pub struct Discard<F>(/* private fields */);Expand description
Map Item and Error to ()
Adapt an existing Future to return unit Item and Error, while still
waiting for the underlying Future to complete.
Implementations§
Trait Implementations§
Source§impl<F> Future for Discard<F>where
F: Future,
impl<F> Future for Discard<F>where
F: Future,
Source§type Error = ()
type Error = ()
The type of error that this future will resolve with if it fails in a
normal fashion.
Source§fn poll(&mut self) -> Poll<Self::Item, Self::Error>
fn poll(&mut self) -> Poll<Self::Item, Self::Error>
Query this future to see if its value has become available, registering
interest if it is not. Read more
Source§fn wait(self) -> Result<Self::Item, Self::Error>where
Self: Sized,
fn wait(self) -> Result<Self::Item, Self::Error>where
Self: Sized,
Block the current thread until this future is resolved. Read more
Source§fn map<F, U>(self, f: F) -> Map<Self, F>
fn map<F, U>(self, f: F) -> Map<Self, F>
Map this future’s result to a different type, returning a new future of
the resulting type. Read more
Source§fn map_err<F, E>(self, f: F) -> MapErr<Self, F>
fn map_err<F, E>(self, f: F) -> MapErr<Self, F>
Map this future’s error to a different error, returning a new future. Read more
Source§fn from_err<E>(self) -> FromErr<Self, E>
fn from_err<E>(self) -> FromErr<Self, E>
Map this future’s error to any error implementing
From for
this future’s Error, returning a new future. Read moreSource§fn then<F, B>(self, f: F) -> Then<Self, B, F>
fn then<F, B>(self, f: F) -> Then<Self, B, F>
Chain on a computation for when a future finished, passing the result of
the future to the provided closure
f. Read moreSource§fn and_then<F, B>(self, f: F) -> AndThen<Self, B, F>
fn and_then<F, B>(self, f: F) -> AndThen<Self, B, F>
Execute another future after this one has resolved successfully. Read more
Source§fn or_else<F, B>(self, f: F) -> OrElse<Self, B, F>
fn or_else<F, B>(self, f: F) -> OrElse<Self, B, F>
Execute another future if this one resolves with an error. Read more
Source§fn select<B>(self, other: B) -> Select<Self, <B as IntoFuture>::Future>
fn select<B>(self, other: B) -> Select<Self, <B as IntoFuture>::Future>
Waits for either one of two futures to complete. Read more
Source§fn select2<B>(self, other: B) -> Select2<Self, <B as IntoFuture>::Future>where
B: IntoFuture,
Self: Sized,
fn select2<B>(self, other: B) -> Select2<Self, <B as IntoFuture>::Future>where
B: IntoFuture,
Self: Sized,
Waits for either one of two differently-typed futures to complete. Read more
Source§fn join<B>(self, other: B) -> Join<Self, <B as IntoFuture>::Future>
fn join<B>(self, other: B) -> Join<Self, <B as IntoFuture>::Future>
Joins the result of two futures, waiting for them both to complete. Read more
Source§fn join3<B, C>(
self,
b: B,
c: C,
) -> Join3<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future>
fn join3<B, C>( self, b: B, c: C, ) -> Join3<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future>
Same as
join, but with more futures.Source§fn join4<B, C, D>(
self,
b: B,
c: C,
d: D,
) -> Join4<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future, <D as IntoFuture>::Future>where
B: IntoFuture<Error = Self::Error>,
C: IntoFuture<Error = Self::Error>,
D: IntoFuture<Error = Self::Error>,
Self: Sized,
fn join4<B, C, D>(
self,
b: B,
c: C,
d: D,
) -> Join4<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future, <D as IntoFuture>::Future>where
B: IntoFuture<Error = Self::Error>,
C: IntoFuture<Error = Self::Error>,
D: IntoFuture<Error = Self::Error>,
Self: Sized,
Same as
join, but with more futures.Source§fn join5<B, C, D, E>(
self,
b: B,
c: C,
d: D,
e: E,
) -> Join5<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future, <D as IntoFuture>::Future, <E as IntoFuture>::Future>where
B: IntoFuture<Error = Self::Error>,
C: IntoFuture<Error = Self::Error>,
D: IntoFuture<Error = Self::Error>,
E: IntoFuture<Error = Self::Error>,
Self: Sized,
fn join5<B, C, D, E>(
self,
b: B,
c: C,
d: D,
e: E,
) -> Join5<Self, <B as IntoFuture>::Future, <C as IntoFuture>::Future, <D as IntoFuture>::Future, <E as IntoFuture>::Future>where
B: IntoFuture<Error = Self::Error>,
C: IntoFuture<Error = Self::Error>,
D: IntoFuture<Error = Self::Error>,
E: IntoFuture<Error = Self::Error>,
Self: Sized,
Same as
join, but with more futures.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 successful result 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. Read moreSource§fn inspect<F>(self, f: F) -> Inspect<Self, F>
fn inspect<F>(self, f: F) -> Inspect<Self, F>
Do something with the item of a future, 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
Auto Trait Implementations§
impl<F> Freeze for Discard<F>where
F: Freeze,
impl<F> RefUnwindSafe for Discard<F>where
F: RefUnwindSafe,
impl<F> Send for Discard<F>where
F: Send,
impl<F> Sync for Discard<F>where
F: Sync,
impl<F> Unpin for Discard<F>where
F: Unpin,
impl<F> UnwindSafe for Discard<F>where
F: 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 Twhere
T: Future,
impl<T> FutureExt for Twhere
T: Future,
Source§fn discard(self) -> Discard<Self>
fn discard(self) -> Discard<Self>
Map a
Future to have Item=() and Error=(). This is
useful when a future is being used to drive a computation
but the actual results aren’t interesting (such as when used
with Handle::spawn()).Source§fn boxify(self) -> BoxFuture<Self::Item, Self::Error>where
Self: 'static + Send,
fn boxify(self) -> BoxFuture<Self::Item, Self::Error>where
Self: 'static + Send,
Create a
Sendable boxed version of this Future.Source§fn boxify_nonsend(self) -> BoxFutureNonSend<Self::Item, Self::Error>where
Self: 'static,
fn boxify_nonsend(self) -> BoxFutureNonSend<Self::Item, Self::Error>where
Self: 'static,
Create a non-
Sendable boxed version of this Future.Source§fn left_future<B>(self) -> Either<Self, B>
fn left_future<B>(self) -> Either<Self, B>
Shorthand for returning
future::Either::ASource§fn right_future<A>(self) -> Either<A, Self>
fn right_future<A>(self) -> Either<A, Self>
Shorthand for returning
future::Either::BSource§fn inspect_err<F>(self, f: F) -> InspectErr<Self, F>
fn inspect_err<F>(self, f: F) -> InspectErr<Self, F>
Similar to
future::Future::inspect, but runs the function on errorSource§fn inspect_result<F>(self, f: F) -> InspectResult<Self, F>
fn inspect_result<F>(self, f: F) -> InspectResult<Self, F>
Similar to
future::Future::inspect, but runs the function on both
output or error of the Future treating it as a regular ResultSource§impl<F> IntoFuture for Fwhere
F: Future,
impl<F> IntoFuture for Fwhere
F: Future,
Source§fn into_future(self) -> F
fn into_future(self) -> F
Consumes this object and produces a future.