[−][src]Struct futures::future::OptionFuture

#[must_use = "futures do nothing unless polled"]

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

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

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

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

Trait Implementations

impl<F> Future for OptionFuture<F> where
    F: Future, [src]

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

The type of value produced on completion.

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

impl<F> Debug for OptionFuture<F> where
    F: Debug, [src]

impl<F> Clone for OptionFuture<F> where
    F: Clone, [src]

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

Performs copy-assignment from source. Read more

Auto Trait Implementations

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

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

Blanket Implementations

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, [src]

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

type Owned = T

The resulting type after obtaining ownership.

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.

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.

impl<T> BorrowMut<T> for T where
    T: ?Sized, [src]

impl<T> Borrow<T> for T where
    T: ?Sized, [src]

impl<T> Any for T where
    T: 'static + ?Sized, [src]

impl<T> FutureExt for T where
    T: Future + ?Sized, [src]

ⓘImportant traits for Map<Fut, F>
fn map<U, F>(self, f: F) -> Map<Self, F> where
    F: FnOnce(Self::Output) -> U, [src]

Map this future's output to a different type, returning a new future of the resulting type. Read more

ⓘImportant traits for Then<Fut1, Fut2, F>
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> where
    F: FnOnce(Self::Output) -> Fut,
    Fut: Future, [src]

Chain on a computation for when a future finished, passing the result of the future to the provided closure f. Read more

ⓘImportant traits for Either<A, B>
fn left_future<B>(self) -> Either<Self, B> where
    B: Future<Output = Self::Output>, [src]

Wrap this future in an Either future, making it the left-hand variant of that Either. Read more

ⓘImportant traits for Either<A, B>
fn right_future<A>(self) -> Either<A, Self> where
    A: Future<Output = Self::Output>, [src]

Wrap this future in an Either future, making it the right-hand variant of that Either. Read more

fn into_stream(self) -> IntoStream<Self>[src]

Convert this future into a single element stream. Read more

ⓘImportant traits for Flatten<Fut>
fn flatten(self) -> Flatten<Self> where
    Self::Output: Future, [src]

Flatten the execution of this future when the successful result of this future is itself another future. Read more

fn flatten_stream(self) -> FlattenStream<Self> where
    Self::Output: Stream, [src]

Flatten the execution of this future when the successful result of this future is a stream. Read more

ⓘImportant traits for Fuse<Fut>
fn fuse(self) -> Fuse<Self>[src]

Fuse a future such that poll will never again be called once it has completed. This method can be used to turn any Future into a FusedFuture. Read more

ⓘImportant traits for Inspect<Fut, F>
fn inspect<F>(self, f: F) -> Inspect<Self, F> where
    F: FnOnce(&Self::Output), [src]

Do something with the output of a future before passing it on. Read more

ⓘImportant traits for CatchUnwind<Fut>
fn catch_unwind(self) -> CatchUnwind<Self> where
    Self: UnwindSafe, [src]

Catches unwinding panics while polling the future. Read more

ⓘImportant traits for Shared<Fut>
fn shared(self) -> Shared<Self> where
    Self::Output: Clone, [src]

Create a cloneable handle to this future where all handles will resolve to the same result. Read more

fn remote_handle(self) -> (Remote<Self>, RemoteHandle<Self::Output>)[src]

Turn this future into a future that yields () on completion and sends its output to another future on a separate task. Read more

ⓘImportant traits for Pin<P>
fn boxed<'a>(self) -> Pin<Box<dyn Future<Output = Self::Output> + 'a + Send>> where
    Self: Send + 'a, [src]

Wrap the future in a Box, pinning it.

ⓘImportant traits for Pin<P>
fn boxed_local<'a>(self) -> Pin<Box<dyn Future<Output = Self::Output> + 'a>> where
    Self: 'a, [src]

Wrap the future in a Box, pinning it. Read more

ⓘImportant traits for UnitError<Fut>
fn unit_error(self) -> UnitError<Self>[src]

Turns a Future<Output = T> into a TryFuture<Ok = T, Error = ()>. Read more

ⓘImportant traits for NeverError<Fut>
fn never_error(self) -> NeverError<Self>[src]

Turns a Future<Output = T> into a TryFuture<Ok = T, Error = !>. Read more

fn poll_unpin(&mut self, cx: &mut Context) -> Poll<Self::Output> where
    Self: Unpin, [src]

A convenience for calling Future::poll on Unpin future types.