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// ADDITIONAL_COMPILE_FLAGS(gcc-style-warnings): -Wno-sign-compare
14// MSVC warning C4242: 'argument': conversion from 'const _Ty' to 'ElementT', possible loss of data
15// MSVC warning C4244: 'argument': conversion from 'const _Ty' to 'ElementT', possible loss of data
16// ADDITIONAL_COMPILE_FLAGS(cl-style-warnings): /wd4242 /wd4244
17
18// template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity>
19// requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
20// constexpr I ranges::find(I first, S last, const T& value, Proj proj = {});
21// template<input_range R, class T, class Proj = identity>
22// requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
23// constexpr borrowed_iterator_t<R>
24// ranges::find(R&& r, const T& value, Proj proj = {});
25
26#include <algorithm>
27#include <array>
28#include <cassert>
29#include <deque>
30#include <ranges>
31#include <vector>
32
33#include "almost_satisfies_types.h"
34#include "test_iterators.h"
35
36struct NotEqualityComparable {};
37
38template <class It, class Sent = It>
39concept HasFindIt = requires(It it, Sent sent) { std::ranges::find(it, sent, *it); };
40static_assert(HasFindIt<int*>);
41static_assert(!HasFindIt<NotEqualityComparable*>);
42static_assert(!HasFindIt<InputIteratorNotDerivedFrom>);
43static_assert(!HasFindIt<InputIteratorNotIndirectlyReadable>);
44static_assert(!HasFindIt<InputIteratorNotInputOrOutputIterator>);
45static_assert(!HasFindIt<cpp20_input_iterator<int*>, SentinelForNotSemiregular>);
46static_assert(!HasFindIt<cpp20_input_iterator<int*>, InputRangeNotSentinelEqualityComparableWith>);
47
48static_assert(!HasFindIt<int*, int>);
49static_assert(!HasFindIt<int, int*>);
50
51template <class Range, class ValT>
52concept HasFindR = requires(Range r) { std::ranges::find(r, ValT{}); };
53static_assert(HasFindR<std::array<int, 1>, int>);
54static_assert(!HasFindR<int, int>);
55static_assert(!HasFindR<std::array<NotEqualityComparable, 1>, NotEqualityComparable>);
56static_assert(!HasFindR<InputRangeNotDerivedFrom, int>);
57static_assert(!HasFindR<InputRangeNotIndirectlyReadable, int>);
58static_assert(!HasFindR<InputRangeNotInputOrOutputIterator, int>);
59static_assert(!HasFindR<InputRangeNotSentinelSemiregular, int>);
60static_assert(!HasFindR<InputRangeNotSentinelEqualityComparableWith, int>);
61
62static std::vector<int> comparable_data;
63
64template <class It, class Sent = It>
65constexpr void test_iterators() {
66 using ValueT = std::iter_value_t<It>;
67 { // simple test
68 {
69 ValueT a[] = {1, 2, 3, 4};
70 std::same_as<It> auto ret = std::ranges::find(It(a), Sent(It(a + 4)), 4);
71 assert(base(ret) == a + 3);
72 assert(*ret == 4);
73 }
74 {
75 ValueT a[] = {1, 2, 3, 4};
76 auto range = std::ranges::subrange(It(a), Sent(It(a + 4)));
77 std::same_as<It> auto ret = std::ranges::find(range, 4);
78 assert(base(ret) == a + 3);
79 assert(*ret == 4);
80 }
81 }
82
83 { // check that an empty range works
84 {
85 std::array<ValueT, 0> a = {};
86 auto ret = std::ranges::find(It(a.data()), Sent(It(a.data())), 1);
87 assert(base(ret) == a.data());
88 }
89 {
90 std::array<ValueT, 0> a = {};
91 auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data())));
92 auto ret = std::ranges::find(range, 1);
93 assert(base(ret) == a.data());
94 }
95 }
96
97 { // check that last is returned with no match
98 {
99 ValueT a[] = {1, 1, 1};
100 auto ret = std::ranges::find(a, a + 3, 0);
101 assert(ret == a + 3);
102 }
103 {
104 ValueT a[] = {1, 1, 1};
105 auto ret = std::ranges::find(a, 0);
106 assert(ret == a + 3);
107 }
108 }
109
110 if (!std::is_constant_evaluated())
111 comparable_data.clear();
112}
113
114template <class ElementT>
115class TriviallyComparable {
116 ElementT el_;
117
118public:
119 TEST_CONSTEXPR TriviallyComparable(ElementT el) : el_(el) {}
120 bool operator==(const TriviallyComparable&) const = default;
121};
122
123constexpr bool test() {
124 types::for_each(types::type_list<char, wchar_t, int, long, TriviallyComparable<char>, TriviallyComparable<wchar_t>>{},
125 []<class T> {
126 types::for_each(types::cpp20_input_iterator_list<T*>{}, []<class Iter> {
127 if constexpr (std::forward_iterator<Iter>)
128 test_iterators<Iter>();
129 test_iterators<Iter, sentinel_wrapper<Iter>>();
130 test_iterators<Iter, sized_sentinel<Iter>>();
131 });
132 });
133
134 // TODO: Remove the `_LIBCPP_ENABLE_EXPERIMENTAL` check once we have the FTM guarded or views::join isn't
135 // experimental anymore
136#if TEST_STD_VER >= 20 && (!defined(_LIBCPP_VERSION) || defined(_LIBCPP_ENABLE_EXPERIMENTAL))
137 {
138 std::vector<std::vector<int>> vec = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
139 auto view = vec | std::views::join;
140 assert(std::ranges::find(view.begin(), view.end(), 4) == std::next(view.begin(), 3));
141 assert(std::ranges::find(view, 4) == std::next(view.begin(), 3));
142 }
143#endif
144
145 { // check that the first element is returned
146 {
147 struct S {
148 int comp;
149 int other;
150 };
151 S a[] = { {.comp: 0, .other: 0}, {.comp: 0, .other: 2}, {.comp: 0, .other: 1} };
152 auto ret = std::ranges::find(a, 0, &S::comp);
153 assert(ret == a);
154 assert(ret->comp == 0);
155 assert(ret->other == 0);
156 }
157 {
158 struct S {
159 int comp;
160 int other;
161 };
162 S a[] = { {.comp: 0, .other: 0}, {.comp: 0, .other: 2}, {.comp: 0, .other: 1} };
163 auto ret = std::ranges::find(a, a + 3, 0, &S::comp);
164 assert(ret == a);
165 assert(ret->comp == 0);
166 assert(ret->other == 0);
167 }
168 }
169
170 {
171 // check that an iterator is returned with a borrowing range
172 int a[] = {1, 2, 3, 4};
173 std::same_as<int*> auto ret = std::ranges::find(std::views::all(a), 1);
174 assert(ret == a);
175 assert(*ret == 1);
176 }
177
178 {
179 // count invocations of the projection
180 {
181 int a[] = {1, 2, 3, 4};
182 int projection_count = 0;
183 auto ret = std::ranges::find(a, a + 4, 2, [&](int i) { ++projection_count; return i; });
184 assert(ret == a + 1);
185 assert(*ret == 2);
186 assert(projection_count == 2);
187 }
188 {
189 int a[] = {1, 2, 3, 4};
190 int projection_count = 0;
191 auto ret = std::ranges::find(a, 2, [&](int i) { ++projection_count; return i; });
192 assert(ret == a + 1);
193 assert(*ret == 2);
194 assert(projection_count == 2);
195 }
196 }
197
198 return true;
199}
200
201template <class IndexT>
202class Comparable {
203 IndexT index_;
204
205public:
206 Comparable(IndexT i)
207 : index_([&]() {
208 IndexT size = static_cast<IndexT>(comparable_data.size());
209 comparable_data.push_back(i);
210 return size;
211 }()) {}
212
213 bool operator==(const Comparable& other) const {
214 return comparable_data[other.index_] == comparable_data[index_];
215 }
216
217 friend bool operator==(const Comparable& lhs, long long rhs) { return comparable_data[lhs.index_] == rhs; }
218};
219
220void test_deque() {
221 { // empty deque
222 std::deque<int> data;
223 assert(std::ranges::find(data, 4) == data.end());
224 assert(std::ranges::find(data.begin(), data.end(), 4) == data.end());
225 }
226
227 { // single element - match
228 std::deque<int> data = {4};
229 assert(std::ranges::find(data, 4) == data.begin());
230 assert(std::ranges::find(data.begin(), data.end(), 4) == data.begin());
231 }
232
233 { // single element - no match
234 std::deque<int> data = {3};
235 assert(std::ranges::find(data, 4) == data.end());
236 assert(std::ranges::find(data.begin(), data.end(), 4) == data.end());
237 }
238
239 // many elements
240 for (auto size : {2, 3, 1023, 1024, 1025, 2047, 2048, 2049}) {
241 { // last element match
242 std::deque<int> data;
243 data.resize(new_size: size);
244 std::fill(first: data.begin(), last: data.end(), value: 3);
245 data[size - 1] = 4;
246 assert(std::ranges::find(data, 4) == data.end() - 1);
247 assert(std::ranges::find(data.begin(), data.end(), 4) == data.end() - 1);
248 }
249
250 { // second-last element match
251 std::deque<int> data;
252 data.resize(new_size: size);
253 std::fill(first: data.begin(), last: data.end(), value: 3);
254 data[size - 2] = 4;
255 assert(std::ranges::find(data, 4) == data.end() - 2);
256 assert(std::ranges::find(data.begin(), data.end(), 4) == data.end() - 2);
257 }
258
259 { // no match
260 std::deque<int> data;
261 data.resize(new_size: size);
262 std::fill(first: data.begin(), last: data.end(), value: 3);
263 assert(std::ranges::find(data, 4) == data.end());
264 assert(std::ranges::find(data.begin(), data.end(), 4) == data.end());
265 }
266 }
267}
268
269int main(int, char**) {
270 test_deque();
271 test();
272 static_assert(test());
273
274 types::for_each(types::cpp20_input_iterator_list<Comparable<char>*>{}, []<class Iter> {
275 if constexpr (std::forward_iterator<Iter>)
276 test_iterators<Iter>();
277 test_iterators<Iter, sentinel_wrapper<Iter>>();
278 test_iterators<Iter, sized_sentinel<Iter>>();
279 });
280
281 types::for_each(types::cpp20_input_iterator_list<Comparable<wchar_t>*>{}, []<class Iter> {
282 if constexpr (std::forward_iterator<Iter>)
283 test_iterators<Iter>();
284 test_iterators<Iter, sentinel_wrapper<Iter>>();
285 test_iterators<Iter, sized_sentinel<Iter>>();
286 });
287
288 return 0;
289}
290

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