xref: /freebsd/contrib/llvm-project/libcxx/include/__concepts/convertible_to.h (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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_CONVERTIBLE_TO_H
10349cc55cSDimitry Andric #define _LIBCPP___CONCEPTS_CONVERTIBLE_TO_H
11349cc55cSDimitry Andric 
12349cc55cSDimitry Andric #include <__config>
13bdd1243dSDimitry Andric #include <__type_traits/is_convertible.h>
1404eeddc0SDimitry Andric #include <__utility/declval.h>
15349cc55cSDimitry Andric 
16349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17349cc55cSDimitry Andric #  pragma GCC system_header
18349cc55cSDimitry Andric #endif
19349cc55cSDimitry Andric 
20349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
21349cc55cSDimitry Andric 
22*06c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20
23349cc55cSDimitry Andric 
24349cc55cSDimitry Andric // [concept.convertible]
25349cc55cSDimitry Andric 
26349cc55cSDimitry Andric template <class _From, class _To>
27*06c3fb27SDimitry Andric concept convertible_to = is_convertible_v<_From, _To> && requires { static_cast<_To>(std::declval<_From>()); };
28349cc55cSDimitry Andric 
29*06c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20
30349cc55cSDimitry Andric 
31349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD
32349cc55cSDimitry Andric 
33349cc55cSDimitry Andric #endif // _LIBCPP___CONCEPTS_CONVERTIBLE_TO_H
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