xref: /freebsd/contrib/llvm-project/libcxx/include/__concepts/common_with.h (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1349cc55cSDimitry Andric //===----------------------------------------------------------------------===//
2349cc55cSDimitry Andric //
3349cc55cSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4349cc55cSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5349cc55cSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6349cc55cSDimitry Andric //
7349cc55cSDimitry Andric //===----------------------------------------------------------------------===//
8349cc55cSDimitry Andric 
9349cc55cSDimitry Andric #ifndef _LIBCPP___CONCEPTS_COMMON_WITH_H
10349cc55cSDimitry Andric #define _LIBCPP___CONCEPTS_COMMON_WITH_H
11349cc55cSDimitry Andric 
12349cc55cSDimitry Andric #include <__concepts/common_reference_with.h>
13349cc55cSDimitry Andric #include <__concepts/same_as.h>
14349cc55cSDimitry Andric #include <__config>
15bdd1243dSDimitry Andric #include <__type_traits/add_lvalue_reference.h>
16bdd1243dSDimitry Andric #include <__type_traits/common_reference.h>
17bdd1243dSDimitry Andric #include <__type_traits/common_type.h>
18bdd1243dSDimitry Andric #include <__utility/declval.h>
19349cc55cSDimitry Andric 
20349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
21349cc55cSDimitry Andric #  pragma GCC system_header
22349cc55cSDimitry Andric #endif
23349cc55cSDimitry Andric 
24349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
25349cc55cSDimitry Andric 
26*06c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20
27349cc55cSDimitry Andric 
28349cc55cSDimitry Andric // [concept.common]
29349cc55cSDimitry Andric 
30*06c3fb27SDimitry Andric // clang-format off
31349cc55cSDimitry Andric template <class _Tp, class _Up>
32349cc55cSDimitry Andric concept common_with =
33349cc55cSDimitry Andric     same_as<common_type_t<_Tp, _Up>, common_type_t<_Up, _Tp>> &&
34349cc55cSDimitry Andric     requires {
35bdd1243dSDimitry Andric         static_cast<common_type_t<_Tp, _Up>>(std::declval<_Tp>());
36bdd1243dSDimitry Andric         static_cast<common_type_t<_Tp, _Up>>(std::declval<_Up>());
37349cc55cSDimitry Andric     } &&
38349cc55cSDimitry Andric     common_reference_with<
39349cc55cSDimitry Andric         add_lvalue_reference_t<const _Tp>,
40349cc55cSDimitry Andric         add_lvalue_reference_t<const _Up>> &&
41349cc55cSDimitry Andric     common_reference_with<
42349cc55cSDimitry Andric         add_lvalue_reference_t<common_type_t<_Tp, _Up>>,
43349cc55cSDimitry Andric         common_reference_t<
44349cc55cSDimitry Andric             add_lvalue_reference_t<const _Tp>,
45349cc55cSDimitry Andric             add_lvalue_reference_t<const _Up>>>;
46*06c3fb27SDimitry Andric // clang-format on
47349cc55cSDimitry Andric 
48*06c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20
49349cc55cSDimitry Andric 
50349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD
51349cc55cSDimitry Andric 
52349cc55cSDimitry Andric #endif // _LIBCPP___CONCEPTS_COMMON_WITH_H
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