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> 40 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 55 _LIBCPP_HIDE_FROM_ABI _MoveSegment(_OutIter& __result) : __result_(__result) {} 56 57 _LIBCPP_HIDE_FROM_ABI void 58 operator()(typename _Traits::__local_iterator __lfirst, typename _Traits::__local_iterator __llast) { 59 __result_ = std::__move<_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, _MoveSegment<_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::__move<_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 99 struct __move_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, 102 __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*> 104 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> 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 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