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_PREDICATE_H 10 #define _LIBCPP___CONCEPTS_PREDICATE_H 11 12 #include <__concepts/boolean_testable.h> 13 #include <__concepts/invocable.h> 14 #include <__config> 15 #include <__functional/invoke.h> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 # pragma GCC system_header 19 #endif 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 #if _LIBCPP_STD_VER >= 20 24 25 // [concept.predicate] 26 27 template <class _Fn, class... _Args> 28 concept predicate = regular_invocable<_Fn, _Args...> && __boolean_testable<invoke_result_t<_Fn, _Args...>>; 29 30 #endif // _LIBCPP_STD_VER >= 20 31 32 _LIBCPP_END_NAMESPACE_STD 33 34 #endif // _LIBCPP___CONCEPTS_PREDICATE_H 35