std::collections::hash_map::OccupiedEntry - Rust
Description: API documentation for the Rust `OccupiedEntry` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, OccupiedEntry

# Struct std::collections::hash_map::OccupiedEntry 1.0.0 [−] [src]

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

A view into an occupied entry in a `HashMap`. It is part of the `Entry` enum.

## Methods

### `impl<'a, K, V> OccupiedEntry<'a, K, V>`
[src]

#### `fn key(&self) -> &K`
1.10.0

Gets a reference to the key in the entry.

# Examples

    use std::collections::HashMap;

    let mut map: HashMap<&str, u32> = HashMap::new();
    map.entry("poneyland").or_insert(12);
    assert_eq!(map.entry("poneyland").key(), &"poneyland");Run

#### `fn remove_entry(self) -> (K, V)`
1.12.0

Take the ownership of the key and value from the map.

# Examples

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

    let mut map: HashMap<&str, u32> = HashMap::new();
    map.entry("poneyland").or_insert(12);

    if let Entry::Occupied(o) = map.entry("poneyland") {
        // We delete the entry from the map.
        o.remove_entry();
    }

    assert_eq!(map.contains_key("poneyland"), false);Run

#### `fn get(&self) -> &V`

Gets a reference to the value in the entry.

# Examples

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

    let mut map: HashMap<&str, u32> = HashMap::new();
    map.entry("poneyland").or_insert(12);

    if let Entry::Occupied(o) = map.entry("poneyland") {
        assert_eq!(o.get(), &12);
    }Run

#### `fn get_mut(&mut self) -> &mut V`

Gets a mutable reference to the value in the entry.

# Examples

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

    let mut map: HashMap<&str, u32> = HashMap::new();
    map.entry("poneyland").or_insert(12);

    assert_eq!(map["poneyland"], 12);
    if let Entry::Occupied(mut o) = map.entry("poneyland") {
         *o.get_mut() += 10;
    }

    assert_eq!(map["poneyland"], 22);Run

#### `fn into_mut(self) -> &'a mut V`

Converts the OccupiedEntry into a mutable reference to the value in the entry with a lifetime bound to the map itself.

# Examples

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

    let mut map: HashMap<&str, u32> = HashMap::new();
    map.entry("poneyland").or_insert(12);

    assert_eq!(map["poneyland"], 12);
    if let Entry::Occupied(o) = map.entry("poneyland") {
        *o.into_mut() += 10;
    }

    assert_eq!(map["poneyland"], 22);Run

#### `fn insert(&mut self, value: V) -> V`

Sets the value of the entry, and returns the entry's old value.

# Examples

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

    let mut map: HashMap<&str, u32> = HashMap::new();
    map.entry("poneyland").or_insert(12);

    if let Entry::Occupied(mut o) = map.entry("poneyland") {
        assert_eq!(o.insert(15), 12);
    }

    assert_eq!(map["poneyland"], 15);Run

#### `fn remove(self) -> V`

Takes the value out of the entry, and returns it.

# Examples

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

    let mut map: HashMap<&str, u32> = HashMap::new();
    map.entry("poneyland").or_insert(12);

    if let Entry::Occupied(o) = map.entry("poneyland") {
        assert_eq!(o.remove(), 12);
    }

    assert_eq!(map.contains_key("poneyland"), false);Run

## Trait Implementations

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

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

Formats the value using the given formatter.

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