| // Copyright (C) 2017-2018 Baidu, Inc. All Rights Reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions |
| // are met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above copyright |
| // notice, this list of conditions and the following disclaimer in |
| // the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Baidu, Inc., nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| use core::borrow::Borrow; |
| use core::fmt; |
| use core::hash::{Hash, BuildHasher}; |
| use core::iter::{Chain, FromIterator, FusedIterator}; |
| use core::ops::{BitOr, BitAnd, BitXor, Sub}; |
| |
| use super::Recover; |
| use super::map::{self, HashMap, Keys, RandomState}; |
| |
| // Future Optimization (FIXME!) |
| // ============================= |
| // |
| // Iteration over zero sized values is a noop. There is no need |
| // for `bucket.val` in the case of HashSet. I suppose we would need HKT |
| // to get rid of it properly. |
| |
| /// A hash set implemented as a `HashMap` where the value is `()`. |
| /// |
| /// As with the [`HashMap`] type, a `HashSet` requires that the elements |
| /// implement the [`Eq`] and [`Hash`] traits. This can frequently be achieved by |
| /// using `#[derive(PartialEq, Eq, Hash)]`. If you implement these yourself, |
| /// it is important that the following property holds: |
| /// |
| /// ```text |
| /// k1 == k2 -> hash(k1) == hash(k2) |
| /// ``` |
| /// |
| /// In other words, if two keys are equal, their hashes must be equal. |
| /// |
| /// |
| /// It is a logic error for an item to be modified in such a way that the |
| /// item's hash, as determined by the [`Hash`] trait, or its equality, as |
| /// determined by the [`Eq`] trait, changes while it is in the set. This is |
| /// normally only possible through [`Cell`], [`RefCell`], global state, I/O, or |
| /// unsafe code. |
| /// |
| #[derive(Clone)] |
| pub struct HashSet<T, S = RandomState> { |
| map: HashMap<T, (), S>, |
| } |
| |
| impl<T: Hash + Eq> HashSet<T, RandomState> { |
| /// Creates an empty `HashSet`. |
| /// |
| /// The hash set is initially created with a capacity of 0, so it will not allocate until it |
| /// is first inserted into. |
| /// |
| #[inline] |
| pub fn new() -> HashSet<T, RandomState> { |
| HashSet { map: HashMap::new() } |
| } |
| |
| /// Creates an empty `HashSet` with the specified capacity. |
| /// |
| /// The hash set will be able to hold at least `capacity` elements without |
| /// reallocating. If `capacity` is 0, the hash set will not allocate. |
| /// |
| #[inline] |
| pub fn with_capacity(capacity: usize) -> HashSet<T, RandomState> { |
| HashSet { map: HashMap::with_capacity(capacity) } |
| } |
| } |
| |
| impl<T, S> HashSet<T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| /// Creates a new empty hash set which will use the given hasher to hash |
| /// keys. |
| /// |
| /// The hash set is also created with the default initial capacity. |
| /// |
| /// Warning: `hasher` is normally randomly generated, and |
| /// is designed to allow `HashSet`s to be resistant to attacks that |
| /// cause many collisions and very poor performance. Setting it |
| /// manually using this function can expose a DoS attack vector. |
| /// |
| #[inline] |
| pub fn with_hasher(hasher: S) -> HashSet<T, S> { |
| HashSet { map: HashMap::with_hasher(hasher) } |
| } |
| |
| /// Creates an empty `HashSet` with with the specified capacity, using |
| /// `hasher` to hash the keys. |
| /// |
| /// The hash set will be able to hold at least `capacity` elements without |
| /// reallocating. If `capacity` is 0, the hash set will not allocate. |
| /// |
| /// Warning: `hasher` is normally randomly generated, and |
| /// is designed to allow `HashSet`s to be resistant to attacks that |
| /// cause many collisions and very poor performance. Setting it |
| /// manually using this function can expose a DoS attack vector. |
| /// |
| #[inline] |
| pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> HashSet<T, S> { |
| HashSet { map: HashMap::with_capacity_and_hasher(capacity, hasher) } |
| } |
| |
| /// Returns a reference to the set's [`BuildHasher`]. |
| /// |
| /// [`BuildHasher`]: ../../std/hash/trait.BuildHasher.html |
| pub fn hasher(&self) -> &S { |
| self.map.hasher() |
| } |
| |
| /// Returns the number of elements the set can hold without reallocating. |
| /// |
| #[inline] |
| pub fn capacity(&self) -> usize { |
| self.map.capacity() |
| } |
| |
| /// Reserves capacity for at least `additional` more elements to be inserted |
| /// in the `HashSet`. The collection may reserve more space to avoid |
| /// frequent reallocations. |
| /// |
| /// # Panics |
| /// |
| /// Panics if the new allocation size overflows `usize`. |
| /// |
| pub fn reserve(&mut self, additional: usize) { |
| self.map.reserve(additional) |
| } |
| |
| /// Shrinks the capacity of the set as much as possible. It will drop |
| /// down as much as possible while maintaining the internal rules |
| /// and possibly leaving some space in accordance with the resize policy. |
| /// |
| pub fn shrink_to_fit(&mut self) { |
| self.map.shrink_to_fit() |
| } |
| |
| /// Shrinks the capacity of the set with a lower limit. It will drop |
| /// down no lower than the supplied limit while maintaining the internal rules |
| /// and possibly leaving some space in accordance with the resize policy. |
| /// |
| /// Panics if the current capacity is smaller than the supplied |
| /// minimum capacity. |
| /// |
| #[inline] |
| pub fn shrink_to(&mut self, min_capacity: usize) { |
| self.map.shrink_to(min_capacity) |
| } |
| |
| /// An iterator visiting all elements in arbitrary order. |
| /// The iterator element type is `&'a T`. |
| /// |
| pub fn iter(&self) -> Iter<T> { |
| Iter { iter: self.map.keys() } |
| } |
| |
| /// Visits the values representing the difference, |
| /// i.e. the values that are in `self` but not in `other`. |
| /// |
| pub fn difference<'a>(&'a self, other: &'a HashSet<T, S>) -> Difference<'a, T, S> { |
| Difference { |
| iter: self.iter(), |
| other: other, |
| } |
| } |
| |
| /// Visits the values representing the symmetric difference, |
| /// i.e. the values that are in `self` or in `other` but not in both. |
| /// |
| pub fn symmetric_difference<'a>(&'a self, |
| other: &'a HashSet<T, S>) |
| -> SymmetricDifference<'a, T, S> { |
| SymmetricDifference { iter: self.difference(other).chain(other.difference(self)) } |
| } |
| |
| /// Visits the values representing the intersection, |
| /// i.e. the values that are both in `self` and `other`. |
| /// |
| pub fn intersection<'a>(&'a self, other: &'a HashSet<T, S>) -> Intersection<'a, T, S> { |
| Intersection { |
| iter: self.iter(), |
| other: other, |
| } |
| } |
| |
| /// Visits the values representing the union, |
| /// i.e. all the values in `self` or `other`, without duplicates. |
| /// |
| pub fn union<'a>(&'a self, other: &'a HashSet<T, S>) -> Union<'a, T, S> { |
| Union { iter: self.iter().chain(other.difference(self)) } |
| } |
| |
| /// Returns the number of elements in the set. |
| /// |
| pub fn len(&self) -> usize { |
| self.map.len() |
| } |
| |
| /// Returns true if the set contains no elements. |
| /// |
| pub fn is_empty(&self) -> bool { |
| self.map.is_empty() |
| } |
| |
| /// Clears the set, returning all elements in an iterator. |
| #[inline] |
| pub fn drain(&mut self) -> Drain<T> { |
| Drain { iter: self.map.drain() } |
| } |
| |
| /// Clears the set, removing all values. |
| /// |
| pub fn clear(&mut self) { |
| self.map.clear() |
| } |
| |
| /// Returns `true` if the set contains a value. |
| /// |
| /// The value may be any borrowed form of the set's value type, but |
| /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for |
| /// the value type. |
| /// |
| pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool |
| where T: Borrow<Q>, |
| Q: Hash + Eq |
| { |
| self.map.contains_key(value) |
| } |
| |
| /// Returns a reference to the value in the set, if any, that is equal to the given value. |
| /// |
| /// The value may be any borrowed form of the set's value type, but |
| /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for |
| /// the value type. |
| /// |
| /// [`Eq`]: ../../std/cmp/trait.Eq.html |
| /// [`Hash`]: ../../std/hash/trait.Hash.html |
| pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T> |
| where T: Borrow<Q>, |
| Q: Hash + Eq |
| { |
| Recover::get(&self.map, value) |
| } |
| |
| /// Returns `true` if `self` has no elements in common with `other`. |
| /// This is equivalent to checking for an empty intersection. |
| /// |
| pub fn is_disjoint(&self, other: &HashSet<T, S>) -> bool { |
| self.iter().all(|v| !other.contains(v)) |
| } |
| |
| /// Returns `true` if the set is a subset of another, |
| /// i.e. `other` contains at least all the values in `self`. |
| /// |
| pub fn is_subset(&self, other: &HashSet<T, S>) -> bool { |
| self.iter().all(|v| other.contains(v)) |
| } |
| |
| /// Returns `true` if the set is a superset of another, |
| /// i.e. `self` contains at least all the values in `other`. |
| /// |
| #[inline] |
| pub fn is_superset(&self, other: &HashSet<T, S>) -> bool { |
| other.is_subset(self) |
| } |
| |
| /// Adds a value to the set. |
| /// |
| /// If the set did not have this value present, `true` is returned. |
| /// |
| /// If the set did have this value present, `false` is returned. |
| /// |
| pub fn insert(&mut self, value: T) -> bool { |
| self.map.insert(value, ()).is_none() |
| } |
| |
| /// Adds a value to the set, replacing the existing value, if any, that is equal to the given |
| /// one. Returns the replaced value. |
| pub fn replace(&mut self, value: T) -> Option<T> { |
| Recover::replace(&mut self.map, value) |
| } |
| |
| /// Removes a value from the set. Returns `true` if the value was |
| /// present in the set. |
| /// |
| /// The value may be any borrowed form of the set's value type, but |
| /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for |
| /// the value type. |
| /// |
| pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool |
| where T: Borrow<Q>, |
| Q: Hash + Eq |
| { |
| self.map.remove(value).is_some() |
| } |
| |
| /// Removes and returns the value in the set, if any, that is equal to the given one. |
| /// |
| /// The value may be any borrowed form of the set's value type, but |
| /// [`Hash`] and [`Eq`] on the borrowed form *must* match those for |
| /// the value type. |
| /// |
| /// [`Eq`]: ../../std/cmp/trait.Eq.html |
| /// [`Hash`]: ../../std/hash/trait.Hash.html |
| pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T> |
| where T: Borrow<Q>, |
| Q: Hash + Eq |
| { |
| Recover::take(&mut self.map, value) |
| } |
| |
| /// Retains only the elements specified by the predicate. |
| /// |
| /// In other words, remove all elements `e` such that `f(&e)` returns `false`. |
| /// |
| pub fn retain<F>(&mut self, mut f: F) |
| where F: FnMut(&T) -> bool |
| { |
| self.map.retain(|k, _| f(k)); |
| } |
| } |
| |
| impl<T, S> PartialEq for HashSet<T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| fn eq(&self, other: &HashSet<T, S>) -> bool { |
| if self.len() != other.len() { |
| return false; |
| } |
| |
| self.iter().all(|key| other.contains(key)) |
| } |
| } |
| |
| impl<T, S> Eq for HashSet<T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| } |
| |
| impl<T, S> fmt::Debug for HashSet<T, S> |
| where T: Eq + Hash + fmt::Debug, |
| S: BuildHasher |
| { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_set().entries(self.iter()).finish() |
| } |
| } |
| |
| impl<T, S> FromIterator<T> for HashSet<T, S> |
| where T: Eq + Hash, |
| S: BuildHasher + Default |
| { |
| fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> HashSet<T, S> { |
| let mut set = HashSet::with_hasher(Default::default()); |
| set.extend(iter); |
| set |
| } |
| } |
| |
| impl<T, S> Extend<T> for HashSet<T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) { |
| self.map.extend(iter.into_iter().map(|k| (k, ()))); |
| } |
| } |
| |
| impl<'a, T, S> Extend<&'a T> for HashSet<T, S> |
| where T: 'a + Eq + Hash + Copy, |
| S: BuildHasher |
| { |
| fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) { |
| self.extend(iter.into_iter().cloned()); |
| } |
| } |
| |
| impl<T, S> Default for HashSet<T, S> |
| where T: Eq + Hash, |
| S: BuildHasher + Default |
| { |
| /// Creates an empty `HashSet<T, S>` with the `Default` value for the hasher. |
| fn default() -> HashSet<T, S> { |
| HashSet { map: HashMap::default() } |
| } |
| } |
| |
| impl<'a, 'b, T, S> BitOr<&'b HashSet<T, S>> for &'a HashSet<T, S> |
| where T: Eq + Hash + Clone, |
| S: BuildHasher + Default |
| { |
| type Output = HashSet<T, S>; |
| |
| /// Returns the union of `self` and `rhs` as a new `HashSet<T, S>`. |
| /// |
| fn bitor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { |
| self.union(rhs).cloned().collect() |
| } |
| } |
| |
| impl<'a, 'b, T, S> BitAnd<&'b HashSet<T, S>> for &'a HashSet<T, S> |
| where T: Eq + Hash + Clone, |
| S: BuildHasher + Default |
| { |
| type Output = HashSet<T, S>; |
| |
| /// Returns the intersection of `self` and `rhs` as a new `HashSet<T, S>`. |
| /// |
| fn bitand(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { |
| self.intersection(rhs).cloned().collect() |
| } |
| } |
| |
| impl<'a, 'b, T, S> BitXor<&'b HashSet<T, S>> for &'a HashSet<T, S> |
| where T: Eq + Hash + Clone, |
| S: BuildHasher + Default |
| { |
| type Output = HashSet<T, S>; |
| |
| /// Returns the symmetric difference of `self` and `rhs` as a new `HashSet<T, S>`. |
| /// |
| fn bitxor(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { |
| self.symmetric_difference(rhs).cloned().collect() |
| } |
| } |
| |
| impl<'a, 'b, T, S> Sub<&'b HashSet<T, S>> for &'a HashSet<T, S> |
| where T: Eq + Hash + Clone, |
| S: BuildHasher + Default |
| { |
| type Output = HashSet<T, S>; |
| |
| /// Returns the difference of `self` and `rhs` as a new `HashSet<T, S>`. |
| /// |
| fn sub(self, rhs: &HashSet<T, S>) -> HashSet<T, S> { |
| self.difference(rhs).cloned().collect() |
| } |
| } |
| |
| /// An iterator over the items of a `HashSet`. |
| /// |
| /// This `struct` is created by the [`iter`] method on [`HashSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`HashSet`]: struct.HashSet.html |
| /// [`iter`]: struct.HashSet.html#method.iter |
| pub struct Iter<'a, K: 'a> { |
| iter: Keys<'a, K, ()>, |
| } |
| |
| /// An owning iterator over the items of a `HashSet`. |
| /// |
| /// This `struct` is created by the [`into_iter`] method on [`HashSet`][`HashSet`] |
| /// (provided by the `IntoIterator` trait). See its documentation for more. |
| /// |
| /// [`HashSet`]: struct.HashSet.html |
| /// [`into_iter`]: struct.HashSet.html#method.into_iter |
| pub struct IntoIter<K> { |
| iter: map::IntoIter<K, ()>, |
| } |
| |
| /// A draining iterator over the items of a `HashSet`. |
| /// |
| /// This `struct` is created by the [`drain`] method on [`HashSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`HashSet`]: struct.HashSet.html |
| /// [`drain`]: struct.HashSet.html#method.drain |
| pub struct Drain<'a, K: 'a> { |
| iter: map::Drain<'a, K, ()>, |
| } |
| |
| /// A lazy iterator producing elements in the intersection of `HashSet`s. |
| /// |
| /// This `struct` is created by the [`intersection`] method on [`HashSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`HashSet`]: struct.HashSet.html |
| /// [`intersection`]: struct.HashSet.html#method.intersection |
| pub struct Intersection<'a, T: 'a, S: 'a> { |
| // iterator of the first set |
| iter: Iter<'a, T>, |
| // the second set |
| other: &'a HashSet<T, S>, |
| } |
| |
| /// A lazy iterator producing elements in the difference of `HashSet`s. |
| /// |
| /// This `struct` is created by the [`difference`] method on [`HashSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`HashSet`]: struct.HashSet.html |
| /// [`difference`]: struct.HashSet.html#method.difference |
| pub struct Difference<'a, T: 'a, S: 'a> { |
| // iterator of the first set |
| iter: Iter<'a, T>, |
| // the second set |
| other: &'a HashSet<T, S>, |
| } |
| |
| /// A lazy iterator producing elements in the symmetric difference of `HashSet`s. |
| /// |
| /// This `struct` is created by the [`symmetric_difference`] method on |
| /// [`HashSet`]. See its documentation for more. |
| /// |
| /// [`HashSet`]: struct.HashSet.html |
| /// [`symmetric_difference`]: struct.HashSet.html#method.symmetric_difference |
| pub struct SymmetricDifference<'a, T: 'a, S: 'a> { |
| iter: Chain<Difference<'a, T, S>, Difference<'a, T, S>>, |
| } |
| |
| /// A lazy iterator producing elements in the union of `HashSet`s. |
| /// |
| /// This `struct` is created by the [`union`] method on [`HashSet`]. |
| /// See its documentation for more. |
| /// |
| /// [`HashSet`]: struct.HashSet.html |
| /// [`union`]: struct.HashSet.html#method.union |
| pub struct Union<'a, T: 'a, S: 'a> { |
| iter: Chain<Iter<'a, T>, Difference<'a, T, S>>, |
| } |
| |
| impl<'a, T, S> IntoIterator for &'a HashSet<T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| type Item = &'a T; |
| type IntoIter = Iter<'a, T>; |
| |
| fn into_iter(self) -> Iter<'a, T> { |
| self.iter() |
| } |
| } |
| |
| impl<T, S> IntoIterator for HashSet<T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| type Item = T; |
| type IntoIter = IntoIter<T>; |
| |
| /// Creates a consuming iterator, that is, one that moves each value out |
| /// of the set in arbitrary order. The set cannot be used after calling |
| /// this. |
| /// |
| fn into_iter(self) -> IntoIter<T> { |
| IntoIter { iter: self.map.into_iter() } |
| } |
| } |
| |
| impl<'a, K> Clone for Iter<'a, K> { |
| fn clone(&self) -> Iter<'a, K> { |
| Iter { iter: self.iter.clone() } |
| } |
| } |
| |
| impl<'a, K> Iterator for Iter<'a, K> { |
| type Item = &'a K; |
| |
| fn next(&mut self) -> Option<&'a K> { |
| self.iter.next() |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.iter.size_hint() |
| } |
| } |
| |
| impl<'a, K> ExactSizeIterator for Iter<'a, K> { |
| fn len(&self) -> usize { |
| self.iter.len() |
| } |
| } |
| |
| impl<'a, K> FusedIterator for Iter<'a, K> {} |
| |
| impl<'a, K: fmt::Debug> fmt::Debug for Iter<'a, K> { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_list().entries(self.clone()).finish() |
| } |
| } |
| |
| impl<K> Iterator for IntoIter<K> { |
| type Item = K; |
| |
| fn next(&mut self) -> Option<K> { |
| self.iter.next().map(|(k, _)| k) |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.iter.size_hint() |
| } |
| } |
| |
| impl<K> ExactSizeIterator for IntoIter<K> { |
| fn len(&self) -> usize { |
| self.iter.len() |
| } |
| } |
| |
| impl<K> FusedIterator for IntoIter<K> {} |
| |
| impl<K: fmt::Debug> fmt::Debug for IntoIter<K> { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| let entries_iter = self.iter |
| .inner |
| .iter() |
| .map(|(k, _)| k); |
| f.debug_list().entries(entries_iter).finish() |
| } |
| } |
| |
| impl<'a, K> Iterator for Drain<'a, K> { |
| type Item = K; |
| |
| fn next(&mut self) -> Option<K> { |
| self.iter.next().map(|(k, _)| k) |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.iter.size_hint() |
| } |
| } |
| |
| impl<'a, K> ExactSizeIterator for Drain<'a, K> { |
| fn len(&self) -> usize { |
| self.iter.len() |
| } |
| } |
| |
| impl<'a, K> FusedIterator for Drain<'a, K> {} |
| |
| impl<'a, K: fmt::Debug> fmt::Debug for Drain<'a, K> { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| let entries_iter = self.iter |
| .inner |
| .iter() |
| .map(|(k, _)| k); |
| f.debug_list().entries(entries_iter).finish() |
| } |
| } |
| |
| impl<'a, T, S> Clone for Intersection<'a, T, S> { |
| fn clone(&self) -> Intersection<'a, T, S> { |
| Intersection { iter: self.iter.clone(), ..*self } |
| } |
| } |
| |
| impl<'a, T, S> Iterator for Intersection<'a, T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| loop { |
| let elt = self.iter.next()?; |
| if self.other.contains(elt) { |
| return Some(elt); |
| } |
| } |
| } |
| |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| let (_, upper) = self.iter.size_hint(); |
| (0, upper) |
| } |
| } |
| |
| impl<'a, T, S> fmt::Debug for Intersection<'a, T, S> |
| where T: fmt::Debug + Eq + Hash, |
| S: BuildHasher |
| { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_list().entries(self.clone()).finish() |
| } |
| } |
| |
| impl<'a, T, S> FusedIterator for Intersection<'a, T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| } |
| |
| impl<'a, T, S> Clone for Difference<'a, T, S> { |
| fn clone(&self) -> Difference<'a, T, S> { |
| Difference { iter: self.iter.clone(), ..*self } |
| } |
| } |
| |
| impl<'a, T, S> Iterator for Difference<'a, T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| loop { |
| let elt = self.iter.next()?; |
| if !self.other.contains(elt) { |
| return Some(elt); |
| } |
| } |
| } |
| |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| let (_, upper) = self.iter.size_hint(); |
| (0, upper) |
| } |
| } |
| |
| impl<'a, T, S> FusedIterator for Difference<'a, T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| } |
| |
| impl<'a, T, S> fmt::Debug for Difference<'a, T, S> |
| where T: fmt::Debug + Eq + Hash, |
| S: BuildHasher |
| { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_list().entries(self.clone()).finish() |
| } |
| } |
| |
| |
| impl<'a, T, S> Clone for SymmetricDifference<'a, T, S> { |
| fn clone(&self) -> SymmetricDifference<'a, T, S> { |
| SymmetricDifference { iter: self.iter.clone() } |
| } |
| } |
| |
| impl<'a, T, S> Iterator for SymmetricDifference<'a, T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| self.iter.next() |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.iter.size_hint() |
| } |
| } |
| |
| impl<'a, T, S> FusedIterator for SymmetricDifference<'a, T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| } |
| |
| impl<'a, T, S> fmt::Debug for SymmetricDifference<'a, T, S> |
| where T: fmt::Debug + Eq + Hash, |
| S: BuildHasher |
| { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_list().entries(self.clone()).finish() |
| } |
| } |
| |
| impl<'a, T, S> Clone for Union<'a, T, S> { |
| fn clone(&self) -> Union<'a, T, S> { |
| Union { iter: self.iter.clone() } |
| } |
| } |
| |
| impl<'a, T, S> FusedIterator for Union<'a, T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| } |
| |
| impl<'a, T, S> fmt::Debug for Union<'a, T, S> |
| where T: fmt::Debug + Eq + Hash, |
| S: BuildHasher |
| { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_list().entries(self.clone()).finish() |
| } |
| } |
| |
| impl<'a, T, S> Iterator for Union<'a, T, S> |
| where T: Eq + Hash, |
| S: BuildHasher |
| { |
| type Item = &'a T; |
| |
| fn next(&mut self) -> Option<&'a T> { |
| self.iter.next() |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.iter.size_hint() |
| } |
| } |
| |
| #[allow(dead_code)] |
| fn assert_covariance() { |
| fn set<'new>(v: HashSet<&'static str>) -> HashSet<&'new str> { |
| v |
| } |
| fn iter<'a, 'new>(v: Iter<'a, &'static str>) -> Iter<'a, &'new str> { |
| v |
| } |
| fn into_iter<'new>(v: IntoIter<&'static str>) -> IntoIter<&'new str> { |
| v |
| } |
| fn difference<'a, 'new>(v: Difference<'a, &'static str, RandomState>) |
| -> Difference<'a, &'new str, RandomState> { |
| v |
| } |
| fn symmetric_difference<'a, 'new>(v: SymmetricDifference<'a, &'static str, RandomState>) |
| -> SymmetricDifference<'a, &'new str, RandomState> { |
| v |
| } |
| fn intersection<'a, 'new>(v: Intersection<'a, &'static str, RandomState>) |
| -> Intersection<'a, &'new str, RandomState> { |
| v |
| } |
| fn union<'a, 'new>(v: Union<'a, &'static str, RandomState>) |
| -> Union<'a, &'new str, RandomState> { |
| v |
| } |
| fn drain<'new>(d: Drain<'static, &'static str>) -> Drain<'new, &'new str> { |
| d |
| } |
| } |