indexmap/
set.rs

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1//! A hash set implemented using `IndexMap`
2
3#[cfg(feature = "rayon")]
4pub use crate::rayon::set as rayon;
5
6#[cfg(has_std)]
7use std::collections::hash_map::RandomState;
8
9use crate::vec::{self, Vec};
10use core::cmp::Ordering;
11use core::fmt;
12use core::hash::{BuildHasher, Hash};
13use core::iter::{Chain, FusedIterator};
14use core::ops::{BitAnd, BitOr, BitXor, Index, RangeBounds, Sub};
15use core::slice;
16
17use super::{Entries, Equivalent, IndexMap};
18
19type Bucket<T> = super::Bucket<T, ()>;
20
21/// A hash set where the iteration order of the values is independent of their
22/// hash values.
23///
24/// The interface is closely compatible with the standard `HashSet`, but also
25/// has additional features.
26///
27/// # Order
28///
29/// The values have a consistent order that is determined by the sequence of
30/// insertion and removal calls on the set. The order does not depend on the
31/// values or the hash function at all. Note that insertion order and value
32/// are not affected if a re-insertion is attempted once an element is
33/// already present.
34///
35/// All iterators traverse the set *in order*.  Set operation iterators like
36/// `union` produce a concatenated order, as do their matching "bitwise"
37/// operators.  See their documentation for specifics.
38///
39/// The insertion order is preserved, with **notable exceptions** like the
40/// `.remove()` or `.swap_remove()` methods. Methods such as `.sort_by()` of
41/// course result in a new order, depending on the sorting order.
42///
43/// # Indices
44///
45/// The values are indexed in a compact range without holes in the range
46/// `0..self.len()`. For example, the method `.get_full` looks up the index for
47/// a value, and the method `.get_index` looks up the value by index.
48///
49/// # Examples
50///
51/// ```
52/// use indexmap::IndexSet;
53///
54/// // Collects which letters appear in a sentence.
55/// let letters: IndexSet<_> = "a short treatise on fungi".chars().collect();
56///
57/// assert!(letters.contains(&'s'));
58/// assert!(letters.contains(&'t'));
59/// assert!(letters.contains(&'u'));
60/// assert!(!letters.contains(&'y'));
61/// ```
62#[cfg(has_std)]
63pub struct IndexSet<T, S = RandomState> {
64    pub(crate) map: IndexMap<T, (), S>,
65}
66#[cfg(not(has_std))]
67pub struct IndexSet<T, S> {
68    pub(crate) map: IndexMap<T, (), S>,
69}
70
71impl<T, S> Clone for IndexSet<T, S>
72where
73    T: Clone,
74    S: Clone,
75{
76    fn clone(&self) -> Self {
77        IndexSet {
78            map: self.map.clone(),
79        }
80    }
81
82    fn clone_from(&mut self, other: &Self) {
83        self.map.clone_from(&other.map);
84    }
85}
86
87impl<T, S> Entries for IndexSet<T, S> {
88    type Entry = Bucket<T>;
89
90    #[inline]
91    fn into_entries(self) -> Vec<Self::Entry> {
92        self.map.into_entries()
93    }
94
95    #[inline]
96    fn as_entries(&self) -> &[Self::Entry] {
97        self.map.as_entries()
98    }
99
100    #[inline]
101    fn as_entries_mut(&mut self) -> &mut [Self::Entry] {
102        self.map.as_entries_mut()
103    }
104
105    fn with_entries<F>(&mut self, f: F)
106    where
107        F: FnOnce(&mut [Self::Entry]),
108    {
109        self.map.with_entries(f);
110    }
111}
112
113impl<T, S> fmt::Debug for IndexSet<T, S>
114where
115    T: fmt::Debug,
116{
117    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
118        if cfg!(not(feature = "test_debug")) {
119            f.debug_set().entries(self.iter()).finish()
120        } else {
121            // Let the inner `IndexMap` print all of its details
122            f.debug_struct("IndexSet").field("map", &self.map).finish()
123        }
124    }
125}
126
127#[cfg(has_std)]
128impl<T> IndexSet<T> {
129    /// Create a new set. (Does not allocate.)
130    pub fn new() -> Self {
131        IndexSet {
132            map: IndexMap::new(),
133        }
134    }
135
136    /// Create a new set with capacity for `n` elements.
137    /// (Does not allocate if `n` is zero.)
138    ///
139    /// Computes in **O(n)** time.
140    pub fn with_capacity(n: usize) -> Self {
141        IndexSet {
142            map: IndexMap::with_capacity(n),
143        }
144    }
145}
146
147impl<T, S> IndexSet<T, S> {
148    /// Create a new set with capacity for `n` elements.
149    /// (Does not allocate if `n` is zero.)
150    ///
151    /// Computes in **O(n)** time.
152    pub fn with_capacity_and_hasher(n: usize, hash_builder: S) -> Self {
153        IndexSet {
154            map: IndexMap::with_capacity_and_hasher(n, hash_builder),
155        }
156    }
157
158    /// Create a new set with `hash_builder`.
159    ///
160    /// This function is `const`, so it
161    /// can be called in `static` contexts.
162    pub const fn with_hasher(hash_builder: S) -> Self {
163        IndexSet {
164            map: IndexMap::with_hasher(hash_builder),
165        }
166    }
167
168    /// Computes in **O(1)** time.
169    pub fn capacity(&self) -> usize {
170        self.map.capacity()
171    }
172
173    /// Return a reference to the set's `BuildHasher`.
174    pub fn hasher(&self) -> &S {
175        self.map.hasher()
176    }
177
178    /// Return the number of elements in the set.
179    ///
180    /// Computes in **O(1)** time.
181    pub fn len(&self) -> usize {
182        self.map.len()
183    }
184
185    /// Returns true if the set contains no elements.
186    ///
187    /// Computes in **O(1)** time.
188    pub fn is_empty(&self) -> bool {
189        self.map.is_empty()
190    }
191
192    /// Return an iterator over the values of the set, in their order
193    pub fn iter(&self) -> Iter<'_, T> {
194        Iter {
195            iter: self.map.as_entries().iter(),
196        }
197    }
198
199    /// Remove all elements in the set, while preserving its capacity.
200    ///
201    /// Computes in **O(n)** time.
202    pub fn clear(&mut self) {
203        self.map.clear();
204    }
205
206    /// Shortens the set, keeping the first `len` elements and dropping the rest.
207    ///
208    /// If `len` is greater than the set's current length, this has no effect.
209    pub fn truncate(&mut self, len: usize) {
210        self.map.truncate(len);
211    }
212
213    /// Clears the `IndexSet` in the given index range, returning those values
214    /// as a drain iterator.
215    ///
216    /// The range may be any type that implements `RangeBounds<usize>`,
217    /// including all of the `std::ops::Range*` types, or even a tuple pair of
218    /// `Bound` start and end values. To drain the set entirely, use `RangeFull`
219    /// like `set.drain(..)`.
220    ///
221    /// This shifts down all entries following the drained range to fill the
222    /// gap, and keeps the allocated memory for reuse.
223    ///
224    /// ***Panics*** if the starting point is greater than the end point or if
225    /// the end point is greater than the length of the set.
226    pub fn drain<R>(&mut self, range: R) -> Drain<'_, T>
227    where
228        R: RangeBounds<usize>,
229    {
230        Drain {
231            iter: self.map.drain(range).iter,
232        }
233    }
234
235    /// Splits the collection into two at the given index.
236    ///
237    /// Returns a newly allocated set containing the elements in the range
238    /// `[at, len)`. After the call, the original set will be left containing
239    /// the elements `[0, at)` with its previous capacity unchanged.
240    ///
241    /// ***Panics*** if `at > len`.
242    pub fn split_off(&mut self, at: usize) -> Self
243    where
244        S: Clone,
245    {
246        Self {
247            map: self.map.split_off(at),
248        }
249    }
250}
251
252impl<T, S> IndexSet<T, S>
253where
254    T: Hash + Eq,
255    S: BuildHasher,
256{
257    /// Reserve capacity for `additional` more values.
258    ///
259    /// Computes in **O(n)** time.
260    pub fn reserve(&mut self, additional: usize) {
261        self.map.reserve(additional);
262    }
263
264    /// Shrink the capacity of the set as much as possible.
265    ///
266    /// Computes in **O(n)** time.
267    pub fn shrink_to_fit(&mut self) {
268        self.map.shrink_to_fit();
269    }
270
271    /// Shrink the capacity of the set with a lower limit.
272    ///
273    /// Computes in **O(n)** time.
274    pub fn shrink_to(&mut self, min_capacity: usize) {
275        self.map.shrink_to(min_capacity);
276    }
277
278    /// Insert the value into the set.
279    ///
280    /// If an equivalent item already exists in the set, it returns
281    /// `false` leaving the original value in the set and without
282    /// altering its insertion order. Otherwise, it inserts the new
283    /// item and returns `true`.
284    ///
285    /// Computes in **O(1)** time (amortized average).
286    pub fn insert(&mut self, value: T) -> bool {
287        self.map.insert(value, ()).is_none()
288    }
289
290    /// Insert the value into the set, and get its index.
291    ///
292    /// If an equivalent item already exists in the set, it returns
293    /// the index of the existing item and `false`, leaving the
294    /// original value in the set and without altering its insertion
295    /// order. Otherwise, it inserts the new item and returns the index
296    /// of the inserted item and `true`.
297    ///
298    /// Computes in **O(1)** time (amortized average).
299    pub fn insert_full(&mut self, value: T) -> (usize, bool) {
300        use super::map::Entry::*;
301
302        match self.map.entry(value) {
303            Occupied(e) => (e.index(), false),
304            Vacant(e) => {
305                let index = e.index();
306                e.insert(());
307                (index, true)
308            }
309        }
310    }
311
312    /// Return an iterator over the values that are in `self` but not `other`.
313    ///
314    /// Values are produced in the same order that they appear in `self`.
315    pub fn difference<'a, S2>(&'a self, other: &'a IndexSet<T, S2>) -> Difference<'a, T, S2>
316    where
317        S2: BuildHasher,
318    {
319        Difference {
320            iter: self.iter(),
321            other,
322        }
323    }
324
325    /// Return an iterator over the values that are in `self` or `other`,
326    /// but not in both.
327    ///
328    /// Values from `self` are produced in their original order, followed by
329    /// values from `other` in their original order.
330    pub fn symmetric_difference<'a, S2>(
331        &'a self,
332        other: &'a IndexSet<T, S2>,
333    ) -> SymmetricDifference<'a, T, S, S2>
334    where
335        S2: BuildHasher,
336    {
337        SymmetricDifference {
338            iter: self.difference(other).chain(other.difference(self)),
339        }
340    }
341
342    /// Return an iterator over the values that are in both `self` and `other`.
343    ///
344    /// Values are produced in the same order that they appear in `self`.
345    pub fn intersection<'a, S2>(&'a self, other: &'a IndexSet<T, S2>) -> Intersection<'a, T, S2>
346    where
347        S2: BuildHasher,
348    {
349        Intersection {
350            iter: self.iter(),
351            other,
352        }
353    }
354
355    /// Return an iterator over all values that are in `self` or `other`.
356    ///
357    /// Values from `self` are produced in their original order, followed by
358    /// values that are unique to `other` in their original order.
359    pub fn union<'a, S2>(&'a self, other: &'a IndexSet<T, S2>) -> Union<'a, T, S>
360    where
361        S2: BuildHasher,
362    {
363        Union {
364            iter: self.iter().chain(other.difference(self)),
365        }
366    }
367
368    /// Return `true` if an equivalent to `value` exists in the set.
369    ///
370    /// Computes in **O(1)** time (average).
371    pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool
372    where
373        Q: Hash + Equivalent<T>,
374    {
375        self.map.contains_key(value)
376    }
377
378    /// Return a reference to the value stored in the set, if it is present,
379    /// else `None`.
380    ///
381    /// Computes in **O(1)** time (average).
382    pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T>
383    where
384        Q: Hash + Equivalent<T>,
385    {
386        self.map.get_key_value(value).map(|(x, &())| x)
387    }
388
389    /// Return item index and value
390    pub fn get_full<Q: ?Sized>(&self, value: &Q) -> Option<(usize, &T)>
391    where
392        Q: Hash + Equivalent<T>,
393    {
394        self.map.get_full(value).map(|(i, x, &())| (i, x))
395    }
396
397    /// Return item index, if it exists in the set
398    pub fn get_index_of<Q: ?Sized>(&self, value: &Q) -> Option<usize>
399    where
400        Q: Hash + Equivalent<T>,
401    {
402        self.map.get_index_of(value)
403    }
404
405    /// Adds a value to the set, replacing the existing value, if any, that is
406    /// equal to the given one, without altering its insertion order. Returns
407    /// the replaced value.
408    ///
409    /// Computes in **O(1)** time (average).
410    pub fn replace(&mut self, value: T) -> Option<T> {
411        self.replace_full(value).1
412    }
413
414    /// Adds a value to the set, replacing the existing value, if any, that is
415    /// equal to the given one, without altering its insertion order. Returns
416    /// the index of the item and its replaced value.
417    ///
418    /// Computes in **O(1)** time (average).
419    pub fn replace_full(&mut self, value: T) -> (usize, Option<T>) {
420        use super::map::Entry::*;
421
422        match self.map.entry(value) {
423            Vacant(e) => {
424                let index = e.index();
425                e.insert(());
426                (index, None)
427            }
428            Occupied(e) => (e.index(), Some(e.replace_key())),
429        }
430    }
431
432    /// Remove the value from the set, and return `true` if it was present.
433    ///
434    /// **NOTE:** This is equivalent to `.swap_remove(value)`, if you want
435    /// to preserve the order of the values in the set, use `.shift_remove(value)`.
436    ///
437    /// Computes in **O(1)** time (average).
438    pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool
439    where
440        Q: Hash + Equivalent<T>,
441    {
442        self.swap_remove(value)
443    }
444
445    /// Remove the value from the set, and return `true` if it was present.
446    ///
447    /// Like `Vec::swap_remove`, the value is removed by swapping it with the
448    /// last element of the set and popping it off. **This perturbs
449    /// the position of what used to be the last element!**
450    ///
451    /// Return `false` if `value` was not in the set.
452    ///
453    /// Computes in **O(1)** time (average).
454    pub fn swap_remove<Q: ?Sized>(&mut self, value: &Q) -> bool
455    where
456        Q: Hash + Equivalent<T>,
457    {
458        self.map.swap_remove(value).is_some()
459    }
460
461    /// Remove the value from the set, and return `true` if it was present.
462    ///
463    /// Like `Vec::remove`, the value is removed by shifting all of the
464    /// elements that follow it, preserving their relative order.
465    /// **This perturbs the index of all of those elements!**
466    ///
467    /// Return `false` if `value` was not in the set.
468    ///
469    /// Computes in **O(n)** time (average).
470    pub fn shift_remove<Q: ?Sized>(&mut self, value: &Q) -> bool
471    where
472        Q: Hash + Equivalent<T>,
473    {
474        self.map.shift_remove(value).is_some()
475    }
476
477    /// Removes and returns the value in the set, if any, that is equal to the
478    /// given one.
479    ///
480    /// **NOTE:** This is equivalent to `.swap_take(value)`, if you need to
481    /// preserve the order of the values in the set, use `.shift_take(value)`
482    /// instead.
483    ///
484    /// Computes in **O(1)** time (average).
485    pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T>
486    where
487        Q: Hash + Equivalent<T>,
488    {
489        self.swap_take(value)
490    }
491
492    /// Removes and returns the value in the set, if any, that is equal to the
493    /// given one.
494    ///
495    /// Like `Vec::swap_remove`, the value is removed by swapping it with the
496    /// last element of the set and popping it off. **This perturbs
497    /// the position of what used to be the last element!**
498    ///
499    /// Return `None` if `value` was not in the set.
500    ///
501    /// Computes in **O(1)** time (average).
502    pub fn swap_take<Q: ?Sized>(&mut self, value: &Q) -> Option<T>
503    where
504        Q: Hash + Equivalent<T>,
505    {
506        self.map.swap_remove_entry(value).map(|(x, ())| x)
507    }
508
509    /// Removes and returns the value in the set, if any, that is equal to the
510    /// given one.
511    ///
512    /// Like `Vec::remove`, the value is removed by shifting all of the
513    /// elements that follow it, preserving their relative order.
514    /// **This perturbs the index of all of those elements!**
515    ///
516    /// Return `None` if `value` was not in the set.
517    ///
518    /// Computes in **O(n)** time (average).
519    pub fn shift_take<Q: ?Sized>(&mut self, value: &Q) -> Option<T>
520    where
521        Q: Hash + Equivalent<T>,
522    {
523        self.map.shift_remove_entry(value).map(|(x, ())| x)
524    }
525
526    /// Remove the value from the set return it and the index it had.
527    ///
528    /// Like `Vec::swap_remove`, the value is removed by swapping it with the
529    /// last element of the set and popping it off. **This perturbs
530    /// the position of what used to be the last element!**
531    ///
532    /// Return `None` if `value` was not in the set.
533    pub fn swap_remove_full<Q: ?Sized>(&mut self, value: &Q) -> Option<(usize, T)>
534    where
535        Q: Hash + Equivalent<T>,
536    {
537        self.map.swap_remove_full(value).map(|(i, x, ())| (i, x))
538    }
539
540    /// Remove the value from the set return it and the index it had.
541    ///
542    /// Like `Vec::remove`, the value is removed by shifting all of the
543    /// elements that follow it, preserving their relative order.
544    /// **This perturbs the index of all of those elements!**
545    ///
546    /// Return `None` if `value` was not in the set.
547    pub fn shift_remove_full<Q: ?Sized>(&mut self, value: &Q) -> Option<(usize, T)>
548    where
549        Q: Hash + Equivalent<T>,
550    {
551        self.map.shift_remove_full(value).map(|(i, x, ())| (i, x))
552    }
553
554    /// Remove the last value
555    ///
556    /// This preserves the order of the remaining elements.
557    ///
558    /// Computes in **O(1)** time (average).
559    pub fn pop(&mut self) -> Option<T> {
560        self.map.pop().map(|(x, ())| x)
561    }
562
563    /// Scan through each value in the set and keep those where the
564    /// closure `keep` returns `true`.
565    ///
566    /// The elements are visited in order, and remaining elements keep their
567    /// order.
568    ///
569    /// Computes in **O(n)** time (average).
570    pub fn retain<F>(&mut self, mut keep: F)
571    where
572        F: FnMut(&T) -> bool,
573    {
574        self.map.retain(move |x, &mut ()| keep(x))
575    }
576
577    /// Sort the set’s values by their default ordering.
578    ///
579    /// See [`sort_by`](Self::sort_by) for details.
580    pub fn sort(&mut self)
581    where
582        T: Ord,
583    {
584        self.map.sort_keys()
585    }
586
587    /// Sort the set’s values in place using the comparison function `cmp`.
588    ///
589    /// Computes in **O(n log n)** time and **O(n)** space. The sort is stable.
590    pub fn sort_by<F>(&mut self, mut cmp: F)
591    where
592        F: FnMut(&T, &T) -> Ordering,
593    {
594        self.map.sort_by(move |a, _, b, _| cmp(a, b));
595    }
596
597    /// Sort the values of the set and return a by-value iterator of
598    /// the values with the result.
599    ///
600    /// The sort is stable.
601    pub fn sorted_by<F>(self, mut cmp: F) -> IntoIter<T>
602    where
603        F: FnMut(&T, &T) -> Ordering,
604    {
605        let mut entries = self.into_entries();
606        entries.sort_by(move |a, b| cmp(&a.key, &b.key));
607        IntoIter {
608            iter: entries.into_iter(),
609        }
610    }
611
612    /// Sort the set's values by their default ordering.
613    ///
614    /// See [`sort_unstable_by`](Self::sort_unstable_by) for details.
615    pub fn sort_unstable(&mut self)
616    where
617        T: Ord,
618    {
619        self.map.sort_unstable_keys()
620    }
621
622    /// Sort the set's values in place using the comparison funtion `cmp`.
623    ///
624    /// Computes in **O(n log n)** time. The sort is unstable.
625    pub fn sort_unstable_by<F>(&mut self, mut cmp: F)
626    where
627        F: FnMut(&T, &T) -> Ordering,
628    {
629        self.map.sort_unstable_by(move |a, _, b, _| cmp(a, b))
630    }
631
632    /// Sort the values of the set and return a by-value iterator of
633    /// the values with the result.
634    pub fn sorted_unstable_by<F>(self, mut cmp: F) -> IntoIter<T>
635    where
636        F: FnMut(&T, &T) -> Ordering,
637    {
638        let mut entries = self.into_entries();
639        entries.sort_unstable_by(move |a, b| cmp(&a.key, &b.key));
640        IntoIter {
641            iter: entries.into_iter(),
642        }
643    }
644
645    /// Reverses the order of the set’s values in place.
646    ///
647    /// Computes in **O(n)** time and **O(1)** space.
648    pub fn reverse(&mut self) {
649        self.map.reverse()
650    }
651}
652
653impl<T, S> IndexSet<T, S> {
654    /// Get a value by index
655    ///
656    /// Valid indices are *0 <= index < self.len()*
657    ///
658    /// Computes in **O(1)** time.
659    pub fn get_index(&self, index: usize) -> Option<&T> {
660        self.as_entries().get(index).map(Bucket::key_ref)
661    }
662
663    /// Get the first value
664    ///
665    /// Computes in **O(1)** time.
666    pub fn first(&self) -> Option<&T> {
667        self.as_entries().first().map(Bucket::key_ref)
668    }
669
670    /// Get the last value
671    ///
672    /// Computes in **O(1)** time.
673    pub fn last(&self) -> Option<&T> {
674        self.as_entries().last().map(Bucket::key_ref)
675    }
676
677    /// Remove the value by index
678    ///
679    /// Valid indices are *0 <= index < self.len()*
680    ///
681    /// Like `Vec::swap_remove`, the value is removed by swapping it with the
682    /// last element of the set and popping it off. **This perturbs
683    /// the position of what used to be the last element!**
684    ///
685    /// Computes in **O(1)** time (average).
686    pub fn swap_remove_index(&mut self, index: usize) -> Option<T> {
687        self.map.swap_remove_index(index).map(|(x, ())| x)
688    }
689
690    /// Remove the value by index
691    ///
692    /// Valid indices are *0 <= index < self.len()*
693    ///
694    /// Like `Vec::remove`, the value is removed by shifting all of the
695    /// elements that follow it, preserving their relative order.
696    /// **This perturbs the index of all of those elements!**
697    ///
698    /// Computes in **O(n)** time (average).
699    pub fn shift_remove_index(&mut self, index: usize) -> Option<T> {
700        self.map.shift_remove_index(index).map(|(x, ())| x)
701    }
702
703    /// Moves the position of a value from one index to another
704    /// by shifting all other values in-between.
705    ///
706    /// * If `from < to`, the other values will shift down while the targeted value moves up.
707    /// * If `from > to`, the other values will shift up while the targeted value moves down.
708    ///
709    /// ***Panics*** if `from` or `to` are out of bounds.
710    ///
711    /// Computes in **O(n)** time (average).
712    pub fn move_index(&mut self, from: usize, to: usize) {
713        self.map.move_index(from, to)
714    }
715
716    /// Swaps the position of two values in the set.
717    ///
718    /// ***Panics*** if `a` or `b` are out of bounds.
719    pub fn swap_indices(&mut self, a: usize, b: usize) {
720        self.map.swap_indices(a, b)
721    }
722}
723
724/// Access `IndexSet` values at indexed positions.
725///
726/// # Examples
727///
728/// ```
729/// use indexmap::IndexSet;
730///
731/// let mut set = IndexSet::new();
732/// for word in "Lorem ipsum dolor sit amet".split_whitespace() {
733///     set.insert(word.to_string());
734/// }
735/// assert_eq!(set[0], "Lorem");
736/// assert_eq!(set[1], "ipsum");
737/// set.reverse();
738/// assert_eq!(set[0], "amet");
739/// assert_eq!(set[1], "sit");
740/// set.sort();
741/// assert_eq!(set[0], "Lorem");
742/// assert_eq!(set[1], "amet");
743/// ```
744///
745/// ```should_panic
746/// use indexmap::IndexSet;
747///
748/// let mut set = IndexSet::new();
749/// set.insert("foo");
750/// println!("{:?}", set[10]); // panics!
751/// ```
752impl<T, S> Index<usize> for IndexSet<T, S> {
753    type Output = T;
754
755    /// Returns a reference to the value at the supplied `index`.
756    ///
757    /// ***Panics*** if `index` is out of bounds.
758    fn index(&self, index: usize) -> &T {
759        self.get_index(index)
760            .expect("IndexSet: index out of bounds")
761    }
762}
763
764/// An owning iterator over the items of a `IndexSet`.
765///
766/// This `struct` is created by the [`into_iter`] method on [`IndexSet`]
767/// (provided by the `IntoIterator` trait). See its documentation for more.
768///
769/// [`IndexSet`]: struct.IndexSet.html
770/// [`into_iter`]: struct.IndexSet.html#method.into_iter
771pub struct IntoIter<T> {
772    iter: vec::IntoIter<Bucket<T>>,
773}
774
775impl<T> Iterator for IntoIter<T> {
776    type Item = T;
777
778    iterator_methods!(Bucket::key);
779}
780
781impl<T> DoubleEndedIterator for IntoIter<T> {
782    double_ended_iterator_methods!(Bucket::key);
783}
784
785impl<T> ExactSizeIterator for IntoIter<T> {
786    fn len(&self) -> usize {
787        self.iter.len()
788    }
789}
790
791impl<T> FusedIterator for IntoIter<T> {}
792
793impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
794    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
795        let iter = self.iter.as_slice().iter().map(Bucket::key_ref);
796        f.debug_list().entries(iter).finish()
797    }
798}
799
800/// An iterator over the items of a `IndexSet`.
801///
802/// This `struct` is created by the [`iter`] method on [`IndexSet`].
803/// See its documentation for more.
804///
805/// [`IndexSet`]: struct.IndexSet.html
806/// [`iter`]: struct.IndexSet.html#method.iter
807pub struct Iter<'a, T> {
808    iter: slice::Iter<'a, Bucket<T>>,
809}
810
811impl<'a, T> Iterator for Iter<'a, T> {
812    type Item = &'a T;
813
814    iterator_methods!(Bucket::key_ref);
815}
816
817impl<T> DoubleEndedIterator for Iter<'_, T> {
818    double_ended_iterator_methods!(Bucket::key_ref);
819}
820
821impl<T> ExactSizeIterator for Iter<'_, T> {
822    fn len(&self) -> usize {
823        self.iter.len()
824    }
825}
826
827impl<T> FusedIterator for Iter<'_, T> {}
828
829impl<T> Clone for Iter<'_, T> {
830    fn clone(&self) -> Self {
831        Iter {
832            iter: self.iter.clone(),
833        }
834    }
835}
836
837impl<T: fmt::Debug> fmt::Debug for Iter<'_, T> {
838    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
839        f.debug_list().entries(self.clone()).finish()
840    }
841}
842
843/// A draining iterator over the items of a `IndexSet`.
844///
845/// This `struct` is created by the [`drain`] method on [`IndexSet`].
846/// See its documentation for more.
847///
848/// [`IndexSet`]: struct.IndexSet.html
849/// [`drain`]: struct.IndexSet.html#method.drain
850pub struct Drain<'a, T> {
851    iter: vec::Drain<'a, Bucket<T>>,
852}
853
854impl<T> Iterator for Drain<'_, T> {
855    type Item = T;
856
857    iterator_methods!(Bucket::key);
858}
859
860impl<T> DoubleEndedIterator for Drain<'_, T> {
861    double_ended_iterator_methods!(Bucket::key);
862}
863
864impl<T> ExactSizeIterator for Drain<'_, T> {
865    fn len(&self) -> usize {
866        self.iter.len()
867    }
868}
869
870impl<T> FusedIterator for Drain<'_, T> {}
871
872impl<T: fmt::Debug> fmt::Debug for Drain<'_, T> {
873    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
874        let iter = self.iter.as_slice().iter().map(Bucket::key_ref);
875        f.debug_list().entries(iter).finish()
876    }
877}
878
879impl<'a, T, S> IntoIterator for &'a IndexSet<T, S> {
880    type Item = &'a T;
881    type IntoIter = Iter<'a, T>;
882
883    fn into_iter(self) -> Self::IntoIter {
884        self.iter()
885    }
886}
887
888impl<T, S> IntoIterator for IndexSet<T, S> {
889    type Item = T;
890    type IntoIter = IntoIter<T>;
891
892    fn into_iter(self) -> Self::IntoIter {
893        IntoIter {
894            iter: self.into_entries().into_iter(),
895        }
896    }
897}
898
899impl<T, S> FromIterator<T> for IndexSet<T, S>
900where
901    T: Hash + Eq,
902    S: BuildHasher + Default,
903{
904    fn from_iter<I: IntoIterator<Item = T>>(iterable: I) -> Self {
905        let iter = iterable.into_iter().map(|x| (x, ()));
906        IndexSet {
907            map: IndexMap::from_iter(iter),
908        }
909    }
910}
911
912#[cfg(has_std)]
913impl<T, const N: usize> From<[T; N]> for IndexSet<T, RandomState>
914where
915    T: Eq + Hash,
916{
917    /// # Examples
918    ///
919    /// ```
920    /// use indexmap::IndexSet;
921    ///
922    /// let set1 = IndexSet::from([1, 2, 3, 4]);
923    /// let set2: IndexSet<_> = [1, 2, 3, 4].into();
924    /// assert_eq!(set1, set2);
925    /// ```
926    fn from(arr: [T; N]) -> Self {
927        Self::from_iter(arr)
928    }
929}
930
931impl<T, S> Extend<T> for IndexSet<T, S>
932where
933    T: Hash + Eq,
934    S: BuildHasher,
935{
936    fn extend<I: IntoIterator<Item = T>>(&mut self, iterable: I) {
937        let iter = iterable.into_iter().map(|x| (x, ()));
938        self.map.extend(iter);
939    }
940}
941
942impl<'a, T, S> Extend<&'a T> for IndexSet<T, S>
943where
944    T: Hash + Eq + Copy + 'a,
945    S: BuildHasher,
946{
947    fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iterable: I) {
948        let iter = iterable.into_iter().copied();
949        self.extend(iter);
950    }
951}
952
953impl<T, S> Default for IndexSet<T, S>
954where
955    S: Default,
956{
957    /// Return an empty `IndexSet`
958    fn default() -> Self {
959        IndexSet {
960            map: IndexMap::default(),
961        }
962    }
963}
964
965impl<T, S1, S2> PartialEq<IndexSet<T, S2>> for IndexSet<T, S1>
966where
967    T: Hash + Eq,
968    S1: BuildHasher,
969    S2: BuildHasher,
970{
971    fn eq(&self, other: &IndexSet<T, S2>) -> bool {
972        self.len() == other.len() && self.is_subset(other)
973    }
974}
975
976impl<T, S> Eq for IndexSet<T, S>
977where
978    T: Eq + Hash,
979    S: BuildHasher,
980{
981}
982
983impl<T, S> IndexSet<T, S>
984where
985    T: Eq + Hash,
986    S: BuildHasher,
987{
988    /// Returns `true` if `self` has no elements in common with `other`.
989    pub fn is_disjoint<S2>(&self, other: &IndexSet<T, S2>) -> bool
990    where
991        S2: BuildHasher,
992    {
993        if self.len() <= other.len() {
994            self.iter().all(move |value| !other.contains(value))
995        } else {
996            other.iter().all(move |value| !self.contains(value))
997        }
998    }
999
1000    /// Returns `true` if all elements of `self` are contained in `other`.
1001    pub fn is_subset<S2>(&self, other: &IndexSet<T, S2>) -> bool
1002    where
1003        S2: BuildHasher,
1004    {
1005        self.len() <= other.len() && self.iter().all(move |value| other.contains(value))
1006    }
1007
1008    /// Returns `true` if all elements of `other` are contained in `self`.
1009    pub fn is_superset<S2>(&self, other: &IndexSet<T, S2>) -> bool
1010    where
1011        S2: BuildHasher,
1012    {
1013        other.is_subset(self)
1014    }
1015}
1016
1017/// A lazy iterator producing elements in the difference of `IndexSet`s.
1018///
1019/// This `struct` is created by the [`difference`] method on [`IndexSet`].
1020/// See its documentation for more.
1021///
1022/// [`IndexSet`]: struct.IndexSet.html
1023/// [`difference`]: struct.IndexSet.html#method.difference
1024pub struct Difference<'a, T, S> {
1025    iter: Iter<'a, T>,
1026    other: &'a IndexSet<T, S>,
1027}
1028
1029impl<'a, T, S> Iterator for Difference<'a, T, S>
1030where
1031    T: Eq + Hash,
1032    S: BuildHasher,
1033{
1034    type Item = &'a T;
1035
1036    fn next(&mut self) -> Option<Self::Item> {
1037        while let Some(item) = self.iter.next() {
1038            if !self.other.contains(item) {
1039                return Some(item);
1040            }
1041        }
1042        None
1043    }
1044
1045    fn size_hint(&self) -> (usize, Option<usize>) {
1046        (0, self.iter.size_hint().1)
1047    }
1048}
1049
1050impl<T, S> DoubleEndedIterator for Difference<'_, T, S>
1051where
1052    T: Eq + Hash,
1053    S: BuildHasher,
1054{
1055    fn next_back(&mut self) -> Option<Self::Item> {
1056        while let Some(item) = self.iter.next_back() {
1057            if !self.other.contains(item) {
1058                return Some(item);
1059            }
1060        }
1061        None
1062    }
1063}
1064
1065impl<T, S> FusedIterator for Difference<'_, T, S>
1066where
1067    T: Eq + Hash,
1068    S: BuildHasher,
1069{
1070}
1071
1072impl<T, S> Clone for Difference<'_, T, S> {
1073    fn clone(&self) -> Self {
1074        Difference {
1075            iter: self.iter.clone(),
1076            ..*self
1077        }
1078    }
1079}
1080
1081impl<T, S> fmt::Debug for Difference<'_, T, S>
1082where
1083    T: fmt::Debug + Eq + Hash,
1084    S: BuildHasher,
1085{
1086    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1087        f.debug_list().entries(self.clone()).finish()
1088    }
1089}
1090
1091/// A lazy iterator producing elements in the intersection of `IndexSet`s.
1092///
1093/// This `struct` is created by the [`intersection`] method on [`IndexSet`].
1094/// See its documentation for more.
1095///
1096/// [`IndexSet`]: struct.IndexSet.html
1097/// [`intersection`]: struct.IndexSet.html#method.intersection
1098pub struct Intersection<'a, T, S> {
1099    iter: Iter<'a, T>,
1100    other: &'a IndexSet<T, S>,
1101}
1102
1103impl<'a, T, S> Iterator for Intersection<'a, T, S>
1104where
1105    T: Eq + Hash,
1106    S: BuildHasher,
1107{
1108    type Item = &'a T;
1109
1110    fn next(&mut self) -> Option<Self::Item> {
1111        while let Some(item) = self.iter.next() {
1112            if self.other.contains(item) {
1113                return Some(item);
1114            }
1115        }
1116        None
1117    }
1118
1119    fn size_hint(&self) -> (usize, Option<usize>) {
1120        (0, self.iter.size_hint().1)
1121    }
1122}
1123
1124impl<T, S> DoubleEndedIterator for Intersection<'_, T, S>
1125where
1126    T: Eq + Hash,
1127    S: BuildHasher,
1128{
1129    fn next_back(&mut self) -> Option<Self::Item> {
1130        while let Some(item) = self.iter.next_back() {
1131            if self.other.contains(item) {
1132                return Some(item);
1133            }
1134        }
1135        None
1136    }
1137}
1138
1139impl<T, S> FusedIterator for Intersection<'_, T, S>
1140where
1141    T: Eq + Hash,
1142    S: BuildHasher,
1143{
1144}
1145
1146impl<T, S> Clone for Intersection<'_, T, S> {
1147    fn clone(&self) -> Self {
1148        Intersection {
1149            iter: self.iter.clone(),
1150            ..*self
1151        }
1152    }
1153}
1154
1155impl<T, S> fmt::Debug for Intersection<'_, T, S>
1156where
1157    T: fmt::Debug + Eq + Hash,
1158    S: BuildHasher,
1159{
1160    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1161        f.debug_list().entries(self.clone()).finish()
1162    }
1163}
1164
1165/// A lazy iterator producing elements in the symmetric difference of `IndexSet`s.
1166///
1167/// This `struct` is created by the [`symmetric_difference`] method on
1168/// [`IndexSet`]. See its documentation for more.
1169///
1170/// [`IndexSet`]: struct.IndexSet.html
1171/// [`symmetric_difference`]: struct.IndexSet.html#method.symmetric_difference
1172pub struct SymmetricDifference<'a, T, S1, S2> {
1173    iter: Chain<Difference<'a, T, S2>, Difference<'a, T, S1>>,
1174}
1175
1176impl<'a, T, S1, S2> Iterator for SymmetricDifference<'a, T, S1, S2>
1177where
1178    T: Eq + Hash,
1179    S1: BuildHasher,
1180    S2: BuildHasher,
1181{
1182    type Item = &'a T;
1183
1184    fn next(&mut self) -> Option<Self::Item> {
1185        self.iter.next()
1186    }
1187
1188    fn size_hint(&self) -> (usize, Option<usize>) {
1189        self.iter.size_hint()
1190    }
1191
1192    fn fold<B, F>(self, init: B, f: F) -> B
1193    where
1194        F: FnMut(B, Self::Item) -> B,
1195    {
1196        self.iter.fold(init, f)
1197    }
1198}
1199
1200impl<T, S1, S2> DoubleEndedIterator for SymmetricDifference<'_, T, S1, S2>
1201where
1202    T: Eq + Hash,
1203    S1: BuildHasher,
1204    S2: BuildHasher,
1205{
1206    fn next_back(&mut self) -> Option<Self::Item> {
1207        self.iter.next_back()
1208    }
1209
1210    fn rfold<B, F>(self, init: B, f: F) -> B
1211    where
1212        F: FnMut(B, Self::Item) -> B,
1213    {
1214        self.iter.rfold(init, f)
1215    }
1216}
1217
1218impl<T, S1, S2> FusedIterator for SymmetricDifference<'_, T, S1, S2>
1219where
1220    T: Eq + Hash,
1221    S1: BuildHasher,
1222    S2: BuildHasher,
1223{
1224}
1225
1226impl<T, S1, S2> Clone for SymmetricDifference<'_, T, S1, S2> {
1227    fn clone(&self) -> Self {
1228        SymmetricDifference {
1229            iter: self.iter.clone(),
1230        }
1231    }
1232}
1233
1234impl<T, S1, S2> fmt::Debug for SymmetricDifference<'_, T, S1, S2>
1235where
1236    T: fmt::Debug + Eq + Hash,
1237    S1: BuildHasher,
1238    S2: BuildHasher,
1239{
1240    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1241        f.debug_list().entries(self.clone()).finish()
1242    }
1243}
1244
1245/// A lazy iterator producing elements in the union of `IndexSet`s.
1246///
1247/// This `struct` is created by the [`union`] method on [`IndexSet`].
1248/// See its documentation for more.
1249///
1250/// [`IndexSet`]: struct.IndexSet.html
1251/// [`union`]: struct.IndexSet.html#method.union
1252pub struct Union<'a, T, S> {
1253    iter: Chain<Iter<'a, T>, Difference<'a, T, S>>,
1254}
1255
1256impl<'a, T, S> Iterator for Union<'a, T, S>
1257where
1258    T: Eq + Hash,
1259    S: BuildHasher,
1260{
1261    type Item = &'a T;
1262
1263    fn next(&mut self) -> Option<Self::Item> {
1264        self.iter.next()
1265    }
1266
1267    fn size_hint(&self) -> (usize, Option<usize>) {
1268        self.iter.size_hint()
1269    }
1270
1271    fn fold<B, F>(self, init: B, f: F) -> B
1272    where
1273        F: FnMut(B, Self::Item) -> B,
1274    {
1275        self.iter.fold(init, f)
1276    }
1277}
1278
1279impl<T, S> DoubleEndedIterator for Union<'_, T, S>
1280where
1281    T: Eq + Hash,
1282    S: BuildHasher,
1283{
1284    fn next_back(&mut self) -> Option<Self::Item> {
1285        self.iter.next_back()
1286    }
1287
1288    fn rfold<B, F>(self, init: B, f: F) -> B
1289    where
1290        F: FnMut(B, Self::Item) -> B,
1291    {
1292        self.iter.rfold(init, f)
1293    }
1294}
1295
1296impl<T, S> FusedIterator for Union<'_, T, S>
1297where
1298    T: Eq + Hash,
1299    S: BuildHasher,
1300{
1301}
1302
1303impl<T, S> Clone for Union<'_, T, S> {
1304    fn clone(&self) -> Self {
1305        Union {
1306            iter: self.iter.clone(),
1307        }
1308    }
1309}
1310
1311impl<T, S> fmt::Debug for Union<'_, T, S>
1312where
1313    T: fmt::Debug + Eq + Hash,
1314    S: BuildHasher,
1315{
1316    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1317        f.debug_list().entries(self.clone()).finish()
1318    }
1319}
1320
1321impl<T, S1, S2> BitAnd<&IndexSet<T, S2>> for &IndexSet<T, S1>
1322where
1323    T: Eq + Hash + Clone,
1324    S1: BuildHasher + Default,
1325    S2: BuildHasher,
1326{
1327    type Output = IndexSet<T, S1>;
1328
1329    /// Returns the set intersection, cloned into a new set.
1330    ///
1331    /// Values are collected in the same order that they appear in `self`.
1332    fn bitand(self, other: &IndexSet<T, S2>) -> Self::Output {
1333        self.intersection(other).cloned().collect()
1334    }
1335}
1336
1337impl<T, S1, S2> BitOr<&IndexSet<T, S2>> for &IndexSet<T, S1>
1338where
1339    T: Eq + Hash + Clone,
1340    S1: BuildHasher + Default,
1341    S2: BuildHasher,
1342{
1343    type Output = IndexSet<T, S1>;
1344
1345    /// Returns the set union, cloned into a new set.
1346    ///
1347    /// Values from `self` are collected in their original order, followed by
1348    /// values that are unique to `other` in their original order.
1349    fn bitor(self, other: &IndexSet<T, S2>) -> Self::Output {
1350        self.union(other).cloned().collect()
1351    }
1352}
1353
1354impl<T, S1, S2> BitXor<&IndexSet<T, S2>> for &IndexSet<T, S1>
1355where
1356    T: Eq + Hash + Clone,
1357    S1: BuildHasher + Default,
1358    S2: BuildHasher,
1359{
1360    type Output = IndexSet<T, S1>;
1361
1362    /// Returns the set symmetric-difference, cloned into a new set.
1363    ///
1364    /// Values from `self` are collected in their original order, followed by
1365    /// values from `other` in their original order.
1366    fn bitxor(self, other: &IndexSet<T, S2>) -> Self::Output {
1367        self.symmetric_difference(other).cloned().collect()
1368    }
1369}
1370
1371impl<T, S1, S2> Sub<&IndexSet<T, S2>> for &IndexSet<T, S1>
1372where
1373    T: Eq + Hash + Clone,
1374    S1: BuildHasher + Default,
1375    S2: BuildHasher,
1376{
1377    type Output = IndexSet<T, S1>;
1378
1379    /// Returns the set difference, cloned into a new set.
1380    ///
1381    /// Values are collected in the same order that they appear in `self`.
1382    fn sub(self, other: &IndexSet<T, S2>) -> Self::Output {
1383        self.difference(other).cloned().collect()
1384    }
1385}
1386
1387#[cfg(test)]
1388mod tests {
1389    use super::*;
1390    use std::string::String;
1391
1392    #[test]
1393    fn it_works() {
1394        let mut set = IndexSet::new();
1395        assert_eq!(set.is_empty(), true);
1396        set.insert(1);
1397        set.insert(1);
1398        assert_eq!(set.len(), 1);
1399        assert!(set.get(&1).is_some());
1400        assert_eq!(set.is_empty(), false);
1401    }
1402
1403    #[test]
1404    fn new() {
1405        let set = IndexSet::<String>::new();
1406        println!("{:?}", set);
1407        assert_eq!(set.capacity(), 0);
1408        assert_eq!(set.len(), 0);
1409        assert_eq!(set.is_empty(), true);
1410    }
1411
1412    #[test]
1413    fn insert() {
1414        let insert = [0, 4, 2, 12, 8, 7, 11, 5];
1415        let not_present = [1, 3, 6, 9, 10];
1416        let mut set = IndexSet::with_capacity(insert.len());
1417
1418        for (i, &elt) in insert.iter().enumerate() {
1419            assert_eq!(set.len(), i);
1420            set.insert(elt);
1421            assert_eq!(set.len(), i + 1);
1422            assert_eq!(set.get(&elt), Some(&elt));
1423        }
1424        println!("{:?}", set);
1425
1426        for &elt in &not_present {
1427            assert!(set.get(&elt).is_none());
1428        }
1429    }
1430
1431    #[test]
1432    fn insert_full() {
1433        let insert = vec![9, 2, 7, 1, 4, 6, 13];
1434        let present = vec![1, 6, 2];
1435        let mut set = IndexSet::with_capacity(insert.len());
1436
1437        for (i, &elt) in insert.iter().enumerate() {
1438            assert_eq!(set.len(), i);
1439            let (index, success) = set.insert_full(elt);
1440            assert!(success);
1441            assert_eq!(Some(index), set.get_full(&elt).map(|x| x.0));
1442            assert_eq!(set.len(), i + 1);
1443        }
1444
1445        let len = set.len();
1446        for &elt in &present {
1447            let (index, success) = set.insert_full(elt);
1448            assert!(!success);
1449            assert_eq!(Some(index), set.get_full(&elt).map(|x| x.0));
1450            assert_eq!(set.len(), len);
1451        }
1452    }
1453
1454    #[test]
1455    fn insert_2() {
1456        let mut set = IndexSet::with_capacity(16);
1457
1458        let mut values = vec![];
1459        values.extend(0..16);
1460        values.extend(if cfg!(miri) { 32..64 } else { 128..267 });
1461
1462        for &i in &values {
1463            let old_set = set.clone();
1464            set.insert(i);
1465            for value in old_set.iter() {
1466                if set.get(value).is_none() {
1467                    println!("old_set: {:?}", old_set);
1468                    println!("set: {:?}", set);
1469                    panic!("did not find {} in set", value);
1470                }
1471            }
1472        }
1473
1474        for &i in &values {
1475            assert!(set.get(&i).is_some(), "did not find {}", i);
1476        }
1477    }
1478
1479    #[test]
1480    fn insert_dup() {
1481        let mut elements = vec![0, 2, 4, 6, 8];
1482        let mut set: IndexSet<u8> = elements.drain(..).collect();
1483        {
1484            let (i, v) = set.get_full(&0).unwrap();
1485            assert_eq!(set.len(), 5);
1486            assert_eq!(i, 0);
1487            assert_eq!(*v, 0);
1488        }
1489        {
1490            let inserted = set.insert(0);
1491            let (i, v) = set.get_full(&0).unwrap();
1492            assert_eq!(set.len(), 5);
1493            assert_eq!(inserted, false);
1494            assert_eq!(i, 0);
1495            assert_eq!(*v, 0);
1496        }
1497    }
1498
1499    #[test]
1500    fn insert_order() {
1501        let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
1502        let mut set = IndexSet::new();
1503
1504        for &elt in &insert {
1505            set.insert(elt);
1506        }
1507
1508        assert_eq!(set.iter().count(), set.len());
1509        assert_eq!(set.iter().count(), insert.len());
1510        for (a, b) in insert.iter().zip(set.iter()) {
1511            assert_eq!(a, b);
1512        }
1513        for (i, v) in (0..insert.len()).zip(set.iter()) {
1514            assert_eq!(set.get_index(i).unwrap(), v);
1515        }
1516    }
1517
1518    #[test]
1519    fn replace() {
1520        let replace = [0, 4, 2, 12, 8, 7, 11, 5];
1521        let not_present = [1, 3, 6, 9, 10];
1522        let mut set = IndexSet::with_capacity(replace.len());
1523
1524        for (i, &elt) in replace.iter().enumerate() {
1525            assert_eq!(set.len(), i);
1526            set.replace(elt);
1527            assert_eq!(set.len(), i + 1);
1528            assert_eq!(set.get(&elt), Some(&elt));
1529        }
1530        println!("{:?}", set);
1531
1532        for &elt in &not_present {
1533            assert!(set.get(&elt).is_none());
1534        }
1535    }
1536
1537    #[test]
1538    fn replace_full() {
1539        let replace = vec![9, 2, 7, 1, 4, 6, 13];
1540        let present = vec![1, 6, 2];
1541        let mut set = IndexSet::with_capacity(replace.len());
1542
1543        for (i, &elt) in replace.iter().enumerate() {
1544            assert_eq!(set.len(), i);
1545            let (index, replaced) = set.replace_full(elt);
1546            assert!(replaced.is_none());
1547            assert_eq!(Some(index), set.get_full(&elt).map(|x| x.0));
1548            assert_eq!(set.len(), i + 1);
1549        }
1550
1551        let len = set.len();
1552        for &elt in &present {
1553            let (index, replaced) = set.replace_full(elt);
1554            assert_eq!(Some(elt), replaced);
1555            assert_eq!(Some(index), set.get_full(&elt).map(|x| x.0));
1556            assert_eq!(set.len(), len);
1557        }
1558    }
1559
1560    #[test]
1561    fn replace_2() {
1562        let mut set = IndexSet::with_capacity(16);
1563
1564        let mut values = vec![];
1565        values.extend(0..16);
1566        values.extend(if cfg!(miri) { 32..64 } else { 128..267 });
1567
1568        for &i in &values {
1569            let old_set = set.clone();
1570            set.replace(i);
1571            for value in old_set.iter() {
1572                if set.get(value).is_none() {
1573                    println!("old_set: {:?}", old_set);
1574                    println!("set: {:?}", set);
1575                    panic!("did not find {} in set", value);
1576                }
1577            }
1578        }
1579
1580        for &i in &values {
1581            assert!(set.get(&i).is_some(), "did not find {}", i);
1582        }
1583    }
1584
1585    #[test]
1586    fn replace_dup() {
1587        let mut elements = vec![0, 2, 4, 6, 8];
1588        let mut set: IndexSet<u8> = elements.drain(..).collect();
1589        {
1590            let (i, v) = set.get_full(&0).unwrap();
1591            assert_eq!(set.len(), 5);
1592            assert_eq!(i, 0);
1593            assert_eq!(*v, 0);
1594        }
1595        {
1596            let replaced = set.replace(0);
1597            let (i, v) = set.get_full(&0).unwrap();
1598            assert_eq!(set.len(), 5);
1599            assert_eq!(replaced, Some(0));
1600            assert_eq!(i, 0);
1601            assert_eq!(*v, 0);
1602        }
1603    }
1604
1605    #[test]
1606    fn replace_order() {
1607        let replace = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
1608        let mut set = IndexSet::new();
1609
1610        for &elt in &replace {
1611            set.replace(elt);
1612        }
1613
1614        assert_eq!(set.iter().count(), set.len());
1615        assert_eq!(set.iter().count(), replace.len());
1616        for (a, b) in replace.iter().zip(set.iter()) {
1617            assert_eq!(a, b);
1618        }
1619        for (i, v) in (0..replace.len()).zip(set.iter()) {
1620            assert_eq!(set.get_index(i).unwrap(), v);
1621        }
1622    }
1623
1624    #[test]
1625    fn grow() {
1626        let insert = [0, 4, 2, 12, 8, 7, 11];
1627        let not_present = [1, 3, 6, 9, 10];
1628        let mut set = IndexSet::with_capacity(insert.len());
1629
1630        for (i, &elt) in insert.iter().enumerate() {
1631            assert_eq!(set.len(), i);
1632            set.insert(elt);
1633            assert_eq!(set.len(), i + 1);
1634            assert_eq!(set.get(&elt), Some(&elt));
1635        }
1636
1637        println!("{:?}", set);
1638        for &elt in &insert {
1639            set.insert(elt * 10);
1640        }
1641        for &elt in &insert {
1642            set.insert(elt * 100);
1643        }
1644        for (i, &elt) in insert.iter().cycle().enumerate().take(100) {
1645            set.insert(elt * 100 + i as i32);
1646        }
1647        println!("{:?}", set);
1648        for &elt in &not_present {
1649            assert!(set.get(&elt).is_none());
1650        }
1651    }
1652
1653    #[test]
1654    fn reserve() {
1655        let mut set = IndexSet::<usize>::new();
1656        assert_eq!(set.capacity(), 0);
1657        set.reserve(100);
1658        let capacity = set.capacity();
1659        assert!(capacity >= 100);
1660        for i in 0..capacity {
1661            assert_eq!(set.len(), i);
1662            set.insert(i);
1663            assert_eq!(set.len(), i + 1);
1664            assert_eq!(set.capacity(), capacity);
1665            assert_eq!(set.get(&i), Some(&i));
1666        }
1667        set.insert(capacity);
1668        assert_eq!(set.len(), capacity + 1);
1669        assert!(set.capacity() > capacity);
1670        assert_eq!(set.get(&capacity), Some(&capacity));
1671    }
1672
1673    #[test]
1674    fn shrink_to_fit() {
1675        let mut set = IndexSet::<usize>::new();
1676        assert_eq!(set.capacity(), 0);
1677        for i in 0..100 {
1678            assert_eq!(set.len(), i);
1679            set.insert(i);
1680            assert_eq!(set.len(), i + 1);
1681            assert!(set.capacity() >= i + 1);
1682            assert_eq!(set.get(&i), Some(&i));
1683            set.shrink_to_fit();
1684            assert_eq!(set.len(), i + 1);
1685            assert_eq!(set.capacity(), i + 1);
1686            assert_eq!(set.get(&i), Some(&i));
1687        }
1688    }
1689
1690    #[test]
1691    fn remove() {
1692        let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
1693        let mut set = IndexSet::new();
1694
1695        for &elt in &insert {
1696            set.insert(elt);
1697        }
1698
1699        assert_eq!(set.iter().count(), set.len());
1700        assert_eq!(set.iter().count(), insert.len());
1701        for (a, b) in insert.iter().zip(set.iter()) {
1702            assert_eq!(a, b);
1703        }
1704
1705        let remove_fail = [99, 77];
1706        let remove = [4, 12, 8, 7];
1707
1708        for &value in &remove_fail {
1709            assert!(set.swap_remove_full(&value).is_none());
1710        }
1711        println!("{:?}", set);
1712        for &value in &remove {
1713            //println!("{:?}", set);
1714            let index = set.get_full(&value).unwrap().0;
1715            assert_eq!(set.swap_remove_full(&value), Some((index, value)));
1716        }
1717        println!("{:?}", set);
1718
1719        for value in &insert {
1720            assert_eq!(set.get(value).is_some(), !remove.contains(value));
1721        }
1722        assert_eq!(set.len(), insert.len() - remove.len());
1723        assert_eq!(set.iter().count(), insert.len() - remove.len());
1724    }
1725
1726    #[test]
1727    fn swap_remove_index() {
1728        let insert = [0, 4, 2, 12, 8, 7, 11, 5, 3, 17, 19, 22, 23];
1729        let mut set = IndexSet::new();
1730
1731        for &elt in &insert {
1732            set.insert(elt);
1733        }
1734
1735        let mut vector = insert.to_vec();
1736        let remove_sequence = &[3, 3, 10, 4, 5, 4, 3, 0, 1];
1737
1738        // check that the same swap remove sequence on vec and set
1739        // have the same result.
1740        for &rm in remove_sequence {
1741            let out_vec = vector.swap_remove(rm);
1742            let out_set = set.swap_remove_index(rm).unwrap();
1743            assert_eq!(out_vec, out_set);
1744        }
1745        assert_eq!(vector.len(), set.len());
1746        for (a, b) in vector.iter().zip(set.iter()) {
1747            assert_eq!(a, b);
1748        }
1749    }
1750
1751    #[test]
1752    fn partial_eq_and_eq() {
1753        let mut set_a = IndexSet::new();
1754        set_a.insert(1);
1755        set_a.insert(2);
1756        let mut set_b = set_a.clone();
1757        assert_eq!(set_a, set_b);
1758        set_b.swap_remove(&1);
1759        assert_ne!(set_a, set_b);
1760
1761        let set_c: IndexSet<_> = set_b.into_iter().collect();
1762        assert_ne!(set_a, set_c);
1763        assert_ne!(set_c, set_a);
1764    }
1765
1766    #[test]
1767    fn extend() {
1768        let mut set = IndexSet::new();
1769        set.extend(vec![&1, &2, &3, &4]);
1770        set.extend(vec![5, 6]);
1771        assert_eq!(set.into_iter().collect::<Vec<_>>(), vec![1, 2, 3, 4, 5, 6]);
1772    }
1773
1774    #[test]
1775    fn comparisons() {
1776        let set_a: IndexSet<_> = (0..3).collect();
1777        let set_b: IndexSet<_> = (3..6).collect();
1778        let set_c: IndexSet<_> = (0..6).collect();
1779        let set_d: IndexSet<_> = (3..9).collect();
1780
1781        assert!(!set_a.is_disjoint(&set_a));
1782        assert!(set_a.is_subset(&set_a));
1783        assert!(set_a.is_superset(&set_a));
1784
1785        assert!(set_a.is_disjoint(&set_b));
1786        assert!(set_b.is_disjoint(&set_a));
1787        assert!(!set_a.is_subset(&set_b));
1788        assert!(!set_b.is_subset(&set_a));
1789        assert!(!set_a.is_superset(&set_b));
1790        assert!(!set_b.is_superset(&set_a));
1791
1792        assert!(!set_a.is_disjoint(&set_c));
1793        assert!(!set_c.is_disjoint(&set_a));
1794        assert!(set_a.is_subset(&set_c));
1795        assert!(!set_c.is_subset(&set_a));
1796        assert!(!set_a.is_superset(&set_c));
1797        assert!(set_c.is_superset(&set_a));
1798
1799        assert!(!set_c.is_disjoint(&set_d));
1800        assert!(!set_d.is_disjoint(&set_c));
1801        assert!(!set_c.is_subset(&set_d));
1802        assert!(!set_d.is_subset(&set_c));
1803        assert!(!set_c.is_superset(&set_d));
1804        assert!(!set_d.is_superset(&set_c));
1805    }
1806
1807    #[test]
1808    fn iter_comparisons() {
1809        use std::iter::empty;
1810
1811        fn check<'a, I1, I2>(iter1: I1, iter2: I2)
1812        where
1813            I1: Iterator<Item = &'a i32>,
1814            I2: Iterator<Item = i32>,
1815        {
1816            assert!(iter1.copied().eq(iter2));
1817        }
1818
1819        let set_a: IndexSet<_> = (0..3).collect();
1820        let set_b: IndexSet<_> = (3..6).collect();
1821        let set_c: IndexSet<_> = (0..6).collect();
1822        let set_d: IndexSet<_> = (3..9).rev().collect();
1823
1824        check(set_a.difference(&set_a), empty());
1825        check(set_a.symmetric_difference(&set_a), empty());
1826        check(set_a.intersection(&set_a), 0..3);
1827        check(set_a.union(&set_a), 0..3);
1828
1829        check(set_a.difference(&set_b), 0..3);
1830        check(set_b.difference(&set_a), 3..6);
1831        check(set_a.symmetric_difference(&set_b), 0..6);
1832        check(set_b.symmetric_difference(&set_a), (3..6).chain(0..3));
1833        check(set_a.intersection(&set_b), empty());
1834        check(set_b.intersection(&set_a), empty());
1835        check(set_a.union(&set_b), 0..6);
1836        check(set_b.union(&set_a), (3..6).chain(0..3));
1837
1838        check(set_a.difference(&set_c), empty());
1839        check(set_c.difference(&set_a), 3..6);
1840        check(set_a.symmetric_difference(&set_c), 3..6);
1841        check(set_c.symmetric_difference(&set_a), 3..6);
1842        check(set_a.intersection(&set_c), 0..3);
1843        check(set_c.intersection(&set_a), 0..3);
1844        check(set_a.union(&set_c), 0..6);
1845        check(set_c.union(&set_a), 0..6);
1846
1847        check(set_c.difference(&set_d), 0..3);
1848        check(set_d.difference(&set_c), (6..9).rev());
1849        check(
1850            set_c.symmetric_difference(&set_d),
1851            (0..3).chain((6..9).rev()),
1852        );
1853        check(set_d.symmetric_difference(&set_c), (6..9).rev().chain(0..3));
1854        check(set_c.intersection(&set_d), 3..6);
1855        check(set_d.intersection(&set_c), (3..6).rev());
1856        check(set_c.union(&set_d), (0..6).chain((6..9).rev()));
1857        check(set_d.union(&set_c), (3..9).rev().chain(0..3));
1858    }
1859
1860    #[test]
1861    fn ops() {
1862        let empty = IndexSet::<i32>::new();
1863        let set_a: IndexSet<_> = (0..3).collect();
1864        let set_b: IndexSet<_> = (3..6).collect();
1865        let set_c: IndexSet<_> = (0..6).collect();
1866        let set_d: IndexSet<_> = (3..9).rev().collect();
1867
1868        #[allow(clippy::eq_op)]
1869        {
1870            assert_eq!(&set_a & &set_a, set_a);
1871            assert_eq!(&set_a | &set_a, set_a);
1872            assert_eq!(&set_a ^ &set_a, empty);
1873            assert_eq!(&set_a - &set_a, empty);
1874        }
1875
1876        assert_eq!(&set_a & &set_b, empty);
1877        assert_eq!(&set_b & &set_a, empty);
1878        assert_eq!(&set_a | &set_b, set_c);
1879        assert_eq!(&set_b | &set_a, set_c);
1880        assert_eq!(&set_a ^ &set_b, set_c);
1881        assert_eq!(&set_b ^ &set_a, set_c);
1882        assert_eq!(&set_a - &set_b, set_a);
1883        assert_eq!(&set_b - &set_a, set_b);
1884
1885        assert_eq!(&set_a & &set_c, set_a);
1886        assert_eq!(&set_c & &set_a, set_a);
1887        assert_eq!(&set_a | &set_c, set_c);
1888        assert_eq!(&set_c | &set_a, set_c);
1889        assert_eq!(&set_a ^ &set_c, set_b);
1890        assert_eq!(&set_c ^ &set_a, set_b);
1891        assert_eq!(&set_a - &set_c, empty);
1892        assert_eq!(&set_c - &set_a, set_b);
1893
1894        assert_eq!(&set_c & &set_d, set_b);
1895        assert_eq!(&set_d & &set_c, set_b);
1896        assert_eq!(&set_c | &set_d, &set_a | &set_d);
1897        assert_eq!(&set_d | &set_c, &set_a | &set_d);
1898        assert_eq!(&set_c ^ &set_d, &set_a | &(&set_d - &set_b));
1899        assert_eq!(&set_d ^ &set_c, &set_a | &(&set_d - &set_b));
1900        assert_eq!(&set_c - &set_d, set_a);
1901        assert_eq!(&set_d - &set_c, &set_d - &set_b);
1902    }
1903
1904    #[test]
1905    #[cfg(has_std)]
1906    fn from_array() {
1907        let set1 = IndexSet::from([1, 2, 3, 4]);
1908        let set2: IndexSet<_> = [1, 2, 3, 4].into();
1909
1910        assert_eq!(set1, set2);
1911    }
1912}
indexmap/set.rs

indexmap/
set.rs
