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Struct std::collections::hash_map::VacantEntry

pub struct VacantEntry<'a, K: 'a, V: 'a> { /* fields omitted */ }

A view into a single empty location in a HashMap. It is part of the Entry enum.

Methods

impl<'a, K: 'a, V: 'a> VacantEntry<'a, K, V> [src]

Gets a reference to the key that would be used when inserting a value through the VacantEntry.

Examples

use std::collections::HashMap;

let mut map: HashMap<&str, u32> = HashMap::new();
assert_eq!(map.entry("poneyland").key(), &"poneyland");

Take ownership of the key.

Examples

use std::collections::HashMap;
use std::collections::hash_map::Entry;

let mut map: HashMap<&str, u32> = HashMap::new();

if let Entry::Vacant(v) = map.entry("poneyland") {
    v.into_key();
}

Sets the value of the entry with the VacantEntry's key, and returns a mutable reference to it.

Examples

use std::collections::HashMap;
use std::collections::hash_map::Entry;

let mut map: HashMap<&str, u32> = HashMap::new();

if let Entry::Vacant(o) = map.entry("poneyland") {
    o.insert(37);
}
assert_eq!(map["poneyland"], 37);

Trait Implementations

impl<'a, K: 'a + Debug, V: 'a> Debug for VacantEntry<'a, K, V>
1.12.0
[src]

Formats the value using the given formatter.

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/collections/hash_map/struct.VacantEntry.html