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// <algorithm>
10
11// UNSUPPORTED: c++03, c++11, c++14, c++17
12
13// template<input_iterator I, sentinel_for<I> S, weakly_incrementable O, class Proj = identity,
14// indirect_unary_predicate<projected<I, Proj>> Pred>
15// requires indirectly_copyable<I, O>
16// constexpr ranges::copy_if_result<I, O>
17// ranges::copy_if(I first, S last, O result, Pred pred, Proj proj = {});
18// template<input_range R, weakly_incrementable O, class Proj = identity,
19// indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
20// requires indirectly_copyable<iterator_t<R>, O>
21// constexpr ranges::copy_if_result<borrowed_iterator_t<R>, O>
22// ranges::copy_if(R&& r, O result, Pred pred, Proj proj = {});
23
24#include <algorithm>
25#include <array>
26#include <cassert>
27#include <ranges>
28
29#include "almost_satisfies_types.h"
30#include "test_iterators.h"
31
32struct Functor {
33 bool operator()(int);
34};
35
36template <class In, class Out = In, class Sent = sentinel_wrapper<In>, class Func = Functor>
37concept HasCopyIfIt = requires(In first, Sent last, Out result) { std::ranges::copy_if(first, last, result, Func{}); };
38
39static_assert(HasCopyIfIt<int*>);
40static_assert(!HasCopyIfIt<InputIteratorNotDerivedFrom>);
41static_assert(!HasCopyIfIt<InputIteratorNotIndirectlyReadable>);
42static_assert(!HasCopyIfIt<InputIteratorNotInputOrOutputIterator>);
43static_assert(!HasCopyIfIt<int*, WeaklyIncrementableNotMovable>);
44struct NotIndirectlyCopyable {};
45static_assert(!HasCopyIfIt<int*, NotIndirectlyCopyable*>);
46static_assert(!HasCopyIfIt<int*, int*, SentinelForNotSemiregular>);
47static_assert(!HasCopyIfIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
48
49static_assert(!HasCopyIfIt<int*, int*, int*, IndirectUnaryPredicateNotCopyConstructible>);
50static_assert(!HasCopyIfIt<int*, int*, int*, IndirectUnaryPredicateNotPredicate>);
51
52template <class Range, class Out, class Func = Functor>
53concept HasCopyIfR = requires(Range range, Out out) { std::ranges::copy_if(range, out, Func{}); };
54
55static_assert(HasCopyIfR<std::array<int, 10>, int*>);
56static_assert(!HasCopyIfR<InputRangeNotDerivedFrom, int*>);
57static_assert(!HasCopyIfR<InputRangeNotIndirectlyReadable, int*>);
58static_assert(!HasCopyIfR<InputRangeNotInputOrOutputIterator, int*>);
59static_assert(!HasCopyIfR<WeaklyIncrementableNotMovable, int*>);
60static_assert(!HasCopyIfR<UncheckedRange<NotIndirectlyCopyable*>, int*>);
61static_assert(!HasCopyIfR<InputRangeNotSentinelSemiregular, int*>);
62static_assert(!HasCopyIfR<InputRangeNotSentinelEqualityComparableWith, int*>);
63
64static_assert(std::is_same_v<std::ranges::copy_if_result<int, long>, std::ranges::in_out_result<int, long>>);
65
66template <class In, class Out, class Sent = In>
67constexpr void test_iterators() {
68 { // simple test
69 {
70 std::array in = {1, 2, 3, 4};
71 std::array<int, 4> out;
72 std::same_as<std::ranges::copy_if_result<In, Out>> auto ret =
73 std::ranges::copy_if(In(in.data()),
74 Sent(In(in.data() + in.size())),
75 Out(out.data()),
76 [](int) { return true; });
77 assert(in == out);
78 assert(base(ret.in) == in.data() + in.size());
79 assert(base(ret.out) == out.data() + out.size());
80 }
81 {
82 std::array in = {1, 2, 3, 4};
83 std::array<int, 4> out;
84 auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data() + in.size())));
85 std::same_as<std::ranges::copy_if_result<In, Out>> auto ret =
86 std::ranges::copy_if(range, Out(out.data()), [](int) { return true; });
87 assert(in == out);
88 assert(base(ret.in) == in.data() + in.size());
89 assert(base(ret.out) == out.data() + out.size());
90 }
91 }
92
93 { // check that an empty range works
94 {
95 std::array<int, 0> in;
96 std::array<int, 0> out;
97 auto ret = std::ranges::copy_if(In(in.data()), Sent(In(in.data())), Out(out.data()), [](int) { return true; });
98 assert(base(ret.in) == in.data());
99 assert(base(ret.out) == out.data());
100 }
101 {
102 std::array<int, 0> in;
103 std::array<int, 0> out;
104 auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data())));
105 auto ret = std::ranges::copy_if(range, Out(out.data()), [](int) { return true; });
106 assert(base(ret.in) == in.data());
107 assert(base(ret.out) == out.data());
108 }
109 }
110
111 { // check that the predicate is used
112 {
113 std::array in = {4, 6, 87, 3, 88, 44, 45, 9};
114 std::array<int, 4> out;
115 auto ret = std::ranges::copy_if(In(in.data()),
116 Sent(In(in.data() + in.size())),
117 Out(out.data()),
118 [](int i) { return i % 2 == 0; });
119 assert((out == std::array{4, 6, 88, 44}));
120 assert(base(ret.in) == in.data() + in.size());
121 assert(base(ret.out) == out.data() + out.size());
122 }
123 {
124 std::array in = {4, 6, 87, 3, 88, 44, 45, 9};
125 std::array<int, 4> out;
126 auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data() + in.size())));
127 auto ret = std::ranges::copy_if(range, Out(out.data()), [](int i) { return i % 2 == 0; });
128 assert((out == std::array{4, 6, 88, 44}));
129 assert(base(ret.in) == in.data() + in.size());
130 assert(base(ret.out) == out.data() + out.size());
131 }
132 }
133}
134
135template <class Out>
136constexpr bool test_in_iterators() {
137 test_iterators<cpp17_input_iterator<int*>, Out, sentinel_wrapper<cpp17_input_iterator<int*>>>();
138 test_iterators<cpp20_input_iterator<int*>, Out, sentinel_wrapper<cpp20_input_iterator<int*>>>();
139 test_iterators<forward_iterator<int*>, Out>();
140 test_iterators<bidirectional_iterator<int*>, Out>();
141 test_iterators<random_access_iterator<int*>, Out>();
142 test_iterators<contiguous_iterator<int*>, Out>();
143 test_iterators<int*, Out>();
144
145 return true;
146}
147
148constexpr bool test() {
149 test_in_iterators<cpp17_output_iterator<int*>>();
150 test_in_iterators<cpp20_output_iterator<int*>>();
151 test_in_iterators<forward_iterator<int*>>();
152 test_in_iterators<bidirectional_iterator<int*>>();
153 test_in_iterators<random_access_iterator<int*>>();
154 test_in_iterators<contiguous_iterator<int*>>();
155 test_in_iterators<int*>();
156
157 { // check that std::invoke is used
158 {
159 struct S { int val; int other; };
160 std::array<S, 4> in = {._M_elems: {{.val: 4, .other: 2}, {.val: 1, .other: 3}, {.val: 3, .other: 4}, {.val: 3, .other: 5}}};
161 std::array<S, 2> out;
162 auto ret = std::ranges::copy_if(in.begin(), in.end(), out.begin(), [](int i) { return i == 3; }, &S::val);
163 assert(ret.in == in.end());
164 assert(ret.out == out.end());
165 assert(out[0].val == 3);
166 assert(out[0].other == 4);
167 assert(out[1].val == 3);
168 assert(out[1].other == 5);
169 }
170 {
171 struct S { int val; int other; };
172 std::array<S, 4> in = {._M_elems: {{.val: 4, .other: 2}, {.val: 1, .other: 3}, {.val: 3, .other: 4}, {.val: 3, .other: 5}}};
173 std::array<S, 2> out;
174 auto ret = std::ranges::copy_if(in, out.begin(), [](int i) { return i == 3; }, &S::val);
175 assert(ret.in == in.end());
176 assert(ret.out == out.end());
177 assert(out[0].val == 3);
178 assert(out[0].other == 4);
179 assert(out[1].val == 3);
180 assert(out[1].other == 5);
181 }
182 }
183
184 { // check that the complexity requirements are met
185 {
186 int predicateCount = 0;
187 int projectionCount = 0;
188 auto pred = [&](int i) { ++predicateCount; return i != 0; };
189 auto proj = [&](int i) { ++projectionCount; return i; };
190
191 int a[] = {5, 4, 3, 2, 1};
192 int b[5];
193 std::ranges::copy_if(a, a + 5, b, pred, proj);
194 assert(predicateCount == 5);
195 assert(projectionCount == 5);
196 }
197 {
198 int predicateCount = 0;
199 int projectionCount = 0;
200 auto pred = [&](int i) { ++predicateCount; return i != 0; };
201 auto proj = [&](int i) { ++projectionCount; return i; };
202
203 int a[] = {5, 4, 3, 2, 1};
204 int b[5];
205 std::ranges::copy_if(a, b, pred, proj);
206 assert(predicateCount == 5);
207 assert(projectionCount == 5);
208 }
209 }
210
211 { // test proxy iterator
212 {
213 std::array in = {4, 6, 87, 3, 88, 44, 45, 9};
214 std::array<int, 4> out;
215
216 ProxyRange proxyIn{in};
217 ProxyRange proxyOut{out};
218
219 std::ranges::copy_if(proxyIn.begin(), proxyIn.end(), proxyOut.begin(),
220 [](auto const& i) { return i.data % 2 == 0; });
221 assert((out == std::array{4, 6, 88, 44}));
222 }
223 {
224 std::array in = {4, 6, 87, 3, 88, 44, 45, 9};
225 std::array<int, 4> out;
226
227 ProxyRange proxyIn{in};
228 ProxyRange proxyOut{out};
229
230 std::ranges::copy_if(proxyIn, proxyOut.begin(), [](const auto& i) { return i.data % 2 == 0; });
231 assert((out == std::array{4, 6, 88, 44}));
232 }
233 }
234
235 return true;
236}
237
238int main(int, char**) {
239 test();
240 static_assert(test());
241
242 return 0;
243}
244

source code of libcxx/test/std/algorithms/alg.modifying.operations/alg.copy/ranges.copy_if.pass.cpp