# Struct futures_util::future::Fuse [−] [src]

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

Future for the `fuse` method.

## Implementations

### `impl<Fut: Future> Fuse<Fut>` [src]

#### `pub fn terminated() -> Self` [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

    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::terminated()` 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> Debug for Fuse<Fut>` [src]

#### `fn fmt(&self, f: &mut Formatter<'_>) -> Result` [src]

Formats the value using the given formatter. Read more

### `impl<Fut: Future> FusedFuture for Fuse<Fut>` [src]

#### `fn is_terminated(&self) -> bool` [src]

Returns `true` if the underlying future should no longer be polled.

### `impl<Fut: Future> Future for Fuse<Fut>` [src]

#### `type Output = Fut::Output`

The type of value produced on completion.

#### `fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Fut::Output>` [src]

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

### `impl<'__pin, Fut> Unpin for Fuse<Fut> where
__Origin<'__pin, Fut>: Unpin,` [src]

## Auto Trait Implementations

### `impl<Fut> RefUnwindSafe for Fuse<Fut> where
Fut: RefUnwindSafe,`

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

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

### `impl<Fut> UnwindSafe for Fuse<Fut> where
Fut: UnwindSafe,`

## Blanket Implementations

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

#### `pub fn type_id(&self) -> TypeId` [src]

Gets the `TypeId` of `self`. Read more

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

#### `pub fn borrow(&self) -> &T` [src]

Immutably borrows from an owned value. Read more

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

#### `pub fn borrow_mut(&mut self) -> &mut T` [src]

Mutably borrows from an owned value. Read more

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

#### `pub fn from(t: T) -> T` [src]

Performs the conversion.

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

#### `pub fn into(self) -> U` [src]

Performs the conversion.

### `impl<F> IntoFuture for F where
F: Future,` [src]

#### `type Output = <F as Future>::Output`

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

The output that the future will produce on completion.

#### `type Future = F`

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

Which kind of future are we turning this into?

#### `pub fn into_future(self) -> <F as IntoFuture>::Future` [src]

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

Creates a future from a value.

### `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.

#### `pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>` [src]

Performs the conversion.

### `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

#### `pub fn try_poll(
self: Pin<&mut F>,
cx: &mut Context<'_>
) -> Poll<<F as Future>::Output>` [src]

Poll this `TryFuture` as if it were a `Future`. Read more

### `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.

#### `pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>` [src]

Performs the conversion.