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>
15 
16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17 #pragma GCC system_header
18 #endif
19 
20 _LIBCPP_PUSH_MACROS
21 #include <__undef_macros>
22 
23 _LIBCPP_BEGIN_NAMESPACE_STD
24 
25 template <class _Tp>
26 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename remove_reference<_Tp>::type&&
27 move(_Tp&& __t) _NOEXCEPT {
28   typedef _LIBCPP_NODEBUG_TYPE typename remove_reference<_Tp>::type _Up;
29   return static_cast<_Up&&>(__t);
30 }
31 
32 #ifndef _LIBCPP_CXX03_LANG
33 template <class _Tp>
34 using __move_if_noexcept_result_t =
35     typename conditional<!is_nothrow_move_constructible<_Tp>::value && is_copy_constructible<_Tp>::value, const _Tp&,
36                          _Tp&&>::type;
37 #else // _LIBCPP_CXX03_LANG
38 template <class _Tp>
39 using __move_if_noexcept_result_t = const _Tp&;
40 #endif
41 
42 template <class _Tp>
43 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 __move_if_noexcept_result_t<_Tp>
44 move_if_noexcept(_Tp& __x) _NOEXCEPT {
45   return _VSTD::move(__x);
46 }
47 
48 _LIBCPP_END_NAMESPACE_STD
49 
50 _LIBCPP_POP_MACROS
51 
52 #endif // _LIBCPP___UTILITY_MOVE_H
53