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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. | |
1a4d82fc | 10 | |
85aaf69f | 11 | use borrow::Borrow; |
1a4d82fc JJ |
12 | use clone::Clone; |
13 | use cmp::{Eq, PartialEq}; | |
14 | use core::marker::Sized; | |
15 | use default::Default; | |
85aaf69f | 16 | use fmt::Debug; |
1a4d82fc | 17 | use fmt; |
85aaf69f | 18 | use hash::Hash; |
c34b1796 | 19 | use iter::{Iterator, IntoIterator, ExactSizeIterator, FromIterator, Map, Chain, Extend}; |
1a4d82fc JJ |
20 | use ops::{BitOr, BitAnd, BitXor, Sub}; |
21 | use option::Option::{Some, None, self}; | |
22 | ||
62682a34 | 23 | use super::map::{self, HashMap, Keys, RandomState}; |
1a4d82fc JJ |
24 | use super::state::HashState; |
25 | ||
62682a34 SL |
26 | const INITIAL_CAPACITY: usize = 32; |
27 | ||
1a4d82fc JJ |
28 | // Future Optimization (FIXME!) |
29 | // ============================= | |
30 | // | |
31 | // Iteration over zero sized values is a noop. There is no need | |
32 | // for `bucket.val` in the case of HashSet. I suppose we would need HKT | |
33 | // to get rid of it properly. | |
34 | ||
35 | /// An implementation of a hash set using the underlying representation of a | |
d9579d0f AL |
36 | /// HashMap where the value is (). |
37 | /// | |
38 | /// As with the `HashMap` type, a `HashSet` requires that the elements | |
39 | /// implement the `Eq` and `Hash` traits. This can frequently be achieved by | |
40 | /// using `#[derive(PartialEq, Eq, Hash)]`. If you implement these yourself, | |
41 | /// it is important that the following property holds: | |
c34b1796 AL |
42 | /// |
43 | /// ```text | |
44 | /// k1 == k2 -> hash(k1) == hash(k2) | |
45 | /// ``` | |
46 | /// | |
47 | /// In other words, if two keys are equal, their hashes must be equal. | |
1a4d82fc | 48 | /// |
c34b1796 AL |
49 | /// |
50 | /// It is a logic error for an item to be modified in such a way that the | |
51 | /// item's hash, as determined by the `Hash` trait, or its equality, as | |
52 | /// determined by the `Eq` trait, changes while it is in the set. This is | |
53 | /// normally only possible through `Cell`, `RefCell`, global state, I/O, or | |
54 | /// unsafe code. | |
55 | /// | |
56 | /// # Examples | |
1a4d82fc JJ |
57 | /// |
58 | /// ``` | |
59 | /// use std::collections::HashSet; | |
60 | /// // Type inference lets us omit an explicit type signature (which | |
61 | /// // would be `HashSet<&str>` in this example). | |
62 | /// let mut books = HashSet::new(); | |
63 | /// | |
64 | /// // Add some books. | |
65 | /// books.insert("A Dance With Dragons"); | |
66 | /// books.insert("To Kill a Mockingbird"); | |
67 | /// books.insert("The Odyssey"); | |
68 | /// books.insert("The Great Gatsby"); | |
69 | /// | |
70 | /// // Check for a specific one. | |
d9579d0f | 71 | /// if !books.contains("The Winds of Winter") { |
1a4d82fc JJ |
72 | /// println!("We have {} books, but The Winds of Winter ain't one.", |
73 | /// books.len()); | |
74 | /// } | |
75 | /// | |
76 | /// // Remove a book. | |
d9579d0f | 77 | /// books.remove("The Odyssey"); |
1a4d82fc JJ |
78 | /// |
79 | /// // Iterate over everything. | |
d9579d0f AL |
80 | /// for book in &books { |
81 | /// println!("{}", book); | |
1a4d82fc JJ |
82 | /// } |
83 | /// ``` | |
84 | /// | |
85 | /// The easiest way to use `HashSet` with a custom type is to derive | |
86 | /// `Eq` and `Hash`. We must also derive `PartialEq`, this will in the | |
87 | /// future be implied by `Eq`. | |
88 | /// | |
89 | /// ``` | |
90 | /// use std::collections::HashSet; | |
85aaf69f | 91 | /// #[derive(Hash, Eq, PartialEq, Debug)] |
1a4d82fc JJ |
92 | /// struct Viking<'a> { |
93 | /// name: &'a str, | |
85aaf69f | 94 | /// power: usize, |
1a4d82fc JJ |
95 | /// } |
96 | /// | |
97 | /// let mut vikings = HashSet::new(); | |
98 | /// | |
85aaf69f SL |
99 | /// vikings.insert(Viking { name: "Einar", power: 9 }); |
100 | /// vikings.insert(Viking { name: "Einar", power: 9 }); | |
101 | /// vikings.insert(Viking { name: "Olaf", power: 4 }); | |
102 | /// vikings.insert(Viking { name: "Harald", power: 8 }); | |
1a4d82fc JJ |
103 | /// |
104 | /// // Use derived implementation to print the vikings. | |
d9579d0f | 105 | /// for x in &vikings { |
1a4d82fc JJ |
106 | /// println!("{:?}", x); |
107 | /// } | |
108 | /// ``` | |
109 | #[derive(Clone)] | |
85aaf69f | 110 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
111 | pub struct HashSet<T, S = RandomState> { |
112 | map: HashMap<T, (), S> | |
113 | } | |
114 | ||
85aaf69f | 115 | impl<T: Hash + Eq> HashSet<T, RandomState> { |
9346a6ac | 116 | /// Creates an empty HashSet. |
1a4d82fc | 117 | /// |
c34b1796 | 118 | /// # Examples |
1a4d82fc JJ |
119 | /// |
120 | /// ``` | |
121 | /// use std::collections::HashSet; | |
85aaf69f | 122 | /// let mut set: HashSet<i32> = HashSet::new(); |
1a4d82fc JJ |
123 | /// ``` |
124 | #[inline] | |
85aaf69f | 125 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
126 | pub fn new() -> HashSet<T, RandomState> { |
127 | HashSet::with_capacity(INITIAL_CAPACITY) | |
128 | } | |
129 | ||
9346a6ac | 130 | /// Creates an empty HashSet with space for at least `n` elements in |
1a4d82fc JJ |
131 | /// the hash table. |
132 | /// | |
c34b1796 | 133 | /// # Examples |
1a4d82fc JJ |
134 | /// |
135 | /// ``` | |
136 | /// use std::collections::HashSet; | |
85aaf69f | 137 | /// let mut set: HashSet<i32> = HashSet::with_capacity(10); |
1a4d82fc JJ |
138 | /// ``` |
139 | #[inline] | |
85aaf69f SL |
140 | #[stable(feature = "rust1", since = "1.0.0")] |
141 | pub fn with_capacity(capacity: usize) -> HashSet<T, RandomState> { | |
1a4d82fc JJ |
142 | HashSet { map: HashMap::with_capacity(capacity) } |
143 | } | |
144 | } | |
145 | ||
85aaf69f SL |
146 | impl<T, S> HashSet<T, S> |
147 | where T: Eq + Hash, S: HashState | |
1a4d82fc JJ |
148 | { |
149 | /// Creates a new empty hash set which will use the given hasher to hash | |
150 | /// keys. | |
151 | /// | |
152 | /// The hash set is also created with the default initial capacity. | |
153 | /// | |
c34b1796 | 154 | /// # Examples |
1a4d82fc JJ |
155 | /// |
156 | /// ``` | |
c1a9b12d SL |
157 | /// #![feature(hashmap_hasher)] |
158 | /// | |
1a4d82fc JJ |
159 | /// use std::collections::HashSet; |
160 | /// use std::collections::hash_map::RandomState; | |
161 | /// | |
162 | /// let s = RandomState::new(); | |
163 | /// let mut set = HashSet::with_hash_state(s); | |
85aaf69f | 164 | /// set.insert(2); |
1a4d82fc JJ |
165 | /// ``` |
166 | #[inline] | |
62682a34 | 167 | #[unstable(feature = "hashmap_hasher", reason = "hasher stuff is unclear")] |
1a4d82fc JJ |
168 | pub fn with_hash_state(hash_state: S) -> HashSet<T, S> { |
169 | HashSet::with_capacity_and_hash_state(INITIAL_CAPACITY, hash_state) | |
170 | } | |
171 | ||
9346a6ac | 172 | /// Creates an empty HashSet with space for at least `capacity` |
1a4d82fc JJ |
173 | /// elements in the hash table, using `hasher` to hash the keys. |
174 | /// | |
175 | /// Warning: `hasher` is normally randomly generated, and | |
176 | /// is designed to allow `HashSet`s to be resistant to attacks that | |
177 | /// cause many collisions and very poor performance. Setting it | |
178 | /// manually using this function can expose a DoS attack vector. | |
179 | /// | |
c34b1796 | 180 | /// # Examples |
1a4d82fc JJ |
181 | /// |
182 | /// ``` | |
c1a9b12d SL |
183 | /// #![feature(hashmap_hasher)] |
184 | /// | |
1a4d82fc JJ |
185 | /// use std::collections::HashSet; |
186 | /// use std::collections::hash_map::RandomState; | |
187 | /// | |
188 | /// let s = RandomState::new(); | |
85aaf69f SL |
189 | /// let mut set = HashSet::with_capacity_and_hash_state(10, s); |
190 | /// set.insert(1); | |
1a4d82fc JJ |
191 | /// ``` |
192 | #[inline] | |
62682a34 | 193 | #[unstable(feature = "hashmap_hasher", reason = "hasher stuff is unclear")] |
85aaf69f | 194 | pub fn with_capacity_and_hash_state(capacity: usize, hash_state: S) |
1a4d82fc JJ |
195 | -> HashSet<T, S> { |
196 | HashSet { | |
197 | map: HashMap::with_capacity_and_hash_state(capacity, hash_state), | |
198 | } | |
199 | } | |
200 | ||
201 | /// Returns the number of elements the set can hold without reallocating. | |
202 | /// | |
c34b1796 | 203 | /// # Examples |
1a4d82fc JJ |
204 | /// |
205 | /// ``` | |
206 | /// use std::collections::HashSet; | |
85aaf69f | 207 | /// let set: HashSet<i32> = HashSet::with_capacity(100); |
1a4d82fc JJ |
208 | /// assert!(set.capacity() >= 100); |
209 | /// ``` | |
210 | #[inline] | |
85aaf69f SL |
211 | #[stable(feature = "rust1", since = "1.0.0")] |
212 | pub fn capacity(&self) -> usize { | |
1a4d82fc JJ |
213 | self.map.capacity() |
214 | } | |
215 | ||
216 | /// Reserves capacity for at least `additional` more elements to be inserted | |
217 | /// in the `HashSet`. The collection may reserve more space to avoid | |
218 | /// frequent reallocations. | |
219 | /// | |
220 | /// # Panics | |
221 | /// | |
85aaf69f | 222 | /// Panics if the new allocation size overflows `usize`. |
1a4d82fc | 223 | /// |
c34b1796 | 224 | /// # Examples |
1a4d82fc JJ |
225 | /// |
226 | /// ``` | |
227 | /// use std::collections::HashSet; | |
85aaf69f | 228 | /// let mut set: HashSet<i32> = HashSet::new(); |
1a4d82fc JJ |
229 | /// set.reserve(10); |
230 | /// ``` | |
85aaf69f SL |
231 | #[stable(feature = "rust1", since = "1.0.0")] |
232 | pub fn reserve(&mut self, additional: usize) { | |
1a4d82fc JJ |
233 | self.map.reserve(additional) |
234 | } | |
235 | ||
236 | /// Shrinks the capacity of the set as much as possible. It will drop | |
237 | /// down as much as possible while maintaining the internal rules | |
238 | /// and possibly leaving some space in accordance with the resize policy. | |
239 | /// | |
c34b1796 | 240 | /// # Examples |
1a4d82fc JJ |
241 | /// |
242 | /// ``` | |
243 | /// use std::collections::HashSet; | |
244 | /// | |
85aaf69f | 245 | /// let mut set = HashSet::with_capacity(100); |
1a4d82fc JJ |
246 | /// set.insert(1); |
247 | /// set.insert(2); | |
248 | /// assert!(set.capacity() >= 100); | |
249 | /// set.shrink_to_fit(); | |
250 | /// assert!(set.capacity() >= 2); | |
251 | /// ``` | |
85aaf69f | 252 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
253 | pub fn shrink_to_fit(&mut self) { |
254 | self.map.shrink_to_fit() | |
255 | } | |
256 | ||
257 | /// An iterator visiting all elements in arbitrary order. | |
258 | /// Iterator element type is &'a T. | |
259 | /// | |
c34b1796 | 260 | /// # Examples |
1a4d82fc JJ |
261 | /// |
262 | /// ``` | |
263 | /// use std::collections::HashSet; | |
264 | /// let mut set = HashSet::new(); | |
265 | /// set.insert("a"); | |
266 | /// set.insert("b"); | |
267 | /// | |
268 | /// // Will print in an arbitrary order. | |
269 | /// for x in set.iter() { | |
270 | /// println!("{}", x); | |
271 | /// } | |
272 | /// ``` | |
85aaf69f | 273 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
274 | pub fn iter(&self) -> Iter<T> { |
275 | Iter { iter: self.map.keys() } | |
276 | } | |
277 | ||
1a4d82fc JJ |
278 | /// Visit the values representing the difference. |
279 | /// | |
c34b1796 | 280 | /// # Examples |
1a4d82fc JJ |
281 | /// |
282 | /// ``` | |
283 | /// use std::collections::HashSet; | |
85aaf69f SL |
284 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
285 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1a4d82fc JJ |
286 | /// |
287 | /// // Can be seen as `a - b`. | |
288 | /// for x in a.difference(&b) { | |
289 | /// println!("{}", x); // Print 1 | |
290 | /// } | |
291 | /// | |
85aaf69f SL |
292 | /// let diff: HashSet<_> = a.difference(&b).cloned().collect(); |
293 | /// assert_eq!(diff, [1].iter().cloned().collect()); | |
1a4d82fc JJ |
294 | /// |
295 | /// // Note that difference is not symmetric, | |
296 | /// // and `b - a` means something else: | |
85aaf69f SL |
297 | /// let diff: HashSet<_> = b.difference(&a).cloned().collect(); |
298 | /// assert_eq!(diff, [4].iter().cloned().collect()); | |
1a4d82fc | 299 | /// ``` |
85aaf69f | 300 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
301 | pub fn difference<'a>(&'a self, other: &'a HashSet<T, S>) -> Difference<'a, T, S> { |
302 | Difference { | |
303 | iter: self.iter(), | |
304 | other: other, | |
305 | } | |
306 | } | |
307 | ||
308 | /// Visit the values representing the symmetric difference. | |
309 | /// | |
c34b1796 | 310 | /// # Examples |
1a4d82fc JJ |
311 | /// |
312 | /// ``` | |
313 | /// use std::collections::HashSet; | |
85aaf69f SL |
314 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
315 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1a4d82fc JJ |
316 | /// |
317 | /// // Print 1, 4 in arbitrary order. | |
318 | /// for x in a.symmetric_difference(&b) { | |
319 | /// println!("{}", x); | |
320 | /// } | |
321 | /// | |
85aaf69f SL |
322 | /// let diff1: HashSet<_> = a.symmetric_difference(&b).cloned().collect(); |
323 | /// let diff2: HashSet<_> = b.symmetric_difference(&a).cloned().collect(); | |
1a4d82fc JJ |
324 | /// |
325 | /// assert_eq!(diff1, diff2); | |
85aaf69f | 326 | /// assert_eq!(diff1, [1, 4].iter().cloned().collect()); |
1a4d82fc | 327 | /// ``` |
85aaf69f | 328 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
329 | pub fn symmetric_difference<'a>(&'a self, other: &'a HashSet<T, S>) |
330 | -> SymmetricDifference<'a, T, S> { | |
331 | SymmetricDifference { iter: self.difference(other).chain(other.difference(self)) } | |
332 | } | |
333 | ||
334 | /// Visit the values representing the intersection. | |
335 | /// | |
c34b1796 | 336 | /// # Examples |
1a4d82fc JJ |
337 | /// |
338 | /// ``` | |
339 | /// use std::collections::HashSet; | |
85aaf69f SL |
340 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
341 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1a4d82fc JJ |
342 | /// |
343 | /// // Print 2, 3 in arbitrary order. | |
344 | /// for x in a.intersection(&b) { | |
345 | /// println!("{}", x); | |
346 | /// } | |
347 | /// | |
85aaf69f SL |
348 | /// let diff: HashSet<_> = a.intersection(&b).cloned().collect(); |
349 | /// assert_eq!(diff, [2, 3].iter().cloned().collect()); | |
1a4d82fc | 350 | /// ``` |
85aaf69f | 351 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
352 | pub fn intersection<'a>(&'a self, other: &'a HashSet<T, S>) -> Intersection<'a, T, S> { |
353 | Intersection { | |
354 | iter: self.iter(), | |
355 | other: other, | |
356 | } | |
357 | } | |
358 | ||
359 | /// Visit the values representing the union. | |
360 | /// | |
c34b1796 | 361 | /// # Examples |
1a4d82fc JJ |
362 | /// |
363 | /// ``` | |
364 | /// use std::collections::HashSet; | |
85aaf69f SL |
365 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
366 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1a4d82fc JJ |
367 | /// |
368 | /// // Print 1, 2, 3, 4 in arbitrary order. | |
369 | /// for x in a.union(&b) { | |
370 | /// println!("{}", x); | |
371 | /// } | |
372 | /// | |
85aaf69f SL |
373 | /// let diff: HashSet<_> = a.union(&b).cloned().collect(); |
374 | /// assert_eq!(diff, [1, 2, 3, 4].iter().cloned().collect()); | |
1a4d82fc | 375 | /// ``` |
85aaf69f | 376 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
377 | pub fn union<'a>(&'a self, other: &'a HashSet<T, S>) -> Union<'a, T, S> { |
378 | Union { iter: self.iter().chain(other.difference(self)) } | |
379 | } | |
380 | ||
9346a6ac | 381 | /// Returns the number of elements in the set. |
1a4d82fc | 382 | /// |
c34b1796 | 383 | /// # Examples |
1a4d82fc JJ |
384 | /// |
385 | /// ``` | |
386 | /// use std::collections::HashSet; | |
387 | /// | |
388 | /// let mut v = HashSet::new(); | |
389 | /// assert_eq!(v.len(), 0); | |
85aaf69f | 390 | /// v.insert(1); |
1a4d82fc JJ |
391 | /// assert_eq!(v.len(), 1); |
392 | /// ``` | |
85aaf69f SL |
393 | #[stable(feature = "rust1", since = "1.0.0")] |
394 | pub fn len(&self) -> usize { self.map.len() } | |
1a4d82fc | 395 | |
9346a6ac | 396 | /// Returns true if the set contains no elements. |
1a4d82fc | 397 | /// |
c34b1796 | 398 | /// # Examples |
1a4d82fc JJ |
399 | /// |
400 | /// ``` | |
401 | /// use std::collections::HashSet; | |
402 | /// | |
403 | /// let mut v = HashSet::new(); | |
404 | /// assert!(v.is_empty()); | |
85aaf69f | 405 | /// v.insert(1); |
1a4d82fc JJ |
406 | /// assert!(!v.is_empty()); |
407 | /// ``` | |
85aaf69f | 408 | #[stable(feature = "rust1", since = "1.0.0")] |
9346a6ac | 409 | pub fn is_empty(&self) -> bool { self.map.is_empty() } |
1a4d82fc JJ |
410 | |
411 | /// Clears the set, returning all elements in an iterator. | |
412 | #[inline] | |
62682a34 | 413 | #[unstable(feature = "drain", |
85aaf69f | 414 | reason = "matches collection reform specification, waiting for dust to settle")] |
1a4d82fc JJ |
415 | pub fn drain(&mut self) -> Drain<T> { |
416 | fn first<A, B>((a, _): (A, B)) -> A { a } | |
417 | let first: fn((T, ())) -> T = first; // coerce to fn pointer | |
418 | ||
419 | Drain { iter: self.map.drain().map(first) } | |
420 | } | |
421 | ||
422 | /// Clears the set, removing all values. | |
423 | /// | |
c34b1796 | 424 | /// # Examples |
1a4d82fc JJ |
425 | /// |
426 | /// ``` | |
427 | /// use std::collections::HashSet; | |
428 | /// | |
429 | /// let mut v = HashSet::new(); | |
85aaf69f | 430 | /// v.insert(1); |
1a4d82fc JJ |
431 | /// v.clear(); |
432 | /// assert!(v.is_empty()); | |
433 | /// ``` | |
85aaf69f | 434 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
435 | pub fn clear(&mut self) { self.map.clear() } |
436 | ||
437 | /// Returns `true` if the set contains a value. | |
438 | /// | |
439 | /// The value may be any borrowed form of the set's value type, but | |
440 | /// `Hash` and `Eq` on the borrowed form *must* match those for | |
441 | /// the value type. | |
442 | /// | |
c34b1796 | 443 | /// # Examples |
1a4d82fc JJ |
444 | /// |
445 | /// ``` | |
446 | /// use std::collections::HashSet; | |
447 | /// | |
85aaf69f | 448 | /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
1a4d82fc JJ |
449 | /// assert_eq!(set.contains(&1), true); |
450 | /// assert_eq!(set.contains(&4), false); | |
451 | /// ``` | |
85aaf69f | 452 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 453 | pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool |
85aaf69f | 454 | where T: Borrow<Q>, Q: Hash + Eq |
1a4d82fc JJ |
455 | { |
456 | self.map.contains_key(value) | |
457 | } | |
458 | ||
459 | /// Returns `true` if the set has no elements in common with `other`. | |
460 | /// This is equivalent to checking for an empty intersection. | |
461 | /// | |
c34b1796 | 462 | /// # Examples |
1a4d82fc JJ |
463 | /// |
464 | /// ``` | |
465 | /// use std::collections::HashSet; | |
466 | /// | |
85aaf69f SL |
467 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
468 | /// let mut b = HashSet::new(); | |
1a4d82fc JJ |
469 | /// |
470 | /// assert_eq!(a.is_disjoint(&b), true); | |
471 | /// b.insert(4); | |
472 | /// assert_eq!(a.is_disjoint(&b), true); | |
473 | /// b.insert(1); | |
474 | /// assert_eq!(a.is_disjoint(&b), false); | |
475 | /// ``` | |
85aaf69f | 476 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
477 | pub fn is_disjoint(&self, other: &HashSet<T, S>) -> bool { |
478 | self.iter().all(|v| !other.contains(v)) | |
479 | } | |
480 | ||
481 | /// Returns `true` if the set is a subset of another. | |
482 | /// | |
c34b1796 | 483 | /// # Examples |
1a4d82fc JJ |
484 | /// |
485 | /// ``` | |
486 | /// use std::collections::HashSet; | |
487 | /// | |
85aaf69f SL |
488 | /// let sup: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
489 | /// let mut set = HashSet::new(); | |
1a4d82fc JJ |
490 | /// |
491 | /// assert_eq!(set.is_subset(&sup), true); | |
492 | /// set.insert(2); | |
493 | /// assert_eq!(set.is_subset(&sup), true); | |
494 | /// set.insert(4); | |
495 | /// assert_eq!(set.is_subset(&sup), false); | |
496 | /// ``` | |
85aaf69f | 497 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
498 | pub fn is_subset(&self, other: &HashSet<T, S>) -> bool { |
499 | self.iter().all(|v| other.contains(v)) | |
500 | } | |
501 | ||
502 | /// Returns `true` if the set is a superset of another. | |
503 | /// | |
c34b1796 | 504 | /// # Examples |
1a4d82fc JJ |
505 | /// |
506 | /// ``` | |
507 | /// use std::collections::HashSet; | |
508 | /// | |
85aaf69f SL |
509 | /// let sub: HashSet<_> = [1, 2].iter().cloned().collect(); |
510 | /// let mut set = HashSet::new(); | |
1a4d82fc JJ |
511 | /// |
512 | /// assert_eq!(set.is_superset(&sub), false); | |
513 | /// | |
514 | /// set.insert(0); | |
515 | /// set.insert(1); | |
516 | /// assert_eq!(set.is_superset(&sub), false); | |
517 | /// | |
518 | /// set.insert(2); | |
519 | /// assert_eq!(set.is_superset(&sub), true); | |
520 | /// ``` | |
521 | #[inline] | |
85aaf69f | 522 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
523 | pub fn is_superset(&self, other: &HashSet<T, S>) -> bool { |
524 | other.is_subset(self) | |
525 | } | |
526 | ||
527 | /// Adds a value to the set. Returns `true` if the value was not already | |
528 | /// present in the set. | |
529 | /// | |
c34b1796 | 530 | /// # Examples |
1a4d82fc JJ |
531 | /// |
532 | /// ``` | |
533 | /// use std::collections::HashSet; | |
534 | /// | |
535 | /// let mut set = HashSet::new(); | |
536 | /// | |
85aaf69f | 537 | /// assert_eq!(set.insert(2), true); |
1a4d82fc JJ |
538 | /// assert_eq!(set.insert(2), false); |
539 | /// assert_eq!(set.len(), 1); | |
540 | /// ``` | |
85aaf69f | 541 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
542 | pub fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()).is_none() } |
543 | ||
544 | /// Removes a value from the set. Returns `true` if the value was | |
545 | /// present in the set. | |
546 | /// | |
547 | /// The value may be any borrowed form of the set's value type, but | |
548 | /// `Hash` and `Eq` on the borrowed form *must* match those for | |
549 | /// the value type. | |
550 | /// | |
c34b1796 | 551 | /// # Examples |
1a4d82fc JJ |
552 | /// |
553 | /// ``` | |
554 | /// use std::collections::HashSet; | |
555 | /// | |
556 | /// let mut set = HashSet::new(); | |
557 | /// | |
85aaf69f | 558 | /// set.insert(2); |
1a4d82fc JJ |
559 | /// assert_eq!(set.remove(&2), true); |
560 | /// assert_eq!(set.remove(&2), false); | |
561 | /// ``` | |
85aaf69f | 562 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 563 | pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool |
85aaf69f | 564 | where T: Borrow<Q>, Q: Hash + Eq |
1a4d82fc JJ |
565 | { |
566 | self.map.remove(value).is_some() | |
567 | } | |
568 | } | |
569 | ||
85aaf69f SL |
570 | #[stable(feature = "rust1", since = "1.0.0")] |
571 | impl<T, S> PartialEq for HashSet<T, S> | |
572 | where T: Eq + Hash, S: HashState | |
1a4d82fc JJ |
573 | { |
574 | fn eq(&self, other: &HashSet<T, S>) -> bool { | |
575 | if self.len() != other.len() { return false; } | |
576 | ||
577 | self.iter().all(|key| other.contains(key)) | |
578 | } | |
579 | } | |
580 | ||
85aaf69f SL |
581 | #[stable(feature = "rust1", since = "1.0.0")] |
582 | impl<T, S> Eq for HashSet<T, S> | |
583 | where T: Eq + Hash, S: HashState | |
1a4d82fc JJ |
584 | {} |
585 | ||
85aaf69f SL |
586 | #[stable(feature = "rust1", since = "1.0.0")] |
587 | impl<T, S> fmt::Debug for HashSet<T, S> | |
588 | where T: Eq + Hash + fmt::Debug, | |
589 | S: HashState | |
1a4d82fc JJ |
590 | { |
591 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
62682a34 | 592 | f.debug_set().entries(self.iter()).finish() |
1a4d82fc JJ |
593 | } |
594 | } | |
595 | ||
85aaf69f SL |
596 | #[stable(feature = "rust1", since = "1.0.0")] |
597 | impl<T, S> FromIterator<T> for HashSet<T, S> | |
598 | where T: Eq + Hash, | |
599 | S: HashState + Default, | |
1a4d82fc | 600 | { |
85aaf69f SL |
601 | fn from_iter<I: IntoIterator<Item=T>>(iterable: I) -> HashSet<T, S> { |
602 | let iter = iterable.into_iter(); | |
1a4d82fc JJ |
603 | let lower = iter.size_hint().0; |
604 | let mut set = HashSet::with_capacity_and_hash_state(lower, Default::default()); | |
605 | set.extend(iter); | |
606 | set | |
607 | } | |
608 | } | |
609 | ||
85aaf69f SL |
610 | #[stable(feature = "rust1", since = "1.0.0")] |
611 | impl<T, S> Extend<T> for HashSet<T, S> | |
612 | where T: Eq + Hash, | |
613 | S: HashState, | |
1a4d82fc | 614 | { |
85aaf69f | 615 | fn extend<I: IntoIterator<Item=T>>(&mut self, iter: I) { |
1a4d82fc JJ |
616 | for k in iter { |
617 | self.insert(k); | |
618 | } | |
619 | } | |
620 | } | |
621 | ||
85aaf69f SL |
622 | #[stable(feature = "rust1", since = "1.0.0")] |
623 | impl<T, S> Default for HashSet<T, S> | |
624 | where T: Eq + Hash, | |
625 | S: HashState + Default, | |
1a4d82fc | 626 | { |
85aaf69f | 627 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
628 | fn default() -> HashSet<T, S> { |
629 | HashSet::with_hash_state(Default::default()) | |
630 | } | |
631 | } | |
632 | ||
85aaf69f SL |
633 | #[stable(feature = "rust1", since = "1.0.0")] |
634 | impl<'a, 'b, T, S> BitOr<&'b HashSet<T, S>> for &'a HashSet<T, S> | |
635 | where T: Eq + Hash + Clone, | |
636 | S: HashState + Default, | |
1a4d82fc JJ |
637 | { |
638 | type Output = HashSet<T, S>; | |
639 | ||
640 | /// Returns the union of `self` and `rhs` as a new `HashSet<T, S>`. | |
641 | /// | |
642 | /// # Examples | |
643 | /// | |
644 | /// ``` | |
645 | /// use std::collections::HashSet; | |
646 | /// | |
85aaf69f SL |
647 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); |
648 | /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); | |
1a4d82fc | 649 | /// |
85aaf69f | 650 | /// let set = &a | &b; |
1a4d82fc JJ |
651 | /// |
652 | /// let mut i = 0; | |
653 | /// let expected = [1, 2, 3, 4, 5]; | |
62682a34 | 654 | /// for x in &set { |
1a4d82fc JJ |
655 | /// assert!(expected.contains(x)); |
656 | /// i += 1; | |
657 | /// } | |
658 | /// assert_eq!(i, expected.len()); | |
659 | /// ``` | |
660 | fn bitor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
661 | self.union(rhs).cloned().collect() | |
662 | } | |
663 | } | |
664 | ||
85aaf69f SL |
665 | #[stable(feature = "rust1", since = "1.0.0")] |
666 | impl<'a, 'b, T, S> BitAnd<&'b HashSet<T, S>> for &'a HashSet<T, S> | |
667 | where T: Eq + Hash + Clone, | |
668 | S: HashState + Default, | |
1a4d82fc JJ |
669 | { |
670 | type Output = HashSet<T, S>; | |
671 | ||
672 | /// Returns the intersection of `self` and `rhs` as a new `HashSet<T, S>`. | |
673 | /// | |
674 | /// # Examples | |
675 | /// | |
676 | /// ``` | |
677 | /// use std::collections::HashSet; | |
678 | /// | |
85aaf69f SL |
679 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); |
680 | /// let b: HashSet<_> = vec![2, 3, 4].into_iter().collect(); | |
1a4d82fc | 681 | /// |
85aaf69f | 682 | /// let set = &a & &b; |
1a4d82fc JJ |
683 | /// |
684 | /// let mut i = 0; | |
685 | /// let expected = [2, 3]; | |
62682a34 | 686 | /// for x in &set { |
1a4d82fc JJ |
687 | /// assert!(expected.contains(x)); |
688 | /// i += 1; | |
689 | /// } | |
690 | /// assert_eq!(i, expected.len()); | |
691 | /// ``` | |
692 | fn bitand(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
693 | self.intersection(rhs).cloned().collect() | |
694 | } | |
695 | } | |
696 | ||
85aaf69f SL |
697 | #[stable(feature = "rust1", since = "1.0.0")] |
698 | impl<'a, 'b, T, S> BitXor<&'b HashSet<T, S>> for &'a HashSet<T, S> | |
699 | where T: Eq + Hash + Clone, | |
700 | S: HashState + Default, | |
1a4d82fc JJ |
701 | { |
702 | type Output = HashSet<T, S>; | |
703 | ||
704 | /// Returns the symmetric difference of `self` and `rhs` as a new `HashSet<T, S>`. | |
705 | /// | |
706 | /// # Examples | |
707 | /// | |
708 | /// ``` | |
709 | /// use std::collections::HashSet; | |
710 | /// | |
85aaf69f SL |
711 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); |
712 | /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); | |
1a4d82fc | 713 | /// |
85aaf69f | 714 | /// let set = &a ^ &b; |
1a4d82fc JJ |
715 | /// |
716 | /// let mut i = 0; | |
717 | /// let expected = [1, 2, 4, 5]; | |
62682a34 | 718 | /// for x in &set { |
1a4d82fc JJ |
719 | /// assert!(expected.contains(x)); |
720 | /// i += 1; | |
721 | /// } | |
722 | /// assert_eq!(i, expected.len()); | |
723 | /// ``` | |
724 | fn bitxor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
725 | self.symmetric_difference(rhs).cloned().collect() | |
726 | } | |
727 | } | |
728 | ||
85aaf69f SL |
729 | #[stable(feature = "rust1", since = "1.0.0")] |
730 | impl<'a, 'b, T, S> Sub<&'b HashSet<T, S>> for &'a HashSet<T, S> | |
731 | where T: Eq + Hash + Clone, | |
732 | S: HashState + Default, | |
1a4d82fc JJ |
733 | { |
734 | type Output = HashSet<T, S>; | |
735 | ||
736 | /// Returns the difference of `self` and `rhs` as a new `HashSet<T, S>`. | |
737 | /// | |
738 | /// # Examples | |
739 | /// | |
740 | /// ``` | |
741 | /// use std::collections::HashSet; | |
742 | /// | |
85aaf69f SL |
743 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); |
744 | /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); | |
1a4d82fc | 745 | /// |
85aaf69f | 746 | /// let set = &a - &b; |
1a4d82fc JJ |
747 | /// |
748 | /// let mut i = 0; | |
749 | /// let expected = [1, 2]; | |
62682a34 | 750 | /// for x in &set { |
1a4d82fc JJ |
751 | /// assert!(expected.contains(x)); |
752 | /// i += 1; | |
753 | /// } | |
754 | /// assert_eq!(i, expected.len()); | |
755 | /// ``` | |
756 | fn sub(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
757 | self.difference(rhs).cloned().collect() | |
758 | } | |
759 | } | |
760 | ||
761 | /// HashSet iterator | |
85aaf69f | 762 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
763 | pub struct Iter<'a, K: 'a> { |
764 | iter: Keys<'a, K, ()> | |
765 | } | |
766 | ||
767 | /// HashSet move iterator | |
85aaf69f | 768 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 769 | pub struct IntoIter<K> { |
85aaf69f | 770 | iter: Map<map::IntoIter<K, ()>, fn((K, ())) -> K> |
1a4d82fc JJ |
771 | } |
772 | ||
773 | /// HashSet drain iterator | |
85aaf69f | 774 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 775 | pub struct Drain<'a, K: 'a> { |
85aaf69f | 776 | iter: Map<map::Drain<'a, K, ()>, fn((K, ())) -> K>, |
1a4d82fc JJ |
777 | } |
778 | ||
779 | /// Intersection iterator | |
85aaf69f | 780 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
781 | pub struct Intersection<'a, T: 'a, S: 'a> { |
782 | // iterator of the first set | |
783 | iter: Iter<'a, T>, | |
784 | // the second set | |
785 | other: &'a HashSet<T, S>, | |
786 | } | |
787 | ||
788 | /// Difference iterator | |
85aaf69f | 789 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
790 | pub struct Difference<'a, T: 'a, S: 'a> { |
791 | // iterator of the first set | |
792 | iter: Iter<'a, T>, | |
793 | // the second set | |
794 | other: &'a HashSet<T, S>, | |
795 | } | |
796 | ||
797 | /// Symmetric difference iterator. | |
85aaf69f | 798 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
799 | pub struct SymmetricDifference<'a, T: 'a, S: 'a> { |
800 | iter: Chain<Difference<'a, T, S>, Difference<'a, T, S>> | |
801 | } | |
802 | ||
803 | /// Set union iterator. | |
85aaf69f | 804 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
805 | pub struct Union<'a, T: 'a, S: 'a> { |
806 | iter: Chain<Iter<'a, T>, Difference<'a, T, S>> | |
807 | } | |
808 | ||
85aaf69f SL |
809 | #[stable(feature = "rust1", since = "1.0.0")] |
810 | impl<'a, T, S> IntoIterator for &'a HashSet<T, S> | |
811 | where T: Eq + Hash, S: HashState | |
812 | { | |
813 | type Item = &'a T; | |
814 | type IntoIter = Iter<'a, T>; | |
815 | ||
816 | fn into_iter(self) -> Iter<'a, T> { | |
817 | self.iter() | |
818 | } | |
819 | } | |
820 | ||
821 | #[stable(feature = "rust1", since = "1.0.0")] | |
822 | impl<T, S> IntoIterator for HashSet<T, S> | |
823 | where T: Eq + Hash, | |
824 | S: HashState | |
825 | { | |
826 | type Item = T; | |
827 | type IntoIter = IntoIter<T>; | |
828 | ||
9346a6ac AL |
829 | /// Creates a consuming iterator, that is, one that moves each value out |
830 | /// of the set in arbitrary order. The set cannot be used after calling | |
831 | /// this. | |
832 | /// | |
833 | /// # Examples | |
834 | /// | |
835 | /// ``` | |
836 | /// use std::collections::HashSet; | |
837 | /// let mut set = HashSet::new(); | |
838 | /// set.insert("a".to_string()); | |
839 | /// set.insert("b".to_string()); | |
840 | /// | |
841 | /// // Not possible to collect to a Vec<String> with a regular `.iter()`. | |
842 | /// let v: Vec<String> = set.into_iter().collect(); | |
843 | /// | |
844 | /// // Will print in an arbitrary order. | |
62682a34 | 845 | /// for x in &v { |
9346a6ac AL |
846 | /// println!("{}", x); |
847 | /// } | |
848 | /// ``` | |
85aaf69f | 849 | fn into_iter(self) -> IntoIter<T> { |
9346a6ac AL |
850 | fn first<A, B>((a, _): (A, B)) -> A { a } |
851 | let first: fn((T, ())) -> T = first; | |
852 | ||
853 | IntoIter { iter: self.map.into_iter().map(first) } | |
85aaf69f SL |
854 | } |
855 | } | |
856 | ||
c34b1796 AL |
857 | impl<'a, K> Clone for Iter<'a, K> { |
858 | fn clone(&self) -> Iter<'a, K> { Iter { iter: self.iter.clone() } } | |
859 | } | |
85aaf69f | 860 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
861 | impl<'a, K> Iterator for Iter<'a, K> { |
862 | type Item = &'a K; | |
863 | ||
864 | fn next(&mut self) -> Option<&'a K> { self.iter.next() } | |
85aaf69f SL |
865 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } |
866 | } | |
867 | #[stable(feature = "rust1", since = "1.0.0")] | |
868 | impl<'a, K> ExactSizeIterator for Iter<'a, K> { | |
869 | fn len(&self) -> usize { self.iter.len() } | |
1a4d82fc JJ |
870 | } |
871 | ||
85aaf69f | 872 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
873 | impl<K> Iterator for IntoIter<K> { |
874 | type Item = K; | |
875 | ||
876 | fn next(&mut self) -> Option<K> { self.iter.next() } | |
85aaf69f SL |
877 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } |
878 | } | |
879 | #[stable(feature = "rust1", since = "1.0.0")] | |
880 | impl<K> ExactSizeIterator for IntoIter<K> { | |
881 | fn len(&self) -> usize { self.iter.len() } | |
1a4d82fc JJ |
882 | } |
883 | ||
85aaf69f SL |
884 | #[stable(feature = "rust1", since = "1.0.0")] |
885 | impl<'a, K> Iterator for Drain<'a, K> { | |
1a4d82fc JJ |
886 | type Item = K; |
887 | ||
888 | fn next(&mut self) -> Option<K> { self.iter.next() } | |
85aaf69f SL |
889 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } |
890 | } | |
891 | #[stable(feature = "rust1", since = "1.0.0")] | |
892 | impl<'a, K> ExactSizeIterator for Drain<'a, K> { | |
893 | fn len(&self) -> usize { self.iter.len() } | |
1a4d82fc JJ |
894 | } |
895 | ||
c34b1796 AL |
896 | impl<'a, T, S> Clone for Intersection<'a, T, S> { |
897 | fn clone(&self) -> Intersection<'a, T, S> { | |
898 | Intersection { iter: self.iter.clone(), ..*self } | |
899 | } | |
900 | } | |
901 | ||
85aaf69f SL |
902 | #[stable(feature = "rust1", since = "1.0.0")] |
903 | impl<'a, T, S> Iterator for Intersection<'a, T, S> | |
904 | where T: Eq + Hash, S: HashState | |
1a4d82fc JJ |
905 | { |
906 | type Item = &'a T; | |
907 | ||
908 | fn next(&mut self) -> Option<&'a T> { | |
909 | loop { | |
910 | match self.iter.next() { | |
911 | None => return None, | |
912 | Some(elt) => if self.other.contains(elt) { | |
913 | return Some(elt) | |
914 | }, | |
915 | } | |
916 | } | |
917 | } | |
918 | ||
85aaf69f | 919 | fn size_hint(&self) -> (usize, Option<usize>) { |
1a4d82fc JJ |
920 | let (_, upper) = self.iter.size_hint(); |
921 | (0, upper) | |
922 | } | |
923 | } | |
924 | ||
c34b1796 AL |
925 | impl<'a, T, S> Clone for Difference<'a, T, S> { |
926 | fn clone(&self) -> Difference<'a, T, S> { | |
927 | Difference { iter: self.iter.clone(), ..*self } | |
928 | } | |
929 | } | |
930 | ||
85aaf69f SL |
931 | #[stable(feature = "rust1", since = "1.0.0")] |
932 | impl<'a, T, S> Iterator for Difference<'a, T, S> | |
933 | where T: Eq + Hash, S: HashState | |
1a4d82fc JJ |
934 | { |
935 | type Item = &'a T; | |
936 | ||
937 | fn next(&mut self) -> Option<&'a T> { | |
938 | loop { | |
939 | match self.iter.next() { | |
940 | None => return None, | |
941 | Some(elt) => if !self.other.contains(elt) { | |
942 | return Some(elt) | |
943 | }, | |
944 | } | |
945 | } | |
946 | } | |
947 | ||
85aaf69f | 948 | fn size_hint(&self) -> (usize, Option<usize>) { |
1a4d82fc JJ |
949 | let (_, upper) = self.iter.size_hint(); |
950 | (0, upper) | |
951 | } | |
952 | } | |
953 | ||
c34b1796 AL |
954 | impl<'a, T, S> Clone for SymmetricDifference<'a, T, S> { |
955 | fn clone(&self) -> SymmetricDifference<'a, T, S> { | |
956 | SymmetricDifference { iter: self.iter.clone() } | |
957 | } | |
958 | } | |
959 | ||
85aaf69f SL |
960 | #[stable(feature = "rust1", since = "1.0.0")] |
961 | impl<'a, T, S> Iterator for SymmetricDifference<'a, T, S> | |
962 | where T: Eq + Hash, S: HashState | |
1a4d82fc JJ |
963 | { |
964 | type Item = &'a T; | |
965 | ||
966 | fn next(&mut self) -> Option<&'a T> { self.iter.next() } | |
85aaf69f | 967 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } |
1a4d82fc JJ |
968 | } |
969 | ||
c34b1796 AL |
970 | impl<'a, T, S> Clone for Union<'a, T, S> { |
971 | fn clone(&self) -> Union<'a, T, S> { Union { iter: self.iter.clone() } } | |
972 | } | |
973 | ||
85aaf69f SL |
974 | #[stable(feature = "rust1", since = "1.0.0")] |
975 | impl<'a, T, S> Iterator for Union<'a, T, S> | |
976 | where T: Eq + Hash, S: HashState | |
1a4d82fc JJ |
977 | { |
978 | type Item = &'a T; | |
979 | ||
980 | fn next(&mut self) -> Option<&'a T> { self.iter.next() } | |
85aaf69f | 981 | fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } |
1a4d82fc JJ |
982 | } |
983 | ||
984 | #[cfg(test)] | |
985 | mod test_set { | |
986 | use prelude::v1::*; | |
987 | ||
988 | use super::HashSet; | |
989 | ||
990 | #[test] | |
991 | fn test_disjoint() { | |
992 | let mut xs = HashSet::new(); | |
993 | let mut ys = HashSet::new(); | |
994 | assert!(xs.is_disjoint(&ys)); | |
995 | assert!(ys.is_disjoint(&xs)); | |
85aaf69f SL |
996 | assert!(xs.insert(5)); |
997 | assert!(ys.insert(11)); | |
1a4d82fc JJ |
998 | assert!(xs.is_disjoint(&ys)); |
999 | assert!(ys.is_disjoint(&xs)); | |
1000 | assert!(xs.insert(7)); | |
1001 | assert!(xs.insert(19)); | |
1002 | assert!(xs.insert(4)); | |
1003 | assert!(ys.insert(2)); | |
1004 | assert!(ys.insert(-11)); | |
1005 | assert!(xs.is_disjoint(&ys)); | |
1006 | assert!(ys.is_disjoint(&xs)); | |
1007 | assert!(ys.insert(7)); | |
1008 | assert!(!xs.is_disjoint(&ys)); | |
1009 | assert!(!ys.is_disjoint(&xs)); | |
1010 | } | |
1011 | ||
1012 | #[test] | |
1013 | fn test_subset_and_superset() { | |
1014 | let mut a = HashSet::new(); | |
85aaf69f | 1015 | assert!(a.insert(0)); |
1a4d82fc JJ |
1016 | assert!(a.insert(5)); |
1017 | assert!(a.insert(11)); | |
1018 | assert!(a.insert(7)); | |
1019 | ||
1020 | let mut b = HashSet::new(); | |
85aaf69f | 1021 | assert!(b.insert(0)); |
1a4d82fc JJ |
1022 | assert!(b.insert(7)); |
1023 | assert!(b.insert(19)); | |
1024 | assert!(b.insert(250)); | |
1025 | assert!(b.insert(11)); | |
1026 | assert!(b.insert(200)); | |
1027 | ||
1028 | assert!(!a.is_subset(&b)); | |
1029 | assert!(!a.is_superset(&b)); | |
1030 | assert!(!b.is_subset(&a)); | |
1031 | assert!(!b.is_superset(&a)); | |
1032 | ||
1033 | assert!(b.insert(5)); | |
1034 | ||
1035 | assert!(a.is_subset(&b)); | |
1036 | assert!(!a.is_superset(&b)); | |
1037 | assert!(!b.is_subset(&a)); | |
1038 | assert!(b.is_superset(&a)); | |
1039 | } | |
1040 | ||
1041 | #[test] | |
1042 | fn test_iterate() { | |
1043 | let mut a = HashSet::new(); | |
85aaf69f | 1044 | for i in 0..32 { |
1a4d82fc JJ |
1045 | assert!(a.insert(i)); |
1046 | } | |
1047 | let mut observed: u32 = 0; | |
85aaf69f | 1048 | for k in &a { |
1a4d82fc JJ |
1049 | observed |= 1 << *k; |
1050 | } | |
1051 | assert_eq!(observed, 0xFFFF_FFFF); | |
1052 | } | |
1053 | ||
1054 | #[test] | |
1055 | fn test_intersection() { | |
1056 | let mut a = HashSet::new(); | |
1057 | let mut b = HashSet::new(); | |
1058 | ||
85aaf69f | 1059 | assert!(a.insert(11)); |
1a4d82fc JJ |
1060 | assert!(a.insert(1)); |
1061 | assert!(a.insert(3)); | |
1062 | assert!(a.insert(77)); | |
1063 | assert!(a.insert(103)); | |
1064 | assert!(a.insert(5)); | |
1065 | assert!(a.insert(-5)); | |
1066 | ||
85aaf69f | 1067 | assert!(b.insert(2)); |
1a4d82fc JJ |
1068 | assert!(b.insert(11)); |
1069 | assert!(b.insert(77)); | |
1070 | assert!(b.insert(-9)); | |
1071 | assert!(b.insert(-42)); | |
1072 | assert!(b.insert(5)); | |
1073 | assert!(b.insert(3)); | |
1074 | ||
1075 | let mut i = 0; | |
1076 | let expected = [3, 5, 11, 77]; | |
1077 | for x in a.intersection(&b) { | |
1078 | assert!(expected.contains(x)); | |
1079 | i += 1 | |
1080 | } | |
1081 | assert_eq!(i, expected.len()); | |
1082 | } | |
1083 | ||
1084 | #[test] | |
1085 | fn test_difference() { | |
1086 | let mut a = HashSet::new(); | |
1087 | let mut b = HashSet::new(); | |
1088 | ||
85aaf69f | 1089 | assert!(a.insert(1)); |
1a4d82fc JJ |
1090 | assert!(a.insert(3)); |
1091 | assert!(a.insert(5)); | |
1092 | assert!(a.insert(9)); | |
1093 | assert!(a.insert(11)); | |
1094 | ||
85aaf69f | 1095 | assert!(b.insert(3)); |
1a4d82fc JJ |
1096 | assert!(b.insert(9)); |
1097 | ||
1098 | let mut i = 0; | |
1099 | let expected = [1, 5, 11]; | |
1100 | for x in a.difference(&b) { | |
1101 | assert!(expected.contains(x)); | |
1102 | i += 1 | |
1103 | } | |
1104 | assert_eq!(i, expected.len()); | |
1105 | } | |
1106 | ||
1107 | #[test] | |
1108 | fn test_symmetric_difference() { | |
1109 | let mut a = HashSet::new(); | |
1110 | let mut b = HashSet::new(); | |
1111 | ||
85aaf69f | 1112 | assert!(a.insert(1)); |
1a4d82fc JJ |
1113 | assert!(a.insert(3)); |
1114 | assert!(a.insert(5)); | |
1115 | assert!(a.insert(9)); | |
1116 | assert!(a.insert(11)); | |
1117 | ||
85aaf69f | 1118 | assert!(b.insert(-2)); |
1a4d82fc JJ |
1119 | assert!(b.insert(3)); |
1120 | assert!(b.insert(9)); | |
1121 | assert!(b.insert(14)); | |
1122 | assert!(b.insert(22)); | |
1123 | ||
1124 | let mut i = 0; | |
1125 | let expected = [-2, 1, 5, 11, 14, 22]; | |
1126 | for x in a.symmetric_difference(&b) { | |
1127 | assert!(expected.contains(x)); | |
1128 | i += 1 | |
1129 | } | |
1130 | assert_eq!(i, expected.len()); | |
1131 | } | |
1132 | ||
1133 | #[test] | |
1134 | fn test_union() { | |
1135 | let mut a = HashSet::new(); | |
1136 | let mut b = HashSet::new(); | |
1137 | ||
85aaf69f | 1138 | assert!(a.insert(1)); |
1a4d82fc JJ |
1139 | assert!(a.insert(3)); |
1140 | assert!(a.insert(5)); | |
1141 | assert!(a.insert(9)); | |
1142 | assert!(a.insert(11)); | |
1143 | assert!(a.insert(16)); | |
1144 | assert!(a.insert(19)); | |
1145 | assert!(a.insert(24)); | |
1146 | ||
85aaf69f | 1147 | assert!(b.insert(-2)); |
1a4d82fc JJ |
1148 | assert!(b.insert(1)); |
1149 | assert!(b.insert(5)); | |
1150 | assert!(b.insert(9)); | |
1151 | assert!(b.insert(13)); | |
1152 | assert!(b.insert(19)); | |
1153 | ||
1154 | let mut i = 0; | |
1155 | let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24]; | |
1156 | for x in a.union(&b) { | |
1157 | assert!(expected.contains(x)); | |
1158 | i += 1 | |
1159 | } | |
1160 | assert_eq!(i, expected.len()); | |
1161 | } | |
1162 | ||
1163 | #[test] | |
1164 | fn test_from_iter() { | |
85aaf69f | 1165 | let xs = [1, 2, 3, 4, 5, 6, 7, 8, 9]; |
1a4d82fc | 1166 | |
85aaf69f | 1167 | let set: HashSet<_> = xs.iter().cloned().collect(); |
1a4d82fc | 1168 | |
85aaf69f | 1169 | for x in &xs { |
1a4d82fc JJ |
1170 | assert!(set.contains(x)); |
1171 | } | |
1172 | } | |
1173 | ||
1174 | #[test] | |
1175 | fn test_move_iter() { | |
1176 | let hs = { | |
1177 | let mut hs = HashSet::new(); | |
1178 | ||
1179 | hs.insert('a'); | |
1180 | hs.insert('b'); | |
1181 | ||
1182 | hs | |
1183 | }; | |
1184 | ||
1185 | let v = hs.into_iter().collect::<Vec<char>>(); | |
c34b1796 | 1186 | assert!(v == ['a', 'b'] || v == ['b', 'a']); |
1a4d82fc JJ |
1187 | } |
1188 | ||
1189 | #[test] | |
1190 | fn test_eq() { | |
1191 | // These constants once happened to expose a bug in insert(). | |
1192 | // I'm keeping them around to prevent a regression. | |
1193 | let mut s1 = HashSet::new(); | |
1194 | ||
85aaf69f | 1195 | s1.insert(1); |
1a4d82fc JJ |
1196 | s1.insert(2); |
1197 | s1.insert(3); | |
1198 | ||
1199 | let mut s2 = HashSet::new(); | |
1200 | ||
85aaf69f | 1201 | s2.insert(1); |
1a4d82fc JJ |
1202 | s2.insert(2); |
1203 | ||
1204 | assert!(s1 != s2); | |
1205 | ||
1206 | s2.insert(3); | |
1207 | ||
1208 | assert_eq!(s1, s2); | |
1209 | } | |
1210 | ||
1211 | #[test] | |
1212 | fn test_show() { | |
85aaf69f SL |
1213 | let mut set = HashSet::new(); |
1214 | let empty = HashSet::<i32>::new(); | |
1a4d82fc | 1215 | |
85aaf69f | 1216 | set.insert(1); |
1a4d82fc JJ |
1217 | set.insert(2); |
1218 | ||
1219 | let set_str = format!("{:?}", set); | |
1220 | ||
c34b1796 AL |
1221 | assert!(set_str == "{1, 2}" || set_str == "{2, 1}"); |
1222 | assert_eq!(format!("{:?}", empty), "{}"); | |
1a4d82fc JJ |
1223 | } |
1224 | ||
1225 | #[test] | |
1226 | fn test_trivial_drain() { | |
85aaf69f | 1227 | let mut s = HashSet::<i32>::new(); |
1a4d82fc JJ |
1228 | for _ in s.drain() {} |
1229 | assert!(s.is_empty()); | |
1230 | drop(s); | |
1231 | ||
85aaf69f | 1232 | let mut s = HashSet::<i32>::new(); |
1a4d82fc JJ |
1233 | drop(s.drain()); |
1234 | assert!(s.is_empty()); | |
1235 | } | |
1236 | ||
1237 | #[test] | |
1238 | fn test_drain() { | |
85aaf69f | 1239 | let mut s: HashSet<_> = (1..100).collect(); |
1a4d82fc JJ |
1240 | |
1241 | // try this a bunch of times to make sure we don't screw up internal state. | |
85aaf69f | 1242 | for _ in 0..20 { |
1a4d82fc JJ |
1243 | assert_eq!(s.len(), 99); |
1244 | ||
1245 | { | |
1246 | let mut last_i = 0; | |
1247 | let mut d = s.drain(); | |
1248 | for (i, x) in d.by_ref().take(50).enumerate() { | |
1249 | last_i = i; | |
1250 | assert!(x != 0); | |
1251 | } | |
1252 | assert_eq!(last_i, 49); | |
1253 | } | |
1254 | ||
85aaf69f | 1255 | for _ in &s { panic!("s should be empty!"); } |
1a4d82fc JJ |
1256 | |
1257 | // reset to try again. | |
85aaf69f | 1258 | s.extend(1..100); |
1a4d82fc JJ |
1259 | } |
1260 | } | |
1261 | } |