Struct futures_util::future::Fuse
source · pub struct Fuse<Fut> {
inner: Option<Fut>,
}
Expand description
Future for the fuse
method.
Fields§
§inner: Option<Fut>
Implementations§
source§impl<Fut: Future> Fuse<Fut>
impl<Fut: Future> Fuse<Fut>
sourcepub fn terminated() -> Self
pub fn terminated() -> Self
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§
source§impl<Fut: Future> FusedFuture for Fuse<Fut>
impl<Fut: Future> FusedFuture for Fuse<Fut>
source§fn is_terminated(&self) -> bool
fn is_terminated(&self) -> bool
Returns
true
if the underlying future should no longer be polled.impl<'__pin, Fut> Unpin for Fuse<Fut>where
PinnedFieldsOf<__Origin<'__pin, Fut>>: Unpin,
Auto Trait Implementations§
impl<Fut> Freeze for Fuse<Fut>where
Fut: Freeze,
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§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
source§impl<T> FutureExt for T
impl<T> FutureExt for T
source§fn map<U, F>(self, f: F) -> Map<Self, F> ⓘ
fn map<U, F>(self, f: F) -> Map<Self, F> ⓘ
Map this future’s output to a different type, returning a new future of
the resulting type. Read more
source§fn map_into<U>(self) -> MapInto<Self, U> ⓘ
fn map_into<U>(self) -> MapInto<Self, U> ⓘ
Map this future’s output to a different type, returning a new future of
the resulting type. Read more
source§fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> ⓘ
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> ⓘ
Chain on a computation for when a future finished, passing the result of
the future to the provided closure
f
. Read moresource§fn left_future<B>(self) -> Either<Self, B> ⓘ
fn left_future<B>(self) -> Either<Self, B> ⓘ
source§fn right_future<A>(self) -> Either<A, Self> ⓘ
fn right_future<A>(self) -> Either<A, Self> ⓘ
source§fn into_stream(self) -> IntoStream<Self>where
Self: Sized,
fn into_stream(self) -> IntoStream<Self>where
Self: Sized,
Convert this future into a single element stream. Read more
source§fn flatten(self) -> Flatten<Self> ⓘ
fn flatten(self) -> Flatten<Self> ⓘ
Flatten the execution of this future when the output of this
future is itself another future. Read more
source§fn flatten_stream(self) -> FlattenStream<Self>
fn flatten_stream(self) -> FlattenStream<Self>
Flatten the execution of this future when the successful result of this
future is a stream. Read more
source§fn fuse(self) -> Fuse<Self> ⓘwhere
Self: Sized,
fn fuse(self) -> Fuse<Self> ⓘwhere
Self: Sized,
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 moresource§fn inspect<F>(self, f: F) -> Inspect<Self, F> ⓘ
fn inspect<F>(self, f: F) -> Inspect<Self, F> ⓘ
Do something with the output of a future before passing it on. Read more
source§fn catch_unwind(self) -> CatchUnwind<Self> ⓘwhere
Self: Sized + UnwindSafe,
fn catch_unwind(self) -> CatchUnwind<Self> ⓘwhere
Self: Sized + UnwindSafe,
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
source§fn remote_handle(self) -> (Remote<Self>, RemoteHandle<Self::Output>)where
Self: Sized,
fn remote_handle(self) -> (Remote<Self>, RemoteHandle<Self::Output>)where
Self: Sized,
Turn this future into a future that yields
()
on completion and sends
its output to another future on a separate task. Read moresource§fn boxed<'a>(self) -> BoxFuture<'a, Self::Output>
fn boxed<'a>(self) -> BoxFuture<'a, Self::Output>
Wrap the future in a Box, pinning it. Read more
source§fn boxed_local<'a>(self) -> LocalBoxFuture<'a, Self::Output>where
Self: Sized + 'a,
fn boxed_local<'a>(self) -> LocalBoxFuture<'a, Self::Output>where
Self: Sized + 'a,
Wrap the future in a Box, pinning it. Read more
source§fn unit_error(self) -> UnitError<Self> ⓘwhere
Self: Sized,
fn unit_error(self) -> UnitError<Self> ⓘwhere
Self: Sized,
Turns a
Future<Output = T>
into a
TryFuture<Ok = T, Error = ()
>.source§fn never_error(self) -> NeverError<Self> ⓘwhere
Self: Sized,
fn never_error(self) -> NeverError<Self> ⓘwhere
Self: Sized,
Turns a
Future<Output = T>
into a
TryFuture<Ok = T, Error = Never
>.source§impl<F> IntoFuture for Fwhere
F: Future,
impl<F> IntoFuture for Fwhere
F: Future,
source§type IntoFuture = F
type IntoFuture = F
Which kind of future are we turning this into?
source§fn into_future(self) -> <F as IntoFuture>::IntoFuture
fn into_future(self) -> <F as IntoFuture>::IntoFuture
Creates a future from a value. Read more
source§impl<Fut> TryFutureExt for Fut
impl<Fut> TryFutureExt for Fut
source§fn flatten_sink<Item>(self) -> FlattenSink<Self, Self::Ok>
fn flatten_sink<Item>(self) -> FlattenSink<Self, Self::Ok>
source§fn map_ok<T, F>(self, f: F) -> MapOk<Self, F> ⓘ
fn map_ok<T, F>(self, f: F) -> MapOk<Self, F> ⓘ
Maps this future’s success value to a different value. Read more
source§fn map_ok_or_else<T, E, F>(self, e: E, f: F) -> MapOkOrElse<Self, F, E> ⓘ
fn map_ok_or_else<T, E, F>(self, e: E, f: F) -> MapOkOrElse<Self, F, E> ⓘ
Maps this future’s success value to a different value, and permits for error handling resulting in the same type. Read more
source§fn map_err<E, F>(self, f: F) -> MapErr<Self, F> ⓘ
fn map_err<E, F>(self, f: F) -> MapErr<Self, F> ⓘ
Maps this future’s error value to a different value. Read more
source§fn and_then<Fut, F>(self, f: F) -> AndThen<Self, Fut, F> ⓘ
fn and_then<Fut, F>(self, f: F) -> AndThen<Self, Fut, F> ⓘ
Executes another future after this one resolves successfully. The
success value is passed to a closure to create this subsequent future. Read more
source§fn or_else<Fut, F>(self, f: F) -> OrElse<Self, Fut, F> ⓘ
fn or_else<Fut, F>(self, f: F) -> OrElse<Self, Fut, F> ⓘ
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
source§fn inspect_ok<F>(self, f: F) -> InspectOk<Self, F> ⓘ
fn inspect_ok<F>(self, f: F) -> InspectOk<Self, F> ⓘ
Do something with the success value of a future before passing it on. Read more
source§fn inspect_err<F>(self, f: F) -> InspectErr<Self, F> ⓘ
fn inspect_err<F>(self, f: F) -> InspectErr<Self, F> ⓘ
Do something with the error value of a future before passing it on. Read more
source§fn try_flatten(self) -> TryFlatten<Self, Self::Ok> ⓘ
fn try_flatten(self) -> TryFlatten<Self, Self::Ok> ⓘ
Flatten the execution of this future when the successful result of this
future is another future. Read more
source§fn try_flatten_stream(self) -> TryFlattenStream<Self>
fn try_flatten_stream(self) -> TryFlattenStream<Self>
Flatten the execution of this future when the successful result of this
future is a stream. Read more