pub struct HashSet<A, S = RandomState> { /* private fields */ }
Expand description
An unordered set.
An immutable hash set using [hash array mapped tries] 1.
Most operations on this set are O(logx n) for a
suitably high x that it should be nearly O(1) for most sets.
Because of this, it’s a great choice for a generic set as long as
you don’t mind that values will need to implement
Hash
and Eq
.
Values will have a predictable order based on the hasher
being used. Unless otherwise specified, this will be the standard
RandomState
hasher.
Implementations
sourceimpl<A> HashSet<A, RandomState>
impl<A> HashSet<A, RandomState>
sourceimpl<A, S> HashSet<A, S>
impl<A, S> HashSet<A, S>
sourcepub fn is_empty(&self) -> bool
pub fn is_empty(&self) -> bool
Test whether a set is empty.
Time: O(1)
Examples
assert!(
!hashset![1, 2, 3].is_empty()
);
assert!(
HashSet::<i32>::new().is_empty()
);
sourcepub fn ptr_eq(&self, other: &Self) -> bool
pub fn ptr_eq(&self, other: &Self) -> bool
Test whether two sets refer to the same content in memory.
This is true if the two sides are references to the same set, or if the two sets refer to the same root node.
This would return true if you’re comparing a set to itself, or if you’re comparing a set to a fresh clone of itself.
Time: O(1)
sourcepub fn with_hasher<RS>(hasher: RS) -> Self where
Arc<S>: From<RS>,
pub fn with_hasher<RS>(hasher: RS) -> Self where
Arc<S>: From<RS>,
Construct an empty hash set using the provided hasher.
sourcepub fn hasher(&self) -> &Arc<S>
pub fn hasher(&self) -> &Arc<S>
Get a reference to the set’s BuildHasher
.
sourcepub fn new_from<A1>(&self) -> HashSet<A1, S> where
A1: Hash + Eq + Clone,
pub fn new_from<A1>(&self) -> HashSet<A1, S> where
A1: Hash + Eq + Clone,
Construct an empty hash set using the same hasher as the current hash set.
sourcepub fn clear(&mut self)
pub fn clear(&mut self)
Discard all elements from the set.
This leaves you with an empty set, and all elements that were previously inside it are dropped.
Time: O(n)
Examples
let mut set = hashset![1, 2, 3];
set.clear();
assert!(set.is_empty());
sourcepub fn iter(&self) -> Iter<'_, A>ⓘNotable traits for Iter<'a, A>impl<'a, A> Iterator for Iter<'a, A> where
A: 'a, type Item = &'a A;
pub fn iter(&self) -> Iter<'_, A>ⓘNotable traits for Iter<'a, A>impl<'a, A> Iterator for Iter<'a, A> where
A: 'a, type Item = &'a A;
A: 'a, type Item = &'a A;
Get an iterator over the values in a hash set.
Please note that the order is consistent between sets using the same hasher, but no other ordering guarantee is offered. Items will not come out in insertion order or sort order. They will, however, come out in the same order every time for the same set.
sourceimpl<A, S> HashSet<A, S> where
A: Hash + Eq,
S: BuildHasher,
impl<A, S> HashSet<A, S> where
A: Hash + Eq,
S: BuildHasher,
sourcepub fn contains<BA>(&self, a: &BA) -> bool where
BA: Hash + Eq + ?Sized,
A: Borrow<BA>,
pub fn contains<BA>(&self, a: &BA) -> bool where
BA: Hash + Eq + ?Sized,
A: Borrow<BA>,
Test if a value is part of a set.
Time: O(log n)
sourcepub fn is_subset<RS>(&self, other: RS) -> bool where
RS: Borrow<Self>,
pub fn is_subset<RS>(&self, other: RS) -> bool where
RS: Borrow<Self>,
Test whether a set is a subset of another set, meaning that all values in our set must also be in the other set.
Time: O(n log n)
sourcepub fn is_proper_subset<RS>(&self, other: RS) -> bool where
RS: Borrow<Self>,
pub fn is_proper_subset<RS>(&self, other: RS) -> bool where
RS: Borrow<Self>,
Test whether a set is a proper subset of another set, meaning that all values in our set must also be in the other set. A proper subset must also be smaller than the other set.
Time: O(n log n)
sourceimpl<A, S> HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher,
impl<A, S> HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher,
sourcepub fn remove<BA>(&mut self, a: &BA) -> Option<A> where
BA: Hash + Eq + ?Sized,
A: Borrow<BA>,
pub fn remove<BA>(&mut self, a: &BA) -> Option<A> where
BA: Hash + Eq + ?Sized,
A: Borrow<BA>,
Remove a value from a set if it exists.
Time: O(log n)
sourcepub fn update(&self, a: A) -> Self
pub fn update(&self, a: A) -> Self
Construct a new set from the current set with the given value added.
Time: O(log n)
Examples
let set = hashset![123];
assert_eq!(
set.update(456),
hashset![123, 456]
);
sourcepub fn without<BA>(&self, a: &BA) -> Self where
BA: Hash + Eq + ?Sized,
A: Borrow<BA>,
pub fn without<BA>(&self, a: &BA) -> Self where
BA: Hash + Eq + ?Sized,
A: Borrow<BA>,
Construct a new set with the given value removed if it’s in the set.
Time: O(log n)
sourcepub fn retain<F>(&mut self, f: F) where
F: FnMut(&A) -> bool,
pub fn retain<F>(&mut self, f: F) where
F: FnMut(&A) -> bool,
Filter out values from a set which don’t satisfy a predicate.
This is slightly more efficient than filtering using an iterator, in that it doesn’t need to rehash the retained values, but it still needs to reconstruct the entire tree structure of the set.
Time: O(n log n)
Examples
let mut set = hashset![1, 2, 3];
set.retain(|v| *v > 1);
let expected = hashset![2, 3];
assert_eq!(expected, set);
sourcepub fn union(self, other: Self) -> Self
pub fn union(self, other: Self) -> Self
Construct the union of two sets.
Time: O(n log n)
Examples
let set1 = hashset!{1, 2};
let set2 = hashset!{2, 3};
let expected = hashset!{1, 2, 3};
assert_eq!(expected, set1.union(set2));
sourcepub fn unions<I>(i: I) -> Self where
I: IntoIterator<Item = Self>,
S: Default,
pub fn unions<I>(i: I) -> Self where
I: IntoIterator<Item = Self>,
S: Default,
Construct the union of multiple sets.
Time: O(n log n)
sourcepub fn difference(self, other: Self) -> Self
pub fn difference(self, other: Self) -> Self
Construct the symmetric difference between two sets.
This is an alias for the
symmetric_difference
method.
Time: O(n log n)
Examples
let set1 = hashset!{1, 2};
let set2 = hashset!{2, 3};
let expected = hashset!{1, 3};
assert_eq!(expected, set1.difference(set2));
sourcepub fn symmetric_difference(self, other: Self) -> Self
pub fn symmetric_difference(self, other: Self) -> Self
Construct the symmetric difference between two sets.
Time: O(n log n)
Examples
let set1 = hashset!{1, 2};
let set2 = hashset!{2, 3};
let expected = hashset!{1, 3};
assert_eq!(expected, set1.symmetric_difference(set2));
sourcepub fn relative_complement(self, other: Self) -> Self
pub fn relative_complement(self, other: Self) -> Self
Construct the relative complement between two sets, that is the set
of values in self
that do not occur in other
.
Time: O(m log n) where m is the size of the other set
Examples
let set1 = ordset!{1, 2};
let set2 = ordset!{2, 3};
let expected = ordset!{1};
assert_eq!(expected, set1.relative_complement(set2));
sourcepub fn intersection(self, other: Self) -> Self
pub fn intersection(self, other: Self) -> Self
Construct the intersection of two sets.
Time: O(n log n)
Examples
let set1 = hashset!{1, 2};
let set2 = hashset!{2, 3};
let expected = hashset!{2};
assert_eq!(expected, set1.intersection(set2));
Trait Implementations
sourceimpl<'a, A, S> Add<&'a HashSet<A, S>> for &'a HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher,
impl<'a, A, S> Add<&'a HashSet<A, S>> for &'a HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher,
sourceimpl<A, S> Arbitrary for HashSet<A, S> where
A: Hash + Eq + Arbitrary + Sync,
S: BuildHasher + Default + Send + Sync + 'static,
impl<A, S> Arbitrary for HashSet<A, S> where
A: Hash + Eq + Arbitrary + Sync,
S: BuildHasher + Default + Send + Sync + 'static,
sourceimpl<'a, A, S> Arbitrary<'a> for HashSet<A, S> where
A: Arbitrary<'a> + Hash + Eq + Clone,
S: BuildHasher + Default + 'static,
impl<'a, A, S> Arbitrary<'a> for HashSet<A, S> where
A: Arbitrary<'a> + Hash + Eq + Clone,
S: BuildHasher + Default + 'static,
sourcefn arbitrary(u: &mut Unstructured<'a>) -> Result<Self>
fn arbitrary(u: &mut Unstructured<'a>) -> Result<Self>
Generate an arbitrary value of Self
from the given unstructured data. Read more
sourcefn arbitrary_take_rest(u: Unstructured<'a>) -> Result<Self>
fn arbitrary_take_rest(u: Unstructured<'a>) -> Result<Self>
Generate an arbitrary value of Self
from the entirety of the given unstructured data. Read more
sourceimpl<A, S> Default for HashSet<A, S> where
S: BuildHasher + Default,
impl<A, S> Default for HashSet<A, S> where
S: BuildHasher + Default,
sourceimpl<'de, A: Deserialize<'de> + Hash + Eq + Clone, S: BuildHasher + Default> Deserialize<'de> for HashSet<A, S>
impl<'de, A: Deserialize<'de> + Hash + Eq + Clone, S: BuildHasher + Default> Deserialize<'de> for HashSet<A, S>
sourcefn deserialize<D>(des: D) -> Result<Self, D::Error> where
D: Deserializer<'de>,
fn deserialize<D>(des: D) -> Result<Self, D::Error> where
D: Deserializer<'de>,
Deserialize this value from the given Serde deserializer. Read more
sourceimpl<A, S, R> Extend<R> for HashSet<A, S> where
A: Hash + Eq + Clone + From<R>,
S: BuildHasher,
impl<A, S, R> Extend<R> for HashSet<A, S> where
A: Hash + Eq + Clone + From<R>,
S: BuildHasher,
sourcefn extend<I>(&mut self, iter: I) where
I: IntoIterator<Item = R>,
fn extend<I>(&mut self, iter: I) where
I: IntoIterator<Item = R>,
Extends a collection with the contents of an iterator. Read more
sourcefn extend_one(&mut self, item: A)
fn extend_one(&mut self, item: A)
extend_one
)Extends a collection with exactly one element.
sourcefn extend_reserve(&mut self, additional: usize)
fn extend_reserve(&mut self, additional: usize)
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
sourceimpl<'a, A, S> From<&'a [A]> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
impl<'a, A, S> From<&'a [A]> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
sourceimpl<'a, A, S> From<&'a BTreeSet<A>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
impl<'a, A, S> From<&'a BTreeSet<A>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
sourceimpl<'a, A, S> From<&'a HashSet<A, RandomState>> for HashSet<A, S> where
A: Eq + Hash + Clone,
S: BuildHasher + Default,
impl<'a, A, S> From<&'a HashSet<A, RandomState>> for HashSet<A, S> where
A: Eq + Hash + Clone,
S: BuildHasher + Default,
sourceimpl<'a, A, S> From<&'a OrdSet<A>> for HashSet<A, S> where
A: Ord + Hash + Eq + Clone,
S: BuildHasher + Default,
impl<'a, A, S> From<&'a OrdSet<A>> for HashSet<A, S> where
A: Ord + Hash + Eq + Clone,
S: BuildHasher + Default,
sourceimpl<'a, A, S> From<&'a Vec<A, Global>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
impl<'a, A, S> From<&'a Vec<A, Global>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
sourceimpl<'a, A, S> From<&'a Vector<A>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
impl<'a, A, S> From<&'a Vector<A>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
sourceimpl<'s, 'a, A, OA, SA, SB> From<&'s HashSet<&'a A, SA>> for HashSet<OA, SB> where
A: ToOwned<Owned = OA> + Hash + Eq + ?Sized,
OA: Borrow<A> + Hash + Eq + Clone,
SA: BuildHasher,
SB: BuildHasher + Default,
impl<'s, 'a, A, OA, SA, SB> From<&'s HashSet<&'a A, SA>> for HashSet<OA, SB> where
A: ToOwned<Owned = OA> + Hash + Eq + ?Sized,
OA: Borrow<A> + Hash + Eq + Clone,
SA: BuildHasher,
SB: BuildHasher + Default,
sourceimpl<A, S> From<HashSet<A, RandomState>> for HashSet<A, S> where
A: Eq + Hash + Clone,
S: BuildHasher + Default,
impl<A, S> From<HashSet<A, RandomState>> for HashSet<A, S> where
A: Eq + Hash + Clone,
S: BuildHasher + Default,
sourceimpl<A, S> From<OrdSet<A>> for HashSet<A, S> where
A: Ord + Hash + Eq + Clone,
S: BuildHasher + Default,
impl<A, S> From<OrdSet<A>> for HashSet<A, S> where
A: Ord + Hash + Eq + Clone,
S: BuildHasher + Default,
sourceimpl<A, S> From<Vec<A, Global>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
impl<A, S> From<Vec<A, Global>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
sourceimpl<A, S> From<Vector<A>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
impl<A, S> From<Vector<A>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
sourceimpl<A, RA, S> FromIterator<RA> for HashSet<A, S> where
A: Hash + Eq + Clone + From<RA>,
S: BuildHasher + Default,
impl<A, RA, S> FromIterator<RA> for HashSet<A, S> where
A: Hash + Eq + Clone + From<RA>,
S: BuildHasher + Default,
sourcefn from_iter<T>(i: T) -> Self where
T: IntoIterator<Item = RA>,
fn from_iter<T>(i: T) -> Self where
T: IntoIterator<Item = RA>,
Creates a value from an iterator. Read more
sourceimpl<'a, A, S> IntoIterator for &'a HashSet<A, S> where
A: Hash + Eq,
S: BuildHasher,
impl<'a, A, S> IntoIterator for &'a HashSet<A, S> where
A: Hash + Eq,
S: BuildHasher,
sourceimpl<A, S> IntoIterator for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher,
impl<A, S> IntoIterator for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher,
type Item = A
type Item = A
The type of the elements being iterated over.
type IntoIter = ConsumingIter<<HashSet<A, S> as IntoIterator>::Item>
type IntoIter = ConsumingIter<<HashSet<A, S> as IntoIterator>::Item>
Which kind of iterator are we turning this into?
sourceimpl<'a, A, S> Mul<&'a HashSet<A, S>> for &'a HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher,
impl<'a, A, S> Mul<&'a HashSet<A, S>> for &'a HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher,
sourceimpl<A, S> Ord for HashSet<A, S> where
A: Hash + Eq + Clone + Ord,
S: BuildHasher + Default,
impl<A, S> Ord for HashSet<A, S> where
A: Hash + Eq + Clone + Ord,
S: BuildHasher + Default,
sourceimpl<A, S> PartialEq<HashSet<A, S>> for HashSet<A, S> where
A: Hash + Eq,
S: BuildHasher + Default,
impl<A, S> PartialEq<HashSet<A, S>> for HashSet<A, S> where
A: Hash + Eq,
S: BuildHasher + Default,
sourceimpl<A, S> PartialOrd<HashSet<A, S>> for HashSet<A, S> where
A: Hash + Eq + Clone + PartialOrd,
S: BuildHasher + Default,
impl<A, S> PartialOrd<HashSet<A, S>> for HashSet<A, S> where
A: Hash + Eq + Clone + PartialOrd,
S: BuildHasher + Default,
sourcefn partial_cmp(&self, other: &Self) -> Option<Ordering>
fn partial_cmp(&self, other: &Self) -> Option<Ordering>
This method returns an ordering between self
and other
values if one exists. Read more
1.0.0 · sourcefn lt(&self, other: &Rhs) -> bool
fn lt(&self, other: &Rhs) -> bool
This method tests less than (for self
and other
) and is used by the <
operator. Read more
1.0.0 · sourcefn le(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
sourceimpl<A, S> Sum<HashSet<A, S>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
impl<A, S> Sum<HashSet<A, S>> for HashSet<A, S> where
A: Hash + Eq + Clone,
S: BuildHasher + Default,
impl<A, S> Eq for HashSet<A, S> where
A: Hash + Eq,
S: BuildHasher + Default,
Auto Trait Implementations
impl<A, S> RefUnwindSafe for HashSet<A, S> where
A: RefUnwindSafe,
S: RefUnwindSafe,
impl<A, S> Send for HashSet<A, S> where
A: Send + Sync,
S: Send + Sync,
impl<A, S> Sync for HashSet<A, S> where
A: Send + Sync,
S: Send + Sync,
impl<A, S> Unpin for HashSet<A, S> where
A: Unpin,
impl<A, S> UnwindSafe for HashSet<A, S> where
A: UnwindSafe + RefUnwindSafe,
S: RefUnwindSafe,
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<T> Pointable for T
impl<T> Pointable for T
sourceimpl<T> ToOwned for T where
T: Clone,
impl<T> ToOwned for T where
T: Clone,
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
sourcefn clone_into(&self, target: &mut T)
fn clone_into(&self, target: &mut T)
toowned_clone_into
)Uses borrowed data to replace owned data, usually by cloning. Read more