v1/__concepts/predicate.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___CONCEPTS_PREDICATE_H
0010 #define _LIBCPP___CONCEPTS_PREDICATE_H
0011
0012 #include <__concepts/boolean_testable.h>
0013 #include <__concepts/invocable.h>
0014 #include <__config>
0015 #include <__type_traits/invoke.h>
0016
0017 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0018 #  pragma GCC system_header
0019 #endif
0020
0021 _LIBCPP_BEGIN_NAMESPACE_STD
0022
0023 #if _LIBCPP_STD_VER >= 20
0024
0025 // [concept.predicate]
0026
0027 template <class _Fn, class... _Args>
0028 concept predicate = regular_invocable<_Fn, _Args...> && __boolean_testable<invoke_result_t<_Fn, _Args...>>;
0029
0030 #endif // _LIBCPP_STD_VER >= 20
0031
0032 _LIBCPP_END_NAMESPACE_STD
0033
0034 #endif // _LIBCPP___CONCEPTS_PREDICATE_H