Struct futures_util::future::OptionFuture

#[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<T> From<Option<T>> for OptionFuture<T>

fn from(option: Option<T>) -> Self

Performs the conversion.

impl<F: Clone> Clone for OptionFuture<F>

Important traits for OptionFuture<F>

impl<F: Future> Future for OptionFuture<F> type Output = Option<F::Output>;

fn clone(&self) -> OptionFuture<F>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<F: Debug> Debug for OptionFuture<F>

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

Formats the value using the given formatter.

impl<F: Future> Future for OptionFuture<F>

type Output = Option<F::Output>

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output>

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

impl<F: FusedFuture> FusedFuture for OptionFuture<F>

fn is_terminated(&self) -> bool

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