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Enum std::collections::btree_map::Entry

pub enum Entry<'a, K, V> where K: 'a, V: 'a {
    Vacant(VacantEntry<'a, K, V>),
    Occupied(OccupiedEntry<'a, K, V>),
}

A view into a single entry in a map, which may either be vacant or occupied. This enum is constructed from the entry method on BTreeMap.

Variants

A vacant Entry

An occupied Entry

Methods

impl<'a, K, V> Entry<'a, K, V> where K: Ord [src]

Ensures a value is in the entry by inserting the default if empty, and returns a mutable reference to the value in the entry.

Examples

use std::collections::BTreeMap;

let mut map: BTreeMap<&str, usize> = BTreeMap::new();
map.entry("poneyland").or_insert(12);

assert_eq!(map["poneyland"], 12);

Ensures a value is in the entry by inserting the result of the default function if empty, and returns a mutable reference to the value in the entry.

Examples

use std::collections::BTreeMap;

let mut map: BTreeMap<&str, String> = BTreeMap::new();
let s = "hoho".to_string();

map.entry("poneyland").or_insert_with(|| s);

assert_eq!(map["poneyland"], "hoho".to_string());

Returns a reference to this entry's key.

Examples

use std::collections::BTreeMap;

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

Trait Implementations

impl<'a, K, V> Debug for Entry<'a, K, V> where K: 'a + Ord + Debug,
        V: 'a + Debug
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/btree_map/enum.Entry.html