# Struct futures_util::future::OptionFuture [−] [src]

    #[must_use = "futures do nothing unless you `.await` or poll them"]pub struct OptionFuture<F> { /* fields omitted */ }

A future representing a value which may or may not be present.

Created by the `From` implementation for `Option`.

# Examples

    use futures::future::OptionFuture;

    let mut a: OptionFuture<_> = Some(async { 123 }).into();
    assert_eq!(a.await, Some(123));

    a = None.into();
    assert_eq!(a.await, None);

## Trait Implementations

### `impl<F: Clone> Clone for OptionFuture<F>` [src]

#### `fn clone(&self) -> OptionFuture<F>ⓘ

### Notable traits for OptionFuture<F>

`impl<F: Future> Future for OptionFuture<F> type Output = Option<F::Output>;`
` [src]

Returns a copy of the value. Read more

#### `pub fn clone_from(&mut self, source: &Self)`1.0.0 [src]

Performs copy-assignment from `source`. Read more

### `impl<F: Debug> Debug for OptionFuture<F>` [src]

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

Formats the value using the given formatter. Read more

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

#### `fn from(option: Option<T>) -> Self` [src]

Performs the conversion.

### `impl<F: FusedFuture> FusedFuture for OptionFuture<F>` [src]

#### `fn is_terminated(&self) -> bool` [src]

Returns `true` if the underlying future should no longer be polled.

### `impl<F: Future> Future for OptionFuture<F>` [src]

#### `type Output = Option<F::Output>`

The type of value produced on completion.

#### `fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>` [src]

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more

### `impl<'__pin, F> Unpin for OptionFuture<F> where
__Origin<'__pin, F>: Unpin,` [src]

## Auto Trait Implementations

### `impl<F> RefUnwindSafe for OptionFuture<F> where
F: RefUnwindSafe,`

### `impl<F> Send for OptionFuture<F> where
F: Send,`

### `impl<F> Sync for OptionFuture<F> where
F: Sync,`

### `impl<F> UnwindSafe for OptionFuture<F> where
F: UnwindSafe,`

## 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<F> IntoFuture for F where
F: Future,` [src]

#### `type Output = <F as Future>::Output`

🔬 This is a nightly-only experimental API. (`into_future`)

The output that the future will produce on completion.

#### `type Future = F`

🔬 This is a nightly-only experimental API. (`into_future`)

Which kind of future are we turning this into?

#### `pub fn into_future(self) -> <F as IntoFuture>::Future` [src]

🔬 This is a nightly-only experimental API. (`into_future`)

Creates a future from a value.

### `impl<T> ToOwned for T where
T: Clone,` [src]

#### `type Owned = T`

The resulting type after obtaining ownership.

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

Creates owned data from borrowed data, usually by cloning. Read more

#### `pub fn clone_into(&self, target: &mut T)` [src]

🔬 This is a nightly-only experimental API. (`toowned_clone_into`)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

### `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.