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_DERIVED_FROM_H
10 #define _LIBCPP___CONCEPTS_DERIVED_FROM_H
11 
12 #include <__config>
13 #include <type_traits>
14 
15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16 #  pragma GCC system_header
17 #endif
18 
19 _LIBCPP_BEGIN_NAMESPACE_STD
20 
21 #if _LIBCPP_STD_VER > 17
22 
23 // [concept.derived]
24 
25 template<class _Dp, class _Bp>
26 concept derived_from =
27   is_base_of_v<_Bp, _Dp> &&
28   is_convertible_v<const volatile _Dp*, const volatile _Bp*>;
29 
30 #endif // _LIBCPP_STD_VER > 17
31 
32 _LIBCPP_END_NAMESPACE_STD
33 
34 #endif // _LIBCPP___CONCEPTS_DERIVED_FROM_H
35