xref: /llvm-project/libcxx/include/__cxx03/__concepts/common_with.h (revision ce7771902dc50d900de639d499a60486b83f70e0)
1e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===//
2e78f53d1SNikolas Klauser //
3e78f53d1SNikolas Klauser // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4e78f53d1SNikolas Klauser // See https://llvm.org/LICENSE.txt for license information.
5e78f53d1SNikolas Klauser // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6e78f53d1SNikolas Klauser //
7e78f53d1SNikolas Klauser //===----------------------------------------------------------------------===//
8e78f53d1SNikolas Klauser 
9*ce777190SNikolas Klauser #ifndef _LIBCPP___CXX03___CONCEPTS_COMMON_WITH_H
10*ce777190SNikolas Klauser #define _LIBCPP___CXX03___CONCEPTS_COMMON_WITH_H
11e78f53d1SNikolas Klauser 
1273fbae83SNikolas Klauser #include <__cxx03/__concepts/common_reference_with.h>
1373fbae83SNikolas Klauser #include <__cxx03/__concepts/same_as.h>
1473fbae83SNikolas Klauser #include <__cxx03/__config>
1573fbae83SNikolas Klauser #include <__cxx03/__type_traits/add_lvalue_reference.h>
1673fbae83SNikolas Klauser #include <__cxx03/__type_traits/common_reference.h>
1773fbae83SNikolas Klauser #include <__cxx03/__type_traits/common_type.h>
1873fbae83SNikolas Klauser #include <__cxx03/__utility/declval.h>
19e78f53d1SNikolas Klauser 
20e78f53d1SNikolas Klauser #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
21e78f53d1SNikolas Klauser #  pragma GCC system_header
22e78f53d1SNikolas Klauser #endif
23e78f53d1SNikolas Klauser 
24e78f53d1SNikolas Klauser _LIBCPP_BEGIN_NAMESPACE_STD
25e78f53d1SNikolas Klauser 
26e78f53d1SNikolas Klauser #if _LIBCPP_STD_VER >= 20
27e78f53d1SNikolas Klauser 
28e78f53d1SNikolas Klauser // [concept.common]
29e78f53d1SNikolas Klauser 
30e78f53d1SNikolas Klauser // clang-format off
31e78f53d1SNikolas Klauser template <class _Tp, class _Up>
32e78f53d1SNikolas Klauser concept common_with =
33e78f53d1SNikolas Klauser     same_as<common_type_t<_Tp, _Up>, common_type_t<_Up, _Tp>> &&
34e78f53d1SNikolas Klauser     requires {
35e78f53d1SNikolas Klauser         static_cast<common_type_t<_Tp, _Up>>(std::declval<_Tp>());
36e78f53d1SNikolas Klauser         static_cast<common_type_t<_Tp, _Up>>(std::declval<_Up>());
37e78f53d1SNikolas Klauser     } &&
38e78f53d1SNikolas Klauser     common_reference_with<
39e78f53d1SNikolas Klauser         add_lvalue_reference_t<const _Tp>,
40e78f53d1SNikolas Klauser         add_lvalue_reference_t<const _Up>> &&
41e78f53d1SNikolas Klauser     common_reference_with<
42e78f53d1SNikolas Klauser         add_lvalue_reference_t<common_type_t<_Tp, _Up>>,
43e78f53d1SNikolas Klauser         common_reference_t<
44e78f53d1SNikolas Klauser             add_lvalue_reference_t<const _Tp>,
45e78f53d1SNikolas Klauser             add_lvalue_reference_t<const _Up>>>;
46e78f53d1SNikolas Klauser // clang-format on
47e78f53d1SNikolas Klauser 
48e78f53d1SNikolas Klauser #endif // _LIBCPP_STD_VER >= 20
49e78f53d1SNikolas Klauser 
50e78f53d1SNikolas Klauser _LIBCPP_END_NAMESPACE_STD
51e78f53d1SNikolas Klauser 
52*ce777190SNikolas Klauser #endif // _LIBCPP___CXX03___CONCEPTS_COMMON_WITH_H
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