Struct futures::future::Fuse

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[+] Expand attributes
#[must_use = "futures do nothing unless polled"]
pub struct Fuse<A: Future> { /* fields omitted */ }

[−] Expand description

A future which "fuses" a future once it's been resolved.

Normally futures can behave unpredictable once they're used after a future has been resolved, but Fuse is always defined to return Async::NotReady from poll after it has resolved successfully or returned an error.

This is created by the Future::fuse method.

Methods

impl<A: Future> Fuse<A>

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pub fn is_done(&self) -> bool

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Returns whether the underlying future has finished or not.

If this method returns true, then all future calls to poll are guaranteed to return Ok(Async::NotReady). If this returns false, then the underlying future has not been driven to completion.

Trait Implementations

impl<A: Future> Future for Fuse<A>

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type Item = A::Item

The type of value that this future will resolved with if it is successful.

type Error = A::Error

The type of error that this future will resolve with if it fails in a normal fashion.

fn poll(&mut self) -> Poll<A::Item, A::Error>

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Query this future to see if its value has become available, registering interest if it is not.

fn wait(self) -> Result<Self::Item, Self::Error> where     Self: Sized,

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Block the current thread until this future is resolved.

fn map<F, U>(self, f: F) -> Map<Self, F> where     F: FnOnce(Self::Item) -> U,     Self: Sized,

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

fn map_err<F, E>(self, f: F) -> MapErr<Self, F> where     F: FnOnce(Self::Error) -> E,     Self: Sized,

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Map this future's error to a different error, returning a new future.

fn from_err<E: From<Self::Error>>(self) -> FromErr<Self, E> where     Self: Sized,

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Map this future's error to any error implementing From for this future's Error, returning a new future.

fn then<F, B>(self, f: F) -> Then<Self, B, F> where     F: FnOnce(Result<Self::Item, Self::Error>) -> B,     B: IntoFuture,     Self: Sized,

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

fn and_then<F, B>(self, f: F) -> AndThen<Self, B, F> where     F: FnOnce(Self::Item) -> B,     B: IntoFuture<Error = Self::Error>,     Self: Sized,

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Execute another future after this one has resolved successfully.

fn or_else<F, B>(self, f: F) -> OrElse<Self, B, F> where     F: FnOnce(Self::Error) -> B,     B: IntoFuture<Item = Self::Item>,     Self: Sized,

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Execute another future if this one resolves with an error.

fn select<B>(self, other: B) -> Select<Self, B::Future> where     B: IntoFuture<Item = Self::Item, Error = Self::Error>,     Self: Sized,

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Waits for either one of two futures to complete.

fn select2<B>(self, other: B) -> Select2<Self, B::Future> where     B: IntoFuture,     Self: Sized,

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Waits for either one of two differently-typed futures to complete.

fn join<B>(self, other: B) -> Join<Self, B::Future> where     B: IntoFuture<Error = Self::Error>,     Self: Sized,

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Joins the result of two futures, waiting for them both to complete.

fn join3<B, C>(self, b: B, c: C) -> Join3<Self, B::Future, C::Future> where     B: IntoFuture<Error = Self::Error>,     C: IntoFuture<Error = Self::Error>,     Self: Sized,

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Same as join, but with more futures.

fn join4<B, C, D>(     self,     b: B,     c: C,     d: D ) -> Join4<Self, B::Future, C::Future, D::Future> where     B: IntoFuture<Error = Self::Error>,     C: IntoFuture<Error = Self::Error>,     D: IntoFuture<Error = Self::Error>,     Self: Sized,

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Same as join, but with more futures.

fn join5<B, C, D, E>(     self,     b: B,     c: C,     d: D,     e: E ) -> Join5<Self, B::Future, C::Future, D::Future, E::Future> where     B: IntoFuture<Error = Self::Error>,     C: IntoFuture<Error = Self::Error>,     D: IntoFuture<Error = Self::Error>,     E: IntoFuture<Error = Self::Error>,     Self: Sized,

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Same as join, but with more futures.

fn into_stream(self) -> IntoStream<Self> where     Self: Sized,

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Convert this future into a single element stream.

fn flatten(self) -> Flatten<Self> where     Self::Item: IntoFuture,     <Self::Item as IntoFuture>::Error: From<Self::Error>,     Self: Sized,

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

fn flatten_stream(self) -> FlattenStream<Self> where     Self::Item: Stream<Error = Self::Error>,     Self: Sized,

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

fn fuse(self) -> Fuse<Self> where     Self: Sized,

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Fuse a future such that poll will never again be called once it has completed.

fn inspect<F>(self, f: F) -> Inspect<Self, F> where     F: FnOnce(&Self::Item),     Self: Sized,

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Do something with the item of a future, passing it on.

fn catch_unwind(self) -> CatchUnwind<Self> where     Self: Sized + UnwindSafe,

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Catches unwinding panics while polling the future.

fn shared(self) -> Shared<Self> where     Self: Sized,

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

impl<A: Debug + Future> Debug for Fuse<A>

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fn fmt(&self, f: &mut Formatter) -> Result

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Formats the value using the given formatter.