moveconstructible]: +
+ +++ ++
++ +expression post-condition ++ +T t(rv) = rvt is equivalent to the value of rv before the construction ++ +... ++In 20.2.1 [utility.arg.requirements] change Table 34: CopyConstructible requirements [copyconstructible]: +
+ ++++
++ +expression post-condition ++ +T t(u) = uthe value of u is unchanged and is equivalent to t ++ +... +Proposed resolution:
--Change definition of identity in 20.3.3 [forward], paragraph 2, to: -
- --template <class T> struct identity { - typedef T type; - - requires ReferentType<T> - const T& operator()(const T& x) const; - }; -...
-- - -requires ReferentType<T> - const T& operator()(const T& x) const; -Rationale:
--The point here is to able to write T& given T and ReferentType is -precisely the concept that guarantees so, according to N2677 -(Foundational concepts). Because of this, it seems preferable than an -explicit check for cv void using SameType/remove_cv as it was suggested -in Sophia. In particular, Daniel remarked that there may be types other -than cv void which aren't referent types (int[], perhaps?). -
+Resolved by n3215. @@ -21375,12 +22056,9 @@ than cv void which aren't referent types (int[], perhaps?).
825. Missing rvalues reference stream insert/extract operators?
-Section: 19.5.2.1 [syserr.errcode.overview], 20.8.15.2.8 -[util.smartptr.shared.io], 22.4.8 [facets.examples], 20.3.7.3 -[bitset.operators], 26.4.6 [complex.ops], 27.6 [stream.buffers], 28.9 -[re.submatch] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2008-04-10 Last modified: 2009-10-26
-View all issues with NAD Editorial status.
+Section: 19.5.2.1 [syserr.errcode.overview], 20.9.10.2.8 [util.smartptr.shared.io], 22.4.8 [facets.examples], 20.5.4 [bitset.operators], 26.4.6 [complex.ops], 27.6 [stream.buffers], 28.9 [re.submatch] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2008-04-10 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 220
@@ -21391,9 +22069,9 @@ operators?
- 19.5.2.1 [syserr.errcode.overview]
-- 20.8.15.2.8 [util.smartptr.shared.io]
+- 20.9.10.2.8 [util.smartptr.shared.io]
- 22.4.8 [facets.examples]
-- 20.3.7.3 [bitset.operators]
+- 20.5.4 [bitset.operators]
- 26.4.6 [complex.ops]
- Doubled signatures in 27.6 [stream.buffers] for character inserters (ref 27.7.2.6.4 [ostream.inserters.character]) @@ -21452,7 +22130,7 @@ Move to NAD Editorial.
826. Equivalent of %'d, or rather, lack thereof?
Section: 22.4.2.2 [locale.nm.put] Status: NAD - Submitter: Peter Dimov Opened: 2008-04-07 Last modified: 2008-06-18
+ Submitter: Peter Dimov Opened: 2008-04-07 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -21509,131 +22187,12 @@ This is not a part of C99. LWG suggests submitting a paper may be appropriate. -
-827. constexpr shared_ptr::shared_ptr()?
-Section: 20.8.15.2.1 [util.smartptr.shared.const] Status: NAD Editorial - Submitter: Peter Dimov Opened: 2008-04-11 Last modified: 2009-10-26
-View all other issues in [util.smartptr.shared.const].
-View all issues with NAD Editorial status.
-Discussion:
--Would anyone object to making the default constructor of shared_ptr (and -weak_ptr and enable_shared_from_this) constexpr? This would enable -static initialization for shared_ptr variables, eliminating another -unfair advantage of raw pointers. -
- -[ -San Francisco: -]
- - --- --It's not clear to us that you can initialize a pointer with the literal -0 in a constant expression. We need to ask CWG to make sure this works. -Bjarne has been appointed to do this. -
--Core got back to us and assured as that nullptr would do the job -nicely here. -
-[ -2009-05-01 Alisdair adds: -]
- - --- --I don't believe that constexpr will buy anything in this case. -shared_ptr/weak_ptr/enable_shared_from_this cannot be literal types as they -have a non-trivial copy constructor. As they do not produce literal types, -then the constexpr default constructor will not guarantee constant -initialization, and so not buy the hoped for optimization. -
--I recommend referring this back to Core to see if we can get static -initialization for types with constexpr constructors, even if they are not -literal types. Otherwise this should be closed as NAD. -
-[ -2009-05-26 Daniel adds: -]
- - --If Alisdair's 2009-05-01 comment is correct, wouldn't that also make -constexpr mutex() useless, because this class has a non-trivial -destructor? (828) -- -[ -2009-07-21 Alisdair adds: -]
- - --- --The feedback from core is that this and similar uses of constexpr -constructors to force static initialization should be supported. If -there are any problems with this in the working draught, we should file -core issues. -
- --Recommend we declare the default constructor constexpr as the issue suggests -(proposed wording added). -
-[ -2009-10 Santa Cruz: -]
- - --NAD Editorial. Solved by -N2994. -- - -Proposed resolution:
--Change 20.8.15.2 [util.smartptr.shared] and 20.8.15.2.1 [util.smartptr.shared.const]: -
- -- -consexpr shared_ptr(); --Change 20.8.15.3 [util.smartptr.weak] and 20.8.15.3.1 [util.smartptr.weak.const]: -
- -- -consexpr weak_ptr(); --Change 20.8.15.4 [util.smartptr.enab] (2 places): -
- -- - - - - -consexpr enable_shared_from_this(); -
828. Static initialization for std::mutex?
-Section: 30.4.1.1 [thread.mutex.class] Status: NAD Editorial - Submitter: Peter Dimov Opened: 2008-04-18 Last modified: 2009-10-26
+Section: 30.4.1.2.1 [thread.mutex.class] Status: NAD Editorial + Submitter: Peter Dimov Opened: 2008-04-18 Last modified: 2010-10-29
View all other issues in [thread.mutex.class].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
[Note: I'm assuming here that 3.6.2 [basic.start.init]/1 will be fixed.] @@ -21703,7 +22262,7 @@ Keep in Review status pending feedback from members of the Concurrency subgroup.
[ -See related comments from Alisdiar and Daniel in 827. +See related comments from Alisdiar and Daniel in 827. ]
@@ -21721,7 +22280,7 @@ NAD Editorial. Solved byProposed resolution:
-Change 30.4.1.1 [thread.mutex.class]: +Change 30.4.1.2.1 [thread.mutex.class]:
class mutex { @@ -21736,10 +22295,10 @@ public:
830. Incomplete list of char_traits specializations
-Section: 21.2 [char.traits] Status: NAD Editorial - Submitter: Dietmar Kühl Opened: 2008-04-23 Last modified: 2009-07-13
+Section: 21.2 [char.traits] Status: NAD Editorial + Submitter: Dietmar Kühl Opened: 2008-04-23 Last modified: 2010-10-29
View all other issues in [char.traits].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Paragraph 4 of 21.2 [char.traits] mentions that this @@ -21856,10 +22415,10 @@ Change Forward declarations 27.3 [iostream.forward]:
831. wrong type for not_eof()
-Section: 21.2.3 [char.traits.specializations] Status: NAD Editorial - Submitter: Dietmar Kühl Opened: 2008-04-23 Last modified: 2008-06-19
+Section: 21.2.3 [char.traits.specializations] Status: NAD Editorial + Submitter: Dietmar Kühl Opened: 2008-04-23 Last modified: 2010-10-29
View all other issues in [char.traits.specializations].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
In Table 56 (Traits requirements) the not_eof() member function @@ -21898,7 +22457,7 @@ Already fixed in WP.
832. Applying constexpr to System error support
Section: 19.5 [syserr] Status: NAD - Submitter: Beman Dawes Opened: 2008-05-14 Last modified: 2008-09-17
+ Submitter: Beman Dawes Opened: 2008-05-14 Last modified: 2010-10-29View all other issues in [syserr].
View all issues with NAD status.
Discussion:
@@ -22186,7 +22745,7 @@ paragraphs 2 and 4, change "category.equivalent(" to-Change 19.5.5.1 [syserr.syserr.overview] Class system_error overview as indicated: +Change 19.5.6.1 [syserr.syserr.overview] Class system_error overview as indicated:
public: @@ -22198,7 +22757,7 @@ Change 19.5.5.1 [syserr.syserr.overview] Class system_error overview as indicate-Change 19.5.5.2 [syserr.syserr.members] Class system_error members as indicated: +Change 19.5.6.2 [syserr.syserr.members] Class system_error members as indicated:
@@ -22246,7 +22805,7 @@ NAD because Beman said so.
833. Freestanding implementations header list needs review for C++0x
Section: 17.6.1.3 [compliance] Status: NAD - Submitter: Beman Dawes Opened: 2008-05-14 Last modified: 2009-07-16
+ Submitter: Beman Dawes Opened: 2008-05-14 Last modified: 2010-10-29View all other issues in [compliance].
View all issues with NAD status.
Discussion:
@@ -22330,11 +22889,10 @@ Move to NAD.837.
-basic_ios::copyfmt()overly loosely specifiedSection: 27.5.4.2 [basic.ios.members] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2009-07-13
-View other active issues in [basic.ios.members].
+Section: 27.5.4.2 [basic.ios.members] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29
View all other issues in [basic.ios.members].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
@@ -22464,10 +23022,10 @@ already there.
839. Maps and sets missing splice operation
-Section: 23.4 [associative], 23.5 [unord] Status: NAD Future - Submitter: Alan Talbot Opened: 2008-05-18 Last modified: 2009-09-20
+Section: 23.6 [associative], 23.7 [unord] Status: NAD Future + Submitter: Alan Talbot Opened: 2008-05-18 Last modified: 2010-10-29
View all other issues in [associative].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
Splice is a very useful feature of list. This functionality is also very @@ -22758,9 +23316,8 @@ for the client.
840. pair default template argument
-Section: 20.3.4 [pairs] Status: NAD - Submitter: Thorsten Ottosen Opened: 2008-05-23 Last modified: 2008-06-18
-View other active issues in [pairs].
+Section: 20.3.5 [pairs] Status: NAD + Submitter: Thorsten Ottosen Opened: 2008-05-23 Last modified: 2010-10-29
View all other issues in [pairs].
View all issues with NAD status.
Discussion:
@@ -22782,7 +23339,7 @@ Change the synopsis in 20.3 [utility] to read:-Change 20.3.4 [pairs] to read: +Change 20.3.5 [pairs] to read:
namespace std { @@ -22803,10 +23360,10 @@ Change 20.3.4 [pairs] to read:
841. cstdint.syn inconsistent with C99
-Section: 18.4.1 [cstdint.syn] Status: NAD Editorial - Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2008-09-17
+Section: 18.4.1 [cstdint.syn] Status: NAD Editorial + Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29
View all other issues in [cstdint.syn].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
@@ -22883,7 +23440,7 @@ and macros are required.
namespace std { // required types @@ -23043,8 +23600,8 @@ and macros are required.
849. missing type traits to compute root class and derived class of types in a class hierachy
-Section: 20.6.7 [meta.trans.other] Status: NAD - Submitter: Thorsten Ottosen Opened: 2008-06-05 Last modified: 2008-09-16
+Section: 20.7.7.6 [meta.trans.other] Status: NAD + Submitter: Thorsten Ottosen Opened: 2008-06-05 Last modified: 2010-10-29
View all other issues in [meta.trans.other].
View all issues with NAD status.
Discussion:
@@ -23078,7 +23635,7 @@ identity transformation. I expect this gives the best overall usability.Proposed resolution:
-Add the following to the synopsis in 20.6.2 [meta.type.synop] under "other transformations": +Add the following to the synopsis in 20.7.2 [meta.type.synop] under "other transformations":
template< class T > struct direct_base_class; @@ -23087,7 +23644,7 @@ template< class T > struct root_base_class;-Add three new entries to table 51 (20.6.7 [meta.trans.other]) with the following content +Add three new entries to table 51 (20.7.7.6 [meta.trans.other]) with the following content
@@ -23128,10 +23685,10 @@ as an accessible unambiguous direct base class. If no such type exists, the memb
851. simplified array construction
-Section: 23.3.1 [array] Status: NAD Future - Submitter: Benjamin Kosnik Opened: 2008-06-05 Last modified: 2009-10-23
+Section: 23.3.1 [array] Status: NAD Future + Submitter: Benjamin Kosnik Opened: 2008-06-05 Last modified: 2010-10-29
View all other issues in [array].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
This is an issue that came up on the libstdc++ list, where a @@ -23322,7 +23879,7 @@ make_array(Args&&... args);
-Append after 23.3.1.7 [array.tuple] Tuple interface to class template array +Append after 23.3.1.8 [array.tuple] Tuple interface to class template array the following new section:
@@ -23404,7 +23961,7 @@ Add to the array synopsis in 23.3 [sequences]:-Append after 23.3.1.7 [array.tuple] "Tuple interface to class template array" the +Append after 23.3.1.8 [array.tuple] "Tuple interface to class template array" the following new section:
@@ -23443,7 +24000,7 @@ array<double, 4>-—end example] +—end example]
855. capacity() and reserve() for deque?
Section: 23.3.2.2 [deque.capacity] Status: NAD - Submitter: Hervé Brönnimann Opened: 2008-06-11 Last modified: 2008-09-22
+ Submitter: Hervé Brönnimann Opened: 2008-06-11 Last modified: 2010-10-29View all other issues in [deque.capacity].
View all issues with NAD status.
Discussion:
@@ -23630,10 +24187,10 @@ Complication outweighs the benefit.
862. Impossible complexity for 'includes'
-Section: 25.4.5.1 [includes] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2008-07-02 Last modified: 2009-07-13
+Section: 25.4.5.1 [includes] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2008-07-02 Last modified: 2010-10-29
View all other issues in [includes].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
In 25.4.5.1 [includes] the complexity is "at most -1 comparisons" if passed @@ -23706,7 +24263,7 @@ Recommend NAD.
863. What is the state of a stream after close() succeeds
Section: 27.9.1 [fstreams] Status: NAD - Submitter: Steve Clamage Opened: 2008-07-08 Last modified: 2009-07-13
+ Submitter: Steve Clamage Opened: 2008-07-08 Last modified: 2010-10-29View all other issues in [fstreams].
View all issues with NAD status.
Discussion:
@@ -23757,10 +24314,11 @@ Move to NAD.
864. Defect in atomic wording
-Section: 29.6 [atomics.types.operations] Status: NAD Editorial - Submitter: Anthony Williams Opened: 2008-07-10 Last modified: 2008-09-17
+Section: 29.6 [atomics.types.operations] Status: NAD Editorial + Submitter: Anthony Williams Opened: 2008-07-10 Last modified: 2010-10-29
+View other active issues in [atomics.types.operations].
View all other issues in [atomics.types.operations].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
There's an error in 29.6 [atomics.types.operations]/p9: @@ -23846,10 +24404,10 @@ Already fixed by the time the LWG processed it.
867. Valarray and value-initialization
-Section: 26.6.2.1 [valarray.cons] Status: NAD Editorial - Submitter: Alberto Ganesh Barbati Opened: 2008-07-20 Last modified: 2009-07-13
+Section: 26.6.2.1 [valarray.cons] Status: NAD Editorial + Submitter: Alberto Ganesh Barbati Opened: 2008-07-20 Last modified: 2010-10-29
View all other issues in [valarray.cons].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
From 26.6.2.1 [valarray.cons], paragraph 2: @@ -23928,9 +24486,9 @@ the third element of the result will be assigned the value of the first element
873. signed integral type and unsigned integral type are not clearly defined
-Section: 3.9.1 [basic.fundamental] Status: NAD Editorial - Submitter: Travis Vitek Opened: 2008-06-30 Last modified: 2009-07-17
-View all issues with NAD Editorial status.
+Section: 3.9.1 [basic.fundamental] Status: NAD Editorial + Submitter: Travis Vitek Opened: 2008-06-30 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
Neither the term "signed integral type" nor the term "unsigned @@ -24014,7 +24572,7 @@ concepts.
<cstdint>header (18.1)... - +@@ -24022,7 +24580,7 @@ concepts. X::difference_type cannot be char or wchar_t, but could be one of the signed or unsigned integer types as appropriate. - 20.2.2 [allocator.requirements] table 40... + 20.2.5 [allocator.requirements] table 40...
Table 40: Allocator requirements @@ -24061,7 +24619,7 @@ concepts. The proposed change makes it clear that make_signed<T>::type must be one of the signed integer types as defined in 3.9.1. Ditto for make_unsigned<T>type and unsigned integer types. - 20.6.6.3 [meta.trans.sign] table 48... + 20.7.7.3 [meta.trans.sign] table 48...Table 48: Sign modifications @@ -24345,10 +24903,10 @@ concepts.
874. Missing initializer_list constructor for discrete_distribution
-Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2008-08-22 Last modified: 2009-03-09
+Section: 26.5.8.5.1 [rand.dist.samp.discrete] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2008-08-22 Last modified: 2010-10-29
View all other issues in [rand.dist.samp.discrete].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
During the Sophia Antipolis meeting it was decided to separate from 793 a @@ -24405,10 +24963,10 @@ Addressed by
875. Missing initializer_list constructor for piecewise_constant_distribution
-Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2008-08-22 Last modified: 2009-03-09
+Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2008-08-22 Last modified: 2010-10-29
View all other issues in [rand.dist.samp.pconst].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
During the Sophia Antipolis meeting it was decided to separate from @@ -24654,11 +25212,11 @@ Addressed by
877. to throw() or to Throw: Nothing.
-Section: 17 [library] Status: NAD Future - Submitter: Martin Sebor Opened: 2008-08-23 Last modified: 2009-07-17
+Section: 17 [library] Status: NAD Future + Submitter: Martin Sebor Opened: 2008-08-23 Last modified: 2010-10-29
View other active issues in [library].
View all other issues in [library].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
@@ -24875,7 +25433,7 @@ common situation when the called function is a C or POSIX function. Alternate, proprietary mechanisms exist (such as GCC __attribute__((nothrow)) or Visual -C++ __declspec(nothrow)) +C++ __declspec(nothrow)) that let implementers mark up non-throwing functions, often without the penalty mentioned in (1) above. The C++ standard shouldn't preclude the use of these potentially more efficient mechanisms. @@ -24891,7 +25449,7 @@ code when the user-defined function isn't also declared not to throw. - +
The answer to point (1) above is that implementers can (and some have) @@ -24990,10 +25548,11 @@ specification with a "Throws: Nothing." clause.
879. Atomic load const qualification
-Section: 29 [atomics] Status: NAD Editorial - Submitter: Alexander Chemeris Opened: 2008-08-24 Last modified: 2009-10-26
+Section: 29 [atomics] Status: NAD Editorial + Submitter: Alexander Chemeris Opened: 2008-08-24 Last modified: 2010-10-29
+View other active issues in [atomics].
View all other issues in [atomics].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
The atomic_address type and atomic<T*> specialization provide atomic @@ -25082,10 +25641,11 @@ bool atomic_compare_exchange_explicit(volatile atomic_address*,
880. Missing atomic exchange parameter
-Section: 29 [atomics] Status: NAD Editorial - Submitter: Lawrence Crowl Opened: 2008-08-24 Last modified: 2009-10-26
+Section: 29 [atomics] Status: NAD Editorial + Submitter: Lawrence Crowl Opened: 2008-08-24 Last modified: 2010-10-29
+View other active issues in [atomics].
View all other issues in [atomics].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Duplicate of: 942
Discussion:
@@ -25159,90 +25719,654 @@ bool atomic_exchange_explicit(volatile atomic_bool*, bool, memory_order -
884. shared_ptr swap
-Section: 20.8.15.2.4 [util.smartptr.shared.mod] Status: NAD Editorial - Submitter: Jonathan Wakely Opened: 2008-09-15 Last modified: 2009-07-13
-View all issues with NAD Editorial status.
+887. issue with condition::wait_...
+Section: 30.5.1 [thread.condition.condvar] Status: NAD + Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2010-10-29
+View all other issues in [thread.condition.condvar].
+View all issues with NAD status.
Discussion:
-#include <memory> -#include <cassert> ++The Posix/C++ working group has identified an inconsistency between +Posix and the C++ working draft in that Posix requires the clock to be +identified at creation, whereas C++ permits identifying the clock at the +call to wait. The latter cannot be implemented with the former. +
-struct A { }; -struct B : A { }; +[ +San Francisco: +]
-int main() + +++Howard recommends NAD with the following explanation: +
+ ++The intent of the current wording is for the condtion_variable::wait_until +be able to handle user-defined clocks as well as clocks the system knows about. +This can be done by providing overloads for the known clocks, and another +overload for unknown clocks which synchs to a known clock before waiting. +For example: +
+ +template <class Duration> +bool +condition_variable::wait_until(unique_lock<mutex>& lock, + const chrono::time_point<chrono::system_clock, Duration>& abs_time) { - std::shared_ptr<A> pa(new A); - std::shared_ptr<B> pb(new B); - std::swap<A>(pa, pb); // N.B. no argument deduction - assert( pa.get() == pb.get() ); - return 0; + using namespace chrono; + nanoseconds d = __round_up<nanoseconds>(abs_time.time_since_epoch()); + __do_timed_wait(lock.mutex()->native_handle(), time_point<system_clock, nanoseconds>(d)); + return system_clock::now() < abs_time; +} + +template <class Clock, class Duration> +bool +condition_variable::wait_until(unique_lock<mutex>& lock, + const chrono::time_point<Clock, Duration>& abs_time) +{ + using namespace chrono; + system_clock::time_point s_entry = system_clock::now(); + typename Clock::time_point c_entry = Clock::now(); + nanoseconds dn = __round_up<nanoseconds>(abs_time.time_since_epoch() - + c_entry.time_since_epoch()); + __do_timed_wait(lock.mutex()->native_handle(), s_entry + dn); + return Clock::now() < abs_time; }-Is this behaviour correct (I believe it is) and if so, is it -unavoidable, or not worth worrying about? +In the above example, system_clock is the only clock which the underlying +condition variable knows how to deal with. One overload just passes that clock +through. The second overload (approximately) converts the unknown clock into +a system_clock time_point prior to passing it down to the native +condition variable.
-This calls the lvalue/rvalue swap overload for shared_ptr: +On Posix systems vendors are free to add implementation defined constructors which +take a clock. That clock can be stored in the condition_variable, and converted +to (or not as necessary) as shown above.
-+ +template<class T> void swap( shared_ptr<T> & a, shared_ptr<T> && b ); ++If an implementation defined constructor takes a clock (for example), then part +of the semantics for that implementation defined ctor might include that a +wait_until using a clock other than the one constructed with results +in an error (exceptional condition) instead of a conversion to the stored clock. +Such a design is up to the vendor as once an implementation defined ctor is used, +the vendor is free to specifiy the behavior of waits and/or notifies however +he pleases (when the cv is constructed in an implementation defined manner). +
+[ +Post Summit: +]
+ + +++ ++"POSIX people will review the proposed NAD resolution at their upcoming NY +meeting. +
+ ++See the minutes at: http://wiki.dinkumware.com/twiki/bin/view/Posix/POSIX-CppBindingWorkingGroupNewYork2009. +
+[ +2009-07 Frankfurt +]
+ + ++Move to NAD. ++ +[ +2009-07-18 Detlef reopens the issue: +]
+ + +++ ++On Friday afternoon in Frankfurt is was decided that 887 is NAD. +This decision was mainly based on a sample implementation presented +by Howard that implemented one clock on top of another. +Unfortunately this implementation doesn't work for the probably most +important case where a system has a monotonic clock and a real-time +clock (or "wall time" clock): +
++If the underlying "system_clock" is a monotonic clock, and +the program waits on the real-time clock, and the real-time clock +is set forward, the wait will unblock too late. +
+ ++If the underlying "system_clock" is a real-time clock, and the +program waits on the monotonic clock, and the real-time clock +is set back, the wait again will unblock too late. +
+ ++Sorry that I didn't remember this on Friday, but it was Friday +afternoon after a busy week... +
+ ++So as the decision was made on a wrong asumption, I propose to re-open +the issue. +
+[ +2009-07-26 Howard adds: +]
+ + +++ ++Detlef correctly argues that condition_variable::wait_until could +return "too late" in the context of clocks being adjusted during the wait. I agree +with his logic. But I disagree that this makes this interface unimplementable +on POSIX. +
+ ++The POSIX spec also does not guarantee that pthread_cond_timedwait does +not return "too late" when clocks are readjusted during the wait. Indeed, the +POSIX specification lacks any requirements at all concerning how soon +pthread_cond_timedwait returns after a time out. This is evidently a +QOI issue by the POSIX standard. Here is a quote of the most relevant normative +text concerning pthread_cond_timedwait found +here. +
+ ++The pthread_cond_timedwait() function shall be equivalent to +pthread_cond_wait(), except that an error is returned if the absolute +time specified by abstime passes (that is, system time equals or exceeds +abstime) before the condition cond is signaled or broadcasted, or if the +absolute time specified by abstime has already been passed at the time +of the call. ++ ++I.e. the POSIX specification speaks of the error code returned in case of a time +out, but not on the timeliness of that return. +
+ ++Might this simply be an oversight, or minor defect in the POSIX specification? +
+ ++I do not believe so. This same section goes on to say in non-normative +text: +
+ ++For cases when the system clock is advanced discontinuously by an +operator, it is expected that implementations process any timed wait +expiring at an intervening time as if that time had actually occurred. ++ ++Here is non-normative wording encouraging the implementation to ignore an advancing +underlying clock and subsequently causing an early (spurious) return. There is +no wording at all which addresses Detlef's example of a "late return". With +pthread_cond_timedwait this would be caused by setting the system clock +backwards. It seems reasonable to assume, based on the wording that is already +in the POSIX spec, that again, the discontinuously changed clock would be ignored +by pthread_cond_timedwait. +
+ ++A noteworthy difference between pthread_cond_timedwait and +condition_variable::wait_until is that the POSIX spec appears to +say that ETIMEDOUT should be returned if pthread_cond_timedwait +returns because of timeout signal, whether or not the system clock was discontinuously +advanced during the wait. In contrast condition_variable::wait_until +always returns: +
+ +Clock::now() < abs_time-silently converting the second argument from shared_ptr<B> to -shared_ptr<A> and binding the rvalue ref to the produced temporary. +That is, the C++ spec requires that the clock be rechecked (detecting discontinuous +adjustments during the wait) at the time of return. condition_variable::wait_until +may indeed return early or late. But regardless it will return a value +reflecting timeout status at the time of return (even if clocks have been adjusted). +Of course the clock may be adjusted after the return value is computed but before the client has +a chance to read the result of the return. Thus there are no iron-clad guarantees +here.
-This is not, in my opinion, a shared_ptr problem; it is a general issue -with the rvalue swap overloads. Do we want to prevent this code from -compiling? If so, how? +condition_variable::wait_until (and pthread_cond_timedwait) +is little more than a convenience function for making sure +condition_variable::wait doesn't hang for an unreasonable amount of +time (where the client gets to define "unreasonable"). I do not think it +is in anyone's interest to try to make it into anything more than that.
-Perhaps we should limit rvalue args to swap to those types that would -benefit from the "swap trick". Or, since we now have shrink_to_fit(), just -eliminate the rvalue swap overloads altogether. The original motivation -was: +I maintain that this is a useful and flexible specification in the spirit of +C++, and is implementable on POSIX. The implementation technique described above +is a reasonable approach. There may also be higher quality approaches. This +specification, like the POSIX specification, gives a wide latitude for QOI.
-+vector<A> v = ...; -... -swap(v, vector<A>(v)); -+I continue to recommend NAD, but would not object to a clarifying note regarding +the behavior of condition_variable::wait_until. At the moment, I do +not have good wording for such a note, but welcome suggestions. +
-N1690. +[ +2009-09-30: See N2969. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++The LWG is in favor of Detlef to supply revision which adopts Option 2 from +N2969 +but is modified by saying that system_clock must be available for wait_until. ++ +[ +2010-02-11 Anthony provided wording. +]
+ + +[ +2010-02-22 Anthony adds: +]
+ + +++ ++I am strongly against +N2999. +
+ ++Firstly, I think that the most appropriate use of a timed wait on a condition +variable is with a monotonic clock, so it ought to be guaranteed to be available +on systems that support such a clock. Also, making the set of supported clocks +implementation defined essentially kills portability around the use of +user-defined clocks. +
+ ++I also think that wait_for is potentially useful, and trivially +implementable given a working templated wait_until and a monotonic +clock. +
+ ++I also disagree with many of Detlef's points in the rationale. In a system with +hard latency limits there is likely to be a monotonic clock, otherwise you have +no way of measuring against these latency limits since the system_clock +may change arbitrarily. In such systems, you want to be able to use +wait_for, or wait_until with a monotonic clock. +
+ ++I disagree that the wait_* functions cannot be implemented correctly on +top of POSIX: I have done so. The only guarantee in the working draft is that +when the function returns certain properties are true; there is no guarantee +that the function will return immediately that the properties are true. +My resolution to issue 887 makes this clear. How small the latency is is QoI. +
+ ++On systems without a monotonic clock, you cannot measure the problem since the +system clock can change arbitrarily so any timing calculations you make may be +wrong due to clock changes. +
+ ++On systems with a monotonic clock, you can choose to use it for your condition +variables. If you are waiting against a system_clock::time_point then +you can check the clock when waking, and either return as a timeout or spurious +wake depending on whether system_clock::now() is before or after the +specified time_point. +
+ ++Windows does provide condition variables from Vista onwards. I choose +not to use them, but they are there. If people are concerned about +implementation difficulty, the Boost implementation can be used for most +purposes; the Boost license is pretty liberal in that regard. +
+ ++My preferred resolution to issue 887 is currently the PR in the issues list. +
+[ +2010 Pittsburgh: +]
+ + +++ + + ++There is no consensus for moving the related paper +N2999 +into the WP. +
++There was support for moving this issue as proposed to Ready, but the support +was insufficient to call a consensus. +
++There was consensus for moving this issue to NAD as opposed to leaving it open. +Rationale added. +
+Rationale:
++The standard as written is sufficiently implementable and self consistent. +
+ + +Proposed resolution:
++Add a new paragraph after 30.2.4 [thread.req.timing]p3: +
+ +++ + + + + ++3 The resolution of timing provided by an implementation depends on both +operating system and hardware. The finest resolution provided by an +implementation is called the native resolution. +
+ ++If a function in this clause takes a timeout argument, and the time point or +elapsed time specified passes before the function returns, the latency between +the timeout occurring and the function returning is unspecified [Note: +Implementations should strive to keep such latency as small as possible, but +portable code should not rely on any specific upper limits — end +note] +
+
+889. thread::id comparisons
+Section: 30.3.1.1 [thread.thread.id] Status: NAD Editorial + Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2010-10-29
+View all other issues in [thread.thread.id].
+View all issues with NAD Editorial status.
+Discussion:
+ +Addresses UK 324
+ ++The thread::id type supports the full set of comparison operators. This +is substantially more than is required for the associative containers that +justified them. Please place an issue against the threads library. +
+ +[ +San Francisco: +]
+ + +++ ++Would depend on proposed extension to POSIX, or non-standard extension. +What about hash? POSIX discussing op. POSIX not known to be considering +support needed for hash, op. +
++Group expresses support for putting ids in both unordered and ordered containers. +
+[ +post San Francisco: +]
+ + +++ ++Howard: It turns out the current working paper +N2723 +already has hash<thread::id> +(20.8 [function.objects], 20.8.15 [unord.hash]). We simply +overlooked it in the meeting. It is a good thing we voted in favor of it +(again). :-) +
++Recommend NAD. +
+ +[ +Post Summit: +]
+ + ++Recommend to close as NAD. For POSIX, see if we need to add a function to +convert pthread_t to integer. ++ +[ +Post Summit, Alisdair adds: +]
+ + +++The recommendation for LWG-889/UK-324 is NAD, already specified. +
++It is not clear to me that the specification is complete. +
++In particular, the synopsis of <functional> in 20.8 [function.objects] does not mention hash< thread::id +> nor hash< error_code >, although their +existence is implied by 20.8.15 [unord.hash], p1. +
++I am fairly uncomfortable putting the declaration for the +thread_id specialization into <functional> as +id is a nested class inside std::thread, so it implies +that <functional> would require the definition of the +thread class template in order to forward declared +thread::id and form this specialization. +
++It seems better to me that the dependency goes the other way around +(<thread> will more typically make use of +<functional> than vice-versa) and the +hash<thread::id> specialization be declared in the +<thread> header. +
++I think hash<error_code> could go into either +<system_error> or <functional> and have no +immediate preference either way. However, it should clearly appear in +the synopsis of one of these two. +
++Recommend moving 889 back to open, and tying in a reference to UK-324. +
+[ Batavia (2009-05): ]
-We agree with the proposed resolution. -Move to NAD Editorial. +Howard observes that thread::id need not be a nested class; +it could be a typedef for a more visible type.+[ +2009-05-24 Alisdair adds: +]
+ ++I do not believe this is correct. thread::id is explicitly documents as a +nested class, rather than as an unspecified typedef analogous to an +iterator. If the intent is that this is not implemented as a nested class +(under the as-if freedoms) then this is a novel form of standardese. ++ +[ +2009-07 Frankfurt +]
+ + ++Decided we want to move hash specialization for thread_id to the thread +header. Alisdair to provide wording. ++ +[ +2009-07-28 Alisdair provided wording, moved to Review. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Add a strike for hash<thread::id>. Move to Ready ++ +[ +2009-11-13 The proposed wording of 1182 is a superset of the +wording in this issue. +]
+ + +[ +2010-02-09 Moved from Ready to Open: +]
+ + +++ ++Issue 1182 is not quite a superset of this issue and it is controversial +whether or not the note: +
+ ++hash template specialization allows thread::id objects to be used as keys in +unordered containers. ++ ++should be added to the WP. +
+ + +[ +2010-02-09 Objections to moving this to NAD Editorial, solved by 1182 have been removed. Set to Tentatively NAD Editorial. +]
+ + + + +Rationale:
++Solved by 1182. +
+Proposed resolution:
+-Recommend NAD Editorial, fixed by -N2844. +Remove the following prototype from the synopsis in +20.8 [function.objects]:
++ ++template <> struct hash<std::thread::id>; ++Add to 30.3 [thread.threads], p1 Header <thread> synopsis: +
+ ++ +template <class T> struct hash; +template <> struct hash<thread::id>; ++Add template specialization below class definition in 30.3.1.1 [thread.thread.id] +
+ ++ +template <> +struct hash<thread::id> : public unary_function<thread::id, size_t> { + size_t operator()(thread::id val) const; +}; ++Extend note in p2 30.3.1.1 [thread.thread.id] with second sentence: +
+ ++[Note: Relational operators allow thread::id objects to be used +as keys in associative containers. +hash template specialization allows thread::id objects to be used as keys +in unordered containers. +— end note] ++ ++Add new paragraph to end of 30.3.1.1 [thread.thread.id] +
+ ++template <> struct hash<thread::id>; +++An explicit specialization of the class template hash (20.8.15 [unord.hash]) +shall be provided for the type thread::id. ++
892. Forward_list issues...
-Section: 23.3.3.5 [forwardlist.ops] Status: NAD Editorial - Submitter: Ed Smith-Rowland Opened: 2008-09-15 Last modified: 2009-03-09
+Section: 23.3.3.5 [forwardlist.ops] Status: NAD Editorial + Submitter: Ed Smith-Rowland Opened: 2008-09-15 Last modified: 2010-10-29
View all other issues in [forwardlist.ops].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
I was looking at the latest draft on forward_list. Especially the splice methods. @@ -25326,10 +26450,10 @@ change:
895. "Requires:" on std::string::at et al
Section: 17.5.1.4 [structure.specifications] Status: Dup - Submitter: James Dennett Opened: 2008-09-16 Last modified: 2009-07-17
+ Submitter: James Dennett Opened: 2008-09-16 Last modified: 2010-10-29View all other issues in [structure.specifications].
View all issues with Dup status.
-Duplicate of: 625
+Duplicate of: 625
Discussion:
Per discussion, we need an issue open to cover looking at "Requires" @@ -25358,9 +26482,10 @@ clauses which are not constraints on user code, such as that on
897. Forward_list issues... Part 2
-Section: 23.3.3.4 [forwardlist.modifiers] Status: NAD Editorial - Submitter: Howard Hinnant Opened: 2008-09-22 Last modified: 2009-10-20
-View all issues with NAD Editorial status.
+Section: 23.3.3.4 [forwardlist.modifiers] Status: NAD Editorial + Submitter: Howard Hinnant Opened: 2008-09-22 Last modified: 2010-10-29
+View all other issues in [forwardlist.modifiers].
+View all issues with NAD Editorial status.
Discussion:
This issue was split off from 892 at the request of the LWG. @@ -25536,7 +26661,7 @@ Move to Review.
We may need a new issue to correct splice_after, because it may no longer be correct to accept an rvalues as an argument. Merge may be -affected, too. This might be issue 1133. (Howard: confirmed) +affected, too. This might be issue 1133. (Howard: confirmed)
Move this to Ready, but the Requires clause of the second form of @@ -25689,7 +26814,7 @@ elements, but they now behave as iterators into *this, not into
901. insert iterators can move from lvalues
Section: 24.5.2.5 [insert.iterator] Status: NAD - Submitter: Alisdair Meredith Opened: 2008-09-24 Last modified: 2009-07-13
+ Submitter: Alisdair Meredith Opened: 2008-09-24 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
Addresses UK 282
@@ -25756,10 +26881,10 @@ Recommend NAD, addressed by 902. Regular is the wrong concept to constrain numeric_limits -Section: 18.3.1 [limits] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2008-09-24 Last modified: 2009-07-16
+Section: 18.3.1 [limits] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2008-09-24 Last modified: 2010-10-29
View all other issues in [limits].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses FR 32 and DE 16
@@ -25815,7 +26940,7 @@ treatment of axioms in clause 14.
903. back_insert_iterator issue
Section: 24.5.2.1 [back.insert.iterator] Status: NAD - Submitter: Dave Abrahams Opened: 2008-09-19 Last modified: 2009-07-16
+ Submitter: Dave Abrahams Opened: 2008-09-19 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -25880,11 +27005,11 @@ to properly reflect the dual nature of built-in operator* as of
905. Mutex specification questions
-Section: 30.4.1.1 [thread.mutex.class] Status: Dup - Submitter: Herb Sutter Opened: 2008-09-18 Last modified: 2009-03-22
+Section: 30.4.1.2.1 [thread.mutex.class] Status: Dup + Submitter: Herb Sutter Opened: 2008-09-18 Last modified: 2010-10-29
View all other issues in [thread.mutex.class].
View all issues with Dup status.
-Duplicate of: 893
+Duplicate of: 893
Discussion:
A few questions on the current WP, @@ -25898,7 +27023,7 @@ exception anyway, such as to report unbalanced unlock operations and unlocking from a thread that does not have ownership. Right?
-30.4.1.1 [thread.mutex.class]/3 (actually numbered paragraph "27" +30.4.1.2.1 [thread.mutex.class]/3 (actually numbered paragraph "27" in the WP; this is just a typo I think) says
@@ -25945,10 +27070,10 @@ fails the program has undefined behaviour and therefore an implementation may throw an exception already.-30.4.1.1 [thread.mutex.class]/3 bullet 2: Already addressed by issue 893. +30.4.1.2.1 [thread.mutex.class]/3 bullet 2: Already addressed by issue 893. -30.4.1.1 [thread.mutex.class]/3 proposed addition: NAD. This is +30.4.1.2.1 [thread.mutex.class]/3 proposed addition: NAD. This is already covered by the mutex requirements, which have ownership as a Precondition. @@ -25965,9 +27090,9 @@ Precondition.
906. ObjectType is the wrong concept to constrain initializer_list
-Section: 18.9 [support.initlist] Status: NAD Concepts - Submitter: Daniel Krügler Opened: 2008-09-26 Last modified: 2009-07-16
-View all issues with NAD Concepts status.
+Section: 18.9 [support.initlist] Status: NAD Concepts + Submitter: Daniel Krügler Opened: 2008-09-26 Last modified: 2010-10-29
+View all issues with NAD Concepts status.
Discussion:
The currently proposed constraint on initializer_list's element type @@ -26099,10 +27224,10 @@ constraint "ValueType".
908. Deleted assignment operators for atomic types must be volatile
-Section: 29.5 [atomics.types] Status: NAD Editorial - Submitter: Anthony Williams Opened: 2008-09-26 Last modified: 2009-10-26
+Section: X [atomics.types] Status: NAD Editorial + Submitter: Anthony Williams Opened: 2008-09-26 Last modified: 2010-10-29
View all other issues in [atomics.types].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses US 90
@@ -26185,12 +27310,197 @@ the assignment from plain bool. +
+910. Effects of MoveAssignable
+Section: 20.2.1 [utility.arg.requirements] Status: NAD Concepts + Submitter: Alberto Ganesh Barbati Opened: 2008-09-29 Last modified: 2010-10-29
+View all other issues in [utility.arg.requirements].
+View all issues with NAD Concepts status.
+Discussion:
+Addresses UK 150
+ ++The description of the effect of operator= in the MoveAssignable +concept, given in paragraph 7 is: +
+ ++ +result_type T::operator=(T&& rv); // inherited from HasAssign<T, T&&> ++ ++Postconditions: the constructed T object is equivalent to the value of +rv before the assignment. [Note: there is no +requirement on the value of rv after the assignment. --end note] +++The sentence contains a typo (what is the "constructed T object"?) +probably due to a cut&paste from MoveConstructible. Moreover, the +discussion of LWG issue 675 shows that the postcondition is too generic +and might not reflect the user expectations. An implementation of the +move assignment that just calls swap() would always fulfill the +postcondition as stated, but might have surprising side-effects in case +the source rvalue refers to an object that is not going to be +immediately destroyed. See LWG issue 900 for another example. Due to +the sometimes intangible nature of the "user expectation", it seems +difficult to have precise normative wording that could cover all cases +without introducing unnecessary restrictions. However a non-normative +clarification could be a very helpful warning sign that swapping is not +always the correct thing to do. +
+ +[ +2009-05-09 Alisdair adds: +]
+ + +++ ++Issue 910 is exactly the reason BSI advanced the Editorial comment UK-150. +
++The post-conditions after assignment are at a minimum that the object +referenced by rv must be safely destructible, and the transaction should not +leak resources. Ideally it should be possible to simply assign rv a new +valid state after the call without invoking undefined behaviour, but any +other use of the referenced object would depend upon additional guarantees +made by that type. +
+[ +2009-05-09 Howard adds: +]
+ + +++ ++The intent of the rvalue reference work is that the moved from rv is +a valid object. Not one in a singular state. If, for example, the moved from +object is a vector, one should be able to do anything on that moved-from +vector that you can do with any other vector. However you would +first have to query it to find out what its current state is. E.g. it might have capacity, +it might not. It might have a non-zero size, it might not. But regardless, +you can push_back on to it if you want. +
+ ++That being said, most standard code is now conceptized. That is, the concepts +list the only operations that can be done with templated types - whether or not +the values have been moved from. +
+ ++Here is user-written code which must be allowed to be legal: +
++ +#include <vector> +#include <cstdio> + +template <class Allocator> +void +inspect(std::vector<double, Allocator>&& v) +{ + std::vector<double, Allocator> result(move(v)); + std::printf("moved from vector has %u size and %u capacity\n", v.size(), v.capacity()); + std::printf("The contents of the vector are:\n"); + typedef typename std::vector<double, Allocator>::iterator I; + for (I i = v.begin(), e = v.end(); i != e; ++i) + printf("%f\n", *i); +} + +int main() +{ + std::vector<double> v1(100, 5.5); + inspect(move(v1)); +} ++The above program does not treat the moved-from vector as singular. It +only treats it as a vector with an unknown value. +
++I believe the current proposed wording is consistent with my view on this. +
+[ +Batavia (2009-05): +]
+ ++We agree that the proposed resolution +is an improvement over the current wording. ++ +[ +2009-07 Frankfurt: +]
+ + ++Need to look at again without concepts. ++ +[ +2009-07 Frankfurt: +]
+ + ++Walter will consult with Dave and Doug. ++ +[ +2009-10 Santa Cruz: +]
+ + ++We believe this is handled by the resolution to issue 1204, +but there is to much going on in this area to be sure. Defer for now. ++ +[ +2010-01-23 Moved to Tentatively NAD Concepts after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + +Rationale:
++The current MoveAssignable requirements say everything that can be said +in general. Each std-defined type has a more detailed specification of move +assignment. +
+ + +Proposed resolution:
++In [concept.copymove], replace the postcondition in paragraph 7 with: +
+ ++Postconditions: *this is equivalent to the value of rv before the +assignment. [Note: there is no requirement on the value of rv after the +assignment, but the +effect should be unsurprising to the user even in case rv is not +immediately destroyed. This may require that resources previously owned +by *this are released instead of transferred to rv. -- end note] ++ + + + +
912. Array swap needs to be conceptualized
-Section: 25.3.3 [alg.swap] Status: NAD Concepts - Submitter: Daniel Krügler Opened: 2008-10-01 Last modified: 2009-07-13
+Section: 25.3.3 [alg.swap] Status: NAD Concepts + Submitter: Daniel Krügler Opened: 2008-10-01 Last modified: 2010-10-29
View all other issues in [alg.swap].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
With the adaption of 809 @@ -26242,10 +27552,10 @@ void swap(T (&a)[N], T (&b)[N]);
913. Superfluous requirements for replace algorithms
-Section: 25.3.5 [alg.replace] Status: NAD Concepts - Submitter: Daniel Krügler Opened: 2008-10-03 Last modified: 2009-07-14
+Section: 25.3.5 [alg.replace] Status: NAD Concepts + Submitter: Daniel Krügler Opened: 2008-10-03 Last modified: 2010-10-29
View all other issues in [alg.replace].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
(A) 25.3.5 [alg.replace]/1: @@ -26363,10 +27673,10 @@ iterator. The ranges [first,last) and [result,result +
914. Superfluous requirement for unique
-Section: 25.3.9 [alg.unique] Status: NAD Concepts - Submitter: Daniel Krügler Opened: 2008-10-03 Last modified: 2009-07-14
+Section: 25.3.9 [alg.unique] Status: NAD Concepts + Submitter: Daniel Krügler Opened: 2008-10-03 Last modified: 2010-10-29
View all other issues in [alg.unique].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
25.3.9 [alg.unique]/2: "Requires: The comparison function shall be an @@ -26424,11 +27734,155 @@ template<ForwardIterator Iter, EquivalenceRelation<auto, Iter::value_type& +
+915. minmax with initializer_list should return +pair of T, not pair of const T&
+Section: 25.4.7 [alg.min.max] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2010-10-29
+View all other issues in [alg.min.max].
+View all issues with NAD Editorial status.
+Discussion:
++It seems that the proposed changes for +N2772 +were not clear enough in +this point: +
+ ++25.4.7 [alg.min.max], before p.23 + p.24 + before p. 27 + p. 28 say that the return +type of the minmax overloads with an initializer_list is +pair<const T&, const T&>, +which is inconsistent with the decision for the other min/max overloads which take +a initializer_list as argument and return a T, not a const T&. +Doing otherwise for minmax would easily lead to unexpected life-time +problems by using minmax instead of min and max separately. ++ +[ +Batavia (2009-05): +]
+ ++We agree with the proposed resolution. +Move to Tentatively Ready. ++ +[ +2009-07 Frankfurt +]
+ + ++Moved from Tentatively Ready to Open only because the wording needs to be +tweaked for concepts removal. ++ +[ +2009-08-18 Daniel adds: +]
+ + ++Recommend NAD since the proposed changes have already been performed +as part of editorial work of +N2914. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Can't find initializer_list form of minmax anymore, only variadic +version. Seems like we had an editing clash with concepts. Leave Open, +at least until editorial issues resolved. Bring this to Editor's +attention. ++ +[ +2010 Pittsburgh: Pete to reapply +N2772. +]
+ + + + +Rationale:
+Solved by reapplying +N2772. + + +Proposed resolution:
++
+ + + + + +- +
++In 25 [algorithms]/2, header <algorithm> synopsis change as indicated: +
+ ++template<classLessThanComparable T> +requires CopyConstructible<T> +pair<constT&,constT&> +minmax(initializer_list<T> t); + +template<class T,classStrictWeakOrder<auto, T> Compare> +requires CopyConstructible<T> +pair<constT&,constT&> +minmax(initializer_list<T> t, Compare comp); +- +
++In 25.4.7 [alg.min.max] change as indicated (Begin: Just before p.20): +
++template<+classLessThanComparable T> + requires CopyConstructible<T> + pair<constT&,constT&> + minmax(initializer_list<T> t); +++ ++
+-20- Requires: T is LessThanComparable and +CopyConstructible.++-21- Returns: pair<
+constT&,const +T&>(x, y) where x is the +smallest value and y the largest value in the initializer_list. +[..]
+template<class T,+ +classStrictWeakOrder<auto, T> Compare> + requires CopyConstructible<T> + pair<constT&,constT&> + minmax(initializer_list<T> t, Compare comp); ++++
+-24- Requires: type T is LessThanComparable and CopyConstructible.++-25- Returns: pair<
+constT&,const +T&>(x, y) where x is the +smallest value and y largest value in the initializer_list. +
916. Redundant move-assignment operator of pair should be removed
-Section: 20.3.4 [pairs] Status: NAD - Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2009-10-23
-View other active issues in [pairs].
+Section: 20.3.5 [pairs] Status: NAD + Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2010-10-29
View all other issues in [pairs].
View all issues with NAD status.
Discussion:
@@ -26436,7 +27890,7 @@ template<ForwardIterator Iter, EquivalenceRelation<auto, Iter::value_type&The current WP provides the following assignment operators for pair -in 20.3.4 [pairs]/1: +in 20.3.5 [pairs]/1:
@@ -26494,7 +27948,7 @@ Leave this open pending the removal of concepts from the WD.
@@ -28239,7 +31166,7 @@ is deliberate.-Mark as NAD, see issue 801. +Mark as NAD, see issue 801.@@ -26503,7 +27957,7 @@ Mark as NAD, see issue-In 20.3.4 [pairs] p. 1, class pair and just before p. 13 remove the declaration: +In 20.3.5 [pairs] p. 1, class pair and just before p. 13 remove the declaration:
requires MoveAssignable<T1> && MoveAssignable<T2> pair& operator=(pair&& p ); @@ -26522,8 +27976,8 @@ Remove p.13+p.14
917. Redundant move-assignment operator of tuple should be removed
-Section: 20.5.2.1 [tuple.cnstr] Status: NAD - Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2009-10-23
+Section: 20.4.2.1 [tuple.cnstr] Status: NAD + Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2010-10-29
View all other issues in [tuple.cnstr].
View all issues with NAD status.
Discussion:
@@ -26579,7 +28033,7 @@ Leave this open pending the removal of concepts from the WD.-Mark as NAD, see issue 801. +Mark as NAD, see issue 801.@@ -26588,7 +28042,7 @@ Mark as NAD, see issue 918. Swap for tuple needs to be conceptualized -Section: 20.5.2.3 [tuple.swap] Status: NAD Concepts - Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2009-07-13
-View all issues with NAD Concepts status.
+Section: 20.4.2.3 [tuple.swap] Status: NAD Concepts + Submitter: Daniel Krügler Opened: 2008-10-04 Last modified: 2010-10-29
+View all issues with NAD Concepts status.
Discussion:
Issue 522 was accepted after tuple had been conceptualized, @@ -26684,7 +28138,7 @@ Move to NAD.
-In both 20.5.1 [tuple.general]/2 and 20.5.2.9 [tuple.special] change +In both 20.4.1 [tuple.general]/2 and 20.4.2.9 [tuple.special] change
template <classSwappable... Types> @@ -26695,8 +28149,8 @@ void swap(tuple<Types...>& x, tuple<Types...>& y);-In 20.5.2 [tuple.tuple], class tuple definition and in -20.5.2.3 [tuple.swap], change +In 20.4.2 [tuple.tuple], class tuple definition and in +20.4.2.3 [tuple.swap], change
requires Swappable<Types>...void swap(tuple&); @@ -26706,7 +28160,7 @@ In 20.5.2 [tuple.tuple], class tuple definition and in-In 20.5.2.3 [tuple.swap] remove the current requires-clause, which says: +In 20.4.2.3 [tuple.swap] remove the current requires-clause, which says:
@@ -26724,7 +28178,7 @@ In 20.5.2.3 [tuple.swap] remove the current requires-clause, which says:
919. (forward_)list specialized remove algorithms are over constrained
Section: 23.3.3.5 [forwardlist.ops], 23.3.4.4 [list.ops] Status: NAD - Submitter: Daniel Krügler Opened: 2008-10-06 Last modified: 2009-10-23
+ Submitter: Daniel Krügler Opened: 2008-10-06 Last modified: 2010-10-29View all other issues in [forwardlist.ops].
View all issues with NAD status.
Discussion:
@@ -26818,10 +28272,11 @@ Replace in 23.3.3.5 [forwardlist.ops] before 11 and in 23.3.4.4 [list.ops] befor
923. atomics with floating-point
-Section: 29 [atomics] Status: NAD Editorial - Submitter: Herb Sutter Opened: 2008-10-17 Last modified: 2009-10-26
+Section: 29 [atomics] Status: NAD Editorial + Submitter: Herb Sutter Opened: 2008-10-17 Last modified: 2010-10-29
+View other active issues in [atomics].
View all other issues in [atomics].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Right now, C++0x doesn't have atomic<float>. We're thinking of adding @@ -26929,10 +28384,11 @@ the same value. -- end note]
924. structs with internal padding
-Section: 29 [atomics] Status: NAD Editorial - Submitter: Herb Sutter Opened: 2008-10-17 Last modified: 2009-10-26
+Section: 29 [atomics] Status: NAD Editorial + Submitter: Herb Sutter Opened: 2008-10-17 Last modified: 2010-10-29
+View other active issues in [atomics].
View all other issues in [atomics].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Right now, the compare_exchange_weak loop should rapidly converge on the @@ -27018,10 +28474,10 @@ NAD Editorial. Solved by
926. Sequentially consistent fences, relaxed operations and modification order
-Section: 29.3 [atomics.order] Status: NAD Editorial - Submitter: Anthony Williams Opened: 2008-10-19 Last modified: 2009-10-26
+Section: 29.3 [atomics.order] Status: NAD Editorial + Submitter: Anthony Williams Opened: 2008-10-19 Last modified: 2010-10-29
View all other issues in [atomics.order].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 313
@@ -27210,9 +28666,9 @@ then B occurs later than A in the modifiction order of
927. Dereferenceable should be HasDereference
-Section: X [allocator.concepts] Status: NAD Concepts - Submitter: Pablo Halpern Opened: 2008-10-23 Last modified: 2009-07-13
-View all issues with NAD Concepts status.
+Section: X [allocator.concepts] Status: NAD Concepts + Submitter: Pablo Halpern Opened: 2008-10-23 Last modified: 2010-10-29
+View all issues with NAD Concepts status.
Discussion:
X [allocator.concepts] contains a reference to a concept named @@ -27259,10 +28715,10 @@ Change all uses of the concept Dereferenceable to
928. Wrong concepts used for tuple's comparison operators
-Section: 20.5.2.7 [tuple.rel] Status: NAD Concepts - Submitter: Joe Gottman Opened: 2008-10-28 Last modified: 2009-07-13
+Section: 20.4.2.7 [tuple.rel] Status: NAD Concepts + Submitter: Joe Gottman Opened: 2008-10-28 Last modified: 2010-10-29
View all other issues in [tuple.rel].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
In the latest working draft for C++0x, tuple's operator== and operator< @@ -27321,7 +28777,7 @@ Recommend Tentatively Ready.
Proposed resolution:
-In 20.5.1 [tuple.general] and 20.5.2.7 [tuple.rel] change: +In 20.4.1 [tuple.general] and 20.4.2.7 [tuple.rel] change:
template<class... TTypes, class... UTypes> @@ -27356,7 +28812,7 @@ template<class... TTypes, class... UTypes>
930. Access to std::array data as built-in array type
Section: 23.3.1 [array] Status: NAD - Submitter: Niels Dekker Opened: 2008-11-17 Last modified: 2009-10-20
+ Submitter: Niels Dekker Opened: 2008-11-17 Last modified: 2010-10-29View all other issues in [array].
View all issues with NAD status.
Discussion:
@@ -27608,10 +29064,10 @@ The idea to resolve the issue by adding explicit conversion operators was abandoned, because it would be inconvenient to use, especially when passing the array to a template function, as mentioned by Daniel. So we reconsidered the original proposed resolution, which appeared -acceptable, except for its proposed changes to 23.3.1.6 [array.zero], which +acceptable, except for its proposed changes to 23.3.1.7 [array.zero], which allowed c_array_type and c_array() to be absent for a zero-sized array. Alisdair argued that such wording would disallow certain generic use -cases. New wording for 23.3.1.6 [array.zero] was agreed upon (Howard: and +cases. New wording for 23.3.1.7 [array.zero] was agreed upon (Howard: and is reflected in the proposed resolution).@@ -27695,7 +29151,7 @@ const c_array_type & c_array() const &;
-Change Zero sized arrays 23.3.1.6 [array.zero]: +Change Zero sized arrays 23.3.1.7 [array.zero]:
@@ -27719,10 +29175,10 @@ The type c_array_type is unspecified for a zero-sized array.
933. Unique_ptr defect
-Section: 20.8.14.2.5 [unique.ptr.single.modifiers] Status: NAD Future - Submitter: Alisdair Meredith Opened: 2008-11-27 Last modified: 2009-10-23
+Section: 20.9.9.2.5 [unique.ptr.single.modifiers] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2008-11-27 Last modified: 2010-10-29
View all other issues in [unique.ptr.single.modifiers].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
If we are supporting stateful deleters, we need an overload for @@ -27775,12 +29231,12 @@ Mark as NAD Future.
935. clock error handling needs to be specified
-Section: 20.9.5 [time.clock] Status: NAD Future - Submitter: Beman Dawes Opened: 2008-11-24 Last modified: 2009-10-23
-View all issues with NAD Future status.
+Section: 20.11.5 [time.clock] Status: NAD Future + Submitter: Beman Dawes Opened: 2008-11-24 Last modified: 2010-10-29
+View all issues with NAD Future status.
Discussion:
-Each of the three clocks specified in Clocks 20.9.5 [time.clock] +Each of the three clocks specified in Clocks 20.11.5 [time.clock] provides the member function:
@@ -27788,9 +29244,9 @@ provides the member function:-The semantics specified by Clock requirements 20.9.1 [time.clock.req] +The semantics specified by Clock requirements 20.11.1 [time.clock.req] make no mention of error handling. Thus the function may throw bad_alloc -or an implementation-defined exception (17.6.4.11 [res.on.exception.handling] +or an implementation-defined exception (17.6.4.12 [res.on.exception.handling] paragraph 4).
@@ -27851,7 +29307,7 @@ Accept the proposed wording of-Change Clock requirements 20.9.1 [time.clock.req] as indicated: +Change Clock requirements 20.11.1 [time.clock.req] as indicated:
@@ -27893,21 +29349,21 @@ both of these calls happen before C1::time_point::max().-Change Class system_clock 20.9.5.1 [time.clock.system] as indicated: +Change Class system_clock 20.11.5.1 [time.clock.system] as indicated:
static time_point now(error_code& ec=throws());-Change Class monotonic_clock 20.9.5.2 [time.clock.monotonic] as indicated: +Change Class monotonic_clock X [time.clock.monotonic] as indicated:
static time_point now(error_code& ec=throws());-Change Class high_resolution_clock 20.9.5.3 [time.clock.hires] as indicated: +Change Class high_resolution_clock 20.11.5.3 [time.clock.hires] as indicated:
static time_point now(error_code& ec=throws()); @@ -27920,11 +29376,10 @@ Change Class high_resolution_clock 20.9.5.3 [time.clock.hires] as indicated:
936. Mutex type overspecified
-Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future - Submitter: Pete Becker Opened: 2008-12-05 Last modified: 2009-10-23
-View other active issues in [thread.mutex.requirements].
+Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future + Submitter: Pete Becker Opened: 2008-12-05 Last modified: 2010-10-29
View all other issues in [thread.mutex.requirements].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Duplicate of: 961
Discussion:
@@ -27935,7 +29390,7 @@ Change Class high_resolution_clock 20.9.5.3 [time.clock.hires] as indicated: a "Mutex type". A Mutex type can be used as the template argument for the Lock type that's passed to condition_variable_any::wait (although Lock seems like the wrong name here, since Lock is given a different -formal meaning in 30.4.3 [thread.lock]) and, although the WD doesn't quite say +formal meaning in 30.4.2 [thread.lock]) and, although the WD doesn't quite say so, as the template argument for lock_guard and unique_lock. @@ -28031,10 +29486,11 @@ and should be rephrased as such.
937. Atomics for standard typedef types
-Section: 29 [atomics] Status: NAD Editorial - Submitter: Clark Nelson Opened: 2008-12-05 Last modified: 2009-05-23
+Section: 29 [atomics] Status: NAD Editorial + Submitter: Clark Nelson Opened: 2008-12-05 Last modified: 2010-10-29
+View other active issues in [atomics].
View all other issues in [atomics].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses US 89
@@ -28105,10 +29561,249 @@ with C. +
+940. std::distance
+Section: 24.4.4 [iterator.operations] Status: NAD Editorial + Submitter: Thomas Opened: 2008-12-14 Last modified: 2010-10-29
+View all other issues in [iterator.operations].
+View all issues with NAD Editorial status.
+Discussion:
+ +Addresses UK 270
+ ++Regarding the std::distance - function, 24.4.4 [iterator.operations] +/ 4 says: +
++Returns the +number of increments or decrements needed to get from first to last. +++This sentence is completely silent about the sign of the return value. +24.4.4 [iterator.operations] / 1 gives more information about the +underlying operations, but +again no inferences about the sign can be made. +Strictly speaking, that is taking that sentence literally, I think this +sentence even implies a positive return value in all cases, as the +number of increments or decrements is clearly a ratio scale variable, +with a natural zero bound. +
++Practically speaking, my implementations did what common sense and +knowledge based on pointer arithmetic forecasts, namely a positive sign +for increments (that is, going from first to last by operator++), and a +negative sign for decrements (going from first to last by operator--). +
++Here are my two questions: +
++First, is that paragraph supposed to be interpreted in the way what I +called 'common sense', that is negative sign for decrements ? I am +fairly sure that's the supposed behavior, but a double-check here in +this group can't hurt. +
++Second, is the present wording (2003 standard version - no idea about +the draft for the upcoming standard) worth an edit to make it a bit more +sensible, to mention the sign of the return value explicitly ? +
+ +[ +Daniel adds: +]
+ + +++ ++My first thought was that resolution 204 would already cover the +issue report, but it seems that current normative wording is in +contradiction to that resolution: +
+ ++Referring to +N2798, +24.4.4 [iterator.operations]/ p.4 says: +
+ ++Effects: Returns the number of increments or decrements needed to get +from first to last. ++ ++IMO the part " or decrements" is in contradiction to p. 5 which says +
+ ++Requires: last shall be reachable from first. ++ ++because "reachable" is defined in X [iterator.concepts]/7 as +
+ ++An iterator j is called reachable from an iterator i if and only if +there is a finite +sequence of applications of the expression ++i that makes i == j.[..] ++ ++Here is wording that would be consistent with this definition of "reachable": +
+ ++Change 24.4.4 [iterator.operations] p4 as follows: +
+ ++Effects: Returns the number of increments+ +or decrements+needed to get from first to last. ++Thomas adds more discussion and an alternative view point +here. +
+ +[ +Summit: +]
+ + ++The proposed wording below was verbally agreed to. Howard provided. ++ +[ +Batavia (2009-05): +]
+ +++ ++Pete reports that a recent similar change has been made +for the advance() function. +
++We agree with the proposed resolution. +Move to Tentatively Ready. +
+[ +2009-07 Frankfurt +]
+ + ++Moved from Tentatively Ready to Open only because the wording needs to be +tweaked for concepts removal. ++ +[ +2009-07 Frankfurt: +]
+ + ++Leave Open pending arrival of a post-Concepts WD. ++ +[ +2009-10-14 Daniel provided de-conceptified wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready, replacing the Effects clause in the proposed wording with +"If InputIterator meets the requirements of random access iterator then +returns (last - first), otherwise returns the number of increments +needed to get from first to list.". ++ +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added below. ++ + + +Rationale:
++Solved by N3066. +
+ + +Proposed resolution:
++
+ + + + + + + + +- +
+ ++Change 24.2.7 [random.access.iterators], Table 105 as indicated [This change is not +essential but it simplifies the specification] for the row with +expression "b - a" +and the column Operational semantics: +
+ ++(a < b) ?distance(a,b) +: -distance(b,a)+- +
++Change 24.4.4 [iterator.operations]/4+5 as indicated: +
+ ++template<class InputIterator> + typename iterator_traits<InputIterator>::difference_type + distance(InputIterator first, InputIterator last); +++++4 Effects: If InputIterator meets the requirements +of random access iterator then returns (last - first), +otherwise
+ +Rreturns the number of increments +or decrementsneeded to get from first to +last. ++5 Requires: If InputIterator meets the requirements +of random access iterator then last shall be reachable from +first or first shall be reachable from last, +otherwise last shall be reachable from first. +
+
941. Ref-qualifiers for assignment operators
Section: 17 [library] Status: NAD - Submitter: Niels Dekker Opened: 2008-12-18 Last modified: 2009-07-17
+ Submitter: Niels Dekker Opened: 2008-12-18 Last modified: 2010-10-29View other active issues in [library].
View all other issues in [library].
View all issues with NAD status.
@@ -28178,7 +29873,8 @@ A proposed resolution is provided by the paper on this subject,
942. Atomics synopsis typo
Section: 29 [atomics] Status: Dup - Submitter: Holger Grund Opened: 2008-12-19 Last modified: 2009-03-22
+ Submitter: Holger Grund Opened: 2008-12-19 Last modified: 2010-10-29 +View other active issues in [atomics].
View all other issues in [atomics].
View all issues with Dup status.
Duplicate of: 880
@@ -28232,10 +29928,10 @@ Change the synopsis in 29 [atomics]/2:
944. atomic<bool> derive from atomic_bool?
-Section: 29.5.3 [atomics.types.generic] Status: NAD Editorial - Submitter: Holger Grund Opened: 2008-12-19 Last modified: 2009-10-26
+Section: 29.5 [atomics.types.generic] Status: NAD Editorial + Submitter: Holger Grund Opened: 2008-12-19 Last modified: 2010-10-29
View all other issues in [atomics.types.generic].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
I think it's fairly obvious that atomic<bool> is supposed to be derived @@ -28248,7 +29944,7 @@ problem.
-29.5.3 [atomics.types.generic]/3 reads +29.5 [atomics.types.generic]/3 reads
@@ -28294,7 +29990,7 @@ NAD Editorial. Solved byProposed resolution:
-Replace paragraph 3 in 29.5.3 [atomics.types.generic] with +Replace paragraph 3 in 29.5 [atomics.types.generic] with
@@ -28315,13 +30011,13 @@ constructors and trivial destructors.
945. system_clock::rep not specified
-Section: 20.9.5.1 [time.clock.system] Status: NAD Editorial - Submitter: Pete Becker Opened: 2008-12-19 Last modified: 2009-07-13
+Section: 20.11.5.1 [time.clock.system] Status: NAD Editorial + Submitter: Pete Becker Opened: 2008-12-19 Last modified: 2010-10-29
View all other issues in [time.clock.system].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
-In 20.9.5.1 [time.clock.system], the declaration of system_clock::rep says "see +In 20.11.5.1 [time.clock.system], the declaration of system_clock::rep says "see below", but there is nothing below that describes it.
@@ -28368,7 +30064,7 @@ Move to NAD Editorial.Proposed resolution:
-Add a note to 20.9.5.1 [time.clock.system], p2: +Add a note to 20.11.5.1 [time.clock.system], p2:
-2- system_clock::duration::min() < system_clock::duration::zero() @@ -28381,12 +30077,12 @@ shall be true. [Note: system_clock::rep shall be s
946. duration_cast improperly specified
-Section: 20.9.3.7 [time.duration.cast] Status: NAD - Submitter: Pete Becker Opened: 2008-12-20 Last modified: 2009-07-13
+Section: 20.11.3.7 [time.duration.cast] Status: NAD + Submitter: Pete Becker Opened: 2008-12-20 Last modified: 2010-10-29
View all other issues in [time.duration.cast].
View all issues with NAD status.
Discussion:
-20.9.3.7 [time.duration.cast]/3: +20.11.3.7 [time.duration.cast]/3:.... All intermediate computations shall be @@ -28450,132 +30146,15 @@ Move to NAD. -
-947. duration arithmetic: contradictory requirements
-Section: 20.9.3.5 [time.duration.nonmember] Status: NAD Editorial - Submitter: Pete Becker Opened: 2008-12-20 Last modified: 2009-10-26
-View all other issues in [time.duration.nonmember].
-View all issues with NAD Editorial status.
-Discussion:
--In 20.9.3.5 [time.duration.nonmember], paragraph 8 says that calling -dur / rep -when rep is an instantiation of duration requires a diagnostic. -That's followed by an operator/ that takes two durations. -So dur1 / dur2 is legal under the second version, -but requires a diagnostic under the first. -
- -[ -Howard adds: -]
- - --Please see the thread starting with c++std-lib-22980 for more information. -- -[ -Batavia (2009-05): -]
- --Move to Open, pending proposed wording (and preferably an implementation). -- -[ -2009-07-27 Howard adds: -]
- - --- --I've addressed this issue under the proposed wording for 1177 which -cleans up several places under 20.9.3 [time.duration] which used the -phrase "diagnostic required". -
--For clarity's sake, here is an example implementation of the constrained operator/: -
- -- -template <class _Duration, class _Rep, bool = __is_duration<_Rep>::value> -struct __duration_divide_result -{ -}; - -template <class _Duration, class _Rep2, - bool = is_convertible<_Rep2, - typename common_type<typename _Duration::rep, _Rep2>::type>::value> -struct __duration_divide_imp -{ -}; - -template <class _Rep1, class _Period, class _Rep2> -struct __duration_divide_imp<duration<_Rep1, _Period>, _Rep2, true> -{ - typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period> type; -}; - -template <class _Rep1, class _Period, class _Rep2> -struct __duration_divide_result<duration<_Rep1, _Period>, _Rep2, false> - : __duration_divide_imp<duration<_Rep1, _Period>, _Rep2> -{ -}; - -template <class _Rep1, class _Period, class _Rep2> -inline -typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type -operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s) -{ - typedef typename common_type<_Rep1, _Rep2>::type _Cr; - duration<_Cr, _Period> __r = __d; - __r /= static_cast<_Cr>(__s); - return __r; -} --__duration_divide_result is basically a custom-built enable_if -that will contain type only if Rep2 is not a duration -and if Rep2 is implicitly convertible to -common_type<typename Duration::rep, Rep2>::type. __is_duration -is simply a private trait that answers false, but is specialized for -duration to answer true. -
- --The constrained operator% works identically. -
-[ -2009-10 Santa Cruz: -]
- - --Mark NAD Editorial, fixed by 1177. -- - - -Proposed resolution:
--
- - - - -
952. Various threading bugs #2
-Section: 20.9.3.7 [time.duration.cast] Status: NAD Editorial - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-07-13
+Section: 20.11.3.7 [time.duration.cast] Status: NAD Editorial + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
View all other issues in [time.duration.cast].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
-20.9.3.7 [time.duration.cast] specifies an implementation and imposes +20.11.3.7 [time.duration.cast] specifies an implementation and imposes requirements in text (and the implementation doesn't satisfy all of the text requirements). Pick one.
@@ -28623,14 +30202,13 @@ Move to NAD Editorial.
955. Various threading bugs #5
-Section: 20.9.1 [time.clock.req] Status: NAD - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26
-View other active issues in [time.clock.req].
+Section: 20.11.1 [time.clock.req] Status: NAD + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
View all other issues in [time.clock.req].
View all issues with NAD status.
Discussion:
-20.9.1 [time.clock.req] requires that a clock type have a member +20.11.1 [time.clock.req] requires that a clock type have a member typedef named time_point that names an instantiation of the template time_point, and a member named duration that names an instantiation of the template duration. This mixing of @@ -28697,13 +30275,13 @@ of those declarations. It seems overly burdensome on the author of do_until
template <class Clock, class Duration> void do_until(const std::chrono::time_point<Clock, Duration>& t) { - typename Clock::time_point_type now = Clock::now(); + typename Clock::time_point_type now = Clock::now(); if (t > now) { typedef typename std::common_type < Duration, - typename std::chrono::system_clock::duration_type + typename std::chrono::system_clock::duration_type >::type CD; typedef std::chrono::duration<double, std::nano> ID; @@ -28831,7 +30409,7 @@ Mark as NAD. No concensus for changing the WP.Proposed resolution:
-Change 20.9 [time]: +Change 20.11 [time]:
... @@ -28840,7 +30418,7 @@ template <class Clock, class Duration = typename Clock::duration_type-Change 20.9.1 [time.clock.req]: +Change 20.11.1 [time.clock.req]:
@@ -28888,7 +30466,7 @@ in time.-Change 20.9.5.1 [time.clock.system]: +Change 20.11.5.1 [time.clock.system]:
@@ -28936,7 +30514,7 @@ precisions of time_t and time_point_type.-Change 20.9.5.2 [time.clock.monotonic]: +Change X [time.clock.monotonic]:
class monotonic_clock { @@ -28952,7 +30530,7 @@ public:-Change 20.9.5.3 [time.clock.hires]: +Change 20.11.5.3 [time.clock.hires]:
class high_resolution_clock { @@ -28974,11 +30552,10 @@ public:
958. Various threading bugs #8
-Section: 30.5.1 [thread.condition.condvar] Status: NAD Editorial - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-23
-View other active issues in [thread.condition.condvar].
+Section: 30.5.1 [thread.condition.condvar] Status: NAD Editorial + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
View all other issues in [thread.condition.condvar].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
30.5.1 [thread.condition.condvar]: the specification for wait_for @@ -29029,13 +30606,79 @@ Mark as NAD Editorial, solved by resolution of Issue 959. Various threading bugs #9 +
Section: 30.5.1 [thread.condition.condvar] Status: NAD + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
+View all other issues in [thread.condition.condvar].
+View all issues with NAD status.
+Discussion:
++30.5.1 [thread.condition.condvar]: condition_variable::wait_for +is required to compute the absolute time by adding the duration value to +chrono::monotonic_clock::now(), but monotonic_clock is not required to +exist. +
+ +[ +Summit: +]
+ + ++Move to open. Associate with LWG 859 and any other monotonic-clock +related issues. ++ +[ +2009-08-01 Howard adds: +]
+ + ++I believe that 859 (currently Ready) addresses this issue, and +that this issue should be marked NAD, solved by 859 (assuming +it moves to WP). ++ +[ +2009-10 Santa Cruz: +]
+ + ++Leave open, but expect to be fixed by N2969 revision that Detlef is writing. ++ +[ +2009-11-18 Moved to Tentatively NAD after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + + +Proposed resolution:
++
+ + +Rationale:
++condition_variable::wait_for no longer refers to +monotonic_clock, so this issue is moot. +
+ + + + +
961. Various threading bugs #11
-Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-10-26
-View other active issues in [thread.mutex.requirements].
+Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
View all other issues in [thread.mutex.requirements].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Duplicate of: 936
Discussion:
@@ -29082,10 +30725,10 @@ Mark as NAD Future.
969. What happened to Library Issue 475?
-Section: 25.2.4 [alg.foreach] Status: NAD Editorial - Submitter: Stephan T. Lavavej Opened: 2009-01-12 Last modified: 2009-07-13
+Section: 25.2.4 [alg.foreach] Status: NAD Editorial + Submitter: Stephan T. Lavavej Opened: 2009-01-12 Last modified: 2010-10-29
View all other issues in [alg.foreach].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Library Issue 475 has CD1 status, but the non-normative note in @@ -29116,7 +30759,7 @@ Restore the non-normative note. It might need to be expressed in terms of concep
971. Spurious diagnostic conversion function
Section: 19.5.2.5 [syserr.errcode.nonmembers] Status: NAD - Submitter: Beman Dawes Opened: 2009-01-19 Last modified: 2009-10-20
+ Submitter: Beman Dawes Opened: 2009-01-19 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -29228,11 +30871,11 @@ generic_category).
972. The term "Assignable" undefined but still in use
-Section: 17 [library] Status: NAD Editorial - Submitter: Niels Dekker Opened: 2009-01-07 Last modified: 2009-07-13
+Section: 17 [library] Status: NAD Editorial + Submitter: Niels Dekker Opened: 2009-01-07 Last modified: 2010-10-29
View other active issues in [library].
View all other issues in [library].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Previous versions of the Draft had a table, defining the Assignable @@ -29271,25 +30914,25 @@ Change Exception Propagation 18.8.5 [propagation]:
-Change Class template reference_wrapper 20.7.5 [refwrap]: +Change Class template reference_wrapper 20.8.4 [refwrap]:
reference_wrapper<T> is a CopyConstructible and CopyAssignable wrapper around a reference to an object of type T.-Change Placeholders 20.7.11.1.4 [func.bind.place]: +Change Placeholders 20.8.10.1.3 [func.bind.place]:
It is implementation defined whether placeholder types are CopyAssignable. CopyAssignable placeholders' copy assignment operators shall not throw exceptions.-Change Class template shared_ptr 20.8.15.2 [util.smartptr.shared]: +Change Class template shared_ptr 20.9.10.2 [util.smartptr.shared]:
Specializations of shared_ptr shall be CopyConstructible, CopyAssignable, and LessThanComparable...-Change Class template weak_ptr 20.8.15.3 [util.smartptr.weak]: +Change Class template weak_ptr 20.9.10.3 [util.smartptr.weak]:
Specializations of weak_ptr shall be CopyConstructible, CopyAssignable, and LessThanComparable... @@ -29310,7 +30953,7 @@ In addition to the requirements set forth below, instances ofNote: The proposed resolution of this issue does not deal with the -instance of the term "Assignable" in D.10.1 [auto.ptr], as this is dealt +instance of the term "Assignable" in D.12.1 [auto.ptr], as this is dealt with more specifically by LWG 973, "auto_ptr characteristics", submitted by Maarten Hilferink.
@@ -29322,13 +30965,13 @@ by Maarten Hilferink.
973. auto_ptr characteristics
-Section: D.10.1 [auto.ptr] Status: NAD Editorial - Submitter: Maarten Hilferink Opened: 2009-01-21 Last modified: 2009-07-13
+Section: D.12.1 [auto.ptr] Status: NAD Editorial + Submitter: Maarten Hilferink Opened: 2009-01-21 Last modified: 2010-10-29
View all other issues in [auto.ptr].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
-I think that the Note of D.10.1 [auto.ptr], paragraph 3 needs a rewrite +I think that the Note of D.12.1 [auto.ptr], paragraph 3 needs a rewrite since "Assignable" is no longer defined as a concept. The relationship of auto_ptr with the new CopyAssignable, MoveAssignable, and MoveConstructible concepts should be clarified. @@ -29348,7 +30991,7 @@ Move to NAD Editorial.
Proposed resolution:
-Change D.10.1 [auto.ptr], paragraph 3: +Change D.12.1 [auto.ptr], paragraph 3:
@@ -29380,12 +31023,12 @@ requirements, but do not meet the CopyConstructible and
976. Class template std::stack should be movable
-Section: 23.3.5.3.1 [stack.defn] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2009-02-01 Last modified: 2009-10-20
-View all issues with NAD Editorial status.
+Section: 23.5.3.1 [stack.defn] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2009-02-01 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
-The synopsis given in 23.3.5.3.1 [stack.defn] does not show up +The synopsis given in 23.5.3.1 [stack.defn] does not show up
requires MoveConstructible<Cont> stack(stack&&); @@ -29431,7 +31074,7 @@ tweaked for concepts removal.-1194 also adds these move members using an editorially different +1194 also adds these move members using an editorially different style.@@ -29441,14 +31084,14 @@ style.-Mark NAD Editorial, solved by issue 1194. +Mark NAD Editorial, solved by issue 1194.Proposed resolution:
-In the class stack synopsis of 23.3.5.3.1 [stack.defn] insert: +In the class stack synopsis of 23.5.3.1 [stack.defn] insert:
template <class T, class Container = deque<T> > @@ -29472,7 +31115,7 @@ class stack {
977. insert iterators inefficient for expensive to move types
Section: 24.5.2 [insert.iterators] Status: NAD - Submitter: Howard Hinnant Opened: 2009-02-02 Last modified: 2009-10-26
+ Submitter: Howard Hinnant Opened: 2009-02-02 Last modified: 2010-10-29View all other issues in [insert.iterators].
View all issues with NAD status.
Discussion:
@@ -29778,9 +31421,9 @@ Change 24.5.2.6.2 [insert.iter.op=]:
979. Bad example
-Section: 24.5.3 [move.iterators] Status: NAD Editorial - Submitter: Howard Hinnant Opened: 2009-02-03 Last modified: 2009-07-13
-View all issues with NAD Editorial status.
+Section: 24.5.3 [move.iterators] Status: NAD Editorial + Submitter: Howard Hinnant Opened: 2009-02-03 Last modified: 2010-10-29
+View all issues with NAD Editorial status.
Discussion:
24.5.3 [move.iterators] has an incorrect example: @@ -29847,8 +31490,7 @@ vector<string> v2(make_move_iterator(s.begin()),
980. mutex lock() missing error conditions
Section: 30.4.1 [thread.mutex.requirements] Status: NAD - Submitter: Ion Gaztańaga Opened: 2009-02-07 Last modified: 2009-03-22
-View other active issues in [thread.mutex.requirements].
+ Submitter: Ion Gaztańaga Opened: 2009-02-07 Last modified: 2010-10-29View all other issues in [thread.mutex.requirements].
View all issues with NAD status.
Discussion:
@@ -29938,7 +31580,7 @@ to detect it.
988. Reflexivity meaningless?
Section: X [concept.comparison] Status: NAD - Submitter: Alisdair Meredith Opened: 2009-02-24 Last modified: 2009-07-16
+ Submitter: Alisdair Meredith Opened: 2009-02-24 Last modified: 2010-10-29View all other issues in [concept.comparison].
View all issues with NAD status.
Discussion:
@@ -29989,11 +31631,11 @@ NAD.
989. late_check and library
-Section: 17 [library] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-02-24 Last modified: 2009-07-16
+Section: 17 [library] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-02-24 Last modified: 2010-10-29
View other active issues in [library].
View all other issues in [library].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
The example in 6.9p2 shows how late_check blocks inhibit concept_map lookup @@ -30037,7 +31679,7 @@ Move to Open, pending proposed wording from Alisdair and/or Doug for further rev
992. Response to UK 169
Section: 17.6.1.1 [contents] Status: NAD - Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2009-07-22
+ Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2010-10-29View all other issues in [contents].
View all issues with NAD status.
Discussion:
@@ -30098,7 +31740,7 @@ nested within namespace std*.-*The C standard library headers D.6 [depr.c.headers] also define +*The C standard library headers D.7 [depr.c.headers] also define names within the global namespace, while the C++ headers for C library facilities 17.6.1.2 [headers] may also define names within the global namespace. @@ -30113,7 +31755,7 @@ the global namespace.
995. Operational Semantics Unclear
Section: 17.5.1.3 [structure.requirements] Status: NAD - Submitter: David Abrahams Opened: 2009-03-06 Last modified: 2009-07-13
+ Submitter: David Abrahams Opened: 2009-03-06 Last modified: 2010-10-29View all issues with NAD status.
Discussion:
@@ -30142,12 +31784,59 @@ perfectly clear. +
+996. Move operation not well specified
+Section: 17 [library] Status: NAD + Submitter: David Abrahams Opened: 2009-03-06 Last modified: 2010-10-29
+View other active issues in [library].
+View all other issues in [library].
+View all issues with NAD status.
+Discussion:
++There are lots of places in the standard where we talk about "the move +constructor" but where we mean "the move operation," i.e. T( move( x ) ). +
++We also don't account for whether that operation modifies x or not, and +we need to. +
+ +[ +Batavia (2009-05): +]
+ ++Move to Open, pending proposed wording from Dave for further +review. ++ + + +[ +2010 Rapperswil: +]
+ + ++Move to NAD. We define what we expect from a moved-from object in Table 34 [movesconstructible]. ++ + + +Proposed resolution:
++
+ + + + +
1000. adjacent_find is over-constrained
-Section: 25.2.8 [alg.adjacent.find] Status: NAD Concepts - Submitter: Chris Jefferson Opened: 2009-03-09 Last modified: 2009-07-15
+Section: 25.2.8 [alg.adjacent.find] Status: NAD Concepts + Submitter: Chris Jefferson Opened: 2009-03-09 Last modified: 2010-10-23
View all other issues in [alg.adjacent.find].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 296 @@ -30217,11 +31906,11 @@ template<ForwardIterator Iter,
EquivalenceRelationPredicate1001. Pointers, concepts and headers
-Section: 17 [library] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-10 Last modified: 2009-07-18
+Section: 17 [library] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-10 Last modified: 2010-10-23
View other active issues in [library].
View all other issues in [library].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 78
@@ -30447,7 +32136,7 @@ if those other headers were included.
1002. Response to UK 170
Section: 17.6.1.2 [headers] Status: NAD - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-15
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23View all other issues in [headers].
View all issues with NAD status.
Discussion:
@@ -30532,7 +32221,7 @@ headers listed in tables 13 and 14. -- end note]
1003. Response to JP 23
Section: 17.6.1.3 [compliance] Status: NAD - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-18
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23View all other issues in [compliance].
View all issues with NAD status.
Discussion:
@@ -30627,9 +32316,9 @@ Add <type_traits> to Table 15.
1005. numeric_limits partial specializations not concept enabled
-Section: 18.3.1.1 [numeric.limits] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-15
-View all issues with NAD Concepts status.
+Section: 18.3.1.1 [numeric.limits] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
Addresses JP 26
@@ -30698,11 +32387,10 @@ template<classRegular T> class numeric_limits<co
1007. throw_with_nested not concept enabled
-Section: 18.8.6 [except.nested] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-15
-View other active issues in [except.nested].
+Section: 18.8.6 [except.nested] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [except.nested].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses JP 29
@@ -30737,10 +32425,70 @@ review. +
+1008. nested_exception wording unclear
+Section: 18.8.6 [except.nested] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
+View all other issues in [except.nested].
+View all issues with NAD status.
+Discussion:
+ +Addresses JP 31
+ ++It is difficult to understand in which case nested_exception is applied. +
+ +[ +Summit: +]
+ + ++Alisdair will add an example in an update to +N2619. ++ +[ +2009-10 Santa Cruz: +]
+ + ++It doesn't appear that N2619 really addresses this. Alisdair to propose wording. ++ +[ +2010 Pittsburgh: +]
+ + ++Mark issue 1008 as NAD, the type is adequately described. ++ + + +Rationale:
++nested_exception is intended to be inherited from by exception classes +that are to be thrown during the handling of another exception, i.e. +when translating from one exception type to another. nested_exception +allows the originally thrown exception to be easily retained in that +scenario. +
+ + +Proposed resolution:
+ + + + +
1009. InputIterator post-increment dangerous
-Section: X [iterator.iterators] Status: NAD - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-22
+Section: 24.2.2 [iterator.iterators] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all issues with NAD status.
Discussion:
@@ -30782,7 +32530,7 @@ is broken.Proposed resolution:
-Change X [iterator.iterators]: +Change 24.2.2 [iterator.iterators]:
concept Iterator<typename X> : Semiregular<X> { @@ -30808,7 +32556,7 @@ Change X [iterator.iterators]:-Change 24.2.1 [input.iterators]: +Change 24.2.3 [input.iterators]:
@@ -30830,7 +32578,7 @@ Change 24.2.1 [input.iterators]:-Change 24.2.2 [output.iterators]: +Change 24.2.4 [output.iterators]:
@@ -30849,7 +32597,7 @@ Change 24.2.2 [output.iterators]:-Change 24.2.3 [forward.iterators]: +Change 24.2.5 [forward.iterators]:
[ @@ -30897,10 +32645,10 @@ way.
1010. operator-= should use default in concept
-Section: 24.2.5 [random.access.iterators] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-16
+Section: 24.2.7 [random.access.iterators] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [random.access.iterators].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 263
@@ -30926,7 +32674,7 @@ Move to Open.Proposed resolution:
-Change 24.2.5 [random.access.iterators]: +Change 24.2.7 [random.access.iterators]:
concept RandomAccessIterator<typename X> : BidirectionalIterator<X>, LessThanComparable<X> { @@ -30943,10 +32691,10 @@ Change 24.2.5 [random.access.iterators]:
1013. Response to UK 305
-Section: 25.4.7 [alg.min.max] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-16
+Section: 25.4.7 [alg.min.max] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [alg.min.max].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 305
@@ -31020,10 +32768,10 @@ template<class T, StrictWeakOrder<auto, T> Compare>
1015. Response to UK 199
-Section: X [concept.transform] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-15
+Section: X [concept.transform] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [concept.transform].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 199
@@ -31107,10 +32855,10 @@ maps for any concept in this section.
1016. Response to JP 33
-Section: X [concept.comparison] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-15
+Section: X [concept.comparison] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [concept.comparison].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses JP 33
@@ -31155,9 +32903,9 @@ Recommend NAD.
1017. Response to US 66
-Section: X [concept.regular] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-15
-View all issues with NAD Concepts status.
+Section: X [concept.regular] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
Addresses US 66
@@ -31206,10 +32954,10 @@ feature.
1018. Response to US 70
-Section: 20.6 [meta] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-15
+Section: 20.7 [meta] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [meta].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses US 70
@@ -31249,8 +32997,8 @@ at the next meeting.
1020. Response to UK 204
-Section: 20.6.7 [meta.trans.other] Status: NAD - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-23
+Section: 20.7.7.6 [meta.trans.other] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [meta.trans.other].
View all issues with NAD status.
Discussion:
@@ -31308,17 +33056,17 @@ Mark NAD as suggested.
1022. Response to UK 212
-Section: 20.8.15.6 [util.dynamic.safety] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-03-12
+Section: 20.9.11 [util.dynamic.safety] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [util.dynamic.safety].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 212
The pointer-safety API is nothing to do with smart pointers, so does not -belong in 20.8.15 [util.smartptr]. In fact it is a set of language +belong in 20.9.10 [util.smartptr]. In fact it is a set of language support features are really belongs in clause 18 [language.support], with the contents declared in a header that deals with language-support of memory management.
@@ -31330,9 +33078,7 @@ Summit:Agree in principle, but not with the proposed resolution. We believe it -belongs either a subsection of either 20 [utilities] or 20.8 [memory] -as part of the general reorganization of 20 [utilities]. The -declaration should stay in +belongs either a subsection of either 20 [utilities] or 20.9 [memory] as part of the general reorganization of 20 [utilities]. The declaration should stay in <memory>.@@ -31346,15 +33092,15 @@ declaration should stay in
1023. Response to DE 22
-Section: 20.7.15.2 [func.wrap.func] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-13
+Section: 20.8.14.2 [func.wrap.func] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [func.wrap.func].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses DE 22
-Related to issue 1114.
+Related to issue 1114.
The conditions for deriving from std::unary_function and @@ -31401,7 +33147,7 @@ Move to NAD Editorial.
-Change synopsis in Class template function 20.7.15.2 [func.wrap.func]: +Change synopsis in Class template function 20.8.14.2 [func.wrap.func]:
template<Returnable R, CopyConstructible... ArgTypes> @@ -31415,7 +33161,7 @@ class function<R(ArgTypes...)>-Add new p1/p2 before 20.7.15.2.1 [func.wrap.func.con]: +Add new p1/p2 before 20.8.14.2.1 [func.wrap.func.con]:
@@ -31445,10 +33191,10 @@ returning R.
1024. Response to JP 39
-Section: 20.7.15.2 [func.wrap.func] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-16
+Section: 20.8.14.2 [func.wrap.func] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [func.wrap.func].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses JP 39
@@ -31491,7 +33237,7 @@ Constructors have no definition.Proposed resolution:
-Correct as follows in 20.7.15.2 [func.wrap.func] (class definition) +Correct as follows in 20.8.14.2 [func.wrap.func] (class definition)
template<class F, Allocator Alloc> @@ -31513,11 +33259,10 @@ Correct as follows in 20.7.15.2 [func.wrap.func] (class definition)
1025. Response to UK 208
-Section: 20.7.16 [unord.hash] Status: NAD Future - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-03-12
-View other active issues in [unord.hash].
+Section: 20.8.15 [unord.hash] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [unord.hash].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
Addresses UK 208
@@ -31538,10 +33283,10 @@ standard containers.
1026. Response to UK 209
-Section: 20.8 [memory] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-15
+Section: 20.9 [memory] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [memory].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 209
@@ -31583,9 +33328,9 @@ possibly enable_shared_from_this.
1027. Response to UK 213
-Section: 20.8.8 [default.allocator] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-15
-View all issues with NAD Concepts status.
+Section: 20.9.5 [default.allocator] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 213
@@ -31628,9 +33373,9 @@ Agree as stated. A future paper will address additional related issues.
1028. Response to UK 214
-Section: 20.8.10 [storage.iterator] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-16
-View all issues with NAD Concepts status.
+Section: 20.9.6 [storage.iterator] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 214
@@ -31659,7 +33404,7 @@ Post Summit Alisdair provided wording and rationale.Proposed resolution:
-20.8 [memory] p2 +20.9 [memory] p2
Update the synopsis for <memory> @@ -31676,7 +33421,7 @@ template <
classForwardIterator OutputIter-20.8.10 [storage.iterator] p1 +20.9.6 [storage.iterator] p1 Replace class template definition with: @@ -31726,10 +33471,10 @@ require some kind of proxy formulation to support generalised InputIterators.
1029. Response to UK 210
-Section: 20.8.13 [specialized.algorithms] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-16
+Section: 20.9.8 [specialized.algorithms] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [specialized.algorithms].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 210
@@ -31804,7 +33549,7 @@ For the record I agree with Daniel's suggestion.Proposed resolution:
-20.8 [memory] p2 +20.9 [memory] p2
Update the synopsis for <memory> @@ -31840,7 +33585,7 @@ Update as follows:
-uninitialized_copy 20.8.13.2 [uninitialized.copy] +uninitialized_copy 20.9.8.2 [uninitialized.copy]
@@ -32200,11 +33945,10 @@ Outstanding iterators, references and pointers may be invalidated.template <classInputIterator InIter, @@ -31894,7 +33639,7 @@ uninitialized_copy 20.8.13.2 [uninitialized.copy]-uninitialized_fill 20.8.13.3 [uninitialized.fill] +uninitialized_fill 20.9.8.3 [uninitialized.fill]
template <classForwardIterator Iter,classObjectType T> @@ -31917,7 +33662,7 @@ uninitialized_fill 20.8.13.3 [uninitialized.fill]-uninitialized_fill_n 20.8.13.4 [uninitialized.fill.n] +uninitialized_fill_n 20.9.8.4 [uninitialized.fill.n]
template <classForwardIterator Iter,classIntegralLike Size,classObjectType T> @@ -31945,10 +33690,10 @@ uninitialized_fill_n 20.8.13.4 [uninitialized.fill.n]
1031. Response to US 78
-Section: 20.8.15.2 [util.smartptr.shared] Status: NAD Future - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-20
+Section: 20.9.10.2 [util.smartptr.shared] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [util.smartptr.shared].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
Addresses US 78
@@ -32065,10 +33810,10 @@ Moved to NAD Future.
1032. Response to JP 45
-Section: 20.9 [time] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-16
+Section: 20.11 [time] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [time].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses JP 45
@@ -32082,7 +33827,7 @@ template <class Clock, class Duration = typename Clock::duration> class tiMake concept for Rep, Period, Clock and Duration. -Fix 20.9 [time] and wait_until +Fix 20.11 [time] and wait_until and wait_for's template parameter at 30 [thread].
@@ -32107,7 +33852,7 @@ this topic. We recommend no action until a paper is available.
1035. Response to UK 226
Section: 23.2.1 [container.requirements.general] Status: NAD - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-20
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23View other active issues in [container.requirements.general].
View all other issues in [container.requirements.general].
View all issues with NAD status.
@@ -32143,7 +33888,7 @@ Agree. The proposed resolution is incomplete. Further work required.-Issue 1099 also suggests +Issue 1099 also suggests adding move constructor to this.@@ -32189,7 +33934,7 @@ Add a paragraph to 23.3.1.2 [array.special]:[Note: Outstanding iterators, references and pointers may be invalidated. -— end note] +— end note]
1036. Response to UK 231
-Section: 23.2.3 [sequence.reqmts] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-07-15
-View other active issues in [sequence.reqmts].
+Section: 23.2.3 [sequence.reqmts] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
View all other issues in [sequence.reqmts].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 231
@@ -32240,11 +33984,11 @@ has constraints similar to
1041. Response to UK 239
-Section: 23.2.4 [associative.reqmts] Status: NAD Future - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-20
+Section: 23.2.4 [associative.reqmts] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
Addresses UK 239
@@ -32385,7 +34129,7 @@ exists, returns a.end().
1042. Response to UK 244
Section: 23.3 [sequences] Status: NAD - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-23
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23View all other issues in [sequences].
View all issues with NAD status.
Discussion:
@@ -32532,7 +34276,7 @@ Add to the synopsis in 23.3.1 [array]:-Change 23.3.6 [vector] p1: +Change 23.4.1 [vector] p1:
@@ -32550,7 +34294,7 @@ vector< T, Alloc>>.-Add at the end of the synopsis in 23.3.6 [vector] p2: +Add at the end of the synopsis in 23.4.1 [vector] p2:
template< typename T, typename A > @@ -32569,10 +34313,11 @@ Solved by removal of concepts.
1043. Response to US 91
-Section: 29.6 [atomics.types.operations] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-26
+Section: 29.6 [atomics.types.operations] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
+View other active issues in [atomics.types.operations].
View all other issues in [atomics.types.operations].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses US 91
@@ -32684,10 +34429,10 @@ operations are atomic load operations.
1046. Response to UK 329
-Section: 30.6 [futures] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-26
+Section: 30.6 [futures] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
View all other issues in [futures].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 329
@@ -32781,10 +34526,10 @@ Proposed resolution: see
1047. Response to UK 334
-Section: 30.6.6 [futures.unique_future] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-26
+Section: 30.6.6 [futures.unique_future] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
View all other issues in [futures.unique_future].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 334
@@ -32821,7 +34566,7 @@ Suggested wording:-Add a paragraph to [futures.shared_future]: +Add a paragraph to 30.6.7 [futures.shared_future]:
-void shared_future<void>::get() const; @@ -32886,10 +34631,10 @@ block on the asynchronous result associated with *this.
1048. Response to UK 335
-Section: 30.6.6 [futures.unique_future] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-26
+Section: 30.6.6 [futures.unique_future] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
View all other issues in [futures.unique_future].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 335
@@ -32904,7 +34649,7 @@ been moved from, and therefore whether or not it is safe to wait for it.std::promise<int> p; std::unique_future<int> uf(p.get_future()); std::unique_future<int> uf2(std::move(uf)); -uf.wait(); // oops, uf has no result to wait for. +uf.wait(); // oops, uf has no result to wait for.@@ -33002,10 +34747,11 @@ NAD Editorial. Solved by
1049. Response to UK 339
-Section: 30.6.5 [futures.promise] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-26
+Section: 30.6.5 [futures.promise] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
+View other active issues in [futures.promise].
View all other issues in [futures.promise].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 339
@@ -33075,10 +34821,11 @@ associated state.
1050. Response to UK 340
-Section: 30.6.5 [futures.promise] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-26
+Section: 30.6.5 [futures.promise] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
+View other active issues in [futures.promise].
View all other issues in [futures.promise].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 340
@@ -33114,8 +34861,8 @@ A promise is used like this:promise<int> p; unique_future<int> f = p.get_future(); -// post 'p' to a thread that calculates a value -// use 'f' to retrieve the value. +// post 'p' to a thread that calculates a value +// use 'f' to retrieve the value.So get_future() must return an object that shares the same associated @@ -33216,7 +34963,7 @@ Add after p13 30.6.5 [futures.promise]:
1051. Response to UK 279
Section: 24.5.1.3.12 [reverse.iter.opindex], 24.5.3.3.12 [move.iter.op.index] Status: NAD - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-24
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23View all issues with NAD status.
Discussion:
@@ -33371,13 +35118,452 @@ does not work yet on gcc 4.4.1. +
+1052. Response to UK 281
+Section: 24.5.1.3.5 [reverse.iter.opref] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
+View all issues with NAD Future status.
+Discussion:
+ +Addresses UK 281
+ ++The current specification for return value for reverse_iterator::operator-> +will always be a true pointer type, but reverse_iterator supports proxy +iterators where the pointer type may be some kind of 'smart pointer'. +
+ +[ +Summit: +]
+ + +++ ++move_iterator avoids this problem by returning a value of the wrapped +Iterator type. +study group formed to come up with a suggested resolution. +
++move_iterator solution shown in proposed wording. +
+[ +2009-07 post-Frankfurt: +]
+ + ++Howard to deconceptize. Move to Review after that happens. ++ +[ +2009-08-01 Howard deconceptized: +]
+ + +++ +[ +2009-10 Santa Cruz: +]
+ + +++ ++We can't think of any reason we can't just define reverse +iterator's pointer types to be the same as the underlying iterator's +pointer type, and get it by calling the right arrow directly. +
++Here is the proposed wording that was replaced: +
++ +template <class Iterator> +class reverse_iterator { + ... + typedeftypename iterator_traits<Iterator>::pointerpointer; ++Change 24.5.1.3.5 [reverse.iter.opref]: +
+ ++pointer operator->() const; +++Returns: +++&(operator*());+this->tmp = current; +--this->tmp; +return this->tmp; +[ +2010-03-03 Daniel opens: +]
+ + +++ ++ +
+ +- +There is a minor problem with the exposition-only declaration of the private +member deref_tmp which is modified in a const member function (and the +same problem occurs in the specification of operator*). The fix is to +make it a mutable member. +
+ +- +
+ ++The more severe problem is that the resolution for some reasons +does not explain in the rationale why it was decided to differ from +the suggested fix (using deref_tmp instead of tmp) in the +[ 2009-10 Santa Cruz] comment: +
+ ++ +this->deref_tmp = current; +--this->deref_tmp; +return this->deref_tmp; ++combined with the change of +
+ ++ +typedef typename iterator_traits<Iterator>::pointer pointer; ++to +
+ ++ +typedef Iterator pointer; ++The problem of the agreed on wording is that the following rather +typical example, that compiled with the wording before 1052 had +been applied, won't compile anymore: +
+ ++ +#include <iterator> +#include <utility> + +int main() { + typedef std::pair<int, double> P; + P op; + std::reverse_iterator<P*> ri(&op + 1); + ri->first; // Error +} ++Comeau online returns (if a correspondingly changed +reverse_iterator is used): +
+ ++ +"error: expression must have class type + return deref_tmp.operator->(); + ^ + detected during instantiation of "Iterator + reverse_iterator<Iterator>::operator->() const [with + Iterator=std::pair<int, double> *]"" ++Thus the change will break valid, existing code based +on std::reverse_iterator. +
+ ++IMO the suggestion proposed in the comment is a necessary fix, which harmonizes +with the similar specification of std::move_iterator and properly +reflects the recursive nature of the evaluation of operator-> +overloads. +
+ ++Suggested resolution: +
+ ++ +
+ +- +
+ ++In the class template reverse_iterator synopsis of 24.5.1.1 [reverse.iterator] change as indicated: +
+ ++namespace std { +template <class Iterator> +class reverse_iterator : public + iterator<typename iterator_traits<Iterator>::iterator_category, + typename iterator_traits<Iterator>::value_type, + typename iterator_traits<Iterator>::difference_type, +typename iterator_traits<Iterator>::pointer, + typename iterator_traits<Iterator>::reference> { +public: + [..] + typedeftypename iterator_traits<Iterator>::pointerpointer; + [..] +protected: + Iterator current; +private: + mutable Iterator deref_tmp; // exposition only +}; +- +Change 24.5.1.3.5 [reverse.iter.opref]/1 as indicated: + +
+ ++ +pointer operator->() const; ++ ++1+ReturnsEffects:&(operator*()).++deref_tmp = current; +--deref_tmp; +return deref_tmp; +[ +2010 Pittsburgh: +]
+ + +++ ++We prefer to make to use a local variable instead of deref_tmp within +operator->(). And although this means that the mutable +change is no longer needed, we prefer to keep it because it is needed for +operator*() anyway. +
+ ++Here is the proposed wording that was replaced: +
+ ++++Change 24.5.1.3.5 [reverse.iter.opref]: +
+ ++ + +pointer operator->() const; ++ ++ +Returns: +++ +&(operator*());+deref_tmp = current; +--deref_tmp; +return deref_tmp::operator->(); +[ +2010-03-10 Howard adds: +]
+ + +++ ++Here are three tests that the current proposed wording passes, and no +other solution I've seen passes all three: +
+ ++
+- +
++Proxy pointer support: +
++#include <iterator> +#include <cassert> + +struct X { int m; }; + +X x; + +struct IterX { + typedef std::bidirectional_iterator_tag iterator_category; + typedef X& reference; + struct pointer + { + pointer(X& v) : value(v) {} + X& value; + X* operator->() const {return &value;} + }; + typedef std::ptrdiff_t difference_type; + typedef X value_type; + // additional iterator requirements not important for this issue + + reference operator*() const { return x; } + pointer operator->() const { return pointer(x); } + IterX& operator--() {return *this;} + +}; + +int main() +{ + std::reverse_iterator<IterX> ix; + assert(&ix->m == &(*ix).m); +} +- +
++Raw pointer support: +
++#include <iterator> +#include <utility> + +int main() { + typedef std::pair<int, double> P; + P op; + std::reverse_iterator<P*> ri(&op + 1); + ri->first; // Error +} +- +
++Caching iterator support: +
++#include <iterator> +#include <cassert> + +struct X { int m; }; + +struct IterX { + typedef std::bidirectional_iterator_tag iterator_category; + typedef X& reference; + typedef X* pointer; + typedef std::ptrdiff_t difference_type; + typedef X value_type; + // additional iterator requirements not important for this issue + + reference operator*() const { return value; } + pointer operator->() const { return &value; } + IterX& operator--() {return *this;} + +private: + mutable X value; +}; + +int main() +{ + std::reverse_iterator<IterX> ix; + assert(&ix->m == &(*ix).m); +} +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Future, rationale added. ++ + + + +Rationale:
++The LWG did not reach a consensus for a change to the WP. +
+ + +Proposed resolution:
+ ++ +
+ + + + + + + + + +- +
+ ++In the class template reverse_iterator synopsis of 24.5.1.1 [reverse.iterator] change as indicated: +
+ ++namespace std { +template <class Iterator> +class reverse_iterator : public + iterator<typename iterator_traits<Iterator>::iterator_category, + typename iterator_traits<Iterator>::value_type, + typename iterator_traits<Iterator>::difference_type, +typename iterator_traits<Iterator&>::pointer, + typename iterator_traits<Iterator>::reference> { +public: + [..] + typedeftypename iterator_traits<Iterator&>::pointerpointer; + [..] +protected: + Iterator current; +private: + mutable Iterator deref_tmp; // exposition only +}; +- +Change 24.5.1.3.5 [reverse.iter.opref]/1 as indicated: + +
+ ++ +pointer operator->() const; ++ ++1+ReturnsEffects:&(operator*()).++deref_tmp = current; +--deref_tmp; +return deref_tmp; +
1053. Response to UK 295
-Section: 25 [algorithms] Status: NAD Future - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-23
-View other active issues in [algorithms].
+Section: 25 [algorithms] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
View all other issues in [algorithms].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
Addresses UK 295
@@ -33443,26 +35629,31 @@ Too inventive, too late, would really need a paper. Moved to NAD Future.
-1054. forward broken
-Section: 20.3.3 [forward] Status: NAD Editorial - Submitter: Howard Hinnant Opened: 2009-03-13 Last modified: 2009-10-26
-View all other issues in [forward].
-View all issues with NAD Editorial status.
+1056. Must all Engines and Distributions be Streamable?
+Section: 26.5 [rand] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
+View all other issues in [rand].
+View all issues with NAD status.
Discussion:
-This is a placeholder issue to track the fact that we (well I) put the standard -into an inconsistent state by requesting that we accept -N2844 -except for the proposed changes to [forward]. +Both the concepts RandomNumberEngine and RandomNumberDistribution have +requirements to be InputStreamable and OutputStreamable.
--There will exist in the post meeting mailing -N2835 -which in its current state reflects the state of affairs prior to the Summit -meeting. I hope to update it in time for the post Summit mailing, but as I write -this issue I have not done so yet. +I have no problems leaving the WP in an inconsistent state on the best-faith +assumption these concepts will be provided later, however disagree with the +proposers that these constraints are not separable, orthogonal to the basic +concepts of generating random number distributions. +
++These constraints should be dropped, and applied to specific algorithms as +needed. +
++If a more refined concept (certainly deemed useful by the proposers) is +proposed there is no objection, but the basic concept should not require +persistence via streaming.
[ @@ -33470,339 +35661,96 @@ Batavia (2009-05): ]
-Move to Open, awaiting the promised paper. +Move to Open.[ -2009-08-02 Howard adds: +2009-05-31 Alisdair adds: ]
-My current preferred solution is: +Working on constraining the stream iterators, I have a few more observations +to make on the concepts proposed while constraining the random number +facility.
- --template <class T> -struct __base_type -{ - typedef typename remove_cv<typename remove_reference<T>::type>::type type; -}; - -template <class T, class U, - class = typename enable_if< - !is_lvalue_reference<T>::value || - is_lvalue_reference<T>::value && - is_lvalue_reference<U>::value>::type, - class = typename enable_if< - is_same<typename __base_type<T>::type, - typename __base_type<U>::type>::value>::type> -inline -T&& -forward(U&& t) -{ - return static_cast<T&&>(t); -} --This has been tested by Bill, Jason and myself. +While I still believe the concerns are orthogonal, I don't believe the +existing constraints go far enough either! The goal we want to achieve is +not that a RandomNumberEngine / RandomNumberDistribution supports the stream +operators, but that it is Serializable. I.e. there is a relationship +between the insert and extract operations that guarantees to restore the +state of the original object. This implies a coupling of the concepts +together in a broader concept (Serializable) with at least one axiom to +assert the semantics.
--It allows the following lvalue/rvalue casts: -
- --
- -- -Cast an lvalue t to an lvalue T (identity). -
-- -Cast an lvalue t to an rvalue T. -
-- -Cast an rvalue t to an rvalue T (identity). -
--It disallows: -
- --
- -- -Cast an rvalue t to an lvalue T. -
-- -Cast one type t to another type T (such as int to double). -
--"a." is disallowed as it can easily lead to dangling references. -"b." is disallowed as this function is meant to only change the lvalue/rvalue -characteristic of an expression. -
- --Jason has expressed concern that "b." is not dangerous and is useful in contexts -where you want to "forward" a derived type as a base type. I find this use case -neither dangerous, nor compelling. I.e. I could live with or without the "b." -constraint. Without it, forward would look like: -
- -- -template <class T, class U, - class = typename enable_if< - !is_lvalue_reference<T>::value || - is_lvalue_reference<T>::value && - is_lvalue_reference<U>::value>::type> -inline -T&& -forward(U&& t) -{ - return static_cast<T&&>(t); -} --Or possibly: -
- -- - -template <class T, class U, - class = typename enable_if< - !is_lvalue_reference<T>::value || - is_lvalue_reference<T>::value && - is_lvalue_reference<U>::value>::type, - class = typename enable_if< - is_base_of<typename __base_type<U>::type, - typename __base_type<T>::type>::value>::type> -inline -T&& -forward(U&& t) -{ - return static_cast<T&&>(t); -} --The "promised paper" is not in the post-Frankfurt mailing only because I'm waiting -for the non-concepts draft. But I'm hoping that by adding this information here -I can keep people up to date. +One problem is that istream and ostream may be fundamentally different +types, although we can hook a relation if we are prepared to drop down to +the char type and char_traits template parameters. Doing so ties us to a +form of serialization that demands implementation via the std iostreams +framework, which seems overly prescriptive. I believe the goal is generally +to support serialization without regard to how it is expressed - although +this is getting even more inventive in terms of concepts we do not have +today.
[ -2009-08-02 David adds: +2009-11-03 Alisdair adds: ]
-forward was originally designed to do one thing: perfect forwarding. -That is, inside a function template whose actual argument can be a const -or non-const lvalue or rvalue, restore the original "rvalue-ness" of the -actual argument: +I can't find the record in the wiki minutes, but it was agreed at both +Frankfurt and Santa Cruz that this issue is NAD.
- --template <class T> -void f(T&& x) -{ - // x is an lvalue here. If the actual argument to f was an - // rvalue, pass static_cast<T&&>(x) to g; otherwise, pass x. - g( forward<T>(x) ); -} --Attempting to engineer forward to accomodate uses other than perfect -forwarding dilutes its idiomatic meaning. The solution proposed here -declares that forward<T>(x) means nothing more than static_cast<T&&>(x), -with a patchwork of restrictions on what T and x can be that can't be -expressed in simple English. +The agreement in SC was that I would provide you with the rationale (see +below) to include when moving to NAD.
- --I would be happy with either of two approaches, whose code I hope (but -can't guarantee) I got right. -
- --
-- -
- --Use a simple definition of forward that accomplishes its original -purpose without complications to accomodate other uses: -
- --template <class T, class U> -T&& forward(U& x) -{ - return static_cast<T&&>(x); -} -- -
--Use a definition of forward that protects the user from as many -potential mistakes as possible, by actively preventing all other -uses: -
- --template <class T, class U> -boost::enable_if_c< - // in forward<T>(x), x is a parameter of the caller, thus an lvalue - is_lvalue_reference<U>::value - // in caller's deduced T&& argument, T can only be non-ref or lvalue ref - && !is_rvalue_reference<T>::value - // Must not cast cv-qualifications or do any type conversions - && is_same<T&,U&>::value - , T&&>::type forward(U&& a) -{ - return static_cast<T&&>(a); -} -[ -2009-09-27 Howard adds: +2009-11-03 Howard adds: ]
-A paper, -N2951, -is available which compares several implementations (including David's) with respect to several -use cases (including Jason's) and provides wording for one implementation. +Moved to Tentatively NAD after 5 positive votes on c++std-lib.-[ -2009-10 Santa Cruz: -]
- - --NAD Editorial. Solved by -N2951. -- -Proposed resolution:
- - - -
-1055. Response to UK 98
-Section: 20.6.7 [meta.trans.other] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-10-26
-View all other issues in [meta.trans.other].
-View all issues with NAD Editorial status.
-Discussion:
- -Addresses UK 98
- +Rationale:
-It would be useful to be able to determine the underlying -type of an arbitrary enumeration type. This would allow -safe casting to an integral type (especially needed for -scoped enums, which do not promote), and would allow -use of numeric_limits. In general it makes generic -programming with enumerations easier. +The issue suggests a more refined concept should be used if we want to +require streaming, to separate concerns from the basic +RandomNumberEngine behaviour. In Frankfurt it was observed +that RandomNumberEngine is that more refined concept, +and the basic concept used in the framework is +UniformRandomNumberGenerator, which it refines.
-[ -Batavia (2009-05): -]
- --Pete observes (and Tom concurs) -that the proposed resolution seems to require compiler support -for its implementation, -as it seems necessary to look at the range of values -of the enumerated type. -To a first approximation, -a library solution could give an answer based on the size of the type. -If the user has specialized numeric_limits for the enumerated type, -then the library might be able to do better, -but there is no such requirement. -Keep status as Open -and solicit input from CWG. -- -[ -2009-05-23 Alisdair adds: -]
- - --Just to confirm that the BSI originator of this comment assumed it did -indeed imply a compiler intrinsic. Rather than request a Core extension, it -seemed in keeping with that the type traits interface provides a library API -to unspecified compiler features - where we require several other traits -(e.g. has_trivial_*) to get the 'right' answer now, unlike in TR1. -- -[ -Addressed in N2947. -]
- - -[ -2009-10 Santa Cruz: -]
- - --NAD Editorial. Solved by -N2984. -- - - -Proposed resolution:
-Add a new row to the table in 20.6.7 [meta.trans.other]: +We concur, and expect this to have no repurcussions re-writing this +clause now concepts are removed.
----
-Table 41 -- Other transformations -- -Template -Condition -Comments -- --template< class T > struct enum_base; - --T shall be an enumeration type (7.2 [dcl.enum]) - --The member typedef type shall name the underlying type -of the enum T. - -
1057. RandomNumberEngineAdaptor
-Section: 26.5 [rand] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-07-15
+Section: 26.5 [rand] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
View all other issues in [rand].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
@@ -33861,11 +35809,10 @@ Move to Open.
1058. New container issue
-Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-07-13
-View other active issues in [sequence.reqmts].
+Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
View all other issues in [sequence.reqmts].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
@@ -33915,10 +35862,10 @@ element constructed from args inserted into a.
1059. Usage of no longer existing FunctionType concept
-Section: 20.7.15.2 [func.wrap.func] Status: NAD Concepts - Submitter: Daniel Krügler Opened: 2009-03-13 Last modified: 2009-07-16
+Section: 20.8.14.2 [func.wrap.func] Status: NAD Concepts + Submitter: Daniel Krügler Opened: 2009-03-13 Last modified: 2010-10-23
View all other issues in [func.wrap.func].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Due to a deliberate core language decision, the earlier called @@ -33930,8 +35877,8 @@ before the first "conceptualized" version of the WP had been prepared. This caused a break of the library, which already used this concept in the adapted definition of std::function -(20.7 [function.objects]/2, header <functional> synopsis and -20.7.15.2 [func.wrap.func]). +(20.8 [function.objects]/2, header <functional> synopsis and +20.8.14.2 [func.wrap.func]).
A simple fix would be to either (a) make std::function's primary template @@ -34006,7 +35953,7 @@ their feedback. Move to Open.
-Change in 20.7 [function.objects]/2, Header <functional> synopsis: +Change in 20.8 [function.objects]/2, Header <functional> synopsis:
// 20.6.16 polymorphic function wrappers: class bad_function_call; @@ -34017,7 +35964,7 @@ class function; // undefined-Change in 20.7.15.2 [func.wrap.func]: +Change in 20.8.14.2 [func.wrap.func]:
namespace std { template<FunctionTypeReferentType F> @@ -34033,9 +35980,9 @@ class function; // undefined
1060. Embedded nulls in NTBS
-Section: 17.5.2.1.4.1 [byte.strings] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-13 Last modified: 2009-07-13
-View all issues with NAD Editorial status.
+Section: 17.5.2.1.4.1 [byte.strings] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-13 Last modified: 2010-10-23
+View all issues with NAD Editorial status.
Discussion:
@@ -34062,9 +36009,9 @@ Move to NAD Editorial.
1061. Bad indexing for tuple access to pair (Editorial?)
-Section: 20.3.5 [pair.astuple] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-03-13 Last modified: 2009-07-13
-View all issues with NAD Editorial status.
+Section: 20.3.5.4 [pair.astuple] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-13 Last modified: 2010-10-23
+View all issues with NAD Editorial status.
Discussion:
@@ -34084,7 +36031,7 @@ Move to NAD Editorial.
Proposed resolution:
-20.3.5 [pair.astuple] p5: +20.3.5.4 [pair.astuple] p5:
template<intsize_t I, class T1, class T2> @@ -34101,7 +36048,7 @@ Move to NAD Editorial.
1062. Missing insert_iterator for stacks/queues
Section: 24.5.2 [insert.iterators] Status: NAD - Submitter: Alisdair Meredith Opened: 2009-03-13 Last modified: 2009-10-20
+ Submitter: Alisdair Meredith Opened: 2009-03-13 Last modified: 2010-10-23View all other issues in [insert.iterators].
View all issues with NAD status.
Discussion:
@@ -34161,9 +36108,9 @@ Moved to NAD. The intent of these adapters are to restrict the interfaces.
1063. 03 iterator compatibilty
-Section: X [iterator.backward] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-15 Last modified: 2009-07-16
-View all issues with NAD Concepts status.
+Section: X [iterator.backward] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-15 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
@@ -34223,8 +36170,8 @@ indicated:
1064. Response to UK 152
-Section: 17.3.15 [defns.obj.state] Status: NAD - Submitter: Howard Hinnant Opened: 2009-03-15 Last modified: 2009-10-23
+Section: 17.3.18 [defns.obj.state] Status: NAD + Submitter: Howard Hinnant Opened: 2009-03-15 Last modified: 2010-10-23
View all issues with NAD status.
Discussion:
@@ -34265,9 +36212,9 @@ Mark as NAD. This will not affect user or implementer code
1067. simplified wording for inner_product
-Section: 26.7 [numeric.ops] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-17 Last modified: 2009-07-14
-View all issues with NAD Concepts status.
+Section: 26.7 [numeric.ops] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-17 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
@@ -34382,20 +36329,117 @@ Change in 26.7 [numeric.ops] and 26.7.4 [adjacent.difference]: +
+1068. class random_device should be movable
+Section: 26.5.6 [rand.device] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-03-18 Last modified: 2010-10-23
+View all other issues in [rand.device].
+View all issues with NAD status.
+Discussion:
+ ++class random_device should be movable. +
+ +[ +Batavia (2009-05): +]
+ ++Move to Open, and recommend this issue be deferred until after the next +Committee Draft is issued. ++ +[ +2009-10 post-Santa Cruz: +]
+ + ++Leave open. Walter to provide drafting as part of his planned paper. ++ +[ +2010 Pittsburgh: Moved to NAD. +]
+ + + + +Rationale:
++WP is correct as written. +
+ + +Proposed resolution:
+ + + + + +
+1069. class seed_seq should support efficient move operations
+Section: 26.5.7.1 [rand.util.seedseq] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-03-18 Last modified: 2010-10-23
+View all other issues in [rand.util.seedseq].
+View all issues with NAD status.
+Discussion:
+ ++class seed_seq should support efficient move operations. +
+ +[ +Batavia (2009-05): +]
+ ++Move to Open, and recommend this issue be deferred until after the next +Committee Draft is issued. ++ +[ +2009-10 post-Santa Cruz: +]
+ + ++Leave open. Walter to provide drafting as part of his planned paper. ++ +[ +2010 Pittsburgh: +]
+ + ++seed_seq is explicitly not copyable, so, much like LWG issue +1068, LWG issue 1069 could be marked NAD to be consistent +with this. ++ + + +Proposed resolution:
+ + + + +
1072. Is std::hash a constrained template or not?
-Section: 20.7.16 [unord.hash] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2009-07-16
-View other active issues in [unord.hash].
+Section: 20.8.15 [unord.hash] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2010-10-23
View all other issues in [unord.hash].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Is std::hash a constrained template or not?
-According to Class template hash 20.7.16 [unord.hash], the definition is: +According to Class template hash 20.8.15 [unord.hash], the definition is:
template <class T> @@ -34409,7 +36453,7 @@ And so unconstrained.According to the <functional> synopsis in p2 Function objects -20.7 [function.objects] the template is declared as: +20.8 [function.objects] the template is declared as:
template <ReferentType T> struct hash; @@ -34454,7 +36498,7 @@ resolution of 1074. concept map broken by N2840 -Section: X [allocator.element.concepts] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2009-07-13
-View all issues with NAD Concepts status.
+Section: X [allocator.element.concepts] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
@@ -34608,245 +36652,312 @@ Change X [allocator.element.concepts]:
-1075. Response to US 65, US 74.1
-Section: 20 [utilities], 23 [containers] Status: NAD Editorial - Submitter: Alan Talbot Opened: 2009-03-20 Last modified: 2009-10-26
-View all other issues in [utilities].
-View all issues with NAD Editorial status.
+1076. unary/binary_negate need constraining and move support
+Section: 20.8.9 [negators] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-03-20 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
-Addresses US 65 and US 74.1
- -US 65:
- --Scoped allocators and allocator propagation traits add a small amount of -utility at the cost of a great deal of machinery. The machinery is user -visible, and it extends to library components that don't have any -obvious connection to allocators, including basic concepts and simple -components like pair and tuple. - -- -Suggested resolution:
--Sketch of proposed resolution: Eliminate scoped allocators, replace -allocator propagation traits with a simple uniform rule (e.g. always -propagate on copy and move), remove all mention of allocators from -components that don't explicitly allocate memory (e.g. pair), and adjust -container interfaces to reflect this simplification. +The class templates unary/binary_negate need constraining and move support.
-Components that I propose eliminating include HasAllocatorType, -is_scoped_allocator, allocator_propagation_map, scoped_allocator_adaptor, -and ConstructibleAsElement. -
-US 74.1:
- ---Scoped allocators represent a poor trade-off for standardization, since -(1) scoped-allocator--aware containers can be implemented outside the -C++ standard library but used with its algorithms, (2) scoped -allocators only benefit a tiny proportion of the C++ community -(since few C++ programmers even use today's allocators), and (3) all C++ -users, especially the vast majority of the C++ community that won't ever -use scoped allocators are forced to cope with the interface complexity -introduced by scoped allocators. +Ideally these classes would be deprecated, allowing unary/binary_function to +also be deprecated. However, until a generic negate adaptor is introduced +that can negate any Callable type, they must be supported so should be +constrained. Likewise, they should be movable, and support adopting a +move-only predicate type.
-In essence, the larger community will suffer to support a very small -subset of the community who can already implement their own -data structures outside of the standard library. Therefore, scoped -allocators should be removed from the working paper. +In order to preserve ABI compatibility, new rvalue overloads are supplied in +preference to changing the existing pass-by-const-ref to pass-by-value.
-Some evidence of the complexity introduced by scoped allocators: +Do not consider the issue of forwarding mutable lvalues at this point, +although remain open to another issue on the topic.
----20.3.4 [pairs], 20.5 [tuple]: Large increase in the -number of pair and tuple constructors. -
--23 [containers]: Confusing "AllocatableElement" requirements throughout. -
-Suggested resolution:
- --Remove support for scoped allocators from the working paper. This -includes at least the following changes: -
- --- --Remove X [allocator.element.concepts] -
--Remove 20.8.9 [allocator.adaptor] -
--Remove 20.8.12 [construct.element] -
--In Clause 23 [containers]: replace requirements naming the -AllocatableElement concept with requirements naming CopyConstructible, -MoveConstructible, DefaultConstructible, or Constructible, as -appropriate. -
-[ -Post Summit Alan moved from NAD to Open. +2009-05-01 Daniel adds: ]
- -[ -2009-05-15 Ganesh adds: -]
- --The requirement AllocatableElement should not be replaced with -Constructible on the emplace_xxx() functions as suggested. In the -one-parameter case the Constructible requirement is not satisfied when -the constructor is explicit (as per [concept.map.fct], twelfth -bullet) but we do want to allow explicit constructors in emplace, as the -following example shows: +IMO the currently proposed resolution needs some updates +because it is ill-formed at several places:
-+ +vector<shared_ptr<int>> v; -v.emplace_back(new int); // should be allowed ++
+- +
++In concept AdaptableUnaryFunction change +
+-typename X::result_type; +typename X::argument_type;-If the issue is accepted and scoped allocators are removed, I suggest to -add a new pair of concepts to [concept.construct], namely: +to +
++Returnable result_type = typename X::result_type; +typename argument_type = typename X::argument_type; ++[The replacement "Returnable result_type" instead of "typename +result_type" is non-editorial, but maybe you prefer that as well] +
+- +
+ ++In concept AdaptableBinaryFunction change +
++typename X::result_type; +typename X::first_argument_type; +typename X::second_argument_type; ++to +
++Returnable result_type = typename X::result_type; +typename first_argument_type = typename X::first_argument_type; +typename second_argument_type = typename X::second_argument_type; ++[The replacement "Returnable result_type" instead of "typename +result_type" is non-editorial, but maybe you prefer that as well.] +
+- +
++In class unary/binary_function +
++
+- +I suggest to change "ReturnType" to "Returnable" in both cases. +
+- +I think you want to replace the remaining occurrences of "Predicate" by "P" +(in both classes in copy/move from a predicate) +
+- +
++I think you need to change the proposed signatures of not1 and not2, because +they would still remain unconstrained: To make them constrained at least a +single requirement needs to be added to enable requirement implication. This +could be done via a dummy ("requires True<true>") or just explicit as follows: +
++
+- +
++template <AdaptableUnaryFunction P> +requires Predicate< P, P::argument_type> +unary_negate<P> not1(const P&& pred); +template <AdaptableUnaryFunction P> +requires Predicate< P, P::argument_type > +unary_negate<P> not1(P&& pred); +++-3- Returns: unary_negate<P>(pred). +++[Don't we want a move call for the second overload as in +
++unary_negate<P>(std::move(pred)) ++in the Returns clause ?] +
+- +
+template <AdaptableBinaryFunction P> +requires Predicate< P, P::first_argument_type, P::second_argument_type > +binary_negate<P> not2(const P& pred); +template <AdaptableBinaryFunction P> +requires Predicate< P, P::first_argument_type, P::second_argument_type > +binary_negate<P> not2(P&& pred); +++-5- Returns: binary_negate<P>(pred). +
++[Don't we want a move call for the second overload as in +
++binary_negate<P>(std::move(pred)) ++in the Returns clause ?] +
+[ +Batavia (2009-05): +]
+ +++ ++There is concern that complicating the solution +to preserve the ABI seems unnecessary, +since we're not in general preserving the ABI. +
++We would prefer a separate paper consolidating all Clause 20 +issues that are for the purpose of providing constrained versions +of the existing facilities. +
++Move to Open. +
+[ +2009-10 post-Santa Cruz: +]
+ + ++Leave open pending the potential move constructor paper. Note that +we consider the "constraining" part NAD Concepts. ++ +[ +2010-01-31 Alisdair removes the current proposed wording from the proposed +wording section because it is based on concepts. That wording is proposed here: +]
+ + +++Add new concepts where appropriate::
-+ +auto concept HasExplicitConstructor<typename T, typename... Args> { - explicit T::T(Args...); +auto concept AdaptableUnaryFunction< typename X > { + typename X::result_type; + typename X::argument_type; } -auto concept ExplicitConstructible<typename T, typename... Args> - : HasExplicitConstructor<T, Args...>, NothrowDestructible<T> -{ } +auto concept AdaptableBinaryFunction< typename X > { + typename X::result_type; + typename X::first_argument_type; + typename X::second_argument_type; +}-We should then use ExplicitConstructible as the requirement for all -emplace_xxx() member functions. -
--For coherence and consistency with the similar concepts -Convertible/ExplicitlyConvertible, we might also consider changing -Constructible to: +Revise as follows:
-+ +auto concept Constructible<typename T, typename... Args> - : HasConstructor<T, Args...>, ExplicitConstructible<T, Args...> -{ } +++Base X [base] (Only change is constrained Result) +
+ +++-1- The following classes are provided to simplify the typedefs of the +argument and result types: +
+namespace std { + template <class Arg,classReturnType Result> + struct unary_function { + typedef Arg argument_type; + typedef Result result_type; + }; + + template <class Arg1, class Arg2,classReturnType Result> + struct binary_function { + typedef Arg1 first_argument_type; + typedef Arg2 second_argument_type; + typedef Result result_type; + }; +}-Moreover, all emplace-related concepts in [container.concepts] -should also use ExplicitConstructible instead of Constructible in the -definitions of their axioms. In fact the concepts in [container.concepts] should be -corrected even if the issue is not accepted. +Negators 20.8.9 [negators]:
+ +-On the other hand, if the issue is not accepted, the scoped allocator -adaptors should be fixed because the following code: +-1- Negators not1 and not2 take a unary and a binary predicate, +respectively, and return their complements (5.3.1).
-+ requires CopyConstructible< P > + explicit unary_negate(const Predicate& pred); + requires MoveConstructible< P > + explicit unary_negate(Predicate && pred); -template <typename T> using scoped_allocator = scoped_allocator_adaptor<allocator<T>>; +template <classAdaptableUnaryFunction Predicate> + requires Predicate< P, P::argument_type > + class unary_negate + : public unary_function<typenamePredicate::argument_type,bool> { + public: + unary_negate(const unary_negate & ) = default; + unary_negate(unary_negate && ); -vector<shared_ptr<int>, scoped_allocator<shared_ptr<int>>> v; -v.emplace_back(new int); // ops! doesn't compile --doesn't compile, as the member function construct() of the scoped -allocator requires non-explicit constructors through concept -ConstructibleWithAllocator. Fixing that is not difficult but probably -more work than it's worth and is therefore, IMHO, one more reason in -support of the complete removal of scoped allocators. -
+ bool operator()(consttypenamePredicate::argument_type& x) const; + }; ++-2 operator() returns !pred(x).+template <class Predicate> + unary_negate<Predicate> not1(const Predicate& pred); +template <class Predicate> + unary_negate<Predicate> not1(Predicate&& pred); +++-3- Returns: unary_negate<Predicate>(pred). ++ +template <+classAdaptableBinaryFunction Predicate> + requires Predicate< P, P::first_argument_type, P::second_argument_type > + class binary_negate + : public binary_function<typenamePredicate::first_argument_type, +typenamePredicate::second_argument_type, bool> { + public: + biary_negate(const binary_negate & ) = default; + binary_negate(binary_negate && ); + + requires CopyConstructible< P > + explicit binary_negate(const Predicate& pred); + requires MoveConstructible< P > + explicit binary_negate(const Predicate& pred); + + bool operator()(consttypenamePredicate::first_argument_type& x, + consttypenamePredicate::second_argument_type& y) const; + }; ++-4- operator() returns !pred(x,y). ++ +template <class Predicate> + binary_negate<Predicate> not2(const Predicate& pred); +template <class Predicate> + binary_negate<Predicate> not2(Predicate&& pred); ++ ++-5- Returns: binary_negate<Predicate>(pred). ++[ -2009-06-09 Alan adds: +2010 Rapperswil: ]
-- --I reopened this issue because I did not think that these National Body -comments were adequately addressed by marking them NAD. My understanding -is that something can be marked NAD if it is clearly a misunderstanding -or trivial, but a substantive issue that has any technical merit -requires a disposition that addresses the concerns. -
--The notes in the NB comment list (US 65 & US 74.1) say that: -
--
-- -this issue has not introduced any new arguments not previously discussed, -
-- -the vote (4-9-3) was not a consensus for removing scoped allocators, -
-- -the issue is resolved by -N2840. -
--My opinion is: -
--
- -- -there are new arguments in both comments regarding concepts (which were -not present in the library when the scoped allocator proposal was voted -in), -
-- -the vote was clearly not a consensus for removal, but just saying there -was a vote does not provide a rationale, -
-- -I do not believe that N2840 addresses these comments (although it does -many other things and was voted in with strong approval). -
--My motivation to open the issue was to ensure that the NB comments were -adequately addressed in a way that would not risk a "no" vote on our -FCD. If there are responses to the technical concerns raised, then -perhaps they should be recorded. If the members of the NB who authored -the comments are satisfied with N2840 and the other disposition remarks -in the comment list, then I am sure they will say so. In either case, -this issue can be closed very quickly in Frankfurt, and hopefully will -have helped make us more confident of approval with little effort. If in -fact there is controversy, my thought is that it is better to know now -rather than later so there is more time to deal with it. -
-[ -2009-10 Santa Cruz: -]
- - --NAD Editorial. Addressed by -N2982. +Move to NAD Concepts. The move-semantic part has been addressed by a core language change, which implicitly generates appropriate move constructors and move-assignment operators.@@ -34854,22 +36965,18 @@ NAD Editorial. Addressed byProposed resolution:
-Rationale:
-Scoped allocators have been revised significantly. - -
1077. Nonesense tuple declarations
-Section: 20.5.2 [tuple.tuple] Status: NAD Editorial - Submitter: Pete Becker Opened: 2009-03-20 Last modified: 2009-07-13
+Section: 20.4.2 [tuple.tuple] Status: NAD Editorial + Submitter: Pete Becker Opened: 2009-03-20 Last modified: 2010-10-23
View all other issues in [tuple.tuple].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
-Class template tuple 20.5.2 [tuple.tuple]: +Class template tuple 20.4.2 [tuple.tuple]:
template <class... UTypes> @@ -34898,7 +37005,7 @@ The resolution looks correct; move to NAD Editorial.Proposed resolution:
-In 20.5.2 [tuple.tuple], class tuple, change as indicated: +In 20.4.2 [tuple.tuple], class tuple, change as indicated:
template <class... UTypes> @@ -34910,7 +37017,7 @@ template <class... UTypes>-[NB.: The corresponding prototypes do already exist in 20.5.2.1 [tuple.cnstr]/7+8] +[NB.: The corresponding prototypes do already exist in 20.4.2.1 [tuple.cnstr]/7+8]
@@ -34919,9 +37026,9 @@ template <class... UTypes>
1078. DE-17: Remove class type_index
-Section: 20.11 [type.index] Status: NAD Concepts - Submitter: Doug Gregor Opened: 2009-03-20 Last modified: 2009-07-16
-View all issues with NAD Concepts status.
+Section: 20.13 [type.index] Status: NAD Concepts + Submitter: Doug Gregor Opened: 2009-03-20 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
Addresses DE 17
@@ -35005,7 +37112,7 @@ needed for name() and before() to work.Remove section 20.11 [type.index]
+Remove section 20.13 [type.index]
@@ -35013,9 +37120,9 @@ needed for name() and before() to work.
1080. Concept ArithmeticLike should provide explicit boolean conversion
-Section: X [concept.arithmetic] Status: NAD Concepts - Submitter: Daniel Krügler Opened: 2009-03-21 Last modified: 2009-07-15
-View all issues with NAD Concepts status.
+Section: X [concept.arithmetic] Status: NAD Concepts + Submitter: Daniel Krügler Opened: 2009-03-21 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
Astonishingly, the current concept ArithmeticLike as specified in @@ -35032,7 +37139,7 @@ via conversion to long long) also took care of such a feature.
Adding such an explicit conversion associated function would also partly solve a currently invalid effects clause in library, which bases -on this property, 24.2.5 [random.access.iterators]/2: +on this property, 24.2.7 [random.access.iterators]/2:
{ difference_type m = n; if (m >= 0) while (m--) ++r; @@ -35066,7 +37173,7 @@ concepts one further concept:-In 24.2.5 [random.access.iterators]/2 change the current effects clause +In 24.2.7 [random.access.iterators]/2 change the current effects clause as indicated [The proposed insertion fixes the problem that the previous implicit construction from integrals has been changed to an explicit constructor]: @@ -35121,10 +37228,10 @@ concepts one further concept:
1081. Response to UK 216
-Section: 21 [strings] Status: NAD Concepts - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-07-15
+Section: 21 [strings] Status: NAD Concepts + Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
View all other issues in [strings].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 216, JP 46, JP 48
@@ -35156,10 +37263,10 @@ extensive proposed wording; start there.
1082. Response to JP 49
-Section: 22 [localization] Status: NAD Concepts - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-07-15
+Section: 22 [localization] Status: NAD Concepts + Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
View all other issues in [localization].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses JP 49
@@ -35189,10 +37296,10 @@ To be handled by Howard Hinnant, Dave Abrahams, Martin Sebor, PJ Plauger.
1083. Response to JP 52, 53
-Section: 22 [localization] Status: NAD Concepts - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-07-15
+Section: 22 [localization] Status: NAD Concepts + Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
View all other issues in [localization].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses JP 52, JP 53
@@ -35225,10 +37332,10 @@ To be handled by Howard Hinnant, Dave Abrahams, Martin Sebor, PJ Plauger.
1084. Response to UK 250
-Section: 24.2.3 [forward.iterators] Status: NAD Concepts - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-07-16
+Section: 24.2.5 [forward.iterators] Status: NAD Concepts + Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
View all other issues in [forward.iterators].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 250
@@ -35274,7 +37381,7 @@ wordings change the same paragraphs.-Change 24.2.3 [forward.iterators]: +Change 24.2.5 [forward.iterators]:
@@ -35304,10 +37411,10 @@ Change 24.2.3 [forward.iterators]:
1085. Response to UK 258
-Section: 24.2.4 [bidirectional.iterators] Status: NAD Concepts - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-07-16
+Section: 24.2.6 [bidirectional.iterators] Status: NAD Concepts + Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
View all other issues in [bidirectional.iterators].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 258
@@ -35344,7 +37451,7 @@ that would render auto-detection of the return typeProposed resolution:
-Change 24.2.4 [bidirectional.iterators]: +Change 24.2.6 [bidirectional.iterators]:
@@ -35369,9 +37476,9 @@ Change 24.2.4 [bidirectional.iterators]:
1086. Response to UK 284
-Section: 24.6 [stream.iterators] Status: NAD Concepts - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-07-15
-View all issues with NAD Concepts status.
+Section: 24.6 [stream.iterators] Status: NAD Concepts + Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 284
@@ -35396,10 +37503,10 @@ We agree. To be handled by Howard, Martin and PJ.
1087. Response to UK 301
-Section: 25.3.5 [alg.replace] Status: NAD Concepts - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-07-15
+Section: 25.3.5 [alg.replace] Status: NAD Concepts + Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
View all other issues in [alg.replace].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses UK 301
@@ -35451,10 +37558,11 @@ template<ForwardIterator Iter, Predicate<auto, Iter::value_type> Pred,
1088. Response to UK 342
-Section: 30.6.5 [futures.promise] Status: NAD Editorial - Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2009-10-26
+Section: 30.6.5 [futures.promise] Status: NAD Editorial + Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
+View other active issues in [futures.promise].
View all other issues in [futures.promise].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 342
@@ -35547,10 +37655,118 @@ void swap(promise<R>& x, promise<R>& y); +
+1090. Missing description of packaged_task member swap, missing non-member swap
+Section: 30.6.10 [futures.task] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2009-03-22 Last modified: 2010-10-23
+View all other issues in [futures.task].
+View all issues with NAD Editorial status.
+Discussion:
++Class template packaged_task in 30.6.10 [futures.task] shows a member swap +declaration, but misses to +document it's effects (No prototype provided). Further on this class +misses to provide a non-member +swap. +
+ +[ +Batavia (2009-05): +]
+ +++ ++Alisdair notes that paragraph 2 of the proposed resolution has already been +applied in the current Working Draft. +
++We note a pending future-related paper by Detlef; +we would like to wait for this paper before proceeding. +
++Move to Open. +
+[ +2009-05-24 Daniel removed part 2 of the proposed resolution. +]
+ + +[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Tentatively Ready, removing bullet 3 from the proposed +resolution but keeping the other two bullets. ++ +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added below. ++ + + +Rationale:
++Solved by N3058. +
+ + +Proposed resolution:
++
+ +- +
++In 30.6.10 [futures.task], immediately after the definition of class +template packaged_task add: +
+++template<class R, class... Argtypes> +void swap(packaged_task<R(ArgTypes...)>&, packaged_task<R(ArgTypes...)>&); + ++ +
+ + + + +- +
++At the end of 30.6.10 [futures.task] (after p. 20), add add the following +prototype description: +
+ +++template<class R, class... Argtypes> +void swap(packaged_task<R(ArgTypes...)>& x, packaged_task<R(ArgTypes...)>& y); +++++Effects: x.swap(y) +
++Throws: Nothing. +
+
1091. Multimap description confusing
-Section: 23.4.2.2 [multimap.modifiers] Status: NAD - Submitter: LWG Opened: 2009-03-22 Last modified: 2009-10-20
+Section: 23.6.2.2 [multimap.modifiers] Status: NAD + Submitter: LWG Opened: 2009-03-22 Last modified: 2010-10-23
View all issues with NAD status.
Discussion:
@@ -35599,7 +37815,7 @@ Mark as NAD, solved by removing concepts.Proposed resolution:
-Strike 23.4.2.2 [multimap.modifiers] entirely +Strike 23.6.2.2 [multimap.modifiers] entirely (but do NOT strike these signatures from the class template definition!).
@@ -35609,10 +37825,10 @@ Strike 23.4.2.2 [multimap.modifiers] entirely
1092. Class template integral_constant should be a constrained template
-Section: 20.6.3 [meta.help] Status: NAD Concepts - Submitter: Daniel Krügler Opened: 2009-03-22 Last modified: 2009-07-15
+Section: 20.7.3 [meta.help] Status: NAD Concepts + Submitter: Daniel Krügler Opened: 2009-03-22 Last modified: 2010-10-23
View all other issues in [meta.help].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
A first step to change the type traits predicates to constrained templates is to @@ -35640,7 +37856,7 @@ until after the next Committee Draft is issued.
-In 20.6.2 [meta.type.synop], Header <type_traits> +In 20.7.2 [meta.type.synop], Header <type_traits> synopsis change as indicated:
namespace std { @@ -35650,7 +37866,7 @@ template <classIntegralConstantExpressionType T, T v>-In 20.6.3 [meta.help] change as indicated: +In 20.7.3 [meta.help] change as indicated:
template <classIntegralConstantExpressionType T, T v> struct integral_constant { @@ -35667,13 +37883,164 @@ struct integral_constant { +
+1093. Multiple definitions for random_shuffle algorithm
+Section: 25.3.12 [alg.random.shuffle] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-03-22 Last modified: 2010-10-23
+View all other issues in [alg.random.shuffle].
+View all issues with NAD Editorial status.
+Discussion:
+ ++There are a couple of issues with the declaration of the random_shuffle +algorithm accepting a random number engine. +
+ ++
+ +- +The Iterators must be shuffle iterators, yet this requirement is missing. +
+- +The RandomNumberEngine concept is now provided by the random number +library +(n2836) +and the placeholder should be removed. +
+[ +2009-05-02 Daniel adds: +]
+ + +++ ++this issue completes adding necessary requirement to the +third new random_shuffle overload. The current suggestion is: +
+ ++ +template<RandomAccessIterator Iter, UniformRandomNumberGenerator Rand> +requires ShuffleIterator<Iter> +void random_shuffle(Iter first, Iter last, Rand&& g); ++IMO this is still insufficient and I suggest to add the requirement +
++Convertible<Rand::result_type, Iter::difference_type> ++to the list (as the two other overloads already have). +
+ ++Rationale: +
+ +++ ++Its true that this third overload is somewhat different from the remaining +two. Nevertheless we know from UniformRandomNumberGenerator, that +it's result_type is an integral type and that it satisfies +UnsignedIntegralLike<result_type>. +
++To realize it's designated task, the algorithm has to invoke the +Callable aspect of g and needs to perform some algebra involving +it's min()/max() limits to compute another index value that +at this point is converted into Iter::difference_type. This is so, +because 24.2.7 [random.access.iterators] uses this type as argument +of it's algebraic operators. Alternatively consider the equivalent +iterator algorithms in 24.4.4 [iterator.operations] with the same result. +
++This argument leads us to the conclusion that we also need +Convertible<Rand::result_type, Iter::difference_type> here. +
+[ +Batavia (2009-05): +]
+ +++ ++Alisdair notes that point (ii) has already been addressed. +
++We agree with the proposed resolution to point (i) +with Daniel's added requirement. +
++Move to Review. +
+[ +2009-06-05 Daniel updated proposed wording as recommended in Batavia. +]
+ + +[ +2009-07-28 Alisdair adds: +]
+ + ++Revert to Open, with a note there is consensus on direction but the +wording needs updating to reflect removal of concepts. ++ +[ +2009-10 post-Santa Cruz: +]
+ + ++Leave Open, Walter to work on it. ++ +[ +2010 Pittsburgh: Moved to NAD Editorial, solved by +N3056. +]
+ + + + +Rationale:
++Solved by +N3056. +
+ + +Proposed resolution:
++Change in [algorithms.syn] and 25.3.12 [alg.random.shuffle]: +
+ ++ + + + + +concept UniformRandomNumberGenerator<typename Rand> { }+template<RandomAccessIterator Iter, UniformRandomNumberGenerator Rand> + requires ShuffleIterator<Iter> && + Convertible<Rand::result_type, Iter::difference_type> + void random_shuffle(Iter first, Iter last, Rand&& g); +
1096. unconstrained rvalue ref parameters
-Section: 17 [library] Status: NAD Concepts - Submitter: David Abrahams Opened: 2009-03-21 Last modified: 2009-07-16
+Section: 17 [library] Status: NAD Concepts + Submitter: David Abrahams Opened: 2009-03-21 Last modified: 2010-10-23
View other active issues in [library].
View all other issues in [library].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
TODO: Look at all cases of unconstrained rvalue ref parameters and check @@ -35703,12 +38070,231 @@ Move to Open, pending proposed wording from Dave for further review. +
+1099. Various issues
+Section: 17 [library] Status: NAD + Submitter: David Abrahams Opened: 2009-03-21 Last modified: 2010-10-23
+View other active issues in [library].
+View all other issues in [library].
+View all issues with NAD status.
+Discussion:
++Notes +
+++ ++[2009-03-21 Sat] p. 535 at the top we need MoveConstructible V1, +MoveConstructible V2 (where V1,V2 are defined on 539). Also make_tuple +on 550 +
+ +++ ++CD-1 reads: +
+ ++ +template <MoveConstructible T1, MoveConstructible T2> +pair<V1, V2> make_pair(T1&&, T2&&); ++Actually I'm guessing we need something like MoveConstructible<V1,T1>, +i.e. "V1 can be constructed from an rvalue of type T1." +
+ ++Ditto for make_tuple +
++[2009-03-21 Sat] p1183 thread ctor, and in general, we need a way to +talk about "copiable from generalized rvalue ref argument" for cases +where we're going to forward and copy. +
++++ This issue may well be quite large. Language in para 4 about "if + an lvalue" is wrong because types aren't expressions. +
+ +++ ++Maybe we should define the term "move" so we can just say in the +effects, "f is moved into the newly-created thread" or something, and +agree (and ideally document) that saying "f is moved" implies +
+ ++ +F x(move(f)) ++is required to work. That would cover both ctors at once. +
++ p1199, call_once has all the same issues. +
++[2009-03-21 Sat] p869 InputIterator pointer type should not be required +to be convertible to const value_type*, rather it needs to have a +operator-> of its own that can be used for the value type. +
+ ++This one is serious and unrelated to the move issue. ++ ++[2009-03-21 Sat] p818 stack has the same problem with default ctor. +
++[2009-03-21 Sat] p816 priority_queue has the same sorts of problems as queue, only more so +
++requires MoveConstructible<Cont> + explicit priority_queue(const Compare& x = Compare(), Cont&& = Cont()); +++ Don't require MoveConstructible when default constructing Cont. + Also missing semantics for move ctor. +
++ [2009-03-21 Sat] Why are Allocators required to be CopyConstructible as + opposed to MoveConstructible? +
++ [2009-03-21 Sat] p813 queue needs a separate default ctor (Cont needn't + be MoveConstructible). No documented semantics for move c'tor. Or + *any* of its 7 ctors! +
++ [2009-03-21 Sat] std::array should have constructors for C++0x, + consequently must consider move construction. +
+ +[ +2009-05-01 Daniel adds: +]
+ + ++This could be done as part of 1035, which already handles +deviation of std::array from container tables. ++ ++ [2009-03-21 Sat] p622 all messed up. +
+++ ++ para 8 "implementation-defined" is the wrong term; should be "see + below" or something. +
++ para 12 "will be selected" doesn't make any sense because we're not + talking about actual arg types. +
++ paras 9-13 need to be totally rewritten for concepts. +
++ [2009-03-21 Sat] Null pointer comparisons (p587) have all become + unconstrained. Need to fix that +
++ [2009-03-21 Sat] mem_fun_t etc. definition doesn't match declaration. + We think CopyConstructible is the right reqt. +
++ make_pair needs Constructible<V1, T1&&> requirements! +
++ make_tuple needs something similar +
++ tuple bug in synopsis: +
++ +template <class... UTypes> + requires Constructible<Types, const UTypes&>... + template <class... UTypes> + requires Constructible<Types, RvalueOf<UTypes>::type>... +++ Note: removal of MoveConstructible requirements in std::function makes + these routines unconstrained! +
+[ +2009-05-02 Daniel adds: +]
+ + ++This part of the issue is already covered by 1077. ++ ++ these unique_ptr constructors are broken [ I think this is covered in "p622 all messed up" ] +
++unique_ptr(pointer p, implementation-defined d); + unique_ptr(pointer p, implementation-defined d); ++ multimap range constructor should not have MoveConstructible<value_type> requirement. +
++ same with insert(..., P&&); multiset has the same issue, as do + unordered_multiset and unordered_multimap. Review these! ++ +[ +Batavia (2009-05): +]
+ ++Move to Open, pending proposed wording from Dave for further review. ++ +[ +2009-10 post-Santa Cruz: +]
+ + ++Tentatively NAD. We are not sure what has been addressed and what hasn't. +Recommend closing unless someone sorts this out into something more readable. ++ + + +Rationale:
++The issue(s) at hand not adequately communicated. +
+ + +Proposed resolution:
++
+ + + + +
1101. unique requirements
-Section: 25.3.9 [alg.unique] Status: NAD Editorial - Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2009-07-13
+Section: 25.3.9 [alg.unique] Status: NAD Editorial + Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2010-10-23
View all other issues in [alg.unique].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
From Message c++std-core-14160 Howard wrote: @@ -35776,8 +38362,8 @@ Note that the synopsis in [algorithms.syn] is already correct.
1102. std::vector's reallocation policy still unclear
-Section: 23.3.6.2 [vector.capacity] Status: NAD - Submitter: Daniel Krügler Opened: 2009-04-20 Last modified: 2009-10-20
+Section: 23.4.1.2 [vector.capacity] Status: NAD + Submitter: Daniel Krügler Opened: 2009-04-20 Last modified: 2010-10-23
View all other issues in [vector.capacity].
View all issues with NAD status.
Discussion:
@@ -35811,20 +38397,20 @@ IMO the problem is due to the fact, that
- the actual memory-reallocation stability of std::vector -is explained in 23.3.6.2 [vector.capacity]/3 and /6 which +is explained in 23.4.1.2 [vector.capacity]/3 and /6 which are describing just the effects of the reserve function, but in many examples (like above) there is no explicit call to reserve involved. Further-more -23.3.6.2 [vector.capacity]/6 does only mention insertions +23.4.1.2 [vector.capacity]/6 does only mention insertions and never mentions the consequences of erasing elements.
the effects clause of std::vector's erase overloads in -23.3.6.4 [vector.modifiers]/4 is silent about capacity changes. This +23.4.1.4 [vector.modifiers]/4 is silent about capacity changes. This easily causes a misunderstanding, because the counter -parting insert functions described in 23.3.6.4 [vector.modifiers]/2 +parting insert functions described in 23.4.1.4 [vector.modifiers]/2 explicitly say, that
@@ -35875,8 +38461,8 @@ general consensus that the standard is correct as written.@@ -37841,7 +40802,7 @@ NAD Editorial. Solved by[ This is a minimum version. I also suggest that the wording explaining the allocation strategy -of std::vector in 23.3.6.2 [vector.capacity]/3 and /6 is moved into -a separate sub paragraph of 23.3.6.2 [vector.capacity] before +of std::vector in 23.4.1.2 [vector.capacity]/3 and /6 is moved into +a separate sub paragraph of 23.4.1.2 [vector.capacity] before any of the prototype's are discussed, but I cannot provide reasonable wording changes now ]
@@ -35885,7 +38471,7 @@ reasonable wording changes now
-Change 23.3.6.2 [vector.capacity]/6 as follows: +Change 23.4.1.2 [vector.capacity]/6 as follows:
It is guaranteed that no reallocation takes place during @@ -35896,7 +38482,7 @@ the size of the vector greater than the value of capacity().-Change 23.3.6.4 [vector.modifiers]/4 as follows: +Change 23.4.1.4 [vector.modifiers]/4 as follows:
Effects: The capacity shall remain unchanged and no reallocation shall @@ -35913,9 +38499,9 @@ of the erase.@@ -37700,10 +40660,11 @@ std::atomic_short::is_lock_free is related to
1105. Shouldn't Range be an auto concept
-Section: X [iterator.concepts.range] Status: NAD Concepts - Submitter: David Abrahams Opened: 2009-04-23 Last modified: 2009-07-15
-View all issues with NAD Concepts status.
+Section: X [iterator.concepts.range] Status: NAD Concepts + Submitter: David Abrahams Opened: 2009-04-23 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
[ @@ -36019,14 +38605,106 @@ Committee Draft is issued.
-1107. constructor shared_future(unique_future) by value?
-Section: 30.6.7 [future.shared_future] Status: NAD Editorial - Submitter: Thomas J. Gritzan Opened: 2009-04-03 Last modified: 2009-07-13
-View all other issues in [future.shared_future].
-View all issues with NAD Editorial status.
+1106. Multiple exceptions from connected shared_future::get()?
+Section: 30.6.7 [futures.shared_future] Status: NAD Editorial + Submitter: Thomas J. Gritzan Opened: 2009-04-03 Last modified: 2010-10-23
+View all other issues in [futures.shared_future].
+View all issues with NAD Editorial status.
Discussion:
-In the shared_future class definition in 30.6.7 [future.shared_future] +It is not clear, if multiple threads are waiting in a +shared_future::get() call, if each will rethrow the stored exception. +
++Paragraph 9 reads: +
++Throws: the stored exception, if an exception was stored and not +retrieved before. +++The "not retrieved before" suggests that only one exception is thrown, +but one exception for each call to get() is needed, and multiple calls +to get() even on the same shared_future object seem to be allowed. +
++I suggest removing "and not retrieved before" from the Throws paragraph. +I recommend adding a note that explains that multiple calls on get() are +allowed, and each call would result in an exception if an exception was +stored. +
+ +[ +Batavia (2009-05): +]
+ +++ ++We note there is a pending paper by Detlef +on such future-related issues; +we would like to wait for his paper before proceeding. +
++Alisdair suggests we may want language to clarify that this +get() function can be called from several threads +with no need for explicit locking. +
++Move to Open. +
+[ +2010-01-23 Moved to Tentatively NAD Editorial after 5 positive votes on +c++std-lib. +]
+ + + + +Rationale:
++Resolved by paper +N2997. +
+ + +Proposed resolution:
++Change 30.6.7 [futures.shared_future]: +
+ ++ + + + + + +const R& shared_future::get() const; +R& shared_future<R&>::get() const; +void shared_future<void>::get() const; ++++...
++-9- Throws: the stored exception, if an exception was stored
+and not retrieved before. + +[Note: Multiple calls on get() are +allowed, and each call would result in an exception if an exception was +stored. — end note] + +
+1107. constructor shared_future(unique_future) by value?
+Section: 30.6.7 [futures.shared_future] Status: NAD Editorial + Submitter: Thomas J. Gritzan Opened: 2009-04-03 Last modified: 2010-10-23
+View all other issues in [futures.shared_future].
+View all issues with NAD Editorial status.
+Discussion:
++In the shared_future class definition in 30.6.7 [futures.shared_future] the move constructor that constructs a shared_future from an unique_future receives the parameter by value. In paragraph 3, the same constructor receives it as @@ -36067,14 +38745,14 @@ The proposed change has already been incorported into the current working draft
Proposed resolution:
-Change the synopsis in 30.6.7 [future.shared_future]: +Change the synopsis in 30.6.7 [futures.shared_future]:
shared_future(unique_future<R>&& rhs);-Change the definition of the constructor in 30.6.7 [future.shared_future]: +Change the definition of the constructor in 30.6.7 [futures.shared_future]:
shared_future(constunique_future<R>&& rhs); @@ -36087,10 +38765,10 @@ Change the definition of the constructor in 30.6.7 [future.shared_future]:
1109. std::includes should require CopyConstructible predicate
-Section: 25.4.5.1 [includes] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-04-28 Last modified: 2009-07-13
+Section: 25.4.5.1 [includes] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-04-28 Last modified: 2010-10-23
View all other issues in [includes].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
All the set operation algorithms require a CopyConstructible predicate, with @@ -36129,10 +38807,10 @@ Change [algorithms.syn] and 25.4.5.1 [includes]:
1111. associative containers underconstrained
-Section: 23.4 [associative] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-04-29 Last modified: 2009-07-16
+Section: 23.6 [associative] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-04-29 Last modified: 2010-10-23
View all other issues in [associative].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
According to table 87 (n2857) the expression X::key_equal for an unordered @@ -36187,7 +38865,7 @@ As in the following declarations:
-Associative containers 23.4 [associative] +Associative containers 23.6 [associative]
1 Headers <map> and <set>: @@ -36490,91 +39168,200 @@ Associative containers 23.4 [associative]
-1116. Literal constructors for tuple
-Section: 20.5.2 [tuple.tuple] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2009-10-26
-View all other issues in [tuple.tuple].
-View all issues with NAD Editorial status.
+1112. bitsets and new style for loop
+Section: 20.5 [template.bitset] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-05-06 Last modified: 2010-10-23
+View all other issues in [template.bitset].
+View all issues with NAD Future status.
Discussion:
-It is not currently possible to construct tuple literal values, -even if the elements are all literal types. This is because parameters -are passed to constructor by reference. +Std::bitset is a homogeneous container-like sequence of bits, yet it does +not model the Range concept so cannot be used with the new for-loop syntax. +It is the only such type in the library that does NOT support the new for +loop.
-An alternative would be to pass all constructor arguments by value, where it -is known that *all* elements are literal types. This can be determined with -concepts, although note that the negative constraint really requires -factoring out a separate concept, as there is no way to provide an 'any of -these fails' constraint inline. +The obvious reason is that bitset does not support iterators.
-Note that we will have similar issues with pair (and -tuple constructors from pair) although I am steering -clear of that class while other constructor-related issues settle. +At least two reasonable solutions are available: +
++
+- +Add an iterator interface to bitset, bringing its interface close to that +of std::array +
+- +Provide an unspecified concept_map for Range<bitset>. +
++The latter will still need some kind of iterator-like adapter for bitset, +but gives implementers greater freedom on the details. E.g. begin/end return +some type that simply invokes operator[] on the object it wraps, and +increments its index on operator++. A vendor can settle for InputIterator +support, rather than wrapping up a full RandomAccessIterator. +
++I have a mild preference for option (ii) as I think it is less work to +specify at this stage of the process, although (i) is probably more useful +in the long run. +
++Hmm, my wording looks a little woolly, as it does not say what the element +type of the range is. Do I get a range of bool, bitset<N>::reference, or +something else entirely? +
++I guess most users will assume the behaviour of reference, but expect to +work with bool. Bool is OK for read-only traversal, but you really need to +take a reference to a bitset::reference if you want to write back.
[ -2009-10 Santa Cruz: +Batavia (2009-05): +]
+ ++Move to Open. +We further recommend this be deferred until after the next Committee Draft. ++ +[ +2009-05-25 Alisdair adds: ]
-NAD Editorial. Solved by -N2994. +++I just stumbled over the Range concept_map for valarray and this should +probably set the precedent on how to write the wording. +
+ +[ +Howard: I've replaced the proposed wording with Alisdair's suggestion. +]
+ +[ +2009-07-24 Daniel modifies the proposed wording for non-concepts. +]
+ + +[ +2009-10 post-Santa Cruz: +]
+ + ++Mark as Tentatively NAD Future due to the loss of concepts. ++ + + +Rationale:
++All concepts-related text has been removed from the draft. +
+ + +Proposed resolution:
++
+ + + + + + + + + + + + +- +
++Modify the section 20.5 [template.bitset] <bitset> synopsis by adding +the following at the end of the synopsis: +
+++// XX.X.X bitset range access [bitset.range] +template<size_t N> unspecified-1 begin(bitset<N>&); +template<size_t N> unspecified-2 begin(const bitset<N>&); +template<size_t N> unspecified-1 end(bitset<N>&); +template<size_t N> unspecified-2 end(const bitset<N>&); + +- +
++Add a new section "bitset range access" [bitset.range] +after the current section 20.5.4 [bitset.operators] with the following series of +paragraphs: +
++++ +1. In the begin and end function templates that follow, unspecified-1 +is a type that meets the requirements of a mutable random access +iterator (24.2.7 [random.access.iterators]) whose value_type is bool and +whose reference type is bitset<N>::reference. +unspecified-2 is a type that meets the requirements of a constant +random access iterator (24.2.7 [random.access.iterators]) whose value_type +is bool and whose reference type is bool. + +
++template<size_t N> unspecified-1 begin(bitset<N>&); +template<size_t N> unspecified-2 begin(const bitset<N>&); + +++2. Returns: an iterator referencing the first bit in the bitset. ++ ++template<size_t N> unspecified-1 end(bitset<N>&); +template<size_t N> unspecified-2 end(const bitset<N>&); ++ ++3. Returns: an iterator referencing one past the last bit in the +bitset. ++
+1115. va_copy missing from Standard macros table
+Section: C.2 [diff.library] Status: NAD Editorial + Submitter: Miles Zhao Opened: 2009-05-23 Last modified: 2010-10-23
+View all other issues in [diff.library].
+View all issues with NAD Editorial status.
+Discussion:
++In "Table 122 -- Standard macros" of C.2 [diff.library], which lists the 56 macros +inherited from C library, va_copy seems to be missing. But in +"Table 21 -- Header <cstdarg> synopsis" (18.10 [support.runtime]), there is. +
+ +[ +2009-10 post-Santa Cruz: +]
+ + ++Mark as Tentatively NAD Editorial, if Pete disagrees, Howard +will move to Tentatively Ready ++ +Proposed resolution:
-Ammend the tuple class template declaration in 20.5.2 [tuple.tuple] as -follows -
- --- --Add the following concept: -
- -- -auto concept AllLiteral< typename ... Types > { - requires LiteralType<Types>...; -} --ammend the constructor -
- -- -template <class... UTypes> - requires AllLiteral<Types...> - && Constructible<Types, UTypes>... - explicit tuple(UTypes...); - -template <class... UTypes> - requires !AllLiteral<Types...> - && Constructible<Types, UTypes&&>... - explicit tuple(UTypes&&...); --ammend the constructor -
- -- -template <class... UTypes> - requires AllLiteral<Types...> - && Constructible<Types, UTypes>... - tuple(tuple<UTypes...>); - -template <class... UTypes> - requires !AllLiteral<Types...> - && Constructible<Types, const UTypes&>... - tuple(const tuple<UTypes...>&); --Update the same signatures in 20.5.2.1 [tuple.cnstr], paras 3 and 5. +Add va_copy to Table 122 -- Standard macros in C.2 [diff.library].
@@ -36582,54 +39369,52 @@ Update the same signatures in 20.5.2.1 [tuple.cnstr], paras 3 and 5.
-1117. tuple copy constructor
-Section: 20.5.2.1 [tuple.cnstr] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2009-10-26
-View all other issues in [tuple.cnstr].
-View all issues with NAD Editorial status.
+1119. tuple query APIs do not support references
+Section: 20.4.2.5 [tuple.helper] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-10-23
+View all other issues in [tuple.helper].
+View all issues with NAD status.
Discussion:
-The copy constructor for the tuple template is constrained. This seems an -unusual strategy, as the copy constructor will be implicitly deleted if the -constraints are not met. This is exactly the same effect as requesting an -=default; constructor. The advantage of the latter is that it retains -triviality, and provides support for tuples as literal types if issue -1116 is also accepted. +The tuple query APIs tuple_size and +tuple_element do not support references-to-tuples. This can be +annoying when a template deduced a parameter type to be a reference, +which must be explicitly stripped with remove_reference before calling +these APIs.
-Actually, it might be worth checking with core if a constrained copy -constructor is treated as a constructor template, and as such does not -suppress the implicit generation of the copy constructor which would hide -the template in this case. +I am not proposing a resolution at this point, as there is a +combinatorial explosion with lvalue/rvalue references and +cv-qualification (see previous issue) that suggests some higher +refactoring is in order. This might be something to kick back over to +Core/Evolution. +
++Note that we have the same problem in numeric_limits.
[ -2009-05-27 Daniel adds: +2009-10 post-Santa Cruz: ]
-This would solve one half of the suggested changes in 801. +Move to Open. Alisdair to provide wording.+[ -2009-10 Santa Cruz: +2010 Rapperswil: ]
-NAD Editorial. Solved by -N2994. +Move to NAD. This is an extension after the FCD, without a clear motivation. May consider as NAD Future if motivating examples come forward.+Proposed resolution:
--Change 20.5.2 [tuple.tuple] and 20.5.2.1 [tuple.cnstr] p4: -
- -@@ -36637,10 +39422,10 @@ Change 20.5.2 [tuple.tuple] and 20.5.2.1 [tuple.cnstr] p4:requires CopyConstructible<Types>...tuple(const tuple&) = default; -
1120. New type trait - remove_all
-Section: 20.6 [meta] Status: NAD Future - Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2009-10-26
+Section: 20.7 [meta] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-10-23
View all other issues in [meta].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
Sometimes it is necessary to remove all qualifiers from a type before @@ -36694,43 +39479,148 @@ NAD Future.
-1122. Ratio values should be constexpr
-Section: 20.4.1 [ratio.ratio] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-05-25 Last modified: 2009-10-26
-View all other issues in [ratio.ratio].
-View all issues with NAD Editorial status.
+1121. Support for multiple arguments
+Section: 20.6.2 [ratio.arithmetic] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-05-25 Last modified: 2010-10-23
+View all other issues in [ratio.arithmetic].
+View all issues with NAD Future status.
Discussion:
-The values num and den in the ratio template -should be declared constexpr. +Both add and multiply could sensibly be called with more than two arguments. +The variadic template facility makes such declarations simple, and is likely +to be frequently wrapped by end users if we do not supply the variant +ourselves. +
++We deliberately ignore divide at this point as it is not transitive. +Likewise, subtract places special meaning on the first argument so I do not +suggest extending that immediately. Both could be supported with analogous +wording to that for add/multiply below. +
++Note that the proposed resolution is potentially incompatible with that +proposed for 921, although the addition of the typedef to ratio would be +equally useful.
[ -2009-10 Santa Cruz: +2009-10-30 Alisdair adds: ]
-NAD Editorial. Solved by -N2994. ++ ++The consensus of the group when we reviewed this in Santa Cruz was that +921 would proceed to Ready as planned, and the +multi-paramater add/multiply templates should be renamed as +ratio_sum and ratio_product to avoid the problem +mixing template aliases with partial specializations. +
+ ++It was also suggested to close this issue as NAD Future as it does not +correspond directly to any NB comment. NBs are free to submit a +specific comment (and re-open) in CD2 though. +
+ ++Walter Brown also had concerns on better directing the order of +evaluation to avoid overflows if we do proceed for 0x rather than TR1, +so wording may not be complete yet. +
+ +[ +Alisdair updates wording. +]
+ + +[ +2009-10-30 Howard: +]
+ + ++Moved to Tentatively NAD Future after 5 positive votes on c++std-lib.-Proposed resolution:
+ +Rationale:
-20.4.1 [ratio.ratio] +Does not have sufficient support at this time. May wish to reconsider for a +future standard.
-namespace std { - template <intmax_t N, intmax_t D = 1> - class ratio { - public: - static constexpr intmax_t num; - static constexpr intmax_t den; - }; -} + +Proposed resolution:
+ ++Add the following type traits to p3 20.6 [ratio] +
+ ++// ratio arithmetic +template <class R1, class R2> struct ratio_add; +template <class R1, class R2> struct ratio_subtract; +template <class R1, class R2> struct ratio_multiply; +template <class R1, class R2> struct ratio_divide; +template <class R1, class ... RList> struct ratio_sum; +template <class R1, class ... RList> struct ratio_product;+after 20.6.2 [ratio.arithmetic] p1: add +
+ ++ +template <class R1, class ... RList> struct ratio_sum; // declared, never defined + +template <class R1> struct ratio_sum<R1> : R1 {}; ++ ++Requires: R1 is a specialization of class template ratio ++ +template <class R1, class R2, class ... RList> + struct ratio_sum<R1, R2, RList...> + : ratio_add< R1, ratio_sum<R2, RList...>> { +}; ++ ++Requires: R1 and each element in parmater pack +RList is a specialization of class template ratio +++after 20.6.2 [ratio.arithmetic] p3: add +
+ ++ + + @@ -36738,10 +39628,10 @@ NAD Editorial. Solved bytemplate <class R1, class ... RList> struct ratio_product; // declared, never defined + +template <class R1> struct ratio_product<R1> : R1 {}; ++ ++Requires: R1 is a specialization of class template ratio ++ +template <class R1, class R2, class ... RList> + struct ratio_sum<R1, R2, RList...> + : ratio_add< R1, ratio_product<R2, RList...>> { +}; ++ ++Requires: R1 and each element in parmater pack +RList is a specialization of class template ratio ++
1124. Invalid definition of concept RvalueOf
-Section: X [concept.transform] Status: NAD Concepts - Submitter: Daniel Krügler Opened: 2009-05-28 Last modified: 2009-07-15
+Section: X [concept.transform] Status: NAD Concepts + Submitter: Daniel Krügler Opened: 2009-05-28 Last modified: 2010-10-23
View all other issues in [concept.transform].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
A recent news group @@ -36792,12 +39682,79 @@ In X [concept.transform] before p. 4 change as indicated: +
+1125. ostream_iterator does not work with movable types
+Section: 24.6.2.2 [ostream.iterator.ops] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2010-10-23
+View all issues with NAD status.
+Discussion:
++ostream_iterator has not been updated to support moveable types, in a +similar manner to the insert iterators. +Note that this is not a problem for ostreambuf_iterator, as the types it is +restricted to dealing with do not support extra-efficient moving. +
+ +[ +2009-11-10 Howard adds: +]
+ + ++Moved to Tentatively NAD after 5 positive votes on c++std-lib. Rationale +added below. ++ + +Proposed resolution:
++Add second operator= overload to class template ostream_iterator +in 24.6.2 [ostream.iterator], para 2: +
+ ++ +ostream_iterator<T,charT,traits>& operator=(const T& value); +ostream_iterator<T,charT,traits>& operator=(T&& value); ++Add a new paragraph: in 24.6.2.2 [ostream.iterator.ops]: +
+ +++ + + +ostream_iterator& operator=(T&& value); +++++-2- Effects: +
++*out_stream << std::move(value); +if(delim != 0) + *out_stream << delim; +return (*this); +Rationale:
++Several objections to move forward with this issue were voiced in the thread +starting with c++std-lib-25438. Among them is that we know of no motivating +use case to make streaming rvalues behave differently than streaming const +lvalues. +
+ + + + +
1127. rvalue references and iterator traits
-Section: 24.4.1 [iterator.traits] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2009-07-15
+Section: 24.4.1 [iterator.traits] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2010-10-23
View all other issues in [iterator.traits].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
The deprecated support for iterator_traits and legacy (unconstrained) @@ -36840,9 +39797,9 @@ template<typename T> concept_map IsReference<T&> { }
1128. Missing definition of iterator_traits<T*>
-Section: X [iterator.syn] Status: NAD Concepts - Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2009-07-16
-View all issues with NAD Concepts status.
+Section: X [iterator.syn] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
The <iterator> header synopsis declares a partial specialization of @@ -36895,9 +39852,10 @@ In X [iterator.syn] strike:
1129. istream(buf)_iterator should support literal sentinel value
-Section: 24.6.1.1 [istream.iterator.cons], 24.6.3 [istreambuf.iterator] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-05-30 Last modified: 2009-10-26
-View all issues with NAD Editorial status.
+Section: 24.6.1.1 [istream.iterator.cons], 24.6.3 [istreambuf.iterator] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-05-30 Last modified: 2010-10-23
+View all other issues in [istream.iterator.cons].
+View all issues with NAD Editorial status.
Discussion:
istream_iterator and istreambuf_iterator should support literal sentinel @@ -37075,8 +40033,7 @@ be a literal constructor.
1132. JP-30: nested exceptions
Section: 18.8.6 [except.nested] Status: NAD - Submitter: Seiji Hayashida Opened: 2009-06-01 Last modified: 2009-10-23
-View other active issues in [except.nested].
+ Submitter: Seiji Hayashida Opened: 2009-06-01 Last modified: 2010-10-23View all other issues in [except.nested].
View all issues with NAD status.
Discussion:
@@ -37291,10 +40248,10 @@ this within the timeframe allowed.
1139. Thread support library not concept enabled
-Section: 30 [thread] Status: NAD Concepts - Submitter: LWG Opened: 2009-06-15 Last modified: 2009-07-15
+Section: 30 [thread] Status: NAD Concepts + Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
View all other issues in [thread].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses US 93, JP 79, UK 333, JP 81
@@ -37313,10 +40270,10 @@ The thread chapter is not concept enabled.
1140. Numerics library not concept enabled
-Section: 26 [numerics] Status: NAD Concepts - Submitter: LWG Opened: 2009-06-15 Last modified: 2009-07-15
+Section: 26 [numerics] Status: NAD Concepts + Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
View all other issues in [numerics].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses US 84
@@ -37341,10 +40298,10 @@ which was accepted in Summit.
1141. Input/Output library not concept enabled
-Section: 27 [input.output] Status: NAD Concepts - Submitter: LWG Opened: 2009-06-15 Last modified: 2009-07-15
+Section: 27 [input.output] Status: NAD Concepts + Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
View all other issues in [input.output].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses US 85, JP 67, JP 68, JP 69, JP 72, UK 308
@@ -37363,10 +40320,10 @@ The input/output chapter is not concept enabled.
1142. Regular expressions library not concept enabled
-Section: 28 [re] Status: NAD Concepts - Submitter: LWG Opened: 2009-06-15 Last modified: 2009-07-15
+Section: 28 [re] Status: NAD Concepts + Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
View all other issues in [re].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
Addresses US 86, UK 309, UK 310
@@ -37385,10 +40342,11 @@ The regular expressions chapter is not concept enabled.
1143. Atomic operations library not concept enabled
-Section: 29 [atomics] Status: NAD Editorial - Submitter: LWG Opened: 2009-06-15 Last modified: 2009-10-26
+Section: 29 [atomics] Status: NAD Editorial + Submitter: LWG Opened: 2009-06-15 Last modified: 2010-10-23
+View other active issues in [atomics].
View all other issues in [atomics].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses US 87, UK 311
@@ -37421,10 +40379,11 @@ NAD Editorial. Solved by
1145. inappropriate headers for atomics
-Section: 29 [atomics] Status: NAD Editorial - Submitter: LWG Opened: 2009-06-16 Last modified: 2009-10-26
+Section: 29 [atomics] Status: NAD Editorial + Submitter: LWG Opened: 2009-06-16 Last modified: 2010-10-23
+View other active issues in [atomics].
View all other issues in [atomics].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 312
@@ -37467,9 +40426,10 @@ we can add corresponding headers to table 14 with a TR.
1146. "lockfree" does not say enough
-Section: 29.4 [atomics.lockfree] Status: NAD Editorial - Submitter: Jeffrey Yasskin Opened: 2009-06-16 Last modified: 2009-10-26
-View all issues with NAD Editorial status.
+Section: 29.4 [atomics.lockfree] Status: NAD Editorial + Submitter: Jeffrey Yasskin Opened: 2009-06-16 Last modified: 2010-10-23
+View all other issues in [atomics.lockfree].
+View all issues with NAD Editorial status.
Discussion:
Addresses US 88
@@ -37687,7 +40647,7 @@ otherwise. std::numeric_limits<short>::max() is related to <limits.h> __LONG_LONG_MAX__, <atomic> std::atomic_short::is_lock_free is related to -<stdatomic.h> and ATOMIC_SHORT_LOCK_FREE — +<stdatomic.h> and ATOMIC_SHORT_LOCK_FREE — end note]
1147. non-volatile atomic functions
-Section: 29.6 [atomics.types.operations] Status: NAD Editorial - Submitter: Jeffrey Yasskin Opened: 2009-06-16 Last modified: 2009-10-26
+Section: 29.6 [atomics.types.operations] Status: NAD Editorial + Submitter: Jeffrey Yasskin Opened: 2009-06-16 Last modified: 2010-10-23
+View other active issues in [atomics.types.operations].
View all other issues in [atomics.types.operations].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses US 90
@@ -37723,7 +40684,7 @@ This qualification means that volatility is preserved when applying these operations to volatile objects. It does not mean that operations on non-volatile objects become volatile. Thus, volatile qualified operations on non-volatile objects -may be merged under some conditions. —end note ] +may be merged under some conditions. —end note ]1148. Wrong argument type of I/O stream manipulators setprecision() and setw()
Section: 27.7 [iostream.format] Status: NAD - Submitter: Marc Steinbach Opened: 2009-06-20 Last modified: 2009-10-20
+ Submitter: Marc Steinbach Opened: 2009-06-20 Last modified: 2010-10-23View all other issues in [iostream.format].
View all issues with NAD status.
Discussion:
@@ -37926,12 +40887,12 @@ In 27.7.3 [std.manip], just before p. 7 change as indicated:
1149. Reformulating NonemptyRange axiom
-Section: 26.5.2.2 [rand.concept.urng] Status: NAD Concepts - Submitter: Walter Brown Opened: 2009-06-25 Last modified: 2009-07-15
-View all issues with NAD Concepts status.
+Section: X [rand.concept.urng] Status: NAD Concepts + Submitter: Walter Brown Opened: 2009-06-25 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
Discussion:
-In 26.5.2.2 [rand.concept.urng], we have the following: +In X [rand.concept.urng], we have the following:
concept UniformRandomNumberGenerator<typename G> : Callable<G> { ... @@ -37965,10 +40926,19 @@ This is not only a simpler statement of the same requirement, but also forces the requirement to be checked. +[ +Post-Rapperswil: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++Proposed resolution:
-In 26.5.2.2 [rand.concept.urng], replace the NonemptyRange axiom by: +In X [rand.concept.urng], replace the NonemptyRange axiom by:
axiom NonemptyRange(G& g) { @@ -37984,9 +40954,9 @@ In 26.5.2.2 [rand.concept.urng], replace the NonemptyRange axiom by:
1150. wchar_t, char16_t and char32_t filenames
-Section: 27.9.1.14 [fstream] Status: NAD Future - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-20
-View all issues with NAD Future status.
+Section: 27.9.1.14 [fstream] Status: NAD Future + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all issues with NAD Future status.
Discussion:
Addresses JP 73
@@ -38032,12 +41002,118 @@ NAD Future. This is a duplicate of 1153. Standard library needs review for constructors to be +explicit to avoid treatment as initializer-list constructor +Section: 17 [library], 30 [thread], D [depr] Status: NAD + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View other active issues in [library].
+View all other issues in [library].
+View all issues with NAD status.
+Discussion:
+ +Addresses DE 2
+ +Description
+Marking a constructor with explicit has semantics + even for a constructor with zero or several parameters: + Such a constructor cannot be used with list-initialization + in a copy-initialization context, see 13.3.1.7 [over.match.list]. The + standard library apparently has not been reviewed for + marking non-single-parameter constructors as explicit.
+Suggestion
+Consider marking zero-parameter and multi-parameter + constructors explicit in classes that have at least one + constructor marked explicit and that do not have an + initializer-list constructor.
+ +Notes
+Robert Klarer to address this one.
+ +[ +2009 Santa Cruz: +]
+ + ++Move to "Open". Robert Klarer has promised to provide wording. ++ +[ +2010 Pittsburgh: Moved to NAD, rationale added below. +]
+ + + + +Rationale:
++We are unaware of any cases where initializer lists cause problem in this +context, but if problems arise in the future the issue can be reopened. +
+ + +Proposed resolution:
+ + + + + +
+1154. complex should accept integral types
+Section: 26.4 [complex.numbers] Status: NAD Future + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all other issues in [complex.numbers].
+View all issues with NAD Future status.
+Discussion:
+ +Addresses FR 35
+ +Description
+Instantiations of the class + template complex<> have to be allowed for integral + types, to reflect existing practice and ISO standards + (LIA-III).
+ +Suggestion
+ +[ +2009-10-26 Proposed wording in +N3002. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Future. Rationale added. ++ + + +Rationale:
++There is no consensus for making this change at this time. +
+ + +Proposed resolution:
+Adopt +N3002. + + + + +
1155. Reference should be to C99
-Section: C.2 [diff.library] Status: NAD Editorial - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-23
+Section: C.2 [diff.library] Status: NAD Editorial + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
View all other issues in [diff.library].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses FR 38
@@ -38075,11 +41151,69 @@ NAD Editorial. Already fixed. +
+1156. Constraints on bitmask and enumeration types to be tightened
+Section: 17.5.2.1.2 [enumerated.types], 17.5.2.1.3 [bitmask.types] Status: NAD + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all issues with NAD status.
+Discussion:
+ +Addresses UK 165
+ +Description
+Constraints on + bitmask and enumeration types were supposed to be tightened + up as part of the motivation for the constexpr feature - + see paper + N2235 + for details
+Suggestion
+Adopt wording in line with the motivation + described in + N2235
+Notes
+Robert Klarer to review
+ +[ +2009 Santa Cruz: +]
+ + ++Move to Open. Ping Robert Klarer to provide wording, using N2235 as +guidance. ++ +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD. Rationale added. ++ + + +Rationale:
++UK NB did not sufficiently describe how to resolve their comment, and +therefore we cannot make a change for the FCD. If a resolution were +provided in the future, we would be happy to apply it. +
+ + +Proposed resolution:
+ + + + +
1160. future_error public constructor is 'exposition only'
-Section: 30.6.3 [futures.future_error] Status: NAD Editorial - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-26
-View all issues with NAD Editorial status.
+Section: 30.6.3 [futures.future_error] Status: NAD Editorial + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 331
@@ -38134,10 +41268,10 @@ NAD Editorial. Solved by
1161. Unnecessary unique_future limitations
-Section: 30.6.6 [futures.unique_future] Status: NAD Editorial - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-26
+Section: 30.6.6 [futures.unique_future] Status: NAD Editorial + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
View all other issues in [futures.unique_future].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 336
@@ -38197,10 +41331,10 @@ NAD Editorial. Solved by
1162. shared_future should support an efficient move constructor
-Section: 30.6.7 [future.shared_future] Status: NAD Editorial - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-26
-View all other issues in [future.shared_future].
-View all issues with NAD Editorial status.
+Section: 30.6.7 [futures.shared_future] Status: NAD Editorial + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all other issues in [futures.shared_future].
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 337
@@ -38250,10 +41384,10 @@ NAD Editorial. Solved by
1163. shared_future is inconsistent with shared_ptr
-Section: 30.6.7 [future.shared_future] Status: NAD Editorial - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-26
-View all other issues in [future.shared_future].
-View all issues with NAD Editorial status.
+Section: 30.6.7 [futures.shared_future] Status: NAD Editorial + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all other issues in [futures.shared_future].
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 338
@@ -38308,7 +41442,7 @@ Pending a paper from Anthony Williams / Detleff Volleman.NAD Editorial. Solved by -N2997. +N2997.@@ -38322,7 +41456,8 @@ NAD Editorial. Solved by
1164. promise::swap should pass by rvalue reference
Section: 30.6.5 [futures.promise] Status: NAD - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-07-17
+ Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23 +View other active issues in [futures.promise].
View all other issues in [futures.promise].
View all issues with NAD status.
Discussion:
@@ -38359,10 +41494,11 @@ NAD, by virtue of the changed rvalue rules and swap signatures from Summit.
1165. Unneeded promise move constructor
-Section: 30.6.5 [futures.promise] Status: NAD Editorial - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-26
+Section: 30.6.5 [futures.promise] Status: NAD Editorial + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View other active issues in [futures.promise].
View all other issues in [futures.promise].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
Addresses UK 343
@@ -38379,7 +41515,7 @@ NAD, by virtue of the changed rvalue rules and swap signatures from Summit. a, promise& rhs);Notes
Create an issue. Detlef will look into it. Will solicit feedback from Pablo. - Note that “rhs” argument should also be an rvalue reference in any case.
+ Note that “rhs” argument should also be an rvalue reference in any case.[ 2009-07 Frankfurt @@ -38411,9 +41547,9 @@ NAD Editorial. Solved by
1166. Allocator-specific move/copy break model of move-constructor and move-assignment
-Section: X [allocator.propagation], X [allocator.propagation.map], 23 [containers] Status: NAD Editorial - Submitter: LWG Opened: 2009-06-28 Last modified: 2009-10-26
-View all issues with NAD Editorial status.
+Section: X [allocator.propagation], X [allocator.propagation.map], 23 [containers] Status: NAD Editorial + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all issues with NAD Editorial status.
Discussion:
Addresses US 77
@@ -38468,11 +41604,10 @@ NAD Editorial. Addressed by
1167. pair<T,U> doesn't model LessThanComparable in unconstrained code even if T and U do.
-Section: 20.3.4 [pairs] Status: NAD Concepts - Submitter: Dave Abrahams Opened: 2009-07-01 Last modified: 2009-07-16
-View other active issues in [pairs].
+Section: 20.3.5 [pairs] Status: NAD Concepts + Submitter: Dave Abrahams Opened: 2009-07-01 Last modified: 2010-10-23
View all other issues in [pairs].
-View all issues with NAD Concepts status.
+View all issues with NAD Concepts status.
Discussion:
LessThanComparable requires (and provides default @@ -38534,16 +41669,16 @@ Alternative Resolution: keep the ugly, complex specification and add the
1168. Odd wording for bitset equality operators
-Section: 20.3.7.2 [bitset.members] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-07-02 Last modified: 2009-07-27
+Section: 20.5.2 [bitset.members] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-07-02 Last modified: 2010-10-23
View all other issues in [bitset.members].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
The following wording seems a little unusual to me:
-p42/43 20.3.7.2 [bitset.members] +p42/43 20.5.2 [bitset.members]
@@ -38590,7 +41725,7 @@ It's obviously editorial. There's no need for further discussion.@@ -38697,71 +41832,124 @@ the allocator should propagate from the existing container, and X().Proposed resolution:
-Change 20.3.7.2 [bitset.members] p42-43: +Change 20.5.2 [bitset.members] p42-43:
@@ -38615,9 +41750,9 @@ Change 20.3.7.2 [bitset.members] p42-43:@@ -38687,7 +41822,7 @@ container to the new container on move construction, otherwise X().Note: x is the allocator of the existing container that is being moved. The most obvious choices for the return value are move(x), if the allocator should propagate from the existing container, and X(). -— end note] +— end note]
1172. select_on_container_(copy|move)_construction over-constrained
-Section: X [allocator.concepts.members] Status: NAD Editorial - Submitter: Alberto Ganesh Barbati Opened: 2009-07-08 Last modified: 2009-10-26
-View all issues with NAD Editorial status.
+Section: X [allocator.concepts.members] Status: NAD Editorial + Submitter: Alberto Ganesh Barbati Opened: 2009-07-08 Last modified: 2010-10-23
+View all issues with NAD Editorial status.
Discussion:
I believe the two functions @@ -38670,7 +41805,7 @@ container to the new container on copy construction, otherwise X().Note: x is the allocator of the existing container that is being copied. The most obvious choices for the return value are x, if the allocator should propagate from the existing container, and X(). -— end note] +— end note]
-1174. type property predicates
-Section: 20.6.4.3 [meta.unary.prop] Status: NAD Editorial - Submitter: Jason Merrill Opened: 2009-07-16 Last modified: 2009-10-26
-View other active issues in [meta.unary.prop].
-View all other issues in [meta.unary.prop].
-View all issues with NAD Editorial status.
+1173. "Equivalence" wishy-washiness
+Section: 17 [library] Status: NAD Future + Submitter: David Abrahams Opened: 2009-07-14 Last modified: 2010-11-24
+View other active issues in [library].
+View all other issues in [library].
+View all issues with NAD Future status.
Discussion:
-I've been implementing compiler support for is_standard_layout, and -noticed a few nits about 20.6.4.3 [meta.unary.prop]: +Issue: The CopyConstructible requirements are wishy-washy. It requires +that the copy is "equivalent" to the original, but "equivalent" is never +defined. +
++I believe this to be an example of a more general lack of rigor around +copy and assignment, although I haven't done the research to dig up all +the instances. +
++It's a problem because if you don't know what CopyConstructible means, +you also don't know what it means to copy a pair of CopyConstructible +types. It doesn't prevent us from writing code, but it is a hole in our +ability to understand the meaning of copy. +
++Furthermore, I'm pretty sure that vector's copy constructor doesn't +require the elements to be EqualityComparable, so that table is actually +referring to some ill-defined notion of equivalence when it uses ==.
--
-- -There's no trait for "trivially copyable type", which is now the -property that lets you do bitwise copying of a type, and therefore seems -useful to be able to query. has_trivial_assign && -has_trivial_copy_constructor && has_trivial_destructor -is similar, but -not identical, specifically with respect to const types. -
-- -has_trivial_copy_constructor and has_trivial_assign lack the "or an -array of such a class type" language that most other traits in that -section, including has_nothrow_copy_constructor and has_nothrow_assign, -have; this seems like an oversight. -
-[ -See the thread starting with c++std-lib-24420 for further discussion. -]
- - -[ -Addressed in N2947. -]
- - -[ -2009-10 Santa Cruz: +2009 Santa Cruz: ]
-NAD Editorial. Solved by -N2984. +Move to "Open". Dave is right that this is a big issue. Paper D2987 +("Defining Move Special Member Functions", Bjarne Stroustrup and +Lawrence Crowl) touches on this but does not solve it. This issue is +discussed in Elements of Programming.+[ +2010 Rapperswil: +]
+ + ++This issue is quite vague, so it is difficult to know if and when it has been resolved. + +John Lakos wrote a paper covering this area a while back, and there is a real interest in providing some sort of clean-up in the future. + +We need a more clearly draughted issues with an addressable set of concerns, ideally with a paper proposing a resolution, but for a future revision of the standard. + +Move to Tentatively NAD Future. ++ +[ +Moved to NAD Future at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ + + + + +
+1176. Make thread constructor non-variadic
+Section: 30.3.1.2 [thread.thread.constr] Status: NAD + Submitter: Howard Hinnant Opened: 2009-07-18 Last modified: 2010-10-23
+View all other issues in [thread.thread.constr].
+View all issues with NAD status.
+Discussion:
++The variadic thread constructor is causing controversy, e.g. +N2901. +This issue has been created as a placeholder for this course of action. +
+ ++ +template <class F, class ...Args> thread(F&& f, Args&&... args); ++See 929 for wording which specifies an rvalue-ref signature but +with "decay behavior", but using variadics. +
+ +[ +2009-11-17 Moved to Tentatively NAD after 5 positive votes on c++std-lib. +Rationale added below. +]
+ +Proposed resolution:
+
Rationale:
++The (tentative) concensus of the LWG is to keep the variadic thread constructor. +
+ +
1179. Probably editorial in [structure.specifications]
-Section: 17.5.1.4 [structure.specifications] Status: NAD Editorial - Submitter: Robert Klarer Opened: 2009-07-21 Last modified: 2009-10-20
+Section: 17.5.1.4 [structure.specifications] Status: NAD Editorial + Submitter: Robert Klarer Opened: 2009-07-21 Last modified: 2010-10-23
View all other issues in [structure.specifications].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
While reviewing 971 I noted that 17.5.1.4 [structure.specifications]/7 says: @@ -38866,10 +42054,10 @@ other things that we say. We believe that this is editorial.
1184. Feature request: dynamic bitset
-Section: 23.3.6 [vector] Status: NAD Future - Submitter: Alisdair Meredith Opened: 2009-07-29 Last modified: 2009-10-26
+Section: 23.4.1 [vector] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-07-29 Last modified: 2010-10-23
View all other issues in [vector].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
Opened at Alisdair's request, steming from 96. @@ -38895,367 +42083,407 @@ don't have time to add one.
-1195. "Diagnostic required" wording is insufficient to prevent UB
-Section: 17 [library] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2009-08-18 Last modified: 2009-10-20
-View other active issues in [library].
-View all other issues in [library].
-View all issues with NAD Editorial status.
+1185. iterator categories and output iterators
+Section: 24.2 [iterator.requirements] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-07-31 Last modified: 2010-10-23
+View all other issues in [iterator.requirements].
+View all issues with NAD Editorial status.
Discussion:
-Several parts of the library use the notion of "Diagnostic required" -to indicate that -in the corresponding situation an error diagnostic should occur, e.g. -20.8.14.1.1 [unique.ptr.dltr.dflt]/2 +(wording relative to +N2723 +pending new working paper)
-void operator()(T *ptr) const; -- --Effects: calls delete on ptr. A diagnostic is required if T is an -incomplete type. ---The problem with this approach is that such a requirement is -insufficient to prevent -undefined behavior, if this situation occurs. According to 1.3.3 [defns.diagnostic] -a diagnostic message is defined as +According to p3 24.2 [iterator.requirements], Forward iterators, +Bidirectional iterators and Random Access iterators all satisfy the +requirements for an Output iterator:
-a message belonging to an implementation-defined subset of the -implementation's output messages. +XXX iterators satisfy all the requirements of the input and output iterators +and can be used whenever either kind is specified ...-which doesn't indicate any relation to an ill-formed program. In fact, -"compiler warnings" -are a typical expression of such diagnostics. This means that above -wording can be interpreted -by compiler writers that they satisfy the requirements of the standard -if they just produce -such a "warning", if the compiler happens to compile code like this: +Meanwhile, p4 goes on to contradict this:
-+#include <memory> ++Besides its category, a forward, bidirectional, or random access +iterator can also be mutable or constant... +-struct Ukn; // defined somewhere else -Ukn* create_ukn(); // defined somewhere else - -int main() { - std::default_delete<Ukn>()(create_ukn()); -} -+... Constant iterators do not satisfy the requirements for output iterators +-In this and other examples discussed here it was the authors intent to -guarantee that the -program is ill-formed with a required diagnostic, therefore such -wording should be used instead. -According to the general rules outlined in 1.4 [intro.compliance] it -should be sufficient -to require that these situations produce an ill-formed program and the -"diagnostic -required" part should be implied. The proposed resolution also -suggests to remove -several redundant wording of "Diagnostics required" to ensure that -the absence of -such saying does not cause a misleading interpretation. +The latter seems to be the overriding concern, as the iterator tag +hierarchy does not define forward_iterator_tag as multiply derived from +both input_iterator_tag and output_iterator_tag. +
+ ++The work on concepts for iterators showed us that output iterator really +is fundamentally a second dimension to the iterator categories, rather +than part of the linear input -> forward -> bidirectional -> +random-access sequence. It would be good to clear up these words to +reflect that, and separately list output iterator requirements in the +requires clauses for the appropriate algorithms and operations.
[ -2009 Santa Cruz: +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3066. +
+ + +Proposed resolution:
+ + + + + +
+1186. Forward list could model a stack
+Section: 23.5.3 [stack] Status: NAD Concepts + Submitter: Alisdair Meredith Opened: 2009-07-31 Last modified: 2010-10-23
+View all issues with NAD Concepts status.
+Discussion:
++The library template forward_list could easily model the idea of a +stack, where the operations work on the front of the list rather than +the back. However, the standard library stack adaptor cannot support +this. +
+ ++It would be relatively easy to write a partial specialization for stack +to support forward_list, but that opens the question of which header to +place it in. A much better solution would be to add a concept_map for +the StackLikeContainer concept to the <forward_list> header and then +everything just works, including a user's own further uses in a +stack-like context. +
+ ++Therefore while I am submitting the issue now so that it is on record, I +strongly recommend we resolve as "NAD Concepts" as any non-concepts +based solution will be inferior to the final goal, and the feature is +not so compelling it must be supported ahead of the concepts-based +library. +
+ +[ +2009-11-02 Howard adds: ]
---Move to NAD. -
-It's not clear that there's any important difference between -"ill-formed" and "diagnostic required". From 1.4 [intro.compliance], -1.3.5 [defns.ill.formed], and 1.3.15 [defns.well.formed] it appears -that an ill-formed program is one -that is not correctly constructed according to the syntax rules and -diagnosable semantic rules, which means that... "a conforming -implementation shall issue at least one diagnostic message." The -author's intent seems to be that we should be requiring a fatal error -instead of a mere warning, but the standard just doesn't have language -to express that distinction. The strongest thing we can ever require is -a "diagnostic". -
--The proposed rewording may be a clearer way of expressing the same thing -that the WP already says, but such a rewording is editorial. -
+Moved to Tentatively NAD Concepts after 5 positive votes on c++std-lib.[ -2009 Santa Cruz: -]
- --Considered again. Group disagrees that the change is technical, but likes -it editorially. Moved to NAD Editorial. -+Rationale:
++Any non-concepts based solution will be inferior to the final goal, and the +feature is not so compelling it must be supported ahead of the concepts-based +library. +
Proposed resolution:
--
- @@ -39263,9 +42491,9 @@ an exhaustive review of this issue.]- + + + + + +
-
+1188. Unordered containers should have a minimum load factor as well as a maximum
+Section: 23.2.5 [unord.req], 23.7 [unord] Status: NAD Future + Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2010-11-24
+View other active issues in [unord.req].
+View all other issues in [unord.req].
+View all issues with NAD Future status.
+Discussion:
-Change 20.4 [ratio]/2 as indicated: +Unordered associative containers have a notion of a maximum load factor: +when the number of elements grows large enough, the containers +automatically perform a rehash so that the number of elements per bucket +stays below a user-specified bound. This ensures that the hash table's +performance characteristics don't change dramatically as the size +increases.
++For similar reasons, Google has found it useful to specify a minimum +load factor: when the number of elements shrinks by a large enough, the +containers automatically perform a rehash so that the number of elements +per bucket stays above a user-specified bound. This is useful for two +reasons. First, it prevents wasting a lot of memory when an unordered +associative container grows temporarily. Second, it prevents amortized +iteration time from being arbitrarily large; consider the case of a hash +table with a billion buckets and only one element. (This was discussed +even before TR1 was published; it was TR issue 6.13, which the LWG +closed as NAD on the grounds that it was a known design feature. +However, the LWG did not consider the approach of a minimum load +factor.) +
+ ++The only interesting question is when shrinking is allowed. In principle +the cleanest solution would be shrinking on erase, just as we grow on +insert. However, that would be a usability problem; it would break a +number of common idioms involving erase. Instead, Google's hash tables +only shrink on insert and rehash. +
+ ++The proposed resolution allows, but does not require, shrinking in +rehash, mostly because a postcondition for rehash that involves the +minimum load factor would be fairly complicated. (It would probably have +to involve a number of special cases and it would probably have to +mention yet another parameter, a minimum bucket count.) +
+ ++The current behavior is equivalent to a minimum load factor of 0. If we +specify that 0 is the default, this change will have no impact on +backward compatibility. +
+ + +[ +2010 Rapperswil: +]
-Throughout this subclause, the template argument types R1 and R2 shall -be specializations of the ratio -template, else the program is ill-formed.-Diagnostic required.+This seems to a useful extension, but is too late for 0x. + +Move to Tentatively NAD Future.- +
- -[ +Moved to NAD Future at 2010-11 Batavia +]
+ + + + +Proposed resolution:
-Change 20.4.1 [ratio.ratio]/1 as indicated: -
- --The template argument D shall not be zero, and the absolute values of -the template arguments N and D shall -be representable by type intmax_t, else the program is ill-formed.
- - -Diagnostic required.[..] -- -
- --Change 20.4.2 [ratio.arithmetic]/1 as indicated: +Add two new rows, and change rehash's postcondition in the unordered +associative container requirements table in 23.2.5 [unord.req]:
-Implementations may use other algorithms to compute these values. -If overflow would occur-s,a diagnostic shall -be issuedthe program shall be ill-formed. ++
Table 87 — Unordered associative container requirements +(in addition to container) + ++ +Expression Return type Assertion/note pre-/post-condition +Complexity ++ + ++a.min_load_factor() + ++float + ++Returns a non-negative number that the container attempts to keep the +load factor greater than or equal to. The container automatically +decreases the number of buckets as necessary to keep the load factor +above this number. + ++constant + ++ +a.min_load_factor(z) +void +Pre: z shall be non-negative. Changes the container's minimum +load factor, using z as a hint. [Footnote: the minimum +load factor should be significantly smaller than the maximum. +If z is too large, the implementation may reduce it to a more sensible value.] + ++constant + ++ +a.rehash(n) +void ++Post: a.bucket_count() >= n, and a.size() <= a.bucket_count() +* a.max_load_factor(). [Footnote: It is intentional that the +postcondition does not mention the minimum load factor. +This member function is primarily intended for cases where the user knows +that the container's size will increase soon, in which case the container's +load factor will temporarily fall below a.min_load_factor().] + ++a.bucket_cout > a.size() / a.max_load_factor() and a.bucket_count() +>= n. +++Average case linear in a.size(), worst case quadratic. + +- - -
-Change 20.4.3 [ratio.comparison]/2 as indicated: -
- --[...] Implementations may use other algorithms to compute this relationship -to avoid overflow. If -overflow- - -occurs, a diagnostic is requiredwould occur, -the program shall be -ill-formed. -- -
- --Change 20.8.14.1.1 [unique.ptr.dltr.dflt]/2 as indicated: +Add a footnote to 23.2.5 [unord.req] p12:
- --Effects: calls delete on ptr.
-A diagnostic is required if T is an -incomplete type.+The insert members shall not affect the validity of references to +container elements, but may invalidate all iterators to the container. +The erase members shall invalidate only iterators and references to the +erased elements.-Remarks: The program shall be ill-formed, if T is an incomplete type. -
++[A consequence of these requirements is that while insert may change the +number of buckets, erase may not. The number of buckets may be reduced +on calls to insert or rehash.] +- -
-Change 20.8.14.1.2 [unique.ptr.dltr.dflt1]/1 as indicated: +Change paragraph 13:
---operator() calls delete[] on ptr.
- -A diagnostic is required if T -is an incomplete type.--Remarks: The program shall be ill-formed, if T is an incomplete type. -
+The insert members shall not affect the validity of iterators if +(N+n) < z * Bzmin * B <= (N+n) <= zmax * B, +where N is the number of elements in +the container prior to the insert operation, n is the number of +elements inserted, B is the container's bucket count, +zmin is the container's minimum load factor, +and zmax is the container's maximum load factor.- - -
-Accept 932. +Add to the unordered_map class synopsis in section 23.7.1 [unord.map], +the unordered_multimap class synopsis +in 23.7.2 [unord.multimap], the unordered_set class synopsis in +23.7.3 [unord.set], and the unordered_multiset class synopsis +in 23.7.4 [unord.multiset]:
-[This is a bullet here to confirm that this list is -an exhaustive review of this issue.]
+-+float min_load_factor() const; +void min_load_factor(float z); +- - -
-Accept 950. -
- -[This is a bullet here to confirm that this list is -an exhaustive review of this issue.]
- -- -
--Change 20.8.14.3 [unique.ptr.runtime]/1 as indicated: +In 23.7.1.1 [unord.map.cnstr], 23.7.2.1 [unord.multimap.cnstr], 23.7.3.1 [unord.set.cnstr], and +23.7.4.1 [unord.multiset.cnstr], change:
-[..] --- Conversions among different types of unique_ptr<T[], D> or to or -from the non-array forms of -unique_ptr-are disallowed (diagnostic required)-produce an ill-formed program. -[..] +... max_load_factor() returns 1.0 and +min_load_factor() returns 0.- + + +
- -
+1190. Setting the maximum load factor should return the previous value
+Section: 23.2.5 [unord.req], 23.7 [unord] Status: NAD + Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2010-11-24
+View other active issues in [unord.req].
+View all other issues in [unord.req].
+View all issues with NAD status.
+Discussion:
-Change 20.9.3 [time.duration]/2 as indicated: +The unordered associative container requirements table specifies that +a.set_max_load_factor(z) has return type void. However, there is a +useful piece of information to return: the previous value. Users who +don't need it can always ignore it. +
+ + +[ +2010 Rapperswil: +]
+ + ++The benefit seems minor, while breaking with the getter/setter idiom these overloads support. + +Move to Tentatively NAD. ++ +[ +Moved to NAD at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++In the unordered associative container requirements table, change:
-Requires: Rep shall be an arithmetic type or a class emulating an -arithmetic type.- -If a program -instantiates duration with a duration type for the template argument -Rep a diagnostic is required.-Remarks: The program shall be ill-formed, if duration is -instantiated with a duration type for the template argument Rep. ++
Table 87 — Unordered associative container requirements +(in addition to container) ++ + +Expression Return type Assertion/note pre-/post-condition +Complexity ++ +a.max_load_factor(z) ++ voidfloatPre: z shall be positive. Changes the container's maximum + +loadload factor, using z as a hint. +Returns: the previous value of +a.max_load_factor(). ++constant + ++ - - -
-Change 20.9.3 [time.duration]/3+4 as indicated: -
- --- - --3
RequiresRemarks: Period shall be a -specialization of ratio,diagnostic -requiredelse the program shall be ill-formed. +Change the return type of set_max_load_factor +in the class synopses in 23.7.1 [unord.map], 23.7.2 [unord.multimap], 23.7.3 [unord.set], +and 23.7.4 [unord.multiset].-4
-RequiresRemarks: Period::num shall be -positive,diagnostic -requiredelse the program shall be ill-formed. +If issue 1188 is also accepted, make the same changes for +min_load_factor.- -
- --Accept 1177 bullet 1. -
- -[This is a bullet here to confirm that this list is -an exhaustive review of this issue.]
- - -- -
- --Accept 1177 bullet 2. -
- -[This is a bullet here to confirm that this list is -an exhaustive review of this issue.]
- - -- -
- --Accept 1177 bullet 3. -
- -[This is a bullet here to confirm that this list is -an exhaustive review of this issue.]
- - -- -
- --Change 20.9.4 [time.point]/2 as indicated: -
- --Duration shall be an instance of duration, else the -program shall be ill-formed.-Diagnostic required.-- -
- --Change 20.9.4.1 [time.point.cons]/3 as indicated: -
- --- --
- -Requires: Duration2 shall be implicitly convertible to duration. -Diagnostic required.--Remarks: Duration2 shall be implicitly convertible to duration, -else this constructor shall -not participate in overload resolution. -
-[This suggestion seems more in sync to the several suggested changes -of 1177, 950, etc.]
- -- -
- --Accept 1177 bullet 4. -
- -[This is a bullet here to confirm that this list is -an exhaustive review of this issue.]
- - -
1196. move semantics undefined for priority_queue
-Section: 23.3.5.2.1 [priqueue.cons] Status: NAD Editorial - Submitter: Alisdair Meredith Opened: 2009-08-19 Last modified: 2009-10-20
-View all issues with NAD Editorial status.
+Section: 23.5.2.1 [priqueue.cons] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-08-19 Last modified: 2010-10-23
+View all issues with NAD Editorial status.
Discussion:
The class template priority_queue declares signatures for a move @@ -39281,7 +42509,7 @@ specifying their behaviour.
-1194 provides wording that solves this issue. +1194 provides wording that solves this issue.[ @@ -39290,7 +42518,7 @@ specifying their behaviour.
-Mark NAD Editorial, solved by issue 1194. +Mark NAD Editorial, solved by issue 1194.@@ -39301,11 +42529,513 @@ Mark NAD Editorial, solved by issue 1200. "surprising" char_traits<T>::int_type requirements +Section: 21.2.2 [char.traits.typedefs] Status: NAD + Submitter: Sean Hunt Opened: 2009-09-03 Last modified: 2010-11-24
+View all other issues in [char.traits.typedefs].
+View all issues with NAD status.
+Discussion:
++The footnote for int_type in 21.2.2 [char.traits.typedefs] says that +
+ ++If eof() +can be held in char_type then some iostreams implementations may give +surprising results. ++ ++This implies that int_type should be a superset of +char_type. However, the requirements for char16_t and char32_t define +int_type to be equal to int_least16_t and int_least32_t respectively. +int_least16_t is likely to be the same size as char_16_t, which may lead +to surprising behavior, even if eof() is not a valid UTF-16 code unit. +The standard should not prescribe surprising behavior, especially +without saying what it is (it's apparently not undefined, just +surprising). The same applies for 32-bit types. +
+ ++I personally recommend that behavior be undefined if eof() is a member +of char_type, and another type be chosen for int_type (my personal +favorite has always been a struct {bool eof; char_type c;}). +Alternatively, the exact results of such a situation should be defined, +at least so far that I/O could be conducted on these types as long as +the code units remain valid. Note that the argument that no one streams +char16_t or char32_t is not really valid as it would be perfectly +reasonable to use a basic_stringstream in conjunction with UTF character +types. +
+ +[ +2009-10-28 Ganesh provides two possible resolutions and expresses a preference +for the second: +]
+ + +++ + ++
+- +
++Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with: +
+ ++The member eof() shall return+ +an implementation-defined +constant that cannot appear as a valid UTF-16 code unit+UINT_LEAST16_MAX [Note: this value is guaranteed to +be a permanently reserved UCS-2 code position if UINT_LEAST16_MAX == +0xFFFF and it's not a UCS-2 code position otherwise — end +note]. ++Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with: +
+ ++The member eof() shall return+an implementation-defined constant that +cannot appear as a Unicode code point+ +UINT_LEAST32_MAX [Note: this value is guaranteed to be a +permanently reserved UCS-4 code position if UINT_LEAST32_MAX == +0xFFFFFFFF and it's not a UCS-4 code position otherwise — end +note]. +- +
++In 21.2.3.2 [char.traits.specializations.char16_t], in the +definition of char_traits<char16_t> replace the definition of nested +typedef int_type with: +
+ ++ +namespace std { + template<> struct char_traits<char16_t> { + typedef char16_t char_type; + typedefuint_least16_tuint_fast16_t int_type; + ... ++Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with: +
+ ++The member eof() shall return+ +an implementation-defined +constant that cannot appear as a valid UTF-16 code unit+UINT_FAST16_MAX [Note: this value is guaranteed to +be a permanently reserved UCS-2 code position if UINT_FAST16_MAX == +0xFFFF and it's not a UCS-2 code position otherwise — end +note]. ++In 21.2.3.3 [char.traits.specializations.char32_t], in the +definition of char_traits<char32_t> replace the definition of nested +typedef int_type with: +
+ ++ +namespace std { + template<> struct char_traits<char32_t> { + typedef char32_t char_type; + typedefuint_least32_tuint_fast32_t int_type; + ... ++Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with: +
+ ++The member eof() shall return+an implementation-defined constant that +cannot appear as a Unicode code point+ +UINT_FAST32_MAX [Note: this value is guaranteed to be a +permanently reserved UCS-4 code position if UINT_FAST32_MAX == +0xFFFFFFFF and it's not a UCS-4 code position otherwise — end +note]. +[ +2010 Rapperswil: +]
+ + ++This seems an overspecification, and it is not clear what problem is being solved - these values can be used portably by using the named functions; there is no need for the value itself to be portable. + +Move to Tentatively NAD. ++ +[ +Moved to NAD at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++
+ + + + + +
+1201. Do we always want to unwrap ref-wrappers in make_tuple
+Section: 20.4.2.4 [tuple.creation], 20.3.5 [pairs] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-09-05 Last modified: 2010-10-23
+View all other issues in [tuple.creation].
+View all issues with NAD Future status.
+Discussion:
++Spotting a recent thread on the boost lists regarding collapsing +optional representations in optional<optional<T>> instances, I wonder if +we have some of the same issues with make_tuple, and now make_pair? +
+ ++Essentially, if my generic code in my own library is handed a +reference_wrapper by a user, and my library in turn delegates some logic +to make_pair or make_tuple, then I am going to end up with a pair/tuple +holding a real reference rather than the intended reference wrapper. +
+ ++There are two things as a library author I can do at this point: +
+ ++
+ +- +document my library also has the same reference-wrapper behaviour as +std::make_tuple +
+- +roll my own make_tuple that does not unwrap rereferences, a lost +opportunity to re-use the standard library. +
++(There may be some metaprogramming approaches my library can use to wrap +the make_tuple call, but all will be significantly more complex than +simply implementing a simplified make_tuple.) +
+ ++Now I don't propose we lose this library facility, I think unwrapping +references will be the common behaviour. However, we might want to +consider adding another overload that does nothing special with +ref-wrappers. Note that we already have a second overload of make_tuple +in the library, called tie. +
+ +[ +2009-09-30 Daniel adds: +]
+ + +++ ++I suggest to change the currently proposed paragraph for +make_simple_pair +
+ ++ +template<typename... Types> + pair<typename decay<Types>::type...> make_simple_pair(Types&&... t); +++++
+Type requirements: sizeof...(Types) == 2.+Remarks: The program shall be ill-formed, if +sizeof...(Types) != 2. ++... +
++or alternatively (but with a slightly different semantic): +
+ +++ ++Remarks: If sizeof...(Types) != 2, this function shall not +participate in overload resolution. +++to follow a currently introduced style and because the library does +not have yet a specific "Type requirements" element. If such thing +would be considered as useful this should be done as a separate +issue. Given the increasing complexity of either of these wordings +it might be preferable to use the normal two-argument-declaration +style again in either of the following ways: +
+ ++
+ +- +
+template<class T1, class T2> +pair<typename decay<T1>::type, typename decay<T2>::type> +make_simple_pair(T1&& t1, T2&& t2); ++- +
+template<class T1, class T2> +pair<V1, V2> make_simple_pair(T1&& t1, T2&& t2); +++Let V1 be typename decay<T1>::type and V2 be +typename decay<T2>::type. ++[ +2009-10 post-Santa Cruz: +]
+ + ++Mark as Tentatively NAD Future. ++ + + +Rationale:
++Does not have sufficient support at this time. May wish to reconsider for a +future standard. +
+ + +Proposed resolution:
++Add the following function to 20.3.5 [pairs] and signature in +appropriate synopses: +
+ ++ +template<typename... Types> + pair<typename decay<Types>::type...> make_simple_pair(Types&&... t); +++++Type requirements: sizeof...(Types) == 2. +
++Returns: pair<typename decay<Types>::type...>(std::forward<Types>(t)...). +
+[ +Draughting note: I chose a variadic representation similar to make_tuple +rather than naming both types as it is easier to read through the +clutter of metaprogramming this way. Given there are exactly two +elements, the committee may prefer to draught with two explicit template +type parameters instead +]
+ + ++Add the following function to 20.4.2.4 [tuple.creation] and +signature in appropriate synopses: +
+ ++ + + + + +template<typename... Types> + tuple<typename decay<Types>::type...> make_simple_tuple(Types&&... t); +++++Returns: tuple<typename decay<Types>::type...>(std::forward<Types>(t)...). +
+
+1202. integral_constant needs a spring clean
+Section: 20.7.3 [meta.help] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-09-05 Last modified: 2010-10-23
+View all other issues in [meta.help].
+View all issues with NAD status.
+Discussion:
++The specification of integral_constant has been inherited +essentially unchanged from TR1: +
+ ++ +template <class T, T v> +struct integral_constant { + static const T value = v; + typedef T value_type; + typedef integral_constant<T,v> type; +}; ++In light of 0x language changes there are several things we might +consider changing, notably the form of specification for value. +
+ ++The current form requires a static data member have storage allocated +for it, where we could now implement without this using the new enum +syntax: +
+ ++ +template <class T, T v> +struct integral_constant { + enum : T { value = v }; + typedef T value_type; + typedef integral_constant type; +}; ++The effective difference between these two implementation is: +
+ ++
+ +- +No requirement to allocate storage for data member (which we hope but do +not guarantee compilers strip today) +
+ +- +You can no longer take the address of the constant as +&integral_constant<T,v>::value; +
++Also note the editorial change to drop the explicit qualification of +integral_constant in the typedef type. This makes it quite clear we +mean the current instantiation, and cannot be mistaken for a recursive +metaprogram. +
+ ++Even if we don't mandate this implementation, it would be nice to give +vendors freedom under QoI to choose their preferred representation. +
+ ++The other side of this issue is if we choose to retain the static +constant form. In that case we should go further and insist on +constexpr, much like we did throughout numeric_limits: +
+ ++ +template <class T, T v> +struct integral_constant { + static constexpr T value = v; + typedef T value_type; + typedef integral_constant type; +}; ++[Footnote] It turns out constexpr is part of the Tentatively Ready +resolution for 1019. I don't want to interfere with that issue, but +would like a new issue to consider if the fixed-base enum implementation +should be allowed. +
+ +[ +2009-09-05 Daniel adds: +]
+ + +++ ++I think that the suggested resolution is incomplete and +may have some possible unwanted side-effects. To understand +why, note that integral_constant is completely specified +by code in 20.7.3 [meta.help]. While this is usually considered +as a good thing, let me give a possible user-defined +specialization that would break given the suggested changes: +
+ ++ +enum NodeColor { Red, Black }; + +std::integral_constant<NodeColor, Red> red; ++The reason why that breaks is due to the fact that +current core language rules does only allow integral +types as enum-bases, see 7.2 [dcl.enum]/2. +
+ ++So, I think that we cannot leave the implementation the +freedom to decide which way they would like to provide +the implementation, because that is easily user-visible +(I don't speak of addresses, but of instantiation errors), +therefore if applied, this should be either specified or +wording must be added that gives a note about this +freedom of implementation. +
+ ++Another possible disadvantage seems to me that user-expectations +are easy to disappoint if they see a failure +of the test +
+ ++ +assert(typeid(std::integral_constant<int, 0>::value) == typeid(int)); ++or of +
+ ++ +static_assert(std::is_same<decltype(std::integral_constant<int, 0>::value), const int>::value, "Bad library"); +[ +2010-01-14 Moved to Tentatively NAD after 5 positive votes on c++std-lib. +]
+ + + + +Rationale:
++We think that the suggested resolution is incomplete and may have some possible +unwanted side-effects. (see Daniel's 2009-09-05 comment for details). +
+ + +Proposed resolution:
+ + + + +
1203. More useful rvalue stream insertion
-Section: 27.7.2.9 [ostream.rvalue], 27.7.1.6 [istream.rvalue] Status: NAD Future - Submitter: Howard Hinnant Opened: 2009-09-06 Last modified: 2009-10-20
-View all issues with NAD Future status.
+Section: 27.7.2.9 [ostream.rvalue], 27.7.1.6 [istream.rvalue] Status: NAD Future + Submitter: Howard Hinnant Opened: 2009-09-06 Last modified: 2010-10-23
+View all issues with NAD Future status.
Discussion:
27.7.2.9 [ostream.rvalue] was created to preserve the ability to insert @@ -39434,12 +43164,291 @@ and only if Ostream is not an lvalue reference type and is derived from +
+1210. iterator reachability should not require a container
+Section: 24.2 [iterator.requirements] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2010-10-23
+View all other issues in [iterator.requirements].
+View all issues with NAD Editorial status.
+Discussion:
++p6 Iterator requirements 24.2 [iterator.requirements] +
+ ++An iterator j is called reachable from an iterator i if and only if +there is a finite sequence of applications of the expression ++i that +makes i == j. If j is reachable from i, they refer to the same +container. ++ ++A good example would be stream iterators, which do not refer to a +container. Typically, the end iterator from a range of stream iterators +will compare equal for many such ranges. I suggest striking the second +sentence. +
+ ++An alternative wording might be: +
+ ++If j is reachable from i, and both i and +j are dereferencable iterators, then they refer to the same +range. ++ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3066. +
+ + +Proposed resolution:
++Change 24.2 [iterator.requirements], p6: +
+ ++An iterator j is called reachable from an iterator +i if and only if there is a finite sequence of applications of +the expression ++i that makes i == j.+ + + + + +If +j is reachable from i, they refer to the same +container.+
+1211. move iterators should be restricted as input iterators
+Section: 24.5.3.1 [move.iterator] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2010-10-23
+View all other issues in [move.iterator].
+View all issues with NAD Editorial status.
+Discussion:
++I contend that while we can support both bidirectional and random access +traversal, the category of a move iterator should never be better than +input_iterator_tag. +
+ ++The contentious point is that you cannot truly have a multipass property +when values are moved from a range. This is contentious if you view a +moved-from object as still holding a valid value within the range. +
+ ++The second reason comes from the Forward Iterator requirements table: +
+ +++ ++Forward iterators 24.2.5 [forward.iterators] +
+ ++Table 102 -- Forward iterator requirements +
+ ++For expression *a the return type is: +"T& if X is mutable, otherwise const T&" +++There is a similar constraint on a->m. +
+ ++There is no support for rvalue references, nor do I believe their should +be. Again, opinions may vary but either this table or the definition of +move_iterator need updating. +
+ ++Note: this requirement probably need updating anyway if we wish to +support proxy iterators but I am waiting to see a new working paper +before filing that issue. +
+ +[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Open. Howard to put his rationale mentioned above into the issue +as a note. ++ +[ +2009-10-26 Howard adds: +]
+ + +++ ++vector::insert(pos, iter, iter) is significantly more effcient when +iter is a random access iterator, as compared to when it is an +input iterator. +
+ ++When iter is an input iterator, the best algorithm +is to append the inserted range to the end of the vector using +push_back. This may involve several reallocations before the input +range is exhausted. After the append, then one can use std::rotate +to place the inserted range into the correct position in the vector. +
+ ++But when iter is a random access iterator, the best algorithm +is to first compute the size of the range to be inserted (last - first), +do a buffer reallocation if necessary, scoot existing elements in the vector +down to make the "hole", and then insert the new elements directly to their correct +place. +
+ ++The insert-with-random-access-iterators algorithm is considerably more efficient +than the insert-with-input-iterators algorithm ++ ++Now consider: +
+ ++ +vector<A> v; +// ... build up a large vector of A ... +vector<A> temp; +// ... build up a large temporary vector of A to later be inserted ... +typedef move_iterator<vector<A>::iterator> MI; +// Now insert the temporary elements: +v.insert(v.begin() + N, MI(temp.begin()), MI(temp.end())); ++A major motivation for using move_iterator in the above example is the +expectation that A is cheap to move but expensive to copy. I.e. the +customer is looking for high performance. If we allow vector::insert +to subtract two MI's to get the distance between them, the customer enjoys +substantially better performance, compared to if we say that vector::insert +can not subtract two MI's. +
+ ++I can find no rationale for not giving this performance boost to our customers. +Therefore I am strongly against restricting move_iterator to the +input_iterator_tag category. +
+ ++I believe that the requirement that forward +iterators have a dereference that returns an lvalue reference to cause unacceptable +pessimization. For example vector<bool>::iterator also does not return +a bool& on dereference. Yet I am not aware of a single vendor that +is willing to ship vector<bool>::iterator as an input iterator. +Everyone classifies it as a random access iterator. Not only does this not +cause any problems, it prevents significant performance problems. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3066. +
+ + +Proposed resolution:
++Class template move_iterator 24.5.3.1 [move.iterator] +
+ ++ + + + + +namespace std { +template <class Iterator> +class move_iterator { +public: + ... + typedeftypename iterator_traits<Iterator>::iterator_categoryinput_iterator_tag iterator_category; +
+1212. result of post-increment/decrement operator
+Section: 24.2 [iterator.requirements] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2009-09-18 Last modified: 2010-10-23
+View all other issues in [iterator.requirements].
+View all issues with NAD Editorial status.
+Discussion:
++Forward iterator and bidirectional iterator place different requirements on the result of post-increment/decrement operator. The same form should be used in each case. +
+ ++Merging row from: +
+ ++ +Table 102 -- Forward iterator requirements +Table 103 -- Bidirectional iterator requirements + + r++ : convertible to const X& + r-- : convertible to const X& + + *r++ : T& if X is mutable, otherwise const T& + *r-- : convertible to T +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3066. +
+ + +Proposed resolution:
+ + + + +
1217. Quaternion support
-Section: 26.4 [complex.numbers] Status: NAD Future - Submitter: Ted Shaneyfelt Opened: 2009-09-26 Last modified: 2009-10-26
+Section: 26.4 [complex.numbers] Status: NAD Future + Submitter: Ted Shaneyfelt Opened: 2009-09-26 Last modified: 2010-10-23
View all other issues in [complex.numbers].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
Concerning mathematically proper operation of the type: @@ -39548,10 +43557,553 @@ NAD Future. There is no consensus or time to move this into C++0X. +
+1219. unique_lock::lock and resource_deadlock_would_occur
+Section: 30.4.2.2.2 [thread.lock.unique.locking] Status: Dup + Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
+View all other issues in [thread.lock.unique.locking].
+View all issues with Dup status.
+Duplicate of: 1159
+Discussion:
+ + + ++unique_lock::lock and friends raise +"resource_deadlock_would_occur -- if the current thread already +owns the mutex (i.e., on entry, owns is true)." 1) +The current thread owning a mutex is not the same as any particular +unique_lock::owns being true. 2) There's no need to +raise this exception for a recursive_mutex if owns is +false. 3) If owns is true, we need to raise some +exception or the unique_lock will lose track of whether to unlock itself +on destruction, but "deadlock" isn't it. For (3), s/bool owns/int +ownership_level/ would fix it. +
+ +[ +2009-11-11 Alisdair notes that this issue is very closely related to 1159, +if not a dup. +]
+ + +[ +2009-11-14 Moved to Tentatively Dup after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+ + + + + +
+1223. condition_variable_any lock matching?
+Section: 30.5.2 [thread.condition.condvarany] Status: NAD + Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
+View all other issues in [thread.condition.condvarany].
+View all issues with NAD status.
+Discussion:
++For condition_variable_any, must all lock arguments to concurrent wait calls +"match" in some way, similar to the requirement in +30.5.1 [thread.condition.condvar] that lock.mutex() returns the same +value for each of the lock arguments supplied by all concurrently +waiting threads (via wait or timed_wait)? +
+ +[ +2010-02-12 Moved to Tentatively NAD after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + + +Rationale:
++The rationale is that it doesn't matter, and you can't check: the lock types may +be different, or the same and user-defined, so the implementation must provide +internal synchronization anyway. +
+ + +Proposed resolution:
+ + + + + +
+1224. condition_variable_any support for recursive mutexes?
+Section: 30.5.2 [thread.condition.condvarany] Status: NAD + Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
+View all other issues in [thread.condition.condvarany].
+View all issues with NAD status.
+Discussion:
++For condition_variable_any, are recursive mutexes allowed? (I think "no") +
+ +[ +2009-11-17 Moved to Tentatively NAD after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + +Proposed resolution:
+ + +Rationale:
++condition_variable_any::wait accepts any type of mutex. It calls +unlock precisely once on entry and lock precisely once on +exit. It is up to the user to ensure that this provides the required +synchronization. Use of a recursive mutex is safe if either its lock count is 1, +so after the single unlock it can be acquired by another thread, or another +mechanism is used to synchronize the data. +
+ + + + + +
+1225. C++0x result_of issue
+Section: X [func.ret] Status: NAD Editorial + Submitter: Sebastian Gesemann Opened: 2009-10-05 Last modified: 2010-10-23
+View all other issues in [func.ret].
+View all issues with NAD Editorial status.
+Discussion:
++I think the text about std::result_of could be a little more precise. +Quoting from +N2960... +
+ +++ ++X [func.ret] Function object return types +
+ +template<class> class result_of; + +template<class Fn, class... ArgTypes> +class result_of<Fn(ArgTypes...)> { +public: + typedef see below type; +}; ++ ++Given an rvalue fn of type Fn and values t1, t2, +..., tN of types T1, T2, ... TN in ArgTypes +respectivly, the type member is the result type of the +expression fn(t1,t2,...,tN). the values ti are lvalues +when the corresponding type Ti is an lvalue-reference type, and +rvalues otherwise. +
++This text doesn't seem to consider lvalue reference types for Fn. +Also, it's not clear whether this class template can be used for +"SFINAE" like std::enable_if. Example: +
+ ++ +template<typename Fn, typename... Args> +typename std::result_of<Fn(Args...)>::type +apply(Fn && fn, Args && ...args) +{ + // Fn may be an lvalue reference, too + return std::forward<Fn>(fn)(std::forward<Args>(args)...); +} ++Either std::result_of<...> can be instantiated and simply may not have +a typedef "type" (-->SFINAE) or instantiating the class template for +some type combinations will be a "hard" compile-time error. +
+ +[ +2010-02-14 Daniel adds: +]
+ + ++This issue should be considered resolved by 1255 and 1270. The wish to change result_of into a compiler-support +trait was beyond the actual intention of the submitter Sebastian. ++ +[ +2010 Pittsburgh: Moved to NAD Editorial, rationale added below. +]
+ + + + +Rationale:
++Solved by 1270. +
+ + +Proposed resolution:
+ +[ +These changes will require compiler support +]
+ + ++Change X [func.ret]: +
+ ++ +template<class> class result_of; // undefined + +template<class Fn, class... ArgTypes> +class result_of<Fn(ArgTypes...)> { +public: ++ +typedefsee belowtype;+}; ++ +
+Given an rvalue fn of type Fn and values t1, t2, +..., tN of types T1, T2, ... TN in ArgTypes +respectivly, the type member is the result type of the +expression fn(t1,t2,...,tN). the values ti are lvalues +when the corresponding type Ti is an lvalue-reference type, and +rvalues otherwise. ++The class template result_of shall meet the requirements of a +TransformationTrait: Given the types Fn, T1, T2, ..., TN every +template specialization result_of<Fn(T1,T2,...,TN)> shall define the +member typedef type equivalent to decltype(RE) if and only if +the expression RE +
+ ++ ++value<Fn>() ( value<T1>(), value<T2>(), ... value<TN>() ) ++would be well-formed. Otherwise, there shall be no member typedef +type defined. +
+ +[ +The value<> helper function is a utility Daniel Krügler +proposed in +N2958. +]
+ + + + + + +
+1226. Incomplete changes of #890
+Section: 30.6.2 [futures.errors] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2009-10-05 Last modified: 2010-10-23
+View all issues with NAD Editorial status.
+Discussion:
++Defect issue 890 overlooked to adapt the future_category from +30.6.1 [futures.overview] and 30.6.2 [futures.errors]: +
+ ++ +extern const error_category* const future_category; ++which should be similarly transformed into function form. +
+ +[ +2009-10-27 Howard: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +2009-11-11 Daniel adds: +]
+ + +++ ++I just observe that the proposed resolution of this issue +is incomplete and needs to reworded. The problem is that the +corresponding declarations +
+ ++ +constexpr error_code make_error_code(future_errc e); +constexpr error_condition make_error_condition(future_errc e); ++as constexpr functions are incompatible to the requirements of constexpr +functions given their specified implementation. Note that the incompatibility +is not a result of the modifications proposed by the issue resolution, +but already existed within the +N2960 +state where we have +
+ ++ +extern const error_category* const future_category; ++combined with +
+ ++ +constexpr error_code make_error_code(future_errc e); +++3 Returns: error_code(static_cast<int>(e), *future_category). ++ +constexpr error_code make_error_condition(future_errc e); +++4 Returns: error_condition(static_cast<int>(e), *future_category). +++Neither is any of the constructors of error_code and error_condition +constexpr, nor does the expression *future_category satisfy the +requirements for a constant expression (5.19 [expr.const]/2 bullet 6 in +N3000). +
+ ++The simple solution is just to remove the constexpr qualifiers for both +functions, which makes sense, because none of the remaining make_error_* +overloads in the library is constexpr. One might consider to realize that +those make_* functions could satisfy the constexpr requirements, but this +looks not like an easy task to me, because it would need to rely on a not +yet existing language feature. If such a change is wanted, a new issue +should be opened after the language extension approval (if at all) [1]. +
+ ++If no-one complaints I would like to ask Howard to add the following +modifications to this issue, alternatively a new issue could be opened but I +don't know what the best solution is that would cause as little overhead +as possible. +
++What-ever the route is, the following is my proposed resolution for this issue +interaction part of the story: +
+ +++ ++In 30.6.1 [futures.overview]/1, Header <future> synopsis and +in 30.6.2 [futures.errors]/3+4 +change as indicated: +
+ ++constexprerror_code make_error_code(future_errc e); +constexprerror_condition make_error_condition(future_errc e); ++[1] Let me add that we have a related NAD issue here: 832 +so the chances for realization are little IMO. +
+ +[ +Howard: I've updated the proposed wording as Daniel suggests and set to Review. +]
+ +[ +2009-11-13 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added below. ++ + + +Rationale:
++Solved by N3058. +
+ + +Proposed resolution:
++
+ + + + + +- +
+ ++Change in 30.6.1 [futures.overview], header <future> synopsis: +
+ ++externconst error_category&* constfuture_category(); +- +
+ ++In 30.6.1 [futures.overview]/1, Header <future> synopsis +change as indicated: +
+ ++constexprerror_code make_error_code(future_errc e); +constexprerror_condition make_error_condition(future_errc e); +- +
++Change in 30.6.2 [futures.errors]: +
+ +++ +externconst error_category&* constfuture_category(); +++ ++
+1- future_category shall point to a statically initialized object +of a type derived from class error_category.++1- Returns: A reference to an object of a type +derived from class error_category. +
++ +constexprerror_code make_error_code(future_errc e); ++3 Returns: error_code(static_cast<int>(e), ++ +*future_category()). ++ +constexprerror_codecondition make_error_condition(future_errc e); ++4 Returns: error_condition(static_cast<int>(e), ++*future_category()). +
+1228. User-specialized nothrow type traits
+Section: 20.7.4.3 [meta.unary.prop] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-10-07 Last modified: 2010-10-23
+View all other issues in [meta.unary.prop].
+View all issues with NAD status.
+Discussion:
++According to p1 20.7.2 [meta.type.synop]: +
+ ++The behavior of a program that adds specializations for any of the class +templates defined in this subclause is undefined unless otherwise +specified. ++ ++I believe we should 'otherwise specify' for the nothrow traits, are +these are exactly the use cases where the end user actually has more +information than the compiler. +
+ +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Open. Definitely need to give the users the ability to ensure +that the traits give the right answers. Unsure we want to give them the +ability to say this in more than one way. Believes the noexcept proposal +already gives this. ++ +[ +2010 Pittsburgh: Moved to NAD, rationale added below. +]
+ + + + +Rationale:
++We believe the solution offered by +N3050 +is superior. +
+ + +Proposed resolution:
++Add the following comment: +
+ ++user specialization permitted to derive from std::true_type when the +operation is known not to throw. ++ ++to the following traits in 20.7.4.3 [meta.unary.prop] Table 43 Type +property predicates. +
+ +[ +This may require a new Comments column +]
+ + ++ + + + +has_nothrow_default_constructor +has_nothrow_copy_constructor +has_nothrow_assign +
1229. error_code operator= typo
Section: 19.5.2.3 [syserr.errcode.modifiers] Status: NAD - Submitter: Stephan T. Lavavej Opened: 2009-10-08 Last modified: 2009-10-26
+ Submitter: Stephan T. Lavavej Opened: 2009-10-08 Last modified: 2010-10-23View all issues with NAD status.
Discussion:
@@ -39586,7 +44138,7 @@ template <class ErrorCodeEnum>
-This is because enable_if is declared as (20.6.7 [meta.trans.other]): +This is because enable_if is declared as (20.7.7.6 [meta.trans.other]):
@@ -39667,7 +44219,7 @@ necessary.-The proposed resolution for issue 1237 makes this issue +The proposed resolution for issue 1237 makes this issue moot, so it should become NAD.@@ -39677,7 +44229,7 @@ moot, so it should become NAD.-NAD, solved by 1237. +NAD, solved by 1237.@@ -39730,11 +44282,11 @@ Change 19.5.3.3 [syserr.errcondition.modifiers]:
1230. mem_fn and variadic templates
-Section: 20.7.14 [func.memfn] Status: Dup - Submitter: Alisdair Meredith Opened: 2009-10-09 Last modified: 2009-10-23
+Section: 20.8.13 [func.memfn] Status: Dup + Submitter: Alisdair Meredith Opened: 2009-10-09 Last modified: 2010-10-23
View all other issues in [func.memfn].
View all issues with Dup status.
-Duplicate of: 920
+Duplicate of: 920
Discussion:
@@ -39764,13 +44316,13 @@ syntax.[ -920 as a similar proposed resolution. +920 as a similar proposed resolution. ]
Proposed resolution:
-Add to 20.7 [function.objects] and 20.7.14 [func.memfn]: +Add to 20.8 [function.objects] and 20.8.13 [func.memfn]:template<class R, class T> unspecified mem_fn(R T::* pm) @@ -39792,7 +44344,7 @@ Add to 20.7 [function.objects] and 20.7.14 [func.memfn]:-Strike 20.7.14 [func.memfn], p5: +Strike 20.8.13 [func.memfn], p5:
@@ -39805,11 +44357,11 @@ of overloaded function templates.
1232. Still swap's with rvalue-references
-Section: 17 [library] Status: NAD Editorial - Submitter: Daniel Krügler Opened: 2009-10-11 Last modified: 2009-10-29
+Section: 17 [library] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2009-10-11 Last modified: 2010-10-23
View other active issues in [library].
View all other issues in [library].
-View all issues with NAD Editorial status.
+View all issues with NAD Editorial status.
Discussion:
The current library contains still rvalue reference-swaps that seem to be @@ -39831,7 +44383,7 @@ Editor accepts as NAD Editorial.
-Change 20.3.4 [pairs]/1 as indicated: +Change 20.3.5 [pairs]/1 as indicated:
template <class T1, class T2> @@ -39844,7 +44396,7 @@ struct pair {-Change 20.3.4 [pairs] before p. 17 as indicated: +Change 20.3.5 [pairs] before p. 17 as indicated:
void swap(pair&&p); @@ -39855,7 +44407,7 @@ Change 20.3.4 [pairs] before p. 17 as indicated:-Change 20.3.4 [pairs] before p. 21 as indicated: +Change 20.3.5 [pairs] before p. 21 as indicated:
template<class T1, class T2> void swap(pair<T1, T2>& x, pair<T1, T2>& y); @@ -39867,7 +44419,7 @@ Change 20.3.4 [pairs] before p. 21 as indicated:-Change 20.5.1 [tuple.general]/2, header <tuple> synopsis, as indicated: +Change 20.4.1 [tuple.general]/2, header <tuple> synopsis, as indicated:
// 20.5.2.9, specialized algorithms: @@ -39883,7 +44435,7 @@ void swap(tuple<Types...>& x, tuple<Types...>&& y);-Change 20.5.2 [tuple.tuple] as indicated: +Change 20.4.2 [tuple.tuple] as indicated:
// 20.5.2.3, tuple swap @@ -39894,7 +44446,7 @@ void swap(tuple&&)-Change 20.5.2.3 [tuple.swap] before 1 as indicated: +Change 20.4.2.3 [tuple.swap] before 1 as indicated:
void swap(tuple&&rhs); @@ -39904,7 +44456,7 @@ Change 20.5.2.3 [tuple.swap] before 1 as indicated:-Change 20.7 [function.objects]/2, header <functional> synopsis, as indicated: +Change 20.8 [function.objects]/2, header <functional> synopsis, as indicated:
template<class R, class... ArgTypes> @@ -39919,7 +44471,7 @@ void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)&&a-Change 20.7.15.2 [func.wrap.func], as indicated: +Change 20.8.14.2 [func.wrap.func], as indicated:
// 20.7.15.2.2, function modifiers: @@ -39941,7 +44493,7 @@ void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&am-Change 20.7.15.2.7 [func.wrap.func.alg] before 1 as indicated: +Change 20.8.14.2.7 [func.wrap.func.alg] before 1 as indicated:
template<class R, class... ArgTypes> @@ -39956,7 +44508,7 @@ void swap(function<R(ArgTypes...)>& f1, function<R(ArgTypes...)>-Change 20.8.15.2 [util.smartptr.shared]/1 as indicated: +Change 20.9.10.2 [util.smartptr.shared]/1 as indicated:
// 20.8.12.2.4, modifiers: @@ -40187,7 +44739,7 @@ void swap(list<T,Allocator>& x, list<T,Allocator>&& y);<- @@ -665,7 +827,7 @@ del {background-color:#FFA0A0}
-Change 23.3.5.1.1 [queue.defn] as indicated: +Change 23.5.1.1 [queue.defn] as indicated:
void swap(queue&&q) { c.swap(q.c); } @@ -40206,7 +44758,7 @@ void swap(queue<T, Container>& x, queue<T, Container>&&-Change 23.3.5.1.3 [queue.special] as indicated: +Change 23.5.1.5 [queue.special] as indicated:
template <class T, class Container> @@ -40221,7 +44773,7 @@ void swap(queue<T, Container>& x, queue<T, Container>&&-Change 23.3.5.2 [priority.queue]/1 as indicated: +Change 23.5.2 [priority.queue]/1 as indicated:
void swap(priority_queue&&); @@ -40239,7 +44791,7 @@ void swap(priority_queue<T, Container, Compare>& x, priority_queue<- @@ -514,13 +676,13 @@ del {background-color:#FFA0A0}
-Change 23.3.5.2.3 [priqueue.special] as indicated: +Change 23.5.2.4 [priqueue.special] as indicated:
template <class T, class Container, Compare> @@ -40254,7 +44806,7 @@ void swap(priority_queue<T, Container, Compare>& x, priority_queue<-Change 23.3.5.3.1 [stack.defn] as indicated: +Change 23.5.3.1 [stack.defn] as indicated:
void swap(stack&&s) { c.swap(s.c); } @@ -40274,7 +44826,7 @@ void swap(stack<T,Allocator>& x, stack<T,Allocator>&& y)-Change 23.3.5.3.3 [stack.special] as indicated: +Change 23.5.3.5 [stack.special] as indicated:
template <class T, class Container> @@ -40289,7 +44841,7 @@ void swap(stack<T, Container>& x, stack<T, Container>&&-Change 23.3.6 [vector]/2 as indicated: +Change 23.4.1 [vector]/2 as indicated:
void swap(vector<T,Allocator>&&); @@ -40310,7 +44862,7 @@ void swap(vector<T,Allocator>& x, vector<T,Allocator>&&- @@ -345,7 +507,7 @@ del {background-color:#FFA0A0}
-Change 23.3.6.2 [vector.capacity] before p. 8 as indicated: +Change 23.4.1.2 [vector.capacity] before p. 8 as indicated:
void swap(vector<T,Allocator>&&x); @@ -40320,7 +44872,7 @@ Change 23.3.6.2 [vector.capacity] before p. 8 as indicated:-Change 23.3.6.5 [vector.special] as indicated: +Change 23.4.1.5 [vector.special] as indicated:
template <class T, class Allocator> @@ -40335,7 +44887,7 @@ void swap(vector<T,Allocator>& x, vector<T,Allocator>&&-Change 23.3.7 [vector.bool]/1 as indicated: +Change 23.4.2 [vector.bool]/1 as indicated:
iterator erase(const_iterator first, const_iterator last); @@ -40347,7 +44899,7 @@ static void swap(reference x, reference y);- @@ -297,28 +459,28 @@ del {background-color:#FFA0A0}
-Change 23.4 [associative]/1, header <map> synopsis as indicated: +Change 23.6 [associative]/1, header <map> synopsis as indicated:
template <class Key, class T, class Compare, class Allocator> @@ -40371,7 +44923,7 @@ void swap(multimap<Key,T,Compare,Allocator& x, multimap<Key,T,Compare,-Change 23.4 [associative]/1, header <set> synopsis as indicated: +Change 23.6 [associative]/1, header <set> synopsis as indicated:
template <class Key, class Compare, class Allocator> @@ -40395,7 +44947,7 @@ void swap(multiset<Key,T,Compare,Allocator& x, multiset<Key,T,Compare,- @@ -283,7 +445,7 @@ del {background-color:#FFA0A0}
-Change 23.4.1 [map]/2 as indicated: +Change 23.6.1 [map]/2 as indicated:
iterator erase(const_iterator first, const_iterator last); @@ -40417,7 +44969,7 @@ void swap(map<Key,T,Compare,Allocator& x, map<Key,T,Compare,Allocator&-Change 23.4.1.5 [map.special] as indicated: +Change 23.6.1.5 [map.special] as indicated:
template <class Key, class T, class Compare, class Allocator> @@ -40432,7 +44984,7 @@ void swap(map<Key,T,Compare,Allocator>& x, map<Key,T,Compare,Alloca-Change 23.4.2 [multimap]/2 as indicated: +Change 23.6.2 [multimap]/2 as indicated:
iterator erase(const_iterator first, const_iterator last); @@ -40454,7 +45006,7 @@ void swap(multimap<Key,T,Compare,Allocator& x, multimap<Key,T,Compare,- @@ -220,7 +382,7 @@ del {background-color:#FFA0A0}
-Change 23.4.2.4 [multimap.special] as indicated: +Change 23.6.2.4 [multimap.special] as indicated:
template <class Key, class T, class Compare, class Allocator> @@ -40469,7 +45021,7 @@ void swap(multimap<Key,T,Compare,Allocator>& x, multimap<Key,T,Comp-Change 23.4.3 [set]/2 and 23.4.3.2 [set.special] as indicated: (twice!) +Change 23.6.3 [set]/2 and 23.6.3.2 [set.special] as indicated: (twice!)
// specialized algorithms: @@ -40485,7 +45037,7 @@ void swap(set<Key,Compare,Allocator& x, set<Key,Compare,Allocator>&- @@ -141,10 +303,10 @@ del {background-color:#FFA0A0}
-Change 23.4.4 [multiset]/2 as indicated: +Change 23.6.4 [multiset]/2 as indicated:
iterator erase(const_iterator first, const_iterator last); @@ -40507,7 +45059,7 @@ void swap(multiset<Key,Compare,Allocator& x, multiset<Key,Compare,Allo-Change 23.4.4.2 [multiset.special] as indicated: +Change 23.6.4.2 [multiset.special] as indicated:
template <class Key, class Compare, class Allocator> @@ -40525,11 +45077,65 @@ void swap(multiset<Key,Compare,Allocator>& x, multiset<Key,Compare, +
+1233. Missing unique_ptr signatures in synopsis
+Section: 20.9 [memory] Status: NAD Editorial + Submitter: Daniel Krügler Opened: 2009-10-11 Last modified: 2010-10-23
+View all other issues in [memory].
+View all issues with NAD Editorial status.
+Discussion:
++Related to 296. Some unique_ptr signatures are missing +from the synopsis in 20.9 [memory]. +
+ +[ +2009-11-04 Howard adds: +]
+ + ++Moved to Tentatively NAD Editorial. The editor has adopted the fix. ++ + +Proposed resolution:
++Add in 20.9 [memory], Header <memory> synopsis +missing declarations as shown below: +
+ ++ + + + +// 20.8.11 Class unique_ptr: +template <class X> class default_delete; +template<class T> struct default_delete<T[]>; +template <class X, class D = default_delete<T>> class unique_ptr; +template<class T, class D> class unique_ptr<T[], D>; + +template<class T, class D> void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y); + +template<class T1, class D1, class T2, class D2> +bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); +template<class T1, class D1, class T2, class D2> +bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); +template<class T1, class D1, class T2, class D2> +bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); +template<class T1, class D1, class T2, class D2> +bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); +template<class T1, class D1, class T2, class D2> +bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); +template<class T1, class D1, class T2, class D2> +bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); +
1235. Issue with C++0x random number proposal
-Section: 26.5.2.5 [rand.concept.dist] Status: NAD Future - Submitter: Matthias Troyer Opened: 2009-10-12 Last modified: 2009-10-26
-View all issues with NAD Future status.
+Section: X [rand.concept.dist] Status: NAD Future + Submitter: Matthias Troyer Opened: 2009-10-12 Last modified: 2010-10-23
+View all issues with NAD Future status.
Discussion:
There exist optimized, vectorized vendor libraries for the creation of @@ -40643,7 +45249,7 @@ NAD Future. No time to add this feature for C++0X.
1236. reserved identifiers in programs not using the library
Section: 17 [library] Status: NAD - Submitter: Sean Hunt Opened: 2009-10-13 Last modified: 2009-10-20
+ Submitter: Sean Hunt Opened: 2009-10-13 Last modified: 2010-10-23View other active issues in [library].
View all other issues in [library].
View all issues with NAD status.
@@ -40667,14 +45273,11 @@ identifiers predefined for programs that do not, at some point, include a standard library header. -Furthermore, it's unclear whether the use of certain identifiers is -UB -or results in an ill-formed program. In particular, 17.6.3.3.1 -[macro.names] uses a "shall not", where 17.6.3.3.2 [global.names] says -that names are "reserved to the +
+Furthermore, it's unclear whether the use of certain identifiers is UB +or results in an ill-formed program. In particular, 17.6.3.3.1 [macro.names] uses a "shall not", where 17.6.3.3.2 [global.names] says that names are "reserved to the implementation". 17.6.3.3 [reserved.names] seems only to cover the -instance of a name being described as "reserved", so are -implementations +instance of a name being described as "reserved", so are implementations required to diagnose a program that performs, as an example, "#undef get"?
@@ -40699,13 +45302,208 @@ believe this rises to the level of a defect. +
+1238. defining algorithms taking iterator for range
+Section: 25 [algorithms] Status: NAD Future + Submitter: Alisdair Meredith Opened: 2009-10-15 Last modified: 2010-10-23
+View all other issues in [algorithms].
+View all issues with NAD Future status.
+Discussion:
++The library has many algorithms that take a source range represented by +a pair of iterators, and the start of some second sequence given by a +single iterator. Internally, these algorithms will produce undefined +behaviour if the second 'range' is not as large as the input range, but +none of the algorithms spell this out in Requires clauses, and there is +no catch-all wording to cover this in clause 17 or the front matter of +25. +
+ ++There was an attempt to provide such wording in paper +n2944 +but this +seems incidental to the focus of the paper, and getting the wording of +this issue right seems substantially more difficult than the simple +approach taken in that paper. Such wording will be removed from an +updated paper, and hopefully tracked via the LWG issues list instead. +
+ ++It seems there are several classes of problems here and finding wording +to solve all in one paragraph could be too much. I suspect we need +several overlapping requirements that should cover the desired range of +behaviours. +
+ ++Motivating examples: +
+ ++A good initial example is the swap_ranges algorithm. Here there is a +clear requirement that first2 refers to the start of a valid range at +least as long as the range [first1, last1). n2944 tries to solve this +by positing a hypothetical last2 iterator that is implied by the +signature, and requires distance(first2,last2) < distance(first1,last1). + This mostly works, although I am uncomfortable assuming that last2 is +clearly defined and well known without any description of how to obtain +it (and I have no idea how to write that). +
+ ++A second motivating example might be the copy algorithm. Specifically, +let us image a call like: +
+ ++ +copy(istream_iterator<int>(is),istream_iterator(),ostream_iterator<int>(os)); ++In this case, our input iterators are literally simple InputIterators, +and the destination is a simple OutputIterator. In neither case am I +happy referring to std::distance, in fact it is not possible for the +ostream_iterator at all as it does not meet the requirements. However, +any wording we provide must cover both cases. Perhaps we might deduce +last2 == ostream_iterator<int>{}, but that might not always be valid for +user-defined iterator types. I can well imagine an 'infinite range' +that writes to /dev/null and has no meaningful last2. +
+ ++The motivating example in n2944 is std::equal, and that seems to fall somewhere between the +two. +
+ ++Outlying examples might be partition_copy that takes two output +iterators, and the _n algorithms where a range is specified by a +specific number of iterations, rather than traditional iterator pair. +We should also not accidentally apply inappropriate constraints to +std::rotate which takes a third iterator that is not intended to be a +separate range at all. +
+ ++I suspect we want some wording similar to: +
+ ++For algorithms that operate on ranges where the end iterator of the +second range is not specified, the second range shall contain at least +as many elements as the first. ++ ++I don't think this quite captures the intent yet though. I am not sure +if 'range' is the right term here rather than sequence. More awkwardly, +I am not convinced we can describe an Output sequence such as produce by +an ostream_iterator as "containing elements", at least not as a +precondition to the call before they have been written. +
+ ++Another idea was to describe require that the trailing iterator support +at least distance(input range) applications of operator++ and may be +written through the same number of times if a mutable/output iterator. +
+ ++We might also consider handling the case of an output range vs. an input +range in separate paragraphs, if that simplifies how we describe some of +these constraints. +
+ +[ +2009-11-03 Howard adds: +]
+ + ++Moved to Tentatively NAD Future after 5 positive votes on c++std-lib. ++ + +Rationale:
++Does not have sufficient support at this time. May wish to reconsider for a +future standard. +
+ + +Proposed resolution:
+ + + + + +
+1239. Defect report
+Section: 20.7.4.3 [meta.unary.prop] Status: NAD Editorial + Submitter: David Abrahams Opened: 2009-10-16 Last modified: 2010-10-23
+View all other issues in [meta.unary.prop].
+View all issues with NAD Editorial status.
+Discussion:
++Table 43 defines a number of traits that yield true for arrays of class +types with the trait's property, but not arrays of other types with that +property. For example, has_trivial_default_constructor: +
+ ++T is a trivial type (3.9) or a class type with a trivial default +constructor (12.1) or an array of such a class type. ++ +[ +2009-10 post-Santa Cruz: +]
+ + +++ + + ++An array of a trivial type is a trivial type. +
++Mark as Tentatively NAD Editorial. The wording is OK as is, +since an array of a trivial type is a trivial type, but the wording as +proposed might be clearer. +
+Rationale:
++The wording is OK as is, since an array of a trivial type is a trivial type. +Project editor may wish to accept the suggested wording as editorial. +
+ + +Proposed resolution:
++Change all the traits in question following this pattern: +
+ ++T is a trivial type (3.9) or a class type with a trivial default + constructor (12.1), or an array of such a+ +classtype. ++i.e., add a comma and delete a "class." +
+ + + + +
1242. Enable SCARY iterators
-Section: 23 [containers] Status: NAD Future - Submitter: Herb Sutter Opened: 2009-10-21 Last modified: 2009-10-21
-View other active issues in [containers].
+Section: 23 [containers] Status: NAD Future + Submitter: Herb Sutter Opened: 2009-10-21 Last modified: 2010-10-23
View all other issues in [containers].
-View all issues with NAD Future status.
+View all issues with NAD Future status.
Discussion:
See @@ -40722,7 +45520,7 @@ See
1243. Missing operator+= (initializer_list<T>) for valarray
Section: 26.6.2.6 [valarray.cassign] Status: NAD - Submitter: Daniel Krügler Opened: 2009-10-22 Last modified: 2009-10-26
+ Submitter: Daniel Krügler Opened: 2009-10-22 Last modified: 2010-10-23View all other issues in [valarray.cassign].
View all issues with NAD status.
Discussion:
@@ -40786,15 +45584,38 @@ Add to 26.6.2.6 [valarray.cassign]:
-1248. Equality comparison for unordered containers
-Section: 23.5 [unord] Status: NAD Future - Submitter: Herb Sutter Opened: 2009-10-25 Last modified: 2009-10-25
-View all other issues in [unord].
-View all issues with NAD Future status.
+1244. wait_*() in *future for synchronous functions
+Section: 30.6 [futures] Status: NAD Editorial + Submitter: Detlef Vollmann Opened: 2009-10-22 Last modified: 2010-10-23
+View all other issues in [futures].
+View all issues with NAD Editorial status.
Discussion:
-See -N2986. +With the addition of async(), a future might be +associated with a function that is not running in a different thread but +is stored to by run synchronously on the get() call. It's not +clear what the wait() functions should do in this case. +
+ ++Suggested resolution: +
+ ++Throw an exception. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3058.
@@ -40804,4 +45625,5511 @@ See +
+1246. vector::resize() missing efficiency guarantee
+Section: 23.4.1.2 [vector.capacity] Status: NAD + Submitter: David Abrahams Opened: 2009-10-24 Last modified: 2010-10-23
+View all other issues in [vector.capacity].
+View all issues with NAD status.
+Discussion:
++If v is a vector, I think repeated calls to +v.resize( v.size() + 1 ) should be amortized O(1), but it's not +clear that's true from the text of the standard: +
+ ++ +void resize(size_type sz); +++Effects: If sz < size(), equivalent to erase(begin() + sz, end());. If +size() < sz, appends sz - size() default constructed elements to the +sequence. +++Seems to me if we used push_back instead of appends, we might be giving +the guarantee I'd like. Thoughts? +
+ +[ +2009-11-10 Howard adds: +]
+ + ++Moved to Tentatively NAD after 5 positive votes on c++std-lib. Rationale added +below. ++ + + +Proposed resolution:
++In 23.4.1.2 [vector.capacity]/10, change +
+ ++ + + +void resize(size_type sz); +++Effects: If sz < size(), equivalent to erase(begin() + sz, end());. If +size() < sz,+appends sz - size() default constructed elements to the +sequence+equivalent to sz - size() consecutive evaluations of push_back(T()). +Rationale:
++The description in terms of push_back led some to believe that +one could expect the exact same growth pattern from both resize and +push_back (e.g.) which could lead to sub-optimal implementations. +Additionally, 23.4.1 [vector], p1 includes a statement that this container +"supports (amortized) constant time insert and erase operations at the end;", +therefore addressing the concern of this issue. +
+ + + + + +
+1248. Equality comparison for unordered containers
+Section: 23.7 [unord] Status: NAD Editorial + Submitter: Herb Sutter Opened: 2009-10-25 Last modified: 2010-10-23
+View all other issues in [unord].
+View all issues with NAD Editorial status.
+Discussion:
++See +N2986. +
+ +[ +2010-01-22 Alisdair Opens. +]
+ + +[ +2010-01-24 Alisdair provides wording. +]
+ + +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3068. +
+ + +Proposed resolution:
++Apply paper +N2986. +
+ + + + + +
+1251. move constructing basic_stringbuf
+Section: 27.8.1.1 [stringbuf.cons] Status: NAD + Submitter: Martin Sebor Opened: 2009-10-29 Last modified: 2010-10-23
+View all other issues in [stringbuf.cons].
+View all issues with NAD status.
+Discussion:
++I just came across issue 1204 -- Global permission to move, which +seems to address the concern raised by the example in c++std-lib-25030. +
++IIUC, the example violates the permission to assume that arguments +bound to rvalue references are unnamed temporaries granted to +implementations by the resolution of issue 1204 - Global permission +to move. +
+ ++I.e., the ostringstream(ostringstream &&rhs) ctor can leave the rhs +pointers pointing to the newly constructed object's buffer just as +long as the dtor doesn't change or invalidate the buffer. The caller +may not make any assumptions about rhs after the move beyond it being +safe to destroy or reassign. +
+ ++So unless I misunderstood something, I still think the basic_stringbuf +move ctor is overspecified. Specifically, I think the third sentence +in the Effects clause and the last 6 bullets in the Postconditions +clause can, and IMO should, be stricken. +
+ +[ +2010-01-31 Moved to Tentatively NAD after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + +Rationale:
++The sense of 1251 appears to be that the basic_stringbuf move +constructor offers more guarantees than the minimum. This is true, and quite +correct. The additional words guarantee that the internal buffer has genuinely +transferred from one object to another, and further operations on the original +will not affect the buffer of the newly created object. This is a very +important guarantee, much as we see that a moved-from unique_ptr is +guaranteed to be empty. +
+ + +Proposed resolution:
++Strike from 27.8.1.1 [stringbuf.cons]: +
+ ++ + + + + + +basic_stringbuf(basic_stringbuf&& rhs); +++++Effects: Move constructs from the rvalue rhs. It is +implementation-defined whether the sequence pointers in *this +(eback(), gptr(), egptr(), pbase(), +pptr(), epptr()) obtain the values which rhs +had.
+ +Whether they do or not, *this and rhs reference +separate buffers (if any at all) after the construction.The openmode, +locale and any other state of rhs is also copied. ++Postconditions: Let rhs_p refer to the state of +rhs just prior to this construction and let rhs_a +referto the state of rhs just after this construction. +
++
+- +str() == rhs_p.str() +
+- +gptr() - eback() == rhs_p.gptr() - rhs_p.eback() +
+- +egptr() - eback() == rhs_p.egptr() - rhs_p.eback() +
+- +pptr() - pbase() == rhs_p.pptr() - rhs_p.pbase() +
+- +epptr() - pbase() == rhs_p.epptr() - rhs_p.pbase() +
+- +
+if (eback()) eback() != rhs_a.eback() +- +
+if (gptr()) gptr() != rhs_a.gptr() +- +
+if (egptr()) egptr() != rhs_a.egptr() +- +
+if (pbase()) pbase() != rhs_a.pbase() +- +
+if (pptr()) pptr() != rhs_a.pptr() +- +
+if (epptr()) epptr() != rhs_a.epptr() +
+1259. Should initializer-list constructors move elements?
+Section: 23.2.3 [sequence.reqmts] Status: NAD + Submitter: Sean Hunt Opened: 2009-11-05 Last modified: 2010-10-23
+View all other issues in [sequence.reqmts].
+View all issues with NAD status.
+Discussion:
++According to 23.2.3 [sequence.reqmts], X(il) is +equivalent to X(il.begin(), il.end()). Should it instead be +equivalent to X(move_iterator(il.begin()), +move_iterator(il.end())) so that needless copies are not made? This +doesn't seem ideal either - it may make more sense to provide two +overloads for the constructor, one for move and one for copy. +
+ +[ +2009-11-10 Howard adds: +]
+ + ++I've moved this issue to Tentatively NAD after 5 positive votes on c++std-lib, +and added a rationale below. ++ + +Proposed resolution:
++
+ + +Rationale:
++There is no consensus at this time within EWG or CWG to make the +required language changes. Therefore this is not something that the LWG +can even consider. Should such language changes be made for a future +standard, no doubt there would need to be an accompanying library impact +survey. +
+ + + + + +
+1263. missing swap overloads for regex
+Section: 28.4 [re.syn] Status: NAD + Submitter: Howard Hinnant Opened: 2009-11-12 Last modified: 2010-10-23
+View all issues with NAD status.
+Discussion:
+ +Addresses: UK 314
+ ++In Message c++std-lib-25529, Alisdair writes: +
+ +++ ++UK comment 314 +requests rvalue swap overloads in a couple of places they +were missed. +
+ ++We have in general reverted to the single swap signature taking lvalue +references, which could be seen as the alternative solution to +UK 314, +bringing consistency to the standard <g> +
+ ++Either way, I no longer expect to see any work to resolve this comment - +the work is complete and it should be either marked Rejected, or +Accepted with Modifications (namely, removing all other rvalue swaps!) +
+[ +Moved to Tentatively NAD after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
+ + +Rationale:
++We have in general reverted to the single swap signature taking +lvalue references, which could be seen as the alternative solution to +UK 314, bringing consistency to the standard. +
+ + + + + +
+1265. longjmp and destructors
+Section: 18.10 [support.runtime] Status: NAD + Submitter: Sean Hunt Opened: 2009-11-16 Last modified: 2010-10-23
+View all other issues in [support.runtime].
+View all issues with NAD status.
+Discussion:
++18.10 [support.runtime]/4 says that longjmp is undefined if +unwinding by the mechanism used by catch and throw would invoke any nontrivial +destructors. However, the text as written is rather vague, in particular when +dealing with catch(...): +
+ ++ +void foo() { + jump_buf buf; + non_trivial_dtor n1; // 1 + if (!setjmp(buf)) { + non_trivial_dtor n2; // 2 + try { + longjmp(buf, 1); + } catch (...) { + } + } +} ++My interpretation of the meaning of 18.10 [support.runtime]/4 is that +declaration 2, but not 1, would cause the longjmp to be undefined +behavior. However, it's not entirely clear from the text. Arguably, replacing +the setjmp and longjmp with catch would still cause +the destructor for n1 to be called after the unwinding, which would +lead to undefined behavior. This is clearly not an intended consequence of the +wording. However, it is probably still UB, as n1 now has +"indeterminate" value, and running its destructor on foo's exit will +cause Bad Things. +
+ ++Declarations 2 has a more interesting issue. The catch(...) muddles up +the definition that uses throw and catch - if +longjmp() were indeed a throw, control would never return to +the setjmp. As such, n2's destructor wouldn't be called +(except by the argument for n1, which is that the destructor would be +called later as the frame was left in the normal control flow). +
+ ++I suggest that paragraph 4 of 18.10 [support.runtime] should be replaced +with the following, or something that reads better but has the same effect: +
+ ++The function signature longjmp(jmp_buf jbuf, int val) has more +restricted behavior in this International Standard. A call to longjmp +has undefined behavior if any non-trivial destructors would be called were the +longjmp call replaced with a throw-expression whose nearest matching +handler were a (possibly imaginary) function-try-block on the function +containing the corresponding setjmp call. ++ +[ +2009-11-17 Moved to Tentatively NAD after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + +Proposed resolution:
++Change 18.10 [support.runtime]/4: +
+ ++The function signature longjmp(jmp_buf jbuf, int val) has more +restricted behavior in this International Standard.+ + +A +setjmp/longjmp call pair has undefined behavior if replacing +the setjmp and longjmp by catch and throw +would invoke any non-trivial destructors for any automatic objects.+A call to longjmp has undefined behavior if any non-trivial +destructors would be called were the longjmp call replaced with a +throw-expression whose nearest matching handler were a (possibly imaginary) +function-try-block on the function containing the corresponding setjmp +call. +Rationale:
++In the given example, it is clear that it is only n2 and not +n1 that is destroyed by the longjmp. +
++At this late stage in the standards process, we are focusing on issues that +impact users or implementers. Trying to rewrite complex wording just for the +sake of improved clarity is likely to do more harm than good. +
+ + + + + +
+1266. shared_future::get and deferred async functions
+Section: 30.6.7 [futures.shared_future] Status: NAD Editorial + Submitter: Anthony Williams Opened: 2009-11-17 Last modified: 2010-10-23
+View all other issues in [futures.shared_future].
+View all issues with NAD Editorial status.
+Discussion:
++If a shared_future is constructed with the result of an async call with a +deferred function, and two or more copies of that shared_future are created, +with multiple threads calling get(), it is not clear which thread runs the +deferred function. 30.6.7 [futures.shared_future]p22 from +N3000 +says (minus editor's note): +
+ ++Effects: if the associated state contains a deferred function, executes +the deferred function. Otherwise, blocks until the associated state is ready. ++ ++In the absence of wording to the contrary, this implies that every thread that +calls wait() will execute the deferred function. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3058. +
+ + +Proposed resolution:
++Replace 30.6.7 [futures.shared_future]p22 with the following: +
+ +++ + + + + ++Effects: If the associated state +
+ +contains a deferred function, executes the deferred function. Otherwise, +blocks until the associated state is ready.+was created by a promise or packaged_task object, block +until the associated state is ready. If the associated state is associated with +a thread created for an async call (30.6.9 [futures.async]), as +if associated-thread.join(). ++If the associated state contains a deferred function, calls to wait() +on all shared_future objects that share the same associated state are +serialized. The first call to wait() that shares a given associated +state executes the deferred function and stores the return value or exception in +the associated state. +
+ ++Synchronization: if the associated state was created by a +promise object, the completion of set_value() or +set_exception() to that promise happens before (1.10 [intro.multithread]) wait() returns. If the associated state +was created by a packaged_task object, the completion of the associated +task happens before wait() returns. If the associated state is +associated with a thread created for an async call (30.6.9 [futures.async]), the completion of the associated thread happens-before +wait() returns. +
+ ++If the associated state contained a deferred function, the invocation of the +deferred function happens-before any call to wait() on a +future that shares that state returns. +
+
+1269. Associated state doesn't account for async
+Section: 30.6.4 [futures.state] Status: NAD Editorial + Submitter: Anthony Williams Opened: 2009-11-18 Last modified: 2010-10-23
+View other active issues in [futures.state].
+View all other issues in [futures.state].
+View all issues with NAD Editorial status.
+Discussion:
++The current description of the associated state in 30.6.4 [futures.state] +does not allow for futures created by an async call. The description +therefore needs to be extended to cover that. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3058. +
+ + +Proposed resolution:
++Add a new sentence to 30.6.4 [futures.state] p2: +
+ ++2 This associated state consists of some state information and some +(possibly not yet evaluated) result, which can be a (possibly +void) value or an exception. If the associated state was created +by a call to async (30.6.9 [futures.async]) then it may also +contain a deferred function or an associated thread. ++ ++Add an extra bullet to 30.6.4 [futures.state] p3: +
+ +++ + + + + ++The result of an associated state can be set by calling: +
++
+- +promise::set_value, +
+- +promise::set_exception,
+or+- +packaged_task::operator()
+., or +- +a call to async (30.6.9 [futures.async]). +
+
+1272. confusing declarations of promise::set_value
+Section: 30.6.5 [futures.promise] Status: NAD Editorial + Submitter: Jonathan Wakely Opened: 2009-11-22 Last modified: 2010-10-23
+View other active issues in [futures.promise].
+View all other issues in [futures.promise].
+View all issues with NAD Editorial status.
+Discussion:
++The definitions of promise::set_value need tidying up, the +synopsis says: +
+ ++ +// setting the result +void set_value(const R& r); +void set_value(see below); ++Why is the first one there? It implies it is always present for all +specialisations of promise, which is not true. +
+ ++The definition says: +
+ ++ +void set_value(const R& r); +void promise::set_value(R&& r); +void promise<R&>::set_value(R& r); +void promise<void>::set_value(); ++The lack of qualification on the first one again implies it's present +for all specialisations, again not true. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3058. +
+ + +Proposed resolution:
++Change the synopsis in 30.6.5 [futures.promise]: +
+ ++ +// setting the result +void set_value(const R& r);+void set_value(see below); ++And the definition be changed by qualifying the first signature: +
+ ++ + + + + +void promise::set_value(const R& r); +void promise::set_value(R&& r); +void promise<R&>::set_value(R& r); +void promise<void>::set_value(); +
+1273. future::valid should be callable on an invalid future
+Section: 30.6.6 [futures.unique_future] Status: NAD Editorial + Submitter: Jonathan Wakely Opened: 2009-11-22 Last modified: 2010-10-23
+View all other issues in [futures.unique_future].
+View all issues with NAD Editorial status.
+Discussion:
++30.6.6 [futures.unique_future]/3 says: +
+ ++The effect of calling any member function other than the destructor or +the move-assignment operator on a future object for which valid() == +false is undefined. ++ ++This means calling future::valid() is undefined unless it will +return true, so you can only use it if you know the answer! +
+ +[ +2009-12-08 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added below. ++ + + +Rationale:
++Solved by N3058. +
+ + +Proposed resolution:
++Change 30.6.6 [futures.unique_future]/3: +
+ ++The effect of calling any member function other than the +destructor, or the move-assignment operator, or +valid, on a future object for which valid() +== false is undefined. ++ + + + + + +
+1274. atomic_future constructor
+Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial + Submitter: Jonathan Wakely Opened: 2009-11-22 Last modified: 2010-10-23
+View all other issues in [futures.atomic_future].
+View all issues with NAD Editorial status.
+Discussion:
++In 30.6.8 [futures.atomic_future] this constructor: +
+ ++ +atomic_future(future<R>&&); ++is declared in the synopsis, but not defined. Instead +n2997 +defines: +
+ ++ +atomic_future(const future<R>&& rhs); ++and +n3000 +defines +
+ ++ +atomic_future(atomic_future<R>&& rhs); ++both of which are wrong. The constructor definition should be changed +to match the synopsis. +
+ +[ +2009-12-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added below. ++ + + +Rationale:
++Solved by N3058. +
+ + +Proposed resolution:
++Adjust the signature above 30.6.8 [futures.atomic_future]/6 like so: +
+ ++ + + + + +atomic_future(atomic_future<R>&& rhs); +
+1275. creating and setting futures
+Section: 30.6 [futures] Status: NAD Editorial + Submitter: Jonathan Wakely Opened: 2009-11-22 Last modified: 2010-10-23
+View all other issues in [futures].
+View all issues with NAD Editorial status.
+Discussion:
++30.6.6 [futures.unique_future]/1 should be updated to mention +async. +
+ ++30.6.7 [futures.shared_future]/1 should also be updated for +async. That paragraph also says +
+ ++... Its value or exception can be set by use of a +shared_future, promise (30.6.5 [futures.promise]), or packaged_task (30.6.10 [futures.task]) object that shares the same associated state. ++ ++How can the value be set by a shared_future? +
+ ++30.6.8 [futures.atomic_future]/1 says +
+ ++An atomic_future object can only be created by use of a +promise (30.6.5 [futures.promise]) or +packaged_task (30.6.10 [futures.task]) object. ++ ++which is wrong, it's created from a std::future, which could +have been default-cosntructed. That paragraph should be closer to the +text of 30.6.7 [futures.shared_future]/1, and should also mention +async. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3058. +
+ + +Proposed resolution:
+ + + + + +
+1281. CopyConstruction and Assignment between ratios having the same normalized form
+Section: 20.6.1 [ratio.ratio] Status: NAD Editorial + Submitter: Vicente Juan Botet Escribá Opened: 2009-12-07 Last modified: 2010-11-24
+View all other issues in [ratio.ratio].
+View all issues with NAD Editorial status.
+Discussion:
++CopyConstruction and Assignment between ratios having the same +normalized form. Current +N3000 +do not allows to copy-construct or assign ratio instances of +ratio classes having the same normalized form. +
+ ++Two ratio classes ratio<N1,D1> and +ratio<N2,D2> have the same normalized form if +
+ ++ +ratio<N1, D1>::num == ratio<N2, D2>::num && +ratio<N1, D1>::den == ratio<N2, D2>::den ++This simple example +
+ ++ +ratio<1,3> r1; +ratio<3,9> r2; +r1 = r2; // (1) ++fails to compile in (1). Other example +
+ ++ +ratio<1,3> r1; +ratio_subtract<ratio<2,3>, ratio<1,3>>::type r2; +r1 = r2; ++The nested type of ratio_subtract<ratio<2,3>, +ratio<1,3>> could be ratio<3,9> so the compilation +could fail. It could also be ratio<1,3> and the compilation +succeeds. +
+ ++In 20.6.2 [ratio.arithmetic] 3 and similar clauses +
+ ++3 The nested typedef type shall be a synonym for ratio<T1, +T2> where T1 has the value R1::num * R2::den - R2::num * +R1::den and T2 has the value R1::den * R2::den. ++ ++the meaning of synonym let think that the result shall be a normalized +ratio equivalent to ratio<T1, T2>, but there is not an +explicit definition of what synonym means in this context. +
+ ++Additionally we should add a typedef for accessing the normalized +ratio, and change 20.6.2 [ratio.arithmetic] to return only this +normalized result. +
+ +[ +2010 Pittsburgh: +]
+ + +++ ++There is no consensus to add the converting copy constructor or converting copy +assignment operator. However there was consensus to add the typedef. +
+ ++Proposed wording modified. Original proposed wording preserved here. Moved to +Review. +
+ +++ ++Make ratio default constructible, copy-constructible and assignable +from any ratio which has the same reduced form. +
+ ++Add to 20.6.1 [ratio.ratio] synopsis +
+ ++ +template <intmax_t N, intmax_t D = 1> +class ratio { +public: + static constexpr intmax_t num; + static constexpr intmax_t den; + + typedef ratio<num, den> type; + + ratio() = default; + template <intmax_t N2, intmax_t D2> + ratio(const ratio<N2, D2>&); + template <intmax_t N2, intmax_t D2> + ratio& operator=(const ratio<N2, D2>&); +}; ++Add to 20.6.1 [ratio.ratio]: +
+ +++ ++Two ratio classes ratio<N1,D1> and ratio<N2,D2> +have the same reduced form if ratio<N1,D1>::type is the same +type as ratio<N2,D2>::type +
+ ++Add a new section: [ratio.cons] +
+ +++ ++Construction and assignment [ratio.cons] +
+ +template <intmax_t N2, intmax_t D2> + ratio(const ratio<N2, D2>& r); ++ +++ ++Effects: Constructs a ratio object. +
++Remarks: This constructor shall not participate in overload resolution +unless r has the same reduced form as *this. +
+template <intmax_t N2, intmax_t D2> + ratio& operator=(const ratio<N2, D2>& r); ++ +++ ++Effects: None. +
++Returns: *this. +
++Remarks: This operator shall not participate in overload resolution +unless r has the same reduced form as *this. +
++Change 20.6.2 [ratio.arithmetic] +
+ +++ ++Implementations may use other algorithms to compute these values. If overflow +occurs, a diagnostic shall be issued. +
+ +template <class R1, class R2> struct ratio_add { + typedef see below type; +}; ++ ++The nested typedef type shall be a synonym for ratio<T1, +T2>::type where T1 has the value R1::num * +R2::den + R2::num * R1::den and T2 has the value R1::den * +R2::den. ++ +template <class R1, class R2> struct ratio_subtract { + typedef see below type; +}; ++ ++The nested typedef type shall be a synonym for ratio<T1, +T2>::type where T1 has the value R1::num * +R2::den - R2::num * R1::den and T2 has the value R1::den * +R2::den. ++ +template <class R1, class R2> struct ratio_multiply { + typedef see below type; +}; ++ ++The nested typedef type shall be a synonym for ratio<T1, +T2>::type where T1 has the value R1::num * +R2::num and T2 has the value R1::den * R2::den. ++ +template <class R1, class R2> struct ratio_divide { + typedef see below type; +}; ++ ++The nested typedef type shall be a synonym for ratio<T1, +T2>::type where T1 has the value R1::num * +R2::den and T2 has the value R1::den * R2::num. ++ +[ +2010-03-27 Howard adds: +]
+ + +++ ++Daniel brought to my attention the recent addition of the typedef type +to the FCD +N3092: +
+ ++ +typedef ratio type; ++This issue was discussed in Pittsburgh, and the decision there was to accept the +typedef as proposed and move to Review. Unfortunately the issue was accidently +applied to the FCD, and incorrectly. The FCD version of the typedef refers to +ratio<N, D>, but the typedef is intended to refer to +ratio<num, den> which in general is not the same type. +
+ ++I've updated the wording to diff against +N3092. +
+ +[Batavia: NAD Editorial - see rationale below]
+ + + + +Rationale:
Already fixed in working draft + +Proposed resolution:
++Add to 20.6.1 [ratio.ratio] synopsis +
+ ++ + + + + + +template <intmax_t N, intmax_t D = 1> +class ratio { +public: + static constexpr intmax_t num; + static constexpr intmax_t den; + + typedef ratio<num, den> type; +}; +
+1282. A proposal to add std::split algorithm
+Section: 25 [algorithms] Status: NAD Future + Submitter: Igor Semenov Opened: 2009-12-07 Last modified: 2010-10-23
+View all other issues in [algorithms].
+View all issues with NAD Future status.
+Discussion:
++ +
+ +- +
+ ++Motivation and Scope +
++Splitting strings into parts by some set of delimiters is an often task, but +there is no simple and generalized solution in C++ Standard. Usually C++ +developers use std::basic_stringstream<> to split string into +parts, but there are several inconvenient restrictions: +
+ ++
+- +we cannot explicitly assign the set of delimiters; +
+- +this approach is suitable only for strings, but not for other types of +containers; +
+- +we have (possible) performance leak due to string instantiation. +
+- +
+ ++Impact on the Standard +
++This algorithm doesn't interfere with any of current standard algorithms. +
+- +
+ ++Design Decisions +
++This algorithm is implemented in terms of input/output iterators. Also, there is +one additional wrapper for const CharType * specified delimiters. +
+- +
+ ++Example implementation +
+template< class It, class DelimIt, class OutIt > +void split( It begin, It end, DelimIt d_begin, DelimIt d_end, OutIt out ) +{ + while ( begin != end ) + { + It it = std::find_first_of( begin, end, d_begin, d_end ); + *out++ = std::make_pair( begin, it ); + begin = std::find_first_of( it, end, d_begin, d_end, + std::not2( std::equal_to< typename It::value_type >() ) ); + } +} + +template< class It, class CharType, class OutIt > +void split( It begin, It end, const CharType * delim, OutIt out ) +{ + split( begin, end, delim, delim + std::strlen( delim ), out ); +} ++- +
+ ++Usage +
+std::string ss( "word1 word2 word3" ); +std::vector< std::pair< std::string::const_iterator, std::string::const_iterator > > v; +split( ss.begin(), ss.end(), " ", std::back_inserter( v ) ); + +for ( int i = 0; i < v.size(); ++i ) +{ + std::cout << std::string( v[ i ].first, v[ i ].second ) << std::endl; +} +// word1 +// word2 +// word3 ++[ +2010-01-22 Moved to Tentatively NAD Future after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + +Rationale:
++The LWG is not considering completely new features for standardization at this +time. We would like to revisit this good suggestion for a future TR and/or +standard. +
+ + +Proposed resolution:
++Add to the synopsis in 25.1 [algorithms.general]: +
+ ++ +template< class ForwardIterator1, class ForwardIterator2, class OutputIterator > + void split( ForwardIterator1 first, ForwardIterator1 last, + ForwardIterator2 delimiter_first, ForwardIterator2 delimiter_last, + OutputIterator result ); + +template< class ForwardIterator1, class CharType, class OutputIterator > + void split( ForwardIterator1 first, ForwardIterator1 last, + const CharType * delimiters, OutputIterator result ); ++Add a new section [alg.split]: +
+ ++ + + + + +template< class ForwardIterator1, class ForwardIterator2, class OutputIterator > + void split( ForwardIterator1 first, ForwardIterator1 last, + ForwardIterator2 delimiter_first, ForwardIterator2 delimiter_last, + OutputIterator result ); ++ +++ ++1. Effects: splits the range [first, last) into parts, using any +element of [delimiter_first, delimiter_last) as a delimiter. Results +are pushed to output iterator in the form of std::pair<ForwardIterator1, +ForwardIterator1>. Each of these pairs specifies a maximal subrange of +[first, last) which does not contain a delimiter. +
++2. Returns: nothing. +
++3. Complexity: Exactly last - first assignments. +
+template< class ForwardIterator1, class CharType, class OutputIterator > + void split( ForwardIterator1 first, ForwardIterator1 last, + const CharType * delimiters, OutputIterator result ); ++ +++ ++1. Effects: split the range [first, last) into parts, using any +element of delimiters (interpreted as zero-terminated string) as a +delimiter. Results are pushed to output iterator in the form of +std::pair<ForwardIterator1, ForwardIterator1>. Each of these +pairs specifies a maximal subrange of [first, last) which does not +contain a delimiter. +
++2. Returns: nothing. +
++3. Complexity: Exactly last - first assignments. +
+
+1289. Generic casting requirements for smart pointers
+Section: 20.3 [utility] Status: NAD Future + Submitter: Ion Gaztańaga Opened: 2009-12-14 Last modified: 2010-11-24
+View all other issues in [utility].
+View all issues with NAD Future status.
+Discussion:
++In section 20.2.5 [allocator.requirements], Table 40 — Allocator requirements, +the following expression is required for allocator pointers: +
+ +++ ++
+Table 40 — Allocator requirements ++ +Expression +Return type +Assertion/note +
pre-/post-conditionDefault ++ +static_cast<X::pointer>(w) +X::pointer +static_cast<X::pointer>(w) == p ++ +To achieve this expression, a smart pointer writer must introduce an explicit +conversion operator from smart_ptr<void> to +smart_ptr<T> so that +static_cast<pointer>(void_ptr) is a valid expression. +Unfortunately this explicit conversion weakens the safety of a smart pointer +since the following expression (invalid for raw pointers) would become valid: +
+ ++ +smart_ptr<void> smart_v = ...; +smart_ptr<T> smart_t(smart_v); ++On the other hand, shared_ptr also defines its own casting functions in +20.9.10.2.10 [util.smartptr.shared.cast], and although it's unlikely that a +programmer will use shared_ptr as allocator::pointer, having +two different ways to do the same cast operation does not seem reasonable. A +possible solution would be to replace static_cast<X::pointer>(w) +expression with a user customizable (via ADL) +static_pointer_cast<value_type>(w), and establish the +xxx_pointer_cast functions introduced by shared_ptr as the +recommended generic casting utilities of the standard. +
+ ++Unfortunately, we've experienced problems in Boost when trying to establish +xxx_pointer_cast as customization points for generic libraries (http://objectmix.com/c/40424-adl-lookup-explicit-template-parameters.html) +because these casting functions are called with explicit template parameters and +the standard says in 14.8.1 [temp.arg.explicit] p.8 "Explicit template +argument specification": +
+ ++8 ...But when a function template with explicit template arguments is used, the +call does not have the correct syntactic form unless there is a function +template with that name visible at the point of the call. If no such name is +visible, the call is not syntactically well-formed and argument-dependent lookup +does not apply. ++ ++So we can do this: +
+ ++ +template<class BasePtr> +void generic_ptr_swap(BasePtr p) +{ + //ADL customization point + swap(p, p); + //... +} ++but not the following: +
+ ++ +template<class BasePtr> +void generic_ptr_algo(BasePtr p) +{ + typedef std::pointer_traits<BasePtr>::template + rebind<Derived> DerivedPtr; + DerivedPtr dp = static_pointer_cast<Derived>(p); +} ++The solution to make static_pointer_cast a customization point is to +add a generic declaration (no definition) of static_pointer_cast in a +namespace (like std) and apply "using +std::static_pointer_cast" declaration to activate ADL: +
+ ++ +namespace std{ + +template<typename U, typename T> +unspecified +static_pointer_cast(T&&) = delete; + +} + +template<class BasePtr> +void generic_ptr_algo(BasePtr p) +{ + typedef std::pointer_traits<BasePtr>::template + rebind<Derived> DerivedPtr; + + //ADL applies because static_pointer_cast is made + // visible according to [temp.arg.explicit]/8 + using std::static_pointer_cast; + + DerivedPtr dp = static_pointer_cast<Derived>(p); + + //... +} ++A complete solution will need also the definition of +static_pointer_cast for raw pointers, and this definition has been +present in Boost (http://www.boost.org/boost/ +pointer_cast.hpp) for years. +
+ +[ +2010-03-26 Daniel made editorial adjustments to the proposed wording. +]
+ + +[ +Moved to NAD Future at 2010-11 Batavia +]
+ ++This is a new feature rather than a defect. +It can be added later: "this is such a hairy area that people will put up with changes" ++ + + +Proposed resolution:
++Add to section 20.3 [utility] Utility components, Header +<utility> synopsis: +
+ ++ +// 20.3.X, generic pointer cast functions + +template<typename U, typename T> +unspecified +static_pointer_cast(T&&) = delete; + +template<typename U, typename T> +unspecified +dynamic_pointer_cast(T&&) = delete; + +template<typename U, typename T> +unspecified +const_pointer_cast(T&&) = delete; + +//Overloads for raw pointers +template<typename U, typename T> +auto static_pointer_cast(T* t) -> decltype(static_cast<U*>(t)); + +template<typename U, typename T> +auto dynamic_pointer_cast(T* t) -> decltype(dynamic_cast<U*>(t)); + +template<typename U, typename T> +auto const_pointer_cast(T* t) -> decltype(const_cast<U*>(t)); ++Add to section 20.3 [utility] Utility components, a new subclause +20.3.X Pointer cast utilities [pointer.cast]: +
+ +++ ++20.3.X Pointer cast utilities [pointer.cast] +
+ ++1 The library defines generic pointer casting function templates so that template code +can explicitly make these names visible and activate argument-dependent lookup +for pointer cast calls. +
+ +//Generic declarations +template<typename U, typename T> +unspecified +static_pointer_cast(T&&) = delete; + +template<typename U, typename T> +unspecified +dynamic_pointer_cast(T&&) = delete; + +template<typename U, typename T> +unspecified +const_pointer_cast(T&&) = delete; ++ ++2 The library also defines overloads of these functions for raw pointers. +
+ +//Overloads for raw pointers +template<typename U, typename T> +auto static_pointer_cast(T* t) -> decltype(static_cast<U*>(t)); ++ ++Returns: static_cast<U*>(t) ++ +template<typename U, typename T> +auto dynamic_pointer_cast(T* t) -> decltype(dynamic_cast<U*>(t)); ++ ++Returns: dynamic_cast<U*>(t) ++ +template<typename U, typename T> +auto const_pointer_cast(T* t) -> decltype(const_cast<U*>(t)); ++ ++Returns: const_cast<U*>(t) ++ ++[Example: +
+ ++ +#include <utility> //static_pointer_cast +#include <memory> //pointer_traits + +class Base{}; +class Derived : public Base{}; + +template<class BasePtr> +void generic_pointer_code(BasePtr b) +{ + typedef std::pointer_traits<BasePtr>::template + rebind<Derived> DerivedPtr; + + using std::static_pointer_cast; + //ADL applies now that static_pointer_cast is visible + DerivedPtr d = static_pointer_cast<Derived>(b); +} ++— end example] +
+ ++Replace in section 20.2.5 [allocator.requirements] Table 40 — Allocator +requirements, the following table entries for allocator pointers: +
+ +++ + + + + + ++
+Table 40 — Allocator requirements ++ + +Expression +Return type +Assertion/note +
pre-/post-conditionDefault ++ + +static_pointer_cast< +X::pointerT>(w)X::pointer +static_pointer_cast< +X::pointerT>(w) == p+ + + +static_pointer_cast< +X::const_pointerconst T>(w)X::const_pointer +static_pointer_cast< +X::const_pointerconst T>(z) == q+
+1291. exceptions thrown during promise::set_value
+Section: 30.6.5 [futures.promise] Status: NAD Editorial + Submitter: Jonathan Wakely Opened: 2009-12-18 Last modified: 2010-10-23
+View other active issues in [futures.promise].
+View all other issues in [futures.promise].
+View all issues with NAD Editorial status.
+Discussion:
++In 30.6.5 [futures.promise] +
+ ++Does promise<R>::set_value return normally if the copy/move +constructor of R throws? +
+ ++The exception could be caught and set using +promise<R>::set_exception, or it could be allowed to leave the +set_value call, but it's not clear which is intended. I suggest the +exception should not be caught. +
+ ++N.B. This doesn't apply to promise<R&>::set_value or +promise<void>::set_value because they don't construct a new +object. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3058. +
+ + +Proposed resolution:
++Change 30.6.5 [futures.promise]/18: +
+ ++18 Throws: future_error if its associated state is already +ready or, for the first version an exception thrown by the copy constructor +of R, or for the second version an exception thrown by the move +constructor of R. ++ + + + + +
+1296. map and multimap value_compare overspecified
+Section: 23.6.1 [map] Status: NAD + Submitter: Alisdair Meredith Opened: 2009-12-22 Last modified: 2010-10-23
+View all other issues in [map].
+View all issues with NAD status.
+Discussion:
++The container class templates map and multimap both contain a +nested type called value_compare, that is used to compare the +value_type pair elements, an adaptor of the user-supplied comparison +function-like object. +
+ ++I believe these types are over-specified, as we require a distinct type for each +template, even though the allocator plays no part in the comparator, and +map and multimap value_compare classes could easily be shared. + The benefits are similar to the SCARY iterator proposal (although on a much +smaller scale!) but unlike SCARY, this is not a QoI issue today but actively +prohibited. +
+ ++If the value_compare classes were marked 'exposition only', a vendor +would be free to experiment with implementations that do not produce so many +template instantiations with negligible impact on conforming programs. (There +is a minor risk that programs could no longer portably overload functions taking +value_compare types. This scenario is extremely unlikely outside +conformance suites.) +
+ ++(Note that there are no similar problems for unordered maps, nor any of the set +variants) +
+ +[ +2010-01-31 Moved to Tentatively NAD after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + +Rationale:
++The value_compare specification is an unfortunate bit from the past +that we have to live with. Fortunately vendors can work around the problems +mentioned in this issue. +
+ + + + +Proposed resolution:
++p2 23.6.1 [map]: +Above the declaration of class value_compare in the map synopsis, add: +
+ ++ + + +template <class Key, class T, class Compare = less<Key>, + class Allocator = allocator<pair<const Key, T> > > +class map { +public: + // types: + ... + // exposition only. + class value_compare + : public binary_function<value_type,value_type,bool> { + ... ++p2 23.6.2 [multimap]: +Above the declaration of class value_compare in the map synopsis, add: +
+ ++ + + + + +template <class Key, class T, class Compare = less<Key>, + class Allocator = allocator<pair<const Key, T> > > +class multimap { +public: + // types: + ... + // exposition only. + class value_compare + : public binary_function<value_type,value_type,bool> { + ... +
+1300. circular definition of promise::swap
+Section: 30.6.5 [futures.promise] Status: NAD Editorial + Submitter: Jonathan Wakely Opened: 2009-12-26 Last modified: 2010-10-23
+View other active issues in [futures.promise].
+View all other issues in [futures.promise].
+View all issues with NAD Editorial status.
+Discussion:
++30.6.5 [futures.promise]/12 defines the effects of +promise::swap(promise&) as +
+ ++ +void swap(promise& other); +++12 Effects: swap(*this, other) +++and 30.6.5 [futures.promise]/25 defines swap(promise<R&>, +promise<R>&) as +
+ ++ +template <class R> + void swap(promise<R>& x, promise<R>& y); +++25 Effects: x.swap(y). ++[ +2010-01-13 Daniel added "Throws: Nothing." +]
+ + +[ +2010-01-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added below. ++ + + +Rationale:
++Solved by N3058. +
+ + +Proposed resolution:
++Change 30.6.5 [futures.promise] paragraph 12 +
+ ++ + + + + + +void swap(promise& other); +++++12 Effects:
+swap(*this, other)Exchanges the +associated +states of *this and other. ++13 ... +
++Throws: Nothing. +
+
+1301. clear() and assignment
+Section: 23.2.3 [sequence.reqmts] Status: NAD Editorial + Submitter: Nicolai Josuttis Opened: 2010-01-01 Last modified: 2010-10-23
+View all other issues in [sequence.reqmts].
+View all issues with NAD Editorial status.
+Discussion:
++I propose that clear() be defined to be equivalent to +erase(begin(),end()) except not using copy or move of elements. +
+ +++ ++To: C++ libraries mailing list
+ +
+Message c++std-lib-26465 ++and specifiying as post: size()==0 might also not be appropriate +because forward-Lists provide no size(), this it should be: +post: empty()==true +
+ ++Bjarne Stroustrup schrieb/wrote: +
+ ++++To: C++ libraries mailing list
+ +
+Message c++std-lib-26458 ++in table 94 we define clear() as: +
+ ++ +a.clear() void erase(begin(), end()) +post: size() == 0 ++Now erase requires assignment (MoveAssignable) which makes +sense if we have to move an element, but why should that be required from +clear() where all elements are destroyed? +
+[ +2010-01-23 Alisdiar provides wording. +]
+ + +[ +2010-01-30 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-01-30 Daniel opens: +]
+ + +++ ++First, I read the newly proposed spec for clear() that it does in +general not invalidate a previous past-the-end iterator value, but +deque says in 23.3.2.3 [deque.modifiers] for the semantics of +erase that erasures at the end will invalidate the past-the-end +iterator. With removal of a direct binding between clear() and +erase() there seem to be some fixes necessary. One way to fix that +would be to mention in Table 94 that this "may also invalidate the past-the-end +iterator" and then to mention for all specific containers where this does not +happen, the exception, [1] e.g. in std::vector. std::vector +has no own specification of clear() and one aspect of the closed issue +1102 was to realize just that (indirectly via erase). IMO +we should now add an extra specification for clear(). Btw.: +std::vector::erase reads to me that it would invalidate previous +past-the-end values (and that seems correct in general). +
++Before I will provide explicit wording, I would like to +discuss these points. +
+ ++[1] std::list does fortunately specify that clear does not invalidate +the past-the-end iterator. +
+[ +2010-02-08 Moved to Tentatively NAD Editorial after 5 positive votes on c++std-lib. +Rationale added below. +]
+ + + + +Rationale:
++Solved as proposed by LWG 704. +
+ + +Proposed resolution:
+ ++Change 23.2.1 [container.requirements.general]/10: +
+ +++ ++Unless otherwise specified (see 23.2.4.1, 23.2.5.1, 23.3.2.3, and 23.3.6.4) all +container types defined in this Clause meet the following additional +requirements: +
+ ++
+ +- +.. +
+ +- +no erase(), clear(), pop_back() or +pop_front() function throws an exception. +
+ +- +... +
++Replace the following words from Table 94 — Sequence container +requirements (in addition to container) in 23.2.3 [sequence.reqmts]: +
+ +++ ++
+Table 94 — Sequence container requirements (in addition to +container) ++ + +Expression +Return type +Assertion/note +
pre-/post-condition+ +a.clear() +void ++ erase(begin(), end())
+Destroys all elements in the container a. Invalidates all references, +pointers, and iterators referring to the elements of a and may +invalidate the past-the-end iterator.
+post:size() == 0a.empty() == true.+Add a new paragraph after 23.3.3.4 [forwardlist.modifiers]/23: +
+ ++ + + + + + +void clear(); ++ ++++23 Effects: Erases all elements in the range [begin(),end()). +
++Remarks: Does not invalidate past-the-end iterators. +
+
+1302. different emplace semantics for sequence and associated containers
+Section: 23.2.4 [associative.reqmts], 23.2.5 [unord.req] Status: NAD + Submitter: Nicolai Josuttis Opened: 2010-01-03 Last modified: 2010-10-23
+View other active issues in [associative.reqmts].
+View all other issues in [associative.reqmts].
+View all issues with NAD status.
+Discussion:
++According to the new naming scheme introduced with +N2680 +
+ ++ +vector<T> v; +v.emplace(v.begin(),x,y,z) ++now has a different semantics than +
+ ++ +set<T> s; +s.emplace(s.begin(),x,y,z); ++While the version for vectors takes the first argument as position and +the remaining for construction, the version for sets takes all +arguments for construction. +
+ ++IMO, this is a serious design mistake for a couple of reasons: +
+ ++
+ +- +
++First, in principle, all STL member functions should have the same behavior with +the same member function to avoid confusion and allow to write proper generic +code. +
++In fact, when I write the following simple function template: +
++template <typename T> +void doEmplace (T& cont) +{ + cont.emplace(cont.begin(),"nico","josuttis",42); +} ++the semantics depends on the type of the container. +
+- +
++In addition, I also guess using the name emplace_hint() instead of +emplace() for associative containers is a design mistake. According to +my knowledge, it was a design goal of the original STL to provide ONE +insert function, which works for ALL containers. This was +insert(pos,val). +
++The trick to declare pos as a hint, allowed that we could implement a +generic insert for all containers. Now, with the new emplace +naming scheme, this trick is gone for the new kind of insertion. +
++I consider this to be a serious design penalty because once this +is specified we can't fix that without breaking backward compatibility. +
+ ++However, we have two choices for a fix: +
+ ++
+ +- +rename emplace_hint(pos,val) for associative containers back to +emplace(pos,val). However to avoid the overloading problems, we also +have to rename the existing emplace(val) functions to something else (I +don't have a good name here at hand). +
+- +Keep emplace(val) for associative containers as it is, but rename +emplace(pos,val) for sequence containers and +emplace_hint(pos,val) to something like emplace_at(pos,val), +declaring that pos is a hint for associative containers. +
+[ +2010 Pittsburgh: Moved to NAD, rationale added below. +]
+ + + + +Rationale:
++There was no consensus to make this change. +
+ + +Proposed resolution:
+In 23.2.5 [unord.req], change:
++++
+ +Table 96 — Associative container requirements (in addition to + container) ++ +expression +Return type +Assertion/note pre-/post-condition +Post-condition ++ +... ++ +a_uniq.emplace_value(args) +pair<iterator, bool> +inserts a T object t constructed with std::forward<Args>(args)... +
+ if and only if there is no element in the container with key equivalent + to the key of t.
+ The bool component of the returned pair is true if and only if the insertion + takes place, and the iterator component of the pair points to the element + with key equivalent to the key of t.logarithmic ++ +a_eq.emplace_value(args) +iterator +inserts a T object t constructed with std::forward<Args>(args)... + and returns the iterator pointing to the newly inserted element. +logarithmic ++ +a.emplace +_hint(p,args)iterator +equivalent to + a.emplace_value(std::forward<Args>(args)...). + Return value is an iterator pointing to the element with the key + equivalent to the newly inserted element. The const_iterator p is a hint + pointing to where the search should start. Implementations are permitted + to ignore the hint. logarithmic in general, but amortized + constant if the element is inserted right after p ++ +... +In 23.2.5 [unord.req], change:
+++ ++
+Table 98 — Unordered associative container requirements (in + addition to container) ++ +expression +Return type +Assertion/note pre-/post-condition +Post-condition ++ +... ++ +a_uniq.emplace_value(args) +pair<iterator, bool> +inserts a T object t constructed with std::forward<Args>(args)... if + and only if there is no element in the container with key equivalent to + the key of t. The bool component of the returned pair is true if and only + if the insertion takes place, and the iterator component of the pair points + to the element with key equivalent to the key of t. +Average case O(1), worst case O(a_uniq.size()). ++ +a_eq.emplace_value(args) +iterator +inserts a T object t constructed with std::forward<Args>(args)... + and returns the iterator pointing to the newly inserted element. +Average case O(1), worst case O(a_eq.size()). ++ +a.emplace +_hint(p,args)iterator +equivalent to + a.emplace_value(std::forward<Args>(args)...). + Return value is an iterator pointing to the element with the key + equivalent to the newly inserted element. The const_iterator p is a hint + pointing to where the search should start. Implementations are permitted + to ignore the hint. Average case O(1), worst case + O(a.size()). ++ +... ++In 23.6.1 [map], 23.6.3 [set], 23.7.1 [unord.map], 23.7.3 [unord.set], change: +
+++ +// modifiers:
+
+ template <class... Args> pair<iterator, bool> emplace_value(Args&&... + args);
+ template <class... Args> iterator emplace_hint(const_iterator + position, Args&&... args);+In 23.6.2 [multimap], 23.6.4 [multiset], 23.7.2 [unord.multimap], 23.7.4 [unord.multiset], change: +
+++ + + + + +// modifiers:
+
template <class... Args> iterator emplace_value(Args&&... + args);
+ template <class... Args> iterator emplace_hint(const_iterator position, + Args&&... args);
+
+1304. missing preconditions for shared_future
+Section: 30.6.7 [futures.shared_future] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2010-01-23 Last modified: 2010-10-23
+View all other issues in [futures.shared_future].
+View all issues with NAD Editorial status.
+Discussion:
+ ++The revised futures package in the current working paper simplified the +is_ready/has_exception/has_value set of APIs, replacing them with a +single 'valid' method. This method is used in many places to signal pre- and +post- conditions, but that edit is not complete. Each method on a +shared_future that requires an associated state should have a +pre-condition that valid() == true. +
+ +[ +2010-01-28 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added below. ++ + + +Rationale:
++Solved by N3058. +
+ + +Proposed resolution:
++Insert the following extra paragraphs: +
+ ++In 30.6.7 [futures.shared_future] +
+ ++ +shared_future(); +++++4 Effects: constructs ... +
+ ++Postcondition: valid() == false. +
+ ++Throws: nothing. +
++ +void wait() const; +++ +++Requires: valid() == true. +
+ ++22 Effects: if the associated ... +
++ +template <class Rep, class Period> + bool wait_for(const chrono::duration<Rep, Period>& rel_time) const; +++ +++Requires: valid() == true. +
+ ++23 Effects: if the associated ... +
++ + + + + + +template <class Clock, class Duration> + bool wait_until(const chrono::time_point<Clock, Duration>& abs_time) const; +++ +++Requires: valid() == true. +
+ ++25 Effects: blocks until ... +
+
+1305. preconditions for atomic_future
+Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2010-01-23 Last modified: 2010-10-23
+View all other issues in [futures.atomic_future].
+View all issues with NAD Editorial status.
+Discussion:
+ ++The revised futures package in the current working paper simplified the +is_ready/has_exception/has_value set of APIs, replacing them with a +single 'valid' method. This method is used in many places to signal pre- and +post- conditions, but that edit is not complete. +
+ ++Atomic future retains the extended earlier API, and provides defined, +synchronized behaviour for all calls. However, some preconditions and throws +clauses are missing, which can easily be built around the new valid() +api. Note that for consistency, I suggest is_ready/has_exception/has_value +throw an exception if valid() is not true, rather than +return false. I think this is implied by the existing pre-condition on +is_ready. +
+ +[ +2010-01-23 See discussion starting with Message c++std-lib-26666. +]
+ + +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3058. +
+ + +Proposed resolution:
++Insert the following extra paragraphs: +
+ ++In 30.6.8 [futures.atomic_future] +
+ ++ +bool is_ready() const; +++++17
+ +PreconditionRequires: valid() == true. ++18 Returns: true only if the associated state is ready. +
+ ++Throws: future_error with an error condition of +no_state if the precondition is not met. +
+ ++ +bool has_exception() const; +++ +++Requires: valid() == true. +
+ ++19 Returns: true only if the associated state is ready and +contains an exception. +
+ ++Throws: future_error with an error condition of +no_state if the precondition is not met. +
+ ++ +bool has_value() const; +++ +++Requires: valid() == true. +
+ ++20 Returns: true only if the associated state is ready and +contains a value. +
+ ++Throws: future_error with an error condition of +no_state if the precondition is not met. +
+ ++ +void wait() const; +++ +++Requires: valid() == true. +
+ ++22 Effects: blocks until ... +
+ ++Throws: future_error with an error condition of +no_state if the precondition is not met. +
+ ++ +template <class Rep, class Period> + bool wait_for(const chrono::duration<Rep, Period>& rel_time) const; +++ +++Requires: valid() == true. +
+ ++23 Effects: blocks until ... +
+ ++24 Returns: true only if ... +
+ ++Throws: future_error with an error condition of +no_state if the precondition is not met. +
+ ++ + + + + + +template <class Clock, class Duration> + bool wait_until(const chrono::time_point<Clock, Duration>& abs_time) const; +++ +++Requires: valid() == true. +
+ ++25 Effects: blocks until ... +
+ ++26 Returns: true only if ... +
+ ++Throws: future_error with an error condition of +no_state if the precondition is not met. +
+ +
+1308. Concerns about initializer_list overloads of min, +max, and minmax
+Section: 25.4.7 [alg.min.max] Status: NAD + Submitter: Niels Dekker Opened: 2010-02-02 Last modified: 2010-10-23
+View all other issues in [alg.min.max].
+View all issues with NAD status.
+Discussion:
++In San Francisco, June 2008, N2722 +was adopted, replacing the variadic templates min, max, and +minmax by overloads that have an initializer_list<T> +parameter. The paper showed benchmark results wherein initializer_list +versions of min appeared to outperform the corresponding variadic +template. Unfortunately, in October 2009 a very serious error was detected in +the benchmark. (c++std-lib-25210). +In fact, an initializer_list<T> version of min often +appears to perform worse than the corresponding variadic template, +especially when T has an expensive copy constructor (c++std-lib-25253, +http://www.xs4all.nl/~nd/dekkerware/issues/n2772_fix). +
++IMO, the biggest problem of the initializer_list overloads is that they +pass and return T objects by value. Which has the following +consequences: +
+ ++
+ +- +They require that T is CopyConstructible. IMO that is too much of a +constraint for a generic, general purpose function like +std::min<T>. +
+- +They potentially throw an exception, even if T's less-than-operator +throws nothing. (And of course, less-than typically throws nothing.) +
+- +They are inconsistent with C++03 std::min and std::max. +Consider the subtle difference between const T& c1 = min(a,b); and +const T& c2 = min({a,b}); (c++std-lib-25265) +
+- +They do not conveniently support use cases that need to have a reference to the +minimum or maximum object itself, rather than just a copy. +
+- +They potentially perform badly: possibly O(n), when the arguments +themselves have a size of n. +
++In the future, this problem might be solvable by using an +initializer_list of const references, instead: +
++ +const T& min(initializer_list<const T&>); +const T& max(initializer_list<const T&>); +pair<const T&, const T&> minmax(initializer_list<const T&>); ++It is unlikely that C++0x will support initializer_list<const +T&>, but technically it seems possible to add such a language +feature after C++0x (c++std-core-15428). +
++Variadic templates of min, max, and minmax, as +proposed by N2551 +(Sylvain Pion), do have some other advantages over initializer_list +overloads: +
++
+ +- +It is likely that those variadic templates can be declared constexpr, +now that +CWG issue #991 is in drafting status. +
+- +They provide complete compile-time protection against accidentally passing zero +arguments. +
++Unfortunately, the variadic templates of min, max, and +minmax may still need further improvement, before having them in the +Standard Library. Especially the optional Compare parameter appears to +be a concern. So for this moment I recommend to keep both versions out of C++0x, +and postpone further discussion until after C++0x. +
+ +[ +2010 Pittsburgh: Discussed and the LWG still prefers the initializer list +solution of +N2772. +]
+ + + + +Rationale:
+We prefer the solution of +N2772 +which will be reapplied. + + +Proposed resolution:
++Remove both variadic templates and initializer_list overloads of +min, max, and minmax from the synopsis in +25.1 [algorithms.general] and from 25.4.7 [alg.min.max]. +
+ +++ + + + + +[ +Note: This proposed resolution will resolve LWG 915 as NAD. +]
+ +
+1311. multi-pass property of Forward Iterator underspecified
+Section: 24.2.5 [forward.iterators] Status: NAD Editorial + Submitter: Alisdair Meredith Opened: 2010-02-07 Last modified: 2010-10-23
+View all other issues in [forward.iterators].
+View all issues with NAD Editorial status.
+Discussion:
++The following example demonstrates code that would meet the guarantees of a +Forward Iterator, but only permits a single traversal of the underlying +sequence: +
+ ++ +template< typename ForwardIterator> +struct bad_iterator { + shared_ptr<ForwardIterator> impl; + + bad_iterator( ForwardIterator iter ) { + : impl{new ForwardIterator{iter} } + { + } + + auto operator*() const -> decltype(*ForwardIterator{}) { + return **impl; + } + + auto operator->() const -> ForwardIterator { + return *impl; + } + + auto operator==(bad_iterator const & rhs) { + return impl == rhs.impl; + } + + auto operator++() { + ++(*imp); + } + // other operations as necessary... +}; ++Here, we use shared_ptr to wrap a forward iterator, so all iterators +constructed from the same original iterator share the same 'value', and +incrementing any one copy increments all others. +
+ ++There is a missing guarantee, expressed by the following code sequence +
+ ++ +FwdIter x = seq.begin(); // obtain forward iterator from a sequence +FwdIter y = x; // copy the iterator +assert(x == y); // iterators must be the same +++x; // increment *just one* iterator +assert(x != y); // iterators *must now be different* +++y; // increment the other iterator +assert(x == y); // now the iterators must be the same again ++That inequality in the middle is an essential guarantee. Note that this list is +simplified, as each assertion should also note that they refer to exactly the +same element (&*x == &*y) but I am not complicating the issue +with tests to support proxy iterators, or value types overloading unary +operator+. +
+ ++I have not yet found a perverse example that can meet this additional +constraint, and not meet the multi-pass expectations of a Forward Iterator +without also violating other Forward Iterator requirements. +
+ ++Note that I do not yet have standard-ready wording to resolve the problem, as +saying this neatly and succinctly in 'standardese' is more difficult. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3066. +
+ + +Proposed resolution:
+ + + + + +
+1313. Seed sequence's param function not useful for pure output iterator
+Section: 26.5.7.1 [rand.util.seedseq] Status: NAD + Submitter: Daniel Krügler Opened: 2010-02-07 Last modified: 2010-10-23
+View all other issues in [rand.util.seedseq].
+View all issues with NAD status.
+Discussion:
++The Seed sequence requirements (26.5.1.2 [rand.req.seedseq]) require the +existence of a member function +
+ ++ +template<typename OutputIterator> +void param(OutputIterator ob); ++The fact that this function returns void instead of the value of +ob after accepting the sequence data leads to the same problem as in +issue 865 - In case of pure output iterators there is no way to +serialize further data into that data sink. +
+ +[ +2010-02-07 Howard adds: +]
+ + ++At the time this issue was opened, the suggested changes are with respect to an +anticipated draft which does not yet exist. ++ +[ +2010 Pittsburgh: +]
+ + ++No technical counterarguments, but it is simply too late in the process +to make this change at this point. ++ + +Proposed resolution:
++
+ + + + + + +- +
+ ++In Table 109 — Seed sequence requirements, expression "r.param(ob)" +change the
+ +
+Return type entry: ++voidOutputIterator +- +
+ ++In 26.5.7.1 [rand.util.seedseq], class seed_seq synopsis change +
+ ++template<class OutputIterator> +voidOutputIterator param(OutputIterator dest) const; +
+1314. NULL and nullptr
+Section: 18.2 [support.types] Status: NAD + Submitter: Sean Hunt Opened: 2010-02-07 Last modified: 2010-10-23
+View all other issues in [support.types].
+View all issues with NAD status.
+Discussion:
++Currently, the 18.2 [support.types]/3 allows NULL to be any +null pointer constant. The footnote marks that 0 or 0L might be appropriate. +However, this definition also allows the implementation to define NULL +to be nullptr. This may lead to overload and conversion issues more +serious than with the C++98 version: +
+ ++ +void f(void*); +void f(int); + +void g() +{ + // calls f(int) if NULL is integral + // calls f(void*) if NULL is nullptr + f(NULL); +} ++Possible resolutions: +
++
+ +- +Forbid NULL from being nullptr +
+- +Require NULL to be nullptr +
+- +Leave it as is +
++Making NULL nullptr would improve code correctness, and +breaking backwards compatibility shouldn't be a huge concern as NULL +shouldn't be used except as a null pointer constant anyways. +
+ +[ +2010-02-10 Chris provided wording. +]
+ + +[ +2010 Pittsburgh: Moved to NAD, rationale added below. +]
+ + + + +Rationale:
++The LWG discussed the proposed resolution and several other options. There was +no concensus to make this or any other changes. +
+ + +Proposed resolution:
++18.2 [support.types] +
+ +++ ++3 The macro NULL is defined to be nullptr.
+ +is +an implementation-defined C++ null pointer constant in this International +Standard (4.10).196++
+196) Possible definitions include 0 and 0L, but not +(void*)0. ++20.9.13 [c.malloc] +
+ ++7 The contents are the same as the Standard C library header +<string.h>, with the change to memchr() specified in +21.6 and the macro NULL defined to be nullptr. ++ + ++20.12 [date.time] +
+ ++2 The contents are the same as the Standard C library header +<time.h>+ + +.232 except the macro +NULL, which is defined to be nullptr. The functions +asctime, ctime, gmtime, and localtime are +not required to avoid data races (17.6.4.8). ++22.6 [c.locales] +
+ ++2 The contents are the same as the Standard C library header +<locale.h> except the macro NULL, which is defined +to be nullptr. ++ ++C.2.2.4 [diff.null] +
+ ++1 The macro NULL, defined in any of <clocale>, +<cstddef>, <cstdio>, <cstdlib>, +<cstring>, <ctime>, or <cwchar>, is +nullptr+ + + + + + +an implementation-defined C++ null pointer constant in +this International Standard (18.2).+
+1315. return type of async
+Section: 30.6.9 [futures.async] Status: NAD Editorial + Submitter: Jonathan Wakely Opened: 2009-02-09 Last modified: 2010-10-23
+View all other issues in [futures.async].
+View all issues with NAD Editorial status.
+Discussion:
++Both overloads of async return future<typename +F::result_type> which requires that F has a nested type. This +prevents async being used with function pointers and makes the example +in 30.6.9 [futures.async] invalid. I believe this is unintentional. +
+ ++The proposed resolution also addresses editorial issues with the +launch_policy function parameter. +
+ ++For the first overload it is not sufficient to return future<typename +result_of<F(ArgTypes...)>::type>. Calling async(launch::xxx, +foo, bar) performs argument deduction on both async overloads, +which for the first overload attempts to instantiate result_of<launch(F, +ArgTypes...)>, which is invalid. SFINAE must be used to prevent that. +
+ +[ +2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-02-12 Daniel opens: +]
+ + +++ ++[..] if decay<F>::type is of type std::launch. +
++or +
++[..] if remove_cv<remove_reference<F>::type>::type is of +type std::launch. +
+ ++The latter is the more specific form, but the former is equivalent to +the latter for all cases that can occur here. I suggest to use the +former for simplicity, but expect that implementations can effectively +use the latter. + +
+[ +2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added below. ++ + + +Rationale:
++Solved by N3058. +
+ + +Proposed resolution:
++In 30.6.1 [futures.overview] paragraph 1: +
+ ++ +template <class F, class... Args> +future<typename F::result_type>+ future<typename result_of<F(Args...)>::type> + async(F&& f, Args&&... args); +template <class F, class... Args> +future<typename F::result_type>+ future<typename result_of<F(Args...)>::type> + async(launch policy, F&& f, Args&&... args); ++In 30.6.9 [futures.async] before paragraph 1 +
+ ++ + + + + + +template <class F, class... Args> ++future<typename F::result_type>+ future<typename result_of<F(Args...)>::type> + async(F&& f, Args&&... args); +template <class F, class... Args> +future<typename F::result_type>+ future<typename result_of<F(Args...)>::type> + async(launch policy, F&& f, Args&&... args); +++...
++Remarks: The first signature shall not participate in overload resolution +if decay<F>::type is std::launch. +
+
+1317. make_hash
+Section: 20.8.15 [unord.hash] Status: NAD Future + Submitter: Nicolai M. Josuttis Opened: 2010-02-10 Last modified: 2010-10-23
+View all other issues in [unord.hash].
+View all issues with NAD Future status.
+Discussion:
++Currently, the library lacks a convenient way to provide a hash function that +can be used with the provided unordered containers to allow the usage of non +trivial element types. +
+ ++While we can easily declare an +
+ ++ +std::unordered_set<int> ++or +
+ ++ +std::unordered_set<std::string> ++we have no easy way to declare an unordered_set for a user defined +type. IMO, this is a big obstacle to use unordered containers in practice. Note +that in Java, the wide usage of HashMap is based on the fact that there +is always a default hash function provided. +
+ ++Of course, a default hash function implies the risk to provide poor hash +functions. But often even poor hash functions are good enough. +
+ ++While I really would like to see a default hash function, I don't propose it +here because this would probably introduce a discussion that's too big for this +state of C++0x. +
+ ++However, I strongly suggest at least to provide a convenience variadic template +function make_hash<>() to allow an easy definition of a (possibly +poor) hash function. +
+ ++As a consequence for a user-defined type such as +
+ ++ +class Customer { + friend class CustomerHash; + private: + string firstname; + string lastname; + long no; + ... + }; ++would allow to specify: +
+ ++ +class CustomerHash : public std::unary_function<Customer, std::size_t> +{ + public: + std::size_t operator() (const Customer& c) const { + return make_hash(c.firstname,c.lastname,c.no); + } +}; ++instead of: +
+ ++ +class CustomerHash : public std::unary_function<Customer, std::size_t> +{ + public: + std::size_t operator() (const Customer& c) const { + return std::hash<std::string>()(c.firstname) + + std::hash<std::string>()(c.lastname) + + std::hash<long>()(c.no); + } +}; ++Note that, in principle, we can either specify that +
+ ++make_hash returns the sum of a call of +std::hash<T>()(x) for each argument x of type +T ++ ++or we can specify that +
+ ++make_hash provides a hash value for each argument, for which a +std::hash() function is provided ++ ++with the possible note that the hash value may be poor or only a good hash value +if the ranges of all passed arguments is equally distributed. +
+ ++For my convenience, I propose wording that describes +the concrete implementation. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial, rationale added below. +]
+ + + + +Rationale:
++There is no consensus to make this change at this time. +
+ + +Proposed resolution:
++In Function objects 20.8 [function.objects] +in paragraph 2 at the end of the Header <functional> synopsis +insert: +
+ ++ +// convenience functions +template <class T> + size_t make_hash (const T&); +template <class T, class... Types> + size_t make_hash (const T&, const Types&...); ++In Class template hash 20.8.15 [unord.hash] +add: +
+ +++ + + + + + ++20.7.16.1 Hash creation functions [hash.creation] +
+ +template <class T> + size_t make_hash (const T& val); ++ ++Returns: hash<T>()(val); ++ +template <class T, class... Types> + size_t make_hash (const T& val, const Types&... args); ++ ++Returns: hash<T>()(val) + std::make_hash(args...) ++ +
+1329. Data races on
+vector<bool>Section: 23.2.2 [container.requirements.dataraces] Status: NAD Editorial + Submitter: Jeffrey Yaskin Opened: 2010-03-09 Last modified: 2010-10-23
+View all issues with NAD Editorial status.
+Discussion:
++The common implementation of vector<bool> is as an +unsynchronized bitfield. The addition of 23.2.2 [container.requirements.dataraces]/2 would require either a +change in representation or a change in access synchronization, both of +which are undesireable with respect to compatibility and performance. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3069. +
+ + +Proposed resolution:
++Container data races 23.2.2 [container.requirements.dataraces] +
+ ++Paragraph 1 is unchanged as follows: +
+ ++1 For purposes of avoiding data races (17.6.4.8), implementations shall +consider the following functions to be+ +const: +begin,end,rbegin, +rend,front,back, +data,find,lower_bound, +upper_bound,equal_range, and, except in +associative containers,operator[]. ++Edit paragraph 2 as follows: +
+ ++2 Notwithstanding (17.6.4.8), implementations are required to avoid data +races when the contents of the contained object in different elements in +the same sequence, excepting+ +vector<bool>, +are modified concurrently. ++Edit paragraph 3 as follows: +
+ ++3 [Note: +For a+ + + + + + +vector<int> xwith a size greater than one, +x[1] = 5and*x.begin() = 10+can be executed concurrently without a data race, +butx[0] = 5and*x.begin() = 10+executed concurrently may result in a data race. +As an exception to the general rule, +for avector<bool> y, +y[i] = truemay race withy[j] = true. +—end note] +
+1331. incorporate move special member functions into library
+Section: 17 [library] Status: NAD + Submitter: Martin Sebor Opened: 2010-03-10 Last modified: 2010-11-29
+View other active issues in [library].
+View all other issues in [library].
+View all issues with NAD status.
+Discussion:
++Review the library portion of the spec and incorporate the newly added +core feature Move Special Member Functions (N3044). +
+ +Rationale:
+2010 Batavia: This has now been done to a large extent. + + + + +Proposed resolution:
+ + + + + +
+1350. [FCD] Implicit contructors accidentally made some library types move-only
+Section: 17 [library] Status: Dup + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-25
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Dup status.
+Duplicate of: 1421
+Discussion:
+Addresses CH-15
++Due to the new rules about implicit copy and move +constructors some library facilities are now move-only. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Make them copyable again. +
+ + +Proposed resolution:
+ + + + + +
+1351. [FCD] Replace dynamic exception specifications with noexcept
+Section: 17 [library] Status: Dup + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-25
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Dup status.
+Duplicate of: 1344
+Discussion:
+ +Addresses CH-16
++Dynamic exception specifications are deprecated. +Deprecated features shouldn't be used in the Standard. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Replace dynamic exception specifications with noexcept. +
+ + +Proposed resolution:
+ + + + + +
+1352. [FCD] Apply noexcept where library specification says "Throws: Nothing"
+Section: 17 [library] Status: Dup + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-25
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Dup status.
+Duplicate of: 1346
+Discussion:
+ +Addresses CH-17
++The introduction of noexcept makes "Throws: Nothing" clauses looking strange. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Consider replacing "Throws: Nothing." clause by +the respective noexcept specification. +
+ + + +Proposed resolution:
+ + + + + +
+1359. [FCD] Add <tuple> and <utility> to freestanding implementations
+Section: 17.6.1.3 [compliance] Status: NAD + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [compliance].
+View all issues with NAD status.
+Discussion:
+Addresses GB-56
++The <utility> header provides support for several +important C++ idioms with move, forward and swap. +Likewise, declval will be frequently used like a type trait. +In order to complete cycles introduced by std::pair, the +<tuple> header should also be made available. This is a +similarly primitive set of functionality, with no dependency +of a hosted environment, but does go beyond the minimal +set of functionality otherwise suggested by the +freestanding libraries. +
++Alternatively, split the move/forward/swap/declval +functions out of <utility> and into a new primitive header, +requiring only that of freestanding implementation. +
+ +[ +Summary of Rapperswil discusions +]
+ ++The preference of the meeting was to extract the rvalue-reference related utilities and swap into a freestanding header, but there was no clear preference for a name. Howard suggested simply dropping them into <type_traits> as both these utilities and type traits are used pretty much everywhere in the library implementation, it is the most convenient place to keep them (from an implementer's perspective). +
+ ++Poll: Two-way: New header for forward, move, swap, move_with_noexcept and declval vs. calling out forward, move, swap, move_with_noexcept and declval as freestanding explicitly? + +SF new header: 4 WF new header: 3 WF call out as freestanding: 1 SF call out as freestanding: 2 + +Alisdair: Willing to write up both solutions, give us some time to think on it. + +Action: Need an issue and proposed wording for GB 56 - Alisdair to draft both options as in the last poll. +
+ +[ +Resolution proposed by ballot comment +]
+ +++ ++Add <utility> and <tuple> to table 15, headers +required for a free-standing implementation. +
+[ +2010-Batavia: +]
+ ++Closed as NAD, reversing the decision at Rapperswil. +
++The consensus was that +any freestanding implementation is going to feel compelled to offer the important +features of <utility> even if we do not make them a freestanding +requirement; breaking out additional small headers may have additional costs at +compile time, and while the critical move-related functions could migrate +to <type_traits>, the header name is far from appealing; adding the +whole of <utility> starts to drag in dependencies on <tuple> +and <memory>, so we prefer to place the burden of slicing or supporting +this whole header on free-standing vendors. +
+ + + +Proposed resolution:
+ + +Rationale:
No consensus for a change at this time. + + + + + +
+1361. [FCD] Does use of std::size_t in a header imply that typedef name is available to users?
+Section: 17.6.2 [using] Status: NAD + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
+View all issues with NAD status.
+Discussion:
+Addresses GB-58
++It is not clear whether a library header specified in terms +of a typedef name makes that same typedef name +available for use, or if it simply requires that the specified +type is an alias of the same type, and so the typedef name +cannot be used without including the specific header that +defines it. For example, is the following code required to +be accepted: +
++#include <vector> +std::size_t x = 0; ++Most often, this question concerns the typedefs defined in +header <cstddef> +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Add a paragraph under 17.6.2 [using] clarifying whether +or not headers specified in terms of std::size_t can +be used to access the typedef size_t, or whether +the header <cstddef> must be included to reliably +use this name. +
+[Batavia: NAD - see rationale below]
+ + + + +Proposed resolution:
+ +Rationale:
The standard is correct as written. + + + + +
+1373. [FCD] Customizable traits should have their own headers
+Section: 20.3 [utility] Status: NAD + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [utility].
+View all issues with NAD status.
+Discussion:
+Addresses GB-79
++The library provides several traits mechanisms intended a +customization points for users. Typically, they are +declared in headers that are growing quite large. This is +not a problem for standard library vendors, who can +manage their internal file structure to avoid large +dependencies, but can be a problem for end users who +have no option but to include these large headers. +
+ +[ +2010 Rapperswil +]
+ ++There was no enthusiasm for touching char_traits or regex_traits. +Consensus to move iterator_traits, allocator_traits +and pointer_traits to their own respective headers once wording supplied. +
+ +[ +2010 Rapperswil +]
+ ++After some discussion, consensus is that moving these features into separate +headers does not buy much in practice, as the larger headers will inevitably +be included anyway. Resolve as NAD. +
+ +[ +Resolution proposed in ballot comment +]
+ ++Move the following traits classes into their own +headers, and require the existing header to +#include the traits header to support backwards +compatibility: +
++ +iterator_traits (plus the iterator tag-types) +allocator_traits +pointer_traits +char_traits +regex_traits +[ +2010 Batavia: +]
+ ++Closed as NAD with the rationale below. +
+ + + +Rationale:
+This suggest is not a defect, as the likely benefit is small, if any, +compared to the cost of not just implementating the feature, but also +explaining/teaching it. + + +Proposed resolution:
+ + + + + +
+1375. [FCD] reference_type should not have been removed from the +allocator requirements
+Section: 20.2.5 [allocator.requirements] Status: Dup + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [allocator.requirements].
+View all issues with Dup status.
+Duplicate of: 1318
+Discussion:
+ +Addresses US-87
++reference_type should not have been removed from the +allocator requirements. Even if it is always the same as +value_type&, it is an important customization point for +extensions and future features. +
+ + +Proposed resolution:
++In [allocator.requirements] Table 42 - Allocotor Requirements, +Add a row (after value_type) with columns: +
++Expression: X::reference_type+
+Return type: T&
+Assertion/note...: (empty)
+Default: T&
++[allocator.traits]: +
++ +Add reference_type to +allocator_traits template, defaulted to +value_type&. + + + + + +namespace std { + template <class Alloc> struct allocator_traits { + typedef Alloc allocator_type; + + typedef typename Alloc::value_type value_type; + + typedef see below pointer; + typedef see below const_pointer; + typedef see below void_pointer; + typedef see below const_void_pointer; + typedef value_type& reference_type; +
+1376. [FCD] Allocator interface is not backward compatible
+Section: 20.2.5 [allocator.requirements] Status: NAD + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [allocator.requirements].
+View all issues with NAD status.
+Discussion:
+Addresses US-88
++Allocator interface is not backward compatible. +
+ +[ +Resolution proposed by ballot comment +]
+ ++See Appendix 1 - Additional Details +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++n3165 provides an alternative resolution. ++ +[ +2910 Batavia: +]
+ ++Closed as NAD - withdrawn by the submitter. +
+ + +Proposed resolution:
+See n3165 + + +Rationale:
Withdrawn by the submitter. + + + + +
+1395. [FCD] Ballot Comment JP-32
+Section: 20.7.6 [meta.rel] Status: NAD Editorial + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [meta.rel].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses JP-32
++Representations of reference link are not unified. +Most reference links to clause (table) number, say X, are +in the form "Clause X" ("Table X") capitalized, and +subsection Y.Y.Y is referenced with its number only in the +form "Y.Y.Y". Whether they are parenthesized or not +depends on the context. +However there are some notations "(Z)" consisting of only +a number Z in parentheses to confer Clause or Table +number Z. +
+ + +Proposed resolution:
+Change "(10)" to "(Clause 10)". + + + + + +
+1398. [FCD] Users should be able to specialize functors without depending on whole <functional> header
+Section: 20.8 [function.objects] Status: NAD + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [function.objects].
+View all issues with NAD status.
+Discussion:
+Addresses GB-96
++The function templates hash, less and equal_to +are important customization points for user-defined types to +be supported by several standard containers. These are +accessed through the <functional> header which has +grown significantly larger in C++0x, exposing many more +facilities than a user is likely to need through there own +header, simply to declare the necessary specialization. +There should be a smaller header available for users to +make the necessary customization. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Provide a tiny forwarding header for important +functor types in the <functional> header that a +user may want to specialize. This should contain +the template declaration for equal_to, hash and +less. +
+ +[ +Rapperswill summary +]
+ +Alisdair: Would recommend NAD unless someone takes the issue.
+ +Daniel: Volunteers to write a paper for this.
+ +[ +2010-11-07 Daniel provides a paper available on the Batavia document list +]
+ + +[ +2010 Batavia: +]
+ ++Closed as NAD - the consensus was that forwarding headers such as +<iosfwd> do not bring the expected benefits, and are +not widely used (to the surprise of some active users in the room!). +Without real experience reporting a benefit, there is no further interest +in pursuing this issue as an extension - hence NAD rather than NAD Future. +
+ + + +Rationale:
No consensus to make a change + +Proposed resolution:
+See paper "Forwarding <functional> functor templates" +on the Batavia LWG document list + + + + + +
+1406. [FCD] Support hashing smart-pointers based on owner
+Section: 20.9.10.2 [util.smartptr.shared] Status: NAD Future + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [util.smartptr.shared].
+View all issues with NAD Future status.
+Discussion:
+Addresses JP-5
++Hash support based on ownership sharing should be +supplied for shared_ptr and weak_ptr. +For two shared_ptr objects p and q, two distinct +equivalence relations can be defined. One is based on +equivalence of pointer values, which is derived from the +expression p.get() == q.get() (hereafter called address based +equivalence relation), the other is based on +equivalence of ownership sharing, which is derived from +the expression !p.owner_before(q) && !q.owner_before(p) +(hereafter called ownership-based equivalence relation). +These two equivalence relations are independent in +general. For example, a shared_ptr object created by the +constructor of the signature shared_ptr(shared_ptr<U> +const &, T *) could reveal a difference between these two +relations. Therefore, hash support based on each +equivalence relation should be supplied for shared_ptr. +However, while the standard library provides the hash +support for address-based one (20.9.11.6 paragraph 2), it +lacks the hash support for ownership-based one. In +addition, associative containers work well in combination +with the shared_ptr's ownership-based comparison but +unordered associative containers don't. This is +inconsistent. +
++For the case of weak_ptr, hash support for the ownership based +equivalence relation can be safely defined on +weak_ptrs, and even on expired ones. The absence of +hash support for the ownership-based equivalence +relation is fatal, especially for expired weak_ptrs. And the +absence of such hash support precludes some quite +effective use-cases, e.g. erasing the unordered_map entry +of an expired weak_ptr key from a customized deleter +supplied to shared_ptrs. +
++Hash support for the ownership-based equivalence +relation cannot be provided by any user-defined manner +because information about ownership sharing is not +available to users at all. Therefore, the only way to provide +ownership-based hash support is to offer it intrusively by +the standard library. +
++As far as we know, such hash support is implementable. +Typical implementation of such hash function could return +the hash value of the pointer of the counter object that is +internally managed by shared_ptr and weak_ptr. +
+ +[2010 Rapperswil:]
+ +++ + +No consensus to make this change at this time.
+Proposed resolution:
++Add the following non-static member functions to +shared_ptr and weak_ptr class template; +
++Update [util.smartptr.shared], 20.9.11.2 paragraph 1 +
+namespace std{ +template<class T> class shared_ptr { +public: +... + size_t owner_hash() const; +... +}; +} +++Update [util.smartptr.weak], 20.9.11.3 paragraph 1 +
+namespace std{ +template<class T> class weak_ptr { +public: +... + size_t owner_hash() const; +... +}; +} +++These functions satisfy the following +requirements. Let p and q be objects of either +shared_ptr or weak_ptr, H be a hypothetical +function object type that satisfies the hash +requirements ([hash.requirements], 20.2.4) and h be an object of the +type H. The expression p.owner_hash() behaves +as if it were equivalent to the expression h(p). In +addition, h(p) == h(q) must become true if p and +q share ownership. +
+ + + + + +
+1411. [FCD] Add a compile-time flag to detect monotonic_clock
+Section: X [time.clock.monotonic] Status: Dup + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-10-26
+View all other issues in [time.clock.monotonic].
+View all issues with Dup status.
+Duplicate of: 1410
+Discussion:
+ +Addresses DE-20
+ +The library component monotonic_clock is conditionally +supported, but no compile-time flag exists that allows +user-code to query its existence. Further-on there exist no +portable means to simulate such a query. (To do so, user +code would be required to add types to namespace +std::chrono.) + + +Proposed resolution:
+Provide a compile-time flag (preferably a macro) +that can be used to query the existence of +monotonic_clock. + + + + + +
+1415. [FCD] iterator stability bans the short-string optimization
+Section: 23.2.1 [container.requirements.general] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [container.requirements.general].
+View all other issues in [container.requirements.general].
+View all issues with NAD Editorial status.
+Discussion:
+Requirements on iterators swapping allegiance would +disallow the small-string optimization. + +[ +Resolved in Rapperswil by paper N3108. +]
+ + + + +Proposed resolution:
+Add an exclusion for basic_string to the sentence +beginning “Every iterator referring to an +element...”. Add a sentence to 21.4.6.8/2 saying +that iterators and references to string elements +remain valid, but it is not specified whether they +refer to the same string or the other string. + + + + + +
+1419. [FCD] Ballot Comment US-117
+Section: 23.3.3 [forwardlist] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [forwardlist].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-117
+ +forward_list::erase_after should return an iterator. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+See Appendix 1 - Additional Details + + + + + +
+1422. [FCD] vector<bool> iterators are not random access
+Section: 23.4.2 [vector.bool] Status: NAD Future + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [vector.bool].
+View all issues with NAD Future status.
+Discussion:
+Addresses GB-118
++vector<bool> iterators are not random access iterators +because their reference type is a special class, and not +bool &. All standard libary operations taking iterators +should treat this iterator as if it was a random access iterator, rather +than a simple input iterator. +
+ +[ +Resolution proposed in ballot comment +]
+ ++Either revise the iterator requirements to support proxy iterators +(restoring functionality that was lost when the Concept facility was +removed) or add an extra paragraph to the vector<bool> +specification requiring the library to treat vector<bool> +iterators as-if they were random access iterators, despite having the wrong +reference type. +
+ +[ +Rapperswil Review +]
+ ++The consensus at Rapperswil is that it is too late for full support for +proxy iterators, but requiring the library to respect vector&;t;bool> +iterators as-if they were random access would be preferable to flagging +this container as deliberately incompatible with standard library algorithms. +
++Alisdair to write the note, which may become normative Remark depending +on the preferences of the project editor. +
+ +[ +Post-Rapperswil Alisdair provides wording +]
+ ++Initial wording is supplied, deliberately using Note in preference to +Remark although the author notes his preference for Remark. The +issue of whether iterator_traits<vector<bool>>::iterator_category +is permitted to report random_access_iterator_tag or must report +input_iterator_tag is not addressed. +
+ +[ +Old Proposed Resolution: +]
+ +++ ++Insert a new paragraph into 23.4.2 [vector.bool] between p4 and p5: +
++[Note All functions in the library that take a pair of iterators to +denote a range shall treat vector<bool> iterators as-if they were +random access iterators, even though the reference type is not a +true reference.-- end note] ++[ +2010-11 Batavia: +]
+ ++Closed as NAD Future, because the current iterator categories cannot correctly describe +vector<bool>::iterator. But saying that they are Random Access Iterators +is also incorrect, because it is not too hard to create a corresponding test that fails. +We should deal with the more general proxy iterator problem in the future, and see no +benefit to take a partial workaround specific to vector<bool> now. ++ + + +Proposed resolution:
+ + +Rationale:
+No consensus to make this change at this time. + + + + + +
+1433. [FCD] Ballot Comment GB-119
+Section: 25.3.12 [alg.random.shuffle] Status: Dup + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-23
+View all other issues in [alg.random.shuffle].
+View all issues with Dup status.
+Duplicate of: 1432
+Discussion:
+Addresses GB-119
+ +The functions random_shuffle and shuffle both take +arguments providing a source of randomness, but one +take its argument by rvalue reference, and the other +requires an lvalue reference. The technical merits of which +form of argument passing should be settled for this +specific case, and a single preferred form used +consistently. + + +Proposed resolution:
+[DEPENDS ON WHETHER RVALUE OR +LVALUE REFERENCE IS THE PREFERRED +FORM] + + + + + +
+1434. [FCD] Ballot Comment US-122
+Section: 25.4.7 [alg.min.max] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [alg.min.max].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-122
+ +It was the LWG's intent in Pittsburgh that N2772 be +applied to the WP. + +[ +Resolved in Rapperswil by paper N3106. +]
+ + + + +Proposed resolution:
+Apply N2772 to the WP. + + + + + +
+1442. [FCD] "happens-before" should be "synchronizes-with"
+Section: 30 [thread] Status: NAD Editorial + Submitter: Canada Opened: 2010-08-25 Last modified: 2010-11-18
+View all other issues in [thread].
+View all issues with NAD Editorial status.
+Duplicate of: 1443
+Discussion:
+Addresses CA-9, GB-122
+ +[CA-9:]
+ + +Imposed happens-before edges should be in +synchronizes-with
+Each use of the words "happens-before" should be +replaced with the words "synchronizes-with" in the +following sentences:
+27.2.3p2
+30.3.1.2p6
+30.3.1.5p7
+30.6.4p7
+30.6.9p5
+30.6.10.1p23
+Rationale: Happens-before is defined in 1.10p11 in a way +that (deliberately) does not make it explicitly transitively +closed. Adding edges to happens-before directly, as in +27.2.3p2 etc., does not provide transitivity with +sequenced-before or any other existing happens-before +edge. This lack of transitivity seems to be unintentional. + +[GB-122]
+ + +At various points in the standard new edges are added to +happens-before, for example 27.2.3:2 adds happens-before edges between +writes and reads from a stream:
+ +If one thread makes a library call a that writes a value to a +stream and, as a result, another thread reads this value from the +stream through a library call b such that this does not result in a +data race, then a happens before b.
+ +Happens-before is defined in 1.10:11 in a deliberate way that makes it +not explicitly transitively closed. Adding edges to happens-before +directly, as in 27.2.3:2, does not provide transitivity with +sequenced-before or any other existing happens-before edge. This lack +of transitivity seems to be unintentional. In order to achieve +transitivity we suggest each edge be added to +inter-thread-happens-before as a synchronises-with edge (as per +conversation with Hans Boehm). In the standard, each use of the words +"happens-before" should be replaced with the words "synchronizes-with" +in the following sentences:
+ +27.2.3:2, +30.3.1.2:6, +30.3.1.5:7, +30.6.4:7, +30.6.9:5, +30.6.10.1:23
+ +Proposed resolution:
+ +[Beman provided specific wording for the proposed resolution.]
+ + +Change 27.2.3 Thread Safety [iostreams.threadsafety] paragraph 2:
+ +If one thread makes a library call a that writes a value to a stream and, as a result, another thread reads this value from the stream through a library call b such that this does not result in a data race, then a
+ +happens beforesynchronizes with b.Change 30.3.1.2 thread constructors [thread.thread.constr] paragraph 6:
+ +Synchronization: The invocation of the constructor
+ +happens beforesynchronizes with the invocation of the copy of f.Change 30.3.1.5 thread members [thread.thread.member] paragraph 7:
+ +Synchronization: The completion of the thread represented by *this
+ +happens beforesynchronizes with (1.10) join()returnsreturning. [ Note: Operations on *this are not synchronized. --end note ]Change 30.6.4 Associated asynchronous state [futures.state] paragraph 7:
+ +Calls to functions that successfully set the stored result of an associated asynchronous state synchronize +with (1.10) calls to functions successfully detecting the ready state resulting from that setting. The storage of the result (whether normal or exceptional) into the associated asynchronous state
+ +happens beforesynchronizes with (1.10) that stateisbeing set to ready.Change 30.6.9 Function template async [futures.async] paragraph 5:
+ +Synchronization: the invocation of async
+ +happens beforesynchronizes with (1.10) the invocation of f. [ Note: this +statement applies even when the corresponding future object is moved to another thread. --end +note ] If the invocation is not deferred, a call to a waiting function on an asynchronous return object +that shares the associated asynchronous state created by this async call shall block until the associated +thread has completed. If the invocation is not deferred, the join() on the created threadhappens beforesynchronizes with +(1.10) the first function that successfully detects the ready status of the associated asynchronous +state returns or before the function that gives up the last reference to the associated asynchronous +state returns, whichever happens first. If the invocation is deferred, the completion of the invocation +of the deferred functionhappens beforesynchronizes with the calls to the waiting functions return.Change 30.6.10.1 packaged_task member functions [futures.task.members] paragraph 23:
+ +Synchronization: a successful call to operator() synchronizes with (1.10) a call to any member function of a future, shared_future, or atomic_future object that shares the associated asynchronous +state of *this. The completion of the invocation of the stored task and the storage of the result +(whether normal or exceptional) into the associated asynchronous state
+ + + + + + +happens beforesynchronizes with (1.10) the +stateisbeing set to ready. [ Note: operator() synchronizes and serializes with other functions through the +associated asynchronous state. —end note ]
+1443. [FCD] Imposed happens-before edges are not made transitive
+Section: 30 [thread] Status: Dup + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-27
+View all other issues in [thread].
+View all issues with Dup status.
+Duplicate of: 1442
+Discussion:
+ + +Addresses GB-122
+ +At various points in the standard new edges are added to +happens-before, for example 27.2.3:2 adds happens-before edges between +writes and reads from a stream:
+ +If one thread makes a library call a that writes a value to a +stream and, as a result, another thread reads this value from the +stream through a library call b such that this does not result in a +data race, then a happens before b.
+ +Happens-before is defined in 1.10:11 in a deliberate way that makes it +not explicitly transitively closed. Adding edges to happens-before +directly, as in 27.2.3:2, does not provide transitivity with +sequenced-before or any other existing happens-before edge. This lack +of transitivity seems to be unintentional. In order to achieve +transitivity we suggest each edge be added to +inter-thread-happens-before as a synchronises-with edge (as per +conversation with Hans Boehm). In the standard, each use of the words +"happens-before" should be replaced with the words "synchronizes-with" +in the following sentences:
+ +27.2.3:2, +30.3.1.2:6, +30.3.1.5:7, +30.6.4:7, +30.6.9:5, +30.6.10.1:23
+ + +Proposed resolution:
+Request the concurrency working group to +determine if changes are needed + + + + + +
+1444. [FCD] OFF_T is not defined
+Section: 27.5.3.2 [fpos.operations] Status: Dup + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-28
+View all other issues in [fpos.operations].
+View all issues with Dup status.
+Duplicate of: 1414
+Discussion:
+ +Addresses GB-123
+ +Several rows in table 124 specify a Return type of +'OFF_T', which does not appear to be a type defined in +this standard. + + +Proposed resolution:
+Resolve outstanding references to the removed +type 'OFF_T'. + + + + + +
+1446. [FCD] Move and swap for I/O streams
+Section: 27.7 [iostream.format] Status: NAD + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [iostream.format].
+View all issues with NAD status.
+Discussion:
+Addresses US-138
+ +For istreams and ostreams, the move-constructor does +not move-construct, the move-assignment operator does +not move-assign, and the swap function does not swap +because these operations do not manage the rdbuf() +pointer. Useful applications of these operations are +prevented both by their incorrect semantics and because +they are protected. + +[ +Resolution proposed by ballot comment: +]
+ ++In short: reverse the resolution of issue 900, then +change the semantics to move and swap the +rdbuf() pointer. Add a new protected constructor +that takes an rvalue reference to a stream and a +pointer to a streambuf, a new protected assign() +operator that takes the same arguments, and a +new protected partial_swap() function that doesn't +swap rdbuf(). +See Appendix 1 - Additional Details +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3179 would solve this issue. ++ +[ +2010-11 Batavia +]
+ ++Closed as NAD. +
++The Library Working Group reviewed n3179 and +concluded that this change alone was not sufficient, as it would require changes to some of the derived stream types in the library. +The preference is to not make such a broad fix, and retain the current semantics. This is closed as NAD rather than NAD future as it +will be difficult to rename the new functions introduced in the C++0x revision of the standard at a later date. ++ + + +Proposed resolution:
+ + + + + +
+1451. [FCD] regex should support allocators
+Section: 28.8 [re.regex] Status: Dup + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [re.regex].
+View all issues with Dup status.
+Duplicate of: 1396
+Discussion:
+ +Addresses US-141
+ +std::basic_regex should have an allocator for all the +reasons that a std::string does. For example, I can use +boost::interprocess to put a string or vector in shared +memory, but not a regex. + + +Proposed resolution:
+Add allocators to regexes; see paper N3171 +in the pre-Batavia mailing. + + + + + +
+1454. [FCD] Ensure C compatibility for atomics
+Section: 29 [atomics] Status: Dup + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-29
+View other active issues in [atomics].
+View all other issues in [atomics].
+View all issues with Dup status.
+Duplicate of: 1455
+Discussion:
+ +Addresses GB-128
++WG14 has made some late changes to their specification +of atomics, and care should be taken to ensure that we +retain a common subset of language/library syntax to +declare headers that are portable to both languages. +Ideally, such headers would not require users to define +their own macros, especially not macros that map to +keywords (which remains undefined behaviour) +
+ + +[ +Resolution proposed by ballot comment +]
+ ++Depends on result of the review of WG14 work, +which is expected to be out to ballot during the +time wg21 is resolving its own ballot comments. +Liaison may also want to file comments in WG14 +to ensure compatibity from both sides. +
+ + +Proposed resolution:
+ + + + + +
+1458. [FCD] Overlapping evaluations are allowed
+Section: 29.3 [atomics.order] Status: Dup + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-26
+View all other issues in [atomics.order].
+View all issues with Dup status.
+Duplicate of: 1459
+Discussion:
+ +Addresses GB-131
+ +29.4 [atomics.lockfree] p.8 states: ++An atomic store shall only store a value that has been computed +from constants and program input values by a finite sequence of +program evaluations, such that each evaluation observes the values +of variables as computed by the last prior assignment in the +sequence. +++... but 1.9 [intro.execution] p.13 states: +
++If A is not sequenced before B and B is not sequenced before A, +then A and B are unsequenced. [ Note: The execution of unsequenced +evaluations can overlap. — end note ] +++Overlapping executions can make it impossible to construct the sequence +described in 29.4 [atomics.lockfree] p.8. We are not sure of the intention here and do not +offer a suggestion for change, but note that 29.4 [atomics.lockfree] p.8 is the condition +that prevents out-of-thin-air reads. +
+ + +Proposed resolution:
+Request the concurrency working group to +determine if changes are needed. Consider +changing the use of "sequence" in 29.4 [atomics.lockfree] + + + + + +
+1463. [FCD] Inconsistent value assignment for atomic_bool
+Section: 29.5.1 [atomics.types.integral] Status: Dup + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [atomics.types.integral].
+View all issues with Dup status.
+Duplicate of: 1462
+Discussion:
+ +Addresses US-157
+ +atomic_bool has a volatile assignment operator but not a +non-volatile operator. The other integral types have both. + + +Proposed resolution:
+Add a non-volatile assignment operator to atomic_bool. + + + + + +
+1470. [FCD] "Same-ness" curiosities
+Section: 29.6 [atomics.types.operations] Status: Dup + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [atomics.types.operations].
+View all other issues in [atomics.types.operations].
+View all issues with Dup status.
+Duplicate of: 1474
+Discussion:
+Addresses US-165
+ +According to 29.6 [atomics.types.operations] p. 23: ++“is the same that same as that of” is not grammatical (and is not clear) ++ + + +Proposed resolution:
+ + + + + +
+1471. [FCD] Default constructor of atomics needs specification
+Section: 29.6 [atomics.types.operations] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-18
+View other active issues in [atomics.types.operations].
+View all other issues in [atomics.types.operations].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-168
+ +29.6 [atomics.types.operations] around p. 4: The definition of the default constructor needs exposition. + + +Proposed resolution:
+Insert a new general prototype description following the current 29.6 [atomics.types.operations] p. 3 as indicated: ++
++3 [Note: Many operations are volatile-qualified. The “volatile as device register” semantics have not changed +in the standard. This qualification means that volatility is preserved when applying these operations to +volatile objects. It does not mean that operations on non-volatile objects become volatile. Thus, volatile +qualified operations on non-volatile objects may be merged under some conditions. -- end note] +++A::A() = default; ++? Effects: Leaves the atomic object in an uninitialized state. +[Note: These semantics ensure compatiblity with C. -- end note] ++ + + + + +constexpr A::A(C desired); +[..] +
+1472. [FCD] Incorrect semantics of atomic_init
+Section: 29.6 [atomics.types.operations] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
+View other active issues in [atomics.types.operations].
+View all other issues in [atomics.types.operations].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-171
+ +As of 29.6 [atomics.types.operations] p. 7: ++The atomic_init definition "Non-atomically assigns the +value" is not quite correct, as the atomic_init purpose is +initialization. + + +
Proposed resolution:
+Change 29.6 [atomics.types.operations] p. 7 as indicated: ++ + + + + +void atomic_init(volatile A *object, C desired); +void atomic_init(A *object, C desired); ++7 Effects:Non-atomically assigns the value desired to *objectInitializes *object with value +desired. Concurrent access from another thread, even via an atomic operation, constitutes a data race. +[Note: This function should only be applied to objects that have been default constructed. These semantics ensure +compatibility with C. — end note] +
+1473. [FCD] Incomplete memory order specifications
+Section: 29.6 [atomics.types.operations] Status: NAD + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
+View other active issues in [atomics.types.operations].
+View all other issues in [atomics.types.operations].
+View all issues with NAD status.
+Discussion:
+Addresses US-172
+ +As of 29.6 [atomics.types.operations] p. 9, 13, 17, 20: ++The order specifications are incomplete because the non-_explicit +functions do not have such parameters. +
+Add a new sentence: "If the program does not specify an order, it shall be +memory_order_seq_cst." Or perhaps: "The non-_explicit +non-member functions shall affect memory as though they were _explicit with +memory_order_seq_cst." + + +
[ +2010 Batavia +]
+ ++The Concurrency subgroup reviewed this, and deemed it NAD according to +29.6 [atomics.types.operations] paragraph 2, bullet 4. +
+ +Rationale:
The working paper is correct as written. + + + +Proposed resolution:
++
+ + + + + +- Change 29.6 [atomics.types.operations] p. 9 as indicated: +
++void atomic_store(volatile A* object, C desired); +void atomic_store(A* object, C desired); +void atomic_store_explicit(volatile A *object, C desired, memory_order order); +void atomic_store_explicit(A* object, C desired, memory_order order); +void A::store(C desired, memory_order order = memory_order_seq_cst) volatile; +void A::store(C desired, memory_order order = memory_order_seq_cst); ++8 Requires: The order argument shall not be memory_order_consume, memory_order_acquire, nor +memory_order_acq_rel. ++9 Effects: Atomically replaces the value pointed to by object or by this with the value of desired. +Memory is affected according to the value of order. If the program does not specify an order, it shall be +memory_order_seq_cst. +
- Change 29.6 [atomics.types.operations] p. 13 as indicated: +
++C atomic_load(const volatile A* object); +C atomic_load(const A* object); +C atomic_load_explicit(const volatile A* object, memory_order); +C atomic_load_explicit(const A* object, memory_order); +C A::load(memory_order order = memory_order_seq_cst) const volatile; +C A::load(memory_order order = memory_order_seq_cst) const; ++12 Requires: The order argument shall not be memory_order_release nor memory_order_acq_rel. ++13 Effects: Memory is affected according to the value of order. If the program does not specify an order, it shall be +memory_order_seq_cst. +
+14 Returns: Atomically returns the value pointed to by object or by this. +
- Change 29.6 [atomics.types.operations] p. 17 as indicated: +
++C atomic_exchange(volatile A* object, C desired); +C atomic_exchange(A* object, C desired); +C atomic_exchange_explicit(volatile A* object, C desired, memory_order); +C atomic_exchange_explicit(A* object, C desired, memory_order); +C A::exchange(C desired, memory_order order = memory_order_seq_cst) volatile; +C A::exchange(C desired, memory_order order = memory_order_seq_cst); ++17 Effects: Atomically replaces the value pointed to by object or by this with desired. Memory +is affected according to the value of order. These operations are atomic read-modify-write operations +(1.10). If the program does not specify an order, it shall be memory_order_seq_cst. ++18 Returns: Atomically returns the value pointed to by object or by this immediately before the effects. +
- Change 29.6 [atomics.types.operations] p. 20 as indicated: +
++bool atomic_compare_exchange_weak(volatile A* object, C * expected, C desired); +bool atomic_compare_exchange_weak(A* object, C * expected, C desired); +bool atomic_compare_exchange_strong(volatile A* object, C * expected, C desired); +bool atomic_compare_exchange_strong(A* object, C * expected, C desired); +bool atomic_compare_exchange_weak_explicit(volatile A* object, C * expected, C desired, + memory_order success, memory_order failure); +bool atomic_compare_exchange_weak_explicit(A* object, C * expected, C desired, + memory_order success, memory_order failure); +bool atomic_compare_exchange_strong_explicit(volatile A* object, C * expected, C desired, + memory_order success, memory_order failure); +bool atomic_compare_exchange_strong_explicit(A* object, C * expected, C desired, + memory_order success, memory_order failure); +bool A::compare_exchange_weak(C & expected, C desired, + memory_order success, memory_order failure) volatile; +bool A::compare_exchange_weak(C & expected, C desired, + memory_order success, memory_order failure); +bool A::compare_exchange_strong(C & expected, C desired, + memory_order success, memory_order failure) volatile; +bool A::compare_exchange_strong(C & expected, C desired, + memory_order success, memory_order failure); +bool A::compare_exchange_weak(C & expected, C desired, + memory_order order = memory_order_seq_cst) volatile; +bool A::compare_exchange_weak(C & expected, C desired, + memory_order order = memory_order_seq_cst); +bool A::compare_exchange_strong(C & expected, C desired, + memory_order order = memory_order_seq_cst) volatile; +bool A::compare_exchange_strong(C & expected, C desired, + memory_order order = memory_order_seq_cst); ++19 Requires: The failure argument shall not be memory_order_release nor memory_order_acq_rel. +The failure argument shall be no stronger than the success argument. ++20 Effects: Atomically, compares the contents of the memory pointed to by object or by this for equality +with that in expected, and if true, replaces the contents of the memory pointed to by object or by +this with that in desired, and if false, updates the contents of the memory in expected with the +contents of the memory pointed to by object or by this. Further, if the comparison is true, memory +is affected according to the value of success, and if the comparison is false, memory is affected +according to the value of failure. When only one memory_order argument is supplied, the value of +success is order, and the value of failure is order except that a value of +memory_order_acq_rel shall be replaced by the value memory_order_acquire and a value of +memory_order_release shall be replaced by the value memory_order_relaxed. If +the program does not specify an order, it shall be memory_order_seq_cst. If the operation returns true, +these operations are atomic read-modify-write operations (1.10). Otherwise, these operations are atomic load operations. +
+[..] +
+1475. [FCD] weak compare-and-exchange confusion II
+Section: 29.6 [atomics.types.operations] Status: Dup + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-29
+View other active issues in [atomics.types.operations].
+View all other issues in [atomics.types.operations].
+View all issues with Dup status.
+Duplicate of: 1474
+Discussion:
+Addresses CH-23
+ +29.6 [atomics.types.operations] p. 23: The first sentence has non-English syntax. + +[ +Resolution proposed in ballot comment: +]
+ + ++Change to "The weak compare-and-exchange +operations may fail spuriously, that is, return false +while leaving the contents of memory pointed to +by expected unchanged." +
+ + +Proposed resolution:
+ + + + + +
+1476. [FCD] Ballot Comment US-177
+Section: 29.6 [atomics.types.operations] Status: Dup + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-07
+View other active issues in [atomics.types.operations].
+View all other issues in [atomics.types.operations].
+View all issues with Dup status.
+Duplicate of: 1474
+Discussion:
+ +Addresses US-177
+ +The first sentence of this paragraph doesn't make sense. + +[ +Resolution proposed in ballot comment +]
+ ++Figure out what it's supposed to say, and say it. +
+ + +Proposed resolution:
+ + + + + +
+1477. [FCD] weak compare-and-exchange confusion III
+Section: 29.6 [atomics.types.operations] Status: Dup + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-31
+View other active issues in [atomics.types.operations].
+View all other issues in [atomics.types.operations].
+View all issues with Dup status.
+Duplicate of: 1474
+Discussion:
+Addresses GB-135
+ +The first sentence of 29.6 [atomics.types.operations] p.23 was changed by n2992 but +now makes no sense: "that is, return false while leaving +the contents of memory pointed to by expected before the +operation is the same that same as that of the object and +the same as that of expected after the operation." +There's a minor editorial difference between n2992 ("is +that same as that" vs "is the same that same as that") but +neither version makes sense. +Also, the remark talks about "object" which should +probably be "object or this" to cover the member functions +which have no object parameter. + +[ +Resolution proposed in ballot comment: +]
+ ++Fix the Remark to say whatever was intended. +
+ + + +Proposed resolution:
+ + + + + +
+1483. [FCD] __STDCPP_THREADS spelling
+Section: 30.3 [thread.threads] Status: NAD Editorial + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-10-26
+View all issues with NAD Editorial status.
+Discussion:
+Addresses DE-23
+ +Predefined macros usually start and end with two +underscores, see 16.8 and FDIS 29124 = WG21 N3060 +clause 7. __STDCPP_THREADS should blend in. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Change the macro name to +__STDCPP_THREADS__. + + + + + +
+1484. [FCD] Need a way to join a thread with a timeout
+Section: 30.3.1 [thread.thread.class] Status: NAD Future + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
+View all issues with NAD Future status.
+Discussion:
+Addresses US-183
+ +There is no way to join a thread with a timeout. + +[ +Resolution proposed by ballot comment: +]
+ ++Add join_for and join_until. Or decide one should +never join a thread with a timeout since pthread_join doesn't have a +timeout version. ++ +[ +2010 Batavia +]
+ ++The concurrency working group deemed this an extension beyond the scope of C++0x. +
+Rationale:
The LWG does not wish to make a change at this time. + + + +Proposed resolution:
+ + + + + +
+1488. [FCD] Improve interoperability between +the C++0x and C1x threads APIs
+Section: 30.4 [thread.mutex] Status: NAD Future + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [thread.mutex].
+View all issues with NAD Future status.
+Discussion:
+Addresses US-185
+ +Cooperate with WG14 to improve interoperability between +the C++0x and C1x threads APIs. In particular, C1x +mutexes should be conveniently usable with a C++0x +lock_guard. Performance overheads for this combination +should be considered. + +[ +Resolution proposed by ballot comment: +]
+ ++Remove C++0x timed_mutex and +timed_recursive_mutex if that facilitates +development of more compatible APIs. ++ +[ +2010 Batavia +]
+ ++The concurrency sub-group reviewed the options, and decided that closer harmony should wait until both standards are published. +
+ +Rationale:
+The LWG does not wish to make any change at this time. + + + + +Proposed resolution:
+ + + + + +
+1489. [FCD] unlock functions and unlock +mutex requirements are inconsistent
+Section: 30.4 [thread.mutex] Status: NAD Editorial + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-12
+View all other issues in [thread.mutex].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses CH-26
+ +Specifications of unlock member functions and unlock +mutex requirements are inconsistent wrt to exceptions and +pre- and postconditions. + +[ +Resolution proposed by ballot comment: +]
+ ++unlock should specifiy the precondition that the +current thread "owns the lock", this will make calls +without holding the locks "undefined behavior". +unlock in [mutex.requirements] should either be +noexcept(true) or be allowed to throw +system_error like unique_lock::unlock, or the latter +should be nothrow(true) and have the precondition +owns == true. +Furthermore unique_lock's postcondition is wrong +in the case of a recursive mutex where owns +might stay true, when it is not the last unlock +needed to be called. ++ + + +Proposed resolution:
+ + + + + +
+1493. [FCD] Add mutex, recursive_mutex, is_locked function
+Section: 30.4.1 [thread.mutex.requirements] Status: NAD Future + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [thread.mutex.requirements].
+View all issues with NAD Future status.
+Discussion:
+Addresses US-189
+ +mutex and recursive_mutex should have an is_locked() +member function. is_locked allows a user to test a lock +without acquiring it and can be used to implement a lightweight +try_try_lock. + +[ +Resolution proposed by ballot comment: +]
+ ++Add a member function: ++ +bool is_locked() const; ++to std::mutex and std::recursive_mutex. These +functions return true if the current thread would +not be able to obtain a mutex. These functions do +not synchronize with anything (and, thus, can +avoid a memory fence). +[ +2010 Batavia +]
+ ++The Concurrency subgroup reviewed this issue and deemed it to be an extension to be handled after publishing C++0x. +
+ +Rationale:
The LWG does not wish to make a change at this time. + + + +Proposed resolution:
+ + + + + +
+1495. [FCD] Condition variable wait_for return insufficient
+Section: 30.5 [thread.condition] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
+View all other issues in [thread.condition].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-191
+ +The condition variable wait_for returning cv_status is insufficient. + +[ +Resolution proposed by ballot comment: +]
+ ++Return a duration of timeout remaining instead. +See Appendix 1 of n3141 - Additional Details, p. 211 ++ + + +Proposed resolution:
+ + + + + +
+1496. [FCD] condition_variable not implementable
+Section: 30.5.1 [thread.condition.condvar] Status: NAD Editorial + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-12
+View all other issues in [thread.condition.condvar].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses CH-28
+ +Requiring wait_until makes it impossible to implement +condition_variable correctly using respective objects +provided by the operating system (i.e. implementing the +native_handle() function) on many platforms (e.g. POSIX, +Windows, MacOS X) or using the same object as for the +condition variable proposed for C. + +[ +Resolution proposed by ballot comment: +]
+ ++Remove the wait_until functions or make them at least conditionally supported. ++ + +Proposed resolution:
+ + + + + +
+1499. [FCD] Condition variables preclude wakeup optimization
+Section: 30.5 [thread.condition] Status: NAD Future + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [thread.condition].
+View all issues with NAD Future status.
+Discussion:
+Addresses US-193
+ +Condition variables preclude a wakeup optimization. + +[ +Resolution proposed by ballot comment: +]
+ + ++Change condition_variable to allow such +optimization. See Appendix 1 - Additional Details ++ +[ +2010 Batavia +]
+ ++The Concurrency subgroup reviewed the issue, and deemed it an extension to be handled after C++0x. +
+ +Rationale:
The LWG does not wish to make the change at this time. + + + +Proposed resolution:
+ + + + + +
+1500. [FCD] Consider removal of native_handle()
+Section: 30.5.2 [thread.condition.condvarany] Status: NAD Editorial + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-10-28
+View all other issues in [thread.condition.condvarany].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses CH-32
+ +Given that the lock type can be something the underlying +doesn't know 'native_handle()' is probably +unimplementable on essentially all platforms. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Consider the removal of 'native_handle()'. + + + + + +
+1506. [FCD] set_exception with a null pointer
+Section: 30.6.5 [futures.promise] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View other active issues in [futures.promise].
+View all other issues in [futures.promise].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-198
+ +promise::set_exception can be called with a null pointer, +but none of the descriptions of the get() functions for the +three types of futures say what happens for this case. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add the following sentence to the end of +30.6.5/22: The behavior of a program that calls +set_exception with a null pointer is undefined. + + + + + +
+1509. [FCD] No restriction on calling future::get more than once
+Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
+View all other issues in [futures.atomic_future].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-202
++The note in this paragraph says "unlike future, calling get +more than once on the same atomic_future object is well +defined and produces the result again." There is nothing +in future that says anything negative about calling get +more than once. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Remove this note, or add words to the +requirements for future that reflect what this note +says. +
+ + +Proposed resolution:
+ + + + + +
+1510. [FCD] Should be undefined behaviour to call atomic_future operations unless valid()
+Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
+View all other issues in [futures.atomic_future].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-203
++Both future and shared_future specify that calling most +member functions on an object for which valid() == false +produces undefined behavior. There is no such statement +for atomic_future. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Add a new paragraph after 30.6.8 [futures.atomic_future]/2 with the same words as +30.6.7 [futures.shared_future]/3. +
+ +[ +2010-11-02 Daniel translates proposed changes into specific deltas and comments: +]
+ + ++While applying the wording, I notice that 30.6.7 [futures.shared_future]/3 does +speak of the move-assignment operator, and not of the copy-assignment operator. +atomic_future obviously needs this to be true for the copy-assignment operator, +but I strongly assume that shared_future needs to mention both special member +assignment operators in this paragraph. To keep this consistent, the following P/R also +provides wording to fix the corresponding location for shared_future. ++ + + +Proposed resolution:
++
+ + + + + +- Change 30.6.7 [futures.shared_future]/3 as indicated: +
++3 The effect of calling any member function other than the destructor, the +copy-assignment operator, the move-assignment operator, or valid() +on a shared_future object for which valid() == false is undefined. ++- Following 30.6.8 [futures.atomic_future]/2, add a new paragraph: +
++? The effect of calling any member function other than the destructor, the copy-assignment operator, or valid() +on a atomic_future object for which valid() == false is undefined. ++
+1511. [FCD] Synchronize the move-constructor for atomic_future
+Section: 30.6.8 [futures.atomic_future] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
+View all other issues in [futures.atomic_future].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-204
++According to the definition of atomic_future, all members +of atomic_future are synchronizing except constructors. +However, it would probably be appropriate for a move +constructor to be synchronizing on the source object. If +not, the postconditions on paragraphs 7-8, might not be +satisfied. This may be applicable if a collection of futures +are being doled out to a set of threads that process their +value. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Make the move constructor for atomic future lock +the source +
+ + + +Proposed resolution:
+ + + + + +
+1512. [FCD] Conflict in spec: block or join?
+Section: 30.6.9 [futures.async] Status: NAD Editorial + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-12
+View all other issues in [futures.async].
+View all issues with NAD Editorial status.
+Discussion:
+Addresses US-205
++30.6.9 [futures.async] p. 3: The third sentence says +"If the invocation is not deferred, a call to a waiting function +on an asynchronous return object that shares the associated asynchronous state +created by this async call shall block until the associated +thread has completed." The next sentence says "If the +invocation is not deferred, the join() on the created +thread..." Blocking until a thread completes is not +necessarily a join. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Decide whether the requirement is to block until +finished or to call join, and rewrite to match. +
+ + + +Proposed resolution:
+ + + + + + + \ No newline at end of file diff --git a/libstdc++-v3/doc/html/ext/lwg-defects.html b/libstdc++-v3/doc/html/ext/lwg-defects.html index 0201cfbd739..c1a3c780b6b 100644 --- a/libstdc++-v3/doc/html/ext/lwg-defects.html +++ b/libstdc++-v3/doc/html/ext/lwg-defects.html @@ -1,43 +1,43 @@ - - - - - + + +C++ Standard Library Defect Report List - + +-
- Doc. no. -N3012=09-0202 +Doc. no. +D3182=10-0172 - Date: -2009-11-08 +Date: +2010-11-29 - Project: -Programming Language C++ +Project: +Programming Language C++ - Reply to: -Howard Hinnant <howard.hinnant@gmail.com> +Reply to: +Alisdair Meredith <lwgchair@gmail.com> C++ Standard Library Defect Report List (Revision R68)
+C++ Standard Library Defect Report List (Revision D73)
+Revised 2010-11-29 at 10:11:56 UTC
Reference ISO/IEC IS 14882:2003(E)
Also see:
@@ -59,6 +59,168 @@ del {background-color:#FFA0A0}Revision History
+
@@ -121,11 +283,11 @@ del {background-color:#FFA0A0}- D73: Batavia meeting preview
++
+- Summary:
++
- 80 open issues, down by 126.
+- 1459 closed issues, up by 145.
+- 1539 issues total, up by 19.
+- Details:
++
- Added the following 11 New issues: 1521, 1523, 2008, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019.
+- Added the following 5 Open issues: 2001, 2003, 2005, 2010, 2011.
+- Added the following Resolved issue: 2002.
+- Added the following Review issue: 2009.
+- Added the following Tentatively NAD issue: 2006.
+- Added the following 3 Tentatively Ready issues: 2000, 2004, 2007.
+- Added the following WP issue: 1522.
+- Changed the following 3 issues from New to Deferred: 1213, 1214, 1330.
+- Changed the following issue from Open to Deferred: 1450.
+- Changed the following 14 issues from Open to Dup: 1350, 1351, 1352, 1375, 1411, 1443, 1451, 1454, 1458, 1463, 1470, 1475, 1476, 1477.
+- Changed the following issue from New to NAD: 1331.
+- Changed the following 8 issues from Open to NAD: 579, 1359, 1361, 1373, 1376, 1398, 1446, 1473.
+- Changed the following 2 issues from Tentatively NAD to NAD: 1190, 1200.
+- Changed the following issue from WP to NAD: 822.
+- Changed the following 11 issues from Open to NAD Editorial: 1395, 1442, 1471, 1472, 1489, 1495, 1496, 1509, 1510, 1511, 1512.
+- Changed the following issue from Review to NAD Editorial: 1281.
+- Changed the following issue from New to NAD Future: 1289.
+- Changed the following 6 issues from Open to NAD Future: 1406, 1422, 1484, 1488, 1493, 1499.
+- Changed the following 2 issues from Tentatively NAD Future to NAD Future: 1173, 1188.
+- Changed the following 2 issues from New to Open: 1252, 1297.
+- Changed the following 3 issues from New to Ready: 1279, 1318, 1332.
+- Changed the following 6 issues from Open to Ready: 1385, 1401, 1408, 1418, 1420, 1438.
+- Changed the following 42 issues from NAD Editorial to Resolved: 353, 431, 482, 525, 594, 625, 635, 658, 697, 719, 742, 786, 815, 816, 823, 827, 834, 884, 932, 947, 950, 953, 983, 1054, 1055, 1075, 1100, 1116, 1117, 1122, 1135, 1151, 1174, 1258, 1260, 1283, 1293, 1307, 1321, 1394, 1405, 1407.
+- Changed the following 5 issues from New to Resolved: 1290, 1322, 1324, 1326, 1328.
+- Changed the following 46 issues from Open to Resolved: 801, 1268, 1327, 1344, 1346, 1347, 1355, 1356, 1357, 1365, 1366, 1377, 1378, 1379, 1380, 1382, 1383, 1389, 1390, 1391, 1392, 1393, 1397, 1409, 1410, 1412, 1445, 1447, 1453, 1455, 1462, 1464, 1465, 1466, 1467, 1468, 1469, 1481, 1482, 1490, 1491, 1492, 1498, 1501, 1508, 1513.
+- Changed the following issue from Open to Review: 1480.
+- Changed the following 2 issues from Open to Tentatively NAD: 1371, 1413.
+- Changed the following issue from New to Tentatively NAD Future: 1320.
+- Changed the following 3 issues from New to Tentatively Ready: 1215, 1253, 1310.
+- Changed the following issue from Open to Tentatively Ready: 1497.
+- Changed the following 24 issues from NAD Editorial to WP: 1360, 1363, 1367, 1372, 1381, 1384, 1386, 1387, 1388, 1399, 1400, 1402, 1403, 1416, 1417, 1423, 1424, 1425, 1426, 1427, 1429, 1430, 1431, 1441.
+- Changed the following issue from New to WP: 1294.
+- Changed the following 10 issues from Open to WP: 1354, 1362, 1368, 1370, 1428, 1435, 1436, 1437, 1439, 1440.
+- Changed the following 2 issues from Ready to WP: 868, 951.
+- Changed the following 33 issues from Tentatively Ready to WP: 956, 1118, 1171, 1181, 1183, 1191, 1198, 1207, 1234, 1240, 1249, 1292, 1295, 1316, 1319, 1323, 1325, 1333, 1334, 1335, 1337, 1338, 1339, 1340, 1404, 1414, 1432, 1449, 1516, 1517, 1518, 1519, 1520.
+- R72: +2010-10-18 pre-Batavia mailing. +
++
+- Summary:
++
- 206 open issues, up by 141.
+- 1314 closed issues, up by 36.
+- 1520 issues total, up by 177.
+- Details:
++
- Added the following Dup issues: 1433, 1444.
+- Added the following NAD Editorial issues: 1360, 1363, 1367, 1372, 1381, 1384, 1386, 1387, 1388, 1394, 1399, 1400, 1402, 1403, 1405, 1407, 1415, 1416, 1417, 1419, 1423, 1424, 1425, 1426, 1427, 1429, 1430, 1431, 1434, 1441, 1483, 1500, 1506.
+- Added the following Open issues: 1344, 1345, 1346, 1347, 1348, 1349, 1350, 1351, 1352, 1353, 1354, 1355, 1356, 1357, 1358, 1359, 1361, 1362, 1364, 1365, 1366, 1368, 1369, 1370, 1371, 1373, 1374, 1375, 1376, 1377, 1378, 1379, 1380, 1382, 1383, 1385, 1389, 1390, 1391, 1392, 1393, 1395, 1396, 1397, 1398, 1401, 1406, 1408, 1409, 1410, 1411, 1412, 1413, 1418, 1420, 1421, 1422, 1428, 1435, 1436, 1437, 1438, 1439, 1440, 1442, 1443, 1445, 1446, 1447, 1448, 1450, 1451, 1452, 1453, 1454, 1455, 1456, 1457, 1458, 1459, 1460, 1461, 1462, 1463, 1464, 1465, 1466, 1467, 1468, 1469, 1470, 1471, 1472, 1473, 1474, 1475, 1476, 1477, 1478, 1479, 1480, 1481, 1482, 1484, 1485, 1486, 1487, 1488, 1489, 1490, 1491, 1492, 1493, 1494, 1495, 1496, 1497, 1498, 1499, 1501, 1502, 1503, 1504, 1505, 1507, 1508, 1509, 1510, 1511, 1512, 1513, 1514, 1515.
+- Added the following Tentatively Ready issues: 1404, 1414, 1432, 1449, 1516, 1517, 1518, 1519, 1520.
+- Changed the following issues from New to NAD Editorial: 1260.
+- Changed the following issues from New to Tentatively Ready: 1181, 1240, 1249, 1292, 1295, 1316, 1319, 1323, 1325, 1333, 1334, 1335, 1337, 1338, 1339, 1340.
+- Changed the following issues from Open to Tentatively Ready: 956, 1118, 1183, 1234.
+- R71: +2010-08-25 post-Rapperswil mailing. +
++
+- Summary:
++
- 65 open issues, up by 2.
+- 1278 closed issues, up by 7.
+- 1343 issues total, up by 9.
+- Details:
++
- Added the following New issues: 1335, 2008, 1337, 1338, 1339, 1340, 2009, 2010, 2011.
+- Changed the following issues from Open to NAD: 996, 1119.
+- Changed the following issues from Open to NAD Concepts: 1076.
+- Changed the following issues from Open to NAD Editorial: 953.
+- Changed the following issues from New to Open: 1169, 1175.
+- Changed the following issues from Open to Ready: 951.
+- Changed the following issues from Review to Ready: 868.
+- Changed the following issues from New to Tentatively NAD: 1190, 1200.
+- Changed the following issues from New to Tentatively NAD Future: 1188.
+- Changed the following issues from Open to Tentatively NAD Future: 1173.
+- Changed the following issues from New to Tentatively Ready: 1198.
+- Changed the following issues from Open to Tentatively Ready: 1171, 1191, 1207.
+- Changed the following issues from Ready to WP: 1187, 1206, 1278.
+- R70: +2010-03-26 post-Pittsburgh mailing. +
++
+- Summary:
++
- 63 open issues, down by 203.
+- 1271 closed issues, up by 219.
+- 1334 issues total, up by 16.
+- Details:
++
- Added the following NAD Editorial issues: 1321, 1329.
+- Added the following New issues: 1319, 1320, 1322, 1323, 1324, 1325, 1326, 1328, 1330, 1331, 1332, 1333, 1334.
+- Added the following Open issues: 1327.
+- Changed the following issues from Tentatively Dup to Dup: 1219.
+- Changed the following issues from New to NAD: 1302, 1308, 1313, 1314.
+- Changed the following issues from Open to NAD: 887, 1008, 1068, 1069, 1153, 1156, 1228.
+- Changed the following issues from Tentatively NAD to NAD: 631, 726, 959, 1056, 1099, 1125, 1176, 1202, 1223, 1224, 1246, 1251, 1259, 1263, 1265, 1296.
+- Changed the following issues from Tentatively NAD Concepts to NAD Concepts: 910, 1186.
+- Changed the following issues from New to NAD Editorial: 1185, 1210, 1212, 1225, 1244, 1266, 1269, 1272, 1275, 1291, 1305, 1307, 1311.
+- Changed the following issues from Open to NAD Editorial: 299, 397, 408, 446, 594, 625, 742, 834, 915, 1093, 1151, 1211, 1248.
+- Changed the following issues from Ready to NAD Editorial: 485, 932, 940, 950, 983, 1100, 1135.
+- Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 815, 816, 889, 1106, 1115, 1233, 1239, 1258, 1283, 1301.
+- Changed the following issues from Tentatively Ready to NAD Editorial: 1090, 1226, 1273, 1274, 1293, 1300, 1304, 1315.
+- Changed the following issues from New to NAD Future: 1154, 1317.
+- Changed the following issues from Ready to NAD Future: 1052.
+- Changed the following issues from Tentatively NAD Future to NAD Future: 1112, 1121, 1201, 1238, 1282.
+- Changed the following issues from New to Open: 1234, 1268.
+- Changed the following issues from Tentatively Ready to Open: 579.
+- Changed the following issues from New to Ready: 1187, 1206, 1278.
+- Changed the following issues from New to Review: 1281.
+- Changed the following issues from Ready to Review: 868.
+- Changed the following issues from New to WP: 1159.
+- Changed the following issues from Open to WP: 427, 430, 774, 819, 835, 861, 885, 896, 900, 911, 1079.
+- Changed the following issues from Ready to WP: 296, 471, 473, 539, 671, 836, 854, 860, 865, 871, 872, 920, 921, 939, 954, 957, 960, 962, 963, 967, 968, 974, 1011, 1030, 1094, 1095, 1097, 1098, 1104, 1123, 1134, 1136, 1144, 1157, 1194, 1204, 1216, 1227, 1237.
+- Changed the following issues from Tentatively Ready to WP: 556, 676, 704, 724, 727, 780, 811, 817, 870, 891, 893, 929, 978, 987, 999, 1033, 1034, 1071, 1089, 1108, 1110, 1113, 1114, 1126, 1130, 1131, 1133, 1137, 1138, 1152, 1158, 1170, 1177, 1180, 1182, 1189, 1192, 1193, 1195, 1197, 1199, 1205, 1208, 1209, 1218, 1220, 1221, 1222, 1231, 1241, 1245, 1247, 1250, 1254, 1255, 1256, 1257, 1261, 1262, 1264, 1267, 1270, 1271, 1276, 1277, 1280, 1284, 1285, 1286, 1287, 1288, 1298, 1299, 1303, 1306, 1309, 1312.
+- R69: +2010-02-12 pre-Pittsburgh mailing. +
+
+- Summary:
++
- 266 open issues, up by 61.
+- 1052 closed issues, down by 3.
+- 1318 issues total, up by 58.
+- Details:
++
- Added the following New issues: 1266, 1268, 1269, 1272, 1275, 1278, 1279, 1281, 1289, 1290, 1291, 1292, 1294, 1295, 1297, 1302, 1305, 1307, 1308, 1310, 1311, 1313, 1314, 1316, 1317, 1318.
+- Added the following Tentatively NAD issues: 1263, 1265, 1296.
+- Added the following Tentatively NAD Editorial issues: 1283, 1301.
+- Added the following Tentatively NAD Future issues: 1282.
+- Added the following Tentatively Ready issues: 1261, 1262, 1264, 1267, 1270, 1271, 1273, 1274, 1276, 1277, 1280, 1284, 1285, 1286, 1287, 1288, 1293, 1298, 1299, 1300, 1303, 1304, 1306, 1309, 1312, 1315.
+- Changed the following issues from NAD to NAD Editorial: 101.
+- Changed the following issues from NAD Future to Open: 1248.
+- Changed the following issues from New to Open: 1207.
+- Changed the following issues from Ready to Open: 1079.
+- Changed the following issues from New to Tentatively Dup: 1219.
+- Changed the following issues from New to Tentatively NAD: 1125, 1176, 1202, 1223, 1224, 1246, 1251, 1259.
+- Changed the following issues from Open to Tentatively NAD: 726, 959.
+- Changed the following issues from Review to Tentatively NAD: 631.
+- Changed the following issues from Open to Tentatively NAD Concepts: 910.
+- Changed the following issues from New to Tentatively NAD Editorial: 1258.
+- Changed the following issues from Open to Tentatively NAD Editorial: 815, 1106.
+- Changed the following issues from Ready to Tentatively NAD Editorial: 816, 889.
+- Changed the following issues from NAD to Tentatively Ready: 579.
+- Changed the following issues from NAD Editorial to Tentatively Ready: 1195.
+- Changed the following issues from New to Tentatively Ready: 1131, 1133, 1137, 1170, 1180, 1182, 1193, 1197, 1199, 1205, 1209, 1218, 1221, 1222, 1245, 1250, 1254, 1255, 1256, 1257.
+- Changed the following issues from Open to Tentatively Ready: 704, 724, 811, 817, 870, 891, 1033, 1034, 1089, 1110.
+- Changed the following issues from Ready to Tentatively Ready: 893, 978, 1177.
+- Changed the following issues from Review to Tentatively Ready: 556, 676, 727, 780, 929, 1130, 1247.
+- Changed the following issues from Pending WP to WP: 970.
+- R68: 2009-11-06 post-Santa Cruz mailing.
@@ -72,42 +234,42 @@ del {background-color:#FFA0A0}
- Added the following NAD issues: 1229, 1236, 1243.
- Added the following NAD Editorial issues: 1232.
- Added the following NAD Future issues: 1235, 1242, 1248.
-- Added the following New issues: 1218, 1219, 1221, 1222, 1223, 1224, 1225, 1234, 1240, 1244, 1245, 1246, 1249, 1250, 1251, 1252, 1253, 1254, 1255, 1256, 1257, 1258, 1259, 1260.
-- Added the following Open issues: 1228.
-- Added the following Ready issues: 1227, 1237.
-- Added the following Review issues: 1247.
-- Added the following Tentatively NAD Editorial issues: 1233, 1239.
-- Added the following Tentatively NAD Future issues: 1238.
-- Added the following Tentatively Ready issues: 1220, 1226, 1231, 1241.
+- Added the following New issues: 1218, 1219, 1221, 1222, 1223, 1224, 1225, 1234, 1240, 1244, 1245, 1246, 1249, 1250, 1251, 1252, 1253, 1254, 1255, 1256, 1257, 1258, 1259, 1260.
+- Added the following Open issues: 1228.
+- Added the following Ready issues: 1227, 1237.
+- Added the following Review issues: 1247.
+- Added the following Tentatively NAD Editorial issues: 1233, 1239.
+- Added the following Tentatively NAD Future issues: 1238.
+- Added the following Tentatively Ready issues: 1220, 1226, 1231, 1241.
- Changed the following issues from New to NAD: 1132, 1148.
- Changed the following issues from Open to NAD: 96, 458, 463, 916, 917, 919, 955, 977, 1009, 1020, 1035, 1042, 1051, 1064.
- Changed the following issues from Review to NAD: 668, 930, 1091, 1102.
- Changed the following issues from Tentatively NAD to NAD: 588, 617, 971.
- Changed the following issues from Tentatively NAD Future to NAD: 1062.
- Changed the following issues from NAD Concepts to NAD Editorial: 1143.
-- Changed the following issues from New to NAD Editorial: 1116, 1117, 1122, 1129, 1145, 1146, 1147, 1155, 1166, 1172, 1174, 1179, 1195, 1196.
-- Changed the following issues from Open to NAD Editorial: 431, 580, 635, 719, 823, 827, 879, 880, 908, 923, 924, 926, 944, 947, 958, 1046, 1048, 1054, 1055, 1075, 1088, 1160, 1161, 1162, 1163, 1165.
+- Changed the following issues from New to NAD Editorial: 1116, 1117, 1122, 1129, 1145, 1146, 1147, 1155, 1166, 1172, 1174, 1179, 1195, 1196.
+- Changed the following issues from Open to NAD Editorial: 431, 580, 635, 719, 823, 827, 879, 880, 908, 923, 924, 926, 944, 947, 958, 1046, 1048, 1054, 1055, 1075, 1088, 1160, 1161, 1162, 1163, 1165.
- Changed the following issues from Review to NAD Editorial: 828, 897, 976, 1043, 1047, 1049, 1050.
- Changed the following issues from New to NAD Future: 1120, 1150, 1184, 1203, 1217.
- Changed the following issues from Open to NAD Future: 484, 532, 851, 933, 935, 936, 961, 1041, 1053.
- Changed the following issues from Tentatively NAD Future to NAD Future: 1031.
-- Changed the following issues from New to Open: 1118, 1119, 1151, 1153, 1156, 1171, 1173, 1183, 1191, 1211.
-- Changed the following issues from Ready to Open: 430, 834.
-- Changed the following issues from Review to Open: 397, 408, 835.
-- Changed the following issues from Tentatively NAD to Open: 625.
-- Changed the following issues from New to Ready: 1123, 1134, 1135, 1136, 1144, 1177, 1194, 1204, 1216.
-- Changed the following issues from Open to Ready: 296, 471, 485, 539, 816, 860, 865, 872, 920, 932, 939, 940, 960, 963, 974, 978, 1011, 1030, 1079, 1098.
-- Changed the following issues from Review to Ready: 473, 671, 836, 854, 868, 871, 889, 893, 921, 950, 954, 957, 962, 967, 968, 983, 1052, 1094, 1095, 1097, 1100, 1104, 1157.
-- Changed the following issues from New to Review: 1130.
-- Changed the following issues from Open to Review: 556, 631, 676, 727, 929.
-- Changed the following issues from Open to Tentatively NAD: 1056, 1099.
-- Changed the following issues from New to Tentatively NAD Concepts: 1186.
-- Changed the following issues from New to Tentatively NAD Editorial: 1115.
-- Changed the following issues from New to Tentatively NAD Future: 1121, 1201.
-- Changed the following issues from Open to Tentatively NAD Future: 1112.
-- Changed the following issues from New to Tentatively Ready: 1126, 1138, 1152, 1158, 1189, 1192, 1208.
-- Changed the following issues from Open to Tentatively Ready: 987, 999, 1071, 1090, 1108, 1113, 1114.
-- Changed the following issues from Ready to WP: 149, 419, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 822, 838, 847, 857, 859, 876, 881, 883, 886, 934, 1004, 1178.
+- Changed the following issues from New to Open: 1118, 1119, 1151, 1153, 1156, 1171, 1173, 1183, 1191, 1211.
+- Changed the following issues from Ready to Open: 430, 834.
+- Changed the following issues from Review to Open: 397, 408, 835.
+- Changed the following issues from Tentatively NAD to Open: 625.
+- Changed the following issues from New to Ready: 1123, 1134, 1135, 1136, 1144, 1177, 1194, 1204, 1216.
+- Changed the following issues from Open to Ready: 296, 471, 485, 539, 816, 860, 865, 872, 920, 932, 939, 940, 960, 963, 974, 978, 1011, 1030, 1079, 1098.
+- Changed the following issues from Review to Ready: 473, 671, 836, 854, 868, 871, 889, 893, 921, 950, 954, 957, 962, 967, 968, 983, 1052, 1094, 1095, 1097, 1100, 1104, 1157.
+- Changed the following issues from New to Review: 1130.
+- Changed the following issues from Open to Review: 556, 631, 676, 727, 929.
+- Changed the following issues from Open to Tentatively NAD: 1056, 1099.
+- Changed the following issues from New to Tentatively NAD Concepts: 1186.
+- Changed the following issues from New to Tentatively NAD Editorial: 1115.
+- Changed the following issues from New to Tentatively NAD Future: 1121, 1201.
+- Changed the following issues from Open to Tentatively NAD Future: 1112.
+- Changed the following issues from New to Tentatively Ready: 1126, 1138, 1152, 1158, 1189, 1192, 1208.
+- Changed the following issues from Open to Tentatively Ready: 987, 999, 1071, 1090, 1108, 1113, 1114.
+- Changed the following issues from Ready to WP: 149, 419, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 822, 838, 847, 857, 859, 876, 881, 883, 886, 934, 1004, 1178.
- Changed the following issues from Tentatively Ready to WP: 1012, 1019.
- 1217 issues total, up by 31.
- Details:
-
- Added the following New issues: 1187, 1188, 1189, 1190, 1191, 1192, 1193, 1194, 1195, 1196, 1197, 1198, 1199, 1200, 1201, 1202, 1203, 1204, 1205, 1206, 1207, 1208, 1209, 1210, 1211, 1212, 1213, 1214, 1215, 1216, 1217.
-- Changed the following issues from NAD to Open: 296.
+- Added the following New issues: 1187, 1188, 1189, 1190, 1191, 1192, 1193, 1194, 1195, 1196, 1197, 1198, 1199, 1200, 1201, 1202, 1203, 1204, 1205, 1206, 1207, 1208, 1209, 1210, 1211, 1212, 1213, 1214, 1215, 1216, 1217.
+- Changed the following issues from NAD to Open: 296.
- Changed the following issues from WP to Pending WP: 970.
-- Changed the following issues from Open to Review: 976, 1052.
-- Changed the following issues from Ready to Review: 780.
+- Changed the following issues from Open to Review: 976, 1052.
+- Changed the following issues from Ready to Review: 780.
- Added the following NAD issues: 1164.
- Added the following NAD Concepts issues: 1149, 1167.
- Added the following NAD Editorial issues: 1168.
-- Added the following New issues: 1144, 1145, 1146, 1147, 1148, 1150, 1151, 1152, 1153, 1154, 1155, 1156, 1158, 1159, 1166, 1169, 1170, 1171, 1172, 1173, 1174, 1175, 1176, 1177, 1179, 1180, 1181, 1182, 1183, 1184, 1185, 1186.
+- Added the following New issues: 1144, 1145, 1146, 1147, 1148, 1150, 1151, 1152, 1153, 1154, 1155, 1156, 1158, 1159, 1166, 1169, 1170, 1171, 1172, 1173, 1174, 1175, 1176, 1177, 1179, 1180, 1181, 1182, 1183, 1184, 1185, 1186.
- Added the following Open issues: 1160, 1161, 1162, 1163, 1165.
- Added the following Ready issues: 1178.
-- Added the following Review issues: 1157.
+- Added the following Review issues: 1157.
- Changed the following issues from Open to Dup: 750, 895.
- Changed the following issues from Open to NAD: 111, 128, 138, 190, 219, 290, 309, 342, 343, 382, 394, 398, 417, 418, 421, 459, 466, 492, 502, 503, 546, 573, 582, 585, 597, 606, 614, 632, 721, 747, 751, 833, 941, 992.
- Changed the following issues from Review to NAD: 1003.
@@ -157,24 +319,24 @@ del {background-color:#FFA0A0}- Changed the following issues from Tentatively NAD Editorial to NAD Concepts: 927, 1109.
- Changed the following issues from Tentatively Ready to NAD Concepts: 906, 913, 914, 928, 1024, 1063, 1067.
- Changed the following issues from Open to NAD Editorial: 718, 873.
-- Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 424, 825, 830, 837, 862, 867, 884, 945, 952, 969, 972, 973, 979, 1023, 1058, 1060, 1061, 1077, 1101.
+- Changed the following issues from Tentatively NAD Editorial to NAD Editorial: 424, 825, 830, 837, 862, 867, 884, 945, 952, 969, 972, 973, 979, 1023, 1058, 1060, 1061, 1077, 1101.
- Changed the following issues from Tentatively Ready to NAD Editorial: 1013, 1107.
- Changed the following issues from Open to NAD Future: 255, 423, 523, 708, 760, 839, 877.
-- Changed the following issues from CD1 to Open: 823.
-- Changed the following issues from NAD Editorial to Open: 299, 484, 532, 556, 594, 631, 676, 704, 724, 742, 811, 870, 872.
-- Changed the following issues from Review to Open: 879, 919, 929, 939, 987, 1009, 1093.
+- Changed the following issues from CD1 to Open: 823.
+- Changed the following issues from NAD Editorial to Open: 299, 484, 532, 556, 594, 631, 676, 704, 724, 742, 811, 870, 872.
+- Changed the following issues from Review to Open: 879, 919, 929, 939, 987, 1009, 1093.
- Changed the following issues from Tentatively NAD to Open: 458.
- Changed the following issues from Tentatively NAD Future to Open: 96.
-- Changed the following issues from Tentatively Ready to Open: 910, 915, 932, 940, 974, 976, 999, 1011.
-- Changed the following issues from Open to Ready: 149, 419, 430, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 834, 838, 847, 857, 859, 876, 881, 883, 886, 1004.
-- Changed the following issues from Review to Ready: 780.
-- Changed the following issues from Tentatively NAD to Ready: 822.
+- Changed the following issues from Tentatively Ready to Open: 910, 915, 932, 940, 974, 976, 999, 1011.
+- Changed the following issues from Open to Ready: 149, 419, 430, 498, 564, 565, 630, 659, 696, 711, 716, 723, 788, 834, 838, 847, 857, 859, 876, 881, 883, 886, 1004.
+- Changed the following issues from Review to Ready: 780.
+- Changed the following issues from Tentatively NAD to Ready: 822.
- Changed the following issues from Tentatively Ready to Ready: 934.
-- Changed the following issues from NAD to Review: 871.
-- Changed the following issues from Open to Review: 397, 408, 473, 671, 836, 868, 889, 893, 930, 954, 962, 967, 968.
+- Changed the following issues from NAD to Review: 871.
+- Changed the following issues from Open to Review: 397, 408, 473, 671, 836, 868, 889, 893, 930, 954, 962, 967, 968.
- Changed the following issues from Tentatively NAD to Review: 668.
-- Changed the following issues from Tentatively Ready to Review: 950, 1100.
-- Changed the following issues from Open to Tentatively NAD: 588, 617, 625, 971.
+- Changed the following issues from Tentatively Ready to Review: 950, 1100.
+- Changed the following issues from Open to Tentatively NAD: 588, 617, 625, 971.
- Changed the following issues from Open to Tentatively NAD Future: 1031, 1062.
- Changed the following issues from Open to Tentatively Ready: 1012, 1019.
- Changed the following issues from Tentatively Ready to WP: 688, 765, 810, 814, 853, 869, 878, 888, 890, 898, 899, 904, 907, 909, 922, 925, 931, 938, 943, 948, 949, 965, 970, 975, 981, 982, 984, 986, 990, 991, 993, 994, 997, 998, 1006, 1014, 1021, 1037, 1038, 1039, 1040, 1044, 1045, 1065, 1066, 1070, 1073, 1103.
@@ -190,24 +352,24 @@ del {background-color:#FFA0A0}- 1143 issues total, up by 32.
- Details:
-
- Added the following New issues: 1115, 1116, 1117, 1118, 1119, 1120, 1121, 1122, 1123, 1124, 1125, 1126, 1127, 1128, 1129, 1130, 1131, 1132, 1133, 1134, 1135, 1136, 1137, 1138, 1139, 1140, 1141, 1142, 1143.
-- Added the following Open issues: 1112, 1113, 1114.
+- Added the following New issues: 1115, 1116, 1117, 1118, 1119, 1120, 1121, 1122, 1123, 1124, 1125, 1126, 1127, 1128, 1129, 1130, 1131, 1132, 1133, 1134, 1135, 1136, 1137, 1138, 1139, 1140, 1141, 1142, 1143.
+- Added the following Open issues: 1112, 1113, 1114.
- Changed the following issues from Pending NAD Editorial to NAD Editorial: 937.
-- Changed the following issues from New to Open: 696, 716, 727, 865, 900, 911, 916, 917, 920, 933, 935, 941, 947, 951, 953, 954, 955, 956, 977, 978, 985, 989, 996, 1033, 1054, 1056, 1057, 1059, 1062, 1068, 1069, 1071, 1072, 1076, 1090, 1092, 1096, 1098, 1099, 1105, 1106, 1108, 1110.
-- Changed the following issues from Review to Open: 817, 971, 992, 1004, 1010, 1012, 1015, 1019.
-- Changed the following issues from New to Review: 780, 835, 897, 919, 939, 957, 983, 1001, 1080, 1091, 1093, 1094, 1095, 1097, 1102, 1104, 1111.
-- Changed the following issues from Open to Review: 921, 987, 1087.
+- Changed the following issues from New to Open: 696, 716, 727, 865, 900, 911, 916, 917, 920, 933, 935, 941, 947, 951, 953, 954, 955, 956, 977, 978, 985, 989, 996, 1033, 1054, 1056, 1057, 1059, 1062, 1068, 1069, 1071, 1072, 1076, 1090, 1092, 1096, 1098, 1099, 1105, 1106, 1108, 1110.
+- Changed the following issues from Review to Open: 817, 971, 992, 1004, 1010, 1012, 1015, 1019.
+- Changed the following issues from New to Review: 780, 835, 897, 919, 939, 957, 983, 1001, 1080, 1091, 1093, 1094, 1095, 1097, 1102, 1104, 1111.
+- Changed the following issues from Open to Review: 921, 987, 1087.
- Changed the following issues from New to Tentatively NAD: 568, 701, 702, 785, 863, 903, 912, 918, 946, 995, 1074.
- Changed the following issues from Open to Tentatively NAD: 458, 644, 667, 668, 669.
- Changed the following issues from Review to Tentatively NAD: 901.
-- Changed the following issues from Tentatively Ready to Tentatively NAD: 822, 988.
+- Changed the following issues from Tentatively Ready to Tentatively NAD: 822, 988.
- Changed the following issues from New to Tentatively NAD Editorial: 837, 862, 867, 927, 945, 952, 969, 972, 973, 979, 1058, 1060, 1061, 1077, 1101, 1109.
-- Changed the following issues from Open to Tentatively NAD Editorial: 424, 825, 830, 884.
+- Changed the following issues from Open to Tentatively NAD Editorial: 424, 825, 830, 884.
- Changed the following issues from Review to Tentatively NAD Editorial: 1023.
- Changed the following issues from Open to Tentatively NAD Future: 96.
-- Changed the following issues from New to Tentatively Ready: 810, 898, 906, 910, 913, 914, 915, 925, 974, 976, 981, 982, 984, 990, 998, 999, 1063, 1067, 1070, 1073, 1100, 1103, 1107.
+- Changed the following issues from New to Tentatively Ready: 810, 898, 906, 910, 913, 914, 915, 925, 974, 976, 981, 982, 984, 990, 998, 999, 1063, 1067, 1070, 1073, 1100, 1103, 1107.
- Changed the following issues from Open to Tentatively Ready: 688, 814.
-- Changed the following issues from Review to Tentatively Ready: 899, 907, 909, 934, 938, 940, 943, 950, 965, 970, 975, 986, 991, 993, 994, 997, 1002, 1006, 1011, 1013, 1014, 1021, 1024, 1037, 1038, 1039, 1040, 1044, 1045, 1065, 1066.
+- Changed the following issues from Review to Tentatively Ready: 899, 907, 909, 934, 938, 940, 943, 950, 965, 970, 975, 986, 991, 993, 994, 997, 1002, 1006, 1011, 1013, 1014, 1021, 1024, 1037, 1038, 1039, 1040, 1044, 1045, 1065, 1066.
- 1111 issues total, up by 19.
- Details:
@@ -237,9 +399,9 @@ del {background-color:#FFA0A0}-
- Added the following New issues: 1093, 1094, 1095, 1096, 1097, 1098, 1099, 1100, 1101, 1102, 1103, 1104, 1105, 1106, 1107, 1108, 1109, 1110, 1111.
+- Added the following New issues: 1093, 1094, 1095, 1096, 1097, 1098, 1099, 1100, 1101, 1102, 1103, 1104, 1105, 1106, 1107, 1108, 1109, 1110, 1111.
- Changed the following issues from DR to CD1: 130, 386, 406, 409, 413, 434, 438, 444, 445, 455, 457, 460, 469, 533.
- Changed the following issues from Review to New: 1070.
- Details:
@@ -270,7 +432,7 @@ del {background-color:#FFA0A0}
- Added the following NAD Editorial issues: 1022.
- Added the following NAD Future issues: 1025.
-- Added the following New issues: 983, 984, 985, 989, 990, 995, 996, 998, 999, 1001, 1033, 1054, 1056, 1057, 1058, 1059, 1060, 1061, 1062, 1063, 1067, 1068, 1069, 1071, 1072, 1073, 1074, 1076, 1077, 1080, 1090, 1091, 1092.
-- Added the following Open issues: 987, 1000, 1007, 1008, 1016, 1017, 1018, 1020, 1026, 1027, 1028, 1029, 1030, 1031, 1032, 1034, 1035, 1036, 1041, 1042, 1046, 1048, 1051, 1052, 1053, 1055, 1064, 1075, 1078, 1079, 1081, 1082, 1083, 1084, 1085, 1086, 1087, 1088, 1089.
-- Added the following Review issues: 986, 991, 992, 993, 994, 997, 1002, 1003, 1004, 1005, 1006, 1009, 1010, 1011, 1012, 1013, 1014, 1015, 1019, 1021, 1023, 1024, 1037, 1038, 1039, 1040, 1043, 1044, 1045, 1047, 1049, 1050, 1065, 1066, 1070.
+- Added the following New issues: 983, 984, 985, 989, 990, 995, 996, 998, 999, 1001, 1033, 1054, 1056, 1057, 1058, 1059, 1060, 1061, 1062, 1063, 1067, 1068, 1069, 1071, 1072, 1073, 1074, 1076, 1077, 1080, 1090, 1091, 1092.
+- Added the following Open issues: 987, 1000, 1007, 1008, 1016, 1017, 1018, 1020, 1026, 1027, 1028, 1029, 1030, 1031, 1032, 1034, 1035, 1036, 1041, 1042, 1046, 1048, 1051, 1052, 1053, 1055, 1064, 1075, 1078, 1079, 1081, 1082, 1083, 1084, 1085, 1086, 1087, 1088, 1089.
+- Added the following Review issues: 986, 991, 992, 993, 994, 997, 1002, 1003, 1004, 1005, 1006, 1009, 1010, 1011, 1012, 1013, 1014, 1015, 1019, 1021, 1023, 1024, 1037, 1038, 1039, 1040, 1043, 1044, 1045, 1047, 1049, 1050, 1065, 1066, 1070.
- Added the following Tentatively Ready issues: 988.
- Changed the following issues from New to Dup: 905, 942.
- Changed the following issues from New to NAD: 980.
@@ -249,14 +411,14 @@ del {background-color:#FFA0A0}- Changed the following issues from Ready to NAD Editorial: 803.
- Changed the following issues from NAD to Open: 466.
- Changed the following issues from NAD Future to Open: 111, 138, 149, 219.
-- Changed the following issues from New to Open: 880, 891, 893, 902, 908, 921, 923, 924, 926, 930, 936, 944, 958, 959, 960, 961, 962, 963, 964, 966, 967, 968.
+- Changed the following issues from New to Open: 880, 891, 893, 902, 908, 921, 923, 924, 926, 930, 936, 944, 958, 959, 960, 961, 962, 963, 964, 966, 967, 968.
- Changed the following issues from Ready to Open: 788.
- Changed the following issues from New to Pending NAD Editorial: 937.
-- Changed the following issues from New to Review: 879, 899, 901, 907, 909, 929, 934, 938, 940, 943, 950, 965, 970, 971, 975.
-- Changed the following issues from Open to Review: 817.
-- Changed the following issues from New to Tentatively Ready: 904, 922, 928, 931, 932, 948, 949.
+- Changed the following issues from New to Review: 879, 899, 901, 907, 909, 929, 934, 938, 940, 943, 950, 965, 970, 971, 975.
+- Changed the following issues from Open to Review: 817.
+- Changed the following issues from New to Tentatively Ready: 904, 922, 928, 931, 932, 948, 949.
- Changed the following issues from Open to Tentatively Ready: 890.
-- Changed the following issues from Review to Tentatively Ready: 765, 822, 853, 869, 878, 888.
+- Changed the following issues from Review to Tentatively Ready: 765, 822, 853, 869, 878, 888.
- Changed the following issues from Ready to WP: 752, 753, 758, 821, 866, 894.
- 982 issues total, up by 44.
- Details:
-
- Added the following New issues: 939, 940, 941, 942, 943, 944, 945, 946, 947, 948, 949, 950, 951, 952, 953, 954, 955, 956, 957, 958, 959, 960, 961, 962, 963, 964, 965, 966, 967, 968, 969, 970, 971, 972, 973, 974, 975, 976, 977, 978, 979, 980, 981, 982.
+- Added the following New issues: 939, 940, 941, 942, 943, 944, 945, 946, 947, 948, 949, 950, 951, 952, 953, 954, 955, 956, 957, 958, 959, 960, 961, 962, 963, 964, 965, 966, 967, 968, 969, 970, 971, 972, 973, 974, 975, 976, 977, 978, 979, 980, 981, 982.
- 938 issues total, up by 20.
- Details:
- Details:
@@ -332,7 +494,7 @@ del {background-color:#FFA0A0}
- Added the following CD1 issues: 882.
-- Added the following New issues: 879, 880, 891, 893, 897, 898, 899, 900, 901, 902, 903, 904, 905, 906, 907, 908, 909, 910, 911, 912, 913, 914, 915, 916, 917, 918.
-- Added the following Open issues: 881, 883, 884, 885, 886, 887, 889, 890, 895, 896.
+- Added the following New issues: 879, 880, 891, 893, 897, 898, 899, 900, 901, 902, 903, 904, 905, 906, 907, 908, 909, 910, 911, 912, 913, 914, 915, 916, 917, 918.
+- Added the following Open issues: 881, 883, 884, 885, 886, 887, 889, 890, 895, 896.
- Added the following Pending NAD Editorial issues: 892.
- Added the following Ready issues: 894.
- Added the following Review issues: 888.
- Changed the following issues from New to CD1: 818, 820, 843, 845, 846, 856, 858.
- Changed the following issues from Ready to CD1: 180, 387, 396, 522, 629, 691, 713, 714, 720, 728, 762, 769, 771, 772, 776, 779, 787, 805, 806, 807, 808, 809, 813, 824, 829, 842, 844, 848, 850, 852.
-- Changed the following issues from Review to CD1: 23, 675, 692, 698, 709, 734, 804, 823.
+- Changed the following issues from Review to CD1: 23, 675, 692, 698, 709, 734, 804, 823.
- Changed the following issues from WP to CD1: 44, 49, 76, 91, 92, 98, 103, 109, 117, 118, 120, 123, 136, 153, 165, 167, 171, 179, 182, 183, 184, 185, 186, 187, 198, 200, 201, 202, 206, 214, 221, 225, 226, 228, 229, 230, 231, 232, 233, 234, 235, 237, 238, 239, 240, 241, 242, 243, 247, 248, 250, 251, 252, 253, 254, 256, 258, 259, 260, 261, 262, 263, 264, 265, 266, 268, 270, 271, 272, 273, 274, 275, 276, 278, 280, 281, 282, 283, 284, 285, 286, 288, 291, 292, 294, 295, 297, 298, 300, 301, 303, 305, 306, 307, 308, 310, 311, 312, 315, 316, 317, 318, 319, 320, 321, 322, 324, 325, 327, 328, 329, 331, 333, 334, 335, 336, 337, 338, 339, 340, 341, 345, 346, 347, 349, 352, 354, 355, 358, 359, 360, 362, 363, 364, 365, 369, 370, 371, 373, 375, 376, 379, 380, 381, 383, 384, 389, 391, 395, 400, 401, 402, 403, 404, 405, 407, 410, 411, 412, 414, 415, 416, 420, 422, 425, 426, 428, 432, 435, 436, 441, 442, 443, 448, 449, 453, 456, 461, 464, 465, 467, 468, 474, 475, 478, 488, 495, 496, 497, 505, 507, 508, 518, 519, 520, 521, 524, 527, 530, 531, 534, 535, 537, 538, 540, 541, 542, 543, 545, 550, 551, 552, 559, 561, 562, 563, 566, 567, 574, 575, 576, 577, 578, 581, 586, 589, 593, 595, 596, 607, 608, 609, 610, 611, 612, 613, 616, 618, 619, 620, 621, 622, 623, 624, 628, 634, 638, 640, 643, 646, 650, 651, 652, 654, 655, 660, 661, 664, 665, 666, 672, 673, 674, 677, 678, 679, 680, 681, 682, 685, 687, 689, 693, 694, 695, 699, 700, 703, 705, 706, 710, 712, 715, 722, 740, 743, 744, 746, 749, 755, 759, 761, 766, 768, 770, 775, 777, 778, 781, 782, 783, 789, 792, 798.
- Changed the following issues from Open to Dup: 670.
-- Changed the following issues from New to NAD: 849, 855, 871.
+- Changed the following issues from New to NAD: 849, 855, 871.
- Changed the following issues from Open to NAD: 454, 832.
-- Changed the following issues from New to NAD Editorial: 811, 812, 841, 864, 870, 872.
-- Changed the following issues from Open to NAD Editorial: 299, 484, 556, 631, 676, 704, 724, 742.
-- Changed the following issues from Pending NAD Editorial to NAD Editorial: 532, 594, 717, 725, 738.
-- Changed the following issues from New to Open: 721, 751, 814, 816, 817, 819, 827, 836, 838, 847, 857, 859, 860, 861, 868, 873, 876, 877.
-- Changed the following issues from Pending NAD Editorial to Open: 424, 625.
+- Changed the following issues from New to NAD Editorial: 811, 812, 841, 864, 870, 872.
+- Changed the following issues from Open to NAD Editorial: 299, 484, 556, 631, 676, 704, 724, 742.
+- Changed the following issues from Pending NAD Editorial to NAD Editorial: 532, 594, 717, 725, 738.
+- Changed the following issues from New to Open: 721, 751, 814, 816, 817, 819, 827, 836, 838, 847, 857, 859, 860, 861, 868, 873, 876, 877.
+- Changed the following issues from Pending NAD Editorial to Open: 424, 625.
- Changed the following issues from Review to Open: 851.
- Changed the following issues from New to Ready: 788, 821, 866.
- Changed the following issues from Open to Ready: 753.
- Changed the following issues from Review to Ready: 752, 758, 803.
-- Changed the following issues from New to Review: 765, 822, 853, 854, 869, 878.
+- Changed the following issues from New to Review: 765, 822, 853, 854, 869, 878.
- Changed the following issues from TC to TC1: 1, 3, 5, 7, 8, 9, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 59, 60, 61, 62, 63, 64, 66, 68, 69, 70, 71, 74, 75, 78, 79, 80, 83, 86, 90, 106, 108, 110, 112, 114, 115, 119, 122, 124, 125, 126, 127, 129, 132, 133, 134, 137, 139, 141, 142, 144, 146, 147, 148, 150, 151, 152, 154, 155, 156, 158, 159, 160, 161, 164, 168, 169, 170, 172, 173, 174, 175, 176, 181, 189, 193, 195, 199, 208, 209, 210, 211, 212, 217, 220, 222, 223, 224, 227.
- 878 issues total, up by 9.
- Details:
- 869 issues total, up by 8.
- Details:
-
- Added the following New issues: 862, 863, 864, 865, 866, 867, 868, 869.
+- Added the following New issues: 862, 863, 864, 865, 866, 867, 868, 869.
- Changed the following issues from Pending NAD Editorial to NAD Editorial: 393, 557, 592, 754, 757.
- Changed the following issues from Pending WP to Open: 644.
- Changed the following issues from WP to Ready: 387, 629.
@@ -363,21 +525,21 @@ del {background-color:#FFA0A0}- Details:
- Added the following NAD issues: 840.
-- Added the following New issues: 841, 843, 845, 846, 847, 849, 853, 854, 855, 856, 857, 858, 859, 860, 861.
+- Added the following New issues: 841, 843, 845, 846, 847, 849, 853, 854, 855, 856, 857, 858, 859, 860, 861.
- Added the following Open issues: 839.
- Added the following Ready issues: 842, 844, 848, 850, 852.
- Added the following Review issues: 851.
- Changed the following issues from New to NAD: 826.
- Changed the following issues from Open to NAD: 570.
-- Changed the following issues from New to NAD Editorial: 786, 831.
+- Changed the following issues from New to NAD Editorial: 786, 831.
- Changed the following issues from Open to NAD Editorial: 756, 767.
-- Changed the following issues from New to Open: 723, 726, 794, 815, 825, 830, 833, 834.
-- Changed the following issues from Ready to Open: 471.
-- Changed the following issues from Review to Open: 539, 711.
+- Changed the following issues from New to Open: 723, 726, 794, 815, 825, 830, 833, 834.
+- Changed the following issues from Ready to Open: 471.
+- Changed the following issues from Review to Open: 539, 711.
- Changed the following issues from New to Ready: 713, 714, 769, 772, 779, 787, 805, 806, 807, 808, 809, 813, 824, 829.
- Changed the following issues from Open to Ready: 180, 396, 522, 720, 762.
- Changed the following issues from Review to Ready: 691, 728, 771, 776.
-- Changed the following issues from New to Review: 692, 698, 752, 804, 823, 828, 832.
+- Changed the following issues from New to Review: 692, 698, 752, 804, 823, 828, 832.
- Changed the following issues from Open to Review: 23, 675, 734, 803.
- Changed the following issues from Ready to Review: 758.
- Changed the following issues from Ready to WP: 387, 518, 550, 574, 595, 596, 612, 618, 629, 638, 672, 673, 685, 710, 715, 722, 740, 743, 744, 746, 749, 755, 759, 761, 766, 768, 770, 775, 777, 778, 781, 782, 783, 789, 792, 798.
@@ -393,7 +555,7 @@ del {background-color:#FFA0A0}- 838 issues total, up by 25.
- Details:
@@ -409,8 +571,8 @@ del {background-color:#FFA0A0}-
- Added the following New issues: 814, 815, 816, 817, 818, 819, 820, 821, 822, 823, 824, 825, 826, 827, 828, 829, 830, 831, 832, 833, 834, 835, 836, 837, 838.
+- Added the following New issues: 814, 815, 816, 817, 818, 819, 820, 821, 822, 823, 824, 825, 826, 827, 828, 829, 830, 831, 832, 833, 834, 835, 836, 837, 838.
- Changed the following issues from New to NAD: 802.
- Details:
@@ -443,10 +605,10 @@ del {background-color:#FFA0A0}
- Added the following Dup issues: 795.
- Added the following NAD issues: 790, 791, 796, 797, 799.
-- Added the following New issues: 788, 794, 802, 804, 805, 806, 807, 808, 809, 810, 811, 812, 813.
-- Added the following Open issues: 793, 800, 801, 803.
+- Added the following New issues: 788, 794, 802, 804, 805, 806, 807, 808, 809, 810, 811, 812, 813.
+- Added the following Open issues: 793, 800, 801, 803.
- Added the following Ready issues: 789, 792, 798.
- Changed the following issues from NAD Future to Dup: 116.
- Changed the following issues from NAD Future to NAD: 188, 323.
@@ -420,15 +582,15 @@ del {background-color:#FFA0A0}- Changed the following issues from Open to NAD Editorial: 529, 626.
- Changed the following issues from Review to NAD Editorial: 645, 684.
- Changed the following issues from NAD Future to Open: 128, 180, 190.
-- Changed the following issues from New to Open: 617, 718, 719, 720, 724, 732, 734, 742, 747, 750, 753, 756, 760, 762, 767, 774.
-- Changed the following issues from Ready to Open: 675, 676, 688.
+- Changed the following issues from New to Open: 617, 718, 719, 720, 724, 732, 734, 742, 747, 750, 753, 756, 760, 762, 767, 774.
+- Changed the following issues from Ready to Open: 675, 676, 688.
- Changed the following issues from New to Pending NAD Editorial: 709, 717, 725, 738, 754, 757.
-- Changed the following issues from Open to Pending NAD Editorial: 424, 557, 625.
+- Changed the following issues from Open to Pending NAD Editorial: 424, 557, 625.
- Changed the following issues from New to Ready: 710, 715, 722, 740, 743, 744, 746, 749, 755, 758, 759, 761, 766, 768, 770, 775, 777, 778, 781, 782, 783.
-- Changed the following issues from Open to Ready: 387, 471, 550, 612, 629, 673.
+- Changed the following issues from Open to Ready: 387, 471, 550, 612, 629, 673.
- Changed the following issues from Review to Ready: 518, 574, 596, 618, 638, 672, 685.
- Changed the following issues from New to Review: 711, 728, 771, 776.
-- Changed the following issues from Open to Review: 539.
+- Changed the following issues from Open to Review: 539.
- Changed the following issues from Ready to WP: 561, 562, 563, 567, 581, 620, 621, 622, 623, 624, 661, 664, 665, 666, 674, 679, 680, 687, 689, 693, 694, 695, 700, 703, 705, 706.
- Changed the following issues from Tentatively Ready to WP: 527.
- 787 issues total, up by 23.
- Details:
@@ -476,14 +638,14 @@ del {background-color:#FFA0A0}-
- Added the following New issues: 765, 766, 767, 768, 769, 770, 771, 772, 773, 774, 775, 776, 777, 778, 779, 780, 781, 782, 783, 784, 785, 786, 787.
+- Added the following New issues: 765, 766, 767, 768, 769, 770, 771, 772, 773, 774, 775, 776, 777, 778, 779, 780, 781, 782, 783, 784, 785, 786, 787.
- Changed the following issues from NAD Future to Dup: 105, 348.
-- Changed the following issues from NAD Future to NAD Editorial: 353.
-- Changed the following issues from New to NAD Editorial: 697.
+- Changed the following issues from NAD Future to NAD Editorial: 353.
+- Changed the following issues from New to NAD Editorial: 697.
- Changed the following issues from NAD Future to Open: 388.
- Changed the following issues from Open to Tentatively Ready: 527.
- 754 issues total, up by 31.
- Details:
-
- Added the following New issues: 724, 725, 726, 727, 728, 729, 730, 731, 732, 733, 734, 735, 736, 737, 738, 739, 740, 741, 742, 743, 744, 745, 746, 747, 748, 749, 750, 751, 752, 753, 754.
+- Added the following New issues: 724, 725, 726, 727, 728, 729, 730, 731, 732, 733, 734, 735, 736, 737, 738, 739, 740, 741, 742, 743, 744, 745, 746, 747, 748, 749, 750, 751, 752, 753, 754.
- Changed the following issues from NAD Future to Dup: 77, 350.
- Changed the following issues from New to NAD: 639, 657, 663.
- Changed the following issues from Open to NAD: 548.
-- Changed the following issues from New to Open: 546, 550, 564, 565, 573, 585, 588, 627, 629, 630, 632, 635, 653, 659, 667, 668, 669, 670, 671, 673, 686, 704, 707, 708.
+- Changed the following issues from New to Open: 546, 550, 564, 565, 573, 585, 588, 627, 629, 630, 632, 635, 653, 659, 667, 668, 669, 670, 671, 673, 686, 704, 707, 708.
- Changed the following issues from New to Pending NAD Editorial: 393, 592.
- Changed the following issues from New to Pending WP: 607, 608, 654, 655, 677, 682.
-- Changed the following issues from New to Ready: 561, 562, 563, 567, 581, 595, 620, 621, 622, 623, 624, 661, 664, 665, 666, 674, 675, 676, 679, 687, 688, 689, 693, 694, 695, 700, 703, 705, 706.
+- Changed the following issues from New to Ready: 561, 562, 563, 567, 581, 595, 620, 621, 622, 623, 624, 661, 664, 665, 666, 674, 675, 676, 679, 687, 688, 689, 693, 694, 695, 700, 703, 705, 706.
- Changed the following issues from Open to Ready: 680.
- Changed the following issues from New to Review: 574, 596, 618, 638, 645, 672, 684, 685, 691.
- Changed the following issues from New to WP: 552, 634, 650, 651, 652, 678, 681, 699, 712.
@@ -501,7 +663,7 @@ del {background-color:#FFA0A0}- 723 issues total, up by 15.
- Details:
- 708 issues total, up by 12.
- Details:
-
- Added the following New issues: 697, 698, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708.
+- Added the following New issues: 697, 698, 699, 700, 701, 702, 703, 704, 705, 706, 707, 708.
- Changed the following issues from New to NAD: 583, 584, 662.
- Changed the following issues from Open to NAD: 528.
-- Changed the following issues from New to NAD Editorial: 637, 647, 658, 690.
-- Changed the following issues from Open to NAD Editorial: 525.
+- Changed the following issues from New to NAD Editorial: 637, 647, 658, 690.
+- Changed the following issues from Open to NAD Editorial: 525.
- Changed the following issues from Pending NAD Editorial to NAD Editorial: 553, 571, 591, 633, 636, 641, 642, 648, 649, 656.
-- Changed the following issues from New to Open: 579, 631, 680.
+- Changed the following issues from New to Open: 579, 631, 680.
- Changed the following issues from Pending WP to Open: 258.
- Changed the following issues from Ready to Pending WP: 644.
- Changed the following issues from New to Ready: 577, 660.
@@ -558,15 +720,15 @@ del {background-color:#FFA0A0}- 676 issues total, up by 20.
- Details:
-
- Added the following New issues: 657, 658, 659, 660, 661, 662, 663, 664, 665, 666, 667, 668, 669, 670, 671, 672, 673, 674, 675, 676.
+- Added the following New issues: 657, 658, 659, 660, 661, 662, 663, 664, 665, 666, 667, 668, 669, 670, 671, 672, 673, 674, 675, 676.
- Changed the following issues from Tentatively Ready to Dup: 479, 536.
- Changed the following issues from Tentatively Ready to NAD: 385, 463, 466, 470, 515, 526, 547, 560, 572.
- Changed the following issues from NAD to NAD Editorial: 351, 357, 368, 499, 504, 512, 513, 514, 516, 544, 549, 555, 558.
-- Changed the following issues from Tentatively Ready to NAD Editorial: 482, 615.
-- Changed the following issues from NAD_Future to NAD Future: 77, 105, 111, 116, 128, 138, 140, 149, 180, 188, 190, 219, 323, 348, 350, 353, 388, 390.
-- Changed the following issues from Tentatively Ready to Open: 471.
+- Changed the following issues from Tentatively Ready to NAD Editorial: 482, 615.
+- Changed the following issues from NAD_Future to NAD Future: 77, 105, 111, 116, 128, 138, 140, 149, 180, 188, 190, 219, 323, 348, 350, 353, 388, 390.
+- Changed the following issues from Tentatively Ready to Open: 471.
- Changed the following issues from New to Pending NAD Editorial: 633, 641, 656.
-- Changed the following issues from Tentatively Ready to Pending NAD Editorial: 532, 553, 571, 591, 594.
+- Changed the following issues from Tentatively Ready to Pending NAD Editorial: 532, 553, 571, 591, 594.
- Changed the following issues from Tentatively Ready to Pending WP: 258.
- Changed the following issues from New to Ready: 566, 628, 640, 643, 644, 646.
- Changed the following issues from Review to Ready: 531, 551, 604.
@@ -585,11 +747,11 @@ del {background-color:#FFA0A0}- 656 issues total, up by 37.
- Details:
@@ -619,10 +781,10 @@ del {background-color:#FFA0A0}-
- Added the following New issues: 620, 621, 622, 623, 624, 627, 628, 629, 630, 631, 632, 633, 634, 635, 636, 637, 638, 639, 640, 641, 642, 643, 644, 645, 646, 647, 648, 649, 650, 651, 652, 653, 654, 655, 656.
-- Added the following Open issues: 625, 626.
+- Added the following New issues: 620, 621, 622, 623, 624, 627, 628, 629, 630, 631, 632, 633, 634, 635, 636, 637, 638, 639, 640, 641, 642, 643, 644, 645, 646, 647, 648, 649, 650, 651, 652, 653, 654, 655, 656.
+- Added the following Open issues: 625, 626.
- Changed the following issues from New to Open: 570, 580, 582, 590, 612, 614.
-- Changed the following issues from New to Tentatively Ready: 547, 553, 560, 571, 572, 575, 576, 578, 586, 589, 591, 593, 594, 609, 610, 611, 613, 615, 616, 619.
-- Changed the following issues from Open to Tentatively Ready: 201, 206, 233, 254, 258, 385, 416, 422, 456, 463, 466, 470, 471, 479, 482, 515, 526, 532, 536, 542, 559.
+- Changed the following issues from New to Tentatively Ready: 547, 553, 560, 571, 572, 575, 576, 578, 586, 589, 591, 593, 594, 609, 610, 611, 613, 615, 616, 619.
+- Changed the following issues from Open to Tentatively Ready: 201, 206, 233, 254, 258, 385, 416, 422, 456, 463, 466, 470, 471, 479, 482, 515, 526, 532, 536, 542, 559.
- Changed the following issues from Review to Tentatively Ready: 534.
- Moved issues 520, 521, 530, 535, 537, 538, 540, 541 to WP.
- Moved issues 504, 512, 516, 544, 549, 554, 555, 558 to NAD.
- Moved issue 569 to Dup.
-- Moved issues 518, 523, 524, 542, 556, 557, 559, 597, 606 to Open.
+- Moved issues 518, 523, 524, 542, 556, 557, 559, 597, 606 to Open.
- Moved issues 543, 545, 549, 549, 598 - 603, 605 to Ready.
- Moved issues 531, 551, 604 to Review.
-- Added new issues 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609.
+- Added new issues 593, 594, 595, 596, 597, 598, 599, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609.
- Details:
- Added new issues 567, 568, 569, 570, 571, 572.
- Moved issues 499, 501, 506, 509, 510, 511, 513, 514, 517 to NAD.
-- Moved issues 502, 503, 515, 516, 522, 525, 526, 527, 528, 529, 532, 536, 539, 548 to Open.
+- Moved issues 502, 503, 515, 516, 522, 525, 526, 527, 528, 529, 532, 536, 539, 548 to Open.
- Moved issue 504, 512, 521, 530, 531, 535, 537, 538, 540, 549 to Ready.
- Moved issues 247, 294, 362, 369, 371, 376, 384, 475, 478, 495, 497, 505, 507, 508, 519 to WP.
- Moved issue 534 to Review.
@@ -681,7 +843,7 @@ del {background-color:#FFA0A0}- 566 issues total, up by 31.
- Details:
@@ -756,7 +918,7 @@ Post-Kona mailing: reflects decisions made at the Kona meeting. Added new issues 432-440.-
- Added new issues 536, 537, 538, 539, 540, 541, 542, 543, 544, 545, 546, 547, 548, 549, 550 ,551, 552, 553, 554, 555, 556, 557, 558, 559, 560, 561, 562, 563, 564, 565, 566.
+- Added new issues 536, 537, 538, 539, 540, 541, 542, 543, 544, 545, 546, 547, 548, 549, 550 ,551, 552, 553, 554, 555, 556, 557, 558, 559, 560, 561, 562, 563, 564, 565, 566.
- Moved 342 from Ready to Open.
- Reopened 309.
- R27: -Pre-Kona mailing. Added new issues 404-431. +Pre-Kona mailing. Added new issues 404-431.
- R26: Post-Oxford mailing: reflects decisions made at the Oxford meeting. @@ -768,21 +930,21 @@ Pre-Oxford mailing. Added new issues 253, which has been given a new proposed resolution, were -moved to DR status. Added new issues 383-389. (Issues 387-389 were discussed -at the meeting.) Made progress on issues 225, 226, 229: 225 and 229 have been moved to Ready status, and the only remaining +meeting. All Ready issues from R23 with the exception of
+, which has been given a new proposed resolution, were +moved to DR status. Added new issues 383- . (Issues 387-389 were discussed +at the meeting.) Made progress on issues 225, , 229: 225 and have been moved to Ready status, and the only remaining concerns with 226 involve wording. - - R23: Pre-Santa Cruz mailing. Added new issues 367-382. Moved issues in the TC to TC status.
- R22: -Post-Curaçao mailing. Added new issues 362-366. -
+Post-Curaçao mailing. Added new issues 362-. + - R21: -Pre-Curaçao mailing. Added new issues 351-361. -
+Pre-Curaçao mailing. Added new issues 351-. + - R20: Post-Redmond mailing; reflects actions taken in Redmond. Added new issues 336-350, of which issues @@ -836,9 +998,9 @@ as NAD.
- R17: Pre-Copenhagen mailing. Converted issues list to XML. Added proposed -resolutions for issues 49, 76, 91, 235, 250, 267. +resolutions for issues 49, 76,
+, 235, 250, 267. Added new issues 278-311. - - R16: post-Toronto mailing; reflects actions taken in Toronto. Added new issues 265-277. Changed status of issues @@ -941,7 +1103,7 @@ format, 1. C library linkage editing oversight
Section: 17.6.2.3 [using.linkage] Status: TC1 - Submitter: Beman Dawes Opened: 1997-11-16 Last modified: 2008-09-26
+ Submitter: Beman Dawes Opened: 1997-11-16 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
The change specified in the proposed resolution below did not make @@ -976,7 +1138,7 @@ from:
3. Atexit registration during atexit() call is not described
Section: 18.5 [support.start.term] Status: TC1 - Submitter: Steve Clamage Opened: 1997-12-12 Last modified: 2008-09-26
+ Submitter: Steve Clamage Opened: 1997-12-12 Last modified: 2010-10-29View all other issues in [support.start.term].
View all issues with TC1 status.
Discussion:
@@ -1110,7 +1272,7 @@ supporting to the proposed resolution.
5. String::compare specification questionable
Section: 21.4.6.8 [string::swap] Status: TC1 - Submitter: Jack Reeves Opened: 1997-12-11 Last modified: 2008-09-26
+ Submitter: Jack Reeves Opened: 1997-12-11 Last modified: 2010-10-29View all other issues in [string::swap].
View all issues with TC1 status.
Duplicate of: 87
@@ -1203,7 +1365,7 @@ identified in issues 7 (item 5) and 87.
7. String clause minor problems
Section: 21 [strings] Status: TC1 - Submitter: Matt Austern Opened: 1997-12-15 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1997-12-15 Last modified: 2010-10-29View all other issues in [strings].
View all issues with TC1 status.
Discussion:
@@ -1284,7 +1446,7 @@ s+n) overlap."
8. Locale::global lacks guarantee
Section: 22.3.1.5 [locale.statics] Status: TC1 - Submitter: Matt Austern Opened: 1997-12-24 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1997-12-24 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
It appears there's an important guarantee missing from clause @@ -1313,7 +1475,7 @@ paragraph 2:
9. Operator new(0) calls should not yield the same pointer
Section: 18.6.1 [new.delete] Status: TC1 - Submitter: Steve Clamage Opened: 1998-01-04 Last modified: 2008-09-26
+ Submitter: Steve Clamage Opened: 1998-01-04 Last modified: 2010-10-29View all other issues in [new.delete].
View all issues with TC1 status.
Discussion:
@@ -1380,9 +1542,8 @@ supporting to the proposed resolution.
11. Bitset minor problems
-Section: 20.3.7 [template.bitset] Status: TC1 - Submitter: Matt Austern Opened: 1998-01-22 Last modified: 2008-09-26
-View other active issues in [template.bitset].
+Section: 20.5 [template.bitset] Status: TC1 + Submitter: Matt Austern Opened: 1998-01-22 Last modified: 2010-10-29
View all other issues in [template.bitset].
View all issues with TC1 status.
Discussion:
@@ -1401,7 +1562,7 @@ go in the Effects clause.Proposed resolution:
ITEMS 1 AND 2:
-In the bitset synopsis (20.3.7 [template.bitset]), +In the bitset synopsis (20.5 [template.bitset]), replace the member function
reference operator[](size_t pos);
@@ -1411,7 +1572,7 @@ with the two member functions
bool operator[](size_t pos) const;
reference operator[](size_t pos);
-Add the following text at the end of 20.3.7.2 [bitset.members], +Add the following text at the end of 20.5.2 [bitset.members], immediately after paragraph 45:@@ -1441,7 +1602,7 @@ input" implies the desired semantics. See 27.7.1.2 [istream.formatted].
13. Eos refuses to die
Section: 27.7.1.2.3 [istream::extractors] Status: TC1 - Submitter: William M. Miller Opened: 1998-03-03 Last modified: 2008-09-26
+ Submitter: William M. Miller Opened: 1998-03-03 Last modified: 2010-10-29View all other issues in [istream::extractors].
View all issues with TC1 status.
Discussion:
@@ -1461,7 +1622,7 @@ it's undefined.
14. Locale::combine should be const
Section: 22.3.1.3 [locale.members] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale.members].
View all issues with TC1 status.
Discussion:
@@ -1491,7 +1652,7 @@ time, but the omission was not noticed.
15. Locale::name requirement inconsistent
Section: 22.3.1.3 [locale.members] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale.members].
View all issues with TC1 status.
Discussion:
@@ -1512,7 +1673,7 @@ constructor, but there is no matching constructor.
16. Bad ctype_byname<char> decl
Section: 22.4.1.4 [locale.codecvt] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with TC1 status.
Discussion:
@@ -1533,8 +1694,7 @@ from 22.4.1.3 [facet.ctype.special].
17. Bad bool parsing
Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
-View other active issues in [facet.num.get.virtuals].
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [facet.num.get.virtuals].
View all issues with TC1 status.
Discussion:
@@ -1625,7 +1785,7 @@ change "&&" to "&".
18. Get(...bool&) omitted
Section: 22.4.2.1.1 [facet.num.get.members] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [facet.num.get.members].
View all issues with TC1 status.
Discussion:
@@ -1647,7 +1807,7 @@ another get member for bool&, copied from the entry in
19. "Noconv" definition too vague
Section: 22.4.1.4 [locale.codecvt] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with TC1 status.
Duplicate of: 10
@@ -1684,7 +1844,7 @@ Change the entry for noconv in the table under paragraph 4 in section
20. Thousands_sep returns wrong type
Section: 22.4.3.1.2 [facet.numpunct.virtuals] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
The synopsis for numpunct<>::do_thousands_sep, and the @@ -1704,7 +1864,7 @@ described as returning a "string_type".
21. Codecvt_byname<> instantiations
Section: 22.3.1.1.1 [locale.category] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale.category].
View all issues with TC1 status.
Discussion:
@@ -1731,7 +1891,7 @@ codecvt_byname<wchar_t,char,mbstate_t>
22. Member open vs. flags
Section: 27.9.1.9 [ifstream.members] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [ifstream.members].
View all issues with TC1 status.
Discussion:
@@ -1771,8 +1931,7 @@ believes to have been the original intent.
23. Num_get overflow result
Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: CD1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
-View other active issues in [facet.num.get.virtuals].
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [facet.num.get.virtuals].
View all issues with CD1 status.
Discussion:
@@ -1970,7 +2129,7 @@ is assigned to err.
24. "do_convert" doesn't exist
Section: 22.4.1.4 [locale.codecvt] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with TC1 status.
Duplicate of: 72
@@ -1993,7 +2152,7 @@ or do_out".
25. String operator<< uses width() value wrong
Section: 21.4.8.9 [string.io] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [string.io].
View all issues with TC1 status.
Duplicate of: 67
@@ -2021,7 +2180,7 @@ to:
26. Bad sentry example
Section: 27.7.1.1.3 [istream::sentry] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [istream::sentry].
View all issues with TC1 status.
Discussion:
@@ -2069,7 +2228,7 @@ example, which might well still contain errors.
27. String::erase(range) yields wrong iterator
Section: 21.4.6.5 [string::erase] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [string::erase].
View all issues with TC1 status.
Discussion:
@@ -2101,7 +2260,7 @@ while 'd' has not been erased.
28. Ctype<char>is ambiguous
Section: 22.4.1.3.2 [facet.ctype.char.members] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [facet.ctype.char.members].
View all issues with TC1 status.
Duplicate of: 236
@@ -2133,7 +2292,7 @@ vec[].
29. Ios_base::init doesn't exist
Section: 27.4.1 [narrow.stream.objects] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [narrow.stream.objects].
View all issues with TC1 status.
Discussion:
@@ -2172,7 +2331,7 @@ should read
30. Wrong header for LC_*
Section: 22.3.1.1.1 [locale.category] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale.category].
View all issues with TC1 status.
Discussion:
@@ -2191,7 +2350,7 @@ where they are in fact defined elsewhere to appear in <clocale>.
31. Immutable locale values
Section: 22.3.1 [locale] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale].
View all issues with TC1 status.
Duplicate of: 378
@@ -2227,7 +2386,7 @@ are manifestly assignable.
32. Pbackfail description inconsistent
Section: 27.6.2.4.4 [streambuf.virt.pback] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
The description of the required state before calling virtual member @@ -2270,7 +2429,7 @@ the argument value.
33. Codecvt<> mentions from_type
Section: 22.4.1.4 [locale.codecvt] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with TC1 status.
Duplicate of: 43
@@ -2301,8 +2460,7 @@ in the table for the case of _error_ with
34. True/falsename() not in ctype<>
Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
-View other active issues in [facet.num.put.virtuals].
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [facet.num.put.virtuals].
View all issues with TC1 status.
Discussion:
@@ -2328,7 +2486,7 @@ string_type s = val ? np.truename() : np.falsename();
35. No manipulator unitbuf in synopsis
Section: 27.5 [iostreams.base] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [iostreams.base].
View all issues with TC1 status.
Discussion:
@@ -2353,7 +2511,7 @@ ios_base& nounitbuf(ios_base& str);
36. Iword & pword storage lifetime omitted
Section: 27.5.2.5 [ios.base.storage] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [ios.base.storage].
View all issues with TC1 status.
Discussion:
@@ -2394,7 +2552,7 @@ paragraph 4, replace the sentence:
37. Leftover "global" reference
Section: 22.3.1 [locale] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [locale].
View all issues with TC1 status.
Discussion:
@@ -2424,7 +2582,7 @@ expression
38. Facet definition incomplete
Section: 22.3.2 [locale.global.templates] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
It has been noticed by Esa Pulkkinen that the definition of @@ -2466,7 +2624,7 @@ contains (not inherits) the public static member
39. istreambuf_iterator<>::operator++(int) definition garbled
Section: 24.6.3.4 [istreambuf.iterator::op++] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
Following the definition of istreambuf_iterator<>::operator++(int) in paragraph @@ -2490,7 +2648,7 @@ end of paragraph 3.
40. Meaningless normative paragraph in examples
Section: 22.4.8 [facets.examples] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [facets.examples].
View all issues with TC1 status.
Discussion:
@@ -2512,7 +2670,7 @@ numbering the same.
41. Ios_base needs clear(), exceptions()
Section: 27.5.2 [ios.base] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [ios.base].
View all issues with TC1 status.
Duplicate of: 157
@@ -2552,7 +2710,7 @@ setstate(badbit).]
42. String ctors specify wrong default allocator
Section: 21.4 [basic.string] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with TC1 status.
Discussion:
@@ -2640,7 +2798,7 @@ reflects the LWG consensus.
44. Iostreams use operator== on int_type values
Section: 27 [input.output] Status: CD1 - Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [input.output].
View all issues with CD1 status.
Discussion:
@@ -2890,13 +3048,13 @@ change uses of == and != to use the traits members instead.
46. Minor Annex D errors
-Section: D.8 [depr.str.strstreams] Status: TC1 - Submitter: Brendan Kehoe Opened: 1998-06-01 Last modified: 2008-09-26
+Section: D.9 [depr.str.strstreams] Status: TC1 + Submitter: Brendan Kehoe Opened: 1998-06-01 Last modified: 2010-10-29
View all issues with TC1 status.
Discussion:
See lib-6522 and edit-814.
Proposed resolution:
-Change D.8.1 [depr.strstreambuf] (since streambuf is a typedef of +
Change D.9.1 [depr.strstreambuf] (since streambuf is a typedef of basic_streambuf<char>) from:
virtual streambuf<char>* setbuf(char* s, streamsize n);@@ -2905,7 +3063,7 @@ basic_streambuf<char>) from:virtual streambuf* setbuf(char* s, streamsize n);-In D.8.4 [depr.strstream] insert the semicolon now missing after +
In D.9.4 [depr.strstream] insert the semicolon now missing after int_type:
namespace std { @@ -2924,7 +3082,7 @@ int_type:
47. Imbue() and getloc() Returns clauses swapped
Section: 27.5.2.3 [ios.base.locales] Status: TC1 - Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2010-10-29View all other issues in [ios.base.locales].
View all issues with TC1 status.
Discussion:
@@ -2945,7 +3103,7 @@ accident?
48. Use of non-existent exception constructor
Section: 27.5.2.1.1 [ios::failure] Status: TC1 - Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2010-10-29View all other issues in [ios::failure].
View all issues with TC1 status.
Discussion:
@@ -2968,7 +3126,7 @@ base class, exception, with exception(msg). Class exception (see
49. Underspecification of ios_base::sync_with_stdio
Section: 27.5.2.4 [ios.members.static] Status: CD1 - Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
Two problems
@@ -3055,7 +3213,7 @@ on the two streams can be mixed arbitrarily.]
50. Copy constructor and assignment operator of ios_base
Section: 27.5.2 [ios.base] Status: TC1 - Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-06-21 Last modified: 2010-10-29View all other issues in [ios.base].
View all issues with TC1 status.
Discussion:
@@ -3095,8 +3253,7 @@ outweighs any benefit of allowing ios_base objects to be copyable.
51. Requirement to not invalidate iterators missing
Section: 23.2 [container.requirements] Status: TC1 - Submitter: David Vandevoorde Opened: 1998-06-23 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+ Submitter: David Vandevoorde Opened: 1998-06-23 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with TC1 status.
Discussion:
@@ -3156,7 +3313,8 @@ of"
52. Small I/O problems
Section: 27.5.3.2 [fpos.operations] Status: TC1 - Submitter: Matt Austern Opened: 1998-06-23 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-06-23 Last modified: 2010-10-29 +View all other issues in [fpos.operations].
View all issues with TC1 status.
Discussion:
First, 27.5.4.1 [basic.ios.cons], table 89. This is pretty obvious: @@ -3194,7 +3352,7 @@ effects".
53. Basic_ios destructor unspecified
Section: 27.5.4.1 [basic.ios.cons] Status: TC1 - Submitter: Matt Austern Opened: 1998-06-23 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-06-23 Last modified: 2010-10-29View all other issues in [basic.ios.cons].
View all issues with TC1 status.
Discussion:
@@ -3227,7 +3385,7 @@ footnote which incorrectly said "rdbuf(0) does not set
54. Basic_streambuf's destructor
Section: 27.6.2.1 [streambuf.cons] Status: TC1 - Submitter: Matt Austern Opened: 1998-06-25 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-06-25 Last modified: 2010-10-29View all other issues in [streambuf.cons].
View all issues with TC1 status.
Discussion:
@@ -3252,7 +3410,7 @@ explicitly.
55. Invalid stream position is undefined
Section: 27 [input.output] Status: TC1 - Submitter: Matt Austern Opened: 1998-06-26 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-06-26 Last modified: 2010-10-29View all other issues in [input.output].
View all issues with TC1 status.
Discussion:
@@ -3278,7 +3436,7 @@ stream position" should not be changed:@@ -3307,11 +3465,11 @@ returns an invalid stream position (_lib.iostreams.definitions_)" to "Otherwise returns pos_type(off_type(-1))" -27.8.1.4 [stringbuf.virtuals], paragraph 14
27.9.1.5 [filebuf.virtuals], paragraph 14
- D.8.1.3 [depr.strstreambuf.virtuals], paragraph 17 + D.9.1.3 [depr.strstreambuf.virtuals], paragraph 17In D.8.1.3 [depr.strstreambuf.virtuals], paragraph 15, change "the object +
In D.9.1.3 [depr.strstreambuf.virtuals], paragraph 15, change "the object stores an invalid stream position" to "the return value is pos_type(off_type(-1))"
-In D.8.1.3 [depr.strstreambuf.virtuals], paragraph 18, change "the object +
In D.9.1.3 [depr.strstreambuf.virtuals], paragraph 18, change "the object stores an invalid stream position" to "the return value is pos_type(off_type(-1))"
@@ -3322,7 +3480,7 @@ stores an invalid stream position" to "the return value is
56. Showmanyc's return type
Section: 27.6.2 [streambuf] Status: TC1 - Submitter: Matt Austern Opened: 1998-06-29 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-06-29 Last modified: 2010-10-29View all other issues in [streambuf].
View all issues with TC1 status.
Discussion:
@@ -3342,7 +3500,7 @@ return type is streamsize.
57. Mistake in char_traits
Section: 21.2.3.4 [char.traits.specializations.wchar.t] Status: TC1 - Submitter: Matt Austern Opened: 1998-07-01 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-07-01 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
21.1.3.2, paragraph 3, says "The types streampos and @@ -3371,7 +3529,7 @@ different..." .
59. Ambiguity in specification of gbump
Section: 27.6.2.3.2 [streambuf.get.area] Status: TC1 - Submitter: Matt Austern Opened: 1998-07-28 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-07-28 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
27.5.2.3.1 says that basic_streambuf::gbump() "Advances the @@ -3410,7 +3568,7 @@ effects.
60. What is a formatted input function?
Section: 27.7.1.2.1 [istream.formatted.reqmts] Status: TC1 - Submitter: Matt Austern Opened: 1998-08-03 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-08-03 Last modified: 2010-10-29View all other issues in [istream.formatted.reqmts].
View all issues with TC1 status.
@@ -3446,13 +3604,11 @@ that the "Common requirements" listed in section 27.6.1.2.1 apply to them.Additional comments from Dietmar Kühl: It appears to be somewhat -nonsensical to consider the functions defined in 27.7.1.2.3 -[istream::extractors] paragraphs 1 to 5 to be "Formatted input +nonsensical to consider the functions defined in 27.7.1.2.3 [istream::extractors] paragraphs 1 to 5 to be "Formatted input function" but since these functions are defined in a section labeled "Formatted input functions" it is unclear to me whether these operators are considered formatted input functions which -have to conform to the "common requirements" from 27.7.1.2.1 -[istream.formatted.reqmts]: If this is the case, all manipulators, not +have to conform to the "common requirements" from 27.7.1.2.1 [istream.formatted.reqmts]: If this is the case, all manipulators, not just ws, would skip whitespace unless noskipws is set (... but setting noskipws using the manipulator syntax would also skip whitespace :-)
It is not clear which functions @@ -3723,7 +3879,7 @@ VI of that paper.
61. Ambiguity in iostreams exception policy
Section: 27.7.1.3 [istream.unformatted] Status: TC1 - Submitter: Matt Austern Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with TC1 status.
Discussion:
@@ -3772,7 +3928,7 @@ resolution as better standardese.
62. Sync's return value
Section: 27.7.1.3 [istream.unformatted] Status: TC1 - Submitter: Matt Austern Opened: 1998-08-06 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-08-06 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with TC1 status.
Discussion:
@@ -3796,7 +3952,7 @@ traits::int_type while the return type of sync() is int.
63. Exception-handling policy for unformatted output
Section: 27.7.2.7 [ostream.unformatted] Status: TC1 - Submitter: Matt Austern Opened: 1998-08-11 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-08-11 Last modified: 2010-10-29View all other issues in [ostream.unformatted].
View all issues with TC1 status.
Discussion:
@@ -3839,7 +3995,7 @@ input, unformatted input, and formatted output.
64. Exception handling in basic_istream::operator>>(basic_streambuf*)
Section: 27.7.1.2.3 [istream::extractors] Status: TC1 - Submitter: Matt Austern Opened: 1998-08-11 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-08-11 Last modified: 2010-10-29View all other issues in [istream::extractors].
View all issues with TC1 status.
Discussion:
@@ -3867,8 +4023,8 @@ elaboration of the first.
66. Strstreambuf::setbuf
-Section: D.8.1.3 [depr.strstreambuf.virtuals] Status: TC1 - Submitter: Matt Austern Opened: 1998-08-18 Last modified: 2008-09-26
+Section: D.9.1.3 [depr.strstreambuf.virtuals] Status: TC1 + Submitter: Matt Austern Opened: 1998-08-18 Last modified: 2010-10-29
View all other issues in [depr.strstreambuf.virtuals].
View all issues with TC1 status.
Discussion:
@@ -3880,7 +4036,7 @@ strstreambuf.Proposed resolution:
-D.8.1.3 [depr.strstreambuf.virtuals], paragraph 19, replace the setbuf effects +
D.9.1.3 [depr.strstreambuf.virtuals], paragraph 19, replace the setbuf effects clause which currently says "Performs an operation that is defined separately for each class derived from strstreambuf" with:
@@ -3897,7 +4053,7 @@ with:
68. Extractors for char* should store null at end
Section: 27.7.1.2.3 [istream::extractors] Status: TC1 - Submitter: Angelika Langer Opened: 1998-07-14 Last modified: 2008-09-26
+ Submitter: Angelika Langer Opened: 1998-07-14 Last modified: 2010-10-29View all other issues in [istream::extractors].
View all issues with TC1 status.
Discussion:
@@ -3934,8 +4090,8 @@ item from:
69. Must elements of a vector be contiguous?
-Section: 23.3.6 [vector] Status: TC1 - Submitter: Andrew Koenig Opened: 1998-07-29 Last modified: 2008-09-26
+Section: 23.4.1 [vector] Status: TC1 + Submitter: Andrew Koenig Opened: 1998-07-29 Last modified: 2010-10-29
View all other issues in [vector].
View all issues with TC1 status.
Discussion:
@@ -3948,7 +4104,7 @@ debugging implementations)Proposed resolution:
-Add the following text to the end of 23.3.6 [vector], +
Add the following text to the end of 23.4.1 [vector], paragraph 1.
@@ -3982,7 +4138,7 @@ directly defined in the standard. Discussion included:
70. Uncaught_exception() missing throw() specification
Section: 18.8 [support.exception], 18.8.4 [uncaught] Status: TC1 - Submitter: Steve Clamage Opened: 1998-08-03 Last modified: 2008-09-26
+ Submitter: Steve Clamage Opened: 1998-08-03 Last modified: 2010-10-29View all other issues in [support.exception].
View all issues with TC1 status.
Discussion:
@@ -3998,8 +4154,7 @@ exception safety is very important.Proposed resolution:
-In 15.5.3 [except.uncaught], paragraph 1, 18.8 [support.exception], -and 18.8.4 [uncaught], add "throw()" to uncaught_exception().
+In 15.5.3 [except.uncaught], paragraph 1, 18.8 [support.exception], and 18.8.4 [uncaught], add "throw()" to uncaught_exception().
@@ -4007,7 +4162,7 @@ and 18.8.4 [uncaught], add "throw()" to uncaught_exception().
71. Do_get_monthname synopsis missing argument
Section: 22.4.5.1 [locale.time.get] Status: TC1 - Submitter: Nathan Myers Opened: 1998-08-13 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-08-13 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
The locale facet member time_get<>::do_get_monthname @@ -4031,7 +4186,7 @@ the declaration of member do_monthname as follows:
74. Garbled text for codecvt::do_max_length
Section: 22.4.1.4 [locale.codecvt] Status: TC1 - Submitter: Matt Austern Opened: 1998-09-08 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-09-08 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with TC1 status.
Discussion:
@@ -4059,7 +4214,7 @@ following:75. Contradiction in codecvt::length's argument types
Section: 22.4.1.4 [locale.codecvt] Status: TC1 Submitter: Matt -Austern Opened: 1998-09-18 Last modified: 2008-09-26
+Austern Opened: 1998-09-18 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with TC1 status.
Discussion:
@@ -4107,7 +4262,7 @@ change the stateT argument type on both member
76. Can a codecvt facet always convert one internal character at a time?
Section: 22.4.1.4 [locale.codecvt] Status: CD1 - Submitter: Matt Austern Opened: 1998-09-25 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-09-25 Last modified: 2010-10-29View all other issues in [locale.codecvt].
View all issues with CD1 status.
Discussion:
@@ -4230,7 +4385,7 @@ return value.]
78. Typo: event_call_back
Section: 27.5.2 [ios.base] Status: TC1 - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2008-09-26
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [ios.base].
View all issues with TC1 status.
Discussion:
@@ -4247,7 +4402,7 @@ return value.]
79. Inconsistent declaration of polar()
Section: 26.4.1 [complex.syn], 26.4.7 [complex.value.ops] Status: TC1 - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2009-03-21
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [complex.syn].
View all issues with TC1 status.
Discussion:
@@ -4274,7 +4429,7 @@ return value.]
80. Global Operators of complex declared twice
Section: 26.4.1 [complex.syn], 26.4.2 [complex] Status: TC1 - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2009-03-21
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [complex.syn].
View all issues with TC1 status.
Discussion:
@@ -4291,7 +4446,7 @@ class complex. This redundancy should be removed.
83. String::npos vs. string::max_size()
Section: 21.4 [basic.string] Status: TC1 - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2008-09-26
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with TC1 status.
Duplicate of: 89
@@ -4324,7 +4479,7 @@ described in this clause...") add a new paragraph:
86. String constructors don't describe exceptions
Section: 21.4.1 [string.require] Status: TC1 - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2008-09-26
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [string.require].
View all issues with TC1 status.
Discussion:
@@ -4356,7 +4511,7 @@ resolution for issue 90. Incorrect description of operator >> for stringsSection: 21.4.8.9 [string.io] Status: TC1 - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2008-09-26
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [string.io].
View all issues with TC1 status.
Discussion:
@@ -4388,7 +4543,7 @@ character c.
91. Description of operator>> and getline() for string<> might cause endless loop
Section: 21.4.8.9 [string.io] Status: CD1 - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2008-09-26
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [string.io].
View all issues with CD1 status.
Discussion:
@@ -4411,8 +4566,7 @@ extracted and appended until any of the following occurs:with:
-Effects: Behaves as a formatted input function (27.7.1.2.1 -[istream.formatted.reqmts]). After constructing a sentry object, if the +Effects: Behaves as a formatted input function (27.7.1.2.1 [istream.formatted.reqmts]). After constructing a sentry object, if the sentry converts to true, calls str.erase() and then extracts characters from is and appends them to str as if by calling str.append(1,c). If is.width() is greater than zero, the maximum @@ -4430,10 +4584,9 @@ them to str as if by calling str.append(1, c) until any of the following occurs:
with:
-Effects: Behaves as an unformatted input function -(27.7.1.3 [istream.unformatted]), except that it does not affect the -value returned -by subsequent calls to basic_istream<>::gcount(). After +
+Effects: Behaves as an unformatted input function (27.7.1.3 [istream.unformatted]), except that it does not affect the value returned +by subsequent calls to basic_istream<>::gcount(). After constructing a sentry object, if the sentry converts to true, calls str.erase() and then extracts characters from is and appends them to str as if by calling str.append(1,c) until any of the following @@ -4467,8 +4620,7 @@ functions do get characters from a streambuf.
92. Incomplete Algorithm Requirements
Section: 25 [algorithms] Status: CD1 - Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2008-09-26
-View other active issues in [algorithms].
+ Submitter: Nico Josuttis Opened: 1998-09-29 Last modified: 2010-10-29View all other issues in [algorithms].
View all issues with CD1 status.
Discussion:
@@ -4576,12 +4728,12 @@ objects by algorithms is unspecified". Consider placing in
98. Input iterator requirements are badly written
-Section: 24.2.1 [input.iterators] Status: CD1 - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2008-09-26
+Section: 24.2.3 [input.iterators] Status: CD1 + Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29
View all other issues in [input.iterators].
View all issues with CD1 status.
Discussion:
-Table 72 in 24.2.1 [input.iterators] specifies semantics for +
Table 72 in 24.2.3 [input.iterators] specifies semantics for *r++ of:
{ T tmp = *r; ++r; return tmp; }
@@ -4600,7 +4752,7 @@ problem.Proposed resolution:
-In Table 72 in 24.2.1 [input.iterators], change the return type +
In Table 72 in 24.2.3 [input.iterators], change the return type for *r++ from T to "convertible to T".
@@ -4631,7 +4783,7 @@ for *r++ from T to "convertible to T".
103. set::iterator is required to be modifiable, but this allows modification of keys
Section: 23.2.4 [associative.reqmts] Status: CD1 - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2008-09-26
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with CD1 status.
@@ -4757,7 +4909,7 @@ conversion from iterator to const_iterator.
106. Numeric library private members are implementation defined
Section: 26.6.5 [template.slice.array] Status: TC1 - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2008-09-26
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View all other issues in [template.slice.array].
View all issues with TC1 status.
Discussion:
@@ -4784,7 +4936,7 @@ Remove the comment which says "// remainder implementation defined" from:
108. Lifetime of exception::what() return unspecified
Section: 18.7.1 [type.info] Status: TC1 - Submitter: AFNOR Opened: 1998-10-07 Last modified: 2008-09-26
+ Submitter: AFNOR Opened: 1998-10-07 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
In 18.6.1, paragraphs 8-9, the lifetime of the return value of @@ -4815,8 +4967,8 @@ returned by what().
109. Missing binders for non-const sequence elements
-Section: D.9 [depr.lib.binders] Status: CD1 - Submitter: Bjarne Stroustrup Opened: 1998-10-07 Last modified: 2008-09-26
+Section: D.11 [depr.lib.binders] Status: CD1 + Submitter: Bjarne Stroustrup Opened: 1998-10-07 Last modified: 2010-10-29
View all other issues in [depr.lib.binders].
View all issues with CD1 status.
Discussion:
@@ -4896,7 +5048,7 @@ public:Howard believes there is a flaw in this resolution. See c++std-lib-9127. We may need to reopen this issue.
-In D.9 [depr.lib.binders] in the declaration of binder1st after:
+In D.11 [depr.lib.binders] in the declaration of binder1st after:
-typename Operation::result_type
@@ -4906,7 +5058,7 @@ See c++std-lib-9127. We may need to reopen this issue.
operator()(const typename Operation::second_argument_type& x) const;typename Operation::result_type
operator()(typename Operation::second_argument_type& x) const;In D.9 [depr.lib.binders] in the declaration of binder2nd after:
+In D.11 [depr.lib.binders] in the declaration of binder2nd after:
typename Operation::result_type
@@ -4936,7 +5088,7 @@ Leave open - 1.]
operator()(const typename Operation::first_argument_type& x) const;
110. istreambuf_iterator::equal not const
Section: 24.6.3 [istreambuf.iterator], 24.6.3.5 [istreambuf.iterator::equal] Status: TC1 - Submitter: Nathan Myers Opened: 1998-10-15 Last modified: 2008-09-26
+ Submitter: Nathan Myers Opened: 1998-10-15 Last modified: 2010-10-29View all other issues in [istreambuf.iterator].
View all issues with TC1 status.
Discussion:
@@ -4966,7 +5118,7 @@ replace:
112. Minor typo in ostreambuf_iterator constructor
Section: 24.6.4.1 [ostreambuf.iter.cons] Status: TC1 - Submitter: Matt Austern Opened: 1998-10-20 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-10-20 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
The requires clause for ostreambuf_iterator's @@ -4995,7 +5147,7 @@ reading:
114. Placement forms example in error twice
Section: 18.6.1.3 [new.delete.placement] Status: TC1 - Submitter: Steve Clamage Opened: 1998-10-28 Last modified: 2008-09-26
+ Submitter: Steve Clamage Opened: 1998-10-28 Last modified: 2010-10-29View all other issues in [new.delete.placement].
View all issues with TC1 status.
Duplicate of: 196
@@ -5032,8 +5184,8 @@ likely to fail.
115. Typo in strstream constructors
-Section: D.8.4.1 [depr.strstream.cons] Status: TC1 - Submitter: Steve Clamage Opened: 1998-11-02 Last modified: 2008-09-26
+Section: D.9.4.1 [depr.strstream.cons] Status: TC1 + Submitter: Steve Clamage Opened: 1998-11-02 Last modified: 2010-10-29
View all issues with TC1 status.
Discussion:
D.7.4.1 strstream constructors paragraph 2 says:
@@ -5054,7 +5206,7 @@ the append bit is set.Proposed resolution:
-In D.8.3.1 [depr.ostrstream.cons] paragraph 2 and D.8.4.1 [depr.strstream.cons] +
In D.9.3.1 [depr.ostrstream.cons] paragraph 2 and D.9.4.1 [depr.strstream.cons] paragraph 2, change the first condition to (mode&app)==0 and the second condition to (mode&app)!=0.
@@ -5065,7 +5217,7 @@ and the second condition to (mode&app)!=0.
117. basic_ostream uses nonexistent num_put member functions
Section: 27.7.2.6.2 [ostream.inserters.arithmetic] Status: CD1 - Submitter: Matt Austern Opened: 1998-11-20 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-11-20 Last modified: 2010-10-29View all other issues in [ostream.inserters.arithmetic].
View all issues with CD1 status.
Discussion:
@@ -5186,7 +5338,7 @@ example, printing short(-1) in hex format should yield 0xffff.)
118. basic_istream uses nonexistent num_get member functions
Section: 27.7.1.2.2 [istream.formatted.arithmetic] Status: CD1 - Submitter: Matt Austern Opened: 1998-11-20 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1998-11-20 Last modified: 2010-10-29View all other issues in [istream.formatted.arithmetic].
View all issues with CD1 status.
Discussion:
@@ -5255,12 +5407,12 @@ operator>>(int& val);
119. Should virtual functions be allowed to strengthen the exception specification?
-Section: 17.6.4.11 [res.on.exception.handling] Status: TC1 - Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2008-09-26
+Section: 17.6.4.12 [res.on.exception.handling] Status: TC1 + Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29
View all other issues in [res.on.exception.handling].
View all issues with TC1 status.
Discussion:
-Section 17.6.4.11 [res.on.exception.handling] states:
+Section 17.6.4.12 [res.on.exception.handling] states:
"An implementation may strengthen the exception-specification for a function by removing listed exceptions."
@@ -5284,7 +5436,7 @@ public:Proposed resolution:
-Change Section 17.6.4.11 [res.on.exception.handling] from:
+Change Section 17.6.4.12 [res.on.exception.handling] from:
"may strengthen the exception-specification for a function"
@@ -5301,7 +5453,7 @@ exception-specification for a non-virtual function".
120. Can an implementor add specializations?
Section: 17.6.3.3 [reserved.names] Status: CD1 - Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2008-09-26
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29View all other issues in [reserved.names].
View all issues with CD1 status.
Discussion:
@@ -5416,7 +5568,7 @@ different explicit instantiations might be harmless.
122. streambuf/wstreambuf description should not say they are specializations
Section: 27.6.2 [streambuf] Status: TC1 - Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2008-09-26
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29View all other issues in [streambuf].
View all issues with TC1 status.
Discussion:
@@ -5453,7 +5605,7 @@ typedefs and that is sufficient.
123. Should valarray helper arrays fill functions be const?
Section: 26.6.5.3 [slice.arr.fill], 26.6.7.3 [gslice.array.fill], 26.6.8.3 [mask.array.fill], 26.6.9.3 [indirect.array.fill] Status: CD1 - Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2008-09-26
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
One of the operator= in the valarray helper arrays is const and one @@ -5582,7 +5734,7 @@ many existing implementations, both versions are already const.
124. ctype_byname<charT>::do_scan_is & do_scan_not return type should be const charT*
Section: 22.4.1.2 [locale.ctype.byname] Status: TC1 - Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2008-09-26
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29View all other issues in [locale.ctype.byname].
View all issues with TC1 status.
Discussion:
@@ -5603,14 +5755,12 @@ charT*.
125. valarray<T>::operator!() return type is inconsistent
Section: 26.6.2 [template.valarray] Status: TC1 - Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2008-09-26
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29View all other issues in [template.valarray].
View all issues with TC1 status.
Discussion:
-In Section 26.6.2 [template.valarray] valarray<T>::operator!() -is -declared to return a valarray<T>, but in Section 26.6.2.5 -[valarray.unary] it is declared to return a valarray<bool>. The +
In Section 26.6.2 [template.valarray] valarray<T>::operator!() is +declared to return a valarray<T>, but in Section 26.6.2.5 [valarray.unary] it is declared to return a valarray<bool>. The latter appears to be correct.
@@ -5625,7 +5775,7 @@ latter appears to be correct.
126. typos in Effects clause of ctype::do_narrow()
Section: 22.4.1.1.2 [locale.ctype.virtuals] Status: TC1 - Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2008-09-26
+ Submitter: Judy Ward Opened: 1998-12-15 Last modified: 2010-10-29View all other issues in [locale.ctype.virtuals].
View all issues with TC1 status.
Discussion:
Typos in 22.2.1.1.2 need to be fixed.
@@ -5653,8 +5803,8 @@ latter appears to be correct.
127. auto_ptr<> conversion issues
-Section: D.10.1 [auto.ptr] Status: TC1 - Submitter: Greg Colvin Opened: 1999-02-17 Last modified: 2008-09-26
+Section: D.12.1 [auto.ptr] Status: TC1 + Submitter: Greg Colvin Opened: 1999-02-17 Last modified: 2010-10-29
View all other issues in [auto.ptr].
View all issues with TC1 status.
Discussion:
@@ -5694,7 +5844,7 @@ object parameter may be bound to an rvalue [13.3.3.1.4/3]Tokyo: The LWG removed the following from the proposed resolution:
-In 20.6.4 [meta.unary], paragraph 2, and 20.6.4.3 [meta.unary.prop], +
In 20.7.4 [meta.unary], paragraph 2, and 20.7.4.3 [meta.unary.prop], paragraph 2, make the conversion to auto_ptr_ref const:
template<class Y> operator auto_ptr_ref<Y>() const throw();@@ -5702,17 +5852,17 @@ object parameter may be bound to an rvalue [13.3.3.1.4/3]Proposed resolution:
-In 20.6.4 [meta.unary], paragraph 2, move +
In 20.7.4 [meta.unary], paragraph 2, move the auto_ptr_ref definition to namespace scope.
-In 20.6.4 [meta.unary], paragraph 2, add +
In 20.7.4 [meta.unary], paragraph 2, add a public assignment operator to the auto_ptr definition:
-auto_ptr& operator=(auto_ptr_ref<X> r) throw();Also add the assignment operator to 20.6.4.3 [meta.unary.prop]:
+Also add the assignment operator to 20.7.4.3 [meta.unary.prop]:
auto_ptr& operator=(auto_ptr_ref<X> r) throw()@@ -5730,7 +5880,7 @@ a public assignment operator to the auto_ptr definition:
129. Need error indication from seekp() and seekg()
Section: 27.7.1.3 [istream.unformatted], 27.7.2.5 [ostream.seeks] Status: TC1 - Submitter: Angelika Langer Opened: 1999-02-22 Last modified: 2008-09-26
+ Submitter: Angelika Langer Opened: 1999-02-22 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with TC1 status.
Discussion:
@@ -5766,7 +5916,7 @@ stream state in case of failure.
130. Return type of container::erase(iterator) differs for associative containers
Section: 23.2.4 [associative.reqmts], 23.2.3 [sequence.reqmts] Status: CD1 - Submitter: Andrew Koenig Opened: 1999-03-02 Last modified: 2009-05-01
+ Submitter: Andrew Koenig Opened: 1999-03-02 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with CD1 status.
@@ -5803,10 +5953,10 @@ q2). Returns q2."-In 23.4.1 [map], in the map class synopsis; and -in 23.4.2 [multimap], in the multimap class synopsis; and -in 23.4.3 [set], in the set class synopsis; and -in 23.4.4 [multiset], in the multiset class synopsis: +In 23.6.1 [map], in the map class synopsis; and +in 23.6.2 [multimap], in the multimap class synopsis; and +in 23.6.3 [set], in the set class synopsis; and +in 23.6.4 [multiset], in the multiset class synopsis: change the signature of the first erase overload to
iterator erase(iterator position); @@ -5847,7 +5997,8 @@ Redmond: formally voted into WP.
132. list::resize description uses random access iterators
Section: 23.3.4.2 [list.capacity] Status: TC1 - Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29 +View all other issues in [list.capacity].
View all issues with TC1 status.
Discussion:
The description reads:
@@ -5889,14 +6040,14 @@ no issue of exception safety with the proposed resolution.]
133. map missing get_allocator()
-Section: 23.4.1 [map] Status: TC1 - Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2008-09-26
+Section: 23.6.1 [map] Status: TC1 + Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29
View all other issues in [map].
View all issues with TC1 status.
Discussion:
The title says it all.
Proposed resolution:
-Insert in 23.4.1 [map], paragraph 2, +
Insert in 23.6.1 [map], paragraph 2, after operator= in the map declaration:
allocator_type get_allocator() const;@@ -5906,8 +6057,8 @@ after operator= in the map declaration:
134. vector constructors over specified
-Section: 23.3.6.1 [vector.cons] Status: TC1 - Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2008-09-26
+Section: 23.4.1.1 [vector.cons] Status: TC1 + Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29
View all issues with TC1 status.
Discussion:
The complexity description says: "It does at most 2N calls to the copy constructor @@ -5918,7 +6069,7 @@ tradeoff for the implementor.
Proposed resolution:
-Change 23.3.6.1 [vector.cons], paragraph 1 to:
+Change 23.4.1.1 [vector.cons], paragraph 1 to:
-1- Complexity: The constructor template <class InputIterator> vector(InputIterator first, InputIterator last) @@ -5941,7 +6092,7 @@ is greater than or equal to 2.
136. seekp, seekg setting wrong streams?
Section: 27.7.1.3 [istream.unformatted] Status: CD1 - Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 1999-03-06 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with CD1 status.
Discussion:
@@ -6017,7 +6168,7 @@ basic_filebuf<>::seekpos.]
137. Do use_facet and has_facet look in the global locale?
Section: 22.3.1 [locale] Status: TC1 - Submitter: Angelika Langer Opened: 1999-03-17 Last modified: 2008-09-26
+ Submitter: Angelika Langer Opened: 1999-03-17 Last modified: 2010-10-29View all other issues in [locale].
View all issues with TC1 status.
Discussion:
@@ -6058,8 +6209,7 @@ in the standard.
139. Optional sequence operation table description unclear
Section: 23.2.3 [sequence.reqmts] Status: TC1 - Submitter: Andrew Koenig Opened: 1999-03-30 Last modified: 2008-09-26
-View other active issues in [sequence.reqmts].
+ Submitter: Andrew Koenig Opened: 1999-03-30 Last modified: 2010-10-29View all other issues in [sequence.reqmts].
View all issues with TC1 status.
Discussion:
@@ -6093,14 +6243,14 @@ with:
141. basic_string::find_last_of, find_last_not_of say pos instead of xpos
Section: 21.4.6.4 [string::insert], 21.4.6.6 [string::replace] Status: TC1 - Submitter: Arch Robison Opened: 1999-04-28 Last modified: 2008-09-26
+ Submitter: Arch Robison Opened: 1999-04-28 Last modified: 2010-10-29View all other issues in [string::insert].
View all issues with TC1 status.
Discussion:
Sections 21.3.6.4 paragraph 1 and 21.3.6.6 paragraph 1 surely have misprints where they say:
+— xpos <= pos and pos < size();
-— xpos <= pos and pos < size();Surely the document meant to say ``xpos < size()'' in both places.
@@ -6112,11 +6262,11 @@ proposed resolution.]Proposed resolution:
Change Sections 21.3.6.4 paragraph 1 and 21.3.6.6 paragraph 1, the line which says:
+— xpos <= pos and xpos < size(); @@ -6124,7 +6274,7 @@ proposed resolution.]
-— xpos <= pos and pos < size();
+— xpos <= pos and pos < size();
to:
-— xpos <= pos and xpos < size();
142. lexicographical_compare complexity wrong
Section: 25.4.8 [alg.lex.comparison] Status: TC1 - Submitter: Howard Hinnant Opened: 1999-06-20 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 1999-06-20 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
The lexicographical_compare complexity is specified as:
@@ -6167,7 +6317,7 @@ right! (and Matt states this complexity in his book)
144. Deque constructor complexity wrong
Section: 23.3.2.1 [deque.cons] Status: TC1 - Submitter: Herb Sutter Opened: 1999-05-09 Last modified: 2008-09-26
+ Submitter: Herb Sutter Opened: 1999-05-09 Last modified: 2010-10-29View all other issues in [deque.cons].
View all issues with TC1 status.
Discussion:
@@ -6209,7 +6359,7 @@ typo):
146. complex<T> Inserter and Extractor need sentries
Section: 26.4.6 [complex.ops] Status: TC1 - Submitter: Angelika Langer Opened: 1999-05-12 Last modified: 2008-09-26
+ Submitter: Angelika Langer Opened: 1999-05-12 Last modified: 2010-10-29View all other issues in [complex.ops].
View all issues with TC1 status.
Discussion:
@@ -6296,7 +6446,7 @@ as written.
147. Library Intro refers to global functions that aren't global
Section: 17.6.4.4 [global.functions] Status: TC1 - Submitter: Lois Goldthwaite Opened: 1999-06-04 Last modified: 2008-09-26
+ Submitter: Lois Goldthwaite Opened: 1999-06-04 Last modified: 2010-10-29View all other issues in [global.functions].
View all issues with TC1 status.
Discussion:
@@ -6372,7 +6522,7 @@ was changed from "non-member" to "global or non-member.
148. Functions in the example facet BoolNames should be const
Section: 22.4.8 [facets.examples] Status: TC1 - Submitter: Jeremy Siek Opened: 1999-06-03 Last modified: 2008-09-26
+ Submitter: Jeremy Siek Opened: 1999-06-03 Last modified: 2010-10-29View all other issues in [facets.examples].
View all issues with TC1 status.
Discussion:
@@ -6396,8 +6546,7 @@ two places:
149. Insert should return iterator to first element inserted
Section: 23.2.3 [sequence.reqmts] Status: WP - Submitter: Andrew Koenig Opened: 1999-06-28 Last modified: 2009-10-26
-View other active issues in [sequence.reqmts].
+ Submitter: Andrew Koenig Opened: 1999-06-28 Last modified: 2010-10-29View all other issues in [sequence.reqmts].
View all issues with WP status.
Discussion:
@@ -6424,9 +6573,7 @@ c.insert(i, c1.begin(), c1.end());and now the first inserted element is at c.begin()+i_loc and one past the last is at c.begin()+i_loc+c1.size().
+But what if c is a list? I can still find the location of one past the last inserted element, because i is still valid. To find the location of the first inserted element, though, I must execute something like
-But what if c is a list? I can still find the location of one past the -last inserted element, because i is still valid. To find the location -of the first inserted element, though, I must execute something like@@ -6695,7 +6842,7 @@ Add the following (missing) declaration-p2 23.3.6 [vector] +p2 23.4.1 [vector]
@@ -6713,7 +6860,7 @@ template <class InputIterator>
-23.3.6.4 [vector.modifiers] change return type from void to iterator on following declarations: +23.4.1.4 [vector.modifiers] change return type from void to iterator on following declarations:
voiditerator insert(const_iterator position, size_type n, const T& x); @@ -6731,7 +6878,7 @@ Add the following (missing) declaration-p1 23.3.7 [vector.bool] Update class definition, change return type from void to iterator: +p1 23.4.2 [vector.bool] Update class definition, change return type from void to iterator:
voiditerator insert (const_iterator position, size_type n, const bool& x); @@ -6824,7 +6971,7 @@ not a defect. It may be worth revisiting for the next standard.
150. Find_first_of says integer instead of iterator
Section: 25.2.7 [alg.find.first.of] Status: TC1 - Submitter: Matt McClure Opened: 1999-06-30 Last modified: 2008-09-26
+ Submitter: Matt McClure Opened: 1999-06-30 Last modified: 2010-10-29View all other issues in [alg.find.first.of].
View all issues with TC1 status.
Discussion:
@@ -6851,8 +6998,7 @@ that for some iterator j in the range [first2, last2) ...
151. Can't currently clear() empty container
Section: 23.2.3 [sequence.reqmts] Status: TC1 - Submitter: Ed Brey Opened: 1999-06-21 Last modified: 2008-09-26
-View other active issues in [sequence.reqmts].
+ Submitter: Ed Brey Opened: 1999-06-21 Last modified: 2010-10-29View all other issues in [sequence.reqmts].
View all issues with TC1 status.
Discussion:
@@ -6899,7 +7045,7 @@ iterators or certain kinds of iterators is unnecessary.
152. Typo in scan_is() semantics
Section: 22.4.1.1.2 [locale.ctype.virtuals] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [locale.ctype.virtuals].
View all issues with TC1 status.
Discussion:
@@ -6926,7 +7072,7 @@ would..."
153. Typo in narrow() semantics
Section: 22.4.1.3.2 [facet.ctype.char.members] Status: CD1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [facet.ctype.char.members].
View all issues with CD1 status.
Duplicate of: 207
@@ -6986,8 +7132,7 @@ same paragraphs.]
154. Missing double specifier for do_get()
Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
-View other active issues in [facet.num.get.virtuals].
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [facet.num.get.virtuals].
View all issues with TC1 status.
Discussion:
@@ -7013,7 +7158,7 @@ Modifier table to say that for double a length modifier
155. Typo in naming the class defining the class Init
Section: 27.4 [iostream.objects] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [iostream.objects].
View all issues with TC1 status.
Discussion:
@@ -7038,7 +7183,7 @@ the change.
156. Typo in imbue() description
Section: 27.5.2.3 [ios.base.locales] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [ios.base.locales].
View all issues with TC1 status.
Discussion:
@@ -7059,7 +7204,7 @@ const&".
158. Underspecified semantics for setbuf()
Section: 27.6.2.4.2 [streambuf.virt.buffer] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [streambuf.virt.buffer].
View all issues with TC1 status.
Discussion:
@@ -7085,7 +7230,7 @@ to: "Default behavior: Does nothing. Returns this."
159. Strange use of underflow()
Section: 27.6.2.4.3 [streambuf.virt.get] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
The description of the meaning of the result of @@ -7108,7 +7253,7 @@ stream".
160. Typo: Use of non-existing function exception()
Section: 27.7.1.1 [istream] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [istream].
View all issues with TC1 status.
Discussion:
@@ -7134,7 +7279,7 @@ is the correct spelling.]
161. Typo: istream_iterator vs. istreambuf_iterator
Section: 27.7.1.2.2 [istream.formatted.arithmetic] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [istream.formatted.arithmetic].
View all issues with TC1 status.
Discussion:
@@ -7160,7 +7305,7 @@ an object of type istreambuf_iterator.
164. do_put() has apparently unused fill argument
Section: 22.4.5.3.2 [locale.time.put.virtuals] Status: TC1 - Submitter: Angelika Langer Opened: 1999-07-23 Last modified: 2008-09-26
+ Submitter: Angelika Langer Opened: 1999-07-23 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
In 22.4.5.3.2 [locale.time.put.virtuals] the do_put() function is specified @@ -7194,7 +7339,7 @@ argument since the standard doesn't say how it's used.
165. xsputn(), pubsync() never called by basic_ostream members?
Section: 27.7.2.1 [ostream] Status: CD1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [ostream].
View all issues with CD1 status.
Discussion:
@@ -7254,7 +7399,7 @@ is allowed to call sync() while other functions are not.]
167. Improper use of traits_type::length()
Section: 27.7.2.6.4 [ostream.inserters.character] Status: CD1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [ostream.inserters.character].
View all issues with CD1 status.
Discussion:
@@ -7334,7 +7479,7 @@ to char_traits<char>
168. Typo: formatted vs. unformatted
Section: 27.7.2.7 [ostream.unformatted] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [ostream.unformatted].
View all issues with TC1 status.
Discussion:
@@ -7359,7 +7504,7 @@ sentences, change the word "formatted" to
169. Bad efficiency of overflow() mandated
Section: 27.8.1.4 [stringbuf.virtuals] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [stringbuf.virtuals].
View all issues with TC1 status.
Discussion:
@@ -7390,7 +7535,7 @@ solution is to handle this in underflow().
170. Inconsistent definition of traits_type
Section: 27.8.4 [stringstream] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
The classes basic_stringstream (27.8.4 [stringstream]), @@ -7415,7 +7560,7 @@ not. This should be consistent.
171. Strange seekpos() semantics due to joint position
Section: 27.9.1.5 [filebuf.virtuals] Status: CD1 - Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 1999-07-20 Last modified: 2010-10-29View all other issues in [filebuf.virtuals].
View all issues with CD1 status.
Discussion:
@@ -7481,7 +7626,7 @@ paragraph 14 from:
172. Inconsistent types for basic_istream::ignore()
Section: 27.7.1.3 [istream.unformatted] Status: TC1 - Submitter: Greg Comeau, Dietmar Kühl Opened: 1999-07-23 Last modified: 2008-09-26
+ Submitter: Greg Comeau, Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with TC1 status.
Discussion:
@@ -7514,7 +7659,7 @@ of int in the description of ignore() to
173. Inconsistent types for basic_filebuf::setbuf()
Section: 27.9.1.5 [filebuf.virtuals] Status: TC1 - Submitter: Greg Comeau, Dietmar Kühl Opened: 1999-07-23 Last modified: 2008-09-26
+ Submitter: Greg Comeau, Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29View all other issues in [filebuf.virtuals].
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Discussion:
@@ -7546,8 +7691,8 @@ as described in issue 174. Typo: OFF_T vs. POS_T -Section: D.7 [depr.ios.members] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-23 Last modified: 2008-09-26
+Section: D.8 [depr.ios.members] Status: TC1 + Submitter: Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29
View all other issues in [depr.ios.members].
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Discussion:
@@ -7557,7 +7702,7 @@ paragraph 6 the streampos gets the type POS_TProposed resolution:
-Change D.7 [depr.ios.members] paragraph 1 from "typedef +
Change D.8 [depr.ios.members] paragraph 1 from "typedef OFF_T streampos;" to "typedef POS_T streampos;"
@@ -7566,8 +7711,8 @@ streampos;"
175. Ambiguity for basic_streambuf::pubseekpos() and a few other functions.
-Section: D.7 [depr.ios.members] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-23 Last modified: 2008-09-26
+Section: D.8 [depr.ios.members] Status: TC1 + Submitter: Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29
View all other issues in [depr.ios.members].
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Discussion:
@@ -7585,7 +7730,7 @@ argument is not specified.Proposed resolution:
-In D.7 [depr.ios.members] paragraph 8, remove the default arguments for +
In D.8 [depr.ios.members] paragraph 8, remove the default arguments for basic_streambuf::pubseekpos(), basic_ifstream::open(), and basic_ofstream::open().
@@ -7595,8 +7740,8 @@ argument is not specified.
176. exceptions() in ios_base...?
-Section: D.7 [depr.ios.members] Status: TC1 - Submitter: Dietmar Kühl Opened: 1999-07-23 Last modified: 2008-09-26
+Section: D.8 [depr.ios.members] Status: TC1 + Submitter: Dietmar Kühl Opened: 1999-07-23 Last modified: 2010-10-29
View all other issues in [depr.ios.members].
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Discussion:
@@ -7609,7 +7754,7 @@ in clause 27 [input.output]."Proposed resolution:
-In D.7 [depr.ios.members] paragraph 8, move the declaration of the +
In D.8 [depr.ios.members] paragraph 8, move the declaration of the function exceptions()into class basic_ios.
@@ -7618,8 +7763,7 @@ function exceptions()into class basic_ios.
179. Comparison of const_iterators to iterators doesn't work
Section: 23.2 [container.requirements] Status: CD1 - Submitter: Judy Ward Opened: 1998-07-02 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+ Submitter: Judy Ward Opened: 1998-07-02 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with CD1 status.
Discussion:
@@ -7741,7 +7885,7 @@ separate issue. (Issue 180. Container member iterator arguments constness has unintended consequencesSection: 21.4 [basic.string] Status: CD1 - Submitter: Dave Abrahams Opened: 1999-07-01 Last modified: 2008-09-26
+ Submitter: Dave Abrahams Opened: 1999-07-01 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with CD1 status.
Discussion:
@@ -7875,9 +8019,8 @@ standard. Also see issue 181. make_pair() unintended behavior -Section: 20.3.4 [pairs] Status: TC1 - Submitter: Andrew Koenig Opened: 1999-08-03 Last modified: 2008-09-26
-View other active issues in [pairs].
+Section: 20.3.5 [pairs] Status: TC1 + Submitter: Andrew Koenig Opened: 1999-08-03 Last modified: 2010-10-29
View all other issues in [pairs].
View all issues with TC1 status.
Discussion:
@@ -7902,7 +8045,7 @@ declaration of make_pair():-template <class T1, class T2> pair<T1,T2> make_pair(T1, T2);In 20.3.4 [pairs] paragraph 7 and the line before, change:
+In 20.3.5 [pairs] paragraph 7 and the line before, change:
template <class T1, class T2> pair<T1, T2> make_pair(const T1& x, const T2& y);@@ -7936,7 +8079,7 @@ proposed resolution passed their test suites.
182. Ambiguous references to size_t
Section: 17 [library] Status: CD1 - Submitter: Al Stevens Opened: 1999-08-15 Last modified: 2008-09-26
+ Submitter: Al Stevens Opened: 1999-08-15 Last modified: 2010-10-29View other active issues in [library].
View all other issues in [library].
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@@ -8016,8 +8159,7 @@ X::length(p): "size_t" by "std::size_t". typedef ptrdiff_t difference_type;
by:
typedef std::ptrdiff_t difference_type; -In [lib.locale.ctype] 22.2.1.1 put namespace std { ...} around the -declaration of template <class charT> class ctype.
+In [lib.locale.ctype] 22.2.1.1 put namespace std { ...} around the declaration of template <class charT> class ctype.
In [lib.iterator.traits] 24.3.1, paragraph 2 put namespace std { ...} around the declaration of:
@@ -8064,7 +8206,7 @@ them to be correct.]
183. I/O stream manipulators don't work for wide character streams
Section: 27.7.3 [std.manip] Status: CD1 - Submitter: Andy Sawyer Opened: 1999-07-07 Last modified: 2008-09-26
+ Submitter: Andy Sawyer Opened: 1999-07-07 Last modified: 2010-10-29View all other issues in [std.manip].
View all issues with CD1 status.
Discussion:
@@ -8101,28 +8243,18 @@ basic_ostream as out"&Replace section 27.7.3 [std.manip] except paragraph 1 with the following:
-2- The type designated smanip in each of the following function -descriptions is implementation-specified and may be different for each +
2- The type designated smanip in each of the following function descriptions is implementation-specified and may be different for each function.
smanip resetiosflags(ios_base::fmtflags mask);
--3- Returns: An object s of unspecified type such that if out is an -instance of basic_ostream<charT,traits> then the expression -out<<s behaves -as if f(s, mask) were called, or if in is an instance of -basic_istream<charT,traits> then the expression in>>s -behaves as if +-3- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves +as if f(s, mask) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if f(s, mask) were called. The function f can be defined as:*
-[Footnote: The expression cin >> resetiosflags(ios_base::skipws) -clears ios_base::skipws in the format flags stored in the -basic_istream<charT,traits> object cin (the same as cin >> -noskipws), and the expression cout << -resetiosflags(ios_base::showbase) clears -ios_base::showbase in the format flags stored in the -basic_ostream<charT,traits> object cout (the same as cout -<< +[Footnote: The expression cin >> resetiosflags(ios_base::skipws) clears ios_base::skipws in the format flags stored in the +basic_istream<charT,traits> object cin (the same as cin >> noskipws), and the expression cout << resetiosflags(ios_base::showbase) clears +ios_base::showbase in the format flags stored in the basic_ostream<charT,traits> object cout (the same as cout << noshowbase). --- end footnote]
ios_base& f(ios_base& str, ios_base::fmtflags mask)
@@ -8137,12 +8269,8 @@ The expression in>>s has type basic_istream<charT,traits>& and v
smanip setiosflags(ios_base::fmtflags mask);
--4- Returns: An object s of unspecified type such that if out is an -instance of basic_ostream<charT,traits> then the expression -out<<s behaves -as if f(s, mask) were called, or if in is an instance of -basic_istream<charT,traits> then the expression in>>s -behaves as if f(s, +-4- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves +as if f(s, mask) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if f(s, mask) were called. The function f can be defined as:
ios_base& f(ios_base& str, ios_base::fmtflags mask)
@@ -8157,12 +8285,8 @@ The expression in>>s has type basic_istream<charT,traits>& and v
smanip setbase(int base);
--5- Returns: An object s of unspecified type such that if out is an -instance of basic_ostream<charT,traits> then the expression -out<<s behaves -as if f(s, base) were called, or if in is an instance of -basic_istream<charT,traits> then the expression in>>s -behaves as if f(s, +-5- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves +as if f(s, base) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if f(s, base) were called. The function f can be defined as:
ios_base& f(ios_base& str, int base)
@@ -8180,11 +8304,8 @@ The expression in>>s has type basic_istream<charT,traits>& and v
smanip setfill(char_type c);
--6- Returns: An object s of unspecified type such that if out is (or is -derived from) basic_ostream<charT,traits> and c has type charT -then the -expression out<<s behaves as if f(s, c) were called. The function -f can be +-6- Returns: An object s of unspecified type such that if out is (or is derived from) basic_ostream<charT,traits> and c has type charT then the +expression out<<s behaves as if f(s, c) were called. The function f can be defined as:
template<class charT, class traits>
@@ -8199,12 +8320,8 @@ The expression out<<s has type basic_ostream<charT,traits>& and
smanip setprecision(int n);
--7- Returns: An object s of unspecified type such that if out is an -instance of basic_ostream<charT,traits> then the expression -out<<s behaves -as if f(s, n) were called, or if in is an instance of -basic_istream<charT,traits> then the expression in>>s -behaves as if f(s, n) +-7- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves +as if f(s, n) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if f(s, n) were called. The function f can be defined as:
ios_base& f(ios_base& str, int n)
@@ -8219,12 +8336,8 @@ The expression in>>s has type basic_istream<charT,traits>& and v .
smanip setw(int n);
--8- Returns: An object s of unspecified type such that if out is an -instance of basic_ostream<charT,traits> then the expression -out<<s behaves -as if f(s, n) were called, or if in is an instance of -basic_istream<charT,traits> then the expression in>>s -behaves as if f(s, n) +-8- Returns: An object s of unspecified type such that if out is an instance of basic_ostream<charT,traits> then the expression out<<s behaves +as if f(s, n) were called, or if in is an instance of basic_istream<charT,traits> then the expression in>>s behaves as if f(s, n) were called. The function f can be defined as:
ios_base& f(ios_base& str, int n)
@@ -8264,7 +8377,7 @@ checked by the LWG.]
184. numeric_limits<bool> wording problems
Section: 18.3.1.5 [numeric.special] Status: CD1 - Submitter: Gabriel Dos Reis Opened: 1999-07-21 Last modified: 2008-09-26
+ Submitter: Gabriel Dos Reis Opened: 1999-07-21 Last modified: 2010-10-29View all other issues in [numeric.special].
View all issues with CD1 status.
Discussion:
@@ -8369,12 +8482,12 @@ Josuttis provided the above wording.]
185. Questionable use of term "inline"
-Section: 20.7 [function.objects] Status: CD1 - Submitter: UK Panel Opened: 1999-07-26 Last modified: 2008-09-26
+Section: 20.8 [function.objects] Status: CD1 + Submitter: UK Panel Opened: 1999-07-26 Last modified: 2010-10-29
View all other issues in [function.objects].
View all issues with CD1 status.
Discussion:
-Paragraph 4 of 20.7 [function.objects] says:
+Paragraph 4 of 20.8 [function.objects] says:
[Example: To negate every element of a: transform(a.begin(), a.end(), a.begin(), negate<double>()); The corresponding functions will inline @@ -8401,17 +8514,17 @@ not required elsewhere.
Proposed resolution:
-In 20.7 [function.objects] paragraph 1, remove the sentence:
+In 20.8 [function.objects] paragraph 1, remove the sentence:
-They are important for the effective use of the library.
Remove 20.7 [function.objects] paragraph 2, which reads:
+Remove 20.8 [function.objects] paragraph 2, which reads:
-Using function objects together with function templates increases the expressive power of the library as well as making the resulting code much more efficient.
In 20.7 [function.objects] paragraph 4, remove the sentence:
+In 20.8 [function.objects] paragraph 4, remove the sentence:
-The corresponding functions will inline the addition and the negation.
@@ -8428,12 +8541,12 @@ not required elsewhere.
186. bitset::set() second parameter should be bool
-Section: 20.3.7.2 [bitset.members] Status: CD1 - Submitter: Darin Adler Opened: 1999-08-13 Last modified: 2008-09-26
+Section: 20.5.2 [bitset.members] Status: CD1 + Submitter: Darin Adler Opened: 1999-08-13 Last modified: 2010-10-29
View all other issues in [bitset.members].
View all issues with CD1 status.
Discussion:
-In section 20.3.7.2 [bitset.members], paragraph 13 defines the +
In section 20.5.2 [bitset.members], paragraph 13 defines the bitset::set operation to take a second parameter of type int. The function tests whether this value is non-zero to determine whether to set the bit to true or false. The type of this second parameter should @@ -8445,7 +8558,7 @@ translating 0 to false and any non-zero value to true.
Proposed resolution:
-In 20.3.7 [template.bitset] Para 1 Replace:
+In 20.5 [template.bitset] Para 1 Replace:
@@ -8453,7 +8566,7 @@ translating 0 to false and any non-zero value to true.bitset<N>& set(size_t pos, int val = true );-bitset<N>& set(size_t pos, bool val = true );In 20.3.7.2 [bitset.members] Para 12(.5) Replace:
+In 20.5.2 [bitset.members] Para 12(.5) Replace:
@@ -8483,7 +8596,7 @@ nonvirtual member of a standard library class.bitset<N>& set(size_t pos, int val = 1 );
187. iter_swap underspecified
Section: 25.3.3 [alg.swap] Status: CD1 - Submitter: Andrew Koenig Opened: 1999-08-14 Last modified: 2008-09-26
+ Submitter: Andrew Koenig Opened: 1999-08-14 Last modified: 2010-10-29View all other issues in [alg.swap].
View all issues with CD1 status.
Discussion:
@@ -8554,7 +8667,7 @@ one list to another. That would surely be inappropriate.
189. setprecision() not specified correctly
Section: 27.5.2.2 [fmtflags.state] Status: TC1 - Submitter: Andrew Koenig Opened: 1999-08-25 Last modified: 2008-09-26
+ Submitter: Andrew Koenig Opened: 1999-08-25 Last modified: 2010-10-29View all other issues in [fmtflags.state].
View all issues with TC1 status.
Discussion:
@@ -8581,7 +8694,7 @@ correct the statement in 27.4.2.2
193. Heap operations description incorrect
Section: 25.4.6 [alg.heap.operations] Status: TC1 - Submitter: Markus Mauhart Opened: 1999-09-24 Last modified: 2008-09-26
+ Submitter: Markus Mauhart Opened: 1999-09-24 Last modified: 2010-10-29View all issues with TC1 status.
Duplicate of: 216
Discussion:
@@ -8596,11 +8709,8 @@ resolution.@@ -8621,7 +8731,7 @@ priority AND time).A-"part of largest equivalence class" instead of "largest", cause 25.3 [lib.alg.sorting] asserts "strict weak ordering" for all its sub clauses.
-B-Take -'an oldest' from that equivalence class, otherwise the heap functions -could not be used for a priority queue as explained in 23.2.3.2.2 -[lib.priqueue.members] (where I assume that a "priority queue" respects -priority AND time).
+B-Take 'an oldest' from that equivalence class, otherwise the heap functions could not be used for a + priority queue as explained in 23.2.3.2.2 [lib.priqueue.members] (where I assume that a "priority queue" respects priority AND time).
195. Should basic_istream::sentry's constructor ever set eofbit?
Section: 27.7.1.1.3 [istream::sentry] Status: TC1 - Submitter: Matt Austern Opened: 1999-10-13 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 1999-10-13 Last modified: 2010-10-29View all other issues in [istream::sentry].
View all issues with TC1 status.
Discussion:
@@ -8680,7 +8790,7 @@ returns traits::eof(), the function calls
198. Validity of pointers and references unspecified after iterator destruction
Section: X [iterator.concepts] Status: CD1 - Submitter: Beman Dawes Opened: 1999-11-03 Last modified: 2008-09-30
+ Submitter: Beman Dawes Opened: 1999-11-03 Last modified: 2010-10-29View all other issues in [iterator.concepts].
View all issues with CD1 status.
Discussion:
@@ -8737,8 +8847,7 @@ effects:Iterator tmp = current; return *--tmp;The definition of reverse_iterator::operator->(), 24.5.1.3.4 -[reverse.iter.op.star], which returns a pointer, defines effects:
+The definition of reverse_iterator::operator->(), 24.5.1.3.4 [reverse.iter.op.star], which returns a pointer, defines effects:
@@ -8788,7 +8897,7 @@ reformulated yet again to reflect this reality.] assumes its underlying iterator has persistent pointers and references. Andy Koenig pointed out that it is possible to rewrite reverse_iterator so that it no longer makes such an assupmption. -However, this issue is related to issue 299. If we +However, this issue is related to issue 299. If we decide it is intentional that p[n] may return by value instead of reference when p is a Random Access Iterator, other changes in reverse_iterator will be necessary.] @@ -8820,8 +8929,8 @@ predefined iterators are as strong as users expect.return &(operator*());
199. What does allocate(0) return?
-Section: 20.2.2 [allocator.requirements] Status: TC1 - Submitter: Matt Austern Opened: 1999-11-19 Last modified: 2008-09-26
+Section: 20.2.5 [allocator.requirements] Status: TC1 + Submitter: Matt Austern Opened: 1999-11-19 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
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Discussion:
@@ -8855,8 +8964,8 @@ would be over-specification to mandate the return value.
200. Forward iterator requirements don't allow constant iterators
-Section: 24.2.3 [forward.iterators] Status: CD1 - Submitter: Matt Austern Opened: 1999-11-19 Last modified: 2008-09-26
+Section: 24.2.5 [forward.iterators] Status: CD1 + Submitter: Matt Austern Opened: 1999-11-19 Last modified: 2010-10-29
View all other issues in [forward.iterators].
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Discussion:
@@ -8902,7 +9011,7 @@ that we also need to worry about *r++ and a->m.]
201. Numeric limits terminology wrong
Section: 18.3.1 [limits] Status: CD1 - Submitter: Stephen Cleary Opened: 1999-12-21 Last modified: 2008-09-26
+ Submitter: Stephen Cleary Opened: 1999-12-21 Last modified: 2010-10-29View all other issues in [limits].
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Discussion:
@@ -8978,7 +9087,7 @@ which do not.
202. unique() effects unclear when predicate not an equivalence relation
Section: 25.3.9 [alg.unique] Status: CD1 - Submitter: Andrew Koenig Opened: 2000-01-13 Last modified: 2008-09-26
+ Submitter: Andrew Koenig Opened: 2000-01-13 Last modified: 2010-10-29View all other issues in [alg.unique].
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Discussion:
@@ -9115,7 +9224,7 @@ existing implementations.
206. operator new(size_t, nothrow) may become unlinked to ordinary operator new if ordinary version replaced
Section: 18.6.1.1 [new.delete.single] Status: CD1 - Submitter: Howard Hinnant Opened: 1999-08-29 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 1999-08-29 Last modified: 2010-10-29View all other issues in [new.delete.single].
View all issues with CD1 status.
Discussion:
@@ -9412,7 +9521,7 @@ his customers.
208. Unnecessary restriction on past-the-end iterators
Section: X [iterator.concepts] Status: TC1 - Submitter: Stephen Cleary Opened: 2000-02-02 Last modified: 2008-09-30
+ Submitter: Stephen Cleary Opened: 2000-02-02 Last modified: 2010-10-29View all other issues in [iterator.concepts].
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Discussion:
@@ -9451,7 +9560,7 @@ iterators. Null pointers are singular.
209. basic_string declarations inconsistent
Section: 21.4 [basic.string] Status: TC1 - Submitter: Igor Stauder Opened: 2000-02-11 Last modified: 2008-09-26
+ Submitter: Igor Stauder Opened: 2000-02-11 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with TC1 status.
Discussion:
@@ -9493,8 +9602,7 @@ change.
210. distance first and last confused
Section: 25 [algorithms] Status: TC1 - Submitter: Lisa Lippincott Opened: 2000-02-15 Last modified: 2008-09-26
-View other active issues in [algorithms].
+ Submitter: Lisa Lippincott Opened: 2000-02-15 Last modified: 2010-10-29View all other issues in [algorithms].
View all issues with TC1 status.
Discussion:
@@ -9525,7 +9633,7 @@ former for consistency.
211. operator>>(istream&, string&) doesn't set failbit
Section: 21.4.8.9 [string.io] Status: TC1 - Submitter: Scott Snyder Opened: 2000-02-04 Last modified: 2008-09-26
+ Submitter: Scott Snyder Opened: 2000-02-04 Last modified: 2010-10-29View all other issues in [string.io].
View all issues with TC1 status.
Discussion:
@@ -9563,7 +9671,7 @@ is.setstate(ios::failbit) which may throw ios_base::failure
212. Empty range behavior unclear for several algorithms
Section: 25.4.7 [alg.min.max] Status: TC1 - Submitter: Nico Josuttis Opened: 2000-02-26 Last modified: 2008-09-26
+ Submitter: Nico Josuttis Opened: 2000-02-26 Last modified: 2010-10-29View all other issues in [alg.min.max].
View all issues with TC1 status.
Discussion:
@@ -9589,8 +9697,8 @@ last.
214. set::find() missing const overload
-Section: 23.4.3 [set], 23.4.4 [multiset] Status: CD1 - Submitter: Judy Ward Opened: 2000-02-28 Last modified: 2008-09-26
+Section: 23.6.3 [set], 23.6.4 [multiset] Status: CD1 + Submitter: Judy Ward Opened: 2000-02-28 Last modified: 2010-10-29
View all other issues in [set].
View all issues with CD1 status.
Duplicate of: 450
@@ -9607,7 +9715,7 @@ and multiset do not, all they have is:Proposed resolution:
Change the prototypes for find(), lower_bound(), upper_bound(), and -equal_range() in section 23.4.3 [set] and section 23.4.4 [multiset] to each have two overloads:
+equal_range() in section 23.6.3 [set] and section 23.6.4 [multiset] to each have two overloads:iterator find(const key_type & x); const_iterator find(const key_type & x) const;@@ -9631,7 +9739,7 @@ equal_range.]
217. Facets example (Classifying Japanese characters) contains errors
Section: 22.4.8 [facets.examples] Status: TC1 - Submitter: Martin Sebor Opened: 2000-02-29 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-02-29 Last modified: 2010-10-29View all other issues in [facets.examples].
View all issues with TC1 status.
Discussion:
@@ -9685,7 +9793,7 @@ declared above.
220. ~ios_base() usage valid?
Section: 27.5.2.7 [ios.base.cons] Status: TC1 - Submitter: Jonathan Schilling, Howard Hinnant Opened: 2000-03-13 Last modified: 2008-09-26
+ Submitter: Jonathan Schilling, Howard Hinnant Opened: 2000-03-13 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
The pre-conditions for the ios_base destructor are described in 27.4.2.7 @@ -9725,10 +9833,9 @@ behavior.
to
-@@ -9737,8 +9844,7 @@ initializations have taken place, the behavior is undefined.Effects: Each ios_base member has an indeterminate -value after construction. These members must be initialized by calling -basic_ios::init. If an ios_base object is destroyed before these -initializations have taken place, the behavior is undefined.
+Effects: Each ios_base member has an indeterminate value after + construction. These members must be initialized by calling basic_ios::init. If an ios_base object is destroyed before these initializations + have taken place, the behavior is undefined.
221. num_get<>::do_get stage 2 processing broken
Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: CD1 - Submitter: Matt Austern Opened: 2000-03-14 Last modified: 2008-09-26
-View other active issues in [facet.num.get.virtuals].
+ Submitter: Matt Austern Opened: 2000-03-14 Last modified: 2010-10-29View all other issues in [facet.num.get.virtuals].
View all issues with CD1 status.
Discussion:
@@ -9785,7 +9891,7 @@ deliberately, with full knowledge of that limitation.
222. Are throw clauses necessary if a throw is already implied by the effects clause?
Section: 17.5.1.4 [structure.specifications] Status: TC1 - Submitter: Judy Ward Opened: 2000-03-17 Last modified: 2008-09-26
+ Submitter: Judy Ward Opened: 2000-03-17 Last modified: 2010-10-29View all other issues in [structure.specifications].
View all issues with TC1 status.
Discussion:
@@ -9839,7 +9945,7 @@ footnote.
223. reverse algorithm should use iter_swap rather than swap
Section: 25.3.10 [alg.reverse] Status: TC1 - Submitter: Dave Abrahams Opened: 2000-03-21 Last modified: 2008-09-26
+ Submitter: Dave Abrahams Opened: 2000-03-21 Last modified: 2010-10-29View all issues with TC1 status.
Discussion:
Shouldn't the effects say "applies iter_swap to all pairs..."?
@@ -9863,7 +9969,7 @@ footnote.
224. clear() complexity for associative containers refers to undefined N
Section: 23.2.4 [associative.reqmts] Status: TC1 - Submitter: Ed Brey Opened: 2000-03-23 Last modified: 2008-09-26
+ Submitter: Ed Brey Opened: 2000-03-23 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with TC1 status.
@@ -9891,7 +9997,7 @@ cut-and-paste from the range version of erase.
225. std:: algorithms use of other unqualified algorithms
Section: 17.6.4.4 [global.functions] Status: CD1 - Submitter: Dave Abrahams Opened: 2000-04-01 Last modified: 2008-09-26
+ Submitter: Dave Abrahams Opened: 2000-04-01 Last modified: 2010-10-29View all other issues in [global.functions].
View all issues with CD1 status.
Discussion:
@@ -10023,7 +10129,7 @@ resolution for this issue is in accordance with Howard's paper.]
226. User supplied specializations or overloads of namespace std function templates
Section: 17.6.3.3 [reserved.names] Status: CD1 - Submitter: Dave Abrahams Opened: 2000-04-01 Last modified: 2008-09-26
+ Submitter: Dave Abrahams Opened: 2000-04-01 Last modified: 2010-10-29View all other issues in [reserved.names].
View all issues with CD1 status.
Discussion:
@@ -10214,7 +10320,7 @@ resolution is the one proposed by Howard.]
227. std::swap() should require CopyConstructible or DefaultConstructible arguments
Section: 25.3.3 [alg.swap] Status: TC1 - Submitter: Dave Abrahams Opened: 2000-04-09 Last modified: 2008-09-26
+ Submitter: Dave Abrahams Opened: 2000-04-09 Last modified: 2010-10-29View all other issues in [alg.swap].
View all issues with TC1 status.
Discussion:
@@ -10267,16 +10373,12 @@ resolution is the one proposed by Howard.]
228. Incorrect specification of "..._byname" facets
Section: 22.4 [locale.categories] Status: CD1 - Submitter: Dietmar Kühl Opened: 2000-04-20 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 2000-04-20 Last modified: 2010-10-29View all other issues in [locale.categories].
View all issues with CD1 status.
Discussion:
-The sections 22.4.1.2 [locale.ctype.byname], 22.4.1.5 -[locale.codecvt.byname], -sref ref="22.2.1.6", 22.4.3.2 [locale.numpunct.byname], 22.4.4.2 -[locale.collate.byname], 22.4.5.4 [locale.time.put.byname], 22.4.6.4 -[locale.moneypunct.byname], and 22.4.7.2 [locale.messages.byname] -overspecify the +
The sections 22.4.1.2 [locale.ctype.byname], 22.4.1.5 [locale.codecvt.byname], +sref ref="22.2.1.6", 22.4.3.2 [locale.numpunct.byname], 22.4.4.2 [locale.collate.byname], 22.4.5.4 [locale.time.put.byname], 22.4.6.4 [locale.moneypunct.byname], and 22.4.7.2 [locale.messages.byname] overspecify the definitions of the "..._byname" classes by listing a bunch of virtual functions. At the same time, no semantics of these functions are defined. Real implementations do not define these @@ -10286,7 +10388,7 @@ the "..._byname" version just provides suitable date used by these implementations. For example, the 'numpunct' methods just return values from a struct. The base class uses a statically initialized struct while the derived version reads the contents of this struct -from a table. However, no virtual function is defined in +from a table. However, no virtual function is defined in 'numpunct_byname'.
For most classes this does not impose a problem but specifically @@ -10417,7 +10519,7 @@ three last virtual functions from messages_byname.]
229. Unqualified references of other library entities
Section: 17.6.1.1 [contents] Status: CD1 - Submitter: Steve Clamage Opened: 2000-04-19 Last modified: 2008-09-26
+ Submitter: Steve Clamage Opened: 2000-04-19 Last modified: 2010-10-29View all other issues in [contents].
View all issues with CD1 status.
Discussion:
@@ -10483,7 +10585,7 @@ resolution for the current issue makes sense.]
230. Assignable specified without also specifying CopyConstructible
Section: 17 [library] Status: CD1 - Submitter: Beman Dawes Opened: 2000-04-26 Last modified: 2008-09-26
+ Submitter: Beman Dawes Opened: 2000-04-26 Last modified: 2010-10-29View other active issues in [library].
View all other issues in [library].
View all issues with CD1 status.
@@ -10496,7 +10598,7 @@ determine if the same defect existed elsewhere.There are a number of places (see proposed resolution below) where Assignable is specified without also specifying CopyConstructible. There are also several cases where both are -specified. For example, X [rand.req].
+specified. For example, 26.5.1 [rand.req].Proposed resolution:
@@ -10510,7 +10612,7 @@ Assignable" CopyConstructible and Assignable"
-In 24.2.2 [output.iterators] paragraph 1, change: +
In 24.2.4 [output.iterators] paragraph 1, change:
A class or a built-in type X satisfies the requirements of an @@ -10554,8 +10656,7 @@ Copy Constructible property.
231. Precision in iostream?
Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: CD1 - Submitter: James Kanze, Stephen Clamage Opened: 2000-04-25 Last modified: 2008-09-26
-View other active issues in [facet.num.put.virtuals].
+ Submitter: James Kanze, Stephen Clamage Opened: 2000-04-25 Last modified: 2010-10-29View all other issues in [facet.num.put.virtuals].
View all issues with CD1 status.
Discussion:
@@ -10638,7 +10739,7 @@ where precision is 0 and mode is %g.]
232. "depends" poorly defined in 17.4.3.1
Section: 17.6.3.3 [reserved.names] Status: CD1 - Submitter: Peter Dimov Opened: 2000-04-18 Last modified: 2008-09-26
+ Submitter: Peter Dimov Opened: 2000-04-18 Last modified: 2010-10-29View all other issues in [reserved.names].
View all issues with CD1 status.
Discussion:
@@ -10691,7 +10792,7 @@ rationale.]
233. Insertion hints in associative containers
Section: 23.2.4 [associative.reqmts] Status: CD1 - Submitter: Andrew Koenig Opened: 2000-04-30 Last modified: 2008-09-26
+ Submitter: Andrew Koenig Opened: 2000-04-30 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with CD1 status.
@@ -10833,7 +10934,7 @@ logarithmic in general, but amortized constant if t is inserted right < before p. - + @@ -10842,8 +10943,8 @@ logarithmic in general, but amortized constant if t is inserted right <
234. Typos in allocator definition
-Section: 20.8.8.1 [allocator.members] Status: CD1 - Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2008-09-26
+Section: 20.9.5.1 [allocator.members] Status: CD1 + Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2010-10-29
View all other issues in [allocator.members].
View all issues with CD1 status.
Discussion:
@@ -10861,7 +10962,7 @@ return void.
235. No specification of default ctor for reverse_iterator
Section: 24.5.1.1 [reverse.iterator] Status: CD1 - Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
The declaration of reverse_iterator lists a default @@ -10891,7 +10992,7 @@ should do.
237. Undefined expression in complexity specification
Section: 23.3.2.1 [deque.cons] Status: CD1 - Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 2000-04-24 Last modified: 2010-10-29View all other issues in [deque.cons].
View all issues with CD1 status.
Discussion:
@@ -10913,7 +11014,7 @@ would have to be last - first.
238. Contradictory results of stringbuf initialization.
Section: 27.8.1.1 [stringbuf.cons] Status: CD1 - Submitter: Dietmar Kühl Opened: 2000-05-11 Last modified: 2008-09-26
+ Submitter: Dietmar Kühl Opened: 2000-05-11 Last modified: 2010-10-29View all other issues in [stringbuf.cons].
View all issues with CD1 status.
Discussion:
@@ -10951,7 +11052,7 @@ in the standard.
239. Complexity of unique() and/or unique_copy incorrect
Section: 25.3.9 [alg.unique] Status: CD1 - Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2008-09-26
+ Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2010-10-29View all other issues in [alg.unique].
View all issues with CD1 status.
Discussion:
@@ -10996,7 +11097,7 @@ applications of the corresponding predicate.
240. Complexity of adjacent_find() is meaningless
Section: 25.2.8 [alg.adjacent.find] Status: CD1 - Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2008-09-26
+ Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2010-10-29View all other issues in [alg.adjacent.find].
View all issues with CD1 status.
Discussion:
@@ -11056,7 +11157,7 @@ bound. The LWG preferred an exact count.]
241. Does unique_copy() require CopyConstructible and Assignable?
Section: 25.3.9 [alg.unique] Status: CD1 - Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2008-09-26
+ Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2010-10-29View all other issues in [alg.unique].
View all issues with CD1 status.
Discussion:
@@ -11070,7 +11171,7 @@ the value type is CopyConstructible and Assignable. specify any additional requirements that they impose on any of the types used by the algorithm. An example of an algorithm that creates temporary copies and correctly specifies the additional requirements -is accumulate(), X [rand.req]. +is accumulate(), 26.5.1 [rand.req].Since the specifications of unique() and unique_copy() do not require CopyConstructible and Assignable of the InputIterator's value @@ -11125,7 +11226,7 @@ minor as not to require re-review.
242. Side effects of function objects
Section: 25.3.4 [alg.transform], 26.5 [rand] Status: CD1 - Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2008-09-26
+ Submitter: Angelika Langer Opened: 2000-05-15 Last modified: 2010-10-29View all other issues in [alg.transform].
View all issues with CD1 status.
Discussion:
@@ -11313,7 +11414,7 @@ intentional.]
243. get and getline when sentry reports failure
Section: 27.7.1.3 [istream.unformatted] Status: CD1 - Submitter: Martin Sebor Opened: 2000-05-15 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-05-15 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with CD1 status.
Discussion:
@@ -11372,12 +11473,12 @@ Jerry Schwarz's message c++std-lib-7618.
247. vector, deque::insert complexity
-Section: 23.3.6.4 [vector.modifiers] Status: CD1 - Submitter: Lisa Lippincott Opened: 2000-06-06 Last modified: 2008-09-26
+Section: 23.4.1.4 [vector.modifiers] Status: CD1 + Submitter: Lisa Lippincott Opened: 2000-06-06 Last modified: 2010-10-29
View all other issues in [vector.modifiers].
View all issues with CD1 status.
Discussion:
-Paragraph 2 of 23.3.6.4 [vector.modifiers] describes the complexity +
Paragraph 2 of 23.4.1.4 [vector.modifiers] describes the complexity of vector::insert:
@@ -11414,7 +11515,7 @@ paragraph 3):
Proposed resolution:
-Change Paragraph 2 of 23.3.6.4 [vector.modifiers] to
+Change Paragraph 2 of 23.4.1.4 [vector.modifiers] to
Complexity: The complexity is linear in the number of elements inserted plus the distance to the end of the vector. @@ -11451,7 +11552,7 @@ paragraph 3):
248. time_get fails to set eofbit
Section: 22.4.5 [category.time] Status: CD1 - Submitter: Martin Sebor Opened: 2000-06-22 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-06-22 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
There is no requirement that any of time_get member functions set @@ -11481,8 +11582,7 @@ input facets.
250. splicing invalidates iterators
Section: 23.3.4.4 [list.ops] Status: CD1 - Submitter: Brian Parker Opened: 2000-07-14 Last modified: 2008-09-26
-View other active issues in [list.ops].
+ Submitter: Brian Parker Opened: 2000-07-14 Last modified: 2010-10-29View all other issues in [list.ops].
View all issues with CD1 status.
Discussion:
@@ -11557,7 +11657,7 @@ allocators compare nonequal is outside the scope of the standard.
251. basic_stringbuf missing allocator_type
Section: 27.8.1 [stringbuf] Status: CD1 - Submitter: Martin Sebor Opened: 2000-07-28 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-07-28 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
The synopsis for the template class basic_stringbuf @@ -11581,7 +11681,7 @@ basic_stringstream (27.7.4) the typedef:
252. missing casts/C-style casts used in iostreams
Section: 27.8 [string.streams] Status: CD1 - Submitter: Martin Sebor Opened: 2000-07-28 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-07-28 Last modified: 2010-10-29View all other issues in [string.streams].
View all issues with CD1 status.
Discussion:
@@ -11627,7 +11727,7 @@ issue is stylistic rather than a matter of correctness.
253. valarray helper functions are almost entirely useless
Section: 26.6.2.1 [valarray.cons], 26.6.2.2 [valarray.assign] Status: CD1 - Submitter: Robert Klarer Opened: 2000-07-31 Last modified: 2008-09-26
+ Submitter: Robert Klarer Opened: 2000-07-31 Last modified: 2010-10-29View all other issues in [valarray.cons].
View all issues with CD1 status.
Discussion:
@@ -11780,7 +11880,7 @@ expectation.
254. Exception types in clause 19 are constructed from std::string
Section: 19.2 [std.exceptions], 27.5.2.1.1 [ios::failure] Status: CD1 - Submitter: Dave Abrahams Opened: 2000-08-01 Last modified: 2008-09-26
+ Submitter: Dave Abrahams Opened: 2000-08-01 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -12230,8 +12330,7 @@ the need to explicit include or construct a std::string.
256. typo in 27.4.4.2, p17: copy_event does not exist
Section: 27.5.4.2 [basic.ios.members] Status: CD1 - Submitter: Martin Sebor Opened: 2000-08-21 Last modified: 2008-09-26
-View other active issues in [basic.ios.members].
+ Submitter: Martin Sebor Opened: 2000-08-21 Last modified: 2010-10-29View all other issues in [basic.ios.members].
View all issues with CD1 status.
Discussion:
@@ -12260,8 +12359,8 @@ copyfmt_event.
258. Missing allocator requirement
-Section: 20.2.2 [allocator.requirements] Status: CD1 - Submitter: Matt Austern Opened: 2000-08-22 Last modified: 2008-09-26
+Section: 20.2.5 [allocator.requirements] Status: CD1 + Submitter: Matt Austern Opened: 2000-08-22 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with CD1 status.
Discussion:
@@ -12370,7 +12469,7 @@ issue to Ready status to be voted into the WP at Kona.
259. basic_string::operator[] and const correctness
Section: 21.4.4 [string.capacity] Status: CD1 - Submitter: Chris Newton Opened: 2000-08-27 Last modified: 2008-09-26
+ Submitter: Chris Newton Opened: 2000-08-27 Last modified: 2010-10-29View all other issues in [string.capacity].
View all issues with CD1 status.
Discussion:
@@ -12404,7 +12503,7 @@ In section 21.3.4, paragraph 1, change
260. Inconsistent return type of istream_iterator::operator++(int)
Section: 24.6.1.2 [istream.iterator.ops] Status: CD1 - Submitter: Martin Sebor Opened: 2000-08-27 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-08-27 Last modified: 2010-10-29View all other issues in [istream.iterator.ops].
View all issues with CD1 status.
Discussion:
@@ -12430,7 +12529,7 @@ given the Effects clause below (since a temporary is returned). The
261. Missing description of istream_iterator::operator!=
Section: 24.6.1.2 [istream.iterator.ops] Status: CD1 - Submitter: Martin Sebor Opened: 2000-08-27 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-08-27 Last modified: 2010-10-29View all other issues in [istream.iterator.ops].
View all issues with CD1 status.
Discussion:
@@ -12467,7 +12566,8 @@ Add paragraph 7 to the end of section 24.5.1.2 with the following text:
262. Bitmask operator ~ specified incorrectly
Section: 17.5.2.1.3 [bitmask.types] Status: CD1 - Submitter: Beman Dawes Opened: 2000-09-03 Last modified: 2008-09-26
+ Submitter: Beman Dawes Opened: 2000-09-03 Last modified: 2010-10-29 +View all other issues in [bitmask.types].
View all issues with CD1 status.
Discussion:
@@ -12498,7 +12598,7 @@ to:
263. Severe restriction on basic_string reference counting
Section: 21.4 [basic.string] Status: CD1 - Submitter: Kevlin Henney Opened: 2000-09-04 Last modified: 2008-09-26
+ Submitter: Kevlin Henney Opened: 2000-09-04 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with CD1 status.
Discussion:
@@ -12579,7 +12679,7 @@ Change the following sentence in 21.3 paragraph 5 from
264. Associative container insert(i, j) complexity requirements are not feasible.
Section: 23.2.4 [associative.reqmts] Status: CD1 - Submitter: John Potter Opened: 2000-09-07 Last modified: 2008-09-26
+ Submitter: John Potter Opened: 2000-09-07 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with CD1 status.
@@ -12633,9 +12733,8 @@ linear in some special cases.
265. std::pair::pair() effects overly restrictive
-Section: 20.3.4 [pairs] Status: CD1 - Submitter: Martin Sebor Opened: 2000-09-11 Last modified: 2008-09-26
-View other active issues in [pairs].
+Section: 20.3.5 [pairs] Status: CD1 + Submitter: Martin Sebor Opened: 2000-09-11 Last modified: 2010-10-29
View all other issues in [pairs].
View all issues with CD1 status.
Discussion:
@@ -12684,8 +12783,8 @@ the straightforward implementation is correct.
266. bad_exception::~bad_exception() missing Effects clause
-Section: 18.8.2.1 [bad.exception] Status: CD1 - Submitter: Martin Sebor Opened: 2000-09-24 Last modified: 2008-09-26
+Section: 18.8.2 [bad.exception] Status: CD1 + Submitter: Martin Sebor Opened: 2000-09-24 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
@@ -12701,7 +12800,7 @@ Remove the destructor from the class synopses of bad_alloc (18.6.2.1 [bad.alloc]), bad_cast (18.7.2 [bad.cast]), bad_typeid (18.7.3 [bad.typeid]), -and bad_exception (18.8.2.1 [bad.exception]). +and bad_exception (18.8.2 [bad.exception]).
@@ -12720,7 +12819,7 @@ described in clause 19.
268. Typo in locale synopsis
Section: 22.3.1 [locale] Status: CD1 - Submitter: Martin Sebor Opened: 2000-10-05 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-10-05 Last modified: 2010-10-29View all other issues in [locale].
View all issues with CD1 status.
Discussion:
@@ -12751,7 +12850,7 @@ are missing.
270. Binary search requirements overly strict
Section: 25.4.3 [alg.binary.search] Status: CD1 - Submitter: Matt Austern Opened: 2000-10-18 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 2000-10-18 Last modified: 2010-10-29View all other issues in [alg.binary.search].
View all issues with CD1 status.
Duplicate of: 472
@@ -13018,7 +13117,7 @@ part of that pair is the lower bound.
271. basic_iostream missing typedefs
Section: 27.7.1.5 [iostreamclass] Status: CD1 - Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -13047,7 +13146,7 @@ basic_iostream<T>::traits_type is ambiguous.
272. Missing parentheses around subexpression
Section: 27.5.4.3 [iostate.flags] Status: CD1 - Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2010-10-29View all other issues in [iostate.flags].
View all issues with CD1 status.
Duplicate of: 569
@@ -13076,7 +13175,7 @@ Add parentheses like so: rdstate()==(state|ios_base::badbit).
273. Missing ios_base qualification on members of a dependent class
Section: 27 [input.output] Status: CD1 - Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2010-10-29View all other issues in [input.output].
View all issues with CD1 status.
Discussion:
@@ -13095,8 +13194,8 @@ members, i.e., ios_base.
274. a missing/impossible allocator requirement
-Section: 20.2.2 [allocator.requirements] Status: CD1 - Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2008-09-26
+Section: 20.2.5 [allocator.requirements] Status: CD1 + Submitter: Martin Sebor Opened: 2000-11-02 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with CD1 status.
Discussion:
@@ -13167,7 +13266,7 @@ excluded from the PR.]
275. Wrong type in num_get::get() overloads
Section: 22.4.2.1.1 [facet.num.get.members] Status: CD1 - Submitter: Matt Austern Opened: 2000-11-02 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 2000-11-02 Last modified: 2010-10-29View all other issues in [facet.num.get.members].
View all issues with CD1 status.
Discussion:
@@ -13226,14 +13325,13 @@ the arguments it was given.
276. Assignable requirement for container value type overly strict
Section: 23.2 [container.requirements] Status: CD1 - Submitter: Peter Dimov Opened: 2000-11-07 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+ Submitter: Peter Dimov Opened: 2000-11-07 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with CD1 status.
Discussion:
23.1/3 states that the objects stored in a container must be -Assignable. 23.4.1 [map], paragraph 2, +Assignable. 23.6.1 [map], paragraph 2, states that map satisfies all requirements for a container, while in the same time defining value_type as pair<const Key, T> - a type that is not Assignable. @@ -13382,8 +13480,7 @@ implement vector::push_back in terms of
278. What does iterator validity mean?
Section: 23.3.4.4 [list.ops] Status: CD1 - Submitter: P.J. Plauger Opened: 2000-11-27 Last modified: 2008-09-30
-View other active issues in [list.ops].
+ Submitter: P.J. Plauger Opened: 2000-11-27 Last modified: 2010-10-29View all other issues in [list.ops].
View all issues with CD1 status.
Discussion:
@@ -13453,7 +13550,7 @@ the wording. Dave provided new wording.]
280. Comparison of reverse_iterator to const reverse_iterator
Section: 24.5.1 [reverse.iterators] Status: CD1 - Submitter: Steve Cleary Opened: 2000-11-27 Last modified: 2008-09-26
+ Submitter: Steve Cleary Opened: 2000-11-27 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -13533,7 +13630,7 @@ this solution is safe and correct.
281. std::min() and max() requirements overly restrictive
Section: 25.4.7 [alg.min.max] Status: CD1 - Submitter: Martin Sebor Opened: 2000-12-02 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-12-02 Last modified: 2010-10-29View all other issues in [alg.min.max].
View all issues with CD1 status.
Duplicate of: 486
@@ -13564,8 +13661,7 @@ is unnecessary.
282. What types does numpunct grouping refer to?
Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: CD1 - Submitter: Howard Hinnant Opened: 2000-12-05 Last modified: 2008-09-26
-View other active issues in [facet.num.put.virtuals].
+ Submitter: Howard Hinnant Opened: 2000-12-05 Last modified: 2010-10-29View all other issues in [facet.num.put.virtuals].
View all issues with CD1 status.
Discussion:
@@ -13623,7 +13719,7 @@ Howard, Bill, Pete, Benjamin, Nathan, Dietmar, Boris, and Martin.]
283. std::replace() requirement incorrect/insufficient
Section: 25.3.5 [alg.replace] Status: CD1 - Submitter: Martin Sebor Opened: 2000-12-15 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-12-15 Last modified: 2010-10-29View all other issues in [alg.replace].
View all issues with CD1 status.
Duplicate of: 483
@@ -13784,11 +13880,11 @@ imposing a greater restriction that what the standard currently says
284. unportable example in 20.3.7, p6
-Section: 20.7.7 [comparisons] Status: CD1 - Submitter: Martin Sebor Opened: 2000-12-26 Last modified: 2008-09-26
+Section: 20.8.6 [comparisons] Status: CD1 + Submitter: Martin Sebor Opened: 2000-12-26 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
-The example in 20.7.7 [comparisons], p6 shows how to use the C +
The example in 20.8.6 [comparisons], p6 shows how to use the C library function strcmp() with the function pointer adapter ptr_fun(). But since it's unspecified whether the C library functions have extern "C" or extern @@ -13800,7 +13896,7 @@ well-formed is unspecified.
Proposed resolution:
-Change 20.7.7 [comparisons] paragraph 6 from:
+Change 20.8.6 [comparisons] paragraph 6 from:
[Example:
replace_if(v.begin(), v.end(), not1(bind2nd(ptr_fun(strcmp), "C")), "C++"); @@ -13840,7 +13936,7 @@ it corresponds to the new code fragment.]-
285. minor editorial errors in fstream ctors
Section: 27.9.1.7 [ifstream.cons] Status: CD1 - Submitter: Martin Sebor Opened: 2000-12-31 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2000-12-31 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
27.9.1.7 [ifstream.cons], p2, 27.9.1.11 [ofstream.cons], p2, and @@ -13869,7 +13965,7 @@ paragraphs mentioned above.
286. <cstdlib> requirements missing size_t typedef
Section: 25.5 [alg.c.library] Status: CD1 - Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2008-09-26
+ Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2010-10-29View all other issues in [alg.c.library].
View all issues with CD1 status.
Discussion:
@@ -13899,7 +13995,7 @@ the type size_t <cstdlib> to Table 97 (section C.2).
288. <cerrno> requirements missing macro EILSEQ
Section: 19.4 [errno] Status: CD1 - Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2008-09-26
+ Submitter: Judy Ward Opened: 2000-12-30 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -13928,7 +14024,7 @@ and Table 95 (section C.2) "Standard Macros" to include EILSEQ.
291. Underspecification of set algorithms
Section: 25.4.5 [alg.set.operations] Status: CD1 - Submitter: Matt Austern Opened: 2001-01-03 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 2001-01-03 Last modified: 2010-10-29View all other issues in [alg.set.operations].
View all issues with CD1 status.
Discussion:
@@ -14044,8 +14140,7 @@ m of these elements from [first2, last2) if m < n.
292. effects of a.copyfmt (a)
Section: 27.5.4.2 [basic.ios.members] Status: CD1 - Submitter: Martin Sebor Opened: 2001-01-05 Last modified: 2008-09-26
-View other active issues in [basic.ios.members].
+ Submitter: Martin Sebor Opened: 2001-01-05 Last modified: 2010-10-29View all other issues in [basic.ios.members].
View all issues with CD1 status.
Discussion:
@@ -14084,7 +14179,8 @@ objects of rhs, except that...
294. User defined macros and standard headers
Section: 17.6.3.3.1 [macro.names] Status: CD1 - Submitter: James Kanze Opened: 2001-01-11 Last modified: 2008-09-26
+ Submitter: James Kanze Opened: 2001-01-11 Last modified: 2010-10-29 +View all other issues in [macro.names].
View all issues with CD1 status.
Discussion:
Paragraph 2 of 17.6.3.3.1 [macro.names] reads: "A @@ -14143,7 +14239,7 @@ it isn't stringent enough.
295. Is abs defined in <cmath>?
Section: 26.8 [c.math] Status: CD1 - Submitter: Jens Maurer Opened: 2001-01-12 Last modified: 2008-09-26
+ Submitter: Jens Maurer Opened: 2001-01-12 Last modified: 2010-10-29View all other issues in [c.math].
View all issues with CD1 status.
Discussion:
@@ -14178,10 +14274,172 @@ putting in <cstdlib>. That's issue 296. Missing descriptions and requirements of pair operators +Section: 20.3.5 [pairs] Status: WP + Submitter: Martin Sebor Opened: 2001-01-14 Last modified: 2010-10-29
+View all other issues in [pairs].
+View all issues with WP status.
+Discussion:
+The synopsis of the header <utility> in 20.3 [utility] +lists the complete set of equality and relational operators for pair +but the section describing the template and the operators only describes +operator==() and operator<(), and it fails to mention +any requirements on the template arguments. The remaining operators are +not mentioned at all. +
+ +[ +2009-09-27 Alisdair reopens. +]
+ + +++ ++The issue is a lack of wording specifying the semantics of std::pair +relational operators. The rationale is that this is covered by +catch-all wording in the relops component, and that as relops directly +precedes pair in the document this is an easy connection to make. +
+ ++Reading the current working paper I make two observations: +
+ ++
+ +- +relops no longer immediately precedes pair in the order of +specification. However, even if it did, there is a lot of pair +specification itself between the (apparently) unrelated relops and the +relational operators for pair. (The catch-all still requires +operator== and operator< to be specified +explicitly) +
+ +- +No other library component relies on the catch-all clause. The following +all explicitly document all six relational operators, usually in a +manner that could have deferred to the relops clause. +
++ +tuple +unique_ptr +duration +time_point +basic_string +queue +stack +move_iterator +reverse_iterator +regex submatch +thread::id ++The container components provide their own (equivalent) definition in +23.2.1 [container.requirements.general] Table 90 -- Container +requirements and do so do not defer to relops. +
+ ++Shared_ptr explicitly documents operator!= and does +not supply the other 3 missing operators +(>,>=,<=) so does not meet the +reqirements of the relops clause. +
+ ++Weak_ptr only supports operator< so would not be +covered by relops. +
+ ++At the very least I would request a note pointing to the relops clause +we rely on to provide this definition. If this route is taken, I would +recommend reducing many of the above listed clauses to a similar note +rather than providing redundant specification. +
+ ++My preference would be to supply the 4 missing specifications consistent +with the rest of the library. +
+ +[ +2009-10-11 Daniel opens 1233 which deals with the same issue as +it pertains to unique_ptr. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready ++ + + +Proposed resolution:
++After p20 20.3.5 [pairs] add: +
+ ++ + +template <class T1, class T2> +bool operator!=(const pair<T1,T2>& x, const pair<T1,T2>& y); ++ ++Returns: !(x==y) ++ +template <class T1, class T2> +bool operator> (const pair<T1,T2>& x, const pair<T1,T2>& y); ++ ++Returns: y < x ++ +template <class T1, class T2> +bool operator>=(const pair<T1,T2>& x, const pair<T1,T2>& y); ++ ++Returns: !(x < y) ++ +template <class T1, class T2> +bool operator<=(const pair<T1,T2>& x, const pair<T1,T2>& y); ++ ++Returns: !(y < x) ++Rationale:
+20.3.1 [operators] paragraph 10 already specifies the semantics. +That paragraph says that, if declarations of operator!=, operator>, +operator<=, and operator>= appear without definitions, they are +defined as specified in 20.3.1 [operators]. There should be no user +confusion, since that paragraph happens to immediately precede the +specification of pair.
+ + + + +
297. const_mem_fun_t<>::argument_type should be const T*
-Section: 20.7.8 [logical.operations] Status: CD1 - Submitter: Martin Sebor Opened: 2001-01-06 Last modified: 2008-09-26
+Section: 20.8.7 [logical.operations] Status: CD1 + Submitter: Martin Sebor Opened: 2001-01-06 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
The class templates const_mem_fun_t in 20.5.8, p8 and @@ -14264,7 +14522,7 @@ and the argument type itself, are not the same.
298. ::operator delete[] requirement incorrect/insufficient
Section: 18.6.1.2 [new.delete.array] Status: CD1 - Submitter: John A. Pedretti Opened: 2001-01-10 Last modified: 2008-09-26
+ Submitter: John A. Pedretti Opened: 2001-01-10 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -14314,8 +14572,7 @@ or operator delete(ptr, std::nothrow) respectively.
300. list::merge() specification incomplete
Section: 23.3.4.4 [list.ops] Status: CD1 - Submitter: John Pedretti Opened: 2001-01-23 Last modified: 2008-09-26
-View other active issues in [list.ops].
+ Submitter: John Pedretti Opened: 2001-01-23 Last modified: 2010-10-29View all other issues in [list.ops].
View all issues with CD1 status.
Discussion:
@@ -14376,7 +14633,7 @@ list" is excessively vague.]
301. basic_string template ctor effects clause omits allocator argument
Section: 21.4.1 [string.require] Status: CD1 - Submitter: Martin Sebor Opened: 2001-01-27 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-01-27 Last modified: 2010-10-29View all other issues in [string.require].
View all issues with CD1 status.
Discussion:
@@ -14413,8 +14670,8 @@ a mistake.
303. Bitset input operator underspecified
-Section: 20.3.7.3 [bitset.operators] Status: CD1 - Submitter: Matt Austern Opened: 2001-02-05 Last modified: 2008-09-26
+Section: 20.5.4 [bitset.operators] Status: CD1 + Submitter: Matt Austern Opened: 2001-02-05 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
@@ -14533,7 +14790,7 @@ consequence of the design choice.
305. Default behavior of codecvt<wchar_t, char, mbstate_t>::length()
Section: 22.4.1.5 [locale.codecvt.byname] Status: CD1 - Submitter: Howard Hinnant Opened: 2001-01-24 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2001-01-24 Last modified: 2010-10-29View all other issues in [locale.codecvt.byname].
View all issues with CD1 status.
Discussion:
@@ -14661,7 +14918,7 @@ example, and it would rule out a fixed-width encoding of UCS-4.
306. offsetof macro and non-POD types
Section: 18.2 [support.types] Status: CD1 - Submitter: Steve Clamage Opened: 2001-02-21 Last modified: 2008-09-26
+ Submitter: Steve Clamage Opened: 2001-02-21 Last modified: 2010-10-29View all other issues in [support.types].
View all issues with CD1 status.
Discussion:
@@ -14699,7 +14956,7 @@ possible.]
307. Lack of reference typedefs in container adaptors
Section: 23.3.4 [list] Status: CD1 - Submitter: Howard Hinnant Opened: 2001-03-13 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2001-03-13 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -14971,7 +15228,7 @@ and it was deliberately not adopted. Nevertheless, the LWG believes
308. Table 82 mentions unrelated headers
Section: 27 [input.output] Status: CD1 - Submitter: Martin Sebor Opened: 2001-03-15 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-03-15 Last modified: 2010-10-29View all other issues in [input.output].
View all issues with CD1 status.
Discussion:
@@ -15003,7 +15260,7 @@ section 27.9 [file.streams], including 27.9.2 [c.files].]
310. Is errno a macro?
Section: 17.6.1.2 [headers], 19.4 [errno] Status: CD1 - Submitter: Steve Clamage Opened: 2001-03-21 Last modified: 2008-09-26
+ Submitter: Steve Clamage Opened: 2001-03-21 Last modified: 2010-10-29View all other issues in [headers].
View all issues with CD1 status.
Discussion:
@@ -15106,7 +15363,7 @@ to be a macro.
311. Incorrect wording in basic_ostream class synopsis
Section: 27.7.2.1 [ostream] Status: CD1 - Submitter: Andy Sawyer Opened: 2001-03-21 Last modified: 2008-09-26
+ Submitter: Andy Sawyer Opened: 2001-03-21 Last modified: 2010-10-29View all other issues in [ostream].
View all issues with CD1 status.
Discussion:
@@ -15148,13 +15405,13 @@ comment in c++std-lib-8939.
312. Table 27 is missing headers
Section: 20 [utilities] Status: CD1 - Submitter: Martin Sebor Opened: 2001-03-29 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-03-29 Last modified: 2010-10-29View all other issues in [utilities].
View all issues with CD1 status.
Discussion:
Table 27 in section 20 lists the header <memory> (only) for Memory (lib.memory) but neglects to mention the headers -<cstdlib> and <cstring> that are discussed in 20.6.5 [meta.rel].
+<cstdlib> and <cstring> that are discussed in 20.7.6 [meta.rel].Proposed resolution:
@@ -15168,8 +15425,7 @@ as <memory>.
315. Bad "range" in list::unique complexity
Section: 23.3.4.4 [list.ops] Status: CD1 - Submitter: Andy Sawyer Opened: 2001-05-01 Last modified: 2008-09-26
-View other active issues in [list.ops].
+ Submitter: Andy Sawyer Opened: 2001-05-01 Last modified: 2010-10-29View all other issues in [list.ops].
View all issues with CD1 status.
Discussion:
@@ -15196,7 +15452,7 @@ Change the "range" from (last - first) to [first, last).
316. Vague text in Table 69
Section: 23.2.4 [associative.reqmts] Status: CD1 - Submitter: Martin Sebor Opened: 2001-05-04 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-05-04 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with CD1 status.
@@ -15229,7 +15485,7 @@ takes place...
317. Instantiation vs. specialization of facets
Section: 22 [localization] Status: CD1 - Submitter: Martin Sebor Opened: 2001-05-04 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-05-04 Last modified: 2010-10-29View all other issues in [localization].
View all issues with CD1 status.
Discussion:
@@ -15295,7 +15551,7 @@ change.
318. Misleading comment in definition of numpunct_byname
Section: 22.4.3.2 [locale.numpunct.byname] Status: CD1 - Submitter: Martin Sebor Opened: 2001-05-12 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-05-12 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
The definition of the numpunct_byname template contains the following @@ -15323,7 +15579,7 @@ resolution of library issue 319. Storage allocation wording confuses "Required behavior", "Requires"
Section: 18.6.1.1 [new.delete.single], 18.6.1.2 [new.delete.array] Status: CD1 - Submitter: Beman Dawes Opened: 2001-05-15 Last modified: 2008-09-26
+ Submitter: Beman Dawes Opened: 2001-05-15 Last modified: 2010-10-29View all other issues in [new.delete.single].
View all issues with CD1 status.
Discussion:
@@ -15371,7 +15627,7 @@ should be specified as "Requires".
320. list::assign overspecified
Section: 23.3.4.1 [list.cons] Status: CD1 - Submitter: Howard Hinnant Opened: 2001-05-17 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2001-05-17 Last modified: 2010-10-29View all other issues in [list.cons].
View all issues with CD1 status.
Discussion:
@@ -15468,8 +15724,7 @@ Changes not deemed serious enough to requre rereview.]
321. Typo in num_get
Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: CD1 - Submitter: Kevin Djang Opened: 2001-05-17 Last modified: 2008-09-26
-View other active issues in [facet.num.get.virtuals].
+ Submitter: Kevin Djang Opened: 2001-05-17 Last modified: 2010-10-29View all other issues in [facet.num.get.virtuals].
View all issues with CD1 status.
Discussion:
@@ -15499,8 +15754,7 @@ to be "A length modifier is added ..."
322. iterator and const_iterator should have the same value type
Section: 23.2 [container.requirements] Status: CD1 - Submitter: Matt Austern Opened: 2001-05-17 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+ Submitter: Matt Austern Opened: 2001-05-17 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with CD1 status.
Discussion:
@@ -15545,8 +15799,8 @@ requires that iterator_traits<const int*>::value_type is int.
324. Do output iterators have value types?
-Section: 24.2.2 [output.iterators] Status: CD1 - Submitter: Dave Abrahams Opened: 2001-06-07 Last modified: 2008-09-26
+Section: 24.2.4 [output.iterators] Status: CD1 + Submitter: Dave Abrahams Opened: 2001-06-07 Last modified: 2010-10-29
View all other issues in [output.iterators].
View all issues with CD1 status.
Discussion:
@@ -15679,7 +15933,7 @@ decision.
325. Misleading text in moneypunct<>::do_grouping
Section: 22.4.6.3.2 [locale.moneypunct.virtuals] Status: CD1 - Submitter: Martin Sebor Opened: 2001-07-02 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-07-02 Last modified: 2010-10-29View all other issues in [locale.moneypunct.virtuals].
View all issues with CD1 status.
Discussion:
@@ -15744,7 +15998,7 @@ integers, not ASCII characters.
327. Typo in time_get facet in table 52
Section: 22.3.1.1.1 [locale.category] Status: CD1 - Submitter: Tiki Wan Opened: 2001-07-06 Last modified: 2008-09-26
+ Submitter: Tiki Wan Opened: 2001-07-06 Last modified: 2010-10-29View all other issues in [locale.category].
View all issues with CD1 status.
Duplicate of: 447
@@ -15779,7 +16033,7 @@ a typo, wchart instead of wchar_t.]
328. Bad sprintf format modifier in money_put<>::do_put()
Section: 22.4.6.2.2 [locale.money.put.virtuals] Status: CD1 - Submitter: Martin Sebor Opened: 2001-07-07 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-07-07 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
The sprintf format string , "%.01f" (that's the digit one), in the @@ -15802,18 +16056,18 @@ modifier.
329. vector capacity, reserve and reallocation
-Section: 23.3.6.2 [vector.capacity], 23.3.6.4 [vector.modifiers] Status: CD1 - Submitter: Anthony Williams Opened: 2001-07-13 Last modified: 2008-09-26
+Section: 23.4.1.2 [vector.capacity], 23.4.1.4 [vector.modifiers] Status: CD1 + Submitter: Anthony Williams Opened: 2001-07-13 Last modified: 2010-10-29
View all other issues in [vector.capacity].
View all issues with CD1 status.
Discussion:
There is an apparent contradiction about which circumstances can cause -a reallocation of a vector in Section 23.3.6.2 [vector.capacity] and -section 23.3.6.4 [vector.modifiers]. +a reallocation of a vector in Section 23.4.1.2 [vector.capacity] and +section 23.4.1.4 [vector.modifiers].
-23.3.6.2 [vector.capacity],p5 says:
+23.4.1.2 [vector.capacity],p5 says:
Notes: Reallocation invalidates all the references, pointers, and iterators referring to the elements in the sequence. It is guaranteed that no @@ -15833,7 +16087,7 @@ greater than the size specified in the most recent call to reserve().
then the implementation may reallocate the vector for the insert, as the size specified in the previous call to reserve was zero.
-However, the previous paragraphs (23.3.6.2 [vector.capacity], p1-2) state:
+However, the previous paragraphs (23.4.1.2 [vector.capacity], p1-2) state:
(capacity) Returns: The total number of elements the vector @@ -15849,7 +16103,7 @@ of capacity() otherwise...
This implies that vec.capacity() is still 23, and so the insert() should not require a reallocation, as vec.size() is 0. This is backed -up by 23.3.6.4 [vector.modifiers], p1: +up by 23.4.1.4 [vector.modifiers], p1:
(insert) Notes: Causes reallocation if the new size is greater than the old @@ -15864,7 +16118,7 @@ than the old capacity, I think the intent is clear.
Proposed resolution:
-Change the wording of 23.3.6.2 [vector.capacity] paragraph 5 to:
+Change the wording of 23.4.1.2 [vector.capacity] paragraph 5 to:
Notes: Reallocation invalidates all the references, pointers, and @@ -15898,12 +16152,12 @@ reallocation guarantees was inadvertant.
331. bad declaration of destructor for ios_base::failure
Section: 27.5.2.1.1 [ios::failure] Status: CD1 - Submitter: PremAnand M. Rao Opened: 2001-08-23 Last modified: 2008-09-26
+ Submitter: PremAnand M. Rao Opened: 2001-08-23 Last modified: 2010-10-29View all other issues in [ios::failure].
View all issues with CD1 status.
Discussion:
-With the change in 17.6.4.11 [res.on.exception.handling] to state +With the change in 17.6.4.12 [res.on.exception.handling] to state "An implementation may strengthen the exception-specification for a non-virtual function by removing listed exceptions." (issue 119) @@ -15948,7 +16202,7 @@ of other classes derived from exception are handled.
333. does endl imply synchronization with the device?
Section: 27.7.2.8 [ostream.manip] Status: CD1 - Submitter: PremAnand M. Rao Opened: 2001-08-27 Last modified: 2008-09-26
+ Submitter: PremAnand M. Rao Opened: 2001-08-27 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
A footnote in 27.7.2.8 [ostream.manip] states:
@@ -15996,8 +16250,8 @@ does.
334. map::operator[] specification forces inefficient implementation
-Section: 23.4.1.2 [map.access] Status: CD1 - Submitter: Andrea Griffini Opened: 2001-09-02 Last modified: 2008-09-26
+Section: 23.6.1.2 [map.access] Status: CD1 + Submitter: Andrea Griffini Opened: 2001-09-02 Last modified: 2010-10-29
View all other issues in [map.access].
View all issues with CD1 status.
Discussion:
@@ -16079,7 +16333,7 @@ non-conforming.Proposed resolution:
-Replace 23.4.1.2 [map.access] paragraph 1 with +Replace 23.6.1.2 [map.access] paragraph 1 with
@@ -16120,7 +16374,7 @@ we are no longer defining operator[] in terms of
335. minor issue with char_traits, table 37
Section: 21.2.1 [char.traits.require] Status: CD1 - Submitter: Andy Sawyer Opened: 2001-09-06 Last modified: 2008-09-26
+ Submitter: Andy Sawyer Opened: 2001-09-06 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -16170,7 +16424,7 @@ and char_traits<wchar_t> in 21.1.3.2...)
336. Clause 17 lack of references to deprecated headers
Section: 17 [library] Status: CD1 - Submitter: Detlef Vollmann Opened: 2001-09-05 Last modified: 2008-09-26
+ Submitter: Detlef Vollmann Opened: 2001-09-05 Last modified: 2010-10-29View other active issues in [library].
View all other issues in [library].
View all issues with CD1 status.
@@ -16206,7 +16460,7 @@ library (though a deprecated one).- 17.6.1.2 [headers] Headers/4
- 17.6.3.6 [replacement.functions] Replacement functions/1
- 17.6.4.4 [global.functions] Global or non-member functions/2
-- 17.6.4.9 [protection.within.classes] Protection within classes/1
+- 17.6.4.10 [protection.within.classes] Protection within classes/1
@@ -16218,7 +16472,7 @@ library (though a deprecated one).
337. replace_copy_if's template parameter should be InputIterator
Section: 25.3.5 [alg.replace] Status: CD1 - Submitter: Detlef Vollmann Opened: 2001-09-07 Last modified: 2008-09-26
+ Submitter: Detlef Vollmann Opened: 2001-09-07 Last modified: 2010-10-29View all other issues in [alg.replace].
View all issues with CD1 status.
Discussion:
@@ -16242,7 +16496,7 @@ parameter name conveys real normative meaning.
338. is whitespace allowed between `-' and a digit?
Section: 22.4 [locale.categories] Status: CD1 - Submitter: Martin Sebor Opened: 2001-09-17 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-09-17 Last modified: 2010-10-29View all other issues in [locale.categories].
View all issues with CD1 status.
Discussion:
@@ -16260,9 +16514,7 @@ The text needs to be clarified to either consistently allow or disallow whitespace between a plusminus and a sign. It might be worthwhile to consider the fact that the C library stdio facility does not permit whitespace embedded in numbers and neither does the C or -C++ core language (the syntax of integer-literals is given in 2.14.2 -[lex.icon], that of floating-point-literals in 2.14.4 [lex.fcon] of the -C++ standard). +C++ core language (the syntax of integer-literals is given in 2.14.2 [lex.icon], that of floating-point-literals in 2.14.4 [lex.fcon] of the C++ standard). @@ -16317,14 +16569,13 @@ resolution removes all mention of "whitespace" from that format.
339. definition of bitmask type restricted to clause 27
Section: 22.4.1 [category.ctype], 17.5.2.1.3 [bitmask.types] Status: CD1 - Submitter: Martin Sebor Opened: 2001-09-17 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-09-17 Last modified: 2010-10-29View all other issues in [category.ctype].
View all issues with CD1 status.
Discussion:
-The ctype_category::mask type is declared to be an enum in 22.4.1 -[category.ctype] with p1 then stating that it is a bitmask type, most -likely referring to the definition of bitmask type in 17.5.2.1.3 -[bitmask.types], p1. However, the said definition only applies to +
+The ctype_category::mask type is declared to be an enum in 22.4.1 [category.ctype] with p1 then stating that it is a bitmask type, most +likely referring to the definition of bitmask type in 17.5.2.1.3 [bitmask.types], p1. However, the said definition only applies to clause 27, making the reference in 22.2.1 somewhat dubious.
@@ -16334,7 +16585,7 @@ clause 27, making the reference in 22.2.1 somewhat dubious.Several types defined in clause 27 are bitmask types. Each bitmask type can be implemented as an enumerated type that overloads certain operators, - as an integer type, or as a bitset (20.3.7 [template.bitset]). + as an integer type, or as a bitset (20.5 [template.bitset]).
to read
@@ -16391,7 +16642,7 @@ consistent with the rest of the standard.]
340. interpretation of has_facet<Facet>(loc)
Section: 22.3.1.1.1 [locale.category] Status: CD1 - Submitter: Martin Sebor Opened: 2001-09-18 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-09-18 Last modified: 2010-10-29View all other issues in [locale.category].
View all issues with CD1 status.
Discussion:
@@ -16462,8 +16713,8 @@ complete list of the ones we need.
341. Vector reallocation and swap
-Section: 23.3.6.2 [vector.capacity] Status: CD1 - Submitter: Anthony Williams Opened: 2001-09-27 Last modified: 2008-09-26
+Section: 23.4.1.2 [vector.capacity] Status: CD1 + Submitter: Anthony Williams Opened: 2001-09-27 Last modified: 2010-10-29
View all other issues in [vector.capacity].
View all issues with CD1 status.
Discussion:
@@ -16475,7 +16726,7 @@ an empty one: // vec is now empty, with minimal capacityHowever, the wording of 23.3.6.2 [vector.capacity]paragraph 5 prevents +
However, the wording of 23.4.1.2 [vector.capacity]paragraph 5 prevents the capacity of a vector being reduced, following a call to reserve(). This invalidates the idiom, as swap() is thus prevented from reducing the capacity. The proposed wording for issue 329 does not affect this. Consequently, the example above @@ -16508,7 +16759,7 @@ referred to one vector now refer to the other, and vice-versa.
Proposed resolution:
-Add a new paragraph after 23.3.6.2 [vector.capacity] paragraph 5:
+Add a new paragraph after 23.4.1.2 [vector.capacity] paragraph 5:
void swap(vector<T,Allocator>& x);@@ -16537,20 +16788,20 @@ the two vectors, including their reallocation guarantees.
345. type tm in <cwchar>
-Section: 21.6 [c.strings] Status: CD1 - Submitter: Clark Nelson Opened: 2001-10-19 Last modified: 2008-09-26
+Section: 21.7 [c.strings] Status: CD1 + Submitter: Clark Nelson Opened: 2001-10-19 Last modified: 2010-10-29
View all other issues in [c.strings].
View all issues with CD1 status.
Discussion:
-C99, and presumably amendment 1 to C90, specify that <wchar.h> -declares struct tm as an incomplete type. However, table 48 in 21.6 -[c.strings] does not mention the type tm as being declared in +
+C99, and presumably amendment 1 to C90, specify that <wchar.h> +declares struct tm as an incomplete type. However, table 48 in 21.7 [c.strings] does not mention the type tm as being declared in <cwchar>. Is this omission intentional or accidental?
Proposed resolution:
-In section 21.6 [c.strings], add "tm" to table 48.
+In section 21.7 [c.strings], add "tm" to table 48.
@@ -16559,7 +16810,7 @@ declares struct tm as an incomplete type. However, table 48 in 21.6
346. Some iterator member functions should be const
Section: X [iterator.concepts] Status: CD1 - Submitter: Jeremy Siek Opened: 2001-10-20 Last modified: 2008-09-30
+ Submitter: Jeremy Siek Opened: 2001-10-20 Last modified: 2010-10-29View all other issues in [iterator.concepts].
View all issues with CD1 status.
Discussion:
@@ -16612,7 +16863,7 @@ the same problem appears there.]
347. locale::category and bitmask requirements
Section: 22.3.1.1.1 [locale.category] Status: CD1 - Submitter: P.J. Plauger, Nathan Myers Opened: 2001-10-23 Last modified: 2008-09-26
+ Submitter: P.J. Plauger, Nathan Myers Opened: 2001-10-23 Last modified: 2010-10-29View all other issues in [locale.category].
View all issues with CD1 status.
Discussion:
@@ -16715,7 +16966,7 @@ of the other enumerated values; implementations may add extra categories.]
349. Minor typographical error in ostream_iterator
Section: 24.6.2 [ostream.iterator] Status: CD1 - Submitter: Andy Sawyer Opened: 2001-10-24 Last modified: 2008-09-26
+ Submitter: Andy Sawyer Opened: 2001-10-24 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
24.5.2 [lib.ostream.iterator] states:
@@ -16743,7 +16994,7 @@ In 24.6.2 [ostream.iterator], replace const char* delim with
352. missing fpos requirements
Section: 21.2.2 [char.traits.typedefs] Status: CD1 - Submitter: Martin Sebor Opened: 2001-12-02 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2001-12-02 Last modified: 2010-10-29View all other issues in [char.traits.typedefs].
View all issues with CD1 status.
Discussion:
@@ -16797,10 +17048,65 @@ be considered NAD. +
+353. std::pair missing template assignment
+Section: 20.3.5 [pairs] Status: Resolved + Submitter: Martin Sebor Opened: 2001-12-02 Last modified: 2010-11-19
+View all other issues in [pairs].
+View all issues with Resolved status.
+Discussion:
++The class template std::pair defines a template ctor (20.2.2, p4) but +no template assignment operator. This may lead to inefficient code since +assigning an object of pair<C, D> to pair<A, B> +where the types C and D are distinct from but convertible to +A and B, respectively, results in a call to the template copy +ctor to construct an unnamed temporary of type pair<A, B> +followed by an ordinary (perhaps implicitly defined) assignment operator, +instead of just a straight assignment. +
+ + +Proposed resolution:
++Add the following declaration to the definition of std::pair: +
+template<class U, class V> + pair& operator=(const pair<U, V> &p); +++And also add a paragraph describing the effects of the function template to the +end of 20.2.2: +
+template<class U, class V> + pair& operator=(const pair<U, V> &p); +++ Effects: first = p.first; + second = p.second; + Returns: *this +
+ +[Curaçao: There is no indication this is was anything other than +a design decision, and thus NAD. May be appropriate for a future +standard.]
+ + +[ +Pre Bellevue: It was recognized that this was taken care of by +N1856, +and thus moved from NAD Future to
+ + + + + +NAD EditorialResolved. +]
354. Associative container lower/upper bound requirements
Section: 23.2.4 [associative.reqmts] Status: CD1 - Submitter: Hans Aberg Opened: 2001-12-17 Last modified: 2008-09-26
+ Submitter: Hans Aberg Opened: 2001-12-17 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with CD1 status.
@@ -16867,8 +17173,7 @@ key greater than k, or a.end() if such an element is not found.
355. Operational semantics for a.back()
Section: 23.2.3 [sequence.reqmts] Status: CD1 - Submitter: Yaroslav Mironov Opened: 2002-01-23 Last modified: 2008-09-26
-View other active issues in [sequence.reqmts].
+ Submitter: Yaroslav Mironov Opened: 2002-01-23 Last modified: 2010-10-29View all other issues in [sequence.reqmts].
View all issues with CD1 status.
Discussion:
@@ -16950,8 +17255,7 @@ LWG would like a new issue opened.]
358. interpreting thousands_sep after a decimal_point
Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: CD1 - Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2008-09-26
-View other active issues in [facet.num.get.virtuals].
+ Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2010-10-29View all other issues in [facet.num.get.virtuals].
View all issues with CD1 status.
Discussion:
@@ -17011,7 +17315,7 @@ Change the first sentence of 22.2.2.1.2, p9 from
359. num_put<>::do_put (..., bool) undocumented
Section: 22.4.2.2.1 [facet.num.put.members] Status: CD1 - Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
22.2.2.2.1, p1:
@@ -17107,7 +17411,7 @@ be a requirement of gratuitous inefficiency.
360. locale mandates inefficient implementation
Section: 22.3.1 [locale] Status: CD1 - Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2002-03-12 Last modified: 2010-10-29View all other issues in [locale].
View all issues with CD1 status.
Discussion:
@@ -17156,13 +17460,13 @@ prevents locale from being implemented efficiently.
362. bind1st/bind2nd type safety
-Section: D.9 [depr.lib.binders] Status: CD1 - Submitter: Andrew Demkin Opened: 2002-04-26 Last modified: 2008-09-26
+Section: D.11 [depr.lib.binders] Status: CD1 + Submitter: Andrew Demkin Opened: 2002-04-26 Last modified: 2010-10-29
View all other issues in [depr.lib.binders].
View all issues with CD1 status.
Discussion:
-The definition of bind1st() (D.9 [depr.lib.binders]) can result in +The definition of bind1st() (D.11 [depr.lib.binders]) can result in the construction of an unsafe binding between incompatible pointer types. For example, given a function whose first parameter type is 'pointer to T', it's possible without error to bind an argument of @@ -17189,19 +17493,17 @@ map its argument to the expected argument type of the bound function
typename Operation::first_argument_type(x)-A functional-style conversion (D.9 [depr.lib.binders]) is defined to -be -semantically equivalent to an explicit cast expression (D.9 -[depr.lib.binders]), which may (according to 5.4, paragraph 5) be -interpreted +
+A functional-style conversion (D.11 [depr.lib.binders]) is defined to be +semantically equivalent to an explicit cast expression (D.11 [depr.lib.binders]), which may (according to 5.4, paragraph 5) be interpreted as a reinterpret_cast, thus masking the error.
-The problem and proposed change also apply to D.9 [depr.lib.binders].
+The problem and proposed change also apply to D.11 [depr.lib.binders].
Proposed resolution:
-Add this sentence to the end of D.9 [depr.lib.binders]/1: +
Add this sentence to the end of D.11 [depr.lib.binders]/1: "Binders bind1st and bind2nd are deprecated in favor of std::tr1::bind."
@@ -17221,7 +17523,7 @@ as a reinterpret_cast, thus masking the error.
363. Missing exception specification in 27.4.2.1.1
Section: 27.5.2.1.1 [ios::failure] Status: CD1 - Submitter: Walter Brown and Marc Paterno Opened: 2002-05-20 Last modified: 2008-09-26
+ Submitter: Walter Brown and Marc Paterno Opened: 2002-05-20 Last modified: 2010-10-29View all other issues in [ios::failure].
View all issues with CD1 status.
Discussion:
@@ -17248,7 +17550,7 @@ declared in this way.
364. Inconsistent wording in 27.5.2.4.2
Section: 27.6.2.4.2 [streambuf.virt.buffer] Status: CD1 - Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2008-09-26
+ Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2010-10-29View all other issues in [streambuf.virt.buffer].
View all issues with CD1 status.
Discussion:
@@ -17294,7 +17596,7 @@ for each class derived from basic_streambuf in this clause
365. Lack of const-qualification in clause 27
Section: 27 [input.output] Status: CD1 - Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2008-09-26
+ Submitter: Walter Brown, Marc Paterno Opened: 2002-05-10 Last modified: 2010-10-29View all other issues in [input.output].
View all issues with CD1 status.
Discussion:
@@ -17347,7 +17649,7 @@ way by providing both overloads; this would be a conforming extension.
369. io stream objects and static ctors
Section: 27.4 [iostream.objects] Status: CD1 - Submitter: Ruslan Abdikeev Opened: 2002-07-08 Last modified: 2008-09-26
+ Submitter: Ruslan Abdikeev Opened: 2002-07-08 Last modified: 2010-10-29View all other issues in [iostream.objects].
View all issues with CD1 status.
Discussion:
@@ -17459,13 +17761,11 @@ do to ensure that stream objects are constructed during startup.
370. Minor error in basic_istream::get
Section: 27.7.1.3 [istream.unformatted] Status: CD1 - Submitter: Ray Lischner Opened: 2002-07-15 Last modified: 2008-09-26
+ Submitter: Ray Lischner Opened: 2002-07-15 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with CD1 status.
Discussion:
-Defect report for description of basic_istream::get (section -27.7.1.3 [istream.unformatted]), paragraph 15. The description for the -get function +
Defect report for description of basic_istream::get (section 27.7.1.3 [istream.unformatted]), paragraph 15. The description for the get function with the following signature:
basic_istream<charT,traits>& get(basic_streambuf<char_type,traits>& @@ -17505,8 +17805,7 @@ with the following signature:
371. Stability of multiset and multimap member functions
Section: 23.2 [container.requirements] Status: CD1 - Submitter: Frank Compagner Opened: 2002-07-20 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+ Submitter: Frank Compagner Opened: 2002-07-20 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with CD1 status.
Discussion:
@@ -17599,7 +17898,7 @@ wording.]
373. Are basic_istream and basic_ostream to use (exceptions()&badbit) != 0 ?
Section: 27.7.1.2.1 [istream.formatted.reqmts], 27.7.2.6.1 [ostream.formatted.reqmts] Status: CD1 - Submitter: Keith Baker Opened: 2002-07-23 Last modified: 2008-09-26
+ Submitter: Keith Baker Opened: 2002-07-23 Last modified: 2010-10-29View all other issues in [istream.formatted.reqmts].
View all issues with CD1 status.
Discussion:
@@ -17630,7 +17929,7 @@ In 27.7.1.2.1 [istream.formatted.reqmts] and 27.7.2.6.1 [ostream.formatted.reqmt
375. basic_ios should be ios_base in 27.7.1.3
Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1 - Submitter: Ray Lischner Opened: 2002-08-14 Last modified: 2008-09-26
+ Submitter: Ray Lischner Opened: 2002-08-14 Last modified: 2010-10-29View all other issues in [stringbuf.virtuals].
View all issues with CD1 status.
Discussion:
@@ -17656,7 +17955,7 @@ paragraph 14 to "ios_base".
376. basic_streambuf semantics
Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1 - Submitter: Ray Lischner Opened: 2002-08-14 Last modified: 2008-09-26
+ Submitter: Ray Lischner Opened: 2002-08-14 Last modified: 2010-10-29View all other issues in [stringbuf.virtuals].
View all issues with CD1 status.
Discussion:
@@ -17706,7 +18005,7 @@ are both true, but case 3 is false.
379. nonsensical ctype::do_widen() requirement
Section: 22.4.1.1.2 [locale.ctype.virtuals] Status: CD1 - Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2010-10-29View all other issues in [locale.ctype.virtuals].
View all issues with CD1 status.
Discussion:
@@ -17762,7 +18061,7 @@ following text:
380. typos in codecvt tables 53 and 54
Section: 22.4.1.5 [locale.codecvt.byname] Status: CD1 - Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2010-10-29View all other issues in [locale.codecvt.byname].
View all issues with CD1 status.
Discussion:
@@ -17800,7 +18099,7 @@ elements was needed to terminate a sequence given the value of state."
381. detection of invalid mbstate_t in codecvt
Section: 22.4.1.5 [locale.codecvt.byname] Status: CD1 - Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2002-09-06 Last modified: 2010-10-29View all other issues in [locale.codecvt.byname].
View all issues with CD1 status.
Discussion:
@@ -17863,8 +18162,8 @@ values, or that choose to detect any other kind of error, may return
383. Bidirectional iterator assertion typo
-Section: 24.2.4 [bidirectional.iterators] Status: CD1 - Submitter: ysapir (submitted via comp.std.c++) Opened: 2002-10-17 Last modified: 2008-09-26
+Section: 24.2.6 [bidirectional.iterators] Status: CD1 + Submitter: ysapir (submitted via comp.std.c++) Opened: 2002-10-17 Last modified: 2010-10-29
View all other issues in [bidirectional.iterators].
View all issues with CD1 status.
Discussion:
@@ -17879,8 +18178,8 @@ with that discussion. I have checked this newsgroup, as well as attempted a search of the Active/Defect/Closed Issues List on the site for the words "s is derefer" so I believe this has not been proposed before. Furthermore, -the "Lists by Index" mentions only DR 299 on section -24.1.4, and DR 299 is not related to this issue. +the "Lists by Index" mentions only DR 299 on section +24.1.4, and DR 299 is not related to this issue.@@ -17933,7 +18232,7 @@ Change the guarantee to "postcondition: r is dereferenceable."
384. equal_range has unimplementable runtime complexity
Section: 25.4.3.3 [equal.range] Status: CD1 - Submitter: Hans Bos Opened: 2002-10-18 Last modified: 2008-09-26
+ Submitter: Hans Bos Opened: 2002-10-18 Last modified: 2010-10-29View all other issues in [equal.range].
View all issues with CD1 status.
Discussion:
@@ -18005,7 +18304,7 @@ to 2*log2(last - first) + O(1).
386. Reverse iterator's operator[] has impossible return type
Section: 24.5.1.3.11 [reverse.iter.op-=] Status: CD1 - Submitter: Matt Austern Opened: 2002-10-23 Last modified: 2009-05-01
+ Submitter: Matt Austern Opened: 2002-10-23 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
In 24.5.1.3.11 [reverse.iter.op-=], reverse_iterator<>::operator[] @@ -18020,7 +18319,7 @@ which is the same as iterator_traits<Iterator>::reference. to Iterator's value type. The return type specified for reverse_iterator's operator[] would thus appear to be impossible.
-With the resolution of issue 299, the type of +
With the resolution of issue 299, the type of a[n] will continue to be required (for random access iterators) to be convertible to the value type, and also a[n] = t will be a valid expression. Implementations of @@ -18044,7 +18343,7 @@ which is the same as iterator_traits<Iterator>::reference.
to:
-@@ -18068,7 +18367,7 @@ Comments from Dave Abrahams: IMO we should resolve 386 by just sayingunspecified operator[](difference_type n) const; // see 24.2.5 [random.access.iterators] +unspecified operator[](difference_type n) const; // see 24.2.7 [random.access.iterators]
387. std::complex over-encapsulated
Section: 26.4 [complex.numbers] Status: CD1 - Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2008-09-26
+ Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2010-10-29View all other issues in [complex.numbers].
View all issues with CD1 status.
Discussion:
@@ -18225,7 +18524,7 @@ existing implementations already have the layout proposed here.
389. Const overload of valarray::operator[] returns by value
Section: 26.6.2.3 [valarray.access] Status: CD1 - Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2008-09-26
+ Submitter: Gabriel Dos Reis Opened: 2002-11-08 Last modified: 2010-10-29View all other issues in [valarray.access].
View all issues with CD1 status.
Duplicate of: 77
@@ -18299,7 +18598,7 @@ impact on allowable optimizations.
391. non-member functions specified as const
Section: 22.3.3.2 [conversions] Status: CD1 - Submitter: James Kanze Opened: 2002-12-10 Last modified: 2008-09-26
+ Submitter: James Kanze Opened: 2002-12-10 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -18322,7 +18621,7 @@ const in the header file synopsis in section 22.3 [locales].
395. inconsistencies in the definitions of rand() and random_shuffle()
Section: 26.8 [c.math] Status: CD1 - Submitter: James Kanze Opened: 2003-01-03 Last modified: 2008-09-26
+ Submitter: James Kanze Opened: 2003-01-03 Last modified: 2010-10-29View all other issues in [c.math].
View all issues with CD1 status.
Discussion:
@@ -18375,8 +18674,8 @@ implementation is permitted to use rand.]
396. what are characters zero and one
-Section: 20.3.7.1 [bitset.cons] Status: CD1 - Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2008-09-26
+Section: 20.5.1 [bitset.cons] Status: CD1 + Submitter: Martin Sebor Opened: 2003-01-05 Last modified: 2010-10-29
View all other issues in [bitset.cons].
View all issues with CD1 status.
Discussion:
@@ -18434,7 +18733,7 @@ We request that Howard submit a separate issue regarding the three to_string oveProposed resolution:
Change the constructor's function declaration immediately before -20.3.7.1 [bitset.cons] p3 to:
+20.5.1 [bitset.cons] p3 to:template <class charT, class traits, class Allocator> explicit bitset(const basic_string<charT, traits, Allocator>& str, @@ -18443,7 +18742,7 @@ We request that Howard submit a separate issue regarding the three to_string ove basic_string<charT, traits, Allocator>::npos, charT zero = charT('0'), charT one = charT('1'))-Change the first two sentences of 20.3.7.1 [bitset.cons] p6 to: "An +
Change the first two sentences of 20.5.1 [bitset.cons] p6 to: "An element of the constructed string has value 0 if the corresponding character in str, beginning at position pos, is zero. Otherwise, the element has the value 1.
@@ -18456,15 +18755,15 @@ is zero. Otherwise, the element has the value 1.Change the declaration of the to_string member function - immediately before 20.3.7.2 [bitset.members] p33 to:
+ immediately before 20.5.2 [bitset.members] p33 to:template <class charT, class traits, class Allocator> basic_string<charT, traits, Allocator> to_string(charT zero = charT('0'), charT one = charT('1')) const;-Change the last sentence of 20.3.7.2 [bitset.members] p33 to: "Bit +
Change the last sentence of 20.5.2 [bitset.members] p33 to: "Bit value 0 becomes the character zero, bit value 1 becomes the character one.
-Change 20.3.7.3 [bitset.operators] p8 to:
+Change 20.5.4 [bitset.operators] p8 to:
Returns:
os << x.template to_string<charT,traits,allocator<charT> >( use_facet<ctype<charT> >(os.getloc()).widen('0'), @@ -18509,13 +18808,13 @@ The proposed wording neglects the 3 newer to_string overloads.
400. redundant type cast in lib.allocator.members
-Section: 20.8.8.1 [allocator.members] Status: CD1 - Submitter: Markus Mauhart Opened: 2003-02-27 Last modified: 2008-09-26
+Section: 20.9.5.1 [allocator.members] Status: CD1 + Submitter: Markus Mauhart Opened: 2003-02-27 Last modified: 2010-10-29
View all other issues in [allocator.members].
View all issues with CD1 status.
Discussion:
-20.8.8.1 [allocator.members] allocator members, contains +20.9.5.1 [allocator.members] allocator members, contains the following 3 lines:
@@ -18543,8 +18842,8 @@ Replace "((T*) p)" with "p".
401. incorrect type casts in table 32 in lib.allocator.requirements
-Section: 20.2.2 [allocator.requirements] Status: CD1 - Submitter: Markus Mauhart Opened: 2003-02-27 Last modified: 2008-09-26
+Section: 20.2.5 [allocator.requirements] Status: CD1 + Submitter: Markus Mauhart Opened: 2003-02-27 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with CD1 status.
Discussion:
@@ -18626,20 +18925,20 @@ issue to Ready status to be voted into the WP at Kona.
402. wrong new expression in [some_]allocator::construct
-Section: 20.2.2 [allocator.requirements], 20.8.8.1 [allocator.members] Status: CD1 - Submitter: Markus Mauhart Opened: 2003-02-27 Last modified: 2008-09-26
+Section: 20.2.5 [allocator.requirements], 20.9.5.1 [allocator.members] Status: CD1 + Submitter: Markus Mauhart Opened: 2003-02-27 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with CD1 status.
Discussion:
This applies to the new expression that is contained in both par12 of -20.8.8.1 [allocator.members] and in par2 (table 32) of [default.con.req]. +20.9.5.1 [allocator.members] and in par2 (table 32) of [default.con.req]. I think this new expression is wrong, involving unintended side effects.
-20.8.8.1 [allocator.members] contains the following 3 lines:
+20.9.5.1 [allocator.members] contains the following 3 lines:
11 Returns: the largest value N for which the call allocate(N,0) might succeed. void construct(pointer p, const_reference val); @@ -18693,7 +18992,7 @@ Replace "new" with "::new" in both cases.
403. basic_string::swap should not throw exceptions
Section: 21.4.6.8 [string::swap] Status: CD1 - Submitter: Beman Dawes Opened: 2003-03-25 Last modified: 2008-09-26
+ Submitter: Beman Dawes Opened: 2003-03-25 Last modified: 2010-10-29View all other issues in [string::swap].
View all issues with CD1 status.
Discussion:
@@ -18761,7 +19060,7 @@ Throws: Shall not throw exceptions.
404. May a replacement allocation function be declared inline?
Section: 17.6.3.6 [replacement.functions], 18.6.1 [new.delete] Status: CD1 - Submitter: Matt Austern Opened: 2003-04-24 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 2003-04-24 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -18818,7 +19117,7 @@ believed to be of limited value.
405. qsort and POD
Section: 25.5 [alg.c.library] Status: CD1 - Submitter: Ray Lischner Opened: 2003-04-08 Last modified: 2008-09-26
+ Submitter: Ray Lischner Opened: 2003-04-08 Last modified: 2010-10-29View all other issues in [alg.c.library].
View all issues with CD1 status.
Discussion:
@@ -18849,8 +19148,8 @@ type."
406. vector::insert(s) exception safety
-Section: 23.3.6.4 [vector.modifiers] Status: CD1 - Submitter: Dave Abrahams Opened: 2003-04-27 Last modified: 2009-05-01
+Section: 23.4.1.4 [vector.modifiers] Status: CD1 + Submitter: Dave Abrahams Opened: 2003-04-27 Last modified: 2010-10-29
View all other issues in [vector.modifiers].
View all issues with CD1 status.
Discussion:
@@ -18866,7 +19165,7 @@ existing implementation.Proposed resolution:
-Replace 23.3.6.4 [vector.modifiers] paragraph 1 with:
+Replace 23.4.1.4 [vector.modifiers] paragraph 1 with:
1- Notes: Causes reallocation if the new size is greater than the old capacity. If no reallocation happens, all the iterators and @@ -18886,7 +19185,7 @@ existing implementation.
407. Can singular iterators be destroyed?
Section: X [iterator.concepts] Status: CD1 - Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2008-09-30
+ Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2010-10-29View all other issues in [iterator.concepts].
View all issues with CD1 status.
Discussion:
@@ -18914,7 +19213,7 @@ of a non-singular value to an iterator that holds a singular value."
409. Closing an fstream should clear error state
Section: 27.9.1.9 [ifstream.members], 27.9.1.13 [ofstream.members] Status: CD1 - Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2009-05-01
+ Submitter: Nathan Myers Opened: 2003-06-03 Last modified: 2010-10-29View all other issues in [ifstream.members].
View all issues with CD1 status.
Discussion:
@@ -18941,44 +19240,37 @@ language, those considerations no longer apply.Change 27.9.1.9 [ifstream.members], para. 3 from:
-Calls rdbuf()->open(s,mode|in). If that function returns a null -pointer, calls setstate(failbit) (which may throw ios_base::failure -[Footnote: (lib.iostate.flags)]. +Calls rdbuf()->open(s,mode|in). If that function returns a null pointer, calls setstate(failbit) (which may throw ios_base::failure [Footnote: (lib.iostate.flags)].
to:
-Calls rdbuf()->open(s,mode|in). If that function -returns a null pointer, calls setstate(failbit) (which may throw -ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear(). +
+Calls rdbuf()->open(s,mode|in). If that function returns a null pointer, calls setstate(failbit) (which may throw ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear().
Change 27.9.1.13 [ofstream.members], para. 3 from:
-Calls rdbuf()->open(s,mode|out). If that function -returns a null pointer, calls setstate(failbit) (which may throw -ios_base::failure [Footnote: (lib.iostate.flags)). +
+Calls rdbuf()->open(s,mode|out). If that function returns a null pointer, calls setstate(failbit) (which may throw ios_base::failure [Footnote: (lib.iostate.flags)).
to:
-Calls rdbuf()->open(s,mode|out). If that function -returns a null pointer, calls setstate(failbit) (which may throw -ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear(). +
+Calls rdbuf()->open(s,mode|out). If that function returns a null pointer, calls setstate(failbit) (which may throw ios_base::failure [Footnote: (lib.iostate.flags)), else calls clear().
Change 27.9.1.17 [fstream.members], para. 3 from:
-Calls rdbuf()->open(s,mode), If that function returns -a null pointer, calls setstate(failbit), (which may throw -ios_base::failure). (lib.iostate.flags) ) +
+Calls rdbuf()->open(s,mode), If that function returns a null pointer, calls setstate(failbit), (which may throw ios_base::failure). (lib.iostate.flags) )
to:
-- +Calls rdbuf()->open(s,mode), If that function returns -a null pointer, calls setstate(failbit), (which may throw -ios_base::failure). (lib.iostate.flags) ), else calls clear(). +
@@ -19004,7 +19296,7 @@ flags.]+Calls rdbuf()->open(s,mode), If that function returns a null pointer, calls setstate(failbit), (which may throw ios_base::failure). (lib.iostate.flags) ), else calls clear().
410. Missing semantics for stack and queue comparison operators
Section: 23.3.4.1 [list.cons], 23.3.4.3 [list.modifiers] Status: CD1 - Submitter: Hans Bos Opened: 2003-06-07 Last modified: 2008-09-26
+ Submitter: Hans Bos Opened: 2003-06-07 Last modified: 2010-10-29View all other issues in [list.cons].
View all issues with CD1 status.
Discussion:
@@ -19088,7 +19380,7 @@ supposed to do, but we ought to spell it out.
411. Wrong names of set member functions
Section: 25.4.5 [alg.set.operations] Status: CD1 - Submitter: Daniel Frey Opened: 2003-07-09 Last modified: 2008-09-26
+ Submitter: Daniel Frey Opened: 2003-07-09 Last modified: 2010-10-29View all other issues in [alg.set.operations].
View all issues with CD1 status.
Discussion:
@@ -19116,7 +19408,7 @@ set_intersection(), not union() and intersection().
412. Typo in 27.4.4.3
Section: 27.5.4.3 [iostate.flags] Status: CD1 - Submitter: Martin Sebor Opened: 2003-07-10 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2003-07-10 Last modified: 2010-10-29View all other issues in [iostate.flags].
View all issues with CD1 status.
Duplicate of: 429
@@ -19152,7 +19444,7 @@ exceptions()) == 0" with "If ((state | (rdbuf() ? goodbit : badbit))
413. Proposed resolution to LDR#64 still wrong
Section: 27.7.1.2.3 [istream::extractors] Status: CD1 - Submitter: Bo Persson Opened: 2003-07-13 Last modified: 2009-05-01
+ Submitter: Bo Persson Opened: 2003-07-13 Last modified: 2010-10-29View all other issues in [istream::extractors].
View all issues with CD1 status.
Discussion:
@@ -19209,8 +19501,8 @@ then the caught exception is rethrown.
414. Which iterators are invalidated by v.erase()?
-Section: 23.3.6.4 [vector.modifiers] Status: CD1 - Submitter: Matt Austern Opened: 2003-08-19 Last modified: 2008-09-26
+Section: 23.4.1.4 [vector.modifiers] Status: CD1 + Submitter: Matt Austern Opened: 2003-08-19 Last modified: 2010-10-29
View all other issues in [vector.modifiers].
View all issues with CD1 status.
Discussion:
@@ -19264,7 +19556,7 @@ techniques.)Proposed resolution:
-In 23.3.6.4 [vector.modifiers] paragraph 3, change "Invalidates all the +In 23.4.1.4 [vector.modifiers] paragraph 3, change "Invalidates all the iterators and references after the point of the erase" to "Invalidates iterators and references at or after the point of the erase". @@ -19285,7 +19577,7 @@ erase".
415. behavior of std::ws
Section: 27.7.1.4 [istream.manip] Status: CD1 - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -19324,7 +19616,7 @@ of paragraph 1, the following text:
416. definitions of XXX_MIN and XXX_MAX macros in climits
Section: 18.3.2 [c.limits] Status: CD1 - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -19394,7 +19686,7 @@ to match the type to which they refer.--end note]
419. istream extractors not setting failbit if eofbit is already set
Section: 27.7.1.1.3 [istream::sentry] Status: WP - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2009-10-26
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all other issues in [istream::sentry].
View all issues with WP status.
Discussion:
@@ -19488,7 +19780,7 @@ you can never seek away from the end of stream. Moved to Ready.Proposed resolution:
@@ -19512,7 +19804,7 @@ Otherwise prepares for formatted or unformatted input. ...
420. is std::FILE a complete type?
Section: 27.9.1 [fstreams] Status: CD1 - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all other issues in [fstreams].
View all issues with CD1 status.
Discussion:
@@ -19546,7 +19838,7 @@ allowed to just declare it without providing a full definition?
422. explicit specializations of member functions of class templates
Section: 17.6.3.3 [reserved.names] Status: CD1 - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all other issues in [reserved.names].
View all issues with CD1 status.
Discussion:
@@ -19613,8 +19905,8 @@ use the right wording.]
425. return value of std::get_temporary_buffer
-Section: 20.8.11 [temporary.buffer] Status: CD1 - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2008-09-26
+Section: 20.9.7 [temporary.buffer] Status: CD1 + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
@@ -19628,7 +19920,7 @@ is when the argument is less than 0.
Proposed resolution:
-Change 20.6.3 [meta.help] paragraph 2 from "...or a pair of 0 +
Change 20.7.3 [meta.help] paragraph 2 from "...or a pair of 0 values if no storage can be obtained" to "...or a pair of 0 values if no storage can be obtained or if n <= 0."
[Kona: Matt provided wording]
@@ -19639,8 +19931,8 @@ no storage can be obtained or if n <= 0."
426. search_n(), fill_n(), and generate_n() with negative n
-Section: 25.2.12 [alg.search], 25.3.6 [alg.fill], 25.3.7 [alg.generate] Status: CD1 - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2008-09-26
+Section: 25.2.13 [alg.search], 25.3.6 [alg.fill], 25.3.7 [alg.generate] Status: CD1 + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
View all other issues in [alg.search].
View all issues with CD1 status.
Discussion:
@@ -19717,10 +20009,767 @@ or 0 otherwise) assignments. +
+427. stage 2 and rationale of DR 221
+Section: 22.4.2.1.2 [facet.num.get.virtuals] Status: WP + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
+View all other issues in [facet.num.get.virtuals].
+View all issues with WP status.
+Discussion:
++The requirements specified in Stage 2 and reiterated in the rationale +of DR 221 (and echoed again in DR 303) specify that num_get<charT>:: +do_get() compares characters on the stream against the widened elements +of "012...abc...ABCX+-" +
+ ++An implementation is required to allow programs to instantiate the num_get +template on any charT that satisfies the requirements on a user-defined +character type. These requirements do not include the ability of the +character type to be equality comparable (the char_traits template must +be used to perform tests for equality). Hence, the num_get template cannot +be implemented to support any arbitrary character type. The num_get template +must either make the assumption that the character type is equality-comparable +(as some popular implementations do), or it may use char_traits<charT> to do +the comparisons (some other popular implementations do that). This diversity +of approaches makes it difficult to write portable programs that attempt to +instantiate the num_get template on user-defined types. +
+ +[Kona: the heart of the problem is that we're theoretically + supposed to use traits classes for all fundamental character + operations like assignment and comparison, but facets don't have + traits parameters. This is a fundamental design flaw and it + appears all over the place, not just in this one place. It's not + clear what the correct solution is, but a thorough review of facets + and traits is in order. The LWG considered and rejected the + possibility of changing numeric facets to use narrowing instead of + widening. This may be a good idea for other reasons (see issue + 459), but it doesn't solve the problem raised by this + issue. Whether we use widen or narrow the num_get facet + still has no idea which traits class the user wants to use for + the comparison, because only streams, not facets, are passed traits + classes. The standard does not require that two different + traits classes with the same char_type must necessarily + have the same behavior.]
+ + +Informally, one possibility: require that some of the basic +character operations, such as eq, lt, +and assign, must behave the same way for all traits classes +with the same char_type. If we accept that limitation on +traits classes, then the facet could reasonably be required to +use char_traits<charT>.
+ +[ +2009-07 Frankfurt +]
+ + +++ ++There was general agreement that the standard only needs to specify the +behavior when the character type is char or wchar_t. +
++Beman: we don't need to worry about C++1x because there is a non-zero +possibility that we would have a replacement facility for iostreams that +would solve these problems. +
++We need to change the following sentence in [locale.category], paragraph +6 to specify that C is char and wchar_t: +
++"A template formal parameter with name C represents the set of all +possible specializations on a parameter that satisfies the requirements +for a character on which any member of the iostream components can be +instantiated." +
++We also need to specify in 27 that the basic character operations, such +as eq, lt, and assign use std::char_traits. +
++Daniel volunteered to provide wording. +
+[ +2009-09-19 Daniel provided wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Leave as Open. Alisdair and/or Tom will provide wording based on discussions. +We want to clearly state that streams and locales work just on char +and wchar_t (except where otherwise specified). ++ +[ +2010-02-06 Tom updated the proposed wording. +]
+ + +++ +[ +The original proposed wording is preserved here: +]
+ + ++++
+ +- +
+ ++Change 22.3.1.1.1 [locale.category]/6: +
+ ++[..] A template formal parameter with name C represents the set of all possible +specializations on a char or wchar_t parameter+that satisfies +the requirements for a character on which any of the iostream components +can be instantiated. [..] +- +
+ ++Add the following sentence to the end of 22.4.2 [category.numeric]/2: +
+ ++[..] These specializations refer to [..], and also for the ctype<> facet to +perform character classification. Implementations are encouraged +but not required to use the char_traits<charT> functions for all +comparisons and assignments of characters of type charT that do +not belong to the set of required specializations. ++- +
+ ++Change 22.4.2.1.2 [facet.num.get.virtuals]/3: +
+ +++ ++Stage 2: If in==end then stage 2 terminates. Otherwise a charT is taken +from in and local variables are initialized as if by +
+ ++ +char_type ct = *in; +using tr = char_traits<char_type>; +const char_type* pos = tr::find(atoms, sizeof(src) - 1, ct); +char c = src[find(atoms, atoms + sizeof(src) - 1, ct) - atoms+ pos ? pos - atoms : sizeof(src) - 1]; +if (tr::eq(ct,ct ==use_facet<numpunct<charT>(loc).decimal_point())) + c = '.'; +bool discard = + tr::eq(ct,ct ==use_facet<numpunct<charT>(loc).thousands_sep()) + && use_facet<numpunct<charT> >(loc).grouping().length() != 0; ++where the values src and atoms are defined as if by: [..] +
++[Remark of the author: I considered to replace the initialization +"char_type ct = *in;" +by the sequence "char_type ct; tr::assign(ct, *in);", but decided +against it, because +it is a copy-initialization context, not an assignment] +
+- +
+ ++Add the following sentence to the end of 22.4.5 [category.time]/1: +
+ ++[..] Their members use [..] , to determine formatting details. +Implementations are encouraged but not required to use the +char_traits<charT> functions for all comparisons and assignments +of characters of type charT that do +not belong to the set of required specializations. ++- +
+ ++Change 22.4.5.1.1 [locale.time.get.members]/8 bullet 4: +
+ ++
+- +
+The next element of fmt is equal to '%'For the next element c +of fmt char_traits<char_type>::eq(c, use_facet<ctype<char_type>>(f.getloc()).widen('%')) == true, +[..] +- +
+ ++Add the following sentence to the end of 22.4.6 [category.monetary]/2: +
+ ++Their members use [..] to determine formatting details. +Implementations are encouraged but not required to use the +char_traits<charT> functions for all comparisons and assignments +of characters of type charT that do +not belong to the set of required specializations. ++- +
+ ++Change 22.4.6.1.2 [locale.money.get.virtuals]/4: +
+ ++++[..] The value units is produced as if by: +
+ ++for (int i = 0; i < n; ++i) + buf2[i] = src[char_traits<charT>::find(atoms,atoms+sizeof(src), buf1[i]) - atoms]; +buf2[n] = 0; +sscanf(buf2, "%Lf", &units); +- +
+ ++Change 22.4.6.2.2 [locale.money.put.virtuals]/1: +
+ ++[..] for character buffers buf1 and buf2. If for the first +character c +in digits or buf2+is equal to +ct.widen('-')char_traits<charT>::eq(c, +ct.widen('-')) == true, [..] +- +
+ ++Add a footnote to the first sentence of 27.7.1.2.2 [istream.formatted.arithmetic]/1: +
+ ++++As in the case of the inserters, these extractors depend on the locale's +num_get<> (22.4.2.1) object to perform parsing the input stream +data.(footnote) [..] +
+ ++ +footnote) If the traits of the input stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
+ ++Add a footnote to the second sentence of 27.7.2.6.2 [ostream.inserters.arithmetic]/1: +
+ ++++Effects: The classes num_get<> and +num_put<> handle locale-dependent numeric formatting and +parsing. These inserter functions use the imbued locale value to perform +numeric formatting.(footnote) [..] +
+ ++ +footnote) If the traits of the output stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
+ ++Add a footnote after the first sentence of 27.7.4 [ext.manip]/4: +
+ ++++Returns: An object of unspecified type such that if in is an object of type +basic_istream<charT, traits> then the expression in >> get_money(mon, intl) +behaves as if it called f(in, mon, intl), where the function f is defined +as:(footnote) [..] +
+ ++ +footnote) If the traits of the input stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
+ ++Add a footnote after the first sentence of 27.7.4 [ext.manip]/5: +
+ ++++Returns: An object of unspecified type such that if out is an object of type +basic_ostream<charT, traits> then the expression out << put_money(mon, intl) +behaves as a formatted input function that calls f(out, mon, intl), where the +function f is defined as:(footnote) [..] +
+ ++ +footnote) If the traits of the output stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
+ ++13) Add a footnote after the first sentence of 27.7.4 [ext.manip]/8: +
+ ++++Returns: An object of unspecified type such that if in is an +object of type basic_istream<charT, traits> then the expression +in >>get_time(tmb, fmt) behaves as if it called f(in, tmb, fmt), +where the function f is defined as:(footnote) [..] +
+ ++ +footnote) If the traits of the input stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
++Add a footnote after the first sentence of 27.7.4 [ext.manip]/10: +
+ ++++Returns: An object of unspecified type such that if out is an object of type +basic_ostream<charT, traits> then the expression out <<put_time(tmb, fmt) +behaves as if it called f(out, tmb, fmt), where the function f is defined +as:(footnote) [..] +
+ ++ +footnote) If the traits of the output stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+[ +2010 Pittsburgh: +]
+ + +++ + + ++Moved to Ready with only two of the bullets. The original wording is preserved +here: +
+ ++++
+- +
+ ++Change 22.3.1.1.1 [locale.category]/6: +
+ ++[..] A template formal parameter with name C represents +the set ++of all possible specializations on a+of types containing char, wchar_t, +and any other implementation-defined character type + +parameter+that satisfies +the requirements for a character on which any of the iostream components +can be instantiated. [..] +- +
+ ++Add the following sentence to the end of 22.4.2 [category.numeric]/2: +
+ ++[..] These specializations refer to [..], and also for the ctype<> facet to +perform character classification. [Note: Implementations are encouraged +but not required to use the char_traits<charT> functions for all +comparisons and assignments of characters of type charT that do +not belong to the set of required specializations - end note]. ++- +
+ ++Change 22.4.2.1.2 [facet.num.get.virtuals]/3: +
+ +++ ++Stage 2: If in==end then stage 2 terminates. Otherwise a charT is taken +from in and local variables are initialized as if by +
+ ++ +char_type ct = *in; +using tr = char_traits<char_type>; +const char_type* pos = tr::find(atoms, sizeof(src) - 1, ct); +char c = src[find(atoms, atoms + sizeof(src) - 1, ct) - atoms+ pos ? pos - atoms : sizeof(src) - 1]; +if (tr::eq(ct,ct ==use_facet<numpunct<charT>(loc).decimal_point())) + c = '.'; +bool discard = + tr::eq(ct,ct ==use_facet<numpunct<charT>(loc).thousands_sep()) + && use_facet<numpunct<charT> >(loc).grouping().length() != 0; ++where the values src and atoms are defined as if by: [..] +
++[Remark of the author: I considered to replace the initialization +"char_type ct = *in;" +by the sequence "char_type ct; tr::assign(ct, *in);", but decided +against it, because +it is a copy-initialization context, not an assignment] +
+- +
+ ++Add the following sentence to the end of 22.4.5 [category.time]/1: +
+ ++[..] Their members use [..] , to determine formatting details. +[Note: Implementations are encouraged but not required to use the +char_traits<charT> functions for all comparisons and assignments +of characters of type charT that do +not belong to the set of required specializations - end note]. ++- +
+ ++Change 22.4.5.1.1 [locale.time.get.members]/8 bullet 4: +
+ ++
+- +
+The next element of fmt is equal to '%'For the next element c +of fmt char_traits<char_type>::eq(c, use_facet<ctype<char_type>>(f.getloc()).widen('%')) == true, +[..] +- +
+ ++Add the following sentence to the end of 22.4.6 [category.monetary]/2: +
+ ++Their members use [..] to determine formatting details. +[Note: Implementations are encouraged but not required to use the +char_traits<charT> functions for all comparisons and assignments +of characters of type charT that do +not belong to the set of required specializations - end note]. ++- +
+ ++Change 22.4.6.1.2 [locale.money.get.virtuals]/4: +
+ ++++[..] The value units is produced as if by: +
+ ++for (int i = 0; i < n; ++i) + buf2[i] = src[char_traits<charT>::find(atoms,atoms+sizeof(src), buf1[i]) - atoms]; +buf2[n] = 0; +sscanf(buf2, "%Lf", &units); +- +
+ ++Change 22.4.6.2.2 [locale.money.put.virtuals]/1: +
+ ++[..] for character buffers buf1 and buf2. If for the first +character c +in digits or buf2+is equal to +ct.widen('-')char_traits<charT>::eq(c, +ct.widen('-')) == true, [..] +- +
+ ++Add a new paragraph after the +first paragraph of 27.2.2 [iostreams.limits.pos]/1: +
++In the classes of clause 27, +a template formal parameter with name charT represents +one of +the set of types +containing char, wchar_t, +and any other implementation-defined character type +that satisfies +the requirements for a character on which any of the iostream components +can be instantiated. ++- +
+ ++Add a footnote to the first sentence of 27.7.1.2.2 [istream.formatted.arithmetic]/1: +
+ ++++As in the case of the inserters, these extractors depend on the locale's +num_get<> (22.4.2.1) object to perform parsing the input stream +data.(footnote) [..] +
+ ++ +footnote) If the traits of the input stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
+ + ++Add a footnote to the second sentence of 27.7.2.6.2 [ostream.inserters.arithmetic]/1: +
+ ++++Effects: The classes num_get<> and +num_put<> handle locale-dependent numeric formatting and +parsing. These inserter functions use the imbued locale value to perform +numeric formatting.(footnote) [..] +
+ ++ +footnote) If the traits of the output stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
+ ++Add a footnote after the first sentence of 27.7.4 [ext.manip]/4: +
+ ++++Returns: An object of unspecified type such that if in is an object of type +basic_istream<charT, traits> then the expression in >> get_money(mon, intl) +behaves as if it called f(in, mon, intl), where the function f is defined +as:(footnote) [..] +
+ ++ +footnote) If the traits of the input stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
+ ++Add a footnote after the first sentence of 27.7.4 [ext.manip]/5: +
+ ++++Returns: An object of unspecified type such that if out is an object of type +basic_ostream<charT, traits> then the expression out << put_money(mon, intl) +behaves as a formatted input function that calls f(out, mon, intl), where the +function f is defined as:(footnote) [..] +
+ ++ +footnote) If the traits of the output stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
+ ++Add a footnote after the first sentence of 27.7.4 [ext.manip]/8: +
+ ++++Returns: An object of unspecified type such that if in is an +object of type basic_istream<charT, traits> then the expression +in >>get_time(tmb, fmt) behaves as if it called f(in, tmb, fmt), +where the function f is defined as:(footnote) [..] +
+ ++ +footnote) If the traits of the input stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+- +
++Add a footnote after the first sentence of 27.7.4 [ext.manip]/10: +
+ ++++Returns: An object of unspecified type such that if out is an object of type +basic_ostream<charT, traits> then the expression out <<put_time(tmb, fmt) +behaves as if it called f(out, tmb, fmt), where the function f is defined +as:(footnote) [..] +
+ ++ +footnote) If the traits of the output stream has different semantics for lt(), +eq(), and assign() than char_traits<char_type>, this may give surprising +results. + +
+Proposed resolution:
++
+ + + +- +
+ ++Change 22.3.1.1.1 [locale.category]/6: +
+ ++[..] A template formal parameter with name C represents +the set ++of all possible specializations on a+of types containing char, wchar_t, +and any other implementation-defined character type + +parameter+that satisfies +the requirements for a character on which any of the iostream components +can be instantiated. [..] +- +
+ ++Add a new paragraph after the +first paragraph of 27.2.2 [iostreams.limits.pos]/1: +
++In the classes of clause 27, +a template formal parameter with name charT represents +one of +the set of types +containing char, wchar_t, +and any other implementation-defined character type +that satisfies +the requirements for a character on which any of the iostream components +can be instantiated. ++
428. string::erase(iterator) validity
Section: 21.4.6.5 [string::erase] Status: CD1 - Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29View all other issues in [string::erase].
View all issues with CD1 status.
Discussion:
@@ -19755,10 +20804,374 @@ which is most likely not the intent. +
+430. valarray subset operations
+Section: 26.6.2.4 [valarray.sub] Status: WP + Submitter: Martin Sebor Opened: 2003-09-18 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++The standard fails to specify the behavior of valarray::operator[](slice) +and other valarray subset operations when they are passed an "invalid" +slice object, i.e., either a slice that doesn't make sense at all (e.g., +slice (0, 1, 0) or one that doesn't specify a valid subset of the valarray +object (e.g., slice (2, 1, 1) for a valarray of size 1). +
+[Kona: the LWG believes that invalid slices should invoke + undefined behavior. Valarrays are supposed to be designed for high + performance, so we don't want to require specific checking. We + need wording to express this decision.]
+ + +[ +Bellevue: +]
+ + ++Please note that the standard also fails to specify the behavior of +slice_array and gslice_array in the valid case. Bill Plauger will +endeavor to provide revised wording for slice_array and gslice_array. ++ +[ +post-Bellevue: Bill provided wording. +]
+ + +[ +2009-07 Frankfurt +]
+ + +++ ++Move to Ready. +
+[ +2009-11-04 Pete opens: +]
+ + ++The resolution to LWG issue 430 has not been applied --- there have been +changes to the underlying text, and the resolution needs to be reworked. ++ +[ +2010-03-09 Matt updated wording. +]
+ + +[ +2010 Pittsburgh: Moved to Ready for Pittsburgh. +]
+ + + + +Proposed resolution:
++Replace 26.6.2.4 [valarray.sub], with the following: +
+ +++ + + + + ++The member operator is overloaded to provide several ways to select +sequences of elements from among those controlled by *this. +Each of these operations returns a subset of the array. The +const-qualified versions return this subset as a new valarray. The +non-const versions return a class template object which has reference +semantics to the original array, working in conjunction with various +overloads of operator= (and other assigning operators) to allow +selective replacement (slicing) of the controlled sequence. In each case +the selected element(s) must exist. +
+ +valarray<T> operator[](slice slicearr) const; ++ +++ ++This function returns an object of class valarray<T> +containing those elements of the controlled sequence designated by +slicearr. [Example: +
+ ++valarray<char> v0("abcdefghijklmnop", 16); +valarray<char> v1("ABCDE", 5); +v0[slice(2, 5, 3)] = v1; +// v0 == valarray<char>("abAdeBghCjkDmnEp", 16) ++end example] +
+valarray<T> operator[](slice slicearr); ++ +++ ++This function selects those elements of the controlled sequence +designated by slicearr. [Example: +
+ ++valarray<char> v0("abcdefghijklmnop", 16); +valarray<char> v1("ABCDE", 5); +v0[slice(2, 5, 3)] = v1; +// v0 == valarray<char>("abAdeBghCjkDmnEp", 16) ++end example] +
+valarray<T> operator[](const gslice& gslicearr) const; ++ +++ ++This function returns an object of class valarray<T> +containing those elements of the controlled sequence designated by +gslicearr. [Example: +
+ ++valarray<char> v0("abcdefghijklmnop", 16); +const size_t lv[] = {2, 3}; +const size_t dv[] = {7, 2}; +const valarray<size_t> len(lv, 2), str(dv, 2); +// v0[gslice(3, len, str)] returns +// valarray<char>("dfhkmo", 6) ++end example] +
+gslice_array<T> operator[](const gslice& gslicearr); ++ +++ ++This function selects those elements of the controlled sequence +designated by gslicearr. [Example: +
+ ++valarray<char> v0("abcdefghijklmnop", 16); +valarray<char> v1("ABCDEF", 6); +const size_t lv[] = {2, 3}; +const size_t dv[] = {7, 2}; +const valarray<size_t> len(lv, 2), str(dv, 2); +v0[gslice(3, len, str)] = v1; +// v0 == valarray<char>("abcAeBgCijDlEnFp", 16) ++end example] +
+valarray<T> operator[](const valarray<bool>& boolarr) const; ++ +++ ++This function returns an object of class valarray<T> +containing those elements of the controlled sequence designated by +boolarr. [Example: +
+ ++valarray<char> v0("abcdefghijklmnop", 16); +const bool vb[] = {false, false, true, true, false, true}; +// v0[valarray<bool>(vb, 6)] returns +// valarray<char>("cdf", 3) ++end example] +
+mask_array<T> operator[](const valarray<bool>& boolarr); ++ +++ ++This function selects those elements of the controlled sequence +designated by boolarr. [Example: +
+ ++valarray<char> v0("abcdefghijklmnop", 16); +valarray<char> v1("ABC", 3); +const bool vb[] = {false, false, true, true, false, true}; +v0[valarray<bool>(vb, 6)] = v1; +// v0 == valarray<char>("abABeCghijklmnop", 16) ++end example] +
+valarray<T> operator[](const valarray<size_t>& indarr) const; ++ +++ ++This function returns an object of class valarray<T> +containing those elements of the controlled sequence designated by +indarr. [Example: +
+ ++valarray<char> v0("abcdefghijklmnop", 16); +const size_t vi[] = {7, 5, 2, 3, 8}; +// v0[valarray<size_t>(vi, 5)] returns +// valarray<char>("hfcdi", 5) ++end example] +
+indirect_array<T> operator[](const valarray<size_t>& indarr); ++ +++ ++This function selects those elements of the controlled sequence +designated by indarr. [Example: +
+ ++valarray<char> v0("abcdefghijklmnop", 16); +valarray<char> v1("ABCDE", 5); +const size_t vi[] = {7, 5, 2, 3, 8}; +v0[valarray<size_t>(vi, 5)] = v1; +// v0 == valarray<char>("abCDeBgAEjklmnop", 16) ++end example] +
+
+431. Swapping containers with unequal allocators
+Section: 20.2.5 [allocator.requirements], 25 [algorithms] Status: Resolved + Submitter: Matt Austern Opened: 2003-09-20 Last modified: 2010-11-20
+View all other issues in [allocator.requirements].
+View all issues with Resolved status.
+Discussion:
+Clause 20.2.5 [allocator.requirements] paragraph 4 says that implementations + are permitted to supply containers that are unable to cope with + allocator instances and that container implementations may assume + that all instances of an allocator type compare equal. We gave + implementers this latitude as a temporary hack, and eventually we + want to get rid of it. What happens when we're dealing with + allocators that don't compare equal? +
+ +In particular: suppose that v1 and v2 are both + objects of type vector<int, my_alloc> and that + v1.get_allocator() != v2.get_allocator(). What happens if + we write v1.swap(v2)? Informally, three possibilities:
+ +1. This operation is illegal. Perhaps we could say that an + implementation is required to check and to throw an exception, or + perhaps we could say it's undefined behavior.
+2. The operation performs a slow swap (i.e. using three + invocations of operator=, leaving each allocator with its + original container. This would be an O(N) operation.
+3. The operation swaps both the vectors' contents and their + allocators. This would be an O(1) operation. That is:
+++ +my_alloc a1(...); + my_alloc a2(...); + assert(a1 != a2); + + vector<int, my_alloc> v1(a1); + vector<int, my_alloc> v2(a2); + assert(a1 == v1.get_allocator()); + assert(a2 == v2.get_allocator()); + + v1.swap(v2); + assert(a1 == v2.get_allocator()); + assert(a2 == v1.get_allocator()); ++[Kona: This is part of a general problem. We need a paper + saying how to deal with unequal allocators in general.]
+ + +[pre-Sydney: Howard argues for option 3 in +N1599. +]
+ + +[ +2007-01-12, Howard: This issue will now tend to come up more often with move constructors +and move assignment operators. For containers, these members transfer resources (i.e. +the allocated memory) just like swap. +]
+ + +[ +Batavia: There is agreement to overload the container swap on the allocator's Swappable +requirement using concepts. If the allocator supports Swappable, then container's swap will +swap allocators, else it will perform a "slow swap" using copy construction and copy assignment. +]
+ + +[ +2009-04-28 Pablo adds: +]
+ ++Fixed in +N2525. +I argued for marking this Tentatively-Ready right after Bellevue, +but there was a concern that +N2525 +would break in the presence of the RVO. (That breakage had nothing to do with +swap, but never-the-less). I addressed that breakage in in +N2840 +(Summit) by means of a non-normative reference: + ++ ++[Note: in situations where the copy constructor for a container is elided, +this function is not called. The behavior in these cases is as if +select_on_container_copy_construction returned x — end note] ++ +[ +2009-10 Santa Cruz: +]
+ + +++ + + +NAD EditorialResolved. Addressed by +N2982. +Proposed resolution:
+ + + + +
432. stringbuf::overflow() makes only one write position available
Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1 - Submitter: Christian W Brock Opened: 2003-09-24 Last modified: 2008-09-26
+ Submitter: Christian W Brock Opened: 2003-09-24 Last modified: 2010-10-29View all other issues in [stringbuf.virtuals].
View all issues with CD1 status.
Discussion:
@@ -20043,8 +21456,8 @@ initialized range.
434. bitset::to_string() hard to use
-Section: 20.3.7.2 [bitset.members] Status: CD1 - Submitter: Martin Sebor Opened: 2003-10-15 Last modified: 2009-05-01
+Section: 20.5.2 [bitset.members] Status: CD1 + Submitter: Martin Sebor Opened: 2003-10-15 Last modified: 2010-10-29
View all other issues in [bitset.members].
View all issues with CD1 status.
Discussion:
@@ -20099,7 +21512,7 @@ to_string() member function template:
435. bug in DR 25
Section: 21.4.8.9 [string.io] Status: CD1 - Submitter: Martin Sebor Opened: 2003-10-15 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2003-10-15 Last modified: 2010-10-29View all other issues in [string.io].
View all issues with CD1 status.
Discussion:
@@ -20163,7 +21576,7 @@ iostreams where the operator does truncate).
436. are cv-qualified facet types valid facets?
Section: 22.3.1.1.2 [locale.facet] Status: CD1 - Submitter: Martin Sebor Opened: 2003-10-15 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2003-10-15 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -20197,8 +21610,7 @@ text.]
438. Ambiguity in the "do the right thing" clause
Section: 23.2.3 [sequence.reqmts] Status: CD1 - Submitter: Howard Hinnant Opened: 2003-10-20 Last modified: 2009-05-01
-View other active issues in [sequence.reqmts].
+ Submitter: Howard Hinnant Opened: 2003-10-20 Last modified: 2010-10-29View all other issues in [sequence.reqmts].
View all issues with CD1 status.
Discussion:
@@ -20538,7 +21950,7 @@ implicitly convertible to B.
441. Is fpos::state const?
Section: 27.5.3 [fpos] Status: CD1 - Submitter: Vincent Leloup Opened: 2003-11-17 Last modified: 2008-09-26
+ Submitter: Vincent Leloup Opened: 2003-11-17 Last modified: 2010-10-29View all other issues in [fpos].
View all issues with CD1 status.
Discussion:
@@ -20561,7 +21973,7 @@ In section 27.5.3.1 [fpos.members], change the declaration of
442. sentry::operator bool() inconsistent signature
Section: 27.7.2.4 [ostream::sentry] Status: CD1 - Submitter: Vincent Leloup Opened: 2003-11-18 Last modified: 2008-09-26
+ Submitter: Vincent Leloup Opened: 2003-11-18 Last modified: 2010-10-29View all other issues in [ostream::sentry].
View all issues with CD1 status.
Discussion:
@@ -20586,7 +21998,7 @@ of sentry::operator bool() to const.
443. filebuf::close() inconsistent use of EOF
Section: 27.9.1.4 [filebuf.members] Status: CD1 - Submitter: Vincent Leloup Opened: 2003-11-20 Last modified: 2008-09-26
+ Submitter: Vincent Leloup Opened: 2003-11-20 Last modified: 2010-10-29View all other issues in [filebuf.members].
View all issues with CD1 status.
Discussion:
@@ -20609,13 +22021,12 @@ Change overflow(EOF) to overflow(traits::eof()).
444. Bad use of casts in fstream
Section: 27.9.1 [fstreams] Status: CD1 - Submitter: Vincent Leloup Opened: 2003-11-20 Last modified: 2009-05-01
+ Submitter: Vincent Leloup Opened: 2003-11-20 Last modified: 2010-10-29View all other issues in [fstreams].
View all issues with CD1 status.
Discussion:
-27.9.1.9 [ifstream.members] p1, 27.9.1.13 [ofstream.members] p1, -27.9.1.17 [fstream.members] p1 seems have same problem as exposed in -LWG issue +
+27.9.1.9 [ifstream.members] p1, 27.9.1.13 [ofstream.members] p1, 27.9.1.17 [fstream.members] p1 seems have same problem as exposed in LWG issue 252.
@@ -20668,7 +22079,7 @@ LWG issue
445. iterator_traits::reference unspecified for some iterator categories
Section: 24.4.1 [iterator.traits] Status: CD1 - Submitter: Dave Abrahams Opened: 2003-12-09 Last modified: 2009-05-01
+ Submitter: Dave Abrahams Opened: 2003-12-09 Last modified: 2010-10-29View all other issues in [iterator.traits].
View all issues with CD1 status.
Discussion:
@@ -20833,8 +22244,8 @@ needed to be changed.
448. Random Access Iterators over abstract classes
-Section: 24.2.5 [random.access.iterators] Status: CD1 - Submitter: Dave Abrahams Opened: 2004-01-07 Last modified: 2008-09-26
+Section: 24.2.7 [random.access.iterators] Status: CD1 + Submitter: Dave Abrahams Opened: 2004-01-07 Last modified: 2010-10-29
View all other issues in [random.access.iterators].
View all issues with CD1 status.
Discussion:
@@ -20858,7 +22269,7 @@ Change the return type to "convertible to T const&".
449. Library Issue 306 Goes Too Far
Section: 18.2 [support.types] Status: CD1 - Submitter: Pete Becker Opened: 2004-01-15 Last modified: 2008-09-26
+ Submitter: Pete Becker Opened: 2004-01-15 Last modified: 2010-10-29View all other issues in [support.types].
View all issues with CD1 status.
Discussion:
@@ -20900,7 +22311,7 @@ undefined."
453. basic_stringbuf::seekoff need not always fail for an empty stream
Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1 - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2008-09-26
+ Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29View all other issues in [stringbuf.virtuals].
View all issues with CD1 status.
Discussion:
@@ -20943,7 +22354,7 @@ is nonzero, the positioning operation fails.
455. cerr::tie() and wcerr::tie() are overspecified
Section: 27.4 [iostream.objects] Status: CD1 - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2009-05-01
+ Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29View all other issues in [iostream.objects].
View all issues with CD1 status.
Discussion:
@@ -20985,7 +22396,7 @@ Its state is otherwise the same as required for basic_ios<wchar_t>::init
456. Traditional C header files are overspecified
Section: 17.6.1.2 [headers] Status: CD1 - Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2008-09-26
+ Submitter: Bill Plauger Opened: 2004-01-30 Last modified: 2010-10-29View all other issues in [headers].
View all issues with CD1 status.
Discussion:
@@ -21092,7 +22503,7 @@ using-declarations (7.3.3 [namespace.udecl]).-Change D.6 [depr.c.headers], para. 2-3: +Change D.7 [depr.c.headers], para. 2-3:
@@ -21124,8 +22535,8 @@ names within the namespace std. -- end example]
457. bitset constructor: incorrect number of initialized bits
-Section: 20.3.7.1 [bitset.cons] Status: CD1 - Submitter: Dag Henriksson Opened: 2004-01-30 Last modified: 2009-05-01
+Section: 20.5.1 [bitset.cons] Status: CD1 + Submitter: Dag Henriksson Opened: 2004-01-30 Last modified: 2010-10-29
View all other issues in [bitset.cons].
View all issues with CD1 status.
Discussion:
@@ -21144,7 +22555,7 @@ guaranteed to have any corresponding bit values in val.Proposed resolution:
-In 20.3.7.1 [bitset.cons] paragraph 2, change "M is the smaller of +
In 20.5.1 [bitset.cons] paragraph 2, change "M is the smaller of N and the value CHAR_BIT * sizeof (unsigned long). (249)" to "M is the smaller of N and the number of bits in the value representation (section 3.9 [basic.types]) of unsigned @@ -21158,7 +22569,7 @@ guaranteed to have any corresponding bit values in val.
460. Default modes missing from basic_fstream member specifications
Section: 27.9.1 [fstreams] Status: CD1 - Submitter: Ben Hutchings Opened: 2004-04-01 Last modified: 2009-05-01
+ Submitter: Ben Hutchings Opened: 2004-04-01 Last modified: 2010-10-29View all other issues in [fstreams].
View all issues with CD1 status.
Discussion:
@@ -21196,7 +22607,7 @@ that it is intended to be callable with one argument.
461. time_get hard or impossible to implement
Section: 22.4.5.1.2 [locale.time.get.virtuals] Status: CD1 - Submitter: Bill Plauger Opened: 2004-03-23 Last modified: 2008-09-26
+ Submitter: Bill Plauger Opened: 2004-03-23 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -21300,8 +22711,8 @@ An implementation may also accept additional implementation-defined formats.
464. Suggestion for new member functions in standard containers
-Section: 23.3.6 [vector], 23.4.1 [map] Status: CD1 - Submitter: Thorsten Ottosen Opened: 2004-05-12 Last modified: 2008-09-26
+Section: 23.4.1 [vector], 23.6.1 [map] Status: CD1 + Submitter: Thorsten Ottosen Opened: 2004-05-12 Last modified: 2010-10-29
View all other issues in [vector].
View all issues with CD1 status.
Discussion:
@@ -21317,9 +22728,7 @@ semantics: if( empty() ) return 0; else return buffer_;Rationale:
-
- To obtain a pointer to the vector's buffer, one must use either -operator[]() (which can give undefined behavior for empty vectors) or -at() (which will then throw if the vector is empty).
+- To obtain a pointer to the vector's buffer, one must use either operator[]() (which can give undefined behavior for empty vectors) or at() (which will then throw if the vector is empty).
- tr1::array<T,sz> already has a data() member
- e cannot use operator[]() when T is not DefaultDonstructible
- Neither when the map is const.
@@ -21330,14 +22739,14 @@ at() (which will then throw if the vector is empty).Proposed resolution:
-In 23.3.6 [vector], add the following to the vector +
In 23.4.1 [vector], add the following to the vector synopsis after "element access" and before "modifiers":
// [lib.vector.data] data access pointer data(); const_pointer data() const;-Add a new subsection of 23.3.6 [vector]:
+Add a new subsection of 23.4.1 [vector]:
-23.2.4.x vector data access
pointer data(); @@ -21349,13 +22758,13 @@ at() (which will then throw if the vector is empty).Throws: Nothing.
In 23.4.1 [map], add the following to the map +
In 23.6.1 [map], add the following to the map synopsis immediately after the line for operator[]:
T& at(const key_type& x); const T& at(const key_type& x) const;-Add the following to 23.4.1.2 [map.access]:
+Add the following to 23.6.1.2 [map.access]:
T& at(const key_type& x); const T& at(const key_type& x) const; @@ -21382,7 +22791,7 @@ synopsis immediately after the line for operator[]:
465. Contents of <ciso646>
Section: 17.6.1.2 [headers] Status: CD1 - Submitter: Steve Clamage Opened: 2004-06-03 Last modified: 2008-09-26
+ Submitter: Steve Clamage Opened: 2004-06-03 Last modified: 2010-10-29View all other issues in [headers].
View all issues with CD1 status.
Discussion:
@@ -21429,7 +22838,7 @@ or <ciso646> has no effect.
467. char_traits::lt(), compare(), and memcmp()
Section: 21.2.3.1 [char.traits.specializations.char] Status: CD1 - Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -21480,7 +22889,7 @@ imposed by Table 37 on compare() when char is signed.
468. unexpected consequences of ios_base::operator void*()
Section: 27.5.4.3 [iostate.flags] Status: CD1 - Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29View all other issues in [iostate.flags].
View all issues with CD1 status.
Discussion:
@@ -21551,8 +22960,8 @@ the value need not be valid.
469. vector<bool> ill-formed relational operators
-Section: 23.3.6 [vector] Status: CD1 - Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2009-05-01
+Section: 23.4.1 [vector] Status: CD1 + Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29
View all other issues in [vector].
View all issues with CD1 status.
Discussion:
@@ -21576,10 +22985,328 @@ vector<bool> from [lib.vector.bool]. +
+471. result of what() implementation-defined
+Section: 18.8.1 [exception] Status: WP + Submitter: Martin Sebor Opened: 2004-06-28 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
+ +[lib.exception] specifies the following:
+exception (const exception&) throw(); + exception& operator= (const exception&) throw(); + + -4- Effects: Copies an exception object. + -5- Notes: The effects of calling what() after assignment + are implementation-defined. ++ ++First, does the Note only apply to the assignment operator? If so, +what are the effects of calling what() on a copy of an object? Is +the returned pointer supposed to point to an identical copy of +the NTBS returned by what() called on the original object or not? +
+ ++Second, is this Note intended to extend to all the derived classes +in section 19? I.e., does the standard provide any guarantee for +the effects of what() called on a copy of any of the derived class +described in section 19? +
+ ++Finally, if the answer to the first question is no, I believe it +constitutes a defect since throwing an exception object typically +implies invoking the copy ctor on the object. If the answer is yes, +then I believe the standard ought to be clarified to spell out +exactly what the effects are on the copy (i.e., after the copy +ctor was called). +
+ +[Redmond: Yes, this is fuzzy. The issue of derived classes is + fuzzy too.]
+ + +[ +Batavia: Howard provided wording. +]
+ + +[ +Bellevue: +]
+ + +++ ++Eric concerned this is unimplementable, due to nothrow guarantees. +Suggested implementation would involve reference counting. +
++Is the implied reference counting subtle enough to call out a note on +implementation? Probably not. +
++If reference counting required, could we tighten specification further +to require same pointer value? Probably an overspecification, especially +if exception classes defer evalutation of final string to calls to +what(). +
++Remember issue moved open and not resolved at Batavia, but cannot +remember who objected to canvas a disenting opinion - please speak up if +you disagree while reading these minutes! +
++Move to Ready as we are accepting words unmodified. +
+[ +Sophia Antipolis: +]
+ + ++The issue was pulled from Ready. It needs to make clear that only homogenous copying +is intended to be supported, not coping from a derived to a base. ++ +[ +Batavia (2009-05): +]
+ +++ ++Howard supplied the following replacement wording +for paragraph 7 of the proposed resolution: +
++-7- Postcondition: what() shall return the same NTBS + as would be obtained by using static_cast + to cast the rhs to the same types as the lhs + and then calling what() on that possibly sliced object. +++Pete asks what "the same NTBS" means. +
+[ +2009-07-30 Niels adds: +]
+ + ++Further discussion in the thread starting with c++std-lib-24512. ++ +[ +2009-09-24 Niels provided updated wording: +]
+ + +++ ++I think the resolution should at least guarantee +that the result of what() is independent of whether the compiler does +copy-elision. And for any class derived from std::excepion that has a +constructor that allows specifying a what_arg, it should make sure that +the text of a user-provided what_arg is preserved, when the object is +copied. Note that all the implementations I've tested already appear to +satisfy the proposed resolution, including MSVC 2008 SP1, Apache +stdcxx-4.2.1, GCC 4.1.2, GCC 4.3.2, and CodeGear C++ 6.13. +
++The proposed resolution was updated with help from Daniel Krügler; +the update aims to clarify that the proposed postcondition only +applies to homogeneous copying. +
+[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready after inserting "publicly accessible" in two places. ++ + + +Proposed resolution:
+ ++Change 18.8.1 [exception] to: +
+ +++ + + + + ++-1- The class exception defines the base class for the types of +objects thrown as exceptions by C++ standard library components, and +certain expressions, to report errors detected during program execution. +
++Each standard library class T that derives from class +exception shall have a publicly accessible copy constructor and a publicly accessible copy assignment +operator that do not exit with an exception. These member functions +shall preserve the following postcondition: If two objects lhs +and rhs both have dynamic type T, and lhs is a +copy of rhs, then strcmp(lhs.what(), +rhs.what()) == 0. +
++ ... +
+ +exception(const exception& rhs) throw(); +exception& operator=(const exception& rhs) throw();+ +++ ++-4- Effects: Copies an exception object. +
++
+-5- Remarks: The effects of calling what() after assignment +are implementation-defined.++-5- Postcondition: + If *this + and rhs both have dynamic type exception + then strcmp(what(), rhs.what()) == 0. +
+ +
+473. underspecified ctype calls
+Section: 22.4.1.1 [locale.ctype] Status: WP + Submitter: Martin Sebor Opened: 2004-07-01 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++Most ctype member functions come in two forms: one that operates +on a single character at a time and another form that operates +on a range of characters. Both forms are typically described by +a single Effects and/or Returns clause. +
++The Returns clause of each of the single-character non-virtual forms +suggests that the function calls the corresponding single character +virtual function, and that the array form calls the corresponding +virtual array form. Neither of the two forms of each virtual member +function is required to be implemented in terms of the other. +
++There are three problems: +
++1. One is that while the standard does suggest that each non-virtual +member function calls the corresponding form of the virtual function, +it doesn't actually explicitly require it. +
++Implementations that cache results from some of the virtual member +functions for some or all values of their arguments might want to +call the array form from the non-array form the first time to fill +the cache and avoid any or most subsequent virtual calls. Programs +that rely on each form of the virtual function being called from +the corresponding non-virtual function will see unexpected behavior +when using such implementations. +
++2. The second problem is that either form of each of the virtual +functions can be overridden by a user-defined function in a derived +class to return a value that is different from the one produced by +the virtual function of the alternate form that has not been +overriden. +
++Thus, it might be possible for, say, ctype::widen(c) to return one +value, while for ctype::widen(&c, &c + 1, &wc) to set +wc to another value. This is almost certainly not intended. Both +forms of every function should be required to return the same result +for the same character, otherwise the same program using an +implementation that calls one form of the functions will behave +differently than when using another implementation that calls the +other form of the function "under the hood." +
++3. The last problem is that the standard text fails to specify whether +one form of any of the virtual functions is permitted to be implemented +in terms of the other form or not, and if so, whether it is required +or permitted to call the overridden virtual function or not. +
++Thus, a program that overrides one of the virtual functions so that +it calls the other form which then calls the base member might end +up in an infinite loop if the called form of the base implementation +of the function in turn calls the other form. +
++Lillehammer: Part of this isn't a real problem. We already talk about +caching. 22.1.1/6 But part is a real problem. ctype virtuals may call +each other, so users don't know which ones to override to avoid avoid +infinite loops.
+ +This is a problem for all facet virtuals, not just ctype virtuals, +so we probably want a blanket statement in clause 22 for all +facets. The LWG is leaning toward a blanket prohibition, that a +facet's virtuals may never call each other. We might want to do that +in clause 27 too, for that matter. A review is necessary. Bill will +provide wording.
+ +[ +2009-07 Frankfurt, Howard provided wording directed by consensus. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++Add paragraph 3 to 22.4 [locale.categories]: +
+ ++-3- Within this clause it is unspecified if one virtual function calls another +virtual function. ++ + + +Rationale:
++We are explicitly not addressing bullet +item #2, thus giving implementors more latitude. Users will have to +override both virtual functions, not just one. +
+ + + +
474. confusing Footnote 297
Section: 27.7.2.6.4 [ostream.inserters.character] Status: CD1 - Submitter: Martin Sebor Opened: 2004-07-01 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2004-07-01 Last modified: 2010-10-29View all other issues in [ostream.inserters.character].
View all issues with CD1 status.
Discussion:
@@ -21603,7 +23330,7 @@ I propose to strike the Footnote.
475. May the function object passed to for_each modify the elements of the iterated sequence?
Section: 25.2.4 [alg.foreach] Status: CD1 - Submitter: Stephan T. Lavavej, Jaakko Jarvi Opened: 2004-07-09 Last modified: 2008-09-26
+ Submitter: Stephan T. Lavavej, Jaakko Jarvi Opened: 2004-07-09 Last modified: 2010-10-29View all other issues in [alg.foreach].
View all issues with CD1 status.
Discussion:
@@ -21687,8 +23414,8 @@ passed to it.
478. Should forward iterator requirements table have a line for r->m?
-Section: 24.2.3 [forward.iterators] Status: CD1 - Submitter: Dave Abrahams Opened: 2004-07-11 Last modified: 2008-09-26
+Section: 24.2.5 [forward.iterators] Status: CD1 + Submitter: Dave Abrahams Opened: 2004-07-11 Last modified: 2010-10-29
View all other issues in [forward.iterators].
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Duplicate of: 477
@@ -21754,10 +23481,52 @@ This is a defect because it constrains an lvalue to returning a modifiable lvalu +
+482. Swapping pairs
+Section: 20.3.5 [pairs], 20.4 [tuple] Status: Resolved + Submitter: Andrew Koenig Opened: 2004-09-14 Last modified: 2010-11-20
+View all other issues in [pairs].
+View all issues with Resolved status.
+Discussion:
+(Based on recent comp.std.c++ discussion)
+ +Pair (and tuple) should specialize std::swap to work in terms of +std::swap on their components. For example, there's no obvious reason +why swapping two objects of type pair<vector<int>, +list<double> > should not take O(1).
+ +[Lillehammer: We agree it should be swappable. Howard will + provide wording.]
+ + +[ +Post Oxford: We got swap for pair but accidently +missed tuple. tuple::swap is being tracked by 522. +]
+ + + + +Proposed resolution:
++Wording provided in +N1856. +
+ +Rationale:
++Recommend
+ + + + +NADResolved, fixed by +N1856. +
488. rotate throws away useful information
Section: 25.3.11 [alg.rotate] Status: CD1 - Submitter: Howard Hinnant Opened: 2004-11-22 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2004-11-22 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -21843,7 +23612,7 @@ Toronto: moved to Ready.
495. Clause 22 template parameter requirements
Section: 22 [localization] Status: CD1 - Submitter: Beman Dawes Opened: 2005-01-10 Last modified: 2008-09-26
+ Submitter: Beman Dawes Opened: 2005-01-10 Last modified: 2010-10-29View all other issues in [localization].
View all issues with CD1 status.
Discussion:
@@ -21918,13 +23687,13 @@ requirements of charT (described in 21 [strings]).
496. Illegal use of "T" in vector<bool>
-Section: 23.3.6 [vector] Status: CD1 - Submitter: richard@ex-parrot.com Opened: 2005-02-10 Last modified: 2008-09-26
+Section: 23.4.1 [vector] Status: CD1 + Submitter: richard@ex-parrot.com Opened: 2005-02-10 Last modified: 2010-10-29
View all other issues in [vector].
View all issues with CD1 status.
Discussion:
-In the synopsis of the std::vector<bool> specialisation in 23.3.6 [vector], +In the synopsis of the std::vector<bool> specialisation in 23.4.1 [vector], the non-template assign() function has the signature
void assign( size_type n, const T& t ); @@ -21943,7 +23712,7 @@ the non-template assign() function has the signature
497. meaning of numeric_limits::traps for floating point types
Section: 18.3.1.2 [numeric.limits.members] Status: CD1 - Submitter: Martin Sebor Opened: 2005-03-02 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2005-03-02 Last modified: 2010-10-29View all other issues in [numeric.limits.members].
View all issues with CD1 status.
Discussion:
@@ -22006,7 +23775,7 @@ at runtime.
498. Requirements for partition() and stable_partition() too strong
Section: 25.3.13 [alg.partitions] Status: WP - Submitter: Sean Parent, Joe Gottman Opened: 2005-05-04 Last modified: 2009-10-26
+ Submitter: Sean Parent, Joe Gottman Opened: 2005-05-04 Last modified: 2010-10-29View all issues with WP status.
Discussion:
@@ -22139,9 +23908,7 @@ that is a digression). I consider the fact that partition isn't defined to work for ForwardIterator a minor embarrassment.
-[Mont Tremblant: Moved to Open, request motivation and use cases -by next meeting. Sean provided further rationale by post-meeting -mailing.]
+[Mont Tremblant: Moved to Open, request motivation and use cases by next meeting. Sean provided further rationale by post-meeting mailing.]
@@ -22151,8 +23918,8 @@ mailing.]
505. Result_type in random distribution requirements
-Section: X [rand.req], TR1 5.1.1 [tr.rand.req] Status: CD1 - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-09-26
+Section: 26.5.1 [rand.req], TR1 5.1.1 [tr.rand.req] Status: CD1 + Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29
View all other issues in [rand.req].
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Discussion:
@@ -22193,7 +23960,7 @@ Berlin: Voted to WP. N1932 adopts the proposed resolution: see Table 5 row 1.
507. Missing requirement for variate_generator::operator()
Section: 26.5 [rand], TR1 5.1.3 [tr.rand.var] Status: CD1 - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-09-26
+ Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29View all other issues in [rand].
View all issues with CD1 status.
Discussion:
@@ -22235,7 +24002,7 @@ Precondition: distribution().operator()(e,value) is well-formed.
508. Bad parameters for ranlux64_base_01
Section: 26.5.5 [rand.predef], TR1 5.1.5 [tr.rand.predef] Status: CD1 - Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2008-09-26
+ Submitter: Walter Brown Opened: 2005-07-03 Last modified: 2010-10-29View all other issues in [rand.predef].
View all issues with CD1 status.
Discussion:
@@ -22319,7 +24086,7 @@ just above paragraph 5.
518. Are insert and erase stable for unordered_multiset and unordered_multimap?
Section: 23.2.5 [unord.req], TR1 6.3.1 [tr.unord.req] Status: CD1 - Submitter: Matt Austern Opened: 2005-07-03 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 2005-07-03 Last modified: 2010-10-29View other active issues in [unord.req].
View all other issues in [unord.req].
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@@ -22388,7 +24155,7 @@ preserves the relative ordering of equivalent elements.
519. Data() undocumented
Section: 23.3.1 [array], TR1 6.2.2 [tr.array.array] Status: CD1 - Submitter: Pete Becker Opened: 2005-07-03 Last modified: 2008-09-26
+ Submitter: Pete Becker Opened: 2005-07-03 Last modified: 2010-10-29View all other issues in [array].
View all issues with CD1 status.
Discussion:
@@ -22421,8 +24188,8 @@ of data() is unspecified.
520. Result_of and pointers to data members
-Section: 20.7.11.1 [func.bind], TR1 3.6 [tr.func.bind] Status: CD1 - Submitter: Pete Becker Opened: 2005-07-03 Last modified: 2008-09-26
+Section: 20.8.10.1 [func.bind], TR1 3.6 [tr.func.bind] Status: CD1 + Submitter: Pete Becker Opened: 2005-07-03 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
@@ -22464,8 +24231,8 @@ Peter provided wording.
521. Garbled requirements for argument_type in reference_wrapper
-Section: 20.7.5 [refwrap], TR1 2.1.2 [tr.util.refwrp.refwrp] Status: CD1 - Submitter: Pete Becker Opened: 2005-07-03 Last modified: 2008-09-26
+Section: 20.8.4 [refwrap], TR1 2.1.2 [tr.util.refwrp.refwrp] Status: CD1 + Submitter: Pete Becker Opened: 2005-07-03 Last modified: 2010-10-29
View all other issues in [refwrap].
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Discussion:
@@ -22536,8 +24303,8 @@ function's cv-qualifiers); the type T1 is cv T0*
522. Tuple doesn't define swap
-Section: 20.5 [tuple], TR1 6.1 [tr.tuple] Status: CD1 - Submitter: Andy Koenig Opened: 2005-07-03 Last modified: 2008-09-26
+Section: 20.4 [tuple], TR1 6.1 [tr.tuple] Status: CD1 + Submitter: Andy Koenig Opened: 2005-07-03 Last modified: 2010-10-29
View all other issues in [tuple].
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Discussion:
@@ -22567,7 +24334,7 @@ Bellevue: Alisdair provided wording.Proposed resolution:
-Add these signatures to 20.5 [tuple] +Add these signatures to 20.4 [tuple]
template <class... Types> @@ -22579,7 +24346,7 @@ template <class... Types>-Add this signature to 20.5.2 [tuple.tuple] +Add this signature to 20.4.2 [tuple.tuple]
void swap(tuple&&); @@ -22638,7 +24405,7 @@ template <class... Types>
524. regex named character classes and case-insensitivity don't mix
Section: 28 [re] Status: CD1 - Submitter: Eric Niebler Opened: 2005-07-01 Last modified: 2008-09-26
+ Submitter: Eric Niebler Opened: 2005-07-01 Last modified: 2010-10-29View all other issues in [re].
View all issues with CD1 status.
Discussion:
@@ -22713,18 +24480,51 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a +
+525. type traits definitions not clear
+Section: 20.7.4 [meta.unary], TR1 4.5 [tr.meta.unary] Status: Resolved + Submitter: Robert Klarer Opened: 2005-07-11 Last modified: 2010-11-19
+View all other issues in [meta.unary].
+View all issues with Resolved status.
+Discussion:
++It is not completely clear how the primary type traits deal with +cv-qualified types. And several of the secondary type traits +seem to be lacking a definition. +
+ +[ +Berlin: Howard to provide wording. +]
+ + + +Proposed resolution:
++Wording provided in N2028. +A +revision (N2157) +provides more detail for motivation. +
+ + +Rationale:
+Solved by revision (N2157) +in the WP. + + + + +
527. tr1::bind has lost its Throws clause
-Section: 20.7.11.1.3 [func.bind.bind], TR1 3.6.3 [tr.func.bind.bind] Status: CD1 - Submitter: Peter Dimov Opened: 2005-10-01 Last modified: 2008-09-26
-View other active issues in [func.bind.bind].
+Section: 20.8.10.1.2 [func.bind.bind], TR1 3.6.3 [tr.func.bind.bind] Status: CD1 + Submitter: Peter Dimov Opened: 2005-10-01 Last modified: 2010-10-29
View all other issues in [func.bind.bind].
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Discussion:
-The original bind proposal gives the guarantee that tr1::bind(f, t1, -..., tN) does not throw when the copy constructors of f, t1, ..., tN -don't. +The original bind proposal gives the guarantee that tr1::bind(f, t1, ..., tN) does not throw when the copy constructors of f, t1, ..., tN don't.
@@ -22783,7 +24583,7 @@ throws an exception.
Proposed resolution:
-In 20.7.11.1.3 [func.bind.bind], add a new paragraph after p2: +In 20.8.10.1.2 [func.bind.bind], add a new paragraph after p2:
@@ -22792,7 +24592,7 @@ in the BoundArgs... pack expansion throws an exception.-In 20.7.11.1.3 [func.bind.bind], add a new paragraph after p4: +In 20.8.10.1.2 [func.bind.bind], add a new paragraph after p4:
@@ -22808,7 +24608,7 @@ in the BoundArgs... pack expansion throws an exception.
530. Must elements of a string be contiguous?
Section: 21.4 [basic.string] Status: CD1 - Submitter: Matt Austern Opened: 2005-11-15 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 2005-11-15 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with CD1 status.
Discussion:
@@ -22816,7 +24616,7 @@ in the BoundArgs... pack expansion throws an exception. that the elements of a vector must be stored in contiguous memory. Should the same also apply to basic_string? -We almost require contiguity already. Clause 23.4.4 [multiset] +
We almost require contiguity already. Clause 23.6.4 [multiset] defines operator[] as data()[pos]. What's missing is a similar guarantee if we access the string's elements via the iterator interface.
@@ -22861,7 +24661,7 @@ more design choices.
531. array forms of unformatted input functions
Section: 27.7.1.3 [istream.unformatted] Status: CD1 - Submitter: Martin Sebor Opened: 2005-11-23 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2005-11-23 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with CD1 status.
Discussion:
@@ -22936,8 +24736,8 @@ writing to out of bounds memory when n == 0. Martin provided fix.
533. typo in 2.2.3.10/1
-Section: 20.8.15.2.11 [util.smartptr.getdeleter], TR1 2.2.3.10 [tr.util.smartptr.getdeleter] Status: CD1 - Submitter: Paolo Carlini Opened: 2005-11-09 Last modified: 2009-05-01
+Section: 20.9.10.2.11 [util.smartptr.getdeleter], TR1 2.2.3.10 [tr.util.smartptr.getdeleter] Status: CD1 + Submitter: Paolo Carlini Opened: 2005-11-09 Last modified: 2010-10-29
View all other issues in [util.smartptr.getdeleter].
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Discussion:
@@ -22968,7 +24768,7 @@ If*thisp owns a deleter d...
534. Missing basic_string members
Section: 21.4 [basic.string] Status: CD1 - Submitter: Alisdair Meredith Opened: 2005-11-16 Last modified: 2008-09-26
+ Submitter: Alisdair Meredith Opened: 2005-11-16 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with CD1 status.
Discussion:
@@ -23102,7 +24902,7 @@ Berlin: Has support. Alisdair provided wording.
535. std::string::swap specification poorly worded
Section: 21.4.6.8 [string::swap] Status: CD1 - Submitter: Beman Dawes Opened: 2005-12-14 Last modified: 2008-09-26
+ Submitter: Beman Dawes Opened: 2005-12-14 Last modified: 2010-10-29View all other issues in [string::swap].
View all issues with CD1 status.
Discussion:
@@ -23149,7 +24949,7 @@ characters thatwerewas in s,
537. Typos in the signatures in 27.6.1.3/42-43 and 27.6.2.4
Section: 27.7.1.3 [istream.unformatted] Status: CD1 - Submitter: Paolo Carlini Opened: 2006-02-12 Last modified: 2008-09-26
+ Submitter: Paolo Carlini Opened: 2006-02-12 Last modified: 2010-10-29View all other issues in [istream.unformatted].
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Discussion:
@@ -23203,7 +25003,7 @@ After 27.6.2.4p3 change:
538. 241 again: Does unique_copy() require CopyConstructible and Assignable?
Section: 25.3.9 [alg.unique] Status: CD1 - Submitter: Howard Hinnant Opened: 2006-02-09 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2006-02-09 Last modified: 2010-10-29View all other issues in [alg.unique].
View all issues with CD1 status.
Discussion:
@@ -23258,10 +25058,374 @@ Otherwise CopyConstructible is not required. +
+539. partial_sum and adjacent_difference should mention requirements
+Section: 26.7.3 [partial.sum] Status: WP + Submitter: Marc Schoolderman Opened: 2006-02-06 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++There are some problems in the definition of partial_sum and +adjacent_difference in 26.4 [lib.numeric.ops] +
+ ++Unlike accumulate and inner_product, these functions are not +parametrized on a "type T", instead, 26.4.3 [lib.partial.sum] simply +specifies the effects clause as; +
+ ++ ++Assigns to every element referred to by iterator i in the range +[result,result + (last - first)) a value correspondingly equal to +
++((...(* first + *( first + 1)) + ...) + *( first + ( i - result ))) ++And similarly for BinaryOperation. Using just this definition, it seems +logical to expect that: +
+ + ++ +char i_array[4] = { 100, 100, 100, 100 }; +int o_array[4]; + +std::partial_sum(i_array, i_array+4, o_array); ++Is equivalent to +
+ ++ +int o_array[4] = { 100, 100+100, 100+100+100, 100+100+100+100 }; ++i.e. 100, 200, 300, 400, with addition happening in the result type, +int. +
+ ++Yet all implementations I have tested produce 100, -56, 44, -112, +because they are using an accumulator of the InputIterator's +value_type, which in this case is char, not int. +
+ ++The issue becomes more noticeable when the result of the expression *i + +*(i+1) or binary_op(*i, *i-1) can't be converted to the +value_type. In a contrived example: +
+ ++ +enum not_int { x = 1, y = 2 }; +... +not_int e_array[4] = { x, x, y, y }; +std::partial_sum(e_array, e_array+4, o_array); ++Is it the intent that the operations happen in the input type, or in +the result type? +
+ ++If the intent is that operations happen in the result type, something +like this should be added to the "Requires" clause of 26.4.3/4 +[lib.partial.sum]: +
+ ++ ++The type of *i + *(i+1) or binary_op(*i, *(i+1)) shall meet the +requirements of CopyConstructible (20.1.3) and Assignable +(23.1) types. +
+(As also required for T in 26.4.1 [lib.accumulate] and 26.4.2 +[lib.inner.product].) +
+ ++The "auto initializer" feature proposed in +N1894 +is not required to +implement partial_sum this way. The 'narrowing' behaviour can still be +obtained by using the std::plus<> function object. +
+ ++If the intent is that operations happen in the input type, then +something like this should be added instead; +
+ ++ ++The type of *first shall meet the requirements of +CopyConstructible (20.1.3) and Assignable (23.1) types. +The result of *i + *(i+1) or binary_op(*i, *(i+1)) shall be +convertible to this type. +
+The 'widening' behaviour can then be obtained by writing a custom proxy +iterator, which is somewhat involved. +
+ ++In both cases, the semantics should probably be clarified. +
+ ++26.4.4 [lib.adjacent.difference] is similarly underspecified, although +all implementations seem to perform operations in the 'result' type: +
+ ++ +unsigned char i_array[4] = { 4, 3, 2, 1 }; +int o_array[4]; + +std::adjacent_difference(i_array, i_array+4, o_array); ++o_array is 4, -1, -1, -1 as expected, not 4, 255, 255, 255. +
+ ++In any case, adjacent_difference doesn't mention the requirements on the +value_type; it can be brought in line with the rest of 26.4 +[lib.numeric.ops] by adding the following to 26.4.4/2 +[lib.adjacent.difference]: +
+ +++The type of *first shall meet the requirements of +CopyConstructible (20.1.3) and Assignable (23.1) types." +
[ +Berlin: Giving output iterator's value_types very controversial. Suggestion of +adding signatures to allow user to specify "accumulator". +]
+ + +[ +Bellevue: +]
+ + ++The intent of the algorithms is to perform their calculations using the type of the input iterator. +Proposed wording provided. ++ +[ +Sophia Antipolis: +]
+ + ++We did not agree that the proposed resolution was correct. For example, +when the arguments are types (float*, float*, double*), the +highest-quality solution would use double as the type of the +accumulator. If the intent of the wording is to require that the type of +the accumulator must be the input_iterator's value_type, the wording +should specify it. ++ +[ +2009-05-09 Alisdair adds: +]
+ + +++ ++Now that we have the facility, the 'best' accumulator type could probably be +deduced as: +
++std::common_type<InIter::value_type, OutIter::reference>::type ++This type would then have additional requirements of constructability and +incrementability/assignability. +
++If this extracting an accumulator type from a pair/set of iterators (with +additional requirements on that type) is a problem for multiple functions, +it might be worth extracting into a SharedAccumulator concept or similar. +
++I'll go no further in writing up wording now, until the group gives a +clearer indication of preferred direction. +
+[ +2009-07 Frankfurt +]
+ + ++The proposed resolution isn't quite right. For example, "the type of +*first" should be changed to "iterator::value_type" or similar. Daniel +volunteered to correct the wording. ++ +[ +2009-07-29 Daniel corrected wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
+ + + ++
+ + + + + + + +- +
+ ++Change 26.7.3 [partial.sum]/1 as indicated: +
+ ++++Effects: Let VT be InputIterator's value type. For a nonempty range, +initializes an accumulator acc of type VT with *first and performs +*result = acc. For every iterator i in [first + 1, last) in order, acc is then +modified by acc = acc + *i or acc = binary_op(acc, *i) and is assigned +to *(result + (i - first)).
+ +Assigns to every element referred to by +iterator i in the range [result,result + (last - first)) a value +correspondingly +equal to++ ++((...(*first + *(first + 1)) + ...) + *(first + (i - result))) ++ +
+or +++binary_op(binary_op(..., + binary_op(*first, *(first + 1)),...), *(first + (i - result))) +- +
+ ++Change 26.7.3 [partial.sum]/3 as indicated: +
+ ++Complexity: Exactly max((last - first) - 1, 0) +applications +of+binary_opthe binary operation. +- +
+ ++Change 26.7.3 [partial.sum]/4 as indicated: +
+ ++Requires: VT shall be constructible from the type of *first, the result of +acc + *i or binary_op(acc, *i) shall be implicitly convertible to VT, and +the result of the expression acc shall be writable to the result +output iterator. In the ranges [first,last] and +[result,result + (last - first)] [..] ++- +
+ ++Change 26.7.4 [adjacent.difference]/1 as indicated: +
+ ++++Effects: Let VT be InputIterator's value type. For a nonempty range, +initializes an accumulator acc of type VT with *first and performs +*result = acc. For every iterator i in [first + 1, last) in order, +initializes a +value val of type VT with *i, assigns the result of val - acc or +binary_op(val, acc) +to *(result + (i - first)) and modifies acc = std::move(val). +
+ +Assigns to every element referred to by iterator i in the range +[result + 1, +result + (last - first)) a value correspondingly equal to++ ++*(first + (i - result)) - *(first + (i - result) - 1) ++ +
+or ++ ++binary_op(*(first + (i - result)), *(first + (i - result) - 1)). ++
+result gets the value of *first.+- +
+ ++Change 26.7.4 [adjacent.difference]/2 as indicated: +
+ ++Requires: VT shall be MoveAssignable ([moveassignable]) +and shall be +constructible from the type of *first. The result +of the expression acc and the result of the expression val - acc or +binary_op(val, acc) +shall be writable to the result output iterator. In the ranges +[first,last] [..] ++- +
++Change 26.7.4 [adjacent.difference]/5 as indicated: +
+ ++Complexity: Exactly max((last - first) - 1, 0) +applications +of+binary_opthe binary operation. +
540. shared_ptr<void>::operator*()
-Section: 20.8.15.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] Status: CD1 - Submitter: Martin Sebor Opened: 2005-10-15 Last modified: 2008-09-26
+Section: 20.9.10.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] Status: CD1 + Submitter: Martin Sebor Opened: 2005-10-15 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared.obs].
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Discussion:
@@ -23318,8 +25482,8 @@ definition) of the function shall be well-formed.
541. shared_ptr template assignment and void
-Section: 20.8.15.2 [util.smartptr.shared], TR1 2.2.3 [tr.util.smartptr.shared] Status: CD1 - Submitter: Martin Sebor Opened: 2005-10-16 Last modified: 2008-09-26
+Section: 20.9.10.2 [util.smartptr.shared], TR1 2.2.3 [tr.util.smartptr.shared] Status: CD1 + Submitter: Martin Sebor Opened: 2005-10-16 Last modified: 2010-10-29
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Discussion:
@@ -23398,8 +25562,8 @@ public:
542. shared_ptr observers
-Section: 20.8.15.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] Status: CD1 - Submitter: Martin Sebor Opened: 2005-10-18 Last modified: 2008-09-26
+Section: 20.9.10.2.5 [util.smartptr.shared.obs], TR1 2.2.3.5 [tr.util.smartptr.shared.obs] Status: CD1 + Submitter: Martin Sebor Opened: 2005-10-18 Last modified: 2010-10-29
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Discussion:
@@ -23438,7 +25602,7 @@ capture the intent.Proposed resolution:
-Change 20.8.15.2.5 [util.smartptr.shared.obs] p12: +Change 20.9.10.2.5 [util.smartptr.shared.obs] p12:
[Note: use_count() is not necessarily efficient.
Use only for @@ -23446,7 +25610,7 @@ debugging and testing purposes, not for production code.--end note-Change 20.8.15.3.5 [util.smartptr.weak.obs] p3: +Change 20.9.10.3.5 [util.smartptr.weak.obs] p3:
@@ -26758,7 +29338,7 @@ the exception is caught but not rethrown (see[Note: use_count() is not necessarily efficient.
Use only for @@ -23460,7 +25624,7 @@ debugging and testing purposes, not for production code.--end note
543. valarray slice default constructor
Section: 26.6.4 [class.slice] Status: CD1 - Submitter: Howard Hinnant Opened: 2005-11-03 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2005-11-03 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -23535,8 +25699,8 @@ lengths, and strides, as explained in the previous section.
545. When is a deleter deleted?
-Section: 20.8.15.2.11 [util.smartptr.getdeleter], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] Status: CD1 - Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2008-09-26
+Section: 20.9.10.2.11 [util.smartptr.getdeleter], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] Status: CD1 + Submitter: Matt Austern Opened: 2006-01-10 Last modified: 2010-10-29
View all other issues in [util.smartptr.getdeleter].
View all issues with CD1 status.
Discussion:
@@ -23553,7 +25717,7 @@ instances). We should say which it is.Proposed resolution:
-Add after the first sentence of 20.8.15.2.11 [util.smartptr.getdeleter]/1: +Add after the first sentence of 20.9.10.2.11 [util.smartptr.getdeleter]/1:
@@ -23574,7 +25738,7 @@ This can happen if the implementation doesn't destroy the deleter until all
550. What should the return type of pow(float,int) be?
Section: 26.8 [c.math] Status: CD1 - Submitter: Howard Hinnant Opened: 2006-01-12 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2006-01-12 Last modified: 2010-10-29View all other issues in [c.math].
View all issues with CD1 status.
Discussion:
@@ -23636,9 +25800,9 @@ resolution")[ -
+
Howard, post Kona: -
+-] +]Unfortunately I strongly disagree with a part of the resolution @@ -23669,7 +25833,7 @@ route (with pow only) and C99 took another (with many math functions in The proposed resolution basically says: C++98 got it wrong and C99 got it right; let's go with C99.
[ @@ -23711,8 +25875,8 @@ The added signatures are:
551. <ccomplex>
-Section: 26.4.11 [cmplxh], TR1 8.3 [tr.c99.cmplxh] Status: CD1 - Submitter: Howard Hinnant Opened: 2006-01-23 Last modified: 2008-09-26
+Section: X [cmplxh], TR1 8.3 [tr.c99.cmplxh] Status: CD1 + Submitter: Howard Hinnant Opened: 2006-01-23 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
@@ -23773,7 +25937,7 @@ note]
552. random_shuffle and its generator
Section: 25.3.12 [alg.random.shuffle] Status: CD1 - Submitter: Martin Sebor Opened: 2006-01-25 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2006-01-25 Last modified: 2010-10-29View all other issues in [alg.random.shuffle].
View all issues with CD1 status.
Discussion:
@@ -23812,10 +25976,215 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a +
+556. is Compare a BinaryPredicate?
+Section: 25.4 [alg.sorting] Status: WP + Submitter: Martin Sebor Opened: 2006-02-05 Last modified: 2010-10-29
+View all other issues in [alg.sorting].
+View all issues with WP status.
+Discussion:
++In 25, p8 we allow BinaryPredicates to return a type that's convertible +to bool but need not actually be bool. That allows predicates to return +things like proxies and requires that implementations be careful about +what kinds of expressions they use the result of the predicate in (e.g., +the expression in if (!pred(a, b)) need not be well-formed since the +negation operator may be inaccessible or return a type that's not +convertible to bool). +
++Here's the text for reference: +
++ ++ ...if an algorithm takes BinaryPredicate binary_pred as its argument + and first1 and first2 as its iterator arguments, it should work + correctly in the construct if (binary_pred(*first1, first2)){...}. +
+In 25.3, p2 we require that the Compare function object return true +of false, which would seem to preclude such proxies. The relevant text +is here: +
++ ++ Compare is used as a function object which returns true if the first + argument is less than the second, and false otherwise... +
[ +Portland: Jack to define "convertible to bool" such that short circuiting isn't +destroyed. +]
+ + +[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Review once wording received. Stefanus to send proposed wording. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Review once wording received. Stefanus to send proposed wording. ++ +[ +2009-10-24 Stefanus supplied wording. +]
+ + ++Move to Review once wording received. Stefanus to send proposed wording. +Old proposed wording here: ++ ++++I think we could fix this by rewording 25.3, p2 to read somthing like: +
+++-2- Compare is
used as a function object which returns +true if the first argumenta BinaryPredicate. The +return value of the function call operator applied to an object of type +Compare, when converted to type bool, yields true +if the first argument of the call is less than the second, and +false otherwise. Compare comp is used throughout for +algorithms assuming an ordering relation. It is assumed that comp +will not apply any non-constant function through the dereferenced iterator. +[ +2010-01-17: +]
+ + +++ ++Howard expresses concern that the current direction of the proposed +wording outlaws expressions such as: +
+ ++ +if (!comp(x, y)) ++Daniel provides wording which addresses that concern. +
+ ++The previous wording is saved here: +
+ ++ ++ ++Change 25.4 [alg.sorting] p2: +
++Compare is used as a function object. The return value of +the function call operator applied to an object of type Compare, when +converted to type bool, yields true if the first argument of the +call+ +which returns true if the first argument+is less than the second, and false otherwise. Compare +comp is used throughout for algorithms assuming an ordering +relation. It is assumed that comp will not apply any +non-constant function through the dereferenced iterator. +[ +2010-01-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
+ ++
+ + + + + +- +
+ ++Change 25.1 [algorithms.general]/7+8 as indicated. [This change is +recommended to bring the return value requirements of BinaryPredicate +and Compare in sync.] +
+ ++++7 The Predicate parameter is used whenever an algorithm expects a +function object that when applied to the result of dereferencing the +corresponding iterator returns a value testable as true. In other +words, if an algorithm takes Predicate pred as its argument and +first as its iterator argument, it should work correctly in the +construct
+ +if (pred(*first)){...}pred(*first) +contextually converted to bool (4 [conv]). The +function object pred shall not apply any nonconstant function through +the dereferenced iterator. This function object may be a pointer to function, or +an object of a type with an appropriate function call operator. ++8 The BinaryPredicate parameter is used whenever an algorithm expects a +function object that when applied to the result of dereferencing two +corresponding iterators or to dereferencing an iterator and type T when +T is part of the signature returns a value testable as true. +In other words, if an algorithm takes BinaryPredicate +binary_pred as its argument and first1 and first2 as +its iterator arguments, it should work correctly in the construct
+if +(binary_pred(*first1, *first2)){...}binary_pred(*first1, +*first2) contextually converted to bool (4 [conv]). BinaryPredicate always takes the first iterator +type as its first argument, that is, in those cases when T value is +part of the signature, it should work correctly in thecontext of if +(binary_pred(*first1, value)){...}construct +binary_pred(*first1, value) contextually converted to bool +(4 [conv]). binary_pred shall not apply any +non-constant function through the dereferenced iterators. +- +
+ ++Change 25.4 [alg.sorting]/2 as indicated: +
+ ++2 Compare is+used asa function object type (20.8 [function.objects]). The return value of the function call operation +applied to an object of type Compare, when contextually converted to +type bool (4 [conv]), yields true if the first +argument of the callwhich returns true if the first +argumentis less than the second, and false otherwise. +Compare comp is used throughout for algorithms assuming an ordering +relation. It is assumed that comp will not apply any non-constant +function through the dereferenced iterator. +
559. numeric_limits<const T>
Section: 18.3.1 [limits] Status: CD1 - Submitter: Martin Sebor Opened: 2006-02-19 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2006-02-19 Last modified: 2010-10-29View all other issues in [limits].
View all issues with CD1 status.
Discussion:
@@ -23890,7 +26259,7 @@ automatically.
561. inserter overly generic
Section: 24.5.2.6.5 [inserter] Status: CD1 - Submitter: Howard Hinnant Opened: 2006-02-21 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2006-02-21 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -24044,9 +26413,8 @@ Change 24.4.2.6.5:
[ -Kona (2007): This issue will probably be addressed as a part of the -concepts overhaul of the library anyway, but the proposed resolution is -correct in the absence of concepts. Proposed Disposition: Ready +Kona (2007): This issue will probably be addressed as a part of the concepts overhaul of the library anyway, but the proposed resolution is correct in the absence of concepts. +Proposed Disposition: Ready ]
@@ -24056,7 +26424,7 @@ correct in the absence of concepts. Proposed Disposition: Ready
562. stringbuf ctor inefficient
Section: 27.8 [string.streams] Status: CD1 - Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29View all other issues in [string.streams].
View all issues with CD1 status.
Discussion:
@@ -24151,7 +26519,7 @@ Kona (2007) Moved to Ready.
563. stringbuf seeking from end
Section: 27.8.1.4 [stringbuf.virtuals] Status: CD1 - Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29View all other issues in [stringbuf.virtuals].
View all issues with CD1 status.
Discussion:
@@ -24209,7 +26577,7 @@ Kona (2007) Moved to Ready.
564. stringbuf seekpos underspecified
Section: 27.8.1.4 [stringbuf.virtuals] Status: WP - Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2009-10-26
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29View all other issues in [stringbuf.virtuals].
View all issues with WP status.
Discussion:
@@ -24281,7 +26649,7 @@ plugs the hole by specifying seekpos() in terms of seekoff().
565. xsputn inefficient
Section: 27.6.2.4.5 [streambuf.virt.put] Status: WP - Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2009-10-26
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29View all issues with WP status.
Discussion:
@@ -24363,7 +26731,7 @@ proposed wording doesn't accomplish that. Proposed Disposition: Open
566. array forms of unformatted input function undefined for zero-element arrays
Section: 27.7.1.3 [istream.unformatted] Status: CD1 - Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2006-02-23 Last modified: 2010-10-29View all other issues in [istream.unformatted].
View all issues with CD1 status.
Discussion:
@@ -24435,7 +26803,7 @@ location of the array.
567. streambuf inserter and extractor should be unformatted
Section: 27.7 [iostream.format] Status: CD1 - Submitter: Martin Sebor Opened: 2006-02-25 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2006-02-25 Last modified: 2010-10-29View all other issues in [iostream.format].
View all issues with CD1 status.
Discussion:
@@ -24502,7 +26870,7 @@ Kona (2007): Proposed Disposition: Ready
574. DR 369 Contradicts Text
Section: 27.4 [iostream.objects] Status: CD1 - Submitter: Pete Becker Opened: 2006-04-18 Last modified: 2008-09-26
+ Submitter: Pete Becker Opened: 2006-04-18 Last modified: 2010-10-29View all other issues in [iostream.objects].
View all issues with CD1 status.
Discussion:
@@ -24553,8 +26921,8 @@ Disposition: Review
575. the specification of ~shared_ptr is MT-unfriendly, makes implementation assumptions
-Section: 20.8.15.2.2 [util.smartptr.shared.dest], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] Status: CD1 - Submitter: Peter Dimov Opened: 2006-04-23 Last modified: 2008-09-26
+Section: 20.9.10.2.2 [util.smartptr.shared.dest], TR1 2.2.3.2 [tr.util.smartptr.shared.dest] Status: CD1 + Submitter: Peter Dimov Opened: 2006-04-23 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared.dest].
View all issues with CD1 status.
Discussion:
@@ -24633,7 +27001,7 @@ after *this is destroyed. --end note]
576. find_first_of is overconstrained
Section: 25.2.7 [alg.find.first.of] Status: CD1 - Submitter: Doug Gregor Opened: 2006-04-25 Last modified: 2008-09-26
+ Submitter: Doug Gregor Opened: 2006-04-25 Last modified: 2010-10-29View all other issues in [alg.find.first.of].
View all issues with CD1 status.
Discussion:
@@ -24686,7 +27054,7 @@ template<classForwardIterator1InputIterator1, class Fo
577. upper_bound(first, last, ...) cannot return last
Section: 25.4.3.2 [upper.bound] Status: CD1 - Submitter: Seungbeom Kim Opened: 2006-05-03 Last modified: 2008-09-26
+ Submitter: Seungbeom Kim Opened: 2006-05-03 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -24735,8 +27103,8 @@ conditions hold: !(value < *j) or comp(value, *j)
578. purpose of hint to allocator::allocate()
-Section: 20.8.8.1 [allocator.members] Status: CD1 - Submitter: Martin Sebor Opened: 2006-05-17 Last modified: 2008-09-26
+Section: 20.9.5.1 [allocator.members] Status: CD1 + Submitter: Martin Sebor Opened: 2006-05-17 Last modified: 2010-10-29
View all other issues in [allocator.members].
View all issues with CD1 status.
Discussion:
@@ -24795,7 +27163,7 @@ adjacent element is often a good choice to pass for this argument.
581.
flush()not unformatted functionSection: 27.7.2.7 [ostream.unformatted] Status: CD1 - Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2006-06-14 Last modified: 2010-10-29View all other issues in [ostream.unformatted].
View all issues with CD1 status.
Discussion:
@@ -24859,7 +27227,7 @@ Kona (2007): Proposed Disposition: Ready
586. string inserter not a formatted function
Section: 21.4.8.9 [string.io] Status: CD1 - Submitter: Martin Sebor Opened: 2006-06-22 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2006-06-22 Last modified: 2010-10-29View all other issues in [string.io].
View all issues with CD1 status.
Discussion:
@@ -24942,8 +27310,7 @@ indicates a failure.
589. Requirements on iterators of member template functions of containers
Section: 23.2 [container.requirements] Status: CD1 - Submitter: Peter Dimov Opened: 2006-08-02 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+ Submitter: Peter Dimov Opened: 2006-08-02 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with CD1 status.
Duplicate of: 536
@@ -25003,7 +27370,7 @@ easy to fix this up as a safety net and as a clear statement of intent.
593. __STDC_CONSTANT_MACROS
Section: 18.4 [cstdint], TR1 8.22 [tr.c99.cstdint] Status: CD1 - Submitter: Walter Brown Opened: 2006-08-28 Last modified: 2008-09-26
+ Submitter: Walter Brown Opened: 2006-08-28 Last modified: 2010-10-29View all other issues in [cstdint].
View all issues with CD1 status.
Discussion:
@@ -25043,10 +27410,227 @@ particular, the symbols __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS +
+594. Disadvantages of defining Swappable in terms of CopyConstructible and Assignable
+Section: 20.2.1 [utility.arg.requirements] Status: Resolved + Submitter: Niels Dekker Opened: 2006-11-02 Last modified: 2010-11-19
+View all other issues in [utility.arg.requirements].
+View all issues with Resolved status.
+Discussion:
+ ++It seems undesirable to define the Swappable requirement in terms of +CopyConstructible and Assignable requirements. And likewise, once the +MoveConstructible and MoveAssignable requirements (N1860) have made it +into the Working Draft, it seems undesirable to define the Swappable +requirement in terms of those requirements. Instead, it appears +preferable to have the Swappable requirement defined exclusively in +terms of the existence of an appropriate swap function. +
+ ++Section 20.1.4 [lib.swappable] of the current Working Draft (N2009) +says: +
+ ++ ++The Swappable requirement is met by satisfying one or more of the +following conditions:
++
+- +T is Swappable if T satisfies the CopyConstructible requirements +(20.1.3) and the Assignable requirements (23.1); +
+- +T is Swappable if a namespace scope function named swap exists in the +same namespace as the definition of T, such that the expression +swap(t,u) is valid and has the semantics described in Table 33. +
++I can think of three disadvantages of this definition: +
+ ++
+ +- +
++If a client's type T satisfies the first condition (T is both +CopyConstructible and Assignable), the client cannot stop T from +satisfying the Swappable requirement without stopping T from +satisfying the first condition. +
++A client might want to stop T from satisfying the Swappable +requirement, because swapping by means of copy construction and +assignment might throw an exception, and she might find a throwing +swap unacceptable for her type. On the other hand, she might not feel +the need to fully implement her own swap function for this type. In +this case she would want to be able to simply prevent algorithms that +would swap objects of type T from being used, e.g., by declaring a +swap function for T, and leaving this function purposely undefined. +This would trigger a link error, if an attempt would be made to use +such an algorithm for this type. For most standard library +implementations, this practice would indeed have the effect of +stopping T from satisfying the Swappable requirement. +
+- +
++A client's type T that does not satisfy the first condition can not be +made Swappable by providing a specialization of std::swap for T. +
++While I'm aware about the fact that people have mixed feelings about +providing a specialization of std::swap, it is well-defined to do so. +It sounds rather counter-intuitive to say that T is not Swappable, if +it has a valid and semantically correct specialization of std::swap. +Also in practice, providing such a specialization will have the same +effect as satisfying the Swappable requirement. +
+- +
++For a client's type T that satisfies both conditions of the Swappable +requirement, it is not specified which of the two conditions prevails. +After reading section 20.1.4 [lib.swappable], one might wonder whether +objects of T will be swapped by doing copy construction and +assignments, or by calling the swap function of T. +
++I'm aware that the intention of the Draft is to prefer calling the +swap function of T over doing copy construction and assignments. Still +in my opinion, it would be better to make this clear in the wording of +the definition of Swappable. +
++I would like to have the Swappable requirement defined in such a way +that the following code fragment will correctly swap two objects of a +type T, if and only if T is Swappable: +
+ +using std::swap; + swap(t, u); // t and u are of type T. ++ ++This is also the way Scott Meyers recommends calling a swap function, +in Effective C++, Third Edition, item 25. +
+ ++Most aspects of this issue have been dealt with in a discussion on +comp.std.c++ about the Swappable requirement, from 13 September to 4 +October 2006, including valuable input by David Abrahams, Pete Becker, +Greg Herlihy, Howard Hinnant and others. +
+ +[ +San Francisco: +]
+ + ++Recommend NAD. Solved by +N2774. ++ +[ +2009-07 Frankfurt +]
+ + ++Moved to Open. Waiting for non-concepts draft. ++ +[ +2009-11-08 Howard adds: +]
+ + ++This issue is very closely related to 742. ++ +[ +2010-02-03 Sean Hunt adds: +]
+ + +++ ++While reading N3000, I independently came across Issue 594. Having seen that +it's an issue under discussion, I think the proposed wording needs fixing to +something more like "...function call swap(t,u) that includes std::swap in its +overload set is valid...", because "...is valid within the namespace std..." +does not allow other libraries to simply use the Swappable requirement by +referring to the standard's definition, since they cannot actually perform any +calls within std. +
+ ++This wording I suggested would also make overloads visible in the same scope as +the `using std::swap` valid for Swappable requirements; a more complex wording +limiting the non-ADL overload set to std::swap might be required. +
+[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial. Rationale added. ++ + + +Rationale:
++Solved by N3048. +
+ + +Proposed resolution:
++Change section 20.1.4 [lib.swappable] as follows: +
++ + + + ++The Swappable requirement is met by satisfying +
+one or more of the following conditions:+the following condition:+ +
+- +
+T is Swappable if T satisfies the CopyConstructible requirements +(20.1.3) and the Assignable requirements (23.1);+- +
++T is Swappable if a namespace scope function named swap exists in the +same namespace as the definition of T, such that the expression +swap(t,u) is valid and has the semantics described in Table 33. ++T is Swappable if an unqualified function call swap(t,u) is valid +within the namespace std, and has the semantics described in Table 33. +
595. TR1/C++0x: fabs(complex<T>) redundant / wrongly specified
Section: 26.4.7 [complex.value.ops] Status: CD1 - Submitter: Stefan Große Pawig Opened: 2006-09-24 Last modified: 2009-03-21
+ Submitter: Stefan Große Pawig Opened: 2006-09-24 Last modified: 2010-10-29View all other issues in [complex.value.ops].
View all issues with CD1 status.
Discussion:
@@ -25199,7 +27783,7 @@ Proposed Disposition: Ready
596. 27.8.1.3 Table 112 omits "a+" and "a+b" modes
Section: 27.9.1.4 [filebuf.members] Status: CD1 - Submitter: Thomas Plum Opened: 2006-09-26 Last modified: 2008-09-26
+ Submitter: Thomas Plum Opened: 2006-09-26 Last modified: 2010-10-29View all other issues in [filebuf.members].
View all issues with CD1 status.
Discussion:
@@ -25336,7 +27920,7 @@ Kona (2007) Added proposed wording and moved to Review.
598. Decimal: Conversion to integral should truncate, not round.
Section: TRDecimal 3.2 [trdec.types.types] Status: TRDec - Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2007-04-21
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29View all other issues in [trdec.types.types].
View all issues with TRDec status.
Discussion:
@@ -25414,7 +27998,7 @@ Change the Returns: clause in 3.2.4.4 to:
599. Decimal: Say "octets" instead of "bytes."
Section: TRDecimal 3.1 [trdec.types.encodings] Status: TRDec - Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2007-04-21
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29View all issues with TRDec status.
Discussion:
@@ -25472,7 +28056,7 @@ decimal128 is a decimal128 number, which is encoded in 16 consecutive <
600. Decimal: Wrong parameters for wcstod* functions
Section: TRDecimal 3.9 [trdec.types.cwchar] Status: TRDec - Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2007-04-21
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29View all issues with TRDec status.
Discussion:
@@ -25505,7 +28089,7 @@ Change "3.9.1 Additions to
<cwchar>synopsis" to:
601. Decimal: numeric_limits typos
Section: TRDecimal 3.3 [trdec.types.limits] Status: TRDec - Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2007-04-21
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29View all issues with TRDec status.
Discussion:
@@ -25547,7 +28131,7 @@ In "3.3 Additions to header
<limits>" change numeric_limits&l
602. Decimal: "generic floating type" not defined.
Section: TRDecimal 3 [trdec.types] Status: TRDec - Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2007-04-21
+ Submitter: Daniel Krugler Opened: 2006-05-28 Last modified: 2010-10-29View all other issues in [trdec.types].
View all issues with TRDec status.
Discussion:
@@ -25576,7 +28160,7 @@ collectively described as the basic floating types.
603. Decimal: Trivially simplifying decimal classes.
Section: TRDecimal 3 [trdec.types] Status: TRDec - Submitter: Martin Sebor Opened: 2006-05-28 Last modified: 2007-04-21
+ Submitter: Martin Sebor Opened: 2006-05-28 Last modified: 2010-10-29View all other issues in [trdec.types].
View all issues with TRDec status.
Discussion:
@@ -25695,7 +28279,7 @@ Change "3.2.4.1 construct/copy/destroy" as follows:
604. Decimal: Storing a reference to a facet unsafe.
Section: TRDecimal 3 [trdec.types] Status: TRDec - Submitter: Martin Sebor Opened: 2006-05-28 Last modified: 2007-07-25
+ Submitter: Martin Sebor Opened: 2006-05-28 Last modified: 2010-10-29View all other issues in [trdec.types].
View all issues with TRDec status.
Discussion:
@@ -25817,13 +28401,11 @@ Redmond: We would prefer to rename "extended" to "decimal".
605. Decimal: <decfloat.h> doesn't live here anymore.
Section: TRDecimal 3.4 [trdec.types.cdecfloat] Status: TRDec - Submitter: Robert Klarer Opened: 2006-10-17 Last modified: 2007-04-21
+ Submitter: Robert Klarer Opened: 2006-10-17 Last modified: 2010-10-29View all issues with TRDec status.
Discussion:
-In Berlin, WG14 decided to drop the <decfloat.h> header. The -contents of that header have been moved into <float.h>. For the -sake of C compatibility, we should make corresponding changes. +In Berlin, WG14 decided to drop the <decfloat.h> header. The contents of that header have been moved into <float.h>. For the sake of C compatibility, we should make corresponding changes.
@@ -25842,10 +28424,7 @@ sake of C compatibility, we should make corresponding changes.Headers<cdecfloat>and<decfloat.h>define characteristics of the decimal floating-point typesdecimal32,decimal64, anddecimal128. As well,<decfloat.h>defines the convenience typedefs_Decimal32,_Decimal64, and_Decimal128, for compatibilty with the C programming language.-The header
<cfloat>is described in [tr.c99.cfloat]. The header<float.h>-is described in [tr.c99.floath]. These headers are extended by this -Technical Report to define characteristics of the decimal -floating-point typesdecimal32,decimal64, anddecimal128. As well,<float.h>is extended to define the convenience typedefs_Decimal32,_Decimal64, and_Decimal128for compatibility with the C programming language. +The header<cfloat>is described in [tr.c99.cfloat]. The header<float.h>is described in [tr.c99.floath]. These headers are extended by this Technical Report to define characteristics of the decimal floating-point typesdecimal32,decimal64, anddecimal128. As well,<float.h>is extended to define the convenience typedefs_Decimal32,_Decimal64, and_Decimal128for compatibility with the C programming language.@@ -25873,7 +28452,7 @@ floating-point types
decimal32,decimal64, andd
607. Concern about short seed vectors
Section: 26.5.7.1 [rand.util.seedseq] Status: CD1 - Submitter: Charles Karney Opened: 2006-10-26 Last modified: 2008-09-26
+ Submitter: Charles Karney Opened: 2006-10-26 Last modified: 2010-10-29View all other issues in [rand.util.seedseq].
View all issues with CD1 status.
Discussion:
@@ -25924,7 +28503,7 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
608. Unclear seed_seq construction details
Section: 26.5.7.1 [rand.util.seedseq] Status: CD1 - Submitter: Charles Karney Opened: 2006-10-26 Last modified: 2008-09-26
+ Submitter: Charles Karney Opened: 2006-10-26 Last modified: 2010-10-29View all other issues in [rand.util.seedseq].
View all issues with CD1 status.
Discussion:
@@ -25959,7 +28538,7 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
609. missing static const
Section: 26.5.4.2 [rand.adapt.ibits], TR1 5.1 [tr.rand] Status: CD1 - Submitter: Walter E. Brown Opened: 2006-11-02 Last modified: 2008-09-26
+ Submitter: Walter E. Brown Opened: 2006-11-02 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -25994,8 +28573,9 @@ and accept my apologies for the oversight.
610. Suggested non-normative note for C++0x
-Section: 20.7.15.2.1 [func.wrap.func.con], TR1 3.7.2.1 [tr.func.wrap.func.con] Status: CD1 - Submitter: Scott Meyers Opened: 2006-11-02 Last modified: 2008-09-26
+Section: 20.8.14.2.1 [func.wrap.func.con], TR1 3.7.2.1 [tr.func.wrap.func.con] Status: CD1 + Submitter: Scott Meyers Opened: 2006-11-02 Last modified: 2010-10-29
+View all other issues in [func.wrap.func.con].
View all issues with CD1 status.
Discussion:
@@ -26066,7 +28646,7 @@ function pointer (a "bound member function").
611. Standard library templates and incomplete types
Section: 17.6.3.8 [res.on.functions] Status: CD1 - Submitter: Nicola Musatti Opened: 2006-11-13 Last modified: 2008-09-26
+ Submitter: Nicola Musatti Opened: 2006-11-13 Last modified: 2010-10-29View all other issues in [res.on.functions].
View all issues with CD1 status.
Discussion:
@@ -26135,7 +28715,7 @@ component.
612. numeric_limits::is_modulo insufficiently defined
Section: 18.3.1.2 [numeric.limits.members] Status: CD1 - Submitter: Chris Jefferson Opened: 2006-11-10 Last modified: 2008-09-26
+ Submitter: Chris Jefferson Opened: 2006-11-10 Last modified: 2010-10-29View all other issues in [numeric.limits.members].
View all issues with CD1 status.
Discussion:
@@ -26190,7 +28770,7 @@ differs from the true value by an integer multiple of (max() - min() +
613. max_digits10 missing from numeric_limits
Section: 18.3.1.5 [numeric.special] Status: CD1 - Submitter: Bo Persson Opened: 2006-11-20 Last modified: 2008-09-26
+ Submitter: Bo Persson Opened: 2006-11-20 Last modified: 2010-10-29View all other issues in [numeric.special].
View all issues with CD1 status.
Discussion:
@@ -26288,7 +28868,7 @@ public:
616. missing 'typename' in ctype_byname
Section: 22.4.1.2 [locale.ctype.byname] Status: CD1 - Submitter: Bo Persson Opened: 2006-12-16 Last modified: 2008-09-26
+ Submitter: Bo Persson Opened: 2006-12-16 Last modified: 2010-10-29View all other issues in [locale.ctype.byname].
View all issues with CD1 status.
Discussion:
@@ -26317,7 +28897,7 @@ as this is a dependent type, it should obviously be
618. valarray::cshift() effects on empty array
Section: 26.6.2.7 [valarray.members] Status: CD1 - Submitter: Gabriel Dos Reis Opened: 2007-01-10 Last modified: 2008-09-26
+ Submitter: Gabriel Dos Reis Opened: 2007-01-10 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -26374,7 +28954,7 @@ Kona (2007) Changed proposed wording, added rationale and set to Review.
619. Longjmp wording problem
Section: 18.10 [support.runtime] Status: CD1 - Submitter: Lawrence Crowl Opened: 2007-01-12 Last modified: 2008-09-26
+ Submitter: Lawrence Crowl Opened: 2007-01-12 Last modified: 2010-10-29View all other issues in [support.runtime].
View all issues with CD1 status.
Discussion:
@@ -26429,7 +29009,7 @@ undefined behavior if replacing the setjmp and longjmp by
620. valid uses of empty valarrays
Section: 26.6.2.1 [valarray.cons] Status: CD1 - Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29View all other issues in [valarray.cons].
View all issues with CD1 status.
Discussion:
@@ -26498,7 +29078,7 @@ function.
621. non-const copy assignment operators of helper arrays
Section: 26.6 [numarray] Status: CD1 - Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29View all other issues in [numarray].
View all issues with CD1 status.
Discussion:
@@ -26605,7 +29185,7 @@ Kona (2007) Added const qualification to the return types and set to Ready.
622. behavior of
filebufdtor andcloseon errorSection: 27.9.1.17 [fstream.members] Status: CD1 - Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -26631,7 +29211,7 @@ dtor? Should the dtor catch and swallow it or should it propagate it to the caller? The text doesn't seem to provide any guidance in this regard other than the general restriction on throwing (but not propagating) exceptions from destructors of library classes in -17.6.4.11 [res.on.exception.handling]. +17.6.4.12 [res.on.exception.handling].
@@ -26679,7 +29259,7 @@ errors.
[ -See 397 and 418 for related issues. +See 397 and 418 for related issues. ]
@@ -26746,7 +29326,7 @@ And to make the following edits in 27.9.1.2 [filebuf.cons].close(). If an exception occurs during the destruction of the object, including the call toclose(), the exception is caught but not rethrown (see -17.6.4.11 [res.on.exception.handling]). +17.6.4.12 [res.on.exception.handling]).
623.
pubimbueforbidden to callimbueSection: 27.2.1 [iostream.limits.imbue] Status: CD1 - Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -26802,7 +29382,7 @@ causes any instance of
basic_ios::imbueor
624.
valarrayassignment and arrays of unequal lengthSection: 26.6.2.2 [valarray.assign] Status: CD1 - Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -26918,10 +29498,184 @@ These operators allow the results of a generalized subscripting operation to be +
+625. mixed up Effects and Returns clauses
+Section: 17 [library] Status: Resolved + Submitter: Martin Sebor Opened: 2007-01-20 Last modified: 2010-11-19
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Resolved status.
+Duplicate of: 895
+Discussion:
++ +Many member functions of
+ +basic_stringare overloaded, +with some of the overloads taking astringargument, +othersvalue_type*, otherssize_type, and +others stilliterators. Often, the requirements on one of +the overloads are expressed in the form of Effects, +Throws, and in the Working Paper +(N2134) +also Remark clauses, while those on the rest of the overloads +via a reference to this overload and using a Returns clause. ++The difference between the two forms of specification is that per +17.5.1.4 [structure.specifications], p3, an Effects clause specifies +"actions performed by the functions," i.e., its observable +effects, while a Returns clause is "a description of the +return value(s) of a function" that does not impose any +requirements on the function's observable effects. +
+ ++Since only Notes are explicitly defined to be informative and +all other paragraphs are explicitly defined to be normative, like +Effects and Returns, the new Remark clauses also +impose normative requirements. +
+ ++So by this strict reading of the standard there are some member +functions of
+ +basic_stringthat are required to throw an +exception under some conditions or use specific traits members while +many other otherwise equivalent overloads, while obliged to return the +same values, aren't required to follow the exact same requirements +with regards to the observable effects. ++Here's an example of this problem that was precipitated by the change +from informative Notes to normative Remarks (presumably made to +address 424): +
+ ++In the Working Paper,
+ +find(string, size_type)contains a +Remark clause (which is just a Note in the current +standard) requiring it to usetraits::eq(). ++
+ +find(const charT *s, size_type pos)is specified to +returnfind(string(s), pos)by a Returns clause +and so it is not required to usetraits::eq(). However, +the Working Paper has replaced the original informative Note +about the function usingtraits::length()with a +normative requirement in the form of a Remark. Calling +traits::length()may be suboptimal, for example when the +argument is a very long array whose initial substring doesn't appear +anywhere in*this. ++Here's another similar example, one that existed even prior to the +introduction of Remarks: +
+ ++
+ +insert(size_type pos, string, size_type, size_type)is +required to throwout_of_rangeifpos > +size(). ++
insert(size_type pos, string str)is specified to return +insert(pos, str, 0, npos)by a Returns clause and +so its effects whenpos > size()are strictly speaking +unspecified. ++ +
+I believe a careful review of the current Effects and +Returns clauses is needed in order to identify all such +problematic cases. In addition, a review of the Working Paper should +be done to make sure that the newly introduced normative Remark +clauses do not impose any undesirable normative requirements in place +of the original informative Notes. + + +[ +Batavia: Alan and Pete to work. +]
+ + +[ +Bellevue: Marked as NAD Editorial. +]
+ + +[ +Post-Sophia Antipolis: +Martin indicates there is still work to be done on this issue. +Reopened. +]
+ + +[ +Batavia (2009-05): +]
+ ++Tom proposes we say that, unless specified otherwise, +it is always the caller's responsibility to verify that supplied arguments +meet the called function's requirements. +If further semantics are specified +(e.g., that the function throws under certain conditions), +then it is up to the implementer to check those conditions. +Alan feels strongly that our current use of Requires in this context +is confusing, especially now that requires is a new keyword. ++ +[ +2009-07 Frankfurt +]
+ + ++Move to Tentatively NAD. ++ +[ +2009 Santa Cruz: +]
+ + ++Move to Open. Martin will work on proposed wording. ++ +[ +2010 Pittsburgh: +]
+ + ++Moved to NAD Editorial, solved by revision to N3021. ++ + + + +Rationale:
++Solved by revision to N3021. +
+ + +Proposed resolution:
++
+ + + + +
628. Inconsistent definition of basic_regex constructor
Section: 28.8 [re.regex] Status: CD1 - Submitter: Bo Persson Opened: 2007-01-23 Last modified: 2008-09-26
+ Submitter: Bo Persson Opened: 2007-01-23 Last modified: 2010-10-29View all other issues in [re.regex].
View all issues with CD1 status.
Discussion:
@@ -26958,7 +29712,7 @@ Change 28.8.2 [re.regex.construct]:
629. complex
insertion and locale dependence Section: 26.4.6 [complex.ops] Status: CD1 - Submitter: Gabriel Dos Reis Opened: 2007-01-28 Last modified: 2008-09-26
+ Submitter: Gabriel Dos Reis Opened: 2007-01-28 Last modified: 2010-10-29View all other issues in [complex.ops].
View all issues with CD1 status.
Discussion:
@@ -27052,7 +29806,7 @@ will extract unambiguously.]
630. arrays of valarray
Section: 26.6.2.1 [valarray.cons] Status: WP - Submitter: Martin Sebor Opened: 2007-01-28 Last modified: 2009-10-26
+ Submitter: Martin Sebor Opened: 2007-01-28 Last modified: 2010-10-29View all other issues in [valarray.cons].
View all issues with WP status.
Discussion:
@@ -27227,15 +29981,15 @@ which you can assign to a valarray of size 0, but not to any other
634. allocator.address() doesn't work for types overloading operator&
-Section: 20.8.8.1 [allocator.members] Status: CD1 - Submitter: Howard Hinnant Opened: 2007-02-07 Last modified: 2008-09-26
+Section: 20.9.5.1 [allocator.members] Status: CD1 + Submitter: Howard Hinnant Opened: 2007-02-07 Last modified: 2010-10-29
View all other issues in [allocator.members].
View all issues with CD1 status.
Duplicate of: 350
Discussion:
-20.8.8.1 [allocator.members] says: +20.9.5.1 [allocator.members] says:
pointer address(reference x) const;@@ -27247,7 +30001,7 @@ which you can assign to a valarray of size 0, but not to any other-20.8.8.1 [allocator.members] defines CopyConstructible which currently not +20.9.5.1 [allocator.members] defines CopyConstructible which currently not only defines the semantics of copy construction, but also restricts what an overloaded operator& may do. I believe proposals are in the works (such as concepts and rvalue reference) to decouple these two requirements. Indeed it is not evident @@ -27278,7 +30032,7 @@ is expected to make use of allocator::address mandatory for containers.
Proposed resolution:
-Change 20.8.8.1 [allocator.members]: +Change 20.9.5.1 [allocator.members]:
@@ -27318,10 +30072,136 @@ issue to Ready status to be voted into the WP at Kona. +
+635. domain of allocator::address
+Section: 20.2.5 [allocator.requirements] Status: Resolved + Submitter: Howard Hinnant Opened: 2007-02-08 Last modified: 2010-11-20
+View all other issues in [allocator.requirements].
+View all issues with Resolved status.
+Discussion:
++The table of allocator requirements in 20.2.5 [allocator.requirements] describes +allocator::address as: +
++a.address(r) +a.address(s) ++where r and s are described as: +
++ ++a value of type X::reference obtained by the expression *p. +
+and p is +
+ ++ ++a value of type X::pointer, obtained by calling a1.allocate, +where a1 == a +
+This all implies that to get the address of some value of type T that +value must have been allocated by this allocator or a copy of it. +
+ ++However sometimes container code needs to compare the address of an external value of +type T with an internal value. For example list::remove(const T& t) +may want to compare the address of the external value t with that of a value +stored within the list. Similarly vector or deque insert may +want to make similar comparisons (to check for self-referencing calls). +
+ ++Mandating that allocator::address can only be called for values which the +allocator allocated seems overly restrictive. +
+ +[ +post San Francisco: +]
+ + ++Pablo recommends NAD Editorial, solved by +N2768. ++ +[ +2009-04-28 Pablo adds: +]
+ + ++Tentatively-ready NAD Editorial as fixed by +N2768. ++ +[ +2009-07 Frankfurt +]
+ + ++Fixed by N2768. ++ +[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + +++ + + +NAD EditorialResolved. Addressed by +N2982. +Proposed resolution:
++Change 20.2.5 [allocator.requirements]: +
+ +++ ++r : a value of type X::reference
+obtained by the expression *p. ++s : a value of type X::const_reference
+obtained by the +expression *q or by conversion from a value r. +[ +post Oxford: This would be rendered NAD Editorial by acceptance of +N2257. +]
+ + +[ +Kona (2007): This issue is section 8 of N2387. There was some discussion of it but +no resolution to this issue was recorded. Moved to Open. +]
+ + + + + + +
638. deque end invalidation during erase
Section: 23.3.2.3 [deque.modifiers] Status: CD1 - Submitter: Steve LoBasso Opened: 2007-02-17 Last modified: 2008-09-26
+ Submitter: Steve LoBasso Opened: 2007-02-17 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -27417,7 +30297,7 @@ Spertus to evaluate and, if need be, file an issue.
640. 27.6.2.5.2 does not handle (unsigned) long long
Section: 27.7.2.6.2 [ostream.inserters.arithmetic] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-02-17 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2007-02-17 Last modified: 2010-10-29View all other issues in [ostream.inserters.arithmetic].
View all issues with CD1 status.
Discussion:
@@ -27466,7 +30346,7 @@ occurs as if it performed the following code fragment:
643. Impossible "as if" clauses
Section: 27.9.1.1 [filebuf], 22.4.2.2.2 [facet.num.put.virtuals] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-02-20 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2007-02-20 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -27531,12 +30411,12 @@ A local variable punct is initialized via
646. const incorrect match_result members
-Section: 28.10.4 [re.results.form] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-02-26 Last modified: 2008-09-26
+Section: 28.10.5 [re.results.form] Status: CD1 + Submitter: Daniel Krügler Opened: 2007-02-26 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
-28.10.4 [re.results.form] (root and para 3) in N2134 defines the two function template +28.10.5 [re.results.form] (root and para 3) in N2134 defines the two function template members format as non-const functions, although they are declared as const in 28.10 [re.results]/3.
@@ -27545,7 +30425,7 @@ as const in 28.10 [re.results]/3.Proposed resolution:
Add the missing const specifier to both format overloads described -in section 28.10.4 [re.results.form]. +in section 28.10.5 [re.results.form].
@@ -27555,14 +30435,12 @@ in section 28.10.4 [re.results.form].
650. regex_token_iterator and const correctness
Section: 28.12.2 [re.tokiter] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-03-05 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2007-03-05 Last modified: 2010-10-29View all other issues in [re.tokiter].
View all issues with CD1 status.
Discussion:
-Both the class definition of regex_token_iterator (28.12.2 -[re.tokiter]/6) and the latter member specifications (28.12.2.2 -[re.tokiter.comp]/1+2) declare both comparison operators as +Both the class definition of regex_token_iterator (28.12.2 [re.tokiter]/6) and the latter member specifications (28.12.2.2 [re.tokiter.comp]/1+2) declare both comparison operators as non-const functions. Furtheron, both dereference operators are unexpectedly also declared as non-const in 28.12.2 [re.tokiter]/6 as well as in (28.12.2.3 [re.tokiter.deref]/1+2). @@ -27610,7 +30488,7 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
651. Missing preconditions for regex_token_iterator c'tors
Section: 28.12.2.1 [re.tokiter.cnstr] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-03-05 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2007-03-05 Last modified: 2010-10-29View all other issues in [re.tokiter.cnstr].
View all issues with CD1 status.
Discussion:
@@ -27659,12 +30537,11 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
652. regex_iterator and const correctness
Section: 28.12.1 [re.regiter] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-03-05 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2007-03-05 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
-Both the class definition of regex_iterator (28.12.1 [re.regiter]/1) -and the latter member specification (28.12.1.2 [re.regiter.comp]/1+2) -declare both comparison operators as +
+Both the class definition of regex_iterator (28.12.1 [re.regiter]/1) and the latter member specification (28.12.1.2 [re.regiter.comp]/1+2) declare both comparison operators as non-const functions. Furtheron, both dereference operators are unexpectedly also declared as non-const in 28.12.1 [re.regiter]/1 as well as in (28.12.1.3 [re.regiter.deref]/1+2). @@ -27711,13 +30588,13 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
654. Missing IO roundtrip for random number engines
-Section: X [rand.req.eng] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-03-08 Last modified: 2009-05-01
+Section: 26.5.1.4 [rand.req.eng] Status: CD1 + Submitter: Daniel Krügler Opened: 2007-03-08 Last modified: 2010-10-29
View all other issues in [rand.req.eng].
View all issues with CD1 status.
Discussion:
-Table 98 and para 5 in X [rand.req.eng] specify +Table 98 and para 5 in 26.5.1.4 [rand.req.eng] specify the IO insertion and extraction semantic of random number engines. It can be shown, v.i., that the specification of the extractor cannot guarantee to fulfill the requirement @@ -27842,12 +30719,12 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
655. Signature of generate_canonical not useful
Section: 26.5.7.2 [rand.util.canonical] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-03-08 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2007-03-08 Last modified: 2010-10-29View all other issues in [rand.util.canonical].
View all issues with CD1 status.
Discussion:
-In 26.5.1 [rand.synopsis] we have the declaration +In 26.5.2 [rand.synopsis] we have the declaration
template<class RealType, class UniformRandomNumberGenerator, @@ -27888,10 +30765,61 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a +- +
+658. Two unspecified function comparators in [function.objects]
+Section: 20.8 [function.objects] Status: Resolved + Submitter: Daniel Krügler Opened: 2007-03-19 Last modified: 2010-11-19
+View all other issues in [function.objects].
+View all issues with Resolved status.
+Discussion:
++The header <functional> synopsis in 20.8 [function.objects] +contains the following two free comparison operator templates +for the function class template +
+ ++ +template<class Function1, class Function2> +void operator==(const function<Function1>&, const function<Function2>&); +template<class Function1, class Function2> +void operator!=(const function<Function1>&, const function<Function2>&); ++which are nowhere described. I assume that they are relicts before the +corresponding two private and undefined member templates in the function +template (see 20.8.14.2 [func.wrap.func] and [func.wrap.func.undef]) have been introduced. The original free +function templates should be removed, because using an undefined entity +would lead to an ODR violation of the user. +
+ + +Proposed resolution:
++Remove the above mentioned two function templates from +the header <functional> synopsis (20.8 [function.objects]) +
+ ++ + + +template<class Function1, class Function2> +void operator==(const function<Function1>&, const function<Function2>&); +template<class Function1, class Function2> +void operator!=(const function<Function1>&, const function<Function2>&);+Rationale:
+Fixed by +N2292 +Standard Library Applications for Deleted Functions. + + + + +
659. istreambuf_iterator should have an operator->()
Section: 24.6.3 [istreambuf.iterator] Status: WP - Submitter: Niels Dekker Opened: 2007-03-25 Last modified: 2009-10-26
+ Submitter: Niels Dekker Opened: 2007-03-25 Last modified: 2010-10-29View all other issues in [istreambuf.iterator].
View all issues with WP status.
Discussion:
@@ -27920,7 +30848,7 @@ Based on Greg's example, the following code demonstrates the issue: i->~C(); // ... so this should be supported! }Of course, operator-> is also needed when the value_type of istreambuf_iterator is a class. @@ -28072,7 +31000,7 @@ Change 24.6.3 [istreambuf.iterator], p1: The class template istreambuf_iterator reads successive characters from the streambuf for which it was constructed. operator* provides access to the current input character, if -any. [Note: operator-> may return a proxy. — +any. [Note: operator-> may return a proxy. — end note] Each time operator++ is evaluated, the iterator advances to the next input character. If the end of stream is reached @@ -28091,12 +31019,12 @@ object suitable for use as an end-of-range.
660. Missing Bitwise Operations
-Section: 20.7 [function.objects] Status: CD1 - Submitter: Beman Dawes Opened: 2007-04-02 Last modified: 2008-09-26
+Section: 20.8 [function.objects] Status: CD1 + Submitter: Beman Dawes Opened: 2007-04-02 Last modified: 2010-10-29
View all other issues in [function.objects].
View all issues with CD1 status.
Discussion:
-Section 20.7 [function.objects] provides function +
Section 20.8 [function.objects] provides function objects for some unary and binary operations, but others are missing. In a LWG reflector discussion, beginning with c++std-lib-18078, pros and cons of adding some of the missing operations @@ -28115,7 +31043,7 @@ resolution is limited to them.
Proposed resolution:
-To 20.7 [function.objects], Function objects, paragraph 2, add to the header +
To 20.8 [function.objects], Function objects, paragraph 2, add to the header <functional> synopsis:
template <class T> struct bit_and; @@ -28153,7 +31081,7 @@ template <class T> struct bit_xor;
661. New 27.6.1.2.2 changes make special extractions useless
Section: 27.7.1.2.2 [istream.formatted.arithmetic] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-04-01 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2007-04-01 Last modified: 2010-10-29View all other issues in [istream.formatted.arithmetic].
View all issues with CD1 status.
Discussion:
@@ -28171,11 +31099,10 @@ contents of the local variable lval is in no case written into val. Furtheron both fragments need a currently missing parentheses in the beginning of the if-statement to be valid C++. -- I would like to ask whether the omission of a similar explicit +
- +I would like to ask whether the omission of a similar explicit extraction of unsigned short and unsigned int in terms of long - -compared to their corresponding new insertions, as described in -27.7.2.6.2 [ostream.inserters.arithmetic], is a deliberate decision or -an +compared to their corresponding new insertions, as described in 27.7.2.6.2 [ostream.inserters.arithmetic], is a deliberate decision or an oversight.
664. do_unshift for codecvt<char, char, mbstate_t>
Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: CD1 - Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2008-09-26
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29View all other issues in [locale.codecvt.virtuals].
View all issues with CD1 status.
Discussion:
@@ -28294,7 +31221,7 @@ mbstate_t> stores no characters.
665. do_unshift return value
Section: 22.4.1.4.2 [locale.codecvt.virtuals] Status: CD1 - Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2008-09-26
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29View all other issues in [locale.codecvt.virtuals].
View all issues with CD1 status.
Discussion:
@@ -28343,7 +31270,7 @@ Change 22.4.1.4.2 [locale.codecvt.virtuals], p8:
666. moneypunct::do_curr_symbol()
Section: 22.4.6.3.2 [locale.moneypunct.virtuals] Status: CD1 - Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2008-09-26
+ Submitter: Thomas Plum Opened: 2007-04-16 Last modified: 2010-10-29View all other issues in [locale.moneypunct.virtuals].
View all issues with CD1 status.
Discussion:
@@ -28389,11 +31316,131 @@ four characters long, usually three letters and a space. +
+671. precision of hexfloat
+Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: WP + Submitter: John Salmon Opened: 2007-04-20 Last modified: 2010-10-29
+View all other issues in [facet.num.put.virtuals].
+View all issues with WP status.
+Discussion:
++I am trying to understand how TR1 supports hex float (%a) output. +
++As far as I can tell, it does so via the following: +
++8.15 Additions to header <locale> [tr.c99.locale] +
++In subclause 22.4.2.2.2 [facet.num.put.virtuals], Table 58 Floating-point conversions, after +the line: +floatfield == ios_base::scientific %E +
++add the two lines: +
++floatfield == ios_base::fixed | ios_base::scientific && !uppercase %a +floatfield == ios_base::fixed | ios_base::scientific %A 2 ++[Note: The additional requirements on print and scan functions, later +in this clause, ensure that the print functions generate hexadecimal +floating-point fields with a %a or %A conversion specifier, and that +the scan functions match hexadecimal floating-point fields with a %g +conversion specifier. end note] +
++Following the thread, in 22.4.2.2.2 [facet.num.put.virtuals], we find: +
++For conversion from a floating-point type, if (flags & fixed) != 0 or +if str.precision() > 0, then str.precision() is specified in the +conversion specification. +
++This would seem to imply that when floatfield == fixed|scientific, the +precision of the conversion specifier is to be taken from +str.precision(). Is this really what's intended? I sincerely hope +that I'm either missing something or this is an oversight. Please +tell me that the committee did not intend to mandate that hex floats +(and doubles) should by default be printed as if by %.6a. +
+ +[ +Howard: I think the fundamental issue we overlooked was that with %f, +%e, %g, the default precision was always 6. With %a the default +precision is not 6, it is infinity. So for the first time, we need to +distinguish between the default value of precision, and the precision +value 6. +]
+ + +[ +2009-07 Frankfurt +]
+ + +++ ++Leave this open for Robert and Daniel to work on. +
++Straw poll: Disposition? +
++
+- Default is %.6a (i.e. NAD): 2
+- Always %a (no precision): 6
+- precision(-1) == %a: 3
++Daniel and Robert have direction to write up wording for the "always %a" solution. +
+ +[ +2009-07-15 Robert provided wording. +]
+ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++Change 22.4.2.2.2 [facet.num.put.virtuals], Stage 1, under p5 (near the end +of Stage 1): +
+ ++For conversion from a floating-point type, str.precision() is specified +as precision in the conversion specification +if floatfield != (ios_base::fixed | ios_base::scientific), else no +precision is specified. ++ + + +[ +Kona (2007): Robert volunteers to propose wording. +]
+ + + + +
672. Swappable requirements need updating
Section: 20.2.1 [utility.arg.requirements] Status: CD1 - Submitter: Howard Hinnant Opened: 2007-05-04 Last modified: 2008-09-26
-View other active issues in [utility.arg.requirements].
+ Submitter: Howard Hinnant Opened: 2007-05-04 Last modified: 2010-10-29View all other issues in [utility.arg.requirements].
View all issues with CD1 status.
Discussion:
@@ -28536,7 +31583,7 @@ Kona (2007): We like the change to the Swappable requirements to use move semantics. The issue relating to the support of proxies is separable from the one relating to move semantics, and it's bigger than just swap. We'd like to address only the move semantics changes under -this issue, and open a separated issue (742) to handle proxies. Also, there +this issue, and open a separated issue (742) to handle proxies. Also, there may be a third issue, in that the current definition of Swappable does not permit rvalues to be operands to a swap operation, and Howard's proposed resolution would allow the right-most operand to be an rvalue, @@ -28551,8 +31598,8 @@ swap to be rvalues).
673. unique_ptr update
-Section: 20.8.14 [unique.ptr] Status: CD1 - Submitter: Howard Hinnant Opened: 2007-05-04 Last modified: 2008-09-26
+Section: 20.9.9 [unique.ptr] Status: CD1 + Submitter: Howard Hinnant Opened: 2007-05-04 Last modified: 2010-10-29
View all other issues in [unique.ptr].
View all issues with CD1 status.
Discussion:
@@ -28673,7 +31720,7 @@ the proposed resolutions below.-Change 20.8.14.2 [unique.ptr.single]: +Change 20.9.9.2 [unique.ptr.single]:
template <class T, class D = default_delete<T>> class unique_ptr { @@ -28684,7 +31731,7 @@ Change 20.8.14.2 [unique.ptr.single]:-Change 20.8.14.2.4 [unique.ptr.single.observers]: +Change 20.9.9.2.4 [unique.ptr.single.observers]:
T&typename add_lvalue_reference<T>::type operator*() const; @@ -28694,7 +31741,7 @@ Change 20.8.14.2.4 [unique.ptr.single.observers]:-Change 20.8.14.2 [unique.ptr.single]: +Change 20.9.9.2 [unique.ptr.single]:
template <class T, class D = default_delete<T>> class unique_ptr { @@ -28726,7 +31773,7 @@ and CopyAssignable.-Change 20.8.14.2.1 [unique.ptr.single.ctor]: +Change 20.9.9.2.1 [unique.ptr.single.ctor]:
unique_ptr(T*pointer p); @@ -28766,7 +31813,7 @@ internally stored deleter which was constructed from-Change 20.8.14.2.3 [unique.ptr.single.asgn]: +Change 20.9.9.2.3 [unique.ptr.single.asgn]:
@@ -28779,7 +31826,7 @@ convertible toT*pointer.-Change 20.8.14.2.4 [unique.ptr.single.observers]: +Change 20.9.9.2.4 [unique.ptr.single.observers]:
@@ -28789,7 +31836,7 @@ Change 20.8.14.2.4 [unique.ptr.single.observers]:-Change 20.8.14.2.5 [unique.ptr.single.modifiers]: +Change 20.9.9.2.5 [unique.ptr.single.modifiers]:
@@ -28799,7 +31846,7 @@ Change 20.8.14.2.5 [unique.ptr.single.modifiers]:-Change 20.8.14.3 [unique.ptr.runtime]: +Change 20.9.9.3 [unique.ptr.runtime]:
template <class T, class D> class unique_ptr<T[], D> { @@ -28819,7 +31866,7 @@ public:-Change 20.8.14.3.1 [unique.ptr.runtime.ctor]: +Change 20.9.9.3.1 [unique.ptr.runtime.ctor]:
@@ -28838,7 +31885,7 @@ these members. -- end note]-Change 20.8.14.3.3 [unique.ptr.runtime.modifiers]: +Change 20.9.9.3.3 [unique.ptr.runtime.modifiers]:
@@ -28858,7 +31905,7 @@ templated overload. -- end note]-Change 20.8.14.2.1 [unique.ptr.single.ctor]: +Change 20.9.9.2.1 [unique.ptr.single.ctor]:
@@ -28892,8 +31939,8 @@ required).
674. shared_ptr interface changes for consistency with N1856
-Section: 20.8.15.2 [util.smartptr.shared] Status: CD1 - Submitter: Peter Dimov Opened: 2007-05-05 Last modified: 2008-09-26
+Section: 20.9.10.2 [util.smartptr.shared] Status: CD1 + Submitter: Peter Dimov Opened: 2007-05-05 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared].
View all issues with CD1 status.
Discussion:
@@ -28907,7 +31954,7 @@ and to interoperate with unique_ptr as it does with auto_ptr.Proposed resolution:
-Change 20.8.15.2 [util.smartptr.shared] as follows: +Change 20.9.10.2 [util.smartptr.shared] as follows:
@@ -28921,7 +31968,7 @@ template<class Y, class D> shared_ptr& operator=(unique_ptr<Y,D>-Change 20.8.15.2.1 [util.smartptr.shared.const] as follows: +Change 20.9.10.2.1 [util.smartptr.shared.const] as follows:
@@ -28929,7 +31976,7 @@ Change 20.8.15.2.1 [util.smartptr.shared.const] as follows:-Add to 20.8.15.2.1 [util.smartptr.shared.const]: +Add to 20.9.10.2.1 [util.smartptr.shared.const]:
@@ -28950,7 +31997,7 @@ Add to 20.8.15.2.1 [util.smartptr.shared.const]:-Change 20.8.15.2.3 [util.smartptr.shared.assign] as follows: +Change 20.9.10.2.3 [util.smartptr.shared.assign] as follows:
@@ -28958,7 +32005,7 @@ Change 20.8.15.2.3 [util.smartptr.shared.assign] as follows:-Add to 20.8.15.2.3 [util.smartptr.shared.assign]: +Add to 20.9.10.2.3 [util.smartptr.shared.assign]:
@@ -28989,8 +32036,7 @@ whether shared_ptr needs an rvalue swap.
675. Move assignment of containers
Section: 23.2 [container.requirements] Status: CD1 - Submitter: Howard Hinnant Opened: 2007-05-05 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+ Submitter: Howard Hinnant Opened: 2007-05-05 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with CD1 status.
Discussion:
@@ -29096,10 +32142,471 @@ post Sophia Antipolis Howard updated proposed wording: +
+676. Moving the unordered containers
+Section: 23.7 [unord] Status: WP + Submitter: Howard Hinnant Opened: 2007-05-05 Last modified: 2010-10-29
+View all other issues in [unord].
+View all issues with WP status.
+Discussion:
++Move semantics are missing from the unordered containers. The proposed +resolution below adds move-support consistent with +N1858 +and the current working draft. +
+ ++The current proposed resolution simply lists the requirements for each function. +These might better be hoisted into the requirements table for unordered associative containers. +Futhermore a mild reorganization of the container requirements could well be in order. +This defect report is purposefully ignoring these larger issues and just focusing +on getting the unordered containers "moved". +
+ +[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-10-17 Removed rvalue-swaps from wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Review. Alisdair will review proposed wording. ++ +[ +2009-10-29 Daniel updates wording. +]
+ + +[ +2010-01-26 Alisdair updates wording. +]
+ + +[ +2010-02-10 Howard updates wording to reference the unordered container +requirements table (modified by 704) as much as possible. +]
+ + +[ +Voted to WP in Bellevue. +]
+ + +[ +post Bellevue, Pete notes: +]
+ + +++ ++Please remind people who are reviewing issues to check that the text +modifications match the current draft. Issue 676, for example, adds two +overloads for unordered_map::insert taking a hint. One takes a +const_iterator and returns a const_iterator, and the other takes an +iterator and returns an iterator. This was correct at the time the issue +was written, but was changed in Toronto so there is only one hint +overload, taking a const_iterator and returning an iterator. +
++This issue is not ready. In addition to the relatively minor signature +problem I mentioned earlier, it puts requirements in the wrong places. +Instead of duplicating requirements throughout the template +specifications, it should put them in the front matter that talks about +requirements for unordered containers in general. This presentation +problem is editorial, but I'm not willing to do the extensive rewrite +that it requires. Please put it back into Open status. +
+[ +2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-02-24 Pete moved to Open: +]
+ + ++The descriptions of the semantics of the added insert functions belong +in the requirements table. That's where the rest of the insert +functions are. ++ +[ +2010 Pittsburgh: +]
+ + ++Move issue 676 to Ready for Pittsburgh. Nico to send Howard an issue for +the broader problem. ++ + + +Rationale:
+[ +San Francisco: +]
+ + ++Solved by +N2776. ++ +[ +Rationale is obsolete. +]
+ + + + + +Proposed resolution:
+ +unordered_map
+ ++Change 23.7.1 [unord.map]: +
+ ++ +class unordered_map +{ + ... + unordered_map(const unordered_map&); + unordered_map(unordered_map&&); + unordered_map(const Allocator&); + unordered_map(const unordered_map&, const Allocator&); + unordered_map(unordered_map&&, const Allocator&); + ... + unordered_map& operator=(const unordered_map&); + unordered_map& operator=(unordered_map&&); + ... + // modifiers + ... +std::pair<iterator, bool> insert(const value_type& obj); + template <class P> pair<iterator, bool> insert(P&& obj); + iterator insert(const_iterator hint, const value_type& obj); + template <class P> iterator insert(const_iterator hint, P&& obj); + ... + mapped_type& operator[](const key_type& k); + mapped_type& operator[](key_type&& k); + ... +}; + ++Add to 23.7.1.2 [unord.map.elem]: +
+ ++ ++ +mapped_type& operator[](const key_type& k);+ +++ +...
++Requires: key_type shall be CopyConstructible +and mapped_type shall be DefaultConstructible. +
+ ++Complexity: Average case O(1), worst case O(size()). +
+ +mapped_type& operator[](key_type&& k);+ +++ ++Requires: key_type shall be MoveConstructible and +mapped_type shall be DefaultConstructible. +
+ ++Effects: If the unordered_map does not already contain an +element whose key is equivalent to k , inserts the value +value_type(std::move(k), mapped_type()). +
+ ++Returns: A reference to x.second, where x is the +(unique) element whose key is equivalent to k. +
+ ++Complexity: Average case O(1), worst case O(size()). +
+ ++Add new section [unord.map.modifiers]: +
+ +++ +template <class P> + pair<iterator, bool> insert(P&& x); ++ ++ ++ + ++Requires: value_type is constructible from +std::forward<P>(x). +
+ ++Effects: Inserts x converted to value_type if and only +if there is no element in the container with key equivalent to the key of +value_type(x). +
+ ++Returns: The bool component of the returned +pair indicates whether the insertion takes place, and the iterator +component points to the element with key equivalent to the key of +value_type(x). +
+ ++Complexity: Average case O(1), worst case O(size()). +
+ ++Remarks: P shall be implicitly convertible to +value_type, else this signature shall not participate in overload +resolution. +
+ +template <class P> + iterator insert(const_iterator hint, P&& x); ++ ++ ++ ++Requires: value_type is constructible from +std::forward<P>(x). +
+ ++Effects: Inserts x converted to value_type if and only +if there is no element in the container with key equivalent to the key of +value_type(x). The iterator hint is a hint pointing to where +the search should start. Implementations are permitted to ignore the hint. +
+ ++Returns: An iterator pointing to the element with key equivalent to the +key of value_type(x). +
+ ++Complexity: Average case O(1), worst case O(size()). +
+ ++Remarks: P shall be implicitly convertible to +value_type, else this signature shall not participate in overload +resolution. +
+ +unordered_multimap
+ ++Change 23.7.2 [unord.multimap]: +
+ ++ +class unordered_multimap +{ + ... + unordered_multimap(const unordered_multimap&); + unordered_multimap(unordered_multimap&&); + unordered_multimap(const Allocator&); + unordered_multimap(const unordered_multimap&, const Allocator&); + unordered_multimap(unordered_multimap&&, const Allocator&); + ... + unordered_multimap& operator=(const unordered_multimap&); + unordered_multimap& operator=(unordered_multimap&&); + ... + // modifiers + ... + iterator insert(const value_type& obj); + template <class P> iterator insert(P&& obj); + iterator insert(const_iterator hint, const value_type& obj); + template <class P> iterator insert(const_iterator hint, P&& obj); + ... +}; + ++Add new section [unord.multimap.modifiers]: +
+ +++ +template <class P> + iterator insert(P&& x); ++ ++ ++ ++Requires: value_type is constructible from +std::forward<P>(x). +
+ ++Effects: Inserts x converted to value_type. +
+ ++Returns: An iterator pointing to the element with key equivalent to the +key of value_type(x). +
+ ++Complexity: Average case O(1), worst case O(size()). +
+ ++Remarks: P shall be implicitly convertible to +value_type, else this signature shall not participate in overload +resolution. +
+ +template <class P> + iterator insert(const_iterator hint, P&& x); ++ ++ ++ ++Requires: value_type is constructible from +std::forward<P>(x). +
+ ++Effects: Inserts x converted to value_type if and only +if there is no element in the container with key equivalent to the key of +value_type(x). The iterator hint is a hint pointing to where +the search should start. Implementations are permitted to ignore the hint. +
+ ++Returns: An iterator pointing to the element with key equivalent to the +key of value_type(x). +
+ ++Complexity: Average case O(1), worst case O(size()). +
+ ++Remarks: P shall be implicitly convertible to +value_type, else this signature shall not participate in overload +resolution. +
+ +unordered_set
+ ++Change 23.7.3 [unord.set]: +
+ ++ +class unordered_set +{ + ... + unordered_set(const unordered_set&); + unordered_set(unordered_set&&); + unordered_set(const Allocator&); + unordered_set(const unordered_set&, const Allocator&); + unordered_set(unordered_set&&, const Allocator&); + ... + unordered_set& operator=(const unordered_set&); + unordered_set& operator=(unordered_set&&); + ... + // modifiers + ... +std::pair<iterator, bool> insert(const value_type& obj); + pair<iterator, bool> insert(value_type&& obj); + iterator insert(const_iterator hint, const value_type& obj); + iterator insert(const_iterator hint, value_type&& obj); + ... +}; +unordered_multiset
+ ++Change 23.7.4 [unord.multiset]: +
+ ++ + + + + +class unordered_multiset +{ + ... + unordered_multiset(const unordered_multiset&); + unordered_multiset(unordered_multiset&&); + unordered_multiset(const Allocator&); + unordered_multiset(const unordered_multiset&, const Allocator&); + unordered_multiset(unordered_multiset&&, const Allocator&); + ... + unordered_multiset& operator=(const unordered_multiset&); + unordered_multiset& operator=(unordered_multiset&&); + ... + // modifiers + ... + iterator insert(const value_type& obj); + iterator insert(value_type&& obj); + iterator insert(const_iterator hint, const value_type& obj); + iterator insert(const_iterator hint, value_type&& obj); + ... +}; + +
677. Weaknesses in seed_seq::randomize [rand.util.seedseq]
Section: 26.5.7.1 [rand.util.seedseq] Status: CD1 - Submitter: Charles Karney Opened: 2007-05-15 Last modified: 2008-09-26
+ Submitter: Charles Karney Opened: 2007-05-15 Last modified: 2010-10-29View all other issues in [rand.util.seedseq].
View all issues with CD1 status.
Discussion:
@@ -29157,8 +32664,8 @@ me by Matsumoto last year. The proposed replacement for seed_seq::randomize is due to Mutsuo Saito, a student of Matsumoto, and is given in the implementation of the SIMD-oriented Fast Mersenne Twister random number generator SFMT. -http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/index.html -http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/SFMT-src-1.2.tar.gz +http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/index.html +http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/SFMT-src-1.2.tar.gzSee @@ -29166,7 +32673,7 @@ Mutsuo Saito, An Application of Finite Field: Design and Implementation of 128-bit Instruction-Based Fast Pseudorandom Number Generator, Master's Thesis, Dept. of Math., Hiroshima University (Feb. 2007) -http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/M062821.pdf +http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/M062821.pdf
One change has been made here, namely to treat the case of small n @@ -29202,13 +32709,13 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
678. Changes for [rand.req.eng]
-Section: X [rand.req.eng] Status: CD1 - Submitter: Charles Karney Opened: 2007-05-15 Last modified: 2008-09-26
+Section: 26.5.1.4 [rand.req.eng] Status: CD1 + Submitter: Charles Karney Opened: 2007-05-15 Last modified: 2010-10-29
View all other issues in [rand.req.eng].
View all issues with CD1 status.
Discussion:
-Section X [rand.req.eng] Random number engine requirements: +Section 26.5.1.4 [rand.req.eng] Random number engine requirements:
@@ -29258,7 +32765,7 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
679. resize parameter by value
Section: 23.3 [sequences] Status: CD1 - Submitter: Howard Hinnant Opened: 2007-06-11 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2007-06-11 Last modified: 2010-10-29View all other issues in [sequences].
View all issues with CD1 status.
Discussion:
@@ -29372,7 +32879,7 @@ Change 23.3.4.2 [list.capacity], p3:-Change 23.3.6 [vector], p2: +Change 23.4.1 [vector], p2:
class vector { @@ -29381,7 +32888,7 @@ Change 23.3.6 [vector], p2:-Change 23.3.6.2 [vector.capacity], p11: +Change 23.4.1.2 [vector.capacity], p11:
void resize(size_type sz, const T& c); @@ -29395,7 +32902,7 @@ Change 23.3.6.2 [vector.capacity], p11:
680. move_iterator operator-> return
Section: 24.5.3.1 [move.iterator] Status: CD1 - Submitter: Howard Hinnant Opened: 2007-06-11 Last modified: 2008-09-26
+ Submitter: Howard Hinnant Opened: 2007-06-11 Last modified: 2010-10-29View all other issues in [move.iterator].
View all issues with CD1 status.
Discussion:
@@ -29460,7 +32967,7 @@ Change the synopsis in 24.5.3.1 [move.iterator]:
681. Operator functions impossible to compare are defined in [re.submatch.op]
Section: 28.9.2 [re.submatch.op] Status: CD1 - Submitter: Nozomu Katoo Opened: 2007-05-27 Last modified: 2009-05-01
+ Submitter: Nozomu Katoo Opened: 2007-05-27 Last modified: 2010-10-29View all other issues in [re.submatch.op].
View all issues with CD1 status.
Discussion:
@@ -29509,7 +33016,7 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
682. basic_regex ctor takes InputIterator or ForwardIterator?
Section: 28.8.2 [re.regex.construct] Status: CD1 - Submitter: Eric Niebler Opened: 2007-06-03 Last modified: 2009-05-01
+ Submitter: Eric Niebler Opened: 2007-06-03 Last modified: 2010-10-29View all other issues in [re.regex.construct].
View all issues with CD1 status.
Discussion:
@@ -29571,7 +33078,7 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
685. reverse_iterator/move_iterator difference has invalid signatures
Section: 24.5.1.3.19 [reverse.iter.opdiff], 24.5.3.3.14 [move.iter.nonmember] Status: CD1 - Submitter: Bo Persson Opened: 2007-06-10 Last modified: 2008-09-26
+ Submitter: Bo Persson Opened: 2007-06-10 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -29679,8 +33186,8 @@ goes in.
687. shared_ptr conversion constructor not constrained
-Section: 20.8.15.2.1 [util.smartptr.shared.const], 20.8.15.3.1 [util.smartptr.weak.const] Status: CD1 - Submitter: Peter Dimov Opened: 2007-05-10 Last modified: 2009-02-02
+Section: 20.9.10.2.1 [util.smartptr.shared.const], 20.9.10.3.1 [util.smartptr.weak.const] Status: CD1 + Submitter: Peter Dimov Opened: 2007-05-10 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared.const].
View all issues with CD1 status.
Discussion:
@@ -29708,7 +33215,7 @@ overload resolution when the pointer types are compatible.Proposed resolution:
-In 20.8.15.2.1 [util.smartptr.shared.const], change: +In 20.9.10.2.1 [util.smartptr.shared.const], change:
@@ -29719,7 +33226,7 @@ to T*.
-In 20.8.15.3.1 [util.smartptr.weak.const], change: +In 20.9.10.3.1 [util.smartptr.weak.const], change:
@@ -29745,8 +33252,8 @@ overload resolution unless Y*shall be
688. reference_wrapper, cref unsafe, allow binding to rvalues
-Section: 20.7.5.1 [refwrap.const] Status: WP - Submitter: Peter Dimov Opened: 2007-05-10 Last modified: 2009-07-18
+Section: 20.8.4.1 [refwrap.const] Status: WP + Submitter: Peter Dimov Opened: 2007-05-10 Last modified: 2010-10-29
View all other issues in [refwrap.const].
View all issues with WP status.
Discussion:
@@ -29848,7 +33355,7 @@ Move to Tentatively Ready.Proposed resolution:
-In 20.7 [function.objects], add the following two signatures to the synopsis: +In 20.8 [function.objects], add the following two signatures to the synopsis:
template <class T> void ref(const T&& t) = delete; @@ -29884,8 +33391,8 @@ the "special deduction rule" is disabled with the const T&& pattern.
689. reference_wrapper constructor overly constrained
-Section: 20.7.5.1 [refwrap.const] Status: CD1 - Submitter: Peter Dimov Opened: 2007-05-10 Last modified: 2008-09-26
+Section: 20.8.4.1 [refwrap.const] Status: CD1 + Submitter: Peter Dimov Opened: 2007-05-10 Last modified: 2010-10-29
View all other issues in [refwrap.const].
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Discussion:
@@ -29914,8 +33421,8 @@ proposed resolution of the previous issue is accepted, remove the
691. const_local_iterator cbegin, cend missing from TR1
-Section: 23.5 [unord], TR1 6.3 [tr.hash] Status: CD1 - Submitter: Joaquín M López Muńoz Opened: 2007-06-14 Last modified: 2008-09-26
+Section: 23.7 [unord], TR1 6.3 [tr.hash] Status: CD1 + Submitter: Joaquín M López Muńoz Opened: 2007-06-14 Last modified: 2010-10-29
View all other issues in [unord].
View all issues with CD1 status.
Discussion:
@@ -29962,7 +33469,7 @@ requirements) in section 23.2.5 [unord.req]:-Add to the synopsis in 23.5.1 [unord.map]: +Add to the synopsis in 23.7.1 [unord.map]:
const_local_iterator cbegin(size_type n) const; @@ -29970,7 +33477,7 @@ const_local_iterator cend(size_type n) const;-Add to the synopsis in 23.5.2 [unord.multimap]: +Add to the synopsis in 23.7.2 [unord.multimap]:
const_local_iterator cbegin(size_type n) const; @@ -29978,7 +33485,7 @@ const_local_iterator cend(size_type n) const;-Add to the synopsis in 23.5.3 [unord.set]: +Add to the synopsis in 23.7.3 [unord.set]:
const_local_iterator cbegin(size_type n) const; @@ -29986,7 +33493,7 @@ const_local_iterator cend(size_type n) const;-Add to the synopsis in 23.5.4 [unord.multiset]: +Add to the synopsis in 23.7.4 [unord.multiset]:
const_local_iterator cbegin(size_type n) const; @@ -30001,7 +33508,7 @@ const_local_iterator cend(size_type n) const;
692.
get_moneyandput_moneyshould be formatted I/O functionsSection: 27.7.4 [ext.manip] Status: CD1 - Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2010-10-29View all other issues in [ext.manip].
View all issues with CD1 status.
Discussion:
@@ -30076,9 +33583,8 @@ Ready.
693.
-std::bitset::all()missingSection: 20.3.7 [template.bitset] Status: CD1 - Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2008-09-26
-View other active issues in [template.bitset].
+Section: 20.5 [template.bitset] Status: CD1 + Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2010-10-29
View all other issues in [template.bitset].
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Discussion:
@@ -30103,7 +33609,7 @@ the first word with a zero bit).Proposed resolution:
Add a declaration of the new member function
@@ -30115,7 +33621,7 @@ bool none() const;all()to the -defintion of thebitsettemplate in 20.3.7 [template.bitset], p1, +defintion of thebitsettemplate in 20.5 [template.bitset], p1, right above the declaration ofany()as shown below:-Add a description of the new member function to the end of 20.3.7.2 [bitset.members] with the following text: +Add a description of the new member function to the end of 20.5.2 [bitset.members] with the following text:
bool all() const;@@ -30156,9 +33662,8 @@ is onecount() == 0.
694.
-std::bitsetandlong longSection: 20.3.7 [template.bitset] Status: CD1 - Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2008-09-26
-View other active issues in [template.bitset].
+Section: 20.5 [template.bitset] Status: CD1 + Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2010-10-29
View all other issues in [template.bitset].
View all issues with CD1 status.
Discussion:
@@ -30197,7 +33702,7 @@ explicit bitset(-Make a corresponding change in 20.3.7.1 [bitset.cons], p2: +Make a corresponding change in 20.5.1 [bitset.cons], p2:
@@ -30220,7 +33725,7 @@ Additionally, introduce a new member function
to_ullong()to make it possible to convertbitsetto values of the new type. Add the following declaration to the definition of the template, immediate after the declaration ofto_ulong()-in 20.3.7 [template.bitset], p1, as shown below: +in 20.5 [template.bitset], p1, as shown below:// element access: @@ -30233,7 +33738,7 @@ basic_string<charT, traits, Allocator> to_string() const;-And add a description of the new member function to 20.3.7.2 [bitset.members], +And add a description of the new member function to 20.5.2 [bitset.members], below the description of the existing
@@ -30258,7 +33763,7 @@ cannot be represented as typeto_ulong()(if possible), with the following text:unsigned long long.
695. ctype<char>::classic_table() not accessible
Section: 22.4.1.3 [facet.ctype.special] Status: CD1 - Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2008-09-26
+ Submitter: Martin Sebor Opened: 2007-06-22 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -30318,7 +33823,7 @@ virtual char do_toupper(char c) const;
696.
istream::operator>>(int&)brokenSection: 27.7.1.2.2 [istream.formatted.arithmetic] Status: WP - Submitter: Martin Sebor Opened: 2007-06-23 Last modified: 2009-10-26
+ Submitter: Martin Sebor Opened: 2007-06-23 Last modified: 2010-10-29View all other issues in [istream.formatted.arithmetic].
View all issues with WP status.
Discussion:
@@ -30536,14 +34041,76 @@ setstate(err); +
+697. New <system_error> header leads to name clashes
+Section: 19.5 [syserr] Status: Resolved + Submitter: Daniel Krügler Opened: 2007-06-24 Last modified: 2010-11-19
+View all other issues in [syserr].
+View all issues with Resolved status.
+Discussion:
++The most recent state of +N2241 +as well as the current draft +N2284 +(section 19.5 [syserr], p.2) proposes a +new +enumeration type posix_errno immediatly in the namespace std. One of +the enumerators has the name invalid_argument, or fully qualified: +std::invalid_argument. This name clashes with the exception type +std::invalid_argument, see 19.2 [std.exceptions]/p.3. This clash makes +e.g. the following snippet invalid: +
+ ++ +#include <system_error> +#include <stdexcept> + +void foo() { throw std::invalid_argument("Don't call us - we call you!"); } ++I propose that this enumeration type (and probably the remaining parts +of +<system_error> as well) should be moved into one additional inner +namespace, e.g. sys or system to reduce foreseeable future clashes +due +to the great number of members that std::posix_errno already contains +(Btw.: Why has the already proposed std::sys sub-namespace from +N2066 +been rejected?). A further clash candidate seems to be +std::protocol_error +(a reasonable name for an exception related to a std network library, +I guess). +
+ ++Another possible resolution would rely on the proposed strongly typed +enums, +as described in N2213. +But maybe the forbidden implicit conversion to integral types would +make +these enumerators less attractive in this special case? +
+ + +Proposed resolution:
++Fixed by issue 7 of N2422. +
+ + + + + +
698. system_error needs const char* constructors
-Section: 19.5.5.1 [syserr.syserr.overview] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-06-24 Last modified: 2008-09-26
+Section: 19.5.6.1 [syserr.syserr.overview] Status: CD1 + Submitter: Daniel Krügler Opened: 2007-06-24 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
-In 19.5.5.1 [syserr.syserr.overview] we have the class definition of +In 19.5.6.1 [syserr.syserr.overview] we have the class definition of std::system_error. In contrast to all exception classes, which are constructible with a what_arg string (see 19.2 [std.exceptions], or ios_base::failure in 27.5.2.1.1 [ios::failure]), only overloads with with @@ -30566,7 +34133,7 @@ This proposed wording assumes issue 699. N2111 changes min/max
Section: 26.5 [rand] Status: CD1 - Submitter: P.J. Plauger Opened: 2007-07-01 Last modified: 2008-09-26
+ Submitter: P.J. Plauger Opened: 2007-07-01 Last modified: 2010-10-29View all other issues in [rand].
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Discussion:
@@ -30656,7 +34223,7 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
700. N1856 defines struct identity
Section: 20.3.3 [forward] Status: CD1 - Submitter: P.J. Plauger Opened: 2007-07-01 Last modified: 2008-09-26
+ Submitter: P.J. Plauger Opened: 2007-07-01 Last modified: 2010-10-29View all other issues in [forward].
View all issues with CD1 status.
Discussion:
@@ -30700,8 +34267,8 @@ Change 20.3.3 [forward]:
703. map::at() need a complexity specification
-Section: 23.4.1.2 [map.access] Status: CD1 - Submitter: Joe Gottman Opened: 2007-07-03 Last modified: 2008-09-26
+Section: 23.6.1.2 [map.access] Status: CD1 + Submitter: Joe Gottman Opened: 2007-07-03 Last modified: 2010-10-29
View all other issues in [map.access].
View all issues with CD1 status.
Discussion:
@@ -30712,7 +34279,7 @@ Change 20.3.3 [forward]:Proposed resolution:
-Add the following to the specification of map::at(), 23.4.1.2 [map.access]: +Add the following to the specification of map::at(), 23.6.1.2 [map.access]:
@@ -30724,15 +34291,1324 @@ Add the following to the specification of map::at(), 23.4.1.2 [map.acce +
+704. MoveAssignable requirement for container value type overly strict
+Section: 23.2 [container.requirements] Status: WP + Submitter: Howard Hinnant Opened: 2007-05-20 Last modified: 2010-10-29
+View all other issues in [container.requirements].
+View all issues with WP status.
+Discussion:
++The move-related changes inadvertently overwrote the intent of 276. +Issue 276 removed the requirement of CopyAssignable from +most of the member functions of node-based containers. But the move-related changes +unnecessarily introduced the MoveAssignable requirement for those members which used to +require CopyAssignable. +
+ ++We also discussed (c++std-lib-18722) the possibility of dropping MoveAssignable +from some of the sequence requirements. Additionally the in-place construction +work may further reduce requirements. For purposes of an easy reference, here are the +minimum sequence requirements as I currently understand them. Those items in requirements +table in the working draft which do not appear below have been purposefully omitted for +brevity as they do not have any requirements of this nature. Some items which do not +have any requirements of this nature are included below just to confirm that they were +not omitted by mistake. +
+ ++
+ +Container Requirements ++ X u(a) value_type must be CopyConstructible + X u(rv) array requires value_type to be CopyConstructible + a = u Sequences require value_type to be CopyConstructible and CopyAssignable. + Associative containers require value_type to be CopyConstructible. + a = rv array requires value_type to be CopyAssignable. + Sequences containers with propagate_on_container_move_assignment == false allocators require value_type to be MoveConstructible and MoveAssignable. + Associative containers with propagate_on_container_move_assignment == false allocators require value_type to be MoveConstructible. + swap(a,u) array requires value_type to be Swappable. +
+ ++
+ +Sequence Requirements ++ X(n) value_type must be DefaultConstructible + X(n, t) value_type must be CopyConstructible + X(i, j) Sequences require value_type to be constructible from *i. Additionally if input_iterators + are used, vector and deque require MoveContructible and MoveAssignable. + a.insert(p, t) The value_type must be CopyConstructible. + The sequences vector and deque also require the value_type to be CopyAssignable. + a.insert(p, rv) The value_type must be MoveConstructible. + The sequences vector and deque also require the value_type to be MoveAssignable. + a.insert(p, n, t) The value_type must be CopyConstructible. + The sequences vector and deque also require the value_type to be CopyAssignable. + a.insert(p, i, j) If the iterators return an lvalue the value_type must be CopyConstructible. + The sequences vector and deque also require the value_type to be CopyAssignable when the iterators return an lvalue. + If the iterators return an rvalue the value_type must be MoveConstructible. + The sequences vector and deque also require the value_type to be MoveAssignable when the iterators return an rvalue. + a.erase(p) The sequences vector and deque require the value_type to be MoveAssignable. + a.erase(q1, q2) The sequences vector and deque require the value_type to be MoveAssignable. + a.clear() + a.assign(i, j) If the iterators return an lvalue the value_type must be CopyConstructible and CopyAssignable. + If the iterators return an rvalue the value_type must be MoveConstructible and MoveAssignable. + a.assign(n, t) The value_type must be CopyConstructible and CopyAssignable. + a.resize(n) The value_type must be DefaultConstructible. + The sequence vector also requires the value_type to be MoveConstructible. + a.resize(n, t) The value_type must be CopyConstructible. +
+ ++
+ +Optional Sequence Requirements ++ a.front() + a.back() + a.push_front(t) The value_type must be CopyConstructible. + a.push_front(rv) The value_type must be MoveConstructible. + a.push_back(t) The value_type must be CopyConstructible. + a.push_back(rv) The value_type must be MoveConstructible. + a.pop_front() + a.pop_back() + a[n] + a.at[n] +
+ ++
+ +Associative Container Requirements ++ X(i, j) If the iterators return an lvalue the value_type must be CopyConstructible. + If the iterators return an rvalue the value_type must be MoveConstructible. + a_uniq.insert(t) The value_type must be CopyConstructible. + a_uniq.insert(rv) The key_type and the mapped_type (if it exists) must be MoveConstructible. + a_eq.insert(t) The value_type must be CopyConstructible. + a_eq.insert(rv) The key_type and the mapped_type (if it exists) must be MoveConstructible. + a.insert(p, t) The value_type must be CopyConstructible. + a.insert(p, rv) The key_type and the mapped_type (if it exists) must be MoveConstructible. + a.insert(i, j) If the iterators return an lvalue the value_type must be CopyConstructible. + If the iterators return an rvalue the key_type and the mapped_type (if it exists) must be MoveConstructible.. +
+ ++
+ +Unordered Associative Container Requirements ++ X(i, j, n, hf, eq) If the iterators return an lvalue the value_type must be CopyConstructible. + If the iterators return an rvalue the value_type must be MoveConstructible. + a_uniq.insert(t) The value_type must be CopyConstructible. + a_uniq.insert(rv) The key_type and the mapped_type (if it exists) must be MoveConstructible. + a_eq.insert(t) The value_type must be CopyConstructible. + a_eq.insert(rv) The key_type and the mapped_type (if it exists) must be MoveConstructible. + a.insert(p, t) The value_type must be CopyConstructible. + a.insert(p, rv) The key_type and the mapped_type (if it exists) must be MoveConstructible. + a.insert(i, j) If the iterators return an lvalue the value_type must be CopyConstructible. + If the iterators return an rvalue the key_type and the mapped_type (if it exists) must be MoveConstructible.. +
+ ++
+ +Miscellaneous Requirements ++ map[lvalue-key] The key_type must be CopyConstructible. + The mapped_type must be DefaultConstructible and MoveConstructible. + map[rvalue-key] The key_type must be MoveConstructible. + The mapped_type must be DefaultConstructible and MoveConstructible. [ +Kona (2007): Howard and Alan to update requirements table in issue with emplace signatures. +]
+ + +[ +Bellevue: This should be handled as part of the concepts work. +]
+ + +[ +2009-07-20 Reopened by Howard: +]
+ + +++ ++This is one of the issues that was "solved by concepts" and is now no longer solved. +
+ ++In a nutshell, concepts adopted the "minimum requirements" philosophy outlined +in the discussion of this issue, and enforced it. My strong suggestion is that +we translate the concepts specification into documentation for the containers. +
+ ++What this means for vendors is that they will have to implement container members +being careful to only use those characteristics of a type that the concepts specification +formally allowed. Note that I am not talking about enable_if'ing +everything. I am simply suggesting that (for example) we tell the vendor he can't call T's +copy constructor or move constructor within the emplace member function, etc. +
+ ++What this means for customers is that they will be able to use types within C++03 +containers which are sometimes not CopyConstructible, and sometimes not even +MoveConstructible, etc. +
+[ +2009-10 Santa Cruz: +]
+ + ++Leave open. Howard to provide wording. ++ +[ +2010-02-06 Howard provides wording. +]
+ + +[ +2010-02-08 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-02-10 Howard opened. I neglected to reduce the requirements on value_type +for the insert function of the ordered and unordered associative containers when +the argument is an rvalue. Fixed it. +]
+ + +[ +2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-03-08 Nico opens: +]
+ + +++ ++I took the task to see whether 868 is covered by 704 +already. +However, by doing that I have the impression that +704 is a big mistake. +
+ ++Take e.g. the second change of 868: +
+ ++++Change 23.3.2.1 [deque.cons] para 5: +
++Effects: Constructs a deque with n default constructed +elements. +++where "default constructed" should be replaced by "value-initialized". +This is the constructor out of a number of elements: +
++ +ContType c(num) ++704 says: +
+ +++ ++Remove the entire section 23.3.2.1 [deque.cons]. +
++[ This section is already specified by the requirements tables. ] +++BUT, there is no requirement table that lists this constructor at all, +which means that we would lose the entire specification of this function +!!! +
+ ++In fact, I found with further investigation, if we follow +704 to remove 23.3.2.1 we +
++
+ +- +have no semantics for + ContType c(num) +
+- +have no complexity and no allocator specification for + ContType c(num,val) +
+- +have no semantics for + ContType c(num,val,alloc) +
+- +- have no complexity and no allocator specification for + ContType c(beg,end) +
+- +- have no semantics for + ContType c(beg,end,alloc) +
+- +- have different wording (which might or might not give + the same guarantees) for the assign functions +
++because all these guarantees are given in the removed +section but nowhere else (as far as I saw). +
++Looks to me that 704 need a significant review before we +take that change, because chances are high that there +are similar flaws in other proposed changes there +(provided I am not missing anything). +
+[ +2010 Pittsburgh: +]
+ + +++ + + ++Removed the parts from the proposed wording that removed existing sections, +and set to Ready for Pittsburgh. +
+Rationale:
+[ +post San Francisco: +]
+ + ++Solved by +N2776. ++ ++This rationale is obsolete. +
+ + + +Proposed resolution:
+ + + ++Change 23.2.1 [container.requirements.general]/4: +
+ ++4 In Tables 91 and 92, X denotes a container class containing objects +of type T, a and b denote values of type X, +u denotes an identifier, r denotes+ +an lvalue or a const +rvaluea non-const value of type X, and rv +denotes a non-const rvalue of type X. ++Change the following rows in Table 91 — Container requirements +23.2.1 [container.requirements.general]: +
+ +++ ++
+ +Table 91 — Container requirements + ++ + +Expression +Return type +Assertion/note +
pre-/post-conditionComplexity ++ + +X::value_type +T +Requires: T is Destructible. +compile time ++Change 23.2.1 [container.requirements.general]/10: +
+ +++ ++Unless otherwise specified (see 23.2.4.1, 23.2.5.1, 23.3.2.3, and 23.3.6.4) all +container types defined in this Clause meet the following additional +requirements: +
+ ++
+ +- +.. +
+ +- +no erase(), clear(), pop_back() or +pop_front() function throws an exception. +
+ +- +... +
++Insert a new paragraph prior to 23.2.1 [container.requirements.general]/14: +
+ +++ ++The descriptions of the requirements of the type T in this section +use the terms CopyConstructible, MoveConstructible, constructible +from *i, and constructible from args. These terms +are equivalent to the following expression using the appropriate arguments: +
+ ++ ++allocator_traits<allocator_type>::construct(x.get_allocator(), q, args...); ++where x is a non-const lvalue of some container type X and +q has type X::value_type*. +
+ ++[Example: The container is going to move construct a T, so will +call: +
+ ++ ++allocator_traits<allocator_type>::construct(get_allocator(), q, std::move(t)); ++The default implementation of construct will call: +
+ ++ ++::new (q) T(std::forward<T>(t)); // where forward is the same as move here, cast to rvalue ++But the allocator author may override the above definition of construct +and do the construction of T by some other means. — end +example] +
+ ++14 ... +
++Add to 23.2.1 [container.requirements.general]/14: +
+ ++14 In Table 93, X denotes an allocator-aware container class with a +value_type of T using allocator of type A, u +denotes a variable, a and b denote non-const lvalues of +type X, t denotes an lvalue or a const rvalue of type +X, rv denotes a non-const rvalue of type X, +m is a value of type A, and Q is an allocator type. ++ ++Change or add the following rows in Table 93 — Allocator-aware container +requirements in 23.2.1 [container.requirements.general]: +
+ +++ ++
+ +Table 93 — Allocator-aware container requirements + ++ + +Expression +Return type +Assertion/note +
pre-/post-conditionComplexity ++ + +X(t, m) +
X u(t, m);+ Requires: T is CopyConstructible. +
+post: u == t,
+get_allocator() == mlinear ++ + +X(rv, m) +
X u(rv, m);+ Requires: T is MoveConstructible. +
+post: u shall have the same elements, or copies of the elements, that +rv had before this construction,
+get_allocator() == mconstant if m == rv.get_allocator(), otherwise linear ++ + +a = t +X& +Requires: T is CopyConstructible and +CopyAssignable +
+post: a == t.linear ++ + +a = rv +X& +Requires: If allocator_traits< allocator_type > +::propagate_on_container_move_assignment ::value is false, +T is MoveConstructible and MoveAssignable. +
+All existing elements of a are either move assigned +to or destroyed.
+a shall be equal to the value that rv had before this +assignmentlinear ++ + +a.swap(b); +void +exchanges the contents of a and b +constant ++Change the following rows in Table 94 — Sequence container requirements +(in addition to container) in 23.2.3 [sequence.reqmts]: +
+ +++ ++
+ +Table 94 — Sequence container requirements (in addition to +container) + ++ + +Expression +Return type +Assertion/note +
pre-/post-condition+ + +X(i, j) +
X a(i, j)+ Requires: +If the iterator's dereference operation returns an +lvalue or a const rvalue, T shall be CopyConstructible.+T shall be constructible from *i.
+If the iterator does not meet the forward iterator requirements (24.2.5 [forward.iterators]), then vector also requires T to +be MoveConstructible.
+Each iterator in the range [i,j) shall be dereferenced exactly +once.
+post: size() == distance between i and j
+Constructs a sequence container equal to the range [i, j)+ + +a = il; +X& +Requires: T is CopyConstructible and +CopyAssignable. +
+a = X(il);
+Assigns the range [il.begin(), il.end()) into a. All +existing elements of a are either assigned or destroyed.
+rReturns *this;+ + +a.emplace(p, args); +iterator +Requires: +ConstructibleAsElement<A, T, +Args>.T is constructible from args. +vector and deque also require T to be +MoveConstructible and MoveAssignable. Inserts an object +of type T constructed with +std::forward<Args>(args)... before p.+ + +a.insert(p, t); +iterator +Requires: +ConstructibleAsElement<A, T, Args> and +T shall be CopyAssignable.T shall be +CopyConstructible. vector and deque also require +T to be CopyAssignable. Inserts a copy t before +p.+ + +a.insert(p, rv); +iterator +Requires: +ConstructibleAsElement<A, T, +T&&> and T shall be MoveAssignable.+T shall be MoveConstructible. vector and +deque also require T to be MoveAssignable. +Inserts a copy rv before p.+ + +a.insert(p, i, j) +iterator +Requires: +If the iterator's dereference operation returns an +lvalue or a const rvalue, T shall be CopyConstructible.+T shall be constructible from *i.
If the +iterator does not meet the forward iterator requirements (24.2.5 [forward.iterators]), then vector also requires T to +be MoveConstructible and MoveAssignable.
Each +iterator in the range [i,j) shall be dereferenced exactly once.
+pre: i and j are not iterators into a.
Inserts +copies of elements in [i, j) before p+ + +a.erase(q); +iterator +Requires: +T and T shall be +MoveAssignable.vector and deque require +T to be MoveAssignable. Erases the element pointed to by +q.+ + +a.erase(q1, q2); +iterator +Requires: +T and T shall be +MoveAssignable.vector and deque require +T to be MoveAssignable. Erases the elements in the range +[q1, q2).+ + +a.clear(); +void ++ erase(begin(), end())
+Destroys all elements in a. Invalidates all references, +pointers, and iterators referring to the elements of a and may +invalidate the past-the-end iterator.
+post:size() == 0a.empty() == true+ + +a.assign(i, j) +void +Requires: +If the iterator's dereference operation returns an +lvalue or a const rvalue, T shall be CopyConstructible and +CopyAssignable.+T shall be constructible and assignable from *i. If the +iterator does not meet the forward iterator requirements (24.2.5 [forward.iterators]), then vector also requires T to +be MoveConstructible.
+Each iterator in the range [i,j) shall be dereferenced exactly +once.
+pre: i, j are not iterators into a.
+Replaces elements in a with a copy of [i, j).+Change the following rows in Table 95 — Optional sequence container operations +in 23.2.3 [sequence.reqmts]: +
+ +++ ++
+ +Table 95 — Optional sequence container operations + ++ + +Expression +Return type +Operational semantics +Container ++ + +a.emplace_front(args) +void ++ a.emplace(a.begin(), std::forward<Args>(args)...)
+Prepends an object of type T constructed with +std::forward<Args>(args)....
+Requires:ConstructibleAsElement<A, T, Args>+T shall be constructible from args.list, deque, forward_list ++ + +a.emplace_back(args) +void ++ a.emplace(a.end(), std::forward<Args>(args)...)
+Appends an object of type T constructed with +std::forward<Args>(args)....
+Requires:ConstructibleAsElement<A, T, Args>+T shall be constructible from args. vector also +requires T to be MoveConstructible.list, deque, vector ++ + +a.push_front(t) +void ++ a.insert(a.begin(), t)
+Prepends a copy of t.
+Requires:ConstructibleAsElement<A, T, T> and +T shall be CopyAssignable.+T shall be CopyConstructible.list, deque, forward_list ++ + +a.push_front(rv) +void ++ a.insert(a.begin(), t)
+Prepends a copy of rv.
+Requires:ConstructibleAsElement<A, T, T&&> and +T shall be MoveAssignable.+T shall be MoveConstructible.list, deque, forward_list ++ + +a.push_back(t) +void ++ a.insert(a.end(), t)
+Appends a copy of t.
+Requires:ConstructibleAsElement<A, T, T> and +T shall be CopyAssignable.+T shall be CopyConstructible.vector, list, deque, basic_string ++ + +a.push_back(rv) +void ++ a.insert(a.end(), t)
+Appends a copy of rv.
+Requires:ConstructibleAsElement<A, T, T&&> and +T shall be MoveAssignable.+T shall be MoveConstructible.vector, list, deque, basic_string ++ + +a.pop_front() +void ++ a.erase(a.begin())
+Destroys the first element.
+Requires: a.empty() shall be false.list, deque, forward_list ++ + +a.pop_back() +void ++ { iterator tmp = a.end();
--tmp;
a.erase(tmp); }
+Destroys the last element.
+Requires: a.empty() shall be false.vector, list, deque, basic_string ++Insert a new paragraph prior to 23.2.4 [associative.reqmts]/7, and +edit paragraph 7: +
+ +++ ++The associative containers meet all of the requirements of Allocator-aware +containers (23.2.1 [container.requirements.general]), except for the +containers map and multimap, the requirements placed on +value_type in Table 93 apply instead directly to key_type and +mapped_type. [Note: For example key_type and +mapped_type are sometimes required to be CopyAssignable even +though the value_type (pair<const key_type, +mapped_type>) is not CopyAssignable. — end note] +
+ ++7 In Table 96, X denotes an associative container class, a denotes a +value of X, a_uniq denotes a value of X when +X supports unique keys, a_eq denotes a value of X +when X supports multiple keys, u denotes an identifier, +
+r denotes an lvalue or a const rvalue of type X, +rv denotes a non-const rvalue of type X,i and +j satisfy input iterator requirements and refer to elements implicitly +convertible to value_type, [i,j) denotes a valid range, +p denotes a valid const iterator to a, q denotes a +valid dereferenceable const iterator to a, [q1, q2) denotes a +valid range of const iterators in a, il designates an object +of type initializer_list<value_type>, t denotes a value +of X::value_type, k denotes a value of X::key_type +and c denotes a value of type X::key_compare. A +denotes the storage allocator used by X, if any, or +std::allocator<X::value_type> otherwise, and m denotes +an allocator of a type convertible to A.+Change or add the following rows in Table 96 — Associative container +requirements (in addition to container) in 23.2.4 [associative.reqmts]: +
+ +++ ++
+ +Table 96 — Associative container requirements (in addition to +container) + ++ + +Expression +Return type +Assertion/note +
pre-/post-conditionComplexity ++ + +X::key_type +Key +Requires: Key is +CopyConstructible and +CopyAssignableDestructiblecompile time ++ + +X::mapped_type (map and multimap only) +T +Requires: T is Destructible +compile time ++ + +X(c) +
X a(c);+ Requires: +ConstructibleAsElement<A, key_compare, +key_compare>.
+key_compare is CopyConstructible.
+Constructs an empty container.
+Uses a copy of c as a comparison object.constant ++ + +X() +
X a;+ Requires: +ConstructibleAsElement<A, key_compare, +key_compare>.
+key_compare is DefaultConstructible.
+Constructs an empty container.
+Uses Compare() as a comparison object.constant ++ + +X(i, j, c) +
X a(i, j, c);+ Requires: +ConstructibleAsElement<A, key_compare, +key_compare>.
+key_compare is CopyConstructible. value_type +shall be constructible from *i.
+Constructs an empty container ans inserts elements from the range [i, +j) into it; uses c as a comparison object.N log N in general (N is the distance from +i to j); linear if [i, j) is sorted with +value_comp() ++ + +X(i, j) +
X a(i, j);+ Requires: +ConstructibleAsElement<A, key_compare, +key_compare>.
value_type shall be constructible +from *i. key_compare is +DefaultConstructible.
Same as above, but uses +Compare() as a comparison object.same as above ++ + +a = il +X& ++ a = X(il);
+return *this;
+Requires: T is CopyConstructible and +CopyAssignable.
+Assigns the range [il.begin(), il.end()) into a. All +existing elements of a are either assigned or destroyed.+ Same as a = X(il).+N log N in general (N is +il.size() added to the existing size of a); linear if +[il.begin(), il.end()) is sorted with value_comp()+ + +a_uniq.emplace(args) +pair<iterator, bool> +Requires: T shall be constructible from +args +
+inserts a T object t constructed with +std::forward<Args>(args)... if and only if there is no element in +the container with key equivalent to the key of t. The bool +component of the returned pair is true if and only if the insertion takes place, +and the iterator component of the pair points to the element with key equivalent +to the key of t.logarithmic ++ + +a_eq.emplace(args) +iterator +Requires: T shall be constructible from +args +
+inserts a T object t constructed with +std::forward<Args>(args)... and returns the iterator pointing to +the newly inserted element.logarithmic ++ + +a_uniq.insert(t) +pair<iterator, bool> +Requires: T shall be MoveConstructible if +t is a non-const rvalue expression, else T shall be +CopyConstructible. +
+inserts t if and only if there is no element in the container with key +equivalent to the key of t. The bool component of the returned +pair is true if and only if the insertion takes place, and the iterator +component of the pair points to the element with key equivalent to the key of +t.logarithmic ++ + +a_eq.insert(t) +iterator +Requires: T shall be MoveConstructible if +t is a non-const rvalue expression, else T shall be +CopyConstructible. +
+inserts t and returns the iterator pointing to the newly inserted +element. If a range containing elements equivalent to t exists in +a_eq, t is inserted at the end of that range.logarithmic ++ + +a.insert(p, t) +iterator +Requires: T shall be MoveConstructible if +t is a non-const rvalue expression, else T shall be +CopyConstructible. +
+inserts t if and only if there is no element with key equivalent to the +key of t in containers with unique keys; always inserts t in +containers with equivalent keys; always returns the iterator pointing to the +element with key equivalent to the key of t. t is inserted as +close as possible to the position just prior to p.logarithmic in general, but amortized constant if t is inserted +right before p. ++ + +a.insert(i, j) +void +Requires: T shall be +constructible from *i. +
+pre: i, j are not iterators into a. inserts each +element from the range [i,j) if and only if there is no element with +key equivalent to the key of that element in containers with unique keys; always +inserts that element in containers with equivalent keys.N log(size() + N ) (N is the distance from i to j) ++Insert a new paragraph prior to 23.2.5 [unord.req]/9: +
+ +++ ++The unordered associative containers meet all of the requirements of +Allocator-aware containers (23.2.1 [container.requirements.general]), +except for the containers unordered_map and unordered_multimap, +the requirements placed on value_type in Table 93 apply instead +directly to key_type and mapped_type. [Note: For +example key_type and mapped_type are sometimes required to be +CopyAssignable even though the value_type (pair<const +key_type, mapped_type>) is not CopyAssignable. — end +note] +
+ ++9 ... +
++Change or add the following rows in Table 98 — Unordered associative +container requirements (in addition to container) in 23.2.5 [unord.req]: +
+ +++ ++
+ +Table 98 — Unordered associative +container requirements (in addition to container) + ++ + +Expression +Return type +Assertion/note +
pre-/post-conditionComplexity ++ + +X::key_type +Key +Requires: Key shall be +CopyAssignable and +CopyConstructibleDestructiblecompile time ++ + +X::mapped_type (unordered_map and +unordered_multimap only) +T +Requires:T is Destructible +compile time ++ + +X(n, hf, eq) +
X a(n, hf, eq)X +Requires: hasher and key_equal are +CopyConstructible. Constructs an empty container with at least +n buckets, using hf as the hash function and eq as +the key equality predicate. +O(N) ++ + +X(n, hf) +
X a(n, hf)X +Requires: hasher is CopyConstructible and +key_equal is DefaultConstructible. Constructs an empty +container with at least n buckets, using hf as the hash +function and key_equal() as the key equality predicate. +O(N) ++ + +X(n) +
X a(n)X +Requires: hasher and key_equal are +DefaultConstructible. Constructs an empty container with at least +n buckets, using hasher() as the hash function and key_equal() as +the key equality predicate. +O(N) ++ + +X() +
X aX +Requires: hasher and key_equal are +DefaultConstructible. Constructs an empty container an unspecified number of buckets, +using hasher() as the hash function and key_equal() as +the key equality predicate. +constant ++ + +X(i, j, n, hf, eq) +
X a(i, j, n, hf, eq)X +Requires: value_type is constructible from +*i. hasher and key_equal are +CopyConstructible. +
+Constructs an empty container with at least n buckets, using +hf as the hash function and eq as the key equality predicate, +and inserts elements from [i, j) into it.Average case O(N) (N is distance(i, j)), worst +case O(N2) ++ + +X(i, j, n, hf) +
X a(i, j, n, hf)X +Requires: value_type is constructible from *i. +hasher is CopyConstructible and key_equal is +DefaultConstructible. +
Constructs an empty container with at +least n buckets, using hf as the hash function and +key_equal() as the key equality predicate, and inserts elements from +[i, j) into it.Average case O(N) (N is distance(i, j)), worst +case O(N2) ++ + +X(i, j, n) +
X a(i, j, n)X +Requires: value_type is constructible from *i. +hasher and key_equal are +DefaultConstructible. +
Constructs an empty container with at +least n buckets, using hasher() as the hash function and +key_equal() as the key equality predicate, and inserts elements from +[i, j) into it.Average case O(N) (N is distance(i, j)), worst +case O(N2) ++ + +X(i, j) +
X a(i, j)X +Requires: value_type is constructible from *i. +hasher and key_equal are +DefaultConstructible. +
Constructs an empty container with an +unspecified number of buckets, using hasher() as the hash function and +key_equal() as the key equality predicate, and inserts elements from +[i, j) into it.Average case O(N) (N is distance(i, j)), worst +case O(N2) ++ + +X(b) +
X a(b)X +Copy constructor. In addition to the +contained elements+requirements of Table 93 (23.2.1 [container.requirements.general]), copies the hash function, +predicate, and maximum load factor.Average case linear in b.size(), worst case quadratic. ++ + +a = b +X& +Copy assignment operator. In addition to the +contained elements+requirements of Table 93 (23.2.1 [container.requirements.general]), copies the hash function, +predicate, and maximum load factor.Average case linear in b.size(), worst case quadratic. ++ + +a = il +X& ++ a = X(il); return *this;
+Requires: T is CopyConstructible and +CopyAssignable.
+Assigns the range [il.begin(), il.end()) into a. All +existing elements of a are either assigned or destroyed.Average case linear in il.size(), worst case quadratic. ++ + +a_uniq.emplace(args) +pair<iterator, bool> +Requires: T shall be constructible from +args +
+inserts a T object t constructed with +std::forward<Args>(args)... if and only if there is no element in +the container with key equivalent to the key of t. The bool +component of the returned pair is true if and only if the insertion takes place, +and the iterator component of the pair points to the element with key equivalent +to the key of t.Average case O(1), worst case O(a_uniq.size()). ++ + +a_eq.emplace(args) +iterator +Requires: T shall be constructible from +args +
+inserts a T object t constructed with +std::forward<Args>(args)... and returns the iterator pointing to +the newly inserted element.Average case O(1), worst case O(a_eq.size()). ++ + +a.emplace_hint(p, args) +iterator +Requires: T shall be constructible from +args +
+equivalent to a.emplace( std::forward<Args>(args)...). Return +value is an iterator pointing to the element with the key equivalent to the +newly inserted element. The const_iterator p is a hint pointing to +where the search should start. Implementations are permitted to ignore the +hint.Average case O(1), worst case O(a.size()). ++ + +a_uniq.insert(t) +pair<iterator, bool> +Requires: T shall be MoveConstructible if +t is a non-const rvalue expression, else T shall be +CopyConstructible. +
+Inserts t if and only if there is no element in the container with key +equivalent to the key of t. The bool component of the returned +pair indicates whether the insertion takes place, and the iterator component +points to the element with key equivalent to the key of t.Average case O(1), worst case O(a_uniq.size()). ++ + +a_eq.insert(t) +iterator +Requires: T shall be MoveConstructible if +t is a non-const rvalue expression, else T shall be +CopyConstructible. +
+Inserts t, and returns an iterator pointing to the newly inserted +element.Average case O(1), worst case O(a_uniq.size()). ++ + +a.insert(q, t) +iterator +Requires: T shall be MoveConstructible if +t is a non-const rvalue expression, else T shall be +CopyConstructible. +
+Equivalent to a.insert(t). Return value is an iterator pointing to the +element with the key equivalent to that of t. The iterator q +is a hint pointing to where the search should start. Implementations are +permitted to ignore the hint.Average case O(1), worst case O(a_uniq.size()). ++ + +a.insert(i, j) +void +Requires: T shall be +constructible from *i. +
+Pre: i and j are not iterators in a. Equivalent to +a.insert(t) for each element in [i,j).Average case O(N), where N is distance(i, j). +Worst case O(N * a.size()). ++Change 23.3.3 [forwardlist]/2: +
+ ++2 A forward_list satisfies all of the requirements of a container +(table 91), except that the size() member function is not provided. +A forward_list also satisfies all of the requirements of an +allocator-aware container (table 93). And forward_list provides the +assign member functions as specified in Table 94, Sequence container +requirements, and several of the optional sequence container requirements (Table +95). +Descriptions are provided here only for operations on forward_list that +are not described in that table or for operations where there is additional +semantic information. ++ ++Add a new paragraph after 23.3.3.4 [forwardlist.modifiers]/23: +
+ ++ +void clear(); ++ ++++23 Effects: Erases all elements in the range [begin(),end()). +
++Remarks: Does not invalidate past-the-end iterators. +
++Change 23.4.1.2 [vector.capacity]/13: +
+ ++ +void resize(size_type sz, const T& c); +++13 Requires: T shall be CopyConstructible. +If value_type has a move constructor, that constructor shall not throw +any exceptions. +++In 23.7.3 [unord.set] and 23.7.4 [unord.multiset] substitute +"Key" for "Value". +
+ +++ + + + + +[ +The above substitution is normative as it ties into the requirements table. +]
+ +
705. type-trait decay incompletely specified
-Section: 20.6.7 [meta.trans.other] Status: CD1 - Submitter: Thorsten Ottosen Opened: 2007-07-08 Last modified: 2008-09-26
+Section: 20.7.7.6 [meta.trans.other] Status: CD1 + Submitter: Thorsten Ottosen Opened: 2007-07-08 Last modified: 2010-10-29
View all other issues in [meta.trans.other].
View all issues with CD1 status.
Discussion:
-The current working draft has a type-trait decay in 20.6.7 [meta.trans.other]. +The current working draft has a type-trait decay in 20.7.7.6 [meta.trans.other].
@@ -30746,7 +35622,7 @@ cv-qualification, as pass-by-value does.
Proposed resolution:
-In 20.6.7 [meta.trans.other] change the last sentence: +In 20.7.7.6 [meta.trans.other] change the last sentence:
@@ -30754,7 +35630,7 @@ Otherwise the member typedef type equals remove_cv<U
-In 20.5.2.4 [tuple.creation]/1 change: +In 20.4.2.4 [tuple.creation]/1 change:
@@ -30777,15 +35653,14 @@ is X& if Ui equals
706. make_pair() should behave as make_tuple() wrt. reference_wrapper()
-Section: 20.3.4 [pairs] Status: CD1 - Submitter: Thorsten Ottosen Opened: 2007-07-08 Last modified: 2008-09-26
-View other active issues in [pairs].
+Section: 20.3.5 [pairs] Status: CD1 + Submitter: Thorsten Ottosen Opened: 2007-07-08 Last modified: 2010-10-29
View all other issues in [pairs].
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Discussion:
-The current draft has make_pair() in 20.3.4 [pairs]/16 -and make_tuple() in 20.5.2.4 [tuple.creation]. +The current draft has make_pair() in 20.3.5 [pairs]/16 +and make_tuple() in 20.4.2.4 [tuple.creation]. make_tuple() detects the presence of reference_wrapper<X> arguments and "unwraps" the reference in such cases. make_pair() would OTOH create a @@ -30805,8 +35680,8 @@ In 20.3 [utility] change the synopsis for make_pair() to read
-In 20.3.4 [pairs]/16 change the declaration to match the above synopsis. -Then change the 20.3.4 [pairs]/17 to: +In 20.3.5 [pairs]/16 change the declaration to match the above synopsis. +Then change the 20.3.5 [pairs]/17 to:
@@ -30828,7 +35703,7 @@ Then change the 20.3.4 [pairs]/17 to:
709. char_traits::not_eof has wrong signature
Section: 21.2.3 [char.traits.specializations] Status: CD1 - Submitter: Bo Persson Opened: 2007-08-13 Last modified: 2008-09-26
+ Submitter: Bo Persson Opened: 2007-08-13 Last modified: 2010-10-29View all other issues in [char.traits.specializations].
View all issues with CD1 status.
Discussion:
@@ -30893,8 +35768,8 @@ Moved from Pending NAD Editorial to Review. The proposed wording appears to be
710. Missing postconditions
-Section: 20.8.15.2 [util.smartptr.shared] Status: CD1 - Submitter: Peter Dimov Opened: 2007-08-24 Last modified: 2008-09-26
+Section: 20.9.10.2 [util.smartptr.shared] Status: CD1 + Submitter: Peter Dimov Opened: 2007-08-24 Last modified: 2010-10-29
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Discussion:
@@ -30926,7 +35801,7 @@ editor should consider rewording "If w is the return value...", e. g. asProposed resolution:
-Add to 20.8.15.2.1 [util.smartptr.shared.const]: +Add to 20.9.10.2.1 [util.smartptr.shared.const]:
@@ -30942,7 +35817,7 @@ shall be empty. r.get() == 0.-Add to 20.8.15.2.10 [util.smartptr.shared.cast]: +Add to 20.9.10.2.10 [util.smartptr.shared.cast]:
@@ -30985,7 +35860,7 @@ the aliasing constructor as follows:-Change 20.8.15.2.10 [util.smartptr.shared.cast]: +Change 20.9.10.2.10 [util.smartptr.shared.cast]:
@@ -31032,8 +35907,8 @@ in the aliasing constructor postcondition "by reference".
711. Contradiction in empty shared_ptr
-Section: 20.8.15.2.5 [util.smartptr.shared.obs] Status: WP - Submitter: Peter Dimov Opened: 2007-08-24 Last modified: 2009-10-26
+Section: 20.9.10.2.5 [util.smartptr.shared.obs] Status: WP + Submitter: Peter Dimov Opened: 2007-08-24 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared.obs].
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Discussion:
@@ -31064,7 +35939,7 @@ with a non-NULL stored pointer.-This is contradicted by the second sentence in the Returns clause of 20.8.15.2.5 [util.smartptr.shared.obs]: +This is contradicted by the second sentence in the Returns clause of 20.9.10.2.5 [util.smartptr.shared.obs]:
@@ -31155,7 +36030,7 @@ Howard: Option 2 commented out for clarity, and can be brought back.Proposed resolution:
-In keeping the N2351 spirit and obviously my preference, change 20.8.15.2.5 [util.smartptr.shared.obs]: +In keeping the N2351 spirit and obviously my preference, change 20.9.10.2.5 [util.smartptr.shared.obs]:
@@ -31176,7 +36051,7 @@ In keeping the N2351 spirit and obviously my preference, change 20.8.15.2.5 [uti
712. seed_seq::size no longer useful
Section: 26.5.7.1 [rand.util.seedseq] Status: CD1 - Submitter: Marc Paterno Opened: 2007-08-25 Last modified: 2008-09-26
+ Submitter: Marc Paterno Opened: 2007-08-25 Last modified: 2010-10-29View all other issues in [rand.util.seedseq].
View all issues with CD1 status.
Discussion:
@@ -31219,7 +36094,7 @@ The LWG voted to accelerate this issue to Ready status to be voted into the WP a
713. sort() complexity is too lax
Section: 25.4.1.1 [sort] Status: CD1 - Submitter: Matt Austern Opened: 2007-08-30 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 2007-08-30 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -31262,13 +36137,13 @@ If the worst case behavior is important stable_sort() (25.3.1.2) or
714. search_n complexity is too lax
-Section: 25.2.12 [alg.search] Status: CD1 - Submitter: Matt Austern Opened: 2007-08-30 Last modified: 2008-09-26
+Section: 25.2.13 [alg.search] Status: CD1 + Submitter: Matt Austern Opened: 2007-08-30 Last modified: 2010-10-29
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Discussion:
-The complexity for search_n (25.2.12 [alg.search] par 7) is specified as "At most +The complexity for search_n (25.2.13 [alg.search] par 7) is specified as "At most (last - first ) * count applications of the corresponding predicate if count is positive, or 0 otherwise." This is unnecessarily pessimistic. Regardless of the value of count, there is no reason to examine any @@ -31309,7 +36184,7 @@ template<class ForwardIterator, class Size, class T,
715. minmax_element complexity is too lax
Section: 25.4.7 [alg.min.max] Status: CD1 - Submitter: Matt Austern Opened: 2007-08-30 Last modified: 2008-09-26
+ Submitter: Matt Austern Opened: 2007-08-30 Last modified: 2010-10-29View all other issues in [alg.min.max].
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Discussion:
@@ -31362,7 +36237,7 @@ correspondingcomparisonspredicate, where N is dis
716. Production in [re.grammar] not actually modified
Section: 28.13 [re.grammar] Status: WP - Submitter: Stephan T. Lavavej Opened: 2007-08-31 Last modified: 2009-10-26
+ Submitter: Stephan T. Lavavej Opened: 2007-08-31 Last modified: 2010-10-29View all issues with WP status.
Discussion:
@@ -31431,10 +36306,140 @@ Remove this mention of the CharacterClass production. +
+719. std::is_literal type traits should be provided
+Section: 20.7 [meta] Status: Resolved + Submitter: Daniel Krügler Opened: 2007-08-25 Last modified: 2010-11-20
+View all other issues in [meta].
+View all issues with Resolved status.
+Duplicate of: 750
+Discussion:
++Since the inclusion of constexpr in the standard draft N2369 we have +a new type category "literal", which is defined in 3.9 [basic.types]/p.11: +
+ +++ ++-11- A type is a literal type if it is: +
++
+- a scalar type; or
+- +
a class type (clause 9) with
++
+- a trivial copy constructor,
+- a trivial destructor,
+- at least one constexpr constructor other than the copy constructor,
+- no virtual base classes, and
+- all non-static data members and base classes of literal types; or
+- an array of literal type.
++I strongly suggest that the standard provides a type traits for +literal types in 20.7.4.3 [meta.unary.prop] for several reasons: +
+ ++
+ +- To keep the traits in sync with existing types.
+- I see many reasons for programmers to use this trait in template + code to provide optimized template definitions for these types, + see below.
+- A user-provided definition of this trait is practically impossible +to write portably.
++The special problem of reason (c) is that I don't see currently a +way to portably test the condition for literal class types: +
+ +++ ++
+- at least one constexpr constructor other than the copy constructor,
+[ +Alisdair is considering preparing a paper listing a number of missing +type traits, and feels that it might be useful to handle them all +together rather than piecemeal. This would affect issue 719 and 750. +These two issues should move to OPEN pending AM paper on type traits. +]
+ + +[ +2009-07 Frankfurt: +]
+ + ++Beman, Daniel, and Alisdair will work on a paper proposing new type traits. ++ +[ +Addressed in N2947. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + +++ + + +NAD EditorialResolved. Solved by +N2984. +Proposed resolution:
++In 20.7.2 [meta.type.synop] in the group "type properties", +just below the line +
+ ++ +template <class T> struct is_pod; ++add a new one: +
+ ++ +template <class T> struct is_literal; ++In 20.7.4.3 [meta.unary.prop], table Type Property Predicates, just +below the line for the is_pod property add a new line: +
+ ++
+ + + + + ++ +Template Condition Preconditions ++ +template <class T> struct is_literal; +T is a literal type (3.9) +T shall be a complete type, an +array of unknown bound, or +(possibly cv-qualified) void. +
720. Omissions in constexpr usages
-Section: 23.3.1 [array], 20.3.7 [template.bitset] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-08-25 Last modified: 2008-09-26
+Section: 23.3.1 [array], 20.5 [template.bitset] Status: CD1 + Submitter: Daniel Krügler Opened: 2007-08-25 Last modified: 2010-10-29
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Discussion:
@@ -31495,12 +36500,12 @@ In order to have a consistent working paper, Alisdair and Daniel produced a new- In the class template definition of 20.3.7 [template.bitset]/p. 1 change
+In the class template definition of 20.5 [template.bitset]/p. 1 change
constexpr bool test(size_t pos ) const;-and in 20.3.7.2 [bitset.members] change +and in 20.5.2 [bitset.members] change
constexpr bool test(size_t pos ) const; @@ -31516,7 +36521,7 @@ and in 20.3.7.2 [bitset.members] change
722. Missing [c.math] functions nanf and nanl
Section: 26.8 [c.math] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-08-27 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2007-08-27 Last modified: 2010-10-29View all other issues in [c.math].
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Discussion:
@@ -31548,7 +36553,7 @@ just after the existing entry nan.
723. basic_regex should be moveable
Section: 28.8 [re.regex] Status: WP - Submitter: Daniel Krügler Opened: 2007-08-29 Last modified: 2009-10-26
+ Submitter: Daniel Krügler Opened: 2007-08-29 Last modified: 2010-10-29View all other issues in [re.regex].
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Discussion:
@@ -31684,10 +36689,709 @@ in a valid state with an unspecified value. +
+724. DefaultConstructible is not defined
+Section: 20.2.1 [utility.arg.requirements] Status: WP + Submitter: Pablo Halpern Opened: 2007-09-12 Last modified: 2010-10-29
+View all other issues in [utility.arg.requirements].
+View all issues with WP status.
+Discussion:
++The DefaultConstructible requirement is referenced in +several places in the August 2007 working draft +N2369, +but is not defined anywhere. +
+ +[ +Bellevue: +]
+ + +++ ++Walking into the default/value-initialization mess... +
++Why two lines? Because we need both expressions to be valid. +
++AJM not sure what the phrase "default constructed" means. This is +unfortunate, as the phrase is already used 24 times in the library! +
++Example: const int would not accept first line, but will accept the second. +
++This is an issue that must be solved by concepts, but we might need to solve it independantly first. +
++It seems that the requirements are the syntax in the proposed first +column is valid, but not clear what semantics we need. +
++A table where there is no post-condition seems odd, but appears to sum up our position best. +
++At a minimum an object is declared and is destuctible. +
++Move to open, as no-one happy to produce wording on the fly. +
+[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-08-17 Daniel adds "[defaultconstructible]" to table title. 408 +depends upon this issue. +]
+ + +[ +2009-08-18 Alisdair adds: +]
+ + +++ ++Looking at the proposed table in this issue, it really needs two rows: +
+ +++ ++
+Table 33: DefaultConstructible requirements [defaultconstructible] ++ + +expression post-condition ++ + +T t; t is default-initialized. ++ +T{} Object of type T is value-initialized. ++Note I am using the new brace-initialization syntax that is unambiguous +in all use cases (no most vexing parse.) +
+[ +2009-10-03 Daniel adds: +]
+ + +++ ++The suggested definition T{} describing it as +value-initialization is wrong, because it belongs to list-initialization +which would - as the current rules are - always prefer a +initializer-list constructor over a default-constructor. I don't +consider this as an appropriate definition of +DefaultConstructible. My primary suggestion is to ask core, +whether the special case T{} (which also easily leads to +ambiguity situations for more than one initializer-list in a class) +would always prefer a default-constructor - if any - before considering +an initializer-list constructor or to provide another syntax form to +prefer value-initialization over list-initialization. If that fails I +would fall back to suggest to use the expression T() instead of +T{} with all it's disadvantages for the meaning of the +expression +
+ ++T t(); +[ +2009-10 Santa Cruz: +]
+ + ++Leave Open. Core is looking to make Alisdair's proposed +resolution correct. ++ +[ +2010-01-24 At Alisdiar's request, moved his proposal into the proposed wording +seciton. The old wording is preserved here: +]
+ + +++ ++In section 20.2.1 [utility.arg.requirements], before table 33, add the +following table: +
+ +Table 33: DefaultConstructible requirements [defaultconstructible]
+ ++ ++ ++
+ ++ ++ +expression
++ +post-condition
++ ++ +T + t;
+
+ T()+ +T + is default constructed.
+[ +2010-02-04: Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Rationale:
+[ +San Francisco: +]
+ ++We believe concepts will solve this problem +(N2774). ++ +[ +Rationale is obsolete. +]
+ + + +Proposed resolution:
++In section 20.2.1 [utility.arg.requirements], before table 33, add the +following table: +
+ +++ + + + + + ++
+Table 33: DefaultConstructible requirements [defaultconstructible] ++ + +expression post-condition ++ + +T t; Object t is default-initialized. ++ + +T u{}; Object u is value-initialized. ++ + +T()
T{}A temporary object of type T is value-initialized. +
+727. regex_replace() doesn't accept basic_strings with custom traits and allocators
+Section: 28.11.4 [re.alg.replace] Status: WP + Submitter: Stephan T. Lavavej Opened: 2007-09-22 Last modified: 2010-10-29
+View all other issues in [re.alg.replace].
+View all issues with WP status.
+Discussion:
++regex_match() and regex_search() take const basic_string<charT, ST, +SA>&. regex_replace() takes const basic_string<charT>&. This prevents +regex_replace() from accepting basic_strings with custom traits and +allocators. +
+ ++Overloads of regex_replace() taking basic_string should be additionally +templated on class ST, class SA and take const basic_string<charT, ST, +SA>&. Consistency with regex_match() and regex_search() would place +class ST, class SA as the first template arguments; compatibility with +existing code using TR1 and giving explicit template arguments to +regex_replace() would place class ST, class SA as the last template +arguments. +
+ +[ +Batavia (2009-05): +]
+ +++ ++Bill comments, "We need to look at the depth of this change." +
++Pete remarks that we are here dealing with a convenience function +that saves a user from calling the iterato-based overload. +
++Move to Open. +
+[ +2009-07 Frankfurt: +]
+ + ++Howard to ask Stephan Lavavej to provide wording. ++ +[ +2009-07-17 Stephan provided wording. +]
+ + +[ +2009-07-25 Daniel tweaks both this issue and 726. +]
+ + +++ ++One relevant part of the proposed resolution below suggests +to add a new overload of the format member function in the +match_results class template that accepts two character pointers +defining the begin and end of a format range. A more general +approach could have proposed a pair of iterators instead, but +the used pair of char pointers reflects existing practice. If the +committee strongly favors an iterator-based signature, this +could be simply changed. I think that the minimum requirement +should be a BidirectionalIterator, but current implementations +take advantage (at least partially) of the RandomAccessIterator +sub interface of the char pointers. +
+ +Suggested Resolution:
+ +[Moved into the proposed resloution]
+ + + +[ +2009-07-30 Stephan agrees with Daniel's wording. Howard places Daniel's wording +in the Proposed Resolution. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Review. Chair is anxious to move this to Ready in Pittsburgh. ++ +[ +2010-01-27 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+ ++
+ + + + + + +- +
+ ++Change 28.4 [re.syn] as indicated: +
+ ++// 28.11.4, function template regex_replace: +template <class OutputIterator, class BidirectionalIterator, + class traits, class charT, class ST, class SA> + OutputIterator + regex_replace(OutputIterator out, + BidirectionalIterator first, BidirectionalIterator last, + const basic_regex<charT, traits>& e, + const basic_string<charT, ST, SA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + + +template <class OutputIterator, class BidirectionalIterator, + class traits, class charT> + OutputIterator + regex_replace(OutputIterator out, + BidirectionalIterator first, BidirectionalIterator last, + const basic_regex<charT, traits>& e, + const charT* fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + + +template <class traits, class charT, class ST, class SA, + class FST, class FSA> + basic_string<charT, ST, SA> + regex_replace(const basic_string<charT, ST, SA>& s, + const basic_regex<charT, traits>& e, + const basic_string<charT, FST, FSA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + + +template <class traits, class charT, class ST, class SA> + basic_string<charT, ST, SA> + regex_replace(const basic_string<charT, ST, SA>& s, + const basic_regex<charT, traits>& e, + const charT* fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + + + +template <class traits, class charT, class ST, class SA> + basic_string<charT> + regex_replace(const charT* s, + const basic_regex<charT, traits>& e, + const basic_string<charT, ST, SA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + + + +template <class traits, class charT> + basic_string<charT> + regex_replace(const charT* s, + const basic_regex<charT, traits>& e, + const charT* fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + +- +
+ ++Change 28.10 [re.results]/3, class template match_results as +indicated: +
+ +++template <class OutputIter> + OutputIter + format(OutputIter out, + const char_type* fmt_first, const char_type* fmt_last, + regex_constants::match_flag_type flags = + regex_constants::format_default) const; + + +template <class OutputIter, class ST, class SA> + OutputIter + format(OutputIter out, + conststring_typebasic_string<char_type, ST, SA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::format_default) const; + +template <class ST, class SA> +string_typebasic_string<char_type, ST, SA> + format(conststring_typebasic_string<char_type, ST, SA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::format_default) const; + + +string_type +format(const char_type* fmt, + regex_constants::match_flag_type flags = + regex_constants::format_default) const; + +- +
+ ++Insert at the very beginning of 28.10.5 [re.results.form] the following: +
+ +++template <class OutputIter> + OutputIter + format(OutputIter out, + const char_type* fmt_first, const char_type* fmt_last, + regex_constants::match_flag_type flags = + regex_constants::format_default) const; + +++ +++1 Requires: The type OutputIter shall satisfy the requirements for an +Output Iterator (24.2.4 [output.iterators]). +
+ ++2 Effects: Copies the character sequence [fmt_first,fmt_last) to +OutputIter out. Replaces each format specifier or escape sequence in +the copied range with either the character(s) it represents or the sequence of +characters within *this to which it refers. The bitmasks specified in +flags determine which format specifiers and escape sequences are +recognized. +
+ ++3 Returns: out. +
+- +
+ ++Change 28.10.5 [re.results.form], before p. 1 until p. 3 as indicated: +
+ ++template <class OutputIter, class ST, class SA> + OutputIter + format(OutputIter out, + const+ +string_typebasic_string<char_type, ST, SA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::format_default) const; ++++
+ +1 Requires: The type OutputIter shall satisfy the requirements for +an Output Iterator (24.2.3).++2 Effects:
+ +Copies the character sequence +[fmt.begin(),fmt.end()) to OutputIter out. Replaces each +format specifier or escape sequence in fmt with either the character(s) +it represents or the sequence of characters within *this to which it +refers. The bitmasks specified in flags determines what format +specifiers and escape sequences are recognizedEquivalent to +return format(out, fmt.data(), fmt.data() + fmt.size(), flags). ++
+3 Returns: out.+- +
+ ++Change 28.10.5 [re.results.form], before p. 4 until p. 4 as indicated: +
+ ++template <class ST, class SA> ++ +string_typebasic_string<char_type, ST, SA> + format(conststring_typebasic_string<char_type, ST, SA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::format_default) const; ++++Effects:
+ +Returns a copy of the string fmt. Replaces each format +specifier or escape sequence +in fmt with either the character(s) it represents or the sequence of +characters within *this to which +it refers. The bitmasks specified in flags determines what format +specifiers and escape sequences are +recognized.Constructs an empty string result of type +basic_string<char_type, ST, SA>, +and calls format(back_inserter(result), fmt, flags). ++Returns: result +
+- +
+ ++At the end of 28.10.5 [re.results.form] insert as indicated: +
+ ++ ++string_type + format(const char_type* fmt, + regex_constants::match_flag_type flags = + regex_constants::format_default) const; ++ ++++Effects: Constructs an empty string result of type string_type, and calls +format(back_inserter(result), fmt, fmt + +char_traits<char_type>::length(fmt), flags). +
++Returns: result +
+- +
+ ++Change 28.11.4 [re.alg.replace] before p. 1 as indicated: +
+ ++template <class OutputIterator, class BidirectionalIterator, + class traits, class charT, class ST, class SA> + OutputIterator + regex_replace(OutputIterator out, + BidirectionalIterator first, BidirectionalIterator last, + const basic_regex<charT, traits>& e, + const basic_string<charT, ST, SA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + + +template <class OutputIterator, class BidirectionalIterator, + class traits, class charT> + OutputIterator + regex_replace(OutputIterator out, + BidirectionalIterator first, BidirectionalIterator last, + const basic_regex<charT, traits>& e, + const charT* fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); ++ ++Effects: [..]. If any matches are found then, for each such match, if !(flags & + regex_constants::format_no_copy) calls std::copy(m.prefix().first, +m.prefix().second, + out), and then calls m.format(out, fmt, flags) for the first +form of the function + and m.format(out, fmt, fmt + char_traits<charT>::length(fmt), flags) +for the second + form. [..]. ++- +
+ ++Change 28.11.4 [re.alg.replace] before p. 3 as indicated: +
+ ++template <class traits, class charT, class ST, class SA, + class FST, class FSA> + basic_string<charT, ST, SA> + regex_replace(const basic_string<charT, ST, SA>& s, + const basic_regex<charT, traits>& e, + const basic_string<charT, FST, FSA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + + +template <class traits, class charT, class ST, class SA> + basic_string<charT, ST, SA> + regex_replace(const basic_string<charT, ST, SA>& s, + const basic_regex<charT, traits>& e, + const charT* fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); ++ ++Effects: Constructs an empty string result of type basic_string<charT, +ST, SA>, calls regex_replace(back_inserter(result), s.begin(), s.end(), +e, fmt, flags), and then returns result. ++- +
+ ++At the end of 28.11.4 [re.alg.replace] add the following new prototype description: +
+ +++template <class traits, class charT, class ST, class SA> + basic_string<charT> + regex_replace(const charT* s, + const basic_regex<charT, traits>& e, + const basic_string<charT, ST, SA>& fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); + + + +template <class traits, class charT> + basic_string<charT> + regex_replace(const charT* s, + const basic_regex<charT, traits>& e, + const charT* fmt, + regex_constants::match_flag_type flags = + regex_constants::match_default); ++ ++ +Effects: Constructs an empty string result of type basic_string<charT>, +calls regex_replace(back_inserter(result), s, s + +char_traits<charT>::length(s), +e, fmt, flags), and then returns result. + ++
728. Problem in [rand.eng.mers]/6
Section: 26.5.3.2 [rand.eng.mers] Status: CD1 - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-09-26
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29View all other issues in [rand.eng.mers].
View all issues with CD1 status.
Discussion:
@@ -31698,7 +37402,7 @@ of an algorithm that was originally developed only for unsigned 32-bit integers for other bit widths. For instance, W could be theoretically 16 and UIntType a 16-bit integer, in which case the given multiplier would not fit into the UIntType. Moreover, T. Nishimura and M. Matsumoto have chosen a dif ferent multiplier for their 64 bit Mersenne Twister -[reference]. +[reference].@@ -31780,7 +37484,7 @@ Note the main part of the issue is resolved by
734. Unnecessary restriction in [rand.dist.norm.chisq]
Section: 26.5.8.4.3 [rand.dist.norm.chisq] Status: CD1 - Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2008-09-26
+ Submitter: Stephan Tolksdorf Opened: 2007-09-21 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -31928,7 +37632,7 @@ Replace both occurrences of "int n() const;" with "RealType n() con
740. Please remove *_ptr<T[N]>
Section: X [unique.ptr.compiletime] Status: CD1 - Submitter: Herb Sutter Opened: 2007-10-04 Last modified: 2008-09-26
+ Submitter: Herb Sutter Opened: 2007-10-04 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -31972,17 +37676,14 @@ Bellevue:
-Suggestion that fixed-size array instantiations are going to fail at -compile time anyway (if we remove specialization) due to pointer decay, -at least that appears to be result from available compilers. +
+Suggestion that fixed-size array instantiations are going to fail at compile time anyway (if we remove specialization) due to pointer decay, at least that appears to be result from available compilers.
So concerns about about requiring static_assert seem unfounded.
-After a little more experimentation with compiler, it appears that -fixed size arrays would only work at all if we supply these explicit -specialization. So removing them appears less breaking than originally -thought. +
+After a little more experimentation with compiler, it appears that fixed size arrays would only work at all if we supply these explicit specialization. So removing them appears less breaking than originally thought.
straw poll unanimous move to Ready. @@ -31993,7 +37694,7 @@ straw poll unanimous move to Ready.
Proposed resolution:
-Change the synopsis under 20.8.14 [unique.ptr] p2: +Change the synopsis under 20.9.9 [unique.ptr] p2:
... @@ -32022,10 +37723,224 @@ and its subsections: [unique.ptr.compiletime.dtor], [unique.ptr.compiletime.ob +
+742. Enabling swap for proxy iterators
+Section: 20.2.1 [utility.arg.requirements] Status: Resolved + Submitter: Howard Hinnant Opened: 2007-10-10 Last modified: 2010-11-20
+View all other issues in [utility.arg.requirements].
+View all issues with Resolved status.
+Discussion:
++This issue was split from 672. 672 now just +deals with changing the requirements of T in the Swappable +requirement from CopyConstructible and CopyAssignable to +MoveConstructible and MoveAssignable. +
+ ++This issue seeks to widen the Swappable requirement to support proxy iterators. Here +is example code: +
+ ++ +namespace Mine { + +template <class T> +struct proxy {...}; + +template <class T> +struct proxied_iterator +{ + typedef T value_type; + typedef proxy<T> reference; + reference operator*() const; + ... +}; + +struct A +{ + // heavy type, has an optimized swap, maybe isn't even copyable or movable, just swappable + void swap(A&); + ... +}; + +void swap(A&, A&); +void swap(proxy<A>, A&); +void swap(A&, proxy<A>); +void swap(proxy<A>, proxy<A>); + +} // Mine + +... + +Mine::proxied_iterator<Mine::A> i(...) +Mine::A a; +swap(*i1, a); ++The key point to note in the above code is that in the call to swap, *i1 +and a are different types (currently types can only be Swappable with the +same type). A secondary point is that to support proxies, one must be able to pass rvalues +to swap. But note that I am not stating that the general purpose std::swap +should accept rvalues! Only that overloaded swaps, as in the example above, be allowed +to take rvalues. +
+ ++That is, no standard library code needs to change. We simply need to have a more flexible +definition of Swappable. +
+ +[ +Bellevue: +]
+ + +++ ++While we believe Concepts work will define a swappable concept, we +should still resolve this issue if possible to give guidance to the +Concepts work. +
++Would an ambiguous swap function in two namespaces found by ADL break +this wording? Suggest that the phrase "valid expression" means such a +pair of types would still not be swappable. +
++Motivation is proxy-iterators, but facility is considerably more +general. Are we happy going so far? +
++We think this wording is probably correct and probably an improvement on +what's there in the WP. On the other hand, what's already there in the +WP is awfully complicated. Why do we need the two bullet points? They're +too implementation-centric. They don't add anything to the semantics of +what swap() means, which is there in the post-condition. What's wrong +with saying that types are swappable if you can call swap() and it +satisfies the semantics of swapping? +
+[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Leave as Open. Dave to provide wording. ++ +[ +2009-11-08 Howard adds: +]
+ + ++Updated wording to sync with +N3000. +Also this issue is very closely related to 594. ++ +[ +2010 Pittsburgh: +]
+ + ++Moved to+ + + +NAD EditorialResolved. Rationale added. +Rationale:
++Solved by N3048. +
+ + +Proposed resolution:
++Change 20.2.1 [utility.arg.requirements]: +
+ ++ ++ + + ++-1- The template definitions in the C++ Standard Library refer to various +named requirements whose details are set out in tables 31-38. In these +tables, T and V are
+ +is atypes to be supplied by a C++ program +instantiating a template; a, b, and c are +values of type const T; s and t are modifiable +lvalues of type T; u is a value of type (possibly +const) T;andrv is a non-const +rvalue of type T; w is a value of type T; and v is a value of type V. ++
+Table 37: Swappable requirements [swappable] ++ expression Return type Post-condition + swap( sw,tv)void +tw has the value originally +held byuv, and +uv has the value originally held +bytw+ + +The Swappable requirement is met by satisfying one or more of the following conditions: +
++
+- +T is Swappable if T and V are +the same type and T satisfies the +MoveConstructible requirements (Table +33) and the +MoveAssignable requirements (Table +35); +
+- +T is Swappable with V if a namespace scope function named +swap exists in the same namespace as the definition of +T or V, such that the expression +swap(
+sw,tv) is valid and has the +semantics described in this table. +- +T is Swappable if T is an array type whose +element type is Swappable. +
+Rationale:
+[ +post San Francisco: +]
+ + ++Solved by +N2758. ++ + + + + +
743. rvalue swap for shared_ptr
-Section: 20.8.15.2.9 [util.smartptr.shared.spec] Status: CD1 - Submitter: Howard Hinnant Opened: 2007-10-10 Last modified: 2008-09-26
+Section: 20.9.10.2.9 [util.smartptr.shared.spec] Status: CD1 + Submitter: Howard Hinnant Opened: 2007-10-10 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
@@ -32066,7 +37981,7 @@ Adopt issue as written.
Proposed resolution:
-Change the synopsis in 20.8.15.2 [util.smartptr.shared]: +Change the synopsis in 20.9.10.2 [util.smartptr.shared]:
void swap(shared_ptr&& r); @@ -32077,14 +37992,14 @@ template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>-Change 20.8.15.2.4 [util.smartptr.shared.mod]: +Change 20.9.10.2.4 [util.smartptr.shared.mod]:
void swap(shared_ptr&& r);-Change 20.8.15.2.9 [util.smartptr.shared.spec]: +Change 20.9.10.2.9 [util.smartptr.shared.spec]:
template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b); @@ -32099,7 +38014,7 @@ template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>
744. What is the lifetime of an exception pointed to by an exception_ptr?
Section: 18.8.5 [propagation] Status: CD1 - Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2008-09-26
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29View other active issues in [propagation].
View all other issues in [propagation].
View all issues with CD1 status.
@@ -32168,7 +38083,7 @@ each time it is called. --end note]
746. current_exception may fail with bad_alloc
Section: 18.8.5 [propagation] Status: CD1 - Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2008-09-26
+ Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29View other active issues in [propagation].
View all other issues in [propagation].
View all issues with CD1 status.
@@ -32223,7 +38138,7 @@ Accept the broad view and move to readyProposed resolution:
-Add the following exemption clause to 17.6.4.11 [res.on.exception.handling]: +Add the following exemption clause to 17.6.4.12 [res.on.exception.handling]:
@@ -32238,9 +38153,8 @@ exception handler for the base type.
749. Currently has_nothrow_copy_constructor<T>::value is true if T has 'a' nothrow copy constructor.
-Section: 20.6.4.3 [meta.unary.prop] Status: CD1 - Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2008-09-26
-View other active issues in [meta.unary.prop].
+Section: 20.7.4.3 [meta.unary.prop] Status: CD1 + Submitter: Alisdair Meredith Opened: 2007-10-10 Last modified: 2010-10-29
View all other issues in [meta.unary.prop].
View all issues with CD1 status.
Discussion:
@@ -32262,7 +38176,7 @@ For instance:Proposed resolution:
-Change 20.6.4.3 [meta.unary.prop]: +Change 20.7.4.3 [meta.unary.prop]:
@@ -32309,13 +38223,13 @@ throw any exceptions or T is an array of such a class type.
752. Allocator complexity requirement
-Section: 20.2.2 [allocator.requirements] Status: WP - Submitter: Hans Boehm Opened: 2007-10-11 Last modified: 2009-03-09
+Section: 20.2.5 [allocator.requirements] Status: WP + Submitter: Hans Boehm Opened: 2007-10-11 Last modified: 2010-10-29
View all other issues in [allocator.requirements].
View all issues with WP status.
Discussion:
-Did LWG recently discuss 20.2.2 [allocator.requirements]-2, which states that "All the operations +Did LWG recently discuss 20.2.5 [allocator.requirements]-2, which states that "All the operations on the allocators are expected to be amortized constant time."?
@@ -32338,7 +38252,7 @@ the constants, not the asymptotic complexity.
Proposed resolution:
-Change 20.2.2 [allocator.requirements]/2: +Change 20.2.5 [allocator.requirements]/2:
@@ -32357,8 +38271,7 @@ requirements on allocator types.
753. Move constructor in draft
Section: 20.2.1 [utility.arg.requirements] Status: WP - Submitter: Yechezkel Mett Opened: 2007-10-14 Last modified: 2009-03-09
-View other active issues in [utility.arg.requirements].
+ Submitter: Yechezkel Mett Opened: 2007-10-14 Last modified: 2010-10-29View all other issues in [utility.arg.requirements].
View all issues with WP status.
Discussion:
@@ -32399,7 +38312,7 @@ in filling the above requirement.For vector::reserve, vector::resize and the vector modifiers given in -23.3.6.4 [vector.modifiers] we have +23.4.1.4 [vector.modifiers] we have
@@ -32486,8 +38399,8 @@ unfortunately pulling it back to Open. But I'm drafting wording to atone for th
755. std::vector and std:string lack explicit shrink-to-fit operations
-Section: 23.3.6.2 [vector.capacity], 21.4.4 [string.capacity] Status: CD1 - Submitter: Beman Dawes Opened: 2007-10-31 Last modified: 2008-09-26
+Section: 23.4.1.2 [vector.capacity], 21.4.4 [string.capacity] Status: CD1 + Submitter: Beman Dawes Opened: 2007-10-31 Last modified: 2010-10-29
View all other issues in [vector.capacity].
View all issues with CD1 status.
Discussion:
@@ -32541,8 +38454,8 @@ takes no arguments to keep the solution simple and focused.Proposed resolution:
To Class template basic_string 21.4 [basic.string] synopsis, -Class template vector 23.3.6 [vector] synopsis, and Class -vector<bool> 23.3.7 [vector.bool] synopsis, add: +Class template vector 23.4.1 [vector] synopsis, and Class +vector<bool> 23.4.2 [vector.bool] synopsis, add:
@@ -32551,7 +38464,7 @@ void shrink_to_fit();To basic_string capacity 21.4.4 [string.capacity] and vector -capacity 23.3.6.2 [vector.capacity], add: +capacity 23.4.1.2 [vector.capacity], add:
@@ -32576,8 +38489,8 @@ allow latitude for implementation-specific optimizations.
758. shared_ptr and nullptr
-Section: 20.8.15.2 [util.smartptr.shared] Status: WP - Submitter: Joe Gottman Opened: 2007-10-31 Last modified: 2009-03-09
+Section: 20.9.10.2 [util.smartptr.shared] Status: WP + Submitter: Joe Gottman Opened: 2007-10-31 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared].
View all issues with WP status.
Discussion:
@@ -32674,7 +38587,7 @@ The following wording changes are less intrusive:-In 20.8.15.2.1 [util.smartptr.shared.const], add: +In 20.9.10.2.1 [util.smartptr.shared.const], add:
shared_ptr(nullptr_t); @@ -32753,7 +38666,7 @@ Disposition: move to review. The review should check the wording in the then-curProposed resolution:
-In 20.8.15.2 [util.smartptr.shared] p4, add to the definition/synopsis +In 20.9.10.2 [util.smartptr.shared] p4, add to the definition/synopsis of shared_ptr:
@@ -32770,7 +38683,7 @@ template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);-In 20.8.15.2.1 [util.smartptr.shared.const] add: +In 20.9.10.2.1 [util.smartptr.shared.const] add:
template<class D> shared_ptr(nullptr_t p, D d); @@ -32786,11 +38699,11 @@ template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);-(reusing the following paragraphs 20.8.15.2.1 [util.smartptr.shared.const]/9-13 that speak of p.) +(reusing the following paragraphs 20.9.10.2.1 [util.smartptr.shared.const]/9-13 that speak of p.)
-In 20.8.15.2.1 [util.smartptr.shared.const]/10, change +In 20.9.10.2.1 [util.smartptr.shared.const]/10, change
@@ -32818,8 +38731,7 @@ San Francisco:
759. A reference is not an object
Section: 23.2 [container.requirements] Status: CD1 - Submitter: Jens Maurer Opened: 2007-11-06 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+ Submitter: Jens Maurer Opened: 2007-11-06 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with CD1 status.
Discussion:
@@ -32868,8 +38780,8 @@ diagnostic required.
761. unordered_map needs an at() member function
-Section: 23.5.1.2 [unord.map.elem] Status: CD1 - Submitter: Joe Gottman Opened: 2007-11-15 Last modified: 2008-09-26
+Section: 23.7.1.2 [unord.map.elem] Status: CD1 + Submitter: Joe Gottman Opened: 2007-11-15 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
@@ -32885,7 +38797,7 @@ in std::unordered_map.
Proposed resolution:
-Add the following functions to the definition of unordered_map under "lookup" (23.5.1 [unord.map]): +Add the following functions to the definition of unordered_map under "lookup" (23.7.1 [unord.map]):
mapped_type& at(const key_type& k); @@ -32893,7 +38805,7 @@ const mapped_type &at(const key_type &k) const;-Add the following definitions to 23.5.1.2 [unord.map.elem]: +Add the following definitions to 23.7.1.2 [unord.map.elem]:
@@ -32924,8 +38836,8 @@ Bellevue: Editorial note: the "(unique)" differs from map.
762. std::unique_ptr requires complete type?
-Section: 20.8.14 [unique.ptr] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-11-30 Last modified: 2008-09-26
+Section: 20.9.9 [unique.ptr] Status: CD1 + Submitter: Daniel Krügler Opened: 2007-11-30 Last modified: 2010-10-29
View all other issues in [unique.ptr].
View all issues with CD1 status.
Discussion:
@@ -32970,7 +38882,7 @@ The specialization unique_ptr<T[]> has some more restrictive cons type-completeness on T than unique_ptr<T>. The following proposed wordings try to cope with that. If the committee sees less usefulness on relaxed constraints on unique_ptr<T[]>, the alternative would be to stop this relaxation -e.g. by adding one further bullet to 20.8.14.3 [unique.ptr.runtime]/1: +e.g. by adding one further bullet to 20.9.9.3 [unique.ptr.runtime]/1: "T shall be a complete type, if used as template argument of unique_ptr<T[], D> @@ -32989,7 +38901,7 @@ current specification of unique_ptr.
-In 20.8.14 [unique.ptr]/2 add as the last sentence to the existing para: +In 20.9.9 [unique.ptr]/2 add as the last sentence to the existing para:
@@ -33008,7 +38920,7 @@ function. -- end note ]-20.8.14.2.1 [unique.ptr.single.ctor]/1: No changes necessary. +20.9.9.2.1 [unique.ptr.single.ctor]/1: No changes necessary.
@@ -33022,7 +38934,7 @@ The current wording says just this.-In 20.8.14.2.1 [unique.ptr.single.ctor]/5 change the requires clause to say: +In 20.9.9.2.1 [unique.ptr.single.ctor]/5 change the requires clause to say:
@@ -33059,7 +38971,7 @@ again requires Completeness of Y, if !SameType<X, Y>-Merge 20.8.14.2.1 [unique.ptr.single.ctor]/12+13 thereby removing the sentence +Merge 20.9.9.2.1 [unique.ptr.single.ctor]/12+13 thereby removing the sentence of 12, but transferring the "requires" to 13:
@@ -33078,10 +38990,10 @@ pointer and the D deleter are well-formed and well-defined.- -20.8.14.2.1 [unique.ptr.single.ctor]/17: No changes necessary. +20.9.9.2.1 [unique.ptr.single.ctor]/17: No changes necessary.
- -
20.8.14.2.1 [unique.ptr.single.ctor]/21:
+20.9.9.2.1 [unique.ptr.single.ctor]/21:
Requires: If D is not a reference type, construction of @@ -33104,7 +39016,7 @@ e.g. "U shall be a complete type."-20.8.14.2.2 [unique.ptr.single.dtor]: Just before p1 add a new paragraph: +20.9.9.2.2 [unique.ptr.single.dtor]: Just before p1 add a new paragraph:
@@ -33123,7 +39035,7 @@ type-completeness of T is delegated to this expression.
-20.8.14.2.3 [unique.ptr.single.asgn]/1: No changes necessary, except the +20.9.9.2.3 [unique.ptr.single.asgn]/1: No changes necessary, except the current editorial issue, that "must shall" has to be changed to "shall", but this change is not a special part of this resolution.
@@ -33137,7 +39049,7 @@ further requirements on the requirements of the effects clause-20.8.14.2.3 [unique.ptr.single.asgn]/6: +20.9.9.2.3 [unique.ptr.single.asgn]/6:
@@ -33158,7 +39070,7 @@ is true, see (6)+(8).-20.8.14.2.3 [unique.ptr.single.asgn]/11: No changes necessary. +20.9.9.2.3 [unique.ptr.single.asgn]/11: No changes necessary.
[ N.B.: Delegation to requirements of effects clause is sufficient. @@ -33167,7 +39079,7 @@ N.B.: Delegation to requirements of effects clause is sufficient.
- -20.8.14.2.4 [unique.ptr.single.observers]/1+4+7+9+11: +20.9.9.2.4 [unique.ptr.single.observers]/1+4+7+9+11:
@@ -33178,12 +39090,12 @@ N.B.: Delegation to requirements of effects clause is sufficient.- -20.8.14.2.5 [unique.ptr.single.modifiers]/1: No changes necessary. +20.9.9.2.5 [unique.ptr.single.modifiers]/1: No changes necessary.
-20.8.14.2.5 [unique.ptr.single.modifiers]/4: Just before p. 4 add a new paragraph: +20.9.9.2.5 [unique.ptr.single.modifiers]/4: Just before p. 4 add a new paragraph:
Requires: The expression get_deleter()(get()) shall be well-formed, @@ -33192,12 +39104,12 @@ shall have well-defined behavior, and shall not throw exceptions.- -20.8.14.2.5 [unique.ptr.single.modifiers]/7: No changes necessary. +20.9.9.2.5 [unique.ptr.single.modifiers]/7: No changes necessary.
-20.8.14.3 [unique.ptr.runtime]: Add one additional bullet on paragraph 1: +20.9.9.3 [unique.ptr.runtime]: Add one additional bullet on paragraph 1:
@@ -33230,7 +39142,7 @@ post Bellevue: Daniel provided revised wording.
765. more on iterator validity
Section: X [iterator.concepts] Status: WP - Submitter: Martin Sebor Opened: 2007-12-14 Last modified: 2009-07-18
+ Submitter: Martin Sebor Opened: 2007-12-14 Last modified: 2010-10-29View all other issues in [iterator.concepts].
View all issues with WP status.
Discussion:
@@ -33307,9 +39219,8 @@ San Francisco:-Pablo: add a note to the last bullet of paragraph 11 of 23.1.1 -clarifying that the end() iterator doesn't refer to an element and that -it can therefore be invalidated. +
+Pablo: add a note to the last bullet of paragraph 11 of 23.1.1 clarifying that the end() iterator doesn't refer to an element and that it can therefore be invalidated.
Proposed wording: @@ -33379,8 +39290,7 @@ subject to being invalidated. -- end note]
766. Inconsistent exception guarantees between ordered and unordered associative containers
Section: 23.2 [container.requirements], 23.2.5.1 [unord.req.except] Status: CD1 - Submitter: Ion Gaztańaga Opened: 2007-12-22 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+ Submitter: Ion Gaztańaga Opened: 2007-12-22 Last modified: 2010-10-29View all other issues in [container.requirements].
View all issues with CD1 status.
Discussion:
@@ -33403,13 +39313,10 @@ additional requirements:-23.3.2.3 [deque.modifiers] and 23.3.6.4 [vector.modifiers] offer +23.3.2.3 [deque.modifiers] and 23.4.1.4 [vector.modifiers] offer additional guarantees for deque/vector insert() and -erase() members. However, 23.2 [container.requirements]p10 -does not mention 23.2.5.1 [unord.req.except] that specifies exception -safety guarantees -for unordered containers. In addition, 23.2.5.1 [unord.req.except]p1 -offers the following guaratee for +erase() members. However, 23.2 [container.requirements]p10 does not mention 23.2.5.1 [unord.req.except] that specifies exception safety guarantees +for unordered containers. In addition, 23.2.5.1 [unord.req.except]p1 offers the following guaratee for erase():
@@ -33537,15 +39444,15 @@ Compare object (if any; see [associative.reqmts]).
768. Typos in [atomics]?
-Section: 29.5.3 [atomics.types.generic] Status: CD1 - Submitter: Alberto Ganesh Barbati Opened: 2007-12-28 Last modified: 2008-09-26
+Section: 29.5 [atomics.types.generic] Status: CD1 + Submitter: Alberto Ganesh Barbati Opened: 2007-12-28 Last modified: 2010-10-29
View all other issues in [atomics.types.generic].
View all issues with CD1 status.
Discussion:
in the latest publicly available draft, paper N2641, -in section 29.5.3 [atomics.types.generic], the following specialization of the template +in section 29.5 [atomics.types.generic], the following specialization of the template atomic<> is provided for pointers:
@@ -33629,7 +39536,7 @@ initialization.Proposed resolution:
-Change the synopsis in 29.5.3 [atomics.types.generic]: +Change the synopsis in 29.5 [atomics.types.generic]:
template <class T> struct atomic<T*> : atomic_address { @@ -33664,13 +39571,13 @@ Change the synopsis in 29.5.3 [atomics.types.generic]:
769. std::function should use nullptr_t instead of "unspecified-null-pointer-type"
-Section: 20.7.15.2 [func.wrap.func] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-01-10 Last modified: 2008-09-26
+Section: 20.8.14.2 [func.wrap.func] Status: CD1 + Submitter: Daniel Krügler Opened: 2008-01-10 Last modified: 2010-10-29
View all other issues in [func.wrap.func].
View all issues with CD1 status.
Discussion:
-N2461 already replaced in 20.7.15.2 [func.wrap.func] it's originally proposed +N2461 already replaced in 20.8.14.2 [func.wrap.func] it's originally proposed (implicit) conversion operator to "unspecified-bool-type" by the new explicit bool conversion, but the inverse conversion should also use the new std::nullptr_t type instead of "unspecified-null-pointer- @@ -33681,7 +39588,7 @@ type".
Proposed resolution:
-In 20.7 [function.objects], header <functional> synopsis replace: +In 20.8 [function.objects], header <functional> synopsis replace:
template<class R, class... ArgTypes> @@ -33695,7 +39602,7 @@ template<class R, class... ArgTypes>-In the class function synopsis of 20.7.15.2 [func.wrap.func] replace +In the class function synopsis of 20.8.14.2 [func.wrap.func] replace
function(unspecified-null-pointer-typenullptr_t); @@ -33704,7 +39611,7 @@ function& operator=(unspecified-null-pointer-typenullptr_t<-In 20.7.15.2 [func.wrap.func], "Null pointer comparisons" replace: +In 20.8.14.2 [func.wrap.func], "Null pointer comparisons" replace:
template <class R, class... ArgTypes> @@ -33718,7 +39625,7 @@ template <class R, class... ArgTypes>-In 20.7.15.2.1 [func.wrap.func.con], replace +In 20.8.14.2.1 [func.wrap.func.con], replace
function(unspecified-null-pointer-typenullptr_t); @@ -33727,7 +39634,7 @@ function& operator=(unspecified-null-pointer-typenullptr_t<-In 20.7.15.2.6 [func.wrap.func.nullptr], replace +In 20.8.14.2.6 [func.wrap.func.nullptr], replace
template <class R, class... ArgTypes> @@ -33753,8 +39660,8 @@ template <class R, class... ArgTypes>
770. std::function should use rvalue swap
-Section: 20.7.15 [func.wrap] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-01-10 Last modified: 2008-09-26
+Section: 20.8.14 [func.wrap] Status: CD1 + Submitter: Daniel Krügler Opened: 2008-01-10 Last modified: 2010-10-29
View all issues with CD1 status.
Discussion:
@@ -33767,7 +39674,7 @@ this class to rvalue swappability.
Proposed resolution:
-In 20.7 [function.objects], header <functional> synopsis, just below of +In 20.8 [function.objects], header <functional> synopsis, just below of
template<class R, class... ArgTypes> @@ -33779,14 +39686,14 @@ template<class R, class... ArgTypes>-In 20.7.15.2 [func.wrap.func] class function definition, change +In 20.8.14.2 [func.wrap.func] class function definition, change
void swap(function&&);-In 20.7.15.2 [func.wrap.func], just below of +In 20.8.14.2 [func.wrap.func], just below of
template <class R, class... ArgTypes> @@ -33798,14 +39705,14 @@ template <class R, class... ArgTypes>-In 20.7.15.2.2 [func.wrap.func.mod] change +In 20.8.14.2.2 [func.wrap.func.mod] change
void swap(function&& other);-In 20.7.15.2.7 [func.wrap.func.alg] add the two overloads +In 20.8.14.2.7 [func.wrap.func.alg] add the two overloads
template<class R, class... ArgTypes> @@ -33822,7 +39729,7 @@ template<class R, class... ArgTypes>
771. Impossible throws clause in [string.conversions]
Section: 21.5 [string.conversions] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-01-13 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2008-01-13 Last modified: 2010-10-29View all other issues in [string.conversions].
View all issues with CD1 status.
Discussion:
@@ -33888,7 +39795,7 @@ string to_string(long double val);
772. Impossible return clause in [string.conversions]
Section: 21.5 [string.conversions] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-01-13 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2008-01-13 Last modified: 2010-10-29View all other issues in [string.conversions].
View all issues with CD1 status.
Discussion:
@@ -33964,11 +39871,921 @@ character buffer of sufficient size. +
+774. Member swap undefined for most containers
+Section: 23 [containers] Status: WP + Submitter: Alisdair Meredith Opened: 2008-01-14 Last modified: 2010-10-29
+View all other issues in [containers].
+View all issues with WP status.
+Discussion:
++It appears most containers declare but do not define a member-swap +function. +
+ ++This is unfortunate, as all overload the swap algorithm to call the +member-swap function! +(required for swappable guarantees [Table 37] and Container Requirements +[Table 87]) +
+ ++Note in particular that Table 87 gives semantics of a.swap(b) as swap(a,b), +yet for all containers we define swap(a,b) to call a.swap(b) - a circular +definition. +
+ ++A quick survey of clause 23 shows that the following containers provide a +definition for member-swap: +
+ ++ +array +queue +stack +vector ++Whereas the following declare it, but do not define the semantics: +
+ ++ +deque +list +map +multimap +multiset +priority_queue +set +unordered_map +unordered_multi_map +unordered_multi_set +unordered_set ++Suggested resolution: +
++Provide a definition for each of the affected containers... ++ +[ +Bellevue: +]
+ + ++Move to Open and ask Alisdair to provide wording. ++ +[ +2009-07 Frankfurt: +]
+ + ++Daniel to provide wording. +N2590 +is no longer applicable. ++ +[ +2009-07-28 Daniel provided wording. +]
+ + +++ ++
+- +It assumes that the proposed resolution for 883 is applied, +which breaks the circularity of definition between member +swap and free swap. +
+ +- +It uses the notation of the pre-concept allocator trait +allocator_propagation_map, which might be renamed after the +next refactoring phase of generalized allocators. +
+ +- +It requires that compare objects, key equal functions and +hash functions in containers are swapped via unqualified free +swap according to 594. +
+[ +2009-09-30 Daniel adds: +]
+ + ++The outcome of this issue should be considered with the outcome of 1198 both in style and in content (e.g. bullet 9 suggests to +define the semantic of void +priority_queue::swap(priority_queue&) in terms of the member +swap of the container). ++ +[ +2009-10 Santa Cruz: +]
+ + ++Looked at, but took no action on as it overlaps too much with +N2982. +Waiting for a new draft WP. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Leave as open. Pablo to provide wording. ++ +[ +2009-10-26 Pablo updated wording. Here is the wording he replaced: +]
+ + +++ ++
+ +- +
+ ++Add a new Throws clause just after X [allocator.propagation.map]/5: +
+ ++static void swap(Alloc& a, Alloc& b); +++++Effects: [..] +
+ ++Throws: Nothing. +
+[ +This exception requirement is added, such that it's combination with the +general container requirements of +N2723 +[container.requirements.general]/9 +make it unambiguously clear that the following descriptions of "swaps the +allocators" have the following meaning: (a) This swap is done by calling +allocator_propagation_map<allocator_type>::swap and (b) This allocator +swap does never propagate an exception +]
+ +- +
+ ++Change 23.2.4.1 [associative.reqmts.except]/3 as indicated: +
+ ++For associative containers, no swap function throws an exception unless that +exception is thrown by the+copy constructor or copy assignment +operator+swap of the container's Pred objects(if any). +- +
+ ++Change 23.2.5.1 [unord.req.except]/3 as indicated: +
+ ++For unordered associative containers, no swap function throws an +exception unless +that exception is thrown by the+copy constructor or copy +assignment operator+swap of the container's Hash or Pred objects, +respectively(if any). +- +
+ ++Insert a new paragraph just after 23.3 [sequences]/1: +
+ ++In addition to being available via inclusion of the <algorithm> header, +the swap function templates in 25.3.3 [alg.swap] are also available when the +header <queue> is included. ++ +[ +There is a new issue in process that will suggest a minimum header for swap +and move. If this one is provided, this text can be removed and the header +dependency should be added to <queue> +]
+ + +- +
+ ++Add one further clause at the end of 23.3.1.2 [array.special]: +
+[This part is added, because otherwise array::swap would otherwise +contradict the +general contract of 23.2.1 [container.requirements.general] p. 10 b. 5]
+ + ++Throws: Nothing, unless one of the element-wise swap calls throws +an exception. ++- +
+ ++
+- +
+ ++In 23.3.2 [deque], class template deque synopsis change as indicated: +
++void swap(deque<T,Alloc>&); +- +
++At the end of 23.3.2.3 [deque.modifiers] add as indicated: +
+ ++void swap(deque& x); +++++Effects: Exchanges the contents and swaps the allocators of *this +with that of x. +
++Complexity: Constant time. +
+- +
+ ++
+- +
+ ++In 23.3.3 [forwardlist], class template forward_list synposis change as indicated: +
+ ++void swap(forward_list<T,Allocator>&); +- +
++At the end of 23.3.3.4 [forwardlist.modifiers] add as indicated: +
+ ++void swap(forward_list& x); +++++Effects: Exchanges the contents and swaps the allocators of *this +with that of x. +
++Complexity: Constant time. +
+- +
+ ++
+- +
+ ++In 23.3.4 [list], class template list synopsis change as indicated: +
+ ++void swap(list<T,Allocator>&); +- +
++At the end of 23.3.4.3 [list.modifiers] add as indicated: +
+ ++void swap(list& x); ++ ++++Effects: Exchanges the contents and swaps the allocators of *this +with that of x. +
+ ++Complexity: Constant time. +
+- +
+ ++At the end of 23.5.2.3 [priqueue.members] add a new prototype description: +
+ ++void swap(priority_queue& q); +++++Requires: Compare shall satisfy the Swappable requirements +( [swappable]). +
+ +[ +This requirement is added to ensure that even a user defined swap +which is found by +ADL for Compare satisfies the Swappable requirements +]
+ + ++Effects: this->c.swap(q.c); swap(this->comp, q.comp); +
++Throws: What and if c.swap(q.c) and swap(comp, q.comp) throws. +
+[ +This part is added, because otherwise priority_queue::swap would otherwise +contradict the general contract of 23.2.1 [container.requirements.general] p. 10 b. 5 +]
+ +- +
+ ++
+- +
+ ++In 23.4.1 [vector], class template vector synopsis change as indicated: +
+ ++void swap(vector<T,Allocator>&); +- +
++Change 23.4.1.2 [vector.capacity]/8 as indicated: +
+ ++void swap(vector+ +<T,Allocator>& x); ++Effects: Exchanges the contents and capacity() and swaps the +allocators +of *this with that of x. ++- +
+ ++Insert a new paragraph just before 23.6 [associative]/1: +
+ ++In addition to being available via inclusion of the <algorithm> header, +the swap function templates in 25.3.3 [alg.swap] are also available when any of the +headers <map> or <set> are included. ++- +
+ ++
+- +
+ ++In 23.6.1 [map], class template map synopsis change as indicated: +
+ ++void swap(map<Key,T,Compare,Allocator>&); +- +
++At the end of 23.6.1.3 [map.modifiers] add as indicated: +
+ ++void swap(map& x); ++ ++++Requires: Compare shall satisfy the Swappable requirements +( [swappable]). +
+ +[ +This requirement is added to ensure that even a user defined swap +which is found by ADL for Compare satisfies the Swappable +requirements +]
+ + ++Effects: Exchanges the contents and swaps the allocators of *this +with that of x, followed by an unqualified swap of the comparison objects +of *this and x. +
+ ++Complexity: Constant time +
+- +
+ ++
+- +
+ ++In 23.6.2 [multimap], class template multimap synopsis change as indicated: +
+ ++void swap(multimap<Key,T,Compare,Allocator>&); +- +
++At the end of 23.6.2.2 [multimap.modifiers] add as indicated: +
+ ++void swap(multimap& x); ++ ++++Requires: Compare shall satisfy the Swappable requirements +( [swappable]). +
++Effects: Exchanges the contents and swaps the allocators of *this +with that of x, followed by an unqualified swap of the comparison objects +of *this and x. +
++Complexity: Constant time +
+- +
+ ++
+- +
+ ++In 23.6.3 [set], class template set synopsis change as indicated: +
+ ++void swap(set<Key,Compare,Allocator>&); +- +
++After section 23.6.3.1 [set.cons] add a new section set modifiers + [set.modifiers] +and add the following paragraphs: +
+ ++void swap(set& x); ++ ++++Requires: Compare shall satisfy the Swappable requirements +( [swappable]). +
+ ++Effects: Exchanges the contents and swaps the allocators of *this +with that of x, followed by an unqualified swap of the comparison objects +of *this and x. +
+ ++Complexity: Constant time +
+- +
+ ++
+- +
+ ++In 23.6.4 [multiset], class template multiset synosis, change as indicated: +
+ ++void swap(multiset<Key,Compare,Allocator>&); +- +
++After section 23.6.4.1 [multiset.cons] add a new section multiset modifiers + [multiset.modifiers] and add the following paragraphs: +
+ ++void swap(multiset& x); ++ ++++Requires: Compare shall satisfy the Swappable requirements +( [swappable]). +
+ ++Effects: Exchanges the contents and swaps the allocators of *this +with that of x, followed by an unqualified swap of the comparison objects +of *this and x. +
+ ++Complexity: Constant time +
+- +
+ ++Insert a new paragraph just before 23.7 [unord]/1: +
+ ++In addition to being available via inclusion of the <algorithm> header, +the swap function templates in 25.3.3 [alg.swap] are also available when any of the +headers <unordered_map> or <unordered_set> are included. ++ +- +
+ ++After section 23.7.1.2 [unord.map.elem] add a new section unordered_map +modifiers [unord.map.modifiers] and add the following paragraphs: +
+ ++void swap(unordered_map& x); ++ ++++Requires: Hash and Pred shall satisfy the Swappable requirements +( [swappable]). +
+ +[ +This requirement is added to ensure that even a user defined swap +which is found by ADL for Hash and Pred satisfies the Swappable +requirements +]
+ + ++Effects: Exchanges the contents and hash policy and swaps the +allocators of *this +with that of x, followed by an unqualified swap of the Pred objects +and an unqualified swap of the Hash objects of *this and x. +
+ ++Complexity: Constant time +
+- +
+ ++After section 23.7.2.1 [unord.multimap.cnstr] add a new section +unordered_multimap +modifiers [unord.multimap.modifiers] and add the following paragraphs: +
+ ++void swap(unordered_multimap& x); ++ ++++Requires: Hash and Pred shall satisfy the Swappable requirements +( [swappable]). +
+ ++Effects: Exchanges the contents and hash policy and swaps the +allocators of *this +with that of x, followed by an unqualified swap of the Pred objects +and an unqualified swap of the Hash objects of *this and x +
++Complexity: Constant time +
+- +
+ ++After section 23.7.3.1 [unord.set.cnstr] add a new section +unordered_set modifiers + [unord.set.modifiers] and add the following paragraphs: +
+ ++void swap(unordered_set& x); ++ ++++Requires: Hash and Pred shall satisfy the Swappable requirements +( [swappable]). +
+ ++Effects: Exchanges the contents and hash policy and swaps the +allocators of *this +with that of x, followed by an unqualified swap of the Pred objects +and an unqualified swap of the Hash objects of *this and x +
+ ++Complexity: Constant time +
+- +
+ ++After section 23.7.4.1 [unord.multiset.cnstr] add a new section +unordered_multiset +modifiers [unord.multiset.modifiers] and add the following paragraphs: +
+ ++void swap(unordered_multiset& x); ++ ++++Requires: Hash and Pred shall satisfy the Swappable requirements +( [swappable]). +
+ ++Effects: Exchanges the contents and hash policy and swaps the +allocators of *this +with that of x, followed by an unqualified swap of the Pred objects +and an unqualified swap of the Hash objects of *this and x +
++Complexity: Constant time +
+[ +2009-10-30 Pablo and Daniel updated wording. +]
+ + +[ +2010 Pittsburgh: Ready for Pittsburgh. +]
+ + + + +Proposed resolution:
+ +[ +This resolution is based on the September 2009 WP, +N2960, +except that it +assumes that +N2982 +and issues 883 and 1232 have already been applied. Note in +particular that Table 91 in +N2960 +is refered to as Table 90 because +N2982 +removed the old Table 90. This resolution also addresses issue 431. +]
+ ++In 23.2.1 [container.requirements.general], replace the a.swap(b) row in table 90, +"container requirements" (was table 91 before the application of N2982 to the +WP): +
++++
++ ++ a.swap(b)+ void+ + swap(a,b)Exchange the contents of a and b.(Note A) ++ ++ swap(a,b)+ void+ + a.swap(b)(Note A) ++Modify the notes immediately following Table 90 in +23.2.1 [container.requirements.general] as follows (The wording below is after the +application of N2982 to N2960. The editor might also want to combine Notes +A and B into one.): +
+++Notes: the algorithms
swap(),equal() and lexicographical_compare() +are defined in Clause 25. Those entries marked "(Note A)" or "(Note B)" +shouldhave linear complexity for array and constant +complexity for all other standard containers. ++In 23.2.1 [container.requirements.general], before paragraph 8, add: +
+++The expression
a.swap(b), for containersa+andbof a standard container type other thanarray, +exchanges the values ofaandbwithout invoking any +move, copy, or swap operations on the individual container elements. +AnyCompare,Pred, orHashfunction +objects belonging toaandbshall be +swappableand are exchanged by unqualified calls +to non-memberswap. If +allocator_traits<allocator_type>::propagate_on_container_swap::value +== true, then the allocators ofaandbare +also exchanged using an unqualified call to non-memberswap. +Otherwise, the behavior is undefined unlessa.get_allocator() == +b.get_allocator(). Each iterator refering to an element in one +container before the swap shall refer to the same element in the other +container after the swap. It is unspecified whether an iterator with +valuea.end()before the swap will have +valueb.end()after the swap. In addition to being available via +inclusion of the<utility>header, theswap+function template in 25.3.3 [alg.swap] is also available within the definition of +every standard container'sswapfunction. +[ +Note to the editor: Paragraph 2 starts with a sentence fragment, +clearly from an editing or source-control error. +]
+ ++Modify 23.2.4.1 [associative.reqmts.except] as follows: +
++++23.2.4.1 Exception safety guarantees 23.2.4.1 [associative.reqmts.except] +
++For associative containers, no
+clear()function throws an +exception.erase(k)does not throw an exception unless that +exception is thrown by the +container'sobject (if any). +PredCompare+For associative containers, if an exception is thrown by any operation from +within an
+insert()function inserting a single element, +theinsert()function has no effect. ++For associative containers, no
swapfunction throws an exception +unless that exception is thrown by thecopy constructor +or copy assignment operatorswap of the +container'sobject (if any). +PredCompare+Modify 23.2.5.1 [unord.req.except], paragraph 3 as follows: +
+++For unordered associative containers, no
swapfunction throws an +exception unless that exception is thrown by thecopy constructor or copy +assignment operatorswap of the container'sHash+orPredobject (if any). ++Modify section 23.3.1.2 [array.special]: +
++++array specialized algorithms 23.3.1.2 [array.special] +
++
+template <class T, size_t N> void swap(array<T,N>& x,array<T,N>& y);++++Effects:
++swap_ranges(x.begin(), x.end(), y.begin() );x.swap(y);+Add a new section after 23.3.1.5 [array.fill] (Note to the editor: array::fill make use +of a concept requirement that must be removed or changed to text.): +
+++ ++array::swap [array.swap] +
++
+void swap(array& y);++++Effects:
+swap_ranges(this->begin(), this->end(), y.begin() );++Throws: Nothing unless one of the element-wise swap calls throws an +exception. +
++[Note: Unlike other containers'
+swapfunctions, +array::swaptakes linear, not constant, time, may exit via an +exception, and does not cause iterators to become associated with the other +container. — end note] ++Insert a new paragraph just after 23.5 [container.adaptors]/1: +
++ + + + + + + + + + + ++For container adaptors, no
swapfunction throws an exception +unless that exception is thrown by the swap of the +adaptor'sContainerorCompareobject (if any). +
775. Tuple indexing should be unsigned?
-Section: 20.5.2.5 [tuple.helper] Status: CD1 - Submitter: Alisdair Meredith Opened: 2008-01-16 Last modified: 2008-09-26
-View other active issues in [tuple.helper].
+Section: 20.4.2.5 [tuple.helper] Status: CD1 + Submitter: Alisdair Meredith Opened: 2008-01-16 Last modified: 2010-10-29
View all other issues in [tuple.helper].
View all issues with CD1 status.
Discussion:
@@ -34022,7 +40839,7 @@ template<intsize_t I, class T1, class T2> constPtypename tuple_element<I, std::pair<T1, T2> >::type & get(const std::pair<T1, T2>&);-Update 20.3.4 [pairs] Pairs +Update 20.3.5 [pairs] Pairs
template<intsize_t I, class T1, class T2>Ptypename tuple_element<I, std::pair<T1, T2> >::type & get(pair<T1, T2>&); @@ -34041,7 +40858,7 @@ template<intsize_t I, class T1, class T2>-Update header <tuple> synopsis in 20.5 [tuple] with a APIs as below: +Update header <tuple> synopsis in 20.4 [tuple] with a APIs as below:
template <intsize_t I, class T> class tuple_element; // undefined template <intsize_t I, class... Types> class tuple_element<I, tuple<Types...> >; @@ -34054,7 +40871,7 @@ template <intsize_t I, class ... types>-Update 20.5.2.5 [tuple.helper] Tuple helper classes +Update 20.4.2.5 [tuple.helper] Tuple helper classes
template <intsize_t I, class... Types> class tuple_element<I, tuple<Types...> > { @@ -34068,7 +40885,7 @@ public: 2 Type:TIis the type of theIth element ofTypes, where indexing is zero-based.-Update 20.5.2.6 [tuple.elem] Element access +Update 20.4.2.6 [tuple.elem] Element access
template <intsize_t I, class... types > typename tuple_element<I, tuple<Types...> >::type& get(tuple<Types...>& t); @@ -34108,7 +40925,7 @@ template <intsize_t I, class T, size_t N>-Update 23.3.1.7 [array.tuple] Tuple interface to class template array +Update 23.3.1.8 [array.tuple] Tuple interface to class template array
tuple_element<size_t I, array<T, N> >::type@@ -34155,7 +40972,7 @@ for pair is also unnecessary.
776. Undescribed assign function of std::array
Section: 23.3.1 [array] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-01-20 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2008-01-20 Last modified: 2010-10-29View all other issues in [array].
View all issues with CD1 status.
Discussion:
@@ -34248,7 +41065,8 @@ Set state to Review given substitution of "fill" for "assign".
777. Atomics Library Issue
Section: 29.6 [atomics.types.operations] Status: CD1 - Submitter: Lawrence Crowl Opened: 2008-01-21 Last modified: 2008-09-26
+ Submitter: Lawrence Crowl Opened: 2008-01-21 Last modified: 2010-10-29 +View other active issues in [atomics.types.operations].
View all other issues in [atomics.types.operations].
View all issues with CD1 status.
Discussion:
@@ -34321,8 +41139,8 @@ C A::load(memory_order order = memory_order_seq_cst) const volatile;
778. std::bitset does not have any constructor taking a string literal
-Section: 20.3.7.1 [bitset.cons] Status: CD1 - Submitter: Thorsten Ottosen Opened: 2008-01-24 Last modified: 2008-09-26
+Section: 20.5.1 [bitset.cons] Status: CD1 + Submitter: Thorsten Ottosen Opened: 2008-01-24 Last modified: 2010-10-29
View all other issues in [bitset.cons].
View all issues with CD1 status.
Duplicate of: 116
@@ -34347,14 +41165,14 @@ to std::bitset.Proposed resolution:
-Add to synopsis in 20.3.7 [template.bitset] +Add to synopsis in 20.5 [template.bitset]
explicit bitset( const char* str );-Add to synopsis in 20.3.7.1 [bitset.cons] +Add to synopsis in 20.5.1 [bitset.cons]
explicit bitset( const char* str ); @@ -34372,7 +41190,7 @@ Add to synopsis in 20.3.7.1 [bitset.cons]
779. Resolution of #283 incomplete
Section: 25.3.8 [alg.remove] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-01-25 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2008-01-25 Last modified: 2010-10-29View all other issues in [alg.remove].
View all issues with CD1 status.
Discussion:
@@ -34399,10 +41217,249 @@ valid. +
+780. std::merge() specification incorrect/insufficient
+Section: 25.4.4 [alg.merge] Status: WP + Submitter: Daniel Krügler Opened: 2008-01-25 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++Though issue 283 has fixed many open issues, it seems that some are still open: +
+ ++Both 25.3.4 [lib.alg.merge] in 14882:2003 and 25.4.4 [alg.merge] in N2461 +have no Requires element and the Effects element contains some requirements, +which is probably editorial. Worse is that: +
+ ++
+ +- +no assignment requirements are specified (neither implicit nor explicit). +
+ +- +the effects clause just speaks of "merges", which is badly worded +near to a circular definition. +
+ +- +p. 2 mentions a range [first, last), which is not defined by the +function arguments or otherwise. +
+ +- +p. 2 says "according to the ordering defined by comp" which is both +incomplete (because +this excludes the first variant with <) and redundant (because the +following subordinate +clause mentions comp again) +
+[ +Post Summit Alisdair adds: +]
+ + +++ ++Suggest: +
++(where last is equal to next(result, distance(first1, last1) + +distance(first2, last2)), such that resulting range will be sorted in +non-decreasing order; that is, for every iterator i in [result,last) other +than result, the condition *i < *prev(i) or, respectively, comp(*i, +*prev(i)) will be false. ++ ++Note that this might still not be technically accurate in the case of +InputIterators, depending on other resolutions working their way through the +system (1011). +
+[ +Post Summit Daniel adds: +]
+ + ++If we want to use prev and next here (Note: merge +is sufficiently satisfied with InputIterator) we should instead *add* more to +25 [algorithms]/6, but I can currently not propose any good wording for this. ++ +[ +Batavia (2009-05): +]
+ +++ ++Pete points out the existing wording in [algorithms]/4 +that permits the use of + in algorithm specifications. +
++Alisdair points out that that wording may not apply to input iterators. +
++Move to Review. +
+[ +2009-07 Frankfurt: +]
+ + ++Move to Ready. ++ +[ +2009-08-23 Daniel reopens: +]
+ + +++ ++The proposed wording must be rephrased, because the part +
+ ++for every iterator i in [result,last) other than result, the condition +*i < *(i - 1) or, respectively, comp(*i, *(i - 1)) will be false" ++ ++isn't meaningful, because the range [result,last) is that of a pure +OutputIterator, which is not readable in general. +
+ +[Howard: Proposed wording updated by Daniel, status moved from Ready to Review.]
+ +[ +2009-10 Santa Cruz: +]
+ + +++ ++Matt has some different words to propose. Those words have been moved into +the proposed wording section, and the original proposed wording now appears +here: +
++++In 25.4.4 [alg.merge] replace p.1+ 2: +
+ ++++Effects:
+ +MergesCopies all the elements of the +two sorted ranges +[first1,last1) and [first2,last2) into the range [result,result + +(last1 - first1) + (last2 - first2)) +, such that resulting range will be sorted in non-decreasing +order; that is for every +pair of iterators i and j of either input ranges, where *i was copied +to the output range +before *j was copied to the output range, the condition *j < *i or, +respectively, comp(*j, *i) +will be false. ++Requires:The resulting range shall not overlap with either +of the original ranges. +
+The list will be sorted in non-decreasing order according to the +ordering defined by +comp; that is, for every iterator i in [first,last) other than first, +the condition *i < *(i - 1) or +comp(*i, *(i - 1)) will be false.+[ +2010-02-10 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+ ++Change 25.4.4 [alg.merge] 1 and 2: +
+ +++ +1
++Effects: Merges two sorted ranges [first1,last1) and +[first2,last2) into the range [result, result + (last1 - +first1) + (last2 - first2)). ++Effects: Copies all the elements of the two ranges +[first1,last1) and [first2,last2) into the range +[result, result_last), where result_last is result ++ (last1 - first1) + (last2 - first2), such that the resulting +range satisfies is_sorted(result, result_last) or +is_sorted(result, result_last, comp), respectively. +
+ ++2 Requires: The ranges [first1,last1) and +[first2,last2) shall be sorted with respect to operator< or +comp. The resulting range shall not overlap with either of the +original ranges.
+ +The list will be sorted in non-decreasing order according +to the ordering defined by comp; that is, for every iterator i +in [first,last) other than first, the condition *i < +*(i - 1) or comp(*i, *(i - 1)) will be false.++Change 25.4.4 [alg.merge]/6+7 as indicated [This ensures harmonization +between inplace_merge and merge] +
+ +++ + + + + ++6 Effects: Merges two
+ +sortedconsecutive ranges +[first,middle) and [middle,last), putting the result of the +merge into the range [first,last). The resulting range will be in +non-decreasing order; that is, for every iterator i in +[first,last) other than first, the condition *i < *(i - +1) or, respectively, comp(*i, *(i - 1)) will be false. ++7 Requires: The ranges [first,middle) and +[middle,last) shall be sorted with respect to operator< or +comp. The type of *first shall satisfy the +Swappable requirements (37), the MoveConstructible +requirements (Table 33), and the the MoveAssignable requirements (Table +35). +
+
781. std::complex should add missing C99 functions
Section: 26.4.7 [complex.value.ops] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-01-26 Last modified: 2009-03-21
+ Submitter: Daniel Krügler Opened: 2008-01-26 Last modified: 2010-10-29View all other issues in [complex.value.ops].
View all issues with CD1 status.
Discussion:
@@ -34490,7 +41547,7 @@ imag real
782. Extended seed_seq constructor is useless
Section: 26.5.7.1 [rand.util.seedseq] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-01-27 Last modified: 2009-05-01
+ Submitter: Daniel Krügler Opened: 2008-01-27 Last modified: 2010-10-29View all other issues in [rand.util.seedseq].
View all issues with CD1 status.
Discussion:
@@ -34517,7 +41574,7 @@ template arguments of function templates, this customization point via the second size_t template parameter is of no advantage, because u can never be deduced, and worse - because it is a constructor function template - it can also never be explicitly -provided (14.9.1 [temp.arg.explicit]/7). +provided (14.8.1 [temp.arg.explicit]/7).@@ -34591,7 +41648,7 @@ seed_seq(InputIterator begin, InputIterator end, implementation-defined s
-In 26.5.1 [rand.synopsis], header <random> synopsis, immediately after the +In 26.5.2 [rand.synopsis], header <random> synopsis, immediately after the class seed_seq declaration and in 26.5.7.1 [rand.util.seedseq]/2, immediately after the class seed_seq definition add:
@@ -34646,7 +41703,7 @@ where u is used to construct an object s of implementation-def
783. thread::id reuse
Section: 30.3.1.1 [thread.thread.id] Status: CD1 - Submitter: Hans Boehm Opened: 2008-02-01 Last modified: 2008-09-26
+ Submitter: Hans Boehm Opened: 2008-02-01 Last modified: 2010-10-29View all other issues in [thread.thread.id].
View all issues with CD1 status.
Discussion:
@@ -34728,10 +41785,137 @@ terminated thread that can no longer be joined. +
+786. Thread library timed waits, UTC and monotonic clocks
+Section: 20.11 [time] Status: Resolved + Submitter: Christopher Kohlhoff, Jeff Garland Opened: 2008-02-03 Last modified: 2010-11-19
+View all other issues in [time].
+View all issues with Resolved status.
+Discussion:
++The draft C++0x thread library requires that the time points of type +system_time and returned by get_system_time() represent Coordinated +Universal Time (UTC) (section [datetime.system]). This can lead to +surprising behavior when a library user performs a duration-based wait, +such as condition_variable::timed_wait(). A complete explanation of the +problem may be found in the +Rationale for the Monotonic Clock +section in POSIX, but in summary: +
+ ++
+ +- +Operations such as condition_variable::timed_wait() (and its POSIX +equivalent, pthread_cond_timedwait()) are specified using absolute times +to address the problem of spurious wakeups. +
+ +- +The typical use of the timed wait operations is to perform a relative +wait. This may be achieved by first calculating an absolute time as the +sum of the current time and the desired duration. In fact, the C++0x +thread library includes duration-based overloads of +condition_variable::timed_wait() that behave as if by calling the +corresponding absolute time overload with a time point value of +get_system_time() + rel_time. +
+ +- +A UTC clock may be affected by changes to the system time, such as +synchronization with an external source, leap seconds, or manual changes +to the clock. +
+ +- +Should the clock change during a timed wait operation, the actual +duration of the wait will not be the expected length. For example, a +user may intend a timed wait of one second duration but, due to an +adjustment of the system clock backwards by a minute, the wait instead +takes 61 seconds. +
++POSIX solves the problem by introducing a new monotonic clock, which is +unaffected by changes to the system time. When a condition variable is +initialized, the user may specify whether the monotonic clock is to be +used. (It is worth noting that on POSIX systems it is not possible to +use condition_variable::native_handle() to access this facility, since +the desired clock type must be specified during construction of the +condition variable object.) +
+ ++In the context of the C++0x thread library, there are added dimensions +to the problem due to the need to support platforms other than POSIX: +
+ ++
+ +- +Some environments (such as embedded systems) do not have a UTC clock, but do have a monotonic clock. +
+ +- +Some environments do not have a monotonic clock, but do have a UTC clock. +
+ +- +The Microsoft Windows API's synchronization functions use relative +timeouts based on an implied monotonic clock. A program that switches +from the Windows API to the C++0x thread library will now find itself +susceptible to clock changes. +
++One possible minimal solution: +
+ ++
+ + + +- +Strike normative references to UTC and an epoch based on 1970-01-01. +
+ +- +Make the semantics of system_time and get_system_time() +implementation-defined (i.e standard library implementors may choose the +appropriate underlying clock based on the capabilities of the target +platform). +
+ +- +Add a non-normative note encouraging use of a monotonic clock. +
+ +- +Remove system_time::seconds_since_epoch(). +
+ +- +Change the constructor explicit system_time(time_t secs, nanoseconds ns += 0) to explicit system_time(nanoseconds ns). +
+Proposed resolution:
++
+ + +Rationale:
+Addressed by +N2661: A Foundation to Sleep On. + + + + +
787. complexity of binary_search
Section: 25.4.3.4 [binary.search] Status: CD1 - Submitter: Daniel Krügler Opened: 2007-09-08 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2007-09-08 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -34785,7 +41969,7 @@ Change 25.4.3.4 [binary.search]/3
788. ambiguity in [istream.iterator]
Section: 24.6.1 [istream.iterator] Status: WP - Submitter: Martin Sebor Opened: 2008-02-06 Last modified: 2009-10-26
+ Submitter: Martin Sebor Opened: 2008-02-06 Last modified: 2010-10-29View all other issues in [istream.iterator].
View all issues with WP status.
Discussion:
@@ -34904,7 +42088,7 @@ is used a new value is read.
789. xor_combine_engine(result_type) should be explicit
Section: X [rand.adapt.xor] Status: CD1 - Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2008-09-26
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29View all other issues in [rand.adapt.xor].
View all issues with CD1 status.
Discussion:
@@ -34929,7 +42113,7 @@ adapter.Proposed resolution:
-Remove xor_combine_engine from synopsis of 26.5.1 [rand.synopsis]. +Remove xor_combine_engine from synopsis of 26.5.2 [rand.synopsis].
Remove X [rand.adapt.xor] xor_combine_engine. @@ -34942,7 +42126,7 @@ Remove X [rand.adapt.xor] xor_combine_engine.
792. piecewise_constant_distribution is undefined for a range with just one endpoint
Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: CD1 - Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2008-09-26
+ Submitter: P.J. Plauger Opened: 2008-02-09 Last modified: 2010-10-29View all other issues in [rand.dist.samp.pconst].
View all issues with CD1 status.
Discussion:
@@ -34967,15 +42151,15 @@ b) If firstB == lastB or the sequence w has the length ze
798. Refactoring of binders lead to interface breakage
-Section: D.9 [depr.lib.binders] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-02-14 Last modified: 2008-09-26
+Section: D.11 [depr.lib.binders] Status: CD1 + Submitter: Daniel Krügler Opened: 2008-02-14 Last modified: 2010-10-29
View all other issues in [depr.lib.binders].
View all issues with CD1 status.
Discussion:
N2521 and its earlier predecessors have moved the old binders from -[lib.binders] to D.9 [depr.lib.binders] thereby introducing some renaming +[lib.binders] to D.11 [depr.lib.binders] thereby introducing some renaming of the template parameter names (Operation -> Fn). During this renaming process the protected data member op was also renamed to fn, which seems as an unnecessary interface breakage to me - even if @@ -34985,7 +42169,7 @@ this user access point is probably rarely used.
Proposed resolution:
-Change D.9.1 [depr.lib.binder.1st]: +Change D.11.1 [depr.lib.binder.1st]:
@@ -35017,7 +42201,7 @@ public:-Change D.9.3 [depr.lib.binder.2nd]: +Change D.11.3 [depr.lib.binder.2nd]:
@@ -35053,10 +42237,207 @@ public: +
+801. tuple and pair trivial members
+Section: 20.4 [tuple] Status: Resolved + Submitter: Lawrence Crowl Opened: 2008-02-18 Last modified: 2010-11-26
+View all other issues in [tuple].
+View all issues with Resolved status.
+Discussion:
++Classes with trivial special member functions are inherently more +efficient than classes without such functions. This efficiency is +particularly pronounced on modern ABIs that can pass small classes +in registers. Examples include value classes such as complex numbers +and floating-point intervals. Perhaps more important, though, are +classes that are simple collections, like pair and tuple. When the +parameter types of these classes are trivial, the pairs and tuples +themselves can be trivial, leading to substantial performance wins. +
++The current working draft make specification of trivial functions +(where possible) much easer through defaulted and deleted functions. +As long as the semantics of defaulted and deleted functions match +the intended semantics, specification of defaulted and deleted +functions will yield more efficient programs. +
++There are at least two cases where specification of an explicitly +defaulted function may be desirable. +
++First, the std::pair template has a non-trivial default constructor, +which prevents static initialization of the pair even when the +types are statically initializable. Changing the definition to +
+ ++ +pair() = default; ++would enable such initialization. Unfortunately, the change is +not semantically neutral in that the current definition effectively +forces value initialization whereas the change would not value +initialize in some contexts. +
+ ++** Does the committee confirm that forced value initialization +was the intent? If not, does the committee wish to change the +behavior of std::pair in C++0x? +
++Second, the same default constructor issue applies to std::tuple. +Furthermore, the tuple copy constructor is current non-trivial, +which effectively prevents passing it in registers. To enable +passing tuples in registers, the copy constructor should be +make explicitly defaulted. The new declarations are: +
+ ++ +tuple() = default; +tuple(const tuple&) = default; ++This changes is not implementation neutral. In particular, it +prevents implementations based on pointers to the parameter +types. It does however, permit implementations using the +parameter types as bases. +
++** How does the committee wish to trade implementation +efficiency versus implementation flexibility? +
+ +[ +Bellevue: +]
+ + +++ ++General agreement; the first half of the issue is NAD. +
++Before voting on the second half, it was agreed that a "Strongly Favor" +vote meant support for trivial tuples (assuming usual requirements met), +even at the expense of other desired qualities. A "Weakly Favor" vote +meant support only if not at the expense of other desired qualities. +
++Concensus: Go forward, but not at expense of other desired qualities. +
++It was agreed to Alisdair should fold this work in with his other +pair/tuple action items, above, and that issue 801 should be "open", but +tabled until Alisdair's proposals are disposed of. +
+[ +2009-05-27 Daniel adds: +]
+ + ++This is partly solved by 1117. ++ +[ +2009-07 Frankfurt: +]
+ + ++Wait for dust to settle from fixing exception safety problem +with rvalue refs. ++ +[ +2009-07-20 Alisdair adds: +]
+ + +++ ++Basically, this issue is what should we do with the default constructor +for pairs and tuples of trivial types. The motivation of the issue was +to force static initialization rather than dynamic initialization, and +was rejected in the case of pair as it would change the meaning of +existing programs. The advice was "do the best we can" for tuple +without changing existing meaning. +
+ ++Frankfurt seems to simply wait and see the resolution on no-throw move +constructors, which (I believe) is only tangentially related to this +issue, but as good as any to defer until Santa Cruz. +
+ ++Looking again now, I think constant (static) initialization for pair can +be salvaged by making the default construct constexpr. I have a +clarification from Core that this is intended to work, even if the +constructor is not trivial/constexpr, so long as no temporaries are +implied in the process (even if elided). +
+[ +2009-10 Santa Cruz: +]
+ + ++Leave as open. Alisdair to provide wording. ++ +[ +2010 Pittsburgh: +]
+ + +++ + ++We believe this may be NAD Editorial since both pair and tuple now have +constexpr default constructors, but we're not sure. +
+[ +2010 Rapperswil: +]
+ + ++Daniel believes his pair/tuple paper will resolve this issue. constexpr will allow static initialization, and he is already changing the move and copy constructors to be defaulted. ++ +[ +2010-10-24 Daniel adds: +]
+ + ++The proposed resolution of n3140 should resolve this issue. ++ + + +Proposed resolution:
++See n3140. +
+ + + + +
804. Some problems with classes error_code/error_condition
Section: 19.5 [syserr] Status: CD1 - Submitter: Daniel Krügler Opened: 2008-02-24 Last modified: 2008-09-26
+ Submitter: Daniel Krügler Opened: 2008-02-24 Last modified: 2010-10-29View all other issues in [syserr].
View all issues with CD1 status.
Discussion:
@@ -35368,7 +42749,7 @@ In 19.5.3.4 [syserr.errcondition.observers], remove the throws clause p. 6.
805. posix_error::posix_errno concerns
Section: 19.5 [syserr] Status: CD1 - Submitter: Jens Maurer Opened: 2008-02-24 Last modified: 2008-09-26
+ Submitter: Jens Maurer Opened: 2008-02-24 Last modified: 2010-10-29View all other issues in [syserr].
View all issues with CD1 status.
Discussion:
@@ -35619,8 +43000,8 @@ intuitive. There are no uses of errc in the current C++ standard.
806. unique_ptr::reset effects incorrect, too permissive
-Section: 20.8.14.2.5 [unique.ptr.single.modifiers] Status: CD1 - Submitter: Peter Dimov Opened: 2008-03-13 Last modified: 2008-09-26
+Section: 20.9.9.2.5 [unique.ptr.single.modifiers] Status: CD1 + Submitter: Peter Dimov Opened: 2008-03-13 Last modified: 2010-10-29
View all other issues in [unique.ptr.single.modifiers].
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Discussion:
@@ -35672,7 +43053,7 @@ scenario, as it definitely doesn't when p and q are separate.Proposed resolution:
-Change 20.8.14.2.5 [unique.ptr.single.modifiers]: +Change 20.9.9.2.5 [unique.ptr.single.modifiers]:
@@ -35684,7 +43065,7 @@ Change 20.8.14.2.5 [unique.ptr.single.modifiers]:-Change 20.8.14.3.3 [unique.ptr.runtime.modifiers]: +Change 20.9.9.3.3 [unique.ptr.runtime.modifiers]:
@@ -35705,8 +43086,8 @@ Change 20.8.14.3.3 [unique.ptr.runtime.modifiers]:
807. tuple construction should not fail unless its element's construction fails
-Section: 20.5.2.1 [tuple.cnstr] Status: CD1 - Submitter: Howard Hinnant Opened: 2008-03-13 Last modified: 2008-09-26
+Section: 20.4.2.1 [tuple.cnstr] Status: CD1 + Submitter: Howard Hinnant Opened: 2008-03-13 Last modified: 2010-10-29
View all other issues in [tuple.cnstr].
View all issues with CD1 status.
Discussion:
@@ -35718,7 +43099,7 @@ should be added to tuple except it ought to take into account move consProposed resolution:
-Add to 20.5.2.1 [tuple.cnstr]: +Add to 20.4.2.1 [tuple.cnstr]:
@@ -35735,7 +43116,7 @@ or assignment of one of the types in Types throws an exception.
808. [forward] incorrect redundant specification
Section: 20.3.3 [forward] Status: CD1 - Submitter: Jens Maurer Opened: 2008-03-13 Last modified: 2008-09-26
+ Submitter: Jens Maurer Opened: 2008-03-13 Last modified: 2010-10-29View all other issues in [forward].
View all issues with CD1 status.
Discussion:
@@ -35750,7 +43131,7 @@ p4 (forward) says: First of all, lvalue-ness and rvalue-ness are properties of an expression, not of a type (see 3.10 [basic.lval]). Thus, the phrasing "Return type" is wrong. Second, the phrase says exactly what the core language wording says for -folding references in 14.4.1 [temp.arg.type]/p4 and for function return values +folding references in 14.3.1 [temp.arg.type]/p4 and for function return values in 5.2.2 [expr.call]/p10. (If we feel the wording should be retained, it should at most be a note with cross-references to those sections.) @@ -35815,7 +43196,7 @@ In both cases, A2 is deduced as double, so 1.414 is forwarded to A<
809. std::swap should be overloaded for array types
Section: 25.3.3 [alg.swap] Status: CD1 - Submitter: Niels Dekker Opened: 2008-02-28 Last modified: 2008-09-26
+ Submitter: Niels Dekker Opened: 2008-02-28 Last modified: 2010-10-29View all other issues in [alg.swap].
View all issues with CD1 status.
Discussion:
@@ -35824,7 +43205,7 @@ For the sake of generic programming, the header<algorithm>s overload ofstd::swapfor array types:template<class T, size_t N> void swap(T (&a)[N], T (&b)[N]);- +It became apparent to me that this overload is missing, when I considered how to write a swap @@ -35865,7 +43246,7 @@ swap(w1, w2); // Ill-formed, just because ADL finds W's swap function!!! This issue is easily solved by providing an overload of
std::swapfor array types. This swap function should be implemented in terms of swapping the elements of the arrays, so that it would be non-throwing for arrays whose element types have a non-throwing swap. - +Note that such an overload of
std::swapshould also support multi-dimensional @@ -35907,7 +43288,7 @@ Add the following to 25.3.3 [alg.swap]:
810. Missing traits dependencies in operational semantics of extended manipulators
Section: 27.7.4 [ext.manip] Status: WP - Submitter: Daniel Krügler Opened: 2008-03-01 Last modified: 2009-07-18
+ Submitter: Daniel Krügler Opened: 2008-03-01 Last modified: 2010-10-29View all other issues in [ext.manip].
View all issues with WP status.
Discussion:
@@ -36014,15 +43395,146 @@ In 27.7 [iostream.format], Header <iomanip> synopsis change: +
+811. pair of pointers no longer works with literal 0
+Section: 20.3.5 [pairs] Status: WP + Submitter: Doug Gregor Opened: 2008-03-14 Last modified: 2010-10-29
+View all other issues in [pairs].
+View all issues with WP status.
+Discussion:
++ +#include <utility> + +int main() +{ + std::pair<char *, char *> p (0,0); +} ++I just got a bug report about that, because it's valid C++03, but not +C++0x. The important realization, for me, is that the emplace +proposal---which made push_back variadic, causing the push_back(0) +issue---didn't cause this break in backward compatibility. The break +actually happened when we added this pair constructor as part of adding +rvalue references into the language, long before variadic templates or +emplace came along: +
+ ++ +template<class U, class V> pair(U&& x, V&& y); ++Now, concepts will address this issue by constraining that pair +constructor to only U's and V's that can properly construct "first" and +"second", e.g. (from +N2322): +
+ ++ +template<class U , class V > +requires Constructible<T1, U&&> && Constructible<T2, V&&> +pair(U&& x , V&& y ); +[ +San Francisco: +]
+ + +++ ++Suggested to resolve using pass-by-value for that case. +
++Side question: Should pair interoperate with tuples? Can construct a +tuple of a pair, but not a pair from a two-element tuple. +
++Related to 885. +
+[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Leave as open. Howard to provide wording. ++ +[ +2010-02-06 Howard provided wording. +]
+ + +[ +2010-02-09 Moved to Tentatively Ready after 6 positive votes on c++std-lib. +]
+ + + + +Rationale:
+[ +San Francisco: +]
+ + ++Solved by +N2770. ++ +[ +The rationale is obsolete. +]
+ + + + +Proposed resolution:
++Add a paragraph to 20.3.5 [pairs]: +
+ +++ + + + + +template<class U, class V> pair(U&& x, V&& y); +++++6 Effects: The constructor initializes first with +std::forward<U>(x) and second with +std::forward<V>(y). +
+ ++Remarks: U shall be implicitly convertible to +first_type and V shall be implicitly convertible to +second_type, else this constructor shall not participate in overload +resolution. +
+
813. "empty" undefined for shared_ptr
-Section: 20.8.15.2 [util.smartptr.shared] Status: CD1 - Submitter: Matt Austern Opened: 2008-02-26 Last modified: 2008-09-26
+Section: 20.9.10.2 [util.smartptr.shared] Status: CD1 + Submitter: Matt Austern Opened: 2008-02-26 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared].
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Discussion:
-Several places in 20.8.15.2 [util.smartptr.shared] refer to an "empty" shared_ptr. +Several places in 20.9.10.2 [util.smartptr.shared] refer to an "empty" shared_ptr. However, that term is nowhere defined. The closest thing we have to a definition is that the default constructor creates an empty shared_ptr and that a copy of a default-constructed shared_ptr is empty. Are any @@ -36038,7 +43550,7 @@ and issue 814. vector<bool>::swap(reference, reference) not defined -
Section: 23.3.7 [vector.bool] Status: WP - Submitter: Alisdair Meredith Opened: 2008-03-17 Last modified: 2009-07-18
+Section: 23.4.2 [vector.bool] Status: WP + Submitter: Alisdair Meredith Opened: 2008-03-17 Last modified: 2010-10-29
View all other issues in [vector.bool].
View all issues with WP status.
Discussion:
@@ -36196,7 +43708,7 @@ Move to Tentatively Ready.Proposed resolution:
-Just after 23.3.7 [vector.bool]/5 add the following prototype and description: +Just after 23.4.2 [vector.bool]/5 add the following prototype and description:
@@ -36219,10 +43731,855 @@ y = b; +
+815. std::function and reference_closure do not use perfect forwarding
+Section: 20.8.14.2.4 [func.wrap.func.inv] Status: Resolved + Submitter: Alisdair Meredith Opened: 2008-03-16 Last modified: 2010-11-19
+View all other issues in [func.wrap.func.inv].
+View all issues with Resolved status.
+Discussion:
++std::function and reference_closure should use "perfect forwarding" as +described in the rvalue core proposal. +
+ +[ +Sophia Antipolis: +]
+ + ++According to Doug Gregor, as far as std::function is concerned, perfect +forwarding can not be obtained because of type erasure. Not everyone +agreed with this diagnosis of forwarding. ++ +[ +2009-05-01 Howard adds: +]
+ + +++ ++Sebastian Gesemann brought to my attention that the CopyConstructible +requirement on function's ArgTypes... is an unnecessary +restriction. +
+ ++ +template<Returnable R, CopyConstructible... ArgTypes> +class function<R(ArgTypes...)> +... ++On further investigation, this complaint seemed to be the same +issue as this one. I believe the reason CopyConstructible was put +on ArgTypes in the first place was because of the nature of the +invoke member: +
+ ++ +template<class R, class ...ArgTypes> +R +function<R(ArgTypes...)>::operator()(ArgTypes... arg) const +{ + if (f_ == 0) + throw bad_function_call(); + return (*f_)(arg...); +} ++However now with rvalue-refs, "by value" no longer implies CopyConstructible +(as Sebastian correctly points out). If rvalue arguments are supplied, MoveConstructible +is sufficient. Furthermore, the constraint need not be applied in function +if I understand correctly. Rather the client must apply the proper constraints +at the call site. Therefore, at the very least, I recommend that CopyConstructible +be removed from the template class function. +
+ ++Furthermore we need to mandate that the invoker is coded as: +
+ ++ +template<class R, class ...ArgTypes> +R +function<R(ArgTypes...)>::operator()(ArgTypes... arg) const +{ + if (f_ == 0) + throw bad_function_call(); + return (*f_)(std::forward<ArgTypes>(arg)...); +} ++Note that ArgTypes&& (the "perfect forwarding signature") is not +appropriate here as this is not a deduced context for ArgTypes. Instead +the client's arguments must implicitly convert to the non-deduced ArgType +type. Catching these arguments by value makes sense to enable decay. +
+ ++Next forward is used to move the ArgTypes as efficiently as +possible, and also with minimum requirements (not CopyConstructible) +to the type-erased functor. For object types, this will be a move. For +reference type ArgTypes, this will be a copy. The end result must be +that the following is a valid program: +
+ ++ +#include <functional> +#include <memory> +#include <cassert> + +std::unique_ptr<int> +f(std::unique_ptr<int> p, int& i) +{ + ++i; + return std::move(p); +} + +int main() +{ + int i = 2; + std::function<std::unique_ptr<int>(std::unique_ptr<int>, + int&> g(f); + std::unique_ptr<int> p = g(std::unique_ptr<int>(new int(1)), i); + assert(*p == 1); + assert(i == 3); +} +[ +Tested in pre-concepts rvalue-ref-enabled compiler. +]
+ + ++In the example above, the first ArgType is unique_ptr<int> +and the second ArgType is int&. Both must work! +
+ +[ +2009-05-27 Daniel adds: +]
+ + +++ ++in the 2009-05-01 comment of above mentioned issue Howard +
+ ++
+- +Recommends to replace the CopyConstructible requirement by a +MoveConstructible requirement +
+- +Says: "Furthermore, the constraint need not be applied in function if I +understand correctly. Rather the client must apply the proper constraints +at the call site" +
++I'm fine with (a), but I think comment (b) is incorrect, at least in the +sense I read these sentences. Let's look at Howard's example code: +
+ ++ +function<R(ArgTypes...)>::operator()(ArgTypes... arg) const +{ + if (f_ == 0) + throw bad_function_call(); + return (*f_)(std::forward<ArgTypes>(arg)...); +} ++In the constrained scope of this operator() overload the expression +"(*f_)(std::forward<ArgTypes>(arg)...)" must be valid. How can it +do so, if ArgTypes aren't at least MoveConstructible? +
+[ +2009-07 Frankfurt: +]
+ + ++Leave this open and wait until concepts are removed from the Working +Draft so that we know how to write the proposed resolution in terms of +diffs to otherwise stable text. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Leave as open. Howard to provide wording. Howard welcomes any help. ++ +[ +2009-12-12 Jonathan Wakely adds: +]
+ + +++ ++20.8.14.2 [func.wrap.func] says +
+ ++2 A function object f of type F is Callable for argument +types T1, T2, ..., TN in ArgTypes and a return type +R, if, given lvalues t1, t2, ..., tN of types T1, T2, ..., +TN, respectively, INVOKE (f, t1, t2, ..., tN) is well formed +(20.7.2) and, if R is not void, convertible to R. ++ ++N.B. lvalues, which means you can't use function<R(T&&)> +or function<R(unique_ptr<T>)> +
+ ++I recently implemented rvalue arguments in GCC's std::function, all +that was needed was to use std::forward<ArgTypes> in a few +places. The example in issue 815 works. +
+ ++I think 815 could be resolved by removing the requirement that the target +function be callable with lvalues. Saying ArgTypes need to be +CopyConstructible is wrong, and IMHO saying MoveConstructible +is unnecessary, since the by-value signature implies that already, but if it is +needed it should only be on operator(), not the whole class (you could +in theory instantiate std::function<R(noncopyable)> as long as +you don't invoke the call operator.) +
+ ++I think defining invocation in terms of INVOKE already implies perfect +forwarding, so we don't need to say explicitly that std::forward should +be used (N.B. the types that are forwarded are those in ArgTypes, which +can differ from the actual parameter types of the target function. The actual +parameter types have gone via type erasure, but that's not a problem - IMHO +forwarding the arguments as ArgTypes is the right thing to do anyway.) +
+ ++Is it sufficient to simply replace "lvalues" with "values"? or do we need to say +something like "lvalues when Ti is an lvalue-reference and rvalues +otherwise"? I prefer the former, so I propose the following resolution for 815: +
+ ++Edit 20.8.14.2 [func.wrap.func] paragraph 2: +
+ ++2 A function object f of type F is Callable for argument +types T1, T2, ..., TN in ArgTypes and a return type +R, if, given+lvalues t1, t2, ..., tN of types +T1, T2, ..., TN, respectively, INVOKE (f, t1, t2, ..., tN) is +well formed (20.7.2) and, if R is not void, convertible to +R. +[ +2009-12-12 Daniel adds: +]
+ + ++I don't like the reduction to "values" and prefer the alternative solution +suggested using "lvalues when Ti is an lvalue-reference and rvalues otherwise". +The reason why I dislike the shorter version is based on different usages of +"values" as part of defining the semantics of requirement tables via +expressions. E.g. 20.2.1 [utility.arg.requirements]/1 says "a, +b, and c are values of type const T;" or similar in +23.2.1 [container.requirements.general]/4 or /14 etc. My current reading +of all these parts is that both rvalues and lvalues are required to be +supported, but this interpretation would violate the intention of the suggested +fix of #815, if I correctly understand Jonathan's rationale. ++ +[ +2009-12-12 Howard adds: +]
+ + +++ ++"lvalues when Ti is an lvalue-reference and rvalues otherwise" +++doesn't quite work here because the Ti aren't deduced. They are +specified by the function type. Ti might be const +int& (an lvalue reference) and a valid ti might be 2 +(a non-const rvalue). I've taken another stab at the wording using +"expressions" and "bindable to". +
+[ +2010-02-09 Wording updated by Jonathan, Ganesh and Daniel. +]
+ + +[ +2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-02-10 Daniel opens to improve wording. +]
+ + +[ +2010-02-11 This issue is now addressed by 870. +]
+ + +[ +2010-02-12 Moved to Tentatively NAD Editorial after 5 positive votes on +c++std-lib. Rationale added below. +]
+ + + + +Rationale:
++Addressed by 870. +
+ + +Proposed resolution:
++Edit 20.8.14.2 [func.wrap.func] paragraph 2: +
+ +++ + + + + ++2 A function object f of type F is Callable for argument +types
+ +T1, T2, ..., TN inArgTypes anda+return type R,if, given lvalues t1, t2, ..., +tN of types T1, T2, ..., TN, respectively,the +expression INVOKE(f, declval<ArgTypes>()..., +Rt1, t2, ..., tN), considered as an unevaluated +operand (5 [expr]), is well formed (20.7.2)and, if +R is not void, convertible to R. +
+816. Should bind()'s returned functor have a nofail copy ctor when bind() is nofail?
+Section: 20.8.10.1.2 [func.bind.bind] Status: Resolved + Submitter: Stephan T. Lavavej Opened: 2008-02-08 Last modified: 2010-11-19
+View all other issues in [func.bind.bind].
+View all issues with Resolved status.
+Discussion:
++Library Issue 527 notes that bind(f, t1, ..., tN) +should be nofail when f, t1, ..., tN have nofail copy ctors. +
++However, no guarantees are provided for the copy ctor of the functor +returned by bind(). (It's guaranteed to have a copy ctor, which can +throw implementation-defined exceptions: bind() returns a forwarding +call wrapper, TR1 3.6.3/2. A forwarding call wrapper is a call wrapper, +TR1 3.3/4. Every call wrapper shall be CopyConstructible, TR1 3.3/4. +Everything without an exception-specification may throw +implementation-defined exceptions unless otherwise specified, C++03 +17.4.4.8/3.) +
++Should the nofail guarantee requested by Library Issue 527 be extended +to cover both calling bind() and copying the returned functor? +
+ +[ +Howard adds: +]
+ + ++tuple construction should probably have a similar guarantee. ++ +[ +San Francisco: +]
+ + ++Howard to provide wording. ++ +[ +Post Summit, Anthony provided wording. +]
+ + +[ +Batavia (2009-05): +]
+ ++Part of all of this issue appears to be rendered moot +by the proposed resolution to issue 817 (q.v.). +We recommend the issues be considered simultaneously +(or possibly even merged) +to ensure there is no overlap. +Move to Open, and likewise for issue 817. ++ +[ +2009-07 Frankfurt: +]
+ + ++Related to 817 (see below). Leave Open. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. Decoupling from issue 817. ++ +[ +2010-02-11 Moved from Ready to Tentatively NAD Editorial, rationale added below. +]
+ + + + +Rationale:
++This issue is solved as proposed by 817. +
+ + +Proposed resolution:
++Add a new sentence to the end of paragraphs 2 and 4 of 20.8.10.1.2 [func.bind.bind]: +
+ +++ + + + + ++-2- Returns: A forwarding call wrapper g with a weak result type (20.6.2). The effect of g(u1, u2, +..., uM) shall be INVOKE(f, v1, v2, ..., vN, Callable<F cv,V1, V2, ..., VN>::result_type), where cv +represents the cv-qualifiers of g and the values and types of the bound arguments +v1, v2, ..., vN are determined as specified below. +The copy constructor and move constructor of the forwarding call wrapper shall throw an +exception if and only if the corresponding constructor of F or any of the types +in BoundArgs... throw an exception. +
+...
++-5- Returns: A forwarding call wrapper g with a nested type result_type defined as a synonym +for R. The effect of g(u1, u2, ..., uM) shall be INVOKE(f, v1, v2, ..., vN, R), where the +values and types of the bound arguments v1, v2, ..., vN are determined as specified below. +The copy constructor and move constructor of the forwarding call wrapper shall throw an +exception if and only if the corresponding constructor of F or any of the types +in BoundArgs... throw an exception. +
+ +
+817. bind needs to be moved
+Section: 20.8.10.1.2 [func.bind.bind] Status: WP + Submitter: Howard Hinnant Opened: 2008-03-17 Last modified: 2010-10-29
+View all other issues in [func.bind.bind].
+View all issues with WP status.
+Discussion:
+Addresses US 72, JP 38 and DE 21
+ ++The functor returned by bind() should have a move constructor that +requires only move construction of its contained functor and bound arguments. +That way move-only functors can be passed to objects such as thread. +
++This issue is related to issue 816. +
+ ++US 72: +
+ ++bind should support move-only functors and bound arguments. ++ ++JP 38: +
+ +++ ++add the move requirement for bind's return type. +
++For example, assume following th1 and th2, +
+ ++ +void f(vector<int> v) { } + +vector<int> v{ ... }; +thread th1([v]{ f(v); }); +thread th2(bind(f, v)); ++When function object are set to thread, v is moved to th1's lambda +expression in a Move Constructor of lambda expression because th1's lambda +expression has a Move Constructor. But bind of th2's +return type doesn't have the requirement of Move, so it may not +moved but copied. +
++Add the requirement of move to get rid of this useless copy. +
++And also, add the MoveConstructible as well as CopyConstructible. +
++DE 21 +
+ ++The specification for bind claims twice that "the values and types for +the bound arguments v1, v2, ..., vN are determined as specified below". +No such specification appears to exist. ++ +[ +San Francisco: +]
+ + ++Howard to provide wording. ++ +[ +Post Summit Alisdair and Howard provided wording. +]
+ + +++ ++Several issues are being combined in this resolution. They are all touching the +same words so this is an attempt to keep one issue from stepping on another, and +a place to see the complete solution in one place. +
+ ++
+- +bind needs to be "moved". +
+- +20.8.10.1.2 [func.bind.bind]/p3, p6 and p7 were accidently removed from N2798. +
+- +Issue 929 argues for a way to pass by && for +efficiency but retain the decaying behavior of pass by value for the +thread constructor. That same solution is applicable here. +
+[ +Batavia (2009-05): +]
+ +++ ++We were going to recommend moving this issue to Tentatively Ready +until we noticed potential overlap with issue 816 (q.v.). +
++Move to Open, +and recommend both issues be considered together +(and possibly merged). +
+[ +2009-07 Frankfurt: +]
+ + ++The proposed resolution uses concepts. Leave Open. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Leave as Open. Howard to provide deconceptified wording. ++ +[ +2009-11-07 Howard updates wording. +]
+ + +[ +2009-11-15 Further updates by Peter, Chris and Daniel. +]
+ + +[ +Moved to Tentatively Ready after 6 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Change 20.8 [function.objects] p2: +
+ ++ +template<class Fn, class...TypesBoundArgs> + unspecified bind(Fn&&,TypesBoundArgs&&...); +template<class R, class Fn, class...TypesBoundArgs> + unspecified bind(Fn&&,TypesBoundArgs&&...); ++Change 20.8.2 [func.require]: +
+ +++ ++4 Every call wrapper (20.8.1 [func.def]) shall be +
+CopyMoveConstructible. A simple call +wrapper is a call wrapper that is CopyConstructible and +CopyAssignable and whose copy constructor, move constructor and assignment operator do not +throw exceptions. A forwarding call wrapper is a call wrapper that can be +called with an argument list. [Note: in a typical implementation +forwarding call wrappers have an overloaded function call operator of the form ++template<class...ArgTypesUnBoundsArgs> +R operator()(ArgTypesUnBoundsArgs&&... unbound_args) cv-qual; ++— end note] +
++Change 20.8.10.1.2 [func.bind.bind]: +
+ +++ + + + + ++Within this clause: +
+ ++
+ +- +Let FD be a synonym for the type decay<F>::type. +
+- +Let fd be an lvalue of type FD constructed from +std::forward<F>(f). +
+- +Let Ti be a synonym for the ith type in the +template parameter pack BoundArgs. +
+- +Let TiD be a synonym for the type decay<Ti>::type. +
+- +Let ti be the ith argument in the function parameter +pack bound_args. +
+- +Let tid be an lvalue of type TiD constructed from +std::forward<Ti>(ti). +
+- +Let Uj be the jth deduced type of the UnBoundArgs&&... +parameter of the operator() of the forwarding call wrapper. +
+- +Let uj be the jth argument associated with Uj. +
+template<class F, class... BoundArgs> + unspecified bind(F&& f, BoundArgs&&... bound_args); ++ +++ ++-1- Requires: +is_constructible<FD, F>::value +shall be true. +For each Ti in BoundArgs, +is_constructible<TiD, Ti>::value shall be +true. +
+F and each Ti in +BoundArgs shall be CopyConstructible.+INVOKE(fd, w1, w2, ..., wN) (20.8.2 [func.require]) shall be a valid expression for some values +w1, w2, ..., wN, where N == sizeof...(bound_args). ++-2- Returns: A forwarding call wrapper g with a weak +result type (20.8.2 [func.require]). The effect of g(u1, u2, +..., uM) shall be INVOKE(fd, v1, v2, ..., vN, +result_of<FD cv (V1, V2, ..., VN)>::type), where +cv represents the cv-qualifiers of g and the +values and types of the bound arguments v1, v2, ..., vN are +determined as specified below. +The copy constructor and move constructor of the forwarding call wrapper shall throw an +exception if and only if the corresponding constructor of FD or of any of the types +TiD throws an exception. +
++-3- Throws: Nothing unless the
+copy+constructionorof +Ffd or of one of the values +tidtypes in the BoundArgs... pack +expansionthrows an exception. ++ +Remarks: The unspecified return type shall satisfy the +requirements of MoveConstructible. If all of FD and +TiD satisfy the requirements of CopyConstructible then +the unspecified return type shall satisfy the requirements of +CopyConstructible. [Note: This implies that all of +FD and TiD shall be MoveConstructible — +end note] + +
+template<class R, class F, class... BoundArgs> + unspecified bind(F&& f, BoundArgs&&... bound_args); ++ +++ ++-4- Requires: +is_constructible<FD, F>::value +shall be true. +For each Ti in BoundArgs, +is_constructible<TiD, Ti>::value shall be +true. +
+F and each Ti in +BoundArgs shall be CopyConstructible.+INVOKE(fd, w1, +w2, ..., wN) shall be a valid expression for some values w1, w2, +..., wN, where N == sizeof...(bound_args). ++-5- Returns: A forwarding call wrapper g with a nested +type result_type defined as a synonym for R. The +effect of g(u1, u2, ..., uM) shall be INVOKE(fd, v1, +v2, ..., vN, R), where the values and types of the bound arguments +v1, v2, ..., vN are determined as specified below. +The copy constructor and move constructor of the forwarding call wrapper shall throw an +exception if and only if the corresponding constructor of FD or of any of the types +TiD throws an exception. +
++-6- Throws: Nothing unless the
+copy+constructionorof +Ffd or of one of the values +tidtypes in the BoundArgs... pack +expansionthrows an exception. ++ +Remarks: The unspecified return type shall satisfy the +requirements of MoveConstructible. If all of FD and +TiD satisfy the requirements of CopyConstructible then +the unspecified return type shall satisfy the requirements of +CopyConstructible. [Note: This implies that all of +FD and TiD shall be MoveConstructible — +end note] + +
++-7- The values of the bound arguments v1, v2, ..., vN and +their corresponding types V1, V2, ..., VN depend on the types +TiD derived from +
+ +of the corresponding argument ti in bound_args of type +Ti in BoundArgs in+the call to bind and the +cv-qualifiers cv of the call wrapper g as +follows: ++
+ +- +if
+tiTiD isof type+reference_wrapper<T> the argument is +tid.get() and its type Vi is T&; +- +if the value of +
+std::is_bind_expression<TiD>::value is +true the argument is tid(std::forward<Uj>(uj)...u1, u2, ..., uM) +and its type Vi is result_of<TiD cv +(Uj...U1&, U2&, ..., UM&)>::type; +- +if the value j of +
+std::is_placeholder<TiD>::value is not zero +the argument is std::forward<Uj>(uj) and its type +Vi is Uj&&; +- +otherwise the value is tid and its type Vi +is TiD cv &. +
+
818. wording for memory ordering
Section: 29.3 [atomics.order] Status: CD1 - Submitter: Jens Maurer Opened: 2008-03-22 Last modified: 2008-09-26
+ Submitter: Jens Maurer Opened: 2008-03-22 Last modified: 2010-10-29View all other issues in [atomics.order].
View all issues with CD1 status.
Discussion:
@@ -36398,7 +44755,7 @@ remove table 136 in 29.3 [atomics.order].-
+ Table 136 — memory_order effectsTable 136 — memory_order effectsElementMeaning@@ -36454,7 +44811,7 @@ it can always be extended to an order that does include lock and unlock operations, since the ordering between those is already included in the happens before ordering. -—end note] +—end note] @@ -36463,10 +44820,104 @@ is already included in the happens before ordering. + memory_order_relaxedthe operation does not order memory
+819. rethrow_if_nested
+Section: 18.8.6 [except.nested] Status: WP + Submitter: Alisdair Meredith Opened: 2008-03-25 Last modified: 2010-10-29
+View all other issues in [except.nested].
+View all issues with WP status.
+Discussion:
++Looking at the wording I submitted for rethrow_if_nested, I don't think I +got it quite right. +
+ ++The current wording says: +
+ +++ +template <class E> void rethrow_if_nested(const E& e); +++++Effects: Calls e.rethrow_nested() only if e +is publicly derived from nested_exception. +
++This is trying to be a bit subtle, by requiring e (not E) to be publicly +derived from nested_exception the idea is that a dynamic_cast would be +required to be sure. Unfortunately, if e is dynamically but not statically +derived from nested_exception, e.rethrow_nested() is ill-formed. +
+ +[ +San Francisco: +]
+ + ++Alisdair was volunteered to provide wording. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Leave as Open. Alisdair to provide wording. ++ +[ +2009-11-09 Alisdair provided wording. +]
+ + +[ +2010-03-10 Dietmar updated wording. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to Ready for Pittsburgh. ++ + + +Proposed resolution:
++Change 18.8.6 [except.nested], p8: +
+ ++ + + + + +template <class E> void rethrow_if_nested(const E& e); +++-8- Effects:+Calls e.rethrow_nested() +oOnly if the dynamic type of e is +publicly and unambiguously derived from +nested_exception this calls +dynamic_cast<const nested_exception&>(e).rethrow_nested(). +
820. current_exception()'s interaction with throwing copy ctors
Section: 18.8.5 [propagation] Status: CD1 - Submitter: Stephan T. Lavavej Opened: 2008-03-26 Last modified: 2008-09-26
+ Submitter: Stephan T. Lavavej Opened: 2008-03-26 Last modified: 2010-10-29View other active issues in [propagation].
View all other issues in [propagation].
View all issues with CD1 status.
@@ -36575,8 +45026,8 @@ Pete will make the required editorial tweaks to rectify this.
821. Minor cleanup : unique_ptr
-Section: 20.8.14.3.3 [unique.ptr.runtime.modifiers] Status: WP - Submitter: Alisdair Meredith Opened: 2008-03-30 Last modified: 2009-03-09
+Section: 20.9.9.3.3 [unique.ptr.runtime.modifiers] Status: WP + Submitter: Alisdair Meredith Opened: 2008-03-30 Last modified: 2010-10-29
View all issues with WP status.
Discussion:
@@ -36604,7 +45055,7 @@ to be a stronger match than the deleted overload. Words...
Proposed resolution:
-Add to class template definition in 20.8.14.3 [unique.ptr.runtime] +Add to class template definition in 20.9.9.3 [unique.ptr.runtime]
@@ -36618,7 +45069,7 @@ void swap(unique_ptr&& u);-Update 20.8.14.3.3 [unique.ptr.runtime.modifiers] +Update 20.9.9.3.3 [unique.ptr.runtime.modifiers]
@@ -36648,132 +45099,133 @@ Note this wording incorporates resolutions for 822. Object with explicit copy constructor no longer CopyConstructible -Section: 20.2.1 [utility.arg.requirements] Status: WP - Submitter: James Kanze Opened: 2008-04-01 Last modified: 2009-10-26
-View other active issues in [utility.arg.requirements].
-View all other issues in [utility.arg.requirements].
-View all issues with WP status.
+823. identity<void> seems broken
+Section: 20.3.3 [forward] Status: Resolved + Submitter: Walter Brown Opened: 2008-04-09 Last modified: 2010-11-20
+View all other issues in [forward].
+View all issues with Resolved status.
Discussion:
-I just noticed that the following program is legal in C++03, but -is forbidden in the current draft: +N2588 seems to have added an operator() member function to the +identity<> helper in 20.3.3 [forward]. I believe this change makes it no +longer possible to instantiate identity<void>, as it would require +forming a reference-to-void type as this operator()'s parameter type.
-#include <vector> -#include <iostream> ++Suggested resolution: Specialize identity<void> so as not to require +the member function's presence. +
-class Toto -{ -public: - Toto() {} - explicit Toto( Toto const& ) {} -} ; +[ +Sophia Antipolis: +]
-int -main() -{ - std::vector< Toto > v( 10 ) ; - return 0 ; -} + +++ ++Jens: suggests to add a requires clause to avoid specializing on void. +
++Alisdair: also consider cv-qualified void. +
++Alberto provided proposed wording. +
+[ +2009-07-30 Daniel reopens: +]
+ + +++This issue became closed, because the ReferentType requirement +fixed the problem - this is no longer the case. In retrospective it seems +to be that the root of current issues around std::identity (823, 700, +939) +is that it was standardized as something very different (an unconditional +type mapper) than traditional usage indicated (a function object that should +derive from std::unary_function), as the SGI definition does. This issue could +be solved, if std::identity is removed (one proposal of 939), but until this +has been decided, this issue should remain open. An alternative for +removing it, would be, to do the following: +
+ ++
- +
+ ++Let identity stay as a real function object, which would +now properly +derive from unary_function: +
+ ++template <class T> struct identity : unary_function<T, T> { + const T& operator()(const T&) const; +}; +- +
++Invent (if needed) a generic type wrapper (corresponding to concept +IdentityOf), +e.g. identity_of, and move it's prototype description back to 20.3.3 [forward]: +
+ +template <class T> struct identity_of { + typedef T type; +};-Is this change intentional? (And if so, what is the -justification? I wouldn't call such code good, but I don't see -any reason to break it unless we get something else in return.) +and adapt the std::forward signature to use identity_of +instead of identity.
- -[ -San Francisco: -]
- - --The subgroup that looked at this felt this was a good change, but it may -already be handled by incoming concepts (we're not sure). +[ -Post Summit: +2009-10 Santa Cruz: ]
-- --Alisdair: Proposed resolution kinda funky as these tables no longer -exist. Move from direct init to copy init. Clarify with Doug, recommends -NAD. -
--Walter: Suggest NAD via introduction of concepts. -
--Recommend close as NAD. -
-[ -2009-07 Frankfurt: -]
- - --Need to look at again without concepts. -- -[ -2009-07 Frankfurt: -]
- - ---Move to Ready with original proposed resolution. -
-[Howard: Original proposed resolution restored.]
- +Mark asNAD EditorialResolved, fixed by 939.Proposed resolution:
-In 20.2.1 [utility.arg.requirements] change Table 33: MoveConstructible requirements [moveconstructible]: +Change definition of identity in 20.3.3 [forward], paragraph 2, to:
--+-
-- -expression post-condition -- -T t(rv) = rvt is equivalent to the value of rv before the construction -- -... -+template <class T> struct identity { + typedef T type; + requires ReferentType<T> + const T& operator()(const T& x) const; + }; +...
++ + +requires ReferentType<T> + const T& operator()(const T& x) const; +Rationale:
-In 20.2.1 [utility.arg.requirements] change Table 34: CopyConstructible requirements [copyconstructible]: +The point here is to able to write T& given T and ReferentType is +precisely the concept that guarantees so, according to N2677 +(Foundational concepts). Because of this, it seems preferable than an +explicit check for cv void using SameType/remove_cv as it was suggested +in Sophia. In particular, Daniel remarked that there may be types other +than cv void which aren't referent types (int[], perhaps?).
--- @@ -36781,7 +45233,7 @@ In 20.2.1 [utility.arg.requirements] change Table 34: CopyConstructible-
-- -expression post-condition -- -T t(u) = uthe value of u is unchanged and is equivalent to t -- -... -
824. rvalue ref issue with basic_string inserter
Section: 21.4.8.9 [string.io] Status: CD1 - Submitter: Alisdair Meredith Opened: 2008-04-10 Last modified: 2008-09-26
+ Submitter: Alisdair Meredith Opened: 2008-04-10 Last modified: 2010-10-29View all other issues in [string.io].
View all issues with CD1 status.
Discussion:
@@ -36838,10 +45290,129 @@ template<class charT, class traits, class Allocator> +
+827. constexpr shared_ptr::shared_ptr()?
+Section: 20.9.10.2.1 [util.smartptr.shared.const] Status: Resolved + Submitter: Peter Dimov Opened: 2008-04-11 Last modified: 2010-11-20
+View all other issues in [util.smartptr.shared.const].
+View all issues with Resolved status.
+Discussion:
++Would anyone object to making the default constructor of shared_ptr (and +weak_ptr and enable_shared_from_this) constexpr? This would enable +static initialization for shared_ptr variables, eliminating another +unfair advantage of raw pointers. +
+ +[ +San Francisco: +]
+ + +++ ++It's not clear to us that you can initialize a pointer with the literal +0 in a constant expression. We need to ask CWG to make sure this works. +Bjarne has been appointed to do this. +
++Core got back to us and assured as that nullptr would do the job +nicely here. +
+[ +2009-05-01 Alisdair adds: +]
+ + +++ ++I don't believe that constexpr will buy anything in this case. +shared_ptr/weak_ptr/enable_shared_from_this cannot be literal types as they +have a non-trivial copy constructor. As they do not produce literal types, +then the constexpr default constructor will not guarantee constant +initialization, and so not buy the hoped for optimization. +
++I recommend referring this back to Core to see if we can get static +initialization for types with constexpr constructors, even if they are not +literal types. Otherwise this should be closed as NAD. +
+[ +2009-05-26 Daniel adds: +]
+ + ++If Alisdair's 2009-05-01 comment is correct, wouldn't that also make +constexpr mutex() useless, because this class has a non-trivial +destructor? (828) ++ +[ +2009-07-21 Alisdair adds: +]
+ + +++ ++The feedback from core is that this and similar uses of constexpr +constructors to force static initialization should be supported. If +there are any problems with this in the working draught, we should file +core issues. +
+ ++Recommend we declare the default constructor constexpr as the issue suggests +(proposed wording added). +
+[ +2009-10 Santa Cruz: +]
+ + +++ + +NAD EditorialResolved. Solved by +N2994. +Proposed resolution:
++Change 20.9.10.2 [util.smartptr.shared] and 20.9.10.2.1 [util.smartptr.shared.const]: +
+ ++ +constexpr shared_ptr(); ++Change 20.9.10.3 [util.smartptr.weak] and 20.9.10.3.1 [util.smartptr.weak.const]: +
+ ++ +constexpr weak_ptr(); ++Change 20.9.10.4 [util.smartptr.enab] (2 places): +
+ ++ + + + + +constexpr enable_shared_from_this(); +
829. current_exception wording unclear about exception type
Section: 18.8.5 [propagation] Status: CD1 - Submitter: Beman Dawes Opened: 2008-04-20 Last modified: 2008-09-26
+ Submitter: Beman Dawes Opened: 2008-04-20 Last modified: 2010-10-29View other active issues in [propagation].
View all other issues in [propagation].
View all issues with CD1 status.
@@ -36935,12 +45506,1076 @@ creates a new copy each time it is called. +
+834. Unique_ptr::pointer requirements underspecified
+Section: 20.9.9.2 [unique.ptr.single] Status: Resolved + Submitter: Daniel Krügler Opened: 2008-05-14 Last modified: 2010-11-19
+View all other issues in [unique.ptr.single].
+View all issues with Resolved status.
+Discussion:
++Issue 673 (including recent updates by 821) proposes a useful +extension point for unique_ptr by granting support for an optional +deleter_type::pointer to act as pointer-like replacement for element_type* +(In the following: pointer). +
++Unfortunately no requirements are specified for the type pointer which has +impact on at least two key features of unique_ptr: +
+ ++
+ +- Operational fail-safety.
+- (Well-)Definedness of expressions.
++Unique_ptr specification makes great efforts to require that essentially *all* +operations cannot throw and therefore adds proper wording to the affected +operations of the deleter as well. If user-provided pointer-emulating types +("smart pointers") will be allowed, either *all* throw-nothing clauses have to +be replaced by weaker "An exception is thrown only if pointer's {op} throws +an exception"-clauses or it has to be said explicitly that all used +operations of +pointer are required *not* to throw. I understand the main focus of unique_ptr +to be as near as possible to the advantages of native pointers which cannot +fail and thus strongly favor the second choice. Also, the alternative position +would make it much harder to write safe and simple template code for +unique_ptr. Additionally, I assume that a general statement need to be given +that all of the expressions of pointer used to define semantics are required to +be well-formed and well-defined (also as back-end for 762). +
+ +[ +Sophia Antipolis: +]
+ + +++ ++Howard: We maybe need a core concept PointerLike, but we don't need the +arithmetic (see shared_ptr vs. vector<T>::iterator. +
++Howard will go through and enumerate the individual requirements wrt. pointer for each member function. +
+[ +2009-07 Frankfurt: +]
+ + ++Move to Ready. ++ +[ +2009-10-15 Alisdair pulls from Ready: +]
+ + +++ ++I hate to pull an issue out of Ready status, but I don't think 834 is +fully baked yet. +
+ ++For reference the proposed resolution is to add the following words: +
+ ++unique_ptr<T, D>::pointer's operations shall be +well-formed, shall have well defined behavior, and shall not throw +exceptions. ++ ++This leaves me with a big question : which operations? +
+ ++Are all pointer operations required to be nothrow, including operations +that have nothing to do with interactions with unique_ptr? This was +much simpler with concepts where we could point to operations within a +certain concept, and so nail down the interactions. +
+[ +2009-10-15 Daniel adds: +]
+ + ++I volunteer to prepare a more fine-grained solution, but I would like +to ask for feedback that helps me doing so. If this question is asked +early in the meeting I might be able to fix it within the week, but I +cannot promise that now. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Leave in open. Daniel to provide wording as already suggested. ++ +[ +2009-12-22 Daniel provided wording and rationale. +]
+ + +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++The here proposed resolution has considerable overlap with the requirements that +are used in the allocator requirements. +
+ ++This might be a convincing argument to isolate the common subset into one +requirement. The reason I did not do that is basically because we might find out +that they are either over-constraining or under-constraining at this late point +of specification. Note also that as a result of the idea of a general +requirement set I added the requirement +
+ ++A default-initialized object may have a singular value ++ ++even though this does not play a relevant role for unique_ptr. +
+ ++One further characteristics of the resolution is that availability of relational +operators of unique_ptr<T, D>::pointer is not part of the basic +requirements, which is in sync with the allocator requirements on pointer-like +(this means that unique_ptr can hold a void_pointer or +const_void_pointer). +
+ ++Solved by +N3073. +
+ + + +Proposed resolution:
+ ++ +
+ + + + + + + +- +
+ ++Change 20.9.9.2 [unique.ptr.single]/1 as indicated: [The intent is to +replace the coupling between T* and the deleter's operator() +by a coupling between unique_ptr<T, D>::pointer and this +operator()] +
+ ++1 - The default type for the template parameter D is +default_delete. A client-supplied template argument D shall be +a function pointer or functor for which, given a value d of type +D and a+pointervalue ptr of type +T*unique_ptr<T, D>::pointer, the +expression d(ptr) is valid and has the effect of deallocating the +pointer as appropriate for that deleter. D may also be an +lvalue-reference to a deleter. +- +
+ ++Change 20.9.9.2 [unique.ptr.single]/3 as indicated: +
+ ++++3 - If the type remove_reference<D>::type::pointer exists, then +unique_ptr<T, D>::pointer shall be a synonym for +remove_reference<D>::type::pointer. Otherwise +unique_ptr<T, D>::pointer shall be a synonym for T*. The +type unique_ptr<T, D>::pointer shall
+besatisfy +the requirements of EqualityComparable, +DefaultConstructible, CopyConstructible(Table 34) +and, CopyAssignable(Table 36), +Swappable, and Destructible (20.2.1 [utility.arg.requirements]). A default-initialized object may have a +singular value. A value-initialized object produces the null value of the type. +The null value shall be equivalent only to itself. An object of this type can be +copy-initialized with a value of type nullptr_t, compared for equality +with a value of type nullptr_t, and assigned a value of type +nullptr_t. The effect shall be as if a value-initialized object had +been used in place of the null pointer constant. An object p of this +type can be contextually converted to bool. The effect shall be as if +p != nullptr had been evaluated in place of p. No operation on +this type which is part of the above mentioned requirements shall exit via an +exception. + ++[Note: Given an allocator type X (20.2.5 [allocator.requirements]), the types X::pointer, +X::const_pointer, X::void_pointer, and +X::const_void_pointer may be used as unique_ptr<T, +D>::pointer — end note] +
+ ++In addition to being available via inclusion of the <utility> +header, the swap function template in 20.3.2 [utility.swap] is +also available within the definition of unique_ptr's swap +function. +
+- +
+ ++Change 20.9.9.2.1 [unique.ptr.single.ctor]/2+3 as indicated: [The first +change ensures that we explicitly say, how the stored pointer is initialized. +This is important for a constexpr function, because this may make a +difference for user-defined pointer-like types] +
+ ++constexpr unique_ptr(); ++++...
++2 - Effects: Constructs a unique_ptr which owns nothing, +value-initializing the stored pointer. +
+ ++3 - Postconditions: get() ==
+0nullptr. +- +
+ ++Change 20.9.9.2.1 [unique.ptr.single.ctor]/6+7 as indicated: [This is a +step-by-fix to ensure consistency to the changes of +N2976] +
+ ++unique_ptr(pointer p); ++++...
++6 - Effects: Constructs a unique_ptr which owns p, +initializing the stored pointer with p. +
+ ++7 - Postconditions: get() == p. get_deleter() returns a +reference to a
+default constructedvalue-initialized +deleter D. +- +
+ ++Insert a new effects clause in 20.9.9.2.1 [unique.ptr.single.ctor] just +before p. 14: [The intent is to fix the current lack of specification in +which way the stored pointer is initialized] +
+ ++unique_ptr(pointer p,+implementation-definedsee below d1); +unique_ptr(pointer p,implementation-definedsee below d2); +++...
++Effects: Constructs a unique_ptr which owns p, +initializing the stored pointer with p and the initializing the deleter +as described above. +
+ ++14 - Postconditions: get() == p. get_deleter() returns a +reference to the internally stored deleter. If D is a reference type +then get_deleter() returns a reference to the lvalue d. +
+- +
+ ++Change 20.9.9.2.1 [unique.ptr.single.ctor]/18+22 as indicated: [The intent +is to clarify that the moved-from source must contain a null pointer, there is +no other choice left] +
+ ++unique_ptr(unique_ptr&& u); ++++ ++[..] +
+ ++18 - Postconditions: get() == value u.get() had before the +construction and u.get() == nullptr. get_deleter() +returns a reference to the internally stored deleter which was constructed from +u.get_deleter(). If D is a reference type then +get_deleter() and u.get_deleter() both reference the same +lvalue deleter. +
+ +template <class U, class E> unique_ptr(unique_ptr<U, E>&& u); ++ ++ +++[..] +
+ ++22 - Postconditions: get() == value u.get() had before the +construction, modulo any required offset adjustments resulting from the cast +from unique_ptr<U, E>::pointer to pointer and +u.get() == nullptr. get_deleter() returns a reference to +the internally stored deleter which was constructed from +u.get_deleter(). +
+- +
+ ++Change 20.9.9.2.1 [unique.ptr.single.ctor]/20 as indicated: [With the +possibility of user-defined pointer-like types the implication does only exist, +if those are built-in pointers. Note that this change should also be applied +with the acceptance of 950] +
+ ++template <class U, class E> unique_ptr(unique_ptr<U, E>&& u); +++20 - Requires: If D is not a reference type, construction of the +deleter D from an rvalue of type E shall be well formed and +shall not throw an exception. If D is a reference type, then E +shall be the same type as D (diagnostic required). unique_ptr<U, +E>::pointer shall be implicitly convertible to pointer. ++[Note: These requirements imply that T and U are +complete types. — end note]+- +
+ ++Change 20.9.9.2.2 [unique.ptr.single.dtor]/2 as indicated: +
+ ++~unique_ptr(); ++++...
++2 - Effects: If get() ==
+0nullptr there +are no effects. Otherwise get_deleter()(get()). +- +
+ ++Change 20.9.9.2.3 [unique.ptr.single.asgn]/3+8 as indicated: [The intent is to +clarify that the moved-from source must contain a null pointer, there +is no other choice left] +
+ ++unique_ptr& operator=(unique_ptr&& u); ++++ +[..]
++3 - Postconditions: This unique_ptr now owns the pointer which u +owned, and u no longer owns it, u.get() == nullptr. +[Note: If D is a reference type, then the referenced lvalue deleters +are move assigned. — end note] +
+template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u); ++ +++[..]
+ ++8 - Postconditions: This unique_ptr now owns the pointer which +u owned, and u no longer owns it, u.get() == +nullptr. +
+- +
+ ++Change 20.9.9.2.3 [unique.ptr.single.asgn]/6 as indicated: [With the +possibility of user-defined pointer-like types the implication does only exist, +if those are built-in pointers. Note that this change should also be applied +with the acceptance of 950] +
+ ++template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u); ++++[..]
++6 - Requires: Assignment of the deleter D from an rvalue +D shall not throw an exception. unique_ptr<U, +E>::pointer shall be implicitly convertible to pointer. +
+[Note: These requirements imply that T and U are +complete types. — end note]+- +
+ ++Change 20.9.9.2.3 [unique.ptr.single.asgn] before p. 11 and p. 12 as +indicated: [The first change is a simple typo fix] +
+ ++unique_ptr& operator=(nullptr_t+ +}); ++++11 - Effects: reset(). +
+ ++12 - Postcondition: get() ==
+0nullptr +- +
+ ++Change 20.9.9.2.4 [unique.ptr.single.observers]/1+4+12 as indicated: +
+ ++typename add_lvalue_reference<T>::type operator*() const; ++++ ++1 - Requires: get() !=
+0nullptr. The +variable definition add_lvalue_reference<T>::type t = *get() +shall be well formed, shall have well-defined behavior, and shall not exit via +an exception. ++[..] +
+ +pointer operator->() const; ++ +++ ++4 - Requires: get() !=
+ +0nullptr. ++[..] +
+ +explicit operator bool() const; ++ ++12 - Returns: get() !=+0nullptr. +- +
+ ++Change 20.9.9.2.5 [unique.ptr.single.modifiers]/1 as indicated: +
+ ++pointer release(); ++ ++1 - Postcondition: get() ==+0nullptr. +- +
+ ++Change 20.9.9.2.5 [unique.ptr.single.modifiers]/9 as indicated: [The +intent is to ensure that potentially user-defined swaps are used. A side-step +fix and harmonization with the specification of the the deleter is realized. +Please note the additional requirement in bullet 2 of this proposed resolution +regarding the availability of the generic swap templates within the +member swap function.] +
+ ++void swap(unique_ptr& u); ++ ++++8 - Requires: The deleter D shall be Swappable and +shall not throw an exception under swap. +
+ ++9 - Effects: The stored pointers of *this and +u are exchanged by an unqualified call to non-member +swap. The stored deleters are
+swap'd +(unqualified)exchanged by an unqualified call to non-member +swap. +- +
+ ++Change 20.9.9.3.2 [unique.ptr.runtime.observers]/1 as indicated: +
+ ++T& operator[](size_t i) const; +++Requires: i < the size of the array to which the stored +pointer points. The variable definition T& t = get()[i] shall +be well formed, shall have well-defined behavior, and shall not exit via an +exception. ++- +
+ ++Change 20.9.9.3.3 [unique.ptr.runtime.modifiers]/1 as indicated: +
+ ++void reset(pointer p = pointer()); +void reset(nullptr_t p); ++ ++1 - Effects: If get() ==+0nullptr there +are no effects. Otherwise get_deleter()(get()). +- +
+ ++Change 20.9.9.4 [unique.ptr.special] as indicated: [We don't add the +relational operators to the basic requirement set, therefore we need special +handling here] +
+ +++template <class T1, class D1, class T2, class D2> + bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ +++ ++Requires: The variable definition bool b = x.get() == +y.get(); shall be well formed, shall have well-defined behavior, and shall +not exit via an exception. +
+ ++2 - Returns: x.get() == y.get(). +
+ ++Throws: nothing. +
+template <class T1, class D1, class T2, class D2> + bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ +++ ++Requires: The variable definition bool b = x.get() != y.get(); +shall be well formed, shall have well-defined behavior, and shall not exit via +an exception. +
+ ++3 - Returns: x.get() != y.get(). +
+ ++Throws: nothing. +
+template <class T1, class D1, class T2, class D2> + bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ +++ ++Requires: The variable definition bool b = x.get() < y.get(); +shall be well formed, shall have well-defined behavior, and shall not exit via +an exception. +
+ ++4 - Returns: x.get() < y.get(). +
+ ++Throws: nothing. +
+template <class T1, class D1, class T2, class D2> + bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ +++ ++Requires: The variable definition bool b = x.get() <= y.get(); +shall be well formed, shall have well-defined behavior, and shall not exit via +an exception. +
+ ++5 - Returns: x.get() <= y.get(). +
+ ++Throws: nothing. +
+template <class T1, class D1, class T2, class D2> + bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ +++ ++Requires: The variable definition bool b = x.get() > y.get(); +shall be well formed, shall have well-defined behavior, and shall not exit via +an exception. +
+ ++6 - Returns: x.get() > y.get(). +
+ ++Throws: nothing. +
+template <class T1, class D1, class T2, class D2> + bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y); ++ +++ ++Requires: The variable definition bool b = x.get() >= y.get(); +shall be well formed, shall have well-defined behavior, and shall not exit via +an exception. +
+ ++7 - Returns: x.get() >= y.get(). +
+ ++Throws: nothing. +
+
+835. tying two streams together (correction to DR 581)
+Section: 27.5.4.2 [basic.ios.members] Status: WP + Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29
+View all other issues in [basic.ios.members].
+View all issues with WP status.
+Discussion:
++ +The fix for +issue 581, +now integrated into the working paper, overlooks a couple of minor +problems. + +
++ +First, being an unformatted function once again,
+flush()+is required to create a sentry object whose constructor must, among +other things, flush the tied stream. When two streams are tied +together, either directly or through another intermediate stream +object, flushing one will also cause a call toflush()on +the other tied stream(s) and vice versa, ad infinitum. The program +below demonstrates the problem. + ++ +Second, as Bo Persson notes in his +comp.lang.c++.moderated post, +for streams with the
+unitbufflag set such +asstd::stderr, the destructor of the sentry object will +again callflush(). This seems to create an infinite +recursion forstd::cerr << std::flush;+ +++ +#include <iostream> + +int main () +{ + std::cout.tie (&std::cerr); + std::cerr.tie (&std::cout); + std::cout << "cout\n"; + std::cerr << "cerr\n"; +} ++[ +Batavia (2009-05): +]
+ ++We agree with the proposed resolution. +Move to Review. ++ +[ +2009-05-26 Daniel adds: +]
+ + +++ ++I think that the most recently suggested change in +27.7.2.4 [ostream::sentry] need some further word-smithing. As +written, it would make the behavior undefined, if under +conditions when pubsync() should be called, but when +in this scenario os.rdbuf() returns 0. +
++This case is explicitly handled in flush() and needs to be +taken care of. My suggested fix is: +
+ ++If ((os.flags() & ios_base::unitbuf) && !uncaught_exception() +&& os.rdbuf() != 0) is true, calls+ +os.flush()+os.rdbuf()->pubsync(). ++Two secondary questions are: +
+ ++
+- +Should pubsync() be invoked in any case or shouldn't a +base requirement for this trial be that os.good() == true +as required in the original flush() case? +
+- +Since uncaught_exception() is explicitly tested, shouldn't +a return value of -1 of pubsync() produce setstate(badbit) +(which may throw ios_base::failure)? +
+[ +2009-07 Frankfurt: +]
+ + +++ ++Daniel volunteered to modify the proposed resolution to address his two questions. +
++Move back to Open. +
+[ +2009-07-26 Daniel provided wording. Moved to Review. +]
+ + +[ +2009-10-13 Daniel adds: +]
+ + ++This proposed wording is written to match the outcome +of 397. ++ +[ +2009 Santa Cruz: +]
+ + ++Move to Open. Martin to propose updated wording that will also resolve +issue 397 consistently. ++ +[ +2010-02-15 Martin provided wording. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to Ready for Pittsburgh. ++ + + +Proposed resolution:
+ ++
+ + + + + + +- +
+ ++Just before 27.5.4.2 [basic.ios.members]/2 insert a new paragraph: +
+ ++Requires: If (tiestr != 0) is true, +tiestr must not be reachable by traversing the linked list of tied +stream objects starting from tiestr->tie(). ++- +
+ ++Change 27.7.2.4 [ostream::sentry]/4 as indicated: +
+ ++If ((os.flags() & ios_base::unitbuf) && !uncaught_exception() +&& os.good()) is true, calls ++os.flush()os.rdbuf()->pubsync(). If that +function returns -1 sets badbit in os.rdstate() without +propagating an exception. +- +
+ ++Add after 27.7.2.4 [ostream::sentry] p17, the following paragraph: +
+ ++Throws: Nothing. ++ +
+836. + effects of
+money_base::spaceand +money_base::noneonmoney_get+Section: 22.4.6.1.2 [locale.money.get.virtuals] Status: WP + Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29
+View all other issues in [locale.money.get.virtuals].
+View all issues with WP status.
+Duplicate of: 670
+Discussion:
+ ++ +In paragraph 2, 22.4.6.1.2 [locale.money.get.virtuals] specifies the following: + +
++ +Where+spaceornoneappears in the format +pattern, except at the end, optional white space (as recognized +byct.is) is consumed after any required space. + ++ +This requirement can be (and has been) interpreted two mutually +exclusive ways by different readers. One possible interpretation +is that: + +
++++
+- + +where
+money_base::spaceappears in the format, at least +one space is required, and + +- + +where
+money_base::noneappears in the format, space is +allowed but not required. + ++ +The other is that: + +
++ +where either+ +money_base::spaceormoney_base::noneappears in the format, white space is optional. + +[ +San Francisco: +]
+ + ++Martin will revise the proposed resolution. ++ +[ +2009-07 Frankfurt: +]
+ + +++ ++There is a noun missing from the proposed resolution. It's not clear +that the last sentence would be helpful, even if the word were not +missing: +
++In either case, any required MISSINGWORD followed by all optional whitespace (as recognized by ct.is()) is consumed. +++Strike this sentence and move to Review. +
+ +[ +Howard: done. +]
+ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++ +I propose to change the text to make it clear that the first +interpretation is intended, that is, to make following change to +22.4.6.1.2 [locale.money.get.virtuals], p2: + +
+ ++ +When+ + + +money_base::space+ormoney_base::noneappears as the last +element in the format pattern,except at the end, optional +white space (as recognized byno white space is consumed. Otherwise, +wherect.is) is consumed after +any required space.money_base::spaceappears in any of the initial +elements of the format pattern, at least one white space character is +required. Wheremoney_base::noneappears in any of the +initial elements of the format pattern, white space is allowed but not +required. +If(str.flags() & str.showbase)isfalse, ... + +
838. can an end-of-stream iterator become a non-end-of-stream one?
Section: 24.6.1 [istream.iterator] Status: WP - Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2009-10-26
+ Submitter: Martin Sebor Opened: 2008-05-17 Last modified: 2010-10-29View all other issues in [istream.iterator].
View all issues with WP status.
Discussion:
@@ -37129,9 +46764,8 @@ return tmp;
842. ConstructibleAsElement and bit containers
-Section: 23.2 [container.requirements], 23.3.7 [vector.bool], 20.3.7 [template.bitset] Status: CD1 - Submitter: Howard Hinnant Opened: 2008-06-03 Last modified: 2008-09-26
-View other active issues in [container.requirements].
+Section: 23.2 [container.requirements], 23.4.2 [vector.bool], 20.5 [template.bitset] Status: CD1 + Submitter: Howard Hinnant Opened: 2008-06-03 Last modified: 2010-10-29
View all other issues in [container.requirements].
View all issues with CD1 status.
Discussion:
@@ -37153,8 +46787,8 @@ with a scoped allocator of type A (i.e., an allocator for which-However vector<bool, A> (23.3.7 [vector.bool]) and bitset<N> -(20.3.7 [template.bitset]) store bits, not bools, and bitset<N> +However vector<bool, A> (23.4.2 [vector.bool]) and bitset<N> +(20.5 [template.bitset]) store bits, not bools, and bitset<N> does not even have an allocator. But these containers are governed by this clause. Clearly this is not implementable.
@@ -37180,7 +46814,7 @@ with a scoped allocator of type A (i.e., an allocator for which-Change 23.3.7 [vector.bool]/p2: +Change 23.4.2 [vector.bool]/p2:
@@ -37190,7 +46824,7 @@ and construct_element (23.2 [container.requirements]) is not used to co-Move 20.3.7 [template.bitset] to clause 20. +Move 20.5 [template.bitset] to clause 20.
@@ -37201,7 +46835,7 @@ Move 20.3.7 [template.bitset] to clause 20.
843. Reference Closure
Section: X [func.referenceclosure.cons] Status: CD1 - Submitter: Lawrence Crowl Opened: 2008-06-02 Last modified: 2008-09-26
+ Submitter: Lawrence Crowl Opened: 2008-06-02 Last modified: 2010-10-29View all issues with CD1 status.
Discussion:
@@ -37279,7 +46913,7 @@ add the member function description
844. complex pow return type is ambiguous
Section: 26.4.9 [cmplx.over] Status: CD1 - Submitter: Howard Hinnant Opened: 2008-06-03 Last modified: 2009-03-21
+ Submitter: Howard Hinnant Opened: 2008-06-03 Last modified: 2010-10-29View all other issues in [cmplx.over].
View all issues with CD1 status.
Discussion:
@@ -37337,8 +46971,8 @@ Strike this pow overload in 26.4.1 [complex.syn] and in 26.4.8 [complex
845. atomics cannot support aggregate initialization
-Section: 29.5 [atomics.types] Status: CD1 - Submitter: Alisdair Meredith Opened: 2008-06-03 Last modified: 2008-09-26
+Section: X [atomics.types] Status: CD1 + Submitter: Alisdair Meredith Opened: 2008-06-03 Last modified: 2010-10-29
View all other issues in [atomics.types].
View all issues with CD1 status.
Discussion:
@@ -37454,7 +47088,7 @@ It shall support aggregate initialization syntax.-within the synopsis of 29.5.3 [atomics.types.generic] edit as follows. +within the synopsis of 29.5 [atomics.types.generic] edit as follows.
@@ -37474,7 +47108,7 @@ template <> struct atomic<T*> : atomic_address {-edit 29.5.3 [atomics.types.generic] paragraph 2 as follows. +edit 29.5 [atomics.types.generic] paragraph 2 as follows.
@@ -37491,8 +47125,8 @@ and a constexpr@@ -37553,7 +47187,7 @@ Construction is not atomic.explicitvalue constructor.
846. No definition for constructor
-Section: 29.5 [atomics.types] Status: CD1 - Submitter: Alisdair Meredith Opened: 2008-06-03 Last modified: 2008-09-26
+Section: X [atomics.types] Status: CD1 + Submitter: Alisdair Meredith Opened: 2008-06-03 Last modified: 2010-10-29
View all other issues in [atomics.types].
View all issues with CD1 status.
Discussion:
@@ -37541,7 +47175,7 @@ constexpr A::A(C desired); Initializes the object with the valuedesired. [Note: Construction is not atomic. -—end note] +—end note]
847. string exception safety guarantees
Section: 21.4.1 [string.require] Status: WP - Submitter: Hervé Brönnimann Opened: 2008-06-05 Last modified: 2009-10-26
+ Submitter: Hervé Brönnimann Opened: 2008-06-05 Last modified: 2010-10-29View all other issues in [string.require].
View all issues with WP status.
Discussion:
@@ -37675,9 +47309,8 @@ or add paragraphs to Effects clauses wherever appropriate.
848. missing std::hash specializations for std::bitset/std::vector<bool>
-Section: 20.7.16 [unord.hash] Status: CD1 - Submitter: Thorsten Ottosen Opened: 2008-06-05 Last modified: 2008-09-26
-View other active issues in [unord.hash].
+Section: 20.8.15 [unord.hash] Status: CD1 + Submitter: Thorsten Ottosen Opened: 2008-06-05 Last modified: 2010-10-29
View all other issues in [unord.hash].
View all issues with CD1 status.
Discussion:
@@ -37693,7 +47326,7 @@ encapsulated in this respect.Proposed resolution:
-Add the following to the synopsis in 20.7 [function.objects]/2: +Add the following to the synopsis in 20.8 [function.objects]/2:
template<class Allocator> struct hash<std::vector<bool,Allocator>>; @@ -37701,7 +47334,7 @@ template<size_t N> struct hash<std::bitset<N>>;-Modify the last sentence of 20.7.16 [unord.hash]/1 to end with: +Modify the last sentence of 20.8.15 [unord.hash]/1 to end with:
@@ -37717,7 +47350,7 @@ Modify the last sentence of 20.7.16 [unord.hash]/1 to end with:@@ -38345,8 +48108,8 @@ The returned value indicates whether the predicate evaluates to
850. Should shrink_to_fit apply to std::deque?
Section: 23.3.2.2 [deque.capacity] Status: CD1 - Submitter: Niels Dekker Opened: 2008-06-05 Last modified: 2008-09-26
+ Submitter: Niels Dekker Opened: 2008-06-05 Last modified: 2010-10-29View all other issues in [deque.capacity].
View all issues with CD1 status.
Discussion:
@@ -37785,8 +47418,8 @@ implementation-specific optimizations. -- end note]
852. unordered containers begin(n) mistakenly const
-Section: 23.5 [unord] Status: CD1 - Submitter: Robert Klarer Opened: 2008-06-12 Last modified: 2008-09-26
+Section: 23.7 [unord] Status: CD1 + Submitter: Robert Klarer Opened: 2008-06-12 Last modified: 2010-10-29
View all other issues in [unord].
View all issues with CD1 status.
Discussion:
@@ -37800,7 +47433,7 @@ In 3 of the four unordered containers the local begin member is mistakeProposed resolution:
-Change the synopsis in 23.5.1 [unord.map], 23.5.2 [unord.multimap], and 23.5.4 [unord.multiset]: +Change the synopsis in 23.7.1 [unord.map], 23.7.2 [unord.multimap], and 23.7.4 [unord.multiset]:
local_iterator begin(size_type n)const; @@ -37812,9 +47445,8 @@ Change the synopsis in 23.5.1 [unord.map], 23.5.2 [unord.multimap], and 23.5.4 [
853. to_string needs updating with zero and one
-Section: 20.3.7 [template.bitset] Status: WP - Submitter: Howard Hinnant Opened: 2008-06-18 Last modified: 2009-07-18
-View other active issues in [template.bitset].
+Section: 20.5 [template.bitset] Status: WP + Submitter: Howard Hinnant Opened: 2008-06-18 Last modified: 2010-10-29
View all other issues in [template.bitset].
View all issues with WP status.
Discussion:
@@ -37856,7 +47488,7 @@ Recommend Tentatively Ready.[ -2009-05-09: See alternative solution in issue 1113. +2009-05-09: See alternative solution in issue 1113. ]
@@ -37865,7 +47497,7 @@ Recommend Tentatively Ready.Proposed resolution:
- -
replace in 20.3.7 [template.bitset]/1 (class bitset) +
replace in 20.5 [template.bitset]/1 (class bitset)
template <class charT, class traits> basic_string<charT, traits, allocator<charT> > @@ -37879,7 +47511,7 @@ basic_string<char, char_traits<char>, allocator<char> >-replace in 20.3.7.2 [bitset.members]/37 +replace in 20.5.2 [bitset.members]/37
template <class charT, class traits> basic_string<charT, traits, allocator<charT> > @@ -37892,7 +47524,7 @@ replace in 20.3.7.2 [bitset.members]/37-replace in 20.3.7.2 [bitset.members]/38 +replace in 20.5.2 [bitset.members]/38
@@ -38332,7 +48095,7 @@ return true; -22- [Note: The returned value indicates whether the predicate evaluates to true regardless of whether the timeout was triggered. -— end note]. +— end note].template <class charT> @@ -37907,7 +47539,7 @@ replace in 20.3.7.2 [bitset.members]/38-replace in 20.3.7.2 [bitset.members]/39 +replace in 20.5.2 [bitset.members]/39
basic_string<char, char_traits<char>, allocator<char> > @@ -37926,10 +47558,142 @@ replace in 20.3.7.2 [bitset.members]/39 +
+854. default_delete converting constructor underspecified
+Section: 20.9.9.1.2 [unique.ptr.dltr.dflt] Status: WP + Submitter: Howard Hinnant Opened: 2008-06-18 Last modified: 2010-10-29
+View all other issues in [unique.ptr.dltr.dflt].
+View all issues with WP status.
+Discussion:
++No relationship between U and T in the converting constructor for default_delete template. +
++Requirements: U* is convertible to T* and has_virtual_destructor<T>; +the latter should also become a concept. +
++Rules out cross-casting. +
++The requirements for unique_ptr conversions should be the same as those on the deleter. +
+ +[ +Howard adds 2008-11-26: +]
+ + +++ ++I believe we need to be careful to not outlaw the following use case, and +I believe the current proposed wording +(requires Convertible<U*, T*> && HasVirtualDestructor<T>) does so: +
+ ++ +#include <memory> + +int main() +{ + std::unique_ptr<int> p1(new int(1)); + std::unique_ptr<const int> p2(move(p1)); + int i = *p2; +// *p2 = i; // should not compile +} ++I've removed "&& HasVirtualDestructor<T>" from the +requires clause in the proposed wording. +
+ +[ +Post Summit: +]
+ + +++ ++Alisdair: This issue has to stay in review pending a paper constraining +unique_ptr. +
++Consensus: We agree with the resolution, but unique_ptr needs +to be constrained, too. +
++Recommend Keep in Review. +
+[ +Batavia (2009-05): +]
+ ++Keep in Review status for the reasons cited. ++ +[ +2009-07 Frankfurt: +]
+ + +++ ++The proposed resolution uses concepts. Howard needs to rewrite the +proposed resolution. +
++Move back to Open. +
+[ +2009-07-26 Howard provided rewritten proposed wording and moved to Review. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++Add after 20.9.9.1.2 [unique.ptr.dltr.dflt], p1: +
+ ++ + + + + +template <class U> default_delete(const default_delete<U>& other); +++++-1- Effects: ... +
++Remarks: This constructor shall participate in overload resolution +if and only if U* is implicitly convertible to T*. +
+
856. Removal of aligned_union
-Section: 20.6.7 [meta.trans.other] Status: CD1 - Submitter: Jens Maurer Opened: 2008-06-12 Last modified: 2008-09-26
+Section: 20.7.7.6 [meta.trans.other] Status: CD1 + Submitter: Jens Maurer Opened: 2008-06-12 Last modified: 2010-10-29
View all other issues in [meta.trans.other].
View all issues with CD1 status.
Discussion:
@@ -37944,13 +47708,13 @@ the "extended unions" core-language facility.Proposed resolution:
-Remove the following signature from 20.6.2 [meta.type.synop]: +Remove the following signature from 20.7.2 [meta.type.synop]:
template <std::size_t Len, class... Types> struct aligned_union;-Remove the second row from table 51 in 20.6.7 [meta.trans.other], +Remove the second row from table 51 in 20.7.7.6 [meta.trans.other], starting with:
@@ -37966,8 +47730,7 @@ struct aligned_union;
857. condition_variable::time_wait return bool error prone
Section: 30.5.1 [thread.condition.condvar] Status: WP - Submitter: Beman Dawes Opened: 2008-06-13 Last modified: 2009-10-26
-View other active issues in [thread.condition.condvar].
+ Submitter: Beman Dawes Opened: 2008-06-13 Last modified: 2010-10-29View all other issues in [thread.condition.condvar].
View all issues with WP status.
Discussion:
@@ -38137,7 +47900,7 @@ cannot be achieved.
- -operation_not_permitted — if the thread does not own the lock. +operation_not_permitted — if the thread does not own the lock.
- equivalent error condition from lock.lock() or lock.unlock(). @@ -38193,7 +47956,7 @@ return true; -25- [Note: The returned value indicates whether the predicate evaluates to true regardless of whether the timeout was triggered. -— end note]. +— end note].
858. Wording for Minimal Support for Garbage Collection
-Section: 20.8.15.6 [util.dynamic.safety] Status: CD1 - Submitter: Pete Becker Opened: 2008-06-21 Last modified: 2008-09-26
+Section: 20.9.11 [util.dynamic.safety] Status: CD1 + Submitter: Pete Becker Opened: 2008-06-21 Last modified: 2010-10-29
View all other issues in [util.dynamic.safety].
View all issues with CD1 status.
Discussion:
@@ -38396,7 +48159,7 @@ to clarify the intent.Proposed resolution:
-In 20.8.15.6 [util.dynamic.safety] +In 20.9.11 [util.dynamic.safety] (N2670, Minimal Support for Garbage Collection)
@@ -38468,13 +48231,12 @@ note]
859. Monotonic Clock is Conditionally Supported?
Section: 30.5 [thread.condition] Status: WP - Submitter: Pete Becker Opened: 2008-06-23 Last modified: 2009-10-26
-View other active issues in [thread.condition].
+ Submitter: Pete Becker Opened: 2008-06-23 Last modified: 2010-10-29View all other issues in [thread.condition].
View all issues with WP status.
Discussion:
- +N2661 @@ -38580,7 +48342,7 @@ Move to Ready.
[ -2009-07-21 Beman added the requested wording changes to 962. +2009-07-21 Beman added the requested wording changes to 962. ]
@@ -38918,22 +48680,717 @@ equivalent error condition from lock.lock() or lock.unlock(). +
+860. Floating-Point State
+Section: 26 [numerics] Status: WP + Submitter: Lawrence Crowl Opened: 2008-06-23 Last modified: 2010-10-29
+View all other issues in [numerics].
+View all issues with WP status.
+Discussion:
++There are a number of functions that affect the floating point state. +These function need to be thread-safe, but I'm unsure of the right +approach in the standard, as we inherit them from C. +
+ +[ +San Francisco: +]
+ + +++ ++Nick: I think we already say that these functions do not introduce data +races; see 17.6.5.6/20 +
++Pete: there's more to it than not introducing data races; are these +states maintained per thread? +
++Howard: 21.5/14 says that strtok and strerror are not required to avoid +data races, and 20.9/2 says the same about asctime, gmtime, ctime, and +gmtime. +
++Nick: POSIX has a list of not-safe functions. All other functions are +implicitly thread safe. +
++Lawrence is to form a group between meetings to attack this issue. Nick +and Tom volunteered to work with Lawrence. +
++Move to Open. +
+[ +Post Summit: +]
+ + +++ ++Hans: Sane oses seem ok. Sensible thing is implementable and makes sense. +
++Nick: Default wording seems to cover this? Hole in POSIX, these +functions need to be added to list of thread-unsafe functions. +
++Lawrence: Not sufficient, not "thread-safe" per our definition, but +think of state as a thread-local variable. Need something like "these +functions only affect state in the current thread." +
++Hans: Suggest the following wording: "The floating point environment is +maintained per-thread." +
++Walter: Any other examples of state being thread safe that are not +already covered elsewhere? +
++Have thread unsafe functions paper which needs to be updated. Should +just fold in 26.3 [cfenv] functions. +
++Recommend Open. Lawrence instead suggests leaving it open until we have +suitable wording that may or may not include the thread local +commentary. +
+[ +2009-09-23 Hans provided wording. +]
+ + ++If I understand the history correctly, Nick, as the Posix liaison, +should probably get a veto on this, since I think it came from Posix (?) +via WG14 and should probably really be addressed there (?). But I think +we are basically in agreement that there is no other sane way to do +this, and hence we don't have to worry too much about stepping on toes. +As far as I can tell, this same issue also exists in the latest Posix +standard (?). ++ +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ + + +Proposed resolution:
++Add at the end of 26.3.1 [cfenv.syn]: +
+ +++ + + + + ++2 The header defines all functions, types, and macros the same as C99 7.6. +
+ ++A separate floating point environment shall be maintained for each +thread. Each function accesses the environment corresponding to its +calling thread. +
+
+861. Incomplete specification of EqualityComparable for std::forward_list
+Section: 23.2 [container.requirements] Status: WP + Submitter: Daniel Krügler Opened: 2008-06-24 Last modified: 2010-10-29
+View all other issues in [container.requirements].
+View all issues with WP status.
+Discussion:
++Table 89, Container requirements, defines operator== in terms of the container +member function size() and the algorithm std::equal: +
+ ++== is an equivalence relation. a.size() == b.size() && +equal(a.begin(), a.end(), b.begin() ++ ++The new container forward_list does not provide a size member function +by design but does provide operator== and operator!= without specifying it's semantic. +
++Other parts of the (sequence) container requirements do also depend on +size(), e.g. empty() +or clear(), but this issue explicitly attempts to solve the missing +EqualityComparable specification, +because of the special design choices of forward_list. +
++I propose to apply one of the following resolutions, which are described as: +
+ ++
+- +Provide a definition, which is optimal for this special container without +previous size test. This choice prevents two O(N) calls of std::distance() +with the corresponding container ranges and instead uses a special +equals implementation which takes two container ranges instead of 1 1/2. +
+- +The simple fix where the usual test is adapted such that size() is replaced +by distance with corresponding performance disadvantages. +
++Both proposal choices are discussed, the preferred choice of the author is +to apply (A). +
+ +[ +San Francisco: +]
+ + +++ ++There's an Option C: change the requirements table to use distance(). +
++LWG found Option C acceptable. +
++Martin will draft the wording for Option C. +
+[ +post San Francisco: +]
+ + ++Martin provided wording for Option C. ++ +[ +2009-07 Frankfurt +]
+ + +++ ++Other operational semantics (see, for example, Tables 82 and 83) are +written in terms of a container's size() member. Daniel to update +proposed resolution C. +
+[ +Howard: Commented out options A and B. +]
+ +[ +2009-07-26 Daniel updated proposed resolution C. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Mark NAD Editorial. Addressed by +N2986. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Reopened. +N2986 +was rejected in full committee on procedural grounds. ++ +[ +2010-01-30 Howard updated Table numbers. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Moved to Ready for Pittsburgh. ++ + + +Proposed resolution:
+ + ++Option (C): +
++ ++ + + + + ++
+ + +- +
+ ++In 23.2.1 [container.requirements.general] change Table 90 -- Container requirements as indicated: +
+ ++
+- +
+ ++Change the text in the Assertion/note column in the row for "X u;" +as follows: +
+ ++post: u.+size() == 0empty() == true +- +
+ ++Change the text in the Assertion/note column in the row for "X();" +as follows: +
+ ++X().+size() == 0empty() == true +- +
+ ++Change the text in the Operational Semantics column in the row for +"a == b" as follows: +
++== is an equivalence relation. ++a.size()distance(a.begin(), a.end()) == +b.size()distance(b.begin(), b.end()) && +equal(a.begin(), a.end(), b.begin()) +- +
+ ++Add text in the Ass./Note/pre-/post-condition column in the row for +"a == b" as follows: +
++Requires: T is EqualityComparable ++- +
+ ++Change the text in the Operational Semantics column in the row for +"a.size()" as follows: +
+ +++a.end() - a.begin()distance(a.begin(), a.end()) +- +
+ ++Change the text in the Operational Semantics column in the row for +"a.max_size()" as follows: +
+ +++size()distance(begin(), end()) of the largest +possible container +- +
++Change the text in the Operational Semantics column in the row for +"a.empty()" as follows: +
+ +++a.size() == 0a.begin() == a.end() +- +
+ ++In 23.2.1 [container.requirements.general] change Table 93 -- Allocator-aware container requirements as indicated: +
+ ++
+- +
+ ++Change the text in the Assertion/note column in the row for "X() / +X u;" as follows: +
+ ++Requires: A is DefaultConstructible post:+u.size() == +0u.empty() == true, get_allocator() == A() +- +
++Change the text in the Assertion/note column in the row for "X(m) / +X u(m);" as follows: +
+ ++post:+u.size() == 0u.empty() == true, +get_allocator() == m +- +
+ ++In 23.2.3 [sequence.reqmts] change Table 94 -- Sequence container requirements as indicated: +
+ ++
+- +
+ ++Change the text in the Assertion/note column in the row for "X(n, +t) / X a(n, t)" as follows: +
+ ++post:+size()distance(begin(), end()) == n [..] +- +
+ ++Change the text in the Assertion/note column in the row for "X(i, +j) / X a(i, j)" as follows: +
+ ++[..] post:+size() == distance between i and +jdistance(begin(), end()) == distance(i, j) [..] +- +
++Change the text in the Assertion/note column in the row for +"a.clear()" as follows: +
++a.erase(a.begin(), a.end()) post: ++size() == 0a.empty() == true +- +
+ ++In 23.2.4 [associative.reqmts] change Table 96 -- Associative container requirements as indicated: +
+ +[ +Not every occurrence of size() was replaced, because all current +associative containers +have a size. The following changes ensure consistency regarding the +semantics of "erase" +for all tables and adds some missing objects +]
+ + ++ +
+- +
+ ++Change the text in the Complexity column in the row for X(i,j,c)/X +a(i,j,c); as follows: +
+ ++N log N in general (N == distance(i, +j)+ +is the distance from i to j); ... +- +
+ ++Change the text in the Complexity column in the row for +"a.insert(i, j)" as follows: +
++N log(a.size() + N)+(N is the distance from i to +j)where N == distance(i, j) +- +
+ ++Change the text in the Complexity column in the row for +"a.erase(k)" as follows: +
++log(a.size()) + a.count(k) ++- +
+ ++Change the text in the Complexity column in the row for +"a.erase(q1, q2)" as follows: +
+ ++log(a.size()) + N where N+is the distance from q1 +to q2+ == distance(q1, q2). +- +
+ ++Change the text in the Assertion/note column in the row for +"a.clear()" as follows: +
+ ++a.erase(a.begin(),a.end()) post:+size() == +0a.empty() == true +- +
+ ++Change the text in the Complexity column in the row for "a.clear()" +as follows: +
+ ++linear in a.size() ++- +
++Change the text in the Complexity column in the row for +"a.count(k)" as follows: +
+ ++log(a.size()) + a.count(k) ++- +
++In 23.2.5 [unord.req] change Table 98 -- Unordered associative container requirements as indicated: +
+[ +The same rational as for Table 96 applies here +]
+ + ++
+- +
++Change the text in the Assertion/note column in the row for +"a.clear()" as follows: +
+ ++[..] Post: a.+size() == 0empty() == true +
+865. More algorithms that throw away information
+Section: 25.3.6 [alg.fill], 25.3.7 [alg.generate] Status: WP + Submitter: Daniel Krügler Opened: 2008-07-13 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++In regard to library defect 488 I found some more algorithms which +unnecessarily throw away information. These are typically algorithms, +which sequentially write into an OutputIterator, but do not return the +final value of this output iterator. These cases are: +
+ ++
+- +
+ +template<class OutputIterator, class Size, class T> +void fill_n(OutputIterator first, Size n, const T& value);- +
+template<class OutputIterator, class Size, class Generator> +void generate_n(OutputIterator first, Size n, Generator gen);+In both cases the minimum requirements on the iterator are +OutputIterator, which means according to the requirements of +24.2.4 [output.iterators]/2 that only single-pass iterations are guaranteed. +So, if users of fill_n and generate_n have *only* an OutputIterator +available, they have no chance to continue pushing further values +into it, which seems to be a severe limitation to me. +
+ +[ +Post Summit Daniel "conceptualized" the wording. +]
+ + +[ +Batavia (2009-05): +]
+ +++ ++Alisdair likes the idea, but has concerns about the specific wording +about the returns clauses. +
++Alan notes this is a feature request. +
++Bill notes we have made similar changes to other algorithms. +
++Move to Open. +
+[ +2009-07 Frankfurt +]
+ + ++We have a consensus for moving forward on this issue, but Daniel needs +to deconceptify it. ++ +[ +2009-07-25 Daniel provided non-concepts wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ + + +Proposed resolution:
+ ++
+ + + + + + +- +
+ ++Replace the current declaration of fill_n in 25 [algorithms]/2, header +<algorithm> synopsis and in 25.3.6 [alg.fill] by +
+ ++ +template<class OutputIterator, class Size, class T> +voidOutputIterator fill_n(OutputIterator first, Size n, const T& value); ++Just after the effects clause add a new returns clause saying: +
+ ++Returns: For fill_n and positive n, returns first + n. Otherwise +returns first for fill_n. ++- +
++Replace the current declaration of generate_n in 25 [algorithms]/2, +header <algorithm> synopsis and in 25.3.7 [alg.generate] by +
+ ++ +template<class OutputIterator, class Size, class Generator> +voidOutputIterator generate_n(OutputIterator first, Size n, Generator gen); ++Just after the effects clause add a new returns clause saying: +
+ ++For generate_n and positive n, returns first + n. Otherwise +returns first for generate_n. ++
866. Qualification of placement new-expressions
-Section: 20.8.13 [specialized.algorithms], 20.8.15.2.6 [util.smartptr.shared.create] Status: WP - Submitter: Alberto Ganesh Barbati Opened: 2008-07-14 Last modified: 2009-03-09
+Section: 20.9.8 [specialized.algorithms], 20.9.10.2.6 [util.smartptr.shared.create] Status: WP + Submitter: Alberto Ganesh Barbati Opened: 2008-07-14 Last modified: 2010-10-29
View all other issues in [specialized.algorithms].
View all issues with WP status.
Discussion:
LWG issue 402 replaced "new" with "::new" in the placement -new-expression in 20.8.8.1 [allocator.members]. I believe the rationale +new-expression in 20.9.5.1 [allocator.members]. I believe the rationale given in 402 applies also to the following other contexts:
-in 20.8.13 [specialized.algorithms], all four algorithms unitialized_copy, +in 20.9.8 [specialized.algorithms], all four algorithms unitialized_copy, unitialized_copy_n, unitialized_fill and unitialized_fill_n use the unqualified placement new-expression in some variation of the form:
@@ -38942,7 +49399,7 @@ the unqualified placement new-expression in some variation of the form:-in 20.8.15.2.6 [util.smartptr.shared.create] there is a reference to the unqualified placement new-expression: +in 20.9.10.2.6 [util.smartptr.shared.create] there is a reference to the unqualified placement new-expression:
@@ -38991,16 +49448,16 @@ Replace "new" with "::new" in:new (pv) T(std::forward<Args>(args)...),@@ -39009,10 +49466,357 @@ Replace "new" with "::new" in: +
- -20.8.13.2 [uninitialized.copy], paragraphs 1 and 3 +20.9.8.2 [uninitialized.copy], paragraphs 1 and 3
- -20.8.13.3 [uninitialized.fill] paragraph 1 +20.9.8.3 [uninitialized.fill] paragraph 1
- -20.8.13.4 [uninitialized.fill.n] paragraph 1 +20.9.8.4 [uninitialized.fill.n] paragraph 1
- -20.8.15.2.6 [util.smartptr.shared.create] once in paragraph 1 and twice in paragraph 2. +20.9.10.2.6 [util.smartptr.shared.create] once in paragraph 1 and twice in paragraph 2.
+868. default construction and value-initialization
+Section: 23 [containers] Status: WP + Submitter: Alberto Ganesh Barbati Opened: 2008-07-22 Last modified: 2010-11-24
+View all other issues in [containers].
+View all issues with WP status.
+Discussion:
++The term "default constructed" is often used in wording that predates +the introduction of the concept of value-initialization. In a few such +places the concept of value-initialization is more correct than the +current wording (for example when the type involved can be a built-in) +so a replacement is in order. Two of such places are already covered by +issue 867. This issue deliberately addresses the hopefully +non-controversial changes in the attempt of being approved more quickly. +A few other occurrences (for example in std::tuple, +std::reverse_iterator and std::move_iterator) are left to separate +issues. For std::reverse_iterator, see also issue 408. This issue is +related with issue 724. +
+ +[ +San Francisco: +]
+ + +++ ++The list provided in the proposed resolution is not complete. James +Dennett will review the library and provide a complete list and will +double-check the vocabulary. +
++This issue relates to Issue 886 tuple construction +
+[ +2009-07 Frankfurt +]
+ + +++ ++The proposed resolution is incomplete. +
++Move to Tentatively NAD Future. Howard will contact Ganesh for wording. +If wording is forthcoming, Howard will move it back to Review. +
+[ +2009-07-18 Ganesh updated the proposed wording. +]
+ + +++ ++Howard: Moved back to Review. Note that 20.2.1 [utility.arg.requirements] +refers to a section that is not in the current working paper, but does refer to +a section that we expect to reappear after the de-concepts merge. This was a +point of confusion we did not recognize when we reviewed this issue in Frankfurt. +
++Howard: Ganesh also includes a survey of places in the WP surveyed for changes +of this nature and purposefully not treated: +
+ +++ ++Places where changes are not being +proposed +
++In the following paragraphs, we are not proposing changes because +it's not clear whether we actually prefer value-initialization over +default-initialization (now partially covered by 1012): +
++
+- +
20.9.9.2.1 [unique.ptr.single.ctor] para 3 e 7
- +
24.5.1.3.1 [reverse.iter.cons] para 1
- +
24.5.3.3.1 [move.iter.op.const] para 1
In the following paragraphs, the expression "default +constructed" need not be changed, because the relevant type does +not depend on a template parameter and has a user-provided +constructor:
++
+- +
[func.referenceclosure.invoke] para 12, type: + reference_closure
- +
30.3.1.2 [thread.thread.constr] para 30, type: thread
- +
30.3.1.5 [thread.thread.member] para 52, type: thread_id
- +
30.3.2 [thread.thread.this], para 1, type: thread_id
[ +2009-08-18 Daniel adds: +]
+ + +++ ++I have no objections against the currently suggested changes, but I +also cross-checked +with the list regarding intentionally excluded changes, and from this +I miss the discussion +of +
+ ++
+ +- +
+ ++21.4.1 [string.require]/2: +
+ ++"[..] The Allocator object used shall be a copy of the Allocator> +object passed to the basic_string object's +constructor or, if the constructor does not take an Allocator +argument, a copy of a default-constructed +Allocator object." ++- +
+ ++N2723, +26.5.1.4 [rand.req.eng], Table 109, expression "T()": +
++Pre-/post-condition: "Creates an engine with the same initial state as +all other default-constructed engines of type X." ++ ++as well as in 26.5.5 [rand.predef]/1-9 (N2914), 26.5.7.1 [rand.util.seedseq]/3, 27.7.1.1.1 [istream.cons]/3, 27.7.2.2 [ostream.cons]/9 (N2914), 28.13 [re.grammar]/2, 30.3.1.4 [thread.thread.assign]/1 (N2914), +
+[ +Candidates for the "the expression "default constructed" need not be +changed" list +]
+ + ++I'm fine, if these would be added to the intentionally exclusion list, +but mentioning them makes it +easier for other potential reviewers to decide on the relevance or +not-relevance of them for this issue. +
+- +
+ ++I suggest to remove the reference of [func.referenceclosure.invoke] +in the "it's not clear" list, because +this component does no longer exist. +
+- +
++I also suggest to add a short comment that all paragraphs in the +resolution whether they refer to N2723 or to N2914 numbering, because e.g. "Change 23.3.2.1 [deque.cons] para 5" is an N2723 coordinate, while "Change 23.3.2.2 [deque.capacity] para 1" is an N2914 coordinate. Even better would be to use one default document +for the numbering (probably N2914) and mention special cases (e.g. "Change 20.2.1 [utility.arg.requirements] para 2" as referring to N2723 numbering). +
+[ +2009-08-18 Alisdair adds: +]
+ + +++ ++I strongly believe the term "default constructed" should not appear in +the library clauses unless we very clearly define a meaning for it, and +I am not sure what that would be. +
+ ++In those cases where we do not want to replace "default constructed" +with "vale initialized" we should be using "default initialized". If we +have a term that could mean either, we reduce portability of programs. +
+ ++I have not done an exhaustive review to clarify if that is a vendor +freedom we have reason to support (e.g. value-init in debug, +default-init in release) so I may yet be convinced that LWG has reason +to define this new term of art, but generally C++ initialization is +confusing enough without supporting further ill-defined terms. +
+[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ +[ +2010 Pittsburgh: +]
+ + ++Moved to review in order to enable conflict resolution with 704. ++ +[ +2010-03-26 Daniel harmonized the wording with the upcoming FCD. +]
+ + + +[ +2010 Rapperswil: +]
+ + ++Move to Ready. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Change 20.2.1 [utility.arg.requirements] para 2: +
+ ++2 In general, a default constructor is +not required. Certain container class member function signatures +specify+ +the default constructorT() +as a default argument. T() shall be a well-defined expression (8.5) +if one of those signatures is called using the default argument +(8.3.6). ++Change 23.3.2.1 [deque.cons] para 3: +
+ ++3 Effects: Constructs a deque with n ++ +default constructedvalue-initialized +elements. ++Change 23.3.2.2 [deque.capacity] para 1: +
+ ++1 Effects: If sz < size(), equivalent +to erase(begin() + sz, end());. If size() < sz, appends sz - +size()+ +default +constructedvalue-initialized +elements to the sequence. ++Change 23.3.3.1 [forwardlist.cons] para 3: +
+ ++3 Effects: Constructs a forward_list object with n+ +default +constructedvalue-initialized +elements. ++Change 23.3.3.4 [forwardlist.modifiers] para 22: +
+ ++22 Effects: [...] For the first signature +the inserted elements are+ +default +constructedvalue-initialized, +and for the second signature they are copies of c. ++Change 23.3.4.1 [list.cons] para 3: +
+ ++3 Effects: Constructs a list with n+ +default +constructedvalue-initialized +elements. ++Change 23.3.4.2 [list.capacity] para 1: +
+ ++1 Effects: If sz < size(), equivalent +to list<T>::iterator it = begin(); advance(it, sz); erase(it, +end());. If size() < sz, appends sz - size()+ +default +constructedvalue-initialized +elements to the sequence. ++Change 23.4.1.1 [vector.cons] para 3: +
+ ++3 Effects: Constructs a vector with n ++ +default constructedvalue-initialized +elements. ++Change 23.4.1.2 [vector.capacity] para 9: +
+ ++9 Effects: If sz < size(), equivalent +to erase(begin() + sz, end());. If size() < sz, appends sz - +size()+ + + + + +default +constructedvalue-initialized +elements to the sequence. +
869. Bucket (local) iterators and iterating past end
Section: 23.2.5 [unord.req] Status: WP - Submitter: Sohail Somani Opened: 2008-07-22 Last modified: 2009-07-18
+ Submitter: Sohail Somani Opened: 2008-07-22 Last modified: 2010-10-29View other active issues in [unord.req].
View all other issues in [unord.req].
View all issues with WP status.
@@ -39089,10 +49893,626 @@ If the bucket is empty, then b.begin(n) == b.end(n). +
+870. Do unordered containers not support function pointers for predicate/hasher?
+Section: 23.2.5 [unord.req] Status: WP + Submitter: Daniel Krügler Opened: 2008-08-17 Last modified: 2010-10-29
+View other active issues in [unord.req].
+View all other issues in [unord.req].
+View all issues with WP status.
+Discussion:
++Good ol' associative containers allow both function pointers and +function objects as feasible +comparators, as described in 23.2.4 [associative.reqmts]/2: +
+ ++Each associative container is parameterized on Key and an ordering +relation Compare that +induces a strict weak ordering (25.3) on elements of Key. [..]. The +object of type Compare is +called the comparison object of a container. This comparison object +may be a pointer to +function or an object of a type with an appropriate function call operator.[..] ++ ++The corresponding wording for unordered containers is not so clear, +but I read it to disallow +function pointers for the hasher and I miss a clear statement for the +equality predicate, see +23.2.5 [unord.req]/3+4+5: +
+ +++ ++Each unordered associative container is parameterized by Key, by a +function object Hash that +acts as a hash function for values of type Key, and by a binary +predicate Pred that induces an +equivalence relation on values of type Key.[..] +
++A hash function is a function object that takes a single argument of +type Key and returns a +value of type std::size_t. +
++Two values k1 and k2 of type Key are considered equal if the +container's equality function object +returns true when passed those values.[..] +
++and table 97 says in the column "assertion...post-condition" for the +expression X::hasher: +
+ ++Hash shall be a unary function object type such that the expression +hf(k) has type std::size_t. ++ ++Note that 20.8 [function.objects]/1 defines as "Function objects are +objects with an operator() defined.[..]" +
++Does this restriction exist by design or is it an oversight? If an +oversight, I suggest that to apply +the following +
+ +[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Ask Daniel to provide proposed wording that: makes it explicit that +function pointers are function objects at the beginning of 20.8 [function.objects]; fixes the "requirements" for typedefs in +20.8.4 [refwrap] to instead state that the function objects +defined in that clause have these typedefs, but not that these typedefs +are requirements on function objects; remove the wording that explicitly +calls out that associative container comparators may be function +pointers. ++ +[ +2009-12-19 Daniel updates wording and rationale. +]
+ + +[ +2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Rationale:
+ ++The below provided wording also affects some part of the library which is +involved with callable types (20.8.1 [func.def]/3). Reason for +this is that callable objects do have a lot in common with function +objects. A simple formula seems to be: +
+ ++callable objects = function objects + pointers to member ++ ++The latter group is excluded from function objects because of the +expression-based usage of function objects in the algorithm clause, +which is incompatible with the notation to dereference pointers to member +without a concept map available in the language. +
+ ++This analysis showed some currently existing normative definition differences +between the above subset of callable objects and function objects which seem to +be unintended: Backed by the Santa Cruz outcome function objects should include +both function pointers and "object[s] with an operator() defined". This clearly +excludes class types with a conversion function to a function pointer or all +similar conversion function situations described in 13.3 [over.match]/2 +b. 2. In contrast to this, the wording for callable types seems to be less +constrained (20.8.1 [func.def]/3): +
+ ++A callable type is a [..] class type whose objects can appear immediately to the +left of a function call operator. ++ ++The rationale given in N1673 +and a recent private communication with Peter Dimov revealed that the intention +of this wording was to cover the above mentioned class types with conversion +functions as well. To me the current wording of callable types can be read +either way and I suggest to make the intention more explicit by replacing +
+ ++[..] class type whose objects can appear immediately to the left of a function +call operator ++ +by + ++[..] class type whose objects can appear as the leftmost subexpression of a +function call expression 5.2.2 [expr.call]. ++ ++and to use the same definition for the class type part of function +objects, because there is no reason to exclude class types with a +conversion function to e.g. pointer to function from being used in algorithms. +
+ ++Now this last term "function objects" itself brings us to a third unsatisfactory +state: The term is used both for objects (e.g. "Function objects are +objects[..]" in 20.8 [function.objects]/1) and for types (e.g. "Each +unordered associative container is parameterized [..] by a function object Hash +that acts as a hash function [..]" in 23.2.5 [unord.req]/3). This +impreciseness should be fixed and I suggest to introduce the term function +object type as the counter part to callable type. This word seems +to be a quite natural choice, because the library already uses it here and there +(e.g. "Hash shall be a unary function object type such that the expression +hf(k) has type std::size_t." in Table 98, "X::hasher" +or "Requires: T shall be a function object type [..]" in 20.8.14.2.5 [func.wrap.func.targ]/3). +
+ ++Finally I would like to add that part of the issue 870 discussion related to the +requirements for typedefs in 20.8.4 [refwrap] during the Santa Cruz +meeting is now handled by the new issue 1290. +
+ ++Obsolete rationale: +
+ +++ + + +[ +San Francisco: +]
+ + ++This is fixed by +N2776. ++ +Proposed resolution:
+ ++ +
+ + + + + + + + +- +
+ ++Change 20.8 [function.objects]/1 as indicated: +
+ ++++1
+Function objects are objects with an operator() +defined.An object type (3.9 [basic.types]) that can be the +type of the postfix-expression in a function call (5.2.2 [expr.call], 13.3.1.1 [over.match.call]) is called a function +object type*. A function object is an object of a +function object type. In the places where one would expect to +pass a pointer to a function to an algorithmic template (Clause 25 [algorithms]), the interface is specified to acceptan object with +an operator() defineda function object. This not only +makes algorithmic templates work with pointers to functions, but also enables +them to work with arbitrary function objects. ++* Such a type is either a function pointer or a class type which often has a +member operator(), but in some cases it can omit that member and +provide a conversion to a pointer to function. ++- +
+ ++Change 20.8.1 [func.def]/3 as indicated: [The intent is to make the +commonality of callable types and function object +types more explicit and to get rid of wording redundancies] +
+ ++3 A callable type is+a pointer to function,a pointer to +memberfunction, a pointer to member data,or aclass type whose +objects can appear immediately to the left of a function call operator+function object type (20.8 [function.objects]). +- +
+ ++Change 20.8.10 [bind]/1 as indicated: +
+ ++1 The function template bind returns an object that binds a ++functioncallable object passed as an argument to +additional arguments. +- +
+ ++Change 20.8.10.1 [func.bind]/1 as indicated: +
+ ++1 This subclause describes a uniform mechanism for binding arguments of ++functioncallable objects. +- +
+ ++Change 20.8.14 [func.wrap]/1 as indicated: +
+ ++1 This subclause describes a polymorphic wrapper class that encapsulates +arbitrary+functioncallable objects. +- +
+ + + ++Change 20.8.14.2 [func.wrap.func]/2 as indicated [The reason for this +change is that 20.8.14.2 [func.wrap.func]/1 clearly says that all callable +types may be wrapped by std::function and current implementations +indeed do provide support for pointer to members as well. One further suggested +improvement is to set the below definition of Callable in italics]: +
+ ++2 A+functioncallable object f of type F +isCallableCallable for argument types +T1, T2, ..., TN inArgTypes andareturn +type R,if, given lvalues t1, t2, ..., tN of +types T1, T2, ..., TN, respectively,the expression +INVOKE(f, declval<ArgTypes>()..., Rt1, t2, ..., +tN), considered as an unevaluated operand (5 [expr]), is well formed (20.7.2)and, if R is not +void, convertible to R. +- +
+ ++Change 20.8.14.2.1 [func.wrap.func.con]/7 as indicated: +
+ ++function(const function& f); +template <class A> function(allocator_arg_t, const A& a, const function& f); ++++...
++7 Throws: shall not throw exceptions if f's target is a function +pointer or a
+functioncallable object passed via +reference_wrapper. Otherwise, may throw bad_alloc or any +exception thrown by the copy constructor of the storedfunction+callable object. [Note: Implementations are encouraged to +avoid the use of dynamically allocated memory for smallfunction+callable objects, e.g., where f's target is an object +holding only a pointer or reference to an object and a member function pointer. +— end note] +- +
+ ++Change 20.8.14.2.1 [func.wrap.func.con]/11 as indicated: +
+ ++template<class F> function(F f); +template <class F, class A> function(allocator_arg_t, const A& a, F f); ++++...
++11 [..] [Note: implementations are encouraged to avoid the use of dynamically +allocated memory for small
+functioncallable objects, for +example, where f's target is an object holding only a pointer or +reference to an object and a member function pointer. — end note] +- +
+ ++Change 20.8.14.2.4 [func.wrap.func.inv]/3 as indicated: +
+ ++R operator()(ArgTypes... args) const ++++...
++3 Throws: bad_function_call if !*this; otherwise, any +exception thrown by the wrapped
+functioncallable object. +- +
+ ++Change 20.8.14.2.5 [func.wrap.func.targ]/3 as indicated: +
+ ++template<typename T> T* target(); +template<typename T> const T* target() const; ++++...
++3 Requires: T shall be a
+function objecttype that is +Callable (20.8.14.2 [func.wrap.func]) for parameter types ArgTypes +and return type R. +- +
+ ++Change 23.2.4 [associative.reqmts]/2 as indicated: [The suggested +removal seems harmless, because 25.4 [alg.sorting]1 already clarifies +that Compare is a function object type. Nevertheless it is recommended, +because the explicit naming of "pointer to function" is misleading] +
+ ++2 Each associative container is parameterized on Key and an ordering +relation Compare that induces a strict weak ordering (25.4 [alg.sorting]) on elements of Key. In addition, map +and multimap associate an arbitrary type T with the +Key. The object of type Compare is called the comparison +object of a container.+This comparison object may be a pointer to function +or an object of a type with an appropriate function call operator.+- +
+ ++Change 23.2.5 [unord.req]/3 as indicated: +
+ ++3 Each unordered associative container is parameterized by Key, by a +function object type Hash that acts as a hash function for +values of type Key, and by a binary predicate Pred that +induces an equivalence relation on values of type Key. [..] ++- +
+ ++Change 25.1 [algorithms.general]/7 as indicated: [The intent is to +bring this part in sync with 20.8 [function.objects]] +
+ ++7 The Predicate parameter is used whenever an algorithm expects a +function object (20.8 [function.objects]) that when applied +to the result of dereferencing the corresponding iterator returns a value +testable as true. In other words, if an algorithm takes Predicate +pred as its argument and first as its iterator argument, it should +work correctly in the construct if (pred(*first)){...}. The function +object pred shall not apply any nonconstant function through the +dereferenced iterator.+This function object may be a pointer to function, +or an object of a type with an appropriate function call operator.+- +
+ ++Change 20.9.9.2 [unique.ptr.single]/1 as indicated: +
+ ++1 The default type for the template parameter D is +default_delete. A client-supplied template argument D shall be +a function+pointer or functorobject type for which, given +a value d of type D and a pointer ptr of type +T*, the expression d(ptr) is valid and has the effect of +deallocating the pointer as appropriate for that deleter. D may also be +an lvalue-reference to a deleter. +
+871. Iota's requirements on T are too strong
+Section: 26.7.5 [numeric.iota] Status: WP + Submitter: Daniel Krügler Opened: 2008-08-20 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++According to the recent WP +N2691, +26.7.5 [numeric.iota]/1, the requires clause +of std::iota says: +
+ ++T shall meet the requirements of CopyConstructible and Assignable types, and +shall be convertible to ForwardIterator's value type.[..] ++ ++Neither CopyConstructible nor Assignable is needed, instead MoveConstructible +seems to be the correct choice. I guess the current wording resulted as an +artifact from comparing it with similar numerical algorithms like accumulate. +
+ ++Note: If this function will be conceptualized, the here proposed +MoveConstructible +requirement can be removed, because this is an implied requirement of +function arguments, see +N2710/[temp.req.impl]/3, last bullet. +
+ +[ +post San Francisco: +]
+ + ++Issue pulled by author prior to review. ++ +[ +2009-07-30 Daniel reopened: +]
+ + ++with the absence of concepts, this issue (closed) is valid again and I +suggest to reopen it. +I also revised by proposed resolution based on N2723 wording: ++ +[ +2009-10 Santa Cruz: +]
+ + ++Change 'convertible' to 'assignable', Move To Ready. ++ + + +Proposed resolution:
++Change the first sentence of 26.7.5 [numeric.iota]/1: +
+ ++Requires: T shall+ + + + + + + + +meet the requirements of CopyConstructible and +Assignable types, and shallbe +assignable to ForwardIterator's value type. [..] +
+872. move_iterator::operator[] has wrong return type
+Section: 24.5.3.3.12 [move.iter.op.index] Status: WP + Submitter: Doug Gregor Opened: 2008-08-21 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++move_iterator's operator[] is declared as: +
+ ++ +reference operator[](difference_type n) const; ++This has the same problem that reverse_iterator's operator[] used to +have: if the underlying iterator's operator[] returns a proxy, the +implicit conversion to value_type&& could end up referencing a temporary +that has already been destroyed. This is essentially the same issue that +we dealt with for reverse_iterator in DR 386. +
+ +[ +2009-07-28 Reopened by Alisdair. No longer solved by concepts. +]
+ + +[ +2009-08-15 Howard adds: +]
+ + ++I recommend closing this as a duplicate of 1051 which addresses +this issue for both move_iterator and reverse_iterator. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. Note that if 1051 is reopened, it may yield a +better resolution, but 1051 is currently marked NAD. ++ + + +Proposed resolution:
++In 24.5.3.1 [move.iterator] and 24.5.3.3.12 [move.iter.op.index], change the declaration of +move_iterator's operator[] to: +
+ ++ + + +referenceunspecified operator[](difference_type n) const; +Rationale:
+[ +San Francisco: +]
+ + ++NAD Editorial, see +N2777. ++ + + +
876. basic_string access operations should give stronger guarantees
Section: 21.4 [basic.string] Status: WP - Submitter: Daniel Krügler Opened: 2008-08-22 Last modified: 2009-10-26
+ Submitter: Daniel Krügler Opened: 2008-08-22 Last modified: 2010-10-29View all other issues in [basic.string].
View all issues with WP status.
Discussion:
@@ -39265,7 +50685,8 @@ in [0, size()].
878. forward_list preconditions
Section: 23.3.3 [forwardlist] Status: WP - Submitter: Martin Sebor Opened: 2008-08-23 Last modified: 2009-07-18
+ Submitter: Martin Sebor Opened: 2008-08-23 Last modified: 2010-10-29 +View all other issues in [forwardlist].
View all issues with WP status.
Discussion:
@@ -39347,8 +50768,8 @@ dereferenceable
881. shared_ptr conversion issue
-Section: 20.8.15.2.1 [util.smartptr.shared.const] Status: WP - Submitter: Peter Dimov Opened: 2008-08-30 Last modified: 2009-10-26
+Section: 20.9.10.2.1 [util.smartptr.shared.const] Status: WP + Submitter: Peter Dimov Opened: 2008-08-30 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared.const].
View all issues with WP status.
Discussion:
@@ -39417,8 +50838,8 @@ in order to actually make the example in 882. duration non-member arithmetic requirements -Section: 20.9.3.5 [time.duration.nonmember] Status: CD1 - Submitter: Howard Hinnant Opened: 2008-09-08 Last modified: 2008-09-26
+Section: 20.11.3.5 [time.duration.nonmember] Status: CD1 + Submitter: Howard Hinnant Opened: 2008-09-08 Last modified: 2010-10-29
View all other issues in [time.duration.nonmember].
View all issues with CD1 status.
Discussion:
@@ -39565,14 +50986,14 @@ It is not necessary for both Reps to be implicitly convertible t the CR. It is only necessary for the rhs Rep to be implicitly convertible to the CR. The Rep within the duration should be allowed to only be explicitly convertible to the CR. The -explicit-conversion-requirement is covered under 20.9.3.7 [time.duration.cast]. +explicit-conversion-requirement is covered under 20.11.3.7 [time.duration.cast].Proposed resolution:
-Change the requirements clauses under 20.9.3.5 [time.duration.nonmember]: +Change the requirements clauses under 20.11.3.5 [time.duration.nonmember]:
@@ -39620,8 +51041,7 @@ be an instantiation of duration. Diagnostic required.
883. swap circular definition
Section: 23 [containers] Status: WP - Submitter: Alisdair Meredith Opened: 2008-09-10 Last modified: 2009-10-26
-View other active issues in [containers].
+ Submitter: Alisdair Meredith Opened: 2008-09-10 Last modified: 2010-10-29View all other issues in [containers].
View all issues with WP status.
Discussion:
@@ -39707,15 +51127,215 @@ Notes: the algorithmsswap(),equal() and +
+884. shared_ptr swap
+Section: 20.9.10.2.4 [util.smartptr.shared.mod] Status: Resolved + Submitter: Jonathan Wakely Opened: 2008-09-15 Last modified: 2010-11-20
+View all issues with Resolved status.
+Discussion:
++ +#include <memory> +#include <cassert> + +struct A { }; +struct B : A { }; + +int main() +{ + std::shared_ptr<A> pa(new A); + std::shared_ptr<B> pb(new B); + std::swap<A>(pa, pb); // N.B. no argument deduction + assert( pa.get() == pb.get() ); + return 0; +} ++Is this behaviour correct (I believe it is) and if so, is it +unavoidable, or not worth worrying about? +
+ ++This calls the lvalue/rvalue swap overload for shared_ptr: +
+ ++ +template<class T> void swap( shared_ptr<T> & a, shared_ptr<T> && b ); ++silently converting the second argument from shared_ptr<B> to +shared_ptr<A> and binding the rvalue ref to the produced temporary. +
+ ++This is not, in my opinion, a shared_ptr problem; it is a general issue +with the rvalue swap overloads. Do we want to prevent this code from +compiling? If so, how? +
+ ++Perhaps we should limit rvalue args to swap to those types that would +benefit from the "swap trick". Or, since we now have shrink_to_fit(), just +eliminate the rvalue swap overloads altogether. The original motivation +was: +
+ ++ +N1690. + +vector<A> v = ...; +... +swap(v, vector<A>(v)); +[ +Batavia (2009-05): +]
+ ++We agree with the proposed resolution. +Move to+ + +NAD EditorialResolved. +Proposed resolution:
++Recommend
+ + + + + +NAD EditorialResolved, fixed by +N2844. +
+885. pair assignment
+Section: 20.3.5 [pairs] Status: WP + Submitter: Alisdair Meredith Opened: 2008-09-15 Last modified: 2010-10-29
+View all other issues in [pairs].
+View all issues with WP status.
+Discussion:
++ +20.2.3 pairs +Missing assignemnt operator: +template<class U , class V> + requires CopyAssignable<T1, U> && CopyAssignable<T2, V> + pair& operator=(pair<U , V> const & p ); ++Well, that's interesting. This assignment operator isn't in the +current working paper, either. Perhaps we deemed it acceptable to +build a temporary of type pair from pair<U, V>, then move-assign +from that temporary? +
++It sounds more like an issue waiting to be opened, unless you want to plug +it now. As written we risk moving from lvalues. +
+ +[ +San Francisco: +]
+ + +++ ++Would be NAD if better ctors fixed it. +
++Related to 811. +
+[ +post San Francisco: +]
+ + ++Possibly NAD Editorial, solved by +N2770. ++ +[ +2009-05-25 Alisdair adds: +]
+ + ++Issue 885 was something I reported while reviewing the library concepts +documents ahead of San Francisco. The missing operator was added as part of +the paper adopted at that meeting +(N2770) +and I can confirm this operator is +present in the current working paper. I recommend NAD. ++ +[ +2009-07 Frankfurt +]
+ + ++We agree with the intent, but we need to wait for the dust to settle on concepts. ++ +[ +2010-03-11 Stefanus provided wording. +]
+ + +[ +2010 Pittsburgh: Moved to Ready for Pittsburgh. +]
+ + + + +Proposed resolution:
++Add the following declaration 20.3.5.2 [pairs.pair], before the +declaration of pair& operator=(pair&& p);: +
+ ++ +template<class U, class V> pair& operator=(const pair<U, V>& p); ++Add the following description to 20.3.5.2 [pairs.pair] after paragraph 11 (before +the description of pair& operator=(pair&& p);): +
+ ++ + + + + +template<class U, class V> pair& operator=(const pair<U, V>& p); +++++Requires: T1 shall satisfy the requirements of +CopyAssignable from U. T2 shall +satisfy the requirements of CopyAssignable from V. +
++Effects: Assigns p.first to first and +p.second to second. +
++Returns: *this. +
+
886. tuple construction
-Section: 20.5.2.1 [tuple.cnstr] Status: WP - Submitter: Alisdair Meredith Opened: 2008-09-15 Last modified: 2009-10-26
+Section: 20.4.2.1 [tuple.cnstr] Status: WP + Submitter: Alisdair Meredith Opened: 2008-09-15 Last modified: 2010-10-29
View all other issues in [tuple.cnstr].
View all issues with WP status.
Discussion:
-20.5.2.1 [tuple.cnstr]: +20.4.2.1 [tuple.cnstr]:
Effects: Default initializes each element. @@ -39754,7 +51374,7 @@ Request resolution text from Alisdair.@@ -39792,7 +51412,7 @@ Move to Ready.-This issue relates to Issue 868 default construction and value-initialization. +This issue relates to Issue 868 default construction and value-initialization.
Proposed resolution:
-Change p2 in Construction 20.5.2.1 [tuple.cnstr]: +Change p2 in Construction 20.4.2.1 [tuple.cnstr]:
requires DefaultConstructible<Types>... tuple(); @@ -39812,7 +51432,9 @@ Change p2 in Construction 20.5.2.1 [tuple.cnstr]:
888. this_thread::yield too strong
Section: 30.3.2 [thread.thread.this] Status: WP - Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2009-07-18
+ Submitter: Lawrence Crowl Opened: 2008-09-15 Last modified: 2010-10-29 +View other active issues in [thread.thread.this].
+View all other issues in [thread.thread.this].
View all issues with WP status.
Discussion:
@@ -39860,7 +51482,7 @@ the opportunity to reschedule.
890. Improving <system_error> initialization
Section: 19.5.1 [syserr.errcat] Status: WP - Submitter: Beman Dawes Opened: 2008-09-14 Last modified: 2009-07-18
+ Submitter: Beman Dawes Opened: 2008-09-14 Last modified: 2010-10-29View all issues with WP status.
Discussion:
@@ -39982,7 +51604,7 @@ been implemented. Seems to be widespread consensus. Move to Tentative Ready.
Proposed resolution:
-Change 17.6.4.13 [value.error.codes] Value of error codes as indicated:
+Change 17.6.4.14 [value.error.codes] Value of error codes as indicated:
Certain functions in the C++ standard library report errors via a std::error_code (19.4.2.2) object. That object's category() member shall @@ -40167,10 +51789,317 @@ function shall return a pointer to the string "iostream".
+
+891. std::thread, std::call_once issue
+Section: 30.3.1.2 [thread.thread.constr], 30.4.4.2 [thread.once.callonce] Status: WP + Submitter: Peter Dimov Opened: 2008-09-15 Last modified: 2010-10-29
+View all other issues in [thread.thread.constr].
+View all issues with WP status.
+Discussion:
++I notice that the vararg overloads of std::thread and std::call_once +(N2723 30.3.1.2 [thread.thread.constr] and 30.4.4.2 [thread.once.callonce]) are no longer specified in terms of +std::bind; instead, some of the std::bind wording has been inlined into +the specification. +
++There are two problems with this. +
++First, the specification (and implementation) in terms of std::bind allows, for example: +
+ ++ +std::thread th( f, 1, std::bind( g ) ); ++which executes f( 1, g() ) in a thread. This can be useful. The +"inlined" formulation changes it to execute f( 1, bind(g) ) in a thread. +
++Second, assuming that we don't want the above, the specification has copied the wording +
+ ++INVOKE(func, w1, w2, ..., wN) (20.6.2) shall be a valid +expression for some values w1, w2, ..., wN ++ ++but this is not needed since we know that our argument list is args; it should simply be +
+ ++INVOKE(func, args...) (20.6.2) shall be a valid expression ++ +[ +Summit: +]
+ + ++Move to open. ++ +[ +Post Summit Anthony provided proposed wording. +]
+ + +[ +2009-07 Frankfurt +]
+ + ++Leave Open. Await decision for thread variadic constructor. ++ +[ +2009-10 Santa Cruz: +]
+ + ++See proposed wording for 929 for this, for the formulation +on how to solve this. 929 modifies the thread constructor to +have "pass by value" behavior with pass by reference efficiency through the use +of the decay trait. This same formula would be useful for call_once. ++ +[ +2010-02-11 Anthony updates wording. +]
+ + +[ +2010-02-12 Moved to Tentatively Ready after 5 postive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Modify 30.4.4.2 [thread.once.callonce] p1-p2 with the following: +
+ +++ + + + + + + +template<class Callable, class ...Args> + void call_once(once_flag& flag, Callable&& func, Args&&... args);++ ++ ++Given a function as follows: +
+ ++ ++template<typename T> typename decay<T>::type decay_copy(T&& v) + { return std::forward<T>(v); } ++1 Requires:
+ +The template parametersCallable and each +Ti in Args shallbe CopyConstructible if an +lvalue and otherwisesatisfy the +MoveConstructible requirements. +INVOKE(decay_copy(std::forward<Callable>(func), +w1, w2, ..., wN+decay_copy(std::forward<Args>(args))...) (20.8.2 [func.require]) shall be a valid expressionfor some values w1, +w2, ..., wN, where N == sizeof...(Args). ++2 Effects: Calls to call_once on the same once_flag +object are serialized. If there has been a prior effective call to +call_once on the same once_flag object, the call to +call_once returns without invoking func. If there has been no +prior effective call to call_once on the same once_flag +object,
+ +the argument func (or a copy thereof) is called as if by +invoking func(args)+INVOKE(decay_copy(std::forward<Callable>(func)), +decay_copy(std::forward<Args>(args))...) is executed. The call +to call_once is effective if and only iffunc(args)+INVOKE(decay_copy(std::forward<Callable>(func)), +decay_copy(std::forward<Args>(args))...) returns without +throwing an exception. If an exception is thrown it is propagated to the caller. +
+893. std::mutex issue
+Section: 30.4.1.2.1 [thread.mutex.class] Status: WP + Submitter: Peter Dimov Opened: 2008-09-15 Last modified: 2010-10-29
+View all other issues in [thread.mutex.class].
+View all issues with WP status.
+Duplicate of: 905
+Discussion:
++30.4.1.2.1 [thread.mutex.class]/27 (in +N2723) +says that the behavior is undefined if: +
++
+- a thread that owns a mutex object calls lock() or +try_lock() on that object
++I don't believe that this is right. Calling lock() or try_lock() on a +locked mutex is well defined in the general case. try_lock() is required +to fail and return false. lock() is required to either throw an +exception (and is allowed to do so if it detects deadlock) or to block +until the mutex is free. These general requirements apply regardless of +the current owner of the mutex; they should apply even if it's owned by +the current thread. +
++Making double lock() undefined behavior probably can be justified (even +though I'd still disagree with the justification), but try_lock() on a +locked mutex must fail. +
+ +[ +Summit: +]
+ +++ ++Move to open. Proposed resolution: +
++
+- +In 30.4.1 [thread.mutex.requirements] paragraph 12, change the error +condition for resource_deadlock_would_occur to: "if the implementation +detects that a deadlock would occur" +
+- +Strike 30.4.1.2.1 [thread.mutex.class] paragraph 3 bullet 2 "a thread that owns a mutex object +calls lock() or try_lock() on that object, or" +
+[ +2009-07 Frankfurt +]
+ + ++Move to Review. Alisdair to provide note. ++ +[ +2009-07-31 Alisdair provided note. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ +[ +2009-11-18 Peter Opens: +]
+ + +++ ++I don't believe that the proposed note: +
+ ++[Note: a program may deadlock if the thread that owns a mutex +object calls lock() or try_lock() on that object. If the program can +detect the deadlock, a resource_deadlock_would_occur error condition may +be observed. — end note] ++ ++is entirely correct. "or try_lock()" should be removed, because +try_lock is non-blocking and doesn't deadlock; it just returns +false when it fails to lock the mutex. +
+ +[ +Howard: I've set to Open and updated the wording per Peter's suggestion. +]
+ + +[ +2009-11-18 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++In 30.4.1 [thread.mutex.requirements] paragraph 12 change: +
+ +++ ++
+- ...
+- +resource_deadlock_would_occur -- if the
+current thread already owns the mutex and is able +to detect itimplementation detects that a deadlock would occur. +- ...
++Strike 30.4.1.2.1 [thread.mutex.class] paragraph 3 bullet 2: +
+++ ++-3- The behavior of a program is undefined if: +
++
+- ...
+- +
+a thread that owns a mutex object calls lock() or try_lock() on that object, or+- ...
++Add the following note after p3 30.4.1.2.1 [thread.mutex.class] +
+ ++[Note: a program may deadlock if the thread that owns a mutex +object calls lock() on that object. If the implementation can detect the +deadlock, a resource_deadlock_would_occur error condition may be +observed. — end note] ++ + + + + +
894. longjmp and destructors
Section: 18.10 [support.runtime] Status: WP - Submitter: Lawrence Crowl, Alisdair Meredith Opened: 2008-09-17 Last modified: 2009-03-09
+ Submitter: Lawrence Crowl, Alisdair Meredith Opened: 2008-09-17 Last modified: 2010-10-29View all other issues in [support.runtime].
View all issues with WP status.
Discussion:
@@ -40199,10 +52128,234 @@ any automatic objects. +
+896. Library thread safety issue
+Section: 20.9.10.2 [util.smartptr.shared] Status: WP + Submitter: Hans Boehm Opened: 2008-09-16 Last modified: 2010-10-29
+View all other issues in [util.smartptr.shared].
+View all issues with WP status.
+Discussion:
++It is unclear whether shared_ptr is thread-safe in the sense that +multiple threads may simultaneously copy a shared_ptr. However this +is a critical piece of information for the client, and it has significant +impact on usability for many applications. (Detlef Vollman thinks it +is currently clear that it is not thread-safe. Hans Boehm thinks +it currently requires thread safety, since the use_count is not an +explicit field, and constructors and assignment take a const reference +to an existing shared_ptr.) +
+ ++Pro thread-safety: +
++Many multi-threaded usages are impossible. A thread-safe version can +be used to destroy an object when the last thread drops it, something +that is often required, and for which we have no other easy mechanism. +
++Against thread-safety: +
++The thread-safe version is well-known to be far more expensive, even +if used by a single thread. Many applications, including all single-threaded +ones, do not care. +
+ +[ +San Francisco: +]
+ + +++ ++Beman: this is a complicated issue, and would like to move this to Open +and await comment from Peter Dimov; we need very careful and complete +rationale for any decision we make; let's go slow +
++Detlef: I think that shared_ptr should not be thread-safe. +
++Hans: When you create a thread with a lambda, it in some cases makes it +very difficult for the lambda to reference anything in the heap. It's +currently ambiguous as to whether you can use a shared_ptr to get at an +object. +
++Leave in Open. Detlef will submit an alternative proposed resolution +that makes shared_ptr explicitly unsafe. +
++A third option is to support both threadsafe and non-safe share_ptrs, +and to let the programmer decide which behavior they want. +
+ ++Beman: Peter, do you support the PR? +
+ ++Peter: +
+++ ++Yes, I support the proposed resolution, and I certainly oppose any +attempts to make shared_ptr thread-unsafe. +
++I'd mildly prefer if +
++[Note: This is true in spite of that fact that such functions often +modify use_count() --end note] +++is changed to +
++[Note: This is true in spite of that fact that such functions often +cause a change in use_count() --end note] +++(or something along these lines) to emphasise that use_count() is not, +conceptually, a variable, but a return value. +
+[ +2009-07 Frankfurt +]
+ + +++ ++Vote: Do we want one thread-safe shared pointer or two? If two, one +would allow concurrent construction and destruction of shared pointers, +and one would not be thread-safe. If one, then it would be thread-safe. +
++No concensus on that vote. +
++Hans to improve wording in consultation with Pete. Leave Open. +
+[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. Ask Editor to clear up wording a little when integrating to +make it clear that the portion after the first comma only applies for +the presence of data races. ++ +[ +2009-10-24 Hans adds: +]
+ + +++ ++I think we need to pull 896 back from ready, unfortunately. My wording +doesn't say the right thing. +
+ ++I suspect we really want to say something along the lines of: +
+ ++For purposes of determining the presence of a data race, member +functions access and modify only the shared_ptr and +weak_ptr objects themselves and not objects they refer to. +Changes in use_count() do not reflect modifications that can +introduce data races. ++ ++But I think this needs further discussion by experts to make sure this +is right. +
+ ++Detlef and I agree continue to disagree on the resolution, but I think +we agree that it would be good to try to expedite this so that it can be +in CD2, since it's likely to generate NB comments no matter what we do. +And lack of clarity of intent is probably the worst option. I think it +would be good to look at this between meetings. +
+[ +2010-01-20 Howard: +]
+ + +++ ++I've moved Hans' suggested wording above into the proposed resolution section +and preserved the previous wording here: +
+ ++++Make it explicitly thread-safe, in this weak sense, as I believe was intended: +
++Insert in 20.9.10.2 [util.smartptr.shared], before p5: +
++++For purposes of determining the presence of a data race, +member functions do not modify const shared_ptr and +const weak_ptr arguments, nor any objects they +refer to. [Note: This is true in spite of that fact that such functions often +cause a change in use_count() --end note] +
++On looking at the text, I'm not sure we need a similar disclaimer +anywhere else, since nothing else has the problem with the modified +use_count(). I think Howard arrived at a similar conclusion. +
+[ +2010 Pittsburgh: Moved to Ready for Pittsburgh +]
+ + + + +Proposed resolution:
+ ++Insert a new paragraph at the end of 20.9.10.2 [util.smartptr.shared]: +
+ ++For purposes of determining the presence of a data race, member functions access +and modify only the shared_ptr and weak_ptr objects themselves +and not objects they refer to. Changes in use_count() do not reflect +modifications that can introduce data races. ++ + + + +
898. Small contradiction in n2723 to forward to committee
Section: 23.3.3.5 [forwardlist.ops] Status: WP - Submitter: Arch Robison Opened: 2008-09-08 Last modified: 2009-07-18
+ Submitter: Arch Robison Opened: 2008-09-08 Last modified: 2010-10-29View all other issues in [forwardlist.ops].
View all issues with WP status.
Discussion:
@@ -40259,8 +52412,8 @@ comparisons.
899. Adjusting shared_ptr for nullptr_t
-Section: 20.8.15.2.2 [util.smartptr.shared.dest] Status: WP - Submitter: Peter Dimov Opened: 2008-09-18 Last modified: 2009-07-18
+Section: 20.9.10.2.2 [util.smartptr.shared.dest] Status: WP + Submitter: Peter Dimov Opened: 2008-09-18 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared.dest].
View all issues with WP status.
Discussion:
@@ -40270,13 +52423,13 @@ James Dennett, message c++std-lib-22442:The wording below addresses one case of this, but opening an issue to address the need to sanity check uses of the term "pointer" -in 20.8.15.2 [util.smartptr.shared] would be a good thing. +in 20.9.10.2 [util.smartptr.shared] would be a good thing.There's one more reference, in ~shared_ptr; we can apply your suggested change to it, too. That is:
-Change 20.8.15.2.2 [util.smartptr.shared.dest]/1 second bullet from: +Change 20.9.10.2.2 [util.smartptr.shared.dest]/1 second bullet from:
Otherwise, if *this owns a pointer p and a deleter d, d(p) is called. @@ -40305,7 +52458,7 @@ Batavia (2009-05):Peter Dimov notes the analogous change has already been made to "the new nullptr_t taking constructors -in 20.8.15.2.1 [util.smartptr.shared.const] p9-13." +in 20.9.10.2.1 [util.smartptr.shared.const] p9-13."
We agree with the proposed resolution. @@ -40316,7 +52469,7 @@ Move to Tentatively Ready.
Proposed resolution:
-Change 20.8.15.2.2 [util.smartptr.shared.dest]/1 second bullet: +Change 20.9.10.2.2 [util.smartptr.shared.dest]/1 second bullet:
@@ -40333,10 +52486,222 @@ deleter d, d(p) is called. +
+900. stream move-assignment
+Section: 27.9.1.8 [ifstream.assign] Status: WP + Submitter: Niels Dekker Opened: 2008-09-20 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++It +appears that we have an issue similar to issue 675 regarding the move-assignment of +stream types. For example, when assigning to an std::ifstream, +ifstream1, it seems preferable to close the file originally held by +ifstream1: +
+ ++ +ifstream1 = std::move(ifstream2); ++The current Draft +(N2723) +specifies that the move-assignment of +stream types like ifstream has the same effect as a swap: +
+ +++ ++Assign and swap 27.9.1.8 [ifstream.assign] +
+basic_ifstream& operator=(basic_ifstream&& rhs); +++Effects: swap(rhs). ++[ +Batavia (2009-05): +]
+ +++ ++Howard agrees with the analysis and the direction proposed. +
++Move to Open pending specific wording to be supplied by Howard. +
+[ +2009-07 Frankfurt: +]
+ + ++Howard is going to write wording. ++ +[ +2009-07-26 Howard provided wording. +]
+ + +[ +2009-09-13 Niels adds: +]
+ + ++Note: The proposed change of 27.9.1.3 [filebuf.assign]/1 depends on the +resolution of LWG 1204, which allows implementations to assume that +*this and rhs refer to different objects. ++ +[ +2009 Santa Cruz: +]
+ + ++Leave as Open. Too closely related to 911 to move on at this time. ++ +[ +2010 Pittsburgh: +]
+ + ++Moved to Ready for Pittsburgh. ++ + + +Proposed resolution:
+ ++Change 27.8.1.2 [stringbuf.assign]/1: +
+ ++ +basic_stringbuf& operator=(basic_stringbuf&& rhs); +++-1- Effects:+swap(rhs).+After the move assignment *this reflects the same observable +state it would have if it had been move constructed from rhs +(27.8.1.1 [stringbuf.cons]). + ++Change 27.8.2.2 [istringstream.assign]/1: +
+ ++ +basic_istringstream& operator=(basic_istringstream&& rhs); +++-1- Effects:+swap(rhs).+Move assigns the base and members of *this with the respective +base and members of rhs. + ++Change 27.8.3.2 [ostringstream.assign]/1: +
+ ++ +basic_ostringstream& operator=(basic_ostringstream&& rhs); +++-1- Effects:+swap(rhs).+Move assigns the base and members of *this with the respective +base and members of rhs. + ++Change 27.8.5.1 [stringstream.assign]/1: +
+ ++ +basic_stringstream& operator=(basic_stringstream&& rhs); +++-1- Effects:+swap(rhs).+Move assigns the base and members of *this with the respective +base and members of rhs. + ++Change 27.9.1.3 [filebuf.assign]/1: +
+ ++ +basic_filebuf& operator=(basic_filebuf&& rhs); +++-1- Effects:+swap(rhs).+Begins by calling this->close(). +After the move assignment *this reflects the same observable +state it would have if it had been move constructed from rhs +(27.9.1.2 [filebuf.cons]). + ++Change 27.9.1.8 [ifstream.assign]/1: +
+ ++ +basic_ifstream& operator=(basic_ifstream&& rhs); +++-1- Effects:+swap(rhs).+Move assigns the base and members of *this with the respective +base and members of rhs. ++Change 27.9.1.12 [ofstream.assign]/1: +
+ ++ +basic_ofstream& operator=(basic_ofstream&& rhs); +++-1- Effects:+swap(rhs).+Move assigns the base and members of *this with the respective +base and members of rhs. ++Change 27.9.1.16 [fstream.assign]/1: +
+ ++ + + + + +basic_fstream& operator=(basic_fstream&& rhs); +++-1- Effects:+swap(rhs).+Move assigns the base and members of *this with the respective +base and members of rhs. +
904. result_of argument types
-Section: 20.7.4 [func.ret] Status: WP - Submitter: Jonathan Wakely Opened: 2008-09-10 Last modified: 2009-07-18
+Section: X [func.ret] Status: WP + Submitter: Jonathan Wakely Opened: 2008-09-10 Last modified: 2010-10-29
View all other issues in [func.ret].
View all issues with WP status.
Discussion:
@@ -40389,7 +52754,7 @@ Recommend Tentatively Ready.Proposed resolution:
-Change 20.7.4 [func.ret], p1: +Change X [func.ret], p1:
@@ -40404,8 +52769,8 @@ and rvalues otherwise.
907. Bitset's immutable element retrieval is inconsistently defined
-Section: 20.3.7.2 [bitset.members] Status: WP - Submitter: Daniel Krügler Opened: 2008-09-26 Last modified: 2009-07-18
+Section: 20.5.2 [bitset.members] Status: WP + Submitter: Daniel Krügler Opened: 2008-09-26 Last modified: 2010-10-29
View all other issues in [bitset.members].
View all issues with WP status.
Discussion:
@@ -40413,8 +52778,8 @@ and rvalues otherwise. The current standard 14882::2003(E) as well as the current draft N2723 have in common a contradiction of the operational semantics -of member function test 20.3.7.2 [bitset.members]/56-58 and the immutable -member operator[] overload 20.3.7.2 [bitset.members]/64-66 (all references +of member function test 20.5.2 [bitset.members]/56-58 and the immutable +member operator[] overload 20.5.2 [bitset.members]/64-66 (all references are defined in terms of N2723): @@ -40496,8 +52861,8 @@ Proposed alternatives:Remove the constexpr specifier in front of operator[] overload and undo that of member test (assuming 720 is accepted) in both the -class declaration 20.3.7 [template.bitset]/1 and in the member description -before 20.3.7.2 [bitset.members]/56 and before /64 to read: +class declaration 20.5 [template.bitset]/1 and in the member description +before 20.5.2 [bitset.members]/56 and before /64 to read:
constexprbool test(size_t pos) const; .. @@ -40527,8 +52892,8 @@ position nothing.Undo the addition of the constexpr specifier to the test member -function in both class declaration 20.3.7 [template.bitset]/1 and in the -member description before 20.3.7.2 [bitset.members]/56, assuming that 720 +function in both class declaration 20.5 [template.bitset]/1 and in the +member description before 20.5.2 [bitset.members]/56, assuming that 720 was applied.
@@ -40572,12 +52937,12 @@ Move to Tentatively Ready.Proposed resolution:
-+
Undo the addition of the constexpr specifier to the test member -function in both class declaration 20.3.7 [template.bitset]/1 and in the -member description before 20.3.7.2 [bitset.members]/56, assuming that 720 +function in both class declaration 20.5 [template.bitset]/1 and in the +member description before 20.5.2 [bitset.members]/56, assuming that 720 was applied.
@@ -40603,7 +52968,7 @@ has the value one, otherwise false.
909. regex_token_iterator should use initializer_list
Section: 28.12.2 [re.tokiter] Status: WP - Submitter: Daniel Krügler Opened: 2008-09-26 Last modified: 2009-07-18
+ Submitter: Daniel Krügler Opened: 2008-09-26 Last modified: 2010-10-29View all other issues in [re.tokiter].
View all issues with WP status.
Discussion:
@@ -40705,7 +53070,7 @@ by the iterator range [&submatches,&submatches + N)Proposed resolution:
-+
@@ -40745,16 +53110,667 @@ by the iterator range [&submatches,&submatches + N) +
+911. I/O streams and move/swap semantic
+Section: 27.7.1 [input.streams], 27.7.2 [output.streams] Status: WP + Submitter: Alberto Ganesh Barbati Opened: 2008-09-29 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++Class template basic_istream, basic_ostream and basic_iostream +implements public move constructors, move assignment operators and swap +method and free functions. This might induce both the user and the +compiler to think that those types are MoveConstructible, MoveAssignable +and Swappable. However, those class templates fail to fulfill the user +expectations. For example: +
+ ++ +std::ostream os(std::ofstream("file.txt")); +assert(os.rdbuf() == 0); // buffer object is not moved to os, file.txt has been closed + +std::vector<std::ostream> v; +v.push_back(std::ofstream("file.txt")); +v.reserve(100); // causes reallocation +assert(v[0].rdbuf() == 0); // file.txt has been closed! + +std::ostream&& os1 = std::ofstream("file1.txt"); +os1 = std::ofstream("file2.txt"); +os1 << "hello, world"; // still writes to file1.txt, not to file2.txt! + +std::ostream&& os1 = std::ofstream("file1.txt"); +std::ostream&& os2 = std::ofstream("file2.txt"); +std::swap(os1, os2); +os1 << "hello, world"; // writes to file1.txt, not to file2.txt! ++This is because the move constructor, the move assignment operator and +swap are all implemented through calls to std::basic_ios member +functions move() and swap() that do not move nor swap the controlled +stream buffers. That can't happen because the stream buffers may have +different types. +
+ ++Notice that for basic_streambuf, the member function swap() is +protected. I believe that is correct and all of basic_istream, +basic_ostream, basic_iostream should do the same as the move ctor, move +assignment operator and swap member function are needed by the derived +fstreams and stringstreams template. The free swap functions for +basic_(i|o|io)stream templates should be removed for the same reason. +
+ +[ +Batavia (2009-05): +]
+ +++ ++We note that the rvalue swap functions have already been removed. +
++Bill is unsure about making the affected functions protected; +he believes they may need to be public. +
++We are also unsure about removing the lvalue swap functions as proposed. +
++Move to Open. +
+[ +2009-07 Frankfurt: +]
+ + +++ ++It's not clear that the use case is compelling. +
++Howard: This needs to be implemented and tested. +
+[ +2009-07-26 Howard adds: +]
+ + +++ ++I started out thinking I would recommend NAD for this one. I've turned around +to agree with the proposed resolution (which I've updated to the current draft). +I did not fully understand Ganesh's rationale, and attempt to describe my +improved understanding below. +
+ ++The move constructor, move assignment operator, and swap function are different +for basic_istream, basic_ostream and basic_iostream +than other classes. A timely conversation with Daniel reminded me of this long +forgotten fact. These members are sufficiently different that they would be +extremely confusing to use in general, but they are very much needed for derived +clients. +
+ ++
+ +- +The move constructor moves everything but the rdbuf pointer. +
+- +The move assignment operator moves everything but the rdbuf pointer. +
+- +The swap function swaps everything but the rdbuf pointer. +
++The reason for this behavior is that for the std-derived classes (stringstreams, +filestreams), the rdbuf pointer points back into the class itself +(self referencing). It can't be swapped or moved. But this fact isn't born out +at the stream level. Rather it is born out at the fstream/sstream +level. And the lower levels just need to deal with that fact by not messing around +with the rdbuf pointer which is stored down at the lower levels. +
+ ++In a nutshell, it is very confusing for all of those who are not so intimately +related with streams that they've implemented them. And it is even fairly +confusing for some of those who have (including myself). I do not think it is +safe to swap or move istreams or ostreams because this will +(by necessary design) separate stream state from streambuffer state. Derived +classes (such as fstream and stringstream must be used to +keep the stream state and stream buffer consistently packaged as one unit during +a move or swap. +
+ ++I've implemented this proposal and am living with it day to day. +
+ +[ +2009 Santa Cruz: +]
+ + ++Leave Open. Pablo expected to propose alternative wording which would rename +move construction, move assignment and swap, and may or may not make them +protected. This will impact issue 900. ++ +[ +2010 Pittsburgh: +]
+ + ++Moved to Ready for Pittsburgh. ++ + + +Proposed resolution:
++27.7.1.1 [istream]: make the following member functions protected: +
+ ++ +basic_istream(basic_istream&& rhs); +basic_istream& operator=(basic_istream&& rhs); +void swap(basic_istream& rhs); ++Ditto: remove the swap free function signature +
+ ++ +// swap: +template <class charT, class traits> + void swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);++27.7.1.1.2 [istream.assign]: remove paragraph 4 +
+ ++ ++template <class charT, class traits> + void swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);+++Effects: x.swap(y).++27.7.1.5 [iostreamclass]: make the following member function protected: +
+ ++ +basic_iostream(basic_iostream&& rhs); +basic_iostream& operator=(basic_iostream&& rhs); +void swap(basic_iostream& rhs); ++Ditto: remove the swap free function signature +
+ ++ +template <class charT, class traits> + void swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);++27.7.1.5.3 [iostream.assign]: remove paragraph 3 +
+ ++ ++template <class charT, class traits> + void swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);+++Effects: x.swap(y).++27.7.2.1 [ostream]: make the following member function protected: +
+ ++ +basic_ostream(basic_ostream&& rhs); +basic_ostream& operator=(basic_ostream&& rhs); +void swap(basic_ostream& rhs); ++Ditto: remove the swap free function signature +
+ ++ +// swap: +template <class charT, class traits> + void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);++27.7.2.3 [ostream.assign]: remove paragraph 4 +
+ ++ + + + + + ++template <class charT, class traits> + void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);+++Effects: x.swap(y).+
+920. Ref-qualification support in the library
+Section: 20.8.13 [func.memfn] Status: WP + Submitter: Bronek Kozicki Opened: 2008-10-06 Last modified: 2010-10-29
+View all other issues in [func.memfn].
+View all issues with WP status.
+Duplicate of: 1230
+Discussion:
++Daniel Krügler wrote: +
+ +++ ++Shouldn't above list be completed for &- and &&-qualified +member functions This would cause to add: +
++ +template<Returnable R, class T, CopyConstructible... Args> +unspecified mem_fn(R (T::* pm)(Args...) &); +template<Returnable R, class T, CopyConstructible... Args> +unspecified mem_fn(R (T::* pm)(Args...) const &); +template<Returnable R, class T, CopyConstructible... Args> +unspecified mem_fn(R (T::* pm)(Args...) volatile &); +template<Returnable R, class T, CopyConstructible... Args> +unspecified mem_fn(R (T::* pm)(Args...) const volatile &); +template<Returnable R, class T, CopyConstructible... Args> +unspecified mem_fn(R (T::* pm)(Args...) &&); +template<Returnable R, class T, CopyConstructible... Args> +unspecified mem_fn(R (T::* pm)(Args...) const &&); +template<Returnable R, class T, CopyConstructible... Args> +unspecified mem_fn(R (T::* pm)(Args...) volatile &&); +template<Returnable R, class T, CopyConstructible... Args> +unspecified mem_fn(R (T::* pm)(Args...) const volatile &&); ++yes, absolutely. Thanks for spotting this. Without this change mem_fn +cannot be initialized from pointer to ref-qualified member function. I +believe semantics of such function pointer is well defined. +
+ +[ +Post Summit Daniel provided wording. +]
+ + +[ +Batavia (2009-05): +]
+ +++ ++We need to think about whether we really want to go down the proposed path +of combinatorial explosion. +Perhaps a Note would suffice. +
++We would really like to have an implementation before proceeding. +
++Move to Open, and recommend this be deferred until after the next +Committee Draft has been issued. +
+[ +2009-10-10 Daniel updated wording to post-concepts. +]
+ + ++1230 has a similar proposed resolution ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++
+ + + + + + +- +
+ ++Change 20.8 [function.objects]/2, header +<functional> synopsis as follows: +
+ ++// 20.7.14, member function adaptors: +template<class R, class T> unspecified mem_fn(R T::*); + +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...)); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile); + +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) &); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const &); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile &); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile &); + +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) &&); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const &&); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) volatile &&); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::*)(Args...) const volatile &&); +- +
+ ++Change the prototype list of 20.8.13 [func.memfn] as follows [NB: The +following text, most notably p.2 and p.3 which +discuss influence of the cv-qualification on the definition of the +base class's first template parameter remains +unchanged. ]: +
+ ++template<class R, class T> unspecified mem_fn(R T::* pm); + +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...)); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile); + +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) &); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const &); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile &); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile &); + +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) &&); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const &&); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) volatile &&); +template<class R, class T, class ...Args> unspecified mem_fn(R (T::* pm)(Args...) const volatile &&); +- +
++Remove 20.8.13 [func.memfn]/5: +
+ +++Remarks: Implementations may implement mem_fn as a set of +overloaded function templates.+
+921. Rational Arithmetic should use template aliases
+Section: 20.6.1 [ratio.ratio] Status: WP + Submitter: Pablo Halpern Opened: 2008-10-07 Last modified: 2010-10-29
+View all other issues in [ratio.ratio].
+View all issues with WP status.
+Discussion:
++The compile-time functions that operate on ratio<N,D> require the +cumbersome and error-prone "evaluation" of a type member using a +meta-programming style that predates the invention of template aliases. +Thus, multiplying three ratios a, b, and c requires the expression: +
+ ++ +ratio_multiply<a, ratio_multiply<b, c>::type>::type ++The simpler expression: +
+ ++ +ratio_multiply<a, ratio_multiply<b, c>> ++Could be used by if template aliases were employed in the definitions. +
+ +[ +Post Summit: +]
+ + +++ ++Jens: not a complete proposed resolution: "would need to make similar change" +
++Consensus: We agree with the direction of the issue. +
++Recommend Open. +
+[ +2009-05-11 Daniel adds: +]
+ + +++ ++Personally I'm not in favor for the addition of: +
++typedef ratio type; ++For a reader of the +standard it's usage or purpose is unclear. I haven't seen similar examples +of attempts to satisfy non-feature complete compilers. +
+[ +2009-05-11 Pablo adds: +]
+ + +++ ++The addition of type to the ratio template allows the previous style +(i.e., in the prototype implementations) to remain valid and permits the +use of transitional library implementations for C++03 compilers. I do +not feel strongly about its inclusion, however, and leave it up to the +reviewers to decide. +
+[ +Batavia (2009-05): +]
+ ++Bill asks for additional discussion in the issue +that spells out more details of the implementation. +Howard points us to issue 948 +which has at least most of the requested details. +Tom is strongly in favor of overflow-checking at compile time. +Pete points out that there is no change of functionality implied. +We agree with the proposed resolution, +but recommend moving the issue to Review +to allow time to improve the discussion if needed. ++ +[ +2009-07-21 Alisdair adds: +]
+ + ++See 1121 for a potentially incompatible proposal. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
+ + ++
+ + + + +- +
++In 20.6 [ratio]/3 change as indicated: +
+ ++// ratio arithmetic +template <class R1, class R2>structusing ratio_add = see below; +template <class R1, class R2>structusing ratio_subtract = see below; +template <class R1, class R2>structusing ratio_multiply = see below; +template <class R1, class R2>structusing ratio_divide = see below; +- +
++In 20.6.1 [ratio.ratio], change as indicated: +
++namespace std { + template <intmax_t N, intmax_t D = 1> + class ratio { + public: + typedef ratio type; + static const intmax_t num; + static const intmax_t den; + }; +} +- +
++In 20.6.2 [ratio.arithmetic] change as indicated: +
+ ++template <class R1, class R2>+ +structusing ratio_add = see below{ + typedef see below type; +}; ++++1 The
+nested typedeftype ratio_add<R1, R2> +shall be a synonym for ratio<T1, T2> +where T1 has the value R1::num * R2::den + R2::num * R1::den and T2 +has the value R1::den * R2::den. ++template <class R1, class R2>+structusing ratio_subtract = see below{ + typedef see below type; +}; ++++2 The
+nested typedeftype ratio_subtract<R1, R2> +shall be a synonym for ratio<T1, T2> +where T1 has the value R1::num * R2::den - R2::num * R1::den and T2 +has the value R1::den * R2::den. ++template <class R1, class R2>+structusing ratio_multiply = see below{ + typedef see below type; +}; ++++3 The
+nested typedeftype ratio_multiply<R1, R2> +shall be a synonym for ratio<T1, T2> +where T1 has the value R1::num * R2::num and T2 has the value R1::den * R2::den. ++template <class R1, class R2>+structusing ratio_divide = see below{ + typedef see below type; +}; ++++4 The
+nested typedeftype ratio_divide<R1, R2> +shall be a synonym for ratio<T1, T2> +where T1 has the value R1::num * R2::den and T2 has the value R1::den * R2::num. +- +
++In 20.11.3.1 [time.duration.cons]/4 change as indicated: +
++++Requires: treat_as_floating_point<rep>::value shall be true or +ratio_divide<Period2, period>::
+type::den shall be 1.[..] +- +
++In 20.11.3.7 [time.duration.cast]/2 change as indicated: +
++++Returns: Let CF be ratio_divide<Period, typename +ToDuration::period>
+::type, and [..] +
922. [func.bind.place] Number of placeholders
Section: B [implimits] Status: WP - Submitter: Sohail Somani Opened: 2008-10-11 Last modified: 2009-07-18
+ Submitter: Sohail Somani Opened: 2008-10-11 Last modified: 2010-10-29View all issues with WP status.
Discussion:
Addresses DE 24
-With respect to the section 20.7.11.1.4 [func.bind.place]: +With respect to the section 20.8.10.1.3 [func.bind.place]:
TR1 dropped some suggested implementation quantities for the number of @@ -40779,7 +53795,7 @@ Tentatively Ready. Original proposed resolution:
-Add 20.7.11.1.4 [func.bind.place]/2: +Add 20.8.10.1.3 [func.bind.place]/2:
@@ -40797,7 +53813,7 @@ Add to B [implimits]:@@ -40808,15 +53824,15 @@ Number of placeholders (20.7.11.1.4 [func.bind.place]) [10].
- -Number of placeholders (20.7.11.1.4 [func.bind.place]) [10]. +Number of placeholders (20.8.10.1.3 [func.bind.place]) [10].
925. shared_ptr's explicit conversion from unique_ptr
-Section: 20.8.15.2.1 [util.smartptr.shared.const] Status: WP - Submitter: Rodolfo Lima Opened: 2008-10-12 Last modified: 2009-07-18
+Section: 20.9.10.2.1 [util.smartptr.shared.const] Status: WP + Submitter: Rodolfo Lima Opened: 2008-10-12 Last modified: 2010-10-29
View all other issues in [util.smartptr.shared.const].
View all issues with WP status.
Discussion:
The current working draft (N2798), -section 20.8.15.2.1 [util.smartptr.shared.const] declares +section 20.9.10.2.1 [util.smartptr.shared.const] declares shared_ptr's constructor that takes a rvalue reference to unique_ptr and auto_ptr as being explicit, affecting several valid smart pointer use cases that would take advantage of this conversion being implicit, for @@ -40877,8 +53893,8 @@ Move to Tentatively Ready.
Proposed resolution:
-In both 20.8.15.2 [util.smartptr.shared] paragraph 1 and -20.8.15.2.1 [util.smartptr.shared.const] change: +In both 20.9.10.2 [util.smartptr.shared] paragraph 1 and +20.9.10.2.1 [util.smartptr.shared.const] change:
template <class Y>explicitshared_ptr(auto_ptr<Y> &&r); @@ -40890,16 +53906,306 @@ template <class Y, class D>explicitshared_ptr(unique_ptr<Y +
+929. Thread constructor
+Section: 30.3.1.2 [thread.thread.constr] Status: WP + Submitter: Anthony Williams Opened: 2008-10-23 Last modified: 2010-10-29
+View all other issues in [thread.thread.constr].
+View all issues with WP status.
+Discussion:
+ +Addresses UK 323
+ ++The thread constructor for starting a new thread with a function and +arguments is overly constrained by the signature requiring rvalue +references for func and args and the CopyConstructible requirements +for the elements of args. The use of an rvalue reference for the +function restricts the potential use of a plain function name, since +the type of the bound parameter will be deduced to be a function +reference and decay to pointer-to-function will not happen. This +therefore complicates the implementation in order to handle a simple +case. Furthermore, the use of rvalue references for args prevents the +array to pointer decay. Since arrays are not CopyConstructible or even +MoveConstructible, this essentially prevents the passing of arrays as +parameters. In particular it prevents the passing of string literals. +Consequently a simple case such as +
+ ++ +void f(const char*); +std::thread t(f,"hello"); ++is ill-formed since the type of the string literal is const char[6]. +
+ ++By changing the signature to take all parameters by value we can +eliminate the CopyConstructible requirement and permit the use of +arrays, as the parameter passing semantics will cause the necessary +array-to-pointer decay. They will also cause the function name to +decay to a pointer to function and allow the implementation to handle +functions and function objects identically. +
+ ++The new signature of the thread constructor for a function and +arguments is thus: +
+ ++ +template<typename F,typename... Args> +thread(F,Args... args); ++Since the parameter pack Args can be empty, the single-parameter +constructor that takes just a function by value is now redundant. +
+ +[ +Howard adds: +]
+ + +++ ++I agree with everything Anthony says in this issue. However I believe we +can optimize in such a way as to get the pass-by-value behavior with the +pass-by-rvalue-ref performance. The performance difference is that the latter +removes a move when passing in an lvalue. +
+ ++This circumstance is very analogous to make_pair (20.3.5 [pairs]) +where we started with passing by const reference, changed to pass by value to +get pointer decay, and then changed to pass by rvalue reference, but modified with +decay<T> to retain the pass-by-value behavior. If we were to +apply the same solution here it would look like: +
+ ++ ++template <class F> explicit thread(F f);+template <class F, class ...Args> thread(F&& f, Args&&... args); ++++-4- Requires: F and each Ti in Args shall be
+CopyConstructible +if an lvalue and otherwiseMoveConstructible. +INVOKE(f, w1, w2, ..., wN) (20.8.2 [func.require]) shall be a valid expression for +some values w1, w2, ... , wN, where N == sizeof...(Args). ++-5- Effects: Constructs an object of type thread +
+and executes INVOKE(f, t1, t2, ..., tN) in a new +thread of execution, where t1, t2, ..., tN are the values in args.... +Constructs +the following objects in memory which is accessible to a new thread of execution +as if: ++typename decay<F>::type g(std::forward<F>(f)); +tuple<typename decay<Args>::type...> w(std::forward<Args>(args)...); ++The new thread of +execution executes INVOKE(g, wi...) where the wi... refers +to the elements stored in the tuple w. +Any return value from g is ignored. +
+If f terminates with an uncaught exception, std::terminate() shall be called.+If the evaluation of INVOKE(g, wi...) terminates +with an uncaught exception, std::terminate() shall be called [Note: +std::terminate() could be called before entering g. -- end note]. Any +exception thrown before the evaluation of INVOKE has started shall be +catchable in the calling thread. ++Text referring to when terminate() is called was contributed by Ganesh. +
+ +[ +Batavia (2009-05): +]
+ ++We agree with the proposed resolution, +but would like the final sentence to be reworded +since "catchable" is not a term of art (and is used nowhere else). ++ +[ +2009-07 Frankfurt: +]
+ + +++ ++This is linked to +N2901. +
++Howard to open a separate issue to remove (1176). +
++In Frankfurt there is no consensus for removing the variadic constructor. +
+[ +2009-10 Santa Cruz: +]
+ + ++We want to move forward with this issue. If we later take it out via 1176 +then that's ok too. Needs small group to improve wording. ++ +[ +2009-10 Santa Cruz: +]
+ + +++ ++Stefanus provided revised wording. Moved to Review Here is the original wording: +
++++Modify the class definition of std::thread in 30.3.1 [thread.thread.class] to remove the +following signature: +
+ ++ +template<class F> explicit thread(F f);+template<class F, class ... Args> explicit thread(F&& f, Args&& ... args); ++Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with +the single constructor as above. Replace paragraph 4 - 6 with the +following: +
+ +++ ++-4- Requires: F and each Ti in Args shall be
+CopyConstructible +if an lvalue and otherwiseMoveConstructible. +INVOKE(f, w1, w2, ..., wN) (20.8.2 [func.require]) shall be a valid expression for +some values w1, w2, ... , wN, where N == sizeof...(Args). ++-5- Effects: Constructs an object of type thread +
+and executes INVOKE(f, t1, t2, ..., tN) in a new +thread of execution, where t1, t2, ..., tN are the values in args.... +Constructs +the following objects: ++typename decay<F>::type g(std::forward<F>(f)); +tuple<typename decay<Args>::type...> w(std::forward<Args>(args)...); ++and executes INVOKE(g, wi...) in a new thread of execution. +These objects shall be destroyed when the new thread of execution completes. +Any return value from g is ignored. +
+If f terminates with an uncaught exception, std::terminate() shall be called.+If the evaluation of INVOKE(g, wi...) terminates +with an uncaught exception, std::terminate() shall be called [Note: +std::terminate() could be called before entering g. -- end note]. Any +exception thrown before the evaluation of INVOKE has started shall be +catchable in the calling thread. ++-6- Synchronization: The invocation of the constructor happens before the +invocation of
+fg. +[ +2010-01-19 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Modify the class definition of std::thread in 30.3.1 [thread.thread.class] to remove the +following signature: +
+ ++ +template<class F> explicit thread(F f);+template<class F, class ... Args> explicit thread(F&& f, Args&& ... args); ++Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with +the single constructor as above. Replace paragraph 4 - 6 with the +following: +
+ +++ + + + + ++Given a function as follows: +
+ ++ ++template<typename T> typename decay<T>::type decay_copy(T&& v) + { return std::forward<T>(v); } ++-4- Requires: F and each Ti in Args shall +
+ +be CopyConstructible if an lvalue and otherwisesatisfy +the MoveConstructible requirements. +INVOKE(f, w1, w2, ..., wN) (20.8.2 [func.require]) +shall be a valid expression for some values w1, w2, ... , wN, where +N == sizeof...(Args).+INVOKE(decay_copy(std::forward<F>(f)), decay_copy(std::forward<Args>(args))...) (20.8.2 [func.require]) shall be a valid expression. ++-5- Effects: Constructs an object of type thread
+ +and executes +INVOKE(f, t1, t2, ..., tN) in a new thread of execution, where +t1, t2, ..., tN are the values in args.... +Any return +value from f is ignored. If f terminates with an +uncaught exception, std::terminate() shall be called.+The new thread of execution executes INVOKE(decay_copy(std::forward<F>(f)), +decay_copy(std::forward<Args>(args))...) with the calls to decay_copy() being evaluated in +the constructing thread. Any return value from this invocation is +ignored. [Note: this implies any exceptions not thrown from the +invocation of the copy of f will be thrown in the constructing thread, +not the new thread. — end note]. +If the invocation of INVOKE(decay_copy(std::forward<F>(f)), +decay_copy(std::forward<Args>(args))...) terminates with an uncaught +exception, std::terminate shall be called. ++-6- Synchronization: The invocation of the constructor happens before the +invocation of the copy of f. +
+
931. type trait extent<T, I>
-Section: 20.6.4.3 [meta.unary.prop] Status: WP - Submitter: Yechezkel Mett Opened: 2008-11-04 Last modified: 2009-07-18
-View other active issues in [meta.unary.prop].
+Section: 20.7.4.3 [meta.unary.prop] Status: WP + Submitter: Yechezkel Mett Opened: 2008-11-04 Last modified: 2010-10-29
View all other issues in [meta.unary.prop].
View all issues with WP status.
Discussion:
-The draft (N2798) says in 20.6.4.3 [meta.unary.prop] Table 44: +The draft (N2798) says in 20.7.4.3 [meta.unary.prop] Table 44:
@@ -40954,7 +54260,7 @@ Recommend Tentatively Ready.
Proposed resolution:
-In Table 44 of 20.6.4.3 [meta.unary.prop], third row, column "Value", +In Table 44 of 20.7.4.3 [meta.unary.prop], third row, column "Value", change the cell content:
@@ -40987,11 +54293,218 @@ Wording supplied by Daniel. +
+932. unique_ptr(pointer p) for pointer deleter types
+Section: 20.9.9.2.1 [unique.ptr.single.ctor] Status: Resolved + Submitter: Howard Hinnant Opened: 2008-11-26 Last modified: 2010-11-19
+View all other issues in [unique.ptr.single.ctor].
+View all issues with Resolved status.
+Discussion:
+ +Addresses US 79
+ ++20.9.9.2.1 [unique.ptr.single.ctor]/5 no longer requires for D +not to be a pointer type. I believe this restriction was accidently removed +when we relaxed the completeness reuqirements on T. The restriction +needs to be put back in. Otherwise we have a run time failure that could +have been caught at compile time: +
+ ++ +{ +unique_ptr<int, void(*)(void*)> p1(malloc(sizeof(int))); // should not compile +} // p1.~unique_ptr() dereferences a null function pointer +unique_ptr<int, void(*)(void*)> p2(malloc(sizeof(int)), free); // ok +[ +Post Summit: +]
+ + ++Recommend Tentatively Ready. ++ +[ +2009-07 Frankfurt +]
+ + ++Moved from Tentatively Ready to Open only because the wording needs to be +improved for enable_if type constraining, possibly following Robert's +formula. ++ +[ +2009-07 Frankfurt: +]
+ + +++ ++We need to consider whether some requirements in the Requires paragraphs +of [unique.ptr] should instead be Remarks. +
++Leave Open. Howard to provide wording, and possibly demonstrate how this +can be implemented using enable_if. +
+[ +2009-07-27 Howard adds: +]
+ + +++ ++The two constructors to which this issue applies are not easily constrained +with enable_if as they are not templated: +
+ ++ +unique_ptr(); +explicit unique_ptr(pointer p); ++To "SFINAE" these constructors away would take heroic effort such as specializing +the entire unique_ptr class template on pointer deleter types. There +is insufficient motivation for such heroics. Here is the expected and +reasonable implementation for these constructors: +
+ ++ +unique_ptr() + : ptr_(pointer()) + { + static_assert(!is_pointer<deleter_type>::value, + "unique_ptr constructed with null function pointer deleter"); + } +explicit unique_ptr(pointer p) + : ptr_(p) + { + static_assert(!is_pointer<deleter_type>::value, + "unique_ptr constructed with null function pointer deleter"); + } ++I.e. just use static_assert to verify that the constructor is not +instantiated with a function pointer for a deleter. The compiler will automatically +take care of issuing a diagnostic if the deleter is a reference type (uninitialized +reference error). +
+ ++In keeping with our discussions in Frankfurt, I'm moving this requirement on +the implementation from the Requires paragraph to a Remarks paragraph. +
+ +[ +2009-08-17 Daniel adds: +]
+ + +++ ++It is insufficient to require a diagnostic. This doesn't imply an +ill-formed program +as of 1.3.6 [defns.diagnostic] (a typical alternative would be a compiler +warning), but +exactly that seems to be the intend. I suggest to use the following +remark instead: +
+ ++Remarks: The program shall be ill-formed if this constructor is +instantiated when D is a pointer type or reference type. ++ ++Via the general standard rules of 1.4 [intro.compliance] the "diagnostic +required" is implied. +
+ +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ +[ +2010-03-14 Howard adds: +]
+ + ++We moved +N3073 +to the formal motions page in Pittsburgh which should obsolete this issue. I've +moved this issue to NAD Editorial, solved by N3073. ++ + + +Rationale:
++Solved by N3073. +
+ + +Proposed resolution:
++Change the description of the default constructor in 20.9.9.2.1 [unique.ptr.single.ctor]: +
+ ++ +unique_ptr(); +++++-1- Requires: D shall be default constructible, and that construction +shall not throw an exception.
+D shall +not be a reference type or pointer type (diagnostic required).+...
++Remarks: The program shall be ill-formed if this constructor is +instantiated when D is a pointer type or reference type. + +
++Add after 20.9.9.2.1 [unique.ptr.single.ctor]/8: +
+ ++ + + + +unique_ptr(pointer p); ++++...
++Remarks: The program shall be ill-formed if this constructor is +instantiated when D is a pointer type or reference type. + +
+
934. duration is missing operator%
-Section: 20.9.3 [time.duration] Status: WP - Submitter: Terry Golubiewski Opened: 2008-11-30 Last modified: 2009-10-26
-View other active issues in [time.duration].
+Section: 20.11.3 [time.duration] Status: WP + Submitter: Terry Golubiewski Opened: 2008-11-30 Last modified: 2010-10-29
View all other issues in [time.duration].
View all issues with WP status.
Discussion:
@@ -41061,9 +54574,9 @@ formula.-Howard to open a separate issue (1177) to handle the removal of member +Howard to open a separate issue (1177) to handle the removal of member functions from overload sets, provide wording, and possibly demonstrate -how this can be implemented using enable_if (see 947). +how this can be implemented using enable_if (see 947).
Move to Ready. @@ -41074,7 +54587,7 @@ Move to Ready.
Proposed resolution:
-Add to the synopsis in 20.9 [time]: +Add to the synopsis in 20.11 [time]:
template <class Rep1, class Period, class Rep2> @@ -41086,7 +54599,7 @@ template <class Rep1, class Period1, class Rep2, class Period2>-Add to the synopsis of duration in 20.9.3 [time.duration]: +Add to the synopsis of duration in 20.11.3 [time.duration]:
template <class Rep, class Period = ratio<1>> @@ -41100,7 +54613,7 @@ public:-Add to 20.9.3.3 [time.duration.arithmetic]: +Add to 20.11.3.3 [time.duration.arithmetic]:
@@ -41128,7 +54641,7 @@ Add to 20.9.3.3 [time.duration.arithmetic]:-Add to 20.9.3.5 [time.duration.nonmember]: +Add to 20.11.3.5 [time.duration.nonmember]:
@@ -41166,8 +54679,8 @@ Add to 20.9.3.5 [time.duration.nonmember]:
938. default_delete<T[]>::operator() should only accept T*
-Section: 20.8.14.1.2 [unique.ptr.dltr.dflt1] Status: WP - Submitter: Howard Hinnant Opened: 2008-12-07 Last modified: 2009-07-18
+Section: 20.9.9.1.3 [unique.ptr.dltr.dflt1] Status: WP + Submitter: Howard Hinnant Opened: 2008-12-07 Last modified: 2010-10-29
View all issues with WP status.
Discussion:
@@ -41176,7 +54689,7 @@ Consider:
derived* p = new derived[3]; std::default_delete<base[]> d; -d(p); // should fail +d(p); // should fail@@ -41205,7 +54718,7 @@ Move to Tentatively Ready.
Proposed resolution:
-Add to 20.8.14.1.2 [unique.ptr.dltr.dflt1]: +Add to 20.9.9.1.3 [unique.ptr.dltr.dflt1]:
namespace std { @@ -41220,10 +54733,198 @@ Add to 20.8.14.1.2 [unique.ptr.dltr.dflt1]: +
+939. Problem with std::identity and reference-to-temporaries
+Section: 20.3.3 [forward] Status: WP + Submitter: Alisdair Meredith Opened: 2008-12-11 Last modified: 2010-10-29
+View all other issues in [forward].
+View all issues with WP status.
+Discussion:
++std::identity takes an argument of type T const & +and returns a result of T const &. +
++Unfortunately, this signature will accept a value of type other than T that +is convertible-to-T, and then return a reference to the dead temporary. The +constraint in the concepts version simply protects against returning +reference-to-void. +
++Solutions: +
++++i/ Return-by-value, potentially slicing bases and rejecting non-copyable +types +
++ii/ Provide an additional overload: +
++template< typename T > +template operator( U & ) = delete; ++This seems closer on intent, but moves beyond the original motivation for +the operator, which is compatibility with existing (non-standard) +implementations. +
++iii/ Remove the operator() overload. This restores the original definition +of the identity, although now effectively a type_trait rather than part of +the perfect forwarding protocol. +
++iv/ Remove std::identity completely; its original reason to exist is +replaced with the IdentityOf concept. +
++My own preference is somewhere between (ii) and (iii) - although I stumbled +over the issue with a specific application hoping for resolution (i)! +
+ +[ +Batavia (2009-05): +]
+ +++ ++We dislike options i and iii, and option ii seems like overkill. +If we remove it (option iv), implementers can still provide it under a +different name. +
++Move to Open pending wording (from Alisdair) for option iv. +
+[ +2009-05-23 Alisdair provided wording for option iv. +]
+ + +[ +2009-07-20 Alisdair adds: +]
+ + +++ ++I'm not sure why this issue was not discussed at Frankfurt (or I missed +the discussion) but the rationale is now fundamentally flawed. With the +removal of concepts, std::identity again becomes an important library +type so we cannot simply remove it. +
++At that point, we need to pick one of the other suggested resolutions, +but have no guidance at the moment. +
+[ +2009-07-20 Howard adds: +]
+ + +++ ++I believe the rationale for not addressing this issue in Frankfurt was that it did +not address a national body comment. +
++I also believe that removal of identity is still a practical option as +my latest reformulation of forward, which is due to comments suggested +at Summit, no longer uses identity. :-) +
+ ++ +template <class T, class U, + class = typename enable_if + < + !is_lvalue_reference<T>::value || + is_lvalue_reference<T>::value && + is_lvalue_reference<U>::value + >::type, + class = typename enable_if + < + is_same<typename remove_all<T>::type, + typename remove_all<U>::type>::value + >::type> +inline +T&& +forward(U&& t) +{ + return static_cast<T&&>(t); + +} ++ +[ +The above code assumes acceptance of 1120 for the definition of +remove_all. This is just to make the syntax a little more palatable. +Without this trait the above is still very implementable. +]
+ + ++Paper with rationale is on the way ... really, I promise this time! ;-) +
+[ +2009-07-30 Daniel adds: See 823 for an alternative resolution. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. Howard will update proposed wording to reflect current draft. ++ + + +Proposed resolution:
++Strike from 20.3 [utility]: +
+ ++ +template <class T> struct identity;++Remove from 20.3.3 [forward]: +
+ +++ + + + + ++template <class T> struct identity { + typedef T type; + + const T& operator()(const T& x) const; +};+ +const T& operator()(const T& x) const;+++-2- Returns: x+
943. ssize_t undefined
Section: 29.5.2 [atomics.types.address] Status: WP - Submitter: Holger Grund Opened: 2008-12-19 Last modified: 2009-07-18
+ Submitter: Holger Grund Opened: 2008-12-19 Last modified: 2010-10-29 +View all other issues in [atomics.types.address].
View all issues with WP status.
Discussion:
@@ -41263,16 +54964,133 @@ Remove the row containing ssize_t from Table 119 +
+947. duration arithmetic: contradictory requirements
+Section: 20.11.3.5 [time.duration.nonmember] Status: Resolved + Submitter: Pete Becker Opened: 2008-12-20 Last modified: 2010-11-20
+View all other issues in [time.duration.nonmember].
+View all issues with Resolved status.
+Discussion:
++In 20.11.3.5 [time.duration.nonmember], paragraph 8 says that calling +dur / rep +when rep is an instantiation of duration requires a diagnostic. +That's followed by an operator/ that takes two durations. +So dur1 / dur2 is legal under the second version, +but requires a diagnostic under the first. +
+ +[ +Howard adds: +]
+ + ++Please see the thread starting with c++std-lib-22980 for more information. ++ +[ +Batavia (2009-05): +]
+ ++Move to Open, pending proposed wording (and preferably an implementation). ++ +[ +2009-07-27 Howard adds: +]
+ + +++ ++I've addressed this issue under the proposed wording for 1177 which +cleans up several places under 20.11.3 [time.duration] which used the +phrase "diagnostic required". +
++For clarity's sake, here is an example implementation of the constrained operator/: +
+ ++ +template <class _Duration, class _Rep, bool = __is_duration<_Rep>::value> +struct __duration_divide_result +{ +}; + +template <class _Duration, class _Rep2, + bool = is_convertible<_Rep2, + typename common_type<typename _Duration::rep, _Rep2>::type>::value> +struct __duration_divide_imp +{ +}; + +template <class _Rep1, class _Period, class _Rep2> +struct __duration_divide_imp<duration<_Rep1, _Period>, _Rep2, true> +{ + typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period> type; +}; + +template <class _Rep1, class _Period, class _Rep2> +struct __duration_divide_result<duration<_Rep1, _Period>, _Rep2, false> + : __duration_divide_imp<duration<_Rep1, _Period>, _Rep2> +{ +}; + +template <class _Rep1, class _Period, class _Rep2> +inline +typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type +operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s) +{ + typedef typename common_type<_Rep1, _Rep2>::type _Cr; + duration<_Cr, _Period> __r = __d; + __r /= static_cast<_Cr>(__s); + return __r; +} ++__duration_divide_result is basically a custom-built enable_if +that will contain type only if Rep2 is not a duration +and if Rep2 is implicitly convertible to +common_type<typename Duration::rep, Rep2>::type. __is_duration +is simply a private trait that answers false, but is specialized for +duration to answer true. +
+ ++The constrained operator% works identically. +
+[ +2009-10 Santa Cruz: +]
+ + ++Mark+ + + +NAD EditorialResolved, fixed by 1177. +Proposed resolution:
++
+ + + + +
948. ratio arithmetic tweak
-Section: 20.4.2 [ratio.arithmetic] Status: WP - Submitter: Howard Hinnant Opened: 2008-12-26 Last modified: 2009-07-18
+Section: 20.6.2 [ratio.arithmetic] Status: WP + Submitter: Howard Hinnant Opened: 2008-12-26 Last modified: 2010-10-29
View all other issues in [ratio.arithmetic].
View all issues with WP status.
Discussion:
N2800, -20.4.2 [ratio.arithmetic] lacks a paragraph from the proposal +20.6.2 [ratio.arithmetic] lacks a paragraph from the proposal N2661:
@@ -41367,7 +55185,7 @@ Recommend Tentatively Ready.Proposed resolution:
-Add a paragraph prior to p1 in 20.4.2 [ratio.arithmetic]: +Add a paragraph prior to p1 in 20.6.2 [ratio.arithmetic]:
@@ -41381,12 +55199,12 @@ If overflow occurs, a diagnostic shall be issued.
949. owner_less
-Section: 20.8.15.3.7 [util.smartptr.ownerless] Status: WP - Submitter: Thomas Plum Opened: 2008-12-30 Last modified: 2009-07-18
+Section: 20.9.10.3.7 [util.smartptr.ownerless] Status: WP + Submitter: Thomas Plum Opened: 2008-12-30 Last modified: 2010-10-29
View all issues with WP status.
Discussion:
-20.8.15.3.7 [util.smartptr.ownerless] (class template owner_less) says that +20.9.10.3.7 [util.smartptr.ownerless] (class template owner_less) says that operator()(x,y) shall return x.before(y).
@@ -41420,7 +55238,7 @@ Recommend Tentatively Ready.
Proposed resolution:
-Change 20.8.15.3.7 [util.smartptr.ownerless] p2: +Change 20.9.10.3.7 [util.smartptr.ownerless] p2:
@@ -41432,11 +55250,1455 @@ Change 20.8.15.3.7 [util.smartptr.ownerless] p2: +
+950. unique_ptr converting ctor shouldn't accept array form
+Section: 20.9.9.2.1 [unique.ptr.single.ctor] Status: Resolved + Submitter: Howard Hinnant Opened: 2009-01-07 Last modified: 2010-11-19
+View all other issues in [unique.ptr.single.ctor].
+View all issues with Resolved status.
+Discussion:
++unique_ptr's of array type should not convert to +unique_ptr's which do not have an array type. +
+ ++ +struct Deleter +{ + void operator()(void*) {} +}; + +int main() +{ + unique_ptr<int[], Deleter> s; + unique_ptr<int, Deleter> s2(std::move(s)); // should not compile +} +[ +Post Summit: +]
+ + +++ ++Walter: Does the "diagnostic required" apply to both arms of the "and"? +
++Tom Plum: suggest to break into several sentences +
++Walter: suggest "comma" before the "and" in both places +
++Recommend Review. +
+[ +Batavia (2009-05): +]
+ ++The post-Summit comments have been applied to the proposed resolution. +We now agree with the proposed resolution. +Move to Tentatively Ready. ++ +[ +2009-07 Frankfurt +]
+ + ++Moved from Tentatively Ready to Open only because the wording needs to be +improved for enable_if type constraining, possibly following Robert's +formula. ++ +[ +2009-08-01 Howard updates wording and sets to Review. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ +[ +2010-02-27 Pete Opens: +]
+ + +++ ++The proposed replacement text doesn't make sense. +
+ ++If D is a reference type, then E shall be the same type as +D, else this constructor shall not participate in overload resolution. ++ ++This imposes two requirements. 1. If D is a reference type, E +has to be D. 2. If D is not a reference type, the constructor +shall not participate in overload resolution. If the latter apples, the language +in the preceding paragraph that this constructor shall not throw an exception if +D is not a reference type is superfluous. I suspect that's not the +intention, but I can't parse this text any other way. +
+ ++U shall not be an array type, else this constructor shall not +participate in overload resolution. ++ ++I don't know what this means. +
+[ +2010-02-27 Peter adds: +]
+ + +++ ++I think that the intent is (proposed text): +
+ +++ ++Remarks: this constructor shall only participate in overload resolution +if: +
+ ++
+ +- +unique_ptr<U, E>::pointer is implicitly convertible to +pointer, +
+ +- +U is not an array type, and +
+ +- +if D is a reference type, E is the same type as D. +
+[ +2010-02-28 Howard adds: +]
+ + +++ ++I like Peter's proposal. Here is a tweak of it made after looking at my +implementation. I believe this fixes a further defect not addressed by the +current proposed wording: +
+ +++ ++Remarks: this constructor shall only participate in overload resolution +if: +
+ ++
+ +- +unique_ptr<U, E>::pointer is implicitly convertible to +pointer, and +
+ +- +U is not an array type, and +
+ +- +if D is a reference type, E is the same type as D, +else E shall be implicitly convertible to D. +
+[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3073. +
+ + +Proposed resolution:
++Change 20.9.9.2.1 [unique.ptr.single.ctor]: +
+ +++ +template <class U, class E> unique_ptr(unique_ptr<U, E>&& u); +++++-20- Requires: If D is not a reference type, +construction of the deleter D from an rvalue of type E +shall be well formed and shall not throw an exception.
+ +If D is +a reference type, then E shall be the same type as D +(diagnostic required). unique_ptr<U, E>::pointer shall be +implicitly convertible to pointer. [Note: These requirements +imply that T and U are complete types. — end note]++Remarks: If D is +a reference type, then E shall be the same type as D, else this +constructor shall not participate in overload resolution. unique_ptr<U, E>::pointer shall be +implicitly convertible to pointer, else this +constructor shall not participate in overload resolution. U shall not be +an array type, else this +constructor shall not participate in overload resolution. [Note: These requirements +imply that T and U are complete types. — end note] +
+ ++Change 20.9.9.2.3 [unique.ptr.single.asgn]: +
+ +++ + + + + + +template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u); +++++-6- Requires: Assignment of the deleter D from an rvalue +D shall not throw an exception.
+ +unique_ptr<U, +E>::pointer shall be implicitly convertible to pointer. +[Note: These requirements imply that T and U +are complete types. — end note]++Remarks: unique_ptr<U, +E>::pointer shall be implicitly convertible to pointer, else this +operator shall not participate in overload resolution. +U shall not be an array type, else this +operator shall not participate in overload resolution. +[Note: These requirements imply that T and U +are complete types. — end note] +
+ +
+951. Various threading bugs #1
+Section: 20.11.2.1 [time.traits.is_fp] Status: WP + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-11-24
+View all issues with WP status.
+Discussion:
+ ++Related to 953. +
+ ++20.11.2.1 [time.traits.is_fp] says that the type Rep "is +assumed to be ... a class emulating an integral type." What are the +requirements for such a type? +
+[ +2009-05-10 Howard adds: +]
+ + ++IntegralLike. ++ +[ +Batavia (2009-05): +]
+ +++ ++As with issue 953, +we recommend this issue be addressed in the context of providing concepts for the entire thread header. +
++We look forward to proposed wording. +
++Move to Open. +
+[ +2009-08-01 Howard adds: +]
+ + +++ ++I have surveyed all clauses of 20.11.2.2 [time.traits.duration_values], +20.11.2.3 [time.traits.specializations] and 20.11.3 [time.duration]. +I can not find any clause which involves the use of a duration::rep type +where the requirements on the rep type are not clearly spelled out. +These requirements were carefully crafted to allow any arithmetic type, or +any user-defined type emulating an arithmetic type. +
+ ++Indeed, treat_as_floating_point +becomes completely superfluous if duration::rep can never be a class type. +
+ ++There will be some Rep types which will not meet the requirements of +every duration operation. This is no different than the fact +that vector<T> can easily be used for types T which are +not DefaultConstructible, even though some members of vector<T> +require T to be DefaultConstructible. This is why the requirements +on Rep are specified for each operation individually. +
+ ++In 20.11.2.1 [time.traits.is_fp] p1: +
+ ++ +template <class Rep> struct treat_as_floating_point + : is_floating_point<Rep> { }; ++ ++The duration template uses the treat_as_floating_point trait to help +determine if a duration object can be converted to another duration +with a different tick period. If treat_as_floating_point<Rep>::value is +true, then Rep is a floating-point type and implicit conversions are +allowed among durations. Otherwise, the implicit convertibility depends +on the tick periods of the durations. If Rep is a class type which +emulates a floating-point type, the author of Rep can specialize +treat_as_floating_point so that duration will treat this Rep as if it +were a floating-point type. Otherwise Rep is assumed to be an integral +type or a class emulating an integral type. +++The phrases "a class type which emulates a floating-point type" and +"a class emulating an integral type" are clarifying phrases which refer to +the summation of all the requirements on the Rep type specified in +detail elsewhere (and should not be repeated here). +
+ ++This specification has been implemented, now multiple times, and the experience +has been favorable. The current specification clearly specifies the requirements +at each point of use (though I'd be happy to fix any place I may have missed, +but none has been pointed out). +
+ ++I am amenable to improved wording of this paragraph (and any others), but do not have any +suggestions for improved wording at this time. I am strongly opposed to +changes which would significantly alter the semantics of the +specification under 20.11 [time] without firmly grounded and +documented rationale, example implementation, testing, and user +experience which relates a positive experience. +
+ ++I recommend NAD unless someone wants to produce some clarifying wording. +
+[ +2009-10 Santa Cruz: +]
+ + ++Stefanus to provide wording to turn this into a note. ++ +[ +2010-02-11 Stefanus provided wording. +]
+ + + +[ +2010 Rapperswil: +]
+ + ++Move to Ready. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Change 20.11.2.1 [time.traits.is_fp]/1: +
+ ++1 The duration template uses the treat_as_floating_point trait +to help determine if a duration object can be converted to another +duration with a different tick period. If +treat_as_floating_point<Rep>::value is true, then ++ + + + + + +Rep is a floating-point type andimplicit conversions are allowed among +durations. Otherwise, the implicit convertibility depends on the tick +periods of the durations.If Rep is a class type which +emulates a floating-point type, the author of Rep can specialize +treat_as_floating_point so that duration will treat this Rep +as if it were a floating-point type. Otherwise Rep is assumed to be an +integral type or a class emulating an integral type.+[Note: The intention of this trait is to indicate whether a given +class behaves like a floating point type, and thus allows division of one value +by another with acceptable loss of precision. If +treat_as_floating_point<Rep>::value is false, +Rep will be treated as if it behaved like an integral type for the +purpose of these conversions. — end note] +
+953. Various threading bugs #3
+Section: 20.11.1 [time.clock.req] Status: Resolved + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-11-20
+View all other issues in [time.clock.req].
+View all issues with Resolved status.
+Discussion:
+ ++Related to 951. +
+ ++20.11.1 [time.clock.req] says that a clock's rep member is "an +arithmetic type or a class emulating an arithmetic type." What are the +requirements for such a type? +
+ +[ +2009-05-10 Howard adds: +]
+ + ++This wording was aimed directly at the ArithmeticLike concept. ++ +[ +Batavia (2009-05): +]
+ +++ ++We recommend this issue be addressed in the context of providing concepts +for the entire thread header. +
++May resolve for now by specifying arithmetic types, +and in future change to ArithmeticLike. +However, Alisdair believes this is not feasible. +
++Bill disagrees. +
++We look forward to proposed wording. Move to Open. +
+[ +2009-08-01 Howard adds: +]
+ + ++See commented dated 2009-08-01 in 951. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Stefanus to provide wording to turn this into a note. ++ +[ +2010-02-11 Stephanus provided wording for 951 which addresses +this issue as well. +]
+ + + +[ +2010 Rapperswil: +]
+ + ++Move to+ + + + +NAD EditorialResolved, resolved by 951. +Proposed resolution:
++
+ + + + + +
+954. Various threading bugs #4
+Section: 20.11.1 [time.clock.req] Status: WP + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
+View all other issues in [time.clock.req].
+View all issues with WP status.
+Discussion:
++Table 55 -- Clock Requirements (in 20.11.1 [time.clock.req]) +
+ ++
+ +- +the requirements for C1::time_point require C1 and C2 +to "refer to the same epoch", but "epoch" is not defined. +
+- +"Different clocks may share a time_point definition if it is +valid to compare their time_points by comparing their +respective durations." What does "valid" mean here? And, since +C1::rep is "**THE** representation type of the native +duration and time_point" (emphasis added), there +doesn't seem to be much room for some other representation. +
+- +C1::is_monotonic has type "const bool". The +"const" should be removed. +
+- +C1::period has type ratio. ratio isn't a type, +it's a template. What is the required type? +
+[ +2009-05-10 Howard adds: +]
+ + ++
+ +- +
++"epoch" is purposefully not defined beyond the common English +definition. The C standard +also chose not to define epoch, though POSIX did. I believe it is a strength +of the C standard that epoch is not defined. When it is known that two time_points +refer to the same epoch, then a definition of the epoch is not needed to compare +the two time_points, or subtract them. +
++A time_point and a Clock implicitly refer to an (unspecified) epoch. +The time_point represents an offset (duration) from an epoch. +
+- +
++The sentence: +
++Different clocks +may share a time_point +definition if it is valid to +compare their time_points by +comparing their respective +durations. ++ ++is redundant and could be removed. I believe the sentence which follows the above: +
+ ++C1 and C2 shall refer to the same epoch. ++ ++is sufficient. If two clocks share the same epoch, then by definition, comparing +their time_points is valid. +
+- +is_monotonic is meant to never change (be const). It is also +desired that this value be usable in compile-time computation and branching. +
+- +
++This should probably instead be worded: +
++An instantiation of ratio. ++[ +Batavia (2009-05): +]
+ +++ ++Re (a): It is not clear to us whether "epoch" is a term of art. +
++Re (b), (c), and (d): We agree with Howard's comments, +and would consider adding to (c) a static constexpr requirement. +
++Move to Open pending proposed wording. +
+[ +2009-05-25 Daniel adds: +]
+ + ++In regards to (d) I suggest to say "a specialization of ratio" instead of +"An instantiation of ratio". This seems to be the better matching standard +core language term for this kind of entity. ++ +[ +2009-05-25 Ganesh adds: +]
+ + +++ ++Regarding (a), I found this paper on the ISO website using the term "epoch" consistently with the current wording: +
+ + ++which is part of ISO/IEC 18026 "Information technology -- Spatial Reference Model (SRM)". +
+[ +2009-08-01 Howard: Moved to Reivew as the wording requested in Batavia has been provided. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++
+- +
++Change 20.11.1 [time.clock.req] p1: +
++-1- A clock is a bundle consisting of a native duration, a native time_point, and a function now() to get the +current time_point. The origin of the clock's time_point is referred to as the clock's epoch as defined in +section 6.3 of ISO/IEC 18026. +A clock shall meet the requirements in Table 45. ++- +
++Remove the sentence from the time_point row of the table "Clock Requirements": +
++
+Clock requirements ++ ++C1::time_point + ++chrono::time_point<C1> or chrono::time_point<C2, C1::duration> + ++The native time_point type of the clock. + +Different clocks may share a time_point definition if it is valid to compare their time_points by comparing their respective durations.+C1 and C2 shall refer to the same epoch. ++
+ + + + + +- +
++Change the row starting with C1::period of the table "Clock Requirements": +
++
+ +Clock requirements ++ ++C1::period + ++a specialization of ratio + ++The tick period of the clock in seconds. + +
+956. Various threading bugs #6
+Section: 20.11.1 [time.clock.req] Status: WP + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-11-24
+View all other issues in [time.clock.req].
+View all issues with WP status.
+Discussion:
++20.11.1 [time.clock.req] uses the word "native" in several places, +but doesn't define it. What is a "native duration"? +
+ +[ +2009-05-10 Howard adds: +]
+ + ++The standard uses "native" in several places without defining it (e.g. +2.14.3 [lex.ccon]). It is meant to mean "that which is defined +by the facility", or something along those lines. In this case it refers +to the nested time_point and duration types of the clock. +Better wording is welcome. ++ +[ +Batavia (2009-05): +]
+ ++Move to Open pending proposed wording from Pete. ++ +[ +2009-10-23 Pete provides wording: +]
+ + +[ +2009-11-18 Daniel adds: +]
+ + +++ ++I see that 30.4.1.3 [thread.timedmutex.requirements]/3 says: +
+ ++Precondition: If the tick period of rel_time is not +exactly convertible to the native tick period, the duration +shall be rounded up to the nearest native tick period. ++ ++I would prefer to see that adapted as well. Following the same style as +the proposed resolution I come up with +
+ ++Precondition: If the tick period of rel_time is not +exactly convertible to the+ +nativetick period of the +execution environment, the duration shall be rounded up to the +nearestnativetick period of the execution +environment. +[ +2010-03-28 Daniel synced wording with N3092 +]
+ + +[ +Post-Rapperswil, Howard provides wording: +]
+ + ++Moved to Tentatively Ready with revised wording from Howard Hinnant after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ ++Change 20.11.1 [time.clock.req]: +
+ +++ + + + + + ++1 A clock is a bundle consisting of a
+ +nativeduration, a +nativetime_point, and a function now() to get the +current time_point. The origin of the clock's time_point is +referred to as the clock's epoch. A clock shall meet the requirements in +Table 56. ++2 ... +
+ ++
+Table 56 — Clock requirements ++ + Expression Return type Operational semantics + + +C1::rep +An arithmetic type or a class emulating an arithmetic type +The representation type of +the native+C1::duration.and +time_point.+ + +C1::period +... +... ++ + +C1::duration +chrono::duration<C1::rep, C1::period> +The +nativeduration type of the clock.+ + +C1::time_point +chrono::time_point<C1> or chrono::time_point<C2, +C1::duration> +The +nativetime_point type of the clock. C1 and +C2 shall refer to the same epoch.+ + +... +
+957. Various threading bugs #7
+Section: 20.11.5.1 [time.clock.system] Status: WP + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
+View all other issues in [time.clock.system].
+View all issues with WP status.
+Discussion:
++20.11.5.1 [time.clock.system]: to_time_t is overspecified. It +requires truncation, but should allow rounding. For example, suppose a +system has a clock that gives times in milliseconds, but time() rounds +those times to the nearest second. Then system_clock can't use any +resolution finer than one second, because if it did, truncating times +between half a second and a full second would produce the wrong time_t +value. +
+ +[ +Post Summit Anthony Williams provided proposed wording. +]
+ + +[ +Batavia (2009-05): +]
+ ++Move to Review pending input from Howard. and other stakeholders. ++ +[ +2009-05-23 Howard adds: +]
+ + ++I am in favor of the wording provided by Anthony. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++In 20.11.5.1 [time.clock.system] replace paragraphs 3 and 4 with: +
+ +++ + + + + +time_t to_time_t(const time_point& t); +++-3- Returns: A time_t object that represents the same +point in time as t when both values are+ +truncated+restricted to the coarser of the precisions of +time_t and time_point. It is implementation +defined whether values are rounded or truncated to the required +precision. +time_point from_time_t(time_t t); +++-4- Returns: A time_point object that represents the +same point in time as t when both values are+truncated+restricted to the +coarser of the precisions of time_t and time_point. +It is implementation defined whether values are +rounded or truncated to the required precision. +
+960. Various threading bugs #10
+Section: 30.4.1 [thread.mutex.requirements] Status: WP + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
+View all other issues in [thread.mutex.requirements].
+View all issues with WP status.
+Discussion:
++30.4.1 [thread.mutex.requirements]: paragraph 4 is entitled +"Error conditions", but according to 17.5.1.4 [structure.specifications], "Error +conditions:" specifies "the error conditions for error codes reported by +the function." It's not clear what this should mean when there is no +function in sight. +
+ +[ +Summit: +]
+ + ++Move to open. ++ +[ +Beman provided proposed wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. Fix the proposed wording with "functions of type Mutex" +-> "functions of Mutex type" ++ + + +Proposed resolution:
++Change 30.4.1 [thread.mutex.requirements] Mutex requirements, +paragraph 4 as indicated: +
+ +++ + + + + ++-4-
+Error conditions:+The error conditions for error codes, if any, reported by member +functions of Mutex type shall be: ++
+- +not_enough_memory -- if there is not enough memory to construct +the mutex object. +
+- +resource_unavailable_try_again -- if any native handle type +manipulated is not available. +
+- +operation_not_permitted -- if the thread does not have the +necessary permission to change the state of the mutex object. +
+- +device_or_resource_busy -- if any native handle type +manipulated is already locked. +
+- +invalid_argument -- if any native handle type manipulated as +part of mutex construction is incorrect. +
+
+962. Various threading bugs #12
+Section: 30.4.2.2.2 [thread.lock.unique.locking] Status: WP + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
+View all other issues in [thread.lock.unique.locking].
+View all issues with WP status.
+Discussion:
++30.4.2.2.2 [thread.lock.unique.locking]: unique_lock::lock is +required to throw an object of type std::system_error "when the +postcondition cannot be achieved." The postcondition is owns == true, +and this is trivial to achieve. Presumably, the requirement is intended +to mean something more than that. +
+ +[ +Summit: +]
+ ++Move to open. ++ +[ +Beman has volunteered to provide proposed wording. +]
+ + +[ +2009-07-21 Beman added wording to address 30.2.2 [thread.req.exception] +in response to the Frankfurt notes in 859. +]
+ + +[ +2009-09-25 Beman: minor update to wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
+ +Change Exceptions 30.2.2 [thread.req.exception] as indicated:
+++ +Some functions described in this Clause are specified to throw exceptions of +type
+system_error(19.5.5). Such exceptions shall be thrown if +any of the Error conditions are detected or a call to an operating +system or other underlying API results in an error that prevents the library +function fromsatisfying its postconditions or from returning a meaningful +valuemeeting its specifications. Failure to +allocate storage shall be reported as described in +17.6.4.12 [res.on.exception.handling].Change thread assignment 30.3.1.5 [thread.thread.member], join(), +paragraph 8 as indicated:
+++ +Throws:
+ +std::system_errorwhenthe postconditions cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change thread assignment 30.3.1.5 [thread.thread.member], detach(), paragraph +13 as indicated:
++ ++ +Throws:
+ +std::system_errorwhenthe effects or +postconditions cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change Mutex requirements 30.4.1 [thread.mutex.requirements], paragraph +11, as indicated:
++ ++Throws:
+std::system_errorwhenthe effects or +postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], +paragraph 3, as indicated:
++ ++Throws:
+std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], +paragraph 8, as indicated:
++ ++Throws:
+std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], +paragraph 13, as indicated:
++ ++Throws:
+std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], +paragraph 18, as indicated:
++ ++Throws:
+std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change unique_lock locking 30.4.2.2.2 [thread.lock.unique.locking], +paragraph 22, as indicated:
++ ++Throws:
+std::system_errorwhenthe postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change Function call_once 30.4.4.2 [thread.once.callonce], paragraph 4, as +indicated
+++Throws:
+std::system_errorwhenthe effects cannot be achievedan exception is required (30.2.2 [thread.req.exception]), + or any exception thrown byfunc.Change Class condition_variable 30.5.1 [thread.condition.condvar], +paragraph 12, as indicated:
++ ++Throws:
+std::system_errorwhenthe effects or +postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change Class condition_variable 30.5.1 [thread.condition.condvar], +paragraph 19, as indicated:
++ ++Throws:
+std::system_errorwhenthe effects or +postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], +paragraph 10, as indicated:
++ ++Throws:
+std::system_errorwhenthe effects or +postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], +paragraph 16, as indicated:
++ ++ +Throws:
+std::system_errorwhenthe returned value, effects, or +postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been +applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as +indicated:
+++ +template <class Rep, class Period> +bool wait_for(unique_lock<mutex>& lock, + const chrono::duration<Rep, Period>& rel_time);+...+ +Throws:
+std::system_errorwhenthe effects or +postcondition cannot be achievedan exception is required ([thread.req.exception]).Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been +applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as +indicated:
+++ +template <class Rep, class Period, class Predicate> + bool wait_for(unique_lock<mutex>& lock, + const chrono::duration<Rep, Period>& rel_time, + Predicate pred);+...+ +Throws:
+std::system_errorwhenthe effects or +postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been +applied to the working paper, change 30.5.2 [thread.condition.condvarany] as +indicated:
+++ +template <class Lock, class Rep, class Period> + bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time);+...+ +Throws:
+std::system_errorwhenthe returned value, effects or +postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).Assuming issue 859, Monotonic Clock is Conditionally Supported?, has been +applied to the working paper, change 30.5.2 [thread.condition.condvarany] as +indicated:
+++ + + + + + +template <class Lock, class Rep, class Period, class Predicate> + bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred);+...+ +Throws:
+std::system_errorwhenthe returned value, effects or +postcondition cannot be achievedan exception is required (30.2.2 [thread.req.exception]).
+963. Various threading bugs #13
+Section: 30.3.1.5 [thread.thread.member] Status: WP + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
+View all other issues in [thread.thread.member].
+View all issues with WP status.
+Discussion:
++30.3.1.5 [thread.thread.member]: thread::detach is required to +throw an exception if the thread is "not a detachable thread". +"Detachable" is never defined. +
+ +[ +Howard adds: +]
+ + ++Due to a mistake on my part, 3 proposed resolutions appeared at approximately +the same time. They are all three noted below in the discussion. ++ +[ +Summit, proposed resolution: +]
+ + +++ ++In 30.3.1.5 [thread.thread.member] change: +
+ ++ +void detach(); ++++ +...
+-14- Error conditions:
++
+- no_such_process -- if the thread is not
+avalidthread.- invalid_argument -- if the thread is not
+a detachablejoinablethread.[ +Post Summit, Jonathan Wakely adds: +]
+ + +++ ++A thread is detachable if it is joinable. As we've defined joinable, +we can just use that. +
++This corresponds to the pthreads specification, where pthread_detach +fails if the thread is not joinable: +
++EINVAL: The implementation has detected that the value specified by +thread does not refer to a joinable thread. +++Jonathan recommends this proposed wording: +
++++In 30.3.1.5 [thread.thread.member] change: +
+ ++void detach(); ++++ +...
+-14- Error conditions:
++
+- ...
+- invalid_argument -- not a
+detachablejoinable thread.[ +Post Summit, Anthony Williams adds: +]
+ + +++ ++This is covered by the precondition that joinable() be true. +
++Anthony recommends this proposed wording: +
+ +++ ++In 30.3.1.5 [thread.thread.member] change: +
+ ++ +void detach(); ++++ +...
+-14- Error conditions:
++
+- ...
+- +
invalid_argument -- not a detachable thread.[ +2009-10 Santa Cruz: +]
+ + ++Mark as Ready with proposed resolution from Summit. ++ + + +Proposed resolution:
+ ++In 30.3.1.5 [thread.thread.member] change: +
+ ++ + + + + +void detach(); ++++ +...
+-14- Error conditions:
++
+- no_such_process -- if the thread is not
+avalidthread.- invalid_argument -- if the thread is not
+a detachablejoinablethread.
965. Various threading bugs #15
Section: 30.5.1 [thread.condition.condvar] Status: WP - Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2009-07-18
-View other active issues in [thread.condition.condvar].
+ Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29View all other issues in [thread.condition.condvar].
View all issues with WP status.
Discussion:
@@ -41496,12 +56758,209 @@ previously-initialized but as of yet undestroyed
-970. addressof overload unneeded
-Section: X [object.addressof] Status: Pending WP - Submitter: Howard Hinnant Opened: 2009-01-16 Last modified: 2009-09-25
+967. Various threading bugs #17
+Section: 30.3.1.2 [thread.thread.constr] Status: WP + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
+View all other issues in [thread.thread.constr].
+View all issues with WP status.
Discussion:
-X [object.addressof] specifies: +the error handling for the constructor for condition_variable +distinguishes lack of memory from lack of other resources, but the error +handling for the thread constructor does not. Is this difference +intentional? +
+ +[ +Beman has volunteered to provide proposed wording. +]
+ + +[ +2009-09-25 Beman provided proposed wording. +]
+ + ++The proposed resolution assumes 962 has been accepted and +its proposed resolution applied to the working paper. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
+ + +Change Mutex requirements 30.4.1 [thread.mutex.requirements], +paragraph 4, as indicated:
++ ++ +Error conditions:
++ +++
+- + +
not_enough_memory— if there is not enough memory to construct +the mutex object.- + +
resource_unavailable_try_again— if any native handle type +manipulated is not available.- + +
operation_not_permitted— if the thread does not have the +necessary permission to change the state of the mutex object.- + +
device_or_resource_busy— if any native handle type +manipulated is already locked.- +
invalid_argument— if any native handle type manipulated as +part of mutex construction is incorrect.Change Class condition_variable 30.5.1 [thread.condition.condvar], +default constructor, as indicated:
+++ + + + + ++
condition_variable();++Effects: Constructs an object of type
+condition_variable.Throws:
+std::system_errorwhen an exception is required (30.2.2 [thread.req.exception]).Error conditions:
++++
+- +
not_enough_memory— if a memory limitation prevents + initialization.- +
resource_unavailable_try_again— if some non-memory + resource limitation prevents initialization.- +
device_or_resource_busy— if attempting to initialize a + previously-initialized but as of yet undestroyedcondition_variable.
+968. Various threading bugs #18
+Section: 30.4.1 [thread.mutex.requirements] Status: WP + Submitter: Pete Becker Opened: 2009-01-07 Last modified: 2010-10-29
+View all other issues in [thread.mutex.requirements].
+View all issues with WP status.
+Discussion:
++30.4.1 [thread.mutex.requirements]: several functions are +required to throw exceptions "if the thread does not have the necessary +permission ...". "The necessary permission" is not defined. +
+ +[ +Summit: +]
+ ++Move to open. ++ + +[ +Beman has volunteered to provide proposed wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready with minor word-smithing in the example. ++ + + +Proposed resolution:
+ + +Change Exceptions 30.2.2 [thread.req.exception] as indicated:
+++ +Some functions described in this Clause are +specified to throw exceptions of type
+ +system_error(19.5.5). Such exceptions +shall be thrown if any of the Error conditions are detected or a call to an operating system or other underlying API +results in an error that prevents the library function from meeting its specifications. +[Note: See 17.6.4.12 [res.on.exception.handling] for exceptions thrown to report +storage allocation failures. —end +note][Example:
+ ++ ++ +Consider a function in this clause that is specified to throw exceptions of type
+ ++system_errorand specifies Error conditions that include+operation_not_permittedfor a thread that does not have the privilege to +perform the operation. Assume that, during the execution of this function, anerrno+ofEPERMis reported by a POSIX API call used by the +implementation. Since POSIX specifies anerrnoofEPERM+when "the caller does not have the privilege to perform the operation", +the implementation mapsEPERMto anerror_condition+ofoperation_not_permitted(19.5 [syserr]) and an exception of type+system_erroris thrown.—end example]
+ +Editorial note: For the sake of exposition, +the existing text above is shown with the changes proposed in issues 962 and 967. The +proposed additional example is independent of whether or not the 962 and 967 +proposed resolutions are accepted.
+ +Change Mutex requirements 30.4.1 [thread.mutex.requirements], +paragraph 4, as indicated:
+ ++ ++ +—
+ +operation_not_permitted— if the thread does not have the +necessary permission to change the state of the mutex objectprivilege to perform the operation.Change Mutex requirements 30.4.1 [thread.mutex.requirements], +paragraph 12, as indicated:
+ ++ ++ + + + + + +—
+ +operation_not_permitted— if the thread does not have the +necessary permission to change the state of the mutexprivilege to perform the operation.
+970. addressof overload unneeded
+Section: 20.9.8.1 [specialized.addressof] Status: WP + Submitter: Howard Hinnant Opened: 2009-01-16 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++20.9.8.1 [specialized.addressof] specifies:
+template <ObjectType T> T* addressof(T& r); @@ -41532,10 +56991,16 @@ We agree with the proposed resolution. Move to Tentatively Ready.[ +2009-11-18 Moved from Pending WP to WP. Confirmed in +N3000. +]
+ +Proposed resolution:
-Change X [object.addressof]: +Change 20.9.8.1 [specialized.addressof]:
template <ObjectType T> T* addressof(T& r); @@ -41547,10 +57012,102 @@ Change X [object.addressof]: +
+974. duration<double> should not implicitly convert to duration<int>
+Section: 20.11.3.1 [time.duration.cons] Status: WP + Submitter: Howard Hinnant Opened: 2009-01-21 Last modified: 2010-10-29
+View all issues with WP status.
+Discussion:
++The following code should not compile because it involves implicit truncation +errors (against the design philosophy of the duration library). +
+ ++ +duration<double> d(3.5); +duration<int> i = d; // implicit truncation, should not compile ++This intent was codified in the example implementation which drove this proposal +but I failed to accurately translate the code into the specification in this +regard. +
+ +[ +Batavia (2009-05): +]
+ +++ ++We agree with the proposed resolution. +
++Move to Tentatively Ready. +
+[ +2009-07 Frankfurt +]
+ + ++Moved from Tentatively Ready to Open only because the wording needs to be +improved for enable_if type constraining, possibly following Robert's +formula. ++ +[ +2009-08-01 Howard adds: +]
+ + ++Addressed by 1177. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Not completely addressed by 1177. Move to Ready. ++ + + +Proposed resolution:
++Change 20.11.3.1 [time.duration.cons], p4: +
+ +++ + + + +template <class Rep2, class Period2> + duration(const duration<Rep2, Period2>& d); +++-4- Requires: treat_as_floating_point<rep>::value +shall be true or both ratio_divide<Period2, +period>::type::den shall be 1 +and treat_as_floating_point<Rep2>::value +shall be false. +Diagnostic required. +[Note: This requirement prevents implicit truncation error when +converting between integral-based duration types. Such a +construction could easily lead to confusion about the value of the +duration. -- end note] ++
975. is_convertible cannot be instantiated for non-convertible types
-Section: 20.6.5 [meta.rel] Status: WP - Submitter: Daniel Krügler Opened: 2009-01-25 Last modified: 2009-07-18
+Section: 20.7.6 [meta.rel] Status: WP + Submitter: Daniel Krügler Opened: 2009-01-25 Last modified: 2010-10-29
View all other issues in [meta.rel].
View all issues with WP status.
Discussion:
@@ -41558,13 +57115,13 @@ Change X [object.addressof]: Addresses UK 206-Related to 1114. +Related to 1114.
The current specification of std::is_convertible (reference is draft N2798) -is basically defined by 20.6.5 [meta.rel]/4: +is basically defined by 20.7.6 [meta.rel]/4:
@@ -41694,7 +57251,7 @@ any implicit conversions to the return type of the function, else Original proposed wording:-In 20.6.5 [meta.rel]/4 change: +In 20.7.6 [meta.rel]/4 change:
@@ -41709,7 +57266,7 @@ is well formed is_convertible<From, To>::value is true,-In 20.6.5 [meta.rel] change: +In 20.7.6 [meta.rel] change:
@@ -41774,7 +57331,7 @@ Move to Tentatively Ready.Proposed resolution:
-In 20.6.5 [meta.rel] change: +In 20.7.6 [meta.rel] change:
@@ -41819,7 +57376,7 @@ function.@@ -41828,10 +57385,197 @@ void types, array types, and function types. — end note] +[Note: This requirement gives well defined results for reference types, -void types, array types, and function types. — end note] +void types, array types, and function types. — end note]
+978. Hashing smart pointers
+Section: 20.8.15 [unord.hash] Status: WP + Submitter: Alisdair Meredith Opened: 2009-02-02 Last modified: 2010-10-29
+View all other issues in [unord.hash].
+View all issues with WP status.
+Discussion:
+Addresses UK 208
++I don't see an open issue on supporting std::hash for smart pointers +(unique_ptr and shared_ptr at least). +
++It seems reasonable to at least expect support for the smart +pointers, especially as they support comparison for use in ordered +associative containers. +
+ +[ +Batavia (2009-05): +]
+ +++ ++Howard points out that the client can always supply a custom hash function. +
++Alisdair replies that the smart pointer classes are highly likely +to be frequently used as hash keys. +
++Bill would prefer to be conservative. +
++Alisdair mentions that this issue may also be viewed as a subissue or +duplicate of issue 1025. +
++Move to Open, and recommend the issue be deferred until after the next +Committee Draft is issued. +
+[ +2009-05-31 Peter adds: +]
+ + +++ ++Howard points out that the client can always supply a custom hash function. +++Not entirely true. The client cannot supply the function that hashes the +address of the control block (the equivalent of the old operator<, now +proudly carrying the awkward name of 'owner_before'). Only the +implementation can do that, not necessarily via specializing hash<>, of +course. +
++This hash function makes sense in certain situations for shared_ptr +(when one needs to switch from set/map using ownership ordering to +unordered_set/map) and is the only hash function that makes sense for +weak_ptr. +
+[ +2009-07-28 Alisdair provides wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ +[ +2009-11-16 Moved from Ready to Open: +]
+ + +++ ++Pete writes: +
+++ ++As far as I can see, "...suitable for using this type as key in unordered +associative containers..." doesn't define any semantics. It's advice to the +reader, and if it's present at all it should be in a note. But we have far too +much of this sort of editorial commentary as it is. +
++And in the resolution of 978 it's clearly wrong: it says that if there is no +hash specialization available for D::pointer, the implementation may provide +hash<unique_ptr<T,D>> if the result is not suitable for use in unordered +containers. +
++Howard writes: +
+ ++Is this a request to pull 978 from Ready? ++ ++Barry writes: +
+++ ++I read this as more than a request. The PE says it's wrong, so it can't be +Ready. +
+[ +2010-01-31 Alisdair: related to 1245 and 1182. +]
+ + +[ +2010-02-08 Beman updates wording. +]
+ + +[ +2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+ +Add the following declarations to the synopsis of <memory> in +20.9 [memory]
+ +++ +// [util.smartptr.hash] hash support +template <class T> struct hash; +template <class T, class D> struct hash<unique_ptr<T,D>>; +template <class T> struct hash<shared_ptr<T>>;+Add a new subclause under 20.9.10 [util.smartptr] called hash support
+ +++ + + + + +hash support [util.smartptr.hash]
+ +template <class T, class D> struct hash<unique_ptr<T,D>>;+ +++ ++Specialization meeting the requirements of class template hash (20.8.15 [unord.hash]). For an object p of type UP, where +UP is a type unique_ptr<T,D>, +hash<UP>()(p) shall evaluate to the same value as +hash<typename UP::pointer>()(p.get()). The specialization +hash<typename UP::pointer> is required to be well-formed. +
+template <class T> struct hash<shared_ptr<T>>;+ ++++Specialization meeting the requirements of class template hash (20.8.15 [unord.hash]). For an object p of type +shared_ptr<T>, hash<shared_ptr<T>>()(p) +shall evaluate to the same value as hash<T*>()(p.get()). +
+
981. Unordered container requirements should add initializer_list support
Section: 23.2.5 [unord.req] Status: WP - Submitter: Daniel Krügler Opened: 2009-02-08 Last modified: 2009-07-18
+ Submitter: Daniel Krügler Opened: 2009-02-08 Last modified: 2010-10-29View other active issues in [unord.req].
View all other issues in [unord.req].
View all issues with WP status.
@@ -41842,7 +57586,7 @@ Refering to all container requirements tables (including those for associative containers) provide useful member function overloads accepting std::initializer_list as argument, the only exception is -Table 87. There seems to be no reason for not providing them, because 23.5 [unord] +Table 87. There seems to be no reason for not providing them, because 23.7 [unord] is already initializer_list-aware. For the sake of library interface consistency and user-expectations corresponding overloads should be added to the table requirements of unordered @@ -41926,7 +57670,7 @@ In 23.2.5 [unord.req], Table 87 insert:
982. Wrong complexity for initializer_list assignment in Table 85
Section: 23.2.4 [associative.reqmts] Status: WP - Submitter: Daniel Krügler Opened: 2009-02-08 Last modified: 2009-07-18
+ Submitter: Daniel Krügler Opened: 2009-02-08 Last modified: 2010-10-29View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with WP status.
@@ -41977,10 +57721,189 @@ In 23.2.4 [associative.reqmts], Table 85 change: +
+983. unique_ptr reference deleters should not be moved from
+Section: 20.9.9.2 [unique.ptr.single] Status: Resolved + Submitter: Howard Hinnant Opened: 2009-02-10 Last modified: 2010-11-19
+View all other issues in [unique.ptr.single].
+View all issues with Resolved status.
+Discussion:
++Dave brought to my attention that when a unique_ptr has a non-const reference +type deleter, move constructing from it, even when the unique_ptr containing +the reference is an rvalue, could have surprising results: +
+ ++ +D d(some-state); +unique_ptr<A, D&> p(new A, d); +unique_ptr<A, D> p2 = std::move(p); +// has d's state changed here? ++I agree with him. It is the unique_ptr that is the rvalue, not the +deleter. When the deleter is a reference type, the unique_ptr should +respect the "lvalueness" of the deleter. +
+ ++Thanks Dave. +
+ +[ +Batavia (2009-05): +]
+ ++Seems correct, but complicated enough that we recommend moving to Review. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ +[ +2010-03-14 Howard adds: +]
+ + ++We moved +N3073 +to the formal motions page in Pittsburgh which should obsolete this issue. I've +moved this issue to NAD Editorial, solved by N3073. ++ + + +Rationale:
++Solved by N3073. +
+ + +Proposed resolution:
++Change 20.9.9.2.1 [unique.ptr.single.ctor], p20-21 +
+ +++ +template <class U, class E> unique_ptr(unique_ptr<U, E>&& u); ++ ++ +++-20- Requires: If
+ +DE is not a reference type, +construction of the deleter D from an rvalue of type E +shall be well formed and shall not throw an exception. + +Otherwise E is a reference type and construction of the deleter +D from an lvalue of type E shall be well formed and +shall not throw an exception. + +If D is +a reference type, then E shall be the same type as D +(diagnostic required). unique_ptr<U, E>::pointer shall be +implicitly convertible to pointer. [Note: These +requirements imply that T and U are complete types. +-- end note] ++-21- Effects: Constructs a unique_ptr which owns the +pointer which u owns (if any). If the deleter +E is not a reference type,
+ +itthis +deleter is move constructed from u's deleter, otherwise +the referencethis deleter is copy constructed +from u.'s deleter. After the construction, u no longer +owns a pointer. [Note: The deleter constructor can be implemented +with std::forward<DE>. -- end +note] ++Change 20.9.9.2.3 [unique.ptr.single.asgn], p1-3 +
+ +++ +unique_ptr& operator=(unique_ptr&& u); +++ +++-1- Requires: If the deleter D is not a reference type, +
+ +Aassignment of the deleter D from an rvalue D shall not throw an exception. + +Otherwise the deleter D is a reference type, +and assignment of the deleter D from an lvalue D shall not throw an exception. ++-2- Effects: reset(u.release()) followed by +an
+ +moveassignment fromu's deleter to this deleter+std::forward<D>(u.get_deleter()). ++-3- Postconditions: This unique_ptr now owns the pointer +which u owned, and u no longer owns it.
+[Note: If +D is a reference type, then the referenced lvalue deleters are +move assigned. -- end note]++Change 20.9.9.2.3 [unique.ptr.single.asgn], p6-7 +
+ +++ + + + + +template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u); +++ +++Requires: If the deleter E is not a reference type, +
+ +Aassignment of the deleter D from an rvalue +DE shall not throw an exception. + +Otherwise the deleter E is a reference type, +and assignment of the deleter D from an lvalue E shall not throw an exception. +unique_ptr<U, E>::pointer shall be implicitly convertible to pointer. +[Note: These requirements imply that T and U> +are complete types. -- end note] ++Effects: reset(u.release()) followed by +an
+ +moveassignment fromu's deleter to this deleter+std::forward<E>(u.get_deleter()). +If either +D or E is a reference type, then the referenced lvalue +deleter participates in the move assignment.+
984. Does <cinttypes> have macro guards?
Section: 27.9.2 [c.files] Status: WP - Submitter: Howard Hinnant Opened: 2009-02-12 Last modified: 2009-07-18
+ Submitter: Howard Hinnant Opened: 2009-02-12 Last modified: 2010-10-29View all issues with WP status.
Discussion:
@@ -42042,12 +57965,12 @@ provided unconditionally. In particular, the symbol
986. Generic try_lock contradiction
-Section: 30.4.4 [thread.lock.algorithm] Status: WP - Submitter: Chris Fairles Opened: 2009-02-14 Last modified: 2009-07-18
+Section: 30.4.3 [thread.lock.algorithm] Status: WP + Submitter: Chris Fairles Opened: 2009-02-14 Last modified: 2010-10-29
View all issues with WP status.
Discussion:
-In 30.4.4 [thread.lock.algorithm], the generic try_lock effects (p2) say that a failed +In 30.4.3 [thread.lock.algorithm], the generic try_lock effects (p2) say that a failed try_lock is when it either returns false or throws an exception. In the event a call to try_lock does fail, by either returning false or throwing an exception, it states that unlock shall be called for all @@ -42079,7 +58002,7 @@ int main() {
The first lock's try_lock succeeded but, being a prior argument to a lock whose try_lock failed, it gets unlocked as per the effects clause -of 30.4.4 [thread.lock.algorithm]. However, 2 locks remain locked in this case but the return +of 30.4.3 [thread.lock.algorithm]. However, 2 locks remain locked in this case but the return clause states that either all arguments shall be locked or none will be. This seems to be a contradiction unless the intent is for implementations to make an effort to unlock not only prior arguments, @@ -42112,7 +58035,7 @@ Move to Tentatively Ready.
Proposed resolution:
-Change 30.4.4 [thread.lock.algorithm], p2: +Change 30.4.3 [thread.lock.algorithm], p2:
@@ -42124,7 +58047,7 @@ all prior arguments and there shall be no further calls to try_lock()-Delete the note from 30.4.4 [thread.lock.algorithm], p3 +Delete the note from 30.4.3 [thread.lock.algorithm], p3
@@ -42139,10 +58062,209 @@ locked or none will be locked. -- end note] ++
+987. reference_wrapper and function types
+Section: 20.8.4 [refwrap] Status: WP + Submitter: Howard Hinnant Opened: 2009-02-18 Last modified: 2010-10-29
+View all other issues in [refwrap].
+View all issues with WP status.
+Discussion:
++The synopsis in 20.8.4 [refwrap] says: +
+ ++ +template <ObjectType T> class reference_wrapper +... ++And then paragraph 3 says: +
+ +++ ++The template instantiation reference_wrapper<T> shall be +derived from std::unary_function<T1, R> only if the type +T is any of the following: +
+ ++
+- +a function type or a pointer to function type taking one argument of +type T1 and returning R +
++But function types are not ObjectTypes. +
+ ++Paragraph 4 contains the same contradiction. +
+ +[ +Post Summit: +]
+ + +++ ++Jens: restricted reference to ObjectType +
++Recommend Review. +
+[ +Post Summit, Peter adds: +]
+ + +++ ++In https://svn.boost.org/trac/boost/ticket/1846 +however Eric Niebler makes the very reasonable point that reference_wrapper<F>, +where F is a function type, represents a reference to a function, +a legitimate entity. So boost::ref was changed to allow it. +
++https://svn.boost.org/trac/boost/browser/trunk/libs/bind/test/ref_fn_test.cpp +
++Therefore, I believe an alternative proposed resolution for issue 987 could simply +allow reference_wrapper to be used with function types. +
+[ +Post Summit, Howard adds: +]
+ + +++ + + ++I agree with Peter (and Eric). I got this one wrong on my first try. Here +is code that demonstrates how easy (and useful) it is to instantiate +reference_wrapper with a function type: +
+ ++ +#include <functional> + +template <class F> +void test(F f); + +void f() {} + +int main() +{ + test(std::ref(f)); +} ++Output (link time error shows type of reference_wrapper instantiated +with function type): +
+ ++ +Undefined symbols: + "void test<std::reference_wrapper<void ()()> >(std::reference_wrapper<void ()()>)",... ++I've taken the liberty of changing the proposed wording to allow function types +and set to Open. I'll also freely admit that I'm not positive ReferentType +is the correct concept. +
+ +[ +Batavia (2009-05): +]
+ +++ ++Howard observed that FunctionType, +a concept not (yet?) in the Working Paper, +is likely the correct constraint to be applied. +However, the proposed resolution provides an adequate approximation. +
++Move to Review. +
+[ +2009-05-23 Alisdair adds: +]
+ + +++ ++By constraining to PointeeType we rule out the ability for T to be a +reference, and call in reference-collapsing. I'm not sure if this is +correct and intended, but would like to be sure the case was considered. +
++Is dis-allowing reference types and the +implied reference collapsing the intended result? +
+[ +2009-07 Frankfurt +]
+ + ++Moved from Review to Open only because the wording needs to be +tweaked for concepts removal. ++ +[ +2009-10-14 Daniel provided de-conceptified wording. +]
+ + +[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Tentatively Ready. ++ + + +Proposed resolution:
++Change 20.8.4 [refwrap]/1 as indicated: +
+ ++reference_wrapper<T> is a CopyConstructible and +CopyAssignable wrapper around a +reference to an object or function of type T. ++ + + + + + + +
990. monotonic_clock::is_monotonic must be true
-Section: 20.9.5.2 [time.clock.monotonic] Status: WP - Submitter: Howard Hinnant Opened: 2009-03-09 Last modified: 2009-07-18
+Section: X [time.clock.monotonic] Status: WP + Submitter: Howard Hinnant Opened: 2009-03-09 Last modified: 2010-10-29
+View all other issues in [time.clock.monotonic].
View all issues with WP status.
Discussion:
@@ -42168,7 +58290,7 @@ Move to Tentatively Ready.
Proposed resolution:
-Change 20.9.5.2 [time.clock.monotonic], p1: +Change X [time.clock.monotonic], p1:
@@ -42186,7 +58308,7 @@ values of time_point never decrease as physical time advances.
991. Response to JP 50
Section: 22.3.3.2.2 [conversions.string] Status: WP - Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2009-07-18
+ Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2010-10-29View all other issues in [conversions.string].
View all issues with WP status.
Discussion:
@@ -42240,7 +58362,7 @@ and byte string objects of class
993. Response to UK 188
Section: 18.5 [support.start.term] Status: WP - Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2009-07-18
+ Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2010-10-29View all other issues in [support.start.term].
View all issues with WP status.
Discussion:
@@ -42304,7 +58426,7 @@ functions passed to atexit() (3.6.3 [basic.start.term]).
994. Response to UK 193
Section: 18.6.2.3 [new.handler] Status: WP - Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2009-07-18
+ Submitter: P.J. Plauger Opened: 2009-03-03 Last modified: 2010-10-29View all issues with WP status.
Discussion:
@@ -42349,7 +58471,7 @@ Change 18.6.2.3 [new.handler], p2:
997. Response to UK 163
Section: 17.5.1.4 [structure.specifications] Status: WP - Submitter: Thomas Plum Opened: 2009-03-03 Last modified: 2009-07-18
+ Submitter: Thomas Plum Opened: 2009-03-03 Last modified: 2010-10-29View all other issues in [structure.specifications].
View all issues with WP status.
Discussion:
@@ -42468,8 +58590,8 @@ supersedes any occurrences of that element in the code-sequence.
998. Smart pointer referencing its owner
-Section: 20.8.14.2.5 [unique.ptr.single.modifiers] Status: WP - Submitter: Pavel Minaev Opened: 2009-02-26 Last modified: 2009-07-18
+Section: 20.9.9.2.5 [unique.ptr.single.modifiers] Status: WP + Submitter: Pavel Minaev Opened: 2009-02-26 Last modified: 2010-10-29
View all other issues in [unique.ptr.single.modifiers].
View all issues with WP status.
Discussion:
@@ -42595,7 +58717,7 @@ Move to Tentatively Ready.Proposed resolution:
-Change 20.8.14.2.5 [unique.ptr.single.modifiers], p5 (Effects clause for reset), and p6: +Change 20.9.9.2.5 [unique.ptr.single.modifiers], p5 (Effects clause for reset), and p6:
@@ -42619,10 +58741,91 @@ expression. -- end note]
+999. Taking the address of a function
+Section: 20.9.8 [specialized.algorithms] Status: WP + Submitter: Peter Dimov Opened: 2009-03-09 Last modified: 2010-10-29
+View all other issues in [specialized.algorithms].
+View all issues with WP status.
+Discussion:
++The same fix (reference 987) may be applied to addressof, which is also constrained to +ObjectType. (That was why boost::ref didn't work with functions - it +tried to apply boost::addressof and the reinterpret_cast<char&> +implementation of addressof failed.) +
+ + + +[ +Batavia (2009-05): +]
+ +++ ++We agree. +
++Move to Tentatively Ready. +
+[ +2009-07 Frankfurt +]
+ + ++Moved from Tentatively Ready to Open only because the wording needs to be +tweaked for concepts removal. ++ +[ +2009-10-10 Daniel updates wording to concept-free. +]
+ + +[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Tentatively Ready. ++ + + +Proposed resolution:
+[ +The resolution assumes that addressof is reintroduced as described in +n2946 +]
+ + ++In 20.9.8 [specialized.algorithms] change as described: +
+ ++ + + + + + +template <class T> T* addressof(T& r); +++Returns: The actual address of the object or function +referenced by r, even in the +presence of an overloaded operator&. ++
1004. Response to UK 179
Section: 17.6.3.8 [res.on.functions] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-26
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23View all other issues in [res.on.functions].
View all issues with WP status.
Discussion:
@@ -42681,7 +58884,7 @@ allowed in the applicable Required behavior: paragraph.
1006. operator delete in garbage collected implementation
Section: 18.6.1 [new.delete] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-18
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23View all other issues in [new.delete].
View all issues with WP status.
Discussion:
@@ -42844,10 +59047,96 @@ be a safely-derived pointer. +
+1011. next/prev wrong iterator type
+Section: 24.4.4 [iterator.operations] Status: WP + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
+View all other issues in [iterator.operations].
+View all issues with WP status.
+Discussion:
+ +Addresses UK 271
+ ++next/prev return an incremented iterator without changing the value of +the original iterator. However, even this may invalidate an +InputIterator. A ForwardIterator is required to guarantee the +'multipass' property. +
+ +[ +Batavia (2009-05): +]
+ ++We agree with the proposed resolution. +Move to Tentatively Ready. ++ +[ +2009-07 Frankfurt +]
+ + ++Moved from Tentatively Ready to Open only because the wording needs to be +tweaked for concepts removal. ++ +[ +2009-10-14 Daniel provided de-conceptified wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ + + +Proposed resolution:
+ + ++
+ + + + + +- +
+ ++Change header <iterator> synopsis 24.3 [iterator.synopsis] as indicated: +
+ ++// 24.4.4, iterator operations: +... +template <classInputForwardIterator> +InputForwardIterator + next(InputForwardIterator x, typename std::iterator_traits<InputForwardIterator>::difference_type n = 1); +- +
++Change 24.4.4 [iterator.operations] before p.6 as indicated: +
+ ++template <classInputForwardIterator> +InputForwardIterator + next(InputForwardIterator x, typename std::iterator_traits<InputForwardIterator>::difference_type n = 1); +
1012. reverse_iterator default ctor should value initialize
Section: 24.5.1.3.1 [reverse.iter.cons] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-26
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23View all issues with WP status.
Discussion:
@@ -42873,7 +59162,7 @@ Agree with option i.-Related issue: 408 +Related issue: 408
[ @@ -42882,7 +59171,7 @@ Batavia (2009-05):
We believe this should be revisited -in conjunction with issue 408, +in conjunction with issue 408, which nearly duplicates this issue. Move to Open.@@ -42953,7 +59242,7 @@ iterator of type Iterator.
1014. Response to UK 317 and JP 74
Section: 28.8.2 [re.regex.construct] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-18
+ Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23View all other issues in [re.regex.construct].
View all issues with WP status.
Discussion:
@@ -43028,8 +59317,8 @@ Add in 28.8.2 [re.regex.construct]:
1019. Response to UK 205
-Section: 20.6.3 [meta.help] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-10-26
+Section: 20.7.3 [meta.help] Status: WP + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all other issues in [meta.help].
View all issues with WP status.
Discussion:
@@ -43122,7 +59411,7 @@ Moved to Ready for this meeting.Proposed resolution:
-Add to the integral_constant struct definition in 20.6.3 [meta.help]: +Add to the integral_constant struct definition in 20.7.3 [meta.help]:
template <class T, T v> @@ -43140,8 +59429,8 @@ struct integral_constant {
1021. Response to UK 211
-Section: 20.8.14.2.3 [unique.ptr.single.asgn] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2009-07-18
+Section: 20.9.9.2.3 [unique.ptr.single.asgn] Status: WP + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
View all issues with WP status.
Discussion:
@@ -43165,14 +59454,14 @@ Move to Tentatively Ready.Proposed resolution:
-Change the synopsis in 20.8.14.2 [unique.ptr.single]: +Change the synopsis in 20.9.9.2 [unique.ptr.single]:
unique_ptr& operator=(unspecified-pointer-typenullptr_t);-Change 20.8.14.2.3 [unique.ptr.single.asgn]: +Change 20.9.9.2.3 [unique.ptr.single.asgn]:
unique_ptr& operator=(unspecified-pointer-typenullptr_t); @@ -43189,11 +59478,491 @@ private data member, avoiding many of the implicit conversion pitfalls. +
+1030. Response to JP 44
+Section: 20.9.10.5 [util.smartptr.shared.atomic] Status: WP + Submitter: Alisdair Meredith Opened: 2009-03-11 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
+ +Addresses JP 44
+ ++The 1st parameter p and 2nd parameter v is now +shared_ptr<T>*. +
++It should be shared_ptr<T>&, or if these are +shared_ptr<T>* then add the "p shall not be a +null pointer" at the requires. +
+ +[ +Summit: +]
+ + ++Agree. All of the functions need a requirement that p (or +v) is a pointer to a valid object. ++ +[ +2009-07 post-Frankfurt: +]
+ + +++ ++Lawrence explained that these signatures match the regular atomics. The +regular atomics must not use references because these signatures are +shared with C. The decision to pass shared_ptrs by pointer rather than +by reference was deliberate and was motivated by the principle of least +surprise. +
++Lawrence to write wording that requires that the pointers not be null. +
+[ +2009-09-20 Lawrence provided wording: +]
+ + +++ ++The parameter types for atomic shared pointer access +were deliberately chosen to be pointers +to match the corresponding parameters of the atomics chapter. +Those in turn were deliberately chosen +to match C functions, +which do not have reference parameters. +
++We adopt the second suggestion, +to require that such pointers not be null. +
+[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ + + +Proposed resolution:
++In section "
+shared_ptratomic access" +20.9.10.5 [util.smartptr.shared.atomic], add to each function the +following clause. ++ + + + + ++Requires:
pshall not be null. +
+1033. thread::join() effects?
+Section: 30.3.1.5 [thread.thread.member] Status: WP + Submitter: Alberto Ganesh Barbati Opened: 2009-03-12 Last modified: 2010-10-23
+View all other issues in [thread.thread.member].
+View all issues with WP status.
+Discussion:
+ ++While looking at thread::join() I think I spotted a couple of +possible defects in the specifications. I could not find a previous +issue or NB comment about that, but I might have missed it. +
+ ++The postconditions clause for thread::join() is: +
+ ++Postconditions: If join() throws an exception, the value +returned by get_id() is unchanged. Otherwise, get_id() == id(). ++ ++and the throws clause is: +
+ ++Throws: std::system_error when the postconditions cannot be achieved. ++ ++Now... how could the postconditions not be achieved? +It's just a matter of resetting the value of get_id() or leave it +unchanged! I bet we can always do that. Moreover, it's a chicken-and-egg +problem: in order to decide whether to throw or not I depend on the +postconditions, but the postconditions are different in the two cases. +
+ ++I believe the throws clause should be: +
+ ++Throws: std::system_error when the effects or postconditions +cannot be achieved. ++ ++as it is in detach(), or, even better, as the postcondition is +trivially satisfiable and to remove the circular dependency: +
+ + ++Throws: std::system_error if the effects cannot be achieved. ++ ++Problem is that... ehm... join() has no "Effects" clause. Is that intentional? +
+ +[ +See the thread starting at c++std-lib-23204 for more discussion. +]
+ + +[ +Batavia (2009-05): +]
+ +++ ++Pete believes there may be some more general language (in frontmatter) +that can address this and related issues such as 962. +
++Move to Open. +
+[ +2009-11-18 Anthony provides wording. +]
+ + + +[ +2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +Proposed resolution:
++Edit 30.3.1.5 [thread.thread.member] as indicated: +
+ ++ + + + + + +void join(); +++++5 Precondition: joinable() is true. +
++Effects: Blocks until the thread represented by *this has completed. +
+ ++6 Synchronization: The completion of the thread represented by +*this happens before (1.10 [intro.multithread]) +join() returns. [Note: Operations on *this are not +synchronized. — end note] +
+ ++7 Postconditions:
+ +If join() throws an exception, the value +returned by get_id() is unchanged. Otherwise,The thread +represented by *this has completed. get_id() == id(). ++8 ... +
+ + +
+1034. Response to UK 222
+Section: 23.2.1 [container.requirements.general] Status: WP + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
+View other active issues in [container.requirements.general].
+View all other issues in [container.requirements.general].
+View all issues with WP status.
+Discussion:
+ +Addresses UK 222
+ ++It is not clear what purpose the Requirement tables serve in the +Containers clause. Are they the definition of a library Container? Or +simply a conventient shorthand to factor common semantics into a single +place, simplifying the description of each subsequent container? This +becomes an issue for 'containers' like array, which does not meet the +default-construct-to-empty requirement, or forward_list which does not +support the size operation. Are these components no longer containers? +Does that mean the remaining requirements don't apply? Or are these +contradictions that need fixing, despite being a clear design decision? +
+ ++Recommend: +
+ ++Clarify all the tables in 23.2 [container.requirements] are +there as a convenience for documentation, rather than a strict set of +requirements. Containers should be allowed to relax specific +requirements if they call attention to them in their documentation. The +introductory text for array should be expanded to mention a +default constructed array is not empty, and +forward_list introduction should mention it does not provide +the required size operation as it cannot be implemented +efficiently. +
+ +[ +Summit: +]
+ + ++Agree in principle. ++ +[ +2009-07 post-Frankfurt: +]
+ + ++We agree in principle, but we have a timetable. This group feels that +the issue should be closed as NAD unless a proposed resolution is +submitted prior to the March 2010 meeting. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Looked at this and still intend to close as NAD in March +2010 unless there is proposed wording that we like. ++ +[ +2010-02-02 Nicolai M. Josuttis updates proposed wording and adds: +]
+ + +++ ++I just came across issue #1034 (response to UK 222), +which covers the role of container requirements. +The reason I found this issue was that I am wondering why +array<> is specified to be a sequence container. +For me, currently, this follows from +Sequence containers 23.2.3 [sequence.reqmts] +saying: +
++The library provides five basic kinds of sequence containers: array, +vector, forward_list, list, and deque. while +later on in Table 94 "Sequence container requirements" are defined. ++ ++IMO, you can hardly argue that this is NAD. +We MUST say somewhere that either array is not a sequence container +or does not provide all operations of a sequence container +(even not all requirements of a container in general). +
++Here is the number of requirements array<> does not meet +(AFAIK): +
++general container requirements: +
++
+ +- +a default constructed array is not empty +
+- +swap has no constant complexity +
++ Note also that swap not only has linear complexity + it also invalidates iterators (or to be more precise, + assigns other values to the elements), which + is different from the effect swap has for other containers. + For this reason, I must say that i tend to propose to + remove swap() for arrays. +
+ ++sequence container requirements: +
+ ++
+ +- +There is no constructor and assignment for a range +
+- +There is no constructor and assignment for n copies of t +
+- + There are no emplace, insert, erase, clear, + assign operations +
++In fact, out of all sequence container requirements array<> only +provides the following operations: +from sequence requirements (Table 94): +
++X(il); +a = il; ++and from optional requirements (Table 95): +
++[], at(), front(), back() ++This is almost nothing! +
+ ++Note in addition, that due to the fact that +array is an aggregate and not a container with +initializer_lists +a construction or assignment with an initializer list is valid +for all sequence containers but not valid for array: +
+ ++ +vector<int> v({1,2,3}); // OK +v = {4,5,6}; // OK + +array<int,3> a({1,2,3}); // Error +array<int,3> a = {1,2,3}; // OK +a = {4,5,6}; // Error ++BTW, for this reason, I am wondering, why <array> includes +<initializer_list>. +
+ ++IMO, we can't really say that array is a sequence container. +array is special. +As the solution to this issue seemed to miss some proposed wording +where all could live with, let me try to suggest some. +
+ +[ +2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010 Pittsburgh: Ok with move to Ready except for "OPEN:" part. +]
+ + + + +Proposed resolution:
+ +In Sequence containers 23.2.3 [sequence.reqmts] modify paragraph 1 as +indicated:
+++1 A sequence container organizes a finite set of objects, all of the same + type, into a strictly linear arrangement. The library provides
+five+ four basic kinds of sequence containers:array,+ vector, forward_list, list, and deque. + In addition, array is provided as a sequence container that + only provides limited sequence operations because it has a fixed number of + elements.ItThe library also provides container adaptors that make it easy to + construct abstract data types, such as stacks or queues, out + of the basic sequence container kinds (or out of other kinds of sequence + containers that the user might define).Modify paragraph 2 as follows (just editorial):
+++2 The
+five basicsequence + containers offer the programmer different complexity trade-offs and should be + used accordingly. vector or array is the type of sequence + container that should be used by default. list or forward_list + should be used when there are frequent insertions and deletions from the + middle of the sequence. deque is the data structure of choice when + most insertions and deletions take place at the beginning or at the end of the + sequence.In Class template array 23.3.1 [array] modify paragraph 3 as indicated: +
+++3
+Unless otherwise specified, all array operations are as + described in 23.2.An array satisfies all of the requirements of a + container and of a reversible container (given in two tables in 23.2 [container.requirements]) + except that a default constructed array is not empty, swap + does not have constant complexity, and swap may throw exceptions. An array satisfies some of the requirements of a + sequence container (given in 23.2.3 [sequence.reqmts]). Descriptions are + provided here only for operations on array that are not described +in that Clausein one of these tables or for operations + where there is additional semantic information.In array specialized algorithms 23.3.1.2 [array.special] add to the +specification of swap():
+++ + + + + + + + +template <class T, size_t N> void swap(array<T,N>& x, array<T,N>& y); ++++1 Effects: ...
+Complexity: Linear in N.
+
1037. Response to UK 232
Section: 23.2.3 [sequence.reqmts] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-07-18
-View other active issues in [sequence.reqmts].
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23View all other issues in [sequence.reqmts].
View all issues with WP status.
Discussion:
@@ -43241,8 +60010,7 @@ In 23.2.3 [sequence.reqmts] Table 84, remove reference to
1038. Response to UK 233
Section: 23.2.3 [sequence.reqmts] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-07-18
-View other active issues in [sequence.reqmts].
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23View all other issues in [sequence.reqmts].
View all issues with WP status.
Discussion:
@@ -43345,8 +60113,7 @@ containers to the following rows:
1039. Response to UK 234
Section: 23.2.3 [sequence.reqmts] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-07-18
-View other active issues in [sequence.reqmts].
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23View all other issues in [sequence.reqmts].
View all issues with WP status.
Discussion:
@@ -43409,7 +60176,7 @@ In 23.2.3 [sequence.reqmts] Table 84, replace iterator with auto in semantics fo
1040. Response to UK 238
Section: 23.2.4 [associative.reqmts] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-07-18
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23View other active issues in [associative.reqmts].
View all other issues in [associative.reqmts].
View all issues with WP status.
@@ -43474,7 +60241,8 @@ in their function parameter lists -- end note]
1044. Response to UK 325
Section: 30.4 [thread.mutex] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-07-18
+ Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23 +View all other issues in [thread.mutex].
View all issues with WP status.
Discussion:
@@ -43527,8 +60295,8 @@ struct adopt_lock_t {};
1045. Response to UK 326
-Section: 30.4.3.2.1 [thread.lock.unique.cons] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2009-07-18
+Section: 30.4.2.2.1 [thread.lock.unique.cons] Status: WP + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-10-23
View all issues with WP status.
Discussion:
@@ -43566,7 +60334,7 @@ Move to Tentatively Ready.Proposed resolution:
-Strike 30.4.3.2.1 [thread.lock.unique.cons] p7: +Strike 30.4.2.2.1 [thread.lock.unique.cons] p7:
unique_lock(mutex_type& m, defer_lock_t); @@ -43582,10 +60350,365 @@ the calling thread does not own the mutex. +
+1054. forward broken
+Section: 20.3.3 [forward] Status: Resolved + Submitter: Howard Hinnant Opened: 2009-03-13 Last modified: 2010-11-20
+View all other issues in [forward].
+View all issues with Resolved status.
+Discussion:
+ ++This is a placeholder issue to track the fact that we (well I) put the standard +into an inconsistent state by requesting that we accept +N2844 +except for the proposed changes to [forward]. +
+ ++There will exist in the post meeting mailing +N2835 +which in its current state reflects the state of affairs prior to the Summit +meeting. I hope to update it in time for the post Summit mailing, but as I write +this issue I have not done so yet. +
+ +[ +Batavia (2009-05): +]
+ ++Move to Open, awaiting the promised paper. ++ +[ +2009-08-02 Howard adds: +]
+ + +++ ++My current preferred solution is: +
+ ++ +template <class T> +struct __base_type +{ + typedef typename remove_cv<typename remove_reference<T>::type>::type type; +}; + +template <class T, class U, + class = typename enable_if< + !is_lvalue_reference<T>::value || + is_lvalue_reference<T>::value && + is_lvalue_reference<U>::value>::type, + class = typename enable_if< + is_same<typename __base_type<T>::type, + typename __base_type<U>::type>::value>::type> +inline +T&& +forward(U&& t) +{ + return static_cast<T&&>(t); +} ++This has been tested by Bill, Jason and myself. +
+ ++It allows the following lvalue/rvalue casts: +
+ ++
+ +- +Cast an lvalue t to an lvalue T (identity). +
+- +Cast an lvalue t to an rvalue T. +
+- +Cast an rvalue t to an rvalue T (identity). +
++It disallows: +
+ ++
+ +- +Cast an rvalue t to an lvalue T. +
+- +Cast one type t to another type T (such as int to double). +
++"a." is disallowed as it can easily lead to dangling references. +"b." is disallowed as this function is meant to only change the lvalue/rvalue +characteristic of an expression. +
+ ++Jason has expressed concern that "b." is not dangerous and is useful in contexts +where you want to "forward" a derived type as a base type. I find this use case +neither dangerous, nor compelling. I.e. I could live with or without the "b." +constraint. Without it, forward would look like: +
+ ++ +template <class T, class U, + class = typename enable_if< + !is_lvalue_reference<T>::value || + is_lvalue_reference<T>::value && + is_lvalue_reference<U>::value>::type> +inline +T&& +forward(U&& t) +{ + return static_cast<T&&>(t); +} ++Or possibly: +
+ ++ + +template <class T, class U, + class = typename enable_if< + !is_lvalue_reference<T>::value || + is_lvalue_reference<T>::value && + is_lvalue_reference<U>::value>::type, + class = typename enable_if< + is_base_of<typename __base_type<U>::type, + typename __base_type<T>::type>::value>::type> +inline +T&& +forward(U&& t) +{ + return static_cast<T&&>(t); +} ++The "promised paper" is not in the post-Frankfurt mailing only because I'm waiting +for the non-concepts draft. But I'm hoping that by adding this information here +I can keep people up to date. +
+[ +2009-08-02 David adds: +]
+ + +++ ++forward was originally designed to do one thing: perfect forwarding. +That is, inside a function template whose actual argument can be a const +or non-const lvalue or rvalue, restore the original "rvalue-ness" of the +actual argument: +
+ ++ +template <class T> +void f(T&& x) +{ + // x is an lvalue here. If the actual argument to f was an + // rvalue, pass static_cast<T&&>(x) to g; otherwise, pass x. + g( forward<T>(x) ); +} ++Attempting to engineer forward to accomodate uses other than perfect +forwarding dilutes its idiomatic meaning. The solution proposed here +declares that forward<T>(x) means nothing more than static_cast<T&&>(x), +with a patchwork of restrictions on what T and x can be that can't be +expressed in simple English. +
+ ++I would be happy with either of two approaches, whose code I hope (but +can't guarantee) I got right. +
+ ++
+ +- +
+ ++Use a simple definition of forward that accomplishes its original +purpose without complications to accomodate other uses: +
+ ++template <class T, class U> +T&& forward(U& x) +{ + return static_cast<T&&>(x); +} +- +
++Use a definition of forward that protects the user from as many +potential mistakes as possible, by actively preventing all other +uses: +
+ ++template <class T, class U> +boost::enable_if_c< + // in forward<T>(x), x is a parameter of the caller, thus an lvalue + is_lvalue_reference<U>::value + // in caller's deduced T&& argument, T can only be non-ref or lvalue ref + && !is_rvalue_reference<T>::value + // Must not cast cv-qualifications or do any type conversions + && is_same<T&,U&>::value + , T&&>::type forward(U&& a) +{ + return static_cast<T&&>(a); +} +[ +2009-09-27 Howard adds: +]
+ + ++A paper, +N2951, +is available which compares several implementations (including David's) with respect to several +use cases (including Jason's) and provides wording for one implementation. ++ +[ +2009-10 Santa Cruz: +]
+ + +++ + + +NAD EditorialResolved. Solved by +N2951. +Proposed resolution:
+ + + + + +
+1055. Response to UK 98
+Section: 20.7.7.6 [meta.trans.other] Status: Resolved + Submitter: Alisdair Meredith Opened: 2009-03-12 Last modified: 2010-11-20
+View all other issues in [meta.trans.other].
+View all issues with Resolved status.
+Discussion:
+ +Addresses UK 98
+ ++It would be useful to be able to determine the underlying +type of an arbitrary enumeration type. This would allow +safe casting to an integral type (especially needed for +scoped enums, which do not promote), and would allow +use of numeric_limits. In general it makes generic +programming with enumerations easier. +
+ +[ +Batavia (2009-05): +]
+ ++Pete observes (and Tom concurs) +that the proposed resolution seems to require compiler support +for its implementation, +as it seems necessary to look at the range of values +of the enumerated type. +To a first approximation, +a library solution could give an answer based on the size of the type. +If the user has specialized numeric_limits for the enumerated type, +then the library might be able to do better, +but there is no such requirement. +Keep status as Open +and solicit input from CWG. ++ +[ +2009-05-23 Alisdair adds: +]
+ + ++Just to confirm that the BSI originator of this comment assumed it did +indeed imply a compiler intrinsic. Rather than request a Core extension, it +seemed in keeping with that the type traits interface provides a library API +to unspecified compiler features - where we require several other traits +(e.g. has_trivial_*) to get the 'right' answer now, unlike in TR1. ++ +[ +Addressed in N2947. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + +++ + + +NAD EditorialResolved. Solved by +N2984. +Proposed resolution:
++Add a new row to the table in 20.7.7.6 [meta.trans.other]: +
+ +++ + + + ++
+Table 41 -- Other transformations ++ +Template +Condition +Comments ++ ++template< class T > struct enum_base; + ++T shall be an enumeration type (7.2 [dcl.enum]) + ++The member typedef type shall name the underlying type +of the enum T. + +
1065. Response to UK 168
Section: 17.6.1.1 [contents] Status: WP - Submitter: Howard Hinnant Opened: 2009-03-15 Last modified: 2009-07-18
+ Submitter: Howard Hinnant Opened: 2009-03-15 Last modified: 2010-10-23View all other issues in [contents].
View all issues with WP status.
Discussion:
@@ -43655,7 +60778,7 @@ multiple configurations of the library.]
1066. Response to UK 189 and JP 27
Section: 18 [language.support] Status: WP - Submitter: Howard Hinnant Opened: 2009-03-15 Last modified: 2009-07-18
+ Submitter: Howard Hinnant Opened: 2009-03-15 Last modified: 2010-10-23View all issues with WP status.
Discussion:
Addresses UK 189 and JP 27
@@ -43723,7 +60846,7 @@ template <class T> void throw_with_nested [[noreturn]] (T&&-Change 18.8.2.4 [unexpected]: +Change D.13.3 [unexpected]:
void unexpected [[noreturn]] (); @@ -43756,13 +60879,13 @@ In the synopsis of 18.8.6 [except.nested] and the definition area change:
1070. Ambiguous move overloads in function
-Section: 20.7.15.2 [func.wrap.func] Status: WP - Submitter: Howard Hinnant Opened: 2009-03-19 Last modified: 2009-07-18
+Section: 20.8.14.2 [func.wrap.func] Status: WP + Submitter: Howard Hinnant Opened: 2009-03-19 Last modified: 2010-10-23
View all other issues in [func.wrap.func].
View all issues with WP status.
Discussion:
-The synopsis in 20.7.15.2 [func.wrap.func] says: +The synopsis in 20.8.14.2 [func.wrap.func] says:
template<Returnable R, CopyConstructible... ArgTypes> @@ -43826,8 +60949,8 @@ Move to Tentatively Ready.Proposed resolution:
-Change the synopsis of 20.7.15.2 [func.wrap.func], and remove the associated definitions in -20.7.15.2.1 [func.wrap.func.con]: +Change the synopsis of 20.8.14.2 [func.wrap.func], and remove the associated definitions in +20.8.14.2.1 [func.wrap.func.con]:
@@ -44150,10 +62732,3454 @@ need not be repeated here). +template<Returnable R, CopyConstructible... ArgTypes> @@ -43863,10 +60986,160 @@ class function<R(ArgTypes...)> +
+1071. is_bind_expression should derive from integral_constant<bool>
+Section: 20.8.10.1.1 [func.bind.isbind] Status: WP + Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2010-10-23
+View all other issues in [func.bind.isbind].
+View all issues with WP status.
+Discussion:
+ ++Class template is_bind_expression 20.8.10.1.1 [func.bind.isbind]: +
+ ++namespace std { + template<class T> struct is_bind_expression { + static const bool value = see below; + }; +} ++is_bind_expression should derive from std::integral_constant<bool> like +other similar trait types. +
+ +[ +Daniel adds: +]
+ ++We need the same thing for the trait is_placeholder as well. ++[ +2009-03-22 Daniel provided wording. +]
+ + +[ +Batavia (2009-05): +]
+ +++ ++We recommend this be deferred until after the next Committee Draft is issued. +
++Move to Open. +
+[ +2009-05-31 Peter adds: +]
+ + +++ ++I am opposed to the proposed resolution and to the premise of the issue +in general. The traits's default definitions should NOT derive from +integral_constant, because this is harmful, as it misleads people into +thinking that is_bind_expression<E> always derives from +integral_constant, whereas it may not. +
++is_bind_expression and is_placeholder allow user +specializations, and in fact, this is their primary purpose. Such user +specializations may not derive from integral_constant, and the +places where is_bind_expression and is_placeholder are +used intentionally do not require such derivation. +
++The long-term approach here is to switch to +BindExpression<E> and Placeholder<P> +explicit concepts, of course, but until that happens, I say leave them +alone. +
+[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Tentatively Ready. We are comfortable with requiring user specializations +to derive from integral_constant. ++ + + +Proposed resolution:
++
+ + + + +- +
++In 20.8.10.1.1 [func.bind.isbind] change as indicated: +
++namespace std { + template<class T> struct is_bind_expression : integral_constant<bool, see below> { };{ + static const bool value = see below; + };+} +- +
++In 20.8.10.1.1 [func.bind.isbind]/2 change as indicated: +
+++static const bool value;++-2-+true if T is a type returned from bind, false otherwise.+ If T is a type returned from bind, is_bind_expression<T> shall +be publicly derived from + integral_constant<bool, true>, otherwise it shall be +publicly derived from + integral_constant<bool, false>. +- +
++In [func.bind.isplace] change as indicated: +
++namespace std { + template<class T> struct is_placeholder : integral_constant<int, see below> { };{ + static const int value = see below; + };+} +- +
++In [func.bind.isplace]/2 change as indicated: +
+++static const int value;++-2-+value is J if T is the type of std::placeholders::_J, 0 otherwise.+ If T is the type of std::placeholders::_J, is_placeholder<T> +shall be publicly + derived from integral_constant<int, J> otherwise it shall +be publicly derived + from integral_constant<int, 0>. +
1073. Declaration of allocator_arg should be constexpr
-Section: 20.8 [memory] Status: WP - Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2009-07-18
+Section: 20.9 [memory] Status: WP + Submitter: Alisdair Meredith Opened: 2009-03-19 Last modified: 2010-10-23
View all other issues in [memory].
View all issues with WP status.
Discussion:
@@ -43887,7 +61160,7 @@ We agree with the proposed resolution. Move to Tentatively Ready.Proposed resolution:
-Change 20.8 [memory] p2: +Change 20.9 [memory] p2:
// 20.8.1, allocator argument tag @@ -43901,13 +61174,1322 @@ constexpr allocator_arg_t allocator_arg = allocator_arg_t();
-1103. system_error constructor postcondition overly strict
-Section: 19.5.5.2 [syserr.syserr.members] Status: WP - Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2009-07-18
+1075. Response to US 65, US 74.1
+Section: 20 [utilities], 23 [containers] Status: Resolved + Submitter: Alan Talbot Opened: 2009-03-20 Last modified: 2010-11-20
+View all other issues in [utilities].
+View all issues with Resolved status.
+Discussion:
+Addresses US 65 and US 74.1
+ +US 65:
+ ++Scoped allocators and allocator propagation traits add a small amount of +utility at the cost of a great deal of machinery. The machinery is user +visible, and it extends to library components that don't have any +obvious connection to allocators, including basic concepts and simple +components like pair and tuple. + ++ +Suggested resolution:
+ ++Sketch of proposed resolution: Eliminate scoped allocators, replace +allocator propagation traits with a simple uniform rule (e.g. always +propagate on copy and move), remove all mention of allocators from +components that don't explicitly allocate memory (e.g. pair), and adjust +container interfaces to reflect this simplification. +
++Components that I propose eliminating include HasAllocatorType, +is_scoped_allocator, allocator_propagation_map, scoped_allocator_adaptor, +and ConstructibleAsElement. +
+US 74.1:
+ +++ ++Scoped allocators represent a poor trade-off for standardization, since +(1) scoped-allocator--aware containers can be implemented outside the +C++ standard library but used with its algorithms, (2) scoped +allocators only benefit a tiny proportion of the C++ community +(since few C++ programmers even use today's allocators), and (3) all C++ +users, especially the vast majority of the C++ community that won't ever +use scoped allocators are forced to cope with the interface complexity +introduced by scoped allocators. +
++In essence, the larger community will suffer to support a very small +subset of the community who can already implement their own +data structures outside of the standard library. Therefore, scoped +allocators should be removed from the working paper. +
++Some evidence of the complexity introduced by scoped allocators: +
++++20.3.5 [pairs], 20.4 [tuple]: Large increase in the +number of pair and tuple constructors. +
++23 [containers]: Confusing "AllocatableElement" requirements throughout. +
+Suggested resolution:
+ ++Remove support for scoped allocators from the working paper. This +includes at least the following changes: +
+ +++ ++Remove X [allocator.element.concepts] +
++Remove 20.10 [allocator.adaptor] +
++Remove [construct.element] +
++In Clause 23 [containers]: replace requirements naming the +AllocatableElement concept with requirements naming CopyConstructible, +MoveConstructible, DefaultConstructible, or Constructible, as +appropriate. +
+[ +Post Summit Alan moved from NAD to Open. +]
+ + +[ +2009-05-15 Ganesh adds: +]
+ + +++ ++The requirement AllocatableElement should not be replaced with +Constructible on the emplace_xxx() functions as suggested. In the +one-parameter case the Constructible requirement is not satisfied when +the constructor is explicit (as per [concept.map.fct], twelfth +bullet) but we do want to allow explicit constructors in emplace, as the +following example shows: +
+ ++ +vector<shared_ptr<int>> v; +v.emplace_back(new int); // should be allowed ++If the issue is accepted and scoped allocators are removed, I suggest to +add a new pair of concepts to [concept.construct], namely: +
+ ++ +auto concept HasExplicitConstructor<typename T, typename... Args> { + explicit T::T(Args...); +} + +auto concept ExplicitConstructible<typename T, typename... Args> + : HasExplicitConstructor<T, Args...>, NothrowDestructible<T> +{ } ++We should then use ExplicitConstructible as the requirement for all +emplace_xxx() member functions. +
++For coherence and consistency with the similar concepts +Convertible/ExplicitlyConvertible, we might also consider changing +Constructible to: +
+ ++ +auto concept Constructible<typename T, typename... Args> + : HasConstructor<T, Args...>, ExplicitConstructible<T, Args...> +{ } ++Moreover, all emplace-related concepts in [container.concepts] +should also use ExplicitConstructible instead of Constructible in the +definitions of their axioms. In fact the concepts in [container.concepts] should be +corrected even if the issue is not accepted. +
++On the other hand, if the issue is not accepted, the scoped allocator +adaptors should be fixed because the following code: +
+ ++ +template <typename T> using scoped_allocator = scoped_allocator_adaptor<allocator<T>>; + +vector<shared_ptr<int>, scoped_allocator<shared_ptr<int>>> v; +v.emplace_back(new int); // ops! doesn't compile ++doesn't compile, as the member function construct() of the scoped +allocator requires non-explicit constructors through concept +ConstructibleWithAllocator. Fixing that is not difficult but probably +more work than it's worth and is therefore, IMHO, one more reason in +support of the complete removal of scoped allocators. +
+[ +2009-06-09 Alan adds: +]
+ + +++ ++I reopened this issue because I did not think that these National Body +comments were adequately addressed by marking them NAD. My understanding +is that something can be marked NAD if it is clearly a misunderstanding +or trivial, but a substantive issue that has any technical merit +requires a disposition that addresses the concerns. +
++The notes in the NB comment list (US 65 & US 74.1) say that: +
++
+- +this issue has not introduced any new arguments not previously discussed, +
+- +the vote (4-9-3) was not a consensus for removing scoped allocators, +
+- +the issue is resolved by +N2840. +
++My opinion is: +
++
+ +- +there are new arguments in both comments regarding concepts (which were +not present in the library when the scoped allocator proposal was voted +in), +
+- +the vote was clearly not a consensus for removal, but just saying there +was a vote does not provide a rationale, +
+- +I do not believe that N2840 addresses these comments (although it does +many other things and was voted in with strong approval). +
++My motivation to open the issue was to ensure that the NB comments were +adequately addressed in a way that would not risk a "no" vote on our +FCD. If there are responses to the technical concerns raised, then +perhaps they should be recorded. If the members of the NB who authored +the comments are satisfied with N2840 and the other disposition remarks +in the comment list, then I am sure they will say so. In either case, +this issue can be closed very quickly in Frankfurt, and hopefully will +have helped make us more confident of approval with little effort. If in +fact there is controversy, my thought is that it is better to know now +rather than later so there is more time to deal with it. +
+[ +2009-10 Santa Cruz: +]
+ + +++ + + +NAD EditorialResolved. Addressed by +N2982. +Proposed resolution:
+ + +Rationale:
+Scoped allocators have been revised significantly. + + + + + +
+1079. UK-265:
+RandomAccessIterator'soperator-has nonsensical effects clauseSection: 24.2.7 [random.access.iterators] Status: WP + Submitter: Doug Gregor Opened: 2009-03-20 Last modified: 2010-10-23
+View all other issues in [random.access.iterators].
+View all issues with WP status.
+Discussion:
+Addresses UK 265
+ +UK-265:
++This effects clause is nonesense. It looks more like an axiom stating +equivalence, and certainly an effects clause cannot change the state of +two arguments passed by const reference +
+ +[ +2009-09-18 Alisdair adds: +]
+ + +++ ++For random access iterators, the definitions of (b-a) and +(a<b) are circular: +
+ ++From table Table 104 -- Random access iterator requirements: +
+ ++b - a :==> (a < b) ? distance(a,b) : -distance(b,a) + +a < b :==> b - a > 0 +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ +[ +2010-02-13 Alisdair opens. +]
+ + +++ ++Looking again at LWG #1079, the wording in the issue no longer exists, and +appears to be entirely an artefact of the concepts wording. +
+ ++This issue is currently on our Ready list (not even Tentative!) but I think it +has to be pulled as there is no way to apply the resolution. +
+ ++Looking at the current paper, I think this issue is now "NAD, solved by the +removal of concepts". Unfortunately it is too late to poll again, so we will +have to perform that review in Pittsburgh. +
+[ +2010-02-13 Daniel updates the wording to address the circularity problem. +]
+ + +++ +[ +The previous wording is preserved here: +]
+ ++ ++Modify 24.2.7 [random.access.iterators]p7-9 as follows:
+ ++ +difference_type operator-(const X& a, const X& b); +++
+- Precondition: there exists a value
+nof +difference_typesuch thata == b + n.- +
Effects:b == a + (b - a)- Returns:
+(a < b) ? distance(a,b) : + -distance(b,a)n[ +2010 Pittsburgh: +]
+ + ++Moved to Ready for Pittsburgh. ++ + + +Proposed resolution:
++Modify Table 105 in 24.2.7 [random.access.iterators]: +
+ +++ + + + + ++
+Table 105 — Random access iterator requirements (in addition to +bidirectional iterator) + ++ + +Expression +Return type +Operational semantics +Assertion/note +
pre-/post-condition+ + +b - a +Distance ++ distance(a,b)+return npre: there exists a value n of Distance such that a + +n == b. b == a + (b - a). +
+1089. Response to JP 76
+Section: 30 [thread] Status: WP + Submitter: Howard Hinnant Opened: 2009-03-22 Last modified: 2010-10-23
+View all other issues in [thread].
+View all issues with WP status.
+Discussion:
+Addresses JP 76
+ ++A description for "Throws: Nothing." are not unified. +
+ ++At the part without throw, "Throws: Nothing." should be described. +
+ ++Add "Throws: Nothing." to the following. +
+ ++
+ +- +30.3.1.6 [thread.thread.static] p1 +
+- +30.4.2.1 [thread.lock.guard] p4 +
+- +30.4.2.2.1 [thread.lock.unique.cons] p6 +
+- +30.5.1 [thread.condition.condvar] p7 and p8 +
+- +30.5.2 [thread.condition.condvarany] p6, p7, p19, p21 and p25 +
+[ +Summit: +]
+ ++Pass on to editor. ++ +[ +Post Summit: Editor declares this non-editorial. +]
+ + +[ +2009-08-01 Howard provided wording: +]
+ + ++ ++ ++The definition of "Throws: Nothing." that I added is probably going to +be controversial, but I beg you to consider it seriously. +
+ +++ ++In C++ there are three "flow control" options for a function: +
+ ++
+ +The above list can be abbreviated with: + +- +It can return, either with a value, or with void. +
+- +It can call a function which never returns, such as std::exit or +std::terminate. +
+- +It can throw an exception. +
++
+ +- Returns.
+- Ends program.
+- Throws exception.
++In general a function can have the behavior of any of these 3, or any combination +of any of these three, depending upon run time data. +
+ ++
+ +- R
+- E
+- T
+- RE
+- RT
+- ET
+- RET
++A function with no throw spec, and no documentation, is in general a RET +function. It may return, it may end the program, or it may throw. When we +specify a function with an empty throw spec: +
+ ++ +void f() throw(); ++We are saying that f() is an RE function: It may return or end +the program, but it will not throw. +
+ ++I posit that there are very few places in the library half of the standard +where we intend for functions to be able to end the program (call terminate). +And none of those places where we do say terminate could be called, +do we currently say "Throws: Nothing.". +
+ ++I believe that if we define "Throws: Nothing." to mean R, +we will both clarify many, many places in the standard, and give us a +good rationale for choosing between "Throws: Nothing." (R) +and throw() (RE) in the future. Indeed, this may give us motivation +to change several throw()s to "Throws: Nothing.". +
++I did not add the following changes as JP 76 requested as I believe we want to +allow these functions to throw: +
+ +++ ++Add a paragraph under 30.4.2.1 [thread.lock.guard] p4: +
+ ++ +explicit lock_guard(mutex_type& m); ++ ++Throws: Nothing. +
++Add a paragraph under 30.4.2.2.1 [thread.lock.unique.cons] p6: +
+ ++ +explicit unique_lock(mutex_type& m); ++ ++Throws: Nothing. +
++Add a paragraph under 30.5.2 [thread.condition.condvarany] p19, p21 and p25: +
+ ++ +template <class Lock, class Rep, class Period> + bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time); ++ ++Throws: Nothing. +
++ +template <class Lock, class Duration, class Predicate> + bool wait_until(Lock& lock, const chrono::time_point<Clock, Duration>& rel_time, Predicate pred); ++ ++Throws: Nothing. +
++ +template <class Lock, class Rep, class Period, class Predicate> + bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred); ++ ++Throws: Nothing. +
+[ +2009-10 Santa Cruz: +]
+ + ++Defer pending further developments with exception restriction annotations. ++ +[ +2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-02-24 Pete moved to Open: +]
+ + ++A "Throws: Nothing" specification is not the place to say that a function +is not allowed to call exit(). While I agree with the thrust of the +proposed resolution, "doesn't throw exceptions" is a subset of "always returns +normally". If it's important to say that most library functions don't call +exit(), say so. ++ +[ +2010 Pittsburgh: +]
+ + ++Move to Ready except for the added paragraph to 17.5.1.4 [structure.specifications]. ++ + + +Proposed resolution:
+ + ++Add a paragraph under 30.3.1.6 [thread.thread.static] p1: +
+ ++ +unsigned hardware_concurrency(); ++ ++-1- Returns: ... +
+ ++Throws: Nothing. +
++Add a paragraph under 30.5.1 [thread.condition.condvar] p7 and p8: +
+ +++ ++[Informational, not to be incluced in the WP: The POSIX spec allows only: +
++
+ +- [EINVAL]
+- The value cond does not refer to an initialized condition variable. — end informational]
+void notify_one(); ++ ++-7- Effects: ... +
+ ++Throws: Nothing. +
++ + +void notify_all(); ++ ++-8- Effects: ... +
+ ++Throws: Nothing. +
++Add a paragraph under 30.5.2 [thread.condition.condvarany] p6 and p7: +
+ +++ +void notify_one(); ++ ++-6- Effects: ... +
+ ++Throws: Nothing. +
++ + + + + + + +void notify_all(); ++ ++-7- Effects: ... +
+ ++Throws: Nothing. +
+
+1094. Response to JP 65 and JP 66
+Section: 27.5.4.3 [iostate.flags] Status: WP + Submitter: P.J. Plauger Opened: 2009-03-24 Last modified: 2010-10-23
+View all other issues in [iostate.flags].
+View all issues with WP status.
+Discussion:
+Addresses JP 65 and JP 66
+ ++Switch from "unspecified-bool-type" to "explicit operator bool() const". +
+ ++Replace operator unspecified-bool-type() const;" with explicit operator bool() const; +
+ +[ +Batavia (2009-05): +]
+ ++We agree with the proposed resolution. +Move to Review. ++ +[ +2009 Santa Cruz: +]
+ + ++Moved to Ready. ++ + + +Proposed resolution:
++Change the synopis in 27.5.4 [ios]: +
+ ++ +explicit operatorunspecified-bool-typebool() const; ++Change 27.5.4.3 [iostate.flags]: +
+ ++ + + + + + + +explicit operator+ +unspecified-bool-typebool() const; ++++-1- Returns: !fail()
+If fail() then a value that will evaluate +false in a boolean context; otherwise a value that will evaluate true in +a boolean context. The value type returned shall not be convertible to +int.++
+[Note: This conversion can be used in contexts where a bool is expected +(e.g., an if condition); however, implicit conversions (e.g., +to int) that can occur with bool are not allowed, +eliminating some sources of user error. One possible implementation +choice for this type is pointer-to-member. -- end note]+
+1095. Shared objects and the library wording unclear
+Section: 17.6.3.10 [res.on.objects] Status: WP + Submitter: Beman Dawes Opened: 2009-03-27 Last modified: 2010-10-23
View all issues with WP status.
Discussion:
-19.5.5.2 [syserr.syserr.members] says: +N2775, +Small library thread-safety revisions, among other changes, removed a note from +17.6.3.10 [res.on.objects] that read: +
+ ++[Note: This prohibition against concurrent non-const access means that +modifying an object of a standard library type shared between threads +without using a locking mechanism may result in a data race. --end note.] ++ ++That resulted in wording which is technically correct but can only be +understood by reading the lengthy and complex 17.6.4.9 [res.on.data.races] +Data race avoidance. This has the effect of making +17.6.3.10 [res.on.objects] unclear, and has already resulted in a query +to the LWG reflector. See c++std-lib-23194. +
+ +[ +Batavia (2009-05): +]
+ +++ ++The proposed wording seems to need a bit of tweaking +("really bad idea" isn't quite up to standardese). +We would like feedback +as to whether the original Note's removal was intentional. +
++Change the phrase "is a really bad idea" +to "risks undefined behavior" and +move to Review status. +
+[ +2009-10 Santa Cruz: +]
+ + ++Note: Change to read: "Modifying...", Delete 'thus', move to Ready ++ + + +Proposed resolution:
++Change 17.6.3.10 [res.on.objects] as indicated: +
+ +++ + + + + ++The behavior of a program is undefined if calls to standard library +functions from different threads may introduce a data race. The +conditions under which this may occur are specified in 17.6.4.7. +
++[Note: Modifying an object of a standard library type shared between +threads risks undefined behavior unless objects of the type are explicitly +specified as being sharable without data races or the user supplies a +locking mechanism. --end note] +
+
+1097. #define __STDCPP_THREADS
+Section: 18.2 [support.types] Status: WP + Submitter: Jens Maurer Opened: 2009-04-03 Last modified: 2010-10-23
+View all other issues in [support.types].
+View all issues with WP status.
+Discussion:
+Addresses DE 18
+ ++Freestanding implementations do not (necessarily) have + support for multiple threads (see 1.10 [intro.multithread]). + Applications and libraries may want to optimize for the + absence of threads. I therefore propose a preprocessor + macro to indicate whether multiple threads can occur. +
+ ++There is ample prior implementation experience for this + feature with various spellings of the macro name. For + example, gcc implicitly defines _REENTRANT + if multi-threading support is selected on the compiler + command-line. +
+ ++While this is submitted as a library issue, it may be more + appropriate to add the macro in 16.8 cpp.predefined in the + core language. +
+ ++See also +N2693. +
+ +[ +Batavia (2009-05): +]
+ +++ ++We agree with the issue, and believe it is properly a library issue. +
++We prefer that the macro be conditionally defined +as part of the <thread> header. +
++Move to Review. +
+[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ +[ +2010-02-25 Pete moved to Open: +]
+ + +++ ++The proposed resolution adds a feature-test macro named +__STDCPP_THREADS, described after the following new text: +
+ ++The standard library defines the following macros; no explicit prior inclusion +of any header file is necessary. ++ ++The correct term here is "header", not "header file". But that's minor. The real +problem is that library entities are always defined in headers. If +__STDCPP_THREADS is defined without including any header it's part of +the language and belongs with the other predefined macros in the Preprocessor +clause. +
+ ++Oddly enough, the comments from Batavia say "We prefer that the macro be +conditionally defined as part of the <thread> header." There's no +mention of a decision to change this. +
+[ +2010-02-26 Ganesh updates wording. +]
+ + +[ +2010 Pittsburgh: Adopt Ganesh's wording and move to Review. +]
+ + +[ +2010-03-08 Pete adds: +]
+ + ++Most macros we have begin and end with with double underbars, this one +only begins with double underbars. ++ +[ +2010 Pittsburgh: Ganesh's wording adopted and moved to Ready for Pittsburgh. +]
+ + + + +Proposed resolution:
+ ++Change 17.6.1.3 [compliance]/3: +
+ ++3 The supplied version of the header <cstdlib> shall +declare at least the functions abort(), atexit(), and +exit() (18.5). The supplied version of the header +<thread> either shall meet the same requirements as for a +hosted implementation or including it shall have no effect. The +other headers listed in this table shall meet the same requirements as +for a hosted implementation. ++ ++Add the following line to table 15: +
+ +++ ++
+ +Table 15 — C++ headers for freestanding implementations + ++ + +Subclause +Header(s) ++ + +... ++ + +30.3 [thread.threads] Threads +<thread> ++Add to the <thread> synopsis in 30.3 [thread.threads]/1 the line: +
+ ++ + + + + + + + + +namespace std { + +#define __STDCPP_THREADS __cplusplus + + class thread; + ... +
+1098. definition of get_pointer_safety()
+Section: 20.9.11 [util.dynamic.safety] Status: WP + Submitter: Jens Maurer Opened: 2009-04-03 Last modified: 2010-10-23
+View all other issues in [util.dynamic.safety].
+View all issues with WP status.
+Discussion:
+Addresses DE 18
+ ++ In 20.9.11 [util.dynamic.safety], get_pointer_safety() purports +to define behavior for + non-safely derived pointers (3.7.4.3 [basic.stc.dynamic.safety]). However, + the cited core-language section in paragraph 4 specifies undefined behavior + for the use of such pointer values. This seems an unfortunate near-contradiction. + I suggest to specify the term relaxed pointer safety in + the core language section and refer to it from the library description. + This issue deals with the library part, the corresponding core issue (c++std-core-13940) + deals with the core modifications. +
+ ++See also +N2693. +
+ +[ +Batavia (2009-05): +]
+ +++ ++We recommend if this issue is to be moved, +the issue be moved concurrently with the cited Core issue. +
++We agree with the intent of the proposed resolution. +We would like input from garbage collection specialists. +
++Move to Open. +
+[ +2009-10 Santa Cruz: +]
+ + ++The core issue is 853 and is in Ready status. ++ + + +Proposed resolution:
++In 20.9.11 [util.dynamic.safety] p16, replace the description of +get_pointer_safety() with: +
+ +++ + + + + ++pointer_safety get_pointer_safety(); +
++++
+Returns: an enumeration value indicating the implementation's treatment +of pointers that are not safely derived (3.7.4.3). Returns +pointer_safety::relaxed if pointers that are not safely derived will be +treated the same as pointers that are safely derived for the duration of +the program. Returns pointer_safety::preferred if pointers that are not +safely derived will be treated the same as pointers that are safely +derived for the duration of the program but allows the implementation to +hint that it could be desirable to avoid dereferencing pointers that are +not safely derived as described. [Example: pointer_safety::preferred +might be returned to detect if a leak detector is running to avoid +spurious leak reports. -- end note] Returns pointer_safety::strict if +pointers that are not safely derived might be treated differently than +pointers that are safely derived.++Returns: Returns pointer_safety::strict if the implementation has + strict pointer safety (3.7.4.3 [basic.stc.dynamic.safety]). It is + implementation-defined whether get_pointer_safety returns + pointer_safety::relaxed or pointer_safety::preferred if the + implementation has relaxed pointer safety + (3.7.4.3 [basic.stc.dynamic.safety]).Footnote +
+ ++Throws: nothing +
+ ++Footnote) pointer_safety::preferred might be returned to indicate to the + program that a leak detector is running so that the program can avoid + spurious leak reports. + +
+ +
+1100. auto_ptr to unique_ptr conversion
+Section: 20.9.9.2.1 [unique.ptr.single.ctor] Status: Resolved + Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2010-11-19
+View all other issues in [unique.ptr.single.ctor].
+View all issues with Resolved status.
+Discussion:
++Message c++std-lib-23182 led to a discussion in which several people +expressed interest in being able to convert an auto_ptr to a +unique_ptr without the need to call release. Below is +wording to accomplish this. +
+ +[ +Batavia (2009-05): +]
+ +++ ++Pete believes it not a good idea to separate parts of a class's definition. +Therefore, if we do this, +it should be part of unique-ptr's specification. +
++Alisdair believes the lvalue overload may be not necessary. +
++Marc believes it is more than just sugar, +as it does ease the transition to unique-ptr. +
++We agree with the resolution as presented. +Move to Tentatively Ready. +
+[ +2009-07 Frankfurt +]
+ + ++Moved from Tentatively Ready to Open only because the wording needs to be +tweaked for concepts removal. ++ +[ +2009-08-01 Howard deconceptifies wording: +]
+ + ++I also moved the change from D.12 [depr.auto.ptr] +to 20.9.9.2 [unique.ptr.single] per the Editor's request +in Batavia (as long as I was making changes anyway). Set back +to Review. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ +[ +2010-03-14 Howard adds: +]
+ + ++We moved +N3073 +to the formal motions page in Pittsburgh which should obsolete this issue. I've +moved this issue to NAD Editorial, solved by N3073. ++ + + +Rationale:
++Solved by N3073. +
+ + +Proposed resolution:
++Add to 20.9.9.2 [unique.ptr.single]: +
+ ++ +template <class T, class D> +class unique_ptr +{ +public: + template <class U> + unique_ptr(auto_ptr<U>& u); + template <class U> + unique_ptr(auto_ptr<U>&& u); +}; ++Add to 20.9.9.2.1 [unique.ptr.single.ctor]: +
+ ++ + + + + + +template <class U> + unique_ptr(auto_ptr<U>& u); +template <class U> + unique_ptr(auto_ptr<U>&& u); +++++Effects: Constructs a unique_ptr with u.release(). +
+ ++Postconditions: get() == the value u.get() had before +the construciton, modulo any required offset adjustments resulting from the cast from +U* to T*. u.get() == nullptr. +
+ ++Throws: nothing. +
+ ++Remarks: U* shall be implicitly convertible to T* and +D shall be the same type as default_delete<T>, else these +constructors shall not participate in overload resolution. +
+
+1103. system_error constructor postcondition overly strict
+Section: 19.5.6.2 [syserr.syserr.members] Status: WP + Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++19.5.6.2 [syserr.syserr.members] says:
system_error(error_code ec, const string& what_arg); @@ -43928,8 +62510,8 @@ However the intent is for:std::system_error se(std::errc::not_a_directory, "In FooBar"); ... -se.what(); // returns something along the lines of: - // "In FooBar: Not a directory" +se.what(); // returns something along the lines of: + // "In FooBar: Not a directory"@@ -43996,7 +62578,7 @@ Move to Tentatively Ready.
Proposed resolution:
-In 19.5.5.2 [syserr.syserr.members], change the following constructor postconditions: +In 19.5.6.2 [syserr.syserr.members], change the following constructor postconditions:
@@ -44049,7 +62631,7 @@ andstrcmp(runtime_error::what(), what_arg) == 0-In 19.5.5.2 [syserr.syserr.members], change the description of what(): +In 19.5.6.2 [syserr.syserr.members], change the description of what():
@@ -44080,7 +62662,7 @@ if (msg.empty()) { return msg.c_str();-— end note] +— end note]
+1104. basic_ios::move should accept lvalues
+Section: 27.5.4.2 [basic.ios.members] Status: WP + Submitter: Howard Hinnant Opened: 2009-04-25 Last modified: 2010-10-23
+View all other issues in [basic.ios.members].
+View all issues with WP status.
+Discussion:
++With the rvalue reference changes in +N2844 +basic_ios::move no longer has the most convenient signature: +
+ ++ +void move(basic_ios&& rhs); ++This signature should be changed to accept lvalues. It does not need to be +overloaded to accept rvalues. This is a special case that only derived clients +will see. The generic move still needs to accept rvalues. +
+ +[ +Batavia (2009-05): +]
+ +++ ++Tom prefers, on general principles, to provide both overloads. +Alisdair agrees. +
++Howard points out that there is no backward compatibility issue +as this is new to C++0X. +
++We agree that both overloads should be provided, +and Howard will provide the additional wording. +Move to Open. +
+[ +2009-05-23 Howard adds: +]
+ + ++Added overload, moved to Review. ++ +[ +2009 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++Add a signature to the existing prototype in the synopsis of 27.5.4 [ios] +and in 27.5.4.2 [basic.ios.members]: +
+ ++ + + + + +void move(basic_ios& rhs); +void move(basic_ios&& rhs); +
+1108. thread.req.exception overly constrains implementations
+Section: 30.2.2 [thread.req.exception] Status: WP + Submitter: Christopher Kohlhoff Opened: 2009-04-25 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++The current formulation of 30.2.2 [thread.req.exception]/2 reads: +
++The error_category of the error_code reported by such an +exception's code() member function is as specified in the error +condition Clause. +++This constraint on the code's associated error_categor means an +implementation must perform a mapping from the system-generated +error to a generic_category() error code. The problems with this +include: +
+ ++
+- +The mapping is always performed, even if the resultant value is + never used. +
+- +
++The original error produced by the operating system is lost. +
++The latter was one of Peter Dimov's main objections (in a private +email discussion) to the original error_code-only design, and led to +the creation of error_condition in the first place. Specifically, +error_code and error_condition are intended to perform the following +roles: +
++
+- +error_code holds the original error produced by the operating + system. +
+- +error_condition and the generic category provide a set of well + known error constants that error codes may be tested against. +
++Any mapping determining correspondence of the returned error code to +the conditions listed in the error condition clause falls under the +"latitude" granted to implementors in 19.5.1.5 [syserr.errcat.objects]. +(Although obviously their latitude is restricted a little by the +need to match the right error condition when returning an error code +from a library function.) +
++It is important that this error_code/error_condition usage is done +correctly for the thread library since it is likely to set the +pattern for future TR libraries that interact with the operating +system. +
+ +[ +Batavia (2009-05): +]
+ ++Move to Open, and recommend the issue be deferred until after the next +Committee Draft is issued. ++ +[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Tentatively Ready. ++ + + +Proposed resolution:
++Change 30.2.2 [thread.req.exception]/2: +
+ +++ + + + + + ++-2-
+The error_category (19.5.1.1) of the error_code reported by +such an exception's code() member function +is as specified in the error condition Clause.+ +The error_code reported by such an exception's code() member +function shall compare equal to one of the conditions specified in +the function's error condition Clause. [Example: When the thread +constructor fails: + ++ ++ec.category() == implementation-defined // probably system_category +ec == errc::resource_unavailable_try_again // holds true ++— end example] +
+ +
+1110. Is for_each overconstrained?
+Section: 25.2.4 [alg.foreach] Status: WP + Submitter: Alisdair Meredith Opened: 2009-04-29 Last modified: 2010-10-23
+View all other issues in [alg.foreach].
+View all issues with WP status.
+Discussion:
++Quoting working paper for reference (25.2.4 [alg.foreach]): +
+ +++ +template<InputIterator Iter, Callable<auto, Iter::reference> Function> + requires CopyConstructible<Function> + Function for_each(Iter first, Iter last, Function f); +++++1 Effects: Applies f to the result of dereferencing every iterator in the + range [first,last), starting from first and proceeding to last - 1. +
++2 Returns: f. +
++3 Complexity: Applies f exactly last - first times. +
++P2 implies the passed object f should be invoked at each stage, rather than +some copy of f. This is important if the return value is to usefully +accumulate changes. So the requirements are an object of type Function can +be passed-by-value, invoked multiple times, and then return by value. In +this case, MoveConstructible is sufficient. This would open support for +move-only functors, which might become important in concurrent code as you +can assume there are no other references (copies) of a move-only type and so +freely use them concurrently without additional locks. +
+ +[ +See further discussion starting with c++std-lib-23686. +]
+ + +[ +Batavia (2009-05): +]
+ +++ ++Pete suggests we may want to look at this in a broader context +involving other algorithms. +We should also consider the implications of parallelism. +
++Move to Open, and recommend the issue be deferred until after the next +Committee Draft is issued. +
+[ +2009-10-14 Daniel de-conceptified the proposed resolution. +]
+ + +++ ++The note in 25.1 [algorithms.general]/9 already says the right thing: +
++Unless otherwise specified, algorithms that take function objects +as arguments are permitted to copy those function objects freely. +++So we only need to ensure that the wording for for_each is sufficiently +clear, which is the intend of the following rewording. +
+[ +2009-10-15 Daniel proposes: +]
+ + +++ ++
+- +
++Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]): +
++++Requires: Function shall be MoveConstructible +( [moveconstructible]), CopyConstructible is not required. +
+- +
++Change 25.2.4 [alg.foreach]/2 as indicated: +
+ ++Returns: std::move(f). ++[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Tentatively Ready, using Daniel's wording without the portion +saying "CopyConstructible is not required". ++ +[ +2009-10-27 Daniel adds: +]
+ + +++ ++I see that during the Santa Cruz meeting the originally proposed addition +
+ ++, CopyConstructible is not required. ++ ++was removed. I don't think that this removal was a good idea. The combination +of 25.1 [algorithms.general]/9 +
+ ++[Note: Unless otherwise specified, algorithms that take function objects +as arguments are permitted to copy those function objects freely.[..] ++ ++with the fact that CopyConstructible is a refinement MoveConstructible +makes it necessary that such an explicit statement is given. Even the +existence of the usage of std::move in the Returns clause doesn't +help much, because this would still be well-formed for a CopyConstructible +without move constructor. Let me add that the originally proposed +addition reflects current practice in the standard, e.g. 25.3.9 [alg.unique]/5 +usages a similar terminology. +
+ ++For similar wording need in case for auto_ptr see 973. +
+ +[ +Howard: Moved from Tentatively Ready to Open. +]
+ +[ +2009-11-20 Howard restores "not CopyConstructible" to the spec. +]
+ + +[ +2009-11-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++
+ + + + + + + + +- +
++Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]): +
++++Requires: Function shall meet the requirements of +MoveConstructible ( [moveconstructible]). +Function need not meet the requirements of +CopyConstructible ( [copyconstructible]). +
+- +
++Change 25.2.4 [alg.foreach]/2 as indicated: +
+ ++Returns: std::move(f). ++
+1113. bitset::to_string could be simplified
+Section: 20.5 [template.bitset] Status: WP + Submitter: Alisdair Meredith Opened: 2009-05-09 Last modified: 2010-10-23
+View all other issues in [template.bitset].
+View all issues with WP status.
+Discussion:
++In 853 our resolution is changing the signature by adding two +defaulting arguments to 3 calls. In principle, this means that ABI breakage +is not an issue, while API is preserved. +
++With that observation, it would be very nice to use the new ability to +supply default template parameters to function templates to collapse all 3 +signatures into 1. In that spirit, this issue offers an alternative resolution +than that of 853. +
+ +[ +Batavia (2009-05): +]
+ ++Move to Open, +and look at the issue again after 853 has been accepted. +We further recommend this be deferred until after the next Committee Draft. ++ +[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Tentatively Ready. ++ + + +Proposed resolution:
+ ++
+ + + + + + +- +
++In 20.5 [template.bitset]/1 (class bitset) ammend: +
++template <class charT = char, + class traits = char_traits<charT>, + class Allocator = allocator<charT>> + basic_string<charT, traits, Allocator> + to_string(charT zero = charT('0'), charT one = charT('1')) const; +template <class charT, class traits> + basic_string<charT, traits, allocator<charT> > to_string() const; +template <class charT> + basic_string<charT, char_traits<charT>, allocator<charT> > to_string() const; +basic_string<char, char_traits<char>, allocator<char> > to_string() const;+- +
++In 20.5.2 [bitset.members] prior to p35 ammend: +
++template <class charT = char, + class traits = char_traits<charT>, + class Allocator = allocator<charT>> + basic_string<charT, traits, Allocator> + to_string(charT zero = charT('0'), charT one = charT('1')) const; +- +Strike 20.5.2 [bitset.members] paragraphs 37 -> 39 (including signature +above 37) +
+
+1114. Type traits underspecified
+Section: 20.7 [meta] Status: WP + Submitter: Daniel Krügler Opened: 2009-05-12 Last modified: 2010-10-23
+View all other issues in [meta].
+View all issues with WP status.
+Discussion:
+ + + ++The current wording in 20.7.1 [meta.rqmts] is still unclear concerning +it's requirements on the type traits classes regarding ambiguities. +Specifically it's unclear +
+ ++
+ +- +if a predicate trait (20.7.4 [meta.unary], 20.7.6 [meta.rel]) could derive from both +true_type/false_type. +
+- +if any of the type traits (20.7.1 [meta.rqmts], 20.7.4 [meta.unary], 20.7.6 [meta.rel]) could ambiguously derive +from the same specified result type. +
+- +if any of the type traits (20.7.1 [meta.rqmts], 20.7.4 [meta.unary], 20.7.6 [meta.rel]) could derive from other +integral_constant types making the contained names ambiguous +
+- +if any of the type traits (20.7.1 [meta.rqmts], 20.7.4 [meta.unary], 20.7.6 [meta.rel]) could have other base +classes that contain members hiding the name of the result type members +or make the contained member names ambiguous. +
+[ +Batavia (2009-05): +]
+ +++ ++Alisdair would prefer to factor some of the repeated text, +but modulo a corner case or two, +he believes the proposed wording is otherwise substantially correct. +
++Move to Open. +
+[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Tentatively Ready. ++ + + +Proposed resolution:
+[ +The usage of the notion of a BaseCharacteristic below might be +useful in other places - e.g. to define the base class relation in 20.8.4 [refwrap], 20.8.13 [func.memfn], or 20.8.14.2 [func.wrap.func]. In this case it's definition should probably +be moved to Clause 17 +]
+ + ++
+ + + + + + +- +
++Change 20.7.1 [meta.rqmts]/1 as indicated: +
++[..] It shall be DefaultConstructible, CopyConstructible, and publicly +and unambiguously derived, directly or indirectly, from +its BaseCharacteristic, which is a specialization of the +template integral_constant (20.6.3), with the arguments to the template +integral_constant determined by the requirements for the particular +property being described. The member names of the +BaseCharacteristic shall be unhidden and unambiguously +available in the UnaryTypeTrait. ++- +
++Change 20.7.1 [meta.rqmts]/2 as indicated: +
++[..] It shall be DefaultConstructible, CopyConstructible, and publicly +and unambiguously derived, directly or indirectly, from ++an instanceits BaseCharacteristic, which is a +specialization of the template integral_constant (20.6.3), with +the arguments to the template integral_constant determined by the +requirements for the particular relationship being described. The +member names of the BaseCharacteristic shall be unhidden +and unambiguously available in the BinaryTypeTrait. +- +
++Change 20.7.4 [meta.unary]/2 as indicated: +
++Each of these templates shall be a UnaryTypeTrait (20.6.1), ++publicly derived directly or indirectly from true_type if the +corresponding condition is true, otherwise from false_type+where its BaseCharacteristic shall be true_type if the +corresponding condition is true, otherwise false_type. +- +
++Change 20.7.6 [meta.rel]/2 as indicated: +
+ ++Each of these templates shall be a BinaryTypeTrait (20.6.1), ++publicly derived directly or indirectly from true_type if the +corresponding condition is true, otherwise from false_type+where its BaseCharacteristic shall be true_type if the +corresponding condition is true, otherwise false_type. +
+1116. Literal constructors for tuple
+Section: 20.4.2 [tuple.tuple] Status: Resolved + Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-11-20
+View all other issues in [tuple.tuple].
+View all issues with Resolved status.
+Discussion:
++It is not currently possible to construct tuple literal values, +even if the elements are all literal types. This is because parameters +are passed to constructor by reference. +
++An alternative would be to pass all constructor arguments by value, where it +is known that *all* elements are literal types. This can be determined with +concepts, although note that the negative constraint really requires +factoring out a separate concept, as there is no way to provide an 'any of +these fails' constraint inline. +
++Note that we will have similar issues with pair (and +tuple constructors from pair) although I am steering +clear of that class while other constructor-related issues settle. +
+ +[ +2009-10 Santa Cruz: +]
+ + +++ + +NAD EditorialResolved. Solved by +N2994. +Proposed resolution:
++Ammend the tuple class template declaration in 20.4.2 [tuple.tuple] as +follows +
+ +++ ++Add the following concept: +
+ ++ +auto concept AllLiteral< typename ... Types > { + requires LiteralType<Types>...; +} ++ammend the constructor +
+ ++ +template <class... UTypes> + requires AllLiteral<Types...> + && Constructible<Types, UTypes>... + explicit tuple(UTypes...); + +template <class... UTypes> + requires !AllLiteral<Types...> + && Constructible<Types, UTypes&&>... + explicit tuple(UTypes&&...); ++ammend the constructor +
+ ++ +template <class... UTypes> + requires AllLiteral<Types...> + && Constructible<Types, UTypes>... + tuple(tuple<UTypes...>); + +template <class... UTypes> + requires !AllLiteral<Types...> + && Constructible<Types, const UTypes&>... + tuple(const tuple<UTypes...>&); ++Update the same signatures in 20.4.2.1 [tuple.cnstr], paras 3 and 5. +
+ + + + + +
+1117. tuple copy constructor
+Section: 20.4.2.1 [tuple.cnstr] Status: Resolved + Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-11-20
+View all other issues in [tuple.cnstr].
+View all issues with Resolved status.
+Discussion:
++The copy constructor for the tuple template is constrained. This seems an +unusual strategy, as the copy constructor will be implicitly deleted if the +constraints are not met. This is exactly the same effect as requesting an +=default; constructor. The advantage of the latter is that it retains +triviality, and provides support for tuples as literal types if issue +1116 is also accepted. +
++Actually, it might be worth checking with core if a constrained copy +constructor is treated as a constructor template, and as such does not +suppress the implicit generation of the copy constructor which would hide +the template in this case. +
+ +[ +2009-05-27 Daniel adds: +]
+ + ++This would solve one half of the suggested changes in 801. ++ +[ +2009-10 Santa Cruz: +]
+ + +++ + +NAD EditorialResolved. Solved by +N2994. +Proposed resolution:
++Change 20.4.2 [tuple.tuple] and 20.4.2.1 [tuple.cnstr] p4: +
+ ++ + + + + +requires CopyConstructible<Types>...tuple(const tuple&) = default; +
+1118. tuple query APIs do not support cv-qualification
+Section: 20.4.2.5 [tuple.helper] Status: WP + Submitter: Alisdair Meredith Opened: 2009-05-23 Last modified: 2010-11-23
+View all other issues in [tuple.helper].
+View all issues with WP status.
+Discussion:
++The APIs tuple_size and tuple_element do not support +cv-qualified tuples, pairs or arrays. +
++The most generic solution would be to supply partial specializations once +for each cv-type in the tuple header. However, requiring this header for +cv-qualified pairs/arrays seems unhelpful. The BSI editorial +suggestion (UK-198/US-69, +N2533) +to merge tuple into <utility> would help with pair, +but not array. That might be resolved by making a dependency between the +<array> header and <utility>, or simply recognising +the dependency be fulfilled in a Remark. +
+ +[ +2009-05-24 Daniel adds: +]
+ + +++ ++All tuple_size templates with a base class need to derive publicly, e.g. +
+ ++ +template <IdentityOf T> class tuple_size< const T > : + public tuple_size<T> {}; ++The same applies to the tuple_element class hierarchies. +
++What is actually meant with the comment +
++this solution relies on 'metafunction forwarding' to inherit the +nested typename type +++? +
++I ask, because all base classes are currently unconstrained and their +instantiation is invalid in the constrained context of the tuple_element partial +template specializations. +
+[ +2009-05-24 Alisdair adds: +]
+ + +++ ++I think a better solution might be to ask Pete editorially to change all +declarations of tupling APIs to use the struct specifier instead of class. +
++"metafunction forwarding" refers to the MPL metafunction protocol, where a +metafunction result is declared as a nested typedef with the name "type", +allowing metafunctions to be chained by means of inheritance. It is a +neater syntax than repeatedly declaring a typedef, and inheritance syntax is +slightly nicer when it comes to additional typename keywords. +
++The constrained template with an unconstrained base is a good observation +though. +
+[ +2009-10 post-Santa Cruz: +]
+ + ++Move to Open, Alisdair to provide wording. Once wording is +provided, Howard will move to Review. ++ +[ +2010-03-28 Daniel deconceptified wording. +]
+ + +[ +Post-Rapperswil - Daniel provides wording: +]
+ + ++The below given P/R reflects the discussion from the Rapperswil meeting that the wording should not constrain +implementation freedom to realize the actual issue target. Thus the original code form was replaced by +normative words. +
++While preparing this wording it turned out that several tuple_size specializations as +that of pair and array are underspecified, because the underlying type of the member +value is not specified except that it is an integral type. For the specializations we could introduce a +canonical one - like size_t - or we could use the same type as the specialization of the +unqualified type uses. The following wording follows the second approach. +
++The wording refers to N3126. +
+ ++Moved to Tentatively Ready after 6 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ ++
+ + + + + + +- Change 20.4.1 [tuple.general]/2, header <tuple> synopsis, as indicated: +
++// 20.4.2.5, tuple helper classes: +template <class T> class tuple_size; // undefined +template <class T> class tuple_size<const T>; +template <class T> class tuple_size<volatile T>; +template <class T> class tuple_size<const volatile T>; + +template <class... Types> class tuple_size<tuple<Types...> >; + +template <size_t I, class T> class tuple_element; // undefined +template <size_t I, class T> class tuple_element<I, const T>; +template <size_t I, class T> class tuple_element<I, volatile T>; +template <size_t I, class T> class tuple_element<I, const volatile T>; + +template <size_t I, class... Types> class tuple_element<I, tuple<Types...> >; +- Add the end of subclause 20.4.2.5 [tuple.helper] insert the following two paragraphs: +
++ +template <class T> class tuple_size<const T>; +template <class T> class tuple_size<volatile T>; +template <class T> class tuple_size<const volatile T>; ++Let TS denote tuple_size<T> of the cv-unqualified type T. +Then each of the three templates shall meet the UnaryTypeTrait requirements (20.7.1) with a BaseCharacteristic of +integral_constant<remove_cv<decltype(TS::value)>::type, TS::value>. ++template <size_t I, class T> class tuple_element<I, const T>; +template <size_t I, class T> class tuple_element<I, volatile T>; +template <size_t I, class T> class tuple_element<I, const volatile T>; ++Let TE denote tuple_element<I, T> of the cv-unqualified type T. Then each of the +three templates shall meet the TransformationTrait requirements (20.7.1) with a member typedef type that shall name the +same type as the following type: ++
+- for the first specialization, the type add_const<TE::type>::type,
+- for the second specialization, the type add_volatile<TE::type>::type, and
+- for the third specialization, the type add_cv<TE::type>::type
+
+1122. Ratio values should be constexpr
+Section: 20.6.1 [ratio.ratio] Status: Resolved + Submitter: Alisdair Meredith Opened: 2009-05-25 Last modified: 2010-11-20
+View all other issues in [ratio.ratio].
+View all issues with Resolved status.
+Discussion:
++The values num and den in the ratio template +should be declared constexpr. +
+ +[ +2009-10 Santa Cruz: +]
+ + +++ + +NAD EditorialResolved. Solved by +N2994. +Proposed resolution:
++20.6.1 [ratio.ratio] +
+ ++ + + + + + +namespace std { + template <intmax_t N, intmax_t D = 1> + class ratio { + public: + static constexpr intmax_t num; + static constexpr intmax_t den; + }; +} +
+1123. no requirement that standard streams be flushed
+Section: 27.5.2.1.6 [ios::Init] Status: WP + Submitter: James Kanze Opened: 2009-05-14 Last modified: 2010-10-23
+View all other issues in [ios::Init].
+View all issues with WP status.
+Discussion:
++As currently formulated, the standard doesn't require that there +is ever a flush of cout, etc. (This implies, for example, that +the classical hello, world program may have no output.) In the +current draft +(N2798), +there is a requirement that the objects +be constructed before main, and before the dynamic +initialization of any non-local objects defined after the +inclusion of <iostream> in the same translation unit. The only +requirement that I can find concerning flushing, however, is in +27.5.2.1.6 [ios::Init], where the destructor of the last +std::ios_base::Init object flushes. But there is, as far as I +can see, no guarantee that such an object ever exists. +
++Also, the wording in [iostreams.objects] says that: +
++The objects +are constructed and the associations are established at some +time prior to or during the first time an object of class +ios_base::Init is constructed, and in any case before the body +of main begins execution. +++In 27.5.2.1.6 [ios::Init], however, as an +effect of the constructor, it says that +
++If init_cnt is zero, +the function stores the value one in init_cnt, then constructs +and initializes the objects cin, cout, cerr, clog +wcin, wcout, wcerr, and wclog" ++ ++which seems to forbid earlier +construction. +
+ ++(Note that with these changes, the exposition only "static +int init_cnt" in ios_base::Init can be dropped.) +
++Of course, a determined programmer can still inhibit the +flush with things like: +
++new std::ios_base::Init ; // never deleted ++or (in a function): +
++std::ios_base::Init ensureConstruction ; +// ... +exit( EXIT_SUCCESS ) ; ++Perhaps some words somewhere to the effect that all +std::ios_base::Init objects should have static lifetime +would be in order. +
+ +[ +2009 Santa Cruz: +]
+ + ++Moved to Ready. Some editorial changes are expected (in addition to the +proposed wording) to remove init_cnt from Init. ++ + + +Proposed resolution:
++Change 27.4 [iostream.objects]/2: +
+ ++-2- The objects are constructed and the associations are established at +some time prior to or during the first time an object of class +ios_base::Init is constructed, and in any case before the body +of main begins execution.292 The objects are not destroyed +during program execution.293 ++ +If a translation unit includes +<iostream> or explicitly constructs an +ios_base::Init object, these stream objects shall be +constructed before dynamic initialization of non-local objects defined +later in that translation unit.+The results of including <iostream> in a translation +unit shall be as if <iostream> defined an instance of +ios_base::Init with static lifetime. Similarly, the entire +program shall behave as if there were at least one instance of +ios_base::Init with static lifetime. ++Change 27.5.2.1.6 [ios::Init]/3: +
+ +++ +Init(); +++-3- Effects: Constructs an object of class Init. ++If init_cnt is zero, the function stores the value one in +init_cnt, then constructs and initializes the objects +cin, cout, cerr, clog (27.4.1), +wcin, wcout, wcerr, and wclog +(27.4.2). In any case, the function then adds one to the value stored in +init_cnt.+Constructs and initializes the objects cin, cout, +cerr, clog, wcin, wcout, +wcerr and wclog if they have not already been +constructed and initialized. ++Change 27.5.2.1.6 [ios::Init]/4: +
+ +++ + + + + + +~Init(); +++-4- Effects: Destroys an object of class Init. ++The function subtracts one from the value stored in init_cnt and, +if the resulting stored value is one,+If there are no other instances of the class still in +existance, +calls cout.flush(), +cerr.flush(), clog.flush(), wcout.flush(), +wcerr.flush(), wclog.flush(). +
+1126. istreambuff_iterator::equal needs a const & parameter
+Section: 24.6.3.5 [istreambuf.iterator::equal] Status: WP + Submitter: Alisdair Meredith Opened: 2009-05-28 Last modified: 2010-10-23
+View all other issues in [istreambuf.iterator::equal].
+View all issues with WP status.
+Discussion:
++The equal member function of istreambuf_iterator is +declared const, but takes its argument by non-const reference. +
++This is not compatible with the operator== free function overload, which is +defined in terms of calling equal yet takes both arguments by reference to +const. +
+ +[ +The proposed wording is consistent with 110 with status TC1. +]
+ + +[ +2009-11-02 Howard adds: +]
+ + ++Set to Tentatively Ready after 5 positive votes on c++std-lib. ++ + + +Proposed resolution:
++Ammend in both:
+ +
+24.6.3 [istreambuf.iterator]
+24.6.3.5 [istreambuf.iterator::equal]
++ + + + + + +bool equal(const istreambuf_iterator& b) const; +
+1130. copy_exception name misleading
+Section: 18.8.5 [propagation] Status: WP + Submitter: Peter Dimov Opened: 2009-05-13 Last modified: 2010-10-23
+View other active issues in [propagation].
+View all other issues in [propagation].
+View all issues with WP status.
+Discussion:
++The naming of std::copy_exception misleads almost everyone +(experts included!) to think that it is the function that copies an +exception_ptr: +
+ ++ +exception_ptr p1 = current_exception(); +exception_ptr p2 = copy_exception( p1 ); ++But this is not at all what it does. The above actually creates an +exception_ptr p2 that contains a copy of p1, not of +the exception to which p1 refers! +
++This is, of course, all my fault; in my defence, I used copy_exception +because I was unable to think of a better name. +
++But I believe that, based on what we've seen so far, any other name would be better. +
++Therefore, I propose copy_exception to be renamed to +create_exception: +
+ ++ +template<class E> exception_ptr create_exception(E e); ++with the following explanatory paragraph after it: +
+ ++Creates an exception_ptr that refers to a copy of e. ++ +[ +2009-05-13 Daniel adds: +]
+ + +++ ++What about +
++make_exception_ptr ++in similarity to make_pair and make_tuple, make_error_code and +make_error_condition, or make_shared? Or, if a stronger symmetry to +current_exception is preferred: +
+ ++make_exception ++We have not a single create_* function in the library, it was always +make_* used. +
+[ +2009-05-13 Peter adds: +]
+ + ++make_exception_ptr works for me. ++ +[ +2009-06-02 Thomas J. Gritzan adds: +]
+ + +++ ++To avoid surprises and unwanted recursion, how about making a call to +std::make_exception_ptr with an exception_ptr illegal? +
++It might work like this: +
++template<class E> +exception_ptr make_exception_ptr(E e); +template<> +exception_ptr make_exception_ptr<exception_ptr>(exception_ptr e) = delete; +[ +2009 Santa Cruz: +]
+ + ++Move to Review for the time being. The subgroup thinks this is a good +idea, but doesn't want to break compatibility unnecessarily if someone +is already shipping this. Let's talk to Benjamin and PJP tomorrow to +make sure neither objects. ++ +[ +2009-11-16 Jonathan Wakely adds: +]
+ + ++GCC 4.4 shipped with copy_exception but we could certainly keep that +symbol in the library (but not the headers) so it can still be found +by any apps foolishly relying on the experimental C++0x mode being ABI +stable. ++ +[ +2009-11-16 Peter adopts wording supplied by Daniel. +]
+ + +[ +2009-11-16 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++
+ + + + + + +- +
+ ++Change 18.8 [support.exception]/1, header <exception> +synopsis as indicated: +
+ ++exception_ptr current_exception(); +void rethrow_exception [[noreturn]] (exception_ptr p); +template<class E> exception_ptrcopy_exceptionmake_exception_ptr(E e); +- +
+ ++Change 18.8.5 [propagation]: +
+ +++template<class E> exception_ptr+ +copy_exceptionmake_exception_ptr(E e); +++ ++-11- Effects: Creates an exception_ptr that refers +to a copy of e, as if +
+ ++ +try { + throw e; +} catch(...) { + return current_exception(); +} +...
+- +
++Change 30.6.5 [futures.promise]/7 as indicated: +
+ ++Effects: if the associated state of *this is not ready, stores an exception +object of type future_error with an error code of broken_promise as if by +this->set_exception(+copy_exceptionmake_exception_ptr( +future_error(future_errc::broken_promise)). Destroys ... +
+1131. C++0x does not need alignment_of
+Section: 20.7.4.3 [meta.unary.prop] Status: WP + Submitter: Niels Dekker Opened: 2009-06-01 Last modified: 2010-10-23
+View all other issues in [meta.unary.prop].
+View all issues with WP status.
+Discussion:
++The alignment_of template is no longer necessary, now that the +core language will provide alignof. Scott Meyers raised this +issue at comp.std.c++, +C++0x: alignof vs. alignment_of, +May 21, 2009. In a reply, Daniel Krügler pointed out that +alignof was added to the working paper after +alignment_of. So it appears that alignment_of is only +part of the current Working Draft +(N2857) +because it is in TR1. +
++Having both alignof and alignment_of would cause +unwanted confusion. In general, I think TR1 functionality should not be +brought into C++0x if it is entirely redundant with other C++0x language +or library features. +
+ +[ +2009-11-16 Chris adds: +]
+ + +++ ++I would like to suggest the following new wording for this issue, based on +recent discussions. Basically this doesn't delete alignment_of, it just +makes it clear that it is just a wrapper for alignof. This deletes the +first part of the proposed resolution, changes the second part by leaving in +alignof(T) but changing the precondition and leaves the 3rd part +unchanged. +
+ ++Suggested Resolution: +
+ ++++Change the first row of Table 44 ("Type property queries"), from Type properties +20.7.4.3 [meta.unary.prop]: +
+ +++ ++
+Table 44 — Type property queries ++ + ++template <class T> struct alignment_of; + ++alignof(T). +
+Precondition:T shall be a complete type, a reference type, +or an array of unknown bound, but shall not be a function type or (possibly +cv-qualified) void.alignof(T) shall be defined ++Change text in Table 51 ("Other transformations"), from Other transformations +20.7.7.6 [meta.trans.other], as follows: +
+ ++++
+Table 51 — Other transformations +...aligned_storage; ++Len shall not be zero. Align shall be equal to + +alignment_of<T>::valuealignof(T) for some +type T or to default-alignment. +... +[ +2010-01-30 Alisdair proposes that Chris' wording be moved into the proposed wording +section and tweaks it on the way. +]
+ + +++ ++Original proposed wording saved here: +
++++Remove from Header <type_traits> synopsis 20.7.2 [meta.type.synop]: +
++ +template <class T> struct alignment_of;++Remove the first row of Table 44 ("Type property queries"), from +Type properties 20.7.4.3 [meta.unary.prop]: +
+++ ++
+Table 44 — Type property queries ++ ++ template <class T> struct alignment_of;+ alignof(T).
+Precondition: T shall be a complete type, a reference +type, or an array of unknown bound, but shall not be a function type or +(possibly cv-qualified) void.++Change text in Table 51 ("Other transformations"), from Other +transformations 20.7.7.6 [meta.trans.other], as follows: +
++++
+Table 51 — Other transformations +...aligned_storage; ++Len shall not be zero. Align shall be equal to + +alignment_of<T>::valuealignof(T) for some +type T or to default-alignment. +... +[ +2010-01-30 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+ ++Change the first row of Table 43 ("Type property queries"), from Type properties +20.7.4.3 [meta.unary.prop]: +
+ +++ ++
+Table 43 — Type property queries ++ + ++template <class T> struct alignment_of; + ++alignof(T). +
+Precondition:T shall be a complete type, a reference type, +or an array of unknown bound, but shall not be a function type or (possibly +cv-qualified) void.alignof(T) is a valid +expression (5.3.6 [expr.alignof]) ++Change text in Table 51 ("Other transformations"), from Other transformations +20.7.7.6 [meta.trans.other], as follows: +
+ +++ + + + + + ++
+Table 51 — Other transformations +...aligned_storage; ++Len shall not be zero. Align shall be equal to + +alignment_of<T>::valuealignof(T) for some +type T or to default-alignment. +... +
+1133. Does N2844 break current specification of list::splice?
+Section: 23.3.3.5 [forwardlist.ops], 23.3.4.4 [list.ops] Status: WP + Submitter: Alisdair Meredith Opened: 2009-05-09 Last modified: 2010-10-23
+View all other issues in [forwardlist.ops].
+View all issues with WP status.
+Discussion:
++IIUC, +N2844 +means that lvalues will no longer bind to rvalue references. +Therefore, the current specification of list::splice (list +operations 23.3.4.4 [list.ops]) will be a breaking change of behaviour for existing +programs. That is because we changed the signature to swallow via an rvalue +reference rather than the lvalue reference used in 03. +
++Retaining this form would be safer, requiring an explicit move when splicing +from lvalues. However, this will break existing programs. +We have the same problem with forward_list, although without the risk of +breaking programs so here it might be viewed as a positive feature. +
++The problem signatures: +
++ +Possible resolutions: + +void splice_after(const_iterator position, forward_list<T,Alloc>&& x); +void splice_after(const_iterator position, forward_list<T,Alloc>&& x, + const_iterator i); +void splice_after(const_iterator position, forward_list<T,Alloc>&& x, + const_iterator first, const_iterator last); + +void splice(const_iterator position, list<T,Alloc>&& x); +void splice(const_iterator position, list<T,Alloc>&& x, + const_iterator i); +void splice(const_iterator position, list<T,Alloc>&& x, + const_iterator first, const_iterator last); ++Option A. Add an additional (non-const) lvalue-reference +overload in each case +
++Option B. Change rvalue reference back to (non-const) +lvalue-reference overload in each case +
++Option C. Add an additional (non-const) lvalue-reference +overload in just the std::list cases +
++I think (B) would be very unfortunate, I really like the forward_list +behaviour in (C) but feel (A) is needed for consistency. +
++My actual preference would be NAD, ship with this as a breaking change as it +is a more explicit interface. I don't think that will fly though! +
+ ++See the thread starting with c++std-lib-23725 for more discussion. +
+ +[ +2009-10-27 Christopher Jefferson provides proposed wording for Option C. +]
+ + +[ +2009-12-08 Jonathan Wakely adds: +]
+ + +++ ++As Bill Plauger pointed out, list::merge needs similar treatment. +
+[ +Wording updated. +]
+ +[ +2009-12-13 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++In 23.3.4 [list] +
+ ++Add lvalue overloads before rvalue ones: +
+ ++ +void splice(const_iterator position, list<T,Allocator>& x); +void splice(const_iterator position, list<T,Allocator>&& x); +void splice(const_iterator position, list<T,Allocator>& x, const_iterator i); +void splice(const_iterator position, list<T,Allocator>&& x, const_iterator i); +void splice(const_iterator position, list<T,Allocator>& x, + const_iterator first, const_iterator last); +void splice(const_iterator position, list<T,Allocator>&& x, + const_iterator first, const_iterator last); +void merge(list<T,Allocator>& x); +template <class Compare> void merge(list<T,Allocator>& x, Compare comp); +void merge(list<T,Allocator>&& x); +template <class Compare> void merge(list<T,Allocator>&& x, Compare comp); + ++In 23.3.4.4 [list.ops], similarly add lvalue overload before each rvalue one: +
++(After paragraph 2) +
+ ++ +void splice(const_iterator position, list<T,Allocator>& x); +void splice(const_iterator position, list<T,Allocator>&& x); ++(After paragraph 6) +
+ ++ +void splice(const_iterator position, list<T,Allocator>& x, const_iterator i); +void splice(const_iterator position, list<T,Allocator>&& x, const_iterator i); ++(After paragraph 10) +
+ ++ +void splice(const_iterator position, list<T,Allocator>& x, + const_iterator first, const_iterator last); +void splice(const_iterator position, list<T,Allocator>&& x, + const_iterator first, const_iterator last); ++In 23.3.4.4 [list.ops], after paragraph 21 +
+ ++ + + + + + +void merge(list<T,Allocator>& x); +template <class Compare> void merge(list<T,Allocator>& x, Compare comp); +void merge(list<T,Allocator>&& x); +template <class Compare> void merge(list<T,Allocator>&& x, Compare comp); +
+1134. Redundant specification of stdint.h, fenv.h, tgmath.h, and maybe complex.h
+Section: X [stdinth], X [fenv], 26.8 [c.math], X [cmplxh] Status: WP + Submitter: Robert Klarer Opened: 2009-05-26 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++This is probably editorial. +
++The following items should be removed from the draft, because they're +redundant with Annex D, and they arguably make some *.h headers +non-deprecated: +
++X [stdinth] (regarding <stdint.h>) +
++X [fenv] (regarding <fenv.h> +
++Line 3 of 26.8 [c.math] (regarding <tgmath.h>) +
++X [cmplxh] (regarding <complex.h>, though the note in this subclause is not redundant) +
+ +[ +2009-06-10 Ganesh adds: +]
+ + ++While searching for stdint in the CD, I found that <stdint.h> is also +mentioned in 3.9.1 [basic.fundamental] /5. It guess it should refer to +<cstdint> instead. ++ +[ +2009 Santa Cruz: +]
+ + ++Real issue. Maybe just editorial, maybe not. Move to Ready. ++ + + +Proposed resolution:
++Remove the section X [stdinth]. +
++Remove the section X [fenv]. +
++Remove 26.8 [c.math], p3: +
+ +++-3- The header <tgmath.h> effectively includes the headers <complex.h> +and <math.h>.++Remove the section X [cmplxh]. +
+ + + + + +
+1135. exception_ptr should support contextual conversion to bool
+Section: 18.8.5 [propagation] Status: Resolved + Submitter: Daniel Krügler Opened: 2007-06-06 Last modified: 2010-11-19
+View other active issues in [propagation].
+View all other issues in [propagation].
+View all issues with Resolved status.
+Discussion:
++As of +N2857 +18.8.5 [propagation]/5, the implementation-defined type +exception_ptr does provide the following ways to check whether +it is a null value: +
++void f(std::exception_ptr p) { + p == nullptr; + p == 0; + p == exception_ptr(); +} ++This is rather cumbersome way of checking for the null value +and I suggest to require support for evaluation in a boolean +context like so: +
+ ++ +void g(std::exception_ptr p) { + if (p) {} + !p; +} +[ +2009 Santa Cruz: +]
+ + ++Move to Ready. Note to editor: considering putting in a cross-reference +to 4 [conv], paragraph 3, which defines the phrase +"contextually converted to bool". ++ +[ +2010-03-14 Howard adds: +]
+ + ++We moved +N3073 +to the formal motions page in Pittsburgh which should obsolete this issue. I've +moved this issue to NAD Editorial, solved by N3073. ++ + + +Rationale:
++Solved by N3073. +
+ + +Proposed resolution:
++In section 18.8.5 [propagation] insert a new paragraph between p.5 and p.6: +
+ ++ +An object e of type exception_ptr can be contextually converted to bool. +The effect shall be as if e != exception_ptr() had been evaluated in place +of e. There shall be no implicit conversion to arithmetic type, to +enumeration type or to pointer type. + ++ + + + + +
+1136. Incomplete specification of nested_exception::rethrow_nested()
+Section: 18.8.6 [except.nested] Status: WP + Submitter: Daniel Krügler Opened: 2007-06-06 Last modified: 2010-10-23
+View all other issues in [except.nested].
+View all issues with WP status.
+Discussion:
++It was recently mentioned in a newsgroup article +http://groups.google.de/group/comp.std.c++/msg/f82022aff68edf3d +that the specification of the member function rethrow_nested() of the +class nested_exception is incomplete, specifically it remains unclear +what happens, if member nested_ptr() returns a null value. In +18.8.6 [except.nested] we find only the following paragraph related to that: +
++void rethrow_nested() const; // [[noreturn]] +++-4- Throws: the stored exception captured by this nested_exception object. +++This is a problem, because it is possible to create an object of +nested_exception with exactly such a state, e.g. +
++#include <exception> +#include <iostream> + +int main() try { + std::nested_exception e; // OK, calls current_exception() and stores it's null value + e.rethrow_nested(); // ? + std::cout << "A" << std::endl; +} +catch(...) { + std::cout << "B" << std::endl; +} ++I suggest to follow the proposal of the reporter, namely to invoke +terminate() if nested_ptr() return a null value of exception_ptr instead +of relying on the fallback position of undefined behavior. This would +be consistent to the behavior of a throw; statement when no +exception is being handled. +
+ +[ +2009 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++Change around 18.8.6 [except.nested]/4 as indicated: +
+++ + + + + ++-4- Throws: the stored exception captured by this nested_exception +object, if nested_ptr() != nullptr +
++- Remarks: If nested_ptr() == nullptr, terminate() +shall be called. +
+
+1137. Return type of conj and proj
+Section: 26.4.9 [cmplx.over] Status: WP + Submitter: Marc Steinbach Opened: 2009-06-11 Last modified: 2010-10-23
+View all other issues in [cmplx.over].
+View all issues with WP status.
+Discussion:
++In clause 1, the Working Draft +(N2857) +specifies overloads of the +functions +
++arg, conj, imag, norm, proj, real ++for non-complex arithmetic types (float, double, +long double, and integers). +The only requirement (clause 2) specifies effective type promotion of arguments. +
++I strongly suggest to add the following requirement on the return types: +
++All the specified overloads must return real (i.e., non-complex) values, +specifically, the nested value_type of effectively promoted arguments. ++ ++(This has no effect on arg, imag, norm, real: +they are real-valued anyway.) +
+Rationale:
++Mathematically, conj() and proj(), like the transcendental functions, are +complex-valued in general but map the (extended) real line to itself. +In fact, both functions act as identity on the reals. +A typical user will expect conj() and proj() to preserve this essential +mathematical property in the same way as exp(), sin(), etc. +A typical use of conj(), e.g., is the generic scalar product of n-vectors: +
+ ++template<typename T> +inline T +scalar_product(size_t n, T const* x, T const* y) { + T result = 0; + for (size_t i = 0; i < n; ++i) + result += x[i] * std::conj(y[i]); + return result; +} ++This will work equally well for real and complex floating-point types T if +conj() returns T. It will not work with real types if conj() +returns complex values. +
++Instead, the implementation of scalar_product becomes either less efficient +and less useful (if a complex result is always returned), or unnecessarily +complicated (if overloaded versions with proper return types are defined). +In the second case, the real-argument overload of conj() cannot be used. +In fact, it must be avoided. +
++Overloaded conj() and proj() are principally needed in generic programming. +All such use cases will benefit from the proposed return type requirement, +in a similar way as the scalar_product example. +The requirement will not harm use cases where a complex return value +is expected, because of implicit conversion to complex. +Without the proposed return type guarantee, I find overloaded versions +of conj() and proj() not only useless but actually troublesome. +
+ + +[ +2009-11-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++Insert a new paragraph after 26.4.9 [cmplx.over]/2: +
+ ++ +All of the specified overloads shall have a return type which is the nested value_type of +the effectively cast arguments. + ++ + + + + +
+1138. unusual return value for operator+
+Section: 21.4.8.1 [string::op+] Status: WP + Submitter: Alisdair Meredith Opened: 2009-06-12 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++Many of the basic_string operator+ overloads return an rvalue-reference. Is +that really intended? +
++I'm considering it might be a mild performance tweak to avoid making +un-necessary copies of a cheaply movable type, but it opens risk to dangling +references in code like: +
+ ++ +auto && s = string{"x"} + string{y}; ++and I'm not sure about: +
+ ++ +auto s = string{"x"} + string{y}; +[ +2009-10-11 Howard updated Returns: clause for each of these. +]
+ + +[ +2009-11-05 Howard adds: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ + +Proposed resolution:
++Strike the && from the return type in the following function +signatures: +
+ +++ + + + + + ++21.3 [string.classes] p2 Header Synopsis +
+ ++ +template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>&&+ operator+(basic_string<charT,traits,Allocator>&& lhs, + const basic_string<charT,traits,Allocator>& rhs); + +template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>&&+ operator+(const basic_string<charT,traits,Allocator>& lhs, + basic_string<charT,traits,Allocator>&& rhs); + +template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>&&+ operator+(basic_string<charT,traits,Allocator>&& lhs, + basic_string<charT,traits,Allocator>&& rhs); + + +template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>&&+ operator+(const charT* lhs, + basic_string<charT,traits,Allocator>&& rhs); + +template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>&&+ operator+(charT lhs, basic_string<charT,traits,Allocator>&& rhs); + +template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>&&+ operator+(basic_string<charT,traits,Allocator>&& lhs, + const charT* rhs); + +template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>&&+ operator+(basic_string<charT,traits,Allocator>&& lhs, charT rhs); ++21.4.8.1 [string::op+] +
+ ++ +template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>+&&+ operator+(basic_string<charT,traits,Allocator>&& lhs, + const basic_string<charT,traits,Allocator>& rhs); ++Returns: std::move(lhs.append(rhs)) ++template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>+&&+ operator+(const basic_string<charT,traits,Allocator>& lhs, + basic_string<charT,traits,Allocator>&& rhs); ++Returns: std::move(rhs.insert(0, lhs)) ++template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>+&&+ operator+(basic_string<charT,traits,Allocator>&& lhs, + basic_string<charT,traits,Allocator>&& rhs); ++Returns: std::move(lhs.append(rhs)) [Note: Or equivalently +std::move(rhs.insert(0, lhs)) — end note] ++template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>+&&+ operator+(const charT* lhs, + basic_string<charT,traits,Allocator>&& rhs); ++Returns: std::move(rhs.insert(0, lhs)). ++template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>+&&+ operator+(charT lhs, basic_string<charT,traits,Allocator>&& rhs); ++Returns: std::move(rhs.insert(0, 1, lhs)). ++template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>+&&+ operator+(basic_string<charT,traits,Allocator>&& lhs, + const charT* rhs); ++Returns: std::move(lhs.append(rhs)). ++template<class charT, class traits, class Allocator> + basic_string<charT,traits,Allocator>+&&+ operator+(basic_string<charT,traits,Allocator>&& lhs, charT rhs); ++Returns: std::move(lhs.append(1, rhs)). ++
+1144. "thread safe" is undefined
+Section: 18.5 [support.start.term] Status: WP + Submitter: LWG Opened: 2009-06-16 Last modified: 2010-10-23
+View all other issues in [support.start.term].
+View all issues with WP status.
+Discussion:
+ +Addresses UK 187
+ ++The term "thread safe" is not defined nor used in this context +anywhere else in the standard. +
+ +Suggested action:
++Clarify the meaning of "thread safe". +
+ +[ +2009 Santa Cruz: +]
+ + +++ + + ++The "thread safe" language has already been change in the WP. It was +changed to "happen before", but the current WP text is still a little +incomplete: "happen before" is binary, but the current WP text only +mentions one thing. +
++Move to Ready. +
+Proposed resolution:
++For the following functions in 18.5 [support.start.term]. +
++ ++extern "C" int at_quick_exit(void (*f)(void)); +extern "C++" int at_quick_exit(void (*f)(void)); ++Edit paragraph 10 as follows. +The intent is +to provide the other half of the happens before relation; +to note indeterminate ordering; +and to clean up some formatting. +
++ ++Effects: +The
at_quick_exit()functions +register the function pointed to byf+to be called without arguments whenquick_exitis called. +It is unspecified whether a call toat_quick_exit()+that does nothappen-beforehappen before (1.10) +all calls toquick_exit+will succeed. +[Note: +theat_quick_exit()functions +shall not introduce a data race (17.6.4.7). +exitnote+—end note] + +[Note: +The order of registration may be indeterminate +ifat_quick_exitwas called from more than one thread. +—end note] + +[Note: Theat_quick_exitregistrations +are distinct from theatexitregistrations, +and applications may need to call both registration functions +with the same argument. +—end note] ++For the following function. +
++ ++void quick_exit [[noreturn]] (int status) ++Edit paragraph 13 as follows. +The intent is to note that thread-local variables may be different. +
++ + + + + ++Effects: +Functions registered by calls to
at_quick_exit+are called in the reverse order of their registration, +except that a function shall be called +after any previously registered functions +that had already been called at the time it was registered. +Objects shall not be destroyed as a result of callingquick_exit. +If control leaves a registered function called byquick_exit+because the function does not provide a handler for a thrown exception, +terminate()shall be called. + +[Note: +Functions registered by one thread may be called by any thread, +and hence should not rely on the identity of thread-storage-duration objects. +—end note] + +After calling registered functions, +quick_exitshall call_Exit(status). +[Note: +The standard file buffers are not flushed. +See: ISO C 7.20.4.4. +—end note] +
+1151. Behavior of the library in the presence of threads is incompletely specified
+Section: 17 [library] Status: Resolved + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-11-19
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Resolved status.
+Discussion:
+Addresses US 63
+ +Description
+The behavior of the library in the presence of threads + is incompletely specified.
+For example, if thread 1 assigns to X, then writes data + to file f, which is read by thread 2, and then accesses + variable X, is thread 2 guaranteed to be able to see the + value assigned to X by thread 1? In other words, does the + write of the data "happen before" the read?
+Another example: does simultaneous access using operator + at() to different characters in the same non-const string + really introduce a data race?
+Suggestion
+Notes
17 SG: should go to threads group; misclassified in document +
+ +Concurrency SG: Create an issue. Hans will look into it.
+ +[ +2009 Santa Cruz: +]
+ + ++Move to "Open". Hans and the rest of the concurrency working group will +study this. We can't make progress without a thorough review and a +paper. ++ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3069. +
+ + +Proposed resolution:
+ + + + + +
+1152. expressions parsed differently than intended
+Section: 22.4.2.2.2 [facet.num.put.virtuals] Status: WP + Submitter: Seungbeom Kim Opened: 2009-06-27 Last modified: 2010-10-23
+View all other issues in [facet.num.put.virtuals].
+View all issues with WP status.
+Discussion:
++In Table 73 -- Floating-point conversions, 22.4.2.2.2 [facet.num.put.virtuals], +in +N2914, +we have the following entries: +
++
+ +Table 73 — Floating-point conversions ++ +State stdio equivalent ++ + +floatfield == ios_base::fixed | ios_base::scientific && !uppercase +%a ++ +floatfield == ios_base::fixed | ios_base::scientific +%A ++These expressions are supposed to mean: +
+ ++floatfield == (ios_base::fixed | ios_base::scientific) && !uppercase +floatfield == (ios_base::fixed | ios_base::scientific) ++but technically parsed as: +
++((floatfield == ios_base::fixed) | ios_base::scientific) && (!uppercase) +((floatfield == ios_base::fixed) | ios_base::scientific) ++and should be corrected with additional parentheses, as shown above. +
+ +[ +2009-10-28 Howard: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ + + +Proposed resolution:
++Change Table 83 — Floating-point conversions in 22.4.2.2.2 [facet.num.put.virtuals]: +
+ ++
+ + + + + +Table 83 — Floating-point conversions ++ +State stdio equivalent ++ + +floatfield == (ios_base::fixed | ios_base::scientific) && !uppercase +%a ++ +floatfield == (ios_base::fixed | ios_base::scientific) +%A +
+1157. Local types can now instantiate templates
+Section: 17.6.3.2.1 [namespace.std] Status: WP + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
+ +Addresses UK 175
+ +Description
+Local types can + now be used to instantiate templates, but don't have + external linkage.
+Suggestion
+Remove the reference to external linkage.
+ +Notes
+We accept the proposed solution. Martin will draft an issue.
+ +[ +2009-07-28 Alisdair provided wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ + + +Proposed resolution:
++17.6.3.2.1 [namespace.std] +
++Strike "of external linkage" in p1 and p2: +
+ +++ + + + + + ++-1- The behavior of a C++ program is undefined if it adds declarations or +definitions to namespace std or to a namespace within namespace std +unless otherwise specified. A program may add a concept map for any +standard library concept or a template specialization for any standard +library template to namespace std only if the declaration depends on a +user-defined type
+ +of external linkageand the specialization meets the +standard library requirements for the original template and is not +explicitly prohibited.179 ++-2- The behavior of a C++ program is undefined if it declares +
++
+- +an explicit specialization of any member function of a standard library +class template, or +
+- +an explicit specialization of any member function template of a standard +library class or class template, or +
+- +an explicit or partial specialization of any member class template of a +standard library class or class template. +
++A program may explicitly instantiate a template defined in the standard +library only if the declaration depends on the name of a user-defined +type
+of external linkageand the instantiation meets the standard +library requirements for the original template. +
+1158. Encouragement to use monotonic clock
+Section: 30.2.4 [thread.req.timing] Status: WP + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all other issues in [thread.req.timing].
+View all issues with WP status.
+Discussion:
+ +Addresses UK 322, US 96
+ +Description
+Not all systems + can provide a monotonic clock. How are they expected to + treat a _for function?
+Suggestion
+Add at least a note explaining the intent + for systems that do not support a monotonic clock.
+ +Notes
+Create an issue, together with UK 96. Note that the specification as is + already allows a non-monotonic clock due to the word “should” rather than + “shall”. If this wording is kept, a footnote should be added to make the + meaning clear.
+ +[ 2009-06-29 Beman provided a proposed resolution. ]
+ +[ +2009-10-31 Howard adds: +]
+ + ++Set to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +2010-02-24 Pete moved to Open: +]
+ + ++LWG 1158's proposed resolution replaces the ISO-specified normative term +"should" with "are encouraged but not required to", which presumably means the +same thing, but has no ISO normative status. The WD used the latter formulation +in quite a few non-normative places, but only three normative ones. I've changed +all the normative uses to "should". ++ +[ +2010-03-06 Beman updates wording. +]
+ + +[ +2010 Pittsburgh: Moved to Ready. +]
+ + + + +Proposed resolution:
+ +Change Timing specifications 30.2.4 [thread.req.timing] as indicated:
+ ++The member functions whose names end in _for take an argument that +specifies a relative time. Implementations should use a monotonic clock to +measure time for these functions. [Note: Implementations are not +required to use a monotonic clock because such a clock may be unavailable. +— end note] +
+ + + + + + +
+1159. Unclear spec for resource_deadlock_would_occur
+Section: 30.4.2.2.2 [thread.lock.unique.locking] Status: WP + Submitter: LWG Opened: 2009-06-28 Last modified: 2010-10-23
+View all other issues in [thread.lock.unique.locking].
+View all issues with WP status.
+Duplicate of: 1219
+Discussion:
+ +Addresses UK 327, UK 328
+ +UK 327 Description
+Not clear what + the specification for error condition + resource_deadlock_would_occur means. It is perfectly + possible for this thread to own the mutex without setting + owns to true on this specific lock object. It is also + possible for lock operations to succeed even if the thread + does own the mutex, if the mutex is recursive. Likewise, if + the mutex is not recursive and the mutex has been locked + externally, it is not always possible to know that this + error condition should be raised, depending on the host + operating system facilities. It is possible that 'i.e.' was + supposed to be 'e.g.' and that suggests that recursive + locks are not allowed. That makes sense, as the + exposition-only member owns is boolean and not a integer to + count recursive locks.
+ +UK 327 Suggestion
+Add a precondition !owns. Change the 'i.e.' + in the error condition to be 'e.g.' to allow for this + condition to propogate deadlock detection by the host OS.
+UK 327 Notes
+Create an issue. Assigned to Lawrence Crowl. Note: not sure what try_lock + means for recursive locks when you are the owner. POSIX has language on + this, which should ideally be followed. Proposed fix is not quite right, for + example, try_lock should have different wording from lock.
+ +UK 328 Description
+ +There is a missing precondition that owns + is true, or an if(owns) test is missing from the effect + clause
+UK 328 Suggestion
+Add a + precondition that owns == true. Add an error condition to + detect a violation, rather than yield undefined behaviour.
+UK 328 Notes
+Handle in same issue as UK 327. Also uncertain that the proposed resolution + is the correct one.
+ +[ +2009-11-11 Alisdair notes that this issue is very closely related to 1219, +if not a dup. +]
+ + +[ +2010-02-12 Anthony provided wording. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++Wording updated and moved to Ready for Pittsburgh. ++ + + +Proposed resolution:
++Modify 30.4.2.2.2 [thread.lock.unique.locking] p3 to say: +
+ +++ +void lock();+++...
++3 Throws: Any exception thrown by pm->lock(). +std::system_error if an exception is required (30.2.2 [thread.req.exception]). +std::system_error with an error condition of +operation_not_permitted if pm is 0. +std::system_error with an error condition of +resource_deadlock_would_occur if on entry owns is true. +
+std::system_error when the +postcondition cannot be achieved.++Remove 30.4.2.2.2 [thread.lock.unique.locking] p4 (Error condition clause). +
+ ++Modify 30.4.2.2.2 [thread.lock.unique.locking] p8 to say: +
+ +++ +bool try_lock();+++...
++8 Throws: Any exception thrown by pm->try_lock(). +std::system_error if an exception is required (30.2.2 [thread.req.exception]). +std::system_error with an error condition of +operation_not_permitted if pm is 0. +std::system_error with an error condition of +resource_deadlock_would_occur if on entry owns is true. +
+std::system_error when the +postcondition cannot be achieved.++Remove 30.4.2.2.2 [thread.lock.unique.locking] p9 (Error condition clause). +
+ ++Modify 30.4.2.2.2 [thread.lock.unique.locking] p13 to say: +
+ +++ +template <class Clock, class Duration> + bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);+++...
++13 Throws: Any exception thrown by pm->try_lock_until(). +std::system_error if an exception is required (30.2.2 [thread.req.exception]). +std::system_error with an error condition of +operation_not_permitted if pm is 0. +std::system_error with an error condition of +resource_deadlock_would_occur if on entry owns is true. +
+std::system_error when the +postcondition cannot be achieved.++Remove 30.4.2.2.2 [thread.lock.unique.locking] p14 (Error condition clause). +
+ ++Modify 30.4.2.2.2 [thread.lock.unique.locking] p18 to say: +
+ +++ +template <class Rep, class Period> + bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);+++...
++18 Throws: Any exception thrown by pm->try_lock_for(). +std::system_error if an exception is required (30.2.2 [thread.req.exception]). +std::system_error with an error condition of +operation_not_permitted if pm is 0. +std::system_error with an error condition of +resource_deadlock_would_occur if on entry owns is true. +
+std::system_error when the +postcondition cannot be achieved.++Remove 30.4.2.2.2 [thread.lock.unique.locking] p19 (Error condition clause). +
+ + + + + + +
+1170. String char-like types no longer PODs
+Section: 21.1 [strings.general] Status: WP + Submitter: Beman Dawes Opened: 2009-06-22 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
+ +Addresses UK 218
+ +Prior to the introduction of constant expressions into the library, +basic_string elements had to be POD types, and thus had to be both trivially +copyable and standard-layout. This ensured that they could be memcpy'ed and +would be compatible with other libraries and languages, particularly the C +language and its library.
++N2349, +Constant Expressions in the Standard Library Revision 2, changed the +requirement in 21/1 from "POD type" to "literal type". That change had the +effect of removing the trivially copyable and standard-layout requirements from +basic_string elements.
+This means that basic_string elements no longer are guaranteed to be +memcpy'able, and are no longer guaranteed to be standard-layout types:
+++3.9/p2 and 3.9/p3 both make it clear that a "trivially copyable type" is + required for memcpy to be guaranteed to work.
+Literal types (3.9p12) may have a non-trivial copy assignment operator, and + that violates the trivially copyable requirements given in 9/p 6, bullet item + 2.
+Literal types (3.9p12) have no standard-layout requirement, either.
+This situation probably arose because the wording for "Constant Expressions +in the Standard Library" was in process at the same time the C++ POD +deconstruction wording was in process.
+Since trivially copyable types meet the C++0x requirements for literal types, +and thus work with constant expressions, it seems an easy fix to revert the +basic_string element wording to its original state.
+ +[ + 2009-07-28 Alisdair adds: + ]
+ + ++When looking for any resolution for this issue, consider the definition of +"character container type" in 17.3.5 [defns.character.container]. This +does require the character type to be a POD, and this term is used in a +number of places through clause 21 and 28. This suggests the PODness +constraint remains, but is much more subtle than before. Meanwhile, I +suspect the change from POD type to literal type was intentional with +the assumption that trivially copyable types with +non-trivial-but-constexpr constructors should serve as well. I don't +believe the current wording offers the right guarantees for either of +the above designs. ++ +[ +2009-11-04 Howard modifies proposed wording to disallow array types as +char-like types. +]
+ + +[ +2010-01-23 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+ +Change General 21.1 [strings.general] as indicated:
+++ + + + + + +This Clause describes components for manipulating sequences of any +
+literalnon-array POD (3.9) type. In this Clause +such types are called char-like types, and objects of char-like +types are called char-like objects or simply +characters.
+1171. duration types should be literal
+Section: 20.11.3 [time.duration] Status: WP + Submitter: Alisdair Meredith Opened: 2009-07-06 Last modified: 2010-11-29
+View all other issues in [time.duration].
+View all issues with WP status.
+Discussion:
++The duration types in 20.11.3 [time.duration] are exactly the sort of type +that should be "literal types" in the new standard. Likewise, +arithmetic operations on durations should be declared constexpr. +
+ +[ +2009-09-21 Daniel adds: +]
+ + ++An alternative (and possibly preferable solution for potentially +heap-allocating big_int representation types) would be to ask the core +language to allow references to const literal types as feasible +arguments for constexpr functions. ++ +[ +2009-10-30 Alisdair adds: +]
+ + +++ ++I suggest this issue moves from New to Open. +
+ ++Half of this issue was dealt with in paper +n2994 +on constexpr constructors. +
+ ++The other half (duration arithmetic) is on hold pending Core support for +const & in constexpr functions. +
+ +[ +2010-03-15 Alisdair updated wording to be consistent with +N3078. +]
+ + + +[ +2010 Rapperswil: +]
+ + ++This issue was the motivation for Core adding the facility for constexpr functions to take parameters by const &. + +Move to Tentatively Ready. ++ +[ +Adopted at 2010-11 Batavia. +]
+ + + + +Proposed resolution:
++Add constexpr to declaration of following functions and constructors: +
++Modify p1 20.11 [time], and the prototype definitions in 20.11.3.5 [time.duration.nonmember], 20.11.3.6 [time.duration.comparisons], +and 20.11.3.7 [time.duration.cast]: +
+ +++ ++Header <chrono> synopsis +
+ +// duration arithmetic +template <class Rep1, class Period1, class Rep2, class Period2> + typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type + constexpr operator+(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); +template <class Rep1, class Period1, class Rep2, class Period2> + typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type + constexpr operator-(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); +template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + constexpr operator*(const duration<Rep1, Period>& d, const Rep2& s); +template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + constexpr operator*(const Rep1& s, const duration<Rep2, Period>& d); +template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + constexpr operator/(const duration<Rep1, Period>& d, const Rep2& s); +template <class Rep1, class Period1, class Rep2, class Period2> + typename common_type<Rep1, Rep2>::type + constexpr operator/(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); + +// duration comparisons +template <class Rep1, class Period1, class Rep2, class Period2> + constexpr bool operator==(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); +template <class Rep1, class Period1, class Rep2, class Period2> + constexpr bool operator!=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); +template <class Rep1, class Period1, class Rep2, class Period2> + constexpr bool operator< (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); +template <class Rep1, class Period1, class Rep2, class Period2> + constexpr bool operator<=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); +template <class Rep1, class Period1, class Rep2, class Period2> + constexpr bool operator> (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); +template <class Rep1, class Period1, class Rep2, class Period2> + constexpr bool operator>=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs); + +// duration_cast +template <class ToDuration, class Rep, class Period> + constexpr ToDuration duration_cast(const duration<Rep, Period>& d); ++ ++Change 20.11.3 [time.duration]: +
+ ++ ++template <class Rep, class Period = ratio<1>> +class duration { + ... +public: + ... + constexpr duration(const duration&) = default; + ... + +}; ++[ +Note - this edit already seems assumed by definition of the duration static members zero/min/max. +They cannot meaningfully be constexpr without this change. +]
+ + + + + + +
+1174. type property predicates
+Section: 20.7.4.3 [meta.unary.prop] Status: Resolved + Submitter: Jason Merrill Opened: 2009-07-16 Last modified: 2010-11-20
+View all other issues in [meta.unary.prop].
+View all issues with Resolved status.
+Discussion:
++I've been implementing compiler support for is_standard_layout, and +noticed a few nits about 20.7.4.3 [meta.unary.prop]: +
+ ++
+ +- +There's no trait for "trivially copyable type", which is now the +property that lets you do bitwise copying of a type, and therefore seems +useful to be able to query. has_trivial_assign && +has_trivial_copy_constructor && has_trivial_destructor +is similar, but +not identical, specifically with respect to const types. +
+- +has_trivial_copy_constructor and has_trivial_assign lack the "or an +array of such a class type" language that most other traits in that +section, including has_nothrow_copy_constructor and has_nothrow_assign, +have; this seems like an oversight. +
+[ +See the thread starting with c++std-lib-24420 for further discussion. +]
+ + +[ +Addressed in N2947. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + +++ + + +NAD EditorialResolved. Solved by +N2984. +Proposed resolution:
++
+ + + + + +
+1177. Improve "diagnostic required" wording
+Section: 20.11.3 [time.duration] Status: WP + Submitter: Howard Hinnant Opened: 2009-07-18 Last modified: 2010-10-23
+View all other issues in [time.duration].
+View all issues with WP status.
+Discussion:
++"diagnostic required" has been used (by me) for code words meaning "use +enable_if to constrain templated functions. This needs to be +improved by referring to the function signature as not participating in +the overload set, and moving this wording to a Remarks paragraph. +
+ +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ +[ +2009-11-19 Pete opens: +]
+ + +++ ++Oh, and speaking of 1177, most of the changes result in rather convoluted prose. +Instead of saying +
+ ++A shall be B, else C ++ ++it should be +
+ ++C if A is not B ++ ++That is: +
+ ++Rep2 shall be implicitly convertible to CR(Rep1, Rep2), else +this signature shall not participate in overload resolution. ++ ++should be +
+ ++This signature shall not participate in overload resolution if Rep2 is +not implicitly convertible to CR(Rep1, Rep2). ++ ++That is clearer, and eliminates the false requirement that Rep2 "shall +be" convertible. +
+ +[ +2009-11-19 Howard adds: +]
+ + ++I've updated the wording to match Pete's suggestion and included bullet 16 +from 1195. ++ +[ +2009-11-19 Jens adds: +]
+ + +++ ++Further wording suggestion using "unless": +
+ ++This signature shall not participate in overload resolution unless Rep2 +is implicitly convertible to CR(Rep1, Rep2). ++[ +2009-11-20 Howard adds: +]
+ + ++I've updated the wording to match Jens' suggestion. ++ +[ +2009-11-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+[ +This proposed resolution addresses 947 and 974. +]
+ + ++
+ + + + + +- +
+ ++Change 20.11.3.1 [time.duration.cons] (and reorder the Remarks +paragraphs per 17.5.1.4 [structure.specifications]): +
+ +++template <class Rep2> + explicit duration(const Rep2& r); ++++ ++
+Requires:Remarks: This constructor shall not +participate in overload resolution unless Rep2shall be+is implicitly convertible to rep and ++
+- +treat_as_floating_point<rep>::value
+shall be+is true, or +- +treat_as_floating_point<Rep2>::value
+shall be+is false. ++
+Diagnostic required[Example: ++ +duration<int, milli> d(3); // OK +duration<int, milli> d(3.5); // error ++— end example] +
+ ++Effects: Constructs an object of type duration. +
+ ++Postcondition: count() == static_cast<rep>(r). +
+ +template <class Rep2, class Period2> + duration(const duration<Rep2, Period2>& d); ++++ + ++
+ +Requires:Remarks: This constructor shall not +participate in overload resolution unless +treat_as_floating_point<rep>::valueshall be+is true or ratio_divide<Period2, +period>::type::denshall beis 1.Diagnostic +required.[Note: This requirement prevents implicit truncation +error when converting between integral-based duration types. Such a construction +could easily lead to confusion about the value of the duration. — end +note] [Example: ++ +duration<int, milli> ms(3); +duration<int, micro> us = ms; // OK +duration<int, milli> ms2 = us; // error ++— end example] +
+ ++Effects: Constructs an object of type duration, constructing +rep_ from +duration_cast<duration>(d).count(). +
+ +- +
+ ++Change the following paragraphs in 20.11.3.5 [time.duration.nonmember]: +
+ +++template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + operator*(const duration<Rep1, Period>& d, const Rep2& s); ++++ +RequiresRemarks: This operator shall not +participate in overload resolution unless Rep2shall +beis implicitly convertible to CR(Rep1, Rep2). +Diagnostic required.+template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + operator*(const Rep1& s, const duration<Rep2, Period>& d); ++++ +RequiresRemarks: This operator shall not +participate in overload resolution unless Rep1shall +beis implicitly convertible to CR(Rep1, Rep2). +Diagnostic required.+template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + operator/(const duration<Rep1, Period>& d, const Rep2& s); ++++ +RequiresRemarks: This operator shall not +participate in overload resolution unless Rep2shall +beis implicitly convertible to CR(Rep1, Rep2) and +Rep2shall not beis not an instantiation of +duration.Diagnostic required.+template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + operator%(const duration<Rep1, Period>& d, const Rep2& s); ++++ +RequiresRemarks: This operator shall not +participate in overload resolution unless Rep2shall +beis implicitly convertible to CR(Rep1, Rep2) and +Rep2shall not beis not an instantiation of +duration.Diagnostic required.+- +
+ ++Change the following paragraphs in 20.11.3.7 [time.duration.cast]: +
+ ++template <class ToDuration, class Rep, class Period> + ToDuration duration_cast(const duration<Rep, Period>& d); ++ +++RequiresRemarks: This function shall not +participate in overload resolution unless ToDurationshall +beis an instantiation of duration.Diagnostic +required.+- +
+ ++Change 20.11.4.1 [time.point.cons]/3 as indicated: +
+ +++ ++
+ +Requires: Duration2 shall be implicitly convertible to duration. +Diagnostic required.++Remarks: This constructor shall not participate in overload +resolution unless Duration2 is implicitly convertible to +duration. +
+- +
++Change the following paragraphs in 20.11.4.7 [time.point.cast]: +
+ ++template <class ToDuration, class Clock, class Duration> + time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t); ++ +++RequiresRemarks: This function shall not +participate in overload resolution unless ToDurationshall +beis an instantiation of duration.Diagnostic +required.+
1178. Header dependencies
Section: 17.6.4.2 [res.on.headers] Status: WP - Submitter: Beman Dawes Opened: 2009-07-18 Last modified: 2009-10-26
+ Submitter: Beman Dawes Opened: 2009-07-18 Last modified: 2010-10-23View all issues with WP status.
Discussion:
@@ -44184,4 +66210,17588 @@ the synopses of those other headers. +
+1180. Missing string_type member typedef in class sub_match
+Section: 28.9.1 [re.submatch.members] Status: WP + Submitter: Daniel Krügler Opened: 2009-07-25 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++The definition of class template sub_match is strongly dependent +on the type basic_string<value_type>, both in interface and effects, +but does not provide a corresponding typedef string_type, as e.g. +class match_results does, which looks like an oversight to me that +should be fixed. +
+ +[ +2009-11-15 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
+ ++
+ + + + + + +- +
+ ++In the class template sub_match synopsis 28.9 [re.submatch]/1 +change as indicated: +
+ ++template <class BidirectionalIterator> +class sub_match : public std::pair<BidirectionalIterator, BidirectionalIterator> { +public: + typedef typename iterator_traits<BidirectionalIterator>::value_type value_type; + typedef typename iterator_traits<BidirectionalIterator>::difference_type difference_type; + typedef BidirectionalIterator iterator; + typedef basic_string<value_type> string_type; + + bool matched; + + difference_type length() const; + operatorbasic_string<value_type>string_type() const; +basic_string<value_type>string_type str() const; + int compare(const sub_match& s) const; + int compare(constbasic_string<value_type>string_type& s) const; + int compare(const value_type* s) const; +}; +- +
+ ++In 28.9.1 [re.submatch.members]/2 change as indicated: +
+ ++operator+ +basic_string<value_type>string_type() const; ++Returns: matched ?+basic_string<value_type>+string_type(first, second) :basic_string<value_type>+string_type(). +- +
+ ++In 28.9.1 [re.submatch.members]/3 change as indicated: +
+ +++ +basic_string<value_type>string_type str() const; ++Returns: matched ?+basic_string<value_type>+string_type(first, second) :basic_string<value_type>+string_type(). +- +
++In 28.9.1 [re.submatch.members]/5 change as indicated: +
+ ++int compare(constbasic_string<value_type>string_type& s) const; +
+1181. Invalid sub_match comparison operators
+Section: 28.9.2 [re.submatch.op] Status: WP + Submitter: Daniel Krügler Opened: 2009-07-25 Last modified: 2010-11-24
+View all other issues in [re.submatch.op].
+View all issues with WP status.
+Discussion:
++Several heterogeneous comparison operators of class template +sub_match are specified by return clauses that are not valid +in general. E.g. 28.9.2 [re.submatch.op]/7: +
+ ++ +template <class BiIter, class ST, class SA> +bool operator==( + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, + const sub_match<BiIter>& rhs); +++Returns: lhs == rhs.str(). +++The returns clause would be ill-formed for all cases where +ST != std::char_traits<iterator_traits<BiIter>::value_type> +or SA != std::allocator<iterator_traits<BiIter>::value_type>. +
++The generic character of the comparison was intended, so +there are basically two approaches to fix the problem: The +first one would define the semantics of the comparison +using the traits class ST (The semantic of basic_string::compare +is defined in terms of the compare function of the corresponding +traits class), the second one would define the semantics of the +comparison using the traits class +
+ ++ +std::char_traits<iterator_traits<BiIter>::value_type> ++which is essentially identical to +
+ ++ +std::char_traits<sub_match<BiIter>::value_type> ++I suggest to follow the second approach, because +this emphasizes the central role of the sub_match +object as part of the comparison and would also +make sure that a sub_match comparison using some +basic_string<char_t, ..> always is equivalent to +a corresponding comparison with a string literal +because of the existence of further overloads (beginning +from 28.9.2 [re.submatch.op]/19). If users really want to +take advantage of their own traits::compare, they can +simply write a corresponding compare function that +does so. +
+ +[ +Post-Rapperswil +]
+ + ++The following update is a result of the discussion during the Rapperswil meeting, the P/R expresses all comparisons by +delegating to sub_match's compare functions. The processing is rather mechanical: Only == and < +where defined by referring to sub_match's compare function, all remaining ones where replaced by the canonical +definitions in terms of these two. +
+ ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++The wording refers to N3126. +
+ ++
+ + + + + + +- Change 28.9.2 [re.submatch.op]/7 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator==( + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, + const sub_match<BiIter>& rhs); ++7 Returns:lhs == rhs.str()rhs.compare(lhs.c_str()) == 0. +- Change 28.9.2 [re.submatch.op]/8 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator!=( + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, + const sub_match<BiIter>& rhs); ++8 Returns:lhs != rhs.str()!(lhs == rhs). +- Change 28.9.2 [re.submatch.op]/9 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator<( + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, + const sub_match<BiIter>& rhs); ++9 Returns:lhs < rhs.str()rhs.compare(lhs.c_str()) > 0. +- Change 28.9.2 [re.submatch.op]/10 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator>( + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, + const sub_match<BiIter>& rhs); ++10 Returns:lhs > rhs.str()rhs < lhs. +- Change 28.9.2 [re.submatch.op]/11 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator>=( + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, + const sub_match<BiIter>& rhs); ++11 Returns:lhs >= rhs.str()!(lhs < rhs). +- Change 28.9.2 [re.submatch.op]/12 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator<=( + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& lhs, + const sub_match<BiIter>& rhs); ++12 Returns:lhs <= rhs.str()!(rhs < lhs). +- Change 28.9.2 [re.submatch.op]/13 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator==(const sub_match<BiIter>& lhs, + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); ++13 Returns:lhs.str() == rhslhs.compare(rhs.c_str()) == 0. +- Change 28.9.2 [re.submatch.op]/14 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator!=(const sub_match<BiIter>& lhs, + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); ++14 Returns:lhs.str() != rhs!(lhs == rhs). +- Change 28.9.2 [re.submatch.op]/15 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator<(const sub_match<BiIter>& lhs, + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); ++15 Returns:lhs.str() < rhslhs.compare(rhs.c_str()) < 0. +- Change 28.9.2 [re.submatch.op]/16 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator>(const sub_match<BiIter>& lhs, + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); ++16 Returns:lhs.str() > rhsrhs < lhs. +- Change 28.9.2 [re.submatch.op]/17 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator>=(const sub_match<BiIter>& lhs, + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); ++17 Returns:lhs.str() >= rhs!(lhs < rhs). +- Change 28.9.2 [re.submatch.op]/18 as indicated: +
++template <class BiIter, class ST, class SA> + bool operator<=(const sub_match<BiIter>& lhs, + const basic_string< + typename iterator_traits<BiIter>::value_type, ST, SA>& rhs); ++18 Returns:lhs.str() <= rhs!(rhs < lhs). +- Change 28.9.2 [re.submatch.op]/19 as indicated: +
++template <class BiIter> + bool operator==(typename iterator_traits<BiIter>::value_type const* lhs, + const sub_match<BiIter>& rhs); ++19 Returns:lhs == rhs.str()rhs.compare(lhs) == 0. +- Change 28.9.2 [re.submatch.op]/20 as indicated: +
++template <class BiIter> + bool operator!=(typename iterator_traits<BiIter>::value_type const* lhs, + const sub_match<BiIter>& rhs); ++20 Returns:lhs != rhs.str()!(lhs == rhs). +- Change 28.9.2 [re.submatch.op]/21 as indicated: +
++template <class BiIter> + bool operator<(typename iterator_traits<BiIter>::value_type const* lhs, + const sub_match<BiIter>& rhs); ++21 Returns:lhs < rhs.str()rhs.compare(lhs) > 0. +- Change 28.9.2 [re.submatch.op]/22 as indicated: +
++template <class BiIter> + bool operator>(typename iterator_traits<BiIter>::value_type const* lhs, + const sub_match<BiIter>& rhs); ++22 Returns:lhs > rhs.str()rhs < lhs. +- Change 28.9.2 [re.submatch.op]/23 as indicated: +
++template <class BiIter> + bool operator>=(typename iterator_traits<BiIter>::value_type const* lhs, + const sub_match<BiIter>& rhs); ++23 Returns:lhs >= rhs.str()!(lhs < rhs). +- Change 28.9.2 [re.submatch.op]/24 as indicated: +
++template <class BiIter> + bool operator<=(typename iterator_traits<BiIter>::value_type const* lhs, + const sub_match<BiIter>& rhs); ++24 Returns:lhs <= rhs.str()!(rhs < lhs). +- Change 28.9.2 [re.submatch.op]/25 as indicated: +
++template <class BiIter> + bool operator==(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const* rhs); ++25 Returns:lhs.str() == rhslhs.compare(rhs) == 0. +- Change 28.9.2 [re.submatch.op]/26 as indicated: +
++template <class BiIter> + bool operator!=(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const* rhs); ++26 Returns:lhs.str() != rhs!(lhs == rhs). +- Change 28.9.2 [re.submatch.op]/27 as indicated: +
++template <class BiIter> + bool operator<(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const* rhs); ++27 Returns:lhs.str() < rhslhs.compare(rhs) < 0. +- Change 28.9.2 [re.submatch.op]/28 as indicated: +
++template <class BiIter> + bool operator>(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const* rhs); ++28 Returns:lhs.str() > rhsrhs < lhs. +- Change 28.9.2 [re.submatch.op]/29 as indicated: +
++template <class BiIter> + bool operator>=(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const* rhs); ++29 Returns:lhs.str() >= rhs!(lhs < rhs). +- Change 28.9.2 [re.submatch.op]/30 as indicated: +
++template <class BiIter> + bool operator<=(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const* rhs); ++30 Returns:lhs.str() <= rhs!(rhs < lhs). +- Change 28.9.2 [re.submatch.op]/31 as indicated: +
++template <class BiIter> + bool operator==(typename iterator_traits<BiIter>::value_type const& lhs, + const sub_match<BiIter>& rhs); ++31 Returns: basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) == rhs.str().
+31 Returns: rhs.compare(typename sub_match<BiIter>::string_type(1, lhs)) == 0. +- Change 28.9.2 [re.submatch.op]/32 as indicated: +
++template <class BiIter> + bool operator!=(typename iterator_traits<BiIter>::value_type const& lhs, + const sub_match<BiIter>& rhs); ++32 Returns:basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) != +rhs.str()!(lhs == rhs). +- Change 28.9.2 [re.submatch.op]/33 as indicated: +
++template <class BiIter> + bool operator<(typename iterator_traits<BiIter>::value_type const& lhs, + const sub_match<BiIter>& rhs); ++33 Returns: basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) < rhs.str().
+33 Returns: rhs.compare(typename sub_match<BiIter>::string_type(1, lhs)) > 0. +- Change 28.9.2 [re.submatch.op]/34 as indicated: +
++template <class BiIter> + bool operator>(typename iterator_traits<BiIter>::value_type const& lhs, + const sub_match<BiIter>& rhs); ++34 Returns:basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) > rhs.str()rhs < lhs. +- Change 28.9.2 [re.submatch.op]/35 as indicated: +
++template <class BiIter> + bool operator>=(typename iterator_traits<BiIter>::value_type const& lhs, + const sub_match<BiIter>& rhs); ++35 Returns:basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) >= rhs.str()!(lhs < rhs). +- Change 28.9.2 [re.submatch.op]/36 as indicated: +
++template <class BiIter> + bool operator<=(typename iterator_traits<BiIter>::value_type const& lhs, + const sub_match<BiIter>& rhs); ++36 Returns:basic_string<typename iterator_traits<BiIter>::value_type>(1, lhs) <= rhs.str()!(rhs < lhs). +- Change 28.9.2 [re.submatch.op]/37 as indicated: +
++template <class BiIter> + bool operator==(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const& rhs); ++37 Returns: lhs.str() == basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs).
+37 Returns: lhs.compare(typename sub_match<BiIter>::string_type(1, rhs)) == 0. +- Change 28.9.2 [re.submatch.op]/38 as indicated: +
++template <class BiIter> + bool operator!=(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const& rhs); ++38 Returns:lhs.str() != basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs)!(lhs == rhs). +- Change 28.9.2 [re.submatch.op]/39 as indicated: +
++template <class BiIter> + bool operator<(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const& rhs); ++39 Returns: lhs.str() < basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs).
+39 Returns: lhs.compare(typename sub_match<BiIter>::string_type(1, rhs)) < 0. +- Change 28.9.2 [re.submatch.op]/40 as indicated: +
++template <class BiIter> + bool operator>(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const& rhs); ++40 Returns:lhs.str() > basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs)rhs < lhs. +- Change 28.9.2 [re.submatch.op]/41 as indicated: +
++template <class BiIter> + bool operator>=(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const& rhs); ++41 Returns:lhs.str() >= basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs)!(lhs < rhs). +- Change 28.9.2 [re.submatch.op]/42 as indicated: +
++template <class BiIter> + bool operator<=(const sub_match<BiIter>& lhs, + typename iterator_traits<BiIter>::value_type const& rhs); ++42 Returns:lhs.str() <= basic_string<typename iterator_traits<BiIter>::value_type>(1, rhs)!(rhs < lhs). +
+1182. Unfortunate hash dependencies
+Section: 20.8.15 [unord.hash] Status: WP + Submitter: Alisdair Meredith Opened: 2009-07-28 Last modified: 2010-10-23
+View all other issues in [unord.hash].
+View all issues with WP status.
+Discussion:
+Addresses UK 324
+ ++The implied library dependencies created by spelling out all the hash +template specializations in the <functional> synopsis are unfortunate. +The potential coupling is greatly reduced if the hash specialization is +declared in the appropriate header for each library type, as it is much +simpler to forward declare the primary template and provide a single +specialization than it is to implement a hash function for a string or +vector without providing a definition for the whole string/vector +template in order to access the necessary bits. +
+ ++Note that the proposed resolution purely involves moving the +declarations of a few specializations, it specifically does not make any +changes to 20.8.15 [unord.hash]. +
+ +[ +2009-09-15 Daniel adds: +]
+ + ++++I suggest to add to the current existing +proposed resolution the following items. +
+ ++
+ +- +
+ ++Add to the very first strike-list of the currently suggested resolution +the following lines: +
+ ++template <> struct hash<std::error_code>;+template <> struct hash<std::thread::id>;+- +
+ ++Add the following declarations to 19.5 [syserr], header +<system_error> synopsis after // 19.5.4: +
+ +++// 19.5.x hash support +template <class T> struct hash; +template <> struct hash<error_code>; + +- +
+ ++Add a new clause 19.5.X (probably after 19.5.4): +
+ ++++19.5.X Hash support [syserr.hash] +
+ ++template <> struct hash<error_code>; ++ ++An explicit specialization of the class template hash (20.8.15 [unord.hash]) +shall be provided +for the type error_code suitable for using this type as key in +unordered associative +containers (23.7 [unord]). ++- +
+ ++Add the following declarations to 30.3.1.1 [thread.thread.id] just after the +declaration of +the comparison operators: +
+ +++template <class T> struct hash; +template <> struct hash<thread::id>; +- +
+ ++Add a new paragraph at the end of 30.3.1.1 [thread.thread.id]: +
+ ++++template <> struct hash<thread::id>; ++ ++An explicit specialization of the class template hash (20.8.15 [unord.hash]) +shall be provided +for the type thread::id suitable for using this type as key in +unordered associative +containers (23.7 [unord]). ++- +Issue 889 independently suggests moving the specialization +std::hash<std::thread::id> to header <thread>. +
+[ +2009-11-13 Alisdair adopts Daniel's suggestion and the extended note from +889. +]
+ + +[ +2010-01-31 Alisdair: related to 1245 and 978. +]
+ + +[ +2010-02-07 Proposed wording updated by Beman, Daniel, Alisdair and Ganesh. +]
+ + +[ +2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+Strike the following specializations declared in the <functional> +synopsis p2 20.8 [function.objects]
++++template <> struct hash<std::string>;+template <> struct hash<std::u16string>;+template <> struct hash<std::u32string>;+template <> struct hash<std::wstring>;+ +template <> struct hash<std::error_code>;+template <> struct hash<std::thread::id>;+template <class Allocator> struct hash<std::vector<bool, Allocator> >;+template <std::size_t N> struct hash<std::bitset<N> >;Add the following at the end of 20.8.15 [unord.hash]:
+++template <> struct hash<bool>; +template <> struct hash<char>; +template <> struct hash<signed char>; +template <> struct hash<unsigned char>; +template <> struct hash<char16_t>; +template <> struct hash<char32_t>; +template <> struct hash<wchar_t>; +template <> struct hash<short>; +template <> struct hash<unsigned short>; +template <> struct hash<int>; +template <> struct hash<unsigned int>; +template <> struct hash<long>; +template <> struct hash<long long>; +template <> struct hash<unsigned long>; +template <> struct hash<unsigned long long>; +template <> struct hash<float>; +template <> struct hash<double>; +template <> struct hash<long double>; +template<class T> struct hash<T*>;++ Specializations meeting the requirements of class template hash 20.8.15 [unord.hash].
+Add the following declarations to 19.5 [syserr], header <system_error> +synopsis after // 19.5.4:
+++// [syserr.hash] hash support +template <class T> struct hash; +template <> struct hash<error_code>;+Add a new clause 19.5.X (probably after 19.5.4):
+++19.5.X Hash support [syserr.hash]
+template <> struct hash<error_code>;+Specialization meeting the requirements of class template hash 20.8.15 [unord.hash].
+Add the following declarations to the synopsis of <string> in 21.3 [string.classes] + +
+++// [basic.string.hash] hash support +template <class T> struct hash; +template <> struct hash<string>; +template <> struct hash<u16string>; +template <> struct hash<u32string>; +template <> struct hash<wstring>;+Add a new clause 21.4.X
+++21.4.X Hash support [basic.string.hash]>
+template <> struct hash<string>; +template <> struct hash<u16string>; +template <> struct hash<u32string>; +template <> struct hash<wstring>;+Specializations meeting the requirements of class template hash 20.8.15 [unord.hash].
+Add the following declarations to the synopsis of <vector> in +23.3 [sequences]
+++// 21.4.x hash support +template <class T> struct hash; +template <class Allocator> struct hash<vector<bool, Allocator>>;+Add a new paragraph to the end of 23.4.2 [vector.bool]
+++template <class Allocator> struct hash<vector<bool, Allocator>>;+Specialization meeting the requirements of class template hash 20.8.15 [unord.hash].
+Add the following declarations to the synopsis of <bitset> in 20.5 [template.bitset]
+++// [bitset.hash] hash support +template <class T> struct hash; +template <size_t N> struct hash<bitset<N> >;+Add a new subclause 20.3.7.X [bitset.hash]
+++20.3.7.X bitset hash support [bitset.hash]
+template <size_t N> struct hash<bitset<N> >;+Specialization meeting the requirements of class template hash 20.8.15 [unord.hash].
+Add the following declarations to 30.3.1.1 [thread.thread.id] synopsis just after the +declaration of the comparison operators:
+++template <class T> struct hash; +template <> struct hash<thread::id>;+Add a new paragraph at the end of 30.3.1.1 [thread.thread.id]:
+++ +template <> struct hash<thread::id>;+Specialization meeting the requirements of class template hash 20.8.15 [unord.hash].
+Change Header <typeindex> synopsis 20.13.1 [type.index.synopsis] as +indicated:
+++ +namespace std { +class type_index; + // [type.index.hash] hash support + template <class T> struct hash; + template<> struct hash<type_index>;+: public unary_function<type_index, size_t> { + size_t operator()(type_index index) const; + }+}Change Template specialization hash<type_index> [type.index.templ] + as indicated:
+ ++ ++ + + + + + +20.11.4
+ +Template specialization hash<type_index> [type.index.templ]+ Hash support [type.index.hash]+size_t operator()(type_index index) const;++ ++
Returns: index.hash_code()template<> struct hash<type_index>;+Specialization meeting the requirements of class template hash [unord.hash]. + For an object index of type type_index, hash<type_index>()(index) + shall evaluate to the same value as index.hash_code().
+ +
+1183. basic_ios::set_rdbuf may break class invariants
+Section: 27.5.4.2 [basic.ios.members] Status: WP + Submitter: Daniel Krügler Opened: 2009-07-28 Last modified: 2010-11-24
+View all other issues in [basic.ios.members].
+View all issues with WP status.
+Discussion:
++The protected member function set_rdbuf had been added during the +process of adding move and swap semantics to IO classes. A relevant +property of this function is described by it's effects in +27.5.4.2 [basic.ios.members]/19: +
+ ++Effects: Associates the basic_streambuf object pointed to by sb with +this stream without calling clear(). ++ ++This means that implementors of or those who derive from existing IO classes +could cause an internal state where the stream buffer could be 0, but the +IO class has the state good(). This would break several currently existing +implementations which rely on the fact that setting a stream buffer via the +currently only ways, i.e. either by calling +
+ ++ +void init(basic_streambuf<charT,traits>* sb); ++or by calling +
+ ++ +basic_streambuf<charT,traits>* rdbuf(basic_streambuf<charT,traits>* sb); ++to set rdstate() to badbit, if the buffer is 0. This has the effect that many +internal functions can simply check rdstate() instead of rdbuf() for being 0. +
+ ++I therefore suggest that a requirement is added for callers of set_rdbuf to +set a non-0 value. +
+ +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Open. Martin volunteers to provide new wording, where +set_rdbuf() sets the badbit but does not cause an +exception to be thrown like a call to clear() would. ++ +[ +2009-10-20 Martin provides wording: +]
+ + ++Change 27.5.4.2 [basic.ios.members] around p. 19 as indicated: +
+ ++ +void set_rdbuf(basic_streambuf<charT, traits>* sb); ++ ++++ +
+Effects: Associates the basic_streambuf object pointed +to by sb with this stream without calling clear(). +Postconditions: rdbuf() == sb. ++Effects: As if: +
+ ++ ++iostate state = rdstate(); +try { rdbuf(sb); } +catch(ios_base::failure) { + if (0 == (state & ios_base::badbit)) + unsetf(badbit); +} ++Throws: Nothing. +
+ +Rationale:
+We need to be able to call set_rdbuf() on stream objects +for which (rdbuf() == 0) holds without causing ios_base::failure to +be thrown. We also don't want badbit to be set as a result of +setting rdbuf() to 0 if it wasn't set before the call. This changed +Effects clause maintains the current behavior (as of N2914) without +requiring that sb be non-null. + + +[ +Post-Rapperswil +]
+ + ++Several reviewers and the submitter believe that the best solution would be to add a pre-condition that the +buffer shall not be a null pointer value. +
+ ++Moved to Tentatively Ready with revised wording provided by Daniel after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++
+ + +- Add a new pre-condition just before 27.5.4.2 [basic.ios.members]/23 as indicated: +
++void set_rdbuf(basic_streambuf<charT, traits>* sb); +++?? Requires: sb != nullptr. ++23 Effects: Associates the basic_streambuf object pointed to by sb with this stream without calling clear(). +
++24 Postconditions: rdbuf() == sb. +
++25 Throws: Nothing. +
+Rationale:
+We believe that setting a nullptr stream buffer can be prevented. + + + + + +
+1187. std::decay
+Section: 20.7.7.6 [meta.trans.other] Status: WP + Submitter: Jason Merrill Opened: 2009-08-07 Last modified: 2010-10-23
+View all other issues in [meta.trans.other].
+View all issues with WP status.
+Discussion:
++I notice that std::decay is specified to strip the cv-quals from +anything but an array or pointer. This seems incorrect for values of +class type, since class rvalues can have cv-qualified type (3.10 [basic.lval]/9). +
+ +[ +2009-08-09 Howard adds: +]
+ + ++See the thread starting with c++std-lib-24568 for further discussion. And +here is a convenience link to the +original proposal. +Also see the closely related issue 705. ++ +[ +2010 Pittsburgh: Moved to Ready. +]
+ + + + +Proposed resolution:
+ ++Add a note to decay in 20.7.7.6 [meta.trans.other]: +
+ ++[Note: This behavior is similar to the lvalue-to-rvalue (4.1), +array-to-pointer (4.2), and function-to-pointer (4.3) conversions +applied when an lvalue expression is used as an rvalue, but also strips +cv-qualifiers from class types in order to more closely model by-value +argument passing. — end note] ++ + + + + + + + +
+1189. Awkward interface for changing the number of buckets in an unordered associative container
+Section: 23.2.5 [unord.req], 23.7 [unord] Status: WP + Submitter: Matt Austern Opened: 2009-08-10 Last modified: 2010-10-23
+View other active issues in [unord.req].
+View all other issues in [unord.req].
+View all issues with WP status.
+Discussion:
++Consider a typical use case: I create an unordered_map and then start +adding elements to it one at a time. I know that it will eventually need +to store a few million elements, so, for performance reasons, I would +like to reserve enough capacity that none of the calls to insert will +trigger a rehash. +
+ ++Unfortunately, the existing interface makes this awkward. The user +naturally sees the problem in terms of the number of elements, but the +interface presents it as buckets. If m is the map and n is the expected +number of elements, this operation is written m.rehash(n / +m.max_load_factor()) — not very novice friendly. +
+ +[ +2009-09-30 Daniel adds: +]
+ + ++I recommend to replace "resize" by a different name like +"reserve", because that would better match the intended +use-case. Rational: Any existing resize function has the on-success +post-condition that the provided size is equal to size(), which +is not satisfied for the proposal. Reserve seems to fit the purpose of +the actual renaming suggestion. ++ +[ +2009-10-28 Ganesh summarizes alternative resolutions and expresses a +strong preference for the second (and opposition to the first): +]
+ + +++ ++
+- +
++In the unordered associative container requirements (23.2.5 [unord.req]), +remove the row for +rehash and replace it with: +
+ +++ ++
+Table 87 — Unordered associative container requirements +(in addition to container) + ++ +Expression Return type Assertion/note pre-/post-condition +Complexity ++ +a. +rehashreserve(n)void ++Post: a.bucket_count > max(a.size(), n) +/ a.max_load_factor() +and a.bucket_count() +>= n. ++Average case linear in a.size(), worst case quadratic. + ++Make the corresponding change in the class synopses in 23.7.1 [unord.map], 23.7.2 [unord.multimap], 23.7.3 [unord.set], and 23.7.4 [unord.multiset]. +
+- + +
++In 23.2.5 [unord.req]/9, table 98, append a new row after the last one: +
+ +++ ++
+Table 87 — Unordered associative container requirements +(in addition to container) + ++ +Expression Return type Assertion/note pre-/post-condition +Complexity ++ +a.rehash(n) +void ++Post: a.bucket_count > a.size() +/ a.max_load_factor() and a.bucket_count() +>= n. + ++Average case linear in a.size(), worst case quadratic. + ++ ++a.reserve(n) + ++void + ++Same as a.rehash(ceil(n / a.max_load_factor())) + ++Average case linear in a.size(), worst case quadratic. + ++In 23.7.1 [unord.map]/3 in the definition of class template unordered_map, in +23.7.2 [unord.multimap]/3 in the definition of class template unordered_multimap, in +23.7.3 [unord.set]/3 in the definition of class template unordered_set and in +23.7.4 [unord.multiset]/3 in the definition of class template unordered_multiset, add the +following line after member function rehash(): +
+ ++ +void reserve(size_type n); +[ +2009-10-28 Howard: +]
+ + +++ + ++Moved to Tentatively Ready after 5 votes in favor of Ganesh's option 2 above. +The original proposed wording now appears here: +
+ ++++Informally: instead of providing rehash(n) provide resize(n), with the +semantics "make the container a good size for n elements". +
+ ++In the unordered associative container requirements (23.2.5 [unord.req]), +remove the row for +rehash and replace it with: +
+ +++ ++
+Table 87 — Unordered associative container requirements +(in addition to container) + ++ +Expression Return type Assertion/note pre-/post-condition +Complexity ++ +a. +rehashresize(n)void ++Post: a.bucket_count > max(a.size(), n) +/ a.max_load_factor() +and a.bucket_count() +>= n. ++Average case linear in a.size(), worst case quadratic. + ++Make the corresponding change in the class synopses in 23.7.1 [unord.map], 23.7.2 [unord.multimap], 23.7.3 [unord.set], and 23.7.4 [unord.multiset]. +
+ +Proposed resolution:
++In 23.2.5 [unord.req]/9, table 98, append a new row after the last one: +
+ +++ ++
+Table 87 — Unordered associative container requirements +(in addition to container) + ++ +Expression Return type Assertion/note pre-/post-condition +Complexity ++ +a.rehash(n) +void ++Post: a.bucket_count > a.size() +/ a.max_load_factor() and a.bucket_count() +>= n. + ++Average case linear in a.size(), worst case quadratic. + ++ ++a.reserve(n) + ++void + ++Same as a.rehash(ceil(n / a.max_load_factor())) + ++Average case linear in a.size(), worst case quadratic. + ++In 23.7.1 [unord.map]/3 in the definition of class template unordered_map, in +23.7.2 [unord.multimap]/3 in the definition of class template unordered_multimap, in +23.7.3 [unord.set]/3 in the definition of class template unordered_set and in +23.7.4 [unord.multiset]/3 in the definition of class template unordered_multiset, add the +following line after member function rehash(): +
+ ++ + + + + +void reserve(size_type n); +
+1191. tuple get API should respect rvalues
+Section: 20.4.2.6 [tuple.elem] Status: WP + Submitter: Alisdair Meredith Opened: 2009-08-18 Last modified: 2010-11-23
+View all issues with WP status.
+Discussion:
++The tuple get API should respect rvalues. This would allow for moving a +single element out of a tuple-like type. +
+ +[ +2009-10-30 Alisdair adds: +]
+ + +++ + ++The issue of rvalue overloads of get for tuple-like types was briefly +discussed in Santa Cruz. +
+ ++The feedback was this would be welcome, but we need full wording for the +other types (pair and array) before advancing. +
+ ++I suggest the issue moves to Open from New as it has been considered, +feedback given, and it has not (yet) been rejected as NAD. +
+[ +2010 Rapperswil: +]
+ + ++Note that wording has been provided, and this issue becomes more important now that we have added a function to support forwarding argument lists as tuples. + +Move to Tentatively Ready. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Add the following signature to p2 20.4.1 [tuple.general] +
+ ++ ++template <size_t I, class ... Types> +typename tuple_element<I, tuple<Types...> >::type&& get(tuple<Types...> &&); ++And again to 20.4.2.6 [tuple.elem]. +
+ ++ ++template <size_t I, class ... Types> +typename tuple_element<I, tuple<Types...> >::type&& get(tuple<Types...>&& t); ++ ++++Effects: Equivalent to return std::forward<typename tuple_element<I, tuple<Types...> >::type&&>(get<I>(t)); +
+ + ++[Note: If a T in Types is some reference type X&, +the return type is X&, not X&&. +However, if the element type is non-reference type T, +the return type is T&&. — end note] +
+ ++Add the following signature to p1 20.3 [utility] +
+ ++ ++template <size_t I, class T1, class T2> +typename tuple_element<I, pair<T1,T2> >::type&& get(pair<T1, T2>&&); ++And to p5 20.3.5.4 [pair.astuple] +
+ ++ ++template <size_t I, class T1, class T2> +typename tuple_element<I, pair<T1,T2> >::type&& get(pair<T1, T2>&& p); ++ +++ ++Returns: If I == 0 returns std::forward<T1&&>(p.first); +if I == 1 +returns std::forward<T2&&>(p.second); otherwise the program is ill-formed. +
+ ++Throws: Nothing. +
+ ++Add the following signature to 23.3 [sequences] <array> synopsis +
+ ++ +template <size_t I, class T, size_t N> +T&& get(array<T,N> &&); ++And after p8 23.3.1.8 [array.tuple] +
+ ++ + + + + + +template <size_t I, class T, size_t N> +T&& get(array<T,N> && a); ++ ++Effects: Equivalent to return std::move(get<I>(a)); ++
+1192. basic_string missing definitions for cbegin / cend / crbegin / crend
+Section: 21.4.3 [string.iterators] Status: WP + Submitter: Jonathan Wakely Opened: 2009-08-14 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++Unlike the containers in clause 23, basic_string has definitions for +begin() and end(), but these have not been updated to include cbegin, +cend, crbegin and crend. +
+ +[ +2009-10-28 Howard: +]
+ + ++Moved to Tentatively NAD after 5 positive votes on c++std-lib. Added +rationale. ++ +[ +2009-10-28 Alisdair disagrees: +]
+ + +++ ++I'm going to have to speak up as the dissenting voice. +
+ ++I agree the issue could be handled editorially, and that would be my +preference if Pete feels this is appropriate. Failing that, I really +think this issue should be accepted and moved to ready. The other +begin/end functions all have a semantic definition for this template, +and it is confusing if a small few are missing. +
+ ++I agree that an alternative would be to strike all the definitions for +begin/end/rbegin/rend and defer completely to the requirements tables in +clause 23. I think that might be confusing without a forward reference +though, as those tables are defined in a *later* clause than the +basic_string template itself. If someone wants to pursue this I would +support it, but recommend it as a separate issue. +
+ ++So my preference is strongly to move Ready over NAD, and a stronger +preference for NAD Editorial if Pete is happy to make these changes. +
+ +[ +2009-10-29 Howard: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. Removed +rationale to mark it NAD. :-) ++ + + +Proposed resolution:
++Add to 21.4.3 [string.iterators] +
+ ++ + + + + +iterator begin(); +const_iterator begin() const; +const_iterator cbegin() const; ++ +...
+ +iterator end(); +const_iterator end() const; +const_iterator cend() const; ++ +...
+ +reverse_iterator rbegin(); +const_reverse_iterator rbegin() const; +const_reverse_iterator crbegin() const; ++ +...
+ +reverse_iterator rend(); +const_reverse_iterator rend() const; +const_reverse_iterator crend() const; ++ +
+1193. default_delete cannot be instantiated with incomplete types
+Section: 20.9.9.1 [unique.ptr.dltr] Status: WP + Submitter: Daniel Krügler Opened: 2009-08-18 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++According to the general rules of 17.6.3.8 [res.on.functions]/2 b 5 the effects +are undefined, if an incomplete type is used to instantiate a library template. But neither in +20.9.9.1 [unique.ptr.dltr] nor +in any other place of the standard such explicit allowance is given. +Since this template is intended to be instantiated with incomplete +types, this must +be fixed. +
+ +[ +2009-11-15 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2009-11-17 Alisdair Opens: +]
+ + +++ ++LWG 1193 tries to support unique_ptr for incomplete types. I believe the +proposed wording goes too far: +
+ ++The template parameter T of default_delete may be an +incomplete type. ++ ++Do we really want to support cv-void? Suggested ammendment: +
+ ++The template parameter T of default_delete may be an +incomplete type other than cv-void. ++ ++We might also consider saying something about arrays of incomplete types. +
+ ++Did we lose support for unique_ptr<function-type> when the +concept-enabled work was shelved? If so, we might want a +default_delete partial specialization for function types that does +nothing. Alternatively, function types should not be supported by +default, but there is no reason a user cannot support them via their own +deletion policy. +
+ ++Function-type support might also lead to conditionally supporting a +function-call operator in the general case, and that seems way too inventive at +this stage to me, even if we could largely steal wording directly from +reference_wrapper. shared_ptr would have similar problems +too. +
+ +[ +2010-01-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++Add two new paragraphs directly to 20.9.9.1 [unique.ptr.dltr] (before +20.9.9.1.2 [unique.ptr.dltr.dflt]) with the following +content: +
+ +++ + + + + ++The class template default_delete serves as the default deleter (destruction policy) for +the class template unique_ptr. +
+ ++The template parameter T of default_delete may be an incomplete type. +
+
+1194. Unintended queue constructor
+Section: 23.5 [container.adaptors] Status: WP + Submitter: Howard Hinnant Opened: 2009-08-20 Last modified: 2010-10-23
+View all other issues in [container.adaptors].
+View all issues with WP status.
+Discussion:
++23.5.1.1 [queue.defn] has the following queue constructor: +
+ ++ +template <class Alloc> explicit queue(const Alloc&); ++This will be implemented like so: +
+ ++ +template <class Alloc> explicit queue(const Alloc& a) : c(a) {} ++The issue is that Alloc can be anything that a container will construct +from, for example an int. Is this intended to compile? +
+ ++ +queue<int> q(5); ++Before the addition of this constructor, queue<int>(5) would not compile. +I ask, not because this crashes, but because it is new and appears to be +unintended. We do not want to be in a position of accidently introducing this +"feature" in C++0X and later attempting to remove it. +
+ ++I've picked on queue. priority_queue and stack have +the same issue. Is it useful to create a priority_queue of 5 +identical elements? +
+ +[ +Daniel, Howard and Pablo collaborated on the proposed wording. +]
+ + +[ +2009-10 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
+ +[ +This resolution includes a semi-editorial clean up, giving definitions to members +which in some cases weren't defined since C++98. +This resolution also offers editorially different wording for 976, +and it also provides wording for 1196. +]
+ + ++Change container.adaptors, p1: +
+ ++The container adaptors each take a Container template parameter, and +each constructor takes a Container reference argument. This container is +copied into the Container member of each adaptor. If the container takes +an allocator, then a compatible allocator may be passed in to the +adaptor's constructor. Otherwise, normal copy or move construction is +used for the container argument.+ +[Note: it is not necessary for an +implementation to distinguish between the one-argument constructor that +takes a Container and the one- argument constructor that takes an +allocator_type. Both forms use their argument to construct an instance +of the container. — end note]++Change queue.defn, p1: +
+ ++ +template <class T, class Container = deque<T> > +class queue { +public: + typedef typename Container::value_type value_type; + typedef typename Container::reference reference; + typedef typename Container::const_reference const_reference; + typedef typename Container::size_type size_type; + typedef Container container_type; +protected: + Container c; + +public: + explicit queue(const Container&); + explicit queue(Container&& = Container()); + queue(queue&& q);: c(std::move(q.c)) {}+ template <class Alloc> explicit queue(const Alloc&); + template <class Alloc> queue(const Container&, const Alloc&); + template <class Alloc> queue(Container&&, const Alloc&); + template <class Alloc> queue(queue&&, const Alloc&); + queue& operator=(queue&& q);{ c = std::move(q.c); return *this; }+ + bool empty() const { return c.empty(); } + ... +}; ++Add a new section after 23.5.1.1 [queue.defn], [queue.cons]: +
+ +++ +queue constructors [queue.cons]
+ +explicit queue(const Container& cont); ++ ++ ++ ++Effects: Initializes c with cont. +
+ +explicit queue(Container&& cont = Container()); ++ ++ ++ ++Effects: Initializes c with std::move(cont). +
+ +queue(queue&& q) ++ ++ ++ ++Effects: Initializes c with std::move(q.c). +
+ ++For each of the following constructors, +if uses_allocator<container_type, Alloc>::value is false, +then the constructor shall not participate in overload resolution. +
+ +template <class Alloc> + explicit queue(const Alloc& a); ++ ++ ++ ++Effects: Initializes c with a. +
+ +template <class Alloc> + queue(const container_type& cont, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with cont as the first +argument and a as the second argument. +
+ +template <class Alloc> + queue(container_type&& cont, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with std::move(cont) as the +first argument and a as the second argument. +
+ +template <class Alloc> + queue(queue&& q, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with std::move(q.c) as the +first argument and a as the second argument. +
+ +queue& operator=(queue&& q); ++ ++ ++ + + ++Effects: Assigns c with std::move(q.c). +
+ ++Returns: *this. +
+ ++Add to 23.5.2.1 [priqueue.cons]: +
+ ++ ++ + + + +priority_queue(priority_queue&& q); ++ ++ ++ ++Effects: Initializes c with std::move(q.c) and +initializes comp with std::move(q.comp). +
+ ++For each of the following constructors, +if uses_allocator<container_type, Alloc>::value is false, +then the constructor shall not participate in overload resolution. +
+ +template <class Alloc> + explicit priority_queue(const Alloc& a); ++ ++ ++ ++Effects: Initializes c with a and value-initializes comp. +
+ +template <class Alloc> + priority_queue(const Compare& compare, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with a and initializes comp +with compare. +
+ +template <class Alloc> + priority_queue(const Compare& compare, const Container& cont, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with cont as the first argument +and a as the second argument, +and initializes comp with compare. +
+ +template <class Alloc> + priority_queue(const Compare& compare, Container&& cont, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with std::move(cont) as +the first argument and a as the second argument, +and initializes comp with compare. +
+ +template <class Alloc> + priority_queue(priority_queue&& q, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with std::move(q.c) as the +first argument and a as the second argument, +and initializes comp with std::move(q.comp). +
+ +priority_queue& operator=(priority_queue&& q); ++ ++ ++ ++Effects: Assigns c with std::move(q.c) and +assigns comp with std::move(q.comp). +
+ ++Returns: *this. +
+ ++Change 23.5.3.1 [stack.defn]: +
+ ++ +template <class T, class Container = deque<T> > +class stack { +public: + typedef typename Container::value_type value_type; + typedef typename Container::reference reference; + typedef typename Container::const_reference const_reference; + typedef typename Container::size_type size_type; + typedef Container container_type; +protected: + Container c; + +public: + explicit stack(const Container&); + explicit stack(Container&& = Container()); + stack(stack&& s); + template <class Alloc> explicit stack(const Alloc&); + template <class Alloc> stack(const Container&, const Alloc&); + template <class Alloc> stack(Container&&, const Alloc&); + template <class Alloc> stack(stack&&, const Alloc&); + stack& operator=(stack&& s); + + bool empty() const { return c.empty(); } + ... +}; ++Add a new section after 23.5.3.1 [stack.defn], [stack.cons]: +
+ +++ + + + + + +stack constructors [stack.cons]
+ +stack(stack&& s); ++ ++ ++ ++Effects: Initializes c with std::move(s.c). +
+ ++For each of the following constructors, +if uses_allocator<container_type, Alloc>::value is false, +then the constructor shall not participate in overload resolution. +
+ +template <class Alloc> + explicit stack(const Alloc& a); ++ ++ ++ ++Effects: Initializes c with a. +
+ +template <class Alloc> + stack(const container_type& cont, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with cont as the +first argument and a as the second argument. +
+ +template <class Alloc> + stack(container_type&& cont, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with std::move(cont) as the +first argument and a as the second argument. +
+ +template <class Alloc> + stack(stack&& s, const Alloc& a); ++ ++ ++ ++Effects: Initializes c with std::move(s.c) as the +first argument and a as the second argument. +
+ +stack& operator=(stack&& s); ++ ++ ++ ++Effects: Assigns c with std::move(s.c). +
+ ++Returns: *this. +
+ +
+1195. "Diagnostic required" wording is insufficient to prevent UB
+Section: 17 [library] Status: WP + Submitter: Daniel Krügler Opened: 2009-08-18 Last modified: 2010-10-23
+View other active issues in [library].
+View all other issues in [library].
+View all issues with WP status.
+Discussion:
++Several parts of the library use the notion of "Diagnostic required" +to indicate that +in the corresponding situation an error diagnostic should occur, e.g. +20.9.9.1.2 [unique.ptr.dltr.dflt]/2 +
++ +void operator()(T *ptr) const; ++ ++Effects: calls delete on ptr. A diagnostic is required if T is an +incomplete type. +++The problem with this approach is that such a requirement is +insufficient to prevent +undefined behavior, if this situation occurs. According to 1.3.6 [defns.diagnostic] +a diagnostic message is defined as +
+ ++a message belonging to an implementation-defined subset of the +implementation's output messages. ++ ++which doesn't indicate any relation to an ill-formed program. In fact, +"compiler warnings" +are a typical expression of such diagnostics. This means that above +wording can be interpreted +by compiler writers that they satisfy the requirements of the standard +if they just produce +such a "warning", if the compiler happens to compile code like this: +
+ ++ +#include <memory> + +struct Ukn; // defined somewhere else +Ukn* create_ukn(); // defined somewhere else + +int main() { + std::default_delete<Ukn>()(create_ukn()); +} ++In this and other examples discussed here it was the authors intent to +guarantee that the +program is ill-formed with a required diagnostic, therefore such +wording should be used instead. +According to the general rules outlined in 1.4 [intro.compliance] it +should be sufficient +to require that these situations produce an ill-formed program and the +"diagnostic +required" part should be implied. The proposed resolution also +suggests to remove +several redundant wording of "Diagnostics required" to ensure that +the absence of +such saying does not cause a misleading interpretation. +
+ +[ +2009 Santa Cruz: +]
+ + +++ ++Move to NAD. +
++It's not clear that there's any important difference between +"ill-formed" and "diagnostic required". From 1.4 [intro.compliance], 1.3.9 [defns.ill.formed], and 1.3.26 [defns.well.formed] it appears that an ill-formed program is one +that is not correctly constructed according to the syntax rules and +diagnosable semantic rules, which means that... "a conforming +implementation shall issue at least one diagnostic message." The +author's intent seems to be that we should be requiring a fatal error +instead of a mere warning, but the standard just doesn't have language +to express that distinction. The strongest thing we can ever require is +a "diagnostic". +
++The proposed rewording may be a clearer way of expressing the same thing +that the WP already says, but such a rewording is editorial. +
+[ +2009 Santa Cruz: +]
+ + ++Considered again. Group disagrees that the change is technical, but likes +it editorially. Moved to NAD Editorial. ++ +[ +2009-11-19: Moved from NAD Editorial to Open. Please see the thread starting +with Message c++std-lib-25916. +]
+ + +[ +2009-11-20 Daniel updated wording. +]
+ + +++ ++The following resolution differs from the previous one by avoiding the unusual +and misleading term "shall be ill-formed", which does also not follow the core +language style. This resolution has the advantage of a minimum impact on the +current wording, but I would like to mention that a more intrusive solution +might be preferrable - at least as a long-term solution: Jens Maurer suggested +the following approach to get rid of the usage of the term "ill-formed" from the +library by introducing a new category to existing elements to the list of 17.5.1.4 [structure.specifications]/3, e.g. "type requirements" or "static +constraints" that define conditions that can be checked during compile-time and +any violation would make the program ill-formed. As an example, the currently +existing phrase 20.4.2.5 [tuple.helper]/1 +
+ ++Requires: I < sizeof...(Types). The program is ill-formed if +I is out of bounds. ++ ++could then be written as +
+ ++Static constraints: I < sizeof...(Types). ++ +[ +2009-11-21 Daniel updated wording. +]
+ + +[ +2009-11-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++
+ + + + + + +- +
+ ++Change 20.6 [ratio]/2 as indicated: +
+ ++Throughout this subclause, if the template argument types R1 +and R2+shall beare not specializations of the +ratio template, the program is ill-formed.Diagnostic +required.+- +
+ ++Change 20.6.1 [ratio.ratio]/1 as indicated: +
+ ++If t
+ +The template argument Dshall not +beis zero, andor the absolute values of +the template arguments N and Dshall beare +not representable by type intmax_t, the program is +ill-formed.Diagnostic required.[..] +- +
+ ++Change 20.6.2 [ratio.arithmetic]/1 as indicated: +
+ ++Implementations may use other algorithms to compute these values. If overflow +occurs, the program is ill-formed+ +a diagnostic shall be +issued. +- +
+ ++Change 20.6.3 [ratio.comparison]/2 as indicated: +
+ ++[...] Implementations may use other algorithms to compute this relationship to +avoid overflow. If overflow occurs, the program is ill-formed+ +a +diagnostic is required. +- +
+ ++Change 20.9.9.1.2 [unique.ptr.dltr.dflt]/2 as indicated: +
+ +++ ++Effects: calls delete on ptr.
+ +A diagnostic is +required if T is an incomplete type.++Remarks: If T is an incomplete type, the program is +ill-formed. +
+- +
+ ++Change 20.9.9.1.3 [unique.ptr.dltr.dflt1]/1 as indicated: +
+ ++ +void operator()(T* ptr) const; +++++Effects:
+operator()calls +delete[] on ptr.A diagnostic is required if T +is an incomplete type.++Remarks: If T is an incomplete type, the program is +ill-formed. +
+- +
+ ++Change 20.9.9.2.1 [unique.ptr.single.ctor] as indicated: [Note: This +editorially improves the currently suggested wording of 932 by +replacing +
++"shall be ill-formed" by "is ill-formed"] ++ ++[If +N3025 +is accepted this bullet is applied identically in that paper as well.] +
+ +++ ++-1- Requires: D shall be default constructible, and that +construction shall not throw an exception.
+ +D shall not be a +reference type or pointer type (diagnostic required).+...
+ ++Remarks: If this constructor is instantiated with a pointer type +or reference type for the template argument D, the program is +ill-formed. +
+- +
+ ++Change 20.9.9.2.1 [unique.ptr.single.ctor]/8 as indicated: [Note: This +editorially improves the currently suggested wording of 932 by +replacing +
++"shall be ill-formed" by "is ill-formed"] ++ ++[If +N3025 +is accepted this bullet is applied identically in that paper as well.] +
+ ++ +unique_ptr(pointer p); ++++...
++Remarks: If this constructor is instantiated with a pointer type +or reference type for the template argument D, the program is +ill-formed. +
+- +
+ ++Change 20.9.9.2.1 [unique.ptr.single.ctor]/13 as indicated: +
+ ++[..] If d is an rvalue, it will bind to the second constructor of this +pair and the program is ill-formed.+ +That constructor shall emit +a diagnostic.[Note: The diagnostic could be implemented using a +static_assert which assures that D is not a reference type. +— end note] Else d is an lvalue and will bind to the first +constructor of this pair. [..] +- +20.9.9.2.1 [unique.ptr.single.ctor]/20: Solved by 950. +
+ +- +
+ ++Change 20.9.9.3 [unique.ptr.runtime]/1 as indicated: +
+ +++ ++A specialization for array types is provided with a slightly altered interface. +
++
+- +Conversions among different types of unique_ptr<T[], D> or to or +from the non-array forms of unique_ptr
+are disallowed (diagnostic +required)produce an ill-formed program. +- ...
+- +
+ ++Change 20.11.3 [time.duration]/2-4 as indicated: +
+ +++ ++2 Requires: Rep shall be an arithmetic type or a class emulating +an arithmetic type.
+If a program instantiates duration with a +duration type for the template argument Rep a diagnostic is +required.++3 Remarks: If duration is instantiated with a +duration type for the template argument Rep, the program is +ill-formed. +
+ ++
+ +34RequiresRemarks: +If Periodshall beis not a +specialization of ratio,diagnostic requiredthe +program is ill-formed. ++
+45RequiresRemarks: +If Period::numshall beis not +positive,diagnostic requiredthe program is ill-formed. +- +20.11.3.1 [time.duration.cons]/1+4: Apply 1177 +
+ +- +20.11.3.5 [time.duration.nonmember]/4+6+8+11: Apply 1177 +
+ +- +20.11.3.7 [time.duration.cast]/1: Apply 1177 +
+ +- +
+ ++Change 20.11.4 [time.point]/2 as indicated: +
++If Duration+shall beis not an +instance of duration, the program is ill-formed. +Diagnostic required.+- +20.11.4.1 [time.point.cons]/3: Apply 1177 +
+ +- +20.11.4.7 [time.point.cast]/1: Apply 1177 +
+ +
+1197. Can unordered containers have bucket_count() == 0?
+Section: 23.2.5 [unord.req] Status: WP + Submitter: Howard Hinnant Opened: 2009-08-24 Last modified: 2010-10-23
+View other active issues in [unord.req].
+View all other issues in [unord.req].
+View all issues with WP status.
+Discussion:
++Table 97 "Unordered associative container requirements" in +23.2.5 [unord.req] says: +
+ +++ ++
+Table 97 — Unordered associative container requirements +(in addition to container) + ++ + +Expression +Return type +Assertion/note pre-/post-condition +Complexity ++ + +b.bucket(k) +size_type +Returns the index of the bucket in which elements with keys +equivalent to k would be found, +if any such element existed. +Post: the return value shall be +in the range [0, +b.bucket_count()). +Constant ++What should b.bucket(k) return if b.bucket_count() == 0? +
+ ++I believe allowing b.bucket_count() == 0 is important. It is a +very reasonable post-condition of the default constructor, or of a moved-from +container. +
+ ++I can think of several reasonable results from b.bucket(k) when +b.bucket_count() == 0: +
+ ++
+ +- +Return 0. +
+- +Return numeric_limits<size_type>::max(). +
+- +Throw a domain_error. +
+- +Requires: b.bucket_count() != 0. +
+[ +2009-08-26 Daniel adds: +]
+ + +++ ++A forth choice would be to add the pre-condition "b.bucket_count() != 0" +and thus imply undefined behavior if this is violated. +
+ +[ +Howard: I like this option too, added to the list. +]
+ + ++Further on here my own favorite solution (rationale see below): +
+ +Suggested resolution:
+ ++[Rationale: I suggest to follow choice (1). The main reason is +that all associative container functions which take a key argument, +are basically free of pre-conditions and non-disrupting, therefore +excluding choices (3) and (4). Option (2) seems a bit unexpected +to me. It would be more natural, if several similar functions +would exist which would also justify the existence of a symbolic +constant like npos for this situation. The value 0 is both simple +and consistent, it has exactly the same role as a past-the-end +iterator value. A typical use-case is: +
+ ++ +size_type pos = m.bucket(key); +if (pos != m.bucket_count()) { + ... +} else { + ... +} +— end Rationale]
+ ++- Change Table 97 in 23.2.5 [unord.req] as follows (Row b.bucket(k), Column "Assertion/..."): +
+ +++ ++
+Table 97 — Unordered associative container requirements +(in addition to container) + ++ + +Expression +Return type +Assertion/note pre-/post-condition +Complexity ++ + +b.bucket(k) +size_type +Returns the index of the bucket in which elements with keys +equivalent to k would be found, +if any such element existed. +Post: if b.bucket_count() != 0, the return value shall be +in the range [0, +b.bucket_count()), otherwise 0. +Constant +[ +2010-01-25 Choice 4 put into proposed resolution section. +]
+ + +[ +2010-01-31 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Change Table 97 in 23.2.5 [unord.req] as follows (Row b.bucket(k), Column +"Assertion/..."): +
+ +++ + + + + + ++
+Table 97 — Unordered associative container requirements +(in addition to container) + ++ + +Expression +Return type +Assertion/note pre-/post-condition +Complexity ++ + +b.bucket(k) +size_type +Pre: b.bucket_count() > 0 Returns the index of the +bucket in which elements with keys equivalent to k would be found, if +any such element existed. Post: the return value shall be in the range [0, +b.bucket_count()). +Constant +
+1198. Container adaptor swap: member or non-member?
+Section: 23.5 [container.adaptors] Status: WP + Submitter: Pablo Halpern Opened: 2009-08-26 Last modified: 2010-11-24
+View all other issues in [container.adaptors].
+View all issues with WP status.
+Discussion:
++Under 23.5 [container.adaptors] of +N2914 +the member function of swap of queue and stack call: +
+ ++ +swap(c, q.c); ++But under 23.5 [container.adaptors] of +N2723 +these members are specified to call: +
+ ++ +c.swap(q.c); ++Neither draft specifies the semantics of member swap for +priority_queue though it is declared. +
+ ++Although the distinction between member swap and non-member +swap is not important when these adaptors are adapting standard +containers, it may be important for user-defined containers. +
++We (Pablo and Howard) feel that +it is more likely for a user-defined container to support a namespace scope +swap than a member swap, and therefore these adaptors +should use the container's namespace scope swap. +
+ +[ +2009-09-30 Daniel adds: +]
+ + ++The outcome of this issue should be considered with the outcome of 774 both in style and in content (e.g. 774 bullet 9 +suggests to define the semantic of void +priority_queue::swap(priority_queue&) in terms of the member +swap of the container). ++ +[ +2010-03-28 Daniel update to diff against N3092. +]
+ + + +[ +2010 Rapperswil: +]
+ + ++Preference to move the wording into normative text, rather than inline function definitions in the class synopsis. + +Move to Tenatively Ready. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ ++Change 23.5.1.1 [queue.defn]: +
+ ++ +template <class T, class Container = deque<T> > +class queue { + ... + void swap(queue& q) { using std::swap; +c.swap(c, q.c); } + ... +}; ++Change 23.5.2 [priority.queue]: +
+ ++ +template <class T, class Container = vector<T>, + class Compare = less<typename Container::value_type> > +class priority_queue { + ... + void swap(priority_queue& q);{ using std::swap; + swap(c, q.c); + swap(comp, q.comp); } + ... +}; ++Change 23.5.3.1 [stack.defn]: +
+ ++ + + + + + +template <class T, class Container = deque<T> > +class stack { + ... + void swap(stack& s) { using std::swap; +c.swap(c, s.c); } + ... +}; +
+1199. Missing extended copy constructor in container adaptors
+Section: 23.5 [container.adaptors] Status: WP + Submitter: Pablo Halpern Opened: 2009-08-26 Last modified: 2010-10-23
+View all other issues in [container.adaptors].
+View all issues with WP status.
+Discussion:
++queue has a constructor: +
+ ++ +template <class Alloc> + queue(queue&&, const Alloc&); ++but it is missing a corresponding constructor: +
+ ++ +template <class Alloc> + queue(const queue&, const Alloc&); ++The same is true of priority_queue, and stack. This +"extended copy constructor" is needed for consistency and to ensure that the +user of a container adaptor can always specify the allocator for his adaptor. +
+ +[ +2010-02-01 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+[ +This resolution has been harmonized with the proposed resolution to issue +1194 +]
+ + +Change 23.5.1.1 [queue.defn], p1:
+ ++ +template <class T, class Container = deque<T> > +class queue { +public: + typedef typename Container::value_type value_type; + typedef typename Container::reference reference; + typedef typename Container::const_reference const_reference; + typedef typename Container::size_type size_type; + typedef Container container_type; +protected: + Container c; + +public: + explicit queue(const Container&); + explicit queue(Container&& = Container()); + queue(queue&& q); + + template <class Alloc> explicit queue(const Alloc&); + template <class Alloc> queue(const Container&, const Alloc&); + template <class Alloc> queue(Container&&, const Alloc&); + template <class Alloc> queue(const queue&, const Alloc&); + template <class Alloc> queue(queue&&, const Alloc&); + queue& operator=(queue&& q); + + bool empty() const { return c.empty(); } + ... +}; ++To the new section 23.5.1.2 [queue.cons], introduced +in 1194, add: +
+ ++ ++ +template <class Alloc> + queue(const queue& q, const Alloc& a); ++ ++ ++Effects: Initializes c with q.c as the +first argument and a as the second argument. +
Change 23.5.2 [priority.queue] as follows (I've an included an editorial change to + move the poorly-placed move-assignment operator):
+ ++ +template <class T, class Container = vector<T>, + class Compare = less<typename Container::value_type> > +class priority_queue { +public: + typedef typename Container::value_type value_type; + typedef typename Container::reference reference; + typedef typename Container::const_reference const_reference; + typedef typename Container::size_type size_type; + typedef Container container_type; +protected: + Container c; + Compare comp; + +public: + priority_queue(const Compare& x, const Container&); + explicit priority_queue(const Compare& x = Compare(), Container&& = Container()); + template <class InputIterator> + priority_queue(InputIterator first, InputIterator last, + const Compare& x, const Container&); + template <class InputIterator> + priority_queue(InputIterator first, InputIterator last, + const Compare& x = Compare(), Container&& = Container()); + priority_queue(priority_queue&&); +priority_queue& operator=(priority_queue&&);+ template <class Alloc> explicit priority_queue(const Alloc&); + template <class Alloc> priority_queue(const Compare&, const Alloc&); + template <class Alloc> priority_queue(const Compare&, + const Container&, const Alloc&); + template <class Alloc> priority_queue(const Compare&, + Container&&, const Alloc&); + template <class Alloc> priority_queue(const priority_queue&, const Alloc&); + template <class Alloc> priority_queue(priority_queue&&, const Alloc&); + + priority_queue& operator=(priority_queue&&); + ... +}; ++Add to 23.5.2.1 [priqueue.cons]: +
+ ++ ++ +template <class Alloc> + priority_queue(const priority_queue& q, const Alloc& a); ++ ++ ++Effects: Initializes c with q.c as the +first argument and a as the second argument, +and initializes comp with q.comp. +
+Change 23.5.3.1 [stack.defn]: +
+ ++ +template <class T, class Container = deque<T> > +class stack { +public: + typedef typename Container::value_type value_type; + typedef typename Container::reference reference; + typedef typename Container::const_reference const_reference; + typedef typename Container::size_type size_type; + typedef Container container_type; +protected: + Container c; + +public: + explicit stack(const Container&); + explicit stack(Container&& = Container()); + stack(stack&& s); + + template <class Alloc> explicit stack(const Alloc&); + template <class Alloc> stack(const Container&, const Alloc&); + template <class Alloc> stack(Container&&, const Alloc&); + template <class Alloc> stack(const stack&, const Alloc&); + template <class Alloc> stack(stack&&, const Alloc&); + stack& operator=(stack&& s); + + bool empty() const { return c.empty(); } + ... +}; ++To the new section 23.5.3.2 [stack.cons], introduced +in 1194, add: +
+ ++ ++ + + + + + +template <class Alloc> + stack(const stack& s, const Alloc& a); ++ +++Effects: Initializes c with s.c as the +first argument and a as the second argument. +
+1204. Global permission to move
+Section: 17.6.3.9 [res.on.arguments] Status: WP + Submitter: Howard Hinnant Opened: 2009-09-12 Last modified: 2010-10-23
+View all other issues in [res.on.arguments].
+View all issues with WP status.
+Discussion:
++When a library function binds an rvalue reference parameter to an argument, the +library must be able to assume that the bound argument is a temporary, and not +a moved-from lvalue. The reason for this is that the library function must be +able to modify that argument without concern that such modifications will corrupt +the logic of the calling code. For example: +
+ ++ +template <class T, class A> +void +vector<T, A>::push_back(value_type&& v) +{ + // This function should move from v, potentially modifying + // the object v is bound to. +} ++If v is truly bound to a temporary, then push_back has the +only reference to this temporary in the entire program. Thus any +modifications will be invisible to the rest of the program. +
+ ++If the client supplies std::move(x) to push_back, the onus is +on the client to ensure that the value of x is no longer important to +the logic of his program after this statement. I.e. the client is making a statement +that push_back may treat x as a temporary. +
+ ++The above statement is the very foundation upon which move semantics is based. ++ ++The standard is currently lacking a global statement to this effect. I propose +the following addition to 17.6.3.9 [res.on.arguments]: +
+ +++ ++Each of the following statements applies to all arguments to functions +defined in the C++ standard library, unless explicitly stated otherwise. +
++
+ +- +If an argument to a function has an invalid value (such as a value +outside the domain of the function, or a pointer invalid for its +intended use), the behavior is undefined. +
+- +If a function argument is described as being an array, the pointer +actually passed to the function shall have a value such that all address +computations and accesses to objects (that would be valid if the pointer +did point to the first element of such an array) are in fact valid. +
+- +If a function argument binds to an rvalue reference parameter, the C++ +standard library may assume that this parameter is a unique reference +to this argument. If the parameter is a generic parameter of the +form T&&, and an lvalue of type A is bound, +then the binding is considered to be to an lvalue reference +(14.8.2.1 [temp.deduct.call]) and thus not covered by this clause. +[Note: +If a program casts an lvalue to an rvalue while passing that lvalue to +a library function (e.g. move(x)), then the program is effectively +asking the library to treat that lvalue as a temporary. The library is at +liberty to optimize away aliasing checks which might be needed if the argument +were an lvalue. +— end note] +
++Such a global statement will eliminate the need for piecemeal statements such as +23.2.1 [container.requirements.general]/13: +
+ ++An object bound to an rvalue reference parameter of a member function of +a container shall not be an element of that container; no diagnostic +required. ++ ++Additionally this clarifies that move assignment operators need not perform the +traditional if (this != &rhs) test commonly found (and needed) in +copy assignment operators. +
+ +[ +2009-09-13 Niels adds: +]
+ + ++Note: This resolution supports the change of 27.9.1.3 [filebuf.assign]/1, +proposed by LWG 900. ++ +[ +2009 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++Add a bullet to 17.6.3.9 [res.on.arguments]: +
+ +++ ++Each of the following statements applies to all arguments to functions +defined in the C++ standard library, unless explicitly stated otherwise. +
++
+- +If an argument to a function has an invalid value (such as a value +outside the domain of the function, or a pointer invalid for its +intended use), the behavior is undefined. +
+- +If a function argument is described as being an array, the pointer +actually passed to the function shall have a value such that all address +computations and accesses to objects (that would be valid if the pointer +did point to the first element of such an array) are in fact valid. +
+- +If a function argument binds to an rvalue reference parameter, the C++ +standard library may assume that this parameter is a unique reference +to this argument. If the parameter is a generic parameter of the +form T&&, and an lvalue of type A is bound, +then the binding is considered to be to an lvalue reference +(14.8.2.1 [temp.deduct.call]) and thus not covered by this clause. +[Note: +If a program casts an lvalue to an rvalue while passing that lvalue to +a library function (e.g. move(x)), then the program is effectively +asking the library to treat that lvalue as a temporary. The library is at +liberty to optimize away aliasing checks which might be needed if the argument +were an lvalue. +— end note] +
++Delete 23.2.1 [container.requirements.general]/13: +
+ ++ + + + + + ++An object bound to an rvalue reference parameter of a member function of +a container shall not be an element of that container; no diagnostic +required. +
+1205. Some algorithms could more clearly document their handling of empty ranges
+Section: 25 [algorithms] Status: WP + Submitter: Alisdair Meredith Opened: 2009-09-13 Last modified: 2010-10-23
+View all other issues in [algorithms].
+View all issues with WP status.
+Discussion:
++There are a number of algorithms whose result might depend on the +handling of an empty range. In some cases the result is not clear, +while in others it would help readers to clearly mention the result +rather than require some subtle intuition of the supplied wording. +
+ ++25.2.1 [alg.all_of] +
+ ++Returns: true if pred(*i) is true for every +iterator i in the range [first,last), ... ++ ++What does this mean if the range is empty? +
+ ++I believe that we intend this to be true and suggest a +non-normative note to clarify: +
+ ++Add to p1 25.2.1 [alg.all_of]: +
+ ++[Note: Returns true if [first,last) is empty. +— end note] ++ ++25.2.3 [alg.none_of] +
+ ++Returns: true if pred(*i) is false for every +iterator i in the range [first,last), ... ++ ++What does this mean if the range empty? +
+ ++I believe that we intend this to be true and suggest a +non-normative note to clarify: +
+ ++Add to p1 25.2.3 [alg.none_of]: +
+ ++[Note: Returns true if [first,last) is empty. +— end note] ++ ++25.2.2 [alg.any_of] +
+ ++The specification for an empty range is actually fairly clear in this +case, but a note wouldn't hurt and would be consistent with proposals +for all_of/none_of algorithms. +
+ ++Add to p1 25.2.2 [alg.any_of]: +
+ ++[Note: Returns false if [first,last) is empty. +— end note] ++ ++25.2.6 [alg.find.end] +
+ ++what does this mean if [first2,last2) is empty? +
+ ++I believe the wording suggests the algorithm should return +last1 in this case, but am not 100% sure. Is this in fact the +correct result anyway? Surely an empty range should always match and the +naive expected result would be first1? +
+ ++My proposed wording is a note to clarify the current semantic: +
+ ++Add to p2 25.2.6 [alg.find.end]: +
+ ++[Note: Returns last1 if [first2,last2) is +empty. — end note] ++ ++I would prefer a normative wording treating empty ranges specially, but +do not believe we can change semantics at this point in the process, +unless existing implementations actually yield this result: +
+ ++Alternative wording: (NOT a note) +
++Add to p2 25.2.6 [alg.find.end]: +
++Returns first1 if [first2,last2) is empty. ++ ++25.2.7 [alg.find.first.of] +
+ ++The phrasing seems precise when [first2, last2) is empty, but a small +note to confirm the reader's understanding might still help. +
+ ++Add to p2 25.2.7 [alg.find.first.of] +
++[Note: Returns last1 if [first2,last2) is +empty. — end note] ++ ++25.2.13 [alg.search] +
+ ++What is the expected result if [first2, last2) is empty? +
+ ++I believe the wording suggests the algorithm should return last1 in this +case, but am not 100% sure. Is this in fact the correct result anyway? +Surely an empty range should always match and the naive expected result +would be first1? +
+ ++My proposed wording is a note to clarify the current semantic: +
+ ++Add to p2 25.2.13 [alg.search]: +
+ ++[Note: Returns last1 if [first2,last2) is +empty. — end note] ++ ++Again, I would prefer a normative wording treating empty ranges +specially, but do not believe we can change semantics at this point in +the process, unless existing implementations actually yield this result: +
+ ++Alternative wording: (NOT a note) +
++Add to p2 25.2.13 [alg.search]: +
+ ++Returns first1 if [first2,last2) is empty. ++ ++25.3.13 [alg.partitions] +
+ ++Is an empty range partitioned or not? +
+ ++Proposed wording: +
+ ++Add to p1 25.3.13 [alg.partitions]: +
+ ++[Note: Returns true if [first,last) is empty. +— end note] ++ ++25.4.5.1 [includes] +
+ ++Returns: true if every element in the range +[first2,last2) is contained in the range +[first1,last1). ... ++ ++I really don't know what this means if [first2,last2) is empty. +I could loosely guess that this implies empty ranges always match, and +my proposed wording is to clarify exactly that: +
+ ++Add to p1 25.4.5.1 [includes]: +
+ ++[Note: Returns true if [first2,last2) is empty. +— end note] ++ ++25.4.6.2 [pop.heap] +
+ ++The effects clause is invalid if the range [first,last) is empty, unlike +all the other heap alogorithms. The should be called out in the +requirements. +
+ ++Proposed wording: +
++Revise p2 25.4.6.2 [pop.heap] +
+ ++Requires: The range [first,last) shall be a valid +non-empty heap. ++ ++[Editorial] Reverse order of 25.4.6.2 [pop.heap] p1 and p2. +
+ ++25.4.7 [alg.min.max] +
+ ++minmax_element does not clearly specify behaviour for an empty +range in the same way that min_element and max_element do. +
+ ++Add to p31 25.4.7 [alg.min.max]: +
+ ++Returns make_pair(first, first) if first == last. ++ ++25.4.8 [alg.lex.comparison] +
+ ++The wording here seems quite clear, especially with the sample algorithm +implementation. A note is recommended purely for consistency with the +rest of these issue resolutions: +
+ ++Add to p1 25.4.8 [alg.lex.comparison]: +
+ ++[Note: An empty sequence is lexicographically less than any other +non-empty sequence, but not to another empty sequence. — end note] ++ +[ +2009-11-11 Howard changes Notes to Remarks and changed search to +return first1 instead of last1. +]
+ + +[ +2009-11-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Add to 25.2.1 [alg.all_of]: +
++Remarks: Returns true if [first,last) is empty. ++ ++Add to 25.2.2 [alg.any_of]: +
+ ++Remarks: Returns false if [first,last) is empty. ++ ++Add to 25.2.3 [alg.none_of]: +
++Remarks: Returns true if [first,last) is empty. ++ ++Add to 25.2.6 [alg.find.end]: +
++Remarks: Returns last1 if [first2,last2) is +empty. ++ ++Add to 25.2.7 [alg.find.first.of] +
++Remarks: Returns last1 if [first2,last2) is +empty. ++ ++Add to 25.2.13 [alg.search]: +
++Remarks: Returns first1 if [first2,last2) is +empty. ++ ++Add to 25.3.13 [alg.partitions]: +
++Remarks: Returns true if [first,last) is empty. ++ ++Add to 25.4.5.1 [includes]: +
++Remarks: Returns true if [first2,last2) is empty. ++ ++Revise p2 25.4.6.2 [pop.heap] +
++Requires: The range [first,last) shall be a valid +non-empty heap. ++ ++[Editorial] +
++Reverse order of 25.4.6.2 [pop.heap] p1 and p2. ++ ++Add to p35 25.4.7 [alg.min.max]: +
++ +template<class ForwardIterator, class Compare> + pair<ForwardIterator, ForwardIterator> + minmax_element(ForwardIterator first, ForwardIterator last, Compare comp); +++Returns: make_pair(m, M), where m is the first iterator in +[first,last) such that no iterator in the range refers to a smaller +element, and where M is the last iterator in [first,last) such that no +iterator in the range refers to a larger element. +Returns make_pair(first, first) if first == last. +++Add to 25.4.8 [alg.lex.comparison]: +
++Remarks: An empty sequence is lexicographically less than any other +non-empty sequence, but not less than another empty sequence. ++ + + + + + +
+1206. Incorrect requires for move_backward and copy_backward
+Section: 25.3.2 [alg.move] Status: WP + Submitter: Howard Hinnant Opened: 2009-09-13 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++25.3.2 [alg.move], p6 says: +
+ +++ +template<class BidirectionalIterator1, class BidirectionalIterator2> + BidirectionalIterator2 + move_backward(BidirectionalIterator1 first, + BidirectionalIterator1 last, + BidirectionalIterator2 result); ++++...
++Requires: result shall not be in the range +[first,last). +
++This is essentially an "off-by-one" error. +
+ ++When result == last, which +is allowed by this specification, then the range [first, last) +is being move assigned into the range [first, last). The move +(forward) algorithm doesn't allow self move assignment, and neither should +move_backward. So last should be included in the range which +result can not be in. +
+ ++Conversely, when result == first, which is not allowed by this +specification, then the range [first, last) +is being move assigned into the range [first - (last-first), first). +I.e. into a non-overlapping range. Therefore first should +not be included in the range which result can not be in. +
+ ++The same argument applies to copy_backward though copy assigning elements +to themselves (result == last) should be harmless (though is disallowed +by copy). +
+ +[ +2010 Pittsburgh: Moved to Ready. +]
+ + + + +Proposed resolution:
++Change 25.3.2 [alg.move], p6: +
+ +++ +template<class BidirectionalIterator1, class BidirectionalIterator2> + BidirectionalIterator2 + move_backward(BidirectionalIterator1 first, + BidirectionalIterator1 last, + BidirectionalIterator2 result); ++++...
++Requires: result shall not be in the range +
+[(first,last]). ++Change 25.3.1 [alg.copy], p13: +
+ +++ + + + + +template<class BidirectionalIterator1, class BidirectionalIterator2> + BidirectionalIterator2 + copy_backward(BidirectionalIterator1 first, + BidirectionalIterator1 last, + BidirectionalIterator2 result); ++++...
++Requires: result shall not be in the range +
+[(first,last]). +
+1207. Underspecified std::list operations?
+Section: 23.3.4.4 [list.ops] Status: WP + Submitter: Loďc Joly Opened: 2009-09-13 Last modified: 2010-11-24
+View all other issues in [list.ops].
+View all issues with WP status.
+Discussion:
++It looks to me like some operations of std::list +(sort, reverse, remove, unique & +merge) do not specify the validity of iterators, pointers & +references to elements of the list after those operations. Is it implied +by some other text in the standard? +
+ ++I believe sort & reverse do not invalidating +anything, remove & unique only invalidates what +refers to erased elements, merge does not invalidate anything +(with the same precision as splice for elements who changed of +container). Are those assumptions correct ? +
+ +[ +2009-12-08 Jonathan Wakely adds: +]
+ + +++ ++23.2.1 [container.requirements.general] paragraph 11 says iterators +aren't invalidated unless specified, so I don't think it needs to be repeated on +every function that doesn't invalidate iterators. list::unique says it +"eliminates" elements, that should probably be "erases" because IMHO that term +is used elsewhere and so makes it clearer that iterators to the erased elements +are invalidated. +
+ ++list::merge coud use the same wording as list::splice w.r.t +iterators and references to moved elements. +
+ ++Suggested resolution: +
+ ++In 23.3.4.4 [list.ops] change paragraph 19 +
+ ++ +void unique(); +template <class BinaryPredicate> void unique(BinaryPredicate binary_pred); +++Effects:+EliminatesErases all but the first +element from every consecutive group ... ++Add to the end of paragraph 23 +
+ ++void merge(list<T,Allocator>&& x); +template <class Compare> void merge(list<T,Allocator>&& x, Compare comp); ++++...
++Effects: ... that is, for every iterator i, in the range other +than the first, the condition comp(*i, *(i - 1) will be false. +Pointers and references to the moved elements of x now refer to +those same elements but as members of *this. Iterators referring to the +moved elements will continue to refer to their elements, but they now behave as +iterators into *this, not into x. +
+[ +2009-12-12 Loďc adds wording. +]
+ + +[ +2010-02-10 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-02-10 Alisdair opens: +]
+ + +++ ++I object to the current resolution of #1207. I believe it is overly strict with +regard to list end iterators, being the only mutating operations to +require such stability. +
+ ++More importantly, the same edits need to be applied to forward_list, +which uses slightly different words to describe some of these operations so may +require subtly different edits (not checked.) +
+ ++I am prepared to pick up the end() iterator as a separate (new) issue, +as part of the FCD ballot review (BSI might tell me 'no' first ;~) but I do want +to see forward_list adjusted at the same time. +
+[ +2010-03-28 Daniel adds the first 5 bullets in an attempt to address Alisdair's +concerns. +]
+ + + +[ +2010 Rapperswil: +]
+ + ++The wording looks good. + +Move to Tentatively Ready. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ ++ +
+ + + + + + +- +
+ ++Change 23.3.3.5 [forwardlist.ops]/12 as indicated: +
+ ++void remove(const T& value); +template <class Predicate> void remove_if(Predicate pred); ++ ++12 Effects: Erases all the elements in the list referred by a list +iterator i for which the following conditions hold: *i == value +(for remove()), pred(*i) is true (for remove_if()). This operation +shall be stable: the relative order of the elements that are not removed is the +same as their relative order in the original list. Invalidates only the +iterators and references to the erased elements. ++- +
+ ++Change 23.3.3.5 [forwardlist.ops]/15 as indicated: +
+ ++template <class BinaryPredicate> void unique(BinaryPredicate pred); ++ ++15 Effects::+EliminatesErases all but the first +element from every consecutive group of equal elements referred to by the +iterator i in the range [first + 1,last) for which *i == +*(i-1) (for the version with no arguments) or pred(*i, *(i - 1)) +(for the version with a predicate argument) holds. Invalidates only the +iterators and references to the erased elements. +- +
+ ++Change 23.3.3.5 [forwardlist.ops]/19 as indicated: +
+ ++void merge(forward_list<T,Allocator>&& x); +template <class Compare> void merge(forward_list<T,Allocator>&& x, Compare comp) ++ ++++[..] +
+ ++19 Effects:: Merges x into *this. This operation shall +be stable: for equivalent elements in the two lists, the elements from +*this shall always precede the elements from x. x is +empty after the merge. If an exception is thrown other than by a comparison +there are no effects. Pointers and references to the moved elements of +x now refer to those same elements but as members of *this. +Iterators referring to the moved elements will continue to refer to their +elements, but they now behave as iterators into *this, not into +x. +
+- +
+ ++Change 23.3.3.5 [forwardlist.ops]/22 as indicated: +
+ ++void sort(); +template <class Compare> void sort(Compare comp); ++ ++++[..] +
+ ++22 Effects:: Sorts the list according to the operator< or the +comp function object. This operation shall be stable: the relative +order of the equivalent elements is preserved. If an exception is thrown the +order of the elements in *this is unspecified. Does not affect the +validity of iterators and references. +
+- +
+ ++Change 23.3.3.5 [forwardlist.ops]/24 as indicated: +
+ ++void reverse(); ++ ++24 Effects:: Reverses the order of the elements in the list. Does +not affect the validity of iterators and references. ++- +
+ ++Change 23.3.4.4 [list.ops], p15: +
+ ++void remove(const T& value); +template <class Predicate> void remove_if(Predicate pred); +++Effects: Erases all the elements in the list referred by a list iterator +i for which the following conditions hold: *i == value, pred(*i) != +false. Invalidates only the iterators and references to the erased +elements. ++- +
+ ++Change 23.3.4.4 [list.ops], p19: +
+ ++void unique(); +template <class BinaryPredicate> void unique(BinaryPredicate binary_pred); +++Effects:+EliminatesErases all but the first +element from every consecutive group of equal elements referred to by the +iterator i in the range [first + 1,last) for which *i == +*(i-1) (for the version of unique with no arguments) or +pred(*i, *(i - 1)) (for the version of unique with a predicate +argument) holds. Invalidates only the iterators and references to the +erased elements. +- +
+ ++Change 23.3.4.4 [list.ops], p23: +
+ ++void merge(list<T,Allocator>&& x); +template <class Compare> void merge(list<T,Allocator>&& x, Compare comp); +++Effects: If (&x == this) does nothing; otherwise, merges the +two sorted ranges [begin(), end()) and [x.begin(), x.end()). +The result is a range in which the elements will be sorted in non-decreasing +order according to the ordering defined by comp; that is, for every +iterator i, in the range other than the first, the condition +comp(*i, *(i - 1) will be false. +Pointers and references to the moved elements of x now refer to +those same elements but as members of *this. Iterators referring to the +moved elements will continue to refer to their elements, but they now behave as +iterators into *this, not into x. ++- +
+ ++Change 23.3.4.4 [list.ops], p26: +
+ ++void reverse(); +++Effects: Reverses the order of the elements in the list. +Does not affect the validity of iterators and references. ++- +
+ ++Change 23.3.4.4 [list.ops], p30: +
+ ++void sort(); +template <class Compare> void sort(Compare comp); +++Effects: Sorts the list according to the operator< or a +Compare function object. +Does not affect the validity of iterators and references. ++
+1208. valarray initializer_list constructor has incorrect effects
+Section: 26.6.2.1 [valarray.cons] Status: WP + Submitter: Howard Hinnant Opened: 2009-09-23 Last modified: 2010-10-23
+View all other issues in [valarray.cons].
+View all issues with WP status.
+Discussion:
++26.6.2.1 [valarray.cons] says: +
+ +++ +valarray(initializer_list<T> il); +++Effects: Same as valarray(il.begin(), il.end()). +++But there is no valarray constructor taking two const T*. +
+ +[ +2009-10-29 Howard: +]
+ + ++Moved to Tentatively Ready after 6 positive votes on c++std-lib. ++ + +Proposed resolution:
++Change 26.6.2.1 [valarray.cons]: +
+ +++ + + + + +valarray(initializer_list<T> il); +++Effects: Same as valarray(il.begin(), il.+endsize()). +
+1209. match_results should be moveable
+Section: 28.10.1 [re.results.const] Status: WP + Submitter: Stephan T. Lavavej Opened: 2009-09-15 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++In Working Draft +N2914, +match_results lacks a move constructor and move +assignment operator. Because it owns dynamically allocated memory, it +should be moveable. +
+ ++As far as I can tell, this isn't tracked by an active issue yet; Library +Issue 723 doesn't talk about match_results. +
+ +[ +2009-09-21 Daniel provided wording. +]
+ + +[ +2009-11-18: Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++
+ + + + + +- +
+ ++Add the following member declarations to 28.10 [re.results]/3: +
+ ++// 28.10.1, construct/copy/destroy: +explicit match_results(const Allocator& a = Allocator()); +match_results(const match_results& m); +match_results(match_results&& m); +match_results& operator=(const match_results& m); +match_results& operator=(match_results&& m); +~match_results(); +- +
+ ++Add the following new prototype descriptions to 28.10.1 [re.results.const] +using the table numbering of +N3000 +(referring to the table titled "match_results assignment operator effects"): +
+ +++match_results(const match_results& m); ++ ++4 Effects: Constructs an object of class match_results, as a +copy of m. ++ +match_results(match_results&& m); ++ +++ ++5 Effects: Move-constructs an object of class match_results +from m satisfying the same postconditions as Table 131. Additionally +the stored Allocator value is move constructed from m.get_allocator(). +After the initialization of *this sets m to an unspecified but valid +state. +
+ ++6 Throws: Nothing if the allocator's move constructor throws nothing. +
+match_results& operator=(const match_results& m); ++ ++7 Effects: Assigns m to *this. The postconditions of this function are +indicated in Table 131. ++ +match_results& operator=(match_results&& m); ++ ++++8 Effects: Move-assigns m to *this. The postconditions of this +function are indicated in Table 131. After the assignment, m is in +a valid but unspecified state. +
+ ++9 Throws: Nothing. +
+
+1216. LWG 1066 Incomplete?
+Section: 18.8.6 [except.nested] Status: WP + Submitter: Pete Becker Opened: 2009-09-25 Last modified: 2010-10-23
+View all other issues in [except.nested].
+View all issues with WP status.
+Discussion:
++LWG 1066 adds [[noreturn]] to a bunch of things. +It doesn't add it to rethrow_nested(), which seems like an obvious +candidate. I've made the changes indicated in the issue, and haven't +changed rethrow_nested(). +
+ +[ +2009 Santa Cruz: +]
+ + ++Move to Ready. ++ + + +Proposed resolution:
++Add [[noreturn]] to rethrow_nested() in 18.8.6 [except.nested]. +
+ + + + + +
+1218. mutex destructor synchronization
+Section: 30.4.1 [thread.mutex.requirements] Status: WP + Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
+View all other issues in [thread.mutex.requirements].
+View all issues with WP status.
+Discussion:
++If an object *o contains a mutex mu and a +correctly-maintained reference count c, is the following code +safe? +
+ ++ +o->mu.lock(); +bool del = (--(o->c) == 0); +o->mu.unlock(); +if (del) { delete o; } ++If the implementation of mutex::unlock() can touch the mutex's +memory after the moment it becomes free, this wouldn't be safe, and +"Construction and destruction of an object of a Mutex type need not be +thread-safe" 30.4.1 [thread.mutex.requirements] may imply that +it's not safe. Still, it's useful to allow mutexes to guard reference +counts, and if it's not allowed, users are likely to write bugs. +
+ +[ +2009-11-18: Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++
+ + + + + +- +
+ ++Add a new paragraph after 30.4.1.2.1 [thread.mutex.class] p1: +
++++1 The class mutex provides a non-recursive mutex ... +
++[Note: After a thread A has called unlock(), releasing +the mutex, it is possible for another thread B to lock the same mutex, +observe that it is no longer in use, unlock and destroy it, before thread +A appears to have returned from its unlock call. Implementations are +required to handle such scenarios correctly, as long as thread A +doesn't access the mutex after the unlock call returns. These cases typically +occur when a reference-counted object contains a mutex that is used to protect +the reference count. — end note] +
+
+1220. What does condition_variable wait on?
+Section: 30.5 [thread.condition] Status: WP + Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
+View all other issues in [thread.condition].
+View all issues with WP status.
+Discussion:
++"Class condition_variable provides a condition variable that can only +wait on an object of type unique_lock" should say "...object of type +unique_lock<mutex>" +
+ +[ +2009-11-06 Howard adds: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ + + +Proposed resolution:
++Change 30.5 [thread.condition], p1: +
+ ++Condition variables provide synchronization primitives used to block a +thread until notified by some other thread that some condition is met or +until a system time is reached. Class condition_variable +provides a condition variable that can only wait on an object of type +unique_lock<mutex>, allowing maximum +efficiency on some platforms. Class condition_variable_any +provides a general condition variable that can wait on objects of +user-supplied lock types. ++ + + + + +
+1221. condition_variable wording
+Section: 30.5.1 [thread.condition.condvar] Status: WP + Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
+View all other issues in [thread.condition.condvar].
+View all issues with WP status.
+Discussion:
++30.5.1 [thread.condition.condvar] says: +
+ +++ +~condition_variable(); +++Precondition: There shall be no thread blocked on *this. +[Note: That is, all threads shall have been notified; they may +subsequently block on the lock specified in the wait. Beware that +destroying a condition_variable object while the corresponding +predicate is false is likely to lead to undefined behavior. +— end note] +++The text hasn't introduced the notion of a "corresponding predicate" +yet. +
+ +[ +2010-02-11 Anthony provided wording. +]
+ + +[ +2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++Modify 30.5.1 [thread.condition.condvar]p4 as follows: +
+ +++ + + + + +~condition_variable();++4 Precondition: There shall be no thread blocked on *this. +[Note: That is, all threads shall have been notified; they may +subsequently block on the lock specified in the wait.+Beware that +destroying a condition_variable object while the corresponding +predicate is false is likely to lead to undefined behavior.The user +must take care to ensure that no threads wait on *this once the +destructor has been started, especially when the waiting threads are calling the +wait functions in a loop or using the overloads of wait, +wait_for or wait_until that take a predicate. — +end note] +
+1222. condition_variable incorrect effects for exception safety
+Section: 30.5 [thread.condition] Status: WP + Submitter: Jeffrey Yasskin Opened: 2009-09-30 Last modified: 2010-10-23
+View all other issues in [thread.condition].
+View all issues with WP status.
+Discussion:
++30.5.1 [thread.condition.condvar] says: +
+ +++ +void wait(unique_lock<mutex>& lock); ++++...
++Effects: +
++
+- ...
+- +If the function exits via an exception, lock.unlock() shall be +called prior to exiting the function scope. +
++Should that be lock.lock()? +
+ +[ +2009-11-17 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
+ ++Change 30.5.1 [thread.condition.condvar] p10: +
+ +++ +void wait(unique_lock<mutex>& lock); ++++...
++Effects: +
++
+- ...
+- +If the function exits via an exception, lock.
+unlock() shall be +called prior to exiting the function scope. ++And make a similar change in p16, and in 30.5.2 [thread.condition.condvarany], +p8 and p13. +
+ + + + + + +
+1227. <bitset> synopsis overspecified
+Section: 20.5 [template.bitset] Status: WP + Submitter: Bo Persson Opened: 2009-10-05 Last modified: 2010-10-23
+View all other issues in [template.bitset].
+View all issues with WP status.
+Discussion:
++The resolutions to some library defect reports, like 1178 +requires that #includes in each synopsis should be taken +literally. This means that the <bitset> header now +must include <stdexcept>, even though none of the +exceptions are mentioned in the <bitset> header. +
++Many other classes are required to throw exceptions like +invalid_argument and out_of_range, without explicitly +including <stdexcept> in their synopsis. It is totally +possible for implementations to throw the needed exceptions from utility +functions, whose implementations are not visible in the headers. +
++I propose that <stdexcept> is removed from the +<bitset> header. +
+ +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ + + +Proposed resolution:
++Change 20.5 [template.bitset]: +
+ ++ + + + + +#include <cstddef> // for size_t +#include <string> +#include <stdexcept> // for invalid_argument,+// out_of_range, overflow_error+#include <iosfwd> // for istream, ostream +namespace std { +... +
+1231. weak_ptr comparisons incompletely resolved
+Section: 20.9.10.3.5 [util.smartptr.weak.obs] Status: WP + Submitter: Daniel Krügler Opened: 2009-10-10 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++The +n2637 +paper suggested several updates of the ordering semantics of +shared_ptr +and weak_ptr, among those the explicit comparison operators of weak_ptr were +removed/deleted, instead a corresponding functor owner_less was added. +The problem +is that +n2637 +did not clearly enough specify, how the previous wording +parts describing +the comparison semantics of weak_ptr should be removed. +
+ +[ +2009-11-06 Howard adds: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ + + +Proposed resolution:
++
+ + + + + +- +
+ ++Change 20.9.10.3 [util.smartptr.weak]/2 as described, the intention is to fix +the now no longer valid +requirement that weak_ptr is LessComparable [Note the deleted comma]: +
+ ++Specializations of weak_ptr shall be CopyConstructible+,+and CopyAssignable, +and LessThanComparable,allowing their use in standard containers. +- +
++In 20.9.10.3.5 [util.smartptr.weak.obs] remove the paragraphs 9-11 including prototype: +
+ +++template<class T, class U> bool operator<(const weak_ptr<T>& a, const weak_ptr<U>& b);+ ++
+Returns: an unspecified value such that++
+ +- +
+operator< is a strict weak ordering as described in 25.4;+- +
+under the equivalence relation defined by operator<, !(a +< b) && !(b < a), two weak_ptr instances are +equivalent if and only if they share ownership or are both empty.++
+ +Throws: nothing.++
+[Note: Allows weak_ptr objects to be used as keys in associative +containers. — end note]+
+1234. "Do the right thing" and NULL
+Section: 23.2.3 [sequence.reqmts] Status: WP + Submitter: Matt Austern Opened: 2009-10-09 Last modified: 2010-11-24
+View all other issues in [sequence.reqmts].
+View all issues with WP status.
+Discussion:
++On g++ 4.2.4 (x86_64-linux-gnu), the following file gives a compile +error: +
+ ++ +#include <vector> +void foo() { std::vector<int*> v(500l, NULL); } ++Is this supposed to work? +
+ ++The issue: if NULL happens to be defined as 0l, this is an invocation of +the constructor with two arguments of the same integral type. +23.2.3 [sequence.reqmts]/14 +(N3035) +says that this will behave as if the the +overloaded constructor +
+ ++ +X(size_type, const value_type& = value_type(), + const allocator_type& = allocator_type()) ++were called instead, with the arguments +static_cast<size_type>(first), last and +alloc, respectively. However, it does not say whether this +actually means invoking that constructor with the exact textual form of +the arguments as supplied by the user, or whether the standard permits +an implementation to invoke that constructor with variables of the same +type and value as what the user passed in. In most cases this is a +distinction without a difference. In this particular case it does make a +difference, since one of those things is a null pointer constant and the +other is not. +
+ ++Note that an implementation based on forwarding functions will use the +latter interpretation. +
+ +[ +2010 Pittsburgh: Moved to Open. +]
+ + +[ +2010-03-19 Daniel provides wording. +]
+ + +++ ++
+ +- +Adapts the numbering used in the discussion to the recent working paper +N3035. +
+ +- +Proposes a resolution that requires implementations to use sfinae-like means to +possibly filter away the too generic template c'tor. In fact this resolution is +equivalent to that used for the pair-NULL problem (811), +the only difference is, that issue 1234 was already a C++03 problem. +
++This issue can be considered as a refinement of 438. +
+ +[ +Post-Rapperswil +]
+ + ++Wording was verified to match with the most recent WP. Jonathan Wakely and Alberto Barbati observed that the current +WP has a defect that should be fixed here as well: The functions signatures fx1 and fx3 are +incorrectly referring to iterator instead of const_iterator. +
+ ++Moved to Tentatively Ready with revised wording after 7 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ + ++Change 23.2.3 [sequence.reqmts]/14+15 as indicated: +
+ +++ + + + + + ++14 For every sequence container defined in this Clause and in Clause 21: +
+ ++
+ +- +
+ ++If the constructor +
+ ++ +template <class InputIterator> +X(InputIterator first, InputIterator last, + const allocator_type& alloc = allocator_type()) + ++is called with a type InputIterator that does not qualify as an input +iterator, then the constructor shall not participate in overload +resolution.
+ +will +behave as if the overloaded constructor:++ ++X(size_type, const value_type& = value_type(), + const allocator_type& = allocator_type()) ++
+were called instead, with the arguments +static_cast<size_type>(first), last and alloc, +respectively. +- + +
+ ++If the member functions of the forms: +
+ ++ +template <class InputIterator> // such as insert() +rt fx1(const_iterator p, InputIterator first, InputIterator last); + +template <class InputIterator> // such as append(), assign() +rt fx2(InputIterator first, InputIterator last); + +template <class InputIterator> // such as replace() +rt fx3(const_iterator i1, const_iterator i2, InputIterator first, InputIterator last); ++are called with a type InputIterator that does not qualify as an input +iterator, then these functions shall not participate in overload +resolution.
+ +will behave as if the overloaded member functions:++ +rt fx1(iterator, size_type, const value_type&);+ +rt fx2(size_type, const value_type&);+ +rt fx3(iterator, iterator, size_type, const value_type&);++
+were called instead, with the same arguments.++
+15 In the previous paragraph the alternative binding will fail if first +is not implicitly convertible to X::size_type or if last is +not implicitly convertible to X::value_type. +
+1237. Constrained error_code/error_condition members
+Section: 19.5 [syserr] Status: WP + Submitter: Daniel Krügler Opened: 2009-10-14 Last modified: 2010-10-23
+View all other issues in [syserr].
+View all issues with WP status.
+Discussion:
++I'm just reflecting on the now SFINAE-constrained constructors +and assignment operators of error_code and error_condition: +
++These are the only library components that are pro-actively +announcing that they are using std::enable_if as constraining tool, +which has IMO several disadvantages: +
+ ++
+ +- +
+ ++With the availability of template default arguments and +decltype, using enable_if in C++0x standard library, seems +unnecessary restricting implementation freedom. E.g. there +should be not need for a useless specification of a dummy +default function argument, which only confuses the reader. +A more reasonable implementation could e.g. be +
+ ++ +template <class ErrorCodeEnum + class = typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type> +error_code(ErrorCodeEnum e); ++As currently specified, the function signatures are so unreadable, +that errors quite easily happen, see e.g. 1229. +
+- +
+ ++We have a lot of constrained functions in other places, that +now have a standard phrase that is easily understandable: +
+ ++Remarks: This constructor/function shall participate in overload +resolution if and only if X. ++ ++where X describes the condition. Why should these components deviate? +
+- +
++If enable_if would not be explicitly specified, the standard library +is much better prepared for the future. It would also be possible, that +libraries with partial support for not-yet-standard-concepts could provide +a much better diagnostic as is possible with enable_if. This again +would allow for experimental concept implementations in the wild, +which as a result would make concept standardization a much more +natural thing, similar to the way as templates were standardized +in C++. +
+ ++In summary: I consider it as a library defect that error_code and +error_condition explicitly require a dependency to enable_if and +do limit implementation freedom and I volunteer to prepare a +corresponding resolution. +
+[ +2009-10-18 Beman adds: +]
+ + ++I support this proposed resolution, and thank Daniel for writing it up. ++ +[ +2009-10 Santa Cruz: +]
+ + ++Moved to Ready. ++ + + +Proposed resolution:
+[ +Should this resolution be accepted, I recommend to resolve 1229 as NAD +]
+ + ++
+ + + + + + +- +
+ ++In 19.5.2.1 [syserr.errcode.overview]/1, class error_code, +change as indicated: +
+ ++// 19.5.2.2 constructors: +error_code(); +error_code(int val, const error_category& cat); +template <class ErrorCodeEnum> + error_code(ErrorCodeEnum e, + typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type * = 0); + +// 19.5.2.3 modifiers: +void assign(int val, const error_category& cat); +template <class ErrorCodeEnum> +typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::typeerror_code& + operator=(ErrorCodeEnum e); +void clear(); +- +
+ ++Change 19.5.2.2 [syserr.errcode.constructors] around the prototype before p. 7: +
+ ++template <class ErrorCodeEnum> +error_code(ErrorCodeEnum e+, + typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type * = 0); ++++Remarks: This constructor shall not participate in overload +resolution, unless +is_error_code_enum<ErrorCodeEnum>::value == true. +
+- +
+ ++Change 19.5.2.3 [syserr.errcode.modifiers] around the prototype before p. 3: +
+ ++template <class ErrorCodeEnum> ++ +typename enable_if<is_error_code_enum<ErrorCodeEnum>::value>::typeerror_code& + operator=(ErrorCodeEnum e); ++Remarks: This operator shall not participate in overload resolution, unless +is_error_code_enum<ErrorCodeEnum>::value == true. ++- +
+ ++In 19.5.3.1 [syserr.errcondition.overview]/1, class error_condition, change +as indicated: +
+ ++// 19.5.3.2 constructors: +error_condition(); +error_condition(int val, const error_category& cat); +template <class ErrorConditionEnum> + error_condition(ErrorConditionEnum e, + typename enable_if<is_error_condition_enum<ErrorConditionEnum>::type* = 0); + +// 19.5.3.3 modifiers: +void assign(int val, const error_category& cat); +template<typenameclass ErrorConditionEnum> +typename enable_if<is_error_condition_enum<ErrorConditionEnum>, error_code>::typeerror_condition & + operator=( ErrorConditionEnum e ); +void clear(); +- +
+ ++Change 19.5.3.2 [syserr.errcondition.constructors] around the +prototype before p. 7: +
+ ++template <class ErrorConditionEnum> + error_condition(ErrorConditionEnum e+, + typename enable_if<is_error_condition_enum<ErrorConditionEnum>::value>::type* = 0); ++Remarks: This constructor shall not participate in overload +resolution, unless +is_error_condition_enum<ErrorConditionEnum>::value == true. ++- +
++Change 19.5.3.3 [syserr.errcondition.modifiers] around the +prototype before p. 3: +
+ ++ +template <class ErrorConditionEnum> ++ +typename enable_if<is_error_condition_enum<ErrorConditionEnum>::value>::typeerror_condition& + operator=(ErrorConditionEnum e); ++++Remarks: This operator shall not participate in overload resolution, unless +is_error_condition_enum<ErrorConditionEnum>::value == true. +
+ ++Postcondition: *this == make_error_condition(e). +
+ ++Returns: *this +
+
+1240. Deleted comparison functions of std::function not needed
+Section: 20.8.14.2 [func.wrap.func] Status: WP + Submitter: Daniel Krügler Opened: 2009-10-18 Last modified: 2010-11-23
+View all other issues in [func.wrap.func].
+View all issues with WP status.
+Discussion:
++The class template std::function contains the following member +declarations: +
+ ++ +// deleted overloads close possible hole in the type system +template<class R2, class... ArgTypes2> + bool operator==(const function<R2(ArgTypes2...)>&) = delete; +template<class R2, class... ArgTypes2> + bool operator!=(const function<R2(ArgTypes2...)>&) = delete; ++The leading comment here is part of the history of std::function, which +was introduced with N1402. +During that time no explicit conversion functions existed, and the +"safe-bool" idiom (based on pointers-to-member) was a popular +technique. The only disadvantage of this idiom was that given two +objects f1 and f2 of type std::function the expression +
+ ++ +f1 == f2; ++was well-formed, just because the built-in operator== for pointer to member +was considered after a single user-defined conversion. To fix this, an +overload set of undefined comparison functions was added, +such that overload resolution would prefer those ending up in a linkage error. +The new language facility of deleted functions provided a much better +diagnostic mechanism to fix this issue. +
+ ++The central point of this issue is, that with the replacement of the +safe-bool idiom by explicit conversion to bool the original "hole in the +type system" does no longer exist and therefore the comment is wrong and +the superfluous function definitions should be removed as well. An +explicit conversion function is considered in direct-initialization +situations only, which indirectly contain the so-called "contextual +conversion to bool" (4 [conv]/3). These conversions are not considered for +== or != as defined by the core language. +
+ +[ +Post-Rapperswil +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++In 20.8.14.2 [func.wrap.func]/1, class function change as indicated: +
+ ++ + + + + +// 20.7.15.2.3, function capacity: +explicit operator bool() const; + +// deleted overloads close possible hole in the type system+template<class R2, class... ArgTypes2>+bool operator==(const function<R2(ArgTypes2...)>&) = delete;+template<class R2, class... ArgTypes2>+bool operator!=(const function<R2(ArgTypes2...)>&) = delete;+
+1241. unique_copy needs to require EquivalenceRelation
+Section: 25.3.9 [alg.unique] Status: WP + Submitter: Daniel Krügler Opened: 2009-10-17 Last modified: 2010-10-23
+View all other issues in [alg.unique].
+View all issues with WP status.
+Discussion:
++A lot of fixes were silently applied during concept-time and we should +not lose them again. The Requires clause of 25.3.9 [alg.unique]/5 +doesn't mention that == and the predicate need to satisfy an +EquivalenceRelation, as it is correctly said for +unique. This was intentionally fixed during conceptification, +were we had: +
+ ++ +template<InputIterator InIter, class OutIter> + requires OutputIterator<OutIter, RvalueOf<InIter::value_type>::type> + && EqualityComparable<InIter::value_type> + && HasAssign<InIter::value_type, InIter::reference> + && Constructible<InIter::value_type, InIter::reference> + OutIter unique_copy(InIter first, InIter last, OutIter result); + +template<InputIterator InIter, class OutIter, + EquivalenceRelation<auto, InIter::value_type> Pred> + requires OutputIterator<OutIter, RvalueOf<InIter::value_type>::type> + && HasAssign<InIter::value_type, InIter::reference> + && Constructible<InIter::value_type, InIter::reference> + && CopyConstructible<Pred> + OutIter unique_copy(InIter first, InIter last, OutIter result, Pred pred); ++Note that EqualityComparable implied an equivalence relation. +
+ +[ +N.B. adjacent_find was also specified to require +EquivalenceRelation, but that was considered as a defect in +concepts, see 1000 +]
+ + +[ +2009-10-31 Howard adds: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ + + +Proposed resolution:
++Change 25.3.9 [alg.unique]/5 as indicated: +
+ ++ + + + + +template<class InputIterator, class OutputIterator> + OutputIterator + unique_copy(InputIterator first, InputIterator last, OutputIterator result); + +template<class InputIterator, class OutputIterator, class BinaryPredicate> + OutputIterator + unique_copy(InputIterator first, InputIterator last, + OutputIterator result, BinaryPredicate pred); +++Requires: The comparison function shall be an equivalence +relation. The ranges [first,last) and +[result,result+(last-first)) shall not overlap. The expression +*result = *first shall be valid. If neither +InputIterator nor OutputIterator meets the +requirements of forward iterator then the value type of +InputIterator shall be CopyConstructible (34) and +CopyAssignable (table 36). Otherwise CopyConstructible +is not required. ++
+1245. std::hash<string> & co
+Section: 20.8.15 [unord.hash] Status: WP + Submitter: Paolo Carlini Opened: 2009-10-22 Last modified: 2010-10-23
+View all other issues in [unord.hash].
+View all issues with WP status.
+Discussion:
++In 20.8.15 [unord.hash], operator() is specified as +taking the argument by value. Moreover, it is said that operator() shall +not throw exceptions. +
+ ++However, for the specializations for class types, like string, wstring, +etc, the former requirement seems suboptimal from the performance point +of view (a specific PR has been filed about this in the GCC Bugzilla) +and, together with the latter requirement, hard if not impossible to +fulfill. It looks like pass by const reference should be allowed in such +cases. +
+ +[ +2009-11-18: Ganesh updates wording. +]
+ + ++I've removed the list of types for which hash shall be instantiated +because it's already explicit in the synopsis of header +<functional> in 20.8 [function.objects]/2. ++ +[ +2009-11-18: Original wording here: +]
+ + +++ ++Add to 20.8.15 [unord.hash]/2: +
+ +++namespace std { + template <class T> + struct hash : public std::unary_function<T, std::size_t> { + std::size_t operator()(T val) const; + }; +} ++ ++The return value of operator() is unspecified, except that +equal arguments shall yield the same result. operator() shall +not throw exceptions. It is also unspecified whether +operator() of std::hash specializations for class +types takes its argument by value or const reference. +
+[ +2009-11-19 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2009-11-24 Ville Opens: +]
+ + ++I have received community requests to ask for this issue to be reopened. +Some users feel that mandating the inheritance is overly constraining. ++ +[ +2010-01-31 Alisdair: related to 978 and 1182. +]
+ + +[ +2010-02-07 Proposed resolution updated by Beman, Daniel and Ganesh. +]
+ + +[ +2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+Insert a new subclause either before or after the current 20.2.5 [allocator.requirements]:
++ ++ +Hash Requirements [hash.requirements]
+ +This subclause defines the named requirement Hash, + used in several clauses of the C++ standard library. A type H meets the Hash requirement if
+ ++
+ +- + +
+it is a function object type (20.8 [function.objects]).
+ +- + +
+it satisfies the requirements of CopyConstructible, and + Destructible (20.2.1 [utility.arg.requirements]),
+ +- + +
+the expressions shown in the following table are valid and have the + indicated semantics, and
+ +- + +
+it satisfies all other requirements of this subclause.
+ +Given Key is an argument type for function objects of + type H, in the table below h is a value of type (possibly const) + H, u is an lvalue of type Key, and + k + is a value of a type convertible to (possibly const) Key:
+ +Table ? - Hash requirements
++
+ ++ +Expression +Return type +Requirement ++ +h(k) +size_t +Shall not throw exceptions. The value returned shall depend only on +the argument k. [Note: Thus all evaluations of the expression + h(k) with the + same value for k yield the same result. — end note] [Note: + For t1 and t2 of different values, the probability that + h(t1) + and h(t2) compare equal should be very small, approaching (1.0/numeric_limits<size_t>::max()). + — end note] Comment + (not to go in WP): The wording for the second note is based on a similar + note in 22.4.4.1.2 [locale.collate.virtuals]/3 ++ +h(u) +size_t +Shall not modify u. +Change 20.8.15 [unord.hash] as indicated: +
+++ +1 The unordered associative containers defined in Clause 23.7 [unord] use + specializations of the class template hash as the default + hash function. For all object types T for which there exists a + specialization hash<T>, the instantiation hash<T> shall:
++
+- satisfy the Hash requirements([hash.requirements]), with T as the + function call argument type, the + DefaultConstructible requirements ([defaultconstructible]), the CopyAssignable + requirements ([copyassignable]), and the + Swappable requirements ([swappable]), +
+- provide two nested types result_type and argument_type which shall + be synonyms for size_t and T, respectively,
+- satisfy the + requirement that if k1 == k2 is true, h(k1) == h(k2) + is true, where h is an object of type hash<T>, and + k1, k2 are objects of type T.
++
This class template is only required to be instantiable + for integer types (3.9.1 [basic.fundamental]), floating-point types (3.9.1 [basic.fundamental]), + pointer types (8.3.1 [dcl.ptr]), and std::string, std::u16string, + std::u32string, std::wstring, std::error_code, + std::thread::id, std::bitset, and std::vector<bool>.+++namespace std { + template <class T> + struct hash : public std::unary_function<T, std::size_t> { + std::size_t operator()(T val) const; + }; +}+ +
2 The return value of operator() is unspecified, except that + equal arguments shall yield the same result. operator() shall not + throw exceptions.Change Unordered associative containers 23.2.5 [unord.req] as indicated:
+++ + + + + + +Each unordered associative container is parameterized by Key, by a + function object type Hash([hash.requirements]) that acts as a hash + function for argument values of type Key, + and by a binary predicate Pred that induces an equivalence relation + on values of type Key. Additionally, unordered_map and + unordered_multimap associate an arbitrary mapped type T with the + Key.
+A hash function is a function object that takes a single argument of type + Key and returns a value of type std::size_t.
+Two values k1 and k2 of type Key are considered +equal if the container's equality function object returns true when passed those +values. If k1 and k2 are equal, the hash function shall return +the same value for both. [Note: Thus supplying a non-default Pred +parameter usually implies the need to supply a non-default Hash +parameter. — end note]
+ +
+1247. auto_ptr is overspecified
+Section: D.12.1 [auto.ptr] Status: WP + Submitter: Alisdair Meredith Opened: 2009-10-24 Last modified: 2010-10-23
+View all other issues in [auto.ptr].
+View all issues with WP status.
+Discussion:
++This issue is extracted as the ongoing point-of-interest from earlier +issue 463. +
+ ++auto_ptr is overspecified as the auto_ptr_ref +implementation detail is formally specified, and the technique is +observable so workarounds for compiler defects can cause a working +implementation of the primary auto_ptr template become +non-conforming. +
+ ++auto_ptr_ref is a documentation aid to describe a possible +mechanism to implement the class. It should be marked exposition only, +as per similar classes, e.g., istreambuf_iterator::proxy +
+ +[ +2009-10-25 Daniel adds: +]
+ + +++ ++I wonder, whether the revised wording shouldn't be as straight as +for istream_buf by adding one further sentence: +
+ ++An implementation is permitted to provide equivalent functionality without +providing a class with this name. ++[ +2009-11-06 Alisdair adds Daniel's suggestion to the proposed wording. +]
+ + +[ +2009-11-06 Howard moves issue to Review. +]
+ + +[ +2009-11-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Add the term "exposition only" in the following two places: +
+ ++Ammend D.12.1 [auto.ptr]p2: +
+ +++ + + + + ++The exposition only class
+ +Ttemplate auto_ptr_ref +holds a reference to an auto_ptr. It is used by the +auto_ptr conversions to allow auto_ptr objects to be +passed to and returned from functions. +An implementation is permitted to provide equivalent functionality +without providing a class with this name. ++namespace std { + template <class Y> struct auto_ptr_ref { }; // exposition only +
+1249. basic_ios default ctor
+Section: 27.5.4.1 [basic.ios.cons] Status: WP + Submitter: Martin Sebor Opened: 2009-10-25 Last modified: 2010-11-24
+View all other issues in [basic.ios.cons].
+View all issues with WP status.
+Discussion:
++The basic_ios default ctor is required to leave the objects members +uninitialized (see below). The paragraph says the object must be +initialized by calling basic_ios::init() before it's destroyed by +I can't find a requirement that it be initialized before calling +any of the class other member functions. Am I not looking in the +right place or that an issue? +
+ +[ +2009-10-25 Daniel adds: +]
+ + +++ ++I agree, that your wording makes that clearer, but suggest to write +
+ ++... calling basic_ios::init+ +()before ... ++Doing so, I recommend to adapt that of ios_base(); as well, where +we have: +
+ ++Effects: Each ios_base member has an indeterminate value +after construction. These members shall be initialized by calling +basic_ios::init. If an ios_base object is destroyed +before these initializations have taken place, the behavior is +undefined. ++[ +Post-Rapperswil: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Change 27.5.2.7 [ios.base.cons] p1: +
+ ++ +ios_base(); +++Effects: Each ios_base member has an indeterminate value +after construction.+TheseThe object's members shall be initialized by calling +basic_ios::init before the object's first use or before + it is destroyed, whichever comes first; otherwise the behavior + is undefined..If an ios_base object is destroyed +before these initializations have taken place, the behavior is +undefined.++Change 27.5.4.1 [basic.ios.cons] p2: +
+ ++ + + + + +basic_ios(); +++Effects: Constructs an object of class basic_ios +(27.5.2.7) leaving its member objects uninitialized. The object shall be +initialized by calling+its+basic_ios::init before its first +use or before it is destroyed, whichever comes first; otherwise the +behavior is undefined.member function. If it is destroyed +before it has been initialized the behavior is undefined.+
+1250. <bitset> still overspecified
+Section: 20.5 [template.bitset] Status: WP + Submitter: Martin Sebor Opened: 2009-10-29 Last modified: 2010-10-23
+View all other issues in [template.bitset].
+View all issues with WP status.
+Discussion:
++Issue 1227 — <bitset> synopsis overspecified makes the observation +that std::bitset, and in fact the whole library, may be implemented +without needing to #include <stdexcept> in any library header. The +proposed resolution removes the #include <stdexcept> directive from +the header. +
+ ++I'd like to add that the <bitset> header (as well as the rest of +the library) has also been implemented without #including the +<cstddef> header in any library header. In the case of std::bitset, +the template is fully usable (i.e., it may be instantiated and all +its member functions may be used) without ever mentioning size_t. +In addition, just like no library header except for <bitset> +#includes <stdexcept> in its synopsis, no header but <bitset> +#includes <cstddef> either. +
+ ++Thus I suggest that the #include <cstddef> directive be similarly +removed from the synopsis of <bitset>. +
+ +[ +2010-02-08 Moved to Tentatively Ready after 6 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++Change 20.5 [template.bitset]: +
+ ++ + + + + +#include <cstddef> // for size_t+#include <string> +#include <iosfwd> // for istream, ostream +namespace std { +... +
+1254. Misleading sentence in vector<bool>::flip
+Section: 23.4.2 [vector.bool] Status: WP + Submitter: Christopher Jefferson Opened: 2009-11-01 Last modified: 2010-10-23
+View all other issues in [vector.bool].
+View all issues with WP status.
+Discussion:
++The effects of vector<bool>::flip has the line: +
+ ++It is unspecified whether the function has any effect on allocated but +unused bits. ++ ++While this is technically true, it is misleading, as any member function +in any standard container may change unused but allocated memory. Users +can never observe such changes as it would also be undefined behaviour +to read such memory. +
+ +[ +2009-11-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Strike second sentence from the definition of vector<bool>::flip(), +23.4.2 [vector.bool], paragraph 5. +
+ ++Effects: Replaces each element in the container with its complement. ++ + + + + +It is unspecified whether the function has any effect on allocated +but unused bits.+
+1255. declval should be added to the library
+Section: 20.3 [utility] Status: WP + Submitter: Daniel Krügler Opened: 2009-11-03 Last modified: 2010-10-23
+View all other issues in [utility].
+View all issues with WP status.
+Discussion:
++During the Santa Cruz meeting it was decided to split off the provision +of the library utility value() proposed in N2979 +from the concrete request of the +UK 300 +comment. +The provision of a new library component that allows the production of +values in unevaluated expressions is considered as important +to realize constrained templates in C++0x where concepts are not +available. +
+ ++The following proposed resolution is an improvement over that suggested in +N2958, +because the proposed component can now be defined without loss of +general usefulness and any use by user-code will make the program ill-formed. +A possible prototype implementation that satisfies the core language +requirements +can be written as: +
+ ++ +template<class T> + struct declval_protector { + static const bool stop = false; + static typename std::add_rvalue_reference<T>::type delegate(); // undefined + }; + +template<class T> +typename std::add_rvalue_reference<T>::type declval() { + static_assert(declval_protector<T>::stop, "declval() must not be used!"); + return declval_protector<T>::delegate(); +} ++Further-on the earlier suggested name value() has been changed to declval() +after discussions with committee members. +
+ ++Finally the suggestion shown below demonstrates that it can simplify +existing standard wording by directly using it in the library +specification, and that it also improves an overlooked corner case for +common_type by adding support for cv void. +
+ +[ +2009-11-19 Moved to Tentatively Ready after 6 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
+[ +The proposed resolution has been updated to +N3000 +numbering and wording +]
+ + ++
+ + + + + + +- +
+ ++Change 20.3 [utility], header <utility> synopsis +as indicated: +
+ ++// 20.3.3, forward/move: +template <class T> struct identity; +template <class T, class U> T&& forward(U&&); +template <class T> typename remove_reference<T>::type&& move(T&&); + +// 20.3.4, declval: +template <class T> typename add_rvalue_reference<T>::type declval(); // as unevaluated operand +- +
+ ++Immediately after the current section 20.3.3 [forward] insert a +new section: +
++20.3.4 Function template declval [declval] +
++The library provides the function template declval to simplify +the definition of expressions which occur as +unevaluated operands (5 [expr]). The +template parameter T of declval may +be an incomplete type. +
+ +template <class T> typename add_rvalue_reference<T>::type declval(); // as unevaluated operand ++ +++ ++Remarks: If this function is used according to 3.2 [basic.def.odr], +the program is ill-formed. +
+ ++[Example: +
+ ++ ++template<class To, class From> +decltype(static_cast<To>(declval<From>())) convert(From&&); ++ +declares a function template convert, which only participates in +overloading if the type From can be explicitly cast to type To. +For another example see class template common_type +(20.7.7.6 [meta.trans.other]). +— end example] +
+- +
+ ++This bullet just makes clear that after applying N2984, the changes in 20.7.4.3 [meta.unary.prop], before +table Type property queries should not use declval, +because the well-formedness requirement of the specification of +is_constructible would become more complicated, because we +would need to make sure that the expression CE is checked in an +unevaluated context. +
+- +
+ ++Also 20.7.6 [meta.rel]/4 is not modified similar to the previous bullet, +because with +the stricter requirements of not using declval() the well-formedness condition +would be harder to specify. The following changes are only editorial ones (e.g. +the removal of the duplicate declaration of create()): +
+ ++++Given the following function prototype: +
+ ++ +template <class T> + typename add_rvalue_reference<T>::type create(); ++the predicate condition for a template specialization +is_convertible<From, To> shall be satisfied if and only +if the return expression in the following code would be well-formed, +including any +implicit conversions to the return type of the function: +
+ ++template <class T> +typename add_rvalue_reference<T>::type create();+To test() { + return create<From>(); +} +- +
+ ++Change the entry in column "Comments" for common_type in Table 51 — +Other transformations (20.7.7.6 [meta.trans.other]): +
+ +[ +NB: This wording change extends the type domain of common_type for cv +void => cv void transformations and thus makes common_type usable for +all binary type combinations that are supported by is_convertible +]
+ + ++The member typedef type shall be defined as set out below. All +types in the parameter pack T shall be complete or +(possibly cv-qualified) void. A program may specialize +this trait if at least one template parameter in the specialization is a +user-defined type. [Note: Such specializations are needed when +only explicit conversions are desired among the template arguments. +— end note] ++- +
+ ++Change 20.7.7.6 [meta.trans.other]/3 as indicated: +
+ +[ +NB: This wording change is more than an editorial simplification of +the definition of common_type: It also extends its usefulness for cv +void types as outlined above +]
+ + ++++The nested typedef common_type::type shall be defined as follows: +
+ ++++[..] +
+template <class T, class U> +struct common_type<T, U> { ++private: + static T&& __t(); + static U&& __u(); +public:+ typedef decltype(true ?__tdeclval<T>() :__udeclval<U>()) type; +}; +- +
++Change X [func.ret]/1 as indicated +[This part solves some main aspects of issue 1225]: +
+ ++namespace std { + template <class> class result_of; // undefined + + template <class Fn, class... ArgTypes> + class result_of<Fn(ArgTypes...)> { + public : ++// types+ typedefsee belowdecltype(declval<Fn>() ( declval<ArgTypes>()... )) type; + }; +} ++
+1 Given an rvalue fn of type Fn and values t1, t2, ..., tN of +types T1, T2, ..., TN in ArgTypes, +respectively, the type member is the result type of the expression +fn(t1, t2, ...,tN). The values ti +are lvalues when the corresponding type Ti is an lvalue-reference +type, and rvalues otherwise.+
+1256. weak_ptr comparison functions should be removed
+Section: 20.9.10.3 [util.smartptr.weak] Status: WP + Submitter: Daniel Krügler Opened: 2009-11-04 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++Additional to the necessary cleanup of the description of the the +weak_ptr component from 20.9.10.3 [util.smartptr.weak] +described in 1231 it turns out that the currently deleted +comparison functions of weak_ptr are not needed at all: There +is no safe-bool conversion from weak_ptr, and it won't silently +chose a conversion to shared_ptr. +
+ +[ +2009-11-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Change 20.9.10.3 [util.smartptr.weak]/1 as indicated: +
+ ++ + + + + +namespace std { +template<class T> class weak_ptr { +public: +... +// comparisons+template<class Y> bool operator<(weak_ptr<Y> const&) const = delete;+template<class Y> bool operator<=(weak_ptr<Y> const&) const = delete;+template<class Y> bool operator>(weak_ptr<Y> const&) const = delete;+template<class Y> bool operator>=(weak_ptr<Y> const&) const = delete;+}; +... +
+1257. Header <ios> still contains a
+concept_mapSection: 27.5 [iostreams.base] Status: WP + Submitter: Beman Dawes Opened: 2009-11-04 Last modified: 2010-10-23
+View all other issues in [iostreams.base].
+View all issues with WP status.
+Discussion:
++The current WP still contains a concept_map. +
+ +[ +2009-11-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Change Iostreams base classes 27.5 [iostreams.base], Header <ios> synopsis, +as indicated: +
+ ++ + + + + + +concept_map ErrorCodeEnum<io_errc> { };+template <> struct is_error_code_enum<io_errc> : true_type { } +error_code make_error_code(io_errc e); +error_condition make_error_condition(io_errc e); +const error_category& iostream_category(); +
+1258. std::function Effects clause impossible to satisfy
+Section: 20.8.14.2.2 [func.wrap.func.mod] Status: Resolved + Submitter: Daniel Krügler Opened: 2009-11-05 Last modified: 2010-11-19
+View all issues with Resolved status.
+Discussion:
++As of 20.8.14.2.2 [func.wrap.func.mod]/2+ we have the following +prototype description: +
+ ++ +template<class F, Allocator Alloc> + void assign(F, const Alloc&); +++Effects: function(f, a).swap(*this) +++Two things: First the concept debris needs to be removed, second and +much more importantly, the effects clause is now impossible to satisfy, +because there is no constructor that would match the parameter sequence +(FunctionObject, Allocator) [plus the fact that no +f and no a is part of the signature]. The most +probable candidate is +
+ ++ +template<class F, class A> function(allocator_arg_t, const A&, F); ++and the effects clause needs to be adapted to use this signature. +
+ +[ +2009-11-13 Daniel brought wording up to date. +]
+ + +[ +2009-11-15 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-02-11 Moved to Tentatively NAD Editorial after 5 positive votes on +c++std-lib. It was noted that this issue was in partial conflict with 1288, and the two issues were merged in 1288. +]
+ + +Rationale:
++Addressed by 1288. +
+ + + + +Proposed resolution:
++Change in 20.8.14.2.2 [func.wrap.func.mod] the complete prototype description as +indicated +
+[ +Question to +the editor: Shouldn't there a paragraph number in front of the Effects clause? +]
+ + ++ + + + + +template<class F,+Allocator Allocclass A> + void assign(F f, const Alloc& a); ++3 Effects: function(+f, aallocator_arg, a, +f).swap(*this) +
+1260. is_constructible<int*,void*> reports true
+Section: 20.7.4.3 [meta.unary.prop] Status: Resolved + Submitter: Peter Dimov Opened: 2009-11-07 Last modified: 2010-11-20
+View all other issues in [meta.unary.prop].
+View all issues with Resolved status.
+Discussion:
++The specification of is_constructible<T,Args...> in +N3000 +uses +
+ ++ +static_cast<T>(create<Args>()...) ++for the one-argument case, but static_cast also permits +unwanted conversions such as void* to T* and +Base* to Derived*. +
+ +[ +Post-Rapperswil: +]
+ + ++Moved to+ + + +NAD EditorialResolved, this issue is addressed by paper +n3047 +Proposed resolution:
++Change 20.7.4.3 [meta.unary.prop], p6: +
+ +++ + + + + ++the predicate condition for a template specialization +is_constructible<T, Args> shall be satisfied, if and only +if the following
+ +expression CEvariable +definition would be well-formed: ++
+- +
++if sizeof...(Args) == 0
+1, the expression: ++static_cast<T>(create<Args>()...)+T t; +- +
++otherwise
+the expression: ++T t(create<Args>()...); +
+1261. Insufficent overloads for to_string / to_wstring
+Section: 21.5 [string.conversions] Status: WP + Submitter: Christopher Jefferson Opened: 2009-11-10 Last modified: 2010-10-23
+View all other issues in [string.conversions].
+View all issues with WP status.
+Discussion:
++Reported on the gcc mailing list. +
+ ++The code "int i; to_string(i);" fails to compile, as +'int' is ambiguous between 'long long' and 'long +long unsigned'. It seems unreasonable to expect users to cast +numbers up to a larger type just to use to_string. ++ +[ +2009-11-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++21.3 [string.classes], change to_string and +to_wstring to: +
+ ++ +string to_string(int val); +string to_string(unsigned val); +string to_string(long val); +string to_string(unsigned long val); +string to_string(long long val); +string to_string(unsigned long long val); +string to_string(float val); +string to_string(double val); +string to_string(long double val); + +wstring to_wstring(int val); +wstring to_wstring(unsigned val); +wstring to_wstring(long val); +wstring to_wstring(unsigned long val); +wstring to_wstring(long long val); +wstring to_wstring(unsigned long long val); +wstring to_wstring(float val); +wstring to_wstring(double val); +wstring to_wstring(long double val); ++In 21.5 [string.conversions], paragraph 7, change to: +
+ ++ +string to_string(int val); +string to_string(unsigned val); +string to_string(long val); +string to_string(unsigned long val); +string to_string(long long val); +string to_string(unsigned long long val); +string to_string(float val); +string to_string(double val); +string to_string(long double val); ++ ++7 Returns: each function returns a string object holding +the character representation of the value of its argument that would be +generated by calling sprintf(buf, fmt, val) with a format +specifier of "%d", "%u", "%ld", +"%lu", "%lld", "%llu", +"%f", "%f", or "%Lf", respectively, +where buf designates an internal character buffer of sufficient +size. +++In 21.5 [string.conversions], paragraph 14, change to: +
+ ++ + + + + +wstring to_wstring(int val); +wstring to_wstring(unsigned val); +wstring to_wstring(long val); +wstring to_wstring(unsigned long val); +wstring to_wstring(long long val); +wstring to_wstring(unsigned long long val); +wstring to_wstring(float val); +wstring to_wstring(double val); +wstring to_wstring(long double val); ++ ++14 Returns: Each function returns a wstring object +holding the character representation of the value of its argument that +would be generated by calling swprintf(buf, buffsz, fmt, val) +with a format specifier of L"%d", L"%u", +L"%ld", L"%lu", L"%lld", +L"%llu", L"%f", L"%f", or +L"%Lf", respectively, where buf designates an internal +character buffer of sufficient size buffsz. ++
+1262. std::less<std::shared_ptr<T>> is underspecified
+Section: 20.9.10.2.7 [util.smartptr.shared.cmp] Status: WP + Submitter: Jonathan Wakely Opened: 2009-11-10 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++20.9.10.2.7 [util.smartptr.shared.cmp]/5 says: +
+ ++For templates greater, less, greater_equal, and less_equal, the +partial specializations for shared_ptr shall yield a total order, even if +the built-in operators <, >, +<=, and >= do not. Moreover, +less<shared_ptr<T> >::operator()(a, b) shall return +std::less<T*>::operator()(a.get(), b.get()). ++ ++This is necessary in order to use shared_ptr as the key in associate +containers because +n2637 +changed operator< on shared_ptrs to be +defined in terms of operator< on the stored pointers (a mistake IMHO +but too late now.) By 5.9 [expr.rel]/2 the result of comparing builtin +pointers is unspecified except in special cases which generally do not +apply to shared_ptr. +
+ ++Earlier versions of the WP +(n2798, +n2857) +had the following note on +that paragraph: +
+ ++[Editor's +note: It's not clear to me whether the first sentence is a requirement +or a note. The second +sentence seems to be a requirement, but it doesn't really belong here, +under operator<.] ++ ++I agree completely - if partial specializations are needed they should +be properly specified. +
+ ++20.9.10.2.7 [util.smartptr.shared.cmp]/6 has a note saying the comparison operator +allows shared_ptr objects to be used as keys in associative +containers, which is misleading because something else like a +std::less partial specialization is needed. If it is not correct that +note should be removed. +
+ ++20.9.10.2.7 [util.smartptr.shared.cmp]/3 refers to 'x' and +'y' but the prototype has parameters 'a' and +'b' - that needs to be fixed even if the rest of the issue is +NAD. +
+ ++I see two ways to fix this, I prefer the first because it removes the +need for any partial specializations and also fixes operator> and +other comparisons when defined in terms of operator<. +
+ ++
+ +- +
+ + ++Replace 20.9.10.2.7 [util.smartptr.shared.cmp]/3 with the following and +remove p5: +
+ ++template<class T, class U> bool operator<(const shared_ptr<T>& a, const shared_ptr<U>& b); +++++3 Returns:
+ +x.get() < y.get().+std::less<V>()(a.get(), b.get()), where V is the +composite pointer type (5.9 [expr.rel]). ++4 Throws: nothing. +
+ ++
+5 For templates greater, less, greater_equal, and less_equal, the +partial specializations for shared_ptr shall yield a total order, even if +the built-in operators <, >, +<=, and >= do not. Moreover, +less<shared_ptr<T> >::operator()(a, b) shall return +std::less<T*>::operator()(a.get(), b.get()). ++6 [Note: Defining a comparison operator allows +shared_ptr objects to be used as keys in associative +containers. — end note] +
+- +
++Add to 20.9.10.2 [util.smartptr.shared]/1 (after the shared_ptr comparisons) +
+ ++ +template<class T> struct greater<shared_ptr<T>>; +template<class T> struct less<shared_ptr<T>>; +template<class T> struct greater_equal<shared_ptr<T>>; +template<class T> struct less_equal<shared_ptr<T>>; ++Remove 20.9.10.2.7 [util.smartptr.shared.cmp]/5 and /6 and replace with: +
+ ++template<class T, class U> bool operator<(const shared_ptr<T>& a, const shared_ptr<U>& b); ++++ ++3 Returns:
+ +xa.get() <yb.get(). ++4 Throws: nothing. +
+ ++
+5 For templates greater, less, greater_equal, and less_equal, the +partial specializations for shared_ptr shall yield a total order, even if +the built-in operators <, >, +<=, and >= do not. Moreover, +less<shared_ptr<T> >::operator()(a, b) shall return +std::less<T*>::operator()(a.get(), b.get()). ++
+6 [Note: Defining a comparison operator allows +shared_ptr objects to be used as keys in associative +containers. — end note] ++template<class T> struct greater<shared_ptr<T>> : +binary_function<shared_ptr<T>, shared_ptr<T>, bool> { + bool operator()(const shared_ptr<T>& a, const shared_ptr<T>& b) const; +}; ++ ++operator() returns greater<T*>()(a.get(), b.get()). ++ ++template<class T> struct less<shared_ptr<T>> : +binary_function<shared_ptr<T>, shared_ptr<T>, bool> { + bool operator()(const shared_ptr<T>& a, const shared_ptr<T>& b) const; +}; ++ ++operator() returns less<T*>()(a.get(), b.get()). ++ ++template<class T> struct greater_equal<shared_ptr<T>> : +binary_function<shared_ptr<T>, shared_ptr<T>, bool> { + bool operator()(const shared_ptr<T>& a, const shared_ptr<T>& b) const; +}; ++ ++operator() returns greater_equal<T*>()(a.get(), b.get()). ++ ++template<class T> struct less_equal<shared_ptr<T>> : +binary_function<shared_ptr<T>, shared_ptr<T>, bool> { + bool operator()(const shared_ptr<T>& a, const shared_ptr<T>& b) const; +}; ++ ++operator() returns less_equal<T*>()(a.get(), b.get()). ++ +[ +2009-11-18: Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++Replace 20.9.10.2.7 [util.smartptr.shared.cmp]/3 with the following and +remove p5: +
+ ++ + + + + + +template<class T, class U> bool operator<(const shared_ptr<T>& a, const shared_ptr<U>& b); +++++3 Returns:
+ +x.get() < y.get().+less<V>()(a.get(), b.get()), where V is the +composite pointer type (5.9 [expr.rel]) of T* and U*. ++4 Throws: nothing. +
+ ++
+5 For templates greater, less, greater_equal, and less_equal, the +partial specializations for shared_ptr shall yield a total order, even if +the built-in operators <, >, +<=, and >= do not. Moreover, +less<shared_ptr<T> >::operator()(a, b) shall return +std::less<T*>::operator()(a.get(), b.get()). ++6 [Note: Defining a comparison operator allows +shared_ptr objects to be used as keys in associative +containers. — end note] +
+
+1264. quick_exit support for freestanding implementations
+Section: 17.6.1.3 [compliance] Status: WP + Submitter: Alisdair Meredith Opened: 2009-11-12 Last modified: 2010-10-23
+View all other issues in [compliance].
+View all issues with WP status.
+Discussion:
+Addresses UK 172
+ ++This issue is a response to NB comment UK-172 +
+ ++The functions quick_exit and at_quick_exit should be +added to the required features of <cstdlib> in a +freestanding implementation. +
+ ++This comment was rejected in Summit saying neither at_exit nor +at_quick_exit should be required. This suggests the comment was +misread, as atexit is already required to be supported. If the LWG +really did wish to not require the registration functions be supported, +then a separate issue should be opened to change the current standard. +
+ ++Given both exit and atexit are required, the UK panel feels it is +appropriate to require the new quick_exit facility is similarly +supported. +
+ +[ +2009-12-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Ammend p3 Freestanding implementations 17.6.1.3 [compliance] +
+ ++3 The supplied version of the header <cstdlib> shall +declare at least the functions abort+ + + + + + +(), atexit(), +at_quick_exit,andexit(), and +quick_exit(18.5 [support.start.term]). The other +headers listed in this table shall meet the same requirements as for a +hosted implementation. +
+1267. Incorrect wording for condition_variable_any::wait_for
+Section: 30.5.2 [thread.condition.condvarany] Status: WP + Submitter: Anthony Williams Opened: 2009-11-17 Last modified: 2010-10-23
+View all other issues in [thread.condition.condvarany].
+View all issues with WP status.
+Discussion:
++30.5.2 [thread.condition.condvarany]p18 and 30.5.2 [thread.condition.condvarany]p27 specify incorrect preconditions for +condition_variable_any::wait_for. The stated preconditions require that +lock has a mutex() member function, and that this produces the +same result for all concurrent calls to wait_for(). This is +inconsistent with wait() and wait_until() which do not impose +such a requirement. +
+ +[ +2009-12-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Remove 30.5.2 [thread.condition.condvarany]p18 and 30.5.2 [thread.condition.condvarany]p27. +
+++ + + + + + +template <class Lock, class Rep, class Period> + cv_status wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time); ++++ ++
+18 Precondition: lock is locked by the calling thread, and either ++
+- +
+no other thread is waiting on this condition_variable object or +- +
+lock.mutex() returns the same value for each of the lock arguments +supplied by all concurrently waiting (via wait, wait_for, or +wait_until) threads. +...
+ +template <class Lock, class Rep, class Period, class Predicate> + bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred); ++ ++ ++ ++
+27 Precondition: lock is locked by the calling thread, and either ++
+ +- +
+no other thread is waiting on this condition_variable object or +- +
+lock.mutex() returns the same value for each of the lock arguments +supplied by all concurrently waiting (via wait, wait_for, or +wait_until) threads. +
+1268. The Mutex requirements in 30.4.1 and 30.4.2 are wrong
+Section: 30.4 [thread.mutex] Status: Resolved + Submitter: Anthony Williams Opened: 2009-11-17 Last modified: 2010-11-26
+View all other issues in [thread.mutex].
+View all issues with Resolved status.
+Discussion:
++The Mutex requirements in 30.4.1 [thread.mutex.requirements] and +30.4.1.3 [thread.timedmutex.requirements] confuse the requirements on the +behaviour of std::mutex et al with the requirements on +Lockable types for use with std::unique_lock, +std::lock_guard and std::condition_variable_any. +
+ +[ +2010 Pittsburgh: +]
+ + +++ ++Concepts of threads chapter and issue presentation are: Lockable < Mutex < +TimedMutex and Lockable < TimedLockable < TimedMutex. +
++Typo in failed deletion of Mutex in 30.4.4 p4 edits. +
++Lockable requirements are too weak for condition_variable_any, but the Mutex +requirements are too strong. +
++Need subset of Lockable requirements for condition_variable_any that does not +include try_lock. E.g. CvLockable < Lockable. +
++Text needs updating to recent draft changes. +
++Needs to specify exception behavior in Lockable. +
++The current standard is fine for what it says, but it places requirements that +are too strong on authors of mutexes and locks. +
++Move to open status. Suggest Anthony look at condition_variable_any +requirements. Suggest Anthony refine requirements/concepts categories. +
+ +[ +2010-03-28 Daniel synced with N3092. +]
+ + +[ +2010-10-25 Daniel adds: +]
+ + ++Accepting n3130 would solve this issue. ++ +[ +2010-11 Batavia: +]
+ + ++Resolved by adopting n3197. ++ + + + +Proposed resolution:
++Add a new section to 30.2 [thread.req] after 30.2.4 [thread.req.timing] as follows: +
+ +++ ++30.2.5 Requirements for Lockable types +
+ ++The standard library templates unique_lock (30.4.2.2 [thread.lock.unique]), lock_guard (30.4.2.1 [thread.lock.guard]), lock, try_lock (30.4.3 [thread.lock.algorithm]) and condition_variable_any (30.5.2 [thread.condition.condvarany]) all operate on user-supplied +Lockable objects. Such an object must support the member functions +specified for either the Lockable Requirements or the +TimedLockable requirements as appropriate to acquire or release +ownership of a lock by a given thread. [Note: the +nature of any lock ownership and any synchronization it may entail are not part +of these requirements. — end note] +
+ ++30.2.5.1 Lockable Requirements +
+ ++In order to qualify as a Lockable type, the following expressions must +be supported, with the specified semantics, where m denotes a value of +type L that supports the Lockable: +
+ ++The expression m.lock() shall be well-formed and have the following +semantics: +
+ ++
+ +- Effects:
- Block until a lock can be acquired for the current thread.
+- Return type:
- void
++The expression m.try_lock() shall be well-formed and have the +following semantics: +
+ ++
+ +- Effects:
- Attempt to acquire a lock for the current thread without blocking.
+- Return type:
- bool
+- Returns:
- true if the lock was + acquired, false otherwise.
++The expression m.unlock() shall be well-formed and have the +following semantics: +
+ ++
+ +- Effects:
- Release a lock on m held by the current thread.
+- Return type:
- void
+- Throws:
- Nothing if the current thread holds a lock on m.
++30.2.5.2 TimedLockable Requirements +
+ ++For a type to qualify as TimedLockable it must meet the +Lockable requirements, and additionally the following +expressions must be well-formed, with the specified semantics, +where m is an instance of a type TL that supports +the TimedLockable requirements, rel_time denotes +instantiation of duration (20.11.3 [time.duration]) and abs_time +denotes an instantiation of time_point (20.11.4 [time.point]) + +
+ ++The expression m.try_lock_for(rel_time) shall be well-formed and have the +following semantics: +
+ ++
+ +- Effects:
- Attempt to acquire a lock for the current + thread within the specified time period.
+- Return type:
- bool
+- Returns:
- true if the lock was + acquired, false otherwise.
++The expression m.try_lock_until(abs_time) shall be well-formed and have the +following semantics: +
+ ++
+- Effects:
- Attempt to acquire a lock for the current + thread before the specified point in time.
+- Return type:
- bool
+- Returns:
- true if the lock was + acquired, false otherwise.
++Replace 30.4.1 [thread.mutex.requirements] paragraph 2 with the +following: +
+ ++2 This section describes requirements on+ +template argument types +used to instantiate templates defined inthe mutex types +supplied by the C++ standard library.The template +definitions in the C++ standard library referThese types shall +conform to the named Mutex requirements whose details are set +out below. In this description, m is an object +ofa Mutex type+one of the standard library mutex types std::mutex, +std::recursive_mutex, std::timed_mutex or +std::recursive_timed_mutex.. ++Add the following paragraph after 30.4.1 [thread.mutex.requirements] +paragraph 2: +
+ ++A Mutex type shall conform to the Lockable +requirements (30.2.5.1). ++ ++Replace 30.4.1.3 [thread.timedmutex.requirements] paragraph 1 with the +following: +
+ ++The C++ standard library TimedMutex types std::timed_mutex + and std::recursive_timed_mutex ++ +A TimedMutex typeshall meet the requirements for +a Mutex type. In addition,itthey shall +meet the requirements set outin this Clause 30.4.2below, +where rel_time denotes an instantiation of duration +(20.11.3 [time.duration]) and abs_time denotes an instantiation +of time_point (20.11.4 [time.point]). ++Add the following paragraph after 30.4.1.3 [thread.timedmutex.requirements] paragraph 1: +
+ ++A TimedMutex type shall conform to the TimedLockable +requirements (30.2.5.1). ++ + ++Add the following paragraph following 30.4.2.1 [thread.lock.guard] +paragraph 1: +
+ ++The supplied Mutex type shall meet the Lockable +requirements +(30.2.5.1). ++ ++Add the following paragraph following 30.4.2.2 [thread.lock.unique] +paragraph 1: +
+ ++The supplied Mutex type shall meet the Lockable +requirements +(30.2.5.1). unique_lock<Mutex> meets the Lockable +requirements. If Mutex meets the TimedLockable +requirements +(30.2.5.2) then unique_lock<Mutex> also meets the +TimedLockable requirements. ++ ++Replace the use of "mutex" or "mutex object" with "lockable object" +throughout clause 30.4.2 [thread.lock] paragraph 1: +
+ ++1 A lock is an object that holds a reference to +a+ +mutexlockable object and may unlock +themutexlockable object during the lock's +destruction (such as when leaving block scope). A thread of execution +may use a lock to aid in managingmutexownership of a +lockable object in an exception safe manner. A lock is said to +own amutexlockable object if it is currently +managing the ownership of thatmutexlockable +object for a thread of execution. A lock does not manage the +lifetime of themutexlockable object it +references. [ Note: Locks are intended to ease the burden of +unlocking themutexlockable object under both +normal and exceptional circumstances. — end note ] +30.4.2 [thread.lock] paragaph 2:
+ ++2 Some lock constructors take tag types which describe what should be +done with the+ +mutexlockable object during the +lock's constuction. +30.4.2.1 [thread.lock.guard] paragaph 1:
+ ++1 An object of type lock_guard controls the ownership of a ++ +mutexlockable object within a scope. A +lock_guard object maintains ownership of +amutexlockable object throughout +the lock_guard object's lifetime. The behavior of a program +is undefined if themutexlockable object +referenced by pm does not exist for the entire lifetime (3.8) +of the lock_guard object. Mutex shall meet + the Lockable requirements (30.2.5.1). +30.4.2.2 [thread.lock.unique] paragaph 1:
+ ++1 An object of type unique_lock controls the ownership of +a+ + +mutexlockable object within a +scope.MutexoOwnership of the +lockable object may be acquired at construction or after +construction, and may be transferred, after acquisition, to +another unique_lock object. Objects of +type unique_lock are not copyable but are movable. The +behavior of a program is undefined if the contained +pointer pm is not null and the mutex pointed to +by pm does not exist for the entire remaining lifetime (3.8) +of the unique_lock object. Mutex shall meet +the Lockable requirements (30.2.5.1). ++Add the following to the precondition of unique_lock(mutex_type& + m, +const chrono::time_point<Clock, Duration>& abs_time) in +30.4.2.2.1 [thread.lock.unique.cons] paragraph 18: +
+ ++ +template <class Clock, class Duration> + unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time); ++ ++18 Requires: If mutex_type is not a recursive mutex +the +calling thread does not own the mutex. The supplied mutex_type +type shall meet the TimedLockable requirements (30.2.5.2). +++Add the following to the precondition of unique_lock(mutex_type& + m, +const chrono::duration<Rep, Period>& rel_time) in +30.4.2.2.1 [thread.lock.unique.cons] +paragraph 22 +
+ ++22 Requires: If mutex_type is not a recursive mutex + the +calling thread does not own the mutex. The supplied mutex_type +type shall meet the TimedLockable requirements (30.2.5.2). ++ ++Add the following as a precondition of bool try_lock_until(const +chrono::time_point<Clock, Duration>& abs_time) before +30.4.2.2.2 [thread.lock.unique.locking] paragraph 8 +
+ ++ +template <class Clock, class Duration> + bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time); +++Requires: The supplied mutex_type type shall meet the +TimedLockable requirements (30.2.5.2). +++Add the following as a precondition of bool try_lock_for(const +chrono::duration<Rep, Period>& rel_time) before +30.4.2.2.2 [thread.lock.unique.locking] paragraph 12 +
+ ++ +template <class Rep, class Period> + bool try_lock_for(const chrono::duration<Rep, Period>& rel_time); +++Requires: The supplied mutex_type type shall meet the +TimedLockable requirements (30.2.5.2). +++Replace 30.4.3 [thread.lock.algorithm] p1 with the following: +
+ ++ +template <class L1, class L2, class... L3> int try_lock(L1&, L2&, L3&...); +++1 Requires: Each template parameter type shall meet the ++MutexLockable requirements +(30.2.5.1)., except that a call to try_lock() +may throw +an exception.[Note: The unique_lock class +template meets +these requirements when suitably instantiated. — end note] ++Replace 30.4.3 [thread.lock.algorithm] p4 with the following: +
+ ++ +template <class L1, class L2, class... L3> void lock(L1&, L2&, L3&...); +++4 Requires: Each template parameter type shall meet the +Mutex+MutexLockable +requirements (30.2.5.1)., except that a call to +try_lock() may throw an exception.[Note: The +unique_lock class template meets these requirements when +suitably +instantiated. — end note] ++Replace 30.5.2 [thread.condition.condvarany] paragraph 1 with: +
+ ++1 A Lock type shall meet the+ + + + + + +requirements for a Mutex +typeLockable requirements (30.2.5.1), except +that +try_lock is not required. [Note: All of the standard +mutex types +meet this requirement. — end note] +
+1270. result_of should be moved to <type_traits>
+Section: X [func.ret] Status: WP + Submitter: Alisdair Meredith Opened: 2009-11-19 Last modified: 2010-10-23
+View all other issues in [func.ret].
+View all issues with WP status.
+Discussion:
+Addresses UK 198
+ ++NB Comment: UK-198 makes this request among others. It refers to a more +detailed issue that BSI did not manage to submit by the CD1 ballot deadline +though. +
+ ++result_of is essentially a metafunction to return the type of an +expression, and belongs with the other library metafunctions in +<type_traits> rather than lurking in <functional>. + The current definition in <functional> made sense when +result_of was nothing more than a protocol to enable several components +in <functional> to provide their own result types, but it has +become a more general tool. For instance, result_of is now used in the +threading and futures components. +
+ ++Now that <type_traits> is a required header for free-standing +implementations it will be much more noticeable (in such environments) that a +particularly useful trait is missing, unless that implementation also chooses to +offer <functional> as an extension. +
+ ++The simplest proposal is to simply move the wording (editorial direction below) +although a more consistent form for type_traits would reformat this as a table. +
+ ++Following the acceptance of 1255, result_of now +depends on the declval function template, tentatively provided +in <utility> which is not (yet) required of a +free-standing implementation. +
+ ++This dependency is less of an issue when result_of continues to +live in <functional>. +
+ ++Personally, I would prefer to clean up the dependencies so both +result_of and declval are available in a free-standing +implementation, but that would require slightly more work than suggested +here. A minimal tweak would be to require <utility> in a +free-standing implementation, although there are a couple of subtle +issues with make_pair, which uses reference_wrapper in +its protocol and that is much harder to separate cleanly from +<functional>. +
+ ++An alternative would be to enact the other half of +N2979 +and create a new minimal header for the new C++0x library facilities to +be added to the freestanding requirements (plus swap.) +
+ ++I have a mild preference for the latter, although there are clearly +reasons to consider better library support for free-standing in general, +and adding the whole of <utility> could be considered a step in that +direction. See NB comment +JP-23 +for other suggestions (array, ratio) +
+ +[ +2010-01-27 Beman updated wording. +]
+ + +++ ++The original wording is preserved here: +
++ +++Move X [func.ret] to a heading below 20.7 [meta]. Note +that in principle we should not change the tag, although this is a new tag for +0x. If it has been stable since TR1 it is clearly immutable though. +
+ ++This wording should obviously adopt any other changes currently in (Tentatively) +Ready status that touch this wording, such as 1255. +
+ +[ +2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+From Function objects 20.8 [function.objects], Header <functional> +synopsis, remove:
+++ +// 20.7.4 result_of: +template <class> class result_of; // undefined +template <class F, class... Args> class result_of<F(ArgTypes...)>;+Remove Function object return types X [func.ret] in its entirety. +This sub-section reads:
+++namespace std { + template <class> class result_of; // undefined + + template <class Fn, class... ArgTypes> + class result_of<Fn(ArgTypes...)> { + public : + // types + typedef see below type; + }; +}+Given an rvalue
+fnof typeFnand values+ t1, t2, ..., tNof types T1, T2, ..., TN inArgTypes, + respectively, the type member is the result type of the expression+ fn(t1, t2, ...,tN). The valuestiare lvalues when the + corresponding typeTiis an lvalue-reference type, and rvalues + otherwise.To Header <type_traits> synopsis 20.7.2 [meta.type.synop], add at +the indicated location:
+++template <class T> struct underlying_type; +template <class T> struct result_of; // not defined +template <class Fn, class... ArgTypes> struct result_of<Fn(ArgTypes...)>;+To Other transformations 20.7.7.6 [meta.trans.other], Table 51 — +Other transformations, add:
++++
++ +Template +Condition +Comments ++ ++ template <class T>
+ struct underlying_type;+ Tshall be an enumeration type + (7.2)The member typedef +typeshall + name the underlying type ofT.+ ++ template <class Fn, class... ArgTypes> + struct result_of<Fn(ArgTypes...)>;+ Fnshall be a function object type + 20.8 [function.objects], reference to function, or reference to + function object type. + decltype(declval<Fn>()(declval<ArgTypes>()...)) shall + be well formed.The member typedef +type+ shall name the typedecltype(declval<Fn>()(declval<ArgTypes>()...)).At the end of Other transformations 20.7.7.6 [meta.trans.other] add:
+ +++ + + + + +[Example: Given these definitions:
+ +typedef bool(&PF1)(); +typedef short(*PF2)(long); + +struct S { + operator PF2() const; + double operator()(char, int&); + };+the following assertions will hold:
+static_assert(std::is_same<+std::result_of<S(int)>::type, short>::value, "Error!"); +static_assert(std::is_same< std::result_of<S&(unsigned char, int&)>::type, double>::value, "Error!"); +static_assert(std::is_same< std::result_of<PF1()>::type, bool>::value, "Error!"); — end example]
+
+1271. CR undefined in duration operators
+Section: 20.11.3.5 [time.duration.nonmember] Status: WP + Submitter: Daniel Krügler Opened: 2009-11-21 Last modified: 2010-10-23
+View all other issues in [time.duration.nonmember].
+View all issues with WP status.
+Discussion:
++IMO CR alone is not really defined (it should be CR(Rep1, +Rep2)). +
+ +[ +2009-12-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Change 20.11.3.5 [time.duration.nonmember] paragraphs 9 and 12: +
+ ++ + + + + +template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + operator/(const duration<Rep1, Period>& d, const Rep2& s); +++9 Returns: duration<CR(Rep1, Rep2), Period>(d) /= s. ++ +template <class Rep1, class Period, class Rep2> + duration<typename common_type<Rep1, Rep2>::type, Period> + operator%(const duration<Rep1, Period>& d, const Rep2& s); +++12 Returns: duration<CR(Rep1, Rep2), Period>(d) %= s. ++ +
+1276. forwardlist missing allocator constructors
+Section: 23.3.3 [forwardlist] Status: WP + Submitter: Daniel Krügler Opened: 2009-12-12 Last modified: 2010-10-23
+View all other issues in [forwardlist].
+View all issues with WP status.
+Discussion:
++I found that forward_list has only +
+ ++ +forward_list(const forward_list<T,Allocator>& x); +forward_list(forward_list<T,Allocator>&& x); ++but misses +
+ ++ +forward_list(const forward_list& x, const Allocator&); +forward_list(forward_list&& x, const Allocator&); ++Note to other reviewers: I also checked the container adaptors for similar +inconsistencies, but as far as I can see these are already handled by the +current active issues 1194 and 1199. +
+ +[ +2010-01-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++In 23.3.3 [forwardlist]/3, class template forward_list synopsis change as +indicated: +
+ ++ + + + + + +forward_list(const forward_list<T,Allocator>& x); +forward_list(forward_list<T,Allocator>&& x); +forward_list(const forward_list&, const Allocator&); +forward_list(forward_list&&, const Allocator&); +
+1277. std::thread::id should be trivially copyable
+Section: 30.3.1.1 [thread.thread.id] Status: WP + Submitter: Anthony Williams Opened: 2009-11-24 Last modified: 2010-10-23
+View all other issues in [thread.thread.id].
+View all issues with WP status.
+Discussion:
++The class definition of std::thread::id in +N3000 +is: +
+ ++ +class thread::id { +public: + id(); +}; ++Typically, I expect that the internal data members will either be +pointers or integers, so that in practice the class will be trivially +copyable. However, I don't think the current wording guarantees it, and +I think it would be useful. In particular, I can see a use for +std::atomic<std::thread::id> to allow a thread +to claim ownership of a data structure atomicly, and +std::atomic<T> requires that T is trivially +copyable. +
+ +[ +2010-02-12 Moved to Tentatively Ready after 7 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++Add a new sentence to 30.3.1.1 [thread.thread.id] p1: +
+ ++1 An object of type thread::id provides a unique identifier for +each thread of execution and a single distinct value for all +thread objects that do not represent a thread of execution +(30.3.1 [thread.thread.class]). Each thread of execution has an +associated thread::id object that is not equal to the +thread::id object of any other thread of execution and that is +not equal to the thread::id object of any std::thread +object that does not represent threads of execution. The library may +reuse the value of a thread::id of a terminated thread that can +no longer be joined. thread::id shall be a trivially +copyable class (9 [class]). ++ + + + + + +
+1278. inconsistent return values for forward_list::insert_after
+Section: 23.3.3.4 [forwardlist.modifiers] Status: WP + Submitter: Bo Persson Opened: 2009-11-25 Last modified: 2010-10-23
+View all other issues in [forwardlist.modifiers].
+View all issues with WP status.
+Discussion:
++After applying LDR149, forward_list now has 5 +overloads of insert_after, all returning an iterator. +
+ ++However, two of those - inserting a single object - return "An iterator +pointing to a copy of x [the inserted object]" while the other +three - inserting zero or more objects - return an iterator equivalent +to the position parameter, pointing before any possibly inserted +objects. +
+ ++Is this the intended change? +
+ ++I don't really know what insert_after(position, empty_range) +should really return, but always returning position seems less +than useful. +
+ +[ +2010-02-04 Howard adds: +]
+ + +++ ++I agree this inconsistency will be error prone and needs to be fixed. +Additionally emplace_after's return value is unspecified. +
+[ +2010-02-04 Nico provides wording. +]
+ + +[ +2010 Pittsburgh: +]
+ + ++We prefer to return an iterator to the last inserted element. Modify the +proposed wording and then set to Ready. ++ +[ +2010-03-15 Howard adds: +]
+ + ++Wording updated and set to Ready. ++ + + +Proposed resolution:
++In forward_list modifiers 23.3.3.4 [forwardlist.modifiers] +make the following modifications: +
+ +++ + + + + + +iterator insert_after(const_iterator position, size_type n, const T& x); ++++ +...
++10 Returns:
+position.An iterator pointing to the last +inserted copy of x or position if n == 0. +template <class InputIterator> + iterator insert_after(const_iterator position, InputIterator first, InputIterator last); ++++ +...
+ ++13 Returns:
+position.An iterator pointing to the last +inserted element or position if first == last. +iterator insert_after(const_iterator position, initializer_list<T> il); ++++ +...
+ ++15 Returns:
+position.An iterator pointing to the last +inserted element or position if il is empty. +template <class... Args> + iterator emplace_after(const_iterator position, Args&&... args); ++++ +...
+17 ...
+ ++Returns: An iterator pointing to the new constructed element from +args. +
+
+1280. initialization of stream iterators
+Section: 24.6.1.1 [istream.iterator.cons], 24.6.2.1 [ostream.iterator.cons.des] Status: WP + Submitter: Jonathan Wakely Opened: 2009-12-04 Last modified: 2010-10-23
+View all other issues in [istream.iterator.cons].
+View all issues with WP status.
+Discussion:
++24.6.1.1 [istream.iterator.cons] describes the effects in terms of: +
+ ++ +basic_istream<charT,traits>* in_stream; // exposition only ++ ++3 Effects: Initializes in_stream with s. +
++That should be &s and similarly for 24.6.2.1 [ostream.iterator.cons.des]. +
+ +[ +2009-12-23 Moved to Tentatively Ready after 6 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Change 24.6.1.1 [istream.iterator.cons] like so: +
+ ++ +istream_iterator(istream_type& s); +++3 Effects: Initializes in_stream with &s. +value ... +++And 24.6.2.1 [ostream.iterator.cons.des] like so: +
+ ++ + + + + + +ostream_iterator(ostream_type& s); +++1 Effects: Initializes out_stream with &s +and delim with null. ++ +ostream_iterator(ostream_type& s, const charT* delimiter); +++2 Effects: Initializes out_stream with &s +and delim with delimiter. ++
+1283. MoveConstructible and MoveAssignable need clarification +of moved-from state
+Section: 20.2.1 [utility.arg.requirements] Status: Resolved + Submitter: Howard Hinnant Opened: 2009-12-12 Last modified: 2010-11-19
+View all other issues in [utility.arg.requirements].
+View all issues with Resolved status.
+Discussion:
+Addresses UK 150
+ ++There is on going confusion over what one can and can not do with a moved-from +object (e.g. +UK 150, +910). +This issue attempts to clarify that moved-from objects are valid objects with an +unknown state. +
+ +[ +2010-01-22 Wording tweaked by Beman. +]
+ + +[ +2010-01-22 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-01-23 Alisdair opens: +]
+ + +++ ++I'm afraid I must register an objection. +
+ ++My primary objection is that I have always been opposed to this kind of a +resolution as over-constraining. My preferred example is a call implementing +the pImpl idiom via unique_ptr. Once the pImpl has been moved from, it +is no longer safe to call the vast majority of the object's methods, yet I see +no reason to make such a type unusable in the standard library. I would prefer +a resolution along the lines suggested in the UK comment, which only requires +that the object can be safely destroyed, and serve as the target of an +assignment operator (if supported.) +
+ ++However, I will not hold the issue up if I am a lone dissenting voice on this +(yes, that is a call to hear more support, or I will drop that objection in +Pittsburgh) +
+ ++With the proposed wording, I'm not clear what the term 'valid object' means. In +my example above, is a pImpl holding a null pointer 'valid'? What about a float +holding a signalling NaN? What determines if an object is valid? Without a +definition of a valid/invalid object, I don't think this wording adds anything, +and this is an objection that I do want resolved. +
+ +[ +2010-01-24 Alisdair removes his objection. +]
+ + +[ +2010-01-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-02-10 Reopened. The wording here has been merged into 1309. +]
+ + +[ +2010-02-10 Moved to Tentatively
+ + + + +NAD EditorialResolved after 5 postive votes on +c++std-lib. Rationale added below. +]Rationale:
++This issue is now addressed by 1309. +
+ + +Proposed resolution:
++Change the follwing tables in 20.2.1 [utility.arg.requirements] as shown: +
+ ++ +++
+ +Table 33 — MoveConstructible requirements [moveconstructible] ++ +Expression +Post-condition ++ ++T t(rv) + ++t is equivalent to the value of rv before the construction. + ++ ++[Note: + +There is no requirement on the value of rv after the +construction.+rv remains a valid object. Its state is unspecified. +— end note] ++ ++ + + + + ++
+ +Table 35 — MoveAssignable requirements [moveassignable] ++ +Expression +Return type +Return value +Post-condition ++ ++t = rv + ++T& + ++t + ++t is equivalent to the value of rv before the assigment. + ++ ++[Note: + +There is no requirement on the value of rv after the +assignment.+rv remains a valid object. Its state is unspecified. +— end note] +
+1284. vector<bool> initializer_list constructor missing an allocator argument
+Section: 23.4.2 [vector.bool] Status: WP + Submitter: Bo Persson Opened: 2009-12-09 Last modified: 2010-10-23
+View all other issues in [vector.bool].
+View all issues with WP status.
+Discussion:
++The specialization for vector<bool> (23.4.2 [vector.bool]) +has a constructor +
+ ++ +vector(initializer_list<bool>); ++which differs from the base template's constructor (and other containers) in +that it has no allocator parameter. +
+ +[ +2009-12-16 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Change the signature in the synopsis of 23.4.2 [vector.bool] to +
+ ++ + + + + +vector(initializer_list<bool>, const Allocator& = Allocator()); +
+1285. allocator_traits call to new
+Section: 20.9.4.2 [allocator.traits.members] Status: WP + Submitter: Howard Hinnant Opened: 2009-12-10 Last modified: 2010-10-23
+View all other issues in [allocator.traits.members].
+View all issues with WP status.
+Discussion:
++LWG issue 402 added "::" to the call to new +within allocator::construct. I suspect we want to retain that fix. +
+ +[ +2009-12-13 Moved to Tentatively Ready after 7 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Change 20.2.5 [allocator.requirements], table 40 "Allocator requirements": +
+ +++ ++
+Table 40 — Allocator requirements ++ +Expression +Return type +Assertion/note +
pre-/post-conditionDefault ++ ++a.construct(c,args) + ++(not used) + ++Effect: Constructs an object of type C at c + ++::new ((void*)c) C(forward<Args>(args)...) + ++Change 20.9.4.2 [allocator.traits.members], p4: +
+ ++ + + + + +template <class T, class... Args> + static void construct(Alloc& a, T* p, Args&&... args); +++4 Effects: calls a.construct(p, +std::forward<Args>(args)...) if that call is well-formed; otherwise, +invokes ::new (static_cast<void*>(p)) +T(std::forward<Args>(args)...). ++
+1286. allocator_traits::select_on_container_copy_construction type-o
+Section: 20.9.4.2 [allocator.traits.members] Status: WP + Submitter: Howard Hinnant Opened: 2009-12-10 Last modified: 2010-10-23
+View all other issues in [allocator.traits.members].
+View all issues with WP status.
+Discussion:
++allocator_traits::select_on_container_copy_construction refers to an +unknown "a": +
+ ++ +static Alloc select_on_container_copy_construction(const Alloc& rhs); ++ ++7 Returns: rhs.select_on_container_copy_construction(a) if that +expression is well-formed; otherwise, rhs. ++[ +2009-12-13 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++Change 20.9.4.2 [allocator.traits.members], p7: +
+ ++ + + + + +static Alloc select_on_container_copy_construction(const Alloc& rhs); ++ ++7 Returns: +rhs.select_on_container_copy_construction(+a) if that +expression is well-formed; otherwise, rhs. +
+1287. std::function requires CopyConstructible target object
+Section: 20.8.14.2.1 [func.wrap.func.con] Status: WP + Submitter: Jonathan Wakely Opened: 2009-12-13 Last modified: 2010-10-23
+View all other issues in [func.wrap.func.con].
+View all issues with WP status.
+Discussion:
++I think std::function should require CopyConstructible for the +target object. +
+ ++I initially thought that MoveConstructible was enough, but it's not. If +F is move-only then function's copy constructor cannot be called, but +because function uses type erasure, F is not known and so the copy +constructor cannot be disabled via enable_if. One option would be to +throw an exception if you try to copy a function with a non-copyable target +type, but I think that would be a terrible idea. +
+ ++So although the constructors require that the target be initialised by +std::move(f), that's only an optimisation, and a copy constructor is +required. +
+ +[ +2009-12-24 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++Add to 20.8.14.2.1 [func.wrap.func.con] paragraph 9: +
+ ++ + + + + + +template<class F> function(F f); +template <class F, class A> function(allocator_arg_t, const A& a, F f); ++ ++9 Requires: F shall be CopyConstructible. +f shall be callable for argument types ArgTypes and return +type R. The copy constructor and destructor of A shall not +throw exceptions. ++
+1288. std::function assignment from rvalues
+Section: 20.8.14.2.1 [func.wrap.func.con] Status: WP + Submitter: Jonathan Wakely Opened: 2009-12-13 Last modified: 2010-10-23
+View all other issues in [func.wrap.func.con].
+View all issues with WP status.
+Discussion:
++In 20.8.14.2.1 [func.wrap.func.con] +
+ ++ +template<class F> function& operator=(F f); +++++20 Effects: function(f).swap(*this); +
++21 Returns: *this +
++This assignment operator can be called such that F is an rvalue-reference e.g. +
+ ++ +func.operator=<F&&>(f); ++There are two issues with this. +
+ ++
+ +- +the effects mean that f is passed as an lvalue and so there will be an +unnecessary copy. The argument should be forwarded, so that the copy can be +avoided. +
+- +It should not be necessary to use that syntax to pass an rvalue. As F +is a deduced context it can be made to work with either lvalues or rvalues. +
++The same issues apply to function::assign. +
+ ++N.B. this issue is not related to 1287 and applies whether that +issue is resolved or not. The wording below assumes the resolution of LWG 1258 has been applied. +
+ +[ +2009-12-16 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +201002-11 Opened by Alisdair for the purpose of merging 1258 into +this issue as there is a minor conflict. +]
+ + +[ +2010-02-11 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++In 20.8.14.2.1 [func.wrap.func.con] +
+ ++ +template<class F> function& operator=(F&& f); +++++20 Effects: +function(std::forward<F>(f)).swap(*this); +
++21 Returns: *this +
++In 20.8.14.2.2 [func.wrap.func.mod] +
+ ++ +template<class F,+Allocator Allocclass A> + void assign(F&& f, const Alloc& a); ++++3 Effects: function(
+f, aallocator_arg, a, +std::forward<F>(f)).swap(*this); ++Update member function signature for class template in 20.8.14.2 [func.wrap.func] +
+ ++ + + + + + + +template<class F> function& operator=(F&&); + +template<class F, class A> void assign(F&&, const A&); +
+1290. Don't require [u|bi]nary_function inheritance
+Section: 20.8 [function.objects] Status: Resolved + Submitter: Daniel Krügler Opened: 2009-12-14 Last modified: 2010-11-26
+View all other issues in [function.objects].
+View all issues with Resolved status.
+Discussion:
++This issue is a follow-up of the discussion on issue 870 during +the 2009 Santa Cruz meeting. +
+ ++The class templates unary_function and binary_function are +actually very simple typedef providers, +
+ ++ +namespace std { + +template <class Arg, class Result> +struct unary_function { + typedef Arg argument_type; + typedef Result result_type; +}; + +template <class Arg1, class Arg2, class Result> +struct binary_function { + typedef Arg1 first_argument_type; + typedef Arg2 second_argument_type; + typedef Result result_type; +}; + +} ++which may be used as base classes (similarly to the iterator template), +but were originally not intended as a customization point. The SGI +documentation introduced the concept Adaptable Unary +Function as function objects "with nested typedefs that define its argument +type and result type" and a similar definition for Adaptable Binary +Function related to binary_function. But as of TR1 a protocol was +introduced that relies on inheritance relations based on these types. 20.8.4 [refwrap]/3 b. 3 requires that a specialization of +reference_wrapper<T> shall derive from unary_function, +if type T is "a class type that is derived from +std::unary_function<T1, R>" and a similar inheritance-based rule +for binary_function exists as well. +
+ ++As another disadvantage it has been pointed out in the TR1 issue list, N1837 +(see section 10.39), that the requirements of mem_fn 20.8.13 [func.memfn]/2+3 to derive from +std::unary_function/std::binary_function under circumstances, where the +provision of corresponding typedefs would be sufficient, unnecessarily prevent +implementations that take advantage of empty-base-class- optimizations. +
+ ++Both requirements should be relaxed in the sense that the +reference_wrapper should provide typedef's argument_type, +first_argument_type, and second_argument_type based on similar +rules as the weak result type rule (20.8.2 [func.require]/3) does +specify the presence of result_type member types. +
+ ++For a related issue see also 1279. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3145 would resolve this issue as NAD editorial. ++ + + +[ +2010-11 Batavia: Solved by N3198 +]
+ ++Resolved by adopting n3198. +
+ ++Previous proposed resolution: + +
[ +The here proposed resolution is an attempt to realize the common denominator of +the reflector threads c++std-lib-26011, c++std-lib-26095, and c++std-lib-26124. +]
+ + ++
+ + +- +
+ ++Change X [base]/1 as indicated: [The intend is to provide an +alternative fix for issue 1279 and some editorial harmonization +with existing wording in the library, like 24.4.2 [iterator.basic]/1] +
+ ++++1 The following class templates are provided to simplify the +definition of typedefs of the argument and result types for +function objects. The behavior of a program that adds specializations for any of +these templates is undefined.
+ +:++namespace std { + template <class Arg, class Result> + struct unary_function { + typedef Arg argument_type; + typedef Result result_type; + }; +} + +namespace std { + template <class Arg1, class Arg2, class Result> + struct binary_function { + typedef Arg1 first_argument_type; + typedef Arg2 second_argument_type; + typedef Result result_type; + }; +} +- +
+ ++Change 20.8.4 [refwrap], class template reference_wrapper +synopsis as indicated: [The intent is to remove the requirement that +reference_wrapper derives from unary_function or +binary_function if the situation requires the definition of the +typedefs argument_type, first_argument_type, or +second_argument_type. This change is suggested, because the new way of +definition uses the same strategy as the weak result type specification +applied to argument types, which provides the following advantages: It creates +less potential conflicts between [u|bi]nary_function bases and typedefs +in a function object and it ensures that user-defined function objects which +provide typedefs but no such bases are handled as first class citizens.] +
+ ++namespace std { + template <class T> class reference_wrapper +: public unary_function<T1, R> // see below+: public binary_function<T1, T2, R> // see below+ { + public : + // types + typedef T type; + typedef see below result_type; // not always defined + typedef see below argument_type; // not always defined + typedef see below first_argument_type; // not always defined + typedef see below second_argument_type; // not always defined + + // construct/copy/destroy + ... + }; +- +
+ ++Change 20.8.4 [refwrap]/3 as indicated: [The intent is to remove the +requirement that reference_wrapper derives from unary_function +if the situation requires the definition of the typedef argument_type +and result_type. Note that this clause does concentrate on +argument_type alone, because the result_type is already ruled +by p. 2 via the weak result type specification. The new way of +specifying argument_type is equivalent to the weak result type +specification] +
+ ++++3 The template instantiation reference_wrapper<T> shall
+be +derived from std::unary_function<T1, R>define a nested +type named argument_type as a synonym for T1 only if the +type T is any of the following: ++
+- a function type or a pointer to function type taking one argument +of type T1
+and returning R+- a pointer to member function R T0::f cv (where +cv represents the member function's cv-qualifiers); +the type T1 is cv T0* +
+- a class type
+that is derived from +std::unary_function<T1, R>with a member type +argument_type; + the type T1 is T::argument_type +- +
+ ++Change 20.8.4 [refwrap]/4 as indicated: [The intent is to remove the +requirement that reference_wrapper derives from +binary_function if the situation requires the definition of the typedef +first_argument_type, second_argument_type, and +result_type. Note that this clause does concentrate on +first_argument_type and second_argument_type alone, because +the result_type is already ruled by p. 2 via the weak result +type specification. The new way of specifying first_argument_type +and second_argument_type is equivalent to the weak result type +specification] +
+ ++++The template instantiation reference_wrapper<T> shall
+be +derived from std::binary_function<T1, T2, R>define two +nested types named first_argument_type and +second_argument_type as a synonym for T1 and T2, +respectively, only if the type T is any of the following: ++
+- a function type or a pointer to function type taking two arguments +of types T1 and T2
+and returning +R+- a pointer to member function R T0::f(T2) cv +(where cv represents the member function's cv-qualifiers); + the type T1 is cv T0* +
+- a class type
+that is derived from +std::binary_function<T1, T2, R>with member +types first_argument_type + and second_argument_type; the type T1 is +T::first_argument_type and the type T2 is + T::second_argument_type +- +
+ ++Change 20.8.13 [func.memfn]/2+3 as indicated: [The intent is to remove +the requirement that mem_fn's return type has to derive +from [u|bi]nary_function. The reason for suggesting the +change here is to better support empty-base-class optimization +choices as has been pointed out in N1837] +
+ ++++2 The simple call wrapper shall
+be derived from +std::unary_function<cv T*, Ret>define +two nested types named argument_type and result_type as a +synonym for cv T* and Ret, respectively, +when pm is a pointer to member function with cv-qualifier cv +and taking no arguments, where Ret is pm's return type. ++3 The simple call wrapper shall
+be derived from +std::binary_function<cv T*, T1, +Ret>define three nested types named +first_argument_type, second_argument_type, and +result_type as a synonym for cv T*, T1, and +Ret, respectively, when pm is a pointer to member +function with cv-qualifier cv and taking one argument of type +T1, where Ret is pm's return type. +Proposed resolution:
+Addressed by paper n3198. + + + + +
+1292. std::function should support all callable types
+Section: 20.8.14.2.1 [func.wrap.func.con] Status: WP + Submitter: Daniel Krügler Opened: 2009-12-19 Last modified: 2010-11-23
+View all other issues in [func.wrap.func.con].
+View all issues with WP status.
+Discussion:
++Some parts of the specification of std::function is unnecessarily +restricted to a subset of all callable types (as defined in 20.8.1 [func.def]/3), even though the intent clearly is to be usable for +all of them as described in 20.8.14.2 [func.wrap.func]/1. This +argument becomes strengthened by the fact that current C++0x-compatible +compilers work fine with them: +
+ ++ +#include <functional> +#include <iostream> + +struct A +{ + int foo(int i) const {return i+1;} +}; + +struct B +{ + int mem; +}; + +int main() +{ + std::function<int(const A&, int)> f(&A::foo); + A a; + std::cout << f(a, 1) << '\n'; + std::cout << f.target_type().name() << '\n'; + typedef int (A::* target_t)(int) const; + target_t* p = f.target<target_t>(); + std::cout << (p != 0) << '\n'; + std::function<int(B&)> f2(&B::mem); + B b = { 42 }; + std::cout << f2(b) << '\n'; + std::cout << f2.target_type().name() << '\n'; + typedef int (B::* target2_t); + target2_t* p2 = f2.target<target2_t>(); + std::cout << (p2 != 0) << '\n'; +} ++The problematics passages are 20.8.14.2.1 [func.wrap.func.con]/10: +
+ ++ +template<class F> function(F f); +template <class F, class A> function(allocator_arg_t, const A& a, F f); ++++...
++10 Postconditions: !*this if any of the following hold: +
++
+- +f is a NULL function pointer. +
+- +f is a NULL member function pointer. +
+- +F is an instance of the function class template, and !f +
++because it does not consider pointer to data member and all constraints based on +function objects which like 20.8.14.2 [func.wrap.func]/2 or 20.8.14.2.5 [func.wrap.func.targ]/3. The latter two will be resolved by the proposed +resolution of 870 and are therefore not handled here. +
+ +[ +Post-Rapperswil: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Change 20.8.14.2.1 [func.wrap.func.con]/10+11 as indicated: +
+ ++ + + + + +template<class F> function(F f); +template <class F, class A> function(allocator_arg_t, const A& a, F f); ++++...
++10 Postconditions: !*this if any of the following hold: +
++
+ +- +f is a NULL function pointer. +
+- +f is a NULL pointer to member
+function pointer. +- +F is an instance of the function class template, and !f +
++11 Otherwise, *this targets a copy of f
+ +or, +initialized with std::move(f)if f is not a pointer +to member function, and targets a copy of mem_fn(f) if f is a +pointer to member function. [Note: implementations are encouraged +to avoid the use of dynamically allocated memory for small function objects, for +example, where f's target is an object holding only a pointer or +reference to an object and a member function pointer. — end note] +
+1293. unique_ptr<T[], D> needs to get rid of unspecified-pointer-type
+Section: 20.9.9.3 [unique.ptr.runtime] Status: Resolved + Submitter: Daniel Krügler Opened: 2009-12-20 Last modified: 2010-11-19
+View all issues with Resolved status.
+Discussion:
+Addresses UK 211
+ ++As a response to UK 211 LWG issue 1021 has replaced the +unspecified-pointer-type by nullptr_t to allow assignment of +type-safe null-pointer literals in the non-array form of +unique_ptr::operator=, but did not the same for the specialization for +arrays of runtime length. But without this parallel change of the signature we +have a status quo, where unique_ptr<T[], D> declares a member +function which is completely unspecified. +
+ +[ +2009-12-21 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-03-14 Howard adds: +]
+ + ++We moved +N3073 +to the formal motions page in Pittsburgh which should obsolete this issue. I've +moved this issue to NAD Editorial, solved by N3073. ++ + + +Rationale:
++Solved by N3073. +
+ + +Proposed resolution:
++In 20.9.9.3 [unique.ptr.runtime], class template unique_ptr<T[], +D> synopsis, change as indicated: +
+ ++ + + + + + +// assignment +unique_ptr& operator=(unique_ptr&& u); +unique_ptr& operator=(unspecified-pointer-typenullptr_t); +
+1294. Difference between callable wrapper and forwarding call wrapper unclear
+Section: 20.8.2 [func.require] Status: WP + Submitter: Jens Maurer Opened: 2009-12-21 Last modified: 2010-11-23
+View all other issues in [func.require].
+View all issues with WP status.
+Discussion:
++The current wording in the standard makes it hard to discriminate the difference +between a "call wrapper" as defined in 20.8.1 [func.def]/5+6: +
+ +++ ++5 A call wrapper type is a type that holds a callable object and supports +a call operation that forwards to that object. +
++6 A call wrapper is an object of a call wrapper type. +
++and a "forwarding call wrapper" as defined in 20.8.2 [func.require]/4: +
+ +++ ++4 [..] A forwarding call wrapper is a call wrapper that can be called +with an argument list. [Note: in a typical implementation forwarding call +wrappers have an overloaded function call operator of the form +
+ ++ +template<class... ArgTypes> +R operator()(ArgTypes&&... args) cv-qual; ++— end note] +
++Reason for this lack of clear difference seems to be that the wording adaption +to variadics and rvalues that were applied after it's original proposal in N1673: +
+ +++ ++[..] A forwarding call wrapper is a call wrapper that can be called +with an argument list t1, t2, ..., tN where each ti is an lvalue. +The effect of calling a forwarding call wrapper with one or more +arguments that are rvalues is implementation defined. [Note: in +a typical implementation forwarding call wrappers have overloaded +function call operators of the form +
+ ++ +template<class T1, class T2, ..., class TN> +R operator()(T1& t1, T2& t2, ..., TN& tN) cv-qual; ++— end note] +
++combined with the fact that the word "forward" has two different meanings in +this context. This issue attempts to clarify the difference better. +
+ +[ +2010-09-14 Daniel provides improved wording and verified that it is correct against N3126. Previous resolution is shown here: +]
+ + +++ ++4 [..] A forwarding call wrapper is a call wrapper that can be called +with an arbitrary argument list and uses perfect forwarding to +deliver the arguments to the wrapped callable object. [Note: in a +typical implementation forwarding call wrappers have an overloaded function call +operator of the form +
+ ++ +template<class... ArgTypes> +R operator()(ArgTypes&&... args) cv-qual; ++— end note] +
+[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Change 20.8.2 [func.require]/4 as indicated: +
+ ++ + + + + + ++[..] A forwarding call wrapper is a call wrapper that can be called with an arbitrary argument +list and delivers the arguments as references to the wrapped callable object. This forwarding step shall ensure +that rvalue arguments are delivered as rvalue-references and lvalue arguments are delivered as lvalue-references. +[Note: in a typical implementation forwarding call wrappers have an overloaded function call operator of the +form +
+ ++template<class... UnBoundArgs> +R operator()(UnBoundArgs&&... unbound_args) cv-qual; ++— end note ] +
+
+1295. Contradictory call wrapper requirements
+Section: 20.8.2 [func.require] Status: WP + Submitter: Daniel Krügler Opened: 2009-12-22 Last modified: 2010-11-23
+View all other issues in [func.require].
+View all issues with WP status.
+Discussion:
++20.8.2 [func.require]/3 b 1 says +
+ +++ ++3 If a call wrapper (20.8.1 [func.def]) has a weak result type the +type of its member type result_type is based on the type T of +the wrapper's target object (20.8.1 [func.def]): +
+ ++
+- +if T is a function, reference to function, or pointer to function type, +result_type shall be a synonym for the return type of T; +
+- +[..] +
++The first two enumerated types (function and reference to function) +can never be valid types for T, because +
+ ++20.8.1 [func.def]/7 +
+ ++7 A target object is the callable object held by a call wrapper. ++ ++and 20.8.1 [func.def]/3 +
+ ++3 A callable type is a pointer to function, a pointer to member function, +a pointer to member data, or a class type whose objects can appear immediately +to the left of a function call operator. ++ ++exclude functions and references to function as "target objects". +
+ +[ +Post-Rapperswil: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Change 20.8.2 [func.require]/3 b 1 as indicated: +
+ +++ + + + + + ++3 If a call wrapper (20.8.1 [func.def]) has a weak result type the +type of its member type result_type is based on the type T of +the wrapper's target object (20.8.1 [func.def]): +
+ ++
+- +if T is a
+function, reference to function, orpointer to +function type, result_type shall be a synonym for the return type of +T; +- +[..] +
+
+1298. Missing specialization of ctype_byname<char>
+Section: 22.2 [locale.syn] Status: WP + Submitter: Alisdair Meredith Opened: 2009-12-25 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++The <locale> synopsis in 22.2 [locale.syn] calls out an +explicit specialization for ctype_byname<char>, however no such +specialization is defined in the standard. The only reference I can find to +ctype_byname<char> is 22.3.1.1.2 [locale.facet]:Table 77 +— Required specializations (for facets) which also refers to +ctype_byname<wchar_t> which has no special consideration. +
+ ++Is the intent an explicit instantiation which would use a slightly +different syntax? Should the explicit specialization simply be struck? +
+ +[ +2010-01-31 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++22.2 [locale.syn] +
+ +++ + + + + ++Strike the explicit specialization for ctype_byname<char> from +the <locale> synopsis +
++... +template <class charT> class ctype_byname; +template <> class ctype_byname<char>; // specialization+... +
+1299. Confusing typo in specification for get_time
+Section: 27.7.4 [ext.manip] Status: WP + Submitter: Alisdair Meredith Opened: 2009-12-25 Last modified: 2010-10-23
+View all other issues in [ext.manip].
+View all issues with WP status.
+Discussion:
++Extended Manipulators 27.7.4 [ext.manip] p8 defines the semantics of +get_time in terms of a function f. +
+ ++ +template <class charT, class traits> +void f(basic_ios<charT, traits>& str, struct tm* tmb, const charT* fmt) { + typedef istreambuf_iterator<charT, traits> Iter; + typedef time_get<charT, Iter> TimeGet; + + ios_base::iostate err = ios_base::goodbit; + const TimeGet& tg = use_facet<TimeGet>(str.getloc()); + + tm.get(Iter(str.rdbuf()), Iter(), str, err, tmb, fmt, fmt + traits::length(fmt)); + + if (err != ios_base::goodbit) + str.setstate(err): +} ++Note the call to tm.get. This is clearly an error, as tm is a +type and not an object. I believe this should be tg.get, rather than +tm, but this is not my area of expertise. +
+ +[ +2010-01-14 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + +Proposed resolution:
++Change 27.7.4 [ext.manip] p8: +
+ ++ + + + + +template <class charT, class traits> +void f(basic_ios<charT, traits>& str, struct tm* tmb, const charT* fmt) { + typedef istreambuf_iterator<charT, traits> Iter; + typedef time_get<charT, Iter> TimeGet; + + ios_base::iostate err = ios_base::goodbit; + const TimeGet& tg = use_facet<TimeGet>(str.getloc()); + + tgm.get(Iter(str.rdbuf()), Iter(), str, err, tmb, fmt, fmt + traits::length(fmt)); + + if (err != ios_base::goodbit) + str.setstate(err): +} +
+1303. shared_ptr, unique_ptr, and rvalue references v2
+Section: 20.9.9.2 [unique.ptr.single], 20.9.10.2 [util.smartptr.shared] Status: WP + Submitter: Stephan T. Lavavej Opened: 2010-01-23 Last modified: 2010-10-23
+View all other issues in [unique.ptr.single].
+View all issues with WP status.
+Discussion:
++N3000 +20.9.10.2 [util.smartptr.shared]/1 still says: +
+ ++ +template <class Y, class D> explicit shared_ptr(const unique_ptr<Y, D>& r) = delete; +template <class Y, class D> shared_ptr& operator=(const unique_ptr<Y, D>& r) = delete; ++I believe that this is unnecessary now that "rvalue references v2" +prevents rvalue references from binding to lvalues, and I didn't +see a Library Issue tracking this. +
+ +[ +2010-02-12 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+ ++Strike from 20.9.9.2 [unique.ptr.single]: +
+ ++ +template <class T, class D = default_delete<T>> class unique_ptr { + ... + unique_ptr(const unique_ptr&) = delete; +template <class U, class E> unique_ptr(const unique_ptr<U, E>&) = delete;+ unique_ptr& operator=(const unique_ptr&) = delete; +template <class U, class E> unique_ptr& operator=(const unique_ptr<U, E>&) = delete;+}; ++Strike from 20.9.10.2 [util.smartptr.shared]: +
+ ++ + + + + + +template<class T> class shared_ptr { + ... +template <class Y, class D> explicit shared_ptr(const unique_ptr<Y, D>& r) = delete;+ ... +template <class Y, class D> shared_ptr& operator=(const unique_ptr<Y, D>& r) = delete;+ ... +}; +
+1306. pointer and const_pointer for <array>
+Section: 23.3.1 [array] Status: WP + Submitter: Nicolai Josuttis Opened: 2010-01-24 Last modified: 2010-10-23
+View all other issues in [array].
+View all issues with WP status.
+Discussion:
++Class <array> is the only sequence container class that has no +types pointer and const_pointer defined. You might argue that +this makes no sense because there is no allocator support, but on the other +hand, types reference and const_reference are defined for +array. +
+ +[ +2010-02-11 Moved to Tentatively Ready after 6 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++Add to Class template array 23.3.1 [array]: +
+ ++ + + + + +namespace std { + template <class T, size_t N > + struct array { + ... + typedef T value_type; + typedef T * pointer; + typedef const T * const_pointer; + ... + }; +} +
+1307. exception_ptr and allocator pointers don't understand !=
+Section: 18.8.5 [propagation] Status: Resolved + Submitter: Daniel Krügler Opened: 2010-01-26 Last modified: 2010-11-19
+View other active issues in [propagation].
+View all other issues in [propagation].
+View all issues with Resolved status.
+Discussion:
++The current requirements for a conforming implementation of +std::exception_ptr (18.8.5 [propagation]/1-6) does not clarify +whether the expression +
+ ++ +e1 != e2 +e1 != nullptr ++with e1 and e2 being two values of type +std::exception_ptr are supported or not. Reason for this oddity is that +the concept EqualityComparable does not provide operator !=. +
+ ++For the same reason programmers working against the types X::pointer, +X::const_pointer, X::void_pointer, and +X::const_void_pointer of any allocator concept X (20.2.5 [allocator.requirements]/4 + Table 40) in a generic context can not rely +on the availability of the != operation, which is rather unnatural and +error-prone. +
+ +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3073. +
+ + +Proposed resolution:
+ + + + + +
+1309. Missing expressions for Move/CopyConstructible
+Section: 20.2.1 [utility.arg.requirements] Status: WP + Submitter: Daniel Krügler Opened: 2010-02-03 Last modified: 2010-10-23
+View all other issues in [utility.arg.requirements].
+View all issues with WP status.
+Discussion:
++Table 33 — MoveConstructible requirements [moveconstructible] and +Table 34 — CopyConstructible requirements [copyconstructible] support +solely the following expression: +
+ ++ +T t(rv) ++where rv is defined to be as "non-const rvalue of type T" and +t as a "modifiable lvalue of type T" in 20.2.1 [utility.arg.requirements]/1. +
+ ++This causes two different defects: +
+ ++
+ +- +
+ ++We cannot move/copy-initialize a const lvalue of type T as in: +
+ ++ +int get_i(); + +const int i1(get_i()); ++both in Table 33 and in Table 34. +
+- +
++The single support for +
+ ++ +T t(rv) ++in case of CopyConstructible means that we cannot provide an +lvalue as a source of a copy as in +
+ ++const int& get_lri(); + +int i2(get_lri()); ++I believe this second defect is due to the fact that this single +expression supported both initialization situations according +to the old (implicit) lvalue reference -> rvalue reference +conversion rules. +
+ ++Finally [copyconstructible] refers to some name u which is not part of +the expression, and both [copyconstructible] and [moveconstructible] should +support construction expressions from temporaries - this would be a stylistic +consequence in the light of the new DefaultConstructible requirements +and compared with existing requirements (see e.g. Container requirements or the +output/forward iterator requirements).. +
+ +[ +2010-02-09 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + +[ +2010-02-10 Reopened. The proposed wording of 1283 has been +merged here. +]
+ + +[ +2010-02-10 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
+ ++ +
+ + + + + + +- +
+ ++Change 20.2.1 [utility.arg.requirements]/1 as indicated: [This change +suggestion is motivated to make type descriptions clearer: First, a, +b, and c may also be non-const T. Second, u +is described in a manner consistent with the container requirements tables.] +
+ ++1 The template definitions in the C++ standard library refer to various named +requirements whose details are set out in tables 31-38. In these tables, +T is an object or reference type to be supplied by a C++ +program instantiating a template; a, b, and c are +values of type (possibly const) T; s and +t are modifiable lvalues of type T; u denotes an +identifier;+is a value of type (possibly const) T; +andrv is annon-constrvalue of type +T; and v is an lvalue of type (possibly const) +T or an rvalue of type const T. +- +
+ ++In 20.2.1 [utility.arg.requirements] Table 33 ([moveconstructible]) +change as indicated [Note: The symbol u is defined to be either a +const or a non-const value and is the right one we need here]: +
+ ++++
+Table 33 — MoveConstructible requirements [moveconstructible] + ++ + +Expression +Post-condition ++ + ++T +tu(rv); ++ +tu is equivalent +to the value of rv before the construction ++ + +T(rv) +T(rv) is equivalent to the value of rv before the +construction ++ +[Note: + +There is no requirement on the value of rv after the +construction.+rv remains a valid object. Its state is unspecified. +— end note]- +
+ ++In 20.2.1 [utility.arg.requirements] Table 34 ([copyconstructible]) +change as indicated [Note: The symbol u is defined to be either a +const or a non-const value and is the right one we need here. The expressions +using a are recommended to ensure that lvalues are supported as sources +of the copy expression]: +
+ +++ ++
+Table 34 — CopyConstructible requirements [copyconstructible] + +
+(in addition to MoveConstructible)+ + +Expression +Post-condition ++ + ++T +tu(rv); ++the value of +uv +is unchanged and is equivalent totu ++ + ++T(v) + +the value of v is unchanged and is equivalent to T(v) + ++ + ++ [Note: A type that satisfies the +CopyConstructible requirements also satisfies the MoveConstructible +requirements. — end note]- +
+ ++In Table 35 — MoveAssignable requirements [moveassignable] change as +indicated: +
+ ++ +++
+ +Table 35 — MoveAssignable requirements [moveassignable] ++ +Expression +Return type +Return value +Post-condition ++ ++t = rv + ++T& + ++t + ++t is equivalent to the value of rv before the assigment. + ++ ++[Note: + +There is no requirement on the value of rv after the +assignment.+rv remains a valid object. Its state is unspecified. +— end note] +- +
++In 20.2.1 [utility.arg.requirements] change Table 36 as indicated: +
+ ++++
+Table 36 — CopyAssignable requirements +[copyassignable] + +
(in addition to MoveAssignable)+ + +Expression +Return type +Return value +Post-condition ++ + +t = +uvT& +t +t is equivalent to +uv, the value of +uv is unchanged+ + ++ [Note: A type that satisfies the CopyAssignable +requirements also satisfies the MoveAssignable requirements. — +end note]
+1312. vector::data no longer returns a raw pointer
+Section: 23.4.1.3 [vector.data] Status: WP + Submitter: Alisdair Meredith Opened: 2010-02-07 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
++The original intent of vector::data was to match array::data +in providing a simple API with direct access to the contiguous buffer of +elements that could be passed to a "classic" C API. At some point, the return +type became the 'pointer' typedef, which is not derived from the +allocator via allocator traits - it is no longer specified to precisely +T *. The return type of this function should be corrected to no longer +use the typedef. +
+ +[ +2010-02-10 Moved to Tentatively Ready after 5 positive votes on c++std-lib. +]
+ + + + +Proposed resolution:
++23.4.1 [vector] +
+ ++Update the class definition in p2: +
+ ++ +// 23.3.6.3 data access +pointerT * data(); +const_pointerconst T * data() const; ++23.4.1.3 [vector.data] +
+ ++Adjust signatures: +
+ ++ + + + + +pointerT * data(); +const_pointerconst T * data() const; +
+1316. scoped_allocator_adaptor operator== has no definition
+Section: 20.10 [allocator.adaptor] Status: WP + Submitter: Pablo Halpern Opened: 2009-02-11 Last modified: 2010-11-24
+View all other issues in [allocator.adaptor].
+View all issues with WP status.
+Discussion:
++The WP +(N3000) +contains these declarations: +
+ +++ +template <class OuterA1, class OuterA2, class... InnerAllocs> + bool operator==(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a, + const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b); +template <class OuterA1, class OuterA2, class... InnerAllocs> + bool operator!=(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a, + const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b);++But does not define what the behavior of these operators are. +
+ +[ +Post-Rapperswil: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Add a new section after 20.10.3 [allocator.adaptor.members]: +
+ +++ + + + + + +Scoped allocator operators [scoped.adaptor.operators]
+ +template <class OuterA1, class OuterA2, class... InnerAllocs> + bool operator==(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a, + const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b);+ ++Returns:+ +a.outer_allocator() == b.outer_allocator()+ifsizeof...(InnerAllocs)is zero; otherwise, +a.outer_allocator() == b.outer_allocator() && +a.inner_allocator() == b.inner_allocator(). +template <class OuterA1, class OuterA2, class... InnerAllocs> + bool operator!=(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a, + const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b);+ ++Returns:+ +!(a == b). +
+1319. Containers should require an iterator that is at least a Forward Iterator
+Section: 23.2.1 [container.requirements.general] Status: WP + Submitter: Alisdair Meredith Opened: 2010-02-16 Last modified: 2010-11-24
+View other active issues in [container.requirements.general].
+View all other issues in [container.requirements.general].
+View all issues with WP status.
+Discussion:
++The requirements on container iterators are spelled out in +23.2.1 [container.requirements.general], table 91. +
+ +++ ++
+Table 91 — Container requirements + ++ + +Expression +Return type +Operational semantics +Assertion/note +
pre-/post-conditionComplexity ++ + ++ ... + + +X::iterator +iterator type whose value type is T ++ any iterator category except output iterator. Convertible to +X::const_iterator. +compile time ++ + +X::const_iterator +constant iterator type whose value type is T ++ any iterator category except output iterator +compile time ++ + ++ ... +As input iterators do not have the multi-pass guarantee, they are not suitable +for iterating over a container. For example, taking two calls to +begin(), incrementing either iterator might invalidate the other. +While data structures might be imagined where this behaviour produces +interesting and useful results, it is very unlikely to meet the full set of +requirements for a standard container. +
+ +[ +Post-Rapperswil: +]
+ + ++Daniel notes: I changed the currently suggested P/R slightly, because it is not robust in regard to new fundamental iterator +catagories. I recommend to say instead that each container::iterator shall satisfy (and thus may refine) the forward +iterator requirements. +
+ ++Moved to Tentatively Ready with revised wording after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ ++
+ + + + + + +- Change Table 93 — Container requirements in [container.requirements.general] as indicated: +
+++ ++
+Table 93 — Container requirements + + ++ + +Expression +Return type +Operational +
semanticsAssertion/note +
pre-/post-conditionComplexity ++ + +... ++ + +X::iterator +iterator type +
whose value
type is T+ any iterator category +except output iterator
that meets the forward iterator requirements. convertible
to
X::const_iteratorcompile time ++ + +X::const_iterator +constant iterator type +
whose value
type is T+ any iterator category +except output iterator
that meets the forward iterator requirements.compile time ++ + +... +
+1321. scoped_allocator_adaptor construct and destroy don't +use allocator_traits
+Section: 20.10.3 [allocator.adaptor.members] Status: Resolved + Submitter: Howard Hinnant Opened: 2010-02-16 Last modified: 2010-11-20
+View all issues with Resolved status.
+Discussion:
++20.10.3 [allocator.adaptor.members] p8-9 says: +
+ ++ ++ +template <class T, class... Args> + void construct(T* p, Args&&... args); ++++ ++8 Effects: let OUTERMOST(x) be x if x +does not have an outer_allocator() function and +OUTERMOST(x.outer_allocator()) otherwise. +
+ ++
+ +- +If uses_allocator<T, inner_allocator_type>::value is +false and is_constructible<T, Args...>::value is +true, calls OUTERMOST(*this).construct(p, +std::forward<Args>(args)...). +
+ +- +Otherwise, if uses_allocator<T, inner_allocator_type>::value is +true and is_constructible<T, allocator_arg_t, +inner_allocator_type, Args...>::value is true, calls +OUTERMOST(*this).construct(p, allocator_arg, +inner_allocator(),std::forward<Args>(args)...). +
+ +- +Otherwise, if uses_allocator<T, inner_allocator_type>::value is +true and is_constructible<T, Args..., +inner_allocator_type>::value is true, calls +OUTERMOST(*this).construct(p, std::forward<Args>(args)..., +inner_allocator()). +
+ +- +Otherwise, the program is ill-formed. [Note: an error will result if +uses_allocator evaluates to true but the specific constructor +does not take an allocator. This definition prevents a silent failure to pass an +inner allocator to a contained element. — end note] +
+template <class T> + void destroy(T* p); +++9 Effects: calls outer_allocator().destroy(p). ++ ++In all other calls where applicable scoped_allocator_adaptor does not +call members of an allocator directly, but rather does so indirectly via +allocator_traits. For example: +
+ +++ +size_type max_size() const; +++7 Returns: +allocator_traits<OuterAlloc>::max_size(outer_allocator()). +++Indeed, without the indirection through allocator_traits the +definitions for construct and destroy are likely to fail at +compile time since the outer_allocator() may not have the members +construct and destroy. +
+ +[ +The proposed wording is a product of Pablo, Daniel and Howard. +]
+ + +[ +2010 Pittsburgh: Moved to NAD Editorial. Rationale added below. +]
+ + + + +Rationale:
++Solved by +N3059. +
+ + +Proposed resolution:
++In 20.10.3 [allocator.adaptor.members] move and change p8 +as indicated, and change p9 as indicated: +
+ ++ ++ + + + + + ++Let OUTERMOST(x) be x if x +does not have an outer_allocator() member function and +OUTERMOST(x.outer_allocator()) otherwise. Let +OUTERMOST_ALLOC_TRAITS(x) be +allocator_traits<decltype(OUTERMOST(x))>. +[Note: OUTERMOST(x) and +OUTERMOST_ALLOC_TRAITS(x) are recursive operations. It is +incumbent upon the definition of outer_allocator() to ensure that the +recursion terminates. It will terminate for all instantiations +of scoped_allocator_adaptor. — end note] + +
+ +template <class T, class... Args> + void construct(T* p, Args&&... args); +++ ++ ++8 Effects:
+ +let OUTERMOST(x) be x if +x does not have an outer_allocator() function and +OUTERMOST(x.outer_allocator()) otherwise.++
+ +- +If uses_allocator<T, inner_allocator_type>::value is +false and is_constructible<T, Args...>::value is +true, calls
+ +OUTERMOST(*this).+OUTERMOST_ALLOC_TRAITS(outer_allocator())::construct( +OUTERMOST(outer_allocator()), p, +std::forward<Args>(args)... ). +- +Otherwise, if uses_allocator<T, inner_allocator_type>::value is +true and is_constructible<T, allocator_arg_t, +inner_allocator_type, Args...>::value is true, calls +
+ +OUTERMOST(*this).+OUTERMOST_ALLOC_TRAITS(outer_allocator())::construct( +OUTERMOST(outer_allocator()), p, allocator_arg, +inner_allocator(), std::forward<Args>(args)... ). +- +Otherwise, if uses_allocator<T, inner_allocator_type>::value is +true and is_constructible<T, Args..., +inner_allocator_type>::value is true, calls +
+ +OUTERMOST(*this).+OUTERMOST_ALLOC_TRAITS(outer_allocator())::construct( +OUTERMOST(outer_allocator()), p, +std::forward<Args>(args)..., inner_allocator() ). +- +Otherwise, the program is ill-formed. [Note: an error will result if +uses_allocator evaluates to true but the specific constructor +does not take an allocator. This definition prevents a silent failure to pass an +inner allocator to a contained element. — end note] +
+template <class T> + void destroy(T* p); +++9 Effects: calls+ +outer_allocator().+OUTERMOST_ALLOC_TRAITS(outer_allocator())::destroy( +OUTERMOST(outer_allocator()), p). +
+1322. Explicit CopyConstructible requirements are insufficient
+Section: 20.2.1 [utility.arg.requirements] Status: Resolved + Submitter: Daniel Krügler Opened: 2010-02-16 Last modified: 2010-11-23
+View all other issues in [utility.arg.requirements].
+View all issues with Resolved status.
+Discussion:
++With the acceptance of library defect 822 only +direct-initialization is supported, and not copy-initialization in the +requirement sets MoveConstructible and CopyConstructible. This +is usually a good thing, if only the library implementation needs to obey these +restrictions, but the Empire strikes back quickly: +
+ ++
+ +- +
+ ++Affects user-code: std::exception_ptr is defined purely via +requirements, among them CopyConstructible. A strict reading of the +standard would make implementations conforming where std::exception_ptr +has an explicit copy-c'tor and user-code must code defensively. This is a very +unwanted effect for such an important component like +std::exception_ptr. +
+- +
+ ++Wrong re-use: Recently proposed requirement sets +(NullablePointer as of +N3025, +Hash) or cleanup of existing requirement sets (e.g. iterator requirements as of +N3046) +tend to reuse existing requirement sets, so reusing CopyConstructible +is attempting, even in cases, where the intend is to support copy-initialization +as well. +
+- +
++Inconsistency: The current iterator requirements set Table 102 (output +iterator requirements) and Table 103 (forward iterator requirements) demonstrate +quite clearly a strong divergence of copy-semantics: The specified semantics of +
+ ++ +X u(a); +X u = a; ++are underspecified compared to the most recent clarifications of the +CopyConstructible requirements, c.f. issue 1309 which is +very unsatisfactory. This will become worse for each further issue that involves +the CopyConstructible specification (for possible directions see 1173). +
++The suggested resolution is to define two further requirements +implicit-MoveConstructible and implicit-CopyConstructible (or +any other reasonable name like MoveConvertible and +CopyConvertible) each with a very succinct but precise meaning solving +all three problems mentioned above. +
+ +[Batavia: Resolved by accepting n3215.]
+ + + + + + + +Proposed resolution:
++
+ + + + + + +- +
+ ++Add the following new table ?? after Table 34 — MoveConstructible +requirements [moveconstructible]: +
+ ++ ++ ++
+Table ?? — Implicit MoveConstructible requirements +[implicit.moveconstructible] (in addition to +MoveConstructible) + ++ + +Expression +Operational Semantics ++ + +T u = rv; +Equivalent to: T u(rv); +- +
+ ++Add the following new table ?? after Table 35 — CopyConstructible +requirements [copyconstructible]: +
+ ++ ++ ++
+Table ?? — Implicit CopyConstructible requirements +[implicit.copyconstructible] (in addition to +CopyConstructible) + ++ + +Expression +Operational Semantics ++ + +T u = v; +Equivalent to: T u(v); +- +
+ ++Change 20.2.3 [nullablepointer.requirements]/1 as follows: +
+ ++++A NullablePointer type is a pointer-like type that supports null +values. A type P meets the requirements of NullablePointer if: +
+ ++
+- +P satisfies the requirements of EqualityComparable, +DefaultConstructible, implicit CopyConstructible, +CopyAssignable, and Destructible, +
+ +- [..]
+- +
+ ++Change 20.2.4 [hash.requirements]/1 as indicated: [explicit +copy-constructible functors could not be provided as arguments +to any algorithm that takes these by value. Also a typo is fixed.] +
+ +++ ++1 A type H meets the Hash requirements if: +
++
+ +- +it is a function object type (20.8), +
+- +it satisfies
+ifesthe requirements of +implicit CopyConstructible and Destructible +(20.2.1), +- +[..] +
+- +
+ ++Change 20.7.1 [meta.rqmts]/1+2 as indicated: +
+ +++ ++1 A UnaryTypeTrait describes a property of a type. It shall be a class +template that takes one template type argument and, optionally, additional +arguments that help define the property being described. It shall be +DefaultConstructible, implicit CopyConstructible, +[..] +
+ ++2 A BinaryTypeTrait describes a relationship between two types. It +shall be a class template that takes two template type arguments and, +optionally, additional arguments that help define the relationship being +described. It shall be DefaultConstructible, +implicit CopyConstructible, and [..] +
+ +- +
+ ++Change 20.8.2 [func.require]/4 as indicated: [explicit +copy-constructible functors could not be provided as arguments to any algorithm +that takes these by value] +
+ ++4 Every call wrapper (20.8.1) shall be implicit +MoveConstructible. A simple call wrapper is a call wrapper that is +implicit CopyConstructible and CopyAssignable and +whose copy constructor, move constructor, and assignment operator do not throw +exceptions. [..] ++- +
+ ++Change 20.8.4 [refwrap]/1 as indicated: +
+ ++1 reference_wrapper<T> is an implicit +CopyConstructible and CopyAssignable wrapper around a +reference to an object or function of type T. ++- +
+ ++Change 20.8.10.1.2 [func.bind.bind]/5+9 as indicated: +
+ +++ ++5 Remarks: The return type shall satisfy the requirements of +implicit MoveConstructible. If all of FD and +TiD satisfy the requirements of CopyConstructible, then the +return type shall satisfy the requirements of implicit +CopyConstructible. [Note: this implies that all of FD and +TiD are MoveConstructible. — end note] +
+ ++[..] +
+ ++9 Remarks: The return type shall satisfy the requirements of +implicit MoveConstructible. If all of FD and +TiD satisfy the requirements of CopyConstructible, then the +return type shall satisfy the requirements of implicit +CopyConstructible. [Note: this implies that all of FD and +TiD are MoveConstructible. — end note] +
+- +
+ ++Change 20.8.10.1.3 [func.bind.place] as indicated: +
+ ++1 All placeholder types shall be DefaultConstructible and +implicit CopyConstructible, and [..] ++- +
+ ++Change 20.9.9 [unique.ptr]/5 as indicated: +
+ ++5 Each object of a type U instantiated form the unique_ptr +template specified in this subclause has the strict ownership semantics, +specified above, of a unique pointer. In partial satisfaction of these +semantics, each such U is implicit +MoveConstructible and MoveAssignable, but is not +CopyConstructible nor CopyAssignable. The template parameter +T of unique_ptr may be an incomplete type. ++- +
+ ++Change 20.9.10.2 [util.smartptr.shared]/2 as indicated: +
+ ++2 Specializations of shared_ptr shall be +implicit CopyConstructible, CopyAssignable, and +LessThanComparable, [..] ++- +
+ ++Change 20.9.10.3 [util.smartptr.weak]/2 as indicated: +
+ ++2 Specializations of weak_ptr shall be implicit +CopyConstructible and CopyAssignable, allowing their use in +standard containers. The template parameter T of weak_ptr may +be an incomplete type. ++- +
+ ++Change 24.2.2 [iterator.iterators]/2 as indicated: [This fixes a +defect in the Iterator requirements. None of the usual algorithms accepting +iterators would be usable with iterators with explicit copy-constructors] +
+ +++ ++2 A type X satisfies the Iterator requirements if: +
+ ++
+ +- +X satisfies the implicit CopyConstructible, +CopyAssignable, and Destructible requirements (20.2.1) +and lvalues of type X are swappable (20.2.2), and [..] +
+- ...
+- +
+ ++Change D.12.1 [auto.ptr]/3 as indicated: +
+ ++3 [..] Instances of auto_ptr meet the requirements of +implicit MoveConstructible and MoveAssignable, but +do not meet the requirements of CopyConstructible and +CopyAssignable. — end note] ++
+1323. basic_string::replace should use const_iterator
+Section: 21.4.6.6 [string::replace] Status: WP + Submitter: Daniel Krügler Opened: 2010-02-19 Last modified: 2010-11-24
+View all other issues in [string::replace].
+View all issues with WP status.
+Discussion:
+ ++In contrast to all library usages of purely positional iterator values several +overloads of std::basic_string::replace still use iterator instead of +const_iterator arguments. The paper +N3021 +quite nicely visualizes the purely positional responsibilities of the function +arguments. +
+ ++This should be fixed to make the library consistent, the proposed changes are +quite mechanic. +
+ +[ +Post-Rapperswil: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++ +
+ + + + + + +- +
+ ++In 21.4 [basic.string], class template basic_string synopsis +change as indicated: +
+ ++// 21.4.6 modifiers: +... +basic_string& replace(const_iterator i1, const_iterator i2, + const basic_string& str); +basic_string& replace(const_iterator i1, const_iterator i2, + const charT* s, size_type n); +basic_string& replace(const_iterator i1, const_iterator i2, + const charT* s); +basic_string& replace(const_iterator i1, const_iterator i2, + size_type n, charT c); +template<class InputIterator> + basic_string& replace(const_iterator i1, const_iterator i2, + InputIterator j1, InputIterator j2); +basic_string& replace(const_iterator, const_iterator, + initializer_list<charT>); +- +
+ ++In 21.4.6.6 [string::replace] before p.18, change the following signatures +as indicated: +
+ ++basic_string& replace(const_iterator i1, const_iterator i2, const basic_string& str); +- +
+ ++In 21.4.6.6 [string::replace] before p.21, change the following signatures +as indicated: +
+ ++basic_string& + replace(const_iterator i1, const_iterator i2, const charT* s, size_type n); +- +
+ ++In 21.4.6.6 [string::replace] before p.24, change the following signatures +as indicated: +
+ ++basic_string& replace(const_iterator i1, const_iterator i2, const charT* s); +- +
+ ++In 21.4.6.6 [string::replace] before p.27, change the following signatures +as indicated: +
+ ++basic_string& replace(const_iterator i1, const_iterator i2, size_type n, + charT c); +- +
+ ++In 21.4.6.6 [string::replace] before p.30, change the following signatures +as indicated: +
+ ++template<class InputIterator> + basic_string& replace(const_iterator i1, const_iterator i2, + InputIterator j1, InputIterator j2); +- +
+ ++In 21.4.6.6 [string::replace] before p.33, change the following signatures +as indicated: +
+ ++basic_string& replace(const_iterator i1, const_iterator i2, + initializer_list<charT> il); +
+1324. Still too many implicit conversions for pair and tuple
+Section: 20.3.5.2 [pairs.pair], 20.4.2.1 [tuple.cnstr] Status: Resolved + Submitter: Daniel Krügler Opened: 2010-03-20 Last modified: 2010-11-26
+View all other issues in [pairs.pair].
+View all issues with Resolved status.
+Discussion:
++In analogy to library defect 811, tuple's variadic +constructor +
+ ++ +template <class... UTypes> +explicit tuple(UTypes&&... u); ++creates the same problem as pair: +
+ ++ +#include <tuple> + +int main() +{ + std::tuple<char*> p(0); +} ++produces a similar compile error for a recent gcc implementation. +
+ ++I suggest to follow the same resolution path as has been applied to +pair's corresponding c'tor, that is require that these c'tors should +not participate in overload resolution, if the arguments are not implicitly +convertible to the element types. +
+ ++Further-on both pair and tuple provide converting constructors +from different pairs/tuples that should be not available, if +the corresponding element types are not implicitly convertible. It seems +astonishing that in the following example +
+ ++ +struct A { + explicit A(int); +}; + +A a = 1; // Error + +std::tuple<A> ta = std::make_tuple(1); // # OK? ++the initialization marked with # could be well-formed. +
+ +[ +Only constraints on constructors are suggested. Adding similar constraints on +assignment operators is considered as QoI, because the assigments wouldn't be +well-formed anyway. +]
+ + ++ +
+- +
+ ++Following 20.3.5.2 [pairs.pair]/5 add a new Remarks element: +
+ ++ +template<class U, class V> pair(const pair<U, V>& p); ++ ++++5 Effects: Initializes members from the corresponding members of the +argument
+ +, performing implicit conversions as needed. ++Remarks: This constructor shall not participate in overload +resolution unless U is implicitly convertible to first_type +and V is implicitly convertible to second_type. +
+- +
+ ++Following 20.3.5.2 [pairs.pair]/6 add a new Remarks element: +
+ ++template<class U, class V> pair(pair<U, V>&& p); ++ ++++6 Effects: The constructor initializes first with +std::move(p.first) and second with std::move(p.second). +
+ ++Remarks: This constructor shall not participate in overload +resolution unless U is implicitly convertible to first_type +and V is implicitly convertible to second_type. +
+- +
+ ++Following 20.4.2.1 [tuple.cnstr]/7 add a new Remarks element: +
+ ++template <class... UTypes> +explicit tuple(UTypes&&... u); ++ ++++6 Requires: Each type in Types shall satisfy the requirements of +MoveConstructible (Table 33) from the corresponding type in +UTypes. sizeof...(Types) == sizeof...(UTypes). +
+ ++7 Effects: Initializes the elements in the tuple with the +corresponding value in std::forward<UTypes>(u). +
+ ++Remarks: This constructor shall not participate in overload +resolution unless each type in UTypes is implicitly convertible to its +corresponding type in Types. +
+- +
+ ++Following 20.4.2.1 [tuple.cnstr]/13 add a new Remarks element: +
+ ++template <class... UTypes> tuple(const tuple<UTypes...>& u); ++ ++++12 Requires: Each type in Types shall be constructible from the +corresponding type in UTypes. sizeof...(Types) == +sizeof...(UTypes). +
+ ++13 Effects: Constructs each element of *this with the +corresponding element of u. +
+ ++Remarks: This constructor shall not participate in overload +resolution unless each type in UTypes is implicitly convertible to its +corresponding type in Types. +
+ ++14 [Note: enable_if can be used to make the converting +constructor and assignment operator exist only in the cases where the source and +target have the same number of elements. — end note] +
+- +
+ ++Following 20.4.2.1 [tuple.cnstr]/16 add a new Remarks element: +
+ ++template <class... UTypes> tuple(tuple<UTypes...>&& u); ++ ++++15 Requires: Each type in Types shall shall satisfy the +requirements of MoveConstructible (Table 33) from the corresponding +type in UTypes. sizeof...(Types) == sizeof...(UTypes). +
+ ++16 Effects: Move-constructs each element of *this with the +corresponding element of u. +
+ ++Remarks: This constructor shall not participate in overload +resolution unless each type in UTypes is implicitly convertible to its +corresponding type in Types. +
+ ++[Note: enable_if can be used to make the converting constructor +and assignment operator exist only in the cases where the source and target have +the same number of elements. — end note] +
+- +
+ ++Following 20.4.2.1 [tuple.cnstr]/18 add a new Remarks element: +
+ ++template <class U1, class U2> tuple(const pair<U1, U2>& u); ++ ++++17 Requires: The first type in Types shall be constructible from +U1 and the second type in Types shall be constructible from +U2. sizeof...(Types) == 2. +
+ ++18 Effects: Constructs the first element with u.first and the +second element with u.second. +
+ ++Remarks: This constructor shall not participate in overload +resolution unless U1 is implicitly convertible to the first type in +Types and U2 is implicitly convertible to the second type in +Types. +
+- +
+ ++Following 20.4.2.1 [tuple.cnstr]/20 add a new Remarks element: +
+ ++template <class U1, class U2> tuple(pair<U1, U2>&& u); ++ ++++19 Requires: The first type in Types shall shall satisfy the +requirements of MoveConstructible(Table 33) from U1 and the +second type in Types shall be move-constructible from U2. +sizeof...(Types) == 2. +
+ ++20 Effects: Constructs the first element with std::move(u.first) +and the second element with std::move(u.second) +
+ ++Remarks: This constructor shall not participate in overload +resolution unless U1 is implicitly convertible to the first type in +Types and U2 is implicitly convertible to the second type in +Types. +
+[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3140 would solve this issue. ++ + +Proposed resolution:
+See n3140. + + + + + + +
+1325. bitset
+Section: 20.5.1 [bitset.cons] Status: WP + Submitter: Christopher Jefferson Opened: 2010-03-07 Last modified: 2010-11-23
+View all other issues in [bitset.cons].
+View all issues with WP status.
+Discussion:
++As mentioned on the boost mailing list: +
+ ++The following code, valid in C++03, is broken in C++0x due to ambiguity +between the "unsigned long long" and "char*" +constructors. +
+ ++ +#include <bitset> +std::bitset<10> b(0); +[ +The proposed resolution has been reviewed by Stephan T. Lavavej. +]
+ + +[ +Post-Rapperswil +]
+ + ++The proposed resolution has two problems: +
++
+ +- +
+it fails to provide support for non-terminated strings, which +could be easily added and constitutes an important use-case. For +example, the following code would invoke UB with the current +P/R:
+++because it requires the evaluation (under the as-if rule, to be fair, +but it doesn't matter) of basic_string<char>(s) +char s[4] = { '0', '1', '0', '1' }; // notice: not null-terminated! +bitset<4> b(s, 0, 4); +- +
+it promotes a consistency between the two bitset +constructors that take a const std::string& and a +const char*, respectively, while practice established by +std::basic_string would recommend a different set of +parameters. In particular, the constructor of +std::basic_string that takes a const char* does +not have a pos parameter
++Moved to Tentatively Ready with revised wording provided by Alberto Ganesh Babati after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ + ++
+ + + + + + +- In the synopsis of header <bitset> in +20.5 [template.bitset]/1, replace the fourth bitset constructor: +
+++explicit bitset(const char *str);+template <class charT> + explicit bitset( + const charT *str, + typename basic_string<charT>::size_type n = basic_string<charT>::npos, + charT zero = charT('0'), charT one = charT('1')); +- In 20.5.1 [bitset.cons]/8: +
+++Effects: Constructs an object of class +bitset<N> as if by +explicit bitset(const char *str);+template <class charT> +explicit +bitset(const charT *str, + typename basic_string<charT>::size_type n = basic_string<charT>::npos, + charT zero = charT('0'), charT one = charT('1')); +bitset(string(str)).+++bitset( + n == basic_string<charT>::npos + ? basic_string<charT>(str) + : basic_string<charT>(str, n), + 0, n, zero, one) +
+1326. Missing/wrong preconditions for pair and tuple functions
+Section: 20.3.5.2 [pairs.pair], 20.4.2.1 [tuple.cnstr] Status: Resolved + Submitter: Daniel Krügler Opened: 2010-03-07 Last modified: 2010-11-26
+View all other issues in [pairs.pair].
+View all issues with Resolved status.
+Discussion:
++There are several constructors and creation functions of std::tuple +that impose requirements on it's arguments, that are unnecessary +restrictive and don't match the intention for the supported argument +types. This is related to the fact that tuple is supposed to accept both +object types and lvalue-references and the usual MoveConstructible and +CopyConstructible requirements are bad descriptions for non-const +references. Some examples: +
+ ++
+ +- +
+ ++20.4.2.1 [tuple.cnstr] before p.4 and p.8, resp.: +
+ ++ +explicit tuple(const Types&...); +++4 Requires: Each type in Types shall be copy constructible. ++ +tuple(const tuple& u) = default; +++8 Requires: Each type in Types shall satisfy the requirements of +CopyConstructible (Table 34). + +++A tuple that contains lvalue-references to non-const can never +satisfy the CopyConstructible requirements. CopyConstructible +requirements refine the MoveConstructible requirements and +this would require that these lvalue-references could bind +rvalues. But the core language does not allow that. Even, if we +would interpret that requirement as referring to the underlying +non-reference type, this requirement would be wrong as well, +because there is no reason to disallow a type such as +
+ ++ +struct NoMoveNoCopy { + NoMoveNoCopy(NoMoveNoCopy&&) = delete; + NoMoveNoCopy(const NoMoveNoCopy&) = delete; + ... +}: ++for the instantiation of std::tuple<NoMoveNoCopy&> and +that of it's copy constructor. +
+ ++A more reasonable requirement for this example would be to require that +"is_constructible<Ti, const Ti&>::value shall +evaluate to true for all Ti in Types". In this case +the special reference-folding and const-merging rules of references +would make this well-formed in all cases. We could also add the further +constraint "if Ti is an object type, it shall satisfy the +CopyConstructible requirements", but this additional +requirement seems not really to help here. Ignoring it would only mean +that if a user would provide a curious object type C that +satisfies the std::is_constructible<C, const C&> +test, but not the "C is CopyConstructible" test would +produce a tuple<C> that does not satisfy the +CopyConstructible requirements as well. +
+- +
++20.4.2.1 [tuple.cnstr] before p.6 and p.10, resp.: +
+ ++ +template <class... UTypes> +explicit tuple(UTypes&&... u); ++ ++6 Requires: Each type in Types shall satisfy the +requirements of MoveConstructible (Table 33) from the +corresponding type in UTypes. sizeof...(Types) == +sizeof...(UTypes). ++ +tuple(tuple&& u); +++10 Requires: Each type in Types shall shall +satisfy the requirements of MoveConstructible (Table 33). +++We have a similar problem as in (a): Non-const lvalue-references +are intended template arguments for std::tuple, but cannot satisfy +the MoveConstructible requirements. In this case the correct +requirements would be +
+ ++is_constructible<Ti, Ui>::value shall evaluate to true +for all Ti in Types and for all Ui in +UTypes ++ ++and +
+ ++is_constructible<Ti, Ti>::value shall evaluate to true +for all Ti in Types ++ ++respectively. +
++Many std::pair member functions do not add proper requirements, e.g. +the default c'tor does not require anything. This is corrected within the +suggested resolution. Further-on the P/R has been adapted to the FCD numbering. +
+ +[ +2010-03-25 Daniel updated wording: +]
+ + ++The issue became updated to fix some minor inconsistencies and to ensure a +similarly required fix for std::pair, which has the same specification +problem as std::tuple, since pair became extended to support +reference members as well. ++ +[Original proposed resolution:]
+ ++ +
+ + +- +
+ ++Change 20.3.5.2 [pairs.pair]/1 as indicated [The changes for the effects +elements are not normative changes, they just ensure +harmonization with existing wording style]: +
+ ++ +constexpr pair(); ++ ++++Requires: first_type and second_type shall satisfy +the DefaultConstructible requirements. +
+ ++1 Effects: Value-initializes first and +second.
+ +Initializes its members as if implemented: pair() +: first(), second() { }.+- +
+ ++Change 20.3.5.2 [pairs.pair]/2 as indicated: +
+ ++ +pair(const T1& x, const T2& y); ++ ++++Requires: is_constructible<T1, const T1&>::value +is true and is_constructible<T2, const T2&>::value +is true. +
+ ++2 Effects: The constructor initializes first with x and +second with y. +
+ +- +
+ ++Change 20.3.5.2 [pairs.pair]/3 as indicated: +
+ ++ +template<class U, class V> pair(U&& x, V&& y); ++ ++++Requires: is_constructible<first_type, U>::value is +true and is_constructible<second_type, V>::value is +true. +
+ ++3 Effects: The constructor initializes first with +std::forward<U>(x) and second with +std::forward<V>(y). +
+ ++4 Remarks: If U is not implicitly convertible to +first_type or V is not implicitly convertible to +second_type this constructor shall not participate in overload +resolution. +
+ +- +
+ ++Change 20.3.5.2 [pairs.pair]/5 as indicated [The change in the effects +element should be non-normatively and is in compatible to the change suggestion +of 1324]: +
+ ++ +template<class U, class V> pair(const pair<U, V>& p); ++ ++++Requires: is_constructible<first_type, const +U&>::value is true and is_constructible<second_type, +const V&>::value is true. +
+ ++5 Effects: Initializes members from the corresponding members of the +argument
+ +, performing implicit conversions as needed. +- +
+ ++Change 20.3.5.2 [pairs.pair]/6 as indicated: +
+ ++template<class U, class V> pair(pair<U, V>&& p); ++ ++++Requires: is_constructible<first_type, U>::value is +true and is_constructible<second_type, V>::value is +true. +
+ ++6 Effects: The constructor initializes first with +std::
+moveforward<U>(p.first) and +second with +std::moveforward<V>(p.second). +- +
+ ++Change 20.3.5.2 [pairs.pair]/7+8 as indicated [The deletion in the effects +element should be non-normatively]: +
+ ++ +template<class... Args1, class... Args2> + pair(piecewise_construct_t, + tuple<Args1...> first_args, tuple<Args2...> second_args); ++ ++++7 Requires: is_constructible<first_type, +Args1...>::value is true and +is_constructible<second_type, Args2...>::value is +true.
+ +All the types in Args1 and Args2 +shall be CopyConstructible (Table 35). T1 shall be +constructible from Args1. T2 shall be constructible from +Args2.++8 Effects: The constructor initializes first with arguments of +types Args1... obtained by forwarding the elements of +first_args and initializes second with arguments of types +Args2... obtained by forwarding the elements of second_args. +
+ +(Here, forwarding an element x of type U within a +tuple object means calling std::forward<U>(x).)+This form of construction, whereby constructor arguments for first and +second are each provided in a separate tuple object, is called +piecewise construction. +- +
+ ++Change 20.3.5.2 [pairs.pair] before 12 as indicated: +
+ ++ +pair& operator=(pair&& p); ++ ++++Requires: first_type and second_type shall satisfy +the MoveAssignable requirements. +
+ ++12 Effects: Assigns to first with std::move(p.first) +and to second with std::move(p.second). +
+ ++13 Returns: *this. +
+ +- +
+ ++Change [pairs.pair] before 14 as indicated: [The heterogeneous usage +of MoveAssignable is actually not defined, +but the library uses it at several places, so we follow this tradition +until a better term has been agreed on. One +alternative could be to write "first_type shall be assignable from an +rvalue of U [..]"] +
+ ++ +template<class U, class V> pair& operator=(pair<U, V>&& p); ++ ++ +++Requires: first_type shall be MoveAssignable from +U and second_type shall be MoveAssignable from +V. +
+ ++14 Effects: Assigns to first with std::move(p.first) +and to second with std::move(p.second). +
+ ++15 Returns: *this. +
+ +- +
+ ++Change 20.4.2.1 [tuple.cnstr]/4+5 as indicated: +
+ ++ +explicit tuple(const Types&...); ++ ++++4 Requires: is_constructible<Ti, const +Ti&>::value == true for e
+ +Each type +Ti in Typesshall be copy +constructible. ++5 Effects:
+ +Copy iInitializes each element with the +value of the corresponding parameter. +- +
+ ++Change 20.4.2.1 [tuple.cnstr]/6 as indicated: +
+ ++template <class... UTypes> +explicit tuple(UTypes&&... u); ++ ++++6 Requires: is_constructible<Ti, Ui>::value == +true for e
+ +Each type Ti in +Typesshall satisfy the requirements of +MoveConstructible (Table 33) fromand for the +corresponding type Ui in UTypes. +sizeof...(Types) == sizeof...(UTypes). ++7 Effects: Initializes the elements in the tuple with the +corresponding value in std::forward<UTypes>(u). +
+ +- +
+ ++Change 20.4.2.1 [tuple.cnstr]/8+9 as indicated: +
+ ++tuple(const tuple& u) = default; ++ ++++8 Requires: is_constructible<Ti, const +Ti&>::value == true for e
+ +Each type +Ti in Typesshall satisfy the +requirements of CopyConstructible(Table 34). ++9 Effects: Initializes
+ +Copy constructseach element +of *this with the corresponding element of u. +- +
+ ++Change 20.4.2.1 [tuple.cnstr]/10+11 as indicated: +
+ ++tuple(tuple&& u); ++ ++++10 Requires: Let i be in [0, sizeof...(Types)) and +let Ti be the ith type in Types. +Then is_constructible<Ti, Ti>::value shall be true for +all i.
+ +Each type in Types shall shall satisfy the +requirements of MoveConstructible (Table 34). ++11 Effects: For each Ti in Types, initializes the +ith
+Move-constructs eachelement of +*this withthe corresponding element of+std::forward<Ti>(get<i>(u)). +- +
+ ++Change 20.4.2.1 [tuple.cnstr]/15+16 as indicated: +
+ ++ +template <class... UTypes> tuple(tuple<UTypes...>&& u); ++ ++++15 Requires: Let i be in [0, sizeof...(Types)), +Ti be the ith type in Types, and +Ui be the ith type in UTypes. Then +is_constructible<Ti, Ui>::value shall be true for all +i.
+ +Each type in Types shall shall satisfy the +requirements of MoveConstructible (Table 34) from the corresponding +type in UTypes. sizeof...(Types) == sizeof...(UTypes). ++16 Effects: For each type Ti, initializes the +ith
+ +Move-constructs eachelement of +*this withthe corresponding element of+std::forward<Ui>(get<i>(u)). +- +
+ ++Change 20.4.2.1 [tuple.cnstr]/19+20 as indicated: +
+ ++template <class U1, class U2> tuple(pair<U1, U2>&& u); ++ ++++19 Requires: is_constructible<T1, U1>::value == +true for t
+ +The first type +T1 in Typesshall shall satisfy the +requirements of MoveConstructible(Table 33) from +U1and is_constructible<T2, U2>::value == +true for the second type T2 in +Typesshall be move-constructible from U2. +sizeof...(Types) == 2. ++20 Effects: Initializes
+ +Constructsthe first +element with +std::forward<U1>move(u.first) and +the second element with +std::forward<U2>move(u.second). +- +
++Change 20.4.2.4 [tuple.creation]/9-16 as indicated: +
+ ++template <class... TTypes, class... UTypes> +tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>& t, const tuple<UTypes...>& u); ++ +++ ++9 Requires: is_constructible<Ti, const +Ti&>::value == true for each type Ti
+ +All +the typesin TTypesshall be +CopyConstructible (Table 34). +is_constructible<Ui, const Ui&>::value == true +for each type UiAll the typesin +UTypesshall be CopyConstructible (Table +34). ++10 Returns: A tuple object constructed by +initializing
+copy constructingits first +sizeof...(TTypes) elements from the corresponding elements of +t and initializingcopy constructingits +last sizeof...(UTypes) elements from the corresponding elements +of u. +template <class... TTypes, class... UTypes> +tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&& t, const tuple<UTypes...>& u); ++ +++ ++11 Requires: Let i be in [0, sizeof...(TTypes)), +Ti be the ith type in Types, +j be in [0, sizeof...(UTypes)), and Uj be the +jth type in UTypes. +is_constructible<Ti, Ti>::value shall be true for each +type Ti and is_constructible<Uj, const Uj&>::value +shall be true for each type Uj
+ +All the types in +TTypes shall be MoveConstructible (Table 34). All the types in +UTypes shall be CopyConstructible (Table 35). ++12 Returns: A tuple object constructed by initializing the +ith element with +std::forward<Ti>(get<i>(t)) for all Ti in +TTypes and initializing the +(j+sizeof...(TTypes))th element with +get<j>(u) for all Uj in UTypes.
+move +constructing its first sizeof...(TTypes) elements from the +corresponding elements of t and copy constructing its last +sizeof...(UTypes) elements from the corresponding elements of +u. +template <class... TTypes, class... UTypes> +tuple<TTypes..., UTypes...> tuple_cat(const tuple<TTypes...>& t, tuple<UTypes...>&& u); ++ +++ ++13 Requires: Let i be in [0, sizeof...(TTypes)), +Ti be the ith type in Types, +j be in [0, sizeof...(UTypes)), and Uj be the +jth type in UTypes. +is_constructible<Ti, const Ti&>::value shall be true +for each type Ti and is_constructible<Uj, Uj>::value +shall be true for each type Uj
+ +All the types in +TTypes shall be CopyConstructible (Table 35). All the types in +UTypes shall be MoveConstructible (Table 34). ++14 Returns: A tuple object constructed by initializing the +ith element with get<i>(t) for each +type Ti and initializing the +(j+sizeof...(TTypes))th element with +std::forward<Uj>(get<j>(u)) for each type Uj +
+copy constructing its first sizeof...(TTypes) elements from the +corresponding elements of t and move constructing its last +sizeof...(UTypes) elements from the corresponding elements of +u. +template <class... TTypes, class... UTypes> +tuple<TTypes..., UTypes...> tuple_cat(tuple<TTypes...>&& t, tuple<UTypes...>&& u); ++ ++++15 Requires: Let i be in [0, sizeof...(TTypes)), +Ti be the ith type in Types, +j be in [0, sizeof...(UTypes)), and Uj be the +jth type in UTypes. +is_constructible<Ti, Ti>::value shall be true for each +type Ti and is_constructible<Uj, Uj>::value shall be +true for each type Uj
+ +All the types in +TTypes shall be MoveConstructible (Table 34). All the types in +UTypes shall be MoveConstructible (Table 34). ++16 Returns: A tuple object constructed by initializing the +ith element with +std::forward<Ti>(get<i>(t)) for each type Ti and +initializing the (j+sizeof...(TTypes))th element with +std::forward<Uj>(get<j>(u)) for each type Uj +
+move constructing its first sizeof...(TTypes) elements from the +corresponding elements of t and move constructing its last +sizeof...(UTypes) elements from the corresponding elements of +u. +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3140 would solve this issue. ++ + +Proposed resolution:
+See n3140. + + + + + + +
+1327. templates defined in <cmath> replacing C macros with the same name
+Section: 26.8 [c.math] Status: Resolved + Submitter: Michael Wong Opened: 2010-03-07 Last modified: 2010-11-29
+View all other issues in [c.math].
+View all issues with Resolved status.
+Discussion:
++In 26.8 [c.math]p12 +The templates defined in <cmath> replace the C99 macros +with the same names. The templates have the following declarations: +
+ ++ +namespace std { +template <class T> bool signbit(T x); +template <class T> int fpclassify(T x); +template <class T> bool isfinite(T x); +template <class T> bool isinf(T x); +template <class T> bool isnan(T x); +template <class T> bool isnormal(T x); +template <class T> bool isgreater(T x, T y); +template <class T> bool isgreaterequal(T x, T y); +template <class T> bool isless(T x, T y); +template <class T> bool islessequal(T x, T y); +template <class T> bool islessgreater(T x, T y); +template <class T> bool isunordered(T x, T y); +} ++and p13: +
+ ++13 The templates behave the same as the C99 macros with corresponding +names defined in C99 7.12.3, Classification macros, and C99 7.12.14, +Comparison macros in the C standard. ++ ++The C Std versions look like this: +
+ +++ ++7.12.14.1/p1: +
++++Synopsis +
++1 #include <math.h> +
+int isgreaterequal(real-floating x, real-floating y); +++which is not necessarily the same types as is required by C++ since the +two parameters may be different. Would it not be better if it were truly +aligned with C? +
+ +[ +2010 Pittsburgh: Bill to ask WG-14 if heterogeneous support for the +two-parameter macros is intended. +]
+ + +[ +2010-09-13 Daniel comments: +]
+ + ++I recommend to resolve this issue as NAD Editorial because +the accepted resolution for NB comment US-136 +by motion 27 does address this. ++ +[ +2010-09-14 Bill comments: +]
+ + ++Motion 27 directly addresses LWG 1327 and solves the problem +presented there. Moreover, the solution has been aired before +WG14 with no dissent. These functions now behave the same for +mixed-mode calls in both C and C++ ++ + + +Proposed resolution:
+Apply proposed resolution for US-136 + + + + + +
+1328. istream extractors not setting failbit if eofbit is already set
+Section: 27.7.1.1.3 [istream::sentry] Status: Resolved + Submitter: Paolo Carlini Opened: 2010-02-17 Last modified: 2010-11-26
+View all other issues in [istream::sentry].
+View all issues with Resolved status.
+Discussion:
++basing on the recent discussion on the library reflector, see c++std-lib-27728 +and follow ups, I hereby formally ask for LWG 419 to be re-opened, the rationale +being that according to the current specifications, per +n3000, +it seems actually impossible to seek away from end of file, contrary to the +rationale which led 342 to its closure as NAD. My request is also +supported by Martin Sebor, and I'd like also to add, as tentative proposed +resolution for the re-opened issue, the wording suggested by Sebor, thus, change +the beginning of 27.7.1.1.3 [istream::sentry]/2, to: +
+ ++2 Effects: If (!noskipws && !is.good()) is ++ +falsetrue, calls is.setstate(failbit). +Otherwise prepares for formatted or unformatted input. ... +[ +2010-10 Batavia" +]
+ ++Resolved by adopting n3168. +
+ ++Previous proposed resolution: +
+Change 27.7.1.1.3 [istream::sentry]/2: +
+ ++2 Effects: If (!noskipws && !is.good()) is ++ + + + + + +falsetrue, calls is.setstate(failbit). +Otherwise prepares for formatted or unformatted input. ... +Proposed resolution:
+Addressed by paper n3168. + + + + + +
+1333. Missing forwarding during std::function invocation
+Section: 20.8.14.2.4 [func.wrap.func.inv] Status: WP + Submitter: Daniel Krügler Opened: 2010-03-26 Last modified: 2010-11-23
+View all other issues in [func.wrap.func.inv].
+View all issues with WP status.
+Discussion:
++The current wording of 20.8.14.2.4 [func.wrap.func.inv]/1: +
+ ++ +R operator()(ArgTypes... args) const ++ ++Effects: INVOKE(f, t1, t2, ..., tN, R) (20.8.2), where +f is the target object (20.8.1) of *this and t1, t2, ..., +tN are the values in args.... +++uses an unclear relation between the actual args and the used variables +ti. It should be made clear, that std::forward has to be used +to conserve the expression lvalueness. +
+ +[ +Post-Rapperswil: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Change 20.8.14.2.4 [func.wrap.func.inv]/1+2 as indicated: +
+ ++ + + + + + +R operator()(ArgTypes... args) const ++ ++++1 Effects:: INVOKE(f, +std::forward<ArgTypes>(args)...
+ +t1, t2, ..., tN, +R) (20.8.2), where f is the target object (20.8.1) of +*thisand t1, t2, ..., tN are the values in +args.... ++2 Returns: Nothing if R is void, otherwise the return +value of INVOKE(f, +std::forward<ArgTypes>(args)...
+ +t1, t2, ..., tN, +R). ++3 Throws: bad_function_call if !*this; otherwise, any +exception thrown by the wrapped callable object. +
+
+1334. Insert iterators are broken for some proxy containers compared to C++03
+Section: 24.5.2.2.2 [back.insert.iter.op=], 24.5.2.4.2 [front.insert.iter.op=], X [insert.insert.iter.op=] Status: WP + Submitter: Daniel Krügler Opened: 2010-03-28 Last modified: 2010-11-24
+View all issues with WP status.
+Discussion:
++In C++03 this was valid code: +
+ ++ +#include <vector> +#include <iterator> + +int main() { + typedef std::vector<bool> Cont; + Cont c; + std::back_insert_iterator<Cont> it = std::back_inserter(c); + *it = true; +} ++In C++0x this code does no longer compile because of an ambiguity error for this +operator= overload pair: +
+ ++ +back_insert_iterator<Container>& +operator=(typename Container::const_reference value); + +back_insert_iterator<Container>& +operator=(typename Container::value_type&& value); ++This is so, because for proxy-containers like std::vector<bool> +the const_reference usually is a non-reference type and in this case +it's identical to Container::value_type, thus forming the ambiguous +overload pair +
+ ++ +back_insert_iterator<Container>& +operator=(bool value); + +back_insert_iterator<Container>& +operator=(bool&& value); ++The same problem exists for std::back_insert_iterator, +std::front_insert_iterator, and std::insert_iterator. +
+ ++One possible fix would be to require that const_reference of a proxy +container must not be the same as the value_type, but this would break +earlier valid code. The alternative would be to change the first signature to +
+ ++ +back_insert_iterator<Container>& +operator=(const typename Container::const_reference& value); ++This would have the effect that this signature always expects an lvalue +or rvalue, but it would not create an ambiguity relative to the second form with +rvalue-references. [For all non-proxy containers the signature will be the same +as before due to reference-collapsing and const folding rules] +
+ + +[ +Post-Rapperswil +]
+ + ++This problem is not restricted to the unspeakable vector<bool>, but is already existing for other proxy +containers like gcc's rope class. The following code does no longer work ([Bug libstdc++/44963]): +
++#include <iostream> +#include <ext/rope> + +using namespace std; + +int main() +{ + __gnu_cxx::crope line("test"); + auto ii(back_inserter(line)); + + *ii++ = 'm'; // #1 + *ii++ = 'e'; // #2 + + cout << line << endl; +} ++Both lines marked with #1 and #2 issue now an error because the library has properly implemented the current +wording state (Thanks to Paolo Calini for making me aware of this real-life example). +
++The following P/R is a revision of the orignal P/R and was initially suggested by Howard +Hinnant. Paolo verified that the approach works in gcc. +
+ ++Moved to Tentatively Ready with revised wording after 6 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+The wording refers to N3126.
+ ++
+ + + + + + +- Change [back.insert.iterator], class back_insert_iterator synopsis as indicated: +
++template <class Container> +class back_insert_iterator : + public iterator<output_iterator_tag,void,void,void,void> { +protected: + Container* container; +public: + [..] + back_insert_iterator<Container>& + operator=(const typename Container::const_referencevalue_type& value); + back_insert_iterator<Container>& + operator=(typename Container::value_type&& value); + [..] +}; +- Change [back.insert.iter.op=] before p. 1 as indicated: +
++back_insert_iterator<Container>& + operator=(const typename Container::+const_referencevalue_type& value); ++1 Effects: container->push_back(value);
+2 Returns: *this. +- Change [front.insert.iterator], class front_insert_iterator synposis as indicated: +
++template <class Container> +class front_insert_iterator : + public iterator<output_iterator_tag,void,void,void,void> { +protected: + Container* container; +public: + [..] + front_insert_iterator<Container>& + operator=(const typename Container::const_referencevalue_type& value); + front_insert_iterator<Container>& + operator=(typename Container::value_type&& value); + [..] +}; +- Change [front.insert.iter.op=] before p.1 as indicated: +
++front_insert_iterator<Container>& + operator=(const typename Container::+const_referencevalue_type& value); ++1 Effects: container->push_front(value);
+2 Returns: *this. +- Change [insert.iterator], class insert_iterator synopsis as indicated: +
++template <class Container> + class insert_iterator : + public iterator<output_iterator_tag,void,void,void,void> { + protected: + Container* container; + typename Container::iterator iter; + public: + [..] + insert_iterator<Container>& + operator=(const typename Container::const_referencevalue_type& value); + insert_iterator<Container>& + operator=(typename Container::value_type&& value); + [..] + }; +- Change [insert.iter.op=] before p. 1 as indicated: +
++insert_iterator<Container>& + operator=(const typename Container::+const_referencevalue_type& value); ++1 Effects: ++2 Returns: *this. +iter = container->insert(iter, value); + ++iter; +
+1335. Insufficient requirements for tuple::operator<()
+Section: 20.4.2.7 [tuple.rel] Status: WP + Submitter: Joe Gottman Opened: 2010-05-15 Last modified: 2010-11-23
+View all other issues in [tuple.rel].
+View all issues with WP status.
+Discussion:
++The requirements section for std::tuple says the following: +
+ ++Requires: For all i, where 0 <= i and i < +sizeof...(Types), get<i>(t) < get<i>(u) is a valid +expression returning a type that is convertible to bool. +sizeof...(TTypes) == sizeof...(UTypes). ++ ++This is necessary but not sufficient, as the algorithm for comparing +tuples also computes get<i>(u) < get<i>(t) +(note the order) +
+ +[ +Post-Rapperswil +]
+ + ++Moved to Tentatively Ready with updated wording correcting change-bars after 6 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ ++
+ + + + + + +- Change [tuple.rel] before p. 4 as indicated [Remark to the editor: This paragraph doesn't have a number yet, +but it seems to me as if it should have one]: +
++template<class... TTypes, class... UTypes> +bool operator<(const tuple<TTypes...>& t, const tuple<UTypes...>& u); +++Requires: For all i, where 0 <= i and i < sizeof...(Types), +get<i>(t) < get<i>(u) and get<i>(u) < get<i>(t)is +a valid expression returning a type that isare valid expressions returning types that +are convertible to bool. sizeof...(TTypes) == sizeof...(UTypes). +
+1337. Swapped arguments in regex_traits::isctype
+Section: 28.7 [re.traits] Status: WP + Submitter: Howard Hinnant Opened: 2010-06-21 Last modified: 2010-11-24
+View all other issues in [re.traits].
+View all issues with WP status.
+Discussion:
++28.7 [re.traits]/12 describes regex_traits::isctype in terms +of ctype::is(c, m), where c is a charT and m +is a ctype_base::mask. Unfortunately 22.4.1.1.1 [locale.ctype.members] +specifies this function as ctype::is(m, c) +
+ +[ +Post-Rapperswil: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Change 28.7 [re.traits]/12: +
+ ++ + + + + +bool isctype(charT c, char_class_type f) const; +++++11 ... +
++12 Returns: Converts f into a value m of type +std::ctype_base::mask in an unspecified manner, and returns +true if use_facet<ctype<charT> +>(getloc()).is(
+cm,mc) is +true. Otherwise returns true if f bitwise or'ed with +the result of calling lookup_classname with an iterator pair that +designates the character sequence "w" is not equal to 0 and c == +'_', or if f bitwise or'ed with the result of calling +lookup_classname with an iterator pair that designates the character +sequence "blank" is not equal to 0 and c is one of an +implementation-defined subset of the characters for which isspace(c, +getloc()) returns true, otherwise returns false. +
+1338. LWG 1205 incorrectly applied
+Section: 25.2.13 [alg.search] Status: WP + Submitter: Howard Hinnant Opened: 2010-06-25 Last modified: 2010-11-24
+View all other issues in [alg.search].
+View all issues with WP status.
+Discussion:
++LWG 1205 (currently in WP) clarified the return value of several +algorithms when dealing with empty ranges. In particular it recommended for +25.2.13 [alg.search]: +
+ ++ +template<class ForwardIterator1, class ForwardIterator2> + ForwardIterator1 + search(ForwardIterator1 first1, ForwardIterator1 last1, + ForwardIterator2 first2, ForwardIterator2 last2); + +template<class ForwardIterator1, class ForwardIterator2, + class BinaryPredicate> + ForwardIterator1 + search(ForwardIterator1 first1, ForwardIterator1 last1, + ForwardIterator2 first2, ForwardIterator2 last2, + BinaryPredicate pred); +++++1 Effects: ... +
++2 Returns: ... Returns last1 if no such iterator is found. +
++3 Remarks: Returns first1 if [first2,last2) is empty. +
++Unfortunately this got translated to an incorrect specification for what gets +returned when no such iterator is found (N3092): +
+ ++ +template<class ForwardIterator1, class ForwardIterator2> + ForwardIterator1 + search(ForwardIterator1 first1, ForwardIterator1 last1, + ForwardIterator2 first2, ForwardIterator2 last2); + +template<class ForwardIterator1, class ForwardIterator2, + class BinaryPredicate> + ForwardIterator1 + search(ForwardIterator1 first1, ForwardIterator1 last1, + ForwardIterator2 first2, ForwardIterator2 last2, + BinaryPredicate pred); +++++1 Effects: ... +
++2 Returns: ... Returns first1 if [first2,last2) is +empty or if no such iterator is found. +
++LWG 1205 is correct and N3092 is not equivalent nor correct. +
+ ++I have not reviewed the other 10 recommendations of 1205. +
+ +[ +Post-Rapperswil +]
+ + ++It was verified that none of the remaining possibly affected algorithms does have any similar problems and a concrete P/R was added +that used a similar style as has been applied to the other cases. ++ ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++
+ + + + + +- Change [alg.search]/2 as indicated: +
++template<class ForwardIterator1, class ForwardIterator2> + ForwardIterator1 + search(ForwardIterator1 first1, ForwardIterator1 last1, + ForwardIterator2 first2, ForwardIterator2 last2); + +template<class ForwardIterator1, class ForwardIterator2, + class BinaryPredicate> + ForwardIterator1 + search(ForwardIterator1 first1, ForwardIterator1 last1, + ForwardIterator2 first2, ForwardIterator2 last2, + BinaryPredicate pred); +++1 - [...] +
+2 - Returns: The first iterator i in the range [first1,last1 - (last2-first2)) such that for any nonnegative +integer n less than last2 - first2 the following corresponding conditions hold: *(i + n) == *(first2 + n), +pred(*(i + n), *(first2 + n)) != false. Returns first1 if [first2,last2) is emptyor, otherwise + returns last1 if no such iterator is found. +
+1339. uninitialized_fill_n should return the end of its range
+Section: 20.9.8.4 [uninitialized.fill.n] Status: WP + Submitter: Jared Hoberock Opened: 2010-07-14 Last modified: 2010-11-23
+View all issues with WP status.
+Discussion:
++N3092's +specification of uninitialized_fill_n discards useful information and +is inconsistent with other algorithms such as fill_n which accept an +iterator and a size. As currently specified, unintialized_fill_n +requires an additional linear traversal to find the end of the range. +
+ ++Instead of returning void, unintialized_fill_n should return +one past the last iterator it dereferenced. +
+ +[ +Post-Rapperswil: +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++In section 20.9 [memory] change:, +
+ ++ + +template <class ForwardIterator, class Size, class T> +voidForwardIterator uninitialized_fill_n(ForwardIterator first, Size n, const T& x); ++In section 20.9.8.4 [uninitialized.fill.n] change, +
+ ++ + + + + + +template <class ForwardIterator, class Size, class T> ++voidForwardIterator uninitialized_fill_n(ForwardIterator first, Size n, const T& x); ++++1 Effects: +
++for (; n--; ++first) + ::new (static_cast<void*>(&*first)) + typename iterator_traits<ForwardIterator>::value_type(x); +return first; +
+1340. Why does forward_list::resize take the object to be copied by value?
+Section: 23.3.3.4 [forwardlist.modifiers] Status: WP + Submitter: +James McNellis Opened: 2010-07-16 Last modified: 2010-11-24
+View all other issues in [forwardlist.modifiers].
+View all issues with WP status.
+Discussion:
++In +N3092 +23.3.3.4 [forwardlist.modifiers], the resize() member function is +declared as: +
+ ++ +void resize(size_type sz, value_type c); ++The other sequence containers (list, deque, and +vector) take 'c' by const reference. +
+ ++Is there a reason for this difference? If not, then resize() should +be declared as: +
+ ++ +void resize(size_type sz, const value_type& c); ++The declaration would need to be changed both at its declaration in the class +definition at 23.3.3 [forwardlist]/3 and where its behavior is specified +at 23.3.3.4 [forwardlist.modifiers]/22. +
+ ++This would make forward_list consistent with the CD1 issue 679. +
+ +[ +Post-Rapperswil +]
+ + ++Daniel changed the P/R slightly, because one paragraph number has been changed since the issue +had been submitted. He also added a similar Requires element that exists in all other containers with +a resize member function. He deliberately did not touch the wrong usage of "default-constructed" because that +will be taken care of by LWG issue 868. +
+ ++Moved to Tentatively Ready with revised wording after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ + ++
+ + + + + + +- Change [forwardlist]/3, class template forward_list synopsis, as indicated: +
++... +void resize(size_type sz); +void resize(size_type sz, const value_type& c); +void clear(); +... +- Change [forwardlist.modifiers]/27 as indicated: +
+++void resize(size_type sz); +void resize(size_type sz, const value_type& c); +++27 Effects: If sz < distance(begin(), end()), erases the last distance(begin(), end()) - sz elements +from the list. Otherwise, inserts sz - distance(begin(), end()) elements at the end of the list. For the first +signature the inserted elements are default constructed, and for the second signature they are copies of c. ++28 - Requires: T shall be DefaultConstructible for the first form and it shall be CopyConstructible + for the second form.
+
+1344. [FCD] Replace throw() with noexcept
+Section: 17 [library] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Resolved status.
+Duplicate of: 1351
+Discussion:
+Addresses GB-60, CH-16
++Dynamic exception specifications are deprecated; the +library should recognise this by replacing all non-throwing +exception specifications of the form throw() with the +noexcept form. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Replace all non-throwing exception specifications +of the form 'throw()' with the 'noexcept' form. +
+ +[ +2010-10-31 Daniel comments: +]
+ + ++The proposed resolution of n3148 +would satisfy this request. ++ +[ +2010-Batavia: +]
+ ++Resolved by adopting n3148. ++ + + +Proposed resolution:
+See n3148 +See n3150 +See n3195 +See n3155 +See n3156 + + + + + +
+1346. [FCD] Apply noexcept where library specification does not permit exceptions
+Section: 17 [library] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Resolved status.
+Duplicate of: 1352
+Discussion:
+Addresses GB-62, CH-17
++Issues with efficiency and unsatisfactory semantics mean +many library functions document they do not throw +exceptions with a Throws: Nothing clause, but do not +advertise it with an exception specification. The semantic +issues are largely resolved with the new 'noexcept' +specifications, and the noexcept operator means we will +want to detect these guarantees programatically in order +to construct programs taking advantage of the guarantee. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Add a noexcept exception specification on each +libary API that offers an unconditional Throws: +Nothing guarantee. Where the guarantee is +conditional, add the appropriate +noexcept(constant-expression) if an appropriate +constant expression exists. +
+ +[ +2010-10-31 Daniel comments: +]
+ + ++The proposed resolution of n3149 +would satisfy this request. ++ +[ +2010-Batavia: +]
+ ++Resolved by adopting n3149. ++ + + +Proposed resolution:
+This issue is resolved by the adoption of n3195 + + + + + +
+1347. [FCD] Apply noexcept judiciously throughout the library
+Section: 17 [library] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
+View other active issues in [library].
+View all other issues in [library].
+View all issues with Resolved status.
+Discussion:
+Addresses GB-63, US-80
++Since the newly introduced operator noexcept makes it +easy (easier than previously) to detect whether or not a +function has been declared with the empty exception +specification (including noexcept) library functions that +cannot throw should be decorated with the empty +exception specification. Failing to do so and leaving it as a +matter of QoI would be detrimental to portability and +efficiency. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Review the whole library, and apply the noexcept +specification where it is appropriate. +
+ +[ +2010-10-31 Daniel comments: +]
+ + ++The proposed resolution of the combination of n3155, +n3156, +n3157, +n3167 +would satisfy this request. The paper n3150 is related +to this as well. ++ +[ +2010 Batavia: +]
+ ++While the LWG expects to see further papers in this area, sufficient action was taken in Batavia to close the issue as Resolved by the listed papers. +
+ + + +Proposed resolution:
+See n3155, +n3156, +n3157, +n3167 and remotely +n3150 + + + + + +
+1354. [FCD] The definition of deadlock excludes cases involving a single thread
+Section: 17.3.8 [defns.deadlock] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
+View all issues with WP status.
+Discussion:
+Addresses GB-52
++The definition of deadlock in 17.3.7 excludes cases +involving a single thread making it incorrect. +
+ +[ +Resolution proposed by ballot comment +]
+ ++The definition should be corrected. +
+ +[ +2010 Batavia Concurrency group provides a Proposed Resolution +]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+Change 17.3.8 [defns.deadlock] as indicated: ++deadlock ++ + + + + ++
twoone or more threads are unable to continue execution because each is blocked waiting for one or more of the +others to satisfy some condition. +
+1355. [FCD] The definition of move-assignment operator is redundant
+Section: 17.3.16 [defns.move.assign.op] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
+View all issues with Resolved status.
+Discussion:
+Addresses GB-50
++This definition of move-assignment operator is redundant +and confusing now that the term move-assignment +operator is defined by the core language in subclause +12.8p21. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3142 provides a superior resolution. ++ +[ +Resolution proposed by ballot comment +]
+ ++Strike subclause 17.3.16 [defns.move.assign.op]. +Add a cross-reference to (12.8) to 17.3.12. +
+ + + +Proposed resolution:
+Resolved by paper n3142. + + + + + +
+1356. [FCD] The definition of move-constructor is redundant
+Section: 17.3.17 [defns.move.ctor] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
+View all issues with Resolved status.
+Discussion:
+Addresses GB-51
++This definition of move-constructor is redundant and +confusing now that the term constructor is defined by the +core language in subclause 12.8p3. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3142 provides a superior resolution. ++ +[ +2010 Batavia: resolved as NAD Editorial by adopting paper n3142. +]
+ ++Original proposed resolution preserved for reference: +
+++ + + ++Strike subclause 17.3.14, [defns.move.ctor] +
+ +++17.3.14 [defns.move.ctor]
+move constructor a constructor which accepts only an rvalue argument of the type being constructed and might modify the argument as a side effect during construction. +Proposed resolution:
+Resolved by paper n3142. + + + + + +
+1357. [FCD] Library bitmask types to not satisfy the bimask type requirements
+Section: 17.5.2.1.3 [bitmask.types] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
+View all other issues in [bitmask.types].
+View all issues with Resolved status.
+Discussion:
+Addresses GB-53
++The bitmask types defined in 27.5.2 and 28.5 contradict +the bitmask type requirements in 17.5.2.1.3, and have +missing or incorrectly defined operators. +
+ +[ +Resolution proposed by ballot comment +]
+ ++See Appendix 1 - Additional Details +
+ +[ +2010 - Rapperswil +]
+ ++The paper n3110 +was made available during the meeting to resolve this comment, but withdrawn from formal motions +to give others time to review the document. There was no technical objection, and it is expected +that this paper will go forward at the next meeting. +
+ + + +Proposed resolution:
+See n3110. + + + + + +
+1360. [FCD] Add <atomic> to free-standing implementations
+Section: 17.6.1.3 [compliance] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
+View all other issues in [compliance].
+View all issues with WP status.
+Discussion:
+Addresses GB-57
++The atomic operations facility is closely tied to clause 1 +and the memory model. It is not easily supplied as an +after-market extension, and should be trivial to implement +of a single-threaded serial machine. The consequence of +not having this facility will be poor interoperability with +future C++ libraries that memory model concerns +seriously, and attempt to treat them in a portable way. +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add <atomic> to table 15, headers required for a +free-standing implementation. + + + + + +
+1362. [FCD] Description of binding to rvalue-references should use the new 'xvalue' vocabulary
+Section: 17.6.3.9 [res.on.arguments] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
+View all other issues in [res.on.arguments].
+View all issues with WP status.
+Discussion:
+Addresses US-82
++17.6.3.9 [res.on.arguments] p.1. b.3: The second Note can benefit by adopting recent nomenclature. +
+ + +[ +Resolution proposed by the ballot comment: +]
+ ++Rephrase the Note in terms of xvalue. +
+ +[ +Pre-Batavia: +]
+ ++Walter Brown provides wording. +
+ +[Batavia: Immediate]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + +Proposed resolution:
+ ++Amend the note in 17.6.3.9 [res.on.arguments] p1 bullet 3. +
++[ Note: If a program casts an lvalue to an+ + + + + + +rvaluexvalue while passing that lvalue to a library function (e.g. by calling the function with the argument move(x)), the program is effectively asking that function to treat that lvalue as a temporary. The implementation is free to optimize away aliasing checks which might be needed if the argument was anlvalue. —endnote] +
+1363. [FCD] offsetof should be marked noexcept
+Section: 18.2 [support.types] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
+View all other issues in [support.types].
+View all issues with WP status.
+Discussion:
+Addresses GB-68
++There is no reason for the offsetof macro to invoke +potentially throwing operations, so the result of +noexcept(offsetof(type,member-designator)) should be +true. +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add to the end of 18.2p4:
++No operation invoked by the offsetof macro shall +throw an exception, and +noexcept(offsetof(type,member-designator)) shall +be true. ++ + + + + +
+1365. [FCD] Thread-safety of handler functions
+Section: 18.6.2 [alloc.errors] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-29
+View all issues with Resolved status.
+Discussion:
+Addresses GB-71
++The thread safety of std::set_new_handler(), +std::set_unexpected(), std::set_terminate(), is +unspecified making the the functions impossible to use in a thread +safe manner. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++The thread safety guarantees for the functions +must be specified and new interfaces should be +provided to make it possible to query and install +handlers in a thread safe way. ++ +[ +2010-10-31 Daniel comments: +]
+ + ++The proposed resolution of n3122 +partially addresses this request. This issue is related to 1366. ++ + +[ +2010-Batavia: +]
+ ++Resolved by adopting n3189. ++ + + +Proposed resolution:
+Resolved in Batavia by accepting n3189. + + + + + +
+1366. [FCD] New-handler and data races
+Section: 18.6.1.4 [new.delete.dataraces] Status: Resolved + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-29
+View all issues with Resolved status.
+Discussion:
+Addresses DE-14
++It is unclear how a user replacement function can +simultaneously satisfy the race-free conditions imposed in +this clause and query the new-handler in case of a failed +allocation with the only available, mutating interface +std::set_new_handler. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Offer a non-mutating interface to query the current new-handler. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3122 would solve this issue. +This issue is related to 1365. ++ +[ +2010-Batavia: +]
+ ++Resolved by adopting n3189. ++ + + +Proposed resolution:
+Resolved in Batavia by accepting n3189. + + + + + +
+1367. [FCD] Deprecate library support for checking dynamic exception specifications
+Section: D.13 [exception.unexpected] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
+View all issues with WP status.
+Discussion:
+Addresses GB-72
++Dynamic exception specifications are deprecated, so +clause 18.8.2 that describes library support for this facility +should move to Annex D, with the exception of the +bad_exception class which is retained to indicate other +failures in the exception dispatch mechanism (e.g. calling +current_exception()). +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+With the exception of 18.8.2.1 [bad.exception], +move clause 18.8.2 diectly to Annex D. +[bad.exception] should simply become the new +18.8.2. + + + + + +
+1368. [FCD] Thread safety of std::uncaught_exception()
+Section: 18.8.4 [uncaught] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
+View all issues with WP status.
+Discussion:
+Addresses GB-73
++The thread safety std::uncaught_exception() and the +result of the function when multiple threads throw +exceptions at the same time are unspecified. To make the +function safe to use in the presence of exceptions in +multiple threads the specification needs to be updated. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Update this clause to support safe calls from +multiple threads without placing synchronization +requirements on the user. +
+ +[ +2010 Batavia Concurrency group provides a Proposed Resolution +]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+Change 18.8.4 [uncaught] p. 1 as follows:
++Returns: true after the current thread has initialized
+ + + + + + +initializing+ an exception object (15.1) until a handler for the exception (including unexpected() or terminate()) + is activated (15.3). [ Note: This includes stack unwinding (15.2). — end note ] +
+1370. [FCD] throw_with_nested should not use perfect forwarding
+Section: 18.8.6 [except.nested] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
+View all other issues in [except.nested].
+View all issues with WP status.
+Discussion:
+Addresses US-84
++The throw_with_nested specification passes in its argument as +T&& (perfect forwarding pattern), but then discusses +requirements on T without taking into account that T +may be an lvalue-reference type. It is also not clear in the spec that +t is intended to be perfectly forwarded. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Patch [except.nested] p6-7 to match the intent with regards to +requirements on T and the use of +std::forward<T>(t). +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3144 would solve this issue. ++ +[2010-11-10 Batavia: LWG accepts Howard's updated wording with +corrected boo boos reported by Sebastian Gesemann and Pete Becker, +which is approved for Immediate adoption this meeting.]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+Change 18.8.7 nested_exception [except.nested] as indicated:
+++ + + + + +[[noreturn]] template <class T> void throw_with_nested(T&& t); ++++Let U be remove_reference<T>::type
+6 Requires:
+TU shall be + CopyConstructible.7 Throws: If
+TU is a non-union + class type not derived from nested_exception, an exception of + unspecified type that is publicly derived from bothTU + and nested_exception and constructed from std::forward<T>(t), + otherwise throws std::forward<T>(t). +
+1372. [FCD] Adopt recommended practice for standard error categories
+Section: 19.5.1.5 [syserr.errcat.objects] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-19
+View all issues with WP status.
+Discussion:
+Addresses GB-76
++The C++0x FCD recommends, in a note (see 19.5.1.1/1), that users +create a single error_category object for each user defined error +category and specifies error_category equality comparsions based on +equality of addresses (19.5.1.3). The Draft apparently ignores this +when specifying standard error category objects in section 19.5.1.5, +by allowing the generic_category() and system_category() +functions to return distinct objects for each invocation. +
+[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
++Append a new sentence to 19.5.1.5 [syserr.errcat.objects]/1, and append +the same sentence to 19.5.1.5/3. +
++All calls of this function return references to the same object. ++ + + + + +
+1377. [FCD] The revised forward is not compatible with access-control
+Section: 20.3 [utility] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-23
+View all other issues in [utility].
+View all issues with Resolved status.
+Discussion:
+Addresses US-90
++In n3090, at variance with previous iterations of the idea +discussed in papers and incorporated in WDs, +std::forward is constrained via std::is_convertible, +thus is not robust wrt access control. This causes problems in +normal uses as implementation detail of member +functions. For example, the following snippet leads to a +compile time failure, whereas that was not the case for an +implementation along the lines of n2835 (using enable_ifs +instead of concepts for the constraining, of course) +
+#include <utility> +struct Base { Base(Base&&); }; + +struct Derived + : private Base +{ + Derived(Derived&& d) + : Base(std::forward<Base>(d)) { } +}; +++In other terms, LWG 1054 can be resolved in a better +way, the present status is not acceptable. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3143 would solve this issue. ++ + + +Proposed resolution:
+Resolved as NAD Editorial by paper n3143. + + + + + +
+1378. [FCD] pair and tuple have too many conversions
+Section: 20.3.5 [pairs] Status: Resolved + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [pairs].
+View all issues with Resolved status.
+Discussion:
+Addresses DE-15
++Several function templates of pair and tuple allow for too +many implicit conversions, for example: +
+#include <tuple> +std::tuple<char*> p(0); // Error? + +struct A { explicit A(int){} }; +A a = 1; // Error +std::tuple<A> ta = std::make_tuple(1); // OK? ++ +[ +Resolution proposed by ballot comment +]
+ ++Consider to add wording to constrain these function templates. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3140 would solve this issue. ++ + + + +Proposed resolution:
+See n3140. + + + + + +
+1379. [FCD] pair copy-assignment not consistent for references
+Section: 20.3.5.2 [pairs.pair] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [pairs.pair].
+View all issues with Resolved status.
+Discussion:
+Addresses US-95
++Copy-assignment for pair is defaulted and does not work +for pairs with reference members. This is inconsistent with +conversion-assignment, which deliberately succeeds even +if one or both elements are reference types, just as for +tuple. The copy-assignment operator should be +consistent with the conversion-assignment operator and +with tuple's assignment operators. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3140 would provide a superior resolution, +because pair does not depend on the semantic requirements of CopyAssignable. ++ +[ +2010-11 Batavia +]
+ ++Resolved by adopting n3140. +
+ + + +Proposed resolution:
+Add to pair synopsis: ++pair& operator=(const pair& p); +++Add before paragraph 9: +
++pair& operator=(const pair& p); ++ + + + + ++++Requires: T1 and T2 shall satisfy the +requirements of CopyAssignable. +
++Effects: Assigns p.first to first and p.second to +second. +Returns: *this. +
+
+1380. [FCD] pair and tuple of references need to better specify move-semantics
+Section: 20.3.5 [pairs] Status: Resolved + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [pairs].
+View all issues with Resolved status.
+Discussion:
+Addresses DE-16
++Several pair and tuple functions in regard to move +operations are incorrectly specified if the member types +are references, because the result of a std::move cannot +be assigned to lvalue-references. In this context the usage +of the requirement sets MoveConstructible and +CopyConstructible also doesn't make sense, because +non-const lvalue-references cannot satisfy these requirements. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Replace the usage of std::move by that of +std::forward and replace MoveConstructible and +CopyConstructible requirements by other requirements. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3140 would solve this issue. ++ +[ +2010-11 Batavia: +]
+ + ++Resolved by adopting n3140. ++ + + +Proposed resolution:
+See n3140. + + + + + +
+1381. [FCD] Ballot Comment GB-85
+Section: X [pair.range] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-19
+View all issues with WP status.
+Discussion:
+Addresses GB-85
++While std::pair may happen to hold a pair of iterators +forming a valid range, this is more likely a coincidence +than a feature guaranteed by the semantics of the pair +template. A distinct range-type should be supplied to +enable the new for-loop syntax rather than overloading an +existing type with a different semantic. +
+ ++If a replacement facility is required for C++0x, +consider n2995. +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Strike 20.3.5.4 and the matching declarations in +20.3 header synopsis. + + + + + +
+1382. [FCD] pair and tuple constructors should forward arguments
+Section: 20.3.5 [pairs] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [pairs].
+View all issues with Resolved status.
+Discussion:
+Addresses US-96
++pair and tuple constructors and assignment operators use +std::move when they should use std::forward. This +causes lvalue references to be erroneously converted to +rvalue references. Related requirements clauses are also +wrong. +
+ +[ +Resolution proposed by ballot comment +]
+ ++See Appendix 1 - Additional Details ++ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3140 would solve this issue. ++ +[ +2010-11 Batavia +]
+ ++Resolved by adopting n3140. +
+ + + +Proposed resolution:
+See n3140. + + + + + +
+1383. [FCD] Inconsistent defaulted move/copy members in pair and tuple
+Section: 20.3.5 [pairs] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [pairs].
+View all issues with Resolved status.
+Discussion:
+Addresses US-97
++pair's class definition in N3092 20.3.5.2 [pairs.pair] +contains "pair(const pair&) = default;" and +"pair& operator=(pair&& p);". The latter is described by +20.3.5.2 [pairs.pair] p.12-13. +
+"pair(const pair&) = default;" is a user-declared explicitly defaulted +copy constructor. According to 12.8 [class.copy]/10, this inhibits +the implicitly-declared move constructor. pair should be move constructible. +(12.8 [class.copy]/7 explains that "pair(pair<U, V>&& p)" +will never be instantiated to move pair<T1, T2> to pair<T1, T2>.)
+"pair& operator=(pair&& p);" is a user-provided move +assignment operator (according to 8.4.2 [dcl.fct.def.default]/4: "A +special member function is user-provided if it is user-declared and not explicitly defaulted +on its first declaration."). According to 12.8 [class.copy]/20, this inhibits +the implicitly-declared copy assignment operator. pair +should be copy assignable, and was in C++98/03. (Again, +12.8 [class.copy]/7 explains that "operator=(const pair<U, V>& p)" +will never be instantiated to copy pair<T1, T2> to pair<T1, T2>.)
+Additionally, "pair& operator=(pair&& p);" is +unconditionally defined, whereas according to 12.8 [class.copy]/25, +defaulted copy/move assignment operators are defined as +deleted in several situations, such as when non-static data +members of reference type are present. ++If "pair(const pair&) = default;" and "pair& operator=(pair&& p);" +were removed from pair's class definition in 20.3.5.2 [pairs.pair] and from +20.3.5.2 [pairs.pair]/12-13, pair would +receive implicitly-declared copy/move constructors and +copy/move assignment operators, and 12.8 [class.copy]/25 would +apply. The implicitly-declared copy/move constructors +would be trivial when T1 and T2 have trivial copy/move +constructors, according to 12.8 [class.copy]/13, and similarly for the +assignment operators, according to12.8 [class.copy]/27. Notes could +be added as a reminder that these functions would be +implicitly-declared, but such notes would not be necessary +(the Standard Library specification already assumes a +high level of familiarity with the Core Language, and +casual readers will simply assume that pair is copyable +and movable). +
+Alternatively, pair could be given explicitly-defaulted +copy/move constructors and copy/move assignment +operators. This is a matter of style. +
+tuple is also affected. tuple's class definition in 20.4 [tuple] contains: +
tuple(const tuple&) = default; +tuple(tuple&&); +tuple& operator=(const tuple&); +tuple& operator=(tuple&&); ++They should all be removed or all be explicitly-defaulted, +to be consistent with pair. Additionally, 20.4.2.1 [tuple.cnstr]/8-9 specifies the +behavior of an explicitly defaulted function, which is currently inconsistent with +pair. + +[ +Resolution proposed by ballot comment: +]
+ ++Either remove "pair(const pair&) = default;" and +"pair& operator=(pair&& p);" from pair's class +definition in 20.3.5.2 [pairs.pair] and from 20.3.5.2 [pairs.pair] p.12-13, or +give pair explicitly-defaulted copy/move constructors and copy/move assignment operators.+ +
+Change tuple to match. +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3140 would solve this issue: +The move/copy constructor will be defaulted, but the corresponding assignment operators need a non-default implementation +because they are supposed to work for references as well. ++ + + +Proposed resolution:
+See n3140. + + + + + +
+1384. [FCD] Ballot Comment US-98
+Section: 20.4.2.4 [tuple.creation] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [tuple.creation].
+View all issues with WP status.
+Discussion:
+Addresses US-98
++pack_arguments is poorly named. It does not reflect the +fact that it is a tuple creation function and that it forwards +arguments. +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Rename pack_arguments to forward_as_tuple +throughout the standard. + + + + + +
+1386. FCD Ballot Comment US-99
+Section: 20.4.2.4 [tuple.creation] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [tuple.creation].
+View all issues with WP status.
+Discussion:
+Addresses US-99
++pack_arguments is overly complex. +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+This issue resulted from a lack of understanding of +how references are forwarded. The definition of +pack_arguments should be simply:
+template <class... Types> +tuple<ATypes&&> +pack_arguments(Types&&...t);
+Types:Let Ti be each type in Types....
+Effects: ...
+Returns:
+tuple<ATypes&&...>(std::forward<Types>(t)...)
+The synopsis should also change to reflect this +simpler signature. + + + + + +
+1387. [FCD] Ballot Comment GB-87
+Section: X [tuple.range] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
+View all issues with WP status.
+Discussion:
+Addresses GB-87
++There is no compelling reason to assume a +heterogeneous tuple of two elements holds a pair of +iterators forming a valid range. Unlike std::pair, there are +no functions in the standard library using this as a return +type with a valid range, so there is even less reason to try +to adapt this type for the new for-loop syntax. +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Strike 20.4.2.10 and the matching declarations in +the header synopsis in 20.4. + + + + + +
+1388. FCD Ballot Comment US-100
+Section: 20.6.1 [ratio.ratio] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [ratio.ratio].
+View all issues with WP status.
+Discussion:
+Addresses US-100
++LWG 1281 was discussed in Pittsburgh, and the decision +there was to accept the typedef as proposed and move to +Review. Unfortunately the issue was accidentally applied +to the FCD, and incorrectly. The FCD version of the +typedef refers to ratio<N, D>, but the typedef is intended +to refer to ratio<num, den> which in general is not the +same type. +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Accept the current proposed wording of LWG +1281 which adds:
+typedef ratio<num, den> type; + + + + + +
+1389. [FCD] Compile-time rational arithmetic and overflow
+Section: 20.6.2 [ratio.arithmetic] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [ratio.arithmetic].
+View all issues with Resolved status.
+Discussion:
+Addresses GB-89
++The alias representations of the ratio arithmetic templates +do not allow implementations to avoid overflow, since they +explicitly specify the form of the aliased template +instantiation. For example +ratio_multiply, ratio<2, LLONG_MAX> is required to +alias ratio<2*LLONG_MAX, LLONG_MAX*2>, which +overflows, so is ill-formed. However, this is trivially equal +to ratio<1, 1>. It also contradicts the opening statement of +20.6.2 [ratio.arithmetic] p. 1 "implementations may use other algorithms to +compute these values". +
+ +[ +2010-10-25 Daniel adds: +]
+ + ++Accepting n3131 would solve this issue. ++ +[Batavia: Resoved by accepting +n3210.]
+ + + + +Proposed resolution:
+Change the wording in 20.6.2 [ratio.arithmetic] p. 2-5 as follows: ++
+template <class R1, class R2> using ratio_add = see below; ++2 The type ratio_add<R1, R2> shall be a synonym forratio<T1, T2>+ratio<U, V> such that ratio<U, V>::num and ratio<U, V>::den +are the same as the corresponding members of ratio<T1, T2> would be in the absence of +arithmetic overflow where T1 has the value R1::num * R2::den + R2::num * R1::den +and T2 has the value R1::den * R2::den. If the required values of ratio<U, V>::num +and ratio<U, V>::den cannot be represented in intmax_t then the program is ill-formed. ++template <class R1, class R2> using ratio_subtract = see below; ++3 The type ratio_subtract<R1, R2> shall be a synonym forratio<T1, T2>+ratio<U, V> such that ratio<U, V>::num and ratio<U, V>::den +are the same as the corresponding members of ratio<T1, T2> would be in the absence of +arithmetic overflow where T1 has the value R1::num * R2::den - R2::num * R1::den +and T2 has the value R1::den * R2::den. If the required values of ratio<U, V>::num +and ratio<U, V>::den cannot be represented in intmax_t then the program is ill-formed. ++template <class R1, class R2> using ratio_multiply = see below; ++4 The type ratio_multiply<R1, R2> shall be a synonym forratio<T1, T2>+ratio<U, V> such that ratio<U, V>::num and ratio<U, V>::den +are the same as the corresponding members of ratio<T1, T2> would be in the absence of +arithmetic overflow where T1 has the value R1::num * R2::num and T2 +has the value R1::den * R2::den. If the required values of ratio<U, V>::num +and ratio<U, V>::den cannot be represented in intmax_t then the program is ill-formed. ++ + + + + +template <class R1, class R2> using ratio_divide = see below; ++5 The type ratio_divide<R1, R2> shall be a synonym forratio<T1, T2>+ratio<U, V> such that ratio<U, V>::num and ratio<U, V>::den +are the same as the corresponding members of ratio<T1, T2> would be in the absence of +arithmetic overflow where T1 has the value R1::num * R2::den and T2 +has the value R1::den * R2::num. If the required values of ratio<U, V>::num +and ratio<U, V>::den cannot be represented in intmax_t then the program is ill-formed. +
+1390. [FCD] Limit speculative compilation for constructible/convertible traits
+Section: 20.7 [meta] Status: Resolved + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-23
+View all other issues in [meta].
+View all issues with Resolved status.
+Discussion:
+Addresses DE-17
++Speculative compilation for std::is_constructible and +std::is_convertible should be limited, similar to the core +language (see 14.8.2 paragraph 8). +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3142 would solve this issue. ++ + + +Proposed resolution:
+Resolved by paper n3142. + + + + + +
+1391. [FCD] constructible/convertible traits and access control
+Section: 20.7 [meta] Status: Resolved + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-23
+View all other issues in [meta].
+View all issues with Resolved status.
+Discussion:
+Addresses DE-18
++Several type traits require compiler support, e.g. +std::is_constructible or std::is_convertible. +Their current specification seems to imply, that the corresponding +test expressions should be well-formed, even in absense of access: +
+class X { X(int){} }; +constexpr bool test = std::is_constructible<X, int>::value; +++The specification does not clarify the context of this test +and because it already goes beyond normal language +rules, it's hard to argue by means of normal language +rules what the context and outcome of the test should be. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Specify that std::is_constructible and +std::is_convertible will return true only for +public constructors/conversion functions. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3142 would solve this issue. ++ + + +Proposed resolution:
+Resolved by paper n3142. + + + + + +
+1392. [FCD] result_of should support pointer-to-data-member
+Section: 20.7.4 [meta.unary] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-23
+View all other issues in [meta.unary].
+View all issues with Resolved status.
+Discussion:
+Addresses US-102
++Despite Library Issue 520's ("result_of and pointers to +data members") resolution of CD1, the FCD's result_of +supports neither pointers to member functions nor +pointers to data members. It should. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Ensure result_of supports pointers to member +functions and pointers to data members. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3123 would solve this issue. ++ + + +Proposed resolution:
+Resolved by n3123. + + + + + +
+1393. [FCD] Trivial traits imply noexcept
+Section: 20.7.4.3 [meta.unary.prop] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
+View all other issues in [meta.unary.prop].
+View all issues with Resolved status.
+Discussion:
+Addresses GB-92
++Trivial functions implicitly declare a noexcept exception +specification, so the references to has_trivial_* traits in the +has_nothrow_* traits are redundant, and should be struck for clarity. +
+ +[ +Resolution proposed by ballot comment +]
+ ++For each of the has_nothrow_something traits, +remove all references to the matching +has_trivial_something traits. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3142 would solve this issue. ++ + + +Proposed resolution:
+Resolved by n3142. + + + + + +
+1394. [FCD] Ballot Comment DE-19
+Section: 20.7.4.3 [meta.unary.prop] Status: Resolved + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-19
+View all other issues in [meta.unary.prop].
+View all issues with Resolved status.
+Discussion:
+Addresses DE-19
++The fundamental trait is_constructible reports false +positives, e.g. +
+is_constructible<char*, void*>::value ++evaluates to true, even though a corresponding variable +initialization would be ill-formed. + +[ +Resolved in Rapperswil by paper N3047. +]
+ + + + +Proposed resolution:
+Remove all false positives from the domain of +is_constructible. + + + + + +
+1397. [FCD] Deprecate '98 binders
+Section: 20.8 [function.objects] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [function.objects].
+View all issues with Resolved status.
+Discussion:
+Addresses GB-95
++The adaptable function protocol supported by +unary_function/binary_function has been superceded by +lambda expressions and std::bind. Despite the name, the +protocol is not very adaptable as it requires intrusive +support in the adaptable types, rather than offering an +external traits-like adaption mechanism. This protocol and +related support functions should be deprecated, and we +should not make onerous requirements for the +specification to support this protocol for callable types +introduced in this standard revision, including those +adopted from TR1. It is expected that high-quality +implementations will provide such support, but we should +not have to write robust standard specifications mixing this +restricted support with more general components such as +function, bind and reference_wrapper. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Move clauses 20.8.3, 20.8.9, 20.8.11 and 20.8.12 +to Annex D. +
++Remove the requirements to conditionally derive from +unary/binary_function from function, +reference_wrapper, and the results of calling mem_fn +and bind. +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3145 would solve this issue. ++ + + +Proposed resolution:
+Resolved by paper N3198. + + + + + +
+1399. [FCD] function does not need an explicit default constructor
+Section: 20.8.14.2 [func.wrap.func] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-24
+View all other issues in [func.wrap.func].
+View all issues with WP status.
+Discussion:
+Addresses JP-3
++explicit default contructor is defined in std::function. +Although it is allowed according to 12.3.1, it seems +unnecessary to qualify the constructor as explicit. +If it is explicit, there will be a limitation in initializer_list. +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Remove explicit. +namespace std { +template<class> class function; +// undefined +template<class R, class... ArgTypes> +class function<R(ArgTypes...)> +: public unary_function<T1, R> +// iff sizeof...(ArgTypes) == 1 and ArgTypes contains T1 +: public binary_function<T1, T2, R> +// iff sizeof...(ArgTypes) == 2 and ArgTypes contains T1 andT2 +{ +public:typedef R result_type; +// 20.8.14.2.1, construct/copy/destroy: ++ + + + + +explicitfunction(); +
+1400. FCD function does not need an explicit default constructor
+Section: 20.8.14.2.1 [func.wrap.func.con] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-24
+View all other issues in [func.wrap.func.con].
+View all issues with WP status.
+Discussion:
+Addresses JP-4
++Really does the function require that default constructor is explicit? +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Remove explicit. +function(); +template <class A> +function(allocator_arg_t, const A& a); ++ + + + + +
+1402. [FCD] nullptr constructors for smart pointers should be constexpr
+Section: 20.9 [memory] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-24
+View all other issues in [memory].
+View all issues with WP status.
+Discussion:
+Addresses GB-100
+ +The unique_ptr and shared_ptr constructors taking +nullptr_t delegate to a constexpr constructor, and could be +constexpr themselves. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+In the 20.9.10.2 [unique.ptr.single] synopsis add +"constexpr" to unique_ptr(nullptr_t).
+In the 20.9.10.3 [unique.ptr.runtime] synopsis add +"constexpr" to unique_ptr(nullptr_t).
+In the 20.9.11.2 [util.smartptr.shared] synopsis +add "constexpr" to shared_ptr(nullptr_t). + + + + + +
+1403. [FCD] Inconsistent definitions for allocator_arg
+Section: 20.9.1 [allocator.tag] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-24
+View all issues with WP status.
+Discussion:
+Addresses JP-85
++There are inconsistent definitions for allocator_arg. +In 20.9 [memory] paragraph 1, +
+constexpr allocator_arg_t allocator_arg = allocator_arg_t(); ++and in 20.9.1, +const allocator_arg_t allocator_arg = allocator_arg_t(); ++ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Change "const" to "constexpr" in 20.9.1 as +follows. +constexpr allocator_arg_t allocator_arg = allocator_arg_t(); ++ + + + + +
+1404. [FCD] pointer_traits should have a size_type member
+Section: 20.9.3 [pointer.traits] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-23
+View all issues with WP status.
+Discussion:
+Addresses US-106
++pointer_traits should have a size_type member for completeness. +
++Add typedef see below size_type; to the generic +pointer_traits template and typedef size_t +size_type; to pointer_traits<T*>. Use +pointer_traits::size_type and +pointer_traits::difference_type as the defaults for +allocator_traits::size_type and +allocator_traits::difference_type. +
++See Appendix 1 - Additional Details +
+ +[ +Post-Rapperswil, Pablo provided wording: +]
+ + ++The original ballot comment reads simply: "pointer_traits should have a +size_type for completeness." The additional details reveal, however, +that the desire for a size_type is actually driven by the needs +of allocator_traits. The allocator_traits template should get its +default difference_type from pointer_traits but if it did, +it should get its size_type from the same source. Unfortunately, +there is no obvious meaning for size_type in pointer_traits. +
++Alisdair suggested, however, that the natural relationship between +difference_type and size_type can be expressed simply by the +std::make_unsigned<T> metafunction. Using this metafunction, +we can easily define size_type for allocator_traits without +artificially adding size_type to pointer_traits. +
+ ++Moved to Tentatively Ready after 6 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + + +Proposed resolution:
++In [allocator.requirements], Table 42, change two rows as follows: +
++++
++ +X::size_type +unsigned integral type +a type that can represent the size of the largest object in the + allocation model ++ +size_t+ make_unsigned<X::difference_type>::type ++ +X::difference_type +signed integral type +a type that can represent the difference between any two pointers in + the allocation model ++ +ptrdiff_t+ pointer_traits<X::pointer>::difference_type ++In [allocator.traits.types], Change the definition of difference_type and +size_type as follows: +
++ typedef see below difference_type; ++ + + + + ++ Type: Alloc::difference_type if such a type exists, + else+ + typedef see below size_type; +ptrdiff_t+ pointer_traits<pointer>::difference_type. ++ Type: Alloc::size_type if such a type exists, + else+size_t+ make_unsigned<difference_type>::type. +
+1405. [FCD] Ballot Comment US-107
+Section: 20.10 [allocator.adaptor] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-19
+View all other issues in [allocator.adaptor].
+View all issues with Resolved status.
+Discussion:
+Addresses US-107
+ +scoped_allocator_adaptor should have its own header. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+See Appendix 1 - Additional Details + + + + + +
+1407. [FCD] Synch shared_ptr constructors taking movable types
+Section: 20.9.10.2.1 [util.smartptr.shared.const] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-19
+View all other issues in [util.smartptr.shared.const].
+View all issues with Resolved status.
+Discussion:
+Addresses US-108
+ +shared_ptr should have the same policy for constructing +from auto_ptr as unique_ptr. Currently it does not. + +[ +Resolved in Rapperswil by paper N3109. +]
+ + + + +Proposed resolution:
+Add “template <class Y> explicit +shared_ptr(auto_ptr<Y>&); to +[util.smartptr.shared.const] (and to the synopsis). + + + + + +
+1409. [FCD] Specify whether monotonic_clock is a distinct type or a typedef
+Section: X [time.clock.monotonic] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [time.clock.monotonic].
+View all issues with Resolved status.
+Discussion:
+Addresses US-111
++What it means for monotonic_clock to be a synonym is +undefined. If it may or may not be a typedef, then certain +classes of programs become unportable. +
+ +[ +Resolution proposed in ballot comment: +]
+ ++Require that it be a distinct class type. +
+ +[ +2010-11-01 Daniel comments: +]
+ ++Paper n3128 addresses +this issue by replacing monotonic_clock with steady_clock, which is not a typedef. ++ + + +Proposed resolution:
+This is resolved by n3191. + + + + + +
+1410. [FCD] Add a feature-detect macro for monotonic_clock
+Section: X [time.clock.monotonic] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [time.clock.monotonic].
+View all issues with Resolved status.
+Duplicate of: 1411
+Discussion:
+Addresses GB-107, DE-20
++1.4 [intro.compliance] p.9 states that which conditionally +supported constructs are available should be provided in the +documentation for the implementation. This doesn't help programmers trying +to write portable code, as they must then rely on +implementation-specific means to determine the +availability of such constructs. In particular, the presence +or absence of std::chrono::monotonic_clock may require +different code paths to be selected. This is the only +conditionally-supported library facility, and differs from the +conditionally-supported language facilities in that it has +standard-defined semantics rather than implementation-defined +semantics. +
+ +[ +Resolution proposed in ballot comment: +]
+ ++Provide feature test macro for determining the +presence of std::chrono::monotonic_clock. Add +_STDCPP_HAS_MONOTONIC_CLOCK to the +<chrono> header, which is defined if +monotonic_clock is present, and not defined if it is +not present. +
+ +[ +2010-11-01 Daniel comments: +]
+ ++Paper n3128 addresses +this issue by replacing monotonic_clock with steady_clock, which is not conditionally supported, +so there is no need to detect it. ++ + + +Proposed resolution:
+This is resolved by n3191. + + + + + +
+1412. [FCD] Make monotonic clocks mandatory
+Section: X [time.clock.monotonic] Status: Resolved + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [time.clock.monotonic].
+View all issues with Resolved status.
+Discussion:
+Addresses CH-21
++Monotonic clocks are generally easy to provide on all +systems and are implicitely required by some of the library +facilities anyway. +
+ +[ +2010-11-01 Daniel comments: +]
+ ++Paper n3128 addresses +this issue by replacing monotonic_clock with steady_clock, which is mandatory. ++ +[ +2010-11-13 Batavia meeting: +]
+ ++This is resolved by adopting n3191. +The original resolution is preserved for reference: +
+++ + + +Make monotonic clocks mandatory.
+Strike X [time.clock.monotonic] p.2
++2+ +The class monotonic_clock is conditionally supported.+Change 30.2.4 [thread.req.timing] p.2 accordingly
++The member functions whose names end in _for take an argument that +specifies a relative time. Implementations should use a monotonic clock to +measure time for these functions.+[ Note: Implementations are not +required to use a monotonic clock because such a clock may not be available. +— end note ]+Proposed resolution:
+This is resolved by n3191. + + + + + +
+1414. [FCD] Fixing remaining dead links to POS_T and OFF_T
+Section: 21.2.3.2 [char.traits.specializations.char16_t] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
+View all issues with WP status.
+Duplicate of: 1444
+Discussion:
+Addresses GB-109, GB-123
+ ++It is not clear what the specification means for +u16streampos, u32streampos or wstreampos when they +refer to the requirements for POS_T in 21.2.2, as there +are no longer any such requirements. Similarly the annex +D.7 refers to the requirements of type POS_T in 27.3 that +no longer exist either. +
++Clarify the meaning of all cross-reference to the +removed type POS_T. +
+ + +[ +Post-Rapperswil, Daniel provides the wording. +]
+ + ++When preparing the wording for this issue I first thought about adding both u16streampos and u32streampos +to the [iostream.forward] header <iosfwd> synopsis similar to streampos and wstreampos, +but decided not to do so, because the IO library does not yet actively support the char16_t and char32_t +character types. Adding those would misleadingly imply that they would be part of the iostreams. Also, the addition +would make them also similarly equal to a typedef to fpos<mbstate_t>, as for streampos and +wstreampos, so there is no loss for users that would like to use the proper fpos instantiation for +these character types. +
++Additionally the way of referencing was chosen to follow the style suggested by NB comment +GB 108. +
+ ++Moved to Tentatively Ready with proposed wording after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++The following wording changes are against N3126. +
+ ++
+ + + + + + +- Change [char.traits.specializations.char16_t]/1 as indicated: +
+++1 - The type u16streampos shall be an implementation-defined type that satisfies the requirements +for
POS_T in 21.2.2pos_type in [iostreams.limits.pos]. +- Change [char.traits.specializations.char32_t]/1 as indicated: +
+++1 - The type u32streampos shall be an implementation-defined type that satisfies the requirements +for
POS_T in 21.2.2pos_type in [iostreams.limits.pos]. +- Change [char.traits.specializations.wchar.t]/2 as indicated: +
+++2 - The type wstreampos shall be an implementation-defined type that satisfies the requirements +for
POS_T in 21.2.2pos_type in [iostreams.limits.pos]. +- Change [fpos.operations], Table 124 — Position type requirements as indicated: +
+++
+
+Table 124 — Position type requirements + + ++ + +Expression +Return type +... ++ +... +... +... ++ +O(p) ++ OFF_Tstreamoff... ++ +... +... +... ++ +o = p - q ++ OFF_Tstreamoff... ++ + +streamsize(o) +
O(sz)streamsize +OFF_Tstreamoff... +- Change [depr.ios.members]/1 as indicated: +
++
+ +namespace std { + class ios_base { + public: + typedef T1 io_state; + typedef T2 open_mode; + typedef T3 seek_dir; + typedefOFF_Timplementation-defined streamoff; + typedefPOS_Timplementation-defined streampos; + // remainder unchanged + }; +} +- Change [depr.ios.members]/5+6 as indicated: +
+++5 - The type streamoff is an implementation-defined type that satisfies the requirements +of
+type OFF_T (27.5.1)off_type in [iostreams.limits.pos]. ++6 - The type streampos is an implementation-defined type that satisfies the requirements +of
type POS_T (27.3)pos_type in [iostreams.limits.pos]. +
+1416. [FCD] forward_list::erase_after should not be allowed to throw
+Section: 23.2 [container.requirements] Status: WP + Submitter: DIN Opened: 2010-08-25 Last modified: 2010-11-19
+View all other issues in [container.requirements].
+View all issues with WP status.
+Discussion:
+Addresses DE-21
+ +23.2.1/11 provides a general no-throw guarantee for +erase() container functions, exceptions from this are +explicitly mentioned for individual containers. Because of +its different name, forward_list's erase_after() function is +not ruled by this but should so. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
++Add a "Throws: Nothing" clause to both +erase_after overloads in 23.3.3.4, [forwardlist.modifiers]. +
+ + + + + +
+1417. [FCD] front/back on a zero-sized +array should be undefined
+Section: 23.3.1.7 [array.zero] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-10-26
+View all issues with WP status.
+Discussion:
+Addresses GB-112
++Should the effect of calling front/back on a zero-sized +array really be implementation defined i.e. require the +implementor to define behaviour? +
+ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Change "implementation defined" to "undefined" + + + + + +
+1423. [FCD] Ballot Comment JP-6
+Section: 23.6.1 [map] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
+View all other issues in [map].
+View all issues with WP status.
+Discussion:
+Addresses JP-6
+ +Constructor accepting an allocator as a single parameter +should be qualified as explicit. +namespace std { +template <class Key, class T, class Compare = +less<Key>, +class Allocator = allocator<pair<const Key, T> > > +class map { +public: +... +map(const Allocator&); ++ +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add explicit. +namespace std { +template <class Key, class T, class Compare = +less<Key>, +class Allocator = allocator<pair<const Key, T> > > +class map { +public: +... +explicit map(const Allocator&); ++ + + + + +
+1424. [FCD] Ballot Comment JP-7
+Section: 23.6.2 [multimap] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
+Constructor accepting an allocator as a single parameter +should be qualified as explicit. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add explicit. +namespace std { +template <class Key, class T, class Compare = +less<Key>, +class Allocator = allocator<pair<const Key, T> > > +class multimap { +public: +... +explicit multimap(const Allocator&); ++ + + + + +
+1425. [FCD] Ballot Comment JP-8
+Section: 23.6.3 [set] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
+View all other issues in [set].
+View all issues with WP status.
+Discussion:
+Addresses JP-8
+Constructor accepting an allocator as a single parameter +should be qualified as explicit. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add explicit. +namespace std { +template <class Key, class Compare = less<Key>, +class Allocator = allocator<Key> > +class set { +public: +... +explicit set(const Allocator&); ++ + + + + +
+1426. [FCD] Ballot Comment JP-9
+Section: 23.6.4 [multiset] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
+Addresses JP-9
+ +Constructor accepting an allocator as a single parameter +should be qualified as explicit. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add explicit. +namespace std { +template <class Key, class Compare = less<Key>, +class Allocator = allocator<Key> > +class multiset { +public: +... +explicit multiset(const Allocator&); ++ + + + + +
+1427. [FCD] Ballot Comment JP-10
+Section: 23.7.1 [unord.map] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
+View all other issues in [unord.map].
+View all issues with WP status.
+Discussion:
+Addresses JP-10
+ +Constructor accepting an allocator as a single parameter +should be qualified as explicit. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add explicit. +namespace std { +template <class Key, +template <class Key, +class T, +class Hash = hash<Key>, +class Pred = std::equal_to<Key>, +class Alloc = std::allocator<std::pair<const Key, +T> > > +class unordered_map +{ +public: +... +explicit unordered_map(const Allocator&); ++ + + + + +
+1428. [FCD] Ballot Comment JP-11
+Section: 23.7.2 [unord.multimap] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
+Addresses JP-11
+ +Constructor accepting an allocator as a single parameter +should be qualified as explicit. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add explicit. +namespace std { +template <class Key, +class T, +class Hash = hash<Key>, +class Pred = std::equal_to<Key>, +class Alloc = std::allocator<std::pair<const Key, +T> > > +class unordered_multimap +{ +public: +... +explicit unordered_multimap(const Allocator&); ++ + + + + +
+1429. [FCD] Ballot Comment JP-12
+Section: 23.7.3 [unord.set] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
+Addresses JP-12
+ +Constructor accepting an allocator as a single parameter +should be qualified as explicit. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add explicit. +namespace std { +template <class Key, +class Hash = hash<Key>, +class Pred = std::equal_to<Key>, +class Alloc = std::allocator<Key> > +class unordered_set +{ +public: +... +explicit unordered_set(const Allocator&); ++ + + + + +
+1430. [FCD] Ballot Comment JP-13
+Section: 23.7.4 [unord.multiset] Status: WP + Submitter: Japan Opened: 2010-08-25 Last modified: 2010-10-23
+View all issues with WP status.
+Discussion:
+Addresses JP-13
+ +Constructor accepting an allocator as a single parameter +should be qualified as explicit. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Add explicit. +namespace std { +template <class Key, +class Hash = hash<Key>, +class Pred = std::equal_to<Key>, +class Alloc = std::allocator<Key> > +class unordered_multiset +{ +public: +... +explicit unordered_multiset(const Allocator&); ++ + + + + +
+1431. [FCD] Ballot Comment US-120
+Section: 25.2.12 [alg.is_permutation] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all issues with WP status.
+Discussion:
+Addresses US-120
+ +is_permutation is underspecified for anything but the +simple case where both ranges have the same value type +and the comparison function is an equivalence relation. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+Restrict is_permutation to the case where it is well +specified. See Appendix 1 - Additional Details + + + + + +
+1432. [FCD] random_shuffle signatures
+Section: 25.3.12 [alg.random.shuffle] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
+View all other issues in [alg.random.shuffle].
+View all issues with WP status.
+Duplicate of: 1433
+Discussion:
+ +Addresses US-121, GB-119
+ ++random_shuffle and shuffle should be consistent in how +they accept their source of randomness: either both by +rvalue reference or both by lvalue reference. +
+ +[ +Post-Rapperswil, Daniel provided wording +]
+ + ++The signatures of the shuffle and random_shuffle algorithms are different +in regard to the support of rvalues and lvalues of the provided generator: +
+ ++
+ + +template<class RandomAccessIterator, class RandomNumberGenerator> +void random_shuffle(RandomAccessIterator first, +RandomAccessIterator last, +RandomNumberGenerator&& rand); ++
+ + +template<class RandomAccessIterator, class UniformRandomNumberGenerator> +void shuffle(RandomAccessIterator first, +RandomAccessIterator last, +UniformRandomNumberGenerator& g); ++The first form uses the perfect forwarding signature and that change compared to +C++03 was done intentionally as shown in the first rvalue proposal +papers. +
+ ++While it is true, that random generators are excellent examples of stateful +functors, there still exist good reasons to support rvalues as arguments: +
+ ++
+
+ + +- If one of the shuffle algorithms is called with the intention to shuffle items with a reproducible ordering + from a given generator class, it makes sense to create a generator exactly at the call point. +
+- Other algorithms with similar need for stateful functors (like std::generate and std::generate_n) + accept both rvalues and lvalues as well. +
+- Given the deduction rules for perfect forwarding it is hard for a user to produce code that does the wrong thing +unintentionally. Any lvalue generator will deduce an lvalue-reference and behave as in C++03. In the specific +cases, where rvalues are provided, the argument will be accepted instead of being rejected. +
++Arguments have been raised that accepting rvalues is error-prone or even fundamentally wrong. The author of this +proposal disagrees with that position for two additional reasons: +
+ ++
+
+ + +- Enforcing lvalues as arguments won't prevent user code to enforce what they +want. So given +
++instead of writing +my_generator get_generator(int size); ++they will just write +std::vector<int> v = ...; +std::shuffle(v.begin(), v.end(), get_generator(v.size())); ++and feel annoyed about the need for it. +std::vector<int> v = ...; +auto gen = get_generator(v.size()); +std::shuffle(v.begin(), v.end(), gen); +- Generators may be copyable and movable, and random number engines are required to be CopyConstructible +and this is obviously a generally useful property for such objects. It is also useful and sometimes necessary to start a +generator with exactly a specific seed again and again and thus to provide a new generator (or a copy) for each call. The +CopyConstructible requirements allow providing rvalues of generators and thus this idiom must be useful as well. +Therefore preventing [random_]shuffle to accept rvalues is an unnecessary restriction which doesn't prevent any +user-error, if there would exist one. +
++Thus this proposal recommends to make both shuffle functions consistent and perfectly forward-able. +
+ ++Moved to Tentatively Ready after 6 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ ++
+ + + + + + +- Change [algorithms.general], header <algorithm> synopsis as indicated: +
++template<class RandomAccessIterator, class UniformRandomNumberGenerator> +void shuffle(RandomAccessIterator first, RandomAccessIterator last, +UniformRandomNumberGenerator&& rand); +- Change the prototype description of [alg.random.shuffle] as indicated: +
++template<class RandomAccessIterator, class UniformRandomNumberGenerator> +void shuffle(RandomAccessIterator first, RandomAccessIterator last, +UniformRandomNumberGenerator&& rand); +
+1435. [FCD] Unclear returns specifications for C99 complex number functions
+Section: 26.4.7 [complex.value.ops] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
+View all other issues in [complex.value.ops].
+View all issues with WP status.
+Discussion:
+Addresses GB-120
+ +The complex number functions added for compatibility +with the C99 standard library are defined purely as a +cross-reference, with no hint of what they should return. +This is distinct from the style of documentation for the +functions in the earlier standard. In the case of the +inverse-trigonometric and hyperbolic functions, a +reasonable guess of the functionality may be made from +the name, this is not true of the cproj function, which +apparently returns the projection on the Reimann Sphere. +A single line description of each function, associated with +the cross-reference, will greatly improve clarity. + +[2010-11-06 Beman provides proposed resolution wording.]
+ + +[ +2010 Batavia: The working group concurred with the issue's Proposed Resolution +]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ +Change 26.4.7 complex value operations [complex.value.ops] as indicated:
+++ +template<class T> complex<T> proj(const complex<T>& x);
+++Returns: the projection of x onto the Riemann + sphere.
++
Effects:Remarks: Behaves the same as the C function cproj, + defined in 7.3.9.4.Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
+++ +template<class T> complex<T> acos(const complex<T>& x);
+++Returns: the complex arc cosine of x.
++
Effects:Remarks: Behaves the same as the C function cacos, + defined in 7.3.5.1.Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
+++ +template<class T> complex<T> asin(const complex<T>& x);
+++Returns: the complex arc sine of x.
++
Effects:Remarks: Behaves the same as the C function casin, + defined in 7.3.5.2.Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
+++ +template<class T> complex<T> atan(const complex<T>& x);
+++Returns: the complex arc tangent of x.
++
Effects:Remarks: Behaves the same as the C function catan, + defined in 7.3.5.3.Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
+++ +template<class T> complex<T> acosh(const complex<T>& x);
+++Returns: the complex arc hyperbolic cosine of + x.
++
Effects:Remarks: Behaves the same as the C function cacosh, + defined in 7.3.6.1.Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
+++ +template<class T> complex<T> asinh(const complex<T>& x);
+++Returns: the complex arc hyperbolic sine of + x.
++
Effects:Remarks: Behaves the same as the C function casinh, + defined in 7.3.6.2.Change 26.4.8 complex transcendentals [complex.transcendentals] as indicated:
+++ + + + + + + +template<class T> complex<T> atanh(const complex<T>& x);
+++Returns: the complex arc hyperbolic tangent of + x.
++
Effects:Remarks: Behaves the same as the C function catanh, + defined in 7.3.6.2.
+1436. [FCD] Random number engine constructor concerns
+Section: 26.5.3 [rand.eng] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-24
+View all other issues in [rand.eng].
+View all issues with WP status.
+Discussion:
+Addresses GB-121
+ +All the random number engine types in this clause have a +constructor taking an unsigned integer type, and a +constructor template for seed sequences. This means that +an attempt to create a random number engine seeded by +an integer literal must remember to add the appropriate +unsigned suffix to the literal, as a signed integer will +attempt to use the seed sequence template, yielding +undefined behaviour, as per 26.5.1.1p1a. It would be +helpful if at least these anticipated cases produced a +defined behaviour, either an erroneous program with +diagnostic, or a conversion to unsigned int forwarding to +the appropriate constructor. + +[ +2010-11-03 Daniel comments and provides a proposed resolution: +]
+ + ++I suggest to apply a similar solution as recently suggested for 1234. +It is basically a requirement for an implementation to constrain the template. +
+ +[ +2010-11-04 Howard suggests to use !is_convertible<Sseq, result_type>::value +as minimum requirement instead of the originally proposed !is_scalar<Sseq>::value. +This would allow for a user-defined type BigNum, that is convertible to result_type, +to be used as argument for a seed instead of a seed sequence. The wording has been updated to +reflect this suggestion. +]
+ + +[ +2010 Batavia: There were some initial concerns regarding the portability and reproducibility of results +when seeded with a negative signed value, but these concerns were allayed after discussion. Thus, after +reviewing the issue, the working group concurred with the issue's Proposed Resolution. +]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+Add the following paragraph at the end of 26.5.3 [rand.eng]: +++ + + + + ++5 Each template specified in this section [rand.eng] requires one or more relationships, involving the value(s) of +its non-type template parameter(s), to hold. A program instantiating any of these templates is ill-formed if +any such required relationship fails to hold. ++ ++? For every random number engine and for every random number engine adaptor X defined in this sub-clause +[rand.eng] and in sub-clause [rand.adapt]: ++ ++
+The extent to which an implementation determines that a type cannot be a seed sequence is unspecified, +except that as a minimum a type shall not qualify as seed sequence, if it is implicitly convertible +to X::result_type. +- If the constructor +
++is called with a type Sseq that does not qualify as a seed sequence, then this constructor +shall not participate in overload resolution. + +template<class Sseq> explicit X(Sseq& q); +- If the member function +
++is called with a type Sseq that does not qualify as a seed sequence, then this function +shall not participate in overload resolution. + +template<class Sseq> void seed(Sseq& q); +
+1437. [FCD] Mersenne twister meaningless for word sizes less than two
+Section: 26.5.3.2 [rand.eng.mers] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
+View all other issues in [rand.eng.mers].
+View all issues with WP status.
+Discussion:
+Addresses US-124
+ +The Mersenne twister algorithm is meaningless for word +sizes less than two, as there are then insufficient bits +available to be “twisted”. + +[ +Resolution proposed by ballot comment: +]
+ ++Insert the following among the relations that are required to hold: 2u < w. ++ +[ +2010 Batavia: The working group concurred with the issue's Proposed Resolution +]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+Change 26.5.3.2 [rand.eng.mers] p. 4 as indicated: ++
+4 The following relations shall hold: 0 < m, m <= n, 2u < w, +r <= w, u <= w, s <= w, t <= w, +l <= w, w <= numeric_limits<UIntType>::digits, +a <= (1u<<w) - 1u, b <= (1u<<w) - 1u, +c <= (1u<<w) - 1u, d <= (1u<<w) - 1u, +and f <= (1u<<w) - 1u. ++ + + + + +
+1439. [FCD] Return from densities() functions?
+Section: 26.5.8.5.2 [rand.dist.samp.pconst] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
+View all other issues in [rand.dist.samp.pconst].
+View all issues with WP status.
+Discussion:
+Addresses US-134
+ +These two distributions have a member function called +densities() which returns a vector<double>. The +distribution is templated on RealType. The distribution +also has another member called intervals() which returns +a vector<RealType>. Why doesn't densities return +vector<RealType> as well? If RealType is long double, +the computed densities property isn't being computed to +the precision the client desires. If RealType is float, the +densities vector is taking up twice as much space as the client desires. + +[ +Resolution proposed by ballot comment: +]
+ ++Change the piecewise constant and linear +distributions to hold / return the densities in a +vector<result_type>. ++ ++If this is not done, at least correct 26.5.8.5.2 [rand.dist.samp.pconst] p. 13 which describes +the return of densities as a vector<result_type>. +
[ +Batavia 2010: After reviewing this issue, the working group concurred with the first of the +suggestions proposed by the NB comment: "Change the piecewise constant and linear distributions +to hold / return the densities in a vector. " +]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++
+ + + + + +- Change 26.5.8.5.2 [rand.dist.samp.pconst] p. 2, class template piecewise_constant_distribution synopsis +and the prototype description 26.5.8.5.2 [rand.dist.samp.pconst] before p. 13 as indicated: +
+ ++vector<doubleresult_type> densities() const; +- Change 26.5.8.5.3 [rand.dist.samp.plinear] p. 2, class template piecewise_linear_distribution synopsis +and the prototype description 26.5.8.5.3 [rand.dist.samp.plinear] before p. 13 as indicated: +
++vector<doubleresult_type> densities() const; +
+1440. [FCD] Incorrect specification for rand.dist.samp.plinear
+Section: 26.5.8.5.3 [rand.dist.samp.plinear] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-24
+View all issues with WP status.
+Discussion:
+Addresses US-135
+ +This paragraph says: Let bk = xmin+k·δ for k = 0,...,n, +and wk = fw(bk +δ) for k = 0,...,n. +However I believe that fw(bk) would be far more desirable. +I strongly suspect that this is nothing but a type-o. + +[ +Resolution proposed by ballot comment: +]
+ ++Change p. 10 to read:+ +
+Let bk = xmin+k·δ for k = 0,...,n, and wk = fw(bk) +for k = 0,...,n. +[ +2010-11-02 Daniel translates into a proposed resolution +]
+ + +[ +2010 Batavia: The working group concurred with the issue's Proposed Resolution +]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+Change 26.5.8.5.3 [rand.dist.samp.plinear] p. 10 as indicated: ++10 Effects: Constructs a piecewise_linear_distribution object with parameters taken or calculated +from the following values: Let bk = xmin+k·δ for +k = 0, . . . , n, and wk = fw(bk+ + + + + ++δ) +for k = 0, . . . , n.
+1441. [FCD] Floating-point test functions are incorrectly specified
+Section: 26.8 [c.math] Status: WP + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-04
+View all other issues in [c.math].
+View all issues with WP status.
+Discussion:
+Addresses US-136
+ +Floating-point test functions are incorrectly specified. + +[ +Resolved in Rapperswil by a motion to directly apply the words from the ballot comment in N3102. +]
+ + + + +Proposed resolution:
+See Appendix 1 - Additional Details + + + + + +
+1445. [FCD] Several iostreams member functions incorrectly specified
+Section: 27.7 [iostream.format] Status: Resolved + Submitter: INCITS/PJ Plauger Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [iostream.format].
+View all issues with Resolved status.
+Discussion:
+Addresses US-137
+ +Several iostreams member functions are incorrectly +specified. + +[ +Resolution proposed by ballot comment: +]
+ ++See Appendix 1 - Additional Details +
+ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3168 would solve this issue. ++ + + +Proposed resolution:
+Addressed by paper n3168. + + + + + +
+1447. [FCD] Request to resolve issue LWG 1328
+Section: 27.7 [iostream.format] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [iostream.format].
+View all issues with Resolved status.
+Discussion:
+Addresses US-139
+ +Resolve issue LWG 1328 one way or the other, but +preferably in the direction outlined in the proposed +resolution, which, however, is not complete as-is: in any +case, the sentry must not set ok_ = false if is.good() == +false, otherwise istream::seekg, being an unformatted +input function, does not take any action because the +sentry object returns false when converted to type bool. +Thus, it remains impossible to seek away from end of file. + + +Proposed resolution:
+Addressed by paper n3168. + + + + + +
+1449. [FCD] Incomplete specification of header <cinttypes>
+Section: 27.8.2 [istringstream] Status: WP + Submitter: Canada Opened: 2010-08-25 Last modified: 2010-11-24
+View all issues with WP status.
+Discussion:
+Addresses CA-4
+ +Subclause 27.9.2 [c.files] specifies that <cinttypes> has +declarations for abs() and div(); however, the signatures +are not present in this subclause. The signatures +proposed under TR1 ([tr.c99.inttypes]) are not present in +FCD (unless if intmax_t happened to be long long). It is +unclear as to which, if any of the abs() and div() functions +in [c.math] are meant to be declared by <cinttypes>. This +subclause mentions imaxabs() and imaxdiv(). These +functions, among other things, are not specified in FCD to +be the functions from Subclause 7.8 of the C Standard. +Finally, <cinttypes> is not specified in FCD to include +<cstdint> (whereas <inttypes.h> includes <stdint.h> in C). + +[ +Post-Rapperswil, Daniel provides wording +]
+ + ++Subclause [c.files] specifies that <cinttypes> has declarations for abs() and div(); +however, the signatures are not present in this subclause. The signatures proposed under TR1 ([tr.c99.inttypes]) are not +present in FCD (unless if intmax_t happened to be long long). It is unclear as to which, if any of the +abs() and div() functions in [c.math] are meant to be declared by <cinttypes>. This +subclause mentions imaxabs() and imaxdiv(). These functions, among other things, are not specified in +FCD to be the functions from subclause 7.8 of the C Standard. Finally, <cinttypes> is not specified +in FCD to include <cstdint> (whereas <inttypes.h> includes <stdint.h> in C). +
+ ++Moved to Tentatively Ready with proposed wording after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++The wording refers to N3126. +
++
+ + + + + +- Add the following series of new paragraphs following [c.files] p.1: +
++Table 132 describes header <cinttypes>. [Note: The macros defined by <cinttypes> are provided unconditionally. +In particular, the symbol __STDC_FORMAT_MACROS, mentioned in footnote 182 of the C standard, plays no role in C++. +— end note ] +++2 - The contents of header <cinttypes> are the same as the Standard C library header <inttypes.h>, +with the following changes: +
++3 - The header <cinttypes> includes the header <cstdint> instead of <stdint.h>. +
++4 - If and only if the type intmax_t designates an extended integer type ([basic.fundamental]), the following function +signatures are added: +
+which shall have the same semantics as the function signatures intmax_t imaxabs(intmax_t) and +imaxdiv_t imaxdiv(intmax_t, intmax_t), respectively. + + +intmax_t abs(intmax_t); +imaxdiv_t div(intmax_t, intmax_t); +
+1453. [FCD] Default constructed match_results behavior for certain operations
+Section: 28.10.4 [re.results.acc] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [re.results.acc].
+View all issues with Resolved status.
+Discussion:
+Addresses GB-126
+ +It's unclear how match_results should behave if it has +been default-constructed. The sub_match objects +returned by operator[], prefix and suffix cannot point to the +end of the sequence that was searched if no search was +done. The iterators held by unmatched sub_match objects +might be singular. + +[ +Resolution proposed by ballot comment: +]
+ + ++Add to match_results::operator[], +match_results::prefix and match_results::suffix:+ +
+Requires: !empty() +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3158 would solve this issue. ++ + + +Proposed resolution:
+Addressed by paper n3158. + + + + + +
+1455. [FCD] C language compatibility for atomics
+Section: 29 [atomics] Status: Resolved + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-26
+View other active issues in [atomics].
+View all other issues in [atomics].
+View all issues with Resolved status.
+Duplicate of: 1454
+Discussion:
+Addresses CH-22, GB-128
++WG14 currently plans to introduce atomic facilities that are +intended to be compatible with the facilities of clause 29. +They should be compatible. +
+ +[ +Resolution proposed by ballot comment +]
+ ++Make sure the headers in clause 29 are defined in +a way that is compatible with the planned C +standard. +
+ +[ +2010 Batavia +]
+ ++Resolved by adoption of n3193. +
+ + +Proposed resolution:
+Solved by n3193. + + + + + +
+1462. [FCD] Ambiguous value assignment to atomic_bool
+Section: 29.5.1 [atomics.types.integral] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [atomics.types.integral].
+View all issues with Resolved status.
+Duplicate of: 1463
+Discussion:
+Addresses GB-132, US-157
+ +The atomic_itype types and atomic_address have two +overloads of operator=; one is volatile qualified, and the +other is not. atomic_bool only has the volatile qualified +version: ++On a non-volatile-qualified object this is ambiguous with +the deleted copy-assignment operator ++bool operator=(bool) volatile; ++due to the need for a single standard conversion in each +case when assigning a bool to an atomic_bool as in: ++atomic_bool& operator=(atomic_bool const&) = delete; ++The conversions are: ++atomic_bool b; +b = true; ++ vs ++atomic_bool& → atomic_bool volatile& ++ ++bool → atomic_bool +[ +Proposed resolution as of NB comment: +]
+ + ++Change 29.5.1 [atomics.types.integral] as indicated: + +
+ + +namespace std { + typedef struct atomic_bool { + [..] + bool operator=(bool) volatile; + bool operator=(bool); + } atomic_bool; + [..] +} +[ +2010-10-27 Daniel adds: +]
+ + ++Accepting n3164 would solve this issue +by replacing atomic_bool by atomic<bool>. ++ +[ +2010 Batavia +]
+ ++Resolved by adoption of n3193. +
+ + +Proposed resolution:
+Solved by n3193. + + + + + +
+1464. [FCD] Underspecified typedefs for atomic integral types
+Section: 29.5.1 [atomics.types.integral] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [atomics.types.integral].
+View all issues with Resolved status.
+Discussion:
+Addresses US-160
+ +The last sentence of 29.5.1 [atomics.types.integral] p.1 says: ++That's nice, but nothing says these are supposed to be part of the implementation, and +they are not listed in the synopsis. + ++Table 143 shows typedefs to atomic integral classes and the corresponding <cstdint> typedefs. +
[ +Proposed resolution as of NB comment +]
+ + ++
+
+ + +- Remove Table 143 — Atomics for standard typedef types. +
++
+- Change 29.5.1 [atomics.types.integral] p.1 as indicated: +
+++1 The name atomic_itype and the functions operating on it in the preceding synopsis are placeholders for a +set of classes and functions. Throughout the preceding synopsis, atomic_itype should be replaced by each +of the class names in Table 142 and integral should be replaced by the integral type corresponding to the +class name.
Table 143 shows typedefs to atomic integral classes and the corresponding <cstdint> typedefs.+[ +2010-10-27 Daniel adds: +]
+ + ++Accepting n3164 would solve this issue. ++ +[ +2010-11 Batavia +]
+ ++Resolved by adopting n3193. +
+ + + +Proposed resolution:
+Solved by n3193. + + + + + +
+1465. [FCD] Missing arithmetic operators for atomic_address
+Section: 29.5.2 [atomics.types.address] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [atomics.types.address].
+View all issues with Resolved status.
+Discussion:
+Addresses US-161
+ +atomic_address has operator+= and operator-=, but no +operator++ or operator--. The template specialization +atomic<Ty*> has all of them. + +[ +2010-10-27 Daniel adds: +]
+ + ++Accepting n3164 would solve this issue by +replacing atomic_address by atomic<void*>. ++ +[ +Resolved in Batavia by accepting +n3193. +]
+ + + + +Proposed resolution:
+Change 29.5.2 [atomics.types.address], class atomic_address synopsis, as indicated: +
+ + + + + + + +namespace std { + typedef struct atomic_address { + [..] + void* operator=(const void*) volatile; + void* operator=(const void*); + void* operator++(int) volatile; + void* operator++(int); + void* operator--(int) volatile; + void* operator--(int); + void* operator++() volatile; + void* operator++(); + void* operator--() volatile; + void* operator--(); + void* operator+=(ptrdiff_t) volatile; + void* operator+=(ptrdiff_t); + void* operator-=(ptrdiff_t) volatile; + void* operator-=(ptrdiff_t); + } atomic_address; + [..] +} +
+1466. [FCD] Silent const breakage by compare_exchange_* member functions
+Section: 29.5.2 [atomics.types.address] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [atomics.types.address].
+View all issues with Resolved status.
+Discussion:
+Addresses US-162
+ +The compare_exchange_weak and compare_exchange_strong member functions that take +const void* arguments lead to a silent removal of const, because the load +member function and other acessors return the stored value as a void*. + +[ +Proposed resolution as of NB comment: +]
+ + ++Change 29.5.2 [atomics.types.address], class atomic_address synopsis, as indicated: + +
+ + + +namespace std { + typedef struct atomic_address { + [..] +bool compare_exchange_weak(const void*&, const void*, + memory_order, memory_order) volatile;+bool compare_exchange_weak(const void*&, const void*, + memory_order, memory_order);+bool compare_exchange_strong(const void*&, const void*, + memory_order, memory_order) volatile;+bool compare_exchange_strong(const void*&, const void*, + memory_order, memory_order);+bool compare_exchange_weak(const void*&, const void*, + memory_order = memory_order_seq_cst) volatile;+bool compare_exchange_weak(const void*&, const void*, + memory_order = memory_order_seq_cst);+bool compare_exchange_strong(const void*&, const void*, + memory_order = memory_order_seq_cst) volatile;+bool compare_exchange_strong(const void*&, const void*, + memory_order = memory_order_seq_cst);+ [..] + } atomic_address; + [..] +} +[ +2010-10-27 Daniel adds: +]
+ + ++Accepting n3164 +would solve this issue by replacing atomic_address by atomic<void*>. ++ +[ +Resolved in Batavia by accepting +n3193. +]
+ + + + +Proposed resolution:
+Solved by n3193. + + + + + +
+1467. [FCD] Deriving atomic<T*> from atomic_address breaks type safety
+Section: 29.5.2 [atomics.types.address] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [atomics.types.address].
+View all issues with Resolved status.
+Discussion:
+Addresses US-163
+ +Requiring atomic<T*> to be derived from atomic_address breaks type safety: ++The last line overwrites ch with a value of type double. + +atomic<double*> ip; +char ch; +atomic_store(&ip, &ch); +*ip.load() = 3.14159; +[ +2010-10-27 Daniel adds: +]
+ + ++++Resolving this issue will also solve 1469 +
+Accepting n3164 would solve this issue by +removing atomic_address. +[ +Resolved in Batavia by accepting +n3193. +]
+ + + +Proposed resolution:
++
+ + + + + + +- Change 29.5 [atomics.types.generic], class template specialization atomic<T*> synopsis, as indicated: +
++namespace std { + template <class T> struct atomic<T*>: atomic_address{ + [..] + }; + [..] +} +- Change 29.5 [atomics.types.generic] p. 4 as indicated: +
++4 There are pointer partial specializations on the atomic class template.+These specializations shall be publicly +derived from atomic_address.The unit of addition/subtraction for these specializations shall be the size +of the referenced type. These specializations shall have trivial default constructors and trivial destructors. +
+1468. [FCD] atomic_address::compare_exchange_* member functions should match atomic_compare_exchange_* free functions
+Section: 29.5.2 [atomics.types.address] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [atomics.types.address].
+View all issues with Resolved status.
+Discussion:
+Addresses US-164
+ +atomic_address has member functions compare_exchange_weak and +compare_exchange_strong that take arguments of type const void*, +in addition to the void* versions. If these member functions survive, +there should be corresponding free functions. + +[ +2010-10-27 Daniel adds: +]
+ + ++Accepting n3164 would solve this issue +differently by removing the overloads with const void* arguments, because they break type-safety. ++[ +Resolved in Batavia by accepting +n3193. +]
+ + + +Proposed resolution:
+Extend the synopsis around atomic_address in 29.5.2 [atomics.types.address] +as indicated: ++ + + + + + +namespace std { + [..] + bool atomic_compare_exchange_weak(volatile atomic_address*, void**, void*); + bool atomic_compare_exchange_weak(atomic_address*, void**, void*); + bool atomic_compare_exchange_strong(volatile atomic_address*, void**, void*); + bool atomic_compare_exchange_strong(atomic_address*, void**, void*); + bool atomic_compare_exchange_weak_explicit(volatile atomic_address*, void**, void*, + memory_order, memory_order); + bool atomic_compare_exchange_weak_explicit(atomic_address*, void**, void*, + memory_order, memory_order); + bool atomic_compare_exchange_strong_explicit(volatile atomic_address*, void**, void*, + memory_order, memory_order); + bool atomic_compare_exchange_strong_explicit(atomic_address*, void**, void*, + memory_order, memory_order); + bool atomic_compare_exchange_weak(volatile atomic_address*, const void**, const void*); + bool atomic_compare_exchange_weak(atomic_address*, const void**, const void*); + bool atomic_compare_exchange_strong(volatile atomic_address*, const void**, const void*); + bool atomic_compare_exchange_strong(atomic_address*, const void**, const void*); + bool atomic_compare_exchange_weak_explicit(volatile atomic_address*, const void**, const void*, + memory_order, memory_order); + bool atomic_compare_exchange_weak_explicit(atomic_address*, const void**, const void*, + memory_order, memory_order); + bool atomic_compare_exchange_strong_explicit(volatile atomic_address*, const void**, const void*, + memory_order, memory_order); + bool atomic_compare_exchange_strong_explicit(volatile atomic_address*, const void**, const void*, + memory_order, memory_order); + bool atomic_compare_exchange_strong_explicit(atomic_address*, const void**, const void*, + memory_order, memory_order); + [..] +} +
+1469. [FCD] atomic<T*> inheritance from atomic_address breaks type safety
+Section: 29.5 [atomics.types.generic] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [atomics.types.generic].
+View all issues with Resolved status.
+Discussion:
+Addresses GB-133
+ +The free functions that operate on atomic_address can be +used to store a pointer to an unrelated type in an atomic<T*> +without a cast. e.g. ++Overload the atomic_store, atomic_exchange and +atomic_compare_exchange_[weak/strong] operations for +atomic<T*> to allow storing only pointers to T. + +int i; +atomic<int*> ai(&i); +string s; +atomic_store(&ai,&s); +[ +2010-10-27 Daniel adds: +]
+ + +++ ++Resolving this issue will also solve 1467 +
+Accepting n3164 would solve this issue by +removing atomic_address. +[Resolved in Batavia by accepting +n3193. +]
+ + + +Proposed resolution:
+Add the following overloads to 29.5 [atomics.types.generic], the synopsis around the specialization +atomic<T*>, as indicated: +
+ + + + + + +namespace std { + [..] + template <class T> struct atomic<T*> : atomic_address { + [..] + }; + + template<typename T> + void atomic_store(atomic<T*>&,T*); + template<typename T> + void atomic_store(atomic<T*>&,void*) = delete; + template<typename T> + void atomic_store_explicit(atomic<T*>&,T*,memory_order); + template<typename T> + void atomic_store_explicit(atomic<T*>&,void*,memory_order) = delete; + template<typename T> + T* atomic_exchange(atomic<T*>&,T*); + template<typename T> + T* atomic_exchange(atomic<T*>&,void*) = delete; + template<typename T> + T* atomic_exchange_explicit(atomic<T*>&,T*,memory_order); + template<typename T> + T* atomic_exchange_explicit(atomic<T*>&,void*,memory_order) = delete; + template<typename T> + T* atomic_compare_exchange_weak(atomic<T*>&,T**,T*); + template<typename T> + T* atomic_compare_exchange_weak(atomic<T*>&,void**,void*) = delete; + template<typename T> + T* atomic_compare_exchange_weak_explicit(atomic<T*>&,T**,T*,memory_order); + template<typename T> + T* atomic_compare_exchange_weak_explicit(atomic<T*>&,void**,void*,memory_order) = delete; + template<typename T> + T* atomic_compare_exchange_strong(atomic<T*>&,T**,T*); + template<typename T> + T* atomic_compare_exchange_strong(atomic<T*>&,void**,void*) = delete; + template<typename T> + T* atomic_compare_exchange_strong_explicit(atomic<T*>&,T**,T*,memory_order); + template<typename T> + T* atomic_compare_exchange_strong_explicit(atomic<T*>&,void**,void*,memory_order) = delete; + +} +
+1481. [FCD] Missing Lockable requirements
+Section: 30.2 [thread.req] Status: Resolved + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-26
+View all issues with Resolved status.
+Discussion:
+Addresses GB-138
+ +The FCD combines the requirements for lockable objects +with those for the standard mutex objects. These should +be separate. This is LWG issue 1268. + +[ +Resolution proposed by ballot comment: +]
+ ++See attached Appendix 1 - Additional Details ++ +[ +2010-11-01 Daniel comments: +]
+ ++Paper n3130 addresses +this issue. ++ + + +Proposed resolution:
+Resolved by n3197. + + + + + +
+1482. [FCD] Timeout operations are under-specified
+Section: 30.2.4 [thread.req.timing] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [thread.req.timing].
+View all issues with Resolved status.
+Discussion:
+Addresses US-181
+ +The timeout operations are under-specified. + +[ +Resolution proposed by ballot comment: +]
+ + ++Define precise semantics for timeout_until and timeout_for. See +n3141 page 193 - Appendix 1 - Additional Details ++ +[ +2010-11-01 Daniel comments: +]
+ + ++Accepting n3128 would solve this issue. ++ + +Proposed resolution:
+Resolved by n3191. + + + + + +
+1490. [FCD] Mutex requirements too stringent
+Section: 30.4.1 [thread.mutex.requirements] Status: Resolved + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [thread.mutex.requirements].
+View all issues with Resolved status.
+Discussion:
+Addresses CH-27
+ +The mutex requirements force try_lock to be +noexcept(true). However, where they are used by the +generic algorithms, those relax this requirement and say +that try_lock may throw. This means the requirement is +too stringent, also a non-throwing try_lock does not allow +for a diagnostic such as system_error that lock() +will give us. + +[ +Resolution proposed by ballot comment: +]
+ ++delete p18, adjust 30.4.4 p1 and p4 accordingly ++ +[ +2010-11-01 Daniel comments: +]
+ + ++Accepting n3130 would solve this issue. ++ + +Proposed resolution:
+Resolved by n3197. + + + + + +
+1491. [FCD] try_lock does not guarantee forward progress
+Section: 30.4.1 [thread.mutex.requirements] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [thread.mutex.requirements].
+View all issues with Resolved status.
+Discussion:
+Addresses US-186
+ +try_lock does not provide a guarantee of forward progress +because it is allowed to spuriously fail. + +[ +Resolution proposed by ballot comment: +]
+ ++The standard mutex types must not fail spuriously +in try_lock. See n3141 page 205 - Appendix 1 - Additional Details ++ +[ +2010-11-01 Daniel comments: +]
+ ++Paper n3152 addresses +this issue. ++ + + +Proposed resolution:
+Resolved by n3209. + + + + + +
+1492. [FCD] Mutex requirements should not be bound to threads
+Section: 30.4.1 [thread.mutex.requirements] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [thread.mutex.requirements].
+View all issues with Resolved status.
+Discussion:
+Addresses US-188
+ +Mutex requirements should not be bound to threads + +[ +Resolution proposed by ballot comment: +]
+ ++See Appendix 1 of n3141 - Additional Details, p. 208. ++ +[ +2010-10-24 Daniel adds: +]
+ + ++Accepting n3130 would solve this issue. ++ + +Proposed resolution:
+Resolved by n3197. + + + + + +
+1498. [FCD] Unclear specification for [thread.condition]
+Section: 30.5 [thread.condition] Status: Resolved + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-29
+View all other issues in [thread.condition].
+View all issues with Resolved status.
+Discussion:
+Addresses CH-29
+ +It is unclear if a spurious wake-up during the loop and reentering +of the blocked state due to a repeated execution +of the loop will adjust the timer of the blocking with the +respect to the previously specified rel_time value. + +[ +Resolution proposed by ballot comment: +]
+ + ++Make it clear (e.g. by a note) that when reexecuting +the loop the waiting time when blocked +will be adjusted with respect to the elapsed time of +the previous loop executions. ++ +[ +2010-08-13 Peter Sommerlad comments and provides wording: +]
+ + ++Problem: It is unclear if a spurious wake-up during the loop and re-entering of the blocked state due +to a repeated execution of the loop will adjust the timer of the blocking with the respect to the +previously specified rel_time value. ++ ++Proposed Resolution from CH29: +
+Make it clear (e.g. by a note) that when re-executing the loop the waiting time when blocked will be +adjusted with respect to the elapsed time of the previous loop executions. +
+Discussion in Rapperswil: +
+Assuming the introduction of a mandatory steady_clock proposed by US-181 to the FCD the +specification of condition_variable::wait_for can be defined in terms of wait_until +using the steady_clock. This is also interleaving with US-181, because that touches the +same paragraph (30.5.1 p 25, p34 and 30.5.2 p 20, p 28 in n3092.pdf) +
+(The "as if" in the proposed solutions should be confirmed by the standardization terminology experts) +
[ +2010-11 Batavia: Resolved by applying n3191 +]
+ + +++ + ++
+ +- Change 30.5.1 [thread.condition.condvar] paragraph 25, wait_for Effects as indicated: +
++template <class Rep, class Period> +cv_status wait_for(unique_lock<mutex>& lock, + const chrono::duration<Rep, Period>& rel_time); ++[..] +++25 Effects: as if +
+return wait_until(lock, chrono::steady_clock::now() + rel_time); ++
+- +
Atomically calls lock.unlock() and blocks on *this.+- +
When unblocked, calls lock.lock() (possibly blocking on the lock), then returns.+- +
The function will unblock when signaled by a call to notify_one() or a call to notify_all(), +by the elapsed time rel_time passing (30.2.4), or spuriously.+- +
If the function exits via an exception, lock.lock() shall be called prior to exiting the function scope.+- Change 30.5.1 [thread.condition.condvar] paragraph 34, wait_for with predicate Effects as indicated: +
+ ++template <class Rep, class Period, class Predicate> +bool wait_for(unique_lock<mutex>& lock, + const chrono::duration<Rep, Period>& rel_time, + Predicate pred); ++[..] +++34 Effects: as if +
+return wait_until(lock, chrono::steady_clock::now() + rel_time, std::move(pred)); ++
+- + +
Executes a loop: Within the loop the function first evaluates pred() and exits the loop if the +result is true. +- + +
Atomically calls lock.unlock() and blocks on *this. +- + +
When unblocked, calls lock.lock() (possibly blocking on the lock). +- + +
The function will unblock when signaled by a call to notify_one() or a call to notify_all(), +by the elapsed time rel_time passing (30.2.4), or spuriously. +- + +
If the function exits via an exception, lock.lock() shall be called prior to exiting the function +scope. +- + +
The loop terminates when pred() returns true or when the time duration specified by rel_time +has elapsed. +- Change 30.5.2 [thread.condition.condvarany] paragraph 20, wait_for Effects as indicated: +
+ ++template <class Lock, class Rep, class Period> +cv_status wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time); ++20 Effects: as if +++return wait_until(lock, chrono::steady_clock::now() + rel_time); ++
+- + +
Atomically calls lock.unlock() and blocks on *this. +- + +
When unblocked, calls lock.lock() (possibly blocking on the lock), then returns. +- + +
The function will unblock when signaled by a call to notify_one() or a call to notify_all(), +by the elapsed time rel_time passing (30.2.4), or spuriously. +- +
If the function exits via an exception, lock.unlock() shall be called prior to exiting the function +scope. +- Change 30.5.2 [thread.condition.condvarany] paragraph 28, wait_for with predicate Effects as indicated: +
+ ++template <class Lock, class Rep, class Period, class Predicate> +bool wait_for(Lock& lock, const chrono::duration<Rep, Period>& rel_time, Predicate pred); ++28 Effects: as if +++return wait_until(lock, chrono::steady_clock::now() + rel_time, std::move(pred)); ++
+- + +
Executes a loop: Within the loop the function first evaluates pred() and exits the loop if the +result is true. +- + +
Atomically calls lock.unlock() and blocks on *this. +- + +
When unblocked, calls lock.lock() (possibly blocking on the lock). +- + +
The function will unblock when signaled by a call to notify_one() or a call to notify_all(), +by the elapsed time rel_time passing (30.2.4), or spuriously. +- + +
If the function exits via an exception, lock.unlock() shall be called prior to exiting the function +scope. +- +
The loop terminates when pred() returns true or when the time duration specified by rel_time +has elapsed. +Proposed resolution:
+Resolved by n3191. + + + + + +
+1501. [FCD] spec for managing associated asynchronous +state has problems
+Section: 30.6 [futures] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [futures].
+View all issues with Resolved status.
+Discussion:
+Addresses US-194
+ +The specification for managing associated asynchronous +state is confusing, sometimes omitted, and redundantly +specified. + +[ +Resolution proposed by ballot comment: +]
+ + ++Define terms-of-art for releasing, making ready, +and abandoning an associated asynchronous +state. Use those terms where appropriate. See +Appendix 1 - Additional Details ++ + +Proposed resolution:
+Resolved in Batavia by accepting +n3192. + + + + + +
+1508. [FCD] Rename packaged_task::operator bool()
+Section: 30.6.10 [futures.task] Status: Resolved + Submitter: INCITS Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [futures.task].
+View all issues with Resolved status.
+Discussion:
+Addresses US-201
++packaged_task provides operator bool() to check whether +an object has an associated asynchronous state. The various future +types provide a member function valid() that does the same thing. +The names of these members should be the same. +
+ +[ +Resolution proposed by ballot comment: +]
+ ++Replaced the name packaged_task::operator bool() with packaged_task::valid() in the synopsis +(30.6.10 [futures.task]/2) and the member function specification (before 30.6.10.1 [futures.task.members]/15). ++ +[ +2010-11-02 Daniel translates proposed wording changes into a proper proposed resolution +and verified that no other places implicitly take advantage of packaged_task +conversion to bool. +]
+ + +[Resolved in Batavia by accepting +n3194. +]
+ + + + +Proposed resolution:
++
+ + + + + +- Change 30.6.10 [futures.task]/2, class template packaged_task synopsis as indicated: +
++template<class R, class... ArgTypes> +class packaged_task<R(ArgTypes...)> { +public: + typedef R result_type; + [..] +explicit operatorbool valid() const; + [..] +}; +- Change 30.6.10 [futures.task] before p. 15 as indicated: +
++explicit operatorbool valid() const; ++15 Returns: true only if *this has an associated asynchronous state. ++16 Throws: nothing. +
+1513. [FCD] 'launch' enum too restrictive
+Section: 30.6 [futures] Status: Resolved + Submitter: Switzerland Opened: 2010-08-25 Last modified: 2010-11-26
+View all other issues in [futures].
+View all issues with Resolved status.
+Discussion:
+Addresses CH-36
+ +Providing only three different possible values for the enum +launch and saying that launch::any means either +launch::sync or launch::async is very restricting. This +hinders future implementors to provide clever +infrastructures that can simply by used by a call to +async(launch::any,...). Also there is no hook for an +implementation to provide additional alternatives to launch +enumeration and no useful means to combine those (i.e. +interpret them like flags). We believe something like +async(launch::sync | launch::async, ...) should be allowed +and can become especially useful if one could say also +something like async(launch::any & ~launch::sync, ....) +respectively. This flexibility might limit the features usable +in the function called through async(), but it will allow a +path to effortless profit from improved hardware/software +without complicating the programming model when just +using async(launch::any,...) + +[ +Resolution proposed by ballot comment: +]
+ ++Change in 30.6.1 [futures.overview] 'enum class launch' to allow +further implementation defined values and provide +the following bit-operators on the launch values +(operator|, operator&, operator~ delivering a +launch value). +
+Note: a possible implementation might use an +unsigned value to represent the launch enums, +but we shouldn't limit the standard to just 32 or 64 +available bits in that case and also should keep +the launch enums in their own enum namespace. +
+Change [future.async] p3 according to the +changes to enum launch. change --launch::any to +"the implementation may choose any of the +policies it provides." Note: this can mean that an +implementation may restrict the called function to +take all required information by copy in case it will +be called in a different address space, or even, on +a different processor type. To ensure that a call is +either performed like launch::async or +launch::sync describe one should call +async(launch::sync|launch::async,...) +
+ +[ +2010-11-02 Daniel comments: +]
+ + ++The new paper n3113 provides concrete wording. ++ + +Proposed resolution:
+Resolved by n3188. + + + + + +
+1516. [FCD] No specification for which header contains auto_ptr
+Section: D.12 [depr.auto.ptr] Status: WP + Submitter: BSI Opened: 2010-08-25 Last modified: 2010-11-23
+View all issues with WP status.
+Discussion:
+Addresses GB-142
++auto_ptr does not appear in the <memory> synopsis and +[depr.auto.ptr] doesn't say which header declares it. +Conversely, the deprecated binders bind1st etc. are in the +<functional> synopsis, this is inconsistent +
++Either auto_ptr should be declared in the +<memory> synopsis, or the deprecated binders +should be removed from the <functional> synopsis +and appendix D should say which header declares +the binders and auto_ptr. +
+ +[ +Post-Rapperswil +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ +Add the following lines to the synopsis of header <memory> +in [memory]/1:
+++ + + + + +// [depr.auto.ptr], Class auto_ptr (deprecated): +template <class X> class auto_ptr;
+
+1517. default_delete's default constructor should be trivial
+Section: 20.9.9.1.2 [unique.ptr.dltr.dflt] Status: WP + Submitter: Daniel Krügler Opened: 2010-09-12 Last modified: 2010-11-23
+View all other issues in [unique.ptr.dltr.dflt].
+View all issues with WP status.
+Discussion:
++The current working draft does specify the default c'tor of default_delete in a manner +to guarantee static initialization for default-constructed objects of static storage duration +as a consequence of the acceptance of the proposal n2976 +but this paper overlooked the fact that the suggested declaration does not ensure that the type +will be a trivial type. The type default_delete was always considered as a simple wrapper for +calling delete or delete[], respectivly and should be a trivial type. +
++In agreement with the new settled core language rules this easy to realize by just changing the declaration to +
+constexpr default_delete() = default; ++This proposal also automatically solves the problem, that the semantics of the default constructor of the +partial specialization default_delete<T[]> is not specified at all. By defaulting its default constructor +as well, the semantics are well-defined. +
+ +[ +Post-Rapperswil +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+The following wording changes are against N3126.
+ ++
+ + + + + +- Change the synopsis of the primary template definition of default_delete in [unique.ptr.dltr.dflt] as indicated: +
++namespace std { + template <class T> struct default_delete { + constexpr default_delete() = default; + template <class U> default_delete(const default_delete<U>&); + void operator()(T*) const; + }; +} +- +Remove the prototype specification of the default_delete default constructor in [unique.ptr.dltr.dflt]/1. This +brings it in harmony with the style used in the partial specialization default_delete<T[]>. Since there are +neither implied nor explicit members, there is no possibility to misinterpret what the constructor does: +
++constexpr default_delete();++1 Effects: Default constructs a default_delete object.+- Change the synopsis of the partial specialization of default_delete in [unique.ptr.dltr.dflt1] as indicated: +
++namespace std { + template <class T> struct default_delete<T[]> { + constexpr default_delete() = default; + void operator()(T*) const; + template <class U> void operator()(U*) const = delete; + }; +}
+1518. Waiting for deferred functions
+Section: 30.6 [futures] Status: WP + Submitter: Alberto Ganesh Barbati Opened: 2010-09-14 Last modified: 2010-11-24
+View all other issues in [futures].
+View all issues with WP status.
+Discussion:
+The current WP N3126 contains ambiguous statements about the +behaviour of functions wait_for/wait_until in +case the future refers to a deferred function. Moreover, I believe +it describes a disputable intent, different from the one contained +in the original async proposals, that may have been introduced +inadvertently during the "async cleanup" that occurred recently. +Consider the following case:
+++int f(); +future<int> x = async(launch::deferred, f); +future_status s = x.wait_for(chrono::milliseconds(100)); +This example raises two questions:
++
+- is f invoked?
+- what is the value of s?
+According to the current WP, the answer to question 1 is yes, +because 30.6.9/3 says "The first call to a function waiting for the +associated asynchronous state created by this async call to become +ready shall invoke the deferred function in the thread that called +the waiting function". The answer to question 2, however, is not as +clear. According to 30.6.6/23, s should be +future_status::deferred because x refers to a +deferred function that is not running, but it should also be +future_status::ready because after executing f +(and we saw that f is always executed) the state becomes +ready. By the way, the expression "deferred function that is not +running" is very unfortunate in itself, because it may apply to +both the case where the function hasn't yet started, as well as the +case where it was executed and completed.
+While we clearly have a defect in the WP answering to question +2, it is my opinion that the answer to question 1 is wrong, which +is even worse. Consider that the execution of the function +f can take an arbitrarily long time. Having +wait_for() invoke f is a potential violation of +the reasonable expectation that the execution of +x.wait_for(chrono::milliseconds(100)) shall take at most +100 milliseconds plus a delay dependent on the quality of implementation +and the quality of management (as described in paper N3128). +In fact, previous versions of the WP +clearly specified that only function wait() is required to +execute the deferred function, while wait_for() and +wait_until() shouldn't.
+The proposed resolution captures the intent that +wait_for() and wait_until() should never attempt +to invoke the deferred function. In other words, the P/R provides +the following answers to the two questions above:
++
+- no
+- future_status::deferred
+In order to simplify the wording, the definition of deferred +function has been tweaked so that the function is no longer +considered deferred once its evaluation has started, as suggested +by Howard.
+Discussions in the reflector questioned whether +wait_for() and wait_until() should return +immediately or actually wait hoping for a second thread to execute +the deferred function. I believe that waiting could be useful only +in a very specific scenario but detrimental in the general case and +would introduce another source of ambiguity: should +wait_for() return future_status::deferred or +future_status::timeout after the wait? Therefore the P/R +specifies that wait_for/wait_until shall return +immediately, which is simpler, easier to explain and more useful in +the general case.
+ +[ +Post-Rapperswil +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ +The proposed wording changes are relative to the Final Committee Draft, +N3126.
+Note to the editor: the proposed wording is meant not be in conflict +with any change proposed by paper N3128 "C++ Timeout Specification". +Ellipsis are deliberately used to avoid any unintended overlapping.
++
+ + + + + + +- +
+In [futures.unique_future] 30.6.6/22:
+Effects: none if the associated asynchronous state contains +a deferred function (30.6.9), otherwise blocks until the +associated asynchronous state is ready or [...].
+- +
+In [futures.unique_future] 30.6.6/23 first bullet:
+— future_status::deferred if the associated asynchronous +state contains a deferred function
+that is not +running.- +
+In [futures.unique_future] 30.6.6/25:
+Effects: none if the associated asynchronous state contains +a deferred function (30.6.9), otherwise blocks until the +associated asynchronous state is ready or [...].
+- +
+In [futures.unique_future] 30.6.6/26 first bullet:
+— future_status::deferred if the associated asynchronous +state contains a deferred function
+that is not +running.- +
+In [futures.shared_future] 30.6.7/27
+Effects: none if the associated asynchronous state contains +a deferred function (30.6.9), otherwise blocks until the +associated asynchronous state is ready or [...].
+- +
+In [futures.unique_future] 30.6.7/28 first bullet:
+— future_status::deferred if the associated asynchronous +state contains a deferred function
+that is not +running.- +
+In [futures.shared_future] 30.6.6/30:
+Effects: none if the associated asynchronous state contains +a deferred function (30.6.9), otherwise blocks until the +associated asynchronous state is ready or [...].
+- +
+In [futures.unique_future] 30.6.7/31 first bullet:
+— future_status::deferred if the associated asynchronous +state contains a deferred function
+that is not +running.- +
+In [futures.atomic_future] 30.6.8/23
+Effects: none if the associated asynchronous state contains +a deferred function (30.6.9), otherwise blocks until the +associated asynchronous state is ready or [...].
+- +
+In [futures.unique_future] 30.6.8/24 first bullet:
+— future_status::deferred if the associated asynchronous +state contains a deferred function
+that is not +running.- +
+In [futures.atomic_future] 30.6.8/27:
+Effects: none if the associated asynchronous state contains +a deferred function (30.6.9), otherwise blocks until the +associated asynchronous state is ready or [...].
+- +
+In [futures.unique_future] 30.6.8/28 first bullet:
+— future_status::deferred if the associated asynchronous +state contains a deferred function
+that is not +running.- +
+In [futures.async] 30.6.9/3 second bullet:
+[...] The first call to a function +
+waitingrequiring a non-timed wait for the +associated asynchronous state created by this async call to become +ready shall invoke the deferred function in the thread that called +the waiting function; once evaluation of INVOKE(g, +xyz) begins, the function is no longer considered +deferredall other calls waiting for the same associated +asynchronous state to become ready shall block until the deferred +function has completed.
+1519. bucketsize() const only for unordered set
+Section: 23.7.1 [unord.map], 23.7.2 [unord.multimap], 23.7.4 [unord.multiset] Status: WP + Submitter: Nicolai Josuttis Opened: 2010-10-09 Last modified: 2010-11-24
+View all other issues in [unord.map].
+View all issues with WP status.
+Discussion:
++While bucket_size() is const for unordered_set, for all other unordered containers it is not defined as +constant member function. +
+ +[ +Post-Rapperswil +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ +The wording refers to N3126.
+ ++
+ + + + + + +- Change 23.7.1 Class template unordered_map [unord.map]/3, as indicated: +
++namespace std { + template <class Key, + class T, + class Hash = hash<Key>, + class Pred = std::equal_to<Key>, + class Alloc = std::allocator<std::pair<const Key, T> > > + class unordered_map + { + public: + [..] + // bucket interface + size_type bucket_count() const; + size_type max_bucket_count() const; + size_type bucket_size(size_type n) const; + [..] +- Change 23.7.2 Class template unordered_multimap [unord.multimap]/3, as indicated: +
++namespace std { + template <class Key, + class T, + class Hash = hash<Key>, + class Pred = std::equal_to<Key>, + class Alloc = std::allocator<std::pair<const Key, T> > > + class unordered_multimap + { + public: + [..] + // bucket interface + size_type bucket_count() const; + size_type max_bucket_count() const; + size_type bucket_size(size_type n) const; + [..] +- Change 23.7.4 Class template unordered_multiset [unord.multiset]/3, as indicated: +
++namespace std { + template <class Key, + class Hash = hash<Key>, + class Pred = std::equal_to<Key>, + class Alloc = std::allocator<Key> > + class unordered_multiset + { + public: + [..] + // bucket interface + size_type bucket_count() const; + size_type max_bucket_count() const; + size_type bucket_size(size_type n) const; + [..] +
+1520. INVOKE on member data pointer with too many arguments
+Section: 20.8.2 [func.require] Status: WP + Submitter: Howard Hinnant Opened: 2010-10-10 Last modified: 2010-11-23
+View all other issues in [func.require].
+View all issues with WP status.
+Discussion:
+ ++20.8.2 [func.require] p1 says: +
+ +++ ++1 Define INVOKE(f, t1, t2, ..., tN) as follows: +
+ ++
+- +(t1.*f)(t2, ..., tN) when f is a pointer to a member function +of a class T and t1 is an object of type T or a +reference to an object of type T or a reference to an object of a type +derived from T; +
+- +((*t1).*f)(t2, ..., tN) when f is a pointer to a member +function of a class T and t1 is not one of the types described +in the previous item; +
+- +t1.*f when f is a pointer to member data of a class T +and t1 is an object of type T or a reference to an object of +type T or a reference to an object of a type derived from T; +
+- +(*t1).*f when f is a pointer to member data of a class +T and t1 is not one of the types described in the previous +item; +
+- +f(t1, t2, ..., tN) in all other cases. +
++The question is: What happens in the 3rd and +4th bullets when N > 1? +
+ ++Does the presence of t2, ..., tN get ignored, or does it make the +INVOKE ill formed? +
+ ++Here is sample code which presents the problem in a concrete example: +
+ ++ +#include <functional> +#include <cassert> + +struct S { + char data; +}; + +typedef char S::*PMD; + +int main() +{ + S s; + PMD pmd = &S::data; + std::reference_wrapper<PMD> r(pmd); + r(s, 3.0) = 'a'; // well formed? + assert(s.data == 'a'); +} ++Without the "3.0" the example is well formed. +
++[Note: Daniel provided wording to make it explicit that the above example is ill-formed. — end note ] +
+ +[ +Post-Rapperswil +]
+ + ++Moved to Tentatively Ready after 5 positive votes on c++std-lib. ++ +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
+ +The wording refers to N3126.
+ ++Change 20.8.2 [func.require]/1 as indicated: +
+++ + + + + + ++1 Define INVOKE(f, t1, t2, ..., tN) as follows: +
+ ++
+- +... +
+- +... +
+- +t1.*f when N == 1 and f is a pointer to +member data of a class T and t1 is an object of type +T or a reference to an object of type T or a reference to an +object of a type derived from T; +
+- +(*t1).*f when N == 1 and f is a pointer to +member data of a class T and t1 is not one of the types +described in the previous item; +
+- +... +
+
+1522. conj specification is now nonsense
+Section: 26.4.9 [cmplx.over] Status: WP + Submitter: P.J. Plauger Opened: 2010-10-14 Last modified: 2010-11-24
+View all other issues in [cmplx.over].
+View all issues with WP status.
+Discussion:
++In Pittsburgh, we accepted the resolution of library issue 1137, to add +a sentence 3 to [cmplx.over]: +
++All the specified overloads shall have a return type which is the nested +value_type of the effectively cast arguments. +++This was already true for four of the six functions except conj and +proj. It is not completely unreasonable to make proj return +the real value only, but the IEC specification does call for an imaginary part +of -0 in some circumstances. The people who care about these distinctions really +care, and it is required by an international standard. +
++Making conj return just the real part breaks it horribly, however. It is +well understood in mathematics that conj(re + i*im) is (re - i*im), +and it is widely used. The accepted new definition makes conj useful only +for pure real operations. This botch absolutely must be fixed. +
+ +[ +2010 Batavia: The working group concurred with the issue's Proposed Resolution +]
+ + +[ +Adopted at 2010-11 Batavia +]
+ + + + +Proposed resolution:
++Remove the recently added paragraph 3 from [cmplx.over]: +
+++ + + + + +3 All the specified overloads shall have a return type which is the nested +value_type of the effectively cast arguments.+
+2002. Class template match_results does not specify the semantics of operator==
+Section: 28.10.8 [re.results.nonmember] Status: Resolved + Submitter: Daniel Krügler Opened: 2010-10-24 Last modified: 2010-11-26
+View all issues with Resolved status.
+Discussion:
++The Returns element of operator== says: +
+ ++true only if the two objects refer to the same match ++ ++It is not really clear what this means: The current specification would allow for an +implementation to return true, only if the address values of m1 and +m2 are the same. While this approach is unproblematic in terms of used operations +this is also a bit unsatisfactory. With identity equality alone there seems to be no convincing +reason to provide this operator at all. It could for example also refer to an comparison based +on iterator values. In this case a user should better know that this will be done, because +there is no guarantee at all that inter-container comparison of iterators +is a feasible operation. This was a clear outcome of the resolution provided in +N3066 +for LWG issue 446. +It could also mean that a character-based comparison of the individual sub_match +elements should be done - this would be equivalent to applying operator== to +the subexpressions, prefix and suffix. +
+ + + +Proposed resolution:
+Addressed by paper n3158. + + + + + + + \ No newline at end of file diff --git a/libstdc++-v3/doc/xml/manual/intro.xml b/libstdc++-v3/doc/xml/manual/intro.xml index 705119b6d3e..36e07b4370f 100644 --- a/libstdc++-v3/doc/xml/manual/intro.xml +++ b/libstdc++-v3/doc/xml/manual/intro.xml @@ -601,7 +601,7 @@ requirements of the license of GCC.- Replace "new" with "::new". 408: + - 408: Is vector<reverse_iterator<char*> > forbidden? @@ -686,7 +686,7 @@ requirements of the license of GCC. input_iterator' value_type.539: + - 539: @@ -803,7 +803,7 @@ requirements of the license of GCC.partial_sum and adjacent_difference should mention requirements Update / add the signatures. 865: + 865: More algorithms that throw away information The traditional HP / SGI return type and value is blessed