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 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
13 
14 // template<input_iterator I, sentinel_for<I> S, weakly_incrementable O, class Proj = identity,
15 //          indirect_unary_predicate<projected<I, Proj>> Pred>
16 //   requires indirectly_copyable<I, O>
17 //   constexpr ranges::copy_if_result<I, O>
18 //     ranges::copy_if(I first, S last, O result, Pred pred, Proj proj = {});
19 // template<input_range R, weakly_incrementable O, class Proj = identity,
20 //          indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
21 //   requires indirectly_copyable<iterator_t<R>, O>
22 //   constexpr ranges::copy_if_result<borrowed_iterator_t<R>, O>
23 //     ranges::copy_if(R&& r, O result, Pred pred, Proj proj = {});
24 
25 #include <algorithm>
26 #include <array>
27 #include <cassert>
28 #include <ranges>
29 
30 #include "almost_satisfies_types.h"
31 #include "test_iterators.h"
32 
33 struct Functor {
34   bool operator()(int);
35 };
36 
37 template <class In, class Out = In, class Sent = sentinel_wrapper<In>, class Func = Functor>
38 concept HasCopyIfIt = requires(In first, Sent last, Out result) { std::ranges::copy_if(first, last, result, Func{}); };
39 
40 static_assert(HasCopyIfIt<int*>);
41 static_assert(!HasCopyIfIt<InputIteratorNotDerivedFrom>);
42 static_assert(!HasCopyIfIt<InputIteratorNotIndirectlyReadable>);
43 static_assert(!HasCopyIfIt<InputIteratorNotInputOrOutputIterator>);
44 static_assert(!HasCopyIfIt<int*, WeaklyIncrementableNotMovable>);
45 struct NotIndirectlyCopyable {};
46 static_assert(!HasCopyIfIt<int*, NotIndirectlyCopyable*>);
47 static_assert(!HasCopyIfIt<int*, int*, SentinelForNotSemiregular>);
48 static_assert(!HasCopyIfIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
49 
50 static_assert(!HasCopyIfIt<int*, int*, int*, IndirectUnaryPredicateNotCopyConstructible>);
51 static_assert(!HasCopyIfIt<int*, int*, int*, IndirectUnaryPredicateNotPredicate>);
52 
53 template <class Range, class Out, class Func = Functor>
54 concept HasCopyIfR = requires(Range range, Out out) { std::ranges::copy_if(range, out, Func{}); };
55 
56 static_assert(HasCopyIfR<std::array<int, 10>, int*>);
57 static_assert(!HasCopyIfR<InputRangeNotDerivedFrom, int*>);
58 static_assert(!HasCopyIfR<InputRangeNotIndirectlyReadable, int*>);
59 static_assert(!HasCopyIfR<InputRangeNotInputOrOutputIterator, int*>);
60 static_assert(!HasCopyIfR<WeaklyIncrementableNotMovable, int*>);
61 static_assert(!HasCopyIfR<UncheckedRange<NotIndirectlyCopyable*>, int*>);
62 static_assert(!HasCopyIfR<InputRangeNotSentinelSemiregular, int*>);
63 static_assert(!HasCopyIfR<InputRangeNotSentinelEqualityComparableWith, int*>);
64 
65 static_assert(std::is_same_v<std::ranges::copy_if_result<int, long>, std::ranges::in_out_result<int, long>>);
66 
67 template <class In, class Out, class Sent = In>
test_iterators()68 constexpr void test_iterators() {
69   { // simple test
70     {
71       std::array in = {1, 2, 3, 4};
72       std::array<int, 4> out;
73       std::same_as<std::ranges::copy_if_result<In, Out>> auto ret =
74           std::ranges::copy_if(In(in.data()),
75                                Sent(In(in.data() + in.size())),
76                                Out(out.data()),
77                                [](int) { return true; });
78       assert(in == out);
79       assert(base(ret.in) == in.data() + in.size());
80       assert(base(ret.out) == out.data() + out.size());
81     }
82     {
83       std::array in = {1, 2, 3, 4};
84       std::array<int, 4> out;
85       auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data() + in.size())));
86       std::same_as<std::ranges::copy_if_result<In, Out>> auto ret =
87           std::ranges::copy_if(range, Out(out.data()), [](int) { return true; });
88       assert(in == out);
89       assert(base(ret.in) == in.data() + in.size());
90       assert(base(ret.out) == out.data() + out.size());
91     }
92   }
93 
94   { // check that an empty range works
95     {
96       std::array<int, 0> in;
97       std::array<int, 0> out;
98       auto ret = std::ranges::copy_if(In(in.data()), Sent(In(in.data())), Out(out.data()), [](int) { return true; });
99       assert(base(ret.in) == in.data());
100       assert(base(ret.out) == out.data());
101     }
102     {
103       std::array<int, 0> in;
104       std::array<int, 0> out;
105       auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data())));
106       auto ret = std::ranges::copy_if(range, Out(out.data()), [](int) { return true; });
107       assert(base(ret.in) == in.data());
108       assert(base(ret.out) == out.data());
109     }
110   }
111 
112   { // check that the predicate is used
113     {
114       std::array in = {4, 6, 87, 3, 88, 44, 45, 9};
115       std::array<int, 4> out;
116       auto ret = std::ranges::copy_if(In(in.data()),
117                                       Sent(In(in.data() + in.size())),
118                                       Out(out.data()),
119                                       [](int i) { return i % 2 == 0; });
120       assert((out == std::array{4, 6, 88, 44}));
121       assert(base(ret.in) == in.data() + in.size());
122       assert(base(ret.out) == out.data() + out.size());
123     }
124     {
125       std::array in = {4, 6, 87, 3, 88, 44, 45, 9};
126       std::array<int, 4> out;
127       auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data() + in.size())));
128       auto ret = std::ranges::copy_if(range, Out(out.data()), [](int i) { return i % 2 == 0; });
129       assert((out == std::array{4, 6, 88, 44}));
130       assert(base(ret.in) == in.data() + in.size());
131       assert(base(ret.out) == out.data() + out.size());
132     }
133   }
134 }
135 
136 template <class Out>
test_in_iterators()137 constexpr bool test_in_iterators() {
138   test_iterators<cpp17_input_iterator<int*>, Out, sentinel_wrapper<cpp17_input_iterator<int*>>>();
139   test_iterators<cpp20_input_iterator<int*>, Out, sentinel_wrapper<cpp20_input_iterator<int*>>>();
140   test_iterators<forward_iterator<int*>, Out>();
141   test_iterators<bidirectional_iterator<int*>, Out>();
142   test_iterators<random_access_iterator<int*>, Out>();
143   test_iterators<contiguous_iterator<int*>, Out>();
144   test_iterators<int*, Out>();
145 
146   return true;
147 }
148 
test()149 constexpr bool test() {
150   test_in_iterators<cpp17_output_iterator<int*>>();
151   test_in_iterators<cpp20_output_iterator<int*>>();
152   test_in_iterators<forward_iterator<int*>>();
153   test_in_iterators<bidirectional_iterator<int*>>();
154   test_in_iterators<random_access_iterator<int*>>();
155   test_in_iterators<contiguous_iterator<int*>>();
156   test_in_iterators<int*>();
157 
158   { // check that std::invoke is used
159     {
160       struct S { int val; int other; };
161       std::array<S, 4> in = {{{4, 2}, {1, 3}, {3, 4}, {3, 5}}};
162       std::array<S, 2> out;
163       auto ret = std::ranges::copy_if(in.begin(), in.end(), out.begin(), [](int i) { return i == 3; }, &S::val);
164       assert(ret.in == in.end());
165       assert(ret.out == out.end());
166       assert(out[0].val == 3);
167       assert(out[0].other == 4);
168       assert(out[1].val == 3);
169       assert(out[1].other == 5);
170     }
171     {
172       struct S { int val; int other; };
173       std::array<S, 4> in = {{{4, 2}, {1, 3}, {3, 4}, {3, 5}}};
174       std::array<S, 2> out;
175       auto ret = std::ranges::copy_if(in, out.begin(), [](int i) { return i == 3; }, &S::val);
176       assert(ret.in == in.end());
177       assert(ret.out == out.end());
178       assert(out[0].val == 3);
179       assert(out[0].other == 4);
180       assert(out[1].val == 3);
181       assert(out[1].other == 5);
182     }
183   }
184 
185   { // check that the complexity requirements are met
186     {
187       int predicateCount = 0;
188       int projectionCount = 0;
189       auto pred = [&](int i) { ++predicateCount; return i != 0; };
190       auto proj = [&](int i) { ++projectionCount; return i; };
191 
192       int a[] = {5, 4, 3, 2, 1};
193       int b[5];
194       std::ranges::copy_if(a, a + 5, b, pred, proj);
195       assert(predicateCount == 5);
196       assert(projectionCount == 5);
197     }
198     {
199       int predicateCount = 0;
200       int projectionCount = 0;
201       auto pred = [&](int i) { ++predicateCount; return i != 0; };
202       auto proj = [&](int i) { ++projectionCount; return i; };
203 
204       int a[] = {5, 4, 3, 2, 1};
205       int b[5];
206       std::ranges::copy_if(a, b, pred, proj);
207       assert(predicateCount == 5);
208       assert(projectionCount == 5);
209     }
210   }
211 
212   { // test proxy iterator
213     {
214       std::array in = {4, 6, 87, 3, 88, 44, 45, 9};
215       std::array<int, 4> out;
216 
217       ProxyRange proxyIn{in};
218       ProxyRange proxyOut{out};
219 
220       std::ranges::copy_if(proxyIn.begin(), proxyIn.end(), proxyOut.begin(),
221                           [](auto const& i) { return i.data % 2 == 0; });
222       assert((out == std::array{4, 6, 88, 44}));
223     }
224     {
225       std::array in = {4, 6, 87, 3, 88, 44, 45, 9};
226       std::array<int, 4> out;
227 
228       ProxyRange proxyIn{in};
229       ProxyRange proxyOut{out};
230 
231       std::ranges::copy_if(proxyIn, proxyOut.begin(), [](const auto& i) { return i.data % 2 == 0; });
232       assert((out == std::array{4, 6, 88, 44}));
233     }
234   }
235 
236   return true;
237 }
238 
main(int,char **)239 int main(int, char**) {
240   test();
241   static_assert(test());
242 
243   return 0;
244 }
245