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 I1, sentinel_for<I1> S1, forward_iterator I2, sentinel_for<I2> S2,
14// class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
15// requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
16// constexpr I1 ranges::find_first_of(I1 first1, S1 last1, I2 first2, S2 last2,
17// Pred pred = {},
18// Proj1 proj1 = {}, Proj2 proj2 = {});
19// template<input_range R1, forward_range R2,
20// class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
21// requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
22// constexpr borrowed_iterator_t<R1>
23// ranges::find_first_of(R1&& r1, R2&& r2,
24// Pred pred = {},
25// Proj1 proj1 = {}, Proj2 proj2 = {});
26
27#include <algorithm>
28#include <array>
29#include <functional>
30#include <ranges>
31
32#include "almost_satisfies_types.h"
33#include "test_iterators.h"
34
35template <class Iter1, class Iter2 = int*, class Sent1 = Iter1, class Sent2 = Iter2>
36concept HasFindFirstOfIt = requires(Iter1 iter1, Sent1 sent1, Iter2 iter2, Sent2 sent2) {
37 std::ranges::find_first_of(iter1, sent1, iter2, sent2);
38 };
39
40static_assert(HasFindFirstOfIt<int*>);
41static_assert(!HasFindFirstOfIt<InputIteratorNotDerivedFrom>);
42static_assert(!HasFindFirstOfIt<InputIteratorNotIndirectlyReadable>);
43static_assert(!HasFindFirstOfIt<InputIteratorNotInputOrOutputIterator>);
44static_assert(!HasFindFirstOfIt<int*, ForwardIteratorNotDerivedFrom>);
45static_assert(!HasFindFirstOfIt<int*, ForwardIteratorNotIncrementable>);
46static_assert(!HasFindFirstOfIt<int*, int*, SentinelForNotSemiregular>);
47static_assert(!HasFindFirstOfIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
48static_assert(!HasFindFirstOfIt<int*, int*, int*, SentinelForNotSemiregular>);
49static_assert(!HasFindFirstOfIt<int*, int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
50static_assert(!HasFindFirstOfIt<int*, int**>); // not indirectly_comparable
51
52template <class Range1, class Range2 = UncheckedRange<int*>>
53concept HasFindFirstOfR = requires(Range1 range1, Range2 range2) {
54 std::ranges::find_first_of(range1, range2);
55 };
56
57static_assert(HasFindFirstOfR<UncheckedRange<int*>>);
58static_assert(!HasFindFirstOfR<InputRangeNotDerivedFrom>);
59static_assert(!HasFindFirstOfR<InputRangeNotIndirectlyReadable>);
60static_assert(!HasFindFirstOfR<InputRangeNotInputOrOutputIterator>);
61static_assert(!HasFindFirstOfR<UncheckedRange<int*>, ForwardRangeNotDerivedFrom>);
62static_assert(!HasFindFirstOfR<UncheckedRange<int*>, ForwardRangeNotIncrementable>);
63static_assert(!HasFindFirstOfR<UncheckedRange<int*>, InputRangeNotSentinelSemiregular>);
64static_assert(!HasFindFirstOfR<UncheckedRange<int*>, InputRangeNotSentinelEqualityComparableWith>);
65static_assert(!HasFindFirstOfR<UncheckedRange<int*>, ForwardRangeNotSentinelSemiregular>);
66static_assert(!HasFindFirstOfR<UncheckedRange<int*>, ForwardRangeNotSentinelEqualityComparableWith>);
67static_assert(!HasFindFirstOfR<UncheckedRange<int*>, UncheckedRange<int**>>); // not indirectly_comparable
68
69template <int N1, int N2>
70struct Data {
71 std::array<int, N1> input1;
72 std::array<int, N2> input2;
73 std::ptrdiff_t expected;
74};
75
76template <class Iter1, class Sent1, class Iter2, class Sent2, int N1, int N2>
77constexpr void test(Data<N1, N2> d) {
78 {
79 std::same_as<Iter1> decltype(auto) ret =
80 std::ranges::find_first_of(Iter1(d.input1.data()), Sent1(Iter1(d.input1.data() + d.input1.size())),
81 Iter2(d.input2.data()), Sent2(Iter2(d.input2.data() + d.input2.size())));
82 assert(base(ret) == d.input1.data() + d.expected);
83 }
84 {
85 auto range1 = std::ranges::subrange(Iter1(d.input1.data()), Sent1(Iter1(d.input1.data() + d.input1.size())));
86 auto range2 = std::ranges::subrange(Iter2(d.input2.data()), Sent2(Iter2(d.input2.data() + d.input2.size())));
87 std::same_as<Iter1> decltype(auto) ret = std::ranges::find_first_of(range1, range2);
88 assert(base(ret) == d.input1.data() + d.expected);
89 }
90}
91
92template <class Iter1, class Sent1, class Iter2, class Sent2 = Iter2>
93constexpr void test_iterators() {
94 // simple test
95 test<Iter1, Sent1, Iter2, Sent2, 4, 2>({.input1 = {1, 2, 3, 4}, .input2 = {2, 3}, .expected = 1});
96 // other elements from input2 are checked
97 test<Iter1, Sent1, Iter2, Sent2, 4, 2>({.input1 = {1, 2, 3, 4}, .input2 = {3, 2}, .expected = 1});
98 // an empty second range returns last
99 test<Iter1, Sent1, Iter2, Sent2, 4, 0>({.input1 = {1, 2, 3, 4}, .input2 = {}, .expected = 4});
100 // check that an empty first range works
101 test<Iter1, Sent1, Iter2, Sent2, 0, 1>({.input1 = {}, .input2 = {1}, .expected = 0});
102 // check both ranges empty works
103 test<Iter1, Sent1, Iter2, Sent2, 0, 0>({.input1 = {}, .input2 = {}, .expected = 0});
104 // the first element is checked properly
105 test<Iter1, Sent1, Iter2, Sent2, 5, 2>({.input1 = {5, 4, 3, 2, 1}, .input2 = {1, 5}, .expected = 0});
106 // the last element is checked properly
107 test<Iter1, Sent1, Iter2, Sent2, 5, 2>({.input1 = {5, 4, 3, 2, 1}, .input2 = {1, 6}, .expected = 4});
108 // no match, one-past-the-end iterator should be returned
109 test<Iter1, Sent1, Iter2, Sent2, 4, 4>({.input1 = {1, 3, 5, 7}, .input2 = {0, 2, 4, 6}, .expected = 4});
110 // input2 contains a single element
111 test<Iter1, Sent1, Iter2, Sent2, 4, 1>({.input1 = {1, 3, 5, 7}, .input2 = {1}, .expected = 0});
112}
113
114template <class Iter1, class Sent1 = Iter1>
115constexpr void test_iterators1() {
116 test_iterators<Iter1, Sent1, forward_iterator<int*>, sentinel_wrapper<forward_iterator<int*>>>();
117 test_iterators<Iter1, Sent1, forward_iterator<int*>>();
118 test_iterators<Iter1, Sent1, bidirectional_iterator<int*>>();
119 test_iterators<Iter1, Sent1, random_access_iterator<int*>>();
120 test_iterators<Iter1, Sent1, contiguous_iterator<int*>>();
121 test_iterators<Iter1, Sent1, int*>();
122}
123
124constexpr bool test() {
125 test_iterators1<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>();
126 test_iterators1<cpp17_input_iterator<int*>, sentinel_wrapper<cpp17_input_iterator<int*>>>();
127 test_iterators1<forward_iterator<int*>>();
128 test_iterators1<bidirectional_iterator<int*>>();
129 test_iterators1<random_access_iterator<int*>>();
130 test_iterators1<contiguous_iterator<int*>>();
131 test_iterators1<int*>();
132
133 { // check that std::ranges::dangling is returned
134 [[maybe_unused]] std::same_as<std::ranges::dangling> decltype(auto) ret =
135 std::ranges::find_first_of(std::array {1}, std::array {1});
136 }
137
138 { // check that the predicate is used
139 int a[] = {1, 2, 3, 4};
140 int b[] = {2};
141 {
142 auto ret = std::ranges::find_first_of(std::begin(a), std::end(a),
143 std::begin(b), std::end(b),
144 std::ranges::greater{});
145 assert(ret == a + 2);
146 }
147 {
148 auto ret = std::ranges::find_first_of(a, b, std::ranges::greater{});
149 assert(ret == a + 2);
150 }
151 }
152
153 { // check that the projections are used
154 int a[] = {1, 2, 3, 4};
155 int b[] = {4};
156 {
157 auto ret = std::ranges::find_first_of(std::begin(a), std::end(a),
158 std::begin(b), std::end(b), {},
159 [](int i) { return i / 2; },
160 [](int i) { return i - 3; });
161 assert(ret == a + 1);
162 }
163 {
164 auto ret = std::ranges::find_first_of(a, b, {}, [](int i) { return i / 2; }, [](int i) { return i - 3; });
165 assert(ret == a + 1);
166 }
167 }
168
169 { // check that std::invoke is used
170 struct S1 {
171 constexpr S1(int i_) : i(i_) {}
172 constexpr bool compare(int j) const { return j == i; }
173 constexpr const S1& identity() const { return *this; }
174 int i;
175 };
176 struct S2 {
177 constexpr S2(int i_) : i(i_) {}
178 int i;
179 };
180
181 {
182 S1 a[] = {1, 2, 3, 4};
183 S2 b[] = {2, 3};
184 auto ret = std::ranges::find_first_of(std::begin(a), std::end(a),
185 std::begin(b), std::end(b), &S1::compare, &S1::identity, &S2::i);
186 assert(ret == a + 1);
187 }
188 {
189 S1 a[] = {1, 2, 3, 4};
190 S2 b[] = {2, 3};
191 auto ret = std::ranges::find_first_of(a, b, &S1::compare, &S1::identity, &S2::i);
192 assert(ret == a + 1);
193 }
194 }
195
196 { // check that the complexity requirements are met
197 int a[] = {1, 2, 3, 4};
198 int b[] = {2, 3};
199 {
200 int predCount = 0;
201 auto predCounter = [&](int, int) { ++predCount; return false; };
202 int proj1Count = 0;
203 auto proj1Counter = [&](int i) { ++proj1Count; return i; };
204 int proj2Count = 0;
205 auto proj2Counter = [&](int i) { ++proj2Count; return i; };
206 auto ret = std::ranges::find_first_of(std::begin(a), std::end(a),
207 std::begin(b), std::end(b), predCounter, proj1Counter, proj2Counter);
208 assert(ret == a + 4);
209 assert(predCount <= 8);
210 assert(proj1Count <= 8);
211 assert(proj2Count <= 8);
212 }
213 {
214 int predCount = 0;
215 auto predCounter = [&](int, int) { ++predCount; return false; };
216 int proj1Count = 0;
217 auto proj1Counter = [&](int i) { ++proj1Count; return i; };
218 int proj2Count = 0;
219 auto proj2Counter = [&](int i) { ++proj2Count; return i; };
220 auto ret = std::ranges::find_first_of(a, b, predCounter, proj1Counter, proj2Counter);
221 assert(ret == a + 4);
222 assert(predCount == 8);
223 assert(proj1Count == 8);
224 assert(proj2Count == 8);
225 }
226 }
227
228 return true;
229}
230
231int main(int, char**) {
232 test();
233 static_assert(test());
234
235 return 0;
236}
237

source code of libcxx/test/std/algorithms/alg.nonmodifying/alg.find.first.of/ranges.find_first_of.pass.cpp