xref: /freebsd/contrib/llvm-project/libcxx/include/__type_traits/is_trivially_relocatable.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
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___TYPE_TRAITS_IS_TRIVIALLY_RELOCATABLE_H
10 #define _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_RELOCATABLE_H
11 
12 #include <__config>
13 #include <__type_traits/enable_if.h>
14 #include <__type_traits/integral_constant.h>
15 #include <__type_traits/is_same.h>
16 #include <__type_traits/is_trivially_copyable.h>
17 
18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
19 #  pragma GCC system_header
20 #endif
21 
22 _LIBCPP_BEGIN_NAMESPACE_STD
23 
24 // A type is trivially relocatable if a move construct + destroy of the original object is equivalent to
25 // `memcpy(dst, src, sizeof(T))`.
26 
27 #if __has_builtin(__is_trivially_relocatable)
28 template <class _Tp, class = void>
29 struct __libcpp_is_trivially_relocatable : integral_constant<bool, __is_trivially_relocatable(_Tp)> {};
30 #else
31 template <class _Tp, class = void>
32 struct __libcpp_is_trivially_relocatable : is_trivially_copyable<_Tp> {};
33 #endif
34 
35 template <class _Tp>
36 struct __libcpp_is_trivially_relocatable<_Tp,
37                                          __enable_if_t<is_same<_Tp, typename _Tp::__trivially_relocatable>::value> >
38     : true_type {};
39 
40 _LIBCPP_END_NAMESPACE_STD
41 
42 #endif // _LIBCPP___TYPE_TRAITS_IS_TRIVIALLY_RELOCATABLE_H
43