procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

libstdc++: Do not add padding for std::print to std::ostream

Browse source 
Tim Song pointed out that although std::print behaves as a formatted
output function, it does "determine padding" using the stream's flags.

libstdc++-v3/ChangeLog:

	* include/std/ostream (vprint_nonunicode, vprint_unicode): Do
	not insert padding.
	* testsuite/27_io/basic_ostream/print/1.cc: Adjust expected
	behaviour.
This commit is contained in:
Jonathan Wakely 2023-12-15 12:21:36 +00:00
parent 3fa689f6ed
commit 8a5cac92e7
2 changed files with 8 additions and 48 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

46
libstdc++-v3/include/std/ostream
View file

@ -891,21 +891,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__try
{
const streamsize __w = __os.width();
const streamsize __n = __out.size();
if (__w > __n)
{
const bool __left
= (__os.flags() & ios_base::adjustfield) == ios_base::left;
if (!__left)
std::__ostream_fill(__os, __w - __n);
if (__os.good())
std::__ostream_write(__os, __out.data(), __n);
if (__left && __os.good())
std::__ostream_fill(__os, __w - __n);
}
else
std::__ostream_write(__os, __out.data(), __n);
std::__ostream_write(__os, __out.data(), __out.size());
}
__catch(const __cxxabiv1::__forced_unwind&)
{
@ -923,11 +909,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
ostream::sentry __cerb(__os);
if (__cerb)
{
const streamsize __w = __os.width();
const bool __left
= (__os.flags() & ios_base::adjustfield) == ios_base::left;
__format::_Str_sink<char> __buf;
std::vformat_to(__buf.out(), __os.getloc(), __fmt, __args);
auto __out = __buf.view();
@ -938,18 +919,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// If stream refers to a terminal, write a Unicode string to it.
if (auto __term = __open_terminal(__os.rdbuf()))
{
__format::_Str_sink<char> __buf2;
if (__w != 0)
{
char __fmt[] = "{0:..{1}}";
__fmt[3] == __os.fill();
__fmt[4] == __left ? '<' : '>';
string_view __str(__out);
std::vformat_to(__buf2.out(), // N.B. no need to use getloc()
__fmt, std::make_format_args(__str, __w));
__out = __buf2.view();
}
ios_base::iostate __err = ios_base::goodbit;
__try
{
@ -981,18 +950,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Otherwise just insert the string as normal.
__try
{
const streamsize __n = __out.size();
if (__w > __n)
{
if (!__left)
std::__ostream_fill(__os, __w - __n);
if (__os.good())
std::__ostream_write(__os, __out.data(), __n);
if (__left && __os.good())
std::__ostream_fill(__os, __w - __n);
}
else
std::__ostream_write(__os, __out.data(), __n);
std::__ostream_write(__os, __out.data(), __out.size());
}
__catch(const __cxxabiv1::__forced_unwind&)
{

10
libstdc++-v3/testsuite/27_io/basic_ostream/print/1.cc
View file

@ -42,14 +42,16 @@ test_print_raw()
}
void
test_print_formatted()
test_print_no_padding()
{
// [ostream.formatted.print] does not say this function "determines padding",
// see https://gcc.gnu.org/pipermail/gcc-patches/2023-December/640680.html
char buf[64];
std::spanstream os(buf);
os << std::setw(20) << std::setfill('*') << std::right;
os << std::setw(60) << std::setfill('?') << std::right; // should be ignored
std::print(os, "{} Luftballons", 99);
std::string_view txt(os.span());
VERIFY( txt == "******99 Luftballons" );
VERIFY( txt == "99 Luftballons" );
}
void
@ -106,7 +108,7 @@ int main()
test_print_ostream();
test_println_ostream();
test_print_raw();
test_print_formatted();
test_print_no_padding();
test_vprint_nonunicode();
test_locale();
}