Struct nom::lib::std::collections::hash_set::HashSet 1.0.0[−][src]
pub struct HashSet<T, S = RandomState> { /* fields omitted */ }
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:
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.
Examples
use std::collections::HashSet; // Type inference lets us omit an explicit type signature (which // would be `HashSet<&str>` in this example). let mut books = HashSet::new(); // Add some books. books.insert("A Dance With Dragons"); books.insert("To Kill a Mockingbird"); books.insert("The Odyssey"); books.insert("The Great Gatsby"); // Check for a specific one. if !books.contains("The Winds of Winter") { println!("We have {} books, but The Winds of Winter ain't one.", books.len()); } // Remove a book. books.remove("The Odyssey"); // Iterate over everything. for book in &books { println!("{}", book); }
The easiest way to use HashSet
with a custom type is to derive
Eq
and Hash
. We must also derive PartialEq
, this will in the
future be implied by Eq
.
use std::collections::HashSet; #[derive(Hash, Eq, PartialEq, Debug)] struct Viking<'a> { name: &'a str, power: usize, } let mut vikings = HashSet::new(); vikings.insert(Viking { name: "Einar", power: 9 }); vikings.insert(Viking { name: "Einar", power: 9 }); vikings.insert(Viking { name: "Olaf", power: 4 }); vikings.insert(Viking { name: "Harald", power: 8 }); // Use derived implementation to print the vikings. for x in &vikings { println!("{:?}", x); }
A HashSet
with fixed list of elements can be initialized from an array:
use std::collections::HashSet; fn main() { let viking_names: HashSet<&str> = [ "Einar", "Olaf", "Harald" ].iter().cloned().collect(); // use the values stored in the set }
Methods
impl<T> HashSet<T, RandomState> where
T: Eq + Hash,
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impl<T> HashSet<T, RandomState> where
T: Eq + Hash,
pub fn new() -> HashSet<T, RandomState>
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pub fn new() -> 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.
Examples
use std::collections::HashSet; let set: HashSet<i32> = HashSet::new();
pub fn with_capacity(capacity: usize) -> HashSet<T, RandomState>
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pub fn with_capacity(capacity: usize) -> HashSet<T, RandomState>
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.
Examples
use std::collections::HashSet; let set: HashSet<i32> = HashSet::with_capacity(10); assert!(set.capacity() >= 10);
impl<T, S> HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
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impl<T, S> HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
pub fn with_hasher(hasher: S) -> HashSet<T, S>
1.7.0[src]
pub fn with_hasher(hasher: S) -> HashSet<T, S>
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.
Examples
use std::collections::HashSet; use std::collections::hash_map::RandomState; let s = RandomState::new(); let mut set = HashSet::with_hasher(s); set.insert(2);
pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> HashSet<T, S>
1.7.0[src]
pub fn with_capacity_and_hasher(capacity: usize, hasher: S) -> HashSet<T, S>
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.
Examples
use std::collections::HashSet; use std::collections::hash_map::RandomState; let s = RandomState::new(); let mut set = HashSet::with_capacity_and_hasher(10, s); set.insert(1);
ⓘImportant traits for &'a mut Rpub fn hasher(&self) -> &S
1.9.0[src]
pub fn hasher(&self) -> &S
Returns a reference to the set's BuildHasher
.
Examples
use std::collections::HashSet; use std::collections::hash_map::RandomState; let hasher = RandomState::new(); let set: HashSet<i32> = HashSet::with_hasher(hasher); let hasher: &RandomState = set.hasher();
pub fn capacity(&self) -> usize
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pub fn capacity(&self) -> usize
Returns the number of elements the set can hold without reallocating.
Examples
use std::collections::HashSet; let set: HashSet<i32> = HashSet::with_capacity(100); assert!(set.capacity() >= 100);
pub fn reserve(&mut self, additional: usize)
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pub fn reserve(&mut self, additional: usize)
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
.
Examples
use std::collections::HashSet; let mut set: HashSet<i32> = HashSet::new(); set.reserve(10); assert!(set.capacity() >= 10);
pub fn shrink_to_fit(&mut self)
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pub fn shrink_to_fit(&mut self)
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.
Examples
use std::collections::HashSet; let mut set = HashSet::with_capacity(100); set.insert(1); set.insert(2); assert!(set.capacity() >= 100); set.shrink_to_fit(); assert!(set.capacity() >= 2);
pub fn shrink_to(&mut self, min_capacity: usize)
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pub fn shrink_to(&mut self, min_capacity: usize)
🔬 This is a nightly-only experimental API. (shrink_to
)
new API
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.
Examples
#![feature(shrink_to)] use std::collections::HashSet; let mut set = HashSet::with_capacity(100); set.insert(1); set.insert(2); assert!(set.capacity() >= 100); set.shrink_to(10); assert!(set.capacity() >= 10); set.shrink_to(0); assert!(set.capacity() >= 2);
ⓘImportant traits for Iter<'a, K>pub fn iter(&self) -> Iter<T>
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pub fn iter(&self) -> Iter<T>
An iterator visiting all elements in arbitrary order.
The iterator element type is &'a T
.
Examples
use std::collections::HashSet; let mut set = HashSet::new(); set.insert("a"); set.insert("b"); // Will print in an arbitrary order. for x in set.iter() { println!("{}", x); }
ⓘImportant traits for Difference<'a, T, S>pub fn difference(&'a self, other: &'a HashSet<T, S>) -> Difference<'a, T, S>
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pub fn difference(&'a self, other: &'a HashSet<T, S>) -> Difference<'a, T, S>
Visits the values representing the difference,
i.e. the values that are in self
but not in other
.
Examples
use std::collections::HashSet; let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); // Can be seen as `a - b`. for x in a.difference(&b) { println!("{}", x); // Print 1 } let diff: HashSet<_> = a.difference(&b).collect(); assert_eq!(diff, [1].iter().collect()); // Note that difference is not symmetric, // and `b - a` means something else: let diff: HashSet<_> = b.difference(&a).collect(); assert_eq!(diff, [4].iter().collect());
ⓘImportant traits for SymmetricDifference<'a, T, S>pub fn symmetric_difference(
&'a self,
other: &'a HashSet<T, S>
) -> SymmetricDifference<'a, T, S>
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pub fn symmetric_difference(
&'a self,
other: &'a HashSet<T, S>
) -> SymmetricDifference<'a, T, S>
Visits the values representing the symmetric difference,
i.e. the values that are in self
or in other
but not in both.
Examples
use std::collections::HashSet; let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); // Print 1, 4 in arbitrary order. for x in a.symmetric_difference(&b) { println!("{}", x); } let diff1: HashSet<_> = a.symmetric_difference(&b).collect(); let diff2: HashSet<_> = b.symmetric_difference(&a).collect(); assert_eq!(diff1, diff2); assert_eq!(diff1, [1, 4].iter().collect());
ⓘImportant traits for Intersection<'a, T, S>pub fn intersection(
&'a self,
other: &'a HashSet<T, S>
) -> Intersection<'a, T, S>
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pub fn intersection(
&'a self,
other: &'a HashSet<T, S>
) -> Intersection<'a, T, S>
Visits the values representing the intersection,
i.e. the values that are both in self
and other
.
Examples
use std::collections::HashSet; let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); // Print 2, 3 in arbitrary order. for x in a.intersection(&b) { println!("{}", x); } let intersection: HashSet<_> = a.intersection(&b).collect(); assert_eq!(intersection, [2, 3].iter().collect());
ⓘImportant traits for Union<'a, T, S>pub fn union(&'a self, other: &'a HashSet<T, S>) -> Union<'a, T, S>
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pub fn union(&'a self, other: &'a HashSet<T, S>) -> Union<'a, T, S>
Visits the values representing the union,
i.e. all the values in self
or other
, without duplicates.
Examples
use std::collections::HashSet; let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); let b: HashSet<_> = [4, 2, 3, 4].iter().cloned().collect(); // Print 1, 2, 3, 4 in arbitrary order. for x in a.union(&b) { println!("{}", x); } let union: HashSet<_> = a.union(&b).collect(); assert_eq!(union, [1, 2, 3, 4].iter().collect());
pub fn len(&self) -> usize
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pub fn len(&self) -> usize
Returns the number of elements in the set.
Examples
use std::collections::HashSet; let mut v = HashSet::new(); assert_eq!(v.len(), 0); v.insert(1); assert_eq!(v.len(), 1);
pub fn is_empty(&self) -> bool
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pub fn is_empty(&self) -> bool
Returns true if the set contains no elements.
Examples
use std::collections::HashSet; let mut v = HashSet::new(); assert!(v.is_empty()); v.insert(1); assert!(!v.is_empty());
ⓘImportant traits for Drain<'a, K>pub fn drain(&mut self) -> Drain<T>
1.6.0[src]
pub fn drain(&mut self) -> Drain<T>
Clears the set, returning all elements in an iterator.
Examples
use std::collections::HashSet; let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); assert!(!set.is_empty()); // print 1, 2, 3 in an arbitrary order for i in set.drain() { println!("{}", i); } assert!(set.is_empty());
pub fn clear(&mut self)
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pub fn clear(&mut self)
Clears the set, removing all values.
Examples
use std::collections::HashSet; let mut v = HashSet::new(); v.insert(1); v.clear(); assert!(v.is_empty());
pub fn contains<Q>(&self, value: &Q) -> bool where
Q: Hash + Eq + ?Sized,
T: Borrow<Q>,
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pub fn contains<Q>(&self, value: &Q) -> bool where
Q: Hash + Eq + ?Sized,
T: Borrow<Q>,
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.
Examples
use std::collections::HashSet; let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); assert_eq!(set.contains(&1), true); assert_eq!(set.contains(&4), false);
pub fn get<Q>(&self, value: &Q) -> Option<&T> where
Q: Hash + Eq + ?Sized,
T: Borrow<Q>,
1.9.0[src]
pub fn get<Q>(&self, value: &Q) -> Option<&T> where
Q: Hash + Eq + ?Sized,
T: Borrow<Q>,
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.
Examples
use std::collections::HashSet; let set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); assert_eq!(set.get(&2), Some(&2)); assert_eq!(set.get(&4), None);
pub fn is_disjoint(&self, other: &HashSet<T, S>) -> bool
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pub fn is_disjoint(&self, other: &HashSet<T, S>) -> bool
Returns true
if self
has no elements in common with other
.
This is equivalent to checking for an empty intersection.
Examples
use std::collections::HashSet; let a: HashSet<_> = [1, 2, 3].iter().cloned().collect(); let mut b = HashSet::new(); assert_eq!(a.is_disjoint(&b), true); b.insert(4); assert_eq!(a.is_disjoint(&b), true); b.insert(1); assert_eq!(a.is_disjoint(&b), false);
pub fn is_subset(&self, other: &HashSet<T, S>) -> bool
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pub fn is_subset(&self, other: &HashSet<T, S>) -> bool
Returns true
if the set is a subset of another,
i.e. other
contains at least all the values in self
.
Examples
use std::collections::HashSet; let sup: HashSet<_> = [1, 2, 3].iter().cloned().collect(); let mut set = HashSet::new(); assert_eq!(set.is_subset(&sup), true); set.insert(2); assert_eq!(set.is_subset(&sup), true); set.insert(4); assert_eq!(set.is_subset(&sup), false);
pub fn is_superset(&self, other: &HashSet<T, S>) -> bool
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pub fn is_superset(&self, other: &HashSet<T, S>) -> bool
Returns true
if the set is a superset of another,
i.e. self
contains at least all the values in other
.
Examples
use std::collections::HashSet; let sub: HashSet<_> = [1, 2].iter().cloned().collect(); let mut set = HashSet::new(); assert_eq!(set.is_superset(&sub), false); set.insert(0); set.insert(1); assert_eq!(set.is_superset(&sub), false); set.insert(2); assert_eq!(set.is_superset(&sub), true);
pub fn insert(&mut self, value: T) -> bool
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pub fn insert(&mut self, value: T) -> bool
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.
Examples
use std::collections::HashSet; let mut set = HashSet::new(); assert_eq!(set.insert(2), true); assert_eq!(set.insert(2), false); assert_eq!(set.len(), 1);
pub fn replace(&mut self, value: T) -> Option<T>
1.9.0[src]
pub fn replace(&mut self, value: T) -> Option<T>
Adds a value to the set, replacing the existing value, if any, that is equal to the given one. Returns the replaced value.
Examples
use std::collections::HashSet; let mut set = HashSet::new(); set.insert(Vec::<i32>::new()); assert_eq!(set.get(&[][..]).unwrap().capacity(), 0); set.replace(Vec::with_capacity(10)); assert_eq!(set.get(&[][..]).unwrap().capacity(), 10);
pub fn remove<Q>(&mut self, value: &Q) -> bool where
Q: Hash + Eq + ?Sized,
T: Borrow<Q>,
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pub fn remove<Q>(&mut self, value: &Q) -> bool where
Q: Hash + Eq + ?Sized,
T: Borrow<Q>,
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.
Examples
use std::collections::HashSet; let mut set = HashSet::new(); set.insert(2); assert_eq!(set.remove(&2), true); assert_eq!(set.remove(&2), false);
pub fn take<Q>(&mut self, value: &Q) -> Option<T> where
Q: Hash + Eq + ?Sized,
T: Borrow<Q>,
1.9.0[src]
pub fn take<Q>(&mut self, value: &Q) -> Option<T> where
Q: Hash + Eq + ?Sized,
T: Borrow<Q>,
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.
Examples
use std::collections::HashSet; let mut set: HashSet<_> = [1, 2, 3].iter().cloned().collect(); assert_eq!(set.take(&2), Some(2)); assert_eq!(set.take(&2), None);
pub fn retain<F>(&mut self, f: F) where
F: FnMut(&T) -> bool,
1.18.0[src]
pub fn retain<F>(&mut self, f: F) where
F: FnMut(&T) -> bool,
Retains only the elements specified by the predicate.
In other words, remove all elements e
such that f(&e)
returns false
.
Examples
use std::collections::HashSet; let xs = [1,2,3,4,5,6]; let mut set: HashSet<i32> = xs.iter().cloned().collect(); set.retain(|&k| k % 2 == 0); assert_eq!(set.len(), 3);
Trait Implementations
impl<T, S> Default for HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash,
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impl<T, S> Default for HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash,
fn default() -> HashSet<T, S>
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fn default() -> HashSet<T, S>
Creates an empty HashSet<T, S>
with the Default
value for the hasher.
impl<T, S> FromIterator<T> for HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash,
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impl<T, S> FromIterator<T> for HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash,
fn from_iter<I>(iter: I) -> HashSet<T, S> where
I: IntoIterator<Item = T>,
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fn from_iter<I>(iter: I) -> HashSet<T, S> where
I: IntoIterator<Item = T>,
Creates a value from an iterator. Read more
impl<'a, 'b, T, S> BitXor<&'b HashSet<T, S>> for &'a HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash + Clone,
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impl<'a, 'b, T, S> BitXor<&'b HashSet<T, S>> for &'a HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash + Clone,
type Output = HashSet<T, S>
The resulting type after applying the ^
operator.
fn bitxor(self, rhs: &HashSet<T, S>) -> HashSet<T, S>
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fn bitxor(self, rhs: &HashSet<T, S>) -> HashSet<T, S>
Returns the symmetric difference of self
and rhs
as a new HashSet<T, S>
.
Examples
use std::collections::HashSet; let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); let set = &a ^ &b; let mut i = 0; let expected = [1, 2, 4, 5]; for x in &set { assert!(expected.contains(x)); i += 1; } assert_eq!(i, expected.len());
impl<T, S> Debug for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash + Debug,
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impl<T, S> Debug for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash + Debug,
fn fmt(&self, f: &mut Formatter) -> Result<(), Error>
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fn fmt(&self, f: &mut Formatter) -> Result<(), Error>
Formats the value using the given formatter. Read more
impl<'a, 'b, T, S> BitOr<&'b HashSet<T, S>> for &'a HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash + Clone,
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impl<'a, 'b, T, S> BitOr<&'b HashSet<T, S>> for &'a HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash + Clone,
type Output = HashSet<T, S>
The resulting type after applying the |
operator.
fn bitor(self, rhs: &HashSet<T, S>) -> HashSet<T, S>
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fn bitor(self, rhs: &HashSet<T, S>) -> HashSet<T, S>
Returns the union of self
and rhs
as a new HashSet<T, S>
.
Examples
use std::collections::HashSet; let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); let set = &a | &b; let mut i = 0; let expected = [1, 2, 3, 4, 5]; for x in &set { assert!(expected.contains(x)); i += 1; } assert_eq!(i, expected.len());
impl<T, S> PartialEq<HashSet<T, S>> for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
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impl<T, S> PartialEq<HashSet<T, S>> for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
fn eq(&self, other: &HashSet<T, S>) -> bool
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fn eq(&self, other: &HashSet<T, S>) -> bool
This method tests for self
and other
values to be equal, and is used by ==
. Read more
fn ne(&self, other: &Rhs) -> bool
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fn ne(&self, other: &Rhs) -> bool
This method tests for !=
.
impl<'a, T, S> Extend<&'a T> for HashSet<T, S> where
S: BuildHasher,
T: 'a + Eq + Hash + Copy,
1.4.0[src]
impl<'a, T, S> Extend<&'a T> for HashSet<T, S> where
S: BuildHasher,
T: 'a + Eq + Hash + Copy,
fn extend<I>(&mut self, iter: I) where
I: IntoIterator<Item = &'a T>,
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fn extend<I>(&mut self, iter: I) where
I: IntoIterator<Item = &'a T>,
Extends a collection with the contents of an iterator. Read more
impl<T, S> Extend<T> for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
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impl<T, S> Extend<T> for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
fn extend<I>(&mut self, iter: I) where
I: IntoIterator<Item = T>,
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fn extend<I>(&mut self, iter: I) where
I: IntoIterator<Item = T>,
Extends a collection with the contents of an iterator. Read more
impl<'a, 'b, T, S> BitAnd<&'b HashSet<T, S>> for &'a HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash + Clone,
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impl<'a, 'b, T, S> BitAnd<&'b HashSet<T, S>> for &'a HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash + Clone,
type Output = HashSet<T, S>
The resulting type after applying the &
operator.
fn bitand(self, rhs: &HashSet<T, S>) -> HashSet<T, S>
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fn bitand(self, rhs: &HashSet<T, S>) -> HashSet<T, S>
Returns the intersection of self
and rhs
as a new HashSet<T, S>
.
Examples
use std::collections::HashSet; let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); let b: HashSet<_> = vec![2, 3, 4].into_iter().collect(); let set = &a & &b; let mut i = 0; let expected = [2, 3]; for x in &set { assert!(expected.contains(x)); i += 1; } assert_eq!(i, expected.len());
impl<T, S> Eq for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
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impl<T, S> Eq for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
impl<T, S> IntoIterator for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
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impl<T, S> IntoIterator for HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
type Item = T
The type of the elements being iterated over.
type IntoIter = IntoIter<T>
Which kind of iterator are we turning this into?
ⓘImportant traits for IntoIter<K>fn into_iter(self) -> IntoIter<T>
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fn into_iter(self) -> 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.
Examples
use std::collections::HashSet; let mut set = HashSet::new(); set.insert("a".to_string()); set.insert("b".to_string()); // Not possible to collect to a Vec<String> with a regular `.iter()`. let v: Vec<String> = set.into_iter().collect(); // Will print in an arbitrary order. for x in &v { println!("{}", x); }
impl<'a, T, S> IntoIterator for &'a HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
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impl<'a, T, S> IntoIterator for &'a HashSet<T, S> where
S: BuildHasher,
T: Eq + Hash,
type Item = &'a T
The type of the elements being iterated over.
type IntoIter = Iter<'a, T>
Which kind of iterator are we turning this into?
ⓘImportant traits for Iter<'a, K>fn into_iter(self) -> Iter<'a, T>
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fn into_iter(self) -> Iter<'a, T>
Creates an iterator from a value. Read more
impl<T, S> Clone for HashSet<T, S> where
S: Clone,
T: Clone,
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impl<T, S> Clone for HashSet<T, S> where
S: Clone,
T: Clone,
fn clone(&self) -> HashSet<T, S>
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fn clone(&self) -> HashSet<T, S>
Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)
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fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
impl<'a, 'b, T, S> Sub<&'b HashSet<T, S>> for &'a HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash + Clone,
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impl<'a, 'b, T, S> Sub<&'b HashSet<T, S>> for &'a HashSet<T, S> where
S: BuildHasher + Default,
T: Eq + Hash + Clone,
type Output = HashSet<T, S>
The resulting type after applying the -
operator.
fn sub(self, rhs: &HashSet<T, S>) -> HashSet<T, S>
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fn sub(self, rhs: &HashSet<T, S>) -> HashSet<T, S>
Returns the difference of self
and rhs
as a new HashSet<T, S>
.
Examples
use std::collections::HashSet; let a: HashSet<_> = vec![1, 2, 3].into_iter().collect(); let b: HashSet<_> = vec![3, 4, 5].into_iter().collect(); let set = &a - &b; let mut i = 0; let expected = [1, 2]; for x in &set { assert!(expected.contains(x)); i += 1; } assert_eq!(i, expected.len());