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1 | // Copyright 2014 The Rust Project Developers. See the COPYRIGHT | |
2 | // file at the top-level directory of this distribution and at | |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | |
8 | // option. This file may not be copied, modified, or distributed | |
9 | // except according to those terms. | |
10 | ||
11 | use borrow::Borrow; | |
12 | use fmt; | |
13 | use hash::{Hash, BuildHasher}; | |
14 | use iter::{Chain, FromIterator}; | |
15 | use ops::{BitOr, BitAnd, BitXor, Sub}; | |
16 | ||
17 | use super::Recover; | |
18 | use super::map::{self, HashMap, Keys, RandomState}; | |
19 | ||
20 | const INITIAL_CAPACITY: usize = 32; | |
21 | ||
22 | // Future Optimization (FIXME!) | |
23 | // ============================= | |
24 | // | |
25 | // Iteration over zero sized values is a noop. There is no need | |
26 | // for `bucket.val` in the case of HashSet. I suppose we would need HKT | |
27 | // to get rid of it properly. | |
28 | ||
29 | /// An implementation of a hash set using the underlying representation of a | |
30 | /// HashMap where the value is (). | |
31 | /// | |
32 | /// As with the `HashMap` type, a `HashSet` requires that the elements | |
33 | /// implement the `Eq` and `Hash` traits. This can frequently be achieved by | |
34 | /// using `#[derive(PartialEq, Eq, Hash)]`. If you implement these yourself, | |
35 | /// it is important that the following property holds: | |
36 | /// | |
37 | /// ```text | |
38 | /// k1 == k2 -> hash(k1) == hash(k2) | |
39 | /// ``` | |
40 | /// | |
41 | /// In other words, if two keys are equal, their hashes must be equal. | |
42 | /// | |
43 | /// | |
44 | /// It is a logic error for an item to be modified in such a way that the | |
45 | /// item's hash, as determined by the `Hash` trait, or its equality, as | |
46 | /// determined by the `Eq` trait, changes while it is in the set. This is | |
47 | /// normally only possible through `Cell`, `RefCell`, global state, I/O, or | |
48 | /// unsafe code. | |
49 | /// | |
50 | /// # Examples | |
51 | /// | |
52 | /// ``` | |
53 | /// use std::collections::HashSet; | |
54 | /// // Type inference lets us omit an explicit type signature (which | |
55 | /// // would be `HashSet<&str>` in this example). | |
56 | /// let mut books = HashSet::new(); | |
57 | /// | |
58 | /// // Add some books. | |
59 | /// books.insert("A Dance With Dragons"); | |
60 | /// books.insert("To Kill a Mockingbird"); | |
61 | /// books.insert("The Odyssey"); | |
62 | /// books.insert("The Great Gatsby"); | |
63 | /// | |
64 | /// // Check for a specific one. | |
65 | /// if !books.contains("The Winds of Winter") { | |
66 | /// println!("We have {} books, but The Winds of Winter ain't one.", | |
67 | /// books.len()); | |
68 | /// } | |
69 | /// | |
70 | /// // Remove a book. | |
71 | /// books.remove("The Odyssey"); | |
72 | /// | |
73 | /// // Iterate over everything. | |
74 | /// for book in &books { | |
75 | /// println!("{}", book); | |
76 | /// } | |
77 | /// ``` | |
78 | /// | |
79 | /// The easiest way to use `HashSet` with a custom type is to derive | |
80 | /// `Eq` and `Hash`. We must also derive `PartialEq`, this will in the | |
81 | /// future be implied by `Eq`. | |
82 | /// | |
83 | /// ``` | |
84 | /// use std::collections::HashSet; | |
85 | /// #[derive(Hash, Eq, PartialEq, Debug)] | |
86 | /// struct Viking<'a> { | |
87 | /// name: &'a str, | |
88 | /// power: usize, | |
89 | /// } | |
90 | /// | |
91 | /// let mut vikings = HashSet::new(); | |
92 | /// | |
93 | /// vikings.insert(Viking { name: "Einar", power: 9 }); | |
94 | /// vikings.insert(Viking { name: "Einar", power: 9 }); | |
95 | /// vikings.insert(Viking { name: "Olaf", power: 4 }); | |
96 | /// vikings.insert(Viking { name: "Harald", power: 8 }); | |
97 | /// | |
98 | /// // Use derived implementation to print the vikings. | |
99 | /// for x in &vikings { | |
100 | /// println!("{:?}", x); | |
101 | /// } | |
102 | /// ``` | |
103 | #[derive(Clone)] | |
104 | #[stable(feature = "rust1", since = "1.0.0")] | |
105 | pub struct HashSet<T, S = RandomState> { | |
106 | map: HashMap<T, (), S> | |
107 | } | |
108 | ||
109 | impl<T: Hash + Eq> HashSet<T, RandomState> { | |
110 | /// Creates an empty HashSet. | |
111 | /// | |
112 | /// # Examples | |
113 | /// | |
114 | /// ``` | |
115 | /// use std::collections::HashSet; | |
116 | /// let mut set: HashSet<i32> = HashSet::new(); | |
117 | /// ``` | |
118 | #[inline] | |
119 | #[stable(feature = "rust1", since = "1.0.0")] | |
120 | pub fn new() -> HashSet<T, RandomState> { | |
121 | HashSet::with_capacity(INITIAL_CAPACITY) | |
122 | } | |
123 | ||
124 | /// Creates an empty HashSet with space for at least `n` elements in | |
125 | /// the hash table. | |
126 | /// | |
127 | /// # Examples | |
128 | /// | |
129 | /// ``` | |
130 | /// use std::collections::HashSet; | |
131 | /// let mut set: HashSet<i32> = HashSet::with_capacity(10); | |
132 | /// ``` | |
133 | #[inline] | |
134 | #[stable(feature = "rust1", since = "1.0.0")] | |
135 | pub fn with_capacity(capacity: usize) -> HashSet<T, RandomState> { | |
136 | HashSet { map: HashMap::with_capacity(capacity) } | |
137 | } | |
138 | } | |
139 | ||
140 | impl<T, S> HashSet<T, S> | |
141 | where T: Eq + Hash, S: BuildHasher | |
142 | { | |
143 | /// Creates a new empty hash set which will use the given hasher to hash | |
144 | /// keys. | |
145 | /// | |
146 | /// The hash set is also created with the default initial capacity. | |
147 | /// | |
148 | /// Warning: `hasher` is normally randomly generated, and | |
149 | /// is designed to allow `HashSet`s to be resistant to attacks that | |
150 | /// cause many collisions and very poor performance. Setting it | |
151 | /// manually using this function can expose a DoS attack vector. | |
152 | /// | |
153 | /// # Examples | |
154 | /// | |
155 | /// ``` | |
156 | /// use std::collections::HashSet; | |
157 | /// use std::collections::hash_map::RandomState; | |
158 | /// | |
159 | /// let s = RandomState::new(); | |
160 | /// let mut set = HashSet::with_hasher(s); | |
161 | /// set.insert(2); | |
162 | /// ``` | |
163 | #[inline] | |
164 | #[stable(feature = "hashmap_build_hasher", since = "1.7.0")] | |
165 | pub fn with_hasher(hasher: S) -> HashSet<T, S> { | |
166 | HashSet::with_capacity_and_hasher(INITIAL_CAPACITY, hasher) | |
167 | } | |
168 | ||
169 | /// Creates an empty HashSet with space for at least `capacity` | |
170 | /// elements in the hash table, using `hasher` to hash the keys. | |
171 | /// | |
172 | /// Warning: `hasher` is normally randomly generated, and | |
173 | /// is designed to allow `HashSet`s to be resistant to attacks that | |
174 | /// cause many collisions and very poor performance. Setting it | |
175 | /// manually using this function can expose a DoS attack vector. | |
176 | /// | |
177 | /// # Examples | |
178 | /// | |
179 | /// ``` | |
180 | /// use std::collections::HashSet; | |
181 | /// use std::collections::hash_map::RandomState; | |
182 | /// | |
183 | /// let s = RandomState::new(); | |
184 | /// let mut set = HashSet::with_capacity_and_hasher(10, s); | |
185 | /// set.insert(1); | |
186 | /// ``` | |
187 | #[inline] | |
188 | #[stable(feature = "hashmap_build_hasher", since = "1.7.0")] | |
189 | pub fn with_capacity_and_hasher(capacity: usize, hasher: S) | |
190 | -> HashSet<T, S> { | |
191 | HashSet { | |
192 | map: HashMap::with_capacity_and_hasher(capacity, hasher), | |
193 | } | |
194 | } | |
195 | ||
196 | /// Returns a reference to the set's hasher. | |
197 | #[stable(feature = "hashmap_public_hasher", since = "1.9.0")] | |
198 | pub fn hasher(&self) -> &S { | |
199 | self.map.hasher() | |
200 | } | |
201 | ||
202 | /// Returns the number of elements the set can hold without reallocating. | |
203 | /// | |
204 | /// # Examples | |
205 | /// | |
206 | /// ``` | |
207 | /// use std::collections::HashSet; | |
208 | /// let set: HashSet<i32> = HashSet::with_capacity(100); | |
209 | /// assert!(set.capacity() >= 100); | |
210 | /// ``` | |
211 | #[inline] | |
212 | #[stable(feature = "rust1", since = "1.0.0")] | |
213 | pub fn capacity(&self) -> usize { | |
214 | self.map.capacity() | |
215 | } | |
216 | ||
217 | /// Reserves capacity for at least `additional` more elements to be inserted | |
218 | /// in the `HashSet`. The collection may reserve more space to avoid | |
219 | /// frequent reallocations. | |
220 | /// | |
221 | /// # Panics | |
222 | /// | |
223 | /// Panics if the new allocation size overflows `usize`. | |
224 | /// | |
225 | /// # Examples | |
226 | /// | |
227 | /// ``` | |
228 | /// use std::collections::HashSet; | |
229 | /// let mut set: HashSet<i32> = HashSet::new(); | |
230 | /// set.reserve(10); | |
231 | /// ``` | |
232 | #[stable(feature = "rust1", since = "1.0.0")] | |
233 | pub fn reserve(&mut self, additional: usize) { | |
234 | self.map.reserve(additional) | |
235 | } | |
236 | ||
237 | /// Shrinks the capacity of the set as much as possible. It will drop | |
238 | /// down as much as possible while maintaining the internal rules | |
239 | /// and possibly leaving some space in accordance with the resize policy. | |
240 | /// | |
241 | /// # Examples | |
242 | /// | |
243 | /// ``` | |
244 | /// use std::collections::HashSet; | |
245 | /// | |
246 | /// let mut set = HashSet::with_capacity(100); | |
247 | /// set.insert(1); | |
248 | /// set.insert(2); | |
249 | /// assert!(set.capacity() >= 100); | |
250 | /// set.shrink_to_fit(); | |
251 | /// assert!(set.capacity() >= 2); | |
252 | /// ``` | |
253 | #[stable(feature = "rust1", since = "1.0.0")] | |
254 | pub fn shrink_to_fit(&mut self) { | |
255 | self.map.shrink_to_fit() | |
256 | } | |
257 | ||
258 | /// An iterator visiting all elements in arbitrary order. | |
259 | /// Iterator element type is &'a T. | |
260 | /// | |
261 | /// # Examples | |
262 | /// | |
263 | /// ``` | |
264 | /// use std::collections::HashSet; | |
265 | /// let mut set = HashSet::new(); | |
266 | /// set.insert("a"); | |
267 | /// set.insert("b"); | |
268 | /// | |
269 | /// // Will print in an arbitrary order. | |
270 | /// for x in set.iter() { | |
271 | /// println!("{}", x); | |
272 | /// } | |
273 | /// ``` | |
274 | #[stable(feature = "rust1", since = "1.0.0")] | |
275 | pub fn iter(&self) -> Iter<T> { | |
276 | Iter { iter: self.map.keys() } | |
277 | } | |
278 | ||
279 | /// Visit the values representing the difference. | |
280 | /// | |
281 | /// # Examples | |
282 | /// | |
283 | /// ``` | |
284 | /// use std::collections::HashSet; | |
285 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
286 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
287 | /// | |
288 | /// // Can be seen as `a - b`. | |
289 | /// for x in a.difference(&b) { | |
290 | /// println!("{}", x); // Print 1 | |
291 | /// } | |
292 | /// | |
293 | /// let diff: HashSet<_> = a.difference(&b).cloned().collect(); | |
294 | /// assert_eq!(diff, [1].iter().cloned().collect()); | |
295 | /// | |
296 | /// // Note that difference is not symmetric, | |
297 | /// // and `b - a` means something else: | |
298 | /// let diff: HashSet<_> = b.difference(&a).cloned().collect(); | |
299 | /// assert_eq!(diff, [4].iter().cloned().collect()); | |
300 | /// ``` | |
301 | #[stable(feature = "rust1", since = "1.0.0")] | |
302 | pub fn difference<'a>(&'a self, other: &'a HashSet<T, S>) -> Difference<'a, T, S> { | |
303 | Difference { | |
304 | iter: self.iter(), | |
305 | other: other, | |
306 | } | |
307 | } | |
308 | ||
309 | /// Visit the values representing the symmetric difference. | |
310 | /// | |
311 | /// # Examples | |
312 | /// | |
313 | /// ``` | |
314 | /// use std::collections::HashSet; | |
315 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
316 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
317 | /// | |
318 | /// // Print 1, 4 in arbitrary order. | |
319 | /// for x in a.symmetric_difference(&b) { | |
320 | /// println!("{}", x); | |
321 | /// } | |
322 | /// | |
323 | /// let diff1: HashSet<_> = a.symmetric_difference(&b).cloned().collect(); | |
324 | /// let diff2: HashSet<_> = b.symmetric_difference(&a).cloned().collect(); | |
325 | /// | |
326 | /// assert_eq!(diff1, diff2); | |
327 | /// assert_eq!(diff1, [1, 4].iter().cloned().collect()); | |
328 | /// ``` | |
329 | #[stable(feature = "rust1", since = "1.0.0")] | |
330 | pub fn symmetric_difference<'a>(&'a self, other: &'a HashSet<T, S>) | |
331 | -> SymmetricDifference<'a, T, S> { | |
332 | SymmetricDifference { iter: self.difference(other).chain(other.difference(self)) } | |
333 | } | |
334 | ||
335 | /// Visit the values representing the intersection. | |
336 | /// | |
337 | /// # Examples | |
338 | /// | |
339 | /// ``` | |
340 | /// use std::collections::HashSet; | |
341 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
342 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
343 | /// | |
344 | /// // Print 2, 3 in arbitrary order. | |
345 | /// for x in a.intersection(&b) { | |
346 | /// println!("{}", x); | |
347 | /// } | |
348 | /// | |
349 | /// let intersection: HashSet<_> = a.intersection(&b).cloned().collect(); | |
350 | /// assert_eq!(intersection, [2, 3].iter().cloned().collect()); | |
351 | /// ``` | |
352 | #[stable(feature = "rust1", since = "1.0.0")] | |
353 | pub fn intersection<'a>(&'a self, other: &'a HashSet<T, S>) -> Intersection<'a, T, S> { | |
354 | Intersection { | |
355 | iter: self.iter(), | |
356 | other: other, | |
357 | } | |
358 | } | |
359 | ||
360 | /// Visit the values representing the union. | |
361 | /// | |
362 | /// # Examples | |
363 | /// | |
364 | /// ``` | |
365 | /// use std::collections::HashSet; | |
366 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
367 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
368 | /// | |
369 | /// // Print 1, 2, 3, 4 in arbitrary order. | |
370 | /// for x in a.union(&b) { | |
371 | /// println!("{}", x); | |
372 | /// } | |
373 | /// | |
374 | /// let union: HashSet<_> = a.union(&b).cloned().collect(); | |
375 | /// assert_eq!(union, [1, 2, 3, 4].iter().cloned().collect()); | |
376 | /// ``` | |
377 | #[stable(feature = "rust1", since = "1.0.0")] | |
378 | pub fn union<'a>(&'a self, other: &'a HashSet<T, S>) -> Union<'a, T, S> { | |
379 | Union { iter: self.iter().chain(other.difference(self)) } | |
380 | } | |
381 | ||
382 | /// Returns the number of elements in the set. | |
383 | /// | |
384 | /// # Examples | |
385 | /// | |
386 | /// ``` | |
387 | /// use std::collections::HashSet; | |
388 | /// | |
389 | /// let mut v = HashSet::new(); | |
390 | /// assert_eq!(v.len(), 0); | |
391 | /// v.insert(1); | |
392 | /// assert_eq!(v.len(), 1); | |
393 | /// ``` | |
394 | #[stable(feature = "rust1", since = "1.0.0")] | |
395 | pub fn len(&self) -> usize { self.map.len() } | |
396 | ||
397 | /// Returns true if the set contains no elements. | |
398 | /// | |
399 | /// # Examples | |
400 | /// | |
401 | /// ``` | |
402 | /// use std::collections::HashSet; | |
403 | /// | |
404 | /// let mut v = HashSet::new(); | |
405 | /// assert!(v.is_empty()); | |
406 | /// v.insert(1); | |
407 | /// assert!(!v.is_empty()); | |
408 | /// ``` | |
409 | #[stable(feature = "rust1", since = "1.0.0")] | |
410 | pub fn is_empty(&self) -> bool { self.map.is_empty() } | |
411 | ||
412 | /// Clears the set, returning all elements in an iterator. | |
413 | #[inline] | |
414 | #[stable(feature = "drain", since = "1.6.0")] | |
415 | pub fn drain(&mut self) -> Drain<T> { | |
416 | Drain { iter: self.map.drain() } | |
417 | } | |
418 | ||
419 | /// Clears the set, removing all values. | |
420 | /// | |
421 | /// # Examples | |
422 | /// | |
423 | /// ``` | |
424 | /// use std::collections::HashSet; | |
425 | /// | |
426 | /// let mut v = HashSet::new(); | |
427 | /// v.insert(1); | |
428 | /// v.clear(); | |
429 | /// assert!(v.is_empty()); | |
430 | /// ``` | |
431 | #[stable(feature = "rust1", since = "1.0.0")] | |
432 | pub fn clear(&mut self) { self.map.clear() } | |
433 | ||
434 | /// Returns `true` if the set contains a value. | |
435 | /// | |
436 | /// The value may be any borrowed form of the set's value type, but | |
437 | /// `Hash` and `Eq` on the borrowed form *must* match those for | |
438 | /// the value type. | |
439 | /// | |
440 | /// # Examples | |
441 | /// | |
442 | /// ``` | |
443 | /// use std::collections::HashSet; | |
444 | /// | |
445 | /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
446 | /// assert_eq!(set.contains(&1), true); | |
447 | /// assert_eq!(set.contains(&4), false); | |
448 | /// ``` | |
449 | #[stable(feature = "rust1", since = "1.0.0")] | |
450 | pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool | |
451 | where T: Borrow<Q>, Q: Hash + Eq | |
452 | { | |
453 | self.map.contains_key(value) | |
454 | } | |
455 | ||
456 | /// Returns a reference to the value in the set, if any, that is equal to the given value. | |
457 | /// | |
458 | /// The value may be any borrowed form of the set's value type, but | |
459 | /// `Hash` and `Eq` on the borrowed form *must* match those for | |
460 | /// the value type. | |
461 | #[stable(feature = "set_recovery", since = "1.9.0")] | |
462 | pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T> | |
463 | where T: Borrow<Q>, Q: Hash + Eq | |
464 | { | |
465 | Recover::get(&self.map, value) | |
466 | } | |
467 | ||
468 | /// Returns `true` if the set has no elements in common with `other`. | |
469 | /// This is equivalent to checking for an empty intersection. | |
470 | /// | |
471 | /// # Examples | |
472 | /// | |
473 | /// ``` | |
474 | /// use std::collections::HashSet; | |
475 | /// | |
476 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
477 | /// let mut b = HashSet::new(); | |
478 | /// | |
479 | /// assert_eq!(a.is_disjoint(&b), true); | |
480 | /// b.insert(4); | |
481 | /// assert_eq!(a.is_disjoint(&b), true); | |
482 | /// b.insert(1); | |
483 | /// assert_eq!(a.is_disjoint(&b), false); | |
484 | /// ``` | |
485 | #[stable(feature = "rust1", since = "1.0.0")] | |
486 | pub fn is_disjoint(&self, other: &HashSet<T, S>) -> bool { | |
487 | self.iter().all(|v| !other.contains(v)) | |
488 | } | |
489 | ||
490 | /// Returns `true` if the set is a subset of another. | |
491 | /// | |
492 | /// # Examples | |
493 | /// | |
494 | /// ``` | |
495 | /// use std::collections::HashSet; | |
496 | /// | |
497 | /// let sup: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
498 | /// let mut set = HashSet::new(); | |
499 | /// | |
500 | /// assert_eq!(set.is_subset(&sup), true); | |
501 | /// set.insert(2); | |
502 | /// assert_eq!(set.is_subset(&sup), true); | |
503 | /// set.insert(4); | |
504 | /// assert_eq!(set.is_subset(&sup), false); | |
505 | /// ``` | |
506 | #[stable(feature = "rust1", since = "1.0.0")] | |
507 | pub fn is_subset(&self, other: &HashSet<T, S>) -> bool { | |
508 | self.iter().all(|v| other.contains(v)) | |
509 | } | |
510 | ||
511 | /// Returns `true` if the set is a superset of another. | |
512 | /// | |
513 | /// # Examples | |
514 | /// | |
515 | /// ``` | |
516 | /// use std::collections::HashSet; | |
517 | /// | |
518 | /// let sub: HashSet<_> = [1, 2].iter().cloned().collect(); | |
519 | /// let mut set = HashSet::new(); | |
520 | /// | |
521 | /// assert_eq!(set.is_superset(&sub), false); | |
522 | /// | |
523 | /// set.insert(0); | |
524 | /// set.insert(1); | |
525 | /// assert_eq!(set.is_superset(&sub), false); | |
526 | /// | |
527 | /// set.insert(2); | |
528 | /// assert_eq!(set.is_superset(&sub), true); | |
529 | /// ``` | |
530 | #[inline] | |
531 | #[stable(feature = "rust1", since = "1.0.0")] | |
532 | pub fn is_superset(&self, other: &HashSet<T, S>) -> bool { | |
533 | other.is_subset(self) | |
534 | } | |
535 | ||
536 | /// Adds a value to the set. | |
537 | /// | |
538 | /// If the set did not have this value present, `true` is returned. | |
539 | /// | |
540 | /// If the set did have this value present, `false` is returned. | |
541 | /// | |
542 | /// # Examples | |
543 | /// | |
544 | /// ``` | |
545 | /// use std::collections::HashSet; | |
546 | /// | |
547 | /// let mut set = HashSet::new(); | |
548 | /// | |
549 | /// assert_eq!(set.insert(2), true); | |
550 | /// assert_eq!(set.insert(2), false); | |
551 | /// assert_eq!(set.len(), 1); | |
552 | /// ``` | |
553 | #[stable(feature = "rust1", since = "1.0.0")] | |
554 | pub fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()).is_none() } | |
555 | ||
556 | /// Adds a value to the set, replacing the existing value, if any, that is equal to the given | |
557 | /// one. Returns the replaced value. | |
558 | #[stable(feature = "set_recovery", since = "1.9.0")] | |
559 | pub fn replace(&mut self, value: T) -> Option<T> { | |
560 | Recover::replace(&mut self.map, value) | |
561 | } | |
562 | ||
563 | /// Removes a value from the set. Returns `true` if the value was | |
564 | /// present in the set. | |
565 | /// | |
566 | /// The value may be any borrowed form of the set's value type, but | |
567 | /// `Hash` and `Eq` on the borrowed form *must* match those for | |
568 | /// the value type. | |
569 | /// | |
570 | /// # Examples | |
571 | /// | |
572 | /// ``` | |
573 | /// use std::collections::HashSet; | |
574 | /// | |
575 | /// let mut set = HashSet::new(); | |
576 | /// | |
577 | /// set.insert(2); | |
578 | /// assert_eq!(set.remove(&2), true); | |
579 | /// assert_eq!(set.remove(&2), false); | |
580 | /// ``` | |
581 | #[stable(feature = "rust1", since = "1.0.0")] | |
582 | pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool | |
583 | where T: Borrow<Q>, Q: Hash + Eq | |
584 | { | |
585 | self.map.remove(value).is_some() | |
586 | } | |
587 | ||
588 | /// Removes and returns the value in the set, if any, that is equal to the given one. | |
589 | /// | |
590 | /// The value may be any borrowed form of the set's value type, but | |
591 | /// `Hash` and `Eq` on the borrowed form *must* match those for | |
592 | /// the value type. | |
593 | #[stable(feature = "set_recovery", since = "1.9.0")] | |
594 | pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T> | |
595 | where T: Borrow<Q>, Q: Hash + Eq | |
596 | { | |
597 | Recover::take(&mut self.map, value) | |
598 | } | |
599 | } | |
600 | ||
601 | #[stable(feature = "rust1", since = "1.0.0")] | |
602 | impl<T, S> PartialEq for HashSet<T, S> | |
603 | where T: Eq + Hash, S: BuildHasher | |
604 | { | |
605 | fn eq(&self, other: &HashSet<T, S>) -> bool { | |
606 | if self.len() != other.len() { return false; } | |
607 | ||
608 | self.iter().all(|key| other.contains(key)) | |
609 | } | |
610 | } | |
611 | ||
612 | #[stable(feature = "rust1", since = "1.0.0")] | |
613 | impl<T, S> Eq for HashSet<T, S> | |
614 | where T: Eq + Hash, S: BuildHasher | |
615 | {} | |
616 | ||
617 | #[stable(feature = "rust1", since = "1.0.0")] | |
618 | impl<T, S> fmt::Debug for HashSet<T, S> | |
619 | where T: Eq + Hash + fmt::Debug, | |
620 | S: BuildHasher | |
621 | { | |
622 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
623 | f.debug_set().entries(self.iter()).finish() | |
624 | } | |
625 | } | |
626 | ||
627 | #[stable(feature = "rust1", since = "1.0.0")] | |
628 | impl<T, S> FromIterator<T> for HashSet<T, S> | |
629 | where T: Eq + Hash, | |
630 | S: BuildHasher + Default, | |
631 | { | |
632 | fn from_iter<I: IntoIterator<Item=T>>(iter: I) -> HashSet<T, S> { | |
633 | let iterator = iter.into_iter(); | |
634 | let lower = iterator.size_hint().0; | |
635 | let mut set = HashSet::with_capacity_and_hasher(lower, Default::default()); | |
636 | set.extend(iterator); | |
637 | set | |
638 | } | |
639 | } | |
640 | ||
641 | #[stable(feature = "rust1", since = "1.0.0")] | |
642 | impl<T, S> Extend<T> for HashSet<T, S> | |
643 | where T: Eq + Hash, | |
644 | S: BuildHasher, | |
645 | { | |
646 | fn extend<I: IntoIterator<Item=T>>(&mut self, iter: I) { | |
647 | for k in iter { | |
648 | self.insert(k); | |
649 | } | |
650 | } | |
651 | } | |
652 | ||
653 | #[stable(feature = "hash_extend_copy", since = "1.4.0")] | |
654 | impl<'a, T, S> Extend<&'a T> for HashSet<T, S> | |
655 | where T: 'a + Eq + Hash + Copy, | |
656 | S: BuildHasher, | |
657 | { | |
658 | fn extend<I: IntoIterator<Item=&'a T>>(&mut self, iter: I) { | |
659 | self.extend(iter.into_iter().cloned()); | |
660 | } | |
661 | } | |
662 | ||
663 | #[stable(feature = "rust1", since = "1.0.0")] | |
664 | impl<T, S> Default for HashSet<T, S> | |
665 | where T: Eq + Hash, | |
666 | S: BuildHasher + Default, | |
667 | { | |
668 | fn default() -> HashSet<T, S> { | |
669 | HashSet::with_hasher(Default::default()) | |
670 | } | |
671 | } | |
672 | ||
673 | #[stable(feature = "rust1", since = "1.0.0")] | |
674 | impl<'a, 'b, T, S> BitOr<&'b HashSet<T, S>> for &'a HashSet<T, S> | |
675 | where T: Eq + Hash + Clone, | |
676 | S: BuildHasher + Default, | |
677 | { | |
678 | type Output = HashSet<T, S>; | |
679 | ||
680 | /// Returns the union of `self` and `rhs` as a new `HashSet<T, S>`. | |
681 | /// | |
682 | /// # Examples | |
683 | /// | |
684 | /// ``` | |
685 | /// use std::collections::HashSet; | |
686 | /// | |
687 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); | |
688 | /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); | |
689 | /// | |
690 | /// let set = &a | &b; | |
691 | /// | |
692 | /// let mut i = 0; | |
693 | /// let expected = [1, 2, 3, 4, 5]; | |
694 | /// for x in &set { | |
695 | /// assert!(expected.contains(x)); | |
696 | /// i += 1; | |
697 | /// } | |
698 | /// assert_eq!(i, expected.len()); | |
699 | /// ``` | |
700 | fn bitor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
701 | self.union(rhs).cloned().collect() | |
702 | } | |
703 | } | |
704 | ||
705 | #[stable(feature = "rust1", since = "1.0.0")] | |
706 | impl<'a, 'b, T, S> BitAnd<&'b HashSet<T, S>> for &'a HashSet<T, S> | |
707 | where T: Eq + Hash + Clone, | |
708 | S: BuildHasher + Default, | |
709 | { | |
710 | type Output = HashSet<T, S>; | |
711 | ||
712 | /// Returns the intersection of `self` and `rhs` as a new `HashSet<T, S>`. | |
713 | /// | |
714 | /// # Examples | |
715 | /// | |
716 | /// ``` | |
717 | /// use std::collections::HashSet; | |
718 | /// | |
719 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); | |
720 | /// let b: HashSet<_> = vec![2, 3, 4].into_iter().collect(); | |
721 | /// | |
722 | /// let set = &a & &b; | |
723 | /// | |
724 | /// let mut i = 0; | |
725 | /// let expected = [2, 3]; | |
726 | /// for x in &set { | |
727 | /// assert!(expected.contains(x)); | |
728 | /// i += 1; | |
729 | /// } | |
730 | /// assert_eq!(i, expected.len()); | |
731 | /// ``` | |
732 | fn bitand(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
733 | self.intersection(rhs).cloned().collect() | |
734 | } | |
735 | } | |
736 | ||
737 | #[stable(feature = "rust1", since = "1.0.0")] | |
738 | impl<'a, 'b, T, S> BitXor<&'b HashSet<T, S>> for &'a HashSet<T, S> | |
739 | where T: Eq + Hash + Clone, | |
740 | S: BuildHasher + Default, | |
741 | { | |
742 | type Output = HashSet<T, S>; | |
743 | ||
744 | /// Returns the symmetric difference of `self` and `rhs` as a new `HashSet<T, S>`. | |
745 | /// | |
746 | /// # Examples | |
747 | /// | |
748 | /// ``` | |
749 | /// use std::collections::HashSet; | |
750 | /// | |
751 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); | |
752 | /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); | |
753 | /// | |
754 | /// let set = &a ^ &b; | |
755 | /// | |
756 | /// let mut i = 0; | |
757 | /// let expected = [1, 2, 4, 5]; | |
758 | /// for x in &set { | |
759 | /// assert!(expected.contains(x)); | |
760 | /// i += 1; | |
761 | /// } | |
762 | /// assert_eq!(i, expected.len()); | |
763 | /// ``` | |
764 | fn bitxor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
765 | self.symmetric_difference(rhs).cloned().collect() | |
766 | } | |
767 | } | |
768 | ||
769 | #[stable(feature = "rust1", since = "1.0.0")] | |
770 | impl<'a, 'b, T, S> Sub<&'b HashSet<T, S>> for &'a HashSet<T, S> | |
771 | where T: Eq + Hash + Clone, | |
772 | S: BuildHasher + Default, | |
773 | { | |
774 | type Output = HashSet<T, S>; | |
775 | ||
776 | /// Returns the difference of `self` and `rhs` as a new `HashSet<T, S>`. | |
777 | /// | |
778 | /// # Examples | |
779 | /// | |
780 | /// ``` | |
781 | /// use std::collections::HashSet; | |
782 | /// | |
783 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); | |
784 | /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); | |
785 | /// | |
786 | /// let set = &a - &b; | |
787 | /// | |
788 | /// let mut i = 0; | |
789 | /// let expected = [1, 2]; | |
790 | /// for x in &set { | |
791 | /// assert!(expected.contains(x)); | |
792 | /// i += 1; | |
793 | /// } | |
794 | /// assert_eq!(i, expected.len()); | |
795 | /// ``` | |
796 | fn sub(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
797 | self.difference(rhs).cloned().collect() | |
798 | } | |
799 | } | |
800 | ||
801 | /// HashSet iterator | |
802 | #[stable(feature = "rust1", since = "1.0.0")] | |
803 | pub struct Iter<'a, K: 'a> { | |
804 | iter: Keys<'a, K, ()> | |
805 | } | |
806 | ||
807 | /// HashSet move iterator | |
808 | #[stable(feature = "rust1", since = "1.0.0")] | |
809 | pub struct IntoIter<K> { | |
810 | iter: map::IntoIter<K, ()> | |
811 | } | |
812 | ||
813 | /// HashSet drain iterator | |
814 | #[stable(feature = "rust1", since = "1.0.0")] | |
815 | pub struct Drain<'a, K: 'a> { | |
816 | iter: map::Drain<'a, K, ()>, | |
817 | } | |
818 | ||
819 | /// Intersection iterator | |
820 | #[stable(feature = "rust1", since = "1.0.0")] | |
821 | pub struct Intersection<'a, T: 'a, S: 'a> { | |
822 | // iterator of the first set | |
823 | iter: Iter<'a, T>, | |
824 | // the second set | |
825 | other: &'a HashSet<T, S>, | |
826 | } | |
827 | ||
828 | /// Difference iterator | |
829 | #[stable(feature = "rust1", since = "1.0.0")] | |
830 | pub struct Difference<'a, T: 'a, S: 'a> { | |
831 | // iterator of the first set | |
832 | iter: Iter<'a, T>, | |
833 | // the second set | |
834 | other: &'a HashSet<T, S>, | |
835 | } | |
836 | ||
837 | /// Symmetric difference iterator. | |
838 | #[stable(feature = "rust1", since = "1.0.0")] | |
839 | pub struct SymmetricDifference<'a, T: 'a, S: 'a> { | |
840 | iter: Chain<Difference<'a, T, S>, Difference<'a, T, S>> | |
841 | } | |
842 | ||
843 | /// Set union iterator. | |
844 | #[stable(feature = "rust1", since = "1.0.0")] | |
845 | pub struct Union<'a, T: 'a, S: 'a> { | |
846 | iter: Chain<Iter<'a, T>, Difference<'a, T, S>> | |
847 | } | |
848 | ||
849 | #[stable(feature = "rust1", since = "1.0.0")] | |
850 | impl<'a, T, S> IntoIterator for &'a HashSet<T, S> | |
851 | where T: Eq + Hash, S: BuildHasher | |
852 | { | |
853 | type Item = &'a T; | |
854 | type IntoIter = Iter<'a, T>; | |
855 | ||
856 | fn into_iter(self) -> Iter<'a, T> { | |
857 | self.iter() | |
858 | } | |
859 | } | |
860 | ||
861 | #[stable(feature = "rust1", since = "1.0.0")] | |
862 | impl<T, S> IntoIterator for HashSet<T, S> | |
863 | where T: Eq + Hash, | |
864 | S: BuildHasher | |
865 | { | |
866 | type Item = T; | |
867 | type IntoIter = IntoIter<T>; | |
868 | ||
869 | /// Creates a consuming iterator, that is, one that moves each value out | |
870 | /// of the set in arbitrary order. The set cannot be used after calling | |
871 | /// this. | |
872 | /// | |
873 | /// # Examples | |
874 | /// | |
875 | /// ``` | |
876 | /// use std::collections::HashSet; | |
877 | /// let mut set = HashSet::new(); | |
878 | /// set.insert("a".to_string()); | |
879 | /// set.insert("b".to_string()); | |
880 | /// | |
881 | /// // Not possible to collect to a Vec<String> with a regular `.iter()`. | |
882 | /// let v: Vec<String> = set.into_iter().collect(); | |
883 | /// | |
884 | /// // Will print in an arbitrary order. | |
885 | /// for x in &v { | |
886 | /// println!("{}", x); | |
887 | /// } | |
888 | /// ``` | |
889 | fn into_iter(self) -> IntoIter<T> { | |
890 | IntoIter { iter: self.map.into_iter() } | |
891 | } | |
892 | } | |
893 | ||
894 | #[stable(feature = "rust1", since = "1.0.0")] | |
895 | impl<'a, K> Clone for Iter<'a, K> { | |
896 | fn clone(&self) -> Iter<'a, K> { Iter { iter: self.iter.clone() } } | |
897 | } | |
898 | #[stable(feature = "rust1", since = "1.0.0")] | |
899 | impl<'a, K> Iterator for Iter<'a, K> { | |
900 | type Item = &'a K; | |
901 | ||
902 | fn next(&mut self) -> Option<&'a K> { self.iter.next() } | |
903 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } | |
904 | } | |
905 | #[stable(feature = "rust1", since = "1.0.0")] | |
906 | impl<'a, K> ExactSizeIterator for Iter<'a, K> { | |
907 | fn len(&self) -> usize { self.iter.len() } | |
908 | } | |
909 | ||
910 | #[stable(feature = "rust1", since = "1.0.0")] | |
911 | impl<K> Iterator for IntoIter<K> { | |
912 | type Item = K; | |
913 | ||
914 | fn next(&mut self) -> Option<K> { self.iter.next().map(|(k, _)| k) } | |
915 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } | |
916 | } | |
917 | #[stable(feature = "rust1", since = "1.0.0")] | |
918 | impl<K> ExactSizeIterator for IntoIter<K> { | |
919 | fn len(&self) -> usize { self.iter.len() } | |
920 | } | |
921 | ||
922 | #[stable(feature = "rust1", since = "1.0.0")] | |
923 | impl<'a, K> Iterator for Drain<'a, K> { | |
924 | type Item = K; | |
925 | ||
926 | fn next(&mut self) -> Option<K> { self.iter.next().map(|(k, _)| k) } | |
927 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } | |
928 | } | |
929 | #[stable(feature = "rust1", since = "1.0.0")] | |
930 | impl<'a, K> ExactSizeIterator for Drain<'a, K> { | |
931 | fn len(&self) -> usize { self.iter.len() } | |
932 | } | |
933 | ||
934 | #[stable(feature = "rust1", since = "1.0.0")] | |
935 | impl<'a, T, S> Clone for Intersection<'a, T, S> { | |
936 | fn clone(&self) -> Intersection<'a, T, S> { | |
937 | Intersection { iter: self.iter.clone(), ..*self } | |
938 | } | |
939 | } | |
940 | ||
941 | #[stable(feature = "rust1", since = "1.0.0")] | |
942 | impl<'a, T, S> Iterator for Intersection<'a, T, S> | |
943 | where T: Eq + Hash, S: BuildHasher | |
944 | { | |
945 | type Item = &'a T; | |
946 | ||
947 | fn next(&mut self) -> Option<&'a T> { | |
948 | loop { | |
949 | match self.iter.next() { | |
950 | None => return None, | |
951 | Some(elt) => if self.other.contains(elt) { | |
952 | return Some(elt) | |
953 | }, | |
954 | } | |
955 | } | |
956 | } | |
957 | ||
958 | fn size_hint(&self) -> (usize, Option<usize>) { | |
959 | let (_, upper) = self.iter.size_hint(); | |
960 | (0, upper) | |
961 | } | |
962 | } | |
963 | ||
964 | #[stable(feature = "rust1", since = "1.0.0")] | |
965 | impl<'a, T, S> Clone for Difference<'a, T, S> { | |
966 | fn clone(&self) -> Difference<'a, T, S> { | |
967 | Difference { iter: self.iter.clone(), ..*self } | |
968 | } | |
969 | } | |
970 | ||
971 | #[stable(feature = "rust1", since = "1.0.0")] | |
972 | impl<'a, T, S> Iterator for Difference<'a, T, S> | |
973 | where T: Eq + Hash, S: BuildHasher | |
974 | { | |
975 | type Item = &'a T; | |
976 | ||
977 | fn next(&mut self) -> Option<&'a T> { | |
978 | loop { | |
979 | match self.iter.next() { | |
980 | None => return None, | |
981 | Some(elt) => if !self.other.contains(elt) { | |
982 | return Some(elt) | |
983 | }, | |
984 | } | |
985 | } | |
986 | } | |
987 | ||
988 | fn size_hint(&self) -> (usize, Option<usize>) { | |
989 | let (_, upper) = self.iter.size_hint(); | |
990 | (0, upper) | |
991 | } | |
992 | } | |
993 | ||
994 | #[stable(feature = "rust1", since = "1.0.0")] | |
995 | impl<'a, T, S> Clone for SymmetricDifference<'a, T, S> { | |
996 | fn clone(&self) -> SymmetricDifference<'a, T, S> { | |
997 | SymmetricDifference { iter: self.iter.clone() } | |
998 | } | |
999 | } | |
1000 | ||
1001 | #[stable(feature = "rust1", since = "1.0.0")] | |
1002 | impl<'a, T, S> Iterator for SymmetricDifference<'a, T, S> | |
1003 | where T: Eq + Hash, S: BuildHasher | |
1004 | { | |
1005 | type Item = &'a T; | |
1006 | ||
1007 | fn next(&mut self) -> Option<&'a T> { self.iter.next() } | |
1008 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } | |
1009 | } | |
1010 | ||
1011 | #[stable(feature = "rust1", since = "1.0.0")] | |
1012 | impl<'a, T, S> Clone for Union<'a, T, S> { | |
1013 | fn clone(&self) -> Union<'a, T, S> { Union { iter: self.iter.clone() } } | |
1014 | } | |
1015 | ||
1016 | #[stable(feature = "rust1", since = "1.0.0")] | |
1017 | impl<'a, T, S> Iterator for Union<'a, T, S> | |
1018 | where T: Eq + Hash, S: BuildHasher | |
1019 | { | |
1020 | type Item = &'a T; | |
1021 | ||
1022 | fn next(&mut self) -> Option<&'a T> { self.iter.next() } | |
1023 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } | |
1024 | } | |
1025 | ||
1026 | #[allow(dead_code)] | |
1027 | fn assert_covariance() { | |
1028 | fn set<'new>(v: HashSet<&'static str>) -> HashSet<&'new str> { v } | |
1029 | fn iter<'a, 'new>(v: Iter<'a, &'static str>) -> Iter<'a, &'new str> { v } | |
1030 | fn into_iter<'new>(v: IntoIter<&'static str>) -> IntoIter<&'new str> { v } | |
1031 | fn difference<'a, 'new>(v: Difference<'a, &'static str, RandomState>) | |
1032 | -> Difference<'a, &'new str, RandomState> { v } | |
1033 | fn symmetric_difference<'a, 'new>(v: SymmetricDifference<'a, &'static str, RandomState>) | |
1034 | -> SymmetricDifference<'a, &'new str, RandomState> { v } | |
1035 | fn intersection<'a, 'new>(v: Intersection<'a, &'static str, RandomState>) | |
1036 | -> Intersection<'a, &'new str, RandomState> { v } | |
1037 | fn union<'a, 'new>(v: Union<'a, &'static str, RandomState>) | |
1038 | -> Union<'a, &'new str, RandomState> { v } | |
1039 | } | |
1040 | ||
1041 | #[cfg(test)] | |
1042 | mod test_set { | |
1043 | use prelude::v1::*; | |
1044 | ||
1045 | use super::HashSet; | |
1046 | ||
1047 | #[test] | |
1048 | fn test_disjoint() { | |
1049 | let mut xs = HashSet::new(); | |
1050 | let mut ys = HashSet::new(); | |
1051 | assert!(xs.is_disjoint(&ys)); | |
1052 | assert!(ys.is_disjoint(&xs)); | |
1053 | assert!(xs.insert(5)); | |
1054 | assert!(ys.insert(11)); | |
1055 | assert!(xs.is_disjoint(&ys)); | |
1056 | assert!(ys.is_disjoint(&xs)); | |
1057 | assert!(xs.insert(7)); | |
1058 | assert!(xs.insert(19)); | |
1059 | assert!(xs.insert(4)); | |
1060 | assert!(ys.insert(2)); | |
1061 | assert!(ys.insert(-11)); | |
1062 | assert!(xs.is_disjoint(&ys)); | |
1063 | assert!(ys.is_disjoint(&xs)); | |
1064 | assert!(ys.insert(7)); | |
1065 | assert!(!xs.is_disjoint(&ys)); | |
1066 | assert!(!ys.is_disjoint(&xs)); | |
1067 | } | |
1068 | ||
1069 | #[test] | |
1070 | fn test_subset_and_superset() { | |
1071 | let mut a = HashSet::new(); | |
1072 | assert!(a.insert(0)); | |
1073 | assert!(a.insert(5)); | |
1074 | assert!(a.insert(11)); | |
1075 | assert!(a.insert(7)); | |
1076 | ||
1077 | let mut b = HashSet::new(); | |
1078 | assert!(b.insert(0)); | |
1079 | assert!(b.insert(7)); | |
1080 | assert!(b.insert(19)); | |
1081 | assert!(b.insert(250)); | |
1082 | assert!(b.insert(11)); | |
1083 | assert!(b.insert(200)); | |
1084 | ||
1085 | assert!(!a.is_subset(&b)); | |
1086 | assert!(!a.is_superset(&b)); | |
1087 | assert!(!b.is_subset(&a)); | |
1088 | assert!(!b.is_superset(&a)); | |
1089 | ||
1090 | assert!(b.insert(5)); | |
1091 | ||
1092 | assert!(a.is_subset(&b)); | |
1093 | assert!(!a.is_superset(&b)); | |
1094 | assert!(!b.is_subset(&a)); | |
1095 | assert!(b.is_superset(&a)); | |
1096 | } | |
1097 | ||
1098 | #[test] | |
1099 | fn test_iterate() { | |
1100 | let mut a = HashSet::new(); | |
1101 | for i in 0..32 { | |
1102 | assert!(a.insert(i)); | |
1103 | } | |
1104 | let mut observed: u32 = 0; | |
1105 | for k in &a { | |
1106 | observed |= 1 << *k; | |
1107 | } | |
1108 | assert_eq!(observed, 0xFFFF_FFFF); | |
1109 | } | |
1110 | ||
1111 | #[test] | |
1112 | fn test_intersection() { | |
1113 | let mut a = HashSet::new(); | |
1114 | let mut b = HashSet::new(); | |
1115 | ||
1116 | assert!(a.insert(11)); | |
1117 | assert!(a.insert(1)); | |
1118 | assert!(a.insert(3)); | |
1119 | assert!(a.insert(77)); | |
1120 | assert!(a.insert(103)); | |
1121 | assert!(a.insert(5)); | |
1122 | assert!(a.insert(-5)); | |
1123 | ||
1124 | assert!(b.insert(2)); | |
1125 | assert!(b.insert(11)); | |
1126 | assert!(b.insert(77)); | |
1127 | assert!(b.insert(-9)); | |
1128 | assert!(b.insert(-42)); | |
1129 | assert!(b.insert(5)); | |
1130 | assert!(b.insert(3)); | |
1131 | ||
1132 | let mut i = 0; | |
1133 | let expected = [3, 5, 11, 77]; | |
1134 | for x in a.intersection(&b) { | |
1135 | assert!(expected.contains(x)); | |
1136 | i += 1 | |
1137 | } | |
1138 | assert_eq!(i, expected.len()); | |
1139 | } | |
1140 | ||
1141 | #[test] | |
1142 | fn test_difference() { | |
1143 | let mut a = HashSet::new(); | |
1144 | let mut b = HashSet::new(); | |
1145 | ||
1146 | assert!(a.insert(1)); | |
1147 | assert!(a.insert(3)); | |
1148 | assert!(a.insert(5)); | |
1149 | assert!(a.insert(9)); | |
1150 | assert!(a.insert(11)); | |
1151 | ||
1152 | assert!(b.insert(3)); | |
1153 | assert!(b.insert(9)); | |
1154 | ||
1155 | let mut i = 0; | |
1156 | let expected = [1, 5, 11]; | |
1157 | for x in a.difference(&b) { | |
1158 | assert!(expected.contains(x)); | |
1159 | i += 1 | |
1160 | } | |
1161 | assert_eq!(i, expected.len()); | |
1162 | } | |
1163 | ||
1164 | #[test] | |
1165 | fn test_symmetric_difference() { | |
1166 | let mut a = HashSet::new(); | |
1167 | let mut b = HashSet::new(); | |
1168 | ||
1169 | assert!(a.insert(1)); | |
1170 | assert!(a.insert(3)); | |
1171 | assert!(a.insert(5)); | |
1172 | assert!(a.insert(9)); | |
1173 | assert!(a.insert(11)); | |
1174 | ||
1175 | assert!(b.insert(-2)); | |
1176 | assert!(b.insert(3)); | |
1177 | assert!(b.insert(9)); | |
1178 | assert!(b.insert(14)); | |
1179 | assert!(b.insert(22)); | |
1180 | ||
1181 | let mut i = 0; | |
1182 | let expected = [-2, 1, 5, 11, 14, 22]; | |
1183 | for x in a.symmetric_difference(&b) { | |
1184 | assert!(expected.contains(x)); | |
1185 | i += 1 | |
1186 | } | |
1187 | assert_eq!(i, expected.len()); | |
1188 | } | |
1189 | ||
1190 | #[test] | |
1191 | fn test_union() { | |
1192 | let mut a = HashSet::new(); | |
1193 | let mut b = HashSet::new(); | |
1194 | ||
1195 | assert!(a.insert(1)); | |
1196 | assert!(a.insert(3)); | |
1197 | assert!(a.insert(5)); | |
1198 | assert!(a.insert(9)); | |
1199 | assert!(a.insert(11)); | |
1200 | assert!(a.insert(16)); | |
1201 | assert!(a.insert(19)); | |
1202 | assert!(a.insert(24)); | |
1203 | ||
1204 | assert!(b.insert(-2)); | |
1205 | assert!(b.insert(1)); | |
1206 | assert!(b.insert(5)); | |
1207 | assert!(b.insert(9)); | |
1208 | assert!(b.insert(13)); | |
1209 | assert!(b.insert(19)); | |
1210 | ||
1211 | let mut i = 0; | |
1212 | let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24]; | |
1213 | for x in a.union(&b) { | |
1214 | assert!(expected.contains(x)); | |
1215 | i += 1 | |
1216 | } | |
1217 | assert_eq!(i, expected.len()); | |
1218 | } | |
1219 | ||
1220 | #[test] | |
1221 | fn test_from_iter() { | |
1222 | let xs = [1, 2, 3, 4, 5, 6, 7, 8, 9]; | |
1223 | ||
1224 | let set: HashSet<_> = xs.iter().cloned().collect(); | |
1225 | ||
1226 | for x in &xs { | |
1227 | assert!(set.contains(x)); | |
1228 | } | |
1229 | } | |
1230 | ||
1231 | #[test] | |
1232 | fn test_move_iter() { | |
1233 | let hs = { | |
1234 | let mut hs = HashSet::new(); | |
1235 | ||
1236 | hs.insert('a'); | |
1237 | hs.insert('b'); | |
1238 | ||
1239 | hs | |
1240 | }; | |
1241 | ||
1242 | let v = hs.into_iter().collect::<Vec<char>>(); | |
1243 | assert!(v == ['a', 'b'] || v == ['b', 'a']); | |
1244 | } | |
1245 | ||
1246 | #[test] | |
1247 | fn test_eq() { | |
1248 | // These constants once happened to expose a bug in insert(). | |
1249 | // I'm keeping them around to prevent a regression. | |
1250 | let mut s1 = HashSet::new(); | |
1251 | ||
1252 | s1.insert(1); | |
1253 | s1.insert(2); | |
1254 | s1.insert(3); | |
1255 | ||
1256 | let mut s2 = HashSet::new(); | |
1257 | ||
1258 | s2.insert(1); | |
1259 | s2.insert(2); | |
1260 | ||
1261 | assert!(s1 != s2); | |
1262 | ||
1263 | s2.insert(3); | |
1264 | ||
1265 | assert_eq!(s1, s2); | |
1266 | } | |
1267 | ||
1268 | #[test] | |
1269 | fn test_show() { | |
1270 | let mut set = HashSet::new(); | |
1271 | let empty = HashSet::<i32>::new(); | |
1272 | ||
1273 | set.insert(1); | |
1274 | set.insert(2); | |
1275 | ||
1276 | let set_str = format!("{:?}", set); | |
1277 | ||
1278 | assert!(set_str == "{1, 2}" || set_str == "{2, 1}"); | |
1279 | assert_eq!(format!("{:?}", empty), "{}"); | |
1280 | } | |
1281 | ||
1282 | #[test] | |
1283 | fn test_trivial_drain() { | |
1284 | let mut s = HashSet::<i32>::new(); | |
1285 | for _ in s.drain() {} | |
1286 | assert!(s.is_empty()); | |
1287 | drop(s); | |
1288 | ||
1289 | let mut s = HashSet::<i32>::new(); | |
1290 | drop(s.drain()); | |
1291 | assert!(s.is_empty()); | |
1292 | } | |
1293 | ||
1294 | #[test] | |
1295 | fn test_drain() { | |
1296 | let mut s: HashSet<_> = (1..100).collect(); | |
1297 | ||
1298 | // try this a bunch of times to make sure we don't screw up internal state. | |
1299 | for _ in 0..20 { | |
1300 | assert_eq!(s.len(), 99); | |
1301 | ||
1302 | { | |
1303 | let mut last_i = 0; | |
1304 | let mut d = s.drain(); | |
1305 | for (i, x) in d.by_ref().take(50).enumerate() { | |
1306 | last_i = i; | |
1307 | assert!(x != 0); | |
1308 | } | |
1309 | assert_eq!(last_i, 49); | |
1310 | } | |
1311 | ||
1312 | for _ in &s { panic!("s should be empty!"); } | |
1313 | ||
1314 | // reset to try again. | |
1315 | s.extend(1..100); | |
1316 | } | |
1317 | } | |
1318 | ||
1319 | #[test] | |
1320 | fn test_replace() { | |
1321 | use hash; | |
1322 | ||
1323 | #[derive(Debug)] | |
1324 | struct Foo(&'static str, i32); | |
1325 | ||
1326 | impl PartialEq for Foo { | |
1327 | fn eq(&self, other: &Self) -> bool { | |
1328 | self.0 == other.0 | |
1329 | } | |
1330 | } | |
1331 | ||
1332 | impl Eq for Foo {} | |
1333 | ||
1334 | impl hash::Hash for Foo { | |
1335 | fn hash<H: hash::Hasher>(&self, h: &mut H) { | |
1336 | self.0.hash(h); | |
1337 | } | |
1338 | } | |
1339 | ||
1340 | let mut s = HashSet::new(); | |
1341 | assert_eq!(s.replace(Foo("a", 1)), None); | |
1342 | assert_eq!(s.len(), 1); | |
1343 | assert_eq!(s.replace(Foo("a", 2)), Some(Foo("a", 1))); | |
1344 | assert_eq!(s.len(), 1); | |
1345 | ||
1346 | let mut it = s.iter(); | |
1347 | assert_eq!(it.next(), Some(&Foo("a", 2))); | |
1348 | assert_eq!(it.next(), None); | |
1349 | } | |
1350 | ||
1351 | #[test] | |
1352 | fn test_extend_ref() { | |
1353 | let mut a = HashSet::new(); | |
1354 | a.insert(1); | |
1355 | ||
1356 | a.extend(&[2, 3, 4]); | |
1357 | ||
1358 | assert_eq!(a.len(), 4); | |
1359 | assert!(a.contains(&1)); | |
1360 | assert!(a.contains(&2)); | |
1361 | assert!(a.contains(&3)); | |
1362 | assert!(a.contains(&4)); | |
1363 | ||
1364 | let mut b = HashSet::new(); | |
1365 | b.insert(5); | |
1366 | b.insert(6); | |
1367 | ||
1368 | a.extend(&b); | |
1369 | ||
1370 | assert_eq!(a.len(), 6); | |
1371 | assert!(a.contains(&1)); | |
1372 | assert!(a.contains(&2)); | |
1373 | assert!(a.contains(&3)); | |
1374 | assert!(a.contains(&4)); | |
1375 | assert!(a.contains(&5)); | |
1376 | assert!(a.contains(&6)); | |
1377 | } | |
1378 | } |