xref: /llvm-project/libcxx/include/__concepts/common_reference_with.h (revision 5aa03b648b827128d439f705cd7d57d59673741d)
158915667SArthur O'Dwyer //===----------------------------------------------------------------------===//
258915667SArthur O'Dwyer //
358915667SArthur O'Dwyer // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
458915667SArthur O'Dwyer // See https://llvm.org/LICENSE.txt for license information.
558915667SArthur O'Dwyer // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
658915667SArthur O'Dwyer //
758915667SArthur O'Dwyer //===----------------------------------------------------------------------===//
858915667SArthur O'Dwyer 
958915667SArthur O'Dwyer #ifndef _LIBCPP___CONCEPTS_COMMON_REFERENCE_WITH_H
1058915667SArthur O'Dwyer #define _LIBCPP___CONCEPTS_COMMON_REFERENCE_WITH_H
1158915667SArthur O'Dwyer 
1258915667SArthur O'Dwyer #include <__concepts/convertible_to.h>
1358915667SArthur O'Dwyer #include <__concepts/same_as.h>
1458915667SArthur O'Dwyer #include <__config>
1566ba7c32SNikolas Klauser #include <__type_traits/common_reference.h>
1658915667SArthur O'Dwyer 
1758915667SArthur O'Dwyer #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1858915667SArthur O'Dwyer #  pragma GCC system_header
1958915667SArthur O'Dwyer #endif
2058915667SArthur O'Dwyer 
2158915667SArthur O'Dwyer _LIBCPP_BEGIN_NAMESPACE_STD
2258915667SArthur O'Dwyer 
234f15267dSNikolas Klauser #if _LIBCPP_STD_VER >= 20
2458915667SArthur O'Dwyer 
2558915667SArthur O'Dwyer // [concept.commonref]
2658915667SArthur O'Dwyer 
2758915667SArthur O'Dwyer template <class _Tp, class _Up>
2858915667SArthur O'Dwyer concept common_reference_with =
2958915667SArthur O'Dwyer     same_as<common_reference_t<_Tp, _Up>, common_reference_t<_Up, _Tp>> &&
30*5aa03b64SLouis Dionne     convertible_to<_Tp, common_reference_t<_Tp, _Up>> && convertible_to<_Up, common_reference_t<_Tp, _Up>>;
3158915667SArthur O'Dwyer 
324f15267dSNikolas Klauser #endif // _LIBCPP_STD_VER >= 20
3358915667SArthur O'Dwyer 
3458915667SArthur O'Dwyer _LIBCPP_END_NAMESPACE_STD
3558915667SArthur O'Dwyer 
3658915667SArthur O'Dwyer #endif // _LIBCPP___CONCEPTS_COMMON_REFERENCE_WITH_H
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