src/liballoc/tests/slice.rs

   1 use std::cell::Cell;
   2 use std::cmp::Ordering::{self, Equal, Greater, Less};
   3 use std::mem;
   4 use std::panic;
   5 use std::rc::Rc;
   6 use std::sync::atomic::{Ordering::Relaxed, AtomicUsize};
   7 use std::thread;
   8
   9 use rand::{Rng, RngCore, thread_rng};
  10 use rand::seq::SliceRandom;
  11 use rand::distributions::Standard;
  12
  13 fn square(n: usize) -> usize {
  14     n * n
  15 }
  16
  17 fn is_odd(n: &usize) -> bool {
  18     *n % 2 == 1
  19 }
  20
  21 #[test]
  22 fn test_from_fn() {
  23     // Test on-stack from_fn.
  24     let mut v: Vec<_> = (0..3).map(square).collect();
  25     {
  26         let v = v;
  27         assert_eq!(v.len(), 3);
  28         assert_eq!(v[0], 0);
  29         assert_eq!(v[1], 1);
  30         assert_eq!(v[2], 4);
  31     }
  32
  33     // Test on-heap from_fn.
  34     v = (0..5).map(square).collect();
  35     {
  36         let v = v;
  37         assert_eq!(v.len(), 5);
  38         assert_eq!(v[0], 0);
  39         assert_eq!(v[1], 1);
  40         assert_eq!(v[2], 4);
  41         assert_eq!(v[3], 9);
  42         assert_eq!(v[4], 16);
  43     }
  44 }
  45
  46 #[test]
  47 fn test_from_elem() {
  48     // Test on-stack from_elem.
  49     let mut v = vec![10, 10];
  50     {
  51         let v = v;
  52         assert_eq!(v.len(), 2);
  53         assert_eq!(v[0], 10);
  54         assert_eq!(v[1], 10);
  55     }
  56
  57     // Test on-heap from_elem.
  58     v = vec![20; 6];
  59     {
  60         let v = &v[..];
  61         assert_eq!(v[0], 20);
  62         assert_eq!(v[1], 20);
  63         assert_eq!(v[2], 20);
  64         assert_eq!(v[3], 20);
  65         assert_eq!(v[4], 20);
  66         assert_eq!(v[5], 20);
  67     }
  68 }
  69
  70 #[test]
  71 fn test_is_empty() {
  72     let xs: [i32; 0] = [];
  73     assert!(xs.is_empty());
  74     assert!(![0].is_empty());
  75 }
  76
  77 #[test]
  78 fn test_len_divzero() {
  79     type Z = [i8; 0];
  80     let v0: &[Z] = &[];
  81     let v1: &[Z] = &[[]];
  82     let v2: &[Z] = &[[], []];
  83     assert_eq!(mem::size_of::<Z>(), 0);
  84     assert_eq!(v0.len(), 0);
  85     assert_eq!(v1.len(), 1);
  86     assert_eq!(v2.len(), 2);
  87 }
  88
  89 #[test]
  90 fn test_get() {
  91     let mut a = vec![11];
  92     assert_eq!(a.get(1), None);
  93     a = vec![11, 12];
  94     assert_eq!(a.get(1).unwrap(), &12);
  95     a = vec![11, 12, 13];
  96     assert_eq!(a.get(1).unwrap(), &12);
  97 }
  98
  99 #[test]
 100 fn test_first() {
 101     let mut a = vec![];
 102     assert_eq!(a.first(), None);
 103     a = vec![11];
 104     assert_eq!(a.first().unwrap(), &11);
 105     a = vec![11, 12];
 106     assert_eq!(a.first().unwrap(), &11);
 107 }
 108
 109 #[test]
 110 fn test_first_mut() {
 111     let mut a = vec![];
 112     assert_eq!(a.first_mut(), None);
 113     a = vec![11];
 114     assert_eq!(*a.first_mut().unwrap(), 11);
 115     a = vec![11, 12];
 116     assert_eq!(*a.first_mut().unwrap(), 11);
 117 }
 118
 119 #[test]
 120 fn test_split_first() {
 121     let mut a = vec![11];
 122     let b: &[i32] = &[];
 123     assert!(b.split_first().is_none());
 124     assert_eq!(a.split_first(), Some((&11, b)));
 125     a = vec![11, 12];
 126     let b: &[i32] = &[12];
 127     assert_eq!(a.split_first(), Some((&11, b)));
 128 }
 129
 130 #[test]
 131 fn test_split_first_mut() {
 132     let mut a = vec![11];
 133     let b: &mut [i32] = &mut [];
 134     assert!(b.split_first_mut().is_none());
 135     assert!(a.split_first_mut() == Some((&mut 11, b)));
 136     a = vec![11, 12];
 137     let b: &mut [_] = &mut [12];
 138     assert!(a.split_first_mut() == Some((&mut 11, b)));
 139 }
 140
 141 #[test]
 142 fn test_split_last() {
 143     let mut a = vec![11];
 144     let b: &[i32] = &[];
 145     assert!(b.split_last().is_none());
 146     assert_eq!(a.split_last(), Some((&11, b)));
 147     a = vec![11, 12];
 148     let b: &[_] = &[11];
 149     assert_eq!(a.split_last(), Some((&12, b)));
 150 }
 151
 152 #[test]
 153 fn test_split_last_mut() {
 154     let mut a = vec![11];
 155     let b: &mut [i32] = &mut [];
 156     assert!(b.split_last_mut().is_none());
 157     assert!(a.split_last_mut() == Some((&mut 11, b)));
 158
 159     a = vec![11, 12];
 160     let b: &mut [_] = &mut [11];
 161     assert!(a.split_last_mut() == Some((&mut 12, b)));
 162 }
 163
 164 #[test]
 165 fn test_last() {
 166     let mut a = vec![];
 167     assert_eq!(a.last(), None);
 168     a = vec![11];
 169     assert_eq!(a.last().unwrap(), &11);
 170     a = vec![11, 12];
 171     assert_eq!(a.last().unwrap(), &12);
 172 }
 173
 174 #[test]
 175 fn test_last_mut() {
 176     let mut a = vec![];
 177     assert_eq!(a.last_mut(), None);
 178     a = vec![11];
 179     assert_eq!(*a.last_mut().unwrap(), 11);
 180     a = vec![11, 12];
 181     assert_eq!(*a.last_mut().unwrap(), 12);
 182 }
 183
 184 #[test]
 185 fn test_slice() {
 186     // Test fixed length vector.
 187     let vec_fixed = [1, 2, 3, 4];
 188     let v_a = vec_fixed[1..vec_fixed.len()].to_vec();
 189     assert_eq!(v_a.len(), 3);
 190
 191     assert_eq!(v_a[0], 2);
 192     assert_eq!(v_a[1], 3);
 193     assert_eq!(v_a[2], 4);
 194
 195     // Test on stack.
 196     let vec_stack: &[_] = &[1, 2, 3];
 197     let v_b = vec_stack[1..3].to_vec();
 198     assert_eq!(v_b.len(), 2);
 199
 200     assert_eq!(v_b[0], 2);
 201     assert_eq!(v_b[1], 3);
 202
 203     // Test `Box<[T]>`
 204     let vec_unique = vec![1, 2, 3, 4, 5, 6];
 205     let v_d = vec_unique[1..6].to_vec();
 206     assert_eq!(v_d.len(), 5);
 207
 208     assert_eq!(v_d[0], 2);
 209     assert_eq!(v_d[1], 3);
 210     assert_eq!(v_d[2], 4);
 211     assert_eq!(v_d[3], 5);
 212     assert_eq!(v_d[4], 6);
 213 }
 214
 215 #[test]
 216 fn test_slice_from() {
 217     let vec: &[_] = &[1, 2, 3, 4];
 218     assert_eq!(&vec[..], vec);
 219     let b: &[_] = &[3, 4];
 220     assert_eq!(&vec[2..], b);
 221     let b: &[_] = &[];
 222     assert_eq!(&vec[4..], b);
 223 }
 224
 225 #[test]
 226 fn test_slice_to() {
 227     let vec: &[_] = &[1, 2, 3, 4];
 228     assert_eq!(&vec[..4], vec);
 229     let b: &[_] = &[1, 2];
 230     assert_eq!(&vec[..2], b);
 231     let b: &[_] = &[];
 232     assert_eq!(&vec[..0], b);
 233 }
 234
 235
 236 #[test]
 237 fn test_pop() {
 238     let mut v = vec![5];
 239     let e = v.pop();
 240     assert_eq!(v.len(), 0);
 241     assert_eq!(e, Some(5));
 242     let f = v.pop();
 243     assert_eq!(f, None);
 244     let g = v.pop();
 245     assert_eq!(g, None);
 246 }
 247
 248 #[test]
 249 fn test_swap_remove() {
 250     let mut v = vec![1, 2, 3, 4, 5];
 251     let mut e = v.swap_remove(0);
 252     assert_eq!(e, 1);
 253     assert_eq!(v, [5, 2, 3, 4]);
 254     e = v.swap_remove(3);
 255     assert_eq!(e, 4);
 256     assert_eq!(v, [5, 2, 3]);
 257 }
 258
 259 #[test]
 260 #[should_panic]
 261 #[cfg(not(miri))] // Miri does not support panics
 262 fn test_swap_remove_fail() {
 263     let mut v = vec![1];
 264     let _ = v.swap_remove(0);
 265     let _ = v.swap_remove(0);
 266 }
 267
 268 #[test]
 269 fn test_swap_remove_noncopyable() {
 270     // Tests that we don't accidentally run destructors twice.
 271     let mut v: Vec<Box<_>> = Vec::new();
 272     v.push(box 0);
 273     v.push(box 0);
 274     v.push(box 0);
 275     let mut _e = v.swap_remove(0);
 276     assert_eq!(v.len(), 2);
 277     _e = v.swap_remove(1);
 278     assert_eq!(v.len(), 1);
 279     _e = v.swap_remove(0);
 280     assert_eq!(v.len(), 0);
 281 }
 282
 283 #[test]
 284 fn test_push() {
 285     // Test on-stack push().
 286     let mut v = vec![];
 287     v.push(1);
 288     assert_eq!(v.len(), 1);
 289     assert_eq!(v[0], 1);
 290
 291     // Test on-heap push().
 292     v.push(2);
 293     assert_eq!(v.len(), 2);
 294     assert_eq!(v[0], 1);
 295     assert_eq!(v[1], 2);
 296 }
 297
 298 #[test]
 299 fn test_truncate() {
 300     let mut v: Vec<Box<_>> = vec![box 6, box 5, box 4];
 301     v.truncate(1);
 302     let v = v;
 303     assert_eq!(v.len(), 1);
 304     assert_eq!(*(v[0]), 6);
 305     // If the unsafe block didn't drop things properly, we blow up here.
 306 }
 307
 308 #[test]
 309 fn test_clear() {
 310     let mut v: Vec<Box<_>> = vec![box 6, box 5, box 4];
 311     v.clear();
 312     assert_eq!(v.len(), 0);
 313     // If the unsafe block didn't drop things properly, we blow up here.
 314 }
 315
 316 #[test]
 317 fn test_retain() {
 318     let mut v = vec![1, 2, 3, 4, 5];
 319     v.retain(is_odd);
 320     assert_eq!(v, [1, 3, 5]);
 321 }
 322
 323 #[test]
 324 fn test_binary_search() {
 325     assert_eq!([1, 2, 3, 4, 5].binary_search(&5).ok(), Some(4));
 326     assert_eq!([1, 2, 3, 4, 5].binary_search(&4).ok(), Some(3));
 327     assert_eq!([1, 2, 3, 4, 5].binary_search(&3).ok(), Some(2));
 328     assert_eq!([1, 2, 3, 4, 5].binary_search(&2).ok(), Some(1));
 329     assert_eq!([1, 2, 3, 4, 5].binary_search(&1).ok(), Some(0));
 330
 331     assert_eq!([2, 4, 6, 8, 10].binary_search(&1).ok(), None);
 332     assert_eq!([2, 4, 6, 8, 10].binary_search(&5).ok(), None);
 333     assert_eq!([2, 4, 6, 8, 10].binary_search(&4).ok(), Some(1));
 334     assert_eq!([2, 4, 6, 8, 10].binary_search(&10).ok(), Some(4));
 335
 336     assert_eq!([2, 4, 6, 8].binary_search(&1).ok(), None);
 337     assert_eq!([2, 4, 6, 8].binary_search(&5).ok(), None);
 338     assert_eq!([2, 4, 6, 8].binary_search(&4).ok(), Some(1));
 339     assert_eq!([2, 4, 6, 8].binary_search(&8).ok(), Some(3));
 340
 341     assert_eq!([2, 4, 6].binary_search(&1).ok(), None);
 342     assert_eq!([2, 4, 6].binary_search(&5).ok(), None);
 343     assert_eq!([2, 4, 6].binary_search(&4).ok(), Some(1));
 344     assert_eq!([2, 4, 6].binary_search(&6).ok(), Some(2));
 345
 346     assert_eq!([2, 4].binary_search(&1).ok(), None);
 347     assert_eq!([2, 4].binary_search(&5).ok(), None);
 348     assert_eq!([2, 4].binary_search(&2).ok(), Some(0));
 349     assert_eq!([2, 4].binary_search(&4).ok(), Some(1));
 350
 351     assert_eq!([2].binary_search(&1).ok(), None);
 352     assert_eq!([2].binary_search(&5).ok(), None);
 353     assert_eq!([2].binary_search(&2).ok(), Some(0));
 354
 355     assert_eq!([].binary_search(&1).ok(), None);
 356     assert_eq!([].binary_search(&5).ok(), None);
 357
 358     assert!([1, 1, 1, 1, 1].binary_search(&1).ok() != None);
 359     assert!([1, 1, 1, 1, 2].binary_search(&1).ok() != None);
 360     assert!([1, 1, 1, 2, 2].binary_search(&1).ok() != None);
 361     assert!([1, 1, 2, 2, 2].binary_search(&1).ok() != None);
 362     assert_eq!([1, 2, 2, 2, 2].binary_search(&1).ok(), Some(0));
 363
 364     assert_eq!([1, 2, 3, 4, 5].binary_search(&6).ok(), None);
 365     assert_eq!([1, 2, 3, 4, 5].binary_search(&0).ok(), None);
 366 }
 367
 368 #[test]
 369 fn test_reverse() {
 370     let mut v = vec![10, 20];
 371     assert_eq!(v[0], 10);
 372     assert_eq!(v[1], 20);
 373     v.reverse();
 374     assert_eq!(v[0], 20);
 375     assert_eq!(v[1], 10);
 376
 377     let mut v3 = Vec::<i32>::new();
 378     v3.reverse();
 379     assert!(v3.is_empty());
 380
 381     // check the 1-byte-types path
 382     let mut v = (-50..51i8).collect::<Vec<_>>();
 383     v.reverse();
 384     assert_eq!(v, (-50..51i8).rev().collect::<Vec<_>>());
 385
 386     // check the 2-byte-types path
 387     let mut v = (-50..51i16).collect::<Vec<_>>();
 388     v.reverse();
 389     assert_eq!(v, (-50..51i16).rev().collect::<Vec<_>>());
 390 }
 391
 392 #[test]
 393 #[cfg(not(miri))] // Miri does not support entropy
 394 fn test_sort() {
 395     let mut rng = thread_rng();
 396
 397     for len in (2..25).chain(500..510) {
 398         for &modulus in &[5, 10, 100, 1000] {
 399             for _ in 0..10 {
 400                 let orig: Vec<_> = rng.sample_iter::<i32, _>(&Standard)
 401                     .map(|x| x % modulus)
 402                     .take(len)
 403                     .collect();
 404
 405                 // Sort in default order.
 406                 let mut v = orig.clone();
 407                 v.sort();
 408                 assert!(v.windows(2).all(|w| w[0] <= w[1]));
 409
 410                 // Sort in ascending order.
 411                 let mut v = orig.clone();
 412                 v.sort_by(|a, b| a.cmp(b));
 413                 assert!(v.windows(2).all(|w| w[0] <= w[1]));
 414
 415                 // Sort in descending order.
 416                 let mut v = orig.clone();
 417                 v.sort_by(|a, b| b.cmp(a));
 418                 assert!(v.windows(2).all(|w| w[0] >= w[1]));
 419
 420                 // Sort in lexicographic order.
 421                 let mut v1 = orig.clone();
 422                 let mut v2 = orig.clone();
 423                 v1.sort_by_key(|x| x.to_string());
 424                 v2.sort_by_cached_key(|x| x.to_string());
 425                 assert!(v1.windows(2).all(|w| w[0].to_string() <= w[1].to_string()));
 426                 assert!(v1 == v2);
 427
 428                 // Sort with many pre-sorted runs.
 429                 let mut v = orig.clone();
 430                 v.sort();
 431                 v.reverse();
 432                 for _ in 0..5 {
 433                     let a = rng.gen::<usize>() % len;
 434                     let b = rng.gen::<usize>() % len;
 435                     if a < b {
 436                         v[a..b].reverse();
 437                     } else {
 438                         v.swap(a, b);
 439                     }
 440                 }
 441                 v.sort();
 442                 assert!(v.windows(2).all(|w| w[0] <= w[1]));
 443             }
 444         }
 445     }
 446
 447     // Sort using a completely random comparison function.
 448     // This will reorder the elements *somehow*, but won't panic.
 449     let mut v = [0; 500];
 450     for i in 0..v.len() {
 451         v[i] = i as i32;
 452     }
 453     v.sort_by(|_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
 454     v.sort();
 455     for i in 0..v.len() {
 456         assert_eq!(v[i], i as i32);
 457     }
 458
 459     // Should not panic.
 460     [0i32; 0].sort();
 461     [(); 10].sort();
 462     [(); 100].sort();
 463
 464     let mut v = [0xDEADBEEFu64];
 465     v.sort();
 466     assert!(v == [0xDEADBEEF]);
 467 }
 468
 469 #[test]
 470 #[cfg(not(miri))] // Miri does not support entropy
 471 fn test_sort_stability() {
 472     for len in (2..25).chain(500..510) {
 473         for _ in 0..10 {
 474             let mut counts = [0; 10];
 475
 476             // create a vector like [(6, 1), (5, 1), (6, 2), ...],
 477             // where the first item of each tuple is random, but
 478             // the second item represents which occurrence of that
 479             // number this element is, i.e., the second elements
 480             // will occur in sorted order.
 481             let orig: Vec<_> = (0..len)
 482                 .map(|_| {
 483                     let n = thread_rng().gen::<usize>() % 10;
 484                     counts[n] += 1;
 485                     (n, counts[n])
 486                 })
 487                 .collect();
 488
 489             let mut v = orig.clone();
 490             // Only sort on the first element, so an unstable sort
 491             // may mix up the counts.
 492             v.sort_by(|&(a, _), &(b, _)| a.cmp(&b));
 493
 494             // This comparison includes the count (the second item
 495             // of the tuple), so elements with equal first items
 496             // will need to be ordered with increasing
 497             // counts... i.e., exactly asserting that this sort is
 498             // stable.
 499             assert!(v.windows(2).all(|w| w[0] <= w[1]));
 500
 501             let mut v = orig.clone();
 502             v.sort_by_cached_key(|&(x, _)| x);
 503             assert!(v.windows(2).all(|w| w[0] <= w[1]));
 504         }
 505     }
 506 }
 507
 508 #[test]
 509 fn test_rotate_left() {
 510     let expected: Vec<_> = (0..13).collect();
 511     let mut v = Vec::new();
 512
 513     // no-ops
 514     v.clone_from(&expected);
 515     v.rotate_left(0);
 516     assert_eq!(v, expected);
 517     v.rotate_left(expected.len());
 518     assert_eq!(v, expected);
 519     let mut zst_array = [(), (), ()];
 520     zst_array.rotate_left(2);
 521
 522     // happy path
 523     v = (5..13).chain(0..5).collect();
 524     v.rotate_left(8);
 525     assert_eq!(v, expected);
 526
 527     let expected: Vec<_> = (0..1000).collect();
 528
 529     // small rotations in large slice, uses ptr::copy
 530     v = (2..1000).chain(0..2).collect();
 531     v.rotate_left(998);
 532     assert_eq!(v, expected);
 533     v = (998..1000).chain(0..998).collect();
 534     v.rotate_left(2);
 535     assert_eq!(v, expected);
 536
 537     // non-small prime rotation, has a few rounds of swapping
 538     v = (389..1000).chain(0..389).collect();
 539     v.rotate_left(1000-389);
 540     assert_eq!(v, expected);
 541 }
 542
 543 #[test]
 544 fn test_rotate_right() {
 545     let expected: Vec<_> = (0..13).collect();
 546     let mut v = Vec::new();
 547
 548     // no-ops
 549     v.clone_from(&expected);
 550     v.rotate_right(0);
 551     assert_eq!(v, expected);
 552     v.rotate_right(expected.len());
 553     assert_eq!(v, expected);
 554     let mut zst_array = [(), (), ()];
 555     zst_array.rotate_right(2);
 556
 557     // happy path
 558     v = (5..13).chain(0..5).collect();
 559     v.rotate_right(5);
 560     assert_eq!(v, expected);
 561
 562     let expected: Vec<_> = (0..1000).collect();
 563
 564     // small rotations in large slice, uses ptr::copy
 565     v = (2..1000).chain(0..2).collect();
 566     v.rotate_right(2);
 567     assert_eq!(v, expected);
 568     v = (998..1000).chain(0..998).collect();
 569     v.rotate_right(998);
 570     assert_eq!(v, expected);
 571
 572     // non-small prime rotation, has a few rounds of swapping
 573     v = (389..1000).chain(0..389).collect();
 574     v.rotate_right(389);
 575     assert_eq!(v, expected);
 576 }
 577
 578 #[test]
 579 fn test_concat() {
 580     let v: [Vec<i32>; 0] = [];
 581     let c = v.concat();
 582     assert_eq!(c, []);
 583     let d = [vec![1], vec![2, 3]].concat();
 584     assert_eq!(d, [1, 2, 3]);
 585
 586     let v: &[&[_]] = &[&[1], &[2, 3]];
 587     assert_eq!(v.join(&0), [1, 0, 2, 3]);
 588     let v: &[&[_]] = &[&[1], &[2], &[3]];
 589     assert_eq!(v.join(&0), [1, 0, 2, 0, 3]);
 590 }
 591
 592 #[test]
 593 fn test_join() {
 594     let v: [Vec<i32>; 0] = [];
 595     assert_eq!(v.join(&0), []);
 596     assert_eq!([vec![1], vec![2, 3]].join(&0), [1, 0, 2, 3]);
 597     assert_eq!([vec![1], vec![2], vec![3]].join(&0), [1, 0, 2, 0, 3]);
 598
 599     let v: [&[_]; 2] = [&[1], &[2, 3]];
 600     assert_eq!(v.join(&0), [1, 0, 2, 3]);
 601     let v: [&[_]; 3] = [&[1], &[2], &[3]];
 602     assert_eq!(v.join(&0), [1, 0, 2, 0, 3]);
 603 }
 604
 605 #[test]
 606 fn test_join_nocopy() {
 607     let v: [String; 0] = [];
 608     assert_eq!(v.join(","), "");
 609     assert_eq!(["a".to_string(), "ab".into()].join(","), "a,ab");
 610     assert_eq!(["a".to_string(), "ab".into(), "abc".into()].join(","), "a,ab,abc");
 611     assert_eq!(["a".to_string(), "ab".into(), "".into()].join(","), "a,ab,");
 612 }
 613
 614 #[test]
 615 fn test_insert() {
 616     let mut a = vec![1, 2, 4];
 617     a.insert(2, 3);
 618     assert_eq!(a, [1, 2, 3, 4]);
 619
 620     let mut a = vec![1, 2, 3];
 621     a.insert(0, 0);
 622     assert_eq!(a, [0, 1, 2, 3]);
 623
 624     let mut a = vec![1, 2, 3];
 625     a.insert(3, 4);
 626     assert_eq!(a, [1, 2, 3, 4]);
 627
 628     let mut a = vec![];
 629     a.insert(0, 1);
 630     assert_eq!(a, [1]);
 631 }
 632
 633 #[test]
 634 #[should_panic]
 635 #[cfg(not(miri))] // Miri does not support panics
 636 fn test_insert_oob() {
 637     let mut a = vec![1, 2, 3];
 638     a.insert(4, 5);
 639 }
 640
 641 #[test]
 642 fn test_remove() {
 643     let mut a = vec![1, 2, 3, 4];
 644
 645     assert_eq!(a.remove(2), 3);
 646     assert_eq!(a, [1, 2, 4]);
 647
 648     assert_eq!(a.remove(2), 4);
 649     assert_eq!(a, [1, 2]);
 650
 651     assert_eq!(a.remove(0), 1);
 652     assert_eq!(a, [2]);
 653
 654     assert_eq!(a.remove(0), 2);
 655     assert_eq!(a, []);
 656 }
 657
 658 #[test]
 659 #[should_panic]
 660 #[cfg(not(miri))] // Miri does not support panics
 661 fn test_remove_fail() {
 662     let mut a = vec![1];
 663     let _ = a.remove(0);
 664     let _ = a.remove(0);
 665 }
 666
 667 #[test]
 668 fn test_capacity() {
 669     let mut v = vec![0];
 670     v.reserve_exact(10);
 671     assert!(v.capacity() >= 11);
 672 }
 673
 674 #[test]
 675 fn test_slice_2() {
 676     let v = vec![1, 2, 3, 4, 5];
 677     let v = &v[1..3];
 678     assert_eq!(v.len(), 2);
 679     assert_eq!(v[0], 2);
 680     assert_eq!(v[1], 3);
 681 }
 682
 683 macro_rules! assert_order {
 684     (Greater, $a:expr, $b:expr) => {
 685         assert_eq!($a.cmp($b), Greater);
 686         assert!($a > $b);
 687     };
 688     (Less, $a:expr, $b:expr) => {
 689         assert_eq!($a.cmp($b), Less);
 690         assert!($a < $b);
 691     };
 692     (Equal, $a:expr, $b:expr) => {
 693         assert_eq!($a.cmp($b), Equal);
 694         assert_eq!($a, $b);
 695     }
 696 }
 697
 698 #[test]
 699 fn test_total_ord_u8() {
 700     let c = &[1u8, 2, 3];
 701     assert_order!(Greater, &[1u8, 2, 3, 4][..], &c[..]);
 702     let c = &[1u8, 2, 3, 4];
 703     assert_order!(Less, &[1u8, 2, 3][..], &c[..]);
 704     let c = &[1u8, 2, 3, 6];
 705     assert_order!(Equal, &[1u8, 2, 3, 6][..], &c[..]);
 706     let c = &[1u8, 2, 3, 4, 5, 6];
 707     assert_order!(Less, &[1u8, 2, 3, 4, 5, 5, 5, 5][..], &c[..]);
 708     let c = &[1u8, 2, 3, 4];
 709     assert_order!(Greater, &[2u8, 2][..], &c[..]);
 710 }
 711
 712
 713 #[test]
 714 fn test_total_ord_i32() {
 715     let c = &[1, 2, 3];
 716     assert_order!(Greater, &[1, 2, 3, 4][..], &c[..]);
 717     let c = &[1, 2, 3, 4];
 718     assert_order!(Less, &[1, 2, 3][..], &c[..]);
 719     let c = &[1, 2, 3, 6];
 720     assert_order!(Equal, &[1, 2, 3, 6][..], &c[..]);
 721     let c = &[1, 2, 3, 4, 5, 6];
 722     assert_order!(Less, &[1, 2, 3, 4, 5, 5, 5, 5][..], &c[..]);
 723     let c = &[1, 2, 3, 4];
 724     assert_order!(Greater, &[2, 2][..], &c[..]);
 725 }
 726
 727 #[test]
 728 fn test_iterator() {
 729     let xs = [1, 2, 5, 10, 11];
 730     let mut it = xs.iter();
 731     assert_eq!(it.size_hint(), (5, Some(5)));
 732     assert_eq!(it.next().unwrap(), &1);
 733     assert_eq!(it.size_hint(), (4, Some(4)));
 734     assert_eq!(it.next().unwrap(), &2);
 735     assert_eq!(it.size_hint(), (3, Some(3)));
 736     assert_eq!(it.next().unwrap(), &5);
 737     assert_eq!(it.size_hint(), (2, Some(2)));
 738     assert_eq!(it.next().unwrap(), &10);
 739     assert_eq!(it.size_hint(), (1, Some(1)));
 740     assert_eq!(it.next().unwrap(), &11);
 741     assert_eq!(it.size_hint(), (0, Some(0)));
 742     assert!(it.next().is_none());
 743 }
 744
 745 #[test]
 746 fn test_iter_size_hints() {
 747     let mut xs = [1, 2, 5, 10, 11];
 748     assert_eq!(xs.iter().size_hint(), (5, Some(5)));
 749     assert_eq!(xs.iter_mut().size_hint(), (5, Some(5)));
 750 }
 751
 752 #[test]
 753 fn test_iter_as_slice() {
 754     let xs = [1, 2, 5, 10, 11];
 755     let mut iter = xs.iter();
 756     assert_eq!(iter.as_slice(), &[1, 2, 5, 10, 11]);
 757     iter.next();
 758     assert_eq!(iter.as_slice(), &[2, 5, 10, 11]);
 759 }
 760
 761 #[test]
 762 fn test_iter_as_ref() {
 763     let xs = [1, 2, 5, 10, 11];
 764     let mut iter = xs.iter();
 765     assert_eq!(iter.as_ref(), &[1, 2, 5, 10, 11]);
 766     iter.next();
 767     assert_eq!(iter.as_ref(), &[2, 5, 10, 11]);
 768 }
 769
 770 #[test]
 771 fn test_iter_clone() {
 772     let xs = [1, 2, 5];
 773     let mut it = xs.iter();
 774     it.next();
 775     let mut jt = it.clone();
 776     assert_eq!(it.next(), jt.next());
 777     assert_eq!(it.next(), jt.next());
 778     assert_eq!(it.next(), jt.next());
 779 }
 780
 781 #[test]
 782 fn test_iter_is_empty() {
 783     let xs = [1, 2, 5, 10, 11];
 784     for i in 0..xs.len() {
 785         for j in i..xs.len() {
 786             assert_eq!(xs[i..j].iter().is_empty(), xs[i..j].is_empty());
 787         }
 788     }
 789 }
 790
 791 #[test]
 792 fn test_mut_iterator() {
 793     let mut xs = [1, 2, 3, 4, 5];
 794     for x in &mut xs {
 795         *x += 1;
 796     }
 797     assert!(xs == [2, 3, 4, 5, 6])
 798 }
 799
 800 #[test]
 801 fn test_rev_iterator() {
 802
 803     let xs = [1, 2, 5, 10, 11];
 804     let ys = [11, 10, 5, 2, 1];
 805     let mut i = 0;
 806     for &x in xs.iter().rev() {
 807         assert_eq!(x, ys[i]);
 808         i += 1;
 809     }
 810     assert_eq!(i, 5);
 811 }
 812
 813 #[test]
 814 fn test_mut_rev_iterator() {
 815     let mut xs = [1, 2, 3, 4, 5];
 816     for (i, x) in xs.iter_mut().rev().enumerate() {
 817         *x += i;
 818     }
 819     assert!(xs == [5, 5, 5, 5, 5])
 820 }
 821
 822 #[test]
 823 fn test_move_iterator() {
 824     let xs = vec![1, 2, 3, 4, 5];
 825     assert_eq!(xs.into_iter().fold(0, |a: usize, b: usize| 10 * a + b),
 826                12345);
 827 }
 828
 829 #[test]
 830 fn test_move_rev_iterator() {
 831     let xs = vec![1, 2, 3, 4, 5];
 832     assert_eq!(xs.into_iter().rev().fold(0, |a: usize, b: usize| 10 * a + b),
 833                54321);
 834 }
 835
 836 #[test]
 837 fn test_splitator() {
 838     let xs = &[1, 2, 3, 4, 5];
 839
 840     let splits: &[&[_]] = &[&[1], &[3], &[5]];
 841     assert_eq!(xs.split(|x| *x % 2 == 0).collect::<Vec<_>>(), splits);
 842     let splits: &[&[_]] = &[&[], &[2, 3, 4, 5]];
 843     assert_eq!(xs.split(|x| *x == 1).collect::<Vec<_>>(), splits);
 844     let splits: &[&[_]] = &[&[1, 2, 3, 4], &[]];
 845     assert_eq!(xs.split(|x| *x == 5).collect::<Vec<_>>(), splits);
 846     let splits: &[&[_]] = &[&[1, 2, 3, 4, 5]];
 847     assert_eq!(xs.split(|x| *x == 10).collect::<Vec<_>>(), splits);
 848     let splits: &[&[_]] = &[&[], &[], &[], &[], &[], &[]];
 849     assert_eq!(xs.split(|_| true).collect::<Vec<&[i32]>>(), splits);
 850
 851     let xs: &[i32] = &[];
 852     let splits: &[&[i32]] = &[&[]];
 853     assert_eq!(xs.split(|x| *x == 5).collect::<Vec<&[i32]>>(), splits);
 854 }
 855
 856 #[test]
 857 fn test_splitnator() {
 858     let xs = &[1, 2, 3, 4, 5];
 859
 860     let splits: &[&[_]] = &[&[1, 2, 3, 4, 5]];
 861     assert_eq!(xs.splitn(1, |x| *x % 2 == 0).collect::<Vec<_>>(), splits);
 862     let splits: &[&[_]] = &[&[1], &[3, 4, 5]];
 863     assert_eq!(xs.splitn(2, |x| *x % 2 == 0).collect::<Vec<_>>(), splits);
 864     let splits: &[&[_]] = &[&[], &[], &[], &[4, 5]];
 865     assert_eq!(xs.splitn(4, |_| true).collect::<Vec<_>>(), splits);
 866
 867     let xs: &[i32] = &[];
 868     let splits: &[&[i32]] = &[&[]];
 869     assert_eq!(xs.splitn(2, |x| *x == 5).collect::<Vec<_>>(), splits);
 870 }
 871
 872 #[test]
 873 fn test_splitnator_mut() {
 874     let xs = &mut [1, 2, 3, 4, 5];
 875
 876     let splits: &[&mut [_]] = &[&mut [1, 2, 3, 4, 5]];
 877     assert_eq!(xs.splitn_mut(1, |x| *x % 2 == 0).collect::<Vec<_>>(),
 878                splits);
 879     let splits: &[&mut [_]] = &[&mut [1], &mut [3, 4, 5]];
 880     assert_eq!(xs.splitn_mut(2, |x| *x % 2 == 0).collect::<Vec<_>>(),
 881                splits);
 882     let splits: &[&mut [_]] = &[&mut [], &mut [], &mut [], &mut [4, 5]];
 883     assert_eq!(xs.splitn_mut(4, |_| true).collect::<Vec<_>>(), splits);
 884
 885     let xs: &mut [i32] = &mut [];
 886     let splits: &[&mut [i32]] = &[&mut []];
 887     assert_eq!(xs.splitn_mut(2, |x| *x == 5).collect::<Vec<_>>(), splits);
 888 }
 889
 890 #[test]
 891 fn test_rsplitator() {
 892     let xs = &[1, 2, 3, 4, 5];
 893
 894     let splits: &[&[_]] = &[&[5], &[3], &[1]];
 895     assert_eq!(xs.split(|x| *x % 2 == 0).rev().collect::<Vec<_>>(), splits);
 896     let splits: &[&[_]] = &[&[2, 3, 4, 5], &[]];
 897     assert_eq!(xs.split(|x| *x == 1).rev().collect::<Vec<_>>(), splits);
 898     let splits: &[&[_]] = &[&[], &[1, 2, 3, 4]];
 899     assert_eq!(xs.split(|x| *x == 5).rev().collect::<Vec<_>>(), splits);
 900     let splits: &[&[_]] = &[&[1, 2, 3, 4, 5]];
 901     assert_eq!(xs.split(|x| *x == 10).rev().collect::<Vec<_>>(), splits);
 902
 903     let xs: &[i32] = &[];
 904     let splits: &[&[i32]] = &[&[]];
 905     assert_eq!(xs.split(|x| *x == 5).rev().collect::<Vec<&[i32]>>(), splits);
 906 }
 907
 908 #[test]
 909 fn test_rsplitnator() {
 910     let xs = &[1, 2, 3, 4, 5];
 911
 912     let splits: &[&[_]] = &[&[1, 2, 3, 4, 5]];
 913     assert_eq!(xs.rsplitn(1, |x| *x % 2 == 0).collect::<Vec<_>>(), splits);
 914     let splits: &[&[_]] = &[&[5], &[1, 2, 3]];
 915     assert_eq!(xs.rsplitn(2, |x| *x % 2 == 0).collect::<Vec<_>>(), splits);
 916     let splits: &[&[_]] = &[&[], &[], &[], &[1, 2]];
 917     assert_eq!(xs.rsplitn(4, |_| true).collect::<Vec<_>>(), splits);
 918
 919     let xs: &[i32] = &[];
 920     let splits: &[&[i32]] = &[&[]];
 921     assert_eq!(xs.rsplitn(2, |x| *x == 5).collect::<Vec<&[i32]>>(), splits);
 922     assert!(xs.rsplitn(0, |x| *x % 2 == 0).next().is_none());
 923 }
 924
 925 #[test]
 926 fn test_windowsator() {
 927     let v = &[1, 2, 3, 4];
 928
 929     let wins: &[&[_]] = &[&[1, 2], &[2, 3], &[3, 4]];
 930     assert_eq!(v.windows(2).collect::<Vec<_>>(), wins);
 931
 932     let wins: &[&[_]] = &[&[1, 2, 3], &[2, 3, 4]];
 933     assert_eq!(v.windows(3).collect::<Vec<_>>(), wins);
 934     assert!(v.windows(6).next().is_none());
 935
 936     let wins: &[&[_]] = &[&[3, 4], &[2, 3], &[1, 2]];
 937     assert_eq!(v.windows(2).rev().collect::<Vec<&[_]>>(), wins);
 938 }
 939
 940 #[test]
 941 #[should_panic]
 942 #[cfg(not(miri))] // Miri does not support panics
 943 fn test_windowsator_0() {
 944     let v = &[1, 2, 3, 4];
 945     let _it = v.windows(0);
 946 }
 947
 948 #[test]
 949 fn test_chunksator() {
 950     let v = &[1, 2, 3, 4, 5];
 951
 952     assert_eq!(v.chunks(2).len(), 3);
 953
 954     let chunks: &[&[_]] = &[&[1, 2], &[3, 4], &[5]];
 955     assert_eq!(v.chunks(2).collect::<Vec<_>>(), chunks);
 956     let chunks: &[&[_]] = &[&[1, 2, 3], &[4, 5]];
 957     assert_eq!(v.chunks(3).collect::<Vec<_>>(), chunks);
 958     let chunks: &[&[_]] = &[&[1, 2, 3, 4, 5]];
 959     assert_eq!(v.chunks(6).collect::<Vec<_>>(), chunks);
 960
 961     let chunks: &[&[_]] = &[&[5], &[3, 4], &[1, 2]];
 962     assert_eq!(v.chunks(2).rev().collect::<Vec<_>>(), chunks);
 963 }
 964
 965 #[test]
 966 #[should_panic]
 967 #[cfg(not(miri))] // Miri does not support panics
 968 fn test_chunksator_0() {
 969     let v = &[1, 2, 3, 4];
 970     let _it = v.chunks(0);
 971 }
 972
 973 #[test]
 974 fn test_chunks_exactator() {
 975     let v = &[1, 2, 3, 4, 5];
 976
 977     assert_eq!(v.chunks_exact(2).len(), 2);
 978
 979     let chunks: &[&[_]] = &[&[1, 2], &[3, 4]];
 980     assert_eq!(v.chunks_exact(2).collect::<Vec<_>>(), chunks);
 981     let chunks: &[&[_]] = &[&[1, 2, 3]];
 982     assert_eq!(v.chunks_exact(3).collect::<Vec<_>>(), chunks);
 983     let chunks: &[&[_]] = &[];
 984     assert_eq!(v.chunks_exact(6).collect::<Vec<_>>(), chunks);
 985
 986     let chunks: &[&[_]] = &[&[3, 4], &[1, 2]];
 987     assert_eq!(v.chunks_exact(2).rev().collect::<Vec<_>>(), chunks);
 988 }
 989
 990 #[test]
 991 #[should_panic]
 992 #[cfg(not(miri))] // Miri does not support panics
 993 fn test_chunks_exactator_0() {
 994     let v = &[1, 2, 3, 4];
 995     let _it = v.chunks_exact(0);
 996 }
 997
 998 #[test]
 999 fn test_rchunksator() {
1000     let v = &[1, 2, 3, 4, 5];
1001
1002     assert_eq!(v.rchunks(2).len(), 3);
1003
1004     let chunks: &[&[_]] = &[&[4, 5], &[2, 3], &[1]];
1005     assert_eq!(v.rchunks(2).collect::<Vec<_>>(), chunks);
1006     let chunks: &[&[_]] = &[&[3, 4, 5], &[1, 2]];
1007     assert_eq!(v.rchunks(3).collect::<Vec<_>>(), chunks);
1008     let chunks: &[&[_]] = &[&[1, 2, 3, 4, 5]];
1009     assert_eq!(v.rchunks(6).collect::<Vec<_>>(), chunks);
1010
1011     let chunks: &[&[_]] = &[&[1], &[2, 3], &[4, 5]];
1012     assert_eq!(v.rchunks(2).rev().collect::<Vec<_>>(), chunks);
1013 }
1014
1015 #[test]
1016 #[should_panic]
1017 #[cfg(not(miri))] // Miri does not support panics
1018 fn test_rchunksator_0() {
1019     let v = &[1, 2, 3, 4];
1020     let _it = v.rchunks(0);
1021 }
1022
1023 #[test]
1024 fn test_rchunks_exactator() {
1025     let v = &[1, 2, 3, 4, 5];
1026
1027     assert_eq!(v.rchunks_exact(2).len(), 2);
1028
1029     let chunks: &[&[_]] = &[&[4, 5], &[2, 3]];
1030     assert_eq!(v.rchunks_exact(2).collect::<Vec<_>>(), chunks);
1031     let chunks: &[&[_]] = &[&[3, 4, 5]];
1032     assert_eq!(v.rchunks_exact(3).collect::<Vec<_>>(), chunks);
1033     let chunks: &[&[_]] = &[];
1034     assert_eq!(v.rchunks_exact(6).collect::<Vec<_>>(), chunks);
1035
1036     let chunks: &[&[_]] = &[&[2, 3], &[4, 5]];
1037     assert_eq!(v.rchunks_exact(2).rev().collect::<Vec<_>>(), chunks);
1038 }
1039
1040 #[test]
1041 #[should_panic]
1042 #[cfg(not(miri))] // Miri does not support panics
1043 fn test_rchunks_exactator_0() {
1044     let v = &[1, 2, 3, 4];
1045     let _it = v.rchunks_exact(0);
1046 }
1047
1048 #[test]
1049 fn test_reverse_part() {
1050     let mut values = [1, 2, 3, 4, 5];
1051     values[1..4].reverse();
1052     assert!(values == [1, 4, 3, 2, 5]);
1053 }
1054
1055 #[test]
1056 fn test_show() {
1057     macro_rules! test_show_vec {
1058         ($x:expr, $x_str:expr) => ({
1059             let (x, x_str) = ($x, $x_str);
1060             assert_eq!(format!("{:?}", x), x_str);
1061             assert_eq!(format!("{:?}", x), x_str);
1062         })
1063     }
1064     let empty = Vec::<i32>::new();
1065     test_show_vec!(empty, "[]");
1066     test_show_vec!(vec![1], "[1]");
1067     test_show_vec!(vec![1, 2, 3], "[1, 2, 3]");
1068     test_show_vec!(vec![vec![], vec![1], vec![1, 1]], "[[], [1], [1, 1]]");
1069
1070     let empty_mut: &mut [i32] = &mut [];
1071     test_show_vec!(empty_mut, "[]");
1072     let v = &mut [1];
1073     test_show_vec!(v, "[1]");
1074     let v = &mut [1, 2, 3];
1075     test_show_vec!(v, "[1, 2, 3]");
1076     let v: &mut [&mut [_]] = &mut [&mut [], &mut [1], &mut [1, 1]];
1077     test_show_vec!(v, "[[], [1], [1, 1]]");
1078 }
1079
1080 #[test]
1081 fn test_vec_default() {
1082     macro_rules! t {
1083         ($ty:ty) => {{
1084             let v: $ty = Default::default();
1085             assert!(v.is_empty());
1086         }}
1087     }
1088
1089     t!(&[i32]);
1090     t!(Vec<i32>);
1091 }
1092
1093 #[test]
1094 #[should_panic]
1095 #[cfg(not(miri))] // Miri does not support panics
1096 fn test_overflow_does_not_cause_segfault() {
1097     let mut v = vec![];
1098     v.reserve_exact(!0);
1099     v.push(1);
1100     v.push(2);
1101 }
1102
1103 #[test]
1104 #[should_panic]
1105 #[cfg(not(miri))] // Miri does not support panics
1106 fn test_overflow_does_not_cause_segfault_managed() {
1107     let mut v = vec![Rc::new(1)];
1108     v.reserve_exact(!0);
1109     v.push(Rc::new(2));
1110 }
1111
1112 #[test]
1113 fn test_mut_split_at() {
1114     let mut values = [1, 2, 3, 4, 5];
1115     {
1116         let (left, right) = values.split_at_mut(2);
1117         {
1118             let left: &[_] = left;
1119             assert!(left[..left.len()] == [1, 2]);
1120         }
1121         for p in left {
1122             *p += 1;
1123         }
1124
1125         {
1126             let right: &[_] = right;
1127             assert!(right[..right.len()] == [3, 4, 5]);
1128         }
1129         for p in right {
1130             *p += 2;
1131         }
1132     }
1133
1134     assert!(values == [2, 3, 5, 6, 7]);
1135 }
1136
1137 #[derive(Clone, PartialEq)]
1138 struct Foo;
1139
1140 #[test]
1141 fn test_iter_zero_sized() {
1142     let mut v = vec![Foo, Foo, Foo];
1143     assert_eq!(v.len(), 3);
1144     let mut cnt = 0;
1145
1146     for f in &v {
1147         assert!(*f == Foo);
1148         cnt += 1;
1149     }
1150     assert_eq!(cnt, 3);
1151
1152     for f in &v[1..3] {
1153         assert!(*f == Foo);
1154         cnt += 1;
1155     }
1156     assert_eq!(cnt, 5);
1157
1158     for f in &mut v {
1159         assert!(*f == Foo);
1160         cnt += 1;
1161     }
1162     assert_eq!(cnt, 8);
1163
1164     for f in v {
1165         assert!(f == Foo);
1166         cnt += 1;
1167     }
1168     assert_eq!(cnt, 11);
1169
1170     let xs: [Foo; 3] = [Foo, Foo, Foo];
1171     cnt = 0;
1172     for f in &xs {
1173         assert!(*f == Foo);
1174         cnt += 1;
1175     }
1176     assert!(cnt == 3);
1177 }
1178
1179 #[test]
1180 fn test_shrink_to_fit() {
1181     let mut xs = vec![0, 1, 2, 3];
1182     for i in 4..100 {
1183         xs.push(i)
1184     }
1185     assert_eq!(xs.capacity(), 128);
1186     xs.shrink_to_fit();
1187     assert_eq!(xs.capacity(), 100);
1188     assert_eq!(xs, (0..100).collect::<Vec<_>>());
1189 }
1190
1191 #[test]
1192 fn test_starts_with() {
1193     assert!(b"foobar".starts_with(b"foo"));
1194     assert!(!b"foobar".starts_with(b"oob"));
1195     assert!(!b"foobar".starts_with(b"bar"));
1196     assert!(!b"foo".starts_with(b"foobar"));
1197     assert!(!b"bar".starts_with(b"foobar"));
1198     assert!(b"foobar".starts_with(b"foobar"));
1199     let empty: &[u8] = &[];
1200     assert!(empty.starts_with(empty));
1201     assert!(!empty.starts_with(b"foo"));
1202     assert!(b"foobar".starts_with(empty));
1203 }
1204
1205 #[test]
1206 fn test_ends_with() {
1207     assert!(b"foobar".ends_with(b"bar"));
1208     assert!(!b"foobar".ends_with(b"oba"));
1209     assert!(!b"foobar".ends_with(b"foo"));
1210     assert!(!b"foo".ends_with(b"foobar"));
1211     assert!(!b"bar".ends_with(b"foobar"));
1212     assert!(b"foobar".ends_with(b"foobar"));
1213     let empty: &[u8] = &[];
1214     assert!(empty.ends_with(empty));
1215     assert!(!empty.ends_with(b"foo"));
1216     assert!(b"foobar".ends_with(empty));
1217 }
1218
1219 #[test]
1220 fn test_mut_splitator() {
1221     let mut xs = [0, 1, 0, 2, 3, 0, 0, 4, 5, 0];
1222     assert_eq!(xs.split_mut(|x| *x == 0).count(), 6);
1223     for slice in xs.split_mut(|x| *x == 0) {
1224         slice.reverse();
1225     }
1226     assert!(xs == [0, 1, 0, 3, 2, 0, 0, 5, 4, 0]);
1227
1228     let mut xs = [0, 1, 0, 2, 3, 0, 0, 4, 5, 0, 6, 7];
1229     for slice in xs.split_mut(|x| *x == 0).take(5) {
1230         slice.reverse();
1231     }
1232     assert!(xs == [0, 1, 0, 3, 2, 0, 0, 5, 4, 0, 6, 7]);
1233 }
1234
1235 #[test]
1236 fn test_mut_splitator_rev() {
1237     let mut xs = [1, 2, 0, 3, 4, 0, 0, 5, 6, 0];
1238     for slice in xs.split_mut(|x| *x == 0).rev().take(4) {
1239         slice.reverse();
1240     }
1241     assert!(xs == [1, 2, 0, 4, 3, 0, 0, 6, 5, 0]);
1242 }
1243
1244 #[test]
1245 fn test_get_mut() {
1246     let mut v = [0, 1, 2];
1247     assert_eq!(v.get_mut(3), None);
1248     v.get_mut(1).map(|e| *e = 7);
1249     assert_eq!(v[1], 7);
1250     let mut x = 2;
1251     assert_eq!(v.get_mut(2), Some(&mut x));
1252 }
1253
1254 #[test]
1255 fn test_mut_chunks() {
1256     let mut v = [0, 1, 2, 3, 4, 5, 6];
1257     assert_eq!(v.chunks_mut(3).len(), 3);
1258     for (i, chunk) in v.chunks_mut(3).enumerate() {
1259         for x in chunk {
1260             *x = i as u8;
1261         }
1262     }
1263     let result = [0, 0, 0, 1, 1, 1, 2];
1264     assert_eq!(v, result);
1265 }
1266
1267 #[test]
1268 fn test_mut_chunks_rev() {
1269     let mut v = [0, 1, 2, 3, 4, 5, 6];
1270     for (i, chunk) in v.chunks_mut(3).rev().enumerate() {
1271         for x in chunk {
1272             *x = i as u8;
1273         }
1274     }
1275     let result = [2, 2, 2, 1, 1, 1, 0];
1276     assert_eq!(v, result);
1277 }
1278
1279 #[test]
1280 #[should_panic]
1281 #[cfg(not(miri))] // Miri does not support panics
1282 fn test_mut_chunks_0() {
1283     let mut v = [1, 2, 3, 4];
1284     let _it = v.chunks_mut(0);
1285 }
1286
1287 #[test]
1288 fn test_mut_chunks_exact() {
1289     let mut v = [0, 1, 2, 3, 4, 5, 6];
1290     assert_eq!(v.chunks_exact_mut(3).len(), 2);
1291     for (i, chunk) in v.chunks_exact_mut(3).enumerate() {
1292         for x in chunk {
1293             *x = i as u8;
1294         }
1295     }
1296     let result = [0, 0, 0, 1, 1, 1, 6];
1297     assert_eq!(v, result);
1298 }
1299
1300 #[test]
1301 fn test_mut_chunks_exact_rev() {
1302     let mut v = [0, 1, 2, 3, 4, 5, 6];
1303     for (i, chunk) in v.chunks_exact_mut(3).rev().enumerate() {
1304         for x in chunk {
1305             *x = i as u8;
1306         }
1307     }
1308     let result = [1, 1, 1, 0, 0, 0, 6];
1309     assert_eq!(v, result);
1310 }
1311
1312 #[test]
1313 #[should_panic]
1314 #[cfg(not(miri))] // Miri does not support panics
1315 fn test_mut_chunks_exact_0() {
1316     let mut v = [1, 2, 3, 4];
1317     let _it = v.chunks_exact_mut(0);
1318 }
1319
1320 #[test]
1321 fn test_mut_rchunks() {
1322     let mut v = [0, 1, 2, 3, 4, 5, 6];
1323     assert_eq!(v.rchunks_mut(3).len(), 3);
1324     for (i, chunk) in v.rchunks_mut(3).enumerate() {
1325         for x in chunk {
1326             *x = i as u8;
1327         }
1328     }
1329     let result = [2, 1, 1, 1, 0, 0, 0];
1330     assert_eq!(v, result);
1331 }
1332
1333 #[test]
1334 fn test_mut_rchunks_rev() {
1335     let mut v = [0, 1, 2, 3, 4, 5, 6];
1336     for (i, chunk) in v.rchunks_mut(3).rev().enumerate() {
1337         for x in chunk {
1338             *x = i as u8;
1339         }
1340     }
1341     let result = [0, 1, 1, 1, 2, 2, 2];
1342     assert_eq!(v, result);
1343 }
1344
1345 #[test]
1346 #[should_panic]
1347 #[cfg(not(miri))] // Miri does not support panics
1348 fn test_mut_rchunks_0() {
1349     let mut v = [1, 2, 3, 4];
1350     let _it = v.rchunks_mut(0);
1351 }
1352
1353 #[test]
1354 fn test_mut_rchunks_exact() {
1355     let mut v = [0, 1, 2, 3, 4, 5, 6];
1356     assert_eq!(v.rchunks_exact_mut(3).len(), 2);
1357     for (i, chunk) in v.rchunks_exact_mut(3).enumerate() {
1358         for x in chunk {
1359             *x = i as u8;
1360         }
1361     }
1362     let result = [0, 1, 1, 1, 0, 0, 0];
1363     assert_eq!(v, result);
1364 }
1365
1366 #[test]
1367 fn test_mut_rchunks_exact_rev() {
1368     let mut v = [0, 1, 2, 3, 4, 5, 6];
1369     for (i, chunk) in v.rchunks_exact_mut(3).rev().enumerate() {
1370         for x in chunk {
1371             *x = i as u8;
1372         }
1373     }
1374     let result = [0, 0, 0, 0, 1, 1, 1];
1375     assert_eq!(v, result);
1376 }
1377
1378 #[test]
1379 #[should_panic]
1380 #[cfg(not(miri))] // Miri does not support panics
1381 fn test_mut_rchunks_exact_0() {
1382     let mut v = [1, 2, 3, 4];
1383     let _it = v.rchunks_exact_mut(0);
1384 }
1385
1386 #[test]
1387 fn test_mut_last() {
1388     let mut x = [1, 2, 3, 4, 5];
1389     let h = x.last_mut();
1390     assert_eq!(*h.unwrap(), 5);
1391
1392     let y: &mut [i32] = &mut [];
1393     assert!(y.last_mut().is_none());
1394 }
1395
1396 #[test]
1397 fn test_to_vec() {
1398     let xs: Box<_> = box [1, 2, 3];
1399     let ys = xs.to_vec();
1400     assert_eq!(ys, [1, 2, 3]);
1401 }
1402
1403 #[test]
1404 fn test_box_slice_clone() {
1405     let data = vec![vec![0, 1], vec![0], vec![1]];
1406     let data2 = data.clone().into_boxed_slice().clone().to_vec();
1407
1408     assert_eq!(data, data2);
1409 }
1410
1411 #[test]
1412 #[allow(unused_must_use)] // here, we care about the side effects of `.clone()`
1413 #[cfg_attr(target_os = "emscripten", ignore)]
1414 #[cfg(not(miri))] // Miri does not support panics
1415 fn test_box_slice_clone_panics() {
1416     use std::sync::Arc;
1417     use std::sync::atomic::{AtomicUsize, Ordering};
1418     use std::thread::spawn;
1419
1420     struct Canary {
1421         count: Arc<AtomicUsize>,
1422         panics: bool,
1423     }
1424
1425     impl Drop for Canary {
1426         fn drop(&mut self) {
1427             self.count.fetch_add(1, Ordering::SeqCst);
1428         }
1429     }
1430
1431     impl Clone for Canary {
1432         fn clone(&self) -> Self {
1433             if self.panics {
1434                 panic!()
1435             }
1436
1437             Canary {
1438                 count: self.count.clone(),
1439                 panics: self.panics,
1440             }
1441         }
1442     }
1443
1444     let drop_count = Arc::new(AtomicUsize::new(0));
1445     let canary = Canary {
1446         count: drop_count.clone(),
1447         panics: false,
1448     };
1449     let panic = Canary {
1450         count: drop_count.clone(),
1451         panics: true,
1452     };
1453
1454     spawn(move || {
1455             // When xs is dropped, +5.
1456             let xs = vec![canary.clone(), canary.clone(), canary.clone(), panic, canary]
1457                 .into_boxed_slice();
1458
1459             // When panic is cloned, +3.
1460             xs.clone();
1461         })
1462         .join()
1463         .unwrap_err();
1464
1465     // Total = 8
1466     assert_eq!(drop_count.load(Ordering::SeqCst), 8);
1467 }
1468
1469 #[test]
1470 fn test_copy_from_slice() {
1471     let src = [0, 1, 2, 3, 4, 5];
1472     let mut dst = [0; 6];
1473     dst.copy_from_slice(&src);
1474     assert_eq!(src, dst)
1475 }
1476
1477 #[test]
1478 #[should_panic(expected = "destination and source slices have different lengths")]
1479 #[cfg(not(miri))] // Miri does not support panics
1480 fn test_copy_from_slice_dst_longer() {
1481     let src = [0, 1, 2, 3];
1482     let mut dst = [0; 5];
1483     dst.copy_from_slice(&src);
1484 }
1485
1486 #[test]
1487 #[should_panic(expected = "destination and source slices have different lengths")]
1488 #[cfg(not(miri))] // Miri does not support panics
1489 fn test_copy_from_slice_dst_shorter() {
1490     let src = [0, 1, 2, 3];
1491     let mut dst = [0; 3];
1492     dst.copy_from_slice(&src);
1493 }
1494
1495 const MAX_LEN: usize = 80;
1496
1497 static DROP_COUNTS: [AtomicUsize; MAX_LEN] = [
1498     // FIXME(RFC 1109): AtomicUsize is not Copy.
1499     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1500     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1501     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1502     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1503     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1504     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1505     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1506     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1507     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1508     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1509     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1510     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1511     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1512     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1513     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1514     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1515     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1516     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1517     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1518     AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
1519 ];
1520
1521 static VERSIONS: AtomicUsize = AtomicUsize::new(0);
1522
1523 #[derive(Clone, Eq)]
1524 struct DropCounter {
1525     x: u32,
1526     id: usize,
1527     version: Cell<usize>,
1528 }
1529
1530 impl PartialEq for DropCounter {
1531     fn eq(&self, other: &Self) -> bool {
1532         self.partial_cmp(other) == Some(Ordering::Equal)
1533     }
1534 }
1535
1536 impl PartialOrd for DropCounter {
1537     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1538         self.version.set(self.version.get() + 1);
1539         other.version.set(other.version.get() + 1);
1540         VERSIONS.fetch_add(2, Relaxed);
1541         self.x.partial_cmp(&other.x)
1542     }
1543 }
1544
1545 impl Ord for DropCounter {
1546     fn cmp(&self, other: &Self) -> Ordering {
1547         self.partial_cmp(other).unwrap()
1548     }
1549 }
1550
1551 impl Drop for DropCounter {
1552     fn drop(&mut self) {
1553         DROP_COUNTS[self.id].fetch_add(1, Relaxed);
1554         VERSIONS.fetch_sub(self.version.get(), Relaxed);
1555     }
1556 }
1557
1558 macro_rules! test {
1559     ($input:ident, $func:ident) => {
1560         let len = $input.len();
1561
1562         // Work out the total number of comparisons required to sort
1563         // this array...
1564         let mut count = 0usize;
1565         $input.to_owned().$func(|a, b| { count += 1; a.cmp(b) });
1566
1567         // ... and then panic on each and every single one.
1568         for panic_countdown in 0..count {
1569             // Refresh the counters.
1570             VERSIONS.store(0, Relaxed);
1571             for i in 0..len {
1572                 DROP_COUNTS[i].store(0, Relaxed);
1573             }
1574
1575             let v = $input.to_owned();
1576             let _ = thread::spawn(move || {
1577                 let mut v = v;
1578                 let mut panic_countdown = panic_countdown;
1579                 v.$func(|a, b| {
1580                     if panic_countdown == 0 {
1581                         SILENCE_PANIC.with(|s| s.set(true));
1582                         panic!();
1583                     }
1584                     panic_countdown -= 1;
1585                     a.cmp(b)
1586                 })
1587             }).join();
1588
1589             // Check that the number of things dropped is exactly
1590             // what we expect (i.e., the contents of `v`).
1591             for (i, c) in DROP_COUNTS.iter().enumerate().take(len) {
1592                 let count = c.load(Relaxed);
1593                 assert!(count == 1,
1594                         "found drop count == {} for i == {}, len == {}",
1595                         count, i, len);
1596             }
1597
1598             // Check that the most recent versions of values were dropped.
1599             assert_eq!(VERSIONS.load(Relaxed), 0);
1600         }
1601     }
1602 }
1603
1604 thread_local!(static SILENCE_PANIC: Cell<bool> = Cell::new(false));
1605
1606 #[test]
1607 #[cfg_attr(target_os = "emscripten", ignore)] // no threads
1608 #[cfg(not(miri))] // Miri does not support panics
1609 fn panic_safe() {
1610     let prev = panic::take_hook();
1611     panic::set_hook(Box::new(move |info| {
1612         if !SILENCE_PANIC.with(|s| s.get()) {
1613             prev(info);
1614         }
1615     }));
1616
1617     let mut rng = thread_rng();
1618
1619     for len in (1..20).chain(70..MAX_LEN) {
1620         for &modulus in &[5, 20, 50] {
1621             for &has_runs in &[false, true] {
1622                 let mut input = (0..len)
1623                     .map(|id| {
1624                         DropCounter {
1625                             x: rng.next_u32() % modulus,
1626                             id: id,
1627                             version: Cell::new(0),
1628                         }
1629                     })
1630                     .collect::<Vec<_>>();
1631
1632                 if has_runs {
1633                     for c in &mut input {
1634                         c.x = c.id as u32;
1635                     }
1636
1637                     for _ in 0..5 {
1638                         let a = rng.gen::<usize>() % len;
1639                         let b = rng.gen::<usize>() % len;
1640                         if a < b {
1641                             input[a..b].reverse();
1642                         } else {
1643                             input.swap(a, b);
1644                         }
1645                     }
1646                 }
1647
1648                 test!(input, sort_by);
1649                 test!(input, sort_unstable_by);
1650             }
1651         }
1652     }
1653 }
1654
1655 #[test]
1656 fn repeat_generic_slice() {
1657     assert_eq!([1, 2].repeat(2), vec![1, 2, 1, 2]);
1658     assert_eq!([1, 2, 3, 4].repeat(0), vec![]);
1659     assert_eq!([1, 2, 3, 4].repeat(1), vec![1, 2, 3, 4]);
1660     assert_eq!(
1661         [1, 2, 3, 4].repeat(3),
1662         vec![1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4]
1663     );
1664 }