[][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]

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, 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]

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 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.

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

fn flatten_sink<Item>(self) -> FlattenSink<Self, Self::Ok> where
    Self::Ok: Sink<Item>,
    <Self::Ok as Sink<Item>>::SinkError == Self::Error
[src]

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

Important traits for MapOk<Fut, F>
fn map_ok<T, F>(self, f: F) -> MapOk<Self, F> where
    F: FnOnce(Self::Ok) -> T, 
[src]

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

Important traits for MapErr<Fut, F>
fn map_err<E, F>(self, f: F) -> MapErr<Self, F> where
    F: FnOnce(Self::Error) -> E, 
[src]

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

Important traits for ErrInto<Fut, E>
fn err_into<E>(self) -> ErrInto<Self, E> where
    Self::Error: Into<E>, 
[src]

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

Important traits for AndThen<Fut1, Fut2, F>
fn and_then<Fut, F>(self, f: F) -> AndThen<Self, Fut, F> where
    F: FnOnce(Self::Ok) -> Fut,
    Fut: TryFuture<Error = Self::Error>, 
[src]

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

Important traits for OrElse<Fut1, Fut2, F>
fn or_else<Fut, F>(self, f: F) -> OrElse<Self, Fut, F> where
    F: FnOnce(Self::Error) -> Fut,
    Fut: TryFuture<Ok = Self::Ok>, 
[src]

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

Important traits for UnwrapOrElse<Fut, F>
fn unwrap_or_else<F>(self, f: F) -> UnwrapOrElse<Self, F> where
    F: FnOnce(Self::Error) -> Self::Ok
[src]

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

Important traits for Compat<W>
fn compat(self) -> Compat<Self> where
    Self: Unpin
[src]

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

Important traits for IntoFuture<Fut>
fn into_future(self) -> IntoFuture<Self>[src]

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