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Commit | Line | Data |
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1b1a35ee XL |
1 | #[cfg(test)] |
2 | mod tests; | |
3 | ||
4 | use hashbrown::hash_set as base; | |
5 | ||
532ac7d7 | 6 | use crate::borrow::Borrow; |
e1599b0c | 7 | use crate::collections::TryReserveError; |
532ac7d7 | 8 | use crate::fmt; |
dfeec247 | 9 | use crate::hash::{BuildHasher, Hash}; |
532ac7d7 | 10 | use crate::iter::{Chain, FromIterator, FusedIterator}; |
dfeec247 | 11 | use crate::ops::{BitAnd, BitOr, BitXor, Sub}; |
1a4d82fc | 12 | |
1b1a35ee | 13 | use super::map::{map_try_reserve_error, RandomState}; |
1a4d82fc JJ |
14 | |
15 | // Future Optimization (FIXME!) | |
532ac7d7 | 16 | // ============================ |
1a4d82fc JJ |
17 | // |
18 | // Iteration over zero sized values is a noop. There is no need | |
19 | // for `bucket.val` in the case of HashSet. I suppose we would need HKT | |
20 | // to get rid of it properly. | |
21 | ||
6a06907d | 22 | /// A [hash set] implemented as a `HashMap` where the value is `()`. |
d9579d0f | 23 | /// |
cc61c64b XL |
24 | /// As with the [`HashMap`] type, a `HashSet` requires that the elements |
25 | /// implement the [`Eq`] and [`Hash`] traits. This can frequently be achieved by | |
d9579d0f AL |
26 | /// using `#[derive(PartialEq, Eq, Hash)]`. If you implement these yourself, |
27 | /// it is important that the following property holds: | |
c34b1796 AL |
28 | /// |
29 | /// ```text | |
30 | /// k1 == k2 -> hash(k1) == hash(k2) | |
31 | /// ``` | |
32 | /// | |
33 | /// In other words, if two keys are equal, their hashes must be equal. | |
1a4d82fc | 34 | /// |
c34b1796 AL |
35 | /// |
36 | /// It is a logic error for an item to be modified in such a way that the | |
cc61c64b XL |
37 | /// item's hash, as determined by the [`Hash`] trait, or its equality, as |
38 | /// determined by the [`Eq`] trait, changes while it is in the set. This is | |
39 | /// normally only possible through [`Cell`], [`RefCell`], global state, I/O, or | |
5869c6ff XL |
40 | /// unsafe code. The behavior resulting from such a logic error is not |
41 | /// specified, but will not result in undefined behavior. This could include | |
42 | /// panics, incorrect results, aborts, memory leaks, and non-termination. | |
c34b1796 AL |
43 | /// |
44 | /// # Examples | |
1a4d82fc JJ |
45 | /// |
46 | /// ``` | |
47 | /// use std::collections::HashSet; | |
48 | /// // Type inference lets us omit an explicit type signature (which | |
94b46f34 | 49 | /// // would be `HashSet<String>` in this example). |
1a4d82fc JJ |
50 | /// let mut books = HashSet::new(); |
51 | /// | |
52 | /// // Add some books. | |
94b46f34 XL |
53 | /// books.insert("A Dance With Dragons".to_string()); |
54 | /// books.insert("To Kill a Mockingbird".to_string()); | |
55 | /// books.insert("The Odyssey".to_string()); | |
56 | /// books.insert("The Great Gatsby".to_string()); | |
1a4d82fc JJ |
57 | /// |
58 | /// // Check for a specific one. | |
d9579d0f | 59 | /// if !books.contains("The Winds of Winter") { |
1a4d82fc JJ |
60 | /// println!("We have {} books, but The Winds of Winter ain't one.", |
61 | /// books.len()); | |
62 | /// } | |
63 | /// | |
64 | /// // Remove a book. | |
d9579d0f | 65 | /// books.remove("The Odyssey"); |
1a4d82fc JJ |
66 | /// |
67 | /// // Iterate over everything. | |
d9579d0f AL |
68 | /// for book in &books { |
69 | /// println!("{}", book); | |
1a4d82fc JJ |
70 | /// } |
71 | /// ``` | |
72 | /// | |
73 | /// The easiest way to use `HashSet` with a custom type is to derive | |
cc61c64b XL |
74 | /// [`Eq`] and [`Hash`]. We must also derive [`PartialEq`], this will in the |
75 | /// future be implied by [`Eq`]. | |
1a4d82fc JJ |
76 | /// |
77 | /// ``` | |
78 | /// use std::collections::HashSet; | |
85aaf69f | 79 | /// #[derive(Hash, Eq, PartialEq, Debug)] |
94b46f34 XL |
80 | /// struct Viking { |
81 | /// name: String, | |
85aaf69f | 82 | /// power: usize, |
1a4d82fc JJ |
83 | /// } |
84 | /// | |
85 | /// let mut vikings = HashSet::new(); | |
86 | /// | |
94b46f34 XL |
87 | /// vikings.insert(Viking { name: "Einar".to_string(), power: 9 }); |
88 | /// vikings.insert(Viking { name: "Einar".to_string(), power: 9 }); | |
89 | /// vikings.insert(Viking { name: "Olaf".to_string(), power: 4 }); | |
90 | /// vikings.insert(Viking { name: "Harald".to_string(), power: 8 }); | |
1a4d82fc JJ |
91 | /// |
92 | /// // Use derived implementation to print the vikings. | |
d9579d0f | 93 | /// for x in &vikings { |
1a4d82fc JJ |
94 | /// println!("{:?}", x); |
95 | /// } | |
96 | /// ``` | |
c30ab7b3 | 97 | /// |
cc61c64b | 98 | /// A `HashSet` with fixed list of elements can be initialized from an array: |
c30ab7b3 SL |
99 | /// |
100 | /// ``` | |
101 | /// use std::collections::HashSet; | |
102 | /// | |
e74abb32 XL |
103 | /// let viking_names: HashSet<&'static str> = |
104 | /// [ "Einar", "Olaf", "Harald" ].iter().cloned().collect(); | |
105 | /// // use the values stored in the set | |
c30ab7b3 | 106 | /// ``` |
cc61c64b | 107 | /// |
6a06907d | 108 | /// [hash set]: crate::collections#use-the-set-variant-of-any-of-these-maps-when |
1b1a35ee | 109 | /// [`HashMap`]: crate::collections::HashMap |
3dfed10e XL |
110 | /// [`RefCell`]: crate::cell::RefCell |
111 | /// [`Cell`]: crate::cell::Cell | |
f9f354fc | 112 | #[cfg_attr(not(test), rustc_diagnostic_item = "hashset_type")] |
85aaf69f | 113 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 114 | pub struct HashSet<T, S = RandomState> { |
1b1a35ee | 115 | base: base::HashSet<T, S>, |
1a4d82fc JJ |
116 | } |
117 | ||
74b04a01 | 118 | impl<T> HashSet<T, RandomState> { |
3b2f2976 | 119 | /// Creates an empty `HashSet`. |
1a4d82fc | 120 | /// |
ea8adc8c XL |
121 | /// The hash set is initially created with a capacity of 0, so it will not allocate until it |
122 | /// is first inserted into. | |
123 | /// | |
c34b1796 | 124 | /// # Examples |
1a4d82fc JJ |
125 | /// |
126 | /// ``` | |
127 | /// use std::collections::HashSet; | |
3b2f2976 | 128 | /// let set: HashSet<i32> = HashSet::new(); |
1a4d82fc JJ |
129 | /// ``` |
130 | #[inline] | |
85aaf69f | 131 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 132 | pub fn new() -> HashSet<T, RandomState> { |
1b1a35ee | 133 | Default::default() |
1a4d82fc JJ |
134 | } |
135 | ||
c30ab7b3 SL |
136 | /// Creates an empty `HashSet` with the specified capacity. |
137 | /// | |
138 | /// The hash set will be able to hold at least `capacity` elements without | |
139 | /// reallocating. If `capacity` is 0, the hash set will not allocate. | |
1a4d82fc | 140 | /// |
c34b1796 | 141 | /// # Examples |
1a4d82fc JJ |
142 | /// |
143 | /// ``` | |
144 | /// use std::collections::HashSet; | |
3b2f2976 XL |
145 | /// let set: HashSet<i32> = HashSet::with_capacity(10); |
146 | /// assert!(set.capacity() >= 10); | |
1a4d82fc JJ |
147 | /// ``` |
148 | #[inline] | |
85aaf69f SL |
149 | #[stable(feature = "rust1", since = "1.0.0")] |
150 | pub fn with_capacity(capacity: usize) -> HashSet<T, RandomState> { | |
1b1a35ee | 151 | HashSet { base: base::HashSet::with_capacity_and_hasher(capacity, Default::default()) } |
1a4d82fc JJ |
152 | } |
153 | } | |
154 | ||
9fa01778 XL |
155 | impl<T, S> HashSet<T, S> { |
156 | /// Returns the number of elements the set can hold without reallocating. | |
157 | /// | |
158 | /// # Examples | |
159 | /// | |
160 | /// ``` | |
161 | /// use std::collections::HashSet; | |
162 | /// let set: HashSet<i32> = HashSet::with_capacity(100); | |
163 | /// assert!(set.capacity() >= 100); | |
164 | /// ``` | |
165 | #[inline] | |
166 | #[stable(feature = "rust1", since = "1.0.0")] | |
167 | pub fn capacity(&self) -> usize { | |
1b1a35ee | 168 | self.base.capacity() |
9fa01778 XL |
169 | } |
170 | ||
171 | /// An iterator visiting all elements in arbitrary order. | |
172 | /// The iterator element type is `&'a T`. | |
173 | /// | |
174 | /// # Examples | |
175 | /// | |
176 | /// ``` | |
177 | /// use std::collections::HashSet; | |
178 | /// let mut set = HashSet::new(); | |
179 | /// set.insert("a"); | |
180 | /// set.insert("b"); | |
181 | /// | |
182 | /// // Will print in an arbitrary order. | |
183 | /// for x in set.iter() { | |
184 | /// println!("{}", x); | |
185 | /// } | |
186 | /// ``` | |
48663c56 | 187 | #[inline] |
9fa01778 | 188 | #[stable(feature = "rust1", since = "1.0.0")] |
532ac7d7 | 189 | pub fn iter(&self) -> Iter<'_, T> { |
1b1a35ee | 190 | Iter { base: self.base.iter() } |
9fa01778 XL |
191 | } |
192 | ||
193 | /// Returns the number of elements in the set. | |
194 | /// | |
195 | /// # Examples | |
196 | /// | |
197 | /// ``` | |
198 | /// use std::collections::HashSet; | |
199 | /// | |
200 | /// let mut v = HashSet::new(); | |
201 | /// assert_eq!(v.len(), 0); | |
202 | /// v.insert(1); | |
203 | /// assert_eq!(v.len(), 1); | |
204 | /// ``` | |
5869c6ff | 205 | #[doc(alias = "length")] |
48663c56 | 206 | #[inline] |
9fa01778 XL |
207 | #[stable(feature = "rust1", since = "1.0.0")] |
208 | pub fn len(&self) -> usize { | |
1b1a35ee | 209 | self.base.len() |
9fa01778 XL |
210 | } |
211 | ||
212 | /// Returns `true` if the set contains no elements. | |
213 | /// | |
214 | /// # Examples | |
215 | /// | |
216 | /// ``` | |
217 | /// use std::collections::HashSet; | |
218 | /// | |
219 | /// let mut v = HashSet::new(); | |
220 | /// assert!(v.is_empty()); | |
221 | /// v.insert(1); | |
222 | /// assert!(!v.is_empty()); | |
223 | /// ``` | |
48663c56 | 224 | #[inline] |
9fa01778 XL |
225 | #[stable(feature = "rust1", since = "1.0.0")] |
226 | pub fn is_empty(&self) -> bool { | |
1b1a35ee | 227 | self.base.is_empty() |
9fa01778 XL |
228 | } |
229 | ||
230 | /// Clears the set, returning all elements in an iterator. | |
231 | /// | |
232 | /// # Examples | |
233 | /// | |
234 | /// ``` | |
235 | /// use std::collections::HashSet; | |
236 | /// | |
237 | /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
238 | /// assert!(!set.is_empty()); | |
239 | /// | |
240 | /// // print 1, 2, 3 in an arbitrary order | |
241 | /// for i in set.drain() { | |
242 | /// println!("{}", i); | |
243 | /// } | |
244 | /// | |
245 | /// assert!(set.is_empty()); | |
246 | /// ``` | |
247 | #[inline] | |
248 | #[stable(feature = "drain", since = "1.6.0")] | |
532ac7d7 | 249 | pub fn drain(&mut self) -> Drain<'_, T> { |
1b1a35ee XL |
250 | Drain { base: self.base.drain() } |
251 | } | |
252 | ||
253 | /// Creates an iterator which uses a closure to determine if a value should be removed. | |
254 | /// | |
255 | /// If the closure returns true, then the value is removed and yielded. | |
256 | /// If the closure returns false, the value will remain in the list and will not be yielded | |
257 | /// by the iterator. | |
258 | /// | |
259 | /// If the iterator is only partially consumed or not consumed at all, each of the remaining | |
260 | /// values will still be subjected to the closure and removed and dropped if it returns true. | |
261 | /// | |
262 | /// It is unspecified how many more values will be subjected to the closure | |
263 | /// if a panic occurs in the closure, or if a panic occurs while dropping a value, or if the | |
264 | /// `DrainFilter` itself is leaked. | |
265 | /// | |
266 | /// # Examples | |
267 | /// | |
268 | /// Splitting a set into even and odd values, reusing the original set: | |
269 | /// | |
270 | /// ``` | |
271 | /// #![feature(hash_drain_filter)] | |
272 | /// use std::collections::HashSet; | |
273 | /// | |
274 | /// let mut set: HashSet<i32> = (0..8).collect(); | |
275 | /// let drained: HashSet<i32> = set.drain_filter(|v| v % 2 == 0).collect(); | |
276 | /// | |
277 | /// let mut evens = drained.into_iter().collect::<Vec<_>>(); | |
278 | /// let mut odds = set.into_iter().collect::<Vec<_>>(); | |
279 | /// evens.sort(); | |
280 | /// odds.sort(); | |
281 | /// | |
282 | /// assert_eq!(evens, vec![0, 2, 4, 6]); | |
283 | /// assert_eq!(odds, vec![1, 3, 5, 7]); | |
284 | /// ``` | |
285 | #[inline] | |
286 | #[unstable(feature = "hash_drain_filter", issue = "59618")] | |
287 | pub fn drain_filter<F>(&mut self, pred: F) -> DrainFilter<'_, T, F> | |
288 | where | |
289 | F: FnMut(&T) -> bool, | |
290 | { | |
291 | DrainFilter { base: self.base.drain_filter(pred) } | |
9fa01778 XL |
292 | } |
293 | ||
294 | /// Clears the set, removing all values. | |
295 | /// | |
296 | /// # Examples | |
297 | /// | |
298 | /// ``` | |
299 | /// use std::collections::HashSet; | |
300 | /// | |
301 | /// let mut v = HashSet::new(); | |
302 | /// v.insert(1); | |
303 | /// v.clear(); | |
304 | /// assert!(v.is_empty()); | |
305 | /// ``` | |
48663c56 | 306 | #[inline] |
9fa01778 XL |
307 | #[stable(feature = "rust1", since = "1.0.0")] |
308 | pub fn clear(&mut self) { | |
1b1a35ee | 309 | self.base.clear() |
9fa01778 | 310 | } |
9fa01778 | 311 | |
1a4d82fc JJ |
312 | /// Creates a new empty hash set which will use the given hasher to hash |
313 | /// keys. | |
314 | /// | |
315 | /// The hash set is also created with the default initial capacity. | |
316 | /// | |
9cc50fc6 SL |
317 | /// Warning: `hasher` is normally randomly generated, and |
318 | /// is designed to allow `HashSet`s to be resistant to attacks that | |
319 | /// cause many collisions and very poor performance. Setting it | |
320 | /// manually using this function can expose a DoS attack vector. | |
321 | /// | |
f9f354fc XL |
322 | /// The `hash_builder` passed should implement the [`BuildHasher`] trait for |
323 | /// the HashMap to be useful, see its documentation for details. | |
324 | /// | |
c34b1796 | 325 | /// # Examples |
1a4d82fc JJ |
326 | /// |
327 | /// ``` | |
328 | /// use std::collections::HashSet; | |
329 | /// use std::collections::hash_map::RandomState; | |
330 | /// | |
331 | /// let s = RandomState::new(); | |
9cc50fc6 | 332 | /// let mut set = HashSet::with_hasher(s); |
85aaf69f | 333 | /// set.insert(2); |
1a4d82fc JJ |
334 | /// ``` |
335 | #[inline] | |
9cc50fc6 SL |
336 | #[stable(feature = "hashmap_build_hasher", since = "1.7.0")] |
337 | pub fn with_hasher(hasher: S) -> HashSet<T, S> { | |
1b1a35ee | 338 | HashSet { base: base::HashSet::with_hasher(hasher) } |
1a4d82fc JJ |
339 | } |
340 | ||
0731742a | 341 | /// Creates an empty `HashSet` with the specified capacity, using |
c30ab7b3 SL |
342 | /// `hasher` to hash the keys. |
343 | /// | |
344 | /// The hash set will be able to hold at least `capacity` elements without | |
345 | /// reallocating. If `capacity` is 0, the hash set will not allocate. | |
1a4d82fc JJ |
346 | /// |
347 | /// Warning: `hasher` is normally randomly generated, and | |
348 | /// is designed to allow `HashSet`s to be resistant to attacks that | |
349 | /// cause many collisions and very poor performance. Setting it | |
350 | /// manually using this function can expose a DoS attack vector. | |
351 | /// | |
f9f354fc XL |
352 | /// The `hash_builder` passed should implement the [`BuildHasher`] trait for |
353 | /// the HashMap to be useful, see its documentation for details. | |
354 | /// | |
c34b1796 | 355 | /// # Examples |
1a4d82fc JJ |
356 | /// |
357 | /// ``` | |
358 | /// use std::collections::HashSet; | |
359 | /// use std::collections::hash_map::RandomState; | |
360 | /// | |
361 | /// let s = RandomState::new(); | |
9cc50fc6 | 362 | /// let mut set = HashSet::with_capacity_and_hasher(10, s); |
85aaf69f | 363 | /// set.insert(1); |
1a4d82fc JJ |
364 | /// ``` |
365 | #[inline] | |
9cc50fc6 | 366 | #[stable(feature = "hashmap_build_hasher", since = "1.7.0")] |
c30ab7b3 | 367 | pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> HashSet<T, S> { |
1b1a35ee | 368 | HashSet { base: base::HashSet::with_capacity_and_hasher(capacity, hasher) } |
9cc50fc6 SL |
369 | } |
370 | ||
cc61c64b XL |
371 | /// Returns a reference to the set's [`BuildHasher`]. |
372 | /// | |
3b2f2976 XL |
373 | /// # Examples |
374 | /// | |
375 | /// ``` | |
376 | /// use std::collections::HashSet; | |
377 | /// use std::collections::hash_map::RandomState; | |
378 | /// | |
379 | /// let hasher = RandomState::new(); | |
380 | /// let set: HashSet<i32> = HashSet::with_hasher(hasher); | |
381 | /// let hasher: &RandomState = set.hasher(); | |
382 | /// ``` | |
48663c56 | 383 | #[inline] |
54a0048b | 384 | #[stable(feature = "hashmap_public_hasher", since = "1.9.0")] |
7453a54e | 385 | pub fn hasher(&self) -> &S { |
1b1a35ee | 386 | self.base.hasher() |
7453a54e | 387 | } |
74b04a01 | 388 | } |
7453a54e | 389 | |
74b04a01 XL |
390 | impl<T, S> HashSet<T, S> |
391 | where | |
392 | T: Eq + Hash, | |
393 | S: BuildHasher, | |
394 | { | |
1a4d82fc JJ |
395 | /// Reserves capacity for at least `additional` more elements to be inserted |
396 | /// in the `HashSet`. The collection may reserve more space to avoid | |
397 | /// frequent reallocations. | |
398 | /// | |
399 | /// # Panics | |
400 | /// | |
85aaf69f | 401 | /// Panics if the new allocation size overflows `usize`. |
1a4d82fc | 402 | /// |
c34b1796 | 403 | /// # Examples |
1a4d82fc JJ |
404 | /// |
405 | /// ``` | |
406 | /// use std::collections::HashSet; | |
85aaf69f | 407 | /// let mut set: HashSet<i32> = HashSet::new(); |
1a4d82fc | 408 | /// set.reserve(10); |
3b2f2976 | 409 | /// assert!(set.capacity() >= 10); |
1a4d82fc | 410 | /// ``` |
48663c56 | 411 | #[inline] |
85aaf69f SL |
412 | #[stable(feature = "rust1", since = "1.0.0")] |
413 | pub fn reserve(&mut self, additional: usize) { | |
1b1a35ee | 414 | self.base.reserve(additional) |
1a4d82fc JJ |
415 | } |
416 | ||
48663c56 | 417 | /// Tries to reserve capacity for at least `additional` more elements to be inserted |
29967ef6 | 418 | /// in the given `HashSet<K, V>`. The collection may reserve more space to avoid |
48663c56 XL |
419 | /// frequent reallocations. |
420 | /// | |
421 | /// # Errors | |
422 | /// | |
423 | /// If the capacity overflows, or the allocator reports a failure, then an error | |
424 | /// is returned. | |
425 | /// | |
426 | /// # Examples | |
427 | /// | |
428 | /// ``` | |
429 | /// #![feature(try_reserve)] | |
430 | /// use std::collections::HashSet; | |
431 | /// let mut set: HashSet<i32> = HashSet::new(); | |
432 | /// set.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?"); | |
433 | /// ``` | |
434 | #[inline] | |
dfeec247 | 435 | #[unstable(feature = "try_reserve", reason = "new API", issue = "48043")] |
e1599b0c | 436 | pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> { |
1b1a35ee | 437 | self.base.try_reserve(additional).map_err(map_try_reserve_error) |
48663c56 XL |
438 | } |
439 | ||
1a4d82fc JJ |
440 | /// Shrinks the capacity of the set as much as possible. It will drop |
441 | /// down as much as possible while maintaining the internal rules | |
442 | /// and possibly leaving some space in accordance with the resize policy. | |
443 | /// | |
c34b1796 | 444 | /// # Examples |
1a4d82fc JJ |
445 | /// |
446 | /// ``` | |
447 | /// use std::collections::HashSet; | |
448 | /// | |
85aaf69f | 449 | /// let mut set = HashSet::with_capacity(100); |
1a4d82fc JJ |
450 | /// set.insert(1); |
451 | /// set.insert(2); | |
452 | /// assert!(set.capacity() >= 100); | |
453 | /// set.shrink_to_fit(); | |
454 | /// assert!(set.capacity() >= 2); | |
455 | /// ``` | |
48663c56 | 456 | #[inline] |
85aaf69f | 457 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 458 | pub fn shrink_to_fit(&mut self) { |
1b1a35ee | 459 | self.base.shrink_to_fit() |
1a4d82fc JJ |
460 | } |
461 | ||
0531ce1d XL |
462 | /// Shrinks the capacity of the set with a lower limit. It will drop |
463 | /// down no lower than the supplied limit while maintaining the internal rules | |
464 | /// and possibly leaving some space in accordance with the resize policy. | |
465 | /// | |
5869c6ff | 466 | /// If the current capacity is less than the lower limit, this is a no-op. |
0531ce1d XL |
467 | /// # Examples |
468 | /// | |
469 | /// ``` | |
470 | /// #![feature(shrink_to)] | |
471 | /// use std::collections::HashSet; | |
472 | /// | |
473 | /// let mut set = HashSet::with_capacity(100); | |
474 | /// set.insert(1); | |
475 | /// set.insert(2); | |
476 | /// assert!(set.capacity() >= 100); | |
477 | /// set.shrink_to(10); | |
478 | /// assert!(set.capacity() >= 10); | |
479 | /// set.shrink_to(0); | |
480 | /// assert!(set.capacity() >= 2); | |
481 | /// ``` | |
482 | #[inline] | |
dfeec247 | 483 | #[unstable(feature = "shrink_to", reason = "new API", issue = "56431")] |
0531ce1d | 484 | pub fn shrink_to(&mut self, min_capacity: usize) { |
1b1a35ee | 485 | self.base.shrink_to(min_capacity) |
0531ce1d XL |
486 | } |
487 | ||
cc61c64b | 488 | /// Visits the values representing the difference, |
0731742a | 489 | /// i.e., the values that are in `self` but not in `other`. |
1a4d82fc | 490 | /// |
c34b1796 | 491 | /// # Examples |
1a4d82fc JJ |
492 | /// |
493 | /// ``` | |
494 | /// use std::collections::HashSet; | |
85aaf69f SL |
495 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
496 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1a4d82fc JJ |
497 | /// |
498 | /// // Can be seen as `a - b`. | |
499 | /// for x in a.difference(&b) { | |
500 | /// println!("{}", x); // Print 1 | |
501 | /// } | |
502 | /// | |
3b2f2976 XL |
503 | /// let diff: HashSet<_> = a.difference(&b).collect(); |
504 | /// assert_eq!(diff, [1].iter().collect()); | |
1a4d82fc JJ |
505 | /// |
506 | /// // Note that difference is not symmetric, | |
507 | /// // and `b - a` means something else: | |
3b2f2976 XL |
508 | /// let diff: HashSet<_> = b.difference(&a).collect(); |
509 | /// assert_eq!(diff, [4].iter().collect()); | |
1a4d82fc | 510 | /// ``` |
48663c56 | 511 | #[inline] |
85aaf69f | 512 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 513 | pub fn difference<'a>(&'a self, other: &'a HashSet<T, S>) -> Difference<'a, T, S> { |
dfeec247 | 514 | Difference { iter: self.iter(), other } |
1a4d82fc JJ |
515 | } |
516 | ||
cc61c64b | 517 | /// Visits the values representing the symmetric difference, |
0731742a | 518 | /// i.e., the values that are in `self` or in `other` but not in both. |
1a4d82fc | 519 | /// |
c34b1796 | 520 | /// # Examples |
1a4d82fc JJ |
521 | /// |
522 | /// ``` | |
523 | /// use std::collections::HashSet; | |
85aaf69f SL |
524 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
525 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1a4d82fc JJ |
526 | /// |
527 | /// // Print 1, 4 in arbitrary order. | |
528 | /// for x in a.symmetric_difference(&b) { | |
529 | /// println!("{}", x); | |
530 | /// } | |
531 | /// | |
3b2f2976 XL |
532 | /// let diff1: HashSet<_> = a.symmetric_difference(&b).collect(); |
533 | /// let diff2: HashSet<_> = b.symmetric_difference(&a).collect(); | |
1a4d82fc JJ |
534 | /// |
535 | /// assert_eq!(diff1, diff2); | |
3b2f2976 | 536 | /// assert_eq!(diff1, [1, 4].iter().collect()); |
1a4d82fc | 537 | /// ``` |
48663c56 | 538 | #[inline] |
85aaf69f | 539 | #[stable(feature = "rust1", since = "1.0.0")] |
dfeec247 XL |
540 | pub fn symmetric_difference<'a>( |
541 | &'a self, | |
542 | other: &'a HashSet<T, S>, | |
543 | ) -> SymmetricDifference<'a, T, S> { | |
1a4d82fc JJ |
544 | SymmetricDifference { iter: self.difference(other).chain(other.difference(self)) } |
545 | } | |
546 | ||
cc61c64b | 547 | /// Visits the values representing the intersection, |
0731742a | 548 | /// i.e., the values that are both in `self` and `other`. |
1a4d82fc | 549 | /// |
c34b1796 | 550 | /// # Examples |
1a4d82fc JJ |
551 | /// |
552 | /// ``` | |
553 | /// use std::collections::HashSet; | |
85aaf69f SL |
554 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
555 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1a4d82fc JJ |
556 | /// |
557 | /// // Print 2, 3 in arbitrary order. | |
558 | /// for x in a.intersection(&b) { | |
559 | /// println!("{}", x); | |
560 | /// } | |
561 | /// | |
3b2f2976 XL |
562 | /// let intersection: HashSet<_> = a.intersection(&b).collect(); |
563 | /// assert_eq!(intersection, [2, 3].iter().collect()); | |
1a4d82fc | 564 | /// ``` |
48663c56 | 565 | #[inline] |
85aaf69f | 566 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 567 | pub fn intersection<'a>(&'a self, other: &'a HashSet<T, S>) -> Intersection<'a, T, S> { |
0731742a | 568 | if self.len() <= other.len() { |
dfeec247 | 569 | Intersection { iter: self.iter(), other } |
0731742a | 570 | } else { |
dfeec247 | 571 | Intersection { iter: other.iter(), other: self } |
1a4d82fc JJ |
572 | } |
573 | } | |
574 | ||
cc61c64b | 575 | /// Visits the values representing the union, |
0731742a | 576 | /// i.e., all the values in `self` or `other`, without duplicates. |
1a4d82fc | 577 | /// |
c34b1796 | 578 | /// # Examples |
1a4d82fc JJ |
579 | /// |
580 | /// ``` | |
581 | /// use std::collections::HashSet; | |
85aaf69f SL |
582 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
583 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1a4d82fc JJ |
584 | /// |
585 | /// // Print 1, 2, 3, 4 in arbitrary order. | |
586 | /// for x in a.union(&b) { | |
587 | /// println!("{}", x); | |
588 | /// } | |
589 | /// | |
3b2f2976 XL |
590 | /// let union: HashSet<_> = a.union(&b).collect(); |
591 | /// assert_eq!(union, [1, 2, 3, 4].iter().collect()); | |
1a4d82fc | 592 | /// ``` |
48663c56 | 593 | #[inline] |
85aaf69f | 594 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 595 | pub fn union<'a>(&'a self, other: &'a HashSet<T, S>) -> Union<'a, T, S> { |
60c5eb7d | 596 | if self.len() >= other.len() { |
dfeec247 | 597 | Union { iter: self.iter().chain(other.difference(self)) } |
0731742a | 598 | } else { |
dfeec247 | 599 | Union { iter: other.iter().chain(self.difference(other)) } |
0731742a | 600 | } |
1a4d82fc JJ |
601 | } |
602 | ||
1a4d82fc JJ |
603 | /// Returns `true` if the set contains a value. |
604 | /// | |
605 | /// The value may be any borrowed form of the set's value type, but | |
cc61c64b | 606 | /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for |
1a4d82fc JJ |
607 | /// the value type. |
608 | /// | |
c34b1796 | 609 | /// # Examples |
1a4d82fc JJ |
610 | /// |
611 | /// ``` | |
612 | /// use std::collections::HashSet; | |
613 | /// | |
85aaf69f | 614 | /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
1a4d82fc JJ |
615 | /// assert_eq!(set.contains(&1), true); |
616 | /// assert_eq!(set.contains(&4), false); | |
617 | /// ``` | |
48663c56 | 618 | #[inline] |
85aaf69f | 619 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 620 | pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool |
dfeec247 XL |
621 | where |
622 | T: Borrow<Q>, | |
623 | Q: Hash + Eq, | |
1a4d82fc | 624 | { |
1b1a35ee | 625 | self.base.contains(value) |
1a4d82fc JJ |
626 | } |
627 | ||
e9174d1e SL |
628 | /// Returns a reference to the value in the set, if any, that is equal to the given value. |
629 | /// | |
630 | /// The value may be any borrowed form of the set's value type, but | |
cc61c64b | 631 | /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for |
e9174d1e | 632 | /// the value type. |
cc61c64b | 633 | /// |
2c00a5a8 XL |
634 | /// # Examples |
635 | /// | |
636 | /// ``` | |
637 | /// use std::collections::HashSet; | |
638 | /// | |
639 | /// let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
640 | /// assert_eq!(set.get(&2), Some(&2)); | |
641 | /// assert_eq!(set.get(&4), None); | |
642 | /// ``` | |
48663c56 | 643 | #[inline] |
54a0048b | 644 | #[stable(feature = "set_recovery", since = "1.9.0")] |
e9174d1e | 645 | pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T> |
dfeec247 XL |
646 | where |
647 | T: Borrow<Q>, | |
648 | Q: Hash + Eq, | |
e9174d1e | 649 | { |
1b1a35ee | 650 | self.base.get(value) |
48663c56 XL |
651 | } |
652 | ||
653 | /// Inserts the given `value` into the set if it is not present, then | |
654 | /// returns a reference to the value in the set. | |
655 | /// | |
656 | /// # Examples | |
657 | /// | |
658 | /// ``` | |
659 | /// #![feature(hash_set_entry)] | |
660 | /// | |
661 | /// use std::collections::HashSet; | |
662 | /// | |
663 | /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
664 | /// assert_eq!(set.len(), 3); | |
665 | /// assert_eq!(set.get_or_insert(2), &2); | |
666 | /// assert_eq!(set.get_or_insert(100), &100); | |
667 | /// assert_eq!(set.len(), 4); // 100 was inserted | |
668 | /// ``` | |
669 | #[inline] | |
670 | #[unstable(feature = "hash_set_entry", issue = "60896")] | |
671 | pub fn get_or_insert(&mut self, value: T) -> &T { | |
672 | // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with | |
673 | // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`. | |
1b1a35ee | 674 | self.base.get_or_insert(value) |
48663c56 XL |
675 | } |
676 | ||
dfeec247 XL |
677 | /// Inserts an owned copy of the given `value` into the set if it is not |
678 | /// present, then returns a reference to the value in the set. | |
679 | /// | |
680 | /// # Examples | |
681 | /// | |
682 | /// ``` | |
683 | /// #![feature(hash_set_entry)] | |
684 | /// | |
685 | /// use std::collections::HashSet; | |
686 | /// | |
687 | /// let mut set: HashSet<String> = ["cat", "dog", "horse"] | |
688 | /// .iter().map(|&pet| pet.to_owned()).collect(); | |
689 | /// | |
690 | /// assert_eq!(set.len(), 3); | |
691 | /// for &pet in &["cat", "dog", "fish"] { | |
692 | /// let value = set.get_or_insert_owned(pet); | |
693 | /// assert_eq!(value, pet); | |
694 | /// } | |
695 | /// assert_eq!(set.len(), 4); // a new "fish" was inserted | |
696 | /// ``` | |
697 | #[inline] | |
698 | #[unstable(feature = "hash_set_entry", issue = "60896")] | |
699 | pub fn get_or_insert_owned<Q: ?Sized>(&mut self, value: &Q) -> &T | |
700 | where | |
701 | T: Borrow<Q>, | |
702 | Q: Hash + Eq + ToOwned<Owned = T>, | |
703 | { | |
704 | // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with | |
705 | // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`. | |
1b1a35ee | 706 | self.base.get_or_insert_owned(value) |
dfeec247 XL |
707 | } |
708 | ||
48663c56 XL |
709 | /// Inserts a value computed from `f` into the set if the given `value` is |
710 | /// not present, then returns a reference to the value in the set. | |
711 | /// | |
712 | /// # Examples | |
713 | /// | |
714 | /// ``` | |
715 | /// #![feature(hash_set_entry)] | |
716 | /// | |
717 | /// use std::collections::HashSet; | |
718 | /// | |
719 | /// let mut set: HashSet<String> = ["cat", "dog", "horse"] | |
720 | /// .iter().map(|&pet| pet.to_owned()).collect(); | |
721 | /// | |
722 | /// assert_eq!(set.len(), 3); | |
723 | /// for &pet in &["cat", "dog", "fish"] { | |
724 | /// let value = set.get_or_insert_with(pet, str::to_owned); | |
725 | /// assert_eq!(value, pet); | |
726 | /// } | |
727 | /// assert_eq!(set.len(), 4); // a new "fish" was inserted | |
728 | /// ``` | |
729 | #[inline] | |
730 | #[unstable(feature = "hash_set_entry", issue = "60896")] | |
731 | pub fn get_or_insert_with<Q: ?Sized, F>(&mut self, value: &Q, f: F) -> &T | |
dfeec247 XL |
732 | where |
733 | T: Borrow<Q>, | |
734 | Q: Hash + Eq, | |
735 | F: FnOnce(&Q) -> T, | |
48663c56 XL |
736 | { |
737 | // Although the raw entry gives us `&mut T`, we only return `&T` to be consistent with | |
738 | // `get`. Key mutation is "raw" because you're not supposed to affect `Eq` or `Hash`. | |
1b1a35ee | 739 | self.base.get_or_insert_with(value, f) |
e9174d1e SL |
740 | } |
741 | ||
8bb4bdeb | 742 | /// Returns `true` if `self` has no elements in common with `other`. |
1a4d82fc JJ |
743 | /// This is equivalent to checking for an empty intersection. |
744 | /// | |
c34b1796 | 745 | /// # Examples |
1a4d82fc JJ |
746 | /// |
747 | /// ``` | |
748 | /// use std::collections::HashSet; | |
749 | /// | |
85aaf69f SL |
750 | /// let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
751 | /// let mut b = HashSet::new(); | |
1a4d82fc JJ |
752 | /// |
753 | /// assert_eq!(a.is_disjoint(&b), true); | |
754 | /// b.insert(4); | |
755 | /// assert_eq!(a.is_disjoint(&b), true); | |
756 | /// b.insert(1); | |
757 | /// assert_eq!(a.is_disjoint(&b), false); | |
758 | /// ``` | |
85aaf69f | 759 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 760 | pub fn is_disjoint(&self, other: &HashSet<T, S>) -> bool { |
0731742a XL |
761 | if self.len() <= other.len() { |
762 | self.iter().all(|v| !other.contains(v)) | |
763 | } else { | |
764 | other.iter().all(|v| !self.contains(v)) | |
765 | } | |
1a4d82fc JJ |
766 | } |
767 | ||
8bb4bdeb | 768 | /// Returns `true` if the set is a subset of another, |
0731742a | 769 | /// i.e., `other` contains at least all the values in `self`. |
1a4d82fc | 770 | /// |
c34b1796 | 771 | /// # Examples |
1a4d82fc JJ |
772 | /// |
773 | /// ``` | |
774 | /// use std::collections::HashSet; | |
775 | /// | |
85aaf69f SL |
776 | /// let sup: HashSet<_> = [1, 2, 3].iter().cloned().collect(); |
777 | /// let mut set = HashSet::new(); | |
1a4d82fc JJ |
778 | /// |
779 | /// assert_eq!(set.is_subset(&sup), true); | |
780 | /// set.insert(2); | |
781 | /// assert_eq!(set.is_subset(&sup), true); | |
782 | /// set.insert(4); | |
783 | /// assert_eq!(set.is_subset(&sup), false); | |
784 | /// ``` | |
85aaf69f | 785 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 786 | pub fn is_subset(&self, other: &HashSet<T, S>) -> bool { |
dfeec247 | 787 | if self.len() <= other.len() { self.iter().all(|v| other.contains(v)) } else { false } |
1a4d82fc JJ |
788 | } |
789 | ||
8bb4bdeb | 790 | /// Returns `true` if the set is a superset of another, |
0731742a | 791 | /// i.e., `self` contains at least all the values in `other`. |
1a4d82fc | 792 | /// |
c34b1796 | 793 | /// # Examples |
1a4d82fc JJ |
794 | /// |
795 | /// ``` | |
796 | /// use std::collections::HashSet; | |
797 | /// | |
85aaf69f SL |
798 | /// let sub: HashSet<_> = [1, 2].iter().cloned().collect(); |
799 | /// let mut set = HashSet::new(); | |
1a4d82fc JJ |
800 | /// |
801 | /// assert_eq!(set.is_superset(&sub), false); | |
802 | /// | |
803 | /// set.insert(0); | |
804 | /// set.insert(1); | |
805 | /// assert_eq!(set.is_superset(&sub), false); | |
806 | /// | |
807 | /// set.insert(2); | |
808 | /// assert_eq!(set.is_superset(&sub), true); | |
809 | /// ``` | |
810 | #[inline] | |
85aaf69f | 811 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
812 | pub fn is_superset(&self, other: &HashSet<T, S>) -> bool { |
813 | other.is_subset(self) | |
814 | } | |
815 | ||
b039eaaf SL |
816 | /// Adds a value to the set. |
817 | /// | |
a7813a04 | 818 | /// If the set did not have this value present, `true` is returned. |
b039eaaf | 819 | /// |
a7813a04 | 820 | /// If the set did have this value present, `false` is returned. |
1a4d82fc | 821 | /// |
c34b1796 | 822 | /// # Examples |
1a4d82fc JJ |
823 | /// |
824 | /// ``` | |
825 | /// use std::collections::HashSet; | |
826 | /// | |
827 | /// let mut set = HashSet::new(); | |
828 | /// | |
85aaf69f | 829 | /// assert_eq!(set.insert(2), true); |
1a4d82fc JJ |
830 | /// assert_eq!(set.insert(2), false); |
831 | /// assert_eq!(set.len(), 1); | |
832 | /// ``` | |
48663c56 | 833 | #[inline] |
85aaf69f | 834 | #[stable(feature = "rust1", since = "1.0.0")] |
c30ab7b3 | 835 | pub fn insert(&mut self, value: T) -> bool { |
1b1a35ee | 836 | self.base.insert(value) |
c30ab7b3 | 837 | } |
1a4d82fc | 838 | |
e9174d1e SL |
839 | /// Adds a value to the set, replacing the existing value, if any, that is equal to the given |
840 | /// one. Returns the replaced value. | |
2c00a5a8 XL |
841 | /// |
842 | /// # Examples | |
843 | /// | |
844 | /// ``` | |
845 | /// use std::collections::HashSet; | |
846 | /// | |
847 | /// let mut set = HashSet::new(); | |
848 | /// set.insert(Vec::<i32>::new()); | |
849 | /// | |
850 | /// assert_eq!(set.get(&[][..]).unwrap().capacity(), 0); | |
851 | /// set.replace(Vec::with_capacity(10)); | |
852 | /// assert_eq!(set.get(&[][..]).unwrap().capacity(), 10); | |
853 | /// ``` | |
48663c56 | 854 | #[inline] |
54a0048b | 855 | #[stable(feature = "set_recovery", since = "1.9.0")] |
e9174d1e | 856 | pub fn replace(&mut self, value: T) -> Option<T> { |
1b1a35ee | 857 | self.base.replace(value) |
e9174d1e SL |
858 | } |
859 | ||
9fa01778 | 860 | /// Removes a value from the set. Returns whether the value was |
1a4d82fc JJ |
861 | /// present in the set. |
862 | /// | |
863 | /// The value may be any borrowed form of the set's value type, but | |
cc61c64b | 864 | /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for |
1a4d82fc JJ |
865 | /// the value type. |
866 | /// | |
c34b1796 | 867 | /// # Examples |
1a4d82fc JJ |
868 | /// |
869 | /// ``` | |
870 | /// use std::collections::HashSet; | |
871 | /// | |
872 | /// let mut set = HashSet::new(); | |
873 | /// | |
85aaf69f | 874 | /// set.insert(2); |
1a4d82fc JJ |
875 | /// assert_eq!(set.remove(&2), true); |
876 | /// assert_eq!(set.remove(&2), false); | |
877 | /// ``` | |
5869c6ff | 878 | #[doc(alias = "delete")] |
48663c56 | 879 | #[inline] |
85aaf69f | 880 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 881 | pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool |
dfeec247 XL |
882 | where |
883 | T: Borrow<Q>, | |
884 | Q: Hash + Eq, | |
1a4d82fc | 885 | { |
1b1a35ee | 886 | self.base.remove(value) |
1a4d82fc | 887 | } |
e9174d1e SL |
888 | |
889 | /// Removes and returns the value in the set, if any, that is equal to the given one. | |
890 | /// | |
891 | /// The value may be any borrowed form of the set's value type, but | |
cc61c64b | 892 | /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for |
e9174d1e | 893 | /// the value type. |
cc61c64b | 894 | /// |
2c00a5a8 XL |
895 | /// # Examples |
896 | /// | |
897 | /// ``` | |
898 | /// use std::collections::HashSet; | |
899 | /// | |
900 | /// let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); | |
901 | /// assert_eq!(set.take(&2), Some(2)); | |
902 | /// assert_eq!(set.take(&2), None); | |
903 | /// ``` | |
48663c56 | 904 | #[inline] |
54a0048b | 905 | #[stable(feature = "set_recovery", since = "1.9.0")] |
e9174d1e | 906 | pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T> |
dfeec247 XL |
907 | where |
908 | T: Borrow<Q>, | |
909 | Q: Hash + Eq, | |
e9174d1e | 910 | { |
1b1a35ee | 911 | self.base.take(value) |
e9174d1e | 912 | } |
8bb4bdeb XL |
913 | |
914 | /// Retains only the elements specified by the predicate. | |
915 | /// | |
916 | /// In other words, remove all elements `e` such that `f(&e)` returns `false`. | |
917 | /// | |
918 | /// # Examples | |
919 | /// | |
920 | /// ``` | |
8bb4bdeb XL |
921 | /// use std::collections::HashSet; |
922 | /// | |
29967ef6 | 923 | /// let xs = [1, 2, 3, 4, 5, 6]; |
0531ce1d | 924 | /// let mut set: HashSet<i32> = xs.iter().cloned().collect(); |
8bb4bdeb XL |
925 | /// set.retain(|&k| k % 2 == 0); |
926 | /// assert_eq!(set.len(), 3); | |
927 | /// ``` | |
cc61c64b | 928 | #[stable(feature = "retain_hash_collection", since = "1.18.0")] |
1b1a35ee | 929 | pub fn retain<F>(&mut self, f: F) |
dfeec247 XL |
930 | where |
931 | F: FnMut(&T) -> bool, | |
8bb4bdeb | 932 | { |
1b1a35ee | 933 | self.base.retain(f) |
8bb4bdeb | 934 | } |
1a4d82fc JJ |
935 | } |
936 | ||
5869c6ff XL |
937 | #[stable(feature = "rust1", since = "1.0.0")] |
938 | impl<T, S> Clone for HashSet<T, S> | |
939 | where | |
940 | T: Clone, | |
941 | S: Clone, | |
942 | { | |
943 | #[inline] | |
944 | fn clone(&self) -> Self { | |
945 | Self { base: self.base.clone() } | |
946 | } | |
947 | ||
948 | #[inline] | |
949 | fn clone_from(&mut self, other: &Self) { | |
950 | self.base.clone_from(&other.base); | |
951 | } | |
952 | } | |
953 | ||
85aaf69f SL |
954 | #[stable(feature = "rust1", since = "1.0.0")] |
955 | impl<T, S> PartialEq for HashSet<T, S> | |
dfeec247 XL |
956 | where |
957 | T: Eq + Hash, | |
958 | S: BuildHasher, | |
1a4d82fc JJ |
959 | { |
960 | fn eq(&self, other: &HashSet<T, S>) -> bool { | |
c30ab7b3 SL |
961 | if self.len() != other.len() { |
962 | return false; | |
963 | } | |
1a4d82fc JJ |
964 | |
965 | self.iter().all(|key| other.contains(key)) | |
966 | } | |
967 | } | |
968 | ||
85aaf69f SL |
969 | #[stable(feature = "rust1", since = "1.0.0")] |
970 | impl<T, S> Eq for HashSet<T, S> | |
dfeec247 XL |
971 | where |
972 | T: Eq + Hash, | |
973 | S: BuildHasher, | |
c30ab7b3 SL |
974 | { |
975 | } | |
1a4d82fc | 976 | |
85aaf69f SL |
977 | #[stable(feature = "rust1", since = "1.0.0")] |
978 | impl<T, S> fmt::Debug for HashSet<T, S> | |
dfeec247 | 979 | where |
74b04a01 | 980 | T: fmt::Debug, |
1a4d82fc | 981 | { |
532ac7d7 | 982 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
62682a34 | 983 | f.debug_set().entries(self.iter()).finish() |
1a4d82fc JJ |
984 | } |
985 | } | |
986 | ||
85aaf69f SL |
987 | #[stable(feature = "rust1", since = "1.0.0")] |
988 | impl<T, S> FromIterator<T> for HashSet<T, S> | |
dfeec247 XL |
989 | where |
990 | T: Eq + Hash, | |
991 | S: BuildHasher + Default, | |
1a4d82fc | 992 | { |
48663c56 | 993 | #[inline] |
c30ab7b3 | 994 | fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> HashSet<T, S> { |
476ff2be SL |
995 | let mut set = HashSet::with_hasher(Default::default()); |
996 | set.extend(iter); | |
1a4d82fc JJ |
997 | set |
998 | } | |
999 | } | |
1000 | ||
85aaf69f SL |
1001 | #[stable(feature = "rust1", since = "1.0.0")] |
1002 | impl<T, S> Extend<T> for HashSet<T, S> | |
dfeec247 XL |
1003 | where |
1004 | T: Eq + Hash, | |
1005 | S: BuildHasher, | |
1a4d82fc | 1006 | { |
48663c56 | 1007 | #[inline] |
c30ab7b3 | 1008 | fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) { |
1b1a35ee | 1009 | self.base.extend(iter); |
1a4d82fc | 1010 | } |
f9f354fc XL |
1011 | |
1012 | #[inline] | |
1013 | fn extend_one(&mut self, item: T) { | |
1b1a35ee | 1014 | self.base.insert(item); |
f9f354fc XL |
1015 | } |
1016 | ||
1017 | #[inline] | |
1018 | fn extend_reserve(&mut self, additional: usize) { | |
1b1a35ee | 1019 | self.base.extend_reserve(additional); |
f9f354fc | 1020 | } |
1a4d82fc JJ |
1021 | } |
1022 | ||
e9174d1e SL |
1023 | #[stable(feature = "hash_extend_copy", since = "1.4.0")] |
1024 | impl<'a, T, S> Extend<&'a T> for HashSet<T, S> | |
dfeec247 XL |
1025 | where |
1026 | T: 'a + Eq + Hash + Copy, | |
1027 | S: BuildHasher, | |
e9174d1e | 1028 | { |
48663c56 | 1029 | #[inline] |
c30ab7b3 | 1030 | fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) { |
e9174d1e SL |
1031 | self.extend(iter.into_iter().cloned()); |
1032 | } | |
f9f354fc XL |
1033 | |
1034 | #[inline] | |
1035 | fn extend_one(&mut self, &item: &'a T) { | |
1b1a35ee | 1036 | self.base.insert(item); |
f9f354fc XL |
1037 | } |
1038 | ||
1039 | #[inline] | |
1040 | fn extend_reserve(&mut self, additional: usize) { | |
1041 | Extend::<T>::extend_reserve(self, additional) | |
1042 | } | |
e9174d1e SL |
1043 | } |
1044 | ||
85aaf69f SL |
1045 | #[stable(feature = "rust1", since = "1.0.0")] |
1046 | impl<T, S> Default for HashSet<T, S> | |
dfeec247 | 1047 | where |
74b04a01 | 1048 | S: Default, |
1a4d82fc | 1049 | { |
9e0c209e | 1050 | /// Creates an empty `HashSet<T, S>` with the `Default` value for the hasher. |
48663c56 | 1051 | #[inline] |
1a4d82fc | 1052 | fn default() -> HashSet<T, S> { |
1b1a35ee | 1053 | HashSet { base: Default::default() } |
1a4d82fc JJ |
1054 | } |
1055 | } | |
1056 | ||
85aaf69f | 1057 | #[stable(feature = "rust1", since = "1.0.0")] |
532ac7d7 | 1058 | impl<T, S> BitOr<&HashSet<T, S>> for &HashSet<T, S> |
dfeec247 XL |
1059 | where |
1060 | T: Eq + Hash + Clone, | |
1061 | S: BuildHasher + Default, | |
1a4d82fc JJ |
1062 | { |
1063 | type Output = HashSet<T, S>; | |
1064 | ||
1065 | /// Returns the union of `self` and `rhs` as a new `HashSet<T, S>`. | |
1066 | /// | |
1067 | /// # Examples | |
1068 | /// | |
1069 | /// ``` | |
1070 | /// use std::collections::HashSet; | |
1071 | /// | |
85aaf69f SL |
1072 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); |
1073 | /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); | |
1a4d82fc | 1074 | /// |
85aaf69f | 1075 | /// let set = &a | &b; |
1a4d82fc JJ |
1076 | /// |
1077 | /// let mut i = 0; | |
1078 | /// let expected = [1, 2, 3, 4, 5]; | |
62682a34 | 1079 | /// for x in &set { |
1a4d82fc JJ |
1080 | /// assert!(expected.contains(x)); |
1081 | /// i += 1; | |
1082 | /// } | |
1083 | /// assert_eq!(i, expected.len()); | |
1084 | /// ``` | |
1085 | fn bitor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
1086 | self.union(rhs).cloned().collect() | |
1087 | } | |
1088 | } | |
1089 | ||
85aaf69f | 1090 | #[stable(feature = "rust1", since = "1.0.0")] |
532ac7d7 | 1091 | impl<T, S> BitAnd<&HashSet<T, S>> for &HashSet<T, S> |
dfeec247 XL |
1092 | where |
1093 | T: Eq + Hash + Clone, | |
1094 | S: BuildHasher + Default, | |
1a4d82fc JJ |
1095 | { |
1096 | type Output = HashSet<T, S>; | |
1097 | ||
1098 | /// Returns the intersection of `self` and `rhs` as a new `HashSet<T, S>`. | |
1099 | /// | |
1100 | /// # Examples | |
1101 | /// | |
1102 | /// ``` | |
1103 | /// use std::collections::HashSet; | |
1104 | /// | |
85aaf69f SL |
1105 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); |
1106 | /// let b: HashSet<_> = vec![2, 3, 4].into_iter().collect(); | |
1a4d82fc | 1107 | /// |
85aaf69f | 1108 | /// let set = &a & &b; |
1a4d82fc JJ |
1109 | /// |
1110 | /// let mut i = 0; | |
1111 | /// let expected = [2, 3]; | |
62682a34 | 1112 | /// for x in &set { |
1a4d82fc JJ |
1113 | /// assert!(expected.contains(x)); |
1114 | /// i += 1; | |
1115 | /// } | |
1116 | /// assert_eq!(i, expected.len()); | |
1117 | /// ``` | |
1118 | fn bitand(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
1119 | self.intersection(rhs).cloned().collect() | |
1120 | } | |
1121 | } | |
1122 | ||
85aaf69f | 1123 | #[stable(feature = "rust1", since = "1.0.0")] |
532ac7d7 | 1124 | impl<T, S> BitXor<&HashSet<T, S>> for &HashSet<T, S> |
dfeec247 XL |
1125 | where |
1126 | T: Eq + Hash + Clone, | |
1127 | S: BuildHasher + Default, | |
1a4d82fc JJ |
1128 | { |
1129 | type Output = HashSet<T, S>; | |
1130 | ||
1131 | /// Returns the symmetric difference of `self` and `rhs` as a new `HashSet<T, S>`. | |
1132 | /// | |
1133 | /// # Examples | |
1134 | /// | |
1135 | /// ``` | |
1136 | /// use std::collections::HashSet; | |
1137 | /// | |
85aaf69f SL |
1138 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); |
1139 | /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); | |
1a4d82fc | 1140 | /// |
85aaf69f | 1141 | /// let set = &a ^ &b; |
1a4d82fc JJ |
1142 | /// |
1143 | /// let mut i = 0; | |
1144 | /// let expected = [1, 2, 4, 5]; | |
62682a34 | 1145 | /// for x in &set { |
1a4d82fc JJ |
1146 | /// assert!(expected.contains(x)); |
1147 | /// i += 1; | |
1148 | /// } | |
1149 | /// assert_eq!(i, expected.len()); | |
1150 | /// ``` | |
1151 | fn bitxor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
1152 | self.symmetric_difference(rhs).cloned().collect() | |
1153 | } | |
1154 | } | |
1155 | ||
85aaf69f | 1156 | #[stable(feature = "rust1", since = "1.0.0")] |
532ac7d7 | 1157 | impl<T, S> Sub<&HashSet<T, S>> for &HashSet<T, S> |
dfeec247 XL |
1158 | where |
1159 | T: Eq + Hash + Clone, | |
1160 | S: BuildHasher + Default, | |
1a4d82fc JJ |
1161 | { |
1162 | type Output = HashSet<T, S>; | |
1163 | ||
1164 | /// Returns the difference of `self` and `rhs` as a new `HashSet<T, S>`. | |
1165 | /// | |
1166 | /// # Examples | |
1167 | /// | |
1168 | /// ``` | |
1169 | /// use std::collections::HashSet; | |
1170 | /// | |
85aaf69f SL |
1171 | /// let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); |
1172 | /// let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); | |
1a4d82fc | 1173 | /// |
85aaf69f | 1174 | /// let set = &a - &b; |
1a4d82fc JJ |
1175 | /// |
1176 | /// let mut i = 0; | |
1177 | /// let expected = [1, 2]; | |
62682a34 | 1178 | /// for x in &set { |
1a4d82fc JJ |
1179 | /// assert!(expected.contains(x)); |
1180 | /// i += 1; | |
1181 | /// } | |
1182 | /// assert_eq!(i, expected.len()); | |
1183 | /// ``` | |
1184 | fn sub(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { | |
1185 | self.difference(rhs).cloned().collect() | |
1186 | } | |
1187 | } | |
1188 | ||
cc61c64b XL |
1189 | /// An iterator over the items of a `HashSet`. |
1190 | /// | |
1191 | /// This `struct` is created by the [`iter`] method on [`HashSet`]. | |
1192 | /// See its documentation for more. | |
1193 | /// | |
3dfed10e | 1194 | /// [`iter`]: HashSet::iter |
1b1a35ee XL |
1195 | /// |
1196 | /// # Examples | |
1197 | /// | |
1198 | /// ``` | |
1199 | /// use std::collections::HashSet; | |
1200 | /// | |
1201 | /// let a: HashSet<u32> = vec![1, 2, 3].into_iter().collect(); | |
1202 | /// | |
1203 | /// let mut iter = a.iter(); | |
1204 | /// ``` | |
85aaf69f | 1205 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 1206 | pub struct Iter<'a, K: 'a> { |
1b1a35ee | 1207 | base: base::Iter<'a, K>, |
1a4d82fc JJ |
1208 | } |
1209 | ||
cc61c64b XL |
1210 | /// An owning iterator over the items of a `HashSet`. |
1211 | /// | |
dfeec247 | 1212 | /// This `struct` is created by the [`into_iter`] method on [`HashSet`] |
cc61c64b XL |
1213 | /// (provided by the `IntoIterator` trait). See its documentation for more. |
1214 | /// | |
3dfed10e | 1215 | /// [`into_iter`]: IntoIterator::into_iter |
1b1a35ee XL |
1216 | /// |
1217 | /// # Examples | |
1218 | /// | |
1219 | /// ``` | |
1220 | /// use std::collections::HashSet; | |
1221 | /// | |
1222 | /// let a: HashSet<u32> = vec![1, 2, 3].into_iter().collect(); | |
1223 | /// | |
1224 | /// let mut iter = a.into_iter(); | |
1225 | /// ``` | |
85aaf69f | 1226 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 1227 | pub struct IntoIter<K> { |
1b1a35ee | 1228 | base: base::IntoIter<K>, |
1a4d82fc JJ |
1229 | } |
1230 | ||
cc61c64b XL |
1231 | /// A draining iterator over the items of a `HashSet`. |
1232 | /// | |
1233 | /// This `struct` is created by the [`drain`] method on [`HashSet`]. | |
1234 | /// See its documentation for more. | |
1235 | /// | |
3dfed10e | 1236 | /// [`drain`]: HashSet::drain |
1b1a35ee XL |
1237 | /// |
1238 | /// # Examples | |
1239 | /// | |
1240 | /// ``` | |
1241 | /// use std::collections::HashSet; | |
1242 | /// | |
1243 | /// let mut a: HashSet<u32> = vec![1, 2, 3].into_iter().collect(); | |
1244 | /// | |
1245 | /// let mut drain = a.drain(); | |
1246 | /// ``` | |
85aaf69f | 1247 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 1248 | pub struct Drain<'a, K: 'a> { |
1b1a35ee XL |
1249 | base: base::Drain<'a, K>, |
1250 | } | |
1251 | ||
1252 | /// A draining, filtering iterator over the items of a `HashSet`. | |
1253 | /// | |
1254 | /// This `struct` is created by the [`drain_filter`] method on [`HashSet`]. | |
1255 | /// | |
1256 | /// [`drain_filter`]: HashSet::drain_filter | |
1257 | /// | |
1258 | /// # Examples | |
1259 | /// | |
1260 | /// ``` | |
1261 | /// #![feature(hash_drain_filter)] | |
1262 | /// | |
1263 | /// use std::collections::HashSet; | |
1264 | /// | |
1265 | /// let mut a: HashSet<u32> = vec![1, 2, 3].into_iter().collect(); | |
1266 | /// | |
1267 | /// let mut drain_filtered = a.drain_filter(|v| v % 2 == 0); | |
1268 | /// ``` | |
1269 | #[unstable(feature = "hash_drain_filter", issue = "59618")] | |
1270 | pub struct DrainFilter<'a, K, F> | |
1271 | where | |
1272 | F: FnMut(&K) -> bool, | |
1273 | { | |
1274 | base: base::DrainFilter<'a, K, F>, | |
1a4d82fc JJ |
1275 | } |
1276 | ||
cc61c64b XL |
1277 | /// A lazy iterator producing elements in the intersection of `HashSet`s. |
1278 | /// | |
1279 | /// This `struct` is created by the [`intersection`] method on [`HashSet`]. | |
1280 | /// See its documentation for more. | |
1281 | /// | |
3dfed10e | 1282 | /// [`intersection`]: HashSet::intersection |
1b1a35ee XL |
1283 | /// |
1284 | /// # Examples | |
1285 | /// | |
1286 | /// ``` | |
1287 | /// use std::collections::HashSet; | |
1288 | /// | |
1289 | /// let a: HashSet<u32> = vec![1, 2, 3].into_iter().collect(); | |
1290 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1291 | /// | |
1292 | /// let mut intersection = a.intersection(&b); | |
1293 | /// ``` | |
85aaf69f | 1294 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1295 | pub struct Intersection<'a, T: 'a, S: 'a> { |
1296 | // iterator of the first set | |
1297 | iter: Iter<'a, T>, | |
1298 | // the second set | |
1299 | other: &'a HashSet<T, S>, | |
1300 | } | |
1301 | ||
cc61c64b XL |
1302 | /// A lazy iterator producing elements in the difference of `HashSet`s. |
1303 | /// | |
1304 | /// This `struct` is created by the [`difference`] method on [`HashSet`]. | |
1305 | /// See its documentation for more. | |
1306 | /// | |
3dfed10e | 1307 | /// [`difference`]: HashSet::difference |
1b1a35ee XL |
1308 | /// |
1309 | /// # Examples | |
1310 | /// | |
1311 | /// ``` | |
1312 | /// use std::collections::HashSet; | |
1313 | /// | |
1314 | /// let a: HashSet<u32> = vec![1, 2, 3].into_iter().collect(); | |
1315 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1316 | /// | |
1317 | /// let mut difference = a.difference(&b); | |
1318 | /// ``` | |
85aaf69f | 1319 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1320 | pub struct Difference<'a, T: 'a, S: 'a> { |
1321 | // iterator of the first set | |
1322 | iter: Iter<'a, T>, | |
1323 | // the second set | |
1324 | other: &'a HashSet<T, S>, | |
1325 | } | |
1326 | ||
cc61c64b XL |
1327 | /// A lazy iterator producing elements in the symmetric difference of `HashSet`s. |
1328 | /// | |
1329 | /// This `struct` is created by the [`symmetric_difference`] method on | |
1330 | /// [`HashSet`]. See its documentation for more. | |
1331 | /// | |
3dfed10e | 1332 | /// [`symmetric_difference`]: HashSet::symmetric_difference |
1b1a35ee XL |
1333 | /// |
1334 | /// # Examples | |
1335 | /// | |
1336 | /// ``` | |
1337 | /// use std::collections::HashSet; | |
1338 | /// | |
1339 | /// let a: HashSet<u32> = vec![1, 2, 3].into_iter().collect(); | |
1340 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1341 | /// | |
1342 | /// let mut intersection = a.symmetric_difference(&b); | |
1343 | /// ``` | |
85aaf69f | 1344 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 1345 | pub struct SymmetricDifference<'a, T: 'a, S: 'a> { |
c30ab7b3 | 1346 | iter: Chain<Difference<'a, T, S>, Difference<'a, T, S>>, |
1a4d82fc JJ |
1347 | } |
1348 | ||
cc61c64b XL |
1349 | /// A lazy iterator producing elements in the union of `HashSet`s. |
1350 | /// | |
1351 | /// This `struct` is created by the [`union`] method on [`HashSet`]. | |
1352 | /// See its documentation for more. | |
1353 | /// | |
3dfed10e | 1354 | /// [`union`]: HashSet::union |
1b1a35ee XL |
1355 | /// |
1356 | /// # Examples | |
1357 | /// | |
1358 | /// ``` | |
1359 | /// use std::collections::HashSet; | |
1360 | /// | |
1361 | /// let a: HashSet<u32> = vec![1, 2, 3].into_iter().collect(); | |
1362 | /// let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); | |
1363 | /// | |
1364 | /// let mut union_iter = a.union(&b); | |
1365 | /// ``` | |
85aaf69f | 1366 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 1367 | pub struct Union<'a, T: 'a, S: 'a> { |
c30ab7b3 | 1368 | iter: Chain<Iter<'a, T>, Difference<'a, T, S>>, |
1a4d82fc JJ |
1369 | } |
1370 | ||
85aaf69f | 1371 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1372 | impl<'a, T, S> IntoIterator for &'a HashSet<T, S> { |
85aaf69f SL |
1373 | type Item = &'a T; |
1374 | type IntoIter = Iter<'a, T>; | |
1375 | ||
48663c56 | 1376 | #[inline] |
85aaf69f SL |
1377 | fn into_iter(self) -> Iter<'a, T> { |
1378 | self.iter() | |
1379 | } | |
1380 | } | |
1381 | ||
1382 | #[stable(feature = "rust1", since = "1.0.0")] | |
9fa01778 | 1383 | impl<T, S> IntoIterator for HashSet<T, S> { |
85aaf69f SL |
1384 | type Item = T; |
1385 | type IntoIter = IntoIter<T>; | |
1386 | ||
9346a6ac AL |
1387 | /// Creates a consuming iterator, that is, one that moves each value out |
1388 | /// of the set in arbitrary order. The set cannot be used after calling | |
1389 | /// this. | |
1390 | /// | |
1391 | /// # Examples | |
1392 | /// | |
1393 | /// ``` | |
1394 | /// use std::collections::HashSet; | |
1395 | /// let mut set = HashSet::new(); | |
1396 | /// set.insert("a".to_string()); | |
1397 | /// set.insert("b".to_string()); | |
1398 | /// | |
1399 | /// // Not possible to collect to a Vec<String> with a regular `.iter()`. | |
1400 | /// let v: Vec<String> = set.into_iter().collect(); | |
1401 | /// | |
1402 | /// // Will print in an arbitrary order. | |
62682a34 | 1403 | /// for x in &v { |
9346a6ac AL |
1404 | /// println!("{}", x); |
1405 | /// } | |
1406 | /// ``` | |
48663c56 | 1407 | #[inline] |
85aaf69f | 1408 | fn into_iter(self) -> IntoIter<T> { |
1b1a35ee | 1409 | IntoIter { base: self.base.into_iter() } |
85aaf69f SL |
1410 | } |
1411 | } | |
1412 | ||
92a42be0 | 1413 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1414 | impl<K> Clone for Iter<'_, K> { |
48663c56 | 1415 | #[inline] |
9fa01778 | 1416 | fn clone(&self) -> Self { |
1b1a35ee | 1417 | Iter { base: self.base.clone() } |
c30ab7b3 | 1418 | } |
c34b1796 | 1419 | } |
85aaf69f | 1420 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1421 | impl<'a, K> Iterator for Iter<'a, K> { |
1422 | type Item = &'a K; | |
1423 | ||
48663c56 | 1424 | #[inline] |
c30ab7b3 | 1425 | fn next(&mut self) -> Option<&'a K> { |
1b1a35ee | 1426 | self.base.next() |
c30ab7b3 | 1427 | } |
48663c56 | 1428 | #[inline] |
c30ab7b3 | 1429 | fn size_hint(&self) -> (usize, Option<usize>) { |
1b1a35ee | 1430 | self.base.size_hint() |
c30ab7b3 | 1431 | } |
85aaf69f SL |
1432 | } |
1433 | #[stable(feature = "rust1", since = "1.0.0")] | |
9fa01778 | 1434 | impl<K> ExactSizeIterator for Iter<'_, K> { |
48663c56 | 1435 | #[inline] |
c30ab7b3 | 1436 | fn len(&self) -> usize { |
1b1a35ee | 1437 | self.base.len() |
c30ab7b3 | 1438 | } |
1a4d82fc | 1439 | } |
0531ce1d | 1440 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1441 | impl<K> FusedIterator for Iter<'_, K> {} |
1a4d82fc | 1442 | |
8bb4bdeb | 1443 | #[stable(feature = "std_debug", since = "1.16.0")] |
9fa01778 | 1444 | impl<K: fmt::Debug> fmt::Debug for Iter<'_, K> { |
532ac7d7 | 1445 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
cc61c64b | 1446 | f.debug_list().entries(self.clone()).finish() |
32a655c1 SL |
1447 | } |
1448 | } | |
1449 | ||
85aaf69f | 1450 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1451 | impl<K> Iterator for IntoIter<K> { |
1452 | type Item = K; | |
1453 | ||
48663c56 | 1454 | #[inline] |
c30ab7b3 | 1455 | fn next(&mut self) -> Option<K> { |
1b1a35ee | 1456 | self.base.next() |
c30ab7b3 | 1457 | } |
48663c56 | 1458 | #[inline] |
c30ab7b3 | 1459 | fn size_hint(&self) -> (usize, Option<usize>) { |
1b1a35ee | 1460 | self.base.size_hint() |
c30ab7b3 | 1461 | } |
85aaf69f SL |
1462 | } |
1463 | #[stable(feature = "rust1", since = "1.0.0")] | |
1464 | impl<K> ExactSizeIterator for IntoIter<K> { | |
48663c56 | 1465 | #[inline] |
c30ab7b3 | 1466 | fn len(&self) -> usize { |
1b1a35ee | 1467 | self.base.len() |
c30ab7b3 | 1468 | } |
1a4d82fc | 1469 | } |
0531ce1d | 1470 | #[stable(feature = "fused", since = "1.26.0")] |
9e0c209e | 1471 | impl<K> FusedIterator for IntoIter<K> {} |
1a4d82fc | 1472 | |
8bb4bdeb | 1473 | #[stable(feature = "std_debug", since = "1.16.0")] |
32a655c1 | 1474 | impl<K: fmt::Debug> fmt::Debug for IntoIter<K> { |
532ac7d7 | 1475 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
1b1a35ee | 1476 | fmt::Debug::fmt(&self.base, f) |
32a655c1 SL |
1477 | } |
1478 | } | |
1479 | ||
85aaf69f SL |
1480 | #[stable(feature = "rust1", since = "1.0.0")] |
1481 | impl<'a, K> Iterator for Drain<'a, K> { | |
1a4d82fc JJ |
1482 | type Item = K; |
1483 | ||
48663c56 | 1484 | #[inline] |
c30ab7b3 | 1485 | fn next(&mut self) -> Option<K> { |
1b1a35ee | 1486 | self.base.next() |
c30ab7b3 | 1487 | } |
48663c56 | 1488 | #[inline] |
c30ab7b3 | 1489 | fn size_hint(&self) -> (usize, Option<usize>) { |
1b1a35ee | 1490 | self.base.size_hint() |
c30ab7b3 | 1491 | } |
85aaf69f SL |
1492 | } |
1493 | #[stable(feature = "rust1", since = "1.0.0")] | |
9fa01778 | 1494 | impl<K> ExactSizeIterator for Drain<'_, K> { |
48663c56 | 1495 | #[inline] |
c30ab7b3 | 1496 | fn len(&self) -> usize { |
1b1a35ee | 1497 | self.base.len() |
c30ab7b3 | 1498 | } |
1a4d82fc | 1499 | } |
0531ce1d | 1500 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1501 | impl<K> FusedIterator for Drain<'_, K> {} |
1a4d82fc | 1502 | |
8bb4bdeb | 1503 | #[stable(feature = "std_debug", since = "1.16.0")] |
9fa01778 | 1504 | impl<K: fmt::Debug> fmt::Debug for Drain<'_, K> { |
532ac7d7 | 1505 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
1b1a35ee XL |
1506 | fmt::Debug::fmt(&self.base, f) |
1507 | } | |
1508 | } | |
1509 | ||
1510 | #[unstable(feature = "hash_drain_filter", issue = "59618")] | |
1511 | impl<K, F> Iterator for DrainFilter<'_, K, F> | |
1512 | where | |
1513 | F: FnMut(&K) -> bool, | |
1514 | { | |
1515 | type Item = K; | |
1516 | ||
1517 | #[inline] | |
1518 | fn next(&mut self) -> Option<K> { | |
1519 | self.base.next() | |
1520 | } | |
1521 | #[inline] | |
1522 | fn size_hint(&self) -> (usize, Option<usize>) { | |
1523 | self.base.size_hint() | |
1524 | } | |
1525 | } | |
1526 | ||
1527 | #[unstable(feature = "hash_drain_filter", issue = "59618")] | |
1528 | impl<K, F> FusedIterator for DrainFilter<'_, K, F> where F: FnMut(&K) -> bool {} | |
1529 | ||
1530 | #[unstable(feature = "hash_drain_filter", issue = "59618")] | |
1531 | impl<'a, K, F> fmt::Debug for DrainFilter<'a, K, F> | |
1532 | where | |
1533 | F: FnMut(&K) -> bool, | |
1534 | { | |
1535 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
cdc7bbd5 | 1536 | f.debug_struct("DrainFilter").finish_non_exhaustive() |
32a655c1 SL |
1537 | } |
1538 | } | |
1539 | ||
92a42be0 | 1540 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1541 | impl<T, S> Clone for Intersection<'_, T, S> { |
48663c56 | 1542 | #[inline] |
9fa01778 | 1543 | fn clone(&self) -> Self { |
c34b1796 AL |
1544 | Intersection { iter: self.iter.clone(), ..*self } |
1545 | } | |
1546 | } | |
1547 | ||
85aaf69f SL |
1548 | #[stable(feature = "rust1", since = "1.0.0")] |
1549 | impl<'a, T, S> Iterator for Intersection<'a, T, S> | |
dfeec247 XL |
1550 | where |
1551 | T: Eq + Hash, | |
1552 | S: BuildHasher, | |
1a4d82fc JJ |
1553 | { |
1554 | type Item = &'a T; | |
1555 | ||
48663c56 | 1556 | #[inline] |
1a4d82fc JJ |
1557 | fn next(&mut self) -> Option<&'a T> { |
1558 | loop { | |
ff7c6d11 XL |
1559 | let elt = self.iter.next()?; |
1560 | if self.other.contains(elt) { | |
1561 | return Some(elt); | |
1a4d82fc JJ |
1562 | } |
1563 | } | |
1564 | } | |
1565 | ||
48663c56 | 1566 | #[inline] |
85aaf69f | 1567 | fn size_hint(&self) -> (usize, Option<usize>) { |
1a4d82fc JJ |
1568 | let (_, upper) = self.iter.size_hint(); |
1569 | (0, upper) | |
1570 | } | |
1571 | } | |
1572 | ||
8bb4bdeb | 1573 | #[stable(feature = "std_debug", since = "1.16.0")] |
9fa01778 | 1574 | impl<T, S> fmt::Debug for Intersection<'_, T, S> |
dfeec247 XL |
1575 | where |
1576 | T: fmt::Debug + Eq + Hash, | |
1577 | S: BuildHasher, | |
32a655c1 | 1578 | { |
532ac7d7 | 1579 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
cc61c64b | 1580 | f.debug_list().entries(self.clone()).finish() |
32a655c1 SL |
1581 | } |
1582 | } | |
1583 | ||
0531ce1d | 1584 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1585 | impl<T, S> FusedIterator for Intersection<'_, T, S> |
dfeec247 XL |
1586 | where |
1587 | T: Eq + Hash, | |
1588 | S: BuildHasher, | |
c30ab7b3 SL |
1589 | { |
1590 | } | |
9e0c209e | 1591 | |
92a42be0 | 1592 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1593 | impl<T, S> Clone for Difference<'_, T, S> { |
48663c56 | 1594 | #[inline] |
9fa01778 | 1595 | fn clone(&self) -> Self { |
c34b1796 AL |
1596 | Difference { iter: self.iter.clone(), ..*self } |
1597 | } | |
1598 | } | |
1599 | ||
85aaf69f SL |
1600 | #[stable(feature = "rust1", since = "1.0.0")] |
1601 | impl<'a, T, S> Iterator for Difference<'a, T, S> | |
dfeec247 XL |
1602 | where |
1603 | T: Eq + Hash, | |
1604 | S: BuildHasher, | |
1a4d82fc JJ |
1605 | { |
1606 | type Item = &'a T; | |
1607 | ||
48663c56 | 1608 | #[inline] |
1a4d82fc JJ |
1609 | fn next(&mut self) -> Option<&'a T> { |
1610 | loop { | |
ff7c6d11 XL |
1611 | let elt = self.iter.next()?; |
1612 | if !self.other.contains(elt) { | |
1613 | return Some(elt); | |
1a4d82fc JJ |
1614 | } |
1615 | } | |
1616 | } | |
1617 | ||
48663c56 | 1618 | #[inline] |
85aaf69f | 1619 | fn size_hint(&self) -> (usize, Option<usize>) { |
1a4d82fc JJ |
1620 | let (_, upper) = self.iter.size_hint(); |
1621 | (0, upper) | |
1622 | } | |
1623 | } | |
1624 | ||
0531ce1d | 1625 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1626 | impl<T, S> FusedIterator for Difference<'_, T, S> |
dfeec247 XL |
1627 | where |
1628 | T: Eq + Hash, | |
1629 | S: BuildHasher, | |
c30ab7b3 SL |
1630 | { |
1631 | } | |
9e0c209e | 1632 | |
8bb4bdeb | 1633 | #[stable(feature = "std_debug", since = "1.16.0")] |
9fa01778 | 1634 | impl<T, S> fmt::Debug for Difference<'_, T, S> |
dfeec247 XL |
1635 | where |
1636 | T: fmt::Debug + Eq + Hash, | |
1637 | S: BuildHasher, | |
32a655c1 | 1638 | { |
532ac7d7 | 1639 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
cc61c64b | 1640 | f.debug_list().entries(self.clone()).finish() |
32a655c1 SL |
1641 | } |
1642 | } | |
1643 | ||
92a42be0 | 1644 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1645 | impl<T, S> Clone for SymmetricDifference<'_, T, S> { |
48663c56 | 1646 | #[inline] |
9fa01778 | 1647 | fn clone(&self) -> Self { |
c34b1796 AL |
1648 | SymmetricDifference { iter: self.iter.clone() } |
1649 | } | |
1650 | } | |
1651 | ||
85aaf69f SL |
1652 | #[stable(feature = "rust1", since = "1.0.0")] |
1653 | impl<'a, T, S> Iterator for SymmetricDifference<'a, T, S> | |
dfeec247 XL |
1654 | where |
1655 | T: Eq + Hash, | |
1656 | S: BuildHasher, | |
1a4d82fc JJ |
1657 | { |
1658 | type Item = &'a T; | |
1659 | ||
48663c56 | 1660 | #[inline] |
c30ab7b3 SL |
1661 | fn next(&mut self) -> Option<&'a T> { |
1662 | self.iter.next() | |
1663 | } | |
48663c56 | 1664 | #[inline] |
c30ab7b3 SL |
1665 | fn size_hint(&self) -> (usize, Option<usize>) { |
1666 | self.iter.size_hint() | |
1667 | } | |
1a4d82fc JJ |
1668 | } |
1669 | ||
0531ce1d | 1670 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1671 | impl<T, S> FusedIterator for SymmetricDifference<'_, T, S> |
dfeec247 XL |
1672 | where |
1673 | T: Eq + Hash, | |
1674 | S: BuildHasher, | |
c30ab7b3 SL |
1675 | { |
1676 | } | |
9e0c209e | 1677 | |
8bb4bdeb | 1678 | #[stable(feature = "std_debug", since = "1.16.0")] |
9fa01778 | 1679 | impl<T, S> fmt::Debug for SymmetricDifference<'_, T, S> |
dfeec247 XL |
1680 | where |
1681 | T: fmt::Debug + Eq + Hash, | |
1682 | S: BuildHasher, | |
32a655c1 | 1683 | { |
532ac7d7 | 1684 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
cc61c64b | 1685 | f.debug_list().entries(self.clone()).finish() |
32a655c1 SL |
1686 | } |
1687 | } | |
1688 | ||
92a42be0 | 1689 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1690 | impl<T, S> Clone for Union<'_, T, S> { |
48663c56 | 1691 | #[inline] |
9fa01778 | 1692 | fn clone(&self) -> Self { |
c30ab7b3 SL |
1693 | Union { iter: self.iter.clone() } |
1694 | } | |
c34b1796 AL |
1695 | } |
1696 | ||
0531ce1d | 1697 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1698 | impl<T, S> FusedIterator for Union<'_, T, S> |
dfeec247 XL |
1699 | where |
1700 | T: Eq + Hash, | |
1701 | S: BuildHasher, | |
c30ab7b3 SL |
1702 | { |
1703 | } | |
9e0c209e | 1704 | |
8bb4bdeb | 1705 | #[stable(feature = "std_debug", since = "1.16.0")] |
9fa01778 | 1706 | impl<T, S> fmt::Debug for Union<'_, T, S> |
dfeec247 XL |
1707 | where |
1708 | T: fmt::Debug + Eq + Hash, | |
1709 | S: BuildHasher, | |
32a655c1 | 1710 | { |
532ac7d7 | 1711 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
cc61c64b | 1712 | f.debug_list().entries(self.clone()).finish() |
32a655c1 SL |
1713 | } |
1714 | } | |
1715 | ||
85aaf69f SL |
1716 | #[stable(feature = "rust1", since = "1.0.0")] |
1717 | impl<'a, T, S> Iterator for Union<'a, T, S> | |
dfeec247 XL |
1718 | where |
1719 | T: Eq + Hash, | |
1720 | S: BuildHasher, | |
1a4d82fc JJ |
1721 | { |
1722 | type Item = &'a T; | |
1723 | ||
48663c56 | 1724 | #[inline] |
c30ab7b3 SL |
1725 | fn next(&mut self) -> Option<&'a T> { |
1726 | self.iter.next() | |
1727 | } | |
48663c56 | 1728 | #[inline] |
c30ab7b3 SL |
1729 | fn size_hint(&self) -> (usize, Option<usize>) { |
1730 | self.iter.size_hint() | |
1731 | } | |
1a4d82fc JJ |
1732 | } |
1733 | ||
54a0048b SL |
1734 | #[allow(dead_code)] |
1735 | fn assert_covariance() { | |
c30ab7b3 SL |
1736 | fn set<'new>(v: HashSet<&'static str>) -> HashSet<&'new str> { |
1737 | v | |
1738 | } | |
1739 | fn iter<'a, 'new>(v: Iter<'a, &'static str>) -> Iter<'a, &'new str> { | |
1740 | v | |
1741 | } | |
1742 | fn into_iter<'new>(v: IntoIter<&'static str>) -> IntoIter<&'new str> { | |
1743 | v | |
1744 | } | |
dfeec247 XL |
1745 | fn difference<'a, 'new>( |
1746 | v: Difference<'a, &'static str, RandomState>, | |
1747 | ) -> Difference<'a, &'new str, RandomState> { | |
c30ab7b3 SL |
1748 | v |
1749 | } | |
dfeec247 XL |
1750 | fn symmetric_difference<'a, 'new>( |
1751 | v: SymmetricDifference<'a, &'static str, RandomState>, | |
1752 | ) -> SymmetricDifference<'a, &'new str, RandomState> { | |
c30ab7b3 SL |
1753 | v |
1754 | } | |
dfeec247 XL |
1755 | fn intersection<'a, 'new>( |
1756 | v: Intersection<'a, &'static str, RandomState>, | |
1757 | ) -> Intersection<'a, &'new str, RandomState> { | |
c30ab7b3 SL |
1758 | v |
1759 | } | |
dfeec247 XL |
1760 | fn union<'a, 'new>( |
1761 | v: Union<'a, &'static str, RandomState>, | |
1762 | ) -> Union<'a, &'new str, RandomState> { | |
c30ab7b3 SL |
1763 | v |
1764 | } | |
1765 | fn drain<'new>(d: Drain<'static, &'static str>) -> Drain<'new, &'new str> { | |
1766 | d | |
1767 | } | |
54a0048b | 1768 | } |