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 <__algorithm/min.h> 15 #include <__config> 16 #include <__iterator/segmented_iterator.h> 17 #include <__type_traits/common_type.h> 18 #include <__type_traits/is_copy_constructible.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 31 template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter> 32 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> 33 __move(_InIter __first, _Sent __last, _OutIter __result); 34 35 template <class _AlgPolicy> 36 struct __move_loop { 37 template <class _InIter, class _Sent, class _OutIter> 38 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> 39 operator()(_InIter __first, _Sent __last, _OutIter __result) const { 40 while (__first != __last) { 41 *__result = _IterOps<_AlgPolicy>::__iter_move(__first); 42 ++__first; 43 ++__result; 44 } 45 return std::make_pair(std::move(__first), std::move(__result)); 46 } 47 48 template <class _InIter, class _OutIter, __enable_if_t<__is_segmented_iterator<_InIter>::value, int> = 0> 49 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> 50 operator()(_InIter __first, _InIter __last, _OutIter __result) const { 51 using _Traits = __segmented_iterator_traits<_InIter>; 52 auto __sfirst = _Traits::__segment(__first); 53 auto __slast = _Traits::__segment(__last); 54 if (__sfirst == __slast) { 55 auto __iters = std::__move<_AlgPolicy>(_Traits::__local(__first), _Traits::__local(__last), std::move(__result)); 56 return std::make_pair(__last, std::move(__iters.second)); 57 } 58 59 __result = std::__move<_AlgPolicy>(_Traits::__local(__first), _Traits::__end(__sfirst), std::move(__result)).second; 60 ++__sfirst; 61 while (__sfirst != __slast) { 62 __result = 63 std::__move<_AlgPolicy>(_Traits::__begin(__sfirst), _Traits::__end(__sfirst), std::move(__result)).second; 64 ++__sfirst; 65 } 66 __result = 67 std::__move<_AlgPolicy>(_Traits::__begin(__sfirst), _Traits::__local(__last), std::move(__result)).second; 68 return std::make_pair(__last, std::move(__result)); 69 } 70 71 template <class _InIter, 72 class _OutIter, 73 __enable_if_t<__is_cpp17_random_access_iterator<_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> 77 operator()(_InIter __first, _InIter __last, _OutIter __result) { 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, 103 __enable_if_t<__can_lower_move_assignment_to_memmove<_In, _Out>::value, int> = 0> 104 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_In*, _Out*> 105 operator()(_In* __first, _In* __last, _Out* __result) const { 106 return std::__copy_trivial_impl(__first, __last, __result); 107 } 108 }; 109 110 template <class _AlgPolicy, class _InIter, class _Sent, class _OutIter> 111 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> 112 __move(_InIter __first, _Sent __last, _OutIter __result) { 113 return std::__dispatch_copy_or_move<_AlgPolicy, __move_loop<_AlgPolicy>, __move_trivial>( 114 std::move(__first), std::move(__last), std::move(__result)); 115 } 116 117 template <class _InputIterator, class _OutputIterator> 118 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator 119 move(_InputIterator __first, _InputIterator __last, _OutputIterator __result) { 120 static_assert(is_copy_constructible<_InputIterator>::value, "Iterators has to be copy constructible."); 121 static_assert(is_copy_constructible<_OutputIterator>::value, "The output iterator has to be copy constructible."); 122 123 return std::__move<_ClassicAlgPolicy>(std::move(__first), std::move(__last), std::move(__result)).second; 124 } 125 126 _LIBCPP_END_NAMESPACE_STD 127 128 _LIBCPP_POP_MACROS 129 130 #endif // _LIBCPP___ALGORITHM_MOVE_H 131