# Struct slab::VacantEntry [−] [src]

    pub struct VacantEntry<'a, T: 'a> { /* fields omitted */ }

A handle to a vacant entry in a `Slab`.

`VacantEntry` allows constructing values with the key that they will be assigned to.

# Examples

    let mut slab = Slab::new();

    let hello = {
        let entry = slab.vacant_entry();
        let key = entry.key();

        entry.insert((key, "hello"));
        key
    };

    assert_eq!(hello, slab[hello].0);
    assert_eq!("hello", slab[hello].1);

## Implementations

### `impl<'a, T> VacantEntry<'a, T>` [src]

#### `pub fn insert(self, val: T) -> &'a mut T` [src]

Insert a value in the entry, returning a mutable reference to the value.

To get the key associated with the value, use `key` prior to calling `insert`.

# Examples

    let mut slab = Slab::new();

    let hello = {
        let entry = slab.vacant_entry();
        let key = entry.key();

        entry.insert((key, "hello"));
        key
    };

    assert_eq!(hello, slab[hello].0);
    assert_eq!("hello", slab[hello].1);

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

Return the key associated with this entry.

A value stored in this entry will be associated with this key.

# Examples

    let mut slab = Slab::new();

    let hello = {
        let entry = slab.vacant_entry();
        let key = entry.key();

        entry.insert((key, "hello"));
        key
    };

    assert_eq!(hello, slab[hello].0);
    assert_eq!("hello", slab[hello].1);

## Trait Implementations

### `impl<'a, T: Debug + 'a> Debug for VacantEntry<'a, T>` [src]

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

Formats the value using the given formatter. Read more

## Auto Trait Implementations

### `impl<'a, T> RefUnwindSafe for VacantEntry<'a, T> where
T: RefUnwindSafe,`

### `impl<'a, T> Send for VacantEntry<'a, T> where
T: Send,`

### `impl<'a, T> Sync for VacantEntry<'a, T> where
T: Sync,`

### `impl<'a, T> Unpin for VacantEntry<'a, T>`

### `impl<'a, T> !UnwindSafe for VacantEntry<'a, T>`

## 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.