pub enum Entry<'a, T, S, A = Global>where
    A: Allocator + Clone,
{ Occupied(OccupiedEntry<'a, T, S, A>), Vacant(VacantEntry<'a, T, S, A>), }
Expand description

A view into a single entry in a set, which may either be vacant or occupied.

This enum is constructed from the entry method on HashSet.

Examples

use hashbrown::hash_set::{Entry, HashSet, OccupiedEntry};

let mut set = HashSet::new();
set.extend(["a", "b", "c"]);
assert_eq!(set.len(), 3);

// Existing value (insert)
let entry: Entry<_, _> = set.entry("a");
let _raw_o: OccupiedEntry<_, _> = entry.insert();
assert_eq!(set.len(), 3);
// Nonexistent value (insert)
set.entry("d").insert();

// Existing value (or_insert)
set.entry("b").or_insert();
// Nonexistent value (or_insert)
set.entry("e").or_insert();

println!("Our HashSet: {:?}", set);

let mut vec: Vec<_> = set.iter().copied().collect();
// The `Iter` iterator produces items in arbitrary order, so the
// items must be sorted to test them against a sorted array.
vec.sort_unstable();
assert_eq!(vec, ["a", "b", "c", "d", "e"]);

Variants

Occupied(OccupiedEntry<'a, T, S, A>)

An occupied entry.

Examples

use hashbrown::hash_set::{Entry, HashSet};
let mut set: HashSet<_> = ["a", "b"].into();

match set.entry("a") {
    Entry::Vacant(_) => unreachable!(),
    Entry::Occupied(_) => { }
}

Vacant(VacantEntry<'a, T, S, A>)

A vacant entry.

Examples

use hashbrown::hash_set::{Entry, HashSet};
let mut set: HashSet<&str> = HashSet::new();

match set.entry("a") {
    Entry::Occupied(_) => unreachable!(),
    Entry::Vacant(_) => { }
}

Implementations

Sets the value of the entry, and returns an OccupiedEntry.

Examples
use hashbrown::HashSet;

let mut set: HashSet<&str> = HashSet::new();
let entry = set.entry("horseyland").insert();

assert_eq!(entry.get(), &"horseyland");

Ensures a value is in the entry by inserting if it was vacant.

Examples
use hashbrown::HashSet;

let mut set: HashSet<&str> = HashSet::new();

// nonexistent key
set.entry("poneyland").or_insert();
assert!(set.contains("poneyland"));

// existing key
set.entry("poneyland").or_insert();
assert!(set.contains("poneyland"));
assert_eq!(set.len(), 1);

Returns a reference to this entry’s value.

Examples
use hashbrown::HashSet;

let mut set: HashSet<&str> = HashSet::new();
set.entry("poneyland").or_insert();
// existing key
assert_eq!(set.entry("poneyland").get(), &"poneyland");
// nonexistent key
assert_eq!(set.entry("horseland").get(), &"horseland");

Trait Implementations

Formats the value using the given formatter. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.