Struct futures_util::future::OptionFuture

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

[−] Expand description

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>[+]

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fn clone(&self) -> OptionFuture<F>[−]

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)[−]

Performs copy-assignment from source.

impl<F: Debug> Debug for OptionFuture<F>[+]

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

Formats the value using the given formatter.

impl<T> From<Option<T>> for OptionFuture<T>[+]

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fn from(option: Option<T>) -> Self[−]

Performs the conversion.

impl<F: FusedFuture> FusedFuture for OptionFuture<F>[+]

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fn is_terminated(&self) -> bool[−]

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

impl<F: Future> Future for OptionFuture<F>[+]

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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<'__pin, F> Unpin for OptionFuture<F> where
    __Origin<'__pin, F>: Unpin,