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_BOOLEAN_TESTABLE_H
10#define _LIBCPP___CONCEPTS_BOOLEAN_TESTABLE_H
11
12#include <__concepts/convertible_to.h>
13#include <__config>
14#include <__utility/forward.h>
15
16#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17# pragma GCC system_header
18#endif
19
20_LIBCPP_BEGIN_NAMESPACE_STD
21
22#if _LIBCPP_STD_VER >= 20
23
24// [concepts.booleantestable]
25
26template <class _Tp>
27concept __boolean_testable_impl = convertible_to<_Tp, bool>;
28
29template <class _Tp>
30concept __boolean_testable = __boolean_testable_impl<_Tp> && requires(_Tp&& __t) {
31 { !std::forward<_Tp>(__t) } -> __boolean_testable_impl;
32};
33
34#endif // _LIBCPP_STD_VER >= 20
35
36_LIBCPP_END_NAMESPACE_STD
37
38#endif // _LIBCPP___CONCEPTS_BOOLEAN_TESTABLE_H
39