# Struct hashbrown::hash_map::OccupiedEntry [−] [src]

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

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

## Implementations

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

#### `pub fn key(&self) -> &K` [src]

Gets a reference to the key in the entry.

# Examples

    use hashbrown::HashMap;

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

#### `pub fn remove_entry(self) -> (K, V)` [src]

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

# Examples

    use hashbrown::HashMap;
    use hashbrown::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);

#### `pub fn get(&self) -> &V` [src]

Gets a reference to the value in the entry.

# Examples

    use hashbrown::HashMap;
    use hashbrown::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);
    }

#### `pub fn get_mut(&mut self) -> &mut V` [src]

Gets a mutable reference to the value in the entry.

If you need a reference to the `OccupiedEntry` which may outlive the destruction of the `Entry` value, see `into_mut`.

# Examples

    use hashbrown::HashMap;
    use hashbrown::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!(*o.get(), 22);

        // We can use the same Entry multiple times.
        *o.get_mut() += 2;
    }

    assert_eq!(map["poneyland"], 24);

#### `pub fn into_mut(self) -> &'a mut V` [src]

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

If you need multiple references to the `OccupiedEntry`, see `get_mut`.

# Examples

    use hashbrown::HashMap;
    use hashbrown::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);

#### `pub fn insert(&mut self, value: V) -> V` [src]

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

# Examples

    use hashbrown::HashMap;
    use hashbrown::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);

#### `pub fn remove(self) -> V` [src]

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

# Examples

    use hashbrown::HashMap;
    use hashbrown::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);

#### `pub fn replace_entry(self, value: V) -> (K, V)` [src]

Replaces the entry, returning the old key and value. The new key in the hash map will be the key used to create this entry.

# Examples

    use hashbrown::hash_map::{Entry, HashMap};
    use std::rc::Rc;

    let mut map: HashMap<Rc<String>, u32> = HashMap::new();
    map.insert(Rc::new("Stringthing".to_string()), 15);

    let my_key = Rc::new("Stringthing".to_string());

    if let Entry::Occupied(entry) = map.entry(my_key) {
        // Also replace the key with a handle to our other key.
        let (old_key, old_value): (Rc<String>, u32) = entry.replace_entry(16);
    }

#### `pub fn replace_key(self) -> K` [src]

Replaces the key in the hash map with the key used to create this entry.

# Examples

    use hashbrown::hash_map::{Entry, HashMap};
    use std::rc::Rc;

    let mut map: HashMap<Rc<String>, u32> = HashMap::new();
    let mut known_strings: Vec<Rc<String>> = Vec::new();

    // Initialise known strings, run program, etc.

    reclaim_memory(&mut map, &known_strings);

    fn reclaim_memory(map: &mut HashMap<Rc<String>, u32>, known_strings: &[Rc<String>] ) {
        for s in known_strings {
            if let Entry::Occupied(entry) = map.entry(s.clone()) {
                // Replaces the entry's key with our version of it in `known_strings`.
                entry.replace_key();
            }
        }
    }

#### `pub fn replace_entry_with<F>(self, f: F) -> Entry<'a, K, V, S> where
F: FnOnce(&K, V) -> Option<V>,` [src]

Provides shared access to the key and owned access to the value of the entry and allows to replace or remove it based on the value of the returned option.

# Examples

    use hashbrown::HashMap;
    use hashbrown::hash_map::Entry;

    let mut map: HashMap<&str, u32> = HashMap::new();
    map.insert("poneyland", 42);

    let entry = match map.entry("poneyland") {
        Entry::Occupied(e) => {
            e.replace_entry_with(|k, v| {
                assert_eq!(k, &"poneyland");
                assert_eq!(v, 42);
                Some(v + 1)
            })
        }
        Entry::Vacant(_) => panic!(),
    };

    match entry {
        Entry::Occupied(e) => {
            assert_eq!(e.key(), &"poneyland");
            assert_eq!(e.get(), &43);
        }
        Entry::Vacant(_) => panic!(),
    }

    assert_eq!(map["poneyland"], 43);

    let entry = match map.entry("poneyland") {
        Entry::Occupied(e) => e.replace_entry_with(|_k, _v| None),
        Entry::Vacant(_) => panic!(),
    };

    match entry {
        Entry::Vacant(e) => {
            assert_eq!(e.key(), &"poneyland");
        }
        Entry::Occupied(_) => panic!(),
    }

    assert!(!map.contains_key("poneyland"));

## Trait Implementations

### `impl<K: Debug, V: Debug, S> Debug for OccupiedEntry<'_, K, V, S>` [src]

#### `fn fmt(&self, f: &mut Formatter<'_>) -> Result` [src]

Formats the value using the given formatter. Read more

### `impl<K, V, S> Send for OccupiedEntry<'_, K, V, S> where
K: Send,
V: Send,
S: Send,` [src]

### `impl<K, V, S> Sync for OccupiedEntry<'_, K, V, S> where
K: Sync,
V: Sync,
S: Sync,` [src]

## Auto Trait Implementations

### `impl<'a, K, V, S> Unpin for OccupiedEntry<'a, K, V, S> where
K: Unpin,`

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `pub fn type_id(&self) -> TypeId` [src]

Gets the `TypeId` of `self`. Read more

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow(&self) -> &T` [src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow_mut(&mut self) -> &mut T` [src]

Mutably borrows from an owned value. Read more

### `impl<T> From<T> for T` [src]

#### `pub fn from(t: T) -> T` [src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `pub fn into(self) -> U` [src]

Performs the conversion.

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>` [src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

#### `pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>` [src]

Performs the conversion.