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_REFERENCE_WITH_H 10349cc55cSDimitry Andric #define _LIBCPP___CONCEPTS_COMMON_REFERENCE_WITH_H 11349cc55cSDimitry Andric 12349cc55cSDimitry Andric #include <__concepts/convertible_to.h> 13349cc55cSDimitry Andric #include <__concepts/same_as.h> 14349cc55cSDimitry Andric #include <__config> 15bdd1243dSDimitry Andric #include <__type_traits/common_reference.h> 16349cc55cSDimitry Andric 17349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18349cc55cSDimitry Andric # pragma GCC system_header 19349cc55cSDimitry Andric #endif 20349cc55cSDimitry Andric 21349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 22349cc55cSDimitry Andric 23*06c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20 24349cc55cSDimitry Andric 25349cc55cSDimitry Andric // [concept.commonref] 26349cc55cSDimitry Andric 27349cc55cSDimitry Andric template <class _Tp, class _Up> 28349cc55cSDimitry Andric concept common_reference_with = 29349cc55cSDimitry Andric same_as<common_reference_t<_Tp, _Up>, common_reference_t<_Up, _Tp>> && 30*06c3fb27SDimitry Andric convertible_to<_Tp, common_reference_t<_Tp, _Up>> && convertible_to<_Up, common_reference_t<_Tp, _Up>>; 31349cc55cSDimitry Andric 32*06c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20 33349cc55cSDimitry Andric 34349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD 35349cc55cSDimitry Andric 36349cc55cSDimitry Andric #endif // _LIBCPP___CONCEPTS_COMMON_REFERENCE_WITH_H 37