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_CONVERTIBLE_TO_H
10 #define _LIBCPP___CONCEPTS_CONVERTIBLE_TO_H
11 
12 #include <__config>
13 #include <__type_traits/is_convertible.h>
14 #include <__utility/declval.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 > 17
23 
24 // [concept.convertible]
25 
26 template<class _From, class _To>
27 concept convertible_to =
28   is_convertible_v<_From, _To> &&
29   requires {
30     static_cast<_To>(std::declval<_From>());
31   };
32 
33 #endif // _LIBCPP_STD_VER > 17
34 
35 _LIBCPP_END_NAMESPACE_STD
36 
37 #endif // _LIBCPP___CONCEPTS_CONVERTIBLE_TO_H
38