1 use core::result::Result::{Err, Ok};
5 let b = [1, 2, 3, 5, 5];
6 assert_eq!(b.iter().position(|&v| v == 9), None);
7 assert_eq!(b.iter().position(|&v| v == 5), Some(3));
8 assert_eq!(b.iter().position(|&v| v == 3), Some(2));
9 assert_eq!(b.iter().position(|&v| v == 0), None);
14 let b = [1, 2, 3, 5, 5];
15 assert_eq!(b.iter().rposition(|&v| v == 9), None);
16 assert_eq!(b.iter().rposition(|&v| v == 5), Some(4));
17 assert_eq!(b.iter().rposition(|&v| v == 3), Some(2));
18 assert_eq!(b.iter().rposition(|&v| v == 0), None);
22 fn test_binary_search() {
24 assert_eq!(b.binary_search(&5), Err(0));
27 assert_eq!(b.binary_search(&3), Err(0));
28 assert_eq!(b.binary_search(&4), Ok(0));
29 assert_eq!(b.binary_search(&5), Err(1));
31 let b = [1, 2, 4, 6, 8, 9];
32 assert_eq!(b.binary_search(&5), Err(3));
33 assert_eq!(b.binary_search(&6), Ok(3));
34 assert_eq!(b.binary_search(&7), Err(4));
35 assert_eq!(b.binary_search(&8), Ok(4));
37 let b = [1, 2, 4, 5, 6, 8];
38 assert_eq!(b.binary_search(&9), Err(6));
40 let b = [1, 2, 4, 6, 7, 8, 9];
41 assert_eq!(b.binary_search(&6), Ok(3));
42 assert_eq!(b.binary_search(&5), Err(3));
43 assert_eq!(b.binary_search(&8), Ok(5));
45 let b = [1, 2, 4, 5, 6, 8, 9];
46 assert_eq!(b.binary_search(&7), Err(5));
47 assert_eq!(b.binary_search(&0), Err(0));
49 let b = [1, 3, 3, 3, 7];
50 assert_eq!(b.binary_search(&0), Err(0));
51 assert_eq!(b.binary_search(&1), Ok(0));
52 assert_eq!(b.binary_search(&2), Err(1));
53 assert!(match b.binary_search(&3) {
57 assert!(match b.binary_search(&3) {
61 assert_eq!(b.binary_search(&4), Err(4));
62 assert_eq!(b.binary_search(&5), Err(4));
63 assert_eq!(b.binary_search(&6), Err(4));
64 assert_eq!(b.binary_search(&7), Ok(4));
65 assert_eq!(b.binary_search(&8), Err(5));
69 // Test implementation specific behavior when finding equivalent elements.
70 // It is ok to break this test but when you do a crater run is highly advisable.
71 fn test_binary_search_implementation_details() {
72 let b = [1, 1, 2, 2, 3, 3, 3];
73 assert_eq!(b.binary_search(&1), Ok(1));
74 assert_eq!(b.binary_search(&2), Ok(3));
75 assert_eq!(b.binary_search(&3), Ok(6));
76 let b = [1, 1, 1, 1, 1, 3, 3, 3, 3];
77 assert_eq!(b.binary_search(&1), Ok(4));
78 assert_eq!(b.binary_search(&3), Ok(8));
79 let b = [1, 1, 1, 1, 3, 3, 3, 3, 3];
80 assert_eq!(b.binary_search(&1), Ok(3));
81 assert_eq!(b.binary_search(&3), Ok(8));
85 fn test_partition_point() {
87 assert_eq!(b.partition_point(|&x| x < 5), 0);
90 assert_eq!(b.partition_point(|&x| x < 3), 0);
91 assert_eq!(b.partition_point(|&x| x < 4), 0);
92 assert_eq!(b.partition_point(|&x| x < 5), 1);
94 let b = [1, 2, 4, 6, 8, 9];
95 assert_eq!(b.partition_point(|&x| x < 5), 3);
96 assert_eq!(b.partition_point(|&x| x < 6), 3);
97 assert_eq!(b.partition_point(|&x| x < 7), 4);
98 assert_eq!(b.partition_point(|&x| x < 8), 4);
100 let b = [1, 2, 4, 5, 6, 8];
101 assert_eq!(b.partition_point(|&x| x < 9), 6);
103 let b = [1, 2, 4, 6, 7, 8, 9];
104 assert_eq!(b.partition_point(|&x| x < 6), 3);
105 assert_eq!(b.partition_point(|&x| x < 5), 3);
106 assert_eq!(b.partition_point(|&x| x < 8), 5);
108 let b = [1, 2, 4, 5, 6, 8, 9];
109 assert_eq!(b.partition_point(|&x| x < 7), 5);
110 assert_eq!(b.partition_point(|&x| x < 0), 0);
112 let b = [1, 3, 3, 3, 7];
113 assert_eq!(b.partition_point(|&x| x < 0), 0);
114 assert_eq!(b.partition_point(|&x| x < 1), 0);
115 assert_eq!(b.partition_point(|&x| x < 2), 1);
116 assert_eq!(b.partition_point(|&x| x < 3), 1);
117 assert_eq!(b.partition_point(|&x| x < 4), 4);
118 assert_eq!(b.partition_point(|&x| x < 5), 4);
119 assert_eq!(b.partition_point(|&x| x < 6), 4);
120 assert_eq!(b.partition_point(|&x| x < 7), 4);
121 assert_eq!(b.partition_point(|&x| x < 8), 5);
125 fn test_iterator_nth() {
126 let v: &[_] = &[0, 1, 2, 3, 4];
127 for i in 0..v.len() {
128 assert_eq!(v.iter().nth(i).unwrap(), &v[i]);
130 assert_eq!(v.iter().nth(v.len()), None);
132 let mut iter = v.iter();
133 assert_eq!(iter.nth(2).unwrap(), &v[2]);
134 assert_eq!(iter.nth(1).unwrap(), &v[4]);
138 fn test_iterator_nth_back() {
139 let v: &[_] = &[0, 1, 2, 3, 4];
140 for i in 0..v.len() {
141 assert_eq!(v.iter().nth_back(i).unwrap(), &v[v.len() - i - 1]);
143 assert_eq!(v.iter().nth_back(v.len()), None);
145 let mut iter = v.iter();
146 assert_eq!(iter.nth_back(2).unwrap(), &v[2]);
147 assert_eq!(iter.nth_back(1).unwrap(), &v[0]);
151 fn test_iterator_last() {
152 let v: &[_] = &[0, 1, 2, 3, 4];
153 assert_eq!(v.iter().last().unwrap(), &4);
154 assert_eq!(v[..1].iter().last().unwrap(), &0);
158 fn test_iterator_count() {
159 let v: &[_] = &[0, 1, 2, 3, 4];
160 assert_eq!(v.iter().count(), 5);
162 let mut iter2 = v.iter();
165 assert_eq!(iter2.count(), 3);
169 fn test_chunks_count() {
170 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
172 assert_eq!(c.count(), 2);
174 let v2: &[i32] = &[0, 1, 2, 3, 4];
175 let c2 = v2.chunks(2);
176 assert_eq!(c2.count(), 3);
178 let v3: &[i32] = &[];
179 let c3 = v3.chunks(2);
180 assert_eq!(c3.count(), 0);
184 fn test_chunks_nth() {
185 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
186 let mut c = v.chunks(2);
187 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
188 assert_eq!(c.next().unwrap(), &[4, 5]);
190 let v2: &[i32] = &[0, 1, 2, 3, 4];
191 let mut c2 = v2.chunks(3);
192 assert_eq!(c2.nth(1).unwrap(), &[3, 4]);
193 assert_eq!(c2.next(), None);
197 fn test_chunks_nth_back() {
198 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
199 let mut c = v.chunks(2);
200 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
201 assert_eq!(c.next().unwrap(), &[0, 1]);
202 assert_eq!(c.next(), None);
204 let v2: &[i32] = &[0, 1, 2, 3, 4];
205 let mut c2 = v2.chunks(3);
206 assert_eq!(c2.nth_back(1).unwrap(), &[0, 1, 2]);
207 assert_eq!(c2.next(), None);
208 assert_eq!(c2.next_back(), None);
210 let v3: &[i32] = &[0, 1, 2, 3, 4];
211 let mut c3 = v3.chunks(10);
212 assert_eq!(c3.nth_back(0).unwrap(), &[0, 1, 2, 3, 4]);
213 assert_eq!(c3.next(), None);
215 let v4: &[i32] = &[0, 1, 2];
216 let mut c4 = v4.chunks(10);
217 assert_eq!(c4.nth_back(1_000_000_000usize), None);
221 fn test_chunks_last() {
222 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
224 assert_eq!(c.last().unwrap()[1], 5);
226 let v2: &[i32] = &[0, 1, 2, 3, 4];
227 let c2 = v2.chunks(2);
228 assert_eq!(c2.last().unwrap()[0], 4);
232 fn test_chunks_zip() {
233 let v1: &[i32] = &[0, 1, 2, 3, 4];
234 let v2: &[i32] = &[6, 7, 8, 9, 10];
239 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
240 .collect::<Vec<_>>();
241 assert_eq!(res, vec![14, 22, 14]);
245 fn test_chunks_mut_count() {
246 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
247 let c = v.chunks_mut(3);
248 assert_eq!(c.count(), 2);
250 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
251 let c2 = v2.chunks_mut(2);
252 assert_eq!(c2.count(), 3);
254 let v3: &mut [i32] = &mut [];
255 let c3 = v3.chunks_mut(2);
256 assert_eq!(c3.count(), 0);
260 fn test_chunks_mut_nth() {
261 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
262 let mut c = v.chunks_mut(2);
263 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
264 assert_eq!(c.next().unwrap(), &[4, 5]);
266 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
267 let mut c2 = v2.chunks_mut(3);
268 assert_eq!(c2.nth(1).unwrap(), &[3, 4]);
269 assert_eq!(c2.next(), None);
273 fn test_chunks_mut_nth_back() {
274 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
275 let mut c = v.chunks_mut(2);
276 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
277 assert_eq!(c.next().unwrap(), &[0, 1]);
279 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
280 let mut c1 = v1.chunks_mut(3);
281 assert_eq!(c1.nth_back(1).unwrap(), &[0, 1, 2]);
282 assert_eq!(c1.next(), None);
284 let v3: &mut [i32] = &mut [0, 1, 2, 3, 4];
285 let mut c3 = v3.chunks_mut(10);
286 assert_eq!(c3.nth_back(0).unwrap(), &[0, 1, 2, 3, 4]);
287 assert_eq!(c3.next(), None);
289 let v4: &mut [i32] = &mut [0, 1, 2];
290 let mut c4 = v4.chunks_mut(10);
291 assert_eq!(c4.nth_back(1_000_000_000usize), None);
295 fn test_chunks_mut_last() {
296 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
297 let c = v.chunks_mut(2);
298 assert_eq!(c.last().unwrap(), &[4, 5]);
300 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
301 let c2 = v2.chunks_mut(2);
302 assert_eq!(c2.last().unwrap(), &[4]);
306 fn test_chunks_mut_zip() {
307 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
308 let v2: &[i32] = &[6, 7, 8, 9, 10];
310 for (a, b) in v1.chunks_mut(2).zip(v2.chunks(2)) {
311 let sum = b.iter().sum::<i32>();
316 assert_eq!(v1, [13, 14, 19, 20, 14]);
320 fn test_chunks_exact_count() {
321 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
322 let c = v.chunks_exact(3);
323 assert_eq!(c.count(), 2);
325 let v2: &[i32] = &[0, 1, 2, 3, 4];
326 let c2 = v2.chunks_exact(2);
327 assert_eq!(c2.count(), 2);
329 let v3: &[i32] = &[];
330 let c3 = v3.chunks_exact(2);
331 assert_eq!(c3.count(), 0);
335 fn test_chunks_exact_nth() {
336 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
337 let mut c = v.chunks_exact(2);
338 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
339 assert_eq!(c.next().unwrap(), &[4, 5]);
341 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
342 let mut c2 = v2.chunks_exact(3);
343 assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
344 assert_eq!(c2.next(), None);
348 fn test_chunks_exact_nth_back() {
349 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
350 let mut c = v.chunks_exact(2);
351 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
352 assert_eq!(c.next().unwrap(), &[0, 1]);
353 assert_eq!(c.next(), None);
355 let v2: &[i32] = &[0, 1, 2, 3, 4];
356 let mut c2 = v2.chunks_exact(3);
357 assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
358 assert_eq!(c2.next(), None);
359 assert_eq!(c2.next_back(), None);
361 let v3: &[i32] = &[0, 1, 2, 3, 4];
362 let mut c3 = v3.chunks_exact(10);
363 assert_eq!(c3.nth_back(0), None);
367 fn test_chunks_exact_last() {
368 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
369 let c = v.chunks_exact(2);
370 assert_eq!(c.last().unwrap(), &[4, 5]);
372 let v2: &[i32] = &[0, 1, 2, 3, 4];
373 let c2 = v2.chunks_exact(2);
374 assert_eq!(c2.last().unwrap(), &[2, 3]);
378 fn test_chunks_exact_remainder() {
379 let v: &[i32] = &[0, 1, 2, 3, 4];
380 let c = v.chunks_exact(2);
381 assert_eq!(c.remainder(), &[4]);
385 fn test_chunks_exact_zip() {
386 let v1: &[i32] = &[0, 1, 2, 3, 4];
387 let v2: &[i32] = &[6, 7, 8, 9, 10];
391 .zip(v2.chunks_exact(2))
392 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
393 .collect::<Vec<_>>();
394 assert_eq!(res, vec![14, 22]);
398 fn test_chunks_exact_mut_count() {
399 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
400 let c = v.chunks_exact_mut(3);
401 assert_eq!(c.count(), 2);
403 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
404 let c2 = v2.chunks_exact_mut(2);
405 assert_eq!(c2.count(), 2);
407 let v3: &mut [i32] = &mut [];
408 let c3 = v3.chunks_exact_mut(2);
409 assert_eq!(c3.count(), 0);
413 fn test_chunks_exact_mut_nth() {
414 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
415 let mut c = v.chunks_exact_mut(2);
416 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
417 assert_eq!(c.next().unwrap(), &[4, 5]);
419 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
420 let mut c2 = v2.chunks_exact_mut(3);
421 assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
422 assert_eq!(c2.next(), None);
426 fn test_chunks_exact_mut_nth_back() {
427 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
428 let mut c = v.chunks_exact_mut(2);
429 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
430 assert_eq!(c.next().unwrap(), &[0, 1]);
431 assert_eq!(c.next(), None);
433 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
434 let mut c2 = v2.chunks_exact_mut(3);
435 assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
436 assert_eq!(c2.next(), None);
437 assert_eq!(c2.next_back(), None);
439 let v3: &mut [i32] = &mut [0, 1, 2, 3, 4];
440 let mut c3 = v3.chunks_exact_mut(10);
441 assert_eq!(c3.nth_back(0), None);
445 fn test_chunks_exact_mut_last() {
446 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
447 let c = v.chunks_exact_mut(2);
448 assert_eq!(c.last().unwrap(), &[4, 5]);
450 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
451 let c2 = v2.chunks_exact_mut(2);
452 assert_eq!(c2.last().unwrap(), &[2, 3]);
456 fn test_chunks_exact_mut_remainder() {
457 let v: &mut [i32] = &mut [0, 1, 2, 3, 4];
458 let c = v.chunks_exact_mut(2);
459 assert_eq!(c.into_remainder(), &[4]);
463 fn test_chunks_exact_mut_zip() {
464 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
465 let v2: &[i32] = &[6, 7, 8, 9, 10];
467 for (a, b) in v1.chunks_exact_mut(2).zip(v2.chunks_exact(2)) {
468 let sum = b.iter().sum::<i32>();
473 assert_eq!(v1, [13, 14, 19, 20, 4]);
477 fn test_array_chunks_infer() {
478 let v: &[i32] = &[0, 1, 2, 3, 4, -4];
479 let c = v.array_chunks();
480 for &[a, b, c] in c {
481 assert_eq!(a + b + c, 3);
484 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
485 let total = v2.array_chunks().map(|&[a, b]| a * b).sum::<i32>();
486 assert_eq!(total, 2 * 3 + 4 * 5);
490 fn test_array_chunks_count() {
491 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
492 let c = v.array_chunks::<3>();
493 assert_eq!(c.count(), 2);
495 let v2: &[i32] = &[0, 1, 2, 3, 4];
496 let c2 = v2.array_chunks::<2>();
497 assert_eq!(c2.count(), 2);
499 let v3: &[i32] = &[];
500 let c3 = v3.array_chunks::<2>();
501 assert_eq!(c3.count(), 0);
505 fn test_array_chunks_nth() {
506 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
507 let mut c = v.array_chunks::<2>();
508 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
509 assert_eq!(c.next().unwrap(), &[4, 5]);
511 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
512 let mut c2 = v2.array_chunks::<3>();
513 assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
514 assert_eq!(c2.next(), None);
518 fn test_array_chunks_nth_back() {
519 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
520 let mut c = v.array_chunks::<2>();
521 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
522 assert_eq!(c.next().unwrap(), &[0, 1]);
523 assert_eq!(c.next(), None);
525 let v2: &[i32] = &[0, 1, 2, 3, 4];
526 let mut c2 = v2.array_chunks::<3>();
527 assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
528 assert_eq!(c2.next(), None);
529 assert_eq!(c2.next_back(), None);
531 let v3: &[i32] = &[0, 1, 2, 3, 4];
532 let mut c3 = v3.array_chunks::<10>();
533 assert_eq!(c3.nth_back(0), None);
537 fn test_array_chunks_last() {
538 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
539 let c = v.array_chunks::<2>();
540 assert_eq!(c.last().unwrap(), &[4, 5]);
542 let v2: &[i32] = &[0, 1, 2, 3, 4];
543 let c2 = v2.array_chunks::<2>();
544 assert_eq!(c2.last().unwrap(), &[2, 3]);
548 fn test_array_chunks_remainder() {
549 let v: &[i32] = &[0, 1, 2, 3, 4];
550 let c = v.array_chunks::<2>();
551 assert_eq!(c.remainder(), &[4]);
555 fn test_array_chunks_zip() {
556 let v1: &[i32] = &[0, 1, 2, 3, 4];
557 let v2: &[i32] = &[6, 7, 8, 9, 10];
561 .zip(v2.array_chunks::<2>())
562 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
563 .collect::<Vec<_>>();
564 assert_eq!(res, vec![14, 22]);
568 fn test_array_chunks_mut_infer() {
569 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
570 for a in v.array_chunks_mut() {
571 let sum = a.iter().sum::<i32>();
574 assert_eq!(v, &[3, 3, 3, 12, 12, 12, 6]);
576 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
577 v2.array_chunks_mut().for_each(|[a, b]| core::mem::swap(a, b));
578 assert_eq!(v2, &[1, 0, 3, 2, 5, 4, 6]);
582 fn test_array_chunks_mut_count() {
583 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
584 let c = v.array_chunks_mut::<3>();
585 assert_eq!(c.count(), 2);
587 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
588 let c2 = v2.array_chunks_mut::<2>();
589 assert_eq!(c2.count(), 2);
591 let v3: &mut [i32] = &mut [];
592 let c3 = v3.array_chunks_mut::<2>();
593 assert_eq!(c3.count(), 0);
597 fn test_array_chunks_mut_nth() {
598 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
599 let mut c = v.array_chunks_mut::<2>();
600 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
601 assert_eq!(c.next().unwrap(), &[4, 5]);
603 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
604 let mut c2 = v2.array_chunks_mut::<3>();
605 assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
606 assert_eq!(c2.next(), None);
610 fn test_array_chunks_mut_nth_back() {
611 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
612 let mut c = v.array_chunks_mut::<2>();
613 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
614 assert_eq!(c.next().unwrap(), &[0, 1]);
615 assert_eq!(c.next(), None);
617 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
618 let mut c2 = v2.array_chunks_mut::<3>();
619 assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
620 assert_eq!(c2.next(), None);
621 assert_eq!(c2.next_back(), None);
623 let v3: &mut [i32] = &mut [0, 1, 2, 3, 4];
624 let mut c3 = v3.array_chunks_mut::<10>();
625 assert_eq!(c3.nth_back(0), None);
629 fn test_array_chunks_mut_last() {
630 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
631 let c = v.array_chunks_mut::<2>();
632 assert_eq!(c.last().unwrap(), &[4, 5]);
634 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
635 let c2 = v2.array_chunks_mut::<2>();
636 assert_eq!(c2.last().unwrap(), &[2, 3]);
640 fn test_array_chunks_mut_remainder() {
641 let v: &mut [i32] = &mut [0, 1, 2, 3, 4];
642 let c = v.array_chunks_mut::<2>();
643 assert_eq!(c.into_remainder(), &[4]);
647 fn test_array_chunks_mut_zip() {
648 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
649 let v2: &[i32] = &[6, 7, 8, 9, 10];
651 for (a, b) in v1.array_chunks_mut::<2>().zip(v2.array_chunks::<2>()) {
652 let sum = b.iter().sum::<i32>();
657 assert_eq!(v1, [13, 14, 19, 20, 4]);
661 fn test_rchunks_count() {
662 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
663 let c = v.rchunks(3);
664 assert_eq!(c.count(), 2);
666 let v2: &[i32] = &[0, 1, 2, 3, 4];
667 let c2 = v2.rchunks(2);
668 assert_eq!(c2.count(), 3);
670 let v3: &[i32] = &[];
671 let c3 = v3.rchunks(2);
672 assert_eq!(c3.count(), 0);
676 fn test_rchunks_nth() {
677 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
678 let mut c = v.rchunks(2);
679 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
680 assert_eq!(c.next().unwrap(), &[0, 1]);
682 let v2: &[i32] = &[0, 1, 2, 3, 4];
683 let mut c2 = v2.rchunks(3);
684 assert_eq!(c2.nth(1).unwrap(), &[0, 1]);
685 assert_eq!(c2.next(), None);
689 fn test_rchunks_nth_back() {
690 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
691 let mut c = v.rchunks(2);
692 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
693 assert_eq!(c.next_back().unwrap(), &[4, 5]);
695 let v2: &[i32] = &[0, 1, 2, 3, 4];
696 let mut c2 = v2.rchunks(3);
697 assert_eq!(c2.nth_back(1).unwrap(), &[2, 3, 4]);
698 assert_eq!(c2.next_back(), None);
702 fn test_rchunks_last() {
703 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
704 let c = v.rchunks(2);
705 assert_eq!(c.last().unwrap()[1], 1);
707 let v2: &[i32] = &[0, 1, 2, 3, 4];
708 let c2 = v2.rchunks(2);
709 assert_eq!(c2.last().unwrap()[0], 0);
713 fn test_rchunks_zip() {
714 let v1: &[i32] = &[0, 1, 2, 3, 4];
715 let v2: &[i32] = &[6, 7, 8, 9, 10];
720 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
721 .collect::<Vec<_>>();
722 assert_eq!(res, vec![26, 18, 6]);
726 fn test_rchunks_mut_count() {
727 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
728 let c = v.rchunks_mut(3);
729 assert_eq!(c.count(), 2);
731 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
732 let c2 = v2.rchunks_mut(2);
733 assert_eq!(c2.count(), 3);
735 let v3: &mut [i32] = &mut [];
736 let c3 = v3.rchunks_mut(2);
737 assert_eq!(c3.count(), 0);
741 fn test_rchunks_mut_nth() {
742 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
743 let mut c = v.rchunks_mut(2);
744 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
745 assert_eq!(c.next().unwrap(), &[0, 1]);
747 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
748 let mut c2 = v2.rchunks_mut(3);
749 assert_eq!(c2.nth(1).unwrap(), &[0, 1]);
750 assert_eq!(c2.next(), None);
754 fn test_rchunks_mut_nth_back() {
755 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
756 let mut c = v.rchunks_mut(2);
757 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
758 assert_eq!(c.next_back().unwrap(), &[4, 5]);
760 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
761 let mut c2 = v2.rchunks_mut(3);
762 assert_eq!(c2.nth_back(1).unwrap(), &[2, 3, 4]);
763 assert_eq!(c2.next_back(), None);
767 fn test_rchunks_mut_last() {
768 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
769 let c = v.rchunks_mut(2);
770 assert_eq!(c.last().unwrap(), &[0, 1]);
772 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
773 let c2 = v2.rchunks_mut(2);
774 assert_eq!(c2.last().unwrap(), &[0]);
778 fn test_rchunks_mut_zip() {
779 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
780 let v2: &[i32] = &[6, 7, 8, 9, 10];
782 for (a, b) in v1.rchunks_mut(2).zip(v2.rchunks(2)) {
783 let sum = b.iter().sum::<i32>();
788 assert_eq!(v1, [6, 16, 17, 22, 23]);
792 fn test_rchunks_exact_count() {
793 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
794 let c = v.rchunks_exact(3);
795 assert_eq!(c.count(), 2);
797 let v2: &[i32] = &[0, 1, 2, 3, 4];
798 let c2 = v2.rchunks_exact(2);
799 assert_eq!(c2.count(), 2);
801 let v3: &[i32] = &[];
802 let c3 = v3.rchunks_exact(2);
803 assert_eq!(c3.count(), 0);
807 fn test_rchunks_exact_nth() {
808 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
809 let mut c = v.rchunks_exact(2);
810 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
811 assert_eq!(c.next().unwrap(), &[0, 1]);
813 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
814 let mut c2 = v2.rchunks_exact(3);
815 assert_eq!(c2.nth(1).unwrap(), &[1, 2, 3]);
816 assert_eq!(c2.next(), None);
820 fn test_rchunks_exact_nth_back() {
821 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
822 let mut c = v.rchunks_exact(2);
823 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
824 assert_eq!(c.next_back().unwrap(), &[4, 5]);
826 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
827 let mut c2 = v2.rchunks_exact(3);
828 assert_eq!(c2.nth_back(1).unwrap(), &[4, 5, 6]);
829 assert_eq!(c2.next(), None);
833 fn test_rchunks_exact_last() {
834 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
835 let c = v.rchunks_exact(2);
836 assert_eq!(c.last().unwrap(), &[0, 1]);
838 let v2: &[i32] = &[0, 1, 2, 3, 4];
839 let c2 = v2.rchunks_exact(2);
840 assert_eq!(c2.last().unwrap(), &[1, 2]);
844 fn test_rchunks_exact_remainder() {
845 let v: &[i32] = &[0, 1, 2, 3, 4];
846 let c = v.rchunks_exact(2);
847 assert_eq!(c.remainder(), &[0]);
851 fn test_rchunks_exact_zip() {
852 let v1: &[i32] = &[0, 1, 2, 3, 4];
853 let v2: &[i32] = &[6, 7, 8, 9, 10];
857 .zip(v2.rchunks_exact(2))
858 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
859 .collect::<Vec<_>>();
860 assert_eq!(res, vec![26, 18]);
864 fn test_rchunks_exact_mut_count() {
865 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
866 let c = v.rchunks_exact_mut(3);
867 assert_eq!(c.count(), 2);
869 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
870 let c2 = v2.rchunks_exact_mut(2);
871 assert_eq!(c2.count(), 2);
873 let v3: &mut [i32] = &mut [];
874 let c3 = v3.rchunks_exact_mut(2);
875 assert_eq!(c3.count(), 0);
879 fn test_rchunks_exact_mut_nth() {
880 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
881 let mut c = v.rchunks_exact_mut(2);
882 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
883 assert_eq!(c.next().unwrap(), &[0, 1]);
885 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
886 let mut c2 = v2.rchunks_exact_mut(3);
887 assert_eq!(c2.nth(1).unwrap(), &[1, 2, 3]);
888 assert_eq!(c2.next(), None);
892 fn test_rchunks_exact_mut_nth_back() {
893 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
894 let mut c = v.rchunks_exact_mut(2);
895 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
896 assert_eq!(c.next_back().unwrap(), &[4, 5]);
898 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
899 let mut c2 = v2.rchunks_exact_mut(3);
900 assert_eq!(c2.nth_back(1).unwrap(), &[4, 5, 6]);
901 assert_eq!(c2.next(), None);
905 fn test_rchunks_exact_mut_last() {
906 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
907 let c = v.rchunks_exact_mut(2);
908 assert_eq!(c.last().unwrap(), &[0, 1]);
910 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
911 let c2 = v2.rchunks_exact_mut(2);
912 assert_eq!(c2.last().unwrap(), &[1, 2]);
916 fn test_rchunks_exact_mut_remainder() {
917 let v: &mut [i32] = &mut [0, 1, 2, 3, 4];
918 let c = v.rchunks_exact_mut(2);
919 assert_eq!(c.into_remainder(), &[0]);
923 fn test_rchunks_exact_mut_zip() {
924 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
925 let v2: &[i32] = &[6, 7, 8, 9, 10];
927 for (a, b) in v1.rchunks_exact_mut(2).zip(v2.rchunks_exact(2)) {
928 let sum = b.iter().sum::<i32>();
933 assert_eq!(v1, [0, 16, 17, 22, 23]);
937 fn test_windows_count() {
938 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
939 let c = v.windows(3);
940 assert_eq!(c.count(), 4);
942 let v2: &[i32] = &[0, 1, 2, 3, 4];
943 let c2 = v2.windows(6);
944 assert_eq!(c2.count(), 0);
946 let v3: &[i32] = &[];
947 let c3 = v3.windows(2);
948 assert_eq!(c3.count(), 0);
952 fn test_windows_nth() {
953 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
954 let mut c = v.windows(2);
955 assert_eq!(c.nth(2).unwrap()[1], 3);
956 assert_eq!(c.next().unwrap()[0], 3);
958 let v2: &[i32] = &[0, 1, 2, 3, 4];
959 let mut c2 = v2.windows(4);
960 assert_eq!(c2.nth(1).unwrap()[1], 2);
961 assert_eq!(c2.next(), None);
965 fn test_windows_nth_back() {
966 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
967 let mut c = v.windows(2);
968 assert_eq!(c.nth_back(2).unwrap()[0], 2);
969 assert_eq!(c.next_back().unwrap()[1], 2);
971 let v2: &[i32] = &[0, 1, 2, 3, 4];
972 let mut c2 = v2.windows(4);
973 assert_eq!(c2.nth_back(1).unwrap()[1], 1);
974 assert_eq!(c2.next_back(), None);
978 fn test_windows_last() {
979 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
980 let c = v.windows(2);
981 assert_eq!(c.last().unwrap()[1], 5);
983 let v2: &[i32] = &[0, 1, 2, 3, 4];
984 let c2 = v2.windows(2);
985 assert_eq!(c2.last().unwrap()[0], 3);
989 fn test_windows_zip() {
990 let v1: &[i32] = &[0, 1, 2, 3, 4];
991 let v2: &[i32] = &[6, 7, 8, 9, 10];
996 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
997 .collect::<Vec<_>>();
999 assert_eq!(res, [14, 18, 22, 26]);
1004 fn test_iter_ref_consistency() {
1005 use std::fmt::Debug;
1007 fn test<T: Copy + Debug + PartialEq>(x: T) {
1008 let v: &[T] = &[x, x, x];
1009 let v_ptrs: [*const T; 3] = match v {
1010 [ref v1, ref v2, ref v3] => [v1 as *const _, v2 as *const _, v3 as *const _],
1011 _ => unreachable!(),
1017 assert_eq!(&v[i] as *const _, v_ptrs[i]); // check the v_ptrs array, just to be sure
1018 let nth = v.iter().nth(i).unwrap();
1019 assert_eq!(nth as *const _, v_ptrs[i]);
1021 assert_eq!(v.iter().nth(len), None, "nth(len) should return None");
1023 // stepping through with nth(0)
1025 let mut it = v.iter();
1027 let next = it.nth(0).unwrap();
1028 assert_eq!(next as *const _, v_ptrs[i]);
1030 assert_eq!(it.nth(0), None);
1035 let mut it = v.iter();
1037 let remaining = len - i;
1038 assert_eq!(it.size_hint(), (remaining, Some(remaining)));
1040 let next = it.next().unwrap();
1041 assert_eq!(next as *const _, v_ptrs[i]);
1043 assert_eq!(it.size_hint(), (0, Some(0)));
1044 assert_eq!(it.next(), None, "The final call to next() should return None");
1049 let mut it = v.iter();
1051 let remaining = len - i;
1052 assert_eq!(it.size_hint(), (remaining, Some(remaining)));
1054 let prev = it.next_back().unwrap();
1055 assert_eq!(prev as *const _, v_ptrs[remaining - 1]);
1057 assert_eq!(it.size_hint(), (0, Some(0)));
1058 assert_eq!(it.next_back(), None, "The final call to next_back() should return None");
1062 fn test_mut<T: Copy + Debug + PartialEq>(x: T) {
1063 let v: &mut [T] = &mut [x, x, x];
1064 let v_ptrs: [*mut T; 3] = match v {
1065 [ref v1, ref v2, ref v3] => {
1066 [v1 as *const _ as *mut _, v2 as *const _ as *mut _, v3 as *const _ as *mut _]
1068 _ => unreachable!(),
1074 assert_eq!(&mut v[i] as *mut _, v_ptrs[i]); // check the v_ptrs array, just to be sure
1075 let nth = v.iter_mut().nth(i).unwrap();
1076 assert_eq!(nth as *mut _, v_ptrs[i]);
1078 assert_eq!(v.iter().nth(len), None, "nth(len) should return None");
1080 // stepping through with nth(0)
1082 let mut it = v.iter();
1084 let next = it.nth(0).unwrap();
1085 assert_eq!(next as *const _, v_ptrs[i]);
1087 assert_eq!(it.nth(0), None);
1092 let mut it = v.iter_mut();
1094 let remaining = len - i;
1095 assert_eq!(it.size_hint(), (remaining, Some(remaining)));
1097 let next = it.next().unwrap();
1098 assert_eq!(next as *mut _, v_ptrs[i]);
1100 assert_eq!(it.size_hint(), (0, Some(0)));
1101 assert_eq!(it.next(), None, "The final call to next() should return None");
1106 let mut it = v.iter_mut();
1108 let remaining = len - i;
1109 assert_eq!(it.size_hint(), (remaining, Some(remaining)));
1111 let prev = it.next_back().unwrap();
1112 assert_eq!(prev as *mut _, v_ptrs[remaining - 1]);
1114 assert_eq!(it.size_hint(), (0, Some(0)));
1115 assert_eq!(it.next_back(), None, "The final call to next_back() should return None");
1119 // Make sure iterators and slice patterns yield consistent addresses for various types,
1123 test([0u32; 0]); // ZST with alignment > 0
1126 test_mut([0u32; 0]); // ZST with alignment > 0
1129 // The current implementation of SliceIndex fails to handle methods
1130 // orthogonally from range types; therefore, it is worth testing
1131 // all of the indexing operations on each input.
1133 // This checks all six indexing methods, given an input range that
1134 // should succeed. (it is NOT suitable for testing invalid inputs)
1135 macro_rules! assert_range_eq {
1136 ($arr:expr, $range:expr, $expected:expr) => {
1138 let mut expected = $expected;
1141 let expected: &[_] = &expected;
1143 assert_eq!(&s[$range], expected, "(in assertion for: index)");
1144 assert_eq!(s.get($range), Some(expected), "(in assertion for: get)");
1147 s.get_unchecked($range),
1149 "(in assertion for: get_unchecked)",
1154 let s: &mut [_] = &mut arr;
1155 let expected: &mut [_] = &mut expected;
1157 assert_eq!(&mut s[$range], expected, "(in assertion for: index_mut)",);
1160 Some(&mut expected[..]),
1161 "(in assertion for: get_mut)",
1165 s.get_unchecked_mut($range),
1167 "(in assertion for: get_unchecked_mut)",
1174 // Make sure the macro can actually detect bugs,
1175 // because if it can't, then what are we even doing here?
1177 // (Be aware this only demonstrates the ability to detect bugs
1178 // in the FIRST method that panics, as the macro is not designed
1179 // to be used in `should_panic`)
1181 #[should_panic(expected = "out of range")]
1182 fn assert_range_eq_can_fail_by_panic() {
1183 assert_range_eq!([0, 1, 2], 0..5, [0, 1, 2]);
1186 // (Be aware this only demonstrates the ability to detect bugs
1187 // in the FIRST method it calls, as the macro is not designed
1188 // to be used in `should_panic`)
1190 #[should_panic(expected = "==")]
1191 fn assert_range_eq_can_fail_by_inequality() {
1192 assert_range_eq!([0, 1, 2], 0..2, [0, 1, 2]);
1195 // Test cases for bad index operations.
1197 // This generates `should_panic` test cases for Index/IndexMut
1198 // and `None` test cases for get/get_mut.
1199 macro_rules! panic_cases {
1201 // each test case needs a unique name to namespace the tests
1202 in mod $case_name:ident {
1207 // one or more similar inputs for which data[input] succeeds,
1208 // and the corresponding output as an array. This helps validate
1209 // "critical points" where an input range straddles the boundary
1210 // between valid and invalid.
1211 // (such as the input `len..len`, which is just barely valid)
1213 good: data[$good:expr] == $output:expr;
1216 bad: data[$bad:expr];
1217 message: $expect_msg:expr;
1225 $( assert_range_eq!($data, $good, $output); )*
1229 assert_eq!(v.get($bad), None, "(in None assertion for get)");
1233 let v: &mut [_] = &mut v;
1234 assert_eq!(v.get_mut($bad), None, "(in None assertion for get_mut)");
1239 #[should_panic(expected = $expect_msg)]
1247 #[should_panic(expected = $expect_msg)]
1248 fn index_mut_fail() {
1250 let v: &mut [_] = &mut v;
1251 let _v = &mut v[$bad];
1259 let v = [0, 1, 2, 3, 4, 5];
1261 assert_range_eq!(v, .., [0, 1, 2, 3, 4, 5]);
1262 assert_range_eq!(v, ..2, [0, 1]);
1263 assert_range_eq!(v, ..=1, [0, 1]);
1264 assert_range_eq!(v, 2.., [2, 3, 4, 5]);
1265 assert_range_eq!(v, 1..4, [1, 2, 3]);
1266 assert_range_eq!(v, 1..=3, [1, 2, 3]);
1270 in mod rangefrom_len {
1271 data: [0, 1, 2, 3, 4, 5];
1273 good: data[6..] == [];
1275 message: "out of range";
1278 in mod rangeto_len {
1279 data: [0, 1, 2, 3, 4, 5];
1281 good: data[..6] == [0, 1, 2, 3, 4, 5];
1283 message: "out of range";
1286 in mod rangetoinclusive_len {
1287 data: [0, 1, 2, 3, 4, 5];
1289 good: data[..=5] == [0, 1, 2, 3, 4, 5];
1291 message: "out of range";
1294 in mod range_len_len {
1295 data: [0, 1, 2, 3, 4, 5];
1297 good: data[6..6] == [];
1299 message: "out of range";
1302 in mod rangeinclusive_len_len {
1303 data: [0, 1, 2, 3, 4, 5];
1305 good: data[6..=5] == [];
1307 message: "out of range";
1312 in mod range_neg_width {
1313 data: [0, 1, 2, 3, 4, 5];
1315 good: data[4..4] == [];
1317 message: "but ends at";
1320 in mod rangeinclusive_neg_width {
1321 data: [0, 1, 2, 3, 4, 5];
1323 good: data[4..=3] == [];
1325 message: "but ends at";
1330 in mod rangeinclusive_overflow {
1333 // note: using 0 specifically ensures that the result of overflowing is 0..0,
1334 // so that `get` doesn't simply return None for the wrong reason.
1335 bad: data[0 ..= usize::MAX];
1336 message: "maximum usize";
1339 in mod rangetoinclusive_overflow {
1342 bad: data[..= usize::MAX];
1343 message: "maximum usize";
1349 fn test_find_rfind() {
1350 let v = [0, 1, 2, 3, 4, 5];
1351 let mut iter = v.iter();
1352 let mut i = v.len();
1353 while let Some(&elt) = iter.rfind(|_| true) {
1355 assert_eq!(elt, v[i]);
1358 assert_eq!(v.iter().rfind(|&&x| x <= 3), Some(&3));
1362 fn test_iter_folds() {
1363 let a = [1, 2, 3, 4, 5]; // len>4 so the unroll is used
1364 assert_eq!(a.iter().fold(0, |acc, &x| 2 * acc + x), 57);
1365 assert_eq!(a.iter().rfold(0, |acc, &x| 2 * acc + x), 129);
1366 let fold = |acc: i32, &x| acc.checked_mul(2)?.checked_add(x);
1367 assert_eq!(a.iter().try_fold(0, &fold), Some(57));
1368 assert_eq!(a.iter().try_rfold(0, &fold), Some(129));
1370 // short-circuiting try_fold, through other methods
1371 let a = [0, 1, 2, 3, 5, 5, 5, 7, 8, 9];
1372 let mut iter = a.iter();
1373 assert_eq!(iter.position(|&x| x == 3), Some(3));
1374 assert_eq!(iter.rfind(|&&x| x == 5), Some(&5));
1375 assert_eq!(iter.len(), 2);
1379 fn test_rotate_left() {
1380 const N: usize = 600;
1381 let a: &mut [_] = &mut [0; N];
1390 assert_eq!(a[(i + k) % N], i);
1395 fn test_rotate_right() {
1396 const N: usize = 600;
1397 let a: &mut [_] = &mut [0; N];
1405 assert_eq!(a[(i + 42) % N], i);
1410 #[cfg_attr(miri, ignore)] // Miri is too slow
1411 fn brute_force_rotate_test_0() {
1412 // In case of edge cases involving multiple algorithms
1416 let mut v = Vec::with_capacity(len);
1420 v[..].rotate_right(s);
1421 for i in 0..v.len() {
1422 assert_eq!(v[i], v.len().wrapping_add(i.wrapping_sub(s)) % v.len());
1429 fn brute_force_rotate_test_1() {
1430 // `ptr_rotate` covers so many kinds of pointer usage, that this is just a good test for
1431 // pointers in general. This uses a `[usize; 4]` to hit all algorithms without overwhelming miri
1435 let mut v: Vec<[usize; 4]> = Vec::with_capacity(len);
1437 v.push([i, 0, 0, 0]);
1439 v[..].rotate_right(s);
1440 for i in 0..v.len() {
1441 assert_eq!(v[i][0], v.len().wrapping_add(i.wrapping_sub(s)) % v.len());
1448 #[cfg(not(target_arch = "wasm32"))]
1449 fn sort_unstable() {
1450 use core::cmp::Ordering::{Equal, Greater, Less};
1451 use core::slice::heapsort;
1452 use rand::{rngs::StdRng, seq::SliceRandom, Rng, SeedableRng};
1454 // Miri is too slow (but still need to `chain` to make the types match)
1455 let lens = if cfg!(miri) { (2..20).chain(0..0) } else { (2..25).chain(500..510) };
1456 let rounds = if cfg!(miri) { 1 } else { 100 };
1458 let mut v = [0; 600];
1459 let mut tmp = [0; 600];
1460 let mut rng = StdRng::from_entropy();
1463 let v = &mut v[0..len];
1464 let tmp = &mut tmp[0..len];
1466 for &modulus in &[5, 10, 100, 1000] {
1467 for _ in 0..rounds {
1469 v[i] = rng.gen::<i32>() % modulus;
1472 // Sort in default order.
1473 tmp.copy_from_slice(v);
1474 tmp.sort_unstable();
1475 assert!(tmp.windows(2).all(|w| w[0] <= w[1]));
1477 // Sort in ascending order.
1478 tmp.copy_from_slice(v);
1479 tmp.sort_unstable_by(|a, b| a.cmp(b));
1480 assert!(tmp.windows(2).all(|w| w[0] <= w[1]));
1482 // Sort in descending order.
1483 tmp.copy_from_slice(v);
1484 tmp.sort_unstable_by(|a, b| b.cmp(a));
1485 assert!(tmp.windows(2).all(|w| w[0] >= w[1]));
1487 // Test heapsort using `<` operator.
1488 tmp.copy_from_slice(v);
1489 heapsort(tmp, |a, b| a < b);
1490 assert!(tmp.windows(2).all(|w| w[0] <= w[1]));
1492 // Test heapsort using `>` operator.
1493 tmp.copy_from_slice(v);
1494 heapsort(tmp, |a, b| a > b);
1495 assert!(tmp.windows(2).all(|w| w[0] >= w[1]));
1500 // Sort using a completely random comparison function.
1501 // This will reorder the elements *somehow*, but won't panic.
1502 for i in 0..v.len() {
1505 v.sort_unstable_by(|_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
1507 for i in 0..v.len() {
1508 assert_eq!(v[i], i as i32);
1511 // Should not panic.
1512 [0i32; 0].sort_unstable();
1513 [(); 10].sort_unstable();
1514 [(); 100].sort_unstable();
1516 let mut v = [0xDEADBEEFu64];
1518 assert!(v == [0xDEADBEEF]);
1522 #[cfg(not(target_arch = "wasm32"))]
1523 #[cfg_attr(miri, ignore)] // Miri is too slow
1524 fn partition_at_index() {
1525 use core::cmp::Ordering::{Equal, Greater, Less};
1526 use rand::rngs::StdRng;
1527 use rand::seq::SliceRandom;
1528 use rand::{Rng, SeedableRng};
1530 let mut rng = StdRng::from_entropy();
1532 for len in (2..21).chain(500..501) {
1533 let mut orig = vec![0; len];
1535 for &modulus in &[5, 10, 1000] {
1538 orig[i] = rng.gen::<i32>() % modulus;
1542 let mut v = orig.clone();
1547 // Sort in default order.
1548 for pivot in 0..len {
1549 let mut v = orig.clone();
1550 v.partition_at_index(pivot);
1552 assert_eq!(v_sorted[pivot], v[pivot]);
1554 for j in pivot..len {
1555 assert!(v[i] <= v[j]);
1560 // Sort in ascending order.
1561 for pivot in 0..len {
1562 let mut v = orig.clone();
1563 let (left, pivot, right) = v.partition_at_index_by(pivot, |a, b| a.cmp(b));
1565 assert_eq!(left.len() + right.len(), len - 1);
1568 assert!(l <= pivot);
1569 for r in right.iter_mut() {
1571 assert!(pivot <= r);
1576 // Sort in descending order.
1577 let sort_descending_comparator = |a: &i32, b: &i32| b.cmp(a);
1578 let v_sorted_descending = {
1579 let mut v = orig.clone();
1580 v.sort_by(sort_descending_comparator);
1584 for pivot in 0..len {
1585 let mut v = orig.clone();
1586 v.partition_at_index_by(pivot, sort_descending_comparator);
1588 assert_eq!(v_sorted_descending[pivot], v[pivot]);
1590 for j in pivot..len {
1591 assert!(v[j] <= v[i]);
1599 // Sort at index using a completely random comparison function.
1600 // This will reorder the elements *somehow*, but won't panic.
1601 let mut v = [0; 500];
1602 for i in 0..v.len() {
1606 for pivot in 0..v.len() {
1607 v.partition_at_index_by(pivot, |_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
1609 for i in 0..v.len() {
1610 assert_eq!(v[i], i as i32);
1614 // Should not panic.
1615 [(); 10].partition_at_index(0);
1616 [(); 10].partition_at_index(5);
1617 [(); 10].partition_at_index(9);
1618 [(); 100].partition_at_index(0);
1619 [(); 100].partition_at_index(50);
1620 [(); 100].partition_at_index(99);
1622 let mut v = [0xDEADBEEFu64];
1623 v.partition_at_index(0);
1624 assert!(v == [0xDEADBEEF]);
1628 #[should_panic(expected = "index 0 greater than length of slice")]
1629 fn partition_at_index_zero_length() {
1630 [0i32; 0].partition_at_index(0);
1634 #[should_panic(expected = "index 20 greater than length of slice")]
1635 fn partition_at_index_past_length() {
1636 [0i32; 10].partition_at_index(20);
1640 use core::slice::memchr::{memchr, memrchr};
1642 // test fallback implementations on all platforms
1645 assert_eq!(Some(0), memchr(b'a', b"a"));
1649 fn matches_begin() {
1650 assert_eq!(Some(0), memchr(b'a', b"aaaa"));
1655 assert_eq!(Some(4), memchr(b'z', b"aaaaz"));
1660 assert_eq!(Some(4), memchr(b'\x00', b"aaaa\x00"));
1664 fn matches_past_nul() {
1665 assert_eq!(Some(5), memchr(b'z', b"aaaa\x00z"));
1669 fn no_match_empty() {
1670 assert_eq!(None, memchr(b'a', b""));
1675 assert_eq!(None, memchr(b'a', b"xyz"));
1679 fn matches_one_reversed() {
1680 assert_eq!(Some(0), memrchr(b'a', b"a"));
1684 fn matches_begin_reversed() {
1685 assert_eq!(Some(3), memrchr(b'a', b"aaaa"));
1689 fn matches_end_reversed() {
1690 assert_eq!(Some(0), memrchr(b'z', b"zaaaa"));
1694 fn matches_nul_reversed() {
1695 assert_eq!(Some(4), memrchr(b'\x00', b"aaaa\x00"));
1699 fn matches_past_nul_reversed() {
1700 assert_eq!(Some(0), memrchr(b'z', b"z\x00aaaa"));
1704 fn no_match_empty_reversed() {
1705 assert_eq!(None, memrchr(b'a', b""));
1709 fn no_match_reversed() {
1710 assert_eq!(None, memrchr(b'a', b"xyz"));
1714 fn each_alignment_reversed() {
1715 let mut data = [1u8; 64];
1719 for start in 0..16 {
1720 assert_eq!(Some(pos - start), memrchr(needle, &data[start..]));
1726 fn test_align_to_simple() {
1727 let bytes = [1u8, 2, 3, 4, 5, 6, 7];
1728 let (prefix, aligned, suffix) = unsafe { bytes.align_to::<u16>() };
1729 assert_eq!(aligned.len(), 3);
1730 assert!(prefix == [1] || suffix == [7]);
1731 let expect1 = [1 << 8 | 2, 3 << 8 | 4, 5 << 8 | 6];
1732 let expect2 = [1 | 2 << 8, 3 | 4 << 8, 5 | 6 << 8];
1733 let expect3 = [2 << 8 | 3, 4 << 8 | 5, 6 << 8 | 7];
1734 let expect4 = [2 | 3 << 8, 4 | 5 << 8, 6 | 7 << 8];
1736 aligned == expect1 || aligned == expect2 || aligned == expect3 || aligned == expect4,
1737 "aligned={:?} expected={:?} || {:?} || {:?} || {:?}",
1747 fn test_align_to_zst() {
1748 let bytes = [1, 2, 3, 4, 5, 6, 7];
1749 let (prefix, aligned, suffix) = unsafe { bytes.align_to::<()>() };
1750 assert_eq!(aligned.len(), 0);
1751 assert!(prefix == [1, 2, 3, 4, 5, 6, 7] || suffix == [1, 2, 3, 4, 5, 6, 7]);
1755 fn test_align_to_non_trivial() {
1757 struct U64(u64, u64);
1759 struct U64U64U32(u64, u64, u32);
1770 let (prefix, aligned, suffix) = unsafe { data.align_to::<U64U64U32>() };
1771 assert_eq!(aligned.len(), 4);
1772 assert_eq!(prefix.len() + suffix.len(), 2);
1776 fn test_align_to_empty_mid() {
1779 // Make sure that we do not create empty unaligned slices for the mid part, even when the
1780 // overall slice is too short to contain an aligned address.
1781 let bytes = [1, 2, 3, 4, 5, 6, 7];
1783 for offset in 0..4 {
1784 let (_, mid, _) = unsafe { bytes[offset..offset + 1].align_to::<Chunk>() };
1785 assert_eq!(mid.as_ptr() as usize % mem::align_of::<Chunk>(), 0);
1790 fn test_align_to_mut_aliasing() {
1791 let mut val = [1u8, 2, 3, 4, 5];
1792 // `align_to_mut` used to create `mid` in a way that there was some intermediate
1793 // incorrect aliasing, invalidating the resulting `mid` slice.
1794 let (begin, mid, end) = unsafe { val.align_to_mut::<[u8; 2]>() };
1795 assert!(begin.len() == 0);
1796 assert!(end.len() == 1);
1798 assert_eq!(val, [3, 4, 3, 4, 5])
1802 fn test_slice_partition_dedup_by() {
1803 let mut slice: [i32; 9] = [1, -1, 2, 3, 1, -5, 5, -2, 2];
1805 let (dedup, duplicates) = slice.partition_dedup_by(|a, b| a.abs() == b.abs());
1807 assert_eq!(dedup, [1, 2, 3, 1, -5, -2]);
1808 assert_eq!(duplicates, [5, -1, 2]);
1812 fn test_slice_partition_dedup_empty() {
1813 let mut slice: [i32; 0] = [];
1815 let (dedup, duplicates) = slice.partition_dedup();
1817 assert_eq!(dedup, []);
1818 assert_eq!(duplicates, []);
1822 fn test_slice_partition_dedup_one() {
1823 let mut slice = [12];
1825 let (dedup, duplicates) = slice.partition_dedup();
1827 assert_eq!(dedup, [12]);
1828 assert_eq!(duplicates, []);
1832 fn test_slice_partition_dedup_multiple_ident() {
1833 let mut slice = [12, 12, 12, 12, 12, 11, 11, 11, 11, 11, 11];
1835 let (dedup, duplicates) = slice.partition_dedup();
1837 assert_eq!(dedup, [12, 11]);
1838 assert_eq!(duplicates, [12, 12, 12, 12, 11, 11, 11, 11, 11]);
1842 fn test_slice_partition_dedup_partialeq() {
1844 struct Foo(i32, i32);
1846 impl PartialEq for Foo {
1847 fn eq(&self, other: &Foo) -> bool {
1852 let mut slice = [Foo(0, 1), Foo(0, 5), Foo(1, 7), Foo(1, 9)];
1854 let (dedup, duplicates) = slice.partition_dedup();
1856 assert_eq!(dedup, [Foo(0, 1), Foo(1, 7)]);
1857 assert_eq!(duplicates, [Foo(0, 5), Foo(1, 9)]);
1861 fn test_copy_within() {
1862 // Start to end, with a RangeTo.
1863 let mut bytes = *b"Hello, World!";
1864 bytes.copy_within(..3, 10);
1865 assert_eq!(&bytes, b"Hello, WorHel");
1867 // End to start, with a RangeFrom.
1868 let mut bytes = *b"Hello, World!";
1869 bytes.copy_within(10.., 0);
1870 assert_eq!(&bytes, b"ld!lo, World!");
1872 // Overlapping, with a RangeInclusive.
1873 let mut bytes = *b"Hello, World!";
1874 bytes.copy_within(0..=11, 1);
1875 assert_eq!(&bytes, b"HHello, World");
1877 // Whole slice, with a RangeFull.
1878 let mut bytes = *b"Hello, World!";
1879 bytes.copy_within(.., 0);
1880 assert_eq!(&bytes, b"Hello, World!");
1882 // Ensure that copying at the end of slice won't cause UB.
1883 let mut bytes = *b"Hello, World!";
1884 bytes.copy_within(13..13, 5);
1885 assert_eq!(&bytes, b"Hello, World!");
1886 bytes.copy_within(5..5, 13);
1887 assert_eq!(&bytes, b"Hello, World!");
1891 #[should_panic(expected = "range end index 14 out of range for slice of length 13")]
1892 fn test_copy_within_panics_src_too_long() {
1893 let mut bytes = *b"Hello, World!";
1894 // The length is only 13, so 14 is out of bounds.
1895 bytes.copy_within(10..14, 0);
1899 #[should_panic(expected = "dest is out of bounds")]
1900 fn test_copy_within_panics_dest_too_long() {
1901 let mut bytes = *b"Hello, World!";
1902 // The length is only 13, so a slice of length 4 starting at index 10 is out of bounds.
1903 bytes.copy_within(0..4, 10);
1906 #[should_panic(expected = "slice index starts at 2 but ends at 1")]
1907 fn test_copy_within_panics_src_inverted() {
1908 let mut bytes = *b"Hello, World!";
1909 // 2 is greater than 1, so this range is invalid.
1910 bytes.copy_within(2..1, 0);
1913 #[should_panic(expected = "attempted to index slice up to maximum usize")]
1914 fn test_copy_within_panics_src_out_of_bounds() {
1915 let mut bytes = *b"Hello, World!";
1916 // an inclusive range ending at usize::MAX would make src_end overflow
1917 bytes.copy_within(usize::MAX..=usize::MAX, 0);
1921 fn test_is_sorted() {
1922 let empty: [i32; 0] = [];
1924 assert!([1, 2, 2, 9].is_sorted());
1925 assert!(![1, 3, 2].is_sorted());
1926 assert!([0].is_sorted());
1927 assert!(empty.is_sorted());
1928 assert!(![0.0, 1.0, f32::NAN].is_sorted());
1929 assert!([-2, -1, 0, 3].is_sorted());
1930 assert!(![-2i32, -1, 0, 3].is_sorted_by_key(|n| n.abs()));
1931 assert!(!["c", "bb", "aaa"].is_sorted());
1932 assert!(["c", "bb", "aaa"].is_sorted_by_key(|s| s.len()));