1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___CONCEPTS_RELATION_H 10 #define _LIBCPP___CONCEPTS_RELATION_H 11 12 #include <__concepts/predicate.h> 13 #include <__config> 14 15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 16 # pragma GCC system_header 17 #endif 18 19 _LIBCPP_BEGIN_NAMESPACE_STD 20 21 #if _LIBCPP_STD_VER >= 20 22 23 // [concept.relation] 24 25 template <class _Rp, class _Tp, class _Up> 26 concept relation = 27 predicate<_Rp, _Tp, _Tp> && predicate<_Rp, _Up, _Up> && predicate<_Rp, _Tp, _Up> && predicate<_Rp, _Up, _Tp>; 28 29 // [concept.equiv] 30 31 template <class _Rp, class _Tp, class _Up> 32 concept equivalence_relation = relation<_Rp, _Tp, _Up>; 33 34 // [concept.strictweakorder] 35 36 template <class _Rp, class _Tp, class _Up> 37 concept strict_weak_order = relation<_Rp, _Tp, _Up>; 38 39 #endif // _LIBCPP_STD_VER >= 20 40 41 _LIBCPP_END_NAMESPACE_STD 42 43 #endif // _LIBCPP___CONCEPTS_RELATION_H 44