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_COPY_H
10#define _LIBCPP___ALGORITHM_COPY_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 <__utility/move.h>
20#include <__utility/pair.h>
21
22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23#  pragma GCC system_header
24#endif
25
26_LIBCPP_PUSH_MACROS
27#include <__undef_macros>
28
29_LIBCPP_BEGIN_NAMESPACE_STD
30
31template <class, class _InIter, class _Sent, class _OutIter>
32inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> __copy(_InIter, _Sent, _OutIter);
33
34template <class _AlgPolicy>
35struct __copy_loop {
36  template <class _InIter, class _Sent, class _OutIter>
37  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
38  operator()(_InIter __first, _Sent __last, _OutIter __result) const {
39    while (__first != __last) {
40      *__result = *__first;
41      ++__first;
42      ++__result;
43    }
44
45    return std::make_pair(std::move(__first), std::move(__result));
46  }
47
48  template <class _InIter, class _OutIter>
49  struct _CopySegment {
50    using _Traits = __segmented_iterator_traits<_InIter>;
51
52    _OutIter& __result_;
53
54    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 explicit _CopySegment(_OutIter& __result)
55        : __result_(__result) {}
56
57    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void
58    operator()(typename _Traits::__local_iterator __lfirst, typename _Traits::__local_iterator __llast) {
59      __result_ = std::__copy<_AlgPolicy>(__lfirst, __llast, std::move(__result_)).second;
60    }
61  };
62
63  template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator<_InIter>::value, int> = 0>
64  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
65  operator()(_InIter __first, _InIter __last, _OutIter __result) const {
66    std::__for_each_segment(__first, __last, _CopySegment<_InIter, _OutIter>(__result));
67    return std::make_pair(__last, std::move(__result));
68  }
69
70  template <class _InIter,
71            class _OutIter,
72            __enable_if_t<__has_random_access_iterator_category<_InIter>::value &&
73                              !__is_segmented_iterator<_InIter>::value && __is_segmented_iterator<_OutIter>::value,
74                          int> = 0>
75  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter>
76  operator()(_InIter __first, _InIter __last, _OutIter __result) const {
77    using _Traits = __segmented_iterator_traits<_OutIter>;
78    using _DiffT  = typename common_type<__iter_diff_t<_InIter>, __iter_diff_t<_OutIter> >::type;
79
80    if (__first == __last)
81      return std::make_pair(std::move(__first), std::move(__result));
82
83    auto __local_first      = _Traits::__local(__result);
84    auto __segment_iterator = _Traits::__segment(__result);
85    while (true) {
86      auto __local_last = _Traits::__end(__segment_iterator);
87      auto __size       = std::min<_DiffT>(__local_last - __local_first, __last - __first);
88      auto __iters      = std::__copy<_AlgPolicy>(__first, __first + __size, __local_first);
89      __first           = std::move(__iters.first);
90
91      if (__first == __last)
92        return std::make_pair(std::move(__first), _Traits::__compose(__segment_iterator, std::move(__iters.second)));
93
94      __local_first = _Traits::__begin(++__segment_iterator);
95    }
96  }
97};
98
99struct __copy_trivial {
100  // At this point, the iterators have been unwrapped so any `contiguous_iterator` has been unwrapped to a pointer.
101  template <class _In, class _Out, __enable_if_t<__can_lower_copy_assignment_to_memmove<_In, _Out>::value, int> = 0>
102  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_In*, _Out*>
103  operator()(_In* __first, _In* __last, _Out* __result) const {
104    return std::__copy_trivial_impl(__first, __last, __result);
105  }
106};
107
108template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter>
109pair<_InIter, _OutIter> inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
110__copy(_InIter __first, _Sent __last, _OutIter __result) {
111  return std::__dispatch_copy_or_move<_AlgPolicy, __copy_loop<_AlgPolicy>, __copy_trivial>(
112      std::move(__first), std::move(__last), std::move(__result));
113}
114
115template <class _InputIterator, class _OutputIterator>
116inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
117copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
118  return std::__copy<_ClassicAlgPolicy>(__first, __last, __result).second;
119}
120
121_LIBCPP_END_NAMESPACE_STD
122
123_LIBCPP_POP_MACROS
124
125#endif // _LIBCPP___ALGORITHM_COPY_H
126