[][src]Struct futures::future::Fuse

#[must_use = "futures do nothing unless you `.await` or poll them"]
pub struct Fuse<Fut> where
    Fut: Future
{ /* fields omitted */ }

Future for the fuse method.

Methods

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

Important traits for Fuse<Fut>
pub fn terminated() -> Fuse<Fut>[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)]
use futures::channel::mpsc;
use futures::future::{Fuse, FusedFuture, FutureExt};
use futures::select;
use futures::stream::StreamExt;
use futures::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> Debug for Fuse<Fut> where
    Fut: Debug + Future
[src]

impl<Fut> FusedFuture for Fuse<Fut> where
    Fut: 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> Unpin for Fuse<Fut> where
    Fut: Unpin

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

impl<Fut> UnwindSafe for Fuse<Fut> where
    Fut: UnwindSafe

impl<Fut> RefUnwindSafe for Fuse<Fut> where
    Fut: RefUnwindSafe

Blanket Implementations

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

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

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<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

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

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