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 <__utility/declval.h> 14 #include <type_traits> 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 !defined(_LIBCPP_HAS_NO_CONCEPTS) 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>(declval<_From>()); 31 }; 32 33 #endif // !defined(_LIBCPP_HAS_NO_CONCEPTS) 34 35 _LIBCPP_END_NAMESPACE_STD 36 37 #endif // _LIBCPP___CONCEPTS_CONVERTIBLE_TO_H 38