mirror of
git://gcc.gnu.org/git/gcc.git
synced 2025-04-04 09:50:43 +08:00
Implement std::common_reference for C++20
* include/std/type_traits (__do_common_type_impl): Implement additional COND-RES(CREF(D1), CRED(D2)) condition for C++20. (basic_common_reference, common_reference, common_reference_t): Define for C++20. * testsuite/20_util/common_reference/requirements/alias_decl.cc: New test. * testsuite/20_util/common_reference/requirements/ explicit_instantiation.cc: New test. * testsuite/20_util/common_reference/requirements/typedefs.cc: New test. From-SVN: r275594
This commit is contained in:
Jonathan Wakely
Jonathan Wakely
parent
e8b0314a58
commit
0f8b14ee8a
@ -1,5 +1,16 @@
|
||||
2019-09-10 Jonathan Wakely <jwakely@redhat.com>
|
||||
|
||||
* include/std/type_traits (__do_common_type_impl): Implement
|
||||
additional COND-RES(CREF(D1), CRED(D2)) condition for C++20.
|
||||
(basic_common_reference, common_reference, common_reference_t): Define
|
||||
for C++20.
|
||||
* testsuite/20_util/common_reference/requirements/alias_decl.cc: New
|
||||
test.
|
||||
* testsuite/20_util/common_reference/requirements/
|
||||
explicit_instantiation.cc: New test.
|
||||
* testsuite/20_util/common_reference/requirements/typedefs.cc: New
|
||||
test.
|
||||
|
||||
* include/std/charconv (to_chars): Rename to __to_chars_i. Define
|
||||
non-template overloads for each signed and unsigned integer type and
|
||||
char. Define deleted overload for bool (LWG 3266).
|
||||
|
||||
@ -2189,6 +2189,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||||
struct conditional<false, _Iftrue, _Iffalse>
|
||||
{ typedef _Iffalse type; };
|
||||
|
||||
// __remove_cvref_t (std::remove_cvref_t for C++11).
|
||||
template<typename _Tp>
|
||||
using __remove_cvref_t
|
||||
= typename remove_cv<typename remove_reference<_Tp>::type>::type;
|
||||
|
||||
/// common_type
|
||||
template<typename... _Tp>
|
||||
struct common_type;
|
||||
@ -2201,12 +2206,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||||
using __cond_t
|
||||
= decltype(true ? std::declval<_Tp>() : std::declval<_Up>());
|
||||
|
||||
// if decay_t<decltype(false ? declval<D1>() : declval<D2>())>
|
||||
// denotes a valid type, let C denote that type.
|
||||
template<typename _Tp, typename _Up>
|
||||
static __success_type<typename decay<__cond_t<_Tp, _Up>>::type>
|
||||
static __success_type<__decay_t<__cond_t<_Tp, _Up>>>
|
||||
_S_test(int);
|
||||
|
||||
#if __cplusplus > 201703L
|
||||
// Otherwise, if COND-RES(CREF(D1), CREF(D2)) denotes a type,
|
||||
// let C denote the type decay_t<COND-RES(CREF(D1), CREF(D2))>.
|
||||
template<typename _Tp, typename _Up>
|
||||
static __success_type<__remove_cvref_t<__cond_t<const _Tp&, const _Up&>>>
|
||||
_S_test_2(int);
|
||||
#endif
|
||||
|
||||
template<typename, typename>
|
||||
static __failure_type
|
||||
_S_test_2(...);
|
||||
|
||||
template<typename _Tp, typename _Up>
|
||||
static decltype(_S_test_2<_Tp, _Up>(0))
|
||||
_S_test(...);
|
||||
};
|
||||
|
||||
@ -2304,11 +2323,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||||
return __declval<_Tp>(0);
|
||||
}
|
||||
|
||||
// __remove_cvref_t (std::remove_cvref_t for C++11).
|
||||
template<typename _Tp>
|
||||
using __remove_cvref_t
|
||||
= typename remove_cv<typename remove_reference<_Tp>::type>::type;
|
||||
|
||||
/// result_of
|
||||
template<typename _Signature>
|
||||
class result_of;
|
||||
@ -3248,6 +3262,164 @@ template <typename _From, typename _To>
|
||||
{ return __builtin_is_constant_evaluated(); }
|
||||
#endif
|
||||
|
||||
template<typename _From, typename _To>
|
||||
using __copy_cv = typename __match_cv_qualifiers<_From, _To>::__type;
|
||||
|
||||
template<typename _Xp, typename _Yp>
|
||||
using __cond_res
|
||||
= decltype(false ? declval<_Xp(&)()>()() : declval<_Yp(&)()>()());
|
||||
|
||||
template<typename _Ap, typename _Bp, typename = void>
|
||||
struct __common_ref_impl
|
||||
{ };
|
||||
|
||||
// [meta.trans.other], COMMON-REF(A, B)
|
||||
template<typename _Ap, typename _Bp>
|
||||
using __common_ref = typename __common_ref_impl<_Ap, _Bp>::type;
|
||||
|
||||
// If A and B are both lvalue reference types, ...
|
||||
template<typename _Xp, typename _Yp>
|
||||
struct __common_ref_impl<_Xp&, _Yp&,
|
||||
__void_t<__cond_res<__copy_cv<_Xp, _Yp>&, __copy_cv<_Yp, _Xp>&>>>
|
||||
{ using type = __cond_res<__copy_cv<_Xp, _Yp>&, __copy_cv<_Yp, _Xp>&>; };
|
||||
|
||||
// let C be remove_reference_t<COMMON-REF(X&, Y&)>&&
|
||||
template<typename _Xp, typename _Yp>
|
||||
using __common_ref_C = remove_reference_t<__common_ref<_Xp&, _Yp&>>&&;
|
||||
|
||||
// If A and B are both rvalue reference types, ...
|
||||
template<typename _Xp, typename _Yp>
|
||||
struct __common_ref_impl<_Xp&&, _Yp&&,
|
||||
_Require<is_convertible<_Xp&&, __common_ref_C<_Xp, _Yp>>,
|
||||
is_convertible<_Yp&&, __common_ref_C<_Xp, _Yp>>>>
|
||||
{ using type = __common_ref_C<_Xp, _Yp>; };
|
||||
|
||||
// let D be COMMON-REF(const X&, Y&)
|
||||
template<typename _Xp, typename _Yp>
|
||||
using __common_ref_D = __common_ref<const _Xp&, _Yp&>;
|
||||
|
||||
// If A is an rvalue reference and B is an lvalue reference, ...
|
||||
template<typename _Xp, typename _Yp>
|
||||
struct __common_ref_impl<_Xp&&, _Yp&,
|
||||
_Require<is_convertible<_Xp&&, __common_ref_D<_Xp, _Yp>>>>
|
||||
{ using type = __common_ref_D<_Xp, _Yp>; };
|
||||
|
||||
// If A is an lvalue reference and B is an rvalue reference, ...
|
||||
template<typename _Xp, typename _Yp>
|
||||
struct __common_ref_impl<_Xp&, _Yp&&>
|
||||
: __common_ref_impl<_Yp&&, _Xp&>
|
||||
{ };
|
||||
|
||||
template<typename _Tp, typename _Up,
|
||||
template<typename> class _TQual, template<typename> class _UQual>
|
||||
struct basic_common_reference
|
||||
{ };
|
||||
|
||||
template<typename _Tp>
|
||||
struct __xref
|
||||
{ template<typename _Up> using __type = __copy_cv<_Tp, _Up>; };
|
||||
|
||||
template<typename _Tp>
|
||||
struct __xref<_Tp&>
|
||||
{ template<typename _Up> using __type = __copy_cv<_Tp, _Up>&; };
|
||||
|
||||
template<typename _Tp>
|
||||
struct __xref<_Tp&&>
|
||||
{ template<typename _Up> using __type = __copy_cv<_Tp, _Up>&&; };
|
||||
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
using __basic_common_ref
|
||||
= typename basic_common_reference<remove_cvref_t<_Tp1>,
|
||||
remove_cvref_t<_Tp2>,
|
||||
__xref<_Tp1>::template __type,
|
||||
__xref<_Tp2>::template __type>::type;
|
||||
|
||||
template<typename... _Tp>
|
||||
struct common_reference;
|
||||
|
||||
template<typename... _Tp>
|
||||
using common_reference_t = typename common_reference<_Tp...>::type;
|
||||
|
||||
// If sizeof...(T) is zero, there shall be no member type.
|
||||
template<>
|
||||
struct common_reference<>
|
||||
{ };
|
||||
|
||||
// If sizeof...(T) is one ...
|
||||
template<typename _Tp0>
|
||||
struct common_reference<_Tp0>
|
||||
{ using type = _Tp0; };
|
||||
|
||||
template<typename _Tp1, typename _Tp2, int _Bullet = 1, typename = void>
|
||||
struct __common_reference_impl
|
||||
: __common_reference_impl<_Tp1, _Tp2, _Bullet + 1>
|
||||
{ };
|
||||
|
||||
// If sizeof...(T) is two ...
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
struct common_reference<_Tp1, _Tp2>
|
||||
: __common_reference_impl<_Tp1, _Tp2>
|
||||
{ };
|
||||
|
||||
// If T1 and T2 are reference types and COMMON-REF(T1, T2) is well-formed, ...
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
struct __common_reference_impl<_Tp1&, _Tp2&, 1,
|
||||
void_t<__common_ref<_Tp1&, _Tp2&>>>
|
||||
{ using type = __common_ref<_Tp1&, _Tp2&>; };
|
||||
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
struct __common_reference_impl<_Tp1&&, _Tp2&&, 1,
|
||||
void_t<__common_ref<_Tp1&&, _Tp2&&>>>
|
||||
{ using type = __common_ref<_Tp1&&, _Tp2&&>; };
|
||||
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
struct __common_reference_impl<_Tp1&, _Tp2&&, 1,
|
||||
void_t<__common_ref<_Tp1&, _Tp2&&>>>
|
||||
{ using type = __common_ref<_Tp1&, _Tp2&&>; };
|
||||
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
struct __common_reference_impl<_Tp1&&, _Tp2&, 1,
|
||||
void_t<__common_ref<_Tp1&&, _Tp2&>>>
|
||||
{ using type = __common_ref<_Tp1&&, _Tp2&>; };
|
||||
|
||||
// Otherwise, if basic_common_reference<...>::type is well-formed, ...
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
struct __common_reference_impl<_Tp1, _Tp2, 2,
|
||||
void_t<__basic_common_ref<_Tp1, _Tp2>>>
|
||||
{ using type = __basic_common_ref<_Tp1, _Tp2>; };
|
||||
|
||||
// Otherwise, if COND-RES(T1, T2) is well-formed, ...
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
struct __common_reference_impl<_Tp1, _Tp2, 3,
|
||||
void_t<__cond_res<_Tp1, _Tp2>>>
|
||||
{ using type = __cond_res<_Tp1, _Tp2>; };
|
||||
|
||||
// Otherwise, if common_type_t<T1, T2> is well-formed, ...
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
struct __common_reference_impl<_Tp1, _Tp2, 4,
|
||||
void_t<common_type_t<_Tp1, _Tp2>>>
|
||||
{ using type = common_type_t<_Tp1, _Tp2>; };
|
||||
|
||||
// Otherwise, there shall be no member type.
|
||||
template<typename _Tp1, typename _Tp2>
|
||||
struct __common_reference_impl<_Tp1, _Tp2, 5, void>
|
||||
{ };
|
||||
|
||||
// Otherwise, if sizeof...(T) is greater than two, ...
|
||||
template<typename _Tp1, typename _Tp2, typename... _Rest>
|
||||
struct common_reference<_Tp1, _Tp2, _Rest...>
|
||||
: __common_type_fold<common_reference<_Tp1, _Tp2>,
|
||||
__common_type_pack<_Rest...>>
|
||||
{ };
|
||||
|
||||
// Reuse __common_type_fold for common_reference<T1, T2, Rest...>
|
||||
template<typename _Tp1, typename _Tp2, typename... _Rest>
|
||||
struct __common_type_fold<common_reference<_Tp1, _Tp2>,
|
||||
__common_type_pack<_Rest...>,
|
||||
void_t<common_reference_t<_Tp1, _Tp2>>>
|
||||
: public common_reference<common_reference_t<_Tp1, _Tp2>, _Rest...>
|
||||
{ };
|
||||
|
||||
#endif // C++2a
|
||||
|
||||
_GLIBCXX_END_NAMESPACE_VERSION
|
||||
|
||||
@ -0,0 +1,30 @@
|
||||
// Copyright (C) 2019 Free Software Foundation, Inc.
|
||||
//
|
||||
// This file is part of the GNU ISO C++ Library. This library is free
|
||||
// software; you can redistribute it and/or modify it under the
|
||||
// terms of the GNU General Public License as published by the
|
||||
// Free Software Foundation; either version 3, or (at your option)
|
||||
// any later version.
|
||||
//
|
||||
// This library is distributed in the hope that it will be useful,
|
||||
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
// GNU General Public License for more details.
|
||||
//
|
||||
// You should have received a copy of the GNU General Public License along
|
||||
// with this library; see the file COPYING3. If not see
|
||||
// <http://www.gnu.org/licenses/>.
|
||||
|
||||
// { dg-options "-std=gnu++2a" }
|
||||
// { dg-do compile { target c++2a } }
|
||||
|
||||
#include <type_traits>
|
||||
|
||||
using namespace std;
|
||||
|
||||
static_assert( is_same_v<common_reference<int>::type,
|
||||
common_reference_t<int>>);
|
||||
static_assert( is_same_v<common_reference<int&, const int&>::type,
|
||||
common_reference_t<int&, const int&>>);
|
||||
static_assert( is_same_v<common_reference<int, long&, char, unsigned&>::type,
|
||||
common_reference_t<int, long&, char, unsigned&>>);
|
||||
@ -0,0 +1,42 @@
|
||||
// Copyright (C) 2019 Free Software Foundation, Inc.
|
||||
//
|
||||
// This file is part of the GNU ISO C++ Library. This library is free
|
||||
// software; you can redistribute it and/or modify it under the
|
||||
// terms of the GNU General Public License as published by the
|
||||
// Free Software Foundation; either version 3, or (at your option)
|
||||
// any later version.
|
||||
|
||||
// This library is distributed in the hope that it will be useful,
|
||||
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
// GNU General Public License for more details.
|
||||
|
||||
// You should have received a copy of the GNU General Public License along
|
||||
// with this library; see the file COPYING3. If not see
|
||||
// <http://www.gnu.org/licenses/>.
|
||||
|
||||
// NB: This file is for testing type_traits with NO OTHER INCLUDES.
|
||||
|
||||
// { dg-options "-std=gnu++2a" }
|
||||
// { dg-do compile { target c++2a } }
|
||||
|
||||
#include <type_traits>
|
||||
|
||||
using test_type1 = int;
|
||||
using test_type2 = int&;
|
||||
using test_type3 = double;
|
||||
using test_type4 = float&;
|
||||
using test_type5 = void;
|
||||
using test_type6 = const void;
|
||||
|
||||
namespace std
|
||||
{
|
||||
template struct common_reference<>;
|
||||
template struct common_reference<test_type1>;
|
||||
template struct common_reference<test_type1, test_type2>;
|
||||
template struct common_reference<test_type1, test_type2, test_type3>;
|
||||
template struct common_reference<test_type1, test_type2, test_type3, test_type4>;
|
||||
|
||||
template struct common_reference<test_type5>;
|
||||
template struct common_reference<test_type5, test_type6>;
|
||||
}
|
||||
@ -0,0 +1,92 @@
|
||||
// Copyright (C) 2019 Free Software Foundation, Inc.
|
||||
//
|
||||
// This file is part of the GNU ISO C++ Library. This library is free
|
||||
// software; you can redistribute it and/or modify it under the
|
||||
// terms of the GNU General Public License as published by the
|
||||
// Free Software Foundation; either version 3, or (at your option)
|
||||
// any later version.
|
||||
//
|
||||
// This library is distributed in the hope that it will be useful,
|
||||
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
// GNU General Public License for more details.
|
||||
//
|
||||
// You should have received a copy of the GNU General Public License along
|
||||
// with this library; see the file COPYING3. If not see
|
||||
// <http://www.gnu.org/licenses/>.
|
||||
|
||||
// { dg-options "-std=gnu++2a" }
|
||||
// { dg-do compile { target c++2a } }
|
||||
|
||||
#include <type_traits>
|
||||
|
||||
template<typename T, typename = void>
|
||||
struct has_type : std::false_type { };
|
||||
|
||||
template<typename T>
|
||||
struct has_type<T, std::void_t<typename T::type>> : std::true_type { };
|
||||
|
||||
template<typename... T>
|
||||
constexpr bool
|
||||
has_common_ref()
|
||||
{
|
||||
return has_type<std::common_reference<T...>>::value;
|
||||
}
|
||||
|
||||
using std::is_same_v;
|
||||
using std::common_reference_t;
|
||||
|
||||
void test01()
|
||||
{
|
||||
|
||||
static_assert( !has_common_ref<>() );
|
||||
static_assert( !has_common_ref<char(*)(), int(*)()>() );
|
||||
static_assert( !has_common_ref<void*, int>() );
|
||||
|
||||
static_assert( is_same_v<common_reference_t<int>, int> );
|
||||
static_assert( is_same_v<common_reference_t<int&>, int&> );
|
||||
static_assert( is_same_v<common_reference_t<void>, void> );
|
||||
static_assert( is_same_v<common_reference_t<const void>, const void> );
|
||||
static_assert( is_same_v<common_reference_t<const void, void>, void> );
|
||||
static_assert( is_same_v<common_reference_t<void(*const)(), void(*)()>, void(*)()> );
|
||||
static_assert( is_same_v<common_reference_t<int, int>, int> );
|
||||
static_assert( is_same_v<common_reference_t<int&, int>, int> );
|
||||
static_assert( is_same_v<common_reference_t<int, int&>, int> );
|
||||
static_assert( is_same_v<common_reference_t<int&&, int>, int> );
|
||||
static_assert( is_same_v<common_reference_t<int&, int&>, int&> );
|
||||
static_assert( is_same_v<common_reference_t<int&, int&&>, const int&> );
|
||||
static_assert( is_same_v<common_reference_t<int&&, int&>, const int&> );
|
||||
static_assert( is_same_v<common_reference_t<int&&, int&&>, int&&> );
|
||||
static_assert( is_same_v<common_reference_t<int&&, const int&&>, const int&&> );
|
||||
static_assert( is_same_v<common_reference_t<int&, int&, int&&>, const int&> );
|
||||
static_assert( is_same_v<common_reference_t<int&&, int&, int&>, const int&> );
|
||||
static_assert( is_same_v<common_reference_t<char&, int&>, int> );
|
||||
static_assert( is_same_v<common_reference_t<long&, int&>, long> );
|
||||
}
|
||||
|
||||
struct A { };
|
||||
struct B { };
|
||||
struct C { };
|
||||
|
||||
template<template<typename> class AQual, template<typename> class BQual>
|
||||
struct std::basic_common_reference<A, B, AQual, BQual>
|
||||
{
|
||||
using type = BQual<AQual<C>>;
|
||||
};
|
||||
|
||||
static_assert( is_same_v<common_reference_t<A, B>, C> );
|
||||
static_assert( is_same_v<common_reference_t<A&, B>, C&> );
|
||||
static_assert( is_same_v<common_reference_t<A&, const B>, C&> );
|
||||
static_assert( is_same_v<common_reference_t<const A, B&>, const C&> );
|
||||
static_assert( is_same_v<common_reference_t<const A&, B&&>, const C&> );
|
||||
static_assert( is_same_v<common_reference_t<const A, B&&>, const C&&> );
|
||||
|
||||
struct D { };
|
||||
struct E { };
|
||||
struct F { };
|
||||
|
||||
template<> struct std::common_type<D, E> { using type = F; };
|
||||
|
||||
static_assert( is_same_v<common_reference_t<D, E>, F> );
|
||||
static_assert( is_same_v<common_reference_t<D&, E>, F> );
|
||||
static_assert( is_same_v<common_reference_t<D&, E&&>, F> );
|
||||
Loading…
x
Reference in New Issue
Block a user