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Refactor std::optional SFINAE constraints

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* include/std/optional (_Optional_payload): Use variable templates
	for conditions in default template arguments and exception
	specifications.
	(optional): Likewise. Adjust indentation.
	(optional::__not_self, optional::__not_tag, optional::_Requires): New
	SFINAE helpers.
	(optional::optional): Use new helpers in constructor constraints.
	* include/std/type_traits (__or_v, __and_v): New variable templates.
	* testsuite/20_util/optional/cons/value_neg.cc: Change dg-error to
	dg-prune-output. Remove unused header.

From-SVN: r263657
This commit is contained in:
Jonathan Wakely 2018-08-20 13:13:25 +01:00 • committed by Jonathan Wakely
parent 285ee4d029
commit b655b8fc7e
4 changed files with 187 additions and 177 deletions
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13
libstdc++-v3/ChangeLog
View file

@ -1,3 +1,16 @@
2018-08-20 Jonathan Wakely <jwakely@redhat.com>
* include/std/optional (_Optional_payload): Use variable templates
for conditions in default template arguments and exception
specifications.
(optional): Likewise. Adjust indentation.
(optional::__not_self, optional::__not_tag, optional::_Requires): New
SFINAE helpers.
(optional::optional): Use new helpers in constructor constraints.
* include/std/type_traits (__or_v, __and_v): New variable templates.
* testsuite/20_util/optional/cons/value_neg.cc: Change dg-error to
dg-prune-output. Remove unused header.
2018-08-18 François Dumont <fdumont@gcc.gnu.org>
* testsuite/25_algorithms/copy/86658.cc: Use dg-options to define

340
libstdc++-v3/include/std/optional
View file

@ -102,11 +102,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Payload for optionals with non-trivial destructor.
template <typename _Tp,
bool /*_HasTrivialDestructor*/ =
is_trivially_destructible<_Tp>::value,
is_trivially_destructible_v<_Tp>,
bool /*_HasTrivialCopyAssignment*/ =
is_trivially_copy_assignable<_Tp>::value,
is_trivially_copy_assignable_v<_Tp>,
bool /*_HasTrivialMoveAssignment*/ =
is_trivially_move_assignable<_Tp>::value>
is_trivially_move_assignable_v<_Tp>>
struct _Optional_payload
{
constexpr _Optional_payload() noexcept : _M_empty() { }
@ -165,8 +165,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Optional_payload&
operator=(_Optional_payload&& __other)
noexcept(__and_<is_nothrow_move_constructible<_Tp>,
is_nothrow_move_assignable<_Tp>>())
noexcept(__and_v<is_nothrow_move_constructible<_Tp>,
is_nothrow_move_assignable<_Tp>>)
{
if (this->_M_engaged && __other._M_engaged)
this->_M_get() = std::move(__other._M_get());
@ -199,7 +199,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename... _Args>
void
_M_construct(_Args&&... __args)
noexcept(is_nothrow_constructible<_Stored_type, _Args...>())
noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
{
::new ((void *) std::__addressof(this->_M_payload))
_Stored_type(std::forward<_Args>(__args)...);
@ -377,7 +377,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename... _Args>
void
_M_construct(_Args&&... __args)
noexcept(is_nothrow_constructible<_Stored_type, _Args...>())
noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
{
::new ((void *) std::__addressof(this->_M_payload))
_Stored_type(std::forward<_Args>(__args)...);
@ -468,8 +468,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Optional_payload&
operator=(_Optional_payload&& __other)
noexcept(__and_<is_nothrow_move_constructible<_Tp>,
is_nothrow_move_assignable<_Tp>>())
noexcept(__and_v<is_nothrow_move_constructible<_Tp>,
is_nothrow_move_assignable<_Tp>>)
{
if (this->_M_engaged && __other._M_engaged)
this->_M_get() = std::move(__other._M_get());
@ -496,7 +496,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename... _Args>
void
_M_construct(_Args&&... __args)
noexcept(is_nothrow_constructible<_Stored_type, _Args...>())
noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
{
::new ((void *) std::__addressof(this->_M_payload))
_Stored_type(std::forward<_Args>(__args)...);
@ -598,8 +598,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Optional_payload&
operator=(_Optional_payload&& __other)
noexcept(__and_<is_nothrow_move_constructible<_Tp>,
is_nothrow_move_assignable<_Tp>>())
noexcept(__and_v<is_nothrow_move_constructible<_Tp>,
is_nothrow_move_assignable<_Tp>>)
{
if (this->_M_engaged && __other._M_engaged)
this->_M_get() = std::move(__other._M_get());
@ -626,7 +626,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename... _Args>
void
_M_construct(_Args&&... __args)
noexcept(is_nothrow_constructible<_Stored_type, _Args...>())
noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
{
::new ((void *) std::__addressof(this->_M_payload))
_Stored_type(std::forward<_Args>(__args)...);
@ -665,7 +665,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename... _Args>
void
_M_construct(_Args&&... __args)
noexcept(is_nothrow_constructible<_Stored_type, _Args...>())
noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
{
::new
(std::__addressof(static_cast<_Dp*>(this)->_M_payload._M_payload))
@ -735,7 +735,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ }
constexpr _Optional_base(_Optional_base&& __other)
noexcept(is_nothrow_move_constructible<_Tp>())
noexcept(is_nothrow_move_constructible_v<_Tp>)
: _M_payload(__other._M_payload._M_engaged,
std::move(__other._M_payload))
{ }
@ -864,7 +864,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
constexpr _Optional_base(const _Optional_base& __other) = default;
constexpr _Optional_base(_Optional_base&& __other)
noexcept(is_nothrow_move_constructible<_Tp>())
noexcept(is_nothrow_move_constructible_v<_Tp>)
: _M_payload(__other._M_payload._M_engaged,
std::move(__other._M_payload))
{ }
@ -985,16 +985,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
class optional
: private _Optional_base<_Tp>,
private _Enable_copy_move<
// Copy constructor.
is_copy_constructible<_Tp>::value,
// Copy assignment.
__and_<is_copy_constructible<_Tp>, is_copy_assignable<_Tp>>::value,
// Move constructor.
is_move_constructible<_Tp>::value,
// Move assignment.
__and_<is_move_constructible<_Tp>, is_move_assignable<_Tp>>::value,
// Unique tag type.
optional<_Tp>>
// Copy constructor.
is_copy_constructible_v<_Tp>,
// Copy assignment.
__and_v<is_copy_constructible<_Tp>, is_copy_assignable<_Tp>>,
// Move constructor.
is_move_constructible_v<_Tp>,
// Move assignment.
__and_v<is_move_constructible<_Tp>, is_move_assignable<_Tp>>,
// Unique tag type.
optional<_Tp>>
{
static_assert(!is_same_v<remove_cv_t<_Tp>, nullopt_t>);
static_assert(!is_same_v<remove_cv_t<_Tp>, in_place_t>);
@ -1003,6 +1003,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
private:
using _Base = _Optional_base<_Tp>;
// SFINAE helpers
template<typename _Up>
using __not_self = __not_<is_same<optional, __remove_cvref_t<_Up>>>;
template<typename _Up>
using __not_tag = __not_<is_same<in_place_t, __remove_cvref_t<_Up>>>;
template<typename... _Cond>
using _Requires = enable_if_t<__and_v<_Cond...>, bool>;
public:
using value_type = _Tp;
@ -1011,171 +1019,158 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
constexpr optional(nullopt_t) noexcept { }
// Converting constructors for engaged optionals.
template <typename _Up = _Tp,
enable_if_t<__and_<
__not_<is_same<optional<_Tp>, decay_t<_Up>>>,
__not_<is_same<in_place_t, decay_t<_Up>>>,
is_constructible<_Tp, _Up&&>,
is_convertible<_Up&&, _Tp>
>::value, bool> = true>
constexpr optional(_Up&& __t)
template<typename _Up = _Tp,
_Requires<__not_self<_Up>, __not_tag<_Up>,
is_constructible<_Tp, _Up&&>,
is_convertible<_Up&&, _Tp>> = true>
constexpr
optional(_Up&& __t)
: _Base(std::in_place, std::forward<_Up>(__t)) { }
template<typename _Up = _Tp,
_Requires<__not_self<_Up>, __not_tag<_Up>,
is_constructible<_Tp, _Up&&>,
__not_<is_convertible<_Up&&, _Tp>>> = false>
explicit constexpr
optional(_Up&& __t)
: _Base(std::in_place, std::forward<_Up>(__t)) { }
template <typename _Up = _Tp,
enable_if_t<__and_<
__not_<is_same<optional<_Tp>, decay_t<_Up>>>,
__not_<is_same<in_place_t, decay_t<_Up>>>,
is_constructible<_Tp, _Up&&>,
__not_<is_convertible<_Up&&, _Tp>>
>::value, bool> = false>
explicit constexpr optional(_Up&& __t)
: _Base(std::in_place, std::forward<_Up>(__t)) { }
template<typename _Up,
_Requires<__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, const _Up&>,
is_convertible<const _Up&, _Tp>,
__not_<__converts_from_optional<_Tp, _Up>>> = true>
constexpr
optional(const optional<_Up>& __t)
{
if (__t)
emplace(*__t);
}
template<typename _Up,
_Requires<__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, const _Up&>,
__not_<is_convertible<const _Up&, _Tp>>,
__not_<__converts_from_optional<_Tp, _Up>>> = false>
explicit constexpr
optional(const optional<_Up>& __t)
{
if (__t)
emplace(*__t);
}
template <typename _Up,
enable_if_t<__and_<
__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, const _Up&>,
is_convertible<const _Up&, _Tp>,
__not_<__converts_from_optional<_Tp, _Up>>
>::value, bool> = true>
constexpr optional(const optional<_Up>& __t)
{
if (__t)
emplace(*__t);
}
_Requires<__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, _Up&&>,
is_convertible<_Up&&, _Tp>,
__not_<__converts_from_optional<_Tp, _Up>>> = true>
constexpr
optional(optional<_Up>&& __t)
{
if (__t)
emplace(std::move(*__t));
}
template <typename _Up,
enable_if_t<__and_<
__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, const _Up&>,
__not_<is_convertible<const _Up&, _Tp>>,
__not_<__converts_from_optional<_Tp, _Up>>
>::value, bool> = false>
explicit constexpr optional(const optional<_Up>& __t)
{
if (__t)
emplace(*__t);
}
template <typename _Up,
enable_if_t<__and_<
__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, _Up&&>,
is_convertible<_Up&&, _Tp>,
__not_<__converts_from_optional<_Tp, _Up>>
>::value, bool> = true>
constexpr optional(optional<_Up>&& __t)
{
if (__t)
emplace(std::move(*__t));
}
template <typename _Up,
enable_if_t<__and_<
__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, _Up&&>,
__not_<is_convertible<_Up&&, _Tp>>,
__not_<__converts_from_optional<_Tp, _Up>>
>::value, bool> = false>
explicit constexpr optional(optional<_Up>&& __t)
{
if (__t)
emplace(std::move(*__t));
}
_Requires<__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, _Up&&>,
__not_<is_convertible<_Up&&, _Tp>>,
__not_<__converts_from_optional<_Tp, _Up>>> = false>
explicit constexpr
optional(optional<_Up>&& __t)
{
if (__t)
emplace(std::move(*__t));
}
template<typename... _Args,
enable_if_t<is_constructible_v<_Tp, _Args&&...>, bool> = false>
explicit constexpr optional(in_place_t, _Args&&... __args)
: _Base(std::in_place, std::forward<_Args>(__args)...) { }
_Requires<is_constructible<_Tp, _Args&&...>> = false>
explicit constexpr
optional(in_place_t, _Args&&... __args)
: _Base(std::in_place, std::forward<_Args>(__args)...) { }
template<typename _Up, typename... _Args,
enable_if_t<is_constructible_v<_Tp,
initializer_list<_Up>&,
_Args&&...>, bool> = false>
explicit constexpr optional(in_place_t,
initializer_list<_Up> __il,
_Args&&... __args)
: _Base(std::in_place, __il, std::forward<_Args>(__args)...) { }
_Requires<is_constructible<_Tp,
initializer_list<_Up>&,
_Args&&...>> = false>
explicit constexpr
optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args)
: _Base(std::in_place, __il, std::forward<_Args>(__args)...) { }
// Assignment operators.
optional&
operator=(nullopt_t) noexcept
{
this->_M_reset();
return *this;
this->_M_reset();
return *this;
}
template<typename _Up = _Tp>
enable_if_t<__and_<
__not_<is_same<optional<_Tp>, decay_t<_Up>>>,
is_constructible<_Tp, _Up>,
__not_<__and_<is_scalar<_Tp>,
is_same<_Tp, decay_t<_Up>>>>,
is_assignable<_Tp&, _Up>>::value,
enable_if_t<__and_v<__not_self<_Up>,
__not_<__and_<is_scalar<_Tp>,
is_same<_Tp, decay_t<_Up>>>>,
is_constructible<_Tp, _Up>,
is_assignable<_Tp&, _Up>>,
optional&>
operator=(_Up&& __u)
{
if (this->_M_is_engaged())
this->_M_get() = std::forward<_Up>(__u);
else
this->_M_construct(std::forward<_Up>(__u));
operator=(_Up&& __u)
{
if (this->_M_is_engaged())
this->_M_get() = std::forward<_Up>(__u);
else
this->_M_construct(std::forward<_Up>(__u));
return *this;
}
return *this;
}
template<typename _Up>
enable_if_t<__and_<
__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, const _Up&>,
is_assignable<_Tp&, _Up>,
__not_<__converts_from_optional<_Tp, _Up>>,
__not_<__assigns_from_optional<_Tp, _Up>>
>::value,
enable_if_t<__and_v<__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, const _Up&>,
is_assignable<_Tp&, _Up>,
__not_<__converts_from_optional<_Tp, _Up>>,
__not_<__assigns_from_optional<_Tp, _Up>>>,
optional&>
operator=(const optional<_Up>& __u)
{
if (__u)
{
if (this->_M_is_engaged())
this->_M_get() = *__u;
else
this->_M_construct(*__u);
}
else
{
this->_M_reset();
}
return *this;
}
operator=(const optional<_Up>& __u)
{
if (__u)
{
if (this->_M_is_engaged())
this->_M_get() = *__u;
else
this->_M_construct(*__u);
}
else
{
this->_M_reset();
}
return *this;
}
template<typename _Up>
enable_if_t<__and_<
__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, _Up>,
is_assignable<_Tp&, _Up>,
__not_<__converts_from_optional<_Tp, _Up>>,
__not_<__assigns_from_optional<_Tp, _Up>>
>::value,
enable_if_t<__and_v<__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, _Up>,
is_assignable<_Tp&, _Up>,
__not_<__converts_from_optional<_Tp, _Up>>,
__not_<__assigns_from_optional<_Tp, _Up>>>,
optional&>
operator=(optional<_Up>&& __u)
{
if (__u)
{
if (this->_M_is_engaged())
this->_M_get() = std::move(*__u);
else
this->_M_construct(std::move(*__u));
}
else
{
this->_M_reset();
}
operator=(optional<_Up>&& __u)
{
if (__u)
{
if (this->_M_is_engaged())
this->_M_get() = std::move(*__u);
else
this->_M_construct(std::move(*__u));
}
else
{
this->_M_reset();
}
return *this;
}
return *this;
}
template<typename... _Args>
enable_if_t<is_constructible<_Tp, _Args&&...>::value, _Tp&>
enable_if_t<is_constructible_v<_Tp, _Args&&...>, _Tp&>
emplace(_Args&&... __args)
{
this->_M_reset();
@ -1184,8 +1179,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Up, typename... _Args>
enable_if_t<is_constructible<_Tp, initializer_list<_Up>&,
_Args&&...>::value, _Tp&>
enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&,
_Args&&...>, _Tp&>
emplace(initializer_list<_Up> __il, _Args&&... __args)
{
this->_M_reset();
@ -1198,19 +1193,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Swap.
void
swap(optional& __other)
noexcept(is_nothrow_move_constructible<_Tp>()
&& is_nothrow_swappable_v<_Tp>)
noexcept(is_nothrow_move_constructible_v<_Tp>
&& is_nothrow_swappable_v<_Tp>)
{
using std::swap;
using std::swap;
if (this->_M_is_engaged() && __other._M_is_engaged())
swap(this->_M_get(), __other._M_get());
else if (this->_M_is_engaged())
if (this->_M_is_engaged() && __other._M_is_engaged())
swap(this->_M_get(), __other._M_get());
else if (this->_M_is_engaged())
{
__other._M_construct(std::move(this->_M_get()));
this->_M_destruct();
}
else if (__other._M_is_engaged())
else if (__other._M_is_engaged())
{
this->_M_construct(std::move(__other._M_get()));
__other._M_destruct();
@ -1307,12 +1302,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
? std::move(this->_M_get())
: static_cast<_Tp>(std::forward<_Up>(__u));
}
void reset() noexcept { this->_M_reset(); }
};
template<typename _Tp>
using __optional_relop_t =
enable_if_t<is_convertible<_Tp, bool>::value, bool>;
enable_if_t<is_convertible<_Tp, bool>::value, bool>;
// Comparisons between optional values.
template<typename _Tp, typename _Up>

5
libstdc++-v3/include/std/type_traits
View file

@ -144,6 +144,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#if __cplusplus >= 201703L
template<typename... _Bn>
inline constexpr bool __or_v = __or_<_Bn...>::value;
template<typename... _Bn>
inline constexpr bool __and_v = __and_<_Bn...>::value;
#define __cpp_lib_logical_traits 201510
template<typename... _Bn>

6
libstdc++-v3/testsuite/20_util/optional/cons/value_neg.cc
View file

@ -19,8 +19,6 @@
// <http://www.gnu.org/licenses/>.
#include <optional>
#include <testsuite_hooks.h>
#include <string>
#include <memory>
@ -37,8 +35,6 @@ int main()
std::optional<std::unique_ptr<int>> oup2 = new int; // { dg-error "conversion" }
struct U { explicit U(std::in_place_t); };
std::optional<U> ou(std::in_place); // { dg-error "no matching" }
// { dg-error "no type" "" { target { *-*-* } } 1020 }
// { dg-error "no type" "" { target { *-*-* } } 1030 }
// { dg-error "no type" "" { target { *-*-* } } 1087 }
}
}
// { dg-prune-output "no type .*enable_if" }