Struct varlink::StringHashSet

pub struct StringHashSet { /* fields omitted */ }

Methods

impl StringHashSet

pub fn new() -> StringHashSet

Methods from Deref<Target = HashSet<String>>

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 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);
}

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

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());

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)

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 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 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 try_reserve(
    &mut self,
    additional: usize
) -> Result<(), CollectionAllocErr>

🔬 This is a nightly-only experimental API. (try_reserve)

new API

Tries to reserve capacity for at least additional more elements to be inserted in the given HashSet<K,V>. The collection may reserve more space to avoid frequent reallocations.

Errors

If the capacity overflows, or the allocator reports a failure, then an error is returned.

Examples

#![feature(try_reserve)]
use std::collections::HashSet;
let mut set: HashSet<i32> = HashSet::new();
set.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?");

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)

🔬 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);

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());

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());

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());

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 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>, 

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

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

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

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

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>

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>, 

Removes a value from the set. Returns whether 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>, 

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, 

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 Default for StringHashSet

fn default() -> StringHashSet

Returns the "default value" for a type.

impl Clone for StringHashSet

fn clone(&self) -> StringHashSet

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl PartialEq<StringHashSet> for StringHashSet

fn eq(&self, other: &StringHashSet) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &StringHashSet) -> bool

This method tests for !=.

impl Deref for StringHashSet

type Target = HashSet<String>

The resulting type after dereferencing.

fn deref(&self) -> &HashSet<String>

Dereferences the value.

impl Debug for StringHashSet

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl DerefMut for StringHashSet

fn deref_mut(&mut self) -> &mut HashSet<String>

Mutably dereferences the value.

impl Serialize for StringHashSet

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl<'de> Deserialize<'de> for StringHashSet

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.