Struct futures::future::OptionFuture

[+] Show declaration

[+] Expand attributes
#[must_use = "futures do nothing unless polled"]
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

#![feature(async_await, await_macro, futures_api)]
use futures::future::{self, OptionFuture};

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

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

Trait Implementations

impl<T> From<Option<T>> for OptionFuture<T>

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

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Performs the conversion.

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

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type Output = Option<<F as Future>::Output>

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

futures in libcore are unstable

The result of the Future.

fn poll(     self: PinMut<OptionFuture<F>>,     cx: &mut Context ) -> Poll<<OptionFuture<F> as Future>::Output>

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

futures in libcore are unstable

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

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

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

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Formats the value using the given formatter.

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

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

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Returns a copy of the value.

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

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Performs copy-assignment from source.