1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // ignore-lexer-test FIXME #15883
13 use borrow::BorrowFrom;
15 use cmp::{Eq, PartialEq};
16 use core::kinds::Sized;
20 use hash::{Hash, Hasher, RandomSipHasher};
21 use iter::{Iterator, IteratorExt, IteratorCloneExt, FromIterator, Map, Chain, Extend};
22 use ops::{BitOr, BitAnd, BitXor, Sub};
23 use option::Option::{Some, None, self};
24 use result::Result::{Ok, Err};
26 use super::map::{self, HashMap, Keys, INITIAL_CAPACITY};
28 // Future Optimization (FIXME!)
29 // =============================
31 // Iteration over zero sized values is a noop. There is no need
32 // for `bucket.val` in the case of HashSet. I suppose we would need HKT
33 // to get rid of it properly.
35 /// An implementation of a hash set using the underlying representation of a
36 /// HashMap where the value is (). As with the `HashMap` type, a `HashSet`
37 /// requires that the elements implement the `Eq` and `Hash` traits.
42 /// use std::collections::HashSet;
43 /// // Type inference lets us omit an explicit type signature (which
44 /// // would be `HashSet<&str>` in this example).
45 /// let mut books = HashSet::new();
47 /// // Add some books.
48 /// books.insert("A Dance With Dragons");
49 /// books.insert("To Kill a Mockingbird");
50 /// books.insert("The Odyssey");
51 /// books.insert("The Great Gatsby");
53 /// // Check for a specific one.
54 /// if !books.contains(&("The Winds of Winter")) {
55 /// println!("We have {} books, but The Winds of Winter ain't one.",
60 /// books.remove(&"The Odyssey");
62 /// // Iterate over everything.
63 /// for book in books.iter() {
64 /// println!("{}", *book);
68 /// The easiest way to use `HashSet` with a custom type is to derive
69 /// `Eq` and `Hash`. We must also derive `PartialEq`, this will in the
70 /// future be implied by `Eq`.
73 /// use std::collections::HashSet;
74 /// #[derive(Hash, Eq, PartialEq, Show)]
75 /// struct Viking<'a> {
80 /// let mut vikings = HashSet::new();
82 /// vikings.insert(Viking { name: "Einar", power: 9u });
83 /// vikings.insert(Viking { name: "Einar", power: 9u });
84 /// vikings.insert(Viking { name: "Olaf", power: 4u });
85 /// vikings.insert(Viking { name: "Harald", power: 8u });
87 /// // Use derived implementation to print the vikings.
88 /// for x in vikings.iter() {
89 /// println!("{}", x);
94 pub struct HashSet<T, H = RandomSipHasher> {
95 map: HashMap<T, (), H>
98 impl<T: Hash + Eq> HashSet<T, RandomSipHasher> {
99 /// Create an empty HashSet.
104 /// use std::collections::HashSet;
105 /// let mut set: HashSet<int> = HashSet::new();
109 pub fn new() -> HashSet<T, RandomSipHasher> {
110 HashSet::with_capacity(INITIAL_CAPACITY)
113 /// Create an empty HashSet with space for at least `n` elements in
119 /// use std::collections::HashSet;
120 /// let mut set: HashSet<int> = HashSet::with_capacity(10);
124 pub fn with_capacity(capacity: uint) -> HashSet<T, RandomSipHasher> {
125 HashSet { map: HashMap::with_capacity(capacity) }
129 impl<T: Eq + Hash<S>, S, H: Hasher<S>> HashSet<T, H> {
130 /// Creates a new empty hash set which will use the given hasher to hash
133 /// The hash set is also created with the default initial capacity.
138 /// use std::collections::HashSet;
139 /// use std::hash::sip::SipHasher;
141 /// let h = SipHasher::new();
142 /// let mut set = HashSet::with_hasher(h);
146 #[unstable = "hasher stuff is unclear"]
147 pub fn with_hasher(hasher: H) -> HashSet<T, H> {
148 HashSet::with_capacity_and_hasher(INITIAL_CAPACITY, hasher)
151 /// Create an empty HashSet with space for at least `capacity`
152 /// elements in the hash table, using `hasher` to hash the keys.
154 /// Warning: `hasher` is normally randomly generated, and
155 /// is designed to allow `HashSet`s to be resistant to attacks that
156 /// cause many collisions and very poor performance. Setting it
157 /// manually using this function can expose a DoS attack vector.
162 /// use std::collections::HashSet;
163 /// use std::hash::sip::SipHasher;
165 /// let h = SipHasher::new();
166 /// let mut set = HashSet::with_capacity_and_hasher(10u, h);
170 #[unstable = "hasher stuff is unclear"]
171 pub fn with_capacity_and_hasher(capacity: uint, hasher: H) -> HashSet<T, H> {
172 HashSet { map: HashMap::with_capacity_and_hasher(capacity, hasher) }
175 /// Returns the number of elements the set can hold without reallocating.
180 /// use std::collections::HashSet;
181 /// let set: HashSet<int> = HashSet::with_capacity(100);
182 /// assert!(set.capacity() >= 100);
186 pub fn capacity(&self) -> uint {
190 /// Reserves capacity for at least `additional` more elements to be inserted
191 /// in the `HashSet`. The collection may reserve more space to avoid
192 /// frequent reallocations.
196 /// Panics if the new allocation size overflows `uint`.
201 /// use std::collections::HashSet;
202 /// let mut set: HashSet<int> = HashSet::new();
206 pub fn reserve(&mut self, additional: uint) {
207 self.map.reserve(additional)
210 /// Shrinks the capacity of the set as much as possible. It will drop
211 /// down as much as possible while maintaining the internal rules
212 /// and possibly leaving some space in accordance with the resize policy.
217 /// use std::collections::HashSet;
219 /// let mut set: HashSet<int> = HashSet::with_capacity(100);
222 /// assert!(set.capacity() >= 100);
223 /// set.shrink_to_fit();
224 /// assert!(set.capacity() >= 2);
227 pub fn shrink_to_fit(&mut self) {
228 self.map.shrink_to_fit()
231 /// An iterator visiting all elements in arbitrary order.
232 /// Iterator element type is &'a T.
237 /// use std::collections::HashSet;
238 /// let mut set = HashSet::new();
242 /// // Will print in an arbitrary order.
243 /// for x in set.iter() {
244 /// println!("{}", x);
248 pub fn iter(&self) -> Iter<T> {
249 Iter { iter: self.map.keys() }
252 /// Creates a consuming iterator, that is, one that moves each value out
253 /// of the set in arbitrary order. The set cannot be used after calling
259 /// use std::collections::HashSet;
260 /// let mut set = HashSet::new();
261 /// set.insert("a".to_string());
262 /// set.insert("b".to_string());
264 /// // Not possible to collect to a Vec<String> with a regular `.iter()`.
265 /// let v: Vec<String> = set.into_iter().collect();
267 /// // Will print in an arbitrary order.
268 /// for x in v.iter() {
269 /// println!("{}", x);
273 pub fn into_iter(self) -> IntoIter<T> {
274 fn first<A, B>((a, _): (A, B)) -> A { a }
275 let first: fn((T, ())) -> T = first;
277 IntoIter { iter: self.map.into_iter().map(first) }
280 /// Visit the values representing the difference.
285 /// use std::collections::HashSet;
286 /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
287 /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
289 /// // Can be seen as `a - b`.
290 /// for x in a.difference(&b) {
291 /// println!("{}", x); // Print 1
294 /// let diff: HashSet<int> = a.difference(&b).map(|&x| x).collect();
295 /// assert_eq!(diff, [1i].iter().map(|&x| x).collect());
297 /// // Note that difference is not symmetric,
298 /// // and `b - a` means something else:
299 /// let diff: HashSet<int> = b.difference(&a).map(|&x| x).collect();
300 /// assert_eq!(diff, [4i].iter().map(|&x| x).collect());
303 pub fn difference<'a>(&'a self, other: &'a HashSet<T, H>) -> Difference<'a, T, H> {
310 /// Visit the values representing the symmetric difference.
315 /// use std::collections::HashSet;
316 /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
317 /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
319 /// // Print 1, 4 in arbitrary order.
320 /// for x in a.symmetric_difference(&b) {
321 /// println!("{}", x);
324 /// let diff1: HashSet<int> = a.symmetric_difference(&b).map(|&x| x).collect();
325 /// let diff2: HashSet<int> = b.symmetric_difference(&a).map(|&x| x).collect();
327 /// assert_eq!(diff1, diff2);
328 /// assert_eq!(diff1, [1i, 4].iter().map(|&x| x).collect());
331 pub fn symmetric_difference<'a>(&'a self, other: &'a HashSet<T, H>)
332 -> SymmetricDifference<'a, T, H> {
333 SymmetricDifference { iter: self.difference(other).chain(other.difference(self)) }
336 /// Visit the values representing the intersection.
341 /// use std::collections::HashSet;
342 /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
343 /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
345 /// // Print 2, 3 in arbitrary order.
346 /// for x in a.intersection(&b) {
347 /// println!("{}", x);
350 /// let diff: HashSet<int> = a.intersection(&b).map(|&x| x).collect();
351 /// assert_eq!(diff, [2i, 3].iter().map(|&x| x).collect());
354 pub fn intersection<'a>(&'a self, other: &'a HashSet<T, H>) -> Intersection<'a, T, H> {
361 /// Visit the values representing the union.
366 /// use std::collections::HashSet;
367 /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
368 /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
370 /// // Print 1, 2, 3, 4 in arbitrary order.
371 /// for x in a.union(&b) {
372 /// println!("{}", x);
375 /// let diff: HashSet<int> = a.union(&b).map(|&x| x).collect();
376 /// assert_eq!(diff, [1i, 2, 3, 4].iter().map(|&x| x).collect());
379 pub fn union<'a>(&'a self, other: &'a HashSet<T, H>) -> Union<'a, T, H> {
380 Union { iter: self.iter().chain(other.difference(self)) }
383 /// Return the number of elements in the set
388 /// use std::collections::HashSet;
390 /// let mut v = HashSet::new();
391 /// assert_eq!(v.len(), 0);
393 /// assert_eq!(v.len(), 1);
396 pub fn len(&self) -> uint { self.map.len() }
398 /// Returns true if the set contains no elements
403 /// use std::collections::HashSet;
405 /// let mut v = HashSet::new();
406 /// assert!(v.is_empty());
408 /// assert!(!v.is_empty());
411 pub fn is_empty(&self) -> bool { self.map.len() == 0 }
413 /// Clears the set, returning all elements in an iterator.
415 #[unstable = "matches collection reform specification, waiting for dust to settle"]
416 pub fn drain(&mut self) -> Drain<T> {
417 fn first<A, B>((a, _): (A, B)) -> A { a }
418 let first: fn((T, ())) -> T = first; // coerce to fn pointer
420 Drain { iter: self.map.drain().map(first) }
423 /// Clears the set, removing all values.
428 /// use std::collections::HashSet;
430 /// let mut v = HashSet::new();
433 /// assert!(v.is_empty());
436 pub fn clear(&mut self) { self.map.clear() }
438 /// Returns `true` if the set contains a value.
440 /// The value may be any borrowed form of the set's value type, but
441 /// `Hash` and `Eq` on the borrowed form *must* match those for
447 /// use std::collections::HashSet;
449 /// let set: HashSet<uint> = [1, 2, 3].iter().map(|&x| x).collect();
450 /// assert_eq!(set.contains(&1), true);
451 /// assert_eq!(set.contains(&4), false);
454 pub fn contains<Sized? Q>(&self, value: &Q) -> bool
455 where Q: BorrowFrom<T> + Hash<S> + Eq
457 self.map.contains_key(value)
460 /// Returns `true` if the set has no elements in common with `other`.
461 /// This is equivalent to checking for an empty intersection.
466 /// use std::collections::HashSet;
468 /// let a: HashSet<uint> = [1, 2, 3].iter().map(|&x| x).collect();
469 /// let mut b: HashSet<uint> = HashSet::new();
471 /// assert_eq!(a.is_disjoint(&b), true);
473 /// assert_eq!(a.is_disjoint(&b), true);
475 /// assert_eq!(a.is_disjoint(&b), false);
478 pub fn is_disjoint(&self, other: &HashSet<T, H>) -> bool {
479 self.iter().all(|v| !other.contains(v))
482 /// Returns `true` if the set is a subset of another.
487 /// use std::collections::HashSet;
489 /// let sup: HashSet<uint> = [1, 2, 3].iter().map(|&x| x).collect();
490 /// let mut set: HashSet<uint> = HashSet::new();
492 /// assert_eq!(set.is_subset(&sup), true);
494 /// assert_eq!(set.is_subset(&sup), true);
496 /// assert_eq!(set.is_subset(&sup), false);
499 pub fn is_subset(&self, other: &HashSet<T, H>) -> bool {
500 self.iter().all(|v| other.contains(v))
503 /// Returns `true` if the set is a superset of another.
508 /// use std::collections::HashSet;
510 /// let sub: HashSet<uint> = [1, 2].iter().map(|&x| x).collect();
511 /// let mut set: HashSet<uint> = HashSet::new();
513 /// assert_eq!(set.is_superset(&sub), false);
517 /// assert_eq!(set.is_superset(&sub), false);
520 /// assert_eq!(set.is_superset(&sub), true);
524 pub fn is_superset(&self, other: &HashSet<T, H>) -> bool {
525 other.is_subset(self)
528 /// Adds a value to the set. Returns `true` if the value was not already
529 /// present in the set.
534 /// use std::collections::HashSet;
536 /// let mut set = HashSet::new();
538 /// assert_eq!(set.insert(2u), true);
539 /// assert_eq!(set.insert(2), false);
540 /// assert_eq!(set.len(), 1);
543 pub fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()).is_none() }
545 /// Removes a value from the set. Returns `true` if the value was
546 /// present in the set.
548 /// The value may be any borrowed form of the set's value type, but
549 /// `Hash` and `Eq` on the borrowed form *must* match those for
555 /// use std::collections::HashSet;
557 /// let mut set = HashSet::new();
560 /// assert_eq!(set.remove(&2), true);
561 /// assert_eq!(set.remove(&2), false);
564 pub fn remove<Sized? Q>(&mut self, value: &Q) -> bool
565 where Q: BorrowFrom<T> + Hash<S> + Eq
567 self.map.remove(value).is_some()
572 impl<T: Eq + Hash<S>, S, H: Hasher<S>> PartialEq for HashSet<T, H> {
573 fn eq(&self, other: &HashSet<T, H>) -> bool {
574 if self.len() != other.len() { return false; }
576 self.iter().all(|key| other.contains(key))
581 impl<T: Eq + Hash<S>, S, H: Hasher<S>> Eq for HashSet<T, H> {}
584 impl<T: Eq + Hash<S> + fmt::Show, S, H: Hasher<S>> fmt::Show for HashSet<T, H> {
585 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
586 try!(write!(f, "{{"));
588 for (i, x) in self.iter().enumerate() {
589 if i != 0 { try!(write!(f, ", ")); }
590 try!(write!(f, "{}", *x));
598 impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> FromIterator<T> for HashSet<T, H> {
599 fn from_iter<I: Iterator<Item=T>>(iter: I) -> HashSet<T, H> {
600 let lower = iter.size_hint().0;
601 let mut set = HashSet::with_capacity_and_hasher(lower, Default::default());
608 impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> Extend<T> for HashSet<T, H> {
609 fn extend<I: Iterator<Item=T>>(&mut self, mut iter: I) {
617 impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> Default for HashSet<T, H> {
619 fn default() -> HashSet<T, H> {
620 HashSet::with_hasher(Default::default())
625 impl<'a, 'b, T: Eq + Hash<S> + Clone, S, H: Hasher<S> + Default>
626 BitOr<&'b HashSet<T, H>> for &'a HashSet<T, H> {
627 type Output = HashSet<T, H>;
629 /// Returns the union of `self` and `rhs` as a new `HashSet<T, H>`.
634 /// use std::collections::HashSet;
636 /// let a: HashSet<int> = vec![1, 2, 3].into_iter().collect();
637 /// let b: HashSet<int> = vec![3, 4, 5].into_iter().collect();
639 /// let set: HashSet<int> = &a | &b;
642 /// let expected = [1, 2, 3, 4, 5];
643 /// for x in set.iter() {
644 /// assert!(expected.contains(x));
647 /// assert_eq!(i, expected.len());
649 fn bitor(self, rhs: &HashSet<T, H>) -> HashSet<T, H> {
650 self.union(rhs).cloned().collect()
655 impl<'a, 'b, T: Eq + Hash<S> + Clone, S, H: Hasher<S> + Default>
656 BitAnd<&'b HashSet<T, H>> for &'a HashSet<T, H> {
657 type Output = HashSet<T, H>;
659 /// Returns the intersection of `self` and `rhs` as a new `HashSet<T, H>`.
664 /// use std::collections::HashSet;
666 /// let a: HashSet<int> = vec![1, 2, 3].into_iter().collect();
667 /// let b: HashSet<int> = vec![2, 3, 4].into_iter().collect();
669 /// let set: HashSet<int> = &a & &b;
672 /// let expected = [2, 3];
673 /// for x in set.iter() {
674 /// assert!(expected.contains(x));
677 /// assert_eq!(i, expected.len());
679 fn bitand(self, rhs: &HashSet<T, H>) -> HashSet<T, H> {
680 self.intersection(rhs).cloned().collect()
685 impl<'a, 'b, T: Eq + Hash<S> + Clone, S, H: Hasher<S> + Default>
686 BitXor<&'b HashSet<T, H>> for &'a HashSet<T, H> {
687 type Output = HashSet<T, H>;
689 /// Returns the symmetric difference of `self` and `rhs` as a new `HashSet<T, H>`.
694 /// use std::collections::HashSet;
696 /// let a: HashSet<int> = vec![1, 2, 3].into_iter().collect();
697 /// let b: HashSet<int> = vec![3, 4, 5].into_iter().collect();
699 /// let set: HashSet<int> = &a ^ &b;
702 /// let expected = [1, 2, 4, 5];
703 /// for x in set.iter() {
704 /// assert!(expected.contains(x));
707 /// assert_eq!(i, expected.len());
709 fn bitxor(self, rhs: &HashSet<T, H>) -> HashSet<T, H> {
710 self.symmetric_difference(rhs).cloned().collect()
715 impl<'a, 'b, T: Eq + Hash<S> + Clone, S, H: Hasher<S> + Default>
716 Sub<&'b HashSet<T, H>> for &'a HashSet<T, H> {
717 type Output = HashSet<T, H>;
719 /// Returns the difference of `self` and `rhs` as a new `HashSet<T, H>`.
724 /// use std::collections::HashSet;
726 /// let a: HashSet<int> = vec![1, 2, 3].into_iter().collect();
727 /// let b: HashSet<int> = vec![3, 4, 5].into_iter().collect();
729 /// let set: HashSet<int> = &a - &b;
732 /// let expected = [1, 2];
733 /// for x in set.iter() {
734 /// assert!(expected.contains(x));
737 /// assert_eq!(i, expected.len());
739 fn sub(self, rhs: &HashSet<T, H>) -> HashSet<T, H> {
740 self.difference(rhs).cloned().collect()
746 pub struct Iter<'a, K: 'a> {
747 iter: Keys<'a, K, ()>
750 /// HashSet move iterator
752 pub struct IntoIter<K> {
753 iter: Map<(K, ()), K, map::IntoIter<K, ()>, fn((K, ())) -> K>
756 /// HashSet drain iterator
758 pub struct Drain<'a, K: 'a> {
759 iter: Map<(K, ()), K, map::Drain<'a, K, ()>, fn((K, ())) -> K>,
762 /// Intersection iterator
764 pub struct Intersection<'a, T: 'a, H: 'a> {
765 // iterator of the first set
768 other: &'a HashSet<T, H>,
771 /// Difference iterator
773 pub struct Difference<'a, T: 'a, H: 'a> {
774 // iterator of the first set
777 other: &'a HashSet<T, H>,
780 /// Symmetric difference iterator.
782 pub struct SymmetricDifference<'a, T: 'a, H: 'a> {
783 iter: Chain<Difference<'a, T, H>, Difference<'a, T, H>>
786 /// Set union iterator.
788 pub struct Union<'a, T: 'a, H: 'a> {
789 iter: Chain<Iter<'a, T>, Difference<'a, T, H>>
793 impl<'a, K> Iterator for Iter<'a, K> {
796 fn next(&mut self) -> Option<&'a K> { self.iter.next() }
797 fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() }
801 impl<K> Iterator for IntoIter<K> {
804 fn next(&mut self) -> Option<K> { self.iter.next() }
805 fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() }
809 impl<'a, K: 'a> Iterator for Drain<'a, K> {
812 fn next(&mut self) -> Option<K> { self.iter.next() }
813 fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() }
817 impl<'a, T, S, H> Iterator for Intersection<'a, T, H>
818 where T: Eq + Hash<S>, H: Hasher<S>
822 fn next(&mut self) -> Option<&'a T> {
824 match self.iter.next() {
826 Some(elt) => if self.other.contains(elt) {
833 fn size_hint(&self) -> (uint, Option<uint>) {
834 let (_, upper) = self.iter.size_hint();
840 impl<'a, T, S, H> Iterator for Difference<'a, T, H>
841 where T: Eq + Hash<S>, H: Hasher<S>
845 fn next(&mut self) -> Option<&'a T> {
847 match self.iter.next() {
849 Some(elt) => if !self.other.contains(elt) {
856 fn size_hint(&self) -> (uint, Option<uint>) {
857 let (_, upper) = self.iter.size_hint();
863 impl<'a, T, S, H> Iterator for SymmetricDifference<'a, T, H>
864 where T: Eq + Hash<S>, H: Hasher<S>
868 fn next(&mut self) -> Option<&'a T> { self.iter.next() }
869 fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() }
873 impl<'a, T, S, H> Iterator for Union<'a, T, H>
874 where T: Eq + Hash<S>, H: Hasher<S>
878 fn next(&mut self) -> Option<&'a T> { self.iter.next() }
879 fn size_hint(&self) -> (uint, Option<uint>) { self.iter.size_hint() }
890 let mut xs = HashSet::new();
891 let mut ys = HashSet::new();
892 assert!(xs.is_disjoint(&ys));
893 assert!(ys.is_disjoint(&xs));
894 assert!(xs.insert(5i));
895 assert!(ys.insert(11i));
896 assert!(xs.is_disjoint(&ys));
897 assert!(ys.is_disjoint(&xs));
898 assert!(xs.insert(7));
899 assert!(xs.insert(19));
900 assert!(xs.insert(4));
901 assert!(ys.insert(2));
902 assert!(ys.insert(-11));
903 assert!(xs.is_disjoint(&ys));
904 assert!(ys.is_disjoint(&xs));
905 assert!(ys.insert(7));
906 assert!(!xs.is_disjoint(&ys));
907 assert!(!ys.is_disjoint(&xs));
911 fn test_subset_and_superset() {
912 let mut a = HashSet::new();
913 assert!(a.insert(0i));
914 assert!(a.insert(5));
915 assert!(a.insert(11));
916 assert!(a.insert(7));
918 let mut b = HashSet::new();
919 assert!(b.insert(0i));
920 assert!(b.insert(7));
921 assert!(b.insert(19));
922 assert!(b.insert(250));
923 assert!(b.insert(11));
924 assert!(b.insert(200));
926 assert!(!a.is_subset(&b));
927 assert!(!a.is_superset(&b));
928 assert!(!b.is_subset(&a));
929 assert!(!b.is_superset(&a));
931 assert!(b.insert(5));
933 assert!(a.is_subset(&b));
934 assert!(!a.is_superset(&b));
935 assert!(!b.is_subset(&a));
936 assert!(b.is_superset(&a));
941 let mut a = HashSet::new();
942 for i in range(0u, 32) {
943 assert!(a.insert(i));
945 let mut observed: u32 = 0;
949 assert_eq!(observed, 0xFFFF_FFFF);
953 fn test_intersection() {
954 let mut a = HashSet::new();
955 let mut b = HashSet::new();
957 assert!(a.insert(11i));
958 assert!(a.insert(1));
959 assert!(a.insert(3));
960 assert!(a.insert(77));
961 assert!(a.insert(103));
962 assert!(a.insert(5));
963 assert!(a.insert(-5));
965 assert!(b.insert(2i));
966 assert!(b.insert(11));
967 assert!(b.insert(77));
968 assert!(b.insert(-9));
969 assert!(b.insert(-42));
970 assert!(b.insert(5));
971 assert!(b.insert(3));
974 let expected = [3, 5, 11, 77];
975 for x in a.intersection(&b) {
976 assert!(expected.contains(x));
979 assert_eq!(i, expected.len());
983 fn test_difference() {
984 let mut a = HashSet::new();
985 let mut b = HashSet::new();
987 assert!(a.insert(1i));
988 assert!(a.insert(3));
989 assert!(a.insert(5));
990 assert!(a.insert(9));
991 assert!(a.insert(11));
993 assert!(b.insert(3i));
994 assert!(b.insert(9));
997 let expected = [1, 5, 11];
998 for x in a.difference(&b) {
999 assert!(expected.contains(x));
1002 assert_eq!(i, expected.len());
1006 fn test_symmetric_difference() {
1007 let mut a = HashSet::new();
1008 let mut b = HashSet::new();
1010 assert!(a.insert(1i));
1011 assert!(a.insert(3));
1012 assert!(a.insert(5));
1013 assert!(a.insert(9));
1014 assert!(a.insert(11));
1016 assert!(b.insert(-2i));
1017 assert!(b.insert(3));
1018 assert!(b.insert(9));
1019 assert!(b.insert(14));
1020 assert!(b.insert(22));
1023 let expected = [-2, 1, 5, 11, 14, 22];
1024 for x in a.symmetric_difference(&b) {
1025 assert!(expected.contains(x));
1028 assert_eq!(i, expected.len());
1033 let mut a = HashSet::new();
1034 let mut b = HashSet::new();
1036 assert!(a.insert(1i));
1037 assert!(a.insert(3));
1038 assert!(a.insert(5));
1039 assert!(a.insert(9));
1040 assert!(a.insert(11));
1041 assert!(a.insert(16));
1042 assert!(a.insert(19));
1043 assert!(a.insert(24));
1045 assert!(b.insert(-2i));
1046 assert!(b.insert(1));
1047 assert!(b.insert(5));
1048 assert!(b.insert(9));
1049 assert!(b.insert(13));
1050 assert!(b.insert(19));
1053 let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24];
1054 for x in a.union(&b) {
1055 assert!(expected.contains(x));
1058 assert_eq!(i, expected.len());
1062 fn test_from_iter() {
1063 let xs = [1i, 2, 3, 4, 5, 6, 7, 8, 9];
1065 let set: HashSet<int> = xs.iter().map(|&x| x).collect();
1067 for x in xs.iter() {
1068 assert!(set.contains(x));
1073 fn test_move_iter() {
1075 let mut hs = HashSet::new();
1083 let v = hs.into_iter().collect::<Vec<char>>();
1084 assert!(['a', 'b'] == v || ['b', 'a'] == v);
1089 // These constants once happened to expose a bug in insert().
1090 // I'm keeping them around to prevent a regression.
1091 let mut s1 = HashSet::new();
1097 let mut s2 = HashSet::new();
1111 let mut set: HashSet<int> = HashSet::new();
1112 let empty: HashSet<int> = HashSet::new();
1117 let set_str = format!("{}", set);
1119 assert!(set_str == "{1, 2}" || set_str == "{2, 1}");
1120 assert_eq!(format!("{}", empty), "{}");
1124 fn test_trivial_drain() {
1125 let mut s = HashSet::<int>::new();
1126 for _ in s.drain() {}
1127 assert!(s.is_empty());
1130 let mut s = HashSet::<int>::new();
1132 assert!(s.is_empty());
1137 let mut s: HashSet<int> = range(1, 100).collect();
1139 // try this a bunch of times to make sure we don't screw up internal state.
1140 for _ in range(0i, 20) {
1141 assert_eq!(s.len(), 99);
1145 let mut d = s.drain();
1146 for (i, x) in d.by_ref().take(50).enumerate() {
1150 assert_eq!(last_i, 49);
1153 for _ in s.iter() { panic!("s should be empty!"); }
1155 // reset to try again.
1156 s.extend(range(1, 100));