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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_RANGES_TRANSFORM_H
10#define _LIBCPP___ALGORITHM_RANGES_TRANSFORM_H
11
12#include <__algorithm/in_in_out_result.h>
13#include <__algorithm/in_out_result.h>
14#include <__concepts/constructible.h>
15#include <__config>
16#include <__functional/identity.h>
17#include <__functional/invoke.h>
18#include <__iterator/concepts.h>
19#include <__iterator/projected.h>
20#include <__ranges/access.h>
21#include <__ranges/concepts.h>
22#include <__ranges/dangling.h>
23#include <__utility/move.h>
24
25#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
26# pragma GCC system_header
27#endif
28
29_LIBCPP_PUSH_MACROS
30#include <__undef_macros>
31
32#if _LIBCPP_STD_VER >= 20
33
34_LIBCPP_BEGIN_NAMESPACE_STD
35
36namespace ranges {
37
38template <class _Ip, class _Op>
39using unary_transform_result = in_out_result<_Ip, _Op>;
40
41template <class _I1, class _I2, class _O1>
42using binary_transform_result = in_in_out_result<_I1, _I2, _O1>;
43
44struct __transform {
45private:
46 template <class _InIter, class _Sent, class _OutIter, class _Func, class _Proj>
47 _LIBCPP_HIDE_FROM_ABI static constexpr unary_transform_result<_InIter, _OutIter>
48 __unary(_InIter __first, _Sent __last, _OutIter __result, _Func& __operation, _Proj& __projection) {
49 while (__first != __last) {
50 *__result = std::invoke(__operation, std::invoke(__projection, *__first));
51 ++__first;
52 ++__result;
53 }
54
55 return {std::move(__first), std::move(__result)};
56 }
57
58 template <class _InIter1,
59 class _Sent1,
60 class _InIter2,
61 class _Sent2,
62 class _OutIter,
63 class _Func,
64 class _Proj1,
65 class _Proj2>
66 _LIBCPP_HIDE_FROM_ABI static constexpr binary_transform_result<_InIter1, _InIter2, _OutIter>
67 __binary(_InIter1 __first1,
68 _Sent1 __last1,
69 _InIter2 __first2,
70 _Sent2 __last2,
71 _OutIter __result,
72 _Func& __binary_operation,
73 _Proj1& __projection1,
74 _Proj2& __projection2) {
75 while (__first1 != __last1 && __first2 != __last2) {
76 *__result =
77 std::invoke(__binary_operation, std::invoke(__projection1, *__first1), std::invoke(__projection2, *__first2));
78 ++__first1;
79 ++__first2;
80 ++__result;
81 }
82 return {std::move(__first1), std::move(__first2), std::move(__result)};
83 }
84
85public:
86 template <input_iterator _InIter,
87 sentinel_for<_InIter> _Sent,
88 weakly_incrementable _OutIter,
89 copy_constructible _Func,
90 class _Proj = identity>
91 requires indirectly_writable<_OutIter, indirect_result_t<_Func&, projected<_InIter, _Proj>>>
92 _LIBCPP_HIDE_FROM_ABI constexpr unary_transform_result<_InIter, _OutIter>
93 operator()(_InIter __first, _Sent __last, _OutIter __result, _Func __operation, _Proj __proj = {}) const {
94 return __unary(std::move(__first), std::move(__last), std::move(__result), __operation, __proj);
95 }
96
97 template <input_range _Range, weakly_incrementable _OutIter, copy_constructible _Func, class _Proj = identity>
98 requires indirectly_writable<_OutIter, indirect_result_t<_Func, projected<iterator_t<_Range>, _Proj>>>
99 _LIBCPP_HIDE_FROM_ABI constexpr unary_transform_result<borrowed_iterator_t<_Range>, _OutIter>
100 operator()(_Range&& __range, _OutIter __result, _Func __operation, _Proj __projection = {}) const {
101 return __unary(ranges::begin(__range), ranges::end(__range), std::move(__result), __operation, __projection);
102 }
103
104 template <input_iterator _InIter1,
105 sentinel_for<_InIter1> _Sent1,
106 input_iterator _InIter2,
107 sentinel_for<_InIter2> _Sent2,
108 weakly_incrementable _OutIter,
109 copy_constructible _Func,
110 class _Proj1 = identity,
111 class _Proj2 = identity>
112 requires indirectly_writable<_OutIter,
113 indirect_result_t<_Func&, projected<_InIter1, _Proj1>, projected<_InIter2, _Proj2>>>
114 _LIBCPP_HIDE_FROM_ABI constexpr binary_transform_result<_InIter1, _InIter2, _OutIter> operator()(
115 _InIter1 __first1,
116 _Sent1 __last1,
117 _InIter2 __first2,
118 _Sent2 __last2,
119 _OutIter __result,
120 _Func __binary_operation,
121 _Proj1 __projection1 = {},
122 _Proj2 __projection2 = {}) const {
123 return __binary(
124 std::move(__first1),
125 std::move(__last1),
126 std::move(__first2),
127 std::move(__last2),
128 std::move(__result),
129 __binary_operation,
130 __projection1,
131 __projection2);
132 }
133
134 template <input_range _Range1,
135 input_range _Range2,
136 weakly_incrementable _OutIter,
137 copy_constructible _Func,
138 class _Proj1 = identity,
139 class _Proj2 = identity>
140 requires indirectly_writable<
141 _OutIter,
142 indirect_result_t<_Func&, projected<iterator_t<_Range1>, _Proj1>, projected<iterator_t<_Range2>, _Proj2>>>
143 _LIBCPP_HIDE_FROM_ABI constexpr binary_transform_result<borrowed_iterator_t<_Range1>,
144 borrowed_iterator_t<_Range2>,
145 _OutIter>
146 operator()(_Range1&& __range1,
147 _Range2&& __range2,
148 _OutIter __result,
149 _Func __binary_operation,
150 _Proj1 __projection1 = {},
151 _Proj2 __projection2 = {}) const {
152 return __binary(
153 ranges::begin(__range1),
154 ranges::end(__range1),
155 ranges::begin(__range2),
156 ranges::end(__range2),
157 std::move(__result),
158 __binary_operation,
159 __projection1,
160 __projection2);
161 }
162};
163
164inline namespace __cpo {
165inline constexpr auto transform = __transform{};
166} // namespace __cpo
167} // namespace ranges
168
169_LIBCPP_END_NAMESPACE_STD
170
171#endif // _LIBCPP_STD_VER >= 20
172
173_LIBCPP_POP_MACROS
174
175#endif // _LIBCPP___ALGORITHM_RANGES_TRANSFORM_H