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Commit | Line | Data |
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1a4d82fc JJ |
1 | // This is pretty much entirely stolen from TreeSet, since BTreeMap has an identical interface |
2 | // to TreeMap | |
3 | ||
c295e0f8 | 4 | use crate::vec::Vec; |
9fa01778 | 5 | use core::borrow::Borrow; |
dfeec247 | 6 | use core::cmp::Ordering::{Equal, Greater, Less}; |
e1599b0c | 7 | use core::cmp::{max, min}; |
9fa01778 | 8 | use core::fmt::{self, Debug}; |
dfeec247 XL |
9 | use core::iter::{FromIterator, FusedIterator, Peekable}; |
10 | use core::ops::{BitAnd, BitOr, BitXor, RangeBounds, Sub}; | |
1a4d82fc | 11 | |
ba9703b0 | 12 | use super::map::{BTreeMap, Keys}; |
29967ef6 | 13 | use super::merge_iter::MergeIterInner; |
e9174d1e | 14 | use super::Recover; |
1a4d82fc JJ |
15 | |
16 | // FIXME(conventions): implement bounded iterators | |
17 | ||
18 | /// A set based on a B-Tree. | |
19 | /// | |
9cc50fc6 | 20 | /// See [`BTreeMap`]'s documentation for a detailed discussion of this collection's performance |
1a4d82fc | 21 | /// benefits and drawbacks. |
c34b1796 AL |
22 | /// |
23 | /// It is a logic error for an item to be modified in such a way that the item's ordering relative | |
9cc50fc6 SL |
24 | /// to any other item, as determined by the [`Ord`] trait, changes while it is in the set. This is |
25 | /// normally only possible through [`Cell`], [`RefCell`], global state, I/O, or unsafe code. | |
5869c6ff XL |
26 | /// The behavior resulting from such a logic error is not specified, but will not result in |
27 | /// undefined behavior. This could include panics, incorrect results, aborts, memory leaks, and | |
28 | /// non-termination. | |
9cc50fc6 | 29 | /// |
3dfed10e XL |
30 | /// [`Ord`]: core::cmp::Ord |
31 | /// [`Cell`]: core::cell::Cell | |
32 | /// [`RefCell`]: core::cell::RefCell | |
54a0048b SL |
33 | /// |
34 | /// # Examples | |
35 | /// | |
36 | /// ``` | |
37 | /// use std::collections::BTreeSet; | |
38 | /// | |
39 | /// // Type inference lets us omit an explicit type signature (which | |
40 | /// // would be `BTreeSet<&str>` in this example). | |
41 | /// let mut books = BTreeSet::new(); | |
42 | /// | |
43 | /// // Add some books. | |
44 | /// books.insert("A Dance With Dragons"); | |
45 | /// books.insert("To Kill a Mockingbird"); | |
46 | /// books.insert("The Odyssey"); | |
47 | /// books.insert("The Great Gatsby"); | |
48 | /// | |
49 | /// // Check for a specific one. | |
50 | /// if !books.contains("The Winds of Winter") { | |
51 | /// println!("We have {} books, but The Winds of Winter ain't one.", | |
52 | /// books.len()); | |
53 | /// } | |
54 | /// | |
55 | /// // Remove a book. | |
56 | /// books.remove("The Odyssey"); | |
57 | /// | |
58 | /// // Iterate over everything. | |
59 | /// for book in &books { | |
60 | /// println!("{}", book); | |
61 | /// } | |
62 | /// ``` | |
94222f64 XL |
63 | /// |
64 | /// A `BTreeSet` with a known list of items can be initialized from an array: | |
65 | /// | |
66 | /// ``` | |
67 | /// use std::collections::BTreeSet; | |
68 | /// | |
69 | /// let set = BTreeSet::from([1, 2, 3]); | |
70 | /// ``` | |
74b04a01 | 71 | #[derive(Hash, PartialEq, Eq, Ord, PartialOrd)] |
85aaf69f | 72 | #[stable(feature = "rust1", since = "1.0.0")] |
6a06907d | 73 | #[cfg_attr(not(test), rustc_diagnostic_item = "BTreeSet")] |
92a42be0 | 74 | pub struct BTreeSet<T> { |
1a4d82fc JJ |
75 | map: BTreeMap<T, ()>, |
76 | } | |
77 | ||
74b04a01 XL |
78 | #[stable(feature = "rust1", since = "1.0.0")] |
79 | impl<T: Clone> Clone for BTreeSet<T> { | |
80 | fn clone(&self) -> Self { | |
81 | BTreeSet { map: self.map.clone() } | |
82 | } | |
83 | ||
84 | fn clone_from(&mut self, other: &Self) { | |
85 | self.map.clone_from(&other.map); | |
86 | } | |
87 | } | |
88 | ||
cc61c64b | 89 | /// An iterator over the items of a `BTreeSet`. |
32a655c1 | 90 | /// |
cc61c64b XL |
91 | /// This `struct` is created by the [`iter`] method on [`BTreeSet`]. |
92 | /// See its documentation for more. | |
32a655c1 | 93 | /// |
3dfed10e | 94 | /// [`iter`]: BTreeSet::iter |
85aaf69f | 95 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 96 | pub struct Iter<'a, T: 'a> { |
92a42be0 | 97 | iter: Keys<'a, T, ()>, |
1a4d82fc JJ |
98 | } |
99 | ||
8bb4bdeb | 100 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
101 | impl<T: fmt::Debug> fmt::Debug for Iter<'_, T> { |
102 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
dfeec247 | 103 | f.debug_tuple("Iter").field(&self.iter.clone()).finish() |
8bb4bdeb XL |
104 | } |
105 | } | |
106 | ||
cc61c64b | 107 | /// An owning iterator over the items of a `BTreeSet`. |
32a655c1 | 108 | /// |
dfeec247 | 109 | /// This `struct` is created by the [`into_iter`] method on [`BTreeSet`] |
c295e0f8 | 110 | /// (provided by the [`IntoIterator`] trait). See its documentation for more. |
32a655c1 | 111 | /// |
3dfed10e | 112 | /// [`into_iter`]: BTreeSet#method.into_iter |
c295e0f8 | 113 | /// [`IntoIterator`]: core::iter::IntoIterator |
85aaf69f | 114 | #[stable(feature = "rust1", since = "1.0.0")] |
8bb4bdeb | 115 | #[derive(Debug)] |
1a4d82fc | 116 | pub struct IntoIter<T> { |
ba9703b0 | 117 | iter: super::map::IntoIter<T, ()>, |
85aaf69f SL |
118 | } |
119 | ||
cc61c64b | 120 | /// An iterator over a sub-range of items in a `BTreeSet`. |
32a655c1 | 121 | /// |
cc61c64b XL |
122 | /// This `struct` is created by the [`range`] method on [`BTreeSet`]. |
123 | /// See its documentation for more. | |
32a655c1 | 124 | /// |
3dfed10e | 125 | /// [`range`]: BTreeSet::range |
8bb4bdeb XL |
126 | #[derive(Debug)] |
127 | #[stable(feature = "btree_range", since = "1.17.0")] | |
85aaf69f | 128 | pub struct Range<'a, T: 'a> { |
ba9703b0 | 129 | iter: super::map::Range<'a, T, ()>, |
1a4d82fc JJ |
130 | } |
131 | ||
cc61c64b | 132 | /// A lazy iterator producing elements in the difference of `BTreeSet`s. |
32a655c1 | 133 | /// |
cc61c64b XL |
134 | /// This `struct` is created by the [`difference`] method on [`BTreeSet`]. |
135 | /// See its documentation for more. | |
32a655c1 | 136 | /// |
3dfed10e | 137 | /// [`difference`]: BTreeSet::difference |
85aaf69f | 138 | #[stable(feature = "rust1", since = "1.0.0")] |
92a42be0 | 139 | pub struct Difference<'a, T: 'a> { |
532ac7d7 XL |
140 | inner: DifferenceInner<'a, T>, |
141 | } | |
e74abb32 | 142 | #[derive(Debug)] |
532ac7d7 XL |
143 | enum DifferenceInner<'a, T: 'a> { |
144 | Stitch { | |
60c5eb7d | 145 | // iterate all of `self` and some of `other`, spotting matches along the way |
532ac7d7 XL |
146 | self_iter: Iter<'a, T>, |
147 | other_iter: Peekable<Iter<'a, T>>, | |
148 | }, | |
149 | Search { | |
60c5eb7d | 150 | // iterate `self`, look up in `other` |
532ac7d7 XL |
151 | self_iter: Iter<'a, T>, |
152 | other_set: &'a BTreeSet<T>, | |
153 | }, | |
60c5eb7d | 154 | Iterate(Iter<'a, T>), // simply produce all values in `self` |
1a4d82fc JJ |
155 | } |
156 | ||
8bb4bdeb | 157 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
158 | impl<T: fmt::Debug> fmt::Debug for Difference<'_, T> { |
159 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
e74abb32 | 160 | f.debug_tuple("Difference").field(&self.inner).finish() |
8bb4bdeb XL |
161 | } |
162 | } | |
163 | ||
cc61c64b | 164 | /// A lazy iterator producing elements in the symmetric difference of `BTreeSet`s. |
32a655c1 | 165 | /// |
cc61c64b XL |
166 | /// This `struct` is created by the [`symmetric_difference`] method on |
167 | /// [`BTreeSet`]. See its documentation for more. | |
32a655c1 | 168 | /// |
3dfed10e | 169 | /// [`symmetric_difference`]: BTreeSet::symmetric_difference |
85aaf69f | 170 | #[stable(feature = "rust1", since = "1.0.0")] |
e74abb32 | 171 | pub struct SymmetricDifference<'a, T: 'a>(MergeIterInner<Iter<'a, T>>); |
1a4d82fc | 172 | |
8bb4bdeb | 173 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
174 | impl<T: fmt::Debug> fmt::Debug for SymmetricDifference<'_, T> { |
175 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
e74abb32 | 176 | f.debug_tuple("SymmetricDifference").field(&self.0).finish() |
8bb4bdeb XL |
177 | } |
178 | } | |
179 | ||
cc61c64b | 180 | /// A lazy iterator producing elements in the intersection of `BTreeSet`s. |
32a655c1 | 181 | /// |
cc61c64b XL |
182 | /// This `struct` is created by the [`intersection`] method on [`BTreeSet`]. |
183 | /// See its documentation for more. | |
32a655c1 | 184 | /// |
3dfed10e | 185 | /// [`intersection`]: BTreeSet::intersection |
85aaf69f | 186 | #[stable(feature = "rust1", since = "1.0.0")] |
92a42be0 | 187 | pub struct Intersection<'a, T: 'a> { |
532ac7d7 XL |
188 | inner: IntersectionInner<'a, T>, |
189 | } | |
e74abb32 | 190 | #[derive(Debug)] |
532ac7d7 XL |
191 | enum IntersectionInner<'a, T: 'a> { |
192 | Stitch { | |
e74abb32 | 193 | // iterate similarly sized sets jointly, spotting matches along the way |
e1599b0c XL |
194 | a: Iter<'a, T>, |
195 | b: Iter<'a, T>, | |
532ac7d7 XL |
196 | }, |
197 | Search { | |
e74abb32 | 198 | // iterate a small set, look up in the large set |
532ac7d7 XL |
199 | small_iter: Iter<'a, T>, |
200 | large_set: &'a BTreeSet<T>, | |
201 | }, | |
e74abb32 | 202 | Answer(Option<&'a T>), // return a specific value or emptiness |
1a4d82fc JJ |
203 | } |
204 | ||
8bb4bdeb | 205 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
206 | impl<T: fmt::Debug> fmt::Debug for Intersection<'_, T> { |
207 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
e74abb32 | 208 | f.debug_tuple("Intersection").field(&self.inner).finish() |
8bb4bdeb XL |
209 | } |
210 | } | |
211 | ||
cc61c64b | 212 | /// A lazy iterator producing elements in the union of `BTreeSet`s. |
32a655c1 | 213 | /// |
cc61c64b XL |
214 | /// This `struct` is created by the [`union`] method on [`BTreeSet`]. |
215 | /// See its documentation for more. | |
32a655c1 | 216 | /// |
3dfed10e | 217 | /// [`union`]: BTreeSet::union |
85aaf69f | 218 | #[stable(feature = "rust1", since = "1.0.0")] |
e74abb32 | 219 | pub struct Union<'a, T: 'a>(MergeIterInner<Iter<'a, T>>); |
1a4d82fc | 220 | |
8bb4bdeb | 221 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
222 | impl<T: fmt::Debug> fmt::Debug for Union<'_, T> { |
223 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
e74abb32 | 224 | f.debug_tuple("Union").field(&self.0).finish() |
8bb4bdeb XL |
225 | } |
226 | } | |
227 | ||
532ac7d7 XL |
228 | // This constant is used by functions that compare two sets. |
229 | // It estimates the relative size at which searching performs better | |
230 | // than iterating, based on the benchmarks in | |
fc512014 | 231 | // https://github.com/ssomers/rust_bench_btreeset_intersection. |
532ac7d7 XL |
232 | // It's used to divide rather than multiply sizes, to rule out overflow, |
233 | // and it's a power of two to make that division cheap. | |
234 | const ITER_PERFORMANCE_TIPPING_SIZE_DIFF: usize = 16; | |
235 | ||
5869c6ff | 236 | impl<T> BTreeSet<T> { |
fc512014 XL |
237 | /// Makes a new, empty `BTreeSet`. |
238 | /// | |
239 | /// Does not allocate anything on its own. | |
1a4d82fc JJ |
240 | /// |
241 | /// # Examples | |
242 | /// | |
243 | /// ``` | |
92a42be0 | 244 | /// # #![allow(unused_mut)] |
1a4d82fc JJ |
245 | /// use std::collections::BTreeSet; |
246 | /// | |
85aaf69f | 247 | /// let mut set: BTreeSet<i32> = BTreeSet::new(); |
1a4d82fc | 248 | /// ``` |
85aaf69f | 249 | #[stable(feature = "rust1", since = "1.0.0")] |
f9f354fc | 250 | #[rustc_const_unstable(feature = "const_btree_new", issue = "71835")] |
c295e0f8 | 251 | #[must_use] |
94222f64 | 252 | pub const fn new() -> BTreeSet<T> { |
1a4d82fc JJ |
253 | BTreeSet { map: BTreeMap::new() } |
254 | } | |
1a4d82fc | 255 | |
32a655c1 SL |
256 | /// Constructs a double-ended iterator over a sub-range of elements in the set. |
257 | /// The simplest way is to use the range syntax `min..max`, thus `range(min..max)` will | |
258 | /// yield elements from min (inclusive) to max (exclusive). | |
259 | /// The range may also be entered as `(Bound<T>, Bound<T>)`, so for example | |
260 | /// `range((Excluded(4), Included(10)))` will yield a left-exclusive, right-inclusive | |
261 | /// range from 4 to 10. | |
85aaf69f SL |
262 | /// |
263 | /// # Examples | |
264 | /// | |
265 | /// ``` | |
266 | /// use std::collections::BTreeSet; | |
0531ce1d | 267 | /// use std::ops::Bound::Included; |
85aaf69f SL |
268 | /// |
269 | /// let mut set = BTreeSet::new(); | |
270 | /// set.insert(3); | |
271 | /// set.insert(5); | |
272 | /// set.insert(8); | |
32a655c1 | 273 | /// for &elem in set.range((Included(&4), Included(&8))) { |
85aaf69f SL |
274 | /// println!("{}", elem); |
275 | /// } | |
32a655c1 | 276 | /// assert_eq!(Some(&5), set.range(4..).next()); |
85aaf69f | 277 | /// ``` |
8bb4bdeb | 278 | #[stable(feature = "btree_range", since = "1.17.0")] |
9fa01778 | 279 | pub fn range<K: ?Sized, R>(&self, range: R) -> Range<'_, T> |
dfeec247 XL |
280 | where |
281 | K: Ord, | |
5869c6ff | 282 | T: Borrow<K> + Ord, |
dfeec247 | 283 | R: RangeBounds<K>, |
e9174d1e | 284 | { |
32a655c1 | 285 | Range { iter: self.map.range(range) } |
85aaf69f | 286 | } |
85aaf69f | 287 | |
8bb4bdeb | 288 | /// Visits the values representing the difference, |
0731742a | 289 | /// i.e., the values that are in `self` but not in `other`, |
8bb4bdeb | 290 | /// in ascending order. |
1a4d82fc JJ |
291 | /// |
292 | /// # Examples | |
293 | /// | |
294 | /// ``` | |
295 | /// use std::collections::BTreeSet; | |
296 | /// | |
297 | /// let mut a = BTreeSet::new(); | |
85aaf69f SL |
298 | /// a.insert(1); |
299 | /// a.insert(2); | |
1a4d82fc JJ |
300 | /// |
301 | /// let mut b = BTreeSet::new(); | |
85aaf69f SL |
302 | /// b.insert(2); |
303 | /// b.insert(3); | |
1a4d82fc | 304 | /// |
62682a34 | 305 | /// let diff: Vec<_> = a.difference(&b).cloned().collect(); |
c34b1796 | 306 | /// assert_eq!(diff, [1]); |
1a4d82fc | 307 | /// ``` |
85aaf69f | 308 | #[stable(feature = "rust1", since = "1.0.0")] |
5869c6ff XL |
309 | pub fn difference<'a>(&'a self, other: &'a BTreeSet<T>) -> Difference<'a, T> |
310 | where | |
311 | T: Ord, | |
312 | { | |
dfeec247 XL |
313 | let (self_min, self_max) = |
314 | if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) { | |
315 | (self_min, self_max) | |
316 | } else { | |
317 | return Difference { inner: DifferenceInner::Iterate(self.iter()) }; | |
e74abb32 | 318 | }; |
dfeec247 XL |
319 | let (other_min, other_max) = |
320 | if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) { | |
321 | (other_min, other_max) | |
322 | } else { | |
323 | return Difference { inner: DifferenceInner::Iterate(self.iter()) }; | |
e74abb32 | 324 | }; |
e74abb32 XL |
325 | Difference { |
326 | inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) { | |
327 | (Greater, _) | (_, Less) => DifferenceInner::Iterate(self.iter()), | |
328 | (Equal, _) => { | |
329 | let mut self_iter = self.iter(); | |
330 | self_iter.next(); | |
331 | DifferenceInner::Iterate(self_iter) | |
332 | } | |
333 | (_, Equal) => { | |
334 | let mut self_iter = self.iter(); | |
335 | self_iter.next_back(); | |
336 | DifferenceInner::Iterate(self_iter) | |
337 | } | |
338 | _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => { | |
dfeec247 | 339 | DifferenceInner::Search { self_iter: self.iter(), other_set: other } |
e74abb32 XL |
340 | } |
341 | _ => DifferenceInner::Stitch { | |
532ac7d7 | 342 | self_iter: self.iter(), |
e74abb32 | 343 | other_iter: other.iter().peekable(), |
532ac7d7 | 344 | }, |
e74abb32 | 345 | }, |
92a42be0 | 346 | } |
1a4d82fc JJ |
347 | } |
348 | ||
8bb4bdeb | 349 | /// Visits the values representing the symmetric difference, |
0731742a | 350 | /// i.e., the values that are in `self` or in `other` but not in both, |
8bb4bdeb | 351 | /// in ascending order. |
1a4d82fc JJ |
352 | /// |
353 | /// # Examples | |
354 | /// | |
355 | /// ``` | |
356 | /// use std::collections::BTreeSet; | |
357 | /// | |
358 | /// let mut a = BTreeSet::new(); | |
85aaf69f SL |
359 | /// a.insert(1); |
360 | /// a.insert(2); | |
1a4d82fc JJ |
361 | /// |
362 | /// let mut b = BTreeSet::new(); | |
85aaf69f SL |
363 | /// b.insert(2); |
364 | /// b.insert(3); | |
1a4d82fc | 365 | /// |
62682a34 | 366 | /// let sym_diff: Vec<_> = a.symmetric_difference(&b).cloned().collect(); |
c34b1796 | 367 | /// assert_eq!(sym_diff, [1, 3]); |
1a4d82fc | 368 | /// ``` |
85aaf69f | 369 | #[stable(feature = "rust1", since = "1.0.0")] |
5869c6ff XL |
370 | pub fn symmetric_difference<'a>(&'a self, other: &'a BTreeSet<T>) -> SymmetricDifference<'a, T> |
371 | where | |
372 | T: Ord, | |
373 | { | |
e74abb32 | 374 | SymmetricDifference(MergeIterInner::new(self.iter(), other.iter())) |
1a4d82fc JJ |
375 | } |
376 | ||
8bb4bdeb | 377 | /// Visits the values representing the intersection, |
0731742a | 378 | /// i.e., the values that are both in `self` and `other`, |
8bb4bdeb | 379 | /// in ascending order. |
1a4d82fc JJ |
380 | /// |
381 | /// # Examples | |
382 | /// | |
383 | /// ``` | |
384 | /// use std::collections::BTreeSet; | |
385 | /// | |
386 | /// let mut a = BTreeSet::new(); | |
85aaf69f SL |
387 | /// a.insert(1); |
388 | /// a.insert(2); | |
1a4d82fc JJ |
389 | /// |
390 | /// let mut b = BTreeSet::new(); | |
85aaf69f SL |
391 | /// b.insert(2); |
392 | /// b.insert(3); | |
1a4d82fc | 393 | /// |
62682a34 | 394 | /// let intersection: Vec<_> = a.intersection(&b).cloned().collect(); |
c34b1796 | 395 | /// assert_eq!(intersection, [2]); |
1a4d82fc | 396 | /// ``` |
85aaf69f | 397 | #[stable(feature = "rust1", since = "1.0.0")] |
5869c6ff XL |
398 | pub fn intersection<'a>(&'a self, other: &'a BTreeSet<T>) -> Intersection<'a, T> |
399 | where | |
400 | T: Ord, | |
401 | { | |
dfeec247 XL |
402 | let (self_min, self_max) = |
403 | if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) { | |
404 | (self_min, self_max) | |
405 | } else { | |
406 | return Intersection { inner: IntersectionInner::Answer(None) }; | |
e74abb32 | 407 | }; |
dfeec247 XL |
408 | let (other_min, other_max) = |
409 | if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) { | |
410 | (other_min, other_max) | |
411 | } else { | |
412 | return Intersection { inner: IntersectionInner::Answer(None) }; | |
e74abb32 | 413 | }; |
e74abb32 XL |
414 | Intersection { |
415 | inner: match (self_min.cmp(other_max), self_max.cmp(other_min)) { | |
416 | (Greater, _) | (_, Less) => IntersectionInner::Answer(None), | |
417 | (Equal, _) => IntersectionInner::Answer(Some(self_min)), | |
418 | (_, Equal) => IntersectionInner::Answer(Some(self_max)), | |
419 | _ if self.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => { | |
dfeec247 | 420 | IntersectionInner::Search { small_iter: self.iter(), large_set: other } |
e74abb32 XL |
421 | } |
422 | _ if other.len() <= self.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF => { | |
dfeec247 | 423 | IntersectionInner::Search { small_iter: other.iter(), large_set: self } |
e74abb32 | 424 | } |
dfeec247 | 425 | _ => IntersectionInner::Stitch { a: self.iter(), b: other.iter() }, |
e74abb32 | 426 | }, |
92a42be0 | 427 | } |
1a4d82fc JJ |
428 | } |
429 | ||
8bb4bdeb | 430 | /// Visits the values representing the union, |
0731742a | 431 | /// i.e., all the values in `self` or `other`, without duplicates, |
8bb4bdeb | 432 | /// in ascending order. |
1a4d82fc JJ |
433 | /// |
434 | /// # Examples | |
435 | /// | |
436 | /// ``` | |
437 | /// use std::collections::BTreeSet; | |
438 | /// | |
439 | /// let mut a = BTreeSet::new(); | |
85aaf69f | 440 | /// a.insert(1); |
1a4d82fc JJ |
441 | /// |
442 | /// let mut b = BTreeSet::new(); | |
85aaf69f | 443 | /// b.insert(2); |
1a4d82fc | 444 | /// |
62682a34 | 445 | /// let union: Vec<_> = a.union(&b).cloned().collect(); |
c34b1796 | 446 | /// assert_eq!(union, [1, 2]); |
1a4d82fc | 447 | /// ``` |
85aaf69f | 448 | #[stable(feature = "rust1", since = "1.0.0")] |
5869c6ff XL |
449 | pub fn union<'a>(&'a self, other: &'a BTreeSet<T>) -> Union<'a, T> |
450 | where | |
451 | T: Ord, | |
452 | { | |
e74abb32 | 453 | Union(MergeIterInner::new(self.iter(), other.iter())) |
1a4d82fc JJ |
454 | } |
455 | ||
1a4d82fc JJ |
456 | /// Clears the set, removing all values. |
457 | /// | |
458 | /// # Examples | |
459 | /// | |
460 | /// ``` | |
461 | /// use std::collections::BTreeSet; | |
462 | /// | |
463 | /// let mut v = BTreeSet::new(); | |
85aaf69f | 464 | /// v.insert(1); |
1a4d82fc JJ |
465 | /// v.clear(); |
466 | /// assert!(v.is_empty()); | |
467 | /// ``` | |
85aaf69f | 468 | #[stable(feature = "rust1", since = "1.0.0")] |
6a06907d | 469 | pub fn clear(&mut self) { |
1a4d82fc JJ |
470 | self.map.clear() |
471 | } | |
472 | ||
473 | /// Returns `true` if the set contains a value. | |
474 | /// | |
475 | /// The value may be any borrowed form of the set's value type, | |
476 | /// but the ordering on the borrowed form *must* match the | |
477 | /// ordering on the value type. | |
478 | /// | |
479 | /// # Examples | |
480 | /// | |
481 | /// ``` | |
482 | /// use std::collections::BTreeSet; | |
483 | /// | |
85aaf69f | 484 | /// let set: BTreeSet<_> = [1, 2, 3].iter().cloned().collect(); |
1a4d82fc JJ |
485 | /// assert_eq!(set.contains(&1), true); |
486 | /// assert_eq!(set.contains(&4), false); | |
487 | /// ``` | |
85aaf69f | 488 | #[stable(feature = "rust1", since = "1.0.0")] |
92a42be0 | 489 | pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool |
dfeec247 | 490 | where |
5869c6ff | 491 | T: Borrow<Q> + Ord, |
dfeec247 | 492 | Q: Ord, |
92a42be0 | 493 | { |
1a4d82fc JJ |
494 | self.map.contains_key(value) |
495 | } | |
496 | ||
e9174d1e SL |
497 | /// Returns a reference to the value in the set, if any, that is equal to the given value. |
498 | /// | |
499 | /// The value may be any borrowed form of the set's value type, | |
500 | /// but the ordering on the borrowed form *must* match the | |
501 | /// ordering on the value type. | |
2c00a5a8 XL |
502 | /// |
503 | /// # Examples | |
504 | /// | |
505 | /// ``` | |
506 | /// use std::collections::BTreeSet; | |
507 | /// | |
508 | /// let set: BTreeSet<_> = [1, 2, 3].iter().cloned().collect(); | |
509 | /// assert_eq!(set.get(&2), Some(&2)); | |
510 | /// assert_eq!(set.get(&4), None); | |
511 | /// ``` | |
54a0048b | 512 | #[stable(feature = "set_recovery", since = "1.9.0")] |
92a42be0 | 513 | pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T> |
dfeec247 | 514 | where |
5869c6ff | 515 | T: Borrow<Q> + Ord, |
dfeec247 | 516 | Q: Ord, |
92a42be0 | 517 | { |
e9174d1e SL |
518 | Recover::get(&self.map, value) |
519 | } | |
520 | ||
8bb4bdeb | 521 | /// Returns `true` if `self` has no elements in common with `other`. |
1a4d82fc JJ |
522 | /// This is equivalent to checking for an empty intersection. |
523 | /// | |
524 | /// # Examples | |
525 | /// | |
526 | /// ``` | |
527 | /// use std::collections::BTreeSet; | |
528 | /// | |
85aaf69f SL |
529 | /// let a: BTreeSet<_> = [1, 2, 3].iter().cloned().collect(); |
530 | /// let mut b = BTreeSet::new(); | |
1a4d82fc JJ |
531 | /// |
532 | /// assert_eq!(a.is_disjoint(&b), true); | |
533 | /// b.insert(4); | |
534 | /// assert_eq!(a.is_disjoint(&b), true); | |
535 | /// b.insert(1); | |
536 | /// assert_eq!(a.is_disjoint(&b), false); | |
537 | /// ``` | |
c295e0f8 | 538 | #[must_use] |
85aaf69f | 539 | #[stable(feature = "rust1", since = "1.0.0")] |
5869c6ff XL |
540 | pub fn is_disjoint(&self, other: &BTreeSet<T>) -> bool |
541 | where | |
542 | T: Ord, | |
543 | { | |
1a4d82fc JJ |
544 | self.intersection(other).next().is_none() |
545 | } | |
546 | ||
8bb4bdeb | 547 | /// Returns `true` if the set is a subset of another, |
0731742a | 548 | /// i.e., `other` contains at least all the values in `self`. |
1a4d82fc JJ |
549 | /// |
550 | /// # Examples | |
551 | /// | |
552 | /// ``` | |
553 | /// use std::collections::BTreeSet; | |
554 | /// | |
85aaf69f SL |
555 | /// let sup: BTreeSet<_> = [1, 2, 3].iter().cloned().collect(); |
556 | /// let mut set = BTreeSet::new(); | |
1a4d82fc JJ |
557 | /// |
558 | /// assert_eq!(set.is_subset(&sup), true); | |
559 | /// set.insert(2); | |
560 | /// assert_eq!(set.is_subset(&sup), true); | |
561 | /// set.insert(4); | |
562 | /// assert_eq!(set.is_subset(&sup), false); | |
563 | /// ``` | |
c295e0f8 | 564 | #[must_use] |
85aaf69f | 565 | #[stable(feature = "rust1", since = "1.0.0")] |
5869c6ff XL |
566 | pub fn is_subset(&self, other: &BTreeSet<T>) -> bool |
567 | where | |
568 | T: Ord, | |
569 | { | |
532ac7d7 | 570 | // Same result as self.difference(other).next().is_none() |
e74abb32 | 571 | // but the code below is faster (hugely in some cases). |
532ac7d7 | 572 | if self.len() > other.len() { |
e74abb32 XL |
573 | return false; |
574 | } | |
dfeec247 XL |
575 | let (self_min, self_max) = |
576 | if let (Some(self_min), Some(self_max)) = (self.first(), self.last()) { | |
577 | (self_min, self_max) | |
578 | } else { | |
579 | return true; // self is empty | |
580 | }; | |
581 | let (other_min, other_max) = | |
582 | if let (Some(other_min), Some(other_max)) = (other.first(), other.last()) { | |
583 | (other_min, other_max) | |
584 | } else { | |
585 | return false; // other is empty | |
586 | }; | |
e74abb32 XL |
587 | let mut self_iter = self.iter(); |
588 | match self_min.cmp(other_min) { | |
589 | Less => return false, | |
590 | Equal => { | |
591 | self_iter.next(); | |
592 | } | |
593 | Greater => (), | |
594 | } | |
595 | match self_max.cmp(other_max) { | |
596 | Greater => return false, | |
597 | Equal => { | |
598 | self_iter.next_back(); | |
599 | } | |
600 | Less => (), | |
601 | } | |
602 | if self_iter.len() <= other.len() / ITER_PERFORMANCE_TIPPING_SIZE_DIFF { | |
e74abb32 XL |
603 | for next in self_iter { |
604 | if !other.contains(next) { | |
532ac7d7 XL |
605 | return false; |
606 | } | |
532ac7d7 | 607 | } |
532ac7d7 | 608 | } else { |
e74abb32 XL |
609 | let mut other_iter = other.iter(); |
610 | other_iter.next(); | |
611 | other_iter.next_back(); | |
612 | let mut self_next = self_iter.next(); | |
613 | while let Some(self1) = self_next { | |
614 | match other_iter.next().map_or(Less, |other1| self1.cmp(other1)) { | |
615 | Less => return false, | |
616 | Equal => self_next = self_iter.next(), | |
617 | Greater => (), | |
532ac7d7 XL |
618 | } |
619 | } | |
1a4d82fc | 620 | } |
e74abb32 | 621 | true |
1a4d82fc JJ |
622 | } |
623 | ||
8bb4bdeb | 624 | /// Returns `true` if the set is a superset of another, |
0731742a | 625 | /// i.e., `self` contains at least all the values in `other`. |
1a4d82fc JJ |
626 | /// |
627 | /// # Examples | |
628 | /// | |
629 | /// ``` | |
630 | /// use std::collections::BTreeSet; | |
631 | /// | |
85aaf69f SL |
632 | /// let sub: BTreeSet<_> = [1, 2].iter().cloned().collect(); |
633 | /// let mut set = BTreeSet::new(); | |
1a4d82fc JJ |
634 | /// |
635 | /// assert_eq!(set.is_superset(&sub), false); | |
636 | /// | |
637 | /// set.insert(0); | |
638 | /// set.insert(1); | |
639 | /// assert_eq!(set.is_superset(&sub), false); | |
640 | /// | |
641 | /// set.insert(2); | |
642 | /// assert_eq!(set.is_superset(&sub), true); | |
643 | /// ``` | |
c295e0f8 | 644 | #[must_use] |
85aaf69f | 645 | #[stable(feature = "rust1", since = "1.0.0")] |
5869c6ff XL |
646 | pub fn is_superset(&self, other: &BTreeSet<T>) -> bool |
647 | where | |
648 | T: Ord, | |
649 | { | |
1a4d82fc JJ |
650 | other.is_subset(self) |
651 | } | |
652 | ||
60c5eb7d XL |
653 | /// Returns a reference to the first value in the set, if any. |
654 | /// This value is always the minimum of all values in the set. | |
655 | /// | |
656 | /// # Examples | |
657 | /// | |
658 | /// Basic usage: | |
659 | /// | |
660 | /// ``` | |
661 | /// #![feature(map_first_last)] | |
662 | /// use std::collections::BTreeSet; | |
663 | /// | |
6a06907d XL |
664 | /// let mut set = BTreeSet::new(); |
665 | /// assert_eq!(set.first(), None); | |
666 | /// set.insert(1); | |
667 | /// assert_eq!(set.first(), Some(&1)); | |
668 | /// set.insert(2); | |
669 | /// assert_eq!(set.first(), Some(&1)); | |
60c5eb7d XL |
670 | /// ``` |
671 | #[unstable(feature = "map_first_last", issue = "62924")] | |
5869c6ff XL |
672 | pub fn first(&self) -> Option<&T> |
673 | where | |
674 | T: Ord, | |
675 | { | |
60c5eb7d XL |
676 | self.map.first_key_value().map(|(k, _)| k) |
677 | } | |
678 | ||
679 | /// Returns a reference to the last value in the set, if any. | |
680 | /// This value is always the maximum of all values in the set. | |
681 | /// | |
682 | /// # Examples | |
683 | /// | |
684 | /// Basic usage: | |
685 | /// | |
686 | /// ``` | |
687 | /// #![feature(map_first_last)] | |
688 | /// use std::collections::BTreeSet; | |
689 | /// | |
6a06907d XL |
690 | /// let mut set = BTreeSet::new(); |
691 | /// assert_eq!(set.last(), None); | |
692 | /// set.insert(1); | |
693 | /// assert_eq!(set.last(), Some(&1)); | |
694 | /// set.insert(2); | |
695 | /// assert_eq!(set.last(), Some(&2)); | |
60c5eb7d XL |
696 | /// ``` |
697 | #[unstable(feature = "map_first_last", issue = "62924")] | |
5869c6ff XL |
698 | pub fn last(&self) -> Option<&T> |
699 | where | |
700 | T: Ord, | |
701 | { | |
60c5eb7d XL |
702 | self.map.last_key_value().map(|(k, _)| k) |
703 | } | |
704 | ||
705 | /// Removes the first value from the set and returns it, if any. | |
706 | /// The first value is always the minimum value in the set. | |
707 | /// | |
708 | /// # Examples | |
709 | /// | |
710 | /// ``` | |
711 | /// #![feature(map_first_last)] | |
712 | /// use std::collections::BTreeSet; | |
713 | /// | |
714 | /// let mut set = BTreeSet::new(); | |
715 | /// | |
716 | /// set.insert(1); | |
717 | /// while let Some(n) = set.pop_first() { | |
718 | /// assert_eq!(n, 1); | |
719 | /// } | |
720 | /// assert!(set.is_empty()); | |
721 | /// ``` | |
722 | #[unstable(feature = "map_first_last", issue = "62924")] | |
5869c6ff XL |
723 | pub fn pop_first(&mut self) -> Option<T> |
724 | where | |
725 | T: Ord, | |
726 | { | |
fc512014 | 727 | self.map.pop_first().map(|kv| kv.0) |
60c5eb7d XL |
728 | } |
729 | ||
730 | /// Removes the last value from the set and returns it, if any. | |
731 | /// The last value is always the maximum value in the set. | |
732 | /// | |
733 | /// # Examples | |
734 | /// | |
735 | /// ``` | |
736 | /// #![feature(map_first_last)] | |
737 | /// use std::collections::BTreeSet; | |
738 | /// | |
739 | /// let mut set = BTreeSet::new(); | |
740 | /// | |
741 | /// set.insert(1); | |
742 | /// while let Some(n) = set.pop_last() { | |
743 | /// assert_eq!(n, 1); | |
744 | /// } | |
745 | /// assert!(set.is_empty()); | |
746 | /// ``` | |
747 | #[unstable(feature = "map_first_last", issue = "62924")] | |
5869c6ff XL |
748 | pub fn pop_last(&mut self) -> Option<T> |
749 | where | |
750 | T: Ord, | |
751 | { | |
fc512014 | 752 | self.map.pop_last().map(|kv| kv.0) |
60c5eb7d XL |
753 | } |
754 | ||
b039eaaf SL |
755 | /// Adds a value to the set. |
756 | /// | |
a7813a04 | 757 | /// If the set did not have this value present, `true` is returned. |
b039eaaf | 758 | /// |
a7813a04 | 759 | /// If the set did have this value present, `false` is returned, and the |
b039eaaf SL |
760 | /// entry is not updated. See the [module-level documentation] for more. |
761 | /// | |
762 | /// [module-level documentation]: index.html#insert-and-complex-keys | |
1a4d82fc JJ |
763 | /// |
764 | /// # Examples | |
765 | /// | |
766 | /// ``` | |
767 | /// use std::collections::BTreeSet; | |
768 | /// | |
769 | /// let mut set = BTreeSet::new(); | |
770 | /// | |
85aaf69f SL |
771 | /// assert_eq!(set.insert(2), true); |
772 | /// assert_eq!(set.insert(2), false); | |
1a4d82fc JJ |
773 | /// assert_eq!(set.len(), 1); |
774 | /// ``` | |
85aaf69f | 775 | #[stable(feature = "rust1", since = "1.0.0")] |
5869c6ff XL |
776 | pub fn insert(&mut self, value: T) -> bool |
777 | where | |
778 | T: Ord, | |
779 | { | |
1a4d82fc JJ |
780 | self.map.insert(value, ()).is_none() |
781 | } | |
782 | ||
e9174d1e SL |
783 | /// Adds a value to the set, replacing the existing value, if any, that is equal to the given |
784 | /// one. Returns the replaced value. | |
2c00a5a8 XL |
785 | /// |
786 | /// # Examples | |
787 | /// | |
788 | /// ``` | |
789 | /// use std::collections::BTreeSet; | |
790 | /// | |
791 | /// let mut set = BTreeSet::new(); | |
792 | /// set.insert(Vec::<i32>::new()); | |
793 | /// | |
794 | /// assert_eq!(set.get(&[][..]).unwrap().capacity(), 0); | |
795 | /// set.replace(Vec::with_capacity(10)); | |
796 | /// assert_eq!(set.get(&[][..]).unwrap().capacity(), 10); | |
797 | /// ``` | |
54a0048b | 798 | #[stable(feature = "set_recovery", since = "1.9.0")] |
5869c6ff XL |
799 | pub fn replace(&mut self, value: T) -> Option<T> |
800 | where | |
801 | T: Ord, | |
802 | { | |
e9174d1e SL |
803 | Recover::replace(&mut self.map, value) |
804 | } | |
805 | ||
9fa01778 | 806 | /// Removes a value from the set. Returns whether the value was |
1a4d82fc JJ |
807 | /// present in the set. |
808 | /// | |
809 | /// The value may be any borrowed form of the set's value type, | |
810 | /// but the ordering on the borrowed form *must* match the | |
811 | /// ordering on the value type. | |
812 | /// | |
813 | /// # Examples | |
814 | /// | |
815 | /// ``` | |
816 | /// use std::collections::BTreeSet; | |
817 | /// | |
818 | /// let mut set = BTreeSet::new(); | |
819 | /// | |
85aaf69f | 820 | /// set.insert(2); |
1a4d82fc JJ |
821 | /// assert_eq!(set.remove(&2), true); |
822 | /// assert_eq!(set.remove(&2), false); | |
823 | /// ``` | |
85aaf69f | 824 | #[stable(feature = "rust1", since = "1.0.0")] |
92a42be0 | 825 | pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool |
dfeec247 | 826 | where |
5869c6ff | 827 | T: Borrow<Q> + Ord, |
dfeec247 | 828 | Q: Ord, |
92a42be0 | 829 | { |
1a4d82fc JJ |
830 | self.map.remove(value).is_some() |
831 | } | |
e9174d1e SL |
832 | |
833 | /// Removes and returns the value in the set, if any, that is equal to the given one. | |
834 | /// | |
835 | /// The value may be any borrowed form of the set's value type, | |
836 | /// but the ordering on the borrowed form *must* match the | |
837 | /// ordering on the value type. | |
2c00a5a8 XL |
838 | /// |
839 | /// # Examples | |
840 | /// | |
841 | /// ``` | |
842 | /// use std::collections::BTreeSet; | |
843 | /// | |
844 | /// let mut set: BTreeSet<_> = [1, 2, 3].iter().cloned().collect(); | |
845 | /// assert_eq!(set.take(&2), Some(2)); | |
846 | /// assert_eq!(set.take(&2), None); | |
847 | /// ``` | |
54a0048b | 848 | #[stable(feature = "set_recovery", since = "1.9.0")] |
92a42be0 | 849 | pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T> |
dfeec247 | 850 | where |
5869c6ff | 851 | T: Borrow<Q> + Ord, |
dfeec247 | 852 | Q: Ord, |
92a42be0 | 853 | { |
e9174d1e SL |
854 | Recover::take(&mut self.map, value) |
855 | } | |
a7813a04 | 856 | |
fc512014 XL |
857 | /// Retains only the elements specified by the predicate. |
858 | /// | |
859 | /// In other words, remove all elements `e` such that `f(&e)` returns `false`. | |
136023e0 | 860 | /// The elements are visited in ascending order. |
fc512014 XL |
861 | /// |
862 | /// # Examples | |
863 | /// | |
864 | /// ``` | |
fc512014 XL |
865 | /// use std::collections::BTreeSet; |
866 | /// | |
867 | /// let xs = [1, 2, 3, 4, 5, 6]; | |
868 | /// let mut set: BTreeSet<i32> = xs.iter().cloned().collect(); | |
869 | /// // Keep only the even numbers. | |
870 | /// set.retain(|&k| k % 2 == 0); | |
871 | /// assert!(set.iter().eq([2, 4, 6].iter())); | |
872 | /// ``` | |
cdc7bbd5 | 873 | #[stable(feature = "btree_retain", since = "1.53.0")] |
fc512014 XL |
874 | pub fn retain<F>(&mut self, mut f: F) |
875 | where | |
5869c6ff | 876 | T: Ord, |
fc512014 XL |
877 | F: FnMut(&T) -> bool, |
878 | { | |
879 | self.drain_filter(|v| !f(v)); | |
880 | } | |
881 | ||
a7813a04 XL |
882 | /// Moves all elements from `other` into `Self`, leaving `other` empty. |
883 | /// | |
884 | /// # Examples | |
885 | /// | |
886 | /// ``` | |
a7813a04 XL |
887 | /// use std::collections::BTreeSet; |
888 | /// | |
889 | /// let mut a = BTreeSet::new(); | |
890 | /// a.insert(1); | |
891 | /// a.insert(2); | |
892 | /// a.insert(3); | |
893 | /// | |
894 | /// let mut b = BTreeSet::new(); | |
895 | /// b.insert(3); | |
896 | /// b.insert(4); | |
897 | /// b.insert(5); | |
898 | /// | |
899 | /// a.append(&mut b); | |
900 | /// | |
901 | /// assert_eq!(a.len(), 5); | |
902 | /// assert_eq!(b.len(), 0); | |
903 | /// | |
904 | /// assert!(a.contains(&1)); | |
905 | /// assert!(a.contains(&2)); | |
906 | /// assert!(a.contains(&3)); | |
907 | /// assert!(a.contains(&4)); | |
908 | /// assert!(a.contains(&5)); | |
909 | /// ``` | |
3157f602 | 910 | #[stable(feature = "btree_append", since = "1.11.0")] |
5869c6ff XL |
911 | pub fn append(&mut self, other: &mut Self) |
912 | where | |
913 | T: Ord, | |
914 | { | |
a7813a04 XL |
915 | self.map.append(&mut other.map); |
916 | } | |
3157f602 | 917 | |
136023e0 XL |
918 | /// Splits the collection into two at the given value. Returns everything after the given value, |
919 | /// including the value. | |
3157f602 XL |
920 | /// |
921 | /// # Examples | |
922 | /// | |
923 | /// Basic usage: | |
924 | /// | |
925 | /// ``` | |
2c00a5a8 | 926 | /// use std::collections::BTreeSet; |
3157f602 | 927 | /// |
2c00a5a8 XL |
928 | /// let mut a = BTreeSet::new(); |
929 | /// a.insert(1); | |
930 | /// a.insert(2); | |
931 | /// a.insert(3); | |
932 | /// a.insert(17); | |
933 | /// a.insert(41); | |
3157f602 XL |
934 | /// |
935 | /// let b = a.split_off(&3); | |
936 | /// | |
937 | /// assert_eq!(a.len(), 2); | |
938 | /// assert_eq!(b.len(), 3); | |
939 | /// | |
2c00a5a8 XL |
940 | /// assert!(a.contains(&1)); |
941 | /// assert!(a.contains(&2)); | |
3157f602 | 942 | /// |
2c00a5a8 XL |
943 | /// assert!(b.contains(&3)); |
944 | /// assert!(b.contains(&17)); | |
945 | /// assert!(b.contains(&41)); | |
3157f602 XL |
946 | /// ``` |
947 | #[stable(feature = "btree_split_off", since = "1.11.0")] | |
136023e0 | 948 | pub fn split_off<Q: ?Sized + Ord>(&mut self, value: &Q) -> Self |
dfeec247 | 949 | where |
5869c6ff | 950 | T: Borrow<Q> + Ord, |
dfeec247 | 951 | { |
136023e0 | 952 | BTreeSet { map: self.map.split_off(value) } |
3157f602 | 953 | } |
ba9703b0 | 954 | |
136023e0 XL |
955 | /// Creates an iterator that visits all values in ascending order and uses a closure |
956 | /// to determine if a value should be removed. | |
ba9703b0 | 957 | /// |
136023e0 XL |
958 | /// If the closure returns `true`, the value is removed from the set and yielded. If |
959 | /// the closure returns `false`, or panics, the value remains in the set and will | |
960 | /// not be yielded. | |
ba9703b0 | 961 | /// |
136023e0 XL |
962 | /// If the iterator is only partially consumed or not consumed at all, each of the |
963 | /// remaining values is still subjected to the closure and removed and dropped if it | |
964 | /// returns `true`. | |
ba9703b0 | 965 | /// |
136023e0 XL |
966 | /// It is unspecified how many more values will be subjected to the closure if a |
967 | /// panic occurs in the closure, or if a panic occurs while dropping a value, or if | |
968 | /// the `DrainFilter` itself is leaked. | |
ba9703b0 XL |
969 | /// |
970 | /// # Examples | |
971 | /// | |
972 | /// Splitting a set into even and odd values, reusing the original set: | |
973 | /// | |
974 | /// ``` | |
975 | /// #![feature(btree_drain_filter)] | |
976 | /// use std::collections::BTreeSet; | |
977 | /// | |
978 | /// let mut set: BTreeSet<i32> = (0..8).collect(); | |
979 | /// let evens: BTreeSet<_> = set.drain_filter(|v| v % 2 == 0).collect(); | |
980 | /// let odds = set; | |
981 | /// assert_eq!(evens.into_iter().collect::<Vec<_>>(), vec![0, 2, 4, 6]); | |
982 | /// assert_eq!(odds.into_iter().collect::<Vec<_>>(), vec![1, 3, 5, 7]); | |
983 | /// ``` | |
984 | #[unstable(feature = "btree_drain_filter", issue = "70530")] | |
985 | pub fn drain_filter<'a, F>(&'a mut self, pred: F) -> DrainFilter<'a, T, F> | |
986 | where | |
5869c6ff | 987 | T: Ord, |
ba9703b0 XL |
988 | F: 'a + FnMut(&T) -> bool, |
989 | { | |
990 | DrainFilter { pred, inner: self.map.drain_filter_inner() } | |
991 | } | |
1a4d82fc | 992 | |
2c00a5a8 XL |
993 | /// Gets an iterator that visits the values in the `BTreeSet` in ascending order. |
994 | /// | |
995 | /// # Examples | |
996 | /// | |
997 | /// ``` | |
998 | /// use std::collections::BTreeSet; | |
999 | /// | |
1000 | /// let set: BTreeSet<usize> = [1, 2, 3].iter().cloned().collect(); | |
1001 | /// let mut set_iter = set.iter(); | |
1002 | /// assert_eq!(set_iter.next(), Some(&1)); | |
1003 | /// assert_eq!(set_iter.next(), Some(&2)); | |
1004 | /// assert_eq!(set_iter.next(), Some(&3)); | |
1005 | /// assert_eq!(set_iter.next(), None); | |
1006 | /// ``` | |
1007 | /// | |
1008 | /// Values returned by the iterator are returned in ascending order: | |
1009 | /// | |
1010 | /// ``` | |
1011 | /// use std::collections::BTreeSet; | |
1012 | /// | |
1013 | /// let set: BTreeSet<usize> = [3, 1, 2].iter().cloned().collect(); | |
1014 | /// let mut set_iter = set.iter(); | |
1015 | /// assert_eq!(set_iter.next(), Some(&1)); | |
1016 | /// assert_eq!(set_iter.next(), Some(&2)); | |
1017 | /// assert_eq!(set_iter.next(), Some(&3)); | |
1018 | /// assert_eq!(set_iter.next(), None); | |
1019 | /// ``` | |
1020 | #[stable(feature = "rust1", since = "1.0.0")] | |
9fa01778 | 1021 | pub fn iter(&self) -> Iter<'_, T> { |
2c00a5a8 XL |
1022 | Iter { iter: self.map.keys() } |
1023 | } | |
1024 | ||
1025 | /// Returns the number of elements in the set. | |
1026 | /// | |
1027 | /// # Examples | |
1028 | /// | |
1029 | /// ``` | |
1030 | /// use std::collections::BTreeSet; | |
1031 | /// | |
1032 | /// let mut v = BTreeSet::new(); | |
1033 | /// assert_eq!(v.len(), 0); | |
1034 | /// v.insert(1); | |
1035 | /// assert_eq!(v.len(), 1); | |
1036 | /// ``` | |
1037 | #[stable(feature = "rust1", since = "1.0.0")] | |
29967ef6 XL |
1038 | #[rustc_const_unstable(feature = "const_btree_new", issue = "71835")] |
1039 | pub const fn len(&self) -> usize { | |
2c00a5a8 XL |
1040 | self.map.len() |
1041 | } | |
1042 | ||
1043 | /// Returns `true` if the set contains no elements. | |
1044 | /// | |
1045 | /// # Examples | |
1046 | /// | |
1047 | /// ``` | |
1048 | /// use std::collections::BTreeSet; | |
1049 | /// | |
1050 | /// let mut v = BTreeSet::new(); | |
1051 | /// assert!(v.is_empty()); | |
1052 | /// v.insert(1); | |
1053 | /// assert!(!v.is_empty()); | |
1054 | /// ``` | |
1055 | #[stable(feature = "rust1", since = "1.0.0")] | |
29967ef6 XL |
1056 | #[rustc_const_unstable(feature = "const_btree_new", issue = "71835")] |
1057 | pub const fn is_empty(&self) -> bool { | |
2c00a5a8 XL |
1058 | self.len() == 0 |
1059 | } | |
1060 | } | |
1061 | ||
85aaf69f | 1062 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 1063 | impl<T: Ord> FromIterator<T> for BTreeSet<T> { |
92a42be0 | 1064 | fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> BTreeSet<T> { |
c295e0f8 XL |
1065 | let mut inputs: Vec<_> = iter.into_iter().collect(); |
1066 | ||
1067 | if inputs.is_empty() { | |
1068 | return BTreeSet::new(); | |
1069 | } | |
1070 | ||
1071 | // use stable sort to preserve the insertion order. | |
1072 | inputs.sort(); | |
1073 | let iter = inputs.into_iter().map(|k| (k, ())); | |
1074 | let map = BTreeMap::bulk_build_from_sorted_iter(iter); | |
1075 | BTreeSet { map } | |
1a4d82fc JJ |
1076 | } |
1077 | } | |
1078 | ||
94222f64 XL |
1079 | #[stable(feature = "std_collections_from_array", since = "1.56.0")] |
1080 | impl<T: Ord, const N: usize> From<[T; N]> for BTreeSet<T> { | |
1081 | /// ``` | |
1082 | /// use std::collections::BTreeSet; | |
1083 | /// | |
1084 | /// let set1 = BTreeSet::from([1, 2, 3, 4]); | |
1085 | /// let set2: BTreeSet<_> = [1, 2, 3, 4].into(); | |
1086 | /// assert_eq!(set1, set2); | |
1087 | /// ``` | |
c295e0f8 XL |
1088 | fn from(mut arr: [T; N]) -> Self { |
1089 | if N == 0 { | |
1090 | return BTreeSet::new(); | |
1091 | } | |
1092 | ||
1093 | // use stable sort to preserve the insertion order. | |
1094 | arr.sort(); | |
1095 | let iter = core::array::IntoIter::new(arr).map(|k| (k, ())); | |
1096 | let map = BTreeMap::bulk_build_from_sorted_iter(iter); | |
1097 | BTreeSet { map } | |
94222f64 XL |
1098 | } |
1099 | } | |
1100 | ||
85aaf69f SL |
1101 | #[stable(feature = "rust1", since = "1.0.0")] |
1102 | impl<T> IntoIterator for BTreeSet<T> { | |
1103 | type Item = T; | |
1104 | type IntoIter = IntoIter<T>; | |
1105 | ||
cc61c64b | 1106 | /// Gets an iterator for moving out the `BTreeSet`'s contents. |
9346a6ac AL |
1107 | /// |
1108 | /// # Examples | |
1109 | /// | |
1110 | /// ``` | |
9346a6ac AL |
1111 | /// use std::collections::BTreeSet; |
1112 | /// | |
1113 | /// let set: BTreeSet<usize> = [1, 2, 3, 4].iter().cloned().collect(); | |
1114 | /// | |
62682a34 | 1115 | /// let v: Vec<_> = set.into_iter().collect(); |
9346a6ac AL |
1116 | /// assert_eq!(v, [1, 2, 3, 4]); |
1117 | /// ``` | |
85aaf69f | 1118 | fn into_iter(self) -> IntoIter<T> { |
9cc50fc6 | 1119 | IntoIter { iter: self.map.into_iter() } |
85aaf69f SL |
1120 | } |
1121 | } | |
1122 | ||
1123 | #[stable(feature = "rust1", since = "1.0.0")] | |
1124 | impl<'a, T> IntoIterator for &'a BTreeSet<T> { | |
1125 | type Item = &'a T; | |
1126 | type IntoIter = Iter<'a, T>; | |
1127 | ||
1128 | fn into_iter(self) -> Iter<'a, T> { | |
1129 | self.iter() | |
1130 | } | |
1131 | } | |
1132 | ||
ba9703b0 XL |
1133 | /// An iterator produced by calling `drain_filter` on BTreeSet. |
1134 | #[unstable(feature = "btree_drain_filter", issue = "70530")] | |
1135 | pub struct DrainFilter<'a, T, F> | |
1136 | where | |
1137 | T: 'a, | |
1138 | F: 'a + FnMut(&T) -> bool, | |
1139 | { | |
1140 | pred: F, | |
1141 | inner: super::map::DrainFilterInner<'a, T, ()>, | |
1142 | } | |
1143 | ||
1144 | #[unstable(feature = "btree_drain_filter", issue = "70530")] | |
1145 | impl<T, F> Drop for DrainFilter<'_, T, F> | |
1146 | where | |
1147 | F: FnMut(&T) -> bool, | |
1148 | { | |
1149 | fn drop(&mut self) { | |
1150 | self.for_each(drop); | |
1151 | } | |
1152 | } | |
1153 | ||
1154 | #[unstable(feature = "btree_drain_filter", issue = "70530")] | |
1155 | impl<T, F> fmt::Debug for DrainFilter<'_, T, F> | |
1156 | where | |
1157 | T: fmt::Debug, | |
1158 | F: FnMut(&T) -> bool, | |
1159 | { | |
1160 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
1161 | f.debug_tuple("DrainFilter").field(&self.inner.peek().map(|(k, _)| k)).finish() | |
1162 | } | |
1163 | } | |
1164 | ||
1165 | #[unstable(feature = "btree_drain_filter", issue = "70530")] | |
1166 | impl<'a, T, F> Iterator for DrainFilter<'_, T, F> | |
1167 | where | |
1168 | F: 'a + FnMut(&T) -> bool, | |
1169 | { | |
1170 | type Item = T; | |
1171 | ||
1172 | fn next(&mut self) -> Option<T> { | |
1173 | let pred = &mut self.pred; | |
1174 | let mut mapped_pred = |k: &T, _v: &mut ()| pred(k); | |
1175 | self.inner.next(&mut mapped_pred).map(|(k, _)| k) | |
1176 | } | |
1177 | ||
1178 | fn size_hint(&self) -> (usize, Option<usize>) { | |
1179 | self.inner.size_hint() | |
1180 | } | |
1181 | } | |
1182 | ||
1183 | #[unstable(feature = "btree_drain_filter", issue = "70530")] | |
1184 | impl<T, F> FusedIterator for DrainFilter<'_, T, F> where F: FnMut(&T) -> bool {} | |
1185 | ||
85aaf69f | 1186 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1187 | impl<T: Ord> Extend<T> for BTreeSet<T> { |
1188 | #[inline] | |
92a42be0 | 1189 | fn extend<Iter: IntoIterator<Item = T>>(&mut self, iter: Iter) { |
532ac7d7 | 1190 | iter.into_iter().for_each(move |elem| { |
1a4d82fc | 1191 | self.insert(elem); |
532ac7d7 | 1192 | }); |
1a4d82fc | 1193 | } |
f9f354fc XL |
1194 | |
1195 | #[inline] | |
1196 | fn extend_one(&mut self, elem: T) { | |
1197 | self.insert(elem); | |
1198 | } | |
1a4d82fc JJ |
1199 | } |
1200 | ||
62682a34 SL |
1201 | #[stable(feature = "extend_ref", since = "1.2.0")] |
1202 | impl<'a, T: 'a + Ord + Copy> Extend<&'a T> for BTreeSet<T> { | |
92a42be0 | 1203 | fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) { |
62682a34 SL |
1204 | self.extend(iter.into_iter().cloned()); |
1205 | } | |
f9f354fc XL |
1206 | |
1207 | #[inline] | |
1208 | fn extend_one(&mut self, &elem: &'a T) { | |
1209 | self.insert(elem); | |
1210 | } | |
62682a34 SL |
1211 | } |
1212 | ||
85aaf69f | 1213 | #[stable(feature = "rust1", since = "1.0.0")] |
94222f64 | 1214 | impl<T> Default for BTreeSet<T> { |
fc512014 | 1215 | /// Creates an empty `BTreeSet`. |
1a4d82fc JJ |
1216 | fn default() -> BTreeSet<T> { |
1217 | BTreeSet::new() | |
1218 | } | |
1219 | } | |
1220 | ||
85aaf69f | 1221 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1222 | impl<T: Ord + Clone> Sub<&BTreeSet<T>> for &BTreeSet<T> { |
1a4d82fc JJ |
1223 | type Output = BTreeSet<T>; |
1224 | ||
1225 | /// Returns the difference of `self` and `rhs` as a new `BTreeSet<T>`. | |
1226 | /// | |
1227 | /// # Examples | |
1228 | /// | |
1229 | /// ``` | |
1230 | /// use std::collections::BTreeSet; | |
1231 | /// | |
85aaf69f SL |
1232 | /// let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect(); |
1233 | /// let b: BTreeSet<_> = vec![3, 4, 5].into_iter().collect(); | |
1a4d82fc | 1234 | /// |
85aaf69f SL |
1235 | /// let result = &a - &b; |
1236 | /// let result_vec: Vec<_> = result.into_iter().collect(); | |
c34b1796 | 1237 | /// assert_eq!(result_vec, [1, 2]); |
1a4d82fc JJ |
1238 | /// ``` |
1239 | fn sub(self, rhs: &BTreeSet<T>) -> BTreeSet<T> { | |
1240 | self.difference(rhs).cloned().collect() | |
1241 | } | |
1242 | } | |
1243 | ||
85aaf69f | 1244 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1245 | impl<T: Ord + Clone> BitXor<&BTreeSet<T>> for &BTreeSet<T> { |
1a4d82fc JJ |
1246 | type Output = BTreeSet<T>; |
1247 | ||
1248 | /// Returns the symmetric difference of `self` and `rhs` as a new `BTreeSet<T>`. | |
1249 | /// | |
1250 | /// # Examples | |
1251 | /// | |
1252 | /// ``` | |
1253 | /// use std::collections::BTreeSet; | |
1254 | /// | |
85aaf69f SL |
1255 | /// let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect(); |
1256 | /// let b: BTreeSet<_> = vec![2, 3, 4].into_iter().collect(); | |
1a4d82fc | 1257 | /// |
85aaf69f SL |
1258 | /// let result = &a ^ &b; |
1259 | /// let result_vec: Vec<_> = result.into_iter().collect(); | |
c34b1796 | 1260 | /// assert_eq!(result_vec, [1, 4]); |
1a4d82fc JJ |
1261 | /// ``` |
1262 | fn bitxor(self, rhs: &BTreeSet<T>) -> BTreeSet<T> { | |
1263 | self.symmetric_difference(rhs).cloned().collect() | |
1264 | } | |
1265 | } | |
1266 | ||
85aaf69f | 1267 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1268 | impl<T: Ord + Clone> BitAnd<&BTreeSet<T>> for &BTreeSet<T> { |
1a4d82fc JJ |
1269 | type Output = BTreeSet<T>; |
1270 | ||
1271 | /// Returns the intersection of `self` and `rhs` as a new `BTreeSet<T>`. | |
1272 | /// | |
1273 | /// # Examples | |
1274 | /// | |
1275 | /// ``` | |
1276 | /// use std::collections::BTreeSet; | |
1277 | /// | |
85aaf69f SL |
1278 | /// let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect(); |
1279 | /// let b: BTreeSet<_> = vec![2, 3, 4].into_iter().collect(); | |
1a4d82fc | 1280 | /// |
85aaf69f SL |
1281 | /// let result = &a & &b; |
1282 | /// let result_vec: Vec<_> = result.into_iter().collect(); | |
c34b1796 | 1283 | /// assert_eq!(result_vec, [2, 3]); |
1a4d82fc JJ |
1284 | /// ``` |
1285 | fn bitand(self, rhs: &BTreeSet<T>) -> BTreeSet<T> { | |
1286 | self.intersection(rhs).cloned().collect() | |
1287 | } | |
1288 | } | |
1289 | ||
85aaf69f | 1290 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1291 | impl<T: Ord + Clone> BitOr<&BTreeSet<T>> for &BTreeSet<T> { |
1a4d82fc JJ |
1292 | type Output = BTreeSet<T>; |
1293 | ||
1294 | /// Returns the union of `self` and `rhs` as a new `BTreeSet<T>`. | |
1295 | /// | |
1296 | /// # Examples | |
1297 | /// | |
1298 | /// ``` | |
1299 | /// use std::collections::BTreeSet; | |
1300 | /// | |
85aaf69f SL |
1301 | /// let a: BTreeSet<_> = vec![1, 2, 3].into_iter().collect(); |
1302 | /// let b: BTreeSet<_> = vec![3, 4, 5].into_iter().collect(); | |
1a4d82fc | 1303 | /// |
85aaf69f SL |
1304 | /// let result = &a | &b; |
1305 | /// let result_vec: Vec<_> = result.into_iter().collect(); | |
c34b1796 | 1306 | /// assert_eq!(result_vec, [1, 2, 3, 4, 5]); |
1a4d82fc JJ |
1307 | /// ``` |
1308 | fn bitor(self, rhs: &BTreeSet<T>) -> BTreeSet<T> { | |
1309 | self.union(rhs).cloned().collect() | |
1310 | } | |
1311 | } | |
1312 | ||
85aaf69f SL |
1313 | #[stable(feature = "rust1", since = "1.0.0")] |
1314 | impl<T: Debug> Debug for BTreeSet<T> { | |
9fa01778 | 1315 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
62682a34 | 1316 | f.debug_set().entries(self.iter()).finish() |
1a4d82fc JJ |
1317 | } |
1318 | } | |
1319 | ||
c30ab7b3 | 1320 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 XL |
1321 | impl<T> Clone for Iter<'_, T> { |
1322 | fn clone(&self) -> Self { | |
92a42be0 SL |
1323 | Iter { iter: self.iter.clone() } |
1324 | } | |
c34b1796 | 1325 | } |
85aaf69f | 1326 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1327 | impl<'a, T> Iterator for Iter<'a, T> { |
1328 | type Item = &'a T; | |
1329 | ||
92a42be0 SL |
1330 | fn next(&mut self) -> Option<&'a T> { |
1331 | self.iter.next() | |
1332 | } | |
f035d41b | 1333 | |
92a42be0 SL |
1334 | fn size_hint(&self) -> (usize, Option<usize>) { |
1335 | self.iter.size_hint() | |
1336 | } | |
f035d41b | 1337 | |
416331ca XL |
1338 | fn last(mut self) -> Option<&'a T> { |
1339 | self.next_back() | |
1340 | } | |
f035d41b XL |
1341 | |
1342 | fn min(mut self) -> Option<&'a T> { | |
1343 | self.next() | |
1344 | } | |
1345 | ||
1346 | fn max(mut self) -> Option<&'a T> { | |
1347 | self.next_back() | |
1348 | } | |
1a4d82fc | 1349 | } |
85aaf69f | 1350 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 1351 | impl<'a, T> DoubleEndedIterator for Iter<'a, T> { |
92a42be0 SL |
1352 | fn next_back(&mut self) -> Option<&'a T> { |
1353 | self.iter.next_back() | |
1354 | } | |
1a4d82fc | 1355 | } |
85aaf69f | 1356 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1357 | impl<T> ExactSizeIterator for Iter<'_, T> { |
dfeec247 XL |
1358 | fn len(&self) -> usize { |
1359 | self.iter.len() | |
1360 | } | |
7453a54e | 1361 | } |
1a4d82fc | 1362 | |
0531ce1d | 1363 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1364 | impl<T> FusedIterator for Iter<'_, T> {} |
1a4d82fc | 1365 | |
85aaf69f | 1366 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1367 | impl<T> Iterator for IntoIter<T> { |
1368 | type Item = T; | |
1369 | ||
92a42be0 | 1370 | fn next(&mut self) -> Option<T> { |
9cc50fc6 | 1371 | self.iter.next().map(|(k, _)| k) |
92a42be0 | 1372 | } |
f035d41b | 1373 | |
92a42be0 SL |
1374 | fn size_hint(&self) -> (usize, Option<usize>) { |
1375 | self.iter.size_hint() | |
1376 | } | |
1a4d82fc | 1377 | } |
85aaf69f | 1378 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 1379 | impl<T> DoubleEndedIterator for IntoIter<T> { |
92a42be0 | 1380 | fn next_back(&mut self) -> Option<T> { |
9cc50fc6 | 1381 | self.iter.next_back().map(|(k, _)| k) |
92a42be0 | 1382 | } |
1a4d82fc | 1383 | } |
85aaf69f | 1384 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 1385 | impl<T> ExactSizeIterator for IntoIter<T> { |
dfeec247 XL |
1386 | fn len(&self) -> usize { |
1387 | self.iter.len() | |
1388 | } | |
7453a54e | 1389 | } |
1a4d82fc | 1390 | |
0531ce1d | 1391 | #[stable(feature = "fused", since = "1.26.0")] |
9e0c209e | 1392 | impl<T> FusedIterator for IntoIter<T> {} |
85aaf69f | 1393 | |
cc61c64b | 1394 | #[stable(feature = "btree_range", since = "1.17.0")] |
9fa01778 XL |
1395 | impl<T> Clone for Range<'_, T> { |
1396 | fn clone(&self) -> Self { | |
92a42be0 SL |
1397 | Range { iter: self.iter.clone() } |
1398 | } | |
c34b1796 | 1399 | } |
cc61c64b XL |
1400 | |
1401 | #[stable(feature = "btree_range", since = "1.17.0")] | |
85aaf69f SL |
1402 | impl<'a, T> Iterator for Range<'a, T> { |
1403 | type Item = &'a T; | |
1404 | ||
92a42be0 | 1405 | fn next(&mut self) -> Option<&'a T> { |
9cc50fc6 | 1406 | self.iter.next().map(|(k, _)| k) |
92a42be0 | 1407 | } |
416331ca XL |
1408 | |
1409 | fn last(mut self) -> Option<&'a T> { | |
1410 | self.next_back() | |
1411 | } | |
f035d41b XL |
1412 | |
1413 | fn min(mut self) -> Option<&'a T> { | |
1414 | self.next() | |
1415 | } | |
1416 | ||
1417 | fn max(mut self) -> Option<&'a T> { | |
1418 | self.next_back() | |
1419 | } | |
85aaf69f | 1420 | } |
cc61c64b XL |
1421 | |
1422 | #[stable(feature = "btree_range", since = "1.17.0")] | |
85aaf69f | 1423 | impl<'a, T> DoubleEndedIterator for Range<'a, T> { |
92a42be0 | 1424 | fn next_back(&mut self) -> Option<&'a T> { |
9cc50fc6 | 1425 | self.iter.next_back().map(|(k, _)| k) |
92a42be0 | 1426 | } |
85aaf69f SL |
1427 | } |
1428 | ||
0531ce1d | 1429 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1430 | impl<T> FusedIterator for Range<'_, T> {} |
9e0c209e | 1431 | |
c30ab7b3 | 1432 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 XL |
1433 | impl<T> Clone for Difference<'_, T> { |
1434 | fn clone(&self) -> Self { | |
92a42be0 | 1435 | Difference { |
532ac7d7 | 1436 | inner: match &self.inner { |
dfeec247 | 1437 | DifferenceInner::Stitch { self_iter, other_iter } => DifferenceInner::Stitch { |
532ac7d7 XL |
1438 | self_iter: self_iter.clone(), |
1439 | other_iter: other_iter.clone(), | |
1440 | }, | |
dfeec247 XL |
1441 | DifferenceInner::Search { self_iter, other_set } => { |
1442 | DifferenceInner::Search { self_iter: self_iter.clone(), other_set } | |
1443 | } | |
e74abb32 | 1444 | DifferenceInner::Iterate(iter) => DifferenceInner::Iterate(iter.clone()), |
532ac7d7 | 1445 | }, |
92a42be0 | 1446 | } |
c34b1796 AL |
1447 | } |
1448 | } | |
85aaf69f | 1449 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1450 | impl<'a, T: Ord> Iterator for Difference<'a, T> { |
1451 | type Item = &'a T; | |
1452 | ||
1453 | fn next(&mut self) -> Option<&'a T> { | |
532ac7d7 | 1454 | match &mut self.inner { |
dfeec247 | 1455 | DifferenceInner::Stitch { self_iter, other_iter } => { |
532ac7d7 XL |
1456 | let mut self_next = self_iter.next()?; |
1457 | loop { | |
dfeec247 | 1458 | match other_iter.peek().map_or(Less, |other_next| self_next.cmp(other_next)) { |
532ac7d7 XL |
1459 | Less => return Some(self_next), |
1460 | Equal => { | |
1461 | self_next = self_iter.next()?; | |
1462 | other_iter.next(); | |
1463 | } | |
1464 | Greater => { | |
1465 | other_iter.next(); | |
1466 | } | |
1467 | } | |
92a42be0 | 1468 | } |
1a4d82fc | 1469 | } |
dfeec247 | 1470 | DifferenceInner::Search { self_iter, other_set } => loop { |
532ac7d7 XL |
1471 | let self_next = self_iter.next()?; |
1472 | if !other_set.contains(&self_next) { | |
1473 | return Some(self_next); | |
1474 | } | |
1475 | }, | |
e74abb32 | 1476 | DifferenceInner::Iterate(iter) => iter.next(), |
1a4d82fc JJ |
1477 | } |
1478 | } | |
7453a54e SL |
1479 | |
1480 | fn size_hint(&self) -> (usize, Option<usize>) { | |
532ac7d7 | 1481 | let (self_len, other_len) = match &self.inner { |
dfeec247 XL |
1482 | DifferenceInner::Stitch { self_iter, other_iter } => { |
1483 | (self_iter.len(), other_iter.len()) | |
1484 | } | |
1485 | DifferenceInner::Search { self_iter, other_set } => (self_iter.len(), other_set.len()), | |
e74abb32 | 1486 | DifferenceInner::Iterate(iter) => (iter.len(), 0), |
532ac7d7 XL |
1487 | }; |
1488 | (self_len.saturating_sub(other_len), Some(self_len)) | |
7453a54e | 1489 | } |
f035d41b XL |
1490 | |
1491 | fn min(mut self) -> Option<&'a T> { | |
1492 | self.next() | |
1493 | } | |
1a4d82fc JJ |
1494 | } |
1495 | ||
0531ce1d | 1496 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1497 | impl<T: Ord> FusedIterator for Difference<'_, T> {} |
9e0c209e | 1498 | |
c30ab7b3 | 1499 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 XL |
1500 | impl<T> Clone for SymmetricDifference<'_, T> { |
1501 | fn clone(&self) -> Self { | |
e74abb32 | 1502 | SymmetricDifference(self.0.clone()) |
c34b1796 AL |
1503 | } |
1504 | } | |
85aaf69f | 1505 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1506 | impl<'a, T: Ord> Iterator for SymmetricDifference<'a, T> { |
1507 | type Item = &'a T; | |
1508 | ||
1509 | fn next(&mut self) -> Option<&'a T> { | |
1510 | loop { | |
29967ef6 | 1511 | let (a_next, b_next) = self.0.nexts(Self::Item::cmp); |
e74abb32 XL |
1512 | if a_next.and(b_next).is_none() { |
1513 | return a_next.or(b_next); | |
1a4d82fc JJ |
1514 | } |
1515 | } | |
1516 | } | |
7453a54e SL |
1517 | |
1518 | fn size_hint(&self) -> (usize, Option<usize>) { | |
e74abb32 XL |
1519 | let (a_len, b_len) = self.0.lens(); |
1520 | // No checked_add, because even if a and b refer to the same set, | |
1521 | // and T is an empty type, the storage overhead of sets limits | |
1522 | // the number of elements to less than half the range of usize. | |
1523 | (0, Some(a_len + b_len)) | |
7453a54e | 1524 | } |
f035d41b XL |
1525 | |
1526 | fn min(mut self) -> Option<&'a T> { | |
1527 | self.next() | |
1528 | } | |
1a4d82fc JJ |
1529 | } |
1530 | ||
0531ce1d | 1531 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1532 | impl<T: Ord> FusedIterator for SymmetricDifference<'_, T> {} |
9e0c209e | 1533 | |
c30ab7b3 | 1534 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 XL |
1535 | impl<T> Clone for Intersection<'_, T> { |
1536 | fn clone(&self) -> Self { | |
92a42be0 | 1537 | Intersection { |
532ac7d7 | 1538 | inner: match &self.inner { |
dfeec247 XL |
1539 | IntersectionInner::Stitch { a, b } => { |
1540 | IntersectionInner::Stitch { a: a.clone(), b: b.clone() } | |
1541 | } | |
1542 | IntersectionInner::Search { small_iter, large_set } => { | |
1543 | IntersectionInner::Search { small_iter: small_iter.clone(), large_set } | |
1544 | } | |
e74abb32 | 1545 | IntersectionInner::Answer(answer) => IntersectionInner::Answer(*answer), |
532ac7d7 | 1546 | }, |
92a42be0 | 1547 | } |
c34b1796 AL |
1548 | } |
1549 | } | |
85aaf69f | 1550 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1551 | impl<'a, T: Ord> Iterator for Intersection<'a, T> { |
1552 | type Item = &'a T; | |
1553 | ||
1554 | fn next(&mut self) -> Option<&'a T> { | |
532ac7d7 | 1555 | match &mut self.inner { |
dfeec247 | 1556 | IntersectionInner::Stitch { a, b } => { |
e1599b0c XL |
1557 | let mut a_next = a.next()?; |
1558 | let mut b_next = b.next()?; | |
532ac7d7 | 1559 | loop { |
e74abb32 | 1560 | match a_next.cmp(b_next) { |
e1599b0c XL |
1561 | Less => a_next = a.next()?, |
1562 | Greater => b_next = b.next()?, | |
1563 | Equal => return Some(a_next), | |
532ac7d7 | 1564 | } |
92a42be0 | 1565 | } |
1a4d82fc | 1566 | } |
dfeec247 | 1567 | IntersectionInner::Search { small_iter, large_set } => loop { |
532ac7d7 XL |
1568 | let small_next = small_iter.next()?; |
1569 | if large_set.contains(&small_next) { | |
1570 | return Some(small_next); | |
1571 | } | |
1572 | }, | |
e74abb32 | 1573 | IntersectionInner::Answer(answer) => answer.take(), |
1a4d82fc JJ |
1574 | } |
1575 | } | |
7453a54e SL |
1576 | |
1577 | fn size_hint(&self) -> (usize, Option<usize>) { | |
e74abb32 XL |
1578 | match &self.inner { |
1579 | IntersectionInner::Stitch { a, b } => (0, Some(min(a.len(), b.len()))), | |
1580 | IntersectionInner::Search { small_iter, .. } => (0, Some(small_iter.len())), | |
1581 | IntersectionInner::Answer(None) => (0, Some(0)), | |
1582 | IntersectionInner::Answer(Some(_)) => (1, Some(1)), | |
1583 | } | |
7453a54e | 1584 | } |
f035d41b XL |
1585 | |
1586 | fn min(mut self) -> Option<&'a T> { | |
1587 | self.next() | |
1588 | } | |
1a4d82fc JJ |
1589 | } |
1590 | ||
0531ce1d | 1591 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1592 | impl<T: Ord> FusedIterator for Intersection<'_, T> {} |
9e0c209e | 1593 | |
c30ab7b3 | 1594 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 XL |
1595 | impl<T> Clone for Union<'_, T> { |
1596 | fn clone(&self) -> Self { | |
e74abb32 | 1597 | Union(self.0.clone()) |
c34b1796 AL |
1598 | } |
1599 | } | |
85aaf69f | 1600 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
1601 | impl<'a, T: Ord> Iterator for Union<'a, T> { |
1602 | type Item = &'a T; | |
1603 | ||
1604 | fn next(&mut self) -> Option<&'a T> { | |
29967ef6 | 1605 | let (a_next, b_next) = self.0.nexts(Self::Item::cmp); |
e74abb32 | 1606 | a_next.or(b_next) |
1a4d82fc | 1607 | } |
7453a54e SL |
1608 | |
1609 | fn size_hint(&self) -> (usize, Option<usize>) { | |
e74abb32 XL |
1610 | let (a_len, b_len) = self.0.lens(); |
1611 | // No checked_add - see SymmetricDifference::size_hint. | |
7453a54e SL |
1612 | (max(a_len, b_len), Some(a_len + b_len)) |
1613 | } | |
f035d41b XL |
1614 | |
1615 | fn min(mut self) -> Option<&'a T> { | |
1616 | self.next() | |
1617 | } | |
1a4d82fc | 1618 | } |
9e0c209e | 1619 | |
0531ce1d | 1620 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1621 | impl<T: Ord> FusedIterator for Union<'_, T> {} |
3dfed10e XL |
1622 | |
1623 | #[cfg(test)] | |
1624 | mod tests; |