xref: /llvm-project/libcxx/include/__algorithm/move.h (revision 5629d492df388bf6b5532a2a5c1ef5fd27d65ab0)
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___ALGORITHM_MOVE_H
10 #define _LIBCPP___ALGORITHM_MOVE_H
11 
12 #include <__algorithm/copy_move_common.h>
13 #include <__algorithm/iterator_operations.h>
14 #include <__config>
15 #include <__type_traits/is_copy_constructible.h>
16 #include <__utility/move.h>
17 #include <__utility/pair.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 _AlgPolicy>
26 struct __move_loop {
27   template <class _InIter, class _Sent, class _OutIter>
28   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
29   operator()(_InIter __first, _Sent __last, _OutIter __result) const {
30     while (__first != __last) {
31       *__result = _IterOps<_AlgPolicy>::__iter_move(__first);
32       ++__first;
33       ++__result;
34     }
35     return std::make_pair(std::move(__first), std::move(__result));
36   }
37 };
38 
39 struct __move_trivial {
40   // At this point, the iterators have been unwrapped so any `contiguous_iterator` has been unwrapped to a pointer.
41   template <class _In, class _Out,
42             __enable_if_t<__can_lower_move_assignment_to_memmove<_In, _Out>::value, int> = 0>
43   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_In*, _Out*>
44   operator()(_In* __first, _In* __last, _Out* __result) const {
45     return std::__copy_trivial_impl(__first, __last, __result);
46   }
47 };
48 
49 template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter>
50 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
51 pair<_InIter, _OutIter>
52 __move(_InIter __first, _Sent __last, _OutIter __result) {
53   return std::__dispatch_copy_or_move<_AlgPolicy, __move_loop<_AlgPolicy>, __move_trivial>(
54       std::move(__first), std::move(__last), std::move(__result));
55 }
56 
57 template <class _InputIterator, class _OutputIterator>
58 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
59 _OutputIterator move(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
60   static_assert(is_copy_constructible<_InputIterator>::value, "Iterators has to be copy constructible.");
61   static_assert(is_copy_constructible<_OutputIterator>::value, "The output iterator has to be copy constructible.");
62 
63   return std::__move<_ClassicAlgPolicy>(
64       std::move(__first), std::move(__last), std::move(__result)).second;
65 }
66 
67 _LIBCPP_END_NAMESPACE_STD
68 
69 #endif // _LIBCPP___ALGORITHM_MOVE_H
70