2 use core::cmp::Ordering;
3 use core::result::Result::{Err, Ok};
7 let b = [1, 2, 3, 5, 5];
8 assert_eq!(b.iter().position(|&v| v == 9), None);
9 assert_eq!(b.iter().position(|&v| v == 5), Some(3));
10 assert_eq!(b.iter().position(|&v| v == 3), Some(2));
11 assert_eq!(b.iter().position(|&v| v == 0), None);
16 let b = [1, 2, 3, 5, 5];
17 assert_eq!(b.iter().rposition(|&v| v == 9), None);
18 assert_eq!(b.iter().rposition(|&v| v == 5), Some(4));
19 assert_eq!(b.iter().rposition(|&v| v == 3), Some(2));
20 assert_eq!(b.iter().rposition(|&v| v == 0), None);
24 fn test_binary_search() {
26 assert_eq!(b.binary_search(&5), Err(0));
29 assert_eq!(b.binary_search(&3), Err(0));
30 assert_eq!(b.binary_search(&4), Ok(0));
31 assert_eq!(b.binary_search(&5), Err(1));
33 let b = [1, 2, 4, 6, 8, 9];
34 assert_eq!(b.binary_search(&5), Err(3));
35 assert_eq!(b.binary_search(&6), Ok(3));
36 assert_eq!(b.binary_search(&7), Err(4));
37 assert_eq!(b.binary_search(&8), Ok(4));
39 let b = [1, 2, 4, 5, 6, 8];
40 assert_eq!(b.binary_search(&9), Err(6));
42 let b = [1, 2, 4, 6, 7, 8, 9];
43 assert_eq!(b.binary_search(&6), Ok(3));
44 assert_eq!(b.binary_search(&5), Err(3));
45 assert_eq!(b.binary_search(&8), Ok(5));
47 let b = [1, 2, 4, 5, 6, 8, 9];
48 assert_eq!(b.binary_search(&7), Err(5));
49 assert_eq!(b.binary_search(&0), Err(0));
51 let b = [1, 3, 3, 3, 7];
52 assert_eq!(b.binary_search(&0), Err(0));
53 assert_eq!(b.binary_search(&1), Ok(0));
54 assert_eq!(b.binary_search(&2), Err(1));
55 assert!(match b.binary_search(&3) {
59 assert!(match b.binary_search(&3) {
63 assert_eq!(b.binary_search(&4), Err(4));
64 assert_eq!(b.binary_search(&5), Err(4));
65 assert_eq!(b.binary_search(&6), Err(4));
66 assert_eq!(b.binary_search(&7), Ok(4));
67 assert_eq!(b.binary_search(&8), Err(5));
69 let b = [(); usize::MAX];
70 assert_eq!(b.binary_search(&()), Ok(usize::MAX / 2));
74 fn test_binary_search_by_overflow() {
75 let b = [(); usize::MAX];
76 assert_eq!(b.binary_search_by(|_| Ordering::Equal), Ok(usize::MAX / 2));
77 assert_eq!(b.binary_search_by(|_| Ordering::Greater), Err(0));
78 assert_eq!(b.binary_search_by(|_| Ordering::Less), Err(usize::MAX));
82 // Test implementation specific behavior when finding equivalent elements.
83 // It is ok to break this test but when you do a crater run is highly advisable.
84 fn test_binary_search_implementation_details() {
85 let b = [1, 1, 2, 2, 3, 3, 3];
86 assert_eq!(b.binary_search(&1), Ok(1));
87 assert_eq!(b.binary_search(&2), Ok(3));
88 assert_eq!(b.binary_search(&3), Ok(5));
89 let b = [1, 1, 1, 1, 1, 3, 3, 3, 3];
90 assert_eq!(b.binary_search(&1), Ok(4));
91 assert_eq!(b.binary_search(&3), Ok(7));
92 let b = [1, 1, 1, 1, 3, 3, 3, 3, 3];
93 assert_eq!(b.binary_search(&1), Ok(2));
94 assert_eq!(b.binary_search(&3), Ok(4));
98 fn test_partition_point() {
100 assert_eq!(b.partition_point(|&x| x < 5), 0);
103 assert_eq!(b.partition_point(|&x| x < 3), 0);
104 assert_eq!(b.partition_point(|&x| x < 4), 0);
105 assert_eq!(b.partition_point(|&x| x < 5), 1);
107 let b = [1, 2, 4, 6, 8, 9];
108 assert_eq!(b.partition_point(|&x| x < 5), 3);
109 assert_eq!(b.partition_point(|&x| x < 6), 3);
110 assert_eq!(b.partition_point(|&x| x < 7), 4);
111 assert_eq!(b.partition_point(|&x| x < 8), 4);
113 let b = [1, 2, 4, 5, 6, 8];
114 assert_eq!(b.partition_point(|&x| x < 9), 6);
116 let b = [1, 2, 4, 6, 7, 8, 9];
117 assert_eq!(b.partition_point(|&x| x < 6), 3);
118 assert_eq!(b.partition_point(|&x| x < 5), 3);
119 assert_eq!(b.partition_point(|&x| x < 8), 5);
121 let b = [1, 2, 4, 5, 6, 8, 9];
122 assert_eq!(b.partition_point(|&x| x < 7), 5);
123 assert_eq!(b.partition_point(|&x| x < 0), 0);
125 let b = [1, 3, 3, 3, 7];
126 assert_eq!(b.partition_point(|&x| x < 0), 0);
127 assert_eq!(b.partition_point(|&x| x < 1), 0);
128 assert_eq!(b.partition_point(|&x| x < 2), 1);
129 assert_eq!(b.partition_point(|&x| x < 3), 1);
130 assert_eq!(b.partition_point(|&x| x < 4), 4);
131 assert_eq!(b.partition_point(|&x| x < 5), 4);
132 assert_eq!(b.partition_point(|&x| x < 6), 4);
133 assert_eq!(b.partition_point(|&x| x < 7), 4);
134 assert_eq!(b.partition_point(|&x| x < 8), 5);
138 fn test_iterator_nth() {
139 let v: &[_] = &[0, 1, 2, 3, 4];
140 for i in 0..v.len() {
141 assert_eq!(v.iter().nth(i).unwrap(), &v[i]);
143 assert_eq!(v.iter().nth(v.len()), None);
145 let mut iter = v.iter();
146 assert_eq!(iter.nth(2).unwrap(), &v[2]);
147 assert_eq!(iter.nth(1).unwrap(), &v[4]);
151 fn test_iterator_nth_back() {
152 let v: &[_] = &[0, 1, 2, 3, 4];
153 for i in 0..v.len() {
154 assert_eq!(v.iter().nth_back(i).unwrap(), &v[v.len() - i - 1]);
156 assert_eq!(v.iter().nth_back(v.len()), None);
158 let mut iter = v.iter();
159 assert_eq!(iter.nth_back(2).unwrap(), &v[2]);
160 assert_eq!(iter.nth_back(1).unwrap(), &v[0]);
164 fn test_iterator_last() {
165 let v: &[_] = &[0, 1, 2, 3, 4];
166 assert_eq!(v.iter().last().unwrap(), &4);
167 assert_eq!(v[..1].iter().last().unwrap(), &0);
171 fn test_iterator_count() {
172 let v: &[_] = &[0, 1, 2, 3, 4];
173 assert_eq!(v.iter().count(), 5);
175 let mut iter2 = v.iter();
178 assert_eq!(iter2.count(), 3);
182 fn test_chunks_count() {
183 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
185 assert_eq!(c.count(), 2);
187 let v2: &[i32] = &[0, 1, 2, 3, 4];
188 let c2 = v2.chunks(2);
189 assert_eq!(c2.count(), 3);
191 let v3: &[i32] = &[];
192 let c3 = v3.chunks(2);
193 assert_eq!(c3.count(), 0);
197 fn test_chunks_nth() {
198 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
199 let mut c = v.chunks(2);
200 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
201 assert_eq!(c.next().unwrap(), &[4, 5]);
203 let v2: &[i32] = &[0, 1, 2, 3, 4];
204 let mut c2 = v2.chunks(3);
205 assert_eq!(c2.nth(1).unwrap(), &[3, 4]);
206 assert_eq!(c2.next(), None);
210 fn test_chunks_nth_back() {
211 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
212 let mut c = v.chunks(2);
213 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
214 assert_eq!(c.next().unwrap(), &[0, 1]);
215 assert_eq!(c.next(), None);
217 let v2: &[i32] = &[0, 1, 2, 3, 4];
218 let mut c2 = v2.chunks(3);
219 assert_eq!(c2.nth_back(1).unwrap(), &[0, 1, 2]);
220 assert_eq!(c2.next(), None);
221 assert_eq!(c2.next_back(), None);
223 let v3: &[i32] = &[0, 1, 2, 3, 4];
224 let mut c3 = v3.chunks(10);
225 assert_eq!(c3.nth_back(0).unwrap(), &[0, 1, 2, 3, 4]);
226 assert_eq!(c3.next(), None);
228 let v4: &[i32] = &[0, 1, 2];
229 let mut c4 = v4.chunks(10);
230 assert_eq!(c4.nth_back(1_000_000_000usize), None);
234 fn test_chunks_last() {
235 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
237 assert_eq!(c.last().unwrap()[1], 5);
239 let v2: &[i32] = &[0, 1, 2, 3, 4];
240 let c2 = v2.chunks(2);
241 assert_eq!(c2.last().unwrap()[0], 4);
245 fn test_chunks_zip() {
246 let v1: &[i32] = &[0, 1, 2, 3, 4];
247 let v2: &[i32] = &[6, 7, 8, 9, 10];
252 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
253 .collect::<Vec<_>>();
254 assert_eq!(res, vec![14, 22, 14]);
258 fn test_chunks_mut_count() {
259 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
260 let c = v.chunks_mut(3);
261 assert_eq!(c.count(), 2);
263 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
264 let c2 = v2.chunks_mut(2);
265 assert_eq!(c2.count(), 3);
267 let v3: &mut [i32] = &mut [];
268 let c3 = v3.chunks_mut(2);
269 assert_eq!(c3.count(), 0);
273 fn test_chunks_mut_nth() {
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(1).unwrap(), &[2, 3]);
277 assert_eq!(c.next().unwrap(), &[4, 5]);
279 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
280 let mut c2 = v2.chunks_mut(3);
281 assert_eq!(c2.nth(1).unwrap(), &[3, 4]);
282 assert_eq!(c2.next(), None);
286 fn test_chunks_mut_nth_back() {
287 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
288 let mut c = v.chunks_mut(2);
289 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
290 assert_eq!(c.next().unwrap(), &[0, 1]);
292 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
293 let mut c1 = v1.chunks_mut(3);
294 assert_eq!(c1.nth_back(1).unwrap(), &[0, 1, 2]);
295 assert_eq!(c1.next(), None);
297 let v3: &mut [i32] = &mut [0, 1, 2, 3, 4];
298 let mut c3 = v3.chunks_mut(10);
299 assert_eq!(c3.nth_back(0).unwrap(), &[0, 1, 2, 3, 4]);
300 assert_eq!(c3.next(), None);
302 let v4: &mut [i32] = &mut [0, 1, 2];
303 let mut c4 = v4.chunks_mut(10);
304 assert_eq!(c4.nth_back(1_000_000_000usize), None);
308 fn test_chunks_mut_last() {
309 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
310 let c = v.chunks_mut(2);
311 assert_eq!(c.last().unwrap(), &[4, 5]);
313 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
314 let c2 = v2.chunks_mut(2);
315 assert_eq!(c2.last().unwrap(), &[4]);
319 fn test_chunks_mut_zip() {
320 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
321 let v2: &[i32] = &[6, 7, 8, 9, 10];
323 for (a, b) in v1.chunks_mut(2).zip(v2.chunks(2)) {
324 let sum = b.iter().sum::<i32>();
329 assert_eq!(v1, [13, 14, 19, 20, 14]);
333 fn test_chunks_exact_count() {
334 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
335 let c = v.chunks_exact(3);
336 assert_eq!(c.count(), 2);
338 let v2: &[i32] = &[0, 1, 2, 3, 4];
339 let c2 = v2.chunks_exact(2);
340 assert_eq!(c2.count(), 2);
342 let v3: &[i32] = &[];
343 let c3 = v3.chunks_exact(2);
344 assert_eq!(c3.count(), 0);
348 fn test_chunks_exact_nth() {
349 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
350 let mut c = v.chunks_exact(2);
351 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
352 assert_eq!(c.next().unwrap(), &[4, 5]);
354 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
355 let mut c2 = v2.chunks_exact(3);
356 assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
357 assert_eq!(c2.next(), None);
361 fn test_chunks_exact_nth_back() {
362 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
363 let mut c = v.chunks_exact(2);
364 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
365 assert_eq!(c.next().unwrap(), &[0, 1]);
366 assert_eq!(c.next(), None);
368 let v2: &[i32] = &[0, 1, 2, 3, 4];
369 let mut c2 = v2.chunks_exact(3);
370 assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
371 assert_eq!(c2.next(), None);
372 assert_eq!(c2.next_back(), None);
374 let v3: &[i32] = &[0, 1, 2, 3, 4];
375 let mut c3 = v3.chunks_exact(10);
376 assert_eq!(c3.nth_back(0), None);
380 fn test_chunks_exact_last() {
381 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
382 let c = v.chunks_exact(2);
383 assert_eq!(c.last().unwrap(), &[4, 5]);
385 let v2: &[i32] = &[0, 1, 2, 3, 4];
386 let c2 = v2.chunks_exact(2);
387 assert_eq!(c2.last().unwrap(), &[2, 3]);
391 fn test_chunks_exact_remainder() {
392 let v: &[i32] = &[0, 1, 2, 3, 4];
393 let c = v.chunks_exact(2);
394 assert_eq!(c.remainder(), &[4]);
398 fn test_chunks_exact_zip() {
399 let v1: &[i32] = &[0, 1, 2, 3, 4];
400 let v2: &[i32] = &[6, 7, 8, 9, 10];
404 .zip(v2.chunks_exact(2))
405 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
406 .collect::<Vec<_>>();
407 assert_eq!(res, vec![14, 22]);
411 fn test_chunks_exact_mut_count() {
412 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
413 let c = v.chunks_exact_mut(3);
414 assert_eq!(c.count(), 2);
416 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
417 let c2 = v2.chunks_exact_mut(2);
418 assert_eq!(c2.count(), 2);
420 let v3: &mut [i32] = &mut [];
421 let c3 = v3.chunks_exact_mut(2);
422 assert_eq!(c3.count(), 0);
426 fn test_chunks_exact_mut_nth() {
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(1).unwrap(), &[2, 3]);
430 assert_eq!(c.next().unwrap(), &[4, 5]);
432 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
433 let mut c2 = v2.chunks_exact_mut(3);
434 assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
435 assert_eq!(c2.next(), None);
439 fn test_chunks_exact_mut_nth_back() {
440 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
441 let mut c = v.chunks_exact_mut(2);
442 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
443 assert_eq!(c.next().unwrap(), &[0, 1]);
444 assert_eq!(c.next(), None);
446 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
447 let mut c2 = v2.chunks_exact_mut(3);
448 assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
449 assert_eq!(c2.next(), None);
450 assert_eq!(c2.next_back(), None);
452 let v3: &mut [i32] = &mut [0, 1, 2, 3, 4];
453 let mut c3 = v3.chunks_exact_mut(10);
454 assert_eq!(c3.nth_back(0), None);
458 fn test_chunks_exact_mut_last() {
459 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
460 let c = v.chunks_exact_mut(2);
461 assert_eq!(c.last().unwrap(), &[4, 5]);
463 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
464 let c2 = v2.chunks_exact_mut(2);
465 assert_eq!(c2.last().unwrap(), &[2, 3]);
469 fn test_chunks_exact_mut_remainder() {
470 let v: &mut [i32] = &mut [0, 1, 2, 3, 4];
471 let c = v.chunks_exact_mut(2);
472 assert_eq!(c.into_remainder(), &[4]);
476 fn test_chunks_exact_mut_zip() {
477 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
478 let v2: &[i32] = &[6, 7, 8, 9, 10];
480 for (a, b) in v1.chunks_exact_mut(2).zip(v2.chunks_exact(2)) {
481 let sum = b.iter().sum::<i32>();
486 assert_eq!(v1, [13, 14, 19, 20, 4]);
490 fn test_array_chunks_infer() {
491 let v: &[i32] = &[0, 1, 2, 3, 4, -4];
492 let c = v.array_chunks();
493 for &[a, b, c] in c {
494 assert_eq!(a + b + c, 3);
497 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
498 let total = v2.array_chunks().map(|&[a, b]| a * b).sum::<i32>();
499 assert_eq!(total, 2 * 3 + 4 * 5);
503 fn test_array_chunks_count() {
504 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
505 let c = v.array_chunks::<3>();
506 assert_eq!(c.count(), 2);
508 let v2: &[i32] = &[0, 1, 2, 3, 4];
509 let c2 = v2.array_chunks::<2>();
510 assert_eq!(c2.count(), 2);
512 let v3: &[i32] = &[];
513 let c3 = v3.array_chunks::<2>();
514 assert_eq!(c3.count(), 0);
518 fn test_array_chunks_nth() {
519 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
520 let mut c = v.array_chunks::<2>();
521 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
522 assert_eq!(c.next().unwrap(), &[4, 5]);
524 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
525 let mut c2 = v2.array_chunks::<3>();
526 assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
527 assert_eq!(c2.next(), None);
531 fn test_array_chunks_nth_back() {
532 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
533 let mut c = v.array_chunks::<2>();
534 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
535 assert_eq!(c.next().unwrap(), &[0, 1]);
536 assert_eq!(c.next(), None);
538 let v2: &[i32] = &[0, 1, 2, 3, 4];
539 let mut c2 = v2.array_chunks::<3>();
540 assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
541 assert_eq!(c2.next(), None);
542 assert_eq!(c2.next_back(), None);
544 let v3: &[i32] = &[0, 1, 2, 3, 4];
545 let mut c3 = v3.array_chunks::<10>();
546 assert_eq!(c3.nth_back(0), None);
550 fn test_array_chunks_last() {
551 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
552 let c = v.array_chunks::<2>();
553 assert_eq!(c.last().unwrap(), &[4, 5]);
555 let v2: &[i32] = &[0, 1, 2, 3, 4];
556 let c2 = v2.array_chunks::<2>();
557 assert_eq!(c2.last().unwrap(), &[2, 3]);
561 fn test_array_chunks_remainder() {
562 let v: &[i32] = &[0, 1, 2, 3, 4];
563 let c = v.array_chunks::<2>();
564 assert_eq!(c.remainder(), &[4]);
568 fn test_array_chunks_zip() {
569 let v1: &[i32] = &[0, 1, 2, 3, 4];
570 let v2: &[i32] = &[6, 7, 8, 9, 10];
574 .zip(v2.array_chunks::<2>())
575 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
576 .collect::<Vec<_>>();
577 assert_eq!(res, vec![14, 22]);
581 fn test_array_chunks_mut_infer() {
582 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
583 for a in v.array_chunks_mut() {
584 let sum = a.iter().sum::<i32>();
587 assert_eq!(v, &[3, 3, 3, 12, 12, 12, 6]);
589 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
590 v2.array_chunks_mut().for_each(|[a, b]| core::mem::swap(a, b));
591 assert_eq!(v2, &[1, 0, 3, 2, 5, 4, 6]);
595 fn test_array_chunks_mut_count() {
596 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
597 let c = v.array_chunks_mut::<3>();
598 assert_eq!(c.count(), 2);
600 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
601 let c2 = v2.array_chunks_mut::<2>();
602 assert_eq!(c2.count(), 2);
604 let v3: &mut [i32] = &mut [];
605 let c3 = v3.array_chunks_mut::<2>();
606 assert_eq!(c3.count(), 0);
610 fn test_array_chunks_mut_nth() {
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(1).unwrap(), &[2, 3]);
614 assert_eq!(c.next().unwrap(), &[4, 5]);
616 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
617 let mut c2 = v2.array_chunks_mut::<3>();
618 assert_eq!(c2.nth(1).unwrap(), &[3, 4, 5]);
619 assert_eq!(c2.next(), None);
623 fn test_array_chunks_mut_nth_back() {
624 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
625 let mut c = v.array_chunks_mut::<2>();
626 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
627 assert_eq!(c.next().unwrap(), &[0, 1]);
628 assert_eq!(c.next(), None);
630 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
631 let mut c2 = v2.array_chunks_mut::<3>();
632 assert_eq!(c2.nth_back(0).unwrap(), &[0, 1, 2]);
633 assert_eq!(c2.next(), None);
634 assert_eq!(c2.next_back(), None);
636 let v3: &mut [i32] = &mut [0, 1, 2, 3, 4];
637 let mut c3 = v3.array_chunks_mut::<10>();
638 assert_eq!(c3.nth_back(0), None);
642 fn test_array_chunks_mut_last() {
643 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
644 let c = v.array_chunks_mut::<2>();
645 assert_eq!(c.last().unwrap(), &[4, 5]);
647 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
648 let c2 = v2.array_chunks_mut::<2>();
649 assert_eq!(c2.last().unwrap(), &[2, 3]);
653 fn test_array_chunks_mut_remainder() {
654 let v: &mut [i32] = &mut [0, 1, 2, 3, 4];
655 let c = v.array_chunks_mut::<2>();
656 assert_eq!(c.into_remainder(), &[4]);
660 fn test_array_chunks_mut_zip() {
661 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
662 let v2: &[i32] = &[6, 7, 8, 9, 10];
664 for (a, b) in v1.array_chunks_mut::<2>().zip(v2.array_chunks::<2>()) {
665 let sum = b.iter().sum::<i32>();
670 assert_eq!(v1, [13, 14, 19, 20, 4]);
674 fn test_array_windows_infer() {
675 let v: &[i32] = &[0, 1, 0, 1];
676 assert_eq!(v.array_windows::<2>().count(), 3);
677 let c = v.array_windows();
679 assert_eq!(a + b, 1);
682 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
683 let total = v2.array_windows().map(|&[a, b, c]| a + b + c).sum::<i32>();
684 assert_eq!(total, 3 + 6 + 9 + 12 + 15);
688 fn test_array_windows_count() {
689 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
690 let c = v.array_windows::<3>();
691 assert_eq!(c.count(), 4);
693 let v2: &[i32] = &[0, 1, 2, 3, 4];
694 let c2 = v2.array_windows::<6>();
695 assert_eq!(c2.count(), 0);
697 let v3: &[i32] = &[];
698 let c3 = v3.array_windows::<2>();
699 assert_eq!(c3.count(), 0);
703 fn test_array_windows_nth() {
704 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
705 let snd = v.array_windows::<4>().nth(1);
706 assert_eq!(snd, Some(&[1, 2, 3, 4]));
707 let mut arr_windows = v.array_windows::<2>();
708 assert_ne!(arr_windows.nth(0), arr_windows.nth(0));
709 let last = v.array_windows::<3>().last();
710 assert_eq!(last, Some(&[3, 4, 5]));
714 fn test_array_windows_nth_back() {
715 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
716 let snd = v.array_windows::<4>().nth_back(1);
717 assert_eq!(snd, Some(&[1, 2, 3, 4]));
718 let mut arr_windows = v.array_windows::<2>();
719 assert_ne!(arr_windows.nth_back(0), arr_windows.nth_back(0));
723 fn test_rchunks_count() {
724 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
725 let c = v.rchunks(3);
726 assert_eq!(c.count(), 2);
728 let v2: &[i32] = &[0, 1, 2, 3, 4];
729 let c2 = v2.rchunks(2);
730 assert_eq!(c2.count(), 3);
732 let v3: &[i32] = &[];
733 let c3 = v3.rchunks(2);
734 assert_eq!(c3.count(), 0);
738 fn test_rchunks_nth() {
739 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
740 let mut c = v.rchunks(2);
741 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
742 assert_eq!(c.next().unwrap(), &[0, 1]);
744 let v2: &[i32] = &[0, 1, 2, 3, 4];
745 let mut c2 = v2.rchunks(3);
746 assert_eq!(c2.nth(1).unwrap(), &[0, 1]);
747 assert_eq!(c2.next(), None);
751 fn test_rchunks_nth_back() {
752 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
753 let mut c = v.rchunks(2);
754 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
755 assert_eq!(c.next_back().unwrap(), &[4, 5]);
757 let v2: &[i32] = &[0, 1, 2, 3, 4];
758 let mut c2 = v2.rchunks(3);
759 assert_eq!(c2.nth_back(1).unwrap(), &[2, 3, 4]);
760 assert_eq!(c2.next_back(), None);
764 fn test_rchunks_last() {
765 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
766 let c = v.rchunks(2);
767 assert_eq!(c.last().unwrap()[1], 1);
769 let v2: &[i32] = &[0, 1, 2, 3, 4];
770 let c2 = v2.rchunks(2);
771 assert_eq!(c2.last().unwrap()[0], 0);
775 fn test_rchunks_zip() {
776 let v1: &[i32] = &[0, 1, 2, 3, 4];
777 let v2: &[i32] = &[6, 7, 8, 9, 10];
782 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
783 .collect::<Vec<_>>();
784 assert_eq!(res, vec![26, 18, 6]);
788 fn test_rchunks_mut_count() {
789 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
790 let c = v.rchunks_mut(3);
791 assert_eq!(c.count(), 2);
793 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
794 let c2 = v2.rchunks_mut(2);
795 assert_eq!(c2.count(), 3);
797 let v3: &mut [i32] = &mut [];
798 let c3 = v3.rchunks_mut(2);
799 assert_eq!(c3.count(), 0);
803 fn test_rchunks_mut_nth() {
804 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
805 let mut c = v.rchunks_mut(2);
806 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
807 assert_eq!(c.next().unwrap(), &[0, 1]);
809 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
810 let mut c2 = v2.rchunks_mut(3);
811 assert_eq!(c2.nth(1).unwrap(), &[0, 1]);
812 assert_eq!(c2.next(), None);
816 fn test_rchunks_mut_nth_back() {
817 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
818 let mut c = v.rchunks_mut(2);
819 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
820 assert_eq!(c.next_back().unwrap(), &[4, 5]);
822 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
823 let mut c2 = v2.rchunks_mut(3);
824 assert_eq!(c2.nth_back(1).unwrap(), &[2, 3, 4]);
825 assert_eq!(c2.next_back(), None);
829 fn test_rchunks_mut_last() {
830 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
831 let c = v.rchunks_mut(2);
832 assert_eq!(c.last().unwrap(), &[0, 1]);
834 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
835 let c2 = v2.rchunks_mut(2);
836 assert_eq!(c2.last().unwrap(), &[0]);
840 fn test_rchunks_mut_zip() {
841 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
842 let v2: &[i32] = &[6, 7, 8, 9, 10];
844 for (a, b) in v1.rchunks_mut(2).zip(v2.rchunks(2)) {
845 let sum = b.iter().sum::<i32>();
850 assert_eq!(v1, [6, 16, 17, 22, 23]);
854 fn test_rchunks_exact_count() {
855 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
856 let c = v.rchunks_exact(3);
857 assert_eq!(c.count(), 2);
859 let v2: &[i32] = &[0, 1, 2, 3, 4];
860 let c2 = v2.rchunks_exact(2);
861 assert_eq!(c2.count(), 2);
863 let v3: &[i32] = &[];
864 let c3 = v3.rchunks_exact(2);
865 assert_eq!(c3.count(), 0);
869 fn test_rchunks_exact_nth() {
870 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
871 let mut c = v.rchunks_exact(2);
872 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
873 assert_eq!(c.next().unwrap(), &[0, 1]);
875 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
876 let mut c2 = v2.rchunks_exact(3);
877 assert_eq!(c2.nth(1).unwrap(), &[1, 2, 3]);
878 assert_eq!(c2.next(), None);
882 fn test_rchunks_exact_nth_back() {
883 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
884 let mut c = v.rchunks_exact(2);
885 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
886 assert_eq!(c.next_back().unwrap(), &[4, 5]);
888 let v2: &[i32] = &[0, 1, 2, 3, 4, 5, 6];
889 let mut c2 = v2.rchunks_exact(3);
890 assert_eq!(c2.nth_back(1).unwrap(), &[4, 5, 6]);
891 assert_eq!(c2.next(), None);
895 fn test_rchunks_exact_last() {
896 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
897 let c = v.rchunks_exact(2);
898 assert_eq!(c.last().unwrap(), &[0, 1]);
900 let v2: &[i32] = &[0, 1, 2, 3, 4];
901 let c2 = v2.rchunks_exact(2);
902 assert_eq!(c2.last().unwrap(), &[1, 2]);
906 fn test_rchunks_exact_remainder() {
907 let v: &[i32] = &[0, 1, 2, 3, 4];
908 let c = v.rchunks_exact(2);
909 assert_eq!(c.remainder(), &[0]);
913 fn test_rchunks_exact_zip() {
914 let v1: &[i32] = &[0, 1, 2, 3, 4];
915 let v2: &[i32] = &[6, 7, 8, 9, 10];
919 .zip(v2.rchunks_exact(2))
920 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
921 .collect::<Vec<_>>();
922 assert_eq!(res, vec![26, 18]);
926 fn test_rchunks_exact_mut_count() {
927 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
928 let c = v.rchunks_exact_mut(3);
929 assert_eq!(c.count(), 2);
931 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
932 let c2 = v2.rchunks_exact_mut(2);
933 assert_eq!(c2.count(), 2);
935 let v3: &mut [i32] = &mut [];
936 let c3 = v3.rchunks_exact_mut(2);
937 assert_eq!(c3.count(), 0);
941 fn test_rchunks_exact_mut_nth() {
942 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
943 let mut c = v.rchunks_exact_mut(2);
944 assert_eq!(c.nth(1).unwrap(), &[2, 3]);
945 assert_eq!(c.next().unwrap(), &[0, 1]);
947 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
948 let mut c2 = v2.rchunks_exact_mut(3);
949 assert_eq!(c2.nth(1).unwrap(), &[1, 2, 3]);
950 assert_eq!(c2.next(), None);
954 fn test_rchunks_exact_mut_nth_back() {
955 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
956 let mut c = v.rchunks_exact_mut(2);
957 assert_eq!(c.nth_back(1).unwrap(), &[2, 3]);
958 assert_eq!(c.next_back().unwrap(), &[4, 5]);
960 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4, 5, 6];
961 let mut c2 = v2.rchunks_exact_mut(3);
962 assert_eq!(c2.nth_back(1).unwrap(), &[4, 5, 6]);
963 assert_eq!(c2.next(), None);
967 fn test_rchunks_exact_mut_last() {
968 let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5];
969 let c = v.rchunks_exact_mut(2);
970 assert_eq!(c.last().unwrap(), &[0, 1]);
972 let v2: &mut [i32] = &mut [0, 1, 2, 3, 4];
973 let c2 = v2.rchunks_exact_mut(2);
974 assert_eq!(c2.last().unwrap(), &[1, 2]);
978 fn test_rchunks_exact_mut_remainder() {
979 let v: &mut [i32] = &mut [0, 1, 2, 3, 4];
980 let c = v.rchunks_exact_mut(2);
981 assert_eq!(c.into_remainder(), &[0]);
985 fn test_rchunks_exact_mut_zip() {
986 let v1: &mut [i32] = &mut [0, 1, 2, 3, 4];
987 let v2: &[i32] = &[6, 7, 8, 9, 10];
989 for (a, b) in v1.rchunks_exact_mut(2).zip(v2.rchunks_exact(2)) {
990 let sum = b.iter().sum::<i32>();
995 assert_eq!(v1, [0, 16, 17, 22, 23]);
999 fn test_windows_count() {
1000 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
1001 let c = v.windows(3);
1002 assert_eq!(c.count(), 4);
1004 let v2: &[i32] = &[0, 1, 2, 3, 4];
1005 let c2 = v2.windows(6);
1006 assert_eq!(c2.count(), 0);
1008 let v3: &[i32] = &[];
1009 let c3 = v3.windows(2);
1010 assert_eq!(c3.count(), 0);
1014 fn test_windows_nth() {
1015 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
1016 let mut c = v.windows(2);
1017 assert_eq!(c.nth(2).unwrap()[1], 3);
1018 assert_eq!(c.next().unwrap()[0], 3);
1020 let v2: &[i32] = &[0, 1, 2, 3, 4];
1021 let mut c2 = v2.windows(4);
1022 assert_eq!(c2.nth(1).unwrap()[1], 2);
1023 assert_eq!(c2.next(), None);
1027 fn test_windows_nth_back() {
1028 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
1029 let mut c = v.windows(2);
1030 assert_eq!(c.nth_back(2).unwrap()[0], 2);
1031 assert_eq!(c.next_back().unwrap()[1], 2);
1033 let v2: &[i32] = &[0, 1, 2, 3, 4];
1034 let mut c2 = v2.windows(4);
1035 assert_eq!(c2.nth_back(1).unwrap()[1], 1);
1036 assert_eq!(c2.next_back(), None);
1040 fn test_windows_last() {
1041 let v: &[i32] = &[0, 1, 2, 3, 4, 5];
1042 let c = v.windows(2);
1043 assert_eq!(c.last().unwrap()[1], 5);
1045 let v2: &[i32] = &[0, 1, 2, 3, 4];
1046 let c2 = v2.windows(2);
1047 assert_eq!(c2.last().unwrap()[0], 3);
1051 fn test_windows_zip() {
1052 let v1: &[i32] = &[0, 1, 2, 3, 4];
1053 let v2: &[i32] = &[6, 7, 8, 9, 10];
1058 .map(|(a, b)| a.iter().sum::<i32>() + b.iter().sum::<i32>())
1059 .collect::<Vec<_>>();
1061 assert_eq!(res, [14, 18, 22, 26]);
1066 fn test_iter_ref_consistency() {
1067 use std::fmt::Debug;
1069 fn test<T: Copy + Debug + PartialEq>(x: T) {
1070 let v: &[T] = &[x, x, x];
1071 let v_ptrs: [*const T; 3] = match v {
1072 [ref v1, ref v2, ref v3] => [v1 as *const _, v2 as *const _, v3 as *const _],
1073 _ => unreachable!(),
1079 assert_eq!(&v[i] as *const _, v_ptrs[i]); // check the v_ptrs array, just to be sure
1080 let nth = v.iter().nth(i).unwrap();
1081 assert_eq!(nth as *const _, v_ptrs[i]);
1083 assert_eq!(v.iter().nth(len), None, "nth(len) should return None");
1085 // stepping through with nth(0)
1087 let mut it = v.iter();
1089 let next = it.nth(0).unwrap();
1090 assert_eq!(next as *const _, v_ptrs[i]);
1092 assert_eq!(it.nth(0), None);
1097 let mut it = v.iter();
1099 let remaining = len - i;
1100 assert_eq!(it.size_hint(), (remaining, Some(remaining)));
1102 let next = it.next().unwrap();
1103 assert_eq!(next as *const _, v_ptrs[i]);
1105 assert_eq!(it.size_hint(), (0, Some(0)));
1106 assert_eq!(it.next(), None, "The final call to next() should return None");
1111 let mut it = v.iter();
1113 let remaining = len - i;
1114 assert_eq!(it.size_hint(), (remaining, Some(remaining)));
1116 let prev = it.next_back().unwrap();
1117 assert_eq!(prev as *const _, v_ptrs[remaining - 1]);
1119 assert_eq!(it.size_hint(), (0, Some(0)));
1120 assert_eq!(it.next_back(), None, "The final call to next_back() should return None");
1124 fn test_mut<T: Copy + Debug + PartialEq>(x: T) {
1125 let v: &mut [T] = &mut [x, x, x];
1126 let v_ptrs: [*mut T; 3] = match v {
1127 [ref v1, ref v2, ref v3] => {
1128 [v1 as *const _ as *mut _, v2 as *const _ as *mut _, v3 as *const _ as *mut _]
1130 _ => unreachable!(),
1136 assert_eq!(&mut v[i] as *mut _, v_ptrs[i]); // check the v_ptrs array, just to be sure
1137 let nth = v.iter_mut().nth(i).unwrap();
1138 assert_eq!(nth as *mut _, v_ptrs[i]);
1140 assert_eq!(v.iter().nth(len), None, "nth(len) should return None");
1142 // stepping through with nth(0)
1144 let mut it = v.iter();
1146 let next = it.nth(0).unwrap();
1147 assert_eq!(next as *const _, v_ptrs[i]);
1149 assert_eq!(it.nth(0), None);
1154 let mut it = v.iter_mut();
1156 let remaining = len - i;
1157 assert_eq!(it.size_hint(), (remaining, Some(remaining)));
1159 let next = it.next().unwrap();
1160 assert_eq!(next as *mut _, v_ptrs[i]);
1162 assert_eq!(it.size_hint(), (0, Some(0)));
1163 assert_eq!(it.next(), None, "The final call to next() should return None");
1168 let mut it = v.iter_mut();
1170 let remaining = len - i;
1171 assert_eq!(it.size_hint(), (remaining, Some(remaining)));
1173 let prev = it.next_back().unwrap();
1174 assert_eq!(prev as *mut _, v_ptrs[remaining - 1]);
1176 assert_eq!(it.size_hint(), (0, Some(0)));
1177 assert_eq!(it.next_back(), None, "The final call to next_back() should return None");
1181 // Make sure iterators and slice patterns yield consistent addresses for various types,
1185 test([0u32; 0]); // ZST with alignment > 0
1188 test_mut([0u32; 0]); // ZST with alignment > 0
1191 // The current implementation of SliceIndex fails to handle methods
1192 // orthogonally from range types; therefore, it is worth testing
1193 // all of the indexing operations on each input.
1195 // This checks all six indexing methods, given an input range that
1196 // should succeed. (it is NOT suitable for testing invalid inputs)
1197 macro_rules! assert_range_eq {
1198 ($arr:expr, $range:expr, $expected:expr) => {
1200 let mut expected = $expected;
1203 let expected: &[_] = &expected;
1205 assert_eq!(&s[$range], expected, "(in assertion for: index)");
1206 assert_eq!(s.get($range), Some(expected), "(in assertion for: get)");
1209 s.get_unchecked($range),
1211 "(in assertion for: get_unchecked)",
1216 let s: &mut [_] = &mut arr;
1217 let expected: &mut [_] = &mut expected;
1219 assert_eq!(&mut s[$range], expected, "(in assertion for: index_mut)",);
1222 Some(&mut expected[..]),
1223 "(in assertion for: get_mut)",
1227 s.get_unchecked_mut($range),
1229 "(in assertion for: get_unchecked_mut)",
1236 // Make sure the macro can actually detect bugs,
1237 // because if it can't, then what are we even doing here?
1239 // (Be aware this only demonstrates the ability to detect bugs
1240 // in the FIRST method that panics, as the macro is not designed
1241 // to be used in `should_panic`)
1243 #[should_panic(expected = "out of range")]
1244 fn assert_range_eq_can_fail_by_panic() {
1245 assert_range_eq!([0, 1, 2], 0..5, [0, 1, 2]);
1248 // (Be aware this only demonstrates the ability to detect bugs
1249 // in the FIRST method it calls, as the macro is not designed
1250 // to be used in `should_panic`)
1252 #[should_panic(expected = "==")]
1253 fn assert_range_eq_can_fail_by_inequality() {
1254 assert_range_eq!([0, 1, 2], 0..2, [0, 1, 2]);
1257 // Test cases for bad index operations.
1259 // This generates `should_panic` test cases for Index/IndexMut
1260 // and `None` test cases for get/get_mut.
1261 macro_rules! panic_cases {
1263 // each test case needs a unique name to namespace the tests
1264 in mod $case_name:ident {
1269 // one or more similar inputs for which data[input] succeeds,
1270 // and the corresponding output as an array. This helps validate
1271 // "critical points" where an input range straddles the boundary
1272 // between valid and invalid.
1273 // (such as the input `len..len`, which is just barely valid)
1275 good: data[$good:expr] == $output:expr;
1278 bad: data[$bad:expr];
1279 message: $expect_msg:expr;
1287 $( assert_range_eq!($data, $good, $output); )*
1291 assert_eq!(v.get($bad), None, "(in None assertion for get)");
1295 let v: &mut [_] = &mut v;
1296 assert_eq!(v.get_mut($bad), None, "(in None assertion for get_mut)");
1301 #[should_panic(expected = $expect_msg)]
1309 #[should_panic(expected = $expect_msg)]
1310 fn index_mut_fail() {
1312 let v: &mut [_] = &mut v;
1313 let _v = &mut v[$bad];
1321 let v = [0, 1, 2, 3, 4, 5];
1323 assert_range_eq!(v, .., [0, 1, 2, 3, 4, 5]);
1324 assert_range_eq!(v, ..2, [0, 1]);
1325 assert_range_eq!(v, ..=1, [0, 1]);
1326 assert_range_eq!(v, 2.., [2, 3, 4, 5]);
1327 assert_range_eq!(v, 1..4, [1, 2, 3]);
1328 assert_range_eq!(v, 1..=3, [1, 2, 3]);
1332 in mod rangefrom_len {
1333 data: [0, 1, 2, 3, 4, 5];
1335 good: data[6..] == [];
1337 message: "out of range";
1340 in mod rangeto_len {
1341 data: [0, 1, 2, 3, 4, 5];
1343 good: data[..6] == [0, 1, 2, 3, 4, 5];
1345 message: "out of range";
1348 in mod rangetoinclusive_len {
1349 data: [0, 1, 2, 3, 4, 5];
1351 good: data[..=5] == [0, 1, 2, 3, 4, 5];
1353 message: "out of range";
1356 in mod rangeinclusive_len {
1357 data: [0, 1, 2, 3, 4, 5];
1359 good: data[0..=5] == [0, 1, 2, 3, 4, 5];
1361 message: "out of range";
1364 in mod range_len_len {
1365 data: [0, 1, 2, 3, 4, 5];
1367 good: data[6..6] == [];
1369 message: "out of range";
1372 in mod rangeinclusive_len_len {
1373 data: [0, 1, 2, 3, 4, 5];
1375 good: data[6..=5] == [];
1377 message: "out of range";
1382 in mod rangeinclusive_exhausted {
1383 data: [0, 1, 2, 3, 4, 5];
1385 good: data[0..=5] == [0, 1, 2, 3, 4, 5];
1387 let mut iter = 0..=5;
1388 iter.by_ref().count(); // exhaust it
1392 // 0..=6 is out of range before exhaustion, so it
1393 // stands to reason that it still would be after.
1395 let mut iter = 0..=6;
1396 iter.by_ref().count(); // exhaust it
1399 message: "out of range";
1404 in mod range_neg_width {
1405 data: [0, 1, 2, 3, 4, 5];
1407 good: data[4..4] == [];
1409 message: "but ends at";
1412 in mod rangeinclusive_neg_width {
1413 data: [0, 1, 2, 3, 4, 5];
1415 good: data[4..=3] == [];
1417 message: "but ends at";
1422 in mod rangeinclusive_overflow {
1425 // note: using 0 specifically ensures that the result of overflowing is 0..0,
1426 // so that `get` doesn't simply return None for the wrong reason.
1427 bad: data[0 ..= usize::MAX];
1428 message: "maximum usize";
1431 in mod rangetoinclusive_overflow {
1434 bad: data[..= usize::MAX];
1435 message: "maximum usize";
1441 fn test_find_rfind() {
1442 let v = [0, 1, 2, 3, 4, 5];
1443 let mut iter = v.iter();
1444 let mut i = v.len();
1445 while let Some(&elt) = iter.rfind(|_| true) {
1447 assert_eq!(elt, v[i]);
1450 assert_eq!(v.iter().rfind(|&&x| x <= 3), Some(&3));
1454 fn test_iter_folds() {
1455 let a = [1, 2, 3, 4, 5]; // len>4 so the unroll is used
1456 assert_eq!(a.iter().fold(0, |acc, &x| 2 * acc + x), 57);
1457 assert_eq!(a.iter().rfold(0, |acc, &x| 2 * acc + x), 129);
1458 let fold = |acc: i32, &x| acc.checked_mul(2)?.checked_add(x);
1459 assert_eq!(a.iter().try_fold(0, &fold), Some(57));
1460 assert_eq!(a.iter().try_rfold(0, &fold), Some(129));
1462 // short-circuiting try_fold, through other methods
1463 let a = [0, 1, 2, 3, 5, 5, 5, 7, 8, 9];
1464 let mut iter = a.iter();
1465 assert_eq!(iter.position(|&x| x == 3), Some(3));
1466 assert_eq!(iter.rfind(|&&x| x == 5), Some(&5));
1467 assert_eq!(iter.len(), 2);
1471 fn test_rotate_left() {
1472 const N: usize = 600;
1473 let a: &mut [_] = &mut [0; N];
1482 assert_eq!(a[(i + k) % N], i);
1487 fn test_rotate_right() {
1488 const N: usize = 600;
1489 let a: &mut [_] = &mut [0; N];
1497 assert_eq!(a[(i + 42) % N], i);
1502 #[cfg_attr(miri, ignore)] // Miri is too slow
1503 fn brute_force_rotate_test_0() {
1504 // In case of edge cases involving multiple algorithms
1508 let mut v = Vec::with_capacity(len);
1512 v[..].rotate_right(s);
1513 for i in 0..v.len() {
1514 assert_eq!(v[i], v.len().wrapping_add(i.wrapping_sub(s)) % v.len());
1521 fn brute_force_rotate_test_1() {
1522 // `ptr_rotate` covers so many kinds of pointer usage, that this is just a good test for
1523 // pointers in general. This uses a `[usize; 4]` to hit all algorithms without overwhelming miri
1527 let mut v: Vec<[usize; 4]> = Vec::with_capacity(len);
1529 v.push([i, 0, 0, 0]);
1531 v[..].rotate_right(s);
1532 for i in 0..v.len() {
1533 assert_eq!(v[i][0], v.len().wrapping_add(i.wrapping_sub(s)) % v.len());
1540 #[cfg(not(target_arch = "wasm32"))]
1541 fn sort_unstable() {
1542 use core::cmp::Ordering::{Equal, Greater, Less};
1543 use core::slice::heapsort;
1544 use rand::{rngs::StdRng, seq::SliceRandom, Rng, SeedableRng};
1546 // Miri is too slow (but still need to `chain` to make the types match)
1547 let lens = if cfg!(miri) { (2..20).chain(0..0) } else { (2..25).chain(500..510) };
1548 let rounds = if cfg!(miri) { 1 } else { 100 };
1550 let mut v = [0; 600];
1551 let mut tmp = [0; 600];
1552 let mut rng = StdRng::from_entropy();
1555 let v = &mut v[0..len];
1556 let tmp = &mut tmp[0..len];
1558 for &modulus in &[5, 10, 100, 1000] {
1559 for _ in 0..rounds {
1561 v[i] = rng.gen::<i32>() % modulus;
1564 // Sort in default order.
1565 tmp.copy_from_slice(v);
1566 tmp.sort_unstable();
1567 assert!(tmp.windows(2).all(|w| w[0] <= w[1]));
1569 // Sort in ascending order.
1570 tmp.copy_from_slice(v);
1571 tmp.sort_unstable_by(|a, b| a.cmp(b));
1572 assert!(tmp.windows(2).all(|w| w[0] <= w[1]));
1574 // Sort in descending order.
1575 tmp.copy_from_slice(v);
1576 tmp.sort_unstable_by(|a, b| b.cmp(a));
1577 assert!(tmp.windows(2).all(|w| w[0] >= w[1]));
1579 // Test heapsort using `<` operator.
1580 tmp.copy_from_slice(v);
1581 heapsort(tmp, |a, b| a < b);
1582 assert!(tmp.windows(2).all(|w| w[0] <= w[1]));
1584 // Test heapsort using `>` operator.
1585 tmp.copy_from_slice(v);
1586 heapsort(tmp, |a, b| a > b);
1587 assert!(tmp.windows(2).all(|w| w[0] >= w[1]));
1592 // Sort using a completely random comparison function.
1593 // This will reorder the elements *somehow*, but won't panic.
1594 for i in 0..v.len() {
1597 v.sort_unstable_by(|_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
1599 for i in 0..v.len() {
1600 assert_eq!(v[i], i as i32);
1603 // Should not panic.
1604 [0i32; 0].sort_unstable();
1605 [(); 10].sort_unstable();
1606 [(); 100].sort_unstable();
1608 let mut v = [0xDEADBEEFu64];
1610 assert!(v == [0xDEADBEEF]);
1614 #[cfg(not(target_arch = "wasm32"))]
1615 #[cfg_attr(miri, ignore)] // Miri is too slow
1616 fn select_nth_unstable() {
1617 use core::cmp::Ordering::{Equal, Greater, Less};
1618 use rand::rngs::StdRng;
1619 use rand::seq::SliceRandom;
1620 use rand::{Rng, SeedableRng};
1622 let mut rng = StdRng::from_entropy();
1624 for len in (2..21).chain(500..501) {
1625 let mut orig = vec![0; len];
1627 for &modulus in &[5, 10, 1000] {
1630 orig[i] = rng.gen::<i32>() % modulus;
1634 let mut v = orig.clone();
1639 // Sort in default order.
1640 for pivot in 0..len {
1641 let mut v = orig.clone();
1642 v.select_nth_unstable(pivot);
1644 assert_eq!(v_sorted[pivot], v[pivot]);
1646 for j in pivot..len {
1647 assert!(v[i] <= v[j]);
1652 // Sort in ascending order.
1653 for pivot in 0..len {
1654 let mut v = orig.clone();
1655 let (left, pivot, right) = v.select_nth_unstable_by(pivot, |a, b| a.cmp(b));
1657 assert_eq!(left.len() + right.len(), len - 1);
1660 assert!(l <= pivot);
1661 for r in right.iter_mut() {
1663 assert!(pivot <= r);
1668 // Sort in descending order.
1669 let sort_descending_comparator = |a: &i32, b: &i32| b.cmp(a);
1670 let v_sorted_descending = {
1671 let mut v = orig.clone();
1672 v.sort_by(sort_descending_comparator);
1676 for pivot in 0..len {
1677 let mut v = orig.clone();
1678 v.select_nth_unstable_by(pivot, sort_descending_comparator);
1680 assert_eq!(v_sorted_descending[pivot], v[pivot]);
1682 for j in pivot..len {
1683 assert!(v[j] <= v[i]);
1691 // Sort at index using a completely random comparison function.
1692 // This will reorder the elements *somehow*, but won't panic.
1693 let mut v = [0; 500];
1694 for i in 0..v.len() {
1698 for pivot in 0..v.len() {
1699 v.select_nth_unstable_by(pivot, |_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
1701 for i in 0..v.len() {
1702 assert_eq!(v[i], i as i32);
1706 // Should not panic.
1707 [(); 10].select_nth_unstable(0);
1708 [(); 10].select_nth_unstable(5);
1709 [(); 10].select_nth_unstable(9);
1710 [(); 100].select_nth_unstable(0);
1711 [(); 100].select_nth_unstable(50);
1712 [(); 100].select_nth_unstable(99);
1714 let mut v = [0xDEADBEEFu64];
1715 v.select_nth_unstable(0);
1716 assert!(v == [0xDEADBEEF]);
1720 #[should_panic(expected = "index 0 greater than length of slice")]
1721 fn select_nth_unstable_zero_length() {
1722 [0i32; 0].select_nth_unstable(0);
1726 #[should_panic(expected = "index 20 greater than length of slice")]
1727 fn select_nth_unstable_past_length() {
1728 [0i32; 10].select_nth_unstable(20);
1732 use core::slice::memchr::{memchr, memrchr};
1734 // test fallback implementations on all platforms
1737 assert_eq!(Some(0), memchr(b'a', b"a"));
1741 fn matches_begin() {
1742 assert_eq!(Some(0), memchr(b'a', b"aaaa"));
1747 assert_eq!(Some(4), memchr(b'z', b"aaaaz"));
1752 assert_eq!(Some(4), memchr(b'\x00', b"aaaa\x00"));
1756 fn matches_past_nul() {
1757 assert_eq!(Some(5), memchr(b'z', b"aaaa\x00z"));
1761 fn no_match_empty() {
1762 assert_eq!(None, memchr(b'a', b""));
1767 assert_eq!(None, memchr(b'a', b"xyz"));
1771 fn matches_one_reversed() {
1772 assert_eq!(Some(0), memrchr(b'a', b"a"));
1776 fn matches_begin_reversed() {
1777 assert_eq!(Some(3), memrchr(b'a', b"aaaa"));
1781 fn matches_end_reversed() {
1782 assert_eq!(Some(0), memrchr(b'z', b"zaaaa"));
1786 fn matches_nul_reversed() {
1787 assert_eq!(Some(4), memrchr(b'\x00', b"aaaa\x00"));
1791 fn matches_past_nul_reversed() {
1792 assert_eq!(Some(0), memrchr(b'z', b"z\x00aaaa"));
1796 fn no_match_empty_reversed() {
1797 assert_eq!(None, memrchr(b'a', b""));
1801 fn no_match_reversed() {
1802 assert_eq!(None, memrchr(b'a', b"xyz"));
1806 fn each_alignment_reversed() {
1807 let mut data = [1u8; 64];
1811 for start in 0..16 {
1812 assert_eq!(Some(pos - start), memrchr(needle, &data[start..]));
1818 fn test_align_to_simple() {
1819 let bytes = [1u8, 2, 3, 4, 5, 6, 7];
1820 let (prefix, aligned, suffix) = unsafe { bytes.align_to::<u16>() };
1821 assert_eq!(aligned.len(), 3);
1822 assert!(prefix == [1] || suffix == [7]);
1823 let expect1 = [1 << 8 | 2, 3 << 8 | 4, 5 << 8 | 6];
1824 let expect2 = [1 | 2 << 8, 3 | 4 << 8, 5 | 6 << 8];
1825 let expect3 = [2 << 8 | 3, 4 << 8 | 5, 6 << 8 | 7];
1826 let expect4 = [2 | 3 << 8, 4 | 5 << 8, 6 | 7 << 8];
1828 aligned == expect1 || aligned == expect2 || aligned == expect3 || aligned == expect4,
1829 "aligned={:?} expected={:?} || {:?} || {:?} || {:?}",
1839 fn test_align_to_zst() {
1840 let bytes = [1, 2, 3, 4, 5, 6, 7];
1841 let (prefix, aligned, suffix) = unsafe { bytes.align_to::<()>() };
1842 assert_eq!(aligned.len(), 0);
1843 assert!(prefix == [1, 2, 3, 4, 5, 6, 7] || suffix == [1, 2, 3, 4, 5, 6, 7]);
1847 fn test_align_to_non_trivial() {
1849 struct U64(u64, u64);
1851 struct U64U64U32(u64, u64, u32);
1862 let (prefix, aligned, suffix) = unsafe { data.align_to::<U64U64U32>() };
1863 assert_eq!(aligned.len(), 4);
1864 assert_eq!(prefix.len() + suffix.len(), 2);
1868 fn test_align_to_empty_mid() {
1871 // Make sure that we do not create empty unaligned slices for the mid part, even when the
1872 // overall slice is too short to contain an aligned address.
1873 let bytes = [1, 2, 3, 4, 5, 6, 7];
1875 for offset in 0..4 {
1876 let (_, mid, _) = unsafe { bytes[offset..offset + 1].align_to::<Chunk>() };
1877 assert_eq!(mid.as_ptr() as usize % mem::align_of::<Chunk>(), 0);
1882 fn test_align_to_mut_aliasing() {
1883 let mut val = [1u8, 2, 3, 4, 5];
1884 // `align_to_mut` used to create `mid` in a way that there was some intermediate
1885 // incorrect aliasing, invalidating the resulting `mid` slice.
1886 let (begin, mid, end) = unsafe { val.align_to_mut::<[u8; 2]>() };
1887 assert!(begin.len() == 0);
1888 assert!(end.len() == 1);
1890 assert_eq!(val, [3, 4, 3, 4, 5])
1894 fn test_slice_partition_dedup_by() {
1895 let mut slice: [i32; 9] = [1, -1, 2, 3, 1, -5, 5, -2, 2];
1897 let (dedup, duplicates) = slice.partition_dedup_by(|a, b| a.abs() == b.abs());
1899 assert_eq!(dedup, [1, 2, 3, 1, -5, -2]);
1900 assert_eq!(duplicates, [5, -1, 2]);
1904 fn test_slice_partition_dedup_empty() {
1905 let mut slice: [i32; 0] = [];
1907 let (dedup, duplicates) = slice.partition_dedup();
1909 assert_eq!(dedup, []);
1910 assert_eq!(duplicates, []);
1914 fn test_slice_partition_dedup_one() {
1915 let mut slice = [12];
1917 let (dedup, duplicates) = slice.partition_dedup();
1919 assert_eq!(dedup, [12]);
1920 assert_eq!(duplicates, []);
1924 fn test_slice_partition_dedup_multiple_ident() {
1925 let mut slice = [12, 12, 12, 12, 12, 11, 11, 11, 11, 11, 11];
1927 let (dedup, duplicates) = slice.partition_dedup();
1929 assert_eq!(dedup, [12, 11]);
1930 assert_eq!(duplicates, [12, 12, 12, 12, 11, 11, 11, 11, 11]);
1934 fn test_slice_partition_dedup_partialeq() {
1936 struct Foo(i32, i32);
1938 impl PartialEq for Foo {
1939 fn eq(&self, other: &Foo) -> bool {
1944 let mut slice = [Foo(0, 1), Foo(0, 5), Foo(1, 7), Foo(1, 9)];
1946 let (dedup, duplicates) = slice.partition_dedup();
1948 assert_eq!(dedup, [Foo(0, 1), Foo(1, 7)]);
1949 assert_eq!(duplicates, [Foo(0, 5), Foo(1, 9)]);
1953 fn test_copy_within() {
1954 // Start to end, with a RangeTo.
1955 let mut bytes = *b"Hello, World!";
1956 bytes.copy_within(..3, 10);
1957 assert_eq!(&bytes, b"Hello, WorHel");
1959 // End to start, with a RangeFrom.
1960 let mut bytes = *b"Hello, World!";
1961 bytes.copy_within(10.., 0);
1962 assert_eq!(&bytes, b"ld!lo, World!");
1964 // Overlapping, with a RangeInclusive.
1965 let mut bytes = *b"Hello, World!";
1966 bytes.copy_within(0..=11, 1);
1967 assert_eq!(&bytes, b"HHello, World");
1969 // Whole slice, with a RangeFull.
1970 let mut bytes = *b"Hello, World!";
1971 bytes.copy_within(.., 0);
1972 assert_eq!(&bytes, b"Hello, World!");
1974 // Ensure that copying at the end of slice won't cause UB.
1975 let mut bytes = *b"Hello, World!";
1976 bytes.copy_within(13..13, 5);
1977 assert_eq!(&bytes, b"Hello, World!");
1978 bytes.copy_within(5..5, 13);
1979 assert_eq!(&bytes, b"Hello, World!");
1983 #[should_panic(expected = "range end index 14 out of range for slice of length 13")]
1984 fn test_copy_within_panics_src_too_long() {
1985 let mut bytes = *b"Hello, World!";
1986 // The length is only 13, so 14 is out of bounds.
1987 bytes.copy_within(10..14, 0);
1991 #[should_panic(expected = "dest is out of bounds")]
1992 fn test_copy_within_panics_dest_too_long() {
1993 let mut bytes = *b"Hello, World!";
1994 // The length is only 13, so a slice of length 4 starting at index 10 is out of bounds.
1995 bytes.copy_within(0..4, 10);
1999 #[should_panic(expected = "slice index starts at 2 but ends at 1")]
2000 fn test_copy_within_panics_src_inverted() {
2001 let mut bytes = *b"Hello, World!";
2002 // 2 is greater than 1, so this range is invalid.
2003 bytes.copy_within(2..1, 0);
2006 #[should_panic(expected = "attempted to index slice up to maximum usize")]
2007 fn test_copy_within_panics_src_out_of_bounds() {
2008 let mut bytes = *b"Hello, World!";
2009 // an inclusive range ending at usize::MAX would make src_end overflow
2010 bytes.copy_within(usize::MAX..=usize::MAX, 0);
2014 fn test_is_sorted() {
2015 let empty: [i32; 0] = [];
2017 assert!([1, 2, 2, 9].is_sorted());
2018 assert!(![1, 3, 2].is_sorted());
2019 assert!([0].is_sorted());
2020 assert!(empty.is_sorted());
2021 assert!(![0.0, 1.0, f32::NAN].is_sorted());
2022 assert!([-2, -1, 0, 3].is_sorted());
2023 assert!(![-2i32, -1, 0, 3].is_sorted_by_key(|n| n.abs()));
2024 assert!(!["c", "bb", "aaa"].is_sorted());
2025 assert!(["c", "bb", "aaa"].is_sorted_by_key(|s| s.len()));
2029 fn test_slice_run_destructors() {
2030 // Make sure that destructors get run on slice literals
2035 impl<'a> Drop for Foo<'a> {
2036 fn drop(&mut self) {
2037 self.x.set(self.x.get() + 1);
2041 fn foo(x: &Cell<isize>) -> Foo<'_> {
2045 let x = &Cell::new(0);
2049 assert_eq!(l[0].x.get(), 0);
2052 assert_eq!(x.get(), 1);