[−][src]Struct futures::future::Fuse

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

pub struct Fuse<Fut> where
    Fut: Future,  { /* fields omitted */ }
[−]

Future for the fuse method.

Methods

impl<Fut> Fuse<Fut> where
    Fut: Future, [src][−]

Creates a new Fuse-wrapped future which is already terminated.

This can be useful in combination with looping and the select! macro, which bypasses terminated futures.

Examples

#![feature(async_await, await_macro, futures_api)]
use futures::channel::mpsc;
use futures::future::{Fuse, FusedFuture, FutureExt};
use futures::select;
use futures::stream::StreamExt;
use pin_utils::pin_mut;

let (sender, mut stream) = mpsc::unbounded();

// Send a few messages into the stream
sender.unbounded_send(()).unwrap();
sender.unbounded_send(()).unwrap();
drop(sender);

// Use `Fuse::termianted()` to create an already-terminated future
// which may be instantiated later.
let foo_printer = Fuse::terminated();
pin_mut!(foo_printer);

loop {
    select! {
        _ = foo_printer => {},
        () = stream.select_next_some() => {
            if !foo_printer.is_terminated() {
                println!("Foo is already being printed!");
            } else {
                foo_printer.set(async {
                    // do some other async operations
                    println!("Printing foo from `foo_printer` future");
                }.fuse());
            }
        },
        complete => break, // `foo_printer` is terminated and the stream is done
    }
}

Trait Implementations

impl<Fut> FusedFuture for Fuse<Fut> where
    Fut: Future, [src][+]

impl<Fut> Debug for Fuse<Fut> where
    Fut: Debug + Future, [src][+]

impl<Fut> Future for Fuse<Fut> where
    Fut: Future, [src][+]

type Output = <Fut as Future>::Output

The type of value produced on completion.

Auto Trait Implementations

impl<Fut> Send for Fuse<Fut> where
    Fut: Send, 

impl<Fut> Sync for Fuse<Fut> where
    Fut: Sync, 

Blanket Implementations

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

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

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

type Error = Infallible

The type returned in the event of a conversion error.

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

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

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

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

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

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

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

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

Convert this future into a single element stream. Read more

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

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

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

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

Catches unwinding panics while polling the future. Read more

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

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

Wrap the future in a Box, pinning it.

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

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

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

impl<Fut> TryFutureExt for Fut where
    Fut: TryFuture + ?Sized, [src][+]

Flattens the execution of this future when the successful result of this future is a [Sink]. Read more

Maps this future's success value to a different value. Read more

Maps this future's error value to a different value. Read more

Maps this future's Error to a new error type using the Into trait. Read more

Executes another future after this one resolves successfully. The success value is passed to a closure to create this subsequent future. Read more

Executes another future if this one resolves to an error. The error value is passed to a closure to create this subsequent future. Read more

Unwraps this future's ouput, producing a future with this future's Ok type as its Output type. Read more

Wraps a [TryFuture] into a future compatable with libraries using futures 0.1 future definitons. Requires the compat feature to enable. Read more

Wraps a [TryFuture] into a type that implements Future. Read more

impl<F, T, E> TryFuture for F where
    F: Future<Output = Result<T, E>> + ?Sized, [src][+]

type Ok = T

The type of successful values yielded by this future

type Error = E

The type of failures yielded by this future