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, input_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 bool ranges::equal(I1 first1, S1 last1, I2 first2, S2 last2,
17// Pred pred = {},
18// Proj1 proj1 = {}, Proj2 proj2 = {});
19// template<input_range R1, input_range R2, class Pred = ranges::equal_to,
20// class Proj1 = identity, class Proj2 = identity>
21// requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
22// constexpr bool ranges::equal(R1&& r1, R2&& r2, Pred pred = {},
23// Proj1 proj1 = {}, Proj2 proj2 = {});
24
25#include <algorithm>
26#include <array>
27#include <cassert>
28#include <concepts>
29#include <functional>
30#include <ranges>
31#include <vector>
32
33#include "almost_satisfies_types.h"
34#include "sized_allocator.h"
35#include "test_iterators.h"
36#include "test_macros.h"
37
38template <class Iter1,
39 class Sent1 = sentinel_wrapper<Iter1>,
40 class Iter2 = Iter1,
41 class Sent2 = sentinel_wrapper<Iter2>>
42concept HasEqualIt = requires(Iter1 first1, Sent1 last1, Iter2 first2, Sent2 last2) {
43 std::ranges::equal(first1, last1, first2, last2);
44};
45
46static_assert(HasEqualIt<int*>);
47static_assert(!HasEqualIt<InputIteratorNotDerivedFrom>);
48static_assert(!HasEqualIt<InputIteratorNotIndirectlyReadable>);
49static_assert(!HasEqualIt<InputIteratorNotInputOrOutputIterator>);
50static_assert(!HasEqualIt<int*, int*, InputIteratorNotDerivedFrom>);
51static_assert(!HasEqualIt<int*, int*, InputIteratorNotIndirectlyReadable>);
52static_assert(!HasEqualIt<int*, int*, InputIteratorNotInputOrOutputIterator>);
53static_assert(!HasEqualIt<int*, SentinelForNotSemiregular>);
54static_assert(!HasEqualIt<int*, SentinelForNotWeaklyEqualityComparableWith>);
55static_assert(!HasEqualIt<int*, int*, int*, SentinelForNotSemiregular>);
56static_assert(!HasEqualIt<int*, int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
57static_assert(!HasEqualIt<int*, int*, int**>);
58
59template <class Range1, class Range2>
60concept HasEqualR = requires(Range1 range1, Range2 range2) { std::ranges::equal(range1, range2); };
61
62static_assert(HasEqualR<UncheckedRange<int*>, UncheckedRange<int*>>);
63static_assert(!HasEqualR<InputRangeNotDerivedFrom, UncheckedRange<int*>>);
64static_assert(!HasEqualR<InputRangeNotIndirectlyReadable, UncheckedRange<int*>>);
65static_assert(!HasEqualR<InputRangeNotInputOrOutputIterator, UncheckedRange<int*>>);
66static_assert(!HasEqualR<InputRangeNotSentinelSemiregular, UncheckedRange<int*>>);
67static_assert(!HasEqualR<InputRangeNotSentinelEqualityComparableWith, UncheckedRange<int*>>);
68static_assert(!HasEqualR<UncheckedRange<int*>, InputRangeNotDerivedFrom>);
69static_assert(!HasEqualR<UncheckedRange<int*>, InputRangeNotIndirectlyReadable>);
70static_assert(!HasEqualR<UncheckedRange<int*>, InputRangeNotInputOrOutputIterator>);
71static_assert(!HasEqualR<UncheckedRange<int*>, InputRangeNotSentinelSemiregular>);
72static_assert(!HasEqualR<UncheckedRange<int*>, InputRangeNotSentinelEqualityComparableWith>);
73static_assert(!HasEqualR<UncheckedRange<int*>, UncheckedRange<int**>>);
74
75template <class Iter1, class Sent1, class Iter2, class Sent2 = Iter2>
76constexpr void test_iterators() {
77 { // simple test
78 {
79 int a[] = {1, 2, 3, 4};
80 int b[] = {1, 2, 3, 4};
81 std::same_as<bool> decltype(auto) ret =
82 std::ranges::equal(Iter1(a), Sent1(Iter1(a + 4)), Iter2(b), Sent2(Iter2(b + 4)));
83 assert(ret);
84 }
85 {
86 int a[] = {1, 2, 3, 4};
87 int b[] = {1, 2, 3, 4};
88 auto range1 = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 4)));
89 auto range2 = std::ranges::subrange(Iter2(b), Sent2(Iter2(b + 4)));
90 std::same_as<bool> decltype(auto) ret = std::ranges::equal(range1, range2);
91 assert(ret);
92 }
93 }
94
95 { // check that false is returned for non-equal ranges
96 {
97 int a[] = {1, 2, 3, 4};
98 int b[] = {1, 2, 4, 4};
99 assert(!std::ranges::equal(Iter1(a), Sent1(Iter1(a + 4)), Iter2(b), Sent2(Iter2(b + 4))));
100 }
101 {
102 int a[] = {1, 2, 3, 4};
103 int b[] = {1, 2, 4, 4};
104 auto range1 = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 4)));
105 auto range2 = std::ranges::subrange(Iter2(b), Sent2(Iter2(b + 4)));
106 assert(!std::ranges::equal(range1, range2));
107 }
108 }
109
110 { // check that the predicate is used (return true)
111 {
112 int a[] = {1, 2, 3, 4};
113 int b[] = {2, 3, 4, 5};
114 auto ret = std::ranges::equal(Iter1(a), Sent1(Iter1(a + 4)), Iter2(b), Sent2(Iter2(b + 4)), [](int l, int r) {
115 return l != r;
116 });
117 assert(ret);
118 }
119 {
120 int a[] = {1, 2, 3, 4};
121 int b[] = {2, 3, 4, 5};
122 auto range1 = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 4)));
123 auto range2 = std::ranges::subrange(Iter2(b), Sent2(Iter2(b + 4)));
124 auto ret = std::ranges::equal(range1, range2, [](int l, int r) { return l != r; });
125 assert(ret);
126 }
127 }
128
129 { // check that the predicate is used (return false)
130 {
131 int a[] = {1, 2, 3, 4};
132 int b[] = {2, 3, 3, 5};
133 auto ret = std::ranges::equal(Iter1(a), Sent1(Iter1(a + 4)), Iter2(b), Sent2(Iter2(b + 4)), [](int l, int r) {
134 return l != r;
135 });
136 assert(!ret);
137 }
138 {
139 int a[] = {1, 2, 3, 4};
140 int b[] = {2, 3, 3, 5};
141 auto range1 = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 4)));
142 auto range2 = std::ranges::subrange(Iter2(b), Sent2(Iter2(b + 4)));
143 auto ret = std::ranges::equal(range1, range2, [](int l, int r) { return l != r; });
144 assert(!ret);
145 }
146 }
147
148 { // check that the projections are used
149 {
150 int a[] = {1, 2, 3, 4, 5};
151 int b[] = {6, 10, 14, 18, 22};
152 auto ret = std::ranges::equal(
153 Iter1(a),
154 Sent1(Iter1(a + 5)),
155 Iter2(b),
156 Sent2(Iter2(b + 5)),
157 {},
158 [](int i) { return i * 4; },
159 [](int i) { return i - 2; });
160 assert(ret);
161 }
162 {
163 int a[] = {1, 2, 3, 4, 5};
164 int b[] = {6, 10, 14, 18, 22};
165 auto range1 = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 5)));
166 auto range2 = std::ranges::subrange(Iter2(b), Sent2(Iter2(b + 5)));
167 auto ret = std::ranges::equal(range1, range2, {}, [](int i) { return i * 4; }, [](int i) { return i - 2; });
168 assert(ret);
169 }
170 }
171
172 { // check that different sized ranges work
173 {
174 int a[] = {4, 3, 2, 1};
175 int b[] = {4, 3, 2, 1, 5, 6, 7};
176 auto ret = std::ranges::equal(Iter1(a), Sent1(Iter1(a + 4)), Iter2(b), Sent2(Iter2(b + 7)));
177 assert(!ret);
178 }
179 {
180 int a[] = {4, 3, 2, 1};
181 int b[] = {4, 3, 2, 1, 5, 6, 7};
182 auto range1 = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 4)));
183 auto range2 = std::ranges::subrange(Iter2(b), Sent2(Iter2(b + 7)));
184 auto ret = std::ranges::equal(range1, range2);
185 assert(!ret);
186 }
187 }
188
189 { // check that two ranges with the same size but different values are different
190 {
191 int a[] = {4, 6, 34, 76, 5};
192 int b[] = {4, 6, 34, 67, 5};
193 auto ret = std::ranges::equal(Iter1(a), Sent1(Iter1(a + 5)), Iter2(b), Sent2(Iter2(b + 5)));
194 assert(!ret);
195 }
196 {
197 int a[] = {4, 6, 34, 76, 5};
198 int b[] = {4, 6, 34, 67, 5};
199 auto range1 = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 5)));
200 auto range2 = std::ranges::subrange(Iter2(b), Sent2(Iter2(b + 5)));
201 auto ret = std::ranges::equal(range1, range2);
202 assert(!ret);
203 }
204 }
205
206 { // check that two empty ranges work
207 {
208 std::array<int, 0> a = {};
209 std::array<int, 0> b = {};
210 auto ret = std::ranges::equal(Iter1(a.data()), Sent1(Iter1(a.data())), Iter2(b.data()), Sent2(Iter2(b.data())));
211 assert(ret);
212 }
213 {
214 std::array<int, 0> a = {};
215 std::array<int, 0> b = {};
216 auto range1 = std::ranges::subrange(Iter1(a.data()), Sent1(Iter1(a.data())));
217 auto range2 = std::ranges::subrange(Iter2(b.data()), Sent2(Iter2(b.data())));
218 auto ret = std::ranges::equal(range1, range2);
219 assert(ret);
220 }
221 }
222
223 { // check that it works with the first range empty
224 {
225 std::array<int, 0> a = {};
226 int b[] = {1, 2};
227 auto ret = std::ranges::equal(Iter1(a.data()), Sent1(Iter1(a.data())), Iter2(b), Sent2(Iter2(b + 2)));
228 assert(!ret);
229 }
230 {
231 std::array<int, 0> a = {};
232 int b[] = {1, 2};
233 auto range1 = std::ranges::subrange(Iter1(a.data()), Sent1(Iter1(a.data())));
234 auto range2 = std::ranges::subrange(Iter2(b), Sent2(Iter2(b + 2)));
235 auto ret = std::ranges::equal(range1, range2);
236 assert(!ret);
237 }
238 }
239
240 { // check that it works with the second range empty
241 {
242 int a[] = {1, 2};
243 std::array<int, 0> b = {};
244 auto ret = std::ranges::equal(Iter1(a), Sent1(Iter1(a + 2)), Iter2(b.data()), Sent2(Iter2(b.data())));
245 assert(!ret);
246 }
247 {
248 int a[] = {1, 2};
249 std::array<int, 0> b = {};
250 auto range1 = std::ranges::subrange(Iter1(a), Sent1(Iter1(a + 2)));
251 auto range2 = std::ranges::subrange(Iter2(b.data()), Sent2(Iter2(b.data())));
252 auto ret = std::ranges::equal(range1, range2);
253 assert(!ret);
254 }
255 }
256}
257
258template <class Iter1, class Sent1 = Iter1>
259constexpr void test_iterators2() {
260 test_iterators<Iter1, Sent1, cpp17_input_iterator<int*>, sentinel_wrapper<cpp17_input_iterator<int*>>>();
261 test_iterators<Iter1, Sent1, cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>();
262 test_iterators<Iter1, Sent1, forward_iterator<int*>>();
263 test_iterators<Iter1, Sent1, bidirectional_iterator<int*>>();
264 test_iterators<Iter1, Sent1, random_access_iterator<int*>>();
265 test_iterators<Iter1, Sent1, contiguous_iterator<int*>>();
266 test_iterators<Iter1, Sent1, int*>();
267 test_iterators<Iter1, Sent1, const int*>();
268}
269
270template <std::size_t N>
271constexpr void test_vector_bool() {
272 std::vector<bool> in(N, false);
273 for (std::size_t i = 0; i < N; i += 2)
274 in[i] = true;
275 { // Test equal() with aligned bytes
276 std::vector<bool> out = in;
277 assert(std::ranges::equal(in, out));
278 }
279 { // Test equal() with unaligned bytes
280 std::vector<bool> out(N + 8);
281 std::copy(in.begin(), in.end(), out.begin() + 4);
282 assert(std::ranges::equal(in.begin(), in.end(), out.begin() + 4, out.end() - 4));
283 }
284}
285
286constexpr bool test() {
287 test_iterators2<cpp17_input_iterator<int*>, sentinel_wrapper<cpp17_input_iterator<int*>>>();
288 test_iterators2<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>();
289 test_iterators2<forward_iterator<int*>>();
290 test_iterators2<bidirectional_iterator<int*>>();
291 test_iterators2<random_access_iterator<int*>>();
292 test_iterators2<contiguous_iterator<int*>>();
293 test_iterators2<int*>();
294 test_iterators2<const int*>();
295
296 { // check that std::invoke is used
297 struct S {
298 constexpr S(int i_) : i(i_) {}
299 constexpr bool equal(int o) { return i == o; }
300 constexpr S& identity() { return *this; }
301 int i;
302 };
303 {
304 S a[] = {7, 8, 9};
305 S b[] = {7, 8, 9};
306 auto ret = std::ranges::equal(a, a + 3, b, b + 3, &S::equal, &S::identity, &S::i);
307 assert(ret);
308 }
309 {
310 S a[] = {7, 8, 9};
311 S b[] = {7, 8, 9};
312 auto ret = std::ranges::equal(a, b, &S::equal, &S::identity, &S::i);
313 assert(ret);
314 }
315 }
316
317 { // check that the complexity requirements are met
318 { // different size
319 {
320 int a[] = {1, 2, 3};
321 int b[] = {1, 2, 3, 4};
322 int predCount = 0;
323 int projCount = 0;
324 auto pred = [&](int l, int r) {
325 ++predCount;
326 return l == r;
327 };
328 auto proj = [&](int i) {
329 ++projCount;
330 return i;
331 };
332 auto ret = std::ranges::equal(a, a + 3, b, b + 4, pred, proj, proj);
333 assert(!ret);
334 assert(predCount == 0);
335 assert(projCount == 0);
336 }
337 {
338 int a[] = {1, 2, 3};
339 int b[] = {1, 2, 3, 4};
340 int predCount = 0;
341 int projCount = 0;
342 auto pred = [&](int l, int r) {
343 ++predCount;
344 return l == r;
345 };
346 auto proj = [&](int i) {
347 ++projCount;
348 return i;
349 };
350 auto ret = std::ranges::equal(a, b, pred, proj, proj);
351 assert(!ret);
352 assert(predCount == 0);
353 assert(projCount == 0);
354 }
355 }
356
357 { // not a sized sentinel
358 {
359 int a[] = {1, 2, 3};
360 int b[] = {1, 2, 3, 4};
361 int predCount = 0;
362 int projCount = 0;
363 auto pred = [&](int l, int r) {
364 ++predCount;
365 return l == r;
366 };
367 auto proj = [&](int i) {
368 ++projCount;
369 return i;
370 };
371 auto ret = std::ranges::equal(a, sentinel_wrapper(a + 3), b, sentinel_wrapper(b + 4), pred, proj, proj);
372 assert(!ret);
373 assert(predCount <= 4);
374 assert(projCount <= 7);
375 }
376 {
377 int a[] = {1, 2, 3};
378 int b[] = {1, 2, 3, 4};
379 int predCount = 0;
380 int projCount = 0;
381 auto pred = [&](int l, int r) {
382 ++predCount;
383 return l == r;
384 };
385 auto proj = [&](int i) {
386 ++projCount;
387 return i;
388 };
389 auto range1 = std::ranges::subrange(a, sentinel_wrapper(a + 3));
390 auto range2 = std::ranges::subrange(b, sentinel_wrapper(b + 4));
391 auto ret = std::ranges::equal(range1, range2, pred, proj, proj);
392 assert(!ret);
393 assert(predCount <= 4);
394 assert(projCount <= 7);
395 }
396 }
397
398 { // same size
399 {
400 int a[] = {1, 2, 3};
401 int b[] = {1, 2, 3};
402 int predCount = 0;
403 int projCount = 0;
404 auto pred = [&](int l, int r) {
405 ++predCount;
406 return l == r;
407 };
408 auto proj = [&](int i) {
409 ++projCount;
410 return i;
411 };
412 auto ret = std::ranges::equal(a, a + 3, b, b + 3, pred, proj, proj);
413 assert(ret);
414 assert(predCount == 3);
415 assert(projCount == 6);
416 }
417 {
418 int a[] = {1, 2, 3};
419 int b[] = {1, 2, 3};
420 int predCount = 0;
421 int projCount = 0;
422 auto pred = [&](int l, int r) {
423 ++predCount;
424 return l == r;
425 };
426 auto proj = [&](int i) {
427 ++projCount;
428 return i;
429 };
430 auto ret = std::ranges::equal(a, b, pred, proj, proj);
431 assert(ret);
432 assert(predCount == 3);
433 assert(projCount == 6);
434 }
435 }
436 }
437
438 { // Test vector<bool>::iterator optimization
439 test_vector_bool<8>();
440 test_vector_bool<19>();
441 test_vector_bool<32>();
442 test_vector_bool<49>();
443 test_vector_bool<64>();
444 test_vector_bool<199>();
445 test_vector_bool<256>();
446 }
447
448 // Make sure std::equal behaves properly with std::vector<bool> iterators with custom size types.
449 // See issue: https://github.com/llvm/llvm-project/issues/126369.
450 {
451 //// Tests for std::equal with aligned bits
452
453 { // Test the first (partial) word for uint8_t
454 using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
455 std::vector<bool, Alloc> in(6, true, Alloc(1));
456 std::vector<bool, Alloc> expected(8, true, Alloc(1));
457 auto a = std::ranges::subrange(in.begin() + 4, in.end());
458 auto b = std::ranges::subrange(expected.begin() + 4, expected.begin() + 4 + a.size());
459 assert(std::ranges::equal(a, b));
460 }
461 { // Test the last word for uint8_t
462 using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
463 std::vector<bool, Alloc> in(12, true, Alloc(1));
464 std::vector<bool, Alloc> expected(16, true, Alloc(1));
465 auto a = std::ranges::subrange(in.begin(), in.end());
466 auto b = std::ranges::subrange(expected.begin(), expected.begin() + a.size());
467 assert(std::ranges::equal(a, b));
468 }
469 { // Test middle words for uint8_t
470 using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
471 std::vector<bool, Alloc> in(24, true, Alloc(1));
472 std::vector<bool, Alloc> expected(29, true, Alloc(1));
473 auto a = std::ranges::subrange(in.begin(), in.end());
474 auto b = std::ranges::subrange(expected.begin(), expected.begin() + a.size());
475 assert(std::ranges::equal(a, b));
476 }
477
478 { // Test the first (partial) word for uint16_t
479 using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
480 std::vector<bool, Alloc> in(12, true, Alloc(1));
481 std::vector<bool, Alloc> expected(16, true, Alloc(1));
482 auto a = std::ranges::subrange(in.begin() + 4, in.end());
483 auto b = std::ranges::subrange(expected.begin() + 4, expected.begin() + 4 + a.size());
484 assert(std::ranges::equal(a, b));
485 }
486 { // Test the last word for uint16_t
487 using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
488 std::vector<bool, Alloc> in(24, true, Alloc(1));
489 std::vector<bool, Alloc> expected(32, true, Alloc(1));
490 auto a = std::ranges::subrange(in.begin(), in.end());
491 auto b = std::ranges::subrange(expected.begin(), expected.begin() + a.size());
492 assert(std::ranges::equal(a, b));
493 }
494 { // Test middle words for uint16_t
495 using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
496 std::vector<bool, Alloc> in(48, true, Alloc(1));
497 std::vector<bool, Alloc> expected(55, true, Alloc(1));
498 auto a = std::ranges::subrange(in.begin(), in.end());
499 auto b = std::ranges::subrange(expected.begin(), expected.begin() + a.size());
500 assert(std::ranges::equal(a, b));
501 }
502
503 //// Tests for std::equal with unaligned bits
504
505 { // Test the first (partial) word for uint8_t
506 using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
507 std::vector<bool, Alloc> in(6, true, Alloc(1));
508 std::vector<bool, Alloc> expected(8, true, Alloc(1));
509 auto a = std::ranges::subrange(in.begin() + 4, in.end());
510 auto b = std::ranges::subrange(expected.begin(), expected.begin() + a.size());
511 assert(std::ranges::equal(a, b));
512 }
513 { // Test the last word for uint8_t
514 using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
515 std::vector<bool, Alloc> in(4, true, Alloc(1));
516 std::vector<bool, Alloc> expected(8, true, Alloc(1));
517 auto a = std::ranges::subrange(in.begin(), in.end());
518 auto b = std::ranges::subrange(expected.begin() + 3, expected.begin() + 3 + a.size());
519 assert(std::ranges::equal(a, b));
520 }
521 { // Test middle words for uint8_t
522 using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
523 std::vector<bool, Alloc> in(16, true, Alloc(1));
524 std::vector<bool, Alloc> expected(24, true, Alloc(1));
525 auto a = std::ranges::subrange(in.begin(), in.end());
526 auto b = std::ranges::subrange(expected.begin() + 4, expected.begin() + 4 + a.size());
527 assert(std::ranges::equal(a, b));
528 }
529
530 { // Test the first (partial) word for uint16_t
531 using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
532 std::vector<bool, Alloc> in(12, true, Alloc(1));
533 std::vector<bool, Alloc> expected(16, true, Alloc(1));
534 auto a = std::ranges::subrange(in.begin() + 4, in.end());
535 auto b = std::ranges::subrange(expected.begin(), expected.begin() + a.size());
536 assert(std::ranges::equal(a, b));
537 }
538 { // Test the last word for uint16_t
539 using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
540 std::vector<bool, Alloc> in(12, true, Alloc(1));
541 std::vector<bool, Alloc> expected(16, true, Alloc(1));
542 auto a = std::ranges::subrange(in.begin(), in.end());
543 auto b = std::ranges::subrange(expected.begin() + 3, expected.begin() + 3 + a.size());
544 assert(std::ranges::equal(a, b));
545 }
546 { // Test the middle words for uint16_t
547 using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
548 std::vector<bool, Alloc> in(32, true, Alloc(1));
549 std::vector<bool, Alloc> expected(64, true, Alloc(1));
550 auto a = std::ranges::subrange(in.begin(), in.end());
551 auto b = std::ranges::subrange(expected.begin() + 4, expected.begin() + 4 + a.size());
552 assert(std::ranges::equal(a, b));
553 }
554 }
555
556 return true;
557}
558
559int main(int, char**) {
560 test();
561 static_assert(test());
562
563 return 0;
564}
565

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