xref: /freebsd/contrib/llvm-project/libcxx/include/__utility/move.h (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef _LIBCPP___UTILITY_MOVE_H
11 #define _LIBCPP___UTILITY_MOVE_H
12 
13 #include <__config>
14 #include <__type_traits/conditional.h>
15 #include <__type_traits/is_copy_constructible.h>
16 #include <__type_traits/is_nothrow_move_constructible.h>
17 #include <__type_traits/remove_reference.h>
18 
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 #  pragma GCC system_header
21 #endif
22 
23 _LIBCPP_BEGIN_NAMESPACE_STD
24 
25 template <class _Tp>
26 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __libcpp_remove_reference_t<_Tp>&&
27 move(_LIBCPP_LIFETIMEBOUND _Tp&& __t) _NOEXCEPT {
28   typedef _LIBCPP_NODEBUG __libcpp_remove_reference_t<_Tp> _Up;
29   return static_cast<_Up&&>(__t);
30 }
31 
32 template <class _Tp>
33 using __move_if_noexcept_result_t =
34     __conditional_t<!is_nothrow_move_constructible<_Tp>::value && is_copy_constructible<_Tp>::value, const _Tp&, _Tp&&>;
35 
36 template <class _Tp>
37 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __move_if_noexcept_result_t<_Tp>
38 move_if_noexcept(_LIBCPP_LIFETIMEBOUND _Tp& __x) _NOEXCEPT {
39   return std::move(__x);
40 }
41 
42 _LIBCPP_END_NAMESPACE_STD
43 
44 #endif // _LIBCPP___UTILITY_MOVE_H
45