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/for_each_segment.h>
14 #include <__algorithm/iterator_operations.h>
15 #include <__algorithm/min.h>
16 #include <__config>
17 #include <__iterator/segmented_iterator.h>
18 #include <__type_traits/common_type.h>
19 #include <__type_traits/is_copy_constructible.h>
20 #include <__utility/move.h>
21 #include <__utility/pair.h>
22
23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24 # pragma GCC system_header
25 #endif
26
27 _LIBCPP_PUSH_MACROS
28 #include <__undef_macros>
29
30 _LIBCPP_BEGIN_NAMESPACE_STD
31
32 template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter>
33 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
34 __move(_InIter __first, _Sent __last, _OutIter __result);
35
36 template <class _AlgPolicy>
37 struct __move_loop {
38 template <class _InIter, class _Sent, class _OutIter>
39 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
operator__move_loop40 operator()(_InIter __first, _Sent __last, _OutIter __result) const {
41 while (__first != __last) {
42 *__result = _IterOps<_AlgPolicy>::__iter_move(__first);
43 ++__first;
44 ++__result;
45 }
46 return std::make_pair(std::move(__first), std::move(__result));
47 }
48
49 template <class _InIter, class _OutIter>
50 struct _MoveSegment {
51 using _Traits = __segmented_iterator_traits<_InIter>;
52
53 _OutIter& __result_;
54
_MoveSegment__move_loop::_MoveSegment55 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit _MoveSegment(_OutIter& __result)
56 : __result_(__result) {}
57
58 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void
operator__move_loop::_MoveSegment59 operator()(typename _Traits::__local_iterator __lfirst, typename _Traits::__local_iterator __llast) {
60 __result_ = std::__move<_AlgPolicy>(__lfirst, __llast, std::move(__result_)).second;
61 }
62 };
63
64 template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator<_InIter>::value, int> = 0>
65 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
operator__move_loop66 operator()(_InIter __first, _InIter __last, _OutIter __result) const {
67 std::__for_each_segment(__first, __last, _MoveSegment<_InIter, _OutIter>(__result));
68 return std::make_pair(__last, std::move(__result));
69 }
70
71 template <class _InIter,
72 class _OutIter,
73 __enable_if_t<__has_random_access_iterator_category<_InIter>::value &&
74 !__is_segmented_iterator<_InIter>::value && __is_segmented_iterator<_OutIter>::value,
75 int> = 0>
76 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
operator__move_loop77 operator()(_InIter __first, _InIter __last, _OutIter __result) const {
78 using _Traits = __segmented_iterator_traits<_OutIter>;
79 using _DiffT = typename common_type<__iter_diff_t<_InIter>, __iter_diff_t<_OutIter> >::type;
80
81 if (__first == __last)
82 return std::make_pair(std::move(__first), std::move(__result));
83
84 auto __local_first = _Traits::__local(__result);
85 auto __segment_iterator = _Traits::__segment(__result);
86 while (true) {
87 auto __local_last = _Traits::__end(__segment_iterator);
88 auto __size = std::min<_DiffT>(__local_last - __local_first, __last - __first);
89 auto __iters = std::__move<_AlgPolicy>(__first, __first + __size, __local_first);
90 __first = std::move(__iters.first);
91
92 if (__first == __last)
93 return std::make_pair(std::move(__first), _Traits::__compose(__segment_iterator, std::move(__iters.second)));
94
95 __local_first = _Traits::__begin(++__segment_iterator);
96 }
97 }
98 };
99
100 struct __move_trivial {
101 // At this point, the iterators have been unwrapped so any `contiguous_iterator` has been unwrapped to a pointer.
102 template <class _In, class _Out, __enable_if_t<__can_lower_move_assignment_to_memmove<_In, _Out>::value, int> = 0>
103 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_In*, _Out*>
operator__move_trivial104 operator()(_In* __first, _In* __last, _Out* __result) const {
105 return std::__copy_trivial_impl(__first, __last, __result);
106 }
107 };
108
109 template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter>
110 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
__move(_InIter __first,_Sent __last,_OutIter __result)111 __move(_InIter __first, _Sent __last, _OutIter __result) {
112 return std::__dispatch_copy_or_move<_AlgPolicy, __move_loop<_AlgPolicy>, __move_trivial>(
113 std::move(__first), std::move(__last), std::move(__result));
114 }
115
116 template <class _InputIterator, class _OutputIterator>
117 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
move(_InputIterator __first,_InputIterator __last,_OutputIterator __result)118 move(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
119 static_assert(is_copy_constructible<_InputIterator>::value, "Iterators has to be copy constructible.");
120 static_assert(is_copy_constructible<_OutputIterator>::value, "The output iterator has to be copy constructible.");
121
122 return std::__move<_ClassicAlgPolicy>(std::move(__first), std::move(__last), std::move(__result)).second;
123 }
124
125 _LIBCPP_END_NAMESPACE_STD
126
127 _LIBCPP_POP_MACROS
128
129 #endif // _LIBCPP___ALGORITHM_MOVE_H
130