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Commit | Line | Data |
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9fa01778 | 1 | use core::borrow::Borrow; |
1a4d82fc | 2 | use core::cmp::Ordering; |
85aaf69f | 3 | use core::fmt::Debug; |
1a4d82fc | 4 | use core::hash::{Hash, Hasher}; |
9e0c209e | 5 | use core::iter::{FromIterator, Peekable, FusedIterator}; |
9cc50fc6 | 6 | use core::marker::PhantomData; |
0531ce1d | 7 | use core::ops::Bound::{Excluded, Included, Unbounded}; |
9fa01778 | 8 | use core::ops::{Index, RangeBounds}; |
9cc50fc6 | 9 | use core::{fmt, intrinsics, mem, ptr}; |
1a4d82fc | 10 | |
9fa01778 XL |
11 | use super::node::{self, Handle, NodeRef, marker, InsertResult::*, ForceResult::*}; |
12 | use super::search::{self, SearchResult::*}; | |
9cc50fc6 | 13 | |
9fa01778 XL |
14 | use UnderflowResult::*; |
15 | use Entry::*; | |
1a4d82fc | 16 | |
1a4d82fc JJ |
17 | /// A map based on a B-Tree. |
18 | /// | |
19 | /// B-Trees represent a fundamental compromise between cache-efficiency and actually minimizing | |
20 | /// the amount of work performed in a search. In theory, a binary search tree (BST) is the optimal | |
21 | /// choice for a sorted map, as a perfectly balanced BST performs the theoretical minimum amount of | |
22 | /// comparisons necessary to find an element (log<sub>2</sub>n). However, in practice the way this | |
23 | /// is done is *very* inefficient for modern computer architectures. In particular, every element | |
24 | /// is stored in its own individually heap-allocated node. This means that every single insertion | |
25 | /// triggers a heap-allocation, and every single comparison should be a cache-miss. Since these | |
26 | /// are both notably expensive things to do in practice, we are forced to at very least reconsider | |
27 | /// the BST strategy. | |
28 | /// | |
29 | /// A B-Tree instead makes each node contain B-1 to 2B-1 elements in a contiguous array. By doing | |
30 | /// this, we reduce the number of allocations by a factor of B, and improve cache efficiency in | |
31 | /// searches. However, this does mean that searches will have to do *more* comparisons on average. | |
32 | /// The precise number of comparisons depends on the node search strategy used. For optimal cache | |
33 | /// efficiency, one could search the nodes linearly. For optimal comparisons, one could search | |
34 | /// the node using binary search. As a compromise, one could also perform a linear search | |
35 | /// that initially only checks every i<sup>th</sup> element for some choice of i. | |
36 | /// | |
37 | /// Currently, our implementation simply performs naive linear search. This provides excellent | |
38 | /// performance on *small* nodes of elements which are cheap to compare. However in the future we | |
39 | /// would like to further explore choosing the optimal search strategy based on the choice of B, | |
40 | /// and possibly other factors. Using linear search, searching for a random element is expected | |
41 | /// to take O(B log<sub>B</sub>n) comparisons, which is generally worse than a BST. In practice, | |
85aaf69f | 42 | /// however, performance is excellent. |
c34b1796 AL |
43 | /// |
44 | /// It is a logic error for a key to be modified in such a way that the key's ordering relative to | |
9e0c209e SL |
45 | /// any other key, as determined by the [`Ord`] trait, changes while it is in the map. This is |
46 | /// normally only possible through [`Cell`], [`RefCell`], global state, I/O, or unsafe code. | |
47 | /// | |
48 | /// [`Ord`]: ../../std/cmp/trait.Ord.html | |
49 | /// [`Cell`]: ../../std/cell/struct.Cell.html | |
50 | /// [`RefCell`]: ../../std/cell/struct.RefCell.html | |
54a0048b SL |
51 | /// |
52 | /// # Examples | |
53 | /// | |
54 | /// ``` | |
55 | /// use std::collections::BTreeMap; | |
56 | /// | |
57 | /// // type inference lets us omit an explicit type signature (which | |
58 | /// // would be `BTreeMap<&str, &str>` in this example). | |
59 | /// let mut movie_reviews = BTreeMap::new(); | |
60 | /// | |
3157f602 | 61 | /// // review some movies. |
54a0048b SL |
62 | /// movie_reviews.insert("Office Space", "Deals with real issues in the workplace."); |
63 | /// movie_reviews.insert("Pulp Fiction", "Masterpiece."); | |
64 | /// movie_reviews.insert("The Godfather", "Very enjoyable."); | |
0bf4aa26 | 65 | /// movie_reviews.insert("The Blues Brothers", "Eye lyked it a lot."); |
54a0048b SL |
66 | /// |
67 | /// // check for a specific one. | |
68 | /// if !movie_reviews.contains_key("Les Misérables") { | |
69 | /// println!("We've got {} reviews, but Les Misérables ain't one.", | |
70 | /// movie_reviews.len()); | |
71 | /// } | |
72 | /// | |
73 | /// // oops, this review has a lot of spelling mistakes, let's delete it. | |
74 | /// movie_reviews.remove("The Blues Brothers"); | |
75 | /// | |
76 | /// // look up the values associated with some keys. | |
77 | /// let to_find = ["Up!", "Office Space"]; | |
416331ca XL |
78 | /// for movie in &to_find { |
79 | /// match movie_reviews.get(movie) { | |
80 | /// Some(review) => println!("{}: {}", movie, review), | |
81 | /// None => println!("{} is unreviewed.", movie) | |
54a0048b SL |
82 | /// } |
83 | /// } | |
84 | /// | |
0731742a XL |
85 | /// // Look up the value for a key (will panic if the key is not found). |
86 | /// println!("Movie review: {}", movie_reviews["Office Space"]); | |
87 | /// | |
54a0048b SL |
88 | /// // iterate over everything. |
89 | /// for (movie, review) in &movie_reviews { | |
90 | /// println!("{}: \"{}\"", movie, review); | |
91 | /// } | |
92 | /// ``` | |
93 | /// | |
94 | /// `BTreeMap` also implements an [`Entry API`](#method.entry), which allows | |
95 | /// for more complex methods of getting, setting, updating and removing keys and | |
96 | /// their values: | |
97 | /// | |
98 | /// ``` | |
99 | /// use std::collections::BTreeMap; | |
100 | /// | |
101 | /// // type inference lets us omit an explicit type signature (which | |
102 | /// // would be `BTreeMap<&str, u8>` in this example). | |
103 | /// let mut player_stats = BTreeMap::new(); | |
104 | /// | |
105 | /// fn random_stat_buff() -> u8 { | |
106 | /// // could actually return some random value here - let's just return | |
107 | /// // some fixed value for now | |
108 | /// 42 | |
109 | /// } | |
110 | /// | |
111 | /// // insert a key only if it doesn't already exist | |
112 | /// player_stats.entry("health").or_insert(100); | |
113 | /// | |
114 | /// // insert a key using a function that provides a new value only if it | |
115 | /// // doesn't already exist | |
116 | /// player_stats.entry("defence").or_insert_with(random_stat_buff); | |
117 | /// | |
118 | /// // update a key, guarding against the key possibly not being set | |
119 | /// let stat = player_stats.entry("attack").or_insert(100); | |
120 | /// *stat += random_stat_buff(); | |
121 | /// ``` | |
85aaf69f | 122 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 123 | pub struct BTreeMap<K, V> { |
9cc50fc6 | 124 | root: node::Root<K, V>, |
3157f602 | 125 | length: usize, |
9cc50fc6 SL |
126 | } |
127 | ||
c30ab7b3 | 128 | #[stable(feature = "btree_drop", since = "1.7.0")] |
32a655c1 | 129 | unsafe impl<#[may_dangle] K, #[may_dangle] V> Drop for BTreeMap<K, V> { |
9cc50fc6 SL |
130 | fn drop(&mut self) { |
131 | unsafe { | |
cc61c64b | 132 | drop(ptr::read(self).into_iter()); |
9cc50fc6 SL |
133 | } |
134 | } | |
135 | } | |
136 | ||
c30ab7b3 | 137 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
138 | impl<K: Clone, V: Clone> Clone for BTreeMap<K, V> { |
139 | fn clone(&self) -> BTreeMap<K, V> { | |
8faf50e0 XL |
140 | fn clone_subtree<'a, K: Clone, V: Clone>( |
141 | node: node::NodeRef<marker::Immut<'a>, K, V, marker::LeafOrInternal> | |
142 | ) -> BTreeMap<K, V> | |
143 | where K: 'a, V: 'a, | |
144 | { | |
9cc50fc6 SL |
145 | match node.force() { |
146 | Leaf(leaf) => { | |
147 | let mut out_tree = BTreeMap { | |
148 | root: node::Root::new_leaf(), | |
3157f602 | 149 | length: 0, |
9cc50fc6 SL |
150 | }; |
151 | ||
152 | { | |
153 | let mut out_node = match out_tree.root.as_mut().force() { | |
154 | Leaf(leaf) => leaf, | |
3157f602 | 155 | Internal(_) => unreachable!(), |
9cc50fc6 SL |
156 | }; |
157 | ||
158 | let mut in_edge = leaf.first_edge(); | |
159 | while let Ok(kv) = in_edge.right_kv() { | |
160 | let (k, v) = kv.into_kv(); | |
161 | in_edge = kv.right_edge(); | |
162 | ||
163 | out_node.push(k.clone(), v.clone()); | |
164 | out_tree.length += 1; | |
165 | } | |
166 | } | |
167 | ||
168 | out_tree | |
3157f602 | 169 | } |
9cc50fc6 SL |
170 | Internal(internal) => { |
171 | let mut out_tree = clone_subtree(internal.first_edge().descend()); | |
172 | ||
173 | { | |
174 | let mut out_node = out_tree.root.push_level(); | |
175 | let mut in_edge = internal.first_edge(); | |
176 | while let Ok(kv) = in_edge.right_kv() { | |
177 | let (k, v) = kv.into_kv(); | |
178 | in_edge = kv.right_edge(); | |
179 | ||
180 | let k = (*k).clone(); | |
181 | let v = (*v).clone(); | |
182 | let subtree = clone_subtree(in_edge.descend()); | |
183 | ||
184 | // We can't destructure subtree directly | |
185 | // because BTreeMap implements Drop | |
186 | let (subroot, sublength) = unsafe { | |
187 | let root = ptr::read(&subtree.root); | |
188 | let length = subtree.length; | |
189 | mem::forget(subtree); | |
190 | (root, length) | |
191 | }; | |
192 | ||
193 | out_node.push(k, v, subroot); | |
194 | out_tree.length += 1 + sublength; | |
195 | } | |
196 | } | |
197 | ||
198 | out_tree | |
199 | } | |
200 | } | |
201 | } | |
202 | ||
416331ca | 203 | if self.is_empty() { |
8faf50e0 XL |
204 | // Ideally we'd call `BTreeMap::new` here, but that has the `K: |
205 | // Ord` constraint, which this method lacks. | |
206 | BTreeMap { | |
207 | root: node::Root::shared_empty_root(), | |
208 | length: 0, | |
209 | } | |
210 | } else { | |
211 | clone_subtree(self.root.as_ref()) | |
212 | } | |
9cc50fc6 | 213 | } |
1a4d82fc JJ |
214 | } |
215 | ||
9cc50fc6 SL |
216 | impl<K, Q: ?Sized> super::Recover<Q> for BTreeMap<K, ()> |
217 | where K: Borrow<Q> + Ord, | |
218 | Q: Ord | |
219 | { | |
220 | type Key = K; | |
221 | ||
222 | fn get(&self, key: &Q) -> Option<&K> { | |
223 | match search::search_tree(self.root.as_ref(), key) { | |
224 | Found(handle) => Some(handle.into_kv().0), | |
3157f602 | 225 | GoDown(_) => None, |
9cc50fc6 SL |
226 | } |
227 | } | |
228 | ||
229 | fn take(&mut self, key: &Q) -> Option<K> { | |
230 | match search::search_tree(self.root.as_mut(), key) { | |
231 | Found(handle) => { | |
232 | Some(OccupiedEntry { | |
3b2f2976 | 233 | handle, |
3157f602 XL |
234 | length: &mut self.length, |
235 | _marker: PhantomData, | |
236 | } | |
237 | .remove_kv() | |
238 | .0) | |
239 | } | |
240 | GoDown(_) => None, | |
9cc50fc6 SL |
241 | } |
242 | } | |
243 | ||
244 | fn replace(&mut self, key: K) -> Option<K> { | |
94b46f34 | 245 | self.ensure_root_is_owned(); |
9fa01778 | 246 | match search::search_tree::<marker::Mut<'_>, K, (), K>(self.root.as_mut(), &key) { |
9cc50fc6 SL |
247 | Found(handle) => Some(mem::replace(handle.into_kv_mut().0, key)), |
248 | GoDown(handle) => { | |
249 | VacantEntry { | |
3b2f2976 XL |
250 | key, |
251 | handle, | |
9cc50fc6 SL |
252 | length: &mut self.length, |
253 | _marker: PhantomData, | |
3157f602 XL |
254 | } |
255 | .insert(()); | |
9cc50fc6 SL |
256 | None |
257 | } | |
258 | } | |
259 | } | |
1a4d82fc JJ |
260 | } |
261 | ||
cc61c64b XL |
262 | /// An iterator over the entries of a `BTreeMap`. |
263 | /// | |
264 | /// This `struct` is created by the [`iter`] method on [`BTreeMap`]. See its | |
265 | /// documentation for more. | |
266 | /// | |
267 | /// [`iter`]: struct.BTreeMap.html#method.iter | |
268 | /// [`BTreeMap`]: struct.BTreeMap.html | |
85aaf69f | 269 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 270 | pub struct Iter<'a, K: 'a, V: 'a> { |
9cc50fc6 | 271 | range: Range<'a, K, V>, |
3157f602 | 272 | length: usize, |
1a4d82fc JJ |
273 | } |
274 | ||
8bb4bdeb | 275 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
276 | impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for Iter<'_, K, V> { |
277 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
8bb4bdeb XL |
278 | f.debug_list().entries(self.clone()).finish() |
279 | } | |
280 | } | |
281 | ||
cc61c64b XL |
282 | /// A mutable iterator over the entries of a `BTreeMap`. |
283 | /// | |
284 | /// This `struct` is created by the [`iter_mut`] method on [`BTreeMap`]. See its | |
285 | /// documentation for more. | |
286 | /// | |
287 | /// [`iter_mut`]: struct.BTreeMap.html#method.iter_mut | |
288 | /// [`BTreeMap`]: struct.BTreeMap.html | |
85aaf69f | 289 | #[stable(feature = "rust1", since = "1.0.0")] |
8bb4bdeb | 290 | #[derive(Debug)] |
1a4d82fc | 291 | pub struct IterMut<'a, K: 'a, V: 'a> { |
9cc50fc6 | 292 | range: RangeMut<'a, K, V>, |
3157f602 | 293 | length: usize, |
1a4d82fc JJ |
294 | } |
295 | ||
cc61c64b XL |
296 | /// An owning iterator over the entries of a `BTreeMap`. |
297 | /// | |
298 | /// This `struct` is created by the [`into_iter`] method on [`BTreeMap`][`BTreeMap`] | |
299 | /// (provided by the `IntoIterator` trait). See its documentation for more. | |
300 | /// | |
301 | /// [`into_iter`]: struct.BTreeMap.html#method.into_iter | |
302 | /// [`BTreeMap`]: struct.BTreeMap.html | |
85aaf69f | 303 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 304 | pub struct IntoIter<K, V> { |
9cc50fc6 SL |
305 | front: Handle<NodeRef<marker::Owned, K, V, marker::Leaf>, marker::Edge>, |
306 | back: Handle<NodeRef<marker::Owned, K, V, marker::Leaf>, marker::Edge>, | |
3157f602 | 307 | length: usize, |
1a4d82fc JJ |
308 | } |
309 | ||
8bb4bdeb XL |
310 | #[stable(feature = "collection_debug", since = "1.17.0")] |
311 | impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for IntoIter<K, V> { | |
9fa01778 | 312 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
8bb4bdeb XL |
313 | let range = Range { |
314 | front: self.front.reborrow(), | |
315 | back: self.back.reborrow(), | |
316 | }; | |
317 | f.debug_list().entries(range).finish() | |
318 | } | |
319 | } | |
320 | ||
cc61c64b XL |
321 | /// An iterator over the keys of a `BTreeMap`. |
322 | /// | |
323 | /// This `struct` is created by the [`keys`] method on [`BTreeMap`]. See its | |
324 | /// documentation for more. | |
325 | /// | |
326 | /// [`keys`]: struct.BTreeMap.html#method.keys | |
327 | /// [`BTreeMap`]: struct.BTreeMap.html | |
85aaf69f | 328 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 329 | pub struct Keys<'a, K: 'a, V: 'a> { |
9cc50fc6 | 330 | inner: Iter<'a, K, V>, |
1a4d82fc JJ |
331 | } |
332 | ||
8bb4bdeb | 333 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
334 | impl<K: fmt::Debug, V> fmt::Debug for Keys<'_, K, V> { |
335 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
041b39d2 | 336 | f.debug_list().entries(self.clone()).finish() |
8bb4bdeb XL |
337 | } |
338 | } | |
339 | ||
cc61c64b XL |
340 | /// An iterator over the values of a `BTreeMap`. |
341 | /// | |
342 | /// This `struct` is created by the [`values`] method on [`BTreeMap`]. See its | |
343 | /// documentation for more. | |
344 | /// | |
345 | /// [`values`]: struct.BTreeMap.html#method.values | |
346 | /// [`BTreeMap`]: struct.BTreeMap.html | |
85aaf69f | 347 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 348 | pub struct Values<'a, K: 'a, V: 'a> { |
9cc50fc6 | 349 | inner: Iter<'a, K, V>, |
85aaf69f SL |
350 | } |
351 | ||
8bb4bdeb | 352 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
353 | impl<K, V: fmt::Debug> fmt::Debug for Values<'_, K, V> { |
354 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
041b39d2 | 355 | f.debug_list().entries(self.clone()).finish() |
8bb4bdeb XL |
356 | } |
357 | } | |
358 | ||
cc61c64b XL |
359 | /// A mutable iterator over the values of a `BTreeMap`. |
360 | /// | |
361 | /// This `struct` is created by the [`values_mut`] method on [`BTreeMap`]. See its | |
362 | /// documentation for more. | |
363 | /// | |
364 | /// [`values_mut`]: struct.BTreeMap.html#method.values_mut | |
365 | /// [`BTreeMap`]: struct.BTreeMap.html | |
a7813a04 | 366 | #[stable(feature = "map_values_mut", since = "1.10.0")] |
8bb4bdeb | 367 | #[derive(Debug)] |
54a0048b SL |
368 | pub struct ValuesMut<'a, K: 'a, V: 'a> { |
369 | inner: IterMut<'a, K, V>, | |
370 | } | |
371 | ||
cc61c64b XL |
372 | /// An iterator over a sub-range of entries in a `BTreeMap`. |
373 | /// | |
374 | /// This `struct` is created by the [`range`] method on [`BTreeMap`]. See its | |
375 | /// documentation for more. | |
376 | /// | |
377 | /// [`range`]: struct.BTreeMap.html#method.range | |
378 | /// [`BTreeMap`]: struct.BTreeMap.html | |
8bb4bdeb | 379 | #[stable(feature = "btree_range", since = "1.17.0")] |
85aaf69f | 380 | pub struct Range<'a, K: 'a, V: 'a> { |
9cc50fc6 | 381 | front: Handle<NodeRef<marker::Immut<'a>, K, V, marker::Leaf>, marker::Edge>, |
3157f602 | 382 | back: Handle<NodeRef<marker::Immut<'a>, K, V, marker::Leaf>, marker::Edge>, |
85aaf69f SL |
383 | } |
384 | ||
8bb4bdeb | 385 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
386 | impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for Range<'_, K, V> { |
387 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
8bb4bdeb XL |
388 | f.debug_list().entries(self.clone()).finish() |
389 | } | |
390 | } | |
391 | ||
cc61c64b XL |
392 | /// A mutable iterator over a sub-range of entries in a `BTreeMap`. |
393 | /// | |
394 | /// This `struct` is created by the [`range_mut`] method on [`BTreeMap`]. See its | |
395 | /// documentation for more. | |
396 | /// | |
397 | /// [`range_mut`]: struct.BTreeMap.html#method.range_mut | |
398 | /// [`BTreeMap`]: struct.BTreeMap.html | |
8bb4bdeb | 399 | #[stable(feature = "btree_range", since = "1.17.0")] |
85aaf69f | 400 | pub struct RangeMut<'a, K: 'a, V: 'a> { |
9cc50fc6 SL |
401 | front: Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::Edge>, |
402 | back: Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::Edge>, | |
403 | ||
404 | // Be invariant in `K` and `V` | |
405 | _marker: PhantomData<&'a mut (K, V)>, | |
1a4d82fc JJ |
406 | } |
407 | ||
8bb4bdeb | 408 | #[stable(feature = "collection_debug", since = "1.17.0")] |
9fa01778 XL |
409 | impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for RangeMut<'_, K, V> { |
410 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
8bb4bdeb XL |
411 | let range = Range { |
412 | front: self.front.reborrow(), | |
413 | back: self.back.reborrow(), | |
414 | }; | |
415 | f.debug_list().entries(range).finish() | |
416 | } | |
417 | } | |
418 | ||
1a4d82fc | 419 | /// A view into a single entry in a map, which may either be vacant or occupied. |
cc61c64b XL |
420 | /// |
421 | /// This `enum` is constructed from the [`entry`] method on [`BTreeMap`]. | |
5bcae85e SL |
422 | /// |
423 | /// [`BTreeMap`]: struct.BTreeMap.html | |
424 | /// [`entry`]: struct.BTreeMap.html#method.entry | |
c34b1796 | 425 | #[stable(feature = "rust1", since = "1.0.0")] |
92a42be0 | 426 | pub enum Entry<'a, K: 'a, V: 'a> { |
cc61c64b | 427 | /// A vacant entry. |
c34b1796 | 428 | #[stable(feature = "rust1", since = "1.0.0")] |
3157f602 XL |
429 | Vacant(#[stable(feature = "rust1", since = "1.0.0")] |
430 | VacantEntry<'a, K, V>), | |
c34b1796 | 431 | |
cc61c64b | 432 | /// An occupied entry. |
c34b1796 | 433 | #[stable(feature = "rust1", since = "1.0.0")] |
3157f602 XL |
434 | Occupied(#[stable(feature = "rust1", since = "1.0.0")] |
435 | OccupiedEntry<'a, K, V>), | |
1a4d82fc JJ |
436 | } |
437 | ||
5bcae85e | 438 | #[stable(feature= "debug_btree_map", since = "1.12.0")] |
9fa01778 XL |
439 | impl<K: Debug + Ord, V: Debug> Debug for Entry<'_, K, V> { |
440 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
5bcae85e SL |
441 | match *self { |
442 | Vacant(ref v) => f.debug_tuple("Entry") | |
443 | .field(v) | |
444 | .finish(), | |
445 | Occupied(ref o) => f.debug_tuple("Entry") | |
446 | .field(o) | |
447 | .finish(), | |
448 | } | |
449 | } | |
450 | } | |
451 | ||
cc61c64b XL |
452 | /// A view into a vacant entry in a `BTreeMap`. |
453 | /// It is part of the [`Entry`] enum. | |
5bcae85e SL |
454 | /// |
455 | /// [`Entry`]: enum.Entry.html | |
c34b1796 | 456 | #[stable(feature = "rust1", since = "1.0.0")] |
92a42be0 | 457 | pub struct VacantEntry<'a, K: 'a, V: 'a> { |
1a4d82fc | 458 | key: K, |
9cc50fc6 SL |
459 | handle: Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::Edge>, |
460 | length: &'a mut usize, | |
461 | ||
462 | // Be invariant in `K` and `V` | |
463 | _marker: PhantomData<&'a mut (K, V)>, | |
1a4d82fc JJ |
464 | } |
465 | ||
5bcae85e | 466 | #[stable(feature= "debug_btree_map", since = "1.12.0")] |
9fa01778 XL |
467 | impl<K: Debug + Ord, V> Debug for VacantEntry<'_, K, V> { |
468 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
5bcae85e SL |
469 | f.debug_tuple("VacantEntry") |
470 | .field(self.key()) | |
471 | .finish() | |
472 | } | |
473 | } | |
474 | ||
cc61c64b XL |
475 | /// A view into an occupied entry in a `BTreeMap`. |
476 | /// It is part of the [`Entry`] enum. | |
5bcae85e SL |
477 | /// |
478 | /// [`Entry`]: enum.Entry.html | |
c34b1796 | 479 | #[stable(feature = "rust1", since = "1.0.0")] |
92a42be0 | 480 | pub struct OccupiedEntry<'a, K: 'a, V: 'a> { |
3157f602 | 481 | handle: Handle<NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal>, marker::KV>, |
9cc50fc6 SL |
482 | |
483 | length: &'a mut usize, | |
484 | ||
485 | // Be invariant in `K` and `V` | |
486 | _marker: PhantomData<&'a mut (K, V)>, | |
1a4d82fc JJ |
487 | } |
488 | ||
5bcae85e | 489 | #[stable(feature= "debug_btree_map", since = "1.12.0")] |
9fa01778 XL |
490 | impl<K: Debug + Ord, V: Debug> Debug for OccupiedEntry<'_, K, V> { |
491 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
5bcae85e SL |
492 | f.debug_struct("OccupiedEntry") |
493 | .field("key", self.key()) | |
494 | .field("value", self.get()) | |
495 | .finish() | |
496 | } | |
497 | } | |
498 | ||
a7813a04 | 499 | // An iterator for merging two sorted sequences into one |
3157f602 | 500 | struct MergeIter<K, V, I: Iterator<Item = (K, V)>> { |
a7813a04 XL |
501 | left: Peekable<I>, |
502 | right: Peekable<I>, | |
503 | } | |
504 | ||
1a4d82fc JJ |
505 | impl<K: Ord, V> BTreeMap<K, V> { |
506 | /// Makes a new empty BTreeMap with a reasonable choice for B. | |
54a0048b SL |
507 | /// |
508 | /// # Examples | |
509 | /// | |
510 | /// Basic usage: | |
511 | /// | |
512 | /// ``` | |
513 | /// use std::collections::BTreeMap; | |
514 | /// | |
515 | /// let mut map = BTreeMap::new(); | |
516 | /// | |
517 | /// // entries can now be inserted into the empty map | |
518 | /// map.insert(1, "a"); | |
519 | /// ``` | |
85aaf69f | 520 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 521 | pub fn new() -> BTreeMap<K, V> { |
1a4d82fc | 522 | BTreeMap { |
94b46f34 | 523 | root: node::Root::shared_empty_root(), |
3157f602 | 524 | length: 0, |
1a4d82fc JJ |
525 | } |
526 | } | |
527 | ||
528 | /// Clears the map, removing all values. | |
529 | /// | |
530 | /// # Examples | |
531 | /// | |
54a0048b SL |
532 | /// Basic usage: |
533 | /// | |
1a4d82fc JJ |
534 | /// ``` |
535 | /// use std::collections::BTreeMap; | |
536 | /// | |
537 | /// let mut a = BTreeMap::new(); | |
85aaf69f | 538 | /// a.insert(1, "a"); |
1a4d82fc JJ |
539 | /// a.clear(); |
540 | /// assert!(a.is_empty()); | |
541 | /// ``` | |
85aaf69f | 542 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 543 | pub fn clear(&mut self) { |
9cc50fc6 | 544 | *self = BTreeMap::new(); |
1a4d82fc JJ |
545 | } |
546 | ||
1a4d82fc JJ |
547 | /// Returns a reference to the value corresponding to the key. |
548 | /// | |
549 | /// The key may be any borrowed form of the map's key type, but the ordering | |
550 | /// on the borrowed form *must* match the ordering on the key type. | |
551 | /// | |
552 | /// # Examples | |
553 | /// | |
54a0048b SL |
554 | /// Basic usage: |
555 | /// | |
1a4d82fc JJ |
556 | /// ``` |
557 | /// use std::collections::BTreeMap; | |
558 | /// | |
559 | /// let mut map = BTreeMap::new(); | |
85aaf69f | 560 | /// map.insert(1, "a"); |
1a4d82fc JJ |
561 | /// assert_eq!(map.get(&1), Some(&"a")); |
562 | /// assert_eq!(map.get(&2), None); | |
563 | /// ``` | |
85aaf69f | 564 | #[stable(feature = "rust1", since = "1.0.0")] |
3157f602 XL |
565 | pub fn get<Q: ?Sized>(&self, key: &Q) -> Option<&V> |
566 | where K: Borrow<Q>, | |
567 | Q: Ord | |
568 | { | |
9cc50fc6 SL |
569 | match search::search_tree(self.root.as_ref(), key) { |
570 | Found(handle) => Some(handle.into_kv().1), | |
3157f602 | 571 | GoDown(_) => None, |
1a4d82fc JJ |
572 | } |
573 | } | |
574 | ||
0531ce1d XL |
575 | /// Returns the key-value pair corresponding to the supplied key. |
576 | /// | |
577 | /// The supplied key may be any borrowed form of the map's key type, but the ordering | |
578 | /// on the borrowed form *must* match the ordering on the key type. | |
579 | /// | |
580 | /// # Examples | |
581 | /// | |
582 | /// ``` | |
0531ce1d XL |
583 | /// use std::collections::BTreeMap; |
584 | /// | |
585 | /// let mut map = BTreeMap::new(); | |
586 | /// map.insert(1, "a"); | |
587 | /// assert_eq!(map.get_key_value(&1), Some((&1, &"a"))); | |
588 | /// assert_eq!(map.get_key_value(&2), None); | |
589 | /// ``` | |
e74abb32 | 590 | #[stable(feature = "map_get_key_value", since = "1.40.0")] |
0531ce1d XL |
591 | pub fn get_key_value<Q: ?Sized>(&self, k: &Q) -> Option<(&K, &V)> |
592 | where K: Borrow<Q>, | |
593 | Q: Ord | |
594 | { | |
595 | match search::search_tree(self.root.as_ref(), k) { | |
596 | Found(handle) => Some(handle.into_kv()), | |
597 | GoDown(_) => None, | |
598 | } | |
599 | } | |
600 | ||
60c5eb7d XL |
601 | /// Returns the first key-value pair in the map. |
602 | /// The key in this pair is the minimum key in the map. | |
603 | /// | |
604 | /// # Examples | |
605 | /// | |
606 | /// Basic usage: | |
607 | /// | |
608 | /// ``` | |
609 | /// #![feature(map_first_last)] | |
610 | /// use std::collections::BTreeMap; | |
611 | /// | |
612 | /// let mut map = BTreeMap::new(); | |
613 | /// assert_eq!(map.first_key_value(), None); | |
614 | /// map.insert(1, "b"); | |
615 | /// map.insert(2, "a"); | |
616 | /// assert_eq!(map.first_key_value(), Some((&1, &"b"))); | |
617 | /// ``` | |
618 | #[unstable(feature = "map_first_last", issue = "62924")] | |
619 | pub fn first_key_value<T: ?Sized>(&self) -> Option<(&K, &V)> | |
620 | where T: Ord, K: Borrow<T> | |
621 | { | |
622 | let front = first_leaf_edge(self.root.as_ref()); | |
623 | front.right_kv().ok().map(Handle::into_kv) | |
624 | } | |
625 | ||
626 | /// Returns the first entry in the map for in-place manipulation. | |
627 | /// The key of this entry is the minimum key in the map. | |
628 | /// | |
629 | /// # Examples | |
630 | /// | |
631 | /// Contrived way to `clear` a map: | |
632 | /// | |
633 | /// ``` | |
634 | /// #![feature(map_first_last)] | |
635 | /// use std::collections::BTreeMap; | |
636 | /// | |
637 | /// let mut map = BTreeMap::new(); | |
638 | /// map.insert(1, "a"); | |
639 | /// map.insert(2, "b"); | |
640 | /// while let Some(entry) = map.first_entry() { | |
641 | /// let (key, val) = entry.remove_entry(); | |
642 | /// assert!(!map.contains_key(&key)); | |
643 | /// } | |
644 | /// ``` | |
645 | #[unstable(feature = "map_first_last", issue = "62924")] | |
646 | pub fn first_entry<T: ?Sized>(&mut self) -> Option<OccupiedEntry<'_, K, V>> | |
647 | where T: Ord, K: Borrow<T> | |
648 | { | |
649 | match self.length { | |
650 | 0 => None, | |
651 | _ => Some(OccupiedEntry { | |
652 | handle: self.root.as_mut().first_kv(), | |
653 | length: &mut self.length, | |
654 | _marker: PhantomData, | |
655 | }), | |
656 | } | |
657 | } | |
658 | ||
659 | /// Returns the last key-value pair in the map. | |
660 | /// The key in this pair is the maximum key in the map. | |
661 | /// | |
662 | /// # Examples | |
663 | /// | |
664 | /// Basic usage: | |
665 | /// | |
666 | /// ``` | |
667 | /// #![feature(map_first_last)] | |
668 | /// use std::collections::BTreeMap; | |
669 | /// | |
670 | /// let mut map = BTreeMap::new(); | |
671 | /// map.insert(1, "b"); | |
672 | /// map.insert(2, "a"); | |
673 | /// assert_eq!(map.last_key_value(), Some((&2, &"a"))); | |
674 | /// ``` | |
675 | #[unstable(feature = "map_first_last", issue = "62924")] | |
676 | pub fn last_key_value<T: ?Sized>(&self) -> Option<(&K, &V)> | |
677 | where T: Ord, K: Borrow<T> | |
678 | { | |
679 | let back = last_leaf_edge(self.root.as_ref()); | |
680 | back.left_kv().ok().map(Handle::into_kv) | |
681 | } | |
682 | ||
683 | /// Returns the last entry in the map for in-place manipulation. | |
684 | /// The key of this entry is the maximum key in the map. | |
685 | /// | |
686 | /// # Examples | |
687 | /// | |
688 | /// Contrived way to `clear` a map: | |
689 | /// | |
690 | /// ``` | |
691 | /// #![feature(map_first_last)] | |
692 | /// use std::collections::BTreeMap; | |
693 | /// | |
694 | /// let mut map = BTreeMap::new(); | |
695 | /// map.insert(1, "a"); | |
696 | /// map.insert(2, "b"); | |
697 | /// while let Some(entry) = map.last_entry() { | |
698 | /// let (key, val) = entry.remove_entry(); | |
699 | /// assert!(!map.contains_key(&key)); | |
700 | /// } | |
701 | /// ``` | |
702 | #[unstable(feature = "map_first_last", issue = "62924")] | |
703 | pub fn last_entry<T: ?Sized>(&mut self) -> Option<OccupiedEntry<'_, K, V>> | |
704 | where T: Ord, K: Borrow<T> | |
705 | { | |
706 | match self.length { | |
707 | 0 => None, | |
708 | _ => Some(OccupiedEntry { | |
709 | handle: self.root.as_mut().last_kv(), | |
710 | length: &mut self.length, | |
711 | _marker: PhantomData, | |
712 | }), | |
713 | } | |
714 | } | |
715 | ||
cc61c64b | 716 | /// Returns `true` if the map contains a value for the specified key. |
1a4d82fc JJ |
717 | /// |
718 | /// The key may be any borrowed form of the map's key type, but the ordering | |
719 | /// on the borrowed form *must* match the ordering on the key type. | |
720 | /// | |
721 | /// # Examples | |
722 | /// | |
54a0048b SL |
723 | /// Basic usage: |
724 | /// | |
1a4d82fc JJ |
725 | /// ``` |
726 | /// use std::collections::BTreeMap; | |
727 | /// | |
728 | /// let mut map = BTreeMap::new(); | |
85aaf69f | 729 | /// map.insert(1, "a"); |
1a4d82fc JJ |
730 | /// assert_eq!(map.contains_key(&1), true); |
731 | /// assert_eq!(map.contains_key(&2), false); | |
732 | /// ``` | |
85aaf69f | 733 | #[stable(feature = "rust1", since = "1.0.0")] |
3157f602 XL |
734 | pub fn contains_key<Q: ?Sized>(&self, key: &Q) -> bool |
735 | where K: Borrow<Q>, | |
736 | Q: Ord | |
737 | { | |
1a4d82fc JJ |
738 | self.get(key).is_some() |
739 | } | |
740 | ||
741 | /// Returns a mutable reference to the value corresponding to the key. | |
742 | /// | |
743 | /// The key may be any borrowed form of the map's key type, but the ordering | |
744 | /// on the borrowed form *must* match the ordering on the key type. | |
745 | /// | |
746 | /// # Examples | |
747 | /// | |
54a0048b SL |
748 | /// Basic usage: |
749 | /// | |
1a4d82fc JJ |
750 | /// ``` |
751 | /// use std::collections::BTreeMap; | |
752 | /// | |
753 | /// let mut map = BTreeMap::new(); | |
85aaf69f | 754 | /// map.insert(1, "a"); |
9346a6ac AL |
755 | /// if let Some(x) = map.get_mut(&1) { |
756 | /// *x = "b"; | |
1a4d82fc | 757 | /// } |
c34b1796 | 758 | /// assert_eq!(map[&1], "b"); |
1a4d82fc JJ |
759 | /// ``` |
760 | // See `get` for implementation notes, this is basically a copy-paste with mut's added | |
85aaf69f | 761 | #[stable(feature = "rust1", since = "1.0.0")] |
3157f602 XL |
762 | pub fn get_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<&mut V> |
763 | where K: Borrow<Q>, | |
764 | Q: Ord | |
765 | { | |
9cc50fc6 SL |
766 | match search::search_tree(self.root.as_mut(), key) { |
767 | Found(handle) => Some(handle.into_kv_mut().1), | |
3157f602 | 768 | GoDown(_) => None, |
1a4d82fc JJ |
769 | } |
770 | } | |
771 | ||
b039eaaf SL |
772 | /// Inserts a key-value pair into the map. |
773 | /// | |
774 | /// If the map did not have this key present, `None` is returned. | |
775 | /// | |
7453a54e SL |
776 | /// If the map did have this key present, the value is updated, and the old |
777 | /// value is returned. The key is not updated, though; this matters for | |
778 | /// types that can be `==` without being identical. See the [module-level | |
779 | /// documentation] for more. | |
b039eaaf SL |
780 | /// |
781 | /// [module-level documentation]: index.html#insert-and-complex-keys | |
1a4d82fc JJ |
782 | /// |
783 | /// # Examples | |
784 | /// | |
54a0048b SL |
785 | /// Basic usage: |
786 | /// | |
1a4d82fc JJ |
787 | /// ``` |
788 | /// use std::collections::BTreeMap; | |
789 | /// | |
790 | /// let mut map = BTreeMap::new(); | |
85aaf69f | 791 | /// assert_eq!(map.insert(37, "a"), None); |
1a4d82fc JJ |
792 | /// assert_eq!(map.is_empty(), false); |
793 | /// | |
794 | /// map.insert(37, "b"); | |
795 | /// assert_eq!(map.insert(37, "c"), Some("b")); | |
c34b1796 | 796 | /// assert_eq!(map[&37], "c"); |
1a4d82fc | 797 | /// ``` |
85aaf69f | 798 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
799 | pub fn insert(&mut self, key: K, value: V) -> Option<V> { |
800 | match self.entry(key) { | |
801 | Occupied(mut entry) => Some(entry.insert(value)), | |
802 | Vacant(entry) => { | |
803 | entry.insert(value); | |
804 | None | |
1a4d82fc JJ |
805 | } |
806 | } | |
807 | } | |
808 | ||
1a4d82fc JJ |
809 | /// Removes a key from the map, returning the value at the key if the key |
810 | /// was previously in the map. | |
811 | /// | |
812 | /// The key may be any borrowed form of the map's key type, but the ordering | |
813 | /// on the borrowed form *must* match the ordering on the key type. | |
814 | /// | |
815 | /// # Examples | |
816 | /// | |
54a0048b SL |
817 | /// Basic usage: |
818 | /// | |
1a4d82fc JJ |
819 | /// ``` |
820 | /// use std::collections::BTreeMap; | |
821 | /// | |
822 | /// let mut map = BTreeMap::new(); | |
85aaf69f | 823 | /// map.insert(1, "a"); |
1a4d82fc JJ |
824 | /// assert_eq!(map.remove(&1), Some("a")); |
825 | /// assert_eq!(map.remove(&1), None); | |
826 | /// ``` | |
85aaf69f | 827 | #[stable(feature = "rust1", since = "1.0.0")] |
3157f602 XL |
828 | pub fn remove<Q: ?Sized>(&mut self, key: &Q) -> Option<V> |
829 | where K: Borrow<Q>, | |
830 | Q: Ord | |
831 | { | |
9cc50fc6 SL |
832 | match search::search_tree(self.root.as_mut(), key) { |
833 | Found(handle) => { | |
834 | Some(OccupiedEntry { | |
3b2f2976 | 835 | handle, |
3157f602 XL |
836 | length: &mut self.length, |
837 | _marker: PhantomData, | |
838 | } | |
839 | .remove()) | |
840 | } | |
841 | GoDown(_) => None, | |
1a4d82fc JJ |
842 | } |
843 | } | |
85aaf69f | 844 | |
a7813a04 XL |
845 | /// Moves all elements from `other` into `Self`, leaving `other` empty. |
846 | /// | |
847 | /// # Examples | |
848 | /// | |
849 | /// ``` | |
a7813a04 XL |
850 | /// use std::collections::BTreeMap; |
851 | /// | |
852 | /// let mut a = BTreeMap::new(); | |
853 | /// a.insert(1, "a"); | |
854 | /// a.insert(2, "b"); | |
855 | /// a.insert(3, "c"); | |
856 | /// | |
857 | /// let mut b = BTreeMap::new(); | |
858 | /// b.insert(3, "d"); | |
859 | /// b.insert(4, "e"); | |
860 | /// b.insert(5, "f"); | |
861 | /// | |
862 | /// a.append(&mut b); | |
863 | /// | |
864 | /// assert_eq!(a.len(), 5); | |
865 | /// assert_eq!(b.len(), 0); | |
866 | /// | |
867 | /// assert_eq!(a[&1], "a"); | |
868 | /// assert_eq!(a[&2], "b"); | |
869 | /// assert_eq!(a[&3], "d"); | |
870 | /// assert_eq!(a[&4], "e"); | |
871 | /// assert_eq!(a[&5], "f"); | |
872 | /// ``` | |
3157f602 | 873 | #[stable(feature = "btree_append", since = "1.11.0")] |
a7813a04 XL |
874 | pub fn append(&mut self, other: &mut Self) { |
875 | // Do we have to append anything at all? | |
416331ca | 876 | if other.is_empty() { |
a7813a04 XL |
877 | return; |
878 | } | |
879 | ||
880 | // We can just swap `self` and `other` if `self` is empty. | |
416331ca | 881 | if self.is_empty() { |
a7813a04 XL |
882 | mem::swap(self, other); |
883 | return; | |
884 | } | |
885 | ||
886 | // First, we merge `self` and `other` into a sorted sequence in linear time. | |
416331ca XL |
887 | let self_iter = mem::take(self).into_iter(); |
888 | let other_iter = mem::take(other).into_iter(); | |
a7813a04 XL |
889 | let iter = MergeIter { |
890 | left: self_iter.peekable(), | |
891 | right: other_iter.peekable(), | |
892 | }; | |
893 | ||
894 | // Second, we build a tree from the sorted sequence in linear time. | |
895 | self.from_sorted_iter(iter); | |
896 | self.fix_right_edge(); | |
897 | } | |
898 | ||
32a655c1 SL |
899 | /// Constructs a double-ended iterator over a sub-range of elements in the map. |
900 | /// The simplest way is to use the range syntax `min..max`, thus `range(min..max)` will | |
901 | /// yield elements from min (inclusive) to max (exclusive). | |
902 | /// The range may also be entered as `(Bound<T>, Bound<T>)`, so for example | |
903 | /// `range((Excluded(4), Included(10)))` will yield a left-exclusive, right-inclusive | |
904 | /// range from 4 to 10. | |
9346a6ac | 905 | /// |
8bb4bdeb XL |
906 | /// # Panics |
907 | /// | |
908 | /// Panics if range `start > end`. | |
909 | /// Panics if range `start == end` and both bounds are `Excluded`. | |
910 | /// | |
9346a6ac AL |
911 | /// # Examples |
912 | /// | |
54a0048b SL |
913 | /// Basic usage: |
914 | /// | |
9346a6ac AL |
915 | /// ``` |
916 | /// use std::collections::BTreeMap; | |
0531ce1d | 917 | /// use std::ops::Bound::Included; |
9346a6ac AL |
918 | /// |
919 | /// let mut map = BTreeMap::new(); | |
9cc50fc6 SL |
920 | /// map.insert(3, "a"); |
921 | /// map.insert(5, "b"); | |
922 | /// map.insert(8, "c"); | |
32a655c1 | 923 | /// for (&key, &value) in map.range((Included(&4), Included(&8))) { |
9346a6ac AL |
924 | /// println!("{}: {}", key, value); |
925 | /// } | |
32a655c1 | 926 | /// assert_eq!(Some((&5, &"b")), map.range(4..).next()); |
9346a6ac | 927 | /// ``` |
8bb4bdeb | 928 | #[stable(feature = "btree_range", since = "1.17.0")] |
9fa01778 | 929 | pub fn range<T: ?Sized, R>(&self, range: R) -> Range<'_, K, V> |
0531ce1d | 930 | where T: Ord, K: Borrow<T>, R: RangeBounds<T> |
9cc50fc6 | 931 | { |
8bb4bdeb XL |
932 | let root1 = self.root.as_ref(); |
933 | let root2 = self.root.as_ref(); | |
934 | let (f, b) = range_search(root1, root2, range); | |
9cc50fc6 | 935 | |
8bb4bdeb | 936 | Range { front: f, back: b} |
9cc50fc6 SL |
937 | } |
938 | ||
32a655c1 SL |
939 | /// Constructs a mutable double-ended iterator over a sub-range of elements in the map. |
940 | /// The simplest way is to use the range syntax `min..max`, thus `range(min..max)` will | |
941 | /// yield elements from min (inclusive) to max (exclusive). | |
942 | /// The range may also be entered as `(Bound<T>, Bound<T>)`, so for example | |
943 | /// `range((Excluded(4), Included(10)))` will yield a left-exclusive, right-inclusive | |
944 | /// range from 4 to 10. | |
9cc50fc6 | 945 | /// |
8bb4bdeb XL |
946 | /// # Panics |
947 | /// | |
948 | /// Panics if range `start > end`. | |
949 | /// Panics if range `start == end` and both bounds are `Excluded`. | |
950 | /// | |
9cc50fc6 SL |
951 | /// # Examples |
952 | /// | |
54a0048b SL |
953 | /// Basic usage: |
954 | /// | |
9cc50fc6 | 955 | /// ``` |
9cc50fc6 | 956 | /// use std::collections::BTreeMap; |
9cc50fc6 | 957 | /// |
a1dfa0c6 XL |
958 | /// let mut map: BTreeMap<&str, i32> = ["Alice", "Bob", "Carol", "Cheryl"] |
959 | /// .iter() | |
960 | /// .map(|&s| (s, 0)) | |
961 | /// .collect(); | |
32a655c1 | 962 | /// for (_, balance) in map.range_mut("B".."Cheryl") { |
9cc50fc6 SL |
963 | /// *balance += 100; |
964 | /// } | |
965 | /// for (name, balance) in &map { | |
966 | /// println!("{} => {}", name, balance); | |
967 | /// } | |
968 | /// ``` | |
8bb4bdeb | 969 | #[stable(feature = "btree_range", since = "1.17.0")] |
9fa01778 | 970 | pub fn range_mut<T: ?Sized, R>(&mut self, range: R) -> RangeMut<'_, K, V> |
0531ce1d | 971 | where T: Ord, K: Borrow<T>, R: RangeBounds<T> |
9cc50fc6 SL |
972 | { |
973 | let root1 = self.root.as_mut(); | |
974 | let root2 = unsafe { ptr::read(&root1) }; | |
8bb4bdeb | 975 | let (f, b) = range_search(root1, root2, range); |
9cc50fc6 SL |
976 | |
977 | RangeMut { | |
8bb4bdeb XL |
978 | front: f, |
979 | back: b, | |
3157f602 | 980 | _marker: PhantomData, |
9cc50fc6 SL |
981 | } |
982 | } | |
983 | ||
984 | /// Gets the given key's corresponding entry in the map for in-place manipulation. | |
985 | /// | |
986 | /// # Examples | |
987 | /// | |
54a0048b SL |
988 | /// Basic usage: |
989 | /// | |
9cc50fc6 SL |
990 | /// ``` |
991 | /// use std::collections::BTreeMap; | |
992 | /// | |
993 | /// let mut count: BTreeMap<&str, usize> = BTreeMap::new(); | |
994 | /// | |
995 | /// // count the number of occurrences of letters in the vec | |
996 | /// for x in vec!["a","b","a","c","a","b"] { | |
997 | /// *count.entry(x).or_insert(0) += 1; | |
998 | /// } | |
999 | /// | |
1000 | /// assert_eq!(count["a"], 3); | |
1001 | /// ``` | |
1002 | #[stable(feature = "rust1", since = "1.0.0")] | |
9fa01778 | 1003 | pub fn entry(&mut self, key: K) -> Entry<'_, K, V> { |
94b46f34 XL |
1004 | // FIXME(@porglezomp) Avoid allocating if we don't insert |
1005 | self.ensure_root_is_owned(); | |
9cc50fc6 | 1006 | match search::search_tree(self.root.as_mut(), &key) { |
3157f602 XL |
1007 | Found(handle) => { |
1008 | Occupied(OccupiedEntry { | |
3b2f2976 | 1009 | handle, |
3157f602 XL |
1010 | length: &mut self.length, |
1011 | _marker: PhantomData, | |
1012 | }) | |
1013 | } | |
1014 | GoDown(handle) => { | |
1015 | Vacant(VacantEntry { | |
3b2f2976 XL |
1016 | key, |
1017 | handle, | |
3157f602 XL |
1018 | length: &mut self.length, |
1019 | _marker: PhantomData, | |
1020 | }) | |
1021 | } | |
9346a6ac | 1022 | } |
85aaf69f | 1023 | } |
a7813a04 | 1024 | |
3157f602 | 1025 | fn from_sorted_iter<I: Iterator<Item = (K, V)>>(&mut self, iter: I) { |
94b46f34 | 1026 | self.ensure_root_is_owned(); |
a7813a04 XL |
1027 | let mut cur_node = last_leaf_edge(self.root.as_mut()).into_node(); |
1028 | // Iterate through all key-value pairs, pushing them into nodes at the right level. | |
1029 | for (key, value) in iter { | |
1030 | // Try to push key-value pair into the current leaf node. | |
1031 | if cur_node.len() < node::CAPACITY { | |
1032 | cur_node.push(key, value); | |
1033 | } else { | |
1034 | // No space left, go up and push there. | |
1035 | let mut open_node; | |
1036 | let mut test_node = cur_node.forget_type(); | |
1037 | loop { | |
1038 | match test_node.ascend() { | |
1039 | Ok(parent) => { | |
1040 | let parent = parent.into_node(); | |
1041 | if parent.len() < node::CAPACITY { | |
1042 | // Found a node with space left, push here. | |
1043 | open_node = parent; | |
1044 | break; | |
1045 | } else { | |
1046 | // Go up again. | |
1047 | test_node = parent.forget_type(); | |
1048 | } | |
3157f602 | 1049 | } |
a7813a04 XL |
1050 | Err(node) => { |
1051 | // We are at the top, create a new root node and push there. | |
1052 | open_node = node.into_root_mut().push_level(); | |
1053 | break; | |
3157f602 | 1054 | } |
a7813a04 XL |
1055 | } |
1056 | } | |
1057 | ||
1058 | // Push key-value pair and new right subtree. | |
1059 | let tree_height = open_node.height() - 1; | |
1060 | let mut right_tree = node::Root::new_leaf(); | |
1061 | for _ in 0..tree_height { | |
1062 | right_tree.push_level(); | |
1063 | } | |
1064 | open_node.push(key, value, right_tree); | |
1065 | ||
1066 | // Go down to the right-most leaf again. | |
1067 | cur_node = last_leaf_edge(open_node.forget_type()).into_node(); | |
1068 | } | |
1069 | ||
1070 | self.length += 1; | |
1071 | } | |
1072 | } | |
1073 | ||
1074 | fn fix_right_edge(&mut self) { | |
1075 | // Handle underfull nodes, start from the top. | |
1076 | let mut cur_node = self.root.as_mut(); | |
1077 | while let Internal(internal) = cur_node.force() { | |
1078 | // Check if right-most child is underfull. | |
1079 | let mut last_edge = internal.last_edge(); | |
1080 | let right_child_len = last_edge.reborrow().descend().len(); | |
3157f602 | 1081 | if right_child_len < node::MIN_LEN { |
a7813a04 XL |
1082 | // We need to steal. |
1083 | let mut last_kv = match last_edge.left_kv() { | |
1084 | Ok(left) => left, | |
1085 | Err(_) => unreachable!(), | |
1086 | }; | |
3157f602 | 1087 | last_kv.bulk_steal_left(node::MIN_LEN - right_child_len); |
a7813a04 XL |
1088 | last_edge = last_kv.right_edge(); |
1089 | } | |
1090 | ||
1091 | // Go further down. | |
1092 | cur_node = last_edge.descend(); | |
1093 | } | |
1094 | } | |
3157f602 XL |
1095 | |
1096 | /// Splits the collection into two at the given key. Returns everything after the given key, | |
1097 | /// including the key. | |
1098 | /// | |
1099 | /// # Examples | |
1100 | /// | |
1101 | /// Basic usage: | |
1102 | /// | |
1103 | /// ``` | |
1104 | /// use std::collections::BTreeMap; | |
1105 | /// | |
1106 | /// let mut a = BTreeMap::new(); | |
1107 | /// a.insert(1, "a"); | |
1108 | /// a.insert(2, "b"); | |
1109 | /// a.insert(3, "c"); | |
1110 | /// a.insert(17, "d"); | |
1111 | /// a.insert(41, "e"); | |
1112 | /// | |
1113 | /// let b = a.split_off(&3); | |
1114 | /// | |
1115 | /// assert_eq!(a.len(), 2); | |
1116 | /// assert_eq!(b.len(), 3); | |
1117 | /// | |
1118 | /// assert_eq!(a[&1], "a"); | |
1119 | /// assert_eq!(a[&2], "b"); | |
1120 | /// | |
1121 | /// assert_eq!(b[&3], "c"); | |
1122 | /// assert_eq!(b[&17], "d"); | |
1123 | /// assert_eq!(b[&41], "e"); | |
1124 | /// ``` | |
1125 | #[stable(feature = "btree_split_off", since = "1.11.0")] | |
1126 | pub fn split_off<Q: ?Sized + Ord>(&mut self, key: &Q) -> Self | |
1127 | where K: Borrow<Q> | |
1128 | { | |
1129 | if self.is_empty() { | |
1130 | return Self::new(); | |
1131 | } | |
1132 | ||
1133 | let total_num = self.len(); | |
1134 | ||
1135 | let mut right = Self::new(); | |
94b46f34 | 1136 | right.root = node::Root::new_leaf(); |
3157f602 XL |
1137 | for _ in 0..(self.root.as_ref().height()) { |
1138 | right.root.push_level(); | |
1139 | } | |
1140 | ||
1141 | { | |
1142 | let mut left_node = self.root.as_mut(); | |
1143 | let mut right_node = right.root.as_mut(); | |
1144 | ||
1145 | loop { | |
1146 | let mut split_edge = match search::search_node(left_node, key) { | |
1147 | // key is going to the right tree | |
1148 | Found(handle) => handle.left_edge(), | |
1149 | GoDown(handle) => handle, | |
1150 | }; | |
1151 | ||
1152 | split_edge.move_suffix(&mut right_node); | |
1153 | ||
1154 | match (split_edge.force(), right_node.force()) { | |
1155 | (Internal(edge), Internal(node)) => { | |
1156 | left_node = edge.descend(); | |
1157 | right_node = node.first_edge().descend(); | |
1158 | } | |
1159 | (Leaf(_), Leaf(_)) => { | |
1160 | break; | |
1161 | } | |
1162 | _ => { | |
1163 | unreachable!(); | |
1164 | } | |
1165 | } | |
1166 | } | |
1167 | } | |
1168 | ||
1169 | self.fix_right_border(); | |
1170 | right.fix_left_border(); | |
1171 | ||
1172 | if self.root.as_ref().height() < right.root.as_ref().height() { | |
1173 | self.recalc_length(); | |
1174 | right.length = total_num - self.len(); | |
1175 | } else { | |
1176 | right.recalc_length(); | |
1177 | self.length = total_num - right.len(); | |
1178 | } | |
1179 | ||
1180 | right | |
1181 | } | |
1182 | ||
1183 | /// Calculates the number of elements if it is incorrect. | |
1184 | fn recalc_length(&mut self) { | |
8faf50e0 XL |
1185 | fn dfs<'a, K, V>( |
1186 | node: NodeRef<marker::Immut<'a>, K, V, marker::LeafOrInternal> | |
1187 | ) -> usize | |
1188 | where K: 'a, V: 'a | |
1189 | { | |
3157f602 XL |
1190 | let mut res = node.len(); |
1191 | ||
1192 | if let Internal(node) = node.force() { | |
1193 | let mut edge = node.first_edge(); | |
1194 | loop { | |
1195 | res += dfs(edge.reborrow().descend()); | |
1196 | match edge.right_kv() { | |
1197 | Ok(right_kv) => { | |
1198 | edge = right_kv.right_edge(); | |
1199 | } | |
1200 | Err(_) => { | |
1201 | break; | |
1202 | } | |
1203 | } | |
1204 | } | |
1205 | } | |
1206 | ||
1207 | res | |
1208 | } | |
1209 | ||
1210 | self.length = dfs(self.root.as_ref()); | |
1211 | } | |
1212 | ||
1213 | /// Removes empty levels on the top. | |
1214 | fn fix_top(&mut self) { | |
1215 | loop { | |
1216 | { | |
1217 | let node = self.root.as_ref(); | |
1218 | if node.height() == 0 || node.len() > 0 { | |
1219 | break; | |
1220 | } | |
1221 | } | |
1222 | self.root.pop_level(); | |
1223 | } | |
1224 | } | |
1225 | ||
1226 | fn fix_right_border(&mut self) { | |
1227 | self.fix_top(); | |
1228 | ||
1229 | { | |
1230 | let mut cur_node = self.root.as_mut(); | |
1231 | ||
1232 | while let Internal(node) = cur_node.force() { | |
1233 | let mut last_kv = node.last_kv(); | |
1234 | ||
1235 | if last_kv.can_merge() { | |
1236 | cur_node = last_kv.merge().descend(); | |
1237 | } else { | |
1238 | let right_len = last_kv.reborrow().right_edge().descend().len(); | |
1239 | // `MINLEN + 1` to avoid readjust if merge happens on the next level. | |
1240 | if right_len < node::MIN_LEN + 1 { | |
1241 | last_kv.bulk_steal_left(node::MIN_LEN + 1 - right_len); | |
1242 | } | |
1243 | cur_node = last_kv.right_edge().descend(); | |
1244 | } | |
1245 | } | |
1246 | } | |
1247 | ||
1248 | self.fix_top(); | |
1249 | } | |
1250 | ||
1251 | /// The symmetric clone of `fix_right_border`. | |
1252 | fn fix_left_border(&mut self) { | |
1253 | self.fix_top(); | |
1254 | ||
1255 | { | |
1256 | let mut cur_node = self.root.as_mut(); | |
1257 | ||
1258 | while let Internal(node) = cur_node.force() { | |
1259 | let mut first_kv = node.first_kv(); | |
1260 | ||
1261 | if first_kv.can_merge() { | |
1262 | cur_node = first_kv.merge().descend(); | |
1263 | } else { | |
1264 | let left_len = first_kv.reborrow().left_edge().descend().len(); | |
1265 | if left_len < node::MIN_LEN + 1 { | |
1266 | first_kv.bulk_steal_right(node::MIN_LEN + 1 - left_len); | |
1267 | } | |
1268 | cur_node = first_kv.left_edge().descend(); | |
1269 | } | |
1270 | } | |
1271 | } | |
1272 | ||
1273 | self.fix_top(); | |
1274 | } | |
94b46f34 XL |
1275 | |
1276 | /// If the root node is the shared root node, allocate our own node. | |
1277 | fn ensure_root_is_owned(&mut self) { | |
1278 | if self.root.is_shared_root() { | |
1279 | self.root = node::Root::new_leaf(); | |
1280 | } | |
1281 | } | |
85aaf69f SL |
1282 | } |
1283 | ||
c30ab7b3 | 1284 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 | 1285 | impl<'a, K: 'a, V: 'a> IntoIterator for &'a BTreeMap<K, V> { |
85aaf69f SL |
1286 | type Item = (&'a K, &'a V); |
1287 | type IntoIter = Iter<'a, K, V>; | |
1288 | ||
1289 | fn into_iter(self) -> Iter<'a, K, V> { | |
1290 | self.iter() | |
1291 | } | |
1292 | } | |
1293 | ||
c30ab7b3 | 1294 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1295 | impl<'a, K: 'a, V: 'a> Iterator for Iter<'a, K, V> { |
1296 | type Item = (&'a K, &'a V); | |
85aaf69f | 1297 | |
9cc50fc6 SL |
1298 | fn next(&mut self) -> Option<(&'a K, &'a V)> { |
1299 | if self.length == 0 { | |
1300 | None | |
1301 | } else { | |
1302 | self.length -= 1; | |
1303 | unsafe { Some(self.range.next_unchecked()) } | |
1304 | } | |
85aaf69f | 1305 | } |
85aaf69f | 1306 | |
9cc50fc6 SL |
1307 | fn size_hint(&self) -> (usize, Option<usize>) { |
1308 | (self.length, Some(self.length)) | |
1309 | } | |
416331ca XL |
1310 | |
1311 | fn last(mut self) -> Option<(&'a K, &'a V)> { | |
1312 | self.next_back() | |
1313 | } | |
1a4d82fc JJ |
1314 | } |
1315 | ||
0531ce1d | 1316 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1317 | impl<K, V> FusedIterator for Iter<'_, K, V> {} |
9e0c209e | 1318 | |
c30ab7b3 | 1319 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1320 | impl<'a, K: 'a, V: 'a> DoubleEndedIterator for Iter<'a, K, V> { |
1321 | fn next_back(&mut self) -> Option<(&'a K, &'a V)> { | |
1322 | if self.length == 0 { | |
1323 | None | |
1324 | } else { | |
1325 | self.length -= 1; | |
1326 | unsafe { Some(self.range.next_back_unchecked()) } | |
85aaf69f SL |
1327 | } |
1328 | } | |
9cc50fc6 | 1329 | } |
85aaf69f | 1330 | |
c30ab7b3 | 1331 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1332 | impl<K, V> ExactSizeIterator for Iter<'_, K, V> { |
3157f602 XL |
1333 | fn len(&self) -> usize { |
1334 | self.length | |
1335 | } | |
9cc50fc6 | 1336 | } |
1a4d82fc | 1337 | |
c30ab7b3 | 1338 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 XL |
1339 | impl<K, V> Clone for Iter<'_, K, V> { |
1340 | fn clone(&self) -> Self { | |
9cc50fc6 SL |
1341 | Iter { |
1342 | range: self.range.clone(), | |
3157f602 | 1343 | length: self.length, |
1a4d82fc JJ |
1344 | } |
1345 | } | |
9cc50fc6 | 1346 | } |
1a4d82fc | 1347 | |
c30ab7b3 | 1348 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1349 | impl<'a, K: 'a, V: 'a> IntoIterator for &'a mut BTreeMap<K, V> { |
1350 | type Item = (&'a K, &'a mut V); | |
1351 | type IntoIter = IterMut<'a, K, V>; | |
1352 | ||
1353 | fn into_iter(self) -> IterMut<'a, K, V> { | |
1354 | self.iter_mut() | |
1a4d82fc | 1355 | } |
9cc50fc6 | 1356 | } |
1a4d82fc | 1357 | |
c30ab7b3 | 1358 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1359 | impl<'a, K: 'a, V: 'a> Iterator for IterMut<'a, K, V> { |
1360 | type Item = (&'a K, &'a mut V); | |
1a4d82fc | 1361 | |
9cc50fc6 SL |
1362 | fn next(&mut self) -> Option<(&'a K, &'a mut V)> { |
1363 | if self.length == 0 { | |
1364 | None | |
1365 | } else { | |
1366 | self.length -= 1; | |
1367 | unsafe { Some(self.range.next_unchecked()) } | |
1368 | } | |
1a4d82fc JJ |
1369 | } |
1370 | ||
9cc50fc6 SL |
1371 | fn size_hint(&self) -> (usize, Option<usize>) { |
1372 | (self.length, Some(self.length)) | |
1a4d82fc | 1373 | } |
416331ca XL |
1374 | |
1375 | fn last(mut self) -> Option<(&'a K, &'a mut V)> { | |
1376 | self.next_back() | |
1377 | } | |
9cc50fc6 | 1378 | } |
1a4d82fc | 1379 | |
c30ab7b3 | 1380 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1381 | impl<'a, K: 'a, V: 'a> DoubleEndedIterator for IterMut<'a, K, V> { |
1382 | fn next_back(&mut self) -> Option<(&'a K, &'a mut V)> { | |
1383 | if self.length == 0 { | |
1384 | None | |
1385 | } else { | |
1386 | self.length -= 1; | |
1387 | unsafe { Some(self.range.next_back_unchecked()) } | |
1388 | } | |
1a4d82fc | 1389 | } |
9cc50fc6 | 1390 | } |
1a4d82fc | 1391 | |
c30ab7b3 | 1392 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1393 | impl<K, V> ExactSizeIterator for IterMut<'_, K, V> { |
3157f602 XL |
1394 | fn len(&self) -> usize { |
1395 | self.length | |
1396 | } | |
9cc50fc6 | 1397 | } |
1a4d82fc | 1398 | |
0531ce1d | 1399 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1400 | impl<K, V> FusedIterator for IterMut<'_, K, V> {} |
9e0c209e | 1401 | |
c30ab7b3 | 1402 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1403 | impl<K, V> IntoIterator for BTreeMap<K, V> { |
1404 | type Item = (K, V); | |
1405 | type IntoIter = IntoIter<K, V>; | |
1a4d82fc | 1406 | |
9cc50fc6 SL |
1407 | fn into_iter(self) -> IntoIter<K, V> { |
1408 | let root1 = unsafe { ptr::read(&self.root).into_ref() }; | |
1409 | let root2 = unsafe { ptr::read(&self.root).into_ref() }; | |
1410 | let len = self.length; | |
1411 | mem::forget(self); | |
1a4d82fc | 1412 | |
9cc50fc6 SL |
1413 | IntoIter { |
1414 | front: first_leaf_edge(root1), | |
1415 | back: last_leaf_edge(root2), | |
3157f602 | 1416 | length: len, |
1a4d82fc JJ |
1417 | } |
1418 | } | |
9cc50fc6 | 1419 | } |
1a4d82fc | 1420 | |
c30ab7b3 | 1421 | #[stable(feature = "btree_drop", since = "1.7.0")] |
9cc50fc6 SL |
1422 | impl<K, V> Drop for IntoIter<K, V> { |
1423 | fn drop(&mut self) { | |
83c7162d | 1424 | self.for_each(drop); |
9cc50fc6 SL |
1425 | unsafe { |
1426 | let leaf_node = ptr::read(&self.front).into_node(); | |
94b46f34 XL |
1427 | if leaf_node.is_shared_root() { |
1428 | return; | |
1429 | } | |
1430 | ||
9cc50fc6 SL |
1431 | if let Some(first_parent) = leaf_node.deallocate_and_ascend() { |
1432 | let mut cur_node = first_parent.into_node(); | |
1433 | while let Some(parent) = cur_node.deallocate_and_ascend() { | |
1434 | cur_node = parent.into_node() | |
1435 | } | |
1a4d82fc JJ |
1436 | } |
1437 | } | |
1438 | } | |
9cc50fc6 | 1439 | } |
1a4d82fc | 1440 | |
c30ab7b3 | 1441 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1442 | impl<K, V> Iterator for IntoIter<K, V> { |
1443 | type Item = (K, V); | |
1a4d82fc | 1444 | |
9cc50fc6 SL |
1445 | fn next(&mut self) -> Option<(K, V)> { |
1446 | if self.length == 0 { | |
1447 | return None; | |
1448 | } else { | |
1449 | self.length -= 1; | |
1a4d82fc | 1450 | } |
1a4d82fc | 1451 | |
9cc50fc6 | 1452 | let handle = unsafe { ptr::read(&self.front) }; |
1a4d82fc | 1453 | |
9cc50fc6 SL |
1454 | let mut cur_handle = match handle.right_kv() { |
1455 | Ok(kv) => { | |
1456 | let k = unsafe { ptr::read(kv.reborrow().into_kv().0) }; | |
1457 | let v = unsafe { ptr::read(kv.reborrow().into_kv().1) }; | |
1458 | self.front = kv.right_edge(); | |
1459 | return Some((k, v)); | |
3157f602 | 1460 | } |
9cc50fc6 SL |
1461 | Err(last_edge) => unsafe { |
1462 | unwrap_unchecked(last_edge.into_node().deallocate_and_ascend()) | |
3157f602 | 1463 | }, |
9cc50fc6 | 1464 | }; |
1a4d82fc | 1465 | |
9cc50fc6 SL |
1466 | loop { |
1467 | match cur_handle.right_kv() { | |
1468 | Ok(kv) => { | |
1469 | let k = unsafe { ptr::read(kv.reborrow().into_kv().0) }; | |
1470 | let v = unsafe { ptr::read(kv.reborrow().into_kv().1) }; | |
1471 | self.front = first_leaf_edge(kv.right_edge().descend()); | |
1472 | return Some((k, v)); | |
3157f602 | 1473 | } |
9cc50fc6 SL |
1474 | Err(last_edge) => unsafe { |
1475 | cur_handle = unwrap_unchecked(last_edge.into_node().deallocate_and_ascend()); | |
3157f602 | 1476 | }, |
1a4d82fc JJ |
1477 | } |
1478 | } | |
1479 | } | |
1480 | ||
9cc50fc6 SL |
1481 | fn size_hint(&self) -> (usize, Option<usize>) { |
1482 | (self.length, Some(self.length)) | |
1483 | } | |
1484 | } | |
1485 | ||
c30ab7b3 | 1486 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1487 | impl<K, V> DoubleEndedIterator for IntoIter<K, V> { |
1488 | fn next_back(&mut self) -> Option<(K, V)> { | |
1489 | if self.length == 0 { | |
1490 | return None; | |
1491 | } else { | |
1492 | self.length -= 1; | |
1a4d82fc JJ |
1493 | } |
1494 | ||
9cc50fc6 SL |
1495 | let handle = unsafe { ptr::read(&self.back) }; |
1496 | ||
1497 | let mut cur_handle = match handle.left_kv() { | |
1498 | Ok(kv) => { | |
1499 | let k = unsafe { ptr::read(kv.reborrow().into_kv().0) }; | |
1500 | let v = unsafe { ptr::read(kv.reborrow().into_kv().1) }; | |
1501 | self.back = kv.left_edge(); | |
1502 | return Some((k, v)); | |
3157f602 | 1503 | } |
9cc50fc6 SL |
1504 | Err(last_edge) => unsafe { |
1505 | unwrap_unchecked(last_edge.into_node().deallocate_and_ascend()) | |
3157f602 | 1506 | }, |
9cc50fc6 | 1507 | }; |
1a4d82fc | 1508 | |
9cc50fc6 SL |
1509 | loop { |
1510 | match cur_handle.left_kv() { | |
1511 | Ok(kv) => { | |
1512 | let k = unsafe { ptr::read(kv.reborrow().into_kv().0) }; | |
1513 | let v = unsafe { ptr::read(kv.reborrow().into_kv().1) }; | |
1514 | self.back = last_leaf_edge(kv.left_edge().descend()); | |
1515 | return Some((k, v)); | |
3157f602 | 1516 | } |
9cc50fc6 SL |
1517 | Err(last_edge) => unsafe { |
1518 | cur_handle = unwrap_unchecked(last_edge.into_node().deallocate_and_ascend()); | |
3157f602 | 1519 | }, |
1a4d82fc JJ |
1520 | } |
1521 | } | |
1522 | } | |
1523 | } | |
1524 | ||
c30ab7b3 | 1525 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 | 1526 | impl<K, V> ExactSizeIterator for IntoIter<K, V> { |
3157f602 XL |
1527 | fn len(&self) -> usize { |
1528 | self.length | |
1529 | } | |
1a4d82fc JJ |
1530 | } |
1531 | ||
0531ce1d | 1532 | #[stable(feature = "fused", since = "1.26.0")] |
9e0c209e SL |
1533 | impl<K, V> FusedIterator for IntoIter<K, V> {} |
1534 | ||
c30ab7b3 | 1535 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1536 | impl<'a, K, V> Iterator for Keys<'a, K, V> { |
1537 | type Item = &'a K; | |
1538 | ||
1539 | fn next(&mut self) -> Option<&'a K> { | |
1540 | self.inner.next().map(|(k, _)| k) | |
1a4d82fc | 1541 | } |
1a4d82fc | 1542 | |
9cc50fc6 SL |
1543 | fn size_hint(&self) -> (usize, Option<usize>) { |
1544 | self.inner.size_hint() | |
62682a34 | 1545 | } |
416331ca XL |
1546 | |
1547 | fn last(mut self) -> Option<&'a K> { | |
1548 | self.next_back() | |
1549 | } | |
62682a34 SL |
1550 | } |
1551 | ||
c30ab7b3 | 1552 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1553 | impl<'a, K, V> DoubleEndedIterator for Keys<'a, K, V> { |
1554 | fn next_back(&mut self) -> Option<&'a K> { | |
1555 | self.inner.next_back().map(|(k, _)| k) | |
1a4d82fc JJ |
1556 | } |
1557 | } | |
1558 | ||
c30ab7b3 | 1559 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1560 | impl<K, V> ExactSizeIterator for Keys<'_, K, V> { |
9cc50fc6 SL |
1561 | fn len(&self) -> usize { |
1562 | self.inner.len() | |
1a4d82fc JJ |
1563 | } |
1564 | } | |
1565 | ||
0531ce1d | 1566 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1567 | impl<K, V> FusedIterator for Keys<'_, K, V> {} |
9e0c209e | 1568 | |
c30ab7b3 | 1569 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 XL |
1570 | impl<K, V> Clone for Keys<'_, K, V> { |
1571 | fn clone(&self) -> Self { | |
3157f602 | 1572 | Keys { inner: self.inner.clone() } |
1a4d82fc JJ |
1573 | } |
1574 | } | |
1575 | ||
c30ab7b3 | 1576 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1577 | impl<'a, K, V> Iterator for Values<'a, K, V> { |
1578 | type Item = &'a V; | |
1a4d82fc | 1579 | |
9cc50fc6 SL |
1580 | fn next(&mut self) -> Option<&'a V> { |
1581 | self.inner.next().map(|(_, v)| v) | |
1a4d82fc | 1582 | } |
1a4d82fc | 1583 | |
9cc50fc6 SL |
1584 | fn size_hint(&self) -> (usize, Option<usize>) { |
1585 | self.inner.size_hint() | |
1a4d82fc | 1586 | } |
416331ca XL |
1587 | |
1588 | fn last(mut self) -> Option<&'a V> { | |
1589 | self.next_back() | |
1590 | } | |
1a4d82fc JJ |
1591 | } |
1592 | ||
c30ab7b3 | 1593 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1594 | impl<'a, K, V> DoubleEndedIterator for Values<'a, K, V> { |
1595 | fn next_back(&mut self) -> Option<&'a V> { | |
1596 | self.inner.next_back().map(|(_, v)| v) | |
1a4d82fc JJ |
1597 | } |
1598 | } | |
1599 | ||
c30ab7b3 | 1600 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1601 | impl<K, V> ExactSizeIterator for Values<'_, K, V> { |
9cc50fc6 SL |
1602 | fn len(&self) -> usize { |
1603 | self.inner.len() | |
1a4d82fc JJ |
1604 | } |
1605 | } | |
1606 | ||
0531ce1d | 1607 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1608 | impl<K, V> FusedIterator for Values<'_, K, V> {} |
9e0c209e | 1609 | |
c30ab7b3 | 1610 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 XL |
1611 | impl<K, V> Clone for Values<'_, K, V> { |
1612 | fn clone(&self) -> Self { | |
3157f602 | 1613 | Values { inner: self.inner.clone() } |
1a4d82fc JJ |
1614 | } |
1615 | } | |
1616 | ||
cc61c64b | 1617 | #[stable(feature = "btree_range", since = "1.17.0")] |
9cc50fc6 SL |
1618 | impl<'a, K, V> Iterator for Range<'a, K, V> { |
1619 | type Item = (&'a K, &'a V); | |
1a4d82fc | 1620 | |
9cc50fc6 SL |
1621 | fn next(&mut self) -> Option<(&'a K, &'a V)> { |
1622 | if self.front == self.back { | |
1623 | None | |
1624 | } else { | |
1625 | unsafe { Some(self.next_unchecked()) } | |
1626 | } | |
1a4d82fc | 1627 | } |
416331ca XL |
1628 | |
1629 | fn last(mut self) -> Option<(&'a K, &'a V)> { | |
1630 | self.next_back() | |
1631 | } | |
1a4d82fc JJ |
1632 | } |
1633 | ||
a7813a04 | 1634 | #[stable(feature = "map_values_mut", since = "1.10.0")] |
54a0048b SL |
1635 | impl<'a, K, V> Iterator for ValuesMut<'a, K, V> { |
1636 | type Item = &'a mut V; | |
1637 | ||
1638 | fn next(&mut self) -> Option<&'a mut V> { | |
1639 | self.inner.next().map(|(_, v)| v) | |
1640 | } | |
1641 | ||
1642 | fn size_hint(&self) -> (usize, Option<usize>) { | |
1643 | self.inner.size_hint() | |
1644 | } | |
416331ca XL |
1645 | |
1646 | fn last(mut self) -> Option<&'a mut V> { | |
1647 | self.next_back() | |
1648 | } | |
54a0048b SL |
1649 | } |
1650 | ||
a7813a04 | 1651 | #[stable(feature = "map_values_mut", since = "1.10.0")] |
54a0048b SL |
1652 | impl<'a, K, V> DoubleEndedIterator for ValuesMut<'a, K, V> { |
1653 | fn next_back(&mut self) -> Option<&'a mut V> { | |
1654 | self.inner.next_back().map(|(_, v)| v) | |
1655 | } | |
1656 | } | |
1657 | ||
a7813a04 | 1658 | #[stable(feature = "map_values_mut", since = "1.10.0")] |
9fa01778 | 1659 | impl<K, V> ExactSizeIterator for ValuesMut<'_, K, V> { |
54a0048b SL |
1660 | fn len(&self) -> usize { |
1661 | self.inner.len() | |
1662 | } | |
1663 | } | |
1664 | ||
0531ce1d | 1665 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1666 | impl<K, V> FusedIterator for ValuesMut<'_, K, V> {} |
9e0c209e | 1667 | |
9cc50fc6 SL |
1668 | impl<'a, K, V> Range<'a, K, V> { |
1669 | unsafe fn next_unchecked(&mut self) -> (&'a K, &'a V) { | |
1670 | let handle = self.front; | |
1a4d82fc | 1671 | |
9cc50fc6 SL |
1672 | let mut cur_handle = match handle.right_kv() { |
1673 | Ok(kv) => { | |
1674 | let ret = kv.into_kv(); | |
1675 | self.front = kv.right_edge(); | |
1676 | return ret; | |
3157f602 | 1677 | } |
9cc50fc6 SL |
1678 | Err(last_edge) => { |
1679 | let next_level = last_edge.into_node().ascend().ok(); | |
1680 | unwrap_unchecked(next_level) | |
1681 | } | |
1682 | }; | |
1a4d82fc | 1683 | |
9cc50fc6 SL |
1684 | loop { |
1685 | match cur_handle.right_kv() { | |
1686 | Ok(kv) => { | |
1687 | let ret = kv.into_kv(); | |
1688 | self.front = first_leaf_edge(kv.right_edge().descend()); | |
1689 | return ret; | |
3157f602 | 1690 | } |
9cc50fc6 SL |
1691 | Err(last_edge) => { |
1692 | let next_level = last_edge.into_node().ascend().ok(); | |
1693 | cur_handle = unwrap_unchecked(next_level); | |
92a42be0 | 1694 | } |
1a4d82fc JJ |
1695 | } |
1696 | } | |
1697 | } | |
9cc50fc6 | 1698 | } |
1a4d82fc | 1699 | |
cc61c64b | 1700 | #[stable(feature = "btree_range", since = "1.17.0")] |
9cc50fc6 SL |
1701 | impl<'a, K, V> DoubleEndedIterator for Range<'a, K, V> { |
1702 | fn next_back(&mut self) -> Option<(&'a K, &'a V)> { | |
1703 | if self.front == self.back { | |
1704 | None | |
1705 | } else { | |
1706 | unsafe { Some(self.next_back_unchecked()) } | |
1707 | } | |
1a4d82fc JJ |
1708 | } |
1709 | } | |
1710 | ||
9cc50fc6 SL |
1711 | impl<'a, K, V> Range<'a, K, V> { |
1712 | unsafe fn next_back_unchecked(&mut self) -> (&'a K, &'a V) { | |
1713 | let handle = self.back; | |
1a4d82fc | 1714 | |
9cc50fc6 SL |
1715 | let mut cur_handle = match handle.left_kv() { |
1716 | Ok(kv) => { | |
1717 | let ret = kv.into_kv(); | |
1718 | self.back = kv.left_edge(); | |
1719 | return ret; | |
3157f602 | 1720 | } |
9cc50fc6 SL |
1721 | Err(last_edge) => { |
1722 | let next_level = last_edge.into_node().ascend().ok(); | |
1723 | unwrap_unchecked(next_level) | |
1724 | } | |
1725 | }; | |
1726 | ||
1727 | loop { | |
1728 | match cur_handle.left_kv() { | |
1729 | Ok(kv) => { | |
1730 | let ret = kv.into_kv(); | |
1731 | self.back = last_leaf_edge(kv.left_edge().descend()); | |
1732 | return ret; | |
3157f602 | 1733 | } |
9cc50fc6 SL |
1734 | Err(last_edge) => { |
1735 | let next_level = last_edge.into_node().ascend().ok(); | |
1736 | cur_handle = unwrap_unchecked(next_level); | |
92a42be0 | 1737 | } |
1a4d82fc JJ |
1738 | } |
1739 | } | |
1740 | } | |
1741 | } | |
1742 | ||
0531ce1d | 1743 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1744 | impl<K, V> FusedIterator for Range<'_, K, V> {} |
9e0c209e | 1745 | |
cc61c64b | 1746 | #[stable(feature = "btree_range", since = "1.17.0")] |
9fa01778 XL |
1747 | impl<K, V> Clone for Range<'_, K, V> { |
1748 | fn clone(&self) -> Self { | |
9cc50fc6 SL |
1749 | Range { |
1750 | front: self.front, | |
3157f602 | 1751 | back: self.back, |
9cc50fc6 | 1752 | } |
92a42be0 | 1753 | } |
1a4d82fc | 1754 | } |
1a4d82fc | 1755 | |
cc61c64b | 1756 | #[stable(feature = "btree_range", since = "1.17.0")] |
9cc50fc6 | 1757 | impl<'a, K, V> Iterator for RangeMut<'a, K, V> { |
1a4d82fc JJ |
1758 | type Item = (&'a K, &'a mut V); |
1759 | ||
92a42be0 | 1760 | fn next(&mut self) -> Option<(&'a K, &'a mut V)> { |
9cc50fc6 SL |
1761 | if self.front == self.back { |
1762 | None | |
1763 | } else { | |
3157f602 | 1764 | unsafe { Some(self.next_unchecked()) } |
9cc50fc6 | 1765 | } |
92a42be0 | 1766 | } |
416331ca XL |
1767 | |
1768 | fn last(mut self) -> Option<(&'a K, &'a mut V)> { | |
1769 | self.next_back() | |
1770 | } | |
1a4d82fc | 1771 | } |
1a4d82fc | 1772 | |
9cc50fc6 SL |
1773 | impl<'a, K, V> RangeMut<'a, K, V> { |
1774 | unsafe fn next_unchecked(&mut self) -> (&'a K, &'a mut V) { | |
1775 | let handle = ptr::read(&self.front); | |
1a4d82fc | 1776 | |
9cc50fc6 SL |
1777 | let mut cur_handle = match handle.right_kv() { |
1778 | Ok(kv) => { | |
9fa01778 XL |
1779 | self.front = ptr::read(&kv).right_edge(); |
1780 | // Doing the descend invalidates the references returned by `into_kv_mut`, | |
1781 | // so we have to do this last. | |
1782 | let (k, v) = kv.into_kv_mut(); | |
1783 | return (k, v); // coerce k from `&mut K` to `&K` | |
3157f602 | 1784 | } |
9cc50fc6 SL |
1785 | Err(last_edge) => { |
1786 | let next_level = last_edge.into_node().ascend().ok(); | |
1787 | unwrap_unchecked(next_level) | |
1788 | } | |
1789 | }; | |
1a4d82fc | 1790 | |
9cc50fc6 SL |
1791 | loop { |
1792 | match cur_handle.right_kv() { | |
1793 | Ok(kv) => { | |
9fa01778 XL |
1794 | self.front = first_leaf_edge(ptr::read(&kv).right_edge().descend()); |
1795 | // Doing the descend invalidates the references returned by `into_kv_mut`, | |
1796 | // so we have to do this last. | |
1797 | let (k, v) = kv.into_kv_mut(); | |
1798 | return (k, v); // coerce k from `&mut K` to `&K` | |
3157f602 | 1799 | } |
9cc50fc6 SL |
1800 | Err(last_edge) => { |
1801 | let next_level = last_edge.into_node().ascend().ok(); | |
1802 | cur_handle = unwrap_unchecked(next_level); | |
1803 | } | |
1804 | } | |
1805 | } | |
92a42be0 | 1806 | } |
c34b1796 | 1807 | } |
1a4d82fc | 1808 | |
cc61c64b | 1809 | #[stable(feature = "btree_range", since = "1.17.0")] |
9cc50fc6 SL |
1810 | impl<'a, K, V> DoubleEndedIterator for RangeMut<'a, K, V> { |
1811 | fn next_back(&mut self) -> Option<(&'a K, &'a mut V)> { | |
1812 | if self.front == self.back { | |
1813 | None | |
1814 | } else { | |
1815 | unsafe { Some(self.next_back_unchecked()) } | |
1816 | } | |
92a42be0 | 1817 | } |
1a4d82fc | 1818 | } |
1a4d82fc | 1819 | |
0531ce1d | 1820 | #[stable(feature = "fused", since = "1.26.0")] |
9fa01778 | 1821 | impl<K, V> FusedIterator for RangeMut<'_, K, V> {} |
9e0c209e | 1822 | |
9cc50fc6 SL |
1823 | impl<'a, K, V> RangeMut<'a, K, V> { |
1824 | unsafe fn next_back_unchecked(&mut self) -> (&'a K, &'a mut V) { | |
1825 | let handle = ptr::read(&self.back); | |
1a4d82fc | 1826 | |
9cc50fc6 SL |
1827 | let mut cur_handle = match handle.left_kv() { |
1828 | Ok(kv) => { | |
9fa01778 XL |
1829 | self.back = ptr::read(&kv).left_edge(); |
1830 | // Doing the descend invalidates the references returned by `into_kv_mut`, | |
1831 | // so we have to do this last. | |
1832 | let (k, v) = kv.into_kv_mut(); | |
1833 | return (k, v); // coerce k from `&mut K` to `&K` | |
3157f602 | 1834 | } |
9cc50fc6 SL |
1835 | Err(last_edge) => { |
1836 | let next_level = last_edge.into_node().ascend().ok(); | |
1837 | unwrap_unchecked(next_level) | |
1838 | } | |
1839 | }; | |
1a4d82fc | 1840 | |
9cc50fc6 SL |
1841 | loop { |
1842 | match cur_handle.left_kv() { | |
1843 | Ok(kv) => { | |
9fa01778 XL |
1844 | self.back = last_leaf_edge(ptr::read(&kv).left_edge().descend()); |
1845 | // Doing the descend invalidates the references returned by `into_kv_mut`, | |
1846 | // so we have to do this last. | |
1847 | let (k, v) = kv.into_kv_mut(); | |
1848 | return (k, v); // coerce k from `&mut K` to `&K` | |
3157f602 | 1849 | } |
9cc50fc6 SL |
1850 | Err(last_edge) => { |
1851 | let next_level = last_edge.into_node().ascend().ok(); | |
1852 | cur_handle = unwrap_unchecked(next_level); | |
1853 | } | |
1854 | } | |
1855 | } | |
92a42be0 | 1856 | } |
1a4d82fc | 1857 | } |
9cc50fc6 | 1858 | |
c30ab7b3 | 1859 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 | 1860 | impl<K: Ord, V> FromIterator<(K, V)> for BTreeMap<K, V> { |
3157f602 | 1861 | fn from_iter<T: IntoIterator<Item = (K, V)>>(iter: T) -> BTreeMap<K, V> { |
9cc50fc6 SL |
1862 | let mut map = BTreeMap::new(); |
1863 | map.extend(iter); | |
1864 | map | |
92a42be0 | 1865 | } |
1a4d82fc | 1866 | } |
1a4d82fc | 1867 | |
c30ab7b3 | 1868 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1869 | impl<K: Ord, V> Extend<(K, V)> for BTreeMap<K, V> { |
1870 | #[inline] | |
3157f602 | 1871 | fn extend<T: IntoIterator<Item = (K, V)>>(&mut self, iter: T) { |
532ac7d7 | 1872 | iter.into_iter().for_each(move |(k, v)| { |
9cc50fc6 | 1873 | self.insert(k, v); |
532ac7d7 | 1874 | }); |
92a42be0 | 1875 | } |
c34b1796 | 1876 | } |
85aaf69f | 1877 | |
c30ab7b3 | 1878 | #[stable(feature = "extend_ref", since = "1.2.0")] |
9cc50fc6 | 1879 | impl<'a, K: Ord + Copy, V: Copy> Extend<(&'a K, &'a V)> for BTreeMap<K, V> { |
3157f602 | 1880 | fn extend<I: IntoIterator<Item = (&'a K, &'a V)>>(&mut self, iter: I) { |
9cc50fc6 | 1881 | self.extend(iter.into_iter().map(|(&key, &value)| (key, value))); |
92a42be0 | 1882 | } |
85aaf69f | 1883 | } |
9cc50fc6 | 1884 | |
c30ab7b3 | 1885 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1886 | impl<K: Hash, V: Hash> Hash for BTreeMap<K, V> { |
1887 | fn hash<H: Hasher>(&self, state: &mut H) { | |
1888 | for elt in self { | |
1889 | elt.hash(state); | |
1890 | } | |
92a42be0 | 1891 | } |
85aaf69f SL |
1892 | } |
1893 | ||
c30ab7b3 | 1894 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 | 1895 | impl<K: Ord, V> Default for BTreeMap<K, V> { |
9e0c209e | 1896 | /// Creates an empty `BTreeMap<K, V>`. |
9cc50fc6 SL |
1897 | fn default() -> BTreeMap<K, V> { |
1898 | BTreeMap::new() | |
92a42be0 | 1899 | } |
85aaf69f | 1900 | } |
9cc50fc6 | 1901 | |
c30ab7b3 | 1902 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1903 | impl<K: PartialEq, V: PartialEq> PartialEq for BTreeMap<K, V> { |
1904 | fn eq(&self, other: &BTreeMap<K, V>) -> bool { | |
3157f602 | 1905 | self.len() == other.len() && self.iter().zip(other).all(|(a, b)| a == b) |
92a42be0 | 1906 | } |
85aaf69f SL |
1907 | } |
1908 | ||
c30ab7b3 | 1909 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 | 1910 | impl<K: Eq, V: Eq> Eq for BTreeMap<K, V> {} |
c34b1796 | 1911 | |
c30ab7b3 | 1912 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1913 | impl<K: PartialOrd, V: PartialOrd> PartialOrd for BTreeMap<K, V> { |
1914 | #[inline] | |
1915 | fn partial_cmp(&self, other: &BTreeMap<K, V>) -> Option<Ordering> { | |
1916 | self.iter().partial_cmp(other.iter()) | |
c34b1796 | 1917 | } |
1a4d82fc JJ |
1918 | } |
1919 | ||
c30ab7b3 | 1920 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
1921 | impl<K: Ord, V: Ord> Ord for BTreeMap<K, V> { |
1922 | #[inline] | |
1923 | fn cmp(&self, other: &BTreeMap<K, V>) -> Ordering { | |
1924 | self.iter().cmp(other.iter()) | |
1a4d82fc JJ |
1925 | } |
1926 | } | |
1927 | ||
c30ab7b3 | 1928 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 | 1929 | impl<K: Debug, V: Debug> Debug for BTreeMap<K, V> { |
9fa01778 | 1930 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
9cc50fc6 | 1931 | f.debug_map().entries(self.iter()).finish() |
1a4d82fc | 1932 | } |
9cc50fc6 | 1933 | } |
1a4d82fc | 1934 | |
c30ab7b3 | 1935 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 1936 | impl<K: Ord, Q: ?Sized, V> Index<&Q> for BTreeMap<K, V> |
3157f602 XL |
1937 | where K: Borrow<Q>, |
1938 | Q: Ord | |
9cc50fc6 SL |
1939 | { |
1940 | type Output = V; | |
1a4d82fc | 1941 | |
2c00a5a8 XL |
1942 | /// Returns a reference to the value corresponding to the supplied key. |
1943 | /// | |
1944 | /// # Panics | |
1945 | /// | |
1946 | /// Panics if the key is not present in the `BTreeMap`. | |
9cc50fc6 SL |
1947 | #[inline] |
1948 | fn index(&self, key: &Q) -> &V { | |
1949 | self.get(key).expect("no entry found for key") | |
1a4d82fc | 1950 | } |
9cc50fc6 | 1951 | } |
1a4d82fc | 1952 | |
3157f602 XL |
1953 | fn first_leaf_edge<BorrowType, K, V> |
1954 | (mut node: NodeRef<BorrowType, K, V, marker::LeafOrInternal>) | |
1955 | -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge> { | |
9cc50fc6 SL |
1956 | loop { |
1957 | match node.force() { | |
1958 | Leaf(leaf) => return leaf.first_edge(), | |
1959 | Internal(internal) => { | |
1960 | node = internal.first_edge().descend(); | |
1961 | } | |
1962 | } | |
1a4d82fc | 1963 | } |
9cc50fc6 | 1964 | } |
1a4d82fc | 1965 | |
3157f602 XL |
1966 | fn last_leaf_edge<BorrowType, K, V> |
1967 | (mut node: NodeRef<BorrowType, K, V, marker::LeafOrInternal>) | |
1968 | -> Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge> { | |
9cc50fc6 SL |
1969 | loop { |
1970 | match node.force() { | |
1971 | Leaf(leaf) => return leaf.last_edge(), | |
1972 | Internal(internal) => { | |
1973 | node = internal.last_edge().descend(); | |
1974 | } | |
1975 | } | |
1a4d82fc JJ |
1976 | } |
1977 | } | |
1978 | ||
0531ce1d | 1979 | fn range_search<BorrowType, K, V, Q: ?Sized, R: RangeBounds<Q>>( |
8bb4bdeb XL |
1980 | root1: NodeRef<BorrowType, K, V, marker::LeafOrInternal>, |
1981 | root2: NodeRef<BorrowType, K, V, marker::LeafOrInternal>, | |
1982 | range: R | |
1983 | )-> (Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge>, | |
1984 | Handle<NodeRef<BorrowType, K, V, marker::Leaf>, marker::Edge>) | |
1985 | where Q: Ord, K: Borrow<Q> | |
1986 | { | |
94b46f34 | 1987 | match (range.start_bound(), range.end_bound()) { |
8bb4bdeb XL |
1988 | (Excluded(s), Excluded(e)) if s==e => |
1989 | panic!("range start and end are equal and excluded in BTreeMap"), | |
1990 | (Included(s), Included(e)) | | |
1991 | (Included(s), Excluded(e)) | | |
1992 | (Excluded(s), Included(e)) | | |
1993 | (Excluded(s), Excluded(e)) if s>e => | |
1994 | panic!("range start is greater than range end in BTreeMap"), | |
1995 | _ => {}, | |
1996 | }; | |
1997 | ||
1998 | let mut min_node = root1; | |
1999 | let mut max_node = root2; | |
2000 | let mut min_found = false; | |
2001 | let mut max_found = false; | |
2002 | let mut diverged = false; | |
2003 | ||
2004 | loop { | |
94b46f34 | 2005 | let min_edge = match (min_found, range.start_bound()) { |
8bb4bdeb XL |
2006 | (false, Included(key)) => match search::search_linear(&min_node, key) { |
2007 | (i, true) => { min_found = true; i }, | |
2008 | (i, false) => i, | |
2009 | }, | |
2010 | (false, Excluded(key)) => match search::search_linear(&min_node, key) { | |
2011 | (i, true) => { min_found = true; i+1 }, | |
2012 | (i, false) => i, | |
2013 | }, | |
2014 | (_, Unbounded) => 0, | |
2015 | (true, Included(_)) => min_node.keys().len(), | |
2016 | (true, Excluded(_)) => 0, | |
2017 | }; | |
2018 | ||
94b46f34 | 2019 | let max_edge = match (max_found, range.end_bound()) { |
8bb4bdeb XL |
2020 | (false, Included(key)) => match search::search_linear(&max_node, key) { |
2021 | (i, true) => { max_found = true; i+1 }, | |
2022 | (i, false) => i, | |
2023 | }, | |
2024 | (false, Excluded(key)) => match search::search_linear(&max_node, key) { | |
2025 | (i, true) => { max_found = true; i }, | |
2026 | (i, false) => i, | |
2027 | }, | |
2028 | (_, Unbounded) => max_node.keys().len(), | |
2029 | (true, Included(_)) => 0, | |
2030 | (true, Excluded(_)) => max_node.keys().len(), | |
2031 | }; | |
2032 | ||
2033 | if !diverged { | |
2034 | if max_edge < min_edge { panic!("Ord is ill-defined in BTreeMap range") } | |
2035 | if min_edge != max_edge { diverged = true; } | |
2036 | } | |
2037 | ||
2038 | let front = Handle::new_edge(min_node, min_edge); | |
2039 | let back = Handle::new_edge(max_node, max_edge); | |
2040 | match (front.force(), back.force()) { | |
2041 | (Leaf(f), Leaf(b)) => { | |
2042 | return (f, b); | |
2043 | }, | |
2044 | (Internal(min_int), Internal(max_int)) => { | |
2045 | min_node = min_int.descend(); | |
2046 | max_node = max_int.descend(); | |
2047 | }, | |
2048 | _ => unreachable!("BTreeMap has different depths"), | |
2049 | }; | |
2050 | } | |
2051 | } | |
2052 | ||
9cc50fc6 SL |
2053 | #[inline(always)] |
2054 | unsafe fn unwrap_unchecked<T>(val: Option<T>) -> T { | |
2055 | val.unwrap_or_else(|| { | |
2056 | if cfg!(debug_assertions) { | |
2057 | panic!("'unchecked' unwrap on None in BTreeMap"); | |
2058 | } else { | |
2059 | intrinsics::unreachable(); | |
2060 | } | |
2061 | }) | |
2062 | } | |
2063 | ||
1a4d82fc | 2064 | impl<K, V> BTreeMap<K, V> { |
7453a54e | 2065 | /// Gets an iterator over the entries of the map, sorted by key. |
1a4d82fc | 2066 | /// |
c34b1796 | 2067 | /// # Examples |
1a4d82fc | 2068 | /// |
54a0048b SL |
2069 | /// Basic usage: |
2070 | /// | |
1a4d82fc JJ |
2071 | /// ``` |
2072 | /// use std::collections::BTreeMap; | |
2073 | /// | |
2074 | /// let mut map = BTreeMap::new(); | |
85aaf69f | 2075 | /// map.insert(3, "c"); |
7453a54e SL |
2076 | /// map.insert(2, "b"); |
2077 | /// map.insert(1, "a"); | |
1a4d82fc JJ |
2078 | /// |
2079 | /// for (key, value) in map.iter() { | |
2080 | /// println!("{}: {}", key, value); | |
2081 | /// } | |
2082 | /// | |
2083 | /// let (first_key, first_value) = map.iter().next().unwrap(); | |
85aaf69f | 2084 | /// assert_eq!((*first_key, *first_value), (1, "a")); |
1a4d82fc | 2085 | /// ``` |
85aaf69f | 2086 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 2087 | pub fn iter(&self) -> Iter<'_, K, V> { |
1a4d82fc | 2088 | Iter { |
9cc50fc6 SL |
2089 | range: Range { |
2090 | front: first_leaf_edge(self.root.as_ref()), | |
3157f602 | 2091 | back: last_leaf_edge(self.root.as_ref()), |
92a42be0 | 2092 | }, |
3157f602 | 2093 | length: self.length, |
1a4d82fc JJ |
2094 | } |
2095 | } | |
2096 | ||
7453a54e | 2097 | /// Gets a mutable iterator over the entries of the map, sorted by key. |
1a4d82fc JJ |
2098 | /// |
2099 | /// # Examples | |
2100 | /// | |
54a0048b SL |
2101 | /// Basic usage: |
2102 | /// | |
1a4d82fc JJ |
2103 | /// ``` |
2104 | /// use std::collections::BTreeMap; | |
2105 | /// | |
2106 | /// let mut map = BTreeMap::new(); | |
85aaf69f SL |
2107 | /// map.insert("a", 1); |
2108 | /// map.insert("b", 2); | |
2109 | /// map.insert("c", 3); | |
1a4d82fc JJ |
2110 | /// |
2111 | /// // add 10 to the value if the key isn't "a" | |
2112 | /// for (key, value) in map.iter_mut() { | |
2113 | /// if key != &"a" { | |
2114 | /// *value += 10; | |
2115 | /// } | |
2116 | /// } | |
2117 | /// ``` | |
85aaf69f | 2118 | #[stable(feature = "rust1", since = "1.0.0")] |
9fa01778 | 2119 | pub fn iter_mut(&mut self) -> IterMut<'_, K, V> { |
9cc50fc6 SL |
2120 | let root1 = self.root.as_mut(); |
2121 | let root2 = unsafe { ptr::read(&root1) }; | |
1a4d82fc | 2122 | IterMut { |
9cc50fc6 SL |
2123 | range: RangeMut { |
2124 | front: first_leaf_edge(root1), | |
2125 | back: last_leaf_edge(root2), | |
2126 | _marker: PhantomData, | |
92a42be0 | 2127 | }, |
3157f602 | 2128 | length: self.length, |
1a4d82fc JJ |
2129 | } |
2130 | } | |
2131 | ||
7453a54e | 2132 | /// Gets an iterator over the keys of the map, in sorted order. |
1a4d82fc JJ |
2133 | /// |
2134 | /// # Examples | |
2135 | /// | |
54a0048b SL |
2136 | /// Basic usage: |
2137 | /// | |
1a4d82fc JJ |
2138 | /// ``` |
2139 | /// use std::collections::BTreeMap; | |
2140 | /// | |
2141 | /// let mut a = BTreeMap::new(); | |
85aaf69f | 2142 | /// a.insert(2, "b"); |
7453a54e | 2143 | /// a.insert(1, "a"); |
1a4d82fc | 2144 | /// |
62682a34 | 2145 | /// let keys: Vec<_> = a.keys().cloned().collect(); |
c34b1796 | 2146 | /// assert_eq!(keys, [1, 2]); |
1a4d82fc | 2147 | /// ``` |
85aaf69f | 2148 | #[stable(feature = "rust1", since = "1.0.0")] |
416331ca | 2149 | pub fn keys(&self) -> Keys<'_, K, V> { |
9cc50fc6 | 2150 | Keys { inner: self.iter() } |
1a4d82fc JJ |
2151 | } |
2152 | ||
7453a54e | 2153 | /// Gets an iterator over the values of the map, in order by key. |
1a4d82fc JJ |
2154 | /// |
2155 | /// # Examples | |
2156 | /// | |
54a0048b SL |
2157 | /// Basic usage: |
2158 | /// | |
1a4d82fc JJ |
2159 | /// ``` |
2160 | /// use std::collections::BTreeMap; | |
2161 | /// | |
2162 | /// let mut a = BTreeMap::new(); | |
7453a54e SL |
2163 | /// a.insert(1, "hello"); |
2164 | /// a.insert(2, "goodbye"); | |
1a4d82fc JJ |
2165 | /// |
2166 | /// let values: Vec<&str> = a.values().cloned().collect(); | |
7453a54e | 2167 | /// assert_eq!(values, ["hello", "goodbye"]); |
1a4d82fc | 2168 | /// ``` |
85aaf69f | 2169 | #[stable(feature = "rust1", since = "1.0.0")] |
416331ca | 2170 | pub fn values(&self) -> Values<'_, K, V> { |
9cc50fc6 | 2171 | Values { inner: self.iter() } |
1a4d82fc JJ |
2172 | } |
2173 | ||
54a0048b SL |
2174 | /// Gets a mutable iterator over the values of the map, in order by key. |
2175 | /// | |
2176 | /// # Examples | |
2177 | /// | |
2178 | /// Basic usage: | |
2179 | /// | |
2180 | /// ``` | |
54a0048b SL |
2181 | /// use std::collections::BTreeMap; |
2182 | /// | |
2183 | /// let mut a = BTreeMap::new(); | |
2184 | /// a.insert(1, String::from("hello")); | |
2185 | /// a.insert(2, String::from("goodbye")); | |
2186 | /// | |
2187 | /// for value in a.values_mut() { | |
2188 | /// value.push_str("!"); | |
2189 | /// } | |
2190 | /// | |
2191 | /// let values: Vec<String> = a.values().cloned().collect(); | |
2192 | /// assert_eq!(values, [String::from("hello!"), | |
2193 | /// String::from("goodbye!")]); | |
2194 | /// ``` | |
a7813a04 | 2195 | #[stable(feature = "map_values_mut", since = "1.10.0")] |
9fa01778 | 2196 | pub fn values_mut(&mut self) -> ValuesMut<'_, K, V> { |
54a0048b SL |
2197 | ValuesMut { inner: self.iter_mut() } |
2198 | } | |
2199 | ||
9346a6ac | 2200 | /// Returns the number of elements in the map. |
1a4d82fc JJ |
2201 | /// |
2202 | /// # Examples | |
2203 | /// | |
54a0048b SL |
2204 | /// Basic usage: |
2205 | /// | |
1a4d82fc JJ |
2206 | /// ``` |
2207 | /// use std::collections::BTreeMap; | |
2208 | /// | |
2209 | /// let mut a = BTreeMap::new(); | |
2210 | /// assert_eq!(a.len(), 0); | |
85aaf69f | 2211 | /// a.insert(1, "a"); |
1a4d82fc JJ |
2212 | /// assert_eq!(a.len(), 1); |
2213 | /// ``` | |
85aaf69f | 2214 | #[stable(feature = "rust1", since = "1.0.0")] |
92a42be0 SL |
2215 | pub fn len(&self) -> usize { |
2216 | self.length | |
2217 | } | |
1a4d82fc | 2218 | |
cc61c64b | 2219 | /// Returns `true` if the map contains no elements. |
1a4d82fc JJ |
2220 | /// |
2221 | /// # Examples | |
2222 | /// | |
54a0048b SL |
2223 | /// Basic usage: |
2224 | /// | |
1a4d82fc JJ |
2225 | /// ``` |
2226 | /// use std::collections::BTreeMap; | |
2227 | /// | |
2228 | /// let mut a = BTreeMap::new(); | |
2229 | /// assert!(a.is_empty()); | |
85aaf69f | 2230 | /// a.insert(1, "a"); |
1a4d82fc JJ |
2231 | /// assert!(!a.is_empty()); |
2232 | /// ``` | |
85aaf69f | 2233 | #[stable(feature = "rust1", since = "1.0.0")] |
92a42be0 SL |
2234 | pub fn is_empty(&self) -> bool { |
2235 | self.len() == 0 | |
2236 | } | |
1a4d82fc JJ |
2237 | } |
2238 | ||
9cc50fc6 SL |
2239 | impl<'a, K: Ord, V> Entry<'a, K, V> { |
2240 | /// Ensures a value is in the entry by inserting the default if empty, and returns | |
2241 | /// a mutable reference to the value in the entry. | |
5bcae85e SL |
2242 | /// |
2243 | /// # Examples | |
2244 | /// | |
2245 | /// ``` | |
2246 | /// use std::collections::BTreeMap; | |
2247 | /// | |
2248 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2249 | /// map.entry("poneyland").or_insert(12); | |
2250 | /// | |
2251 | /// assert_eq!(map["poneyland"], 12); | |
2252 | /// ``` | |
9cc50fc6 SL |
2253 | #[stable(feature = "rust1", since = "1.0.0")] |
2254 | pub fn or_insert(self, default: V) -> &'a mut V { | |
2255 | match self { | |
2256 | Occupied(entry) => entry.into_mut(), | |
2257 | Vacant(entry) => entry.insert(default), | |
2258 | } | |
2259 | } | |
85aaf69f | 2260 | |
9cc50fc6 SL |
2261 | /// Ensures a value is in the entry by inserting the result of the default function if empty, |
2262 | /// and returns a mutable reference to the value in the entry. | |
5bcae85e SL |
2263 | /// |
2264 | /// # Examples | |
2265 | /// | |
2266 | /// ``` | |
2267 | /// use std::collections::BTreeMap; | |
2268 | /// | |
2269 | /// let mut map: BTreeMap<&str, String> = BTreeMap::new(); | |
32a655c1 | 2270 | /// let s = "hoho".to_string(); |
5bcae85e SL |
2271 | /// |
2272 | /// map.entry("poneyland").or_insert_with(|| s); | |
2273 | /// | |
32a655c1 | 2274 | /// assert_eq!(map["poneyland"], "hoho".to_string()); |
5bcae85e | 2275 | /// ``` |
9cc50fc6 SL |
2276 | #[stable(feature = "rust1", since = "1.0.0")] |
2277 | pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V { | |
2278 | match self { | |
2279 | Occupied(entry) => entry.into_mut(), | |
2280 | Vacant(entry) => entry.insert(default()), | |
2281 | } | |
2282 | } | |
a7813a04 XL |
2283 | |
2284 | /// Returns a reference to this entry's key. | |
5bcae85e SL |
2285 | /// |
2286 | /// # Examples | |
2287 | /// | |
2288 | /// ``` | |
2289 | /// use std::collections::BTreeMap; | |
2290 | /// | |
2291 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2292 | /// assert_eq!(map.entry("poneyland").key(), &"poneyland"); | |
2293 | /// ``` | |
a7813a04 XL |
2294 | #[stable(feature = "map_entry_keys", since = "1.10.0")] |
2295 | pub fn key(&self) -> &K { | |
2296 | match *self { | |
2297 | Occupied(ref entry) => entry.key(), | |
2298 | Vacant(ref entry) => entry.key(), | |
2299 | } | |
2300 | } | |
ea8adc8c XL |
2301 | |
2302 | /// Provides in-place mutable access to an occupied entry before any | |
2303 | /// potential inserts into the map. | |
2304 | /// | |
2305 | /// # Examples | |
2306 | /// | |
2307 | /// ``` | |
ea8adc8c XL |
2308 | /// use std::collections::BTreeMap; |
2309 | /// | |
2310 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2311 | /// | |
2312 | /// map.entry("poneyland") | |
2313 | /// .and_modify(|e| { *e += 1 }) | |
2314 | /// .or_insert(42); | |
2315 | /// assert_eq!(map["poneyland"], 42); | |
2316 | /// | |
2317 | /// map.entry("poneyland") | |
2318 | /// .and_modify(|e| { *e += 1 }) | |
2319 | /// .or_insert(42); | |
2320 | /// assert_eq!(map["poneyland"], 43); | |
2321 | /// ``` | |
0531ce1d XL |
2322 | #[stable(feature = "entry_and_modify", since = "1.26.0")] |
2323 | pub fn and_modify<F>(self, f: F) -> Self | |
2324 | where F: FnOnce(&mut V) | |
ea8adc8c XL |
2325 | { |
2326 | match self { | |
2327 | Occupied(mut entry) => { | |
2328 | f(entry.get_mut()); | |
2329 | Occupied(entry) | |
2330 | }, | |
2331 | Vacant(entry) => Vacant(entry), | |
2332 | } | |
2333 | } | |
2334 | } | |
2335 | ||
2336 | impl<'a, K: Ord, V: Default> Entry<'a, K, V> { | |
94b46f34 | 2337 | #[stable(feature = "entry_or_default", since = "1.28.0")] |
ea8adc8c XL |
2338 | /// Ensures a value is in the entry by inserting the default value if empty, |
2339 | /// and returns a mutable reference to the value in the entry. | |
2340 | /// | |
2341 | /// # Examples | |
2342 | /// | |
2343 | /// ``` | |
ea8adc8c XL |
2344 | /// use std::collections::BTreeMap; |
2345 | /// | |
2346 | /// let mut map: BTreeMap<&str, Option<usize>> = BTreeMap::new(); | |
2347 | /// map.entry("poneyland").or_default(); | |
2348 | /// | |
2349 | /// assert_eq!(map["poneyland"], None); | |
ea8adc8c XL |
2350 | /// ``` |
2351 | pub fn or_default(self) -> &'a mut V { | |
2352 | match self { | |
2353 | Occupied(entry) => entry.into_mut(), | |
2354 | Vacant(entry) => entry.insert(Default::default()), | |
2355 | } | |
2356 | } | |
2357 | ||
9cc50fc6 | 2358 | } |
85aaf69f | 2359 | |
9cc50fc6 | 2360 | impl<'a, K: Ord, V> VacantEntry<'a, K, V> { |
54a0048b SL |
2361 | /// Gets a reference to the key that would be used when inserting a value |
2362 | /// through the VacantEntry. | |
5bcae85e SL |
2363 | /// |
2364 | /// # Examples | |
2365 | /// | |
2366 | /// ``` | |
2367 | /// use std::collections::BTreeMap; | |
2368 | /// | |
2369 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2370 | /// assert_eq!(map.entry("poneyland").key(), &"poneyland"); | |
2371 | /// ``` | |
a7813a04 | 2372 | #[stable(feature = "map_entry_keys", since = "1.10.0")] |
54a0048b SL |
2373 | pub fn key(&self) -> &K { |
2374 | &self.key | |
2375 | } | |
2376 | ||
3157f602 | 2377 | /// Take ownership of the key. |
5bcae85e SL |
2378 | /// |
2379 | /// # Examples | |
2380 | /// | |
2381 | /// ``` | |
2382 | /// use std::collections::BTreeMap; | |
2383 | /// use std::collections::btree_map::Entry; | |
2384 | /// | |
2385 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2386 | /// | |
2387 | /// if let Entry::Vacant(v) = map.entry("poneyland") { | |
2388 | /// v.into_key(); | |
2389 | /// } | |
2390 | /// ``` | |
2391 | #[stable(feature = "map_entry_recover_keys2", since = "1.12.0")] | |
3157f602 XL |
2392 | pub fn into_key(self) -> K { |
2393 | self.key | |
2394 | } | |
2395 | ||
9e0c209e | 2396 | /// Sets the value of the entry with the `VacantEntry`'s key, |
9cc50fc6 | 2397 | /// and returns a mutable reference to it. |
5bcae85e SL |
2398 | /// |
2399 | /// # Examples | |
2400 | /// | |
2401 | /// ``` | |
2402 | /// use std::collections::BTreeMap; | |
2403 | /// | |
2404 | /// let mut count: BTreeMap<&str, usize> = BTreeMap::new(); | |
2405 | /// | |
2406 | /// // count the number of occurrences of letters in the vec | |
2407 | /// for x in vec!["a","b","a","c","a","b"] { | |
2408 | /// *count.entry(x).or_insert(0) += 1; | |
2409 | /// } | |
2410 | /// | |
2411 | /// assert_eq!(count["a"], 3); | |
2412 | /// ``` | |
9cc50fc6 SL |
2413 | #[stable(feature = "rust1", since = "1.0.0")] |
2414 | pub fn insert(self, value: V) -> &'a mut V { | |
2415 | *self.length += 1; | |
2416 | ||
2417 | let out_ptr; | |
2418 | ||
2419 | let mut ins_k; | |
2420 | let mut ins_v; | |
2421 | let mut ins_edge; | |
2422 | ||
2423 | let mut cur_parent = match self.handle.insert(self.key, value) { | |
2424 | (Fit(handle), _) => return handle.into_kv_mut().1, | |
2425 | (Split(left, k, v, right), ptr) => { | |
2426 | ins_k = k; | |
2427 | ins_v = v; | |
2428 | ins_edge = right; | |
2429 | out_ptr = ptr; | |
2430 | left.ascend().map_err(|n| n.into_root_mut()) | |
85aaf69f | 2431 | } |
9cc50fc6 | 2432 | }; |
85aaf69f | 2433 | |
9cc50fc6 SL |
2434 | loop { |
2435 | match cur_parent { | |
3157f602 XL |
2436 | Ok(parent) => { |
2437 | match parent.insert(ins_k, ins_v, ins_edge) { | |
2438 | Fit(_) => return unsafe { &mut *out_ptr }, | |
2439 | Split(left, k, v, right) => { | |
2440 | ins_k = k; | |
2441 | ins_v = v; | |
2442 | ins_edge = right; | |
2443 | cur_parent = left.ascend().map_err(|n| n.into_root_mut()); | |
2444 | } | |
9cc50fc6 | 2445 | } |
3157f602 | 2446 | } |
9cc50fc6 SL |
2447 | Err(root) => { |
2448 | root.push_level().push(ins_k, ins_v, ins_edge); | |
2449 | return unsafe { &mut *out_ptr }; | |
85aaf69f SL |
2450 | } |
2451 | } | |
2452 | } | |
9cc50fc6 | 2453 | } |
85aaf69f SL |
2454 | } |
2455 | ||
9cc50fc6 | 2456 | impl<'a, K: Ord, V> OccupiedEntry<'a, K, V> { |
54a0048b | 2457 | /// Gets a reference to the key in the entry. |
5bcae85e SL |
2458 | /// |
2459 | /// # Examples | |
2460 | /// | |
2461 | /// ``` | |
2462 | /// use std::collections::BTreeMap; | |
2463 | /// | |
2464 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2465 | /// map.entry("poneyland").or_insert(12); | |
2466 | /// assert_eq!(map.entry("poneyland").key(), &"poneyland"); | |
2467 | /// ``` | |
a7813a04 | 2468 | #[stable(feature = "map_entry_keys", since = "1.10.0")] |
54a0048b SL |
2469 | pub fn key(&self) -> &K { |
2470 | self.handle.reborrow().into_kv().0 | |
2471 | } | |
2472 | ||
5bcae85e SL |
2473 | /// Take ownership of the key and value from the map. |
2474 | /// | |
2475 | /// # Examples | |
2476 | /// | |
2477 | /// ``` | |
2478 | /// use std::collections::BTreeMap; | |
2479 | /// use std::collections::btree_map::Entry; | |
2480 | /// | |
2481 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2482 | /// map.entry("poneyland").or_insert(12); | |
2483 | /// | |
2484 | /// if let Entry::Occupied(o) = map.entry("poneyland") { | |
2485 | /// // We delete the entry from the map. | |
2486 | /// o.remove_entry(); | |
2487 | /// } | |
2488 | /// | |
2489 | /// // If now try to get the value, it will panic: | |
2490 | /// // println!("{}", map["poneyland"]); | |
2491 | /// ``` | |
2492 | #[stable(feature = "map_entry_recover_keys2", since = "1.12.0")] | |
2493 | pub fn remove_entry(self) -> (K, V) { | |
3157f602 XL |
2494 | self.remove_kv() |
2495 | } | |
2496 | ||
9cc50fc6 | 2497 | /// Gets a reference to the value in the entry. |
5bcae85e SL |
2498 | /// |
2499 | /// # Examples | |
2500 | /// | |
2501 | /// ``` | |
2502 | /// use std::collections::BTreeMap; | |
2503 | /// use std::collections::btree_map::Entry; | |
2504 | /// | |
2505 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2506 | /// map.entry("poneyland").or_insert(12); | |
2507 | /// | |
2508 | /// if let Entry::Occupied(o) = map.entry("poneyland") { | |
2509 | /// assert_eq!(o.get(), &12); | |
2510 | /// } | |
2511 | /// ``` | |
9cc50fc6 SL |
2512 | #[stable(feature = "rust1", since = "1.0.0")] |
2513 | pub fn get(&self) -> &V { | |
2514 | self.handle.reborrow().into_kv().1 | |
85aaf69f SL |
2515 | } |
2516 | ||
9cc50fc6 | 2517 | /// Gets a mutable reference to the value in the entry. |
5bcae85e | 2518 | /// |
9fa01778 | 2519 | /// If you need a reference to the `OccupiedEntry` that may outlive the |
94b46f34 XL |
2520 | /// destruction of the `Entry` value, see [`into_mut`]. |
2521 | /// | |
2522 | /// [`into_mut`]: #method.into_mut | |
2523 | /// | |
5bcae85e SL |
2524 | /// # Examples |
2525 | /// | |
2526 | /// ``` | |
2527 | /// use std::collections::BTreeMap; | |
2528 | /// use std::collections::btree_map::Entry; | |
2529 | /// | |
2530 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2531 | /// map.entry("poneyland").or_insert(12); | |
2532 | /// | |
2533 | /// assert_eq!(map["poneyland"], 12); | |
2534 | /// if let Entry::Occupied(mut o) = map.entry("poneyland") { | |
94b46f34 XL |
2535 | /// *o.get_mut() += 10; |
2536 | /// assert_eq!(*o.get(), 22); | |
2537 | /// | |
2538 | /// // We can use the same Entry multiple times. | |
2539 | /// *o.get_mut() += 2; | |
5bcae85e | 2540 | /// } |
94b46f34 | 2541 | /// assert_eq!(map["poneyland"], 24); |
5bcae85e | 2542 | /// ``` |
9cc50fc6 SL |
2543 | #[stable(feature = "rust1", since = "1.0.0")] |
2544 | pub fn get_mut(&mut self) -> &mut V { | |
2545 | self.handle.kv_mut().1 | |
85aaf69f SL |
2546 | } |
2547 | ||
9cc50fc6 | 2548 | /// Converts the entry into a mutable reference to its value. |
5bcae85e | 2549 | /// |
94b46f34 XL |
2550 | /// If you need multiple references to the `OccupiedEntry`, see [`get_mut`]. |
2551 | /// | |
2552 | /// [`get_mut`]: #method.get_mut | |
2553 | /// | |
5bcae85e SL |
2554 | /// # Examples |
2555 | /// | |
2556 | /// ``` | |
2557 | /// use std::collections::BTreeMap; | |
2558 | /// use std::collections::btree_map::Entry; | |
2559 | /// | |
2560 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2561 | /// map.entry("poneyland").or_insert(12); | |
2562 | /// | |
2563 | /// assert_eq!(map["poneyland"], 12); | |
2564 | /// if let Entry::Occupied(o) = map.entry("poneyland") { | |
2565 | /// *o.into_mut() += 10; | |
2566 | /// } | |
2567 | /// assert_eq!(map["poneyland"], 22); | |
2568 | /// ``` | |
85aaf69f | 2569 | #[stable(feature = "rust1", since = "1.0.0")] |
9cc50fc6 SL |
2570 | pub fn into_mut(self) -> &'a mut V { |
2571 | self.handle.into_kv_mut().1 | |
1a4d82fc | 2572 | } |
e9174d1e | 2573 | |
9e0c209e | 2574 | /// Sets the value of the entry with the `OccupiedEntry`'s key, |
9cc50fc6 | 2575 | /// and returns the entry's old value. |
5bcae85e SL |
2576 | /// |
2577 | /// # Examples | |
2578 | /// | |
2579 | /// ``` | |
2580 | /// use std::collections::BTreeMap; | |
2581 | /// use std::collections::btree_map::Entry; | |
2582 | /// | |
2583 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2584 | /// map.entry("poneyland").or_insert(12); | |
2585 | /// | |
2586 | /// if let Entry::Occupied(mut o) = map.entry("poneyland") { | |
2587 | /// assert_eq!(o.insert(15), 12); | |
2588 | /// } | |
2589 | /// assert_eq!(map["poneyland"], 15); | |
2590 | /// ``` | |
9cc50fc6 SL |
2591 | #[stable(feature = "rust1", since = "1.0.0")] |
2592 | pub fn insert(&mut self, value: V) -> V { | |
2593 | mem::replace(self.get_mut(), value) | |
2594 | } | |
e9174d1e | 2595 | |
9cc50fc6 | 2596 | /// Takes the value of the entry out of the map, and returns it. |
5bcae85e SL |
2597 | /// |
2598 | /// # Examples | |
2599 | /// | |
2600 | /// ``` | |
2601 | /// use std::collections::BTreeMap; | |
2602 | /// use std::collections::btree_map::Entry; | |
2603 | /// | |
2604 | /// let mut map: BTreeMap<&str, usize> = BTreeMap::new(); | |
2605 | /// map.entry("poneyland").or_insert(12); | |
2606 | /// | |
2607 | /// if let Entry::Occupied(o) = map.entry("poneyland") { | |
2608 | /// assert_eq!(o.remove(), 12); | |
2609 | /// } | |
2610 | /// // If we try to get "poneyland"'s value, it'll panic: | |
2611 | /// // println!("{}", map["poneyland"]); | |
2612 | /// ``` | |
9cc50fc6 SL |
2613 | #[stable(feature = "rust1", since = "1.0.0")] |
2614 | pub fn remove(self) -> V { | |
2615 | self.remove_kv().1 | |
e9174d1e SL |
2616 | } |
2617 | ||
9cc50fc6 SL |
2618 | fn remove_kv(self) -> (K, V) { |
2619 | *self.length -= 1; | |
e9174d1e | 2620 | |
9cc50fc6 SL |
2621 | let (small_leaf, old_key, old_val) = match self.handle.force() { |
2622 | Leaf(leaf) => { | |
2623 | let (hole, old_key, old_val) = leaf.remove(); | |
2624 | (hole.into_node(), old_key, old_val) | |
3157f602 | 2625 | } |
9cc50fc6 SL |
2626 | Internal(mut internal) => { |
2627 | let key_loc = internal.kv_mut().0 as *mut K; | |
2628 | let val_loc = internal.kv_mut().1 as *mut V; | |
2629 | ||
2630 | let to_remove = first_leaf_edge(internal.right_edge().descend()).right_kv().ok(); | |
2631 | let to_remove = unsafe { unwrap_unchecked(to_remove) }; | |
2632 | ||
2633 | let (hole, key, val) = to_remove.remove(); | |
2634 | ||
3157f602 XL |
2635 | let old_key = unsafe { mem::replace(&mut *key_loc, key) }; |
2636 | let old_val = unsafe { mem::replace(&mut *val_loc, val) }; | |
9cc50fc6 SL |
2637 | |
2638 | (hole.into_node(), old_key, old_val) | |
2639 | } | |
2640 | }; | |
2641 | ||
2642 | // Handle underflow | |
2643 | let mut cur_node = small_leaf.forget_type(); | |
2644 | while cur_node.len() < node::CAPACITY / 2 { | |
2645 | match handle_underfull_node(cur_node) { | |
2646 | AtRoot => break, | |
2647 | EmptyParent(_) => unreachable!(), | |
3157f602 XL |
2648 | Merged(parent) => { |
2649 | if parent.len() == 0 { | |
2650 | // We must be at the root | |
2651 | parent.into_root_mut().pop_level(); | |
2652 | break; | |
2653 | } else { | |
2654 | cur_node = parent.forget_type(); | |
2655 | } | |
2656 | } | |
2657 | Stole(_) => break, | |
e9174d1e SL |
2658 | } |
2659 | } | |
9cc50fc6 SL |
2660 | |
2661 | (old_key, old_val) | |
e9174d1e | 2662 | } |
9cc50fc6 | 2663 | } |
e9174d1e | 2664 | |
9cc50fc6 SL |
2665 | enum UnderflowResult<'a, K, V> { |
2666 | AtRoot, | |
2667 | EmptyParent(NodeRef<marker::Mut<'a>, K, V, marker::Internal>), | |
2668 | Merged(NodeRef<marker::Mut<'a>, K, V, marker::Internal>), | |
3157f602 | 2669 | Stole(NodeRef<marker::Mut<'a>, K, V, marker::Internal>), |
9cc50fc6 SL |
2670 | } |
2671 | ||
416331ca XL |
2672 | fn handle_underfull_node<K, V>(node: NodeRef<marker::Mut<'_>, K, V, marker::LeafOrInternal>) |
2673 | -> UnderflowResult<'_, K, V> { | |
9cc50fc6 SL |
2674 | let parent = if let Ok(parent) = node.ascend() { |
2675 | parent | |
2676 | } else { | |
2677 | return AtRoot; | |
2678 | }; | |
2679 | ||
2680 | let (is_left, mut handle) = match parent.left_kv() { | |
2681 | Ok(left) => (true, left), | |
3157f602 XL |
2682 | Err(parent) => { |
2683 | match parent.right_kv() { | |
2684 | Ok(right) => (false, right), | |
2685 | Err(parent) => { | |
2686 | return EmptyParent(parent.into_node()); | |
2687 | } | |
9cc50fc6 SL |
2688 | } |
2689 | } | |
2690 | }; | |
2691 | ||
2692 | if handle.can_merge() { | |
a7813a04 | 2693 | Merged(handle.merge().into_node()) |
9cc50fc6 | 2694 | } else { |
a7813a04 XL |
2695 | if is_left { |
2696 | handle.steal_left(); | |
2697 | } else { | |
2698 | handle.steal_right(); | |
2699 | } | |
2700 | Stole(handle.into_node()) | |
2701 | } | |
2702 | } | |
e9174d1e | 2703 | |
3157f602 | 2704 | impl<K: Ord, V, I: Iterator<Item = (K, V)>> Iterator for MergeIter<K, V, I> { |
a7813a04 | 2705 | type Item = (K, V); |
e9174d1e | 2706 | |
a7813a04 XL |
2707 | fn next(&mut self) -> Option<(K, V)> { |
2708 | let res = match (self.left.peek(), self.right.peek()) { | |
2709 | (Some(&(ref left_key, _)), Some(&(ref right_key, _))) => left_key.cmp(right_key), | |
2710 | (Some(_), None) => Ordering::Less, | |
2711 | (None, Some(_)) => Ordering::Greater, | |
2712 | (None, None) => return None, | |
2713 | }; | |
9cc50fc6 | 2714 | |
a7813a04 XL |
2715 | // Check which elements comes first and only advance the corresponding iterator. |
2716 | // If two keys are equal, take the value from `right`. | |
2717 | match res { | |
3157f602 XL |
2718 | Ordering::Less => self.left.next(), |
2719 | Ordering::Greater => self.right.next(), | |
a7813a04 XL |
2720 | Ordering::Equal => { |
2721 | self.left.next(); | |
2722 | self.right.next() | |
3157f602 | 2723 | } |
a7813a04 | 2724 | } |
e9174d1e SL |
2725 | } |
2726 | } |