Struct futures::future::PollImmediate
source · pub struct PollImmediate<T> { /* private fields */ }
Expand description
Future for the poll_immediate
function.
It will never return Poll::Pending
Trait Implementations§
source§impl<T> Clone for PollImmediate<T>where
T: Clone,
impl<T> Clone for PollImmediate<T>where T: Clone,
source§impl<T> Debug for PollImmediate<T>where
T: Debug,
impl<T> Debug for PollImmediate<T>where T: Debug,
source§impl<T> FusedFuture for PollImmediate<T>where
T: Future,
impl<T> FusedFuture for PollImmediate<T>where T: Future,
source§fn is_terminated(&self) -> bool
fn is_terminated(&self) -> bool
Returns
true
if the underlying future should no longer be polled.source§impl<T, F> Future for PollImmediate<F>where
F: Future<Output = T>,
impl<T, F> Future for PollImmediate<F>where F: Future<Output = T>,
source§impl<T, F> Stream for PollImmediate<F>where
F: Future<Output = T>,
impl<T, F> Stream for PollImmediate<F>where F: Future<Output = T>,
A Stream implementation that can be polled repeatedly until the future is done. The stream will never return Poll::Pending so polling it in a tight loop is worse than using a blocking synchronous function.
use futures::task::Poll;
use futures::{StreamExt, future, pin_mut};
use future::FusedFuture;
let f = async { 1_u32 };
pin_mut!(f);
let mut r = future::poll_immediate(f);
assert_eq!(r.next().await, Some(Poll::Ready(1)));
let f = async {futures::pending!(); 42_u8};
pin_mut!(f);
let mut p = future::poll_immediate(f);
assert_eq!(p.next().await, Some(Poll::Pending));
assert!(!p.is_terminated());
assert_eq!(p.next().await, Some(Poll::Ready(42)));
assert!(p.is_terminated());
assert_eq!(p.next().await, None);
source§fn poll_next(
self: Pin<&mut PollImmediate<F>>,
cx: &mut Context<'_>
) -> Poll<Option<<PollImmediate<F> as Stream>::Item>>
fn poll_next( self: Pin<&mut PollImmediate<F>>, cx: &mut Context<'_> ) -> Poll<Option<<PollImmediate<F> as Stream>::Item>>
Attempt to pull out the next value of this stream, registering the
current task for wakeup if the value is not yet available, and returning
None
if the stream is exhausted. Read moreimpl<'__pin, T> Unpin for PollImmediate<T>where __Origin<'__pin, T>: Unpin,
Auto Trait Implementations§
impl<T> RefUnwindSafe for PollImmediate<T>where T: RefUnwindSafe,
impl<T> Send for PollImmediate<T>where T: Send,
impl<T> Sync for PollImmediate<T>where T: Sync,
impl<T> UnwindSafe for PollImmediate<T>where T: 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 + ?Sized,
impl<T> FutureExt for Twhere T: Future + ?Sized,
source§fn map<U, F>(self, f: F) -> Map<Self, F> ⓘwhere
F: FnOnce(Self::Output) -> U,
Self: Sized,
fn map<U, F>(self, f: F) -> Map<Self, F> ⓘwhere F: FnOnce(Self::Output) -> U, Self: Sized,
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> ⓘwhere
Self::Output: Into<U>,
Self: Sized,
fn map_into<U>(self) -> MapInto<Self, U> ⓘwhere Self::Output: Into<U>, Self: Sized,
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> ⓘwhere
F: FnOnce(Self::Output) -> Fut,
Fut: Future,
Self: Sized,
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F> ⓘwhere F: FnOnce(Self::Output) -> Fut, Fut: Future, Self: Sized,
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> ⓘwhere
B: Future<Output = Self::Output>,
Self: Sized,
fn left_future<B>(self) -> Either<Self, B> ⓘwhere B: Future<Output = Self::Output>, Self: Sized,
source§fn right_future<A>(self) -> Either<A, Self> ⓘwhere
A: Future<Output = Self::Output>,
Self: Sized,
fn right_future<A>(self) -> Either<A, Self> ⓘwhere A: Future<Output = Self::Output>, Self: Sized,
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> ⓘwhere
Self::Output: Future,
Self: Sized,
fn flatten(self) -> Flatten<Self> ⓘwhere Self::Output: Future, Self: Sized,
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>where
Self::Output: Stream,
Self: Sized,
fn flatten_stream(self) -> FlattenStream<Self>where Self::Output: Stream, Self: Sized,
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> ⓘwhere
F: FnOnce(&Self::Output),
Self: Sized,
fn inspect<F>(self, f: F) -> Inspect<Self, F> ⓘwhere F: FnOnce(&Self::Output), Self: Sized,
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,
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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
) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'a, Global>>where
Self: Sized + Send + 'a,
fn boxed<'a>( self ) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'a, Global>>where Self: Sized + Send + 'a,
Wrap the future in a Box, pinning it. Read more
source§fn boxed_local<'a>(
self
) -> Pin<Box<dyn Future<Output = Self::Output> + 'a, Global>>where
Self: Sized + 'a,
fn boxed_local<'a>( self ) -> Pin<Box<dyn Future<Output = Self::Output> + 'a, Global>>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,
§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<T> StreamExt for Twhere
T: Stream + ?Sized,
impl<T> StreamExt for Twhere T: Stream + ?Sized,
source§fn next(&mut self) -> Next<'_, Self> ⓘwhere
Self: Unpin,
fn next(&mut self) -> Next<'_, Self> ⓘwhere Self: Unpin,
Creates a future that resolves to the next item in the stream. Read more
source§fn into_future(self) -> StreamFuture<Self> ⓘwhere
Self: Sized + Unpin,
fn into_future(self) -> StreamFuture<Self> ⓘwhere Self: Sized + Unpin,
source§fn map<T, F>(self, f: F) -> Map<Self, F>where
F: FnMut(Self::Item) -> T,
Self: Sized,
fn map<T, F>(self, f: F) -> Map<Self, F>where F: FnMut(Self::Item) -> T, Self: Sized,
Maps this stream’s items to a different type, returning a new stream of
the resulting type. Read more
source§fn enumerate(self) -> Enumerate<Self>where
Self: Sized,
fn enumerate(self) -> Enumerate<Self>where Self: Sized,
Creates a stream which gives the current iteration count as well as
the next value. Read more
source§fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F>where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
Self: Sized,
fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F>where F: FnMut(&Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,
Filters the values produced by this stream according to the provided
asynchronous predicate. Read more
source§fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F>where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = Option<T>>,
Self: Sized,
fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F>where F: FnMut(Self::Item) -> Fut, Fut: Future<Output = Option<T>>, Self: Sized,
Filters the values produced by this stream while simultaneously mapping
them to a different type according to the provided asynchronous closure. Read more
source§fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F>where
F: FnMut(Self::Item) -> Fut,
Fut: Future,
Self: Sized,
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F>where F: FnMut(Self::Item) -> Fut, Fut: Future, Self: Sized,
Computes from this stream’s items new items of a different type using
an asynchronous closure. Read more
source§fn collect<C>(self) -> Collect<Self, C> ⓘwhere
C: Default + Extend<Self::Item>,
Self: Sized,
fn collect<C>(self) -> Collect<Self, C> ⓘwhere C: Default + Extend<Self::Item>, Self: Sized,
Transforms a stream into a collection, returning a
future representing the result of that computation. Read more
source§fn unzip<A, B, FromA, FromB>(self) -> Unzip<Self, FromA, FromB> ⓘwhere
FromA: Default + Extend<A>,
FromB: Default + Extend<B>,
Self: Sized + Stream<Item = (A, B)>,
fn unzip<A, B, FromA, FromB>(self) -> Unzip<Self, FromA, FromB> ⓘwhere FromA: Default + Extend<A>, FromB: Default + Extend<B>, Self: Sized + Stream<Item = (A, B)>,
Converts a stream of pairs into a future, which
resolves to pair of containers. Read more
source§fn concat(self) -> Concat<Self> ⓘwhere
Self: Sized,
Self::Item: Extend<<Self::Item as IntoIterator>::Item> + IntoIterator + Default,
fn concat(self) -> Concat<Self> ⓘwhere Self: Sized, Self::Item: Extend<<Self::Item as IntoIterator>::Item> + IntoIterator + Default,
Concatenate all items of a stream into a single extendable
destination, returning a future representing the end result. Read more
source§fn count(self) -> Count<Self>where
Self: Sized,
fn count(self) -> Count<Self>where Self: Sized,
Drives the stream to completion, counting the number of items. Read more
source§fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F> ⓘwhere
F: FnMut(T, Self::Item) -> Fut,
Fut: Future<Output = T>,
Self: Sized,
fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F> ⓘwhere F: FnMut(T, Self::Item) -> Fut, Fut: Future<Output = T>, Self: Sized,
Execute an accumulating asynchronous computation over a stream,
collecting all the values into one final result. Read more
source§fn any<Fut, F>(self, f: F) -> Any<Self, Fut, F>where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = bool>,
Self: Sized,
fn any<Fut, F>(self, f: F) -> Any<Self, Fut, F>where F: FnMut(Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,
Execute predicate over asynchronous stream, and return
true
if any element in stream satisfied a predicate. Read moresource§fn all<Fut, F>(self, f: F) -> All<Self, Fut, F>where
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = bool>,
Self: Sized,
fn all<Fut, F>(self, f: F) -> All<Self, Fut, F>where F: FnMut(Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,
Execute predicate over asynchronous stream, and return
true
if all element in stream satisfied a predicate. Read moresource§fn flatten(self) -> Flatten<Self>where
Self::Item: Stream,
Self: Sized,
fn flatten(self) -> Flatten<Self>where Self::Item: Stream, Self: Sized,
Flattens a stream of streams into just one continuous stream. Read more
source§fn flatten_unordered(
self,
limit: impl Into<Option<usize>>
) -> FlattenUnordered<Self>where
Self::Item: Stream + Unpin,
Self: Sized,
fn flatten_unordered( self, limit: impl Into<Option<usize>> ) -> FlattenUnordered<Self>where Self::Item: Stream + Unpin, Self: Sized,
Flattens a stream of streams into just one continuous stream. Polls
inner streams concurrently. Read more
source§fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>where
F: FnMut(Self::Item) -> U,
U: Stream,
Self: Sized,
fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>where F: FnMut(Self::Item) -> U, U: Stream, Self: Sized,
source§fn flat_map_unordered<U, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> FlatMapUnordered<Self, U, F>where
U: Stream + Unpin,
F: FnMut(Self::Item) -> U,
Self: Sized,
fn flat_map_unordered<U, F>( self, limit: impl Into<Option<usize>>, f: F ) -> FlatMapUnordered<Self, U, F>where U: Stream + Unpin, F: FnMut(Self::Item) -> U, Self: Sized,
Maps a stream like
StreamExt::map
but flattens nested Stream
s
and polls them concurrently, yielding items in any order, as they made
available. Read moresource§fn scan<S, B, Fut, F>(self, initial_state: S, f: F) -> Scan<Self, S, Fut, F>where
F: FnMut(&mut S, Self::Item) -> Fut,
Fut: Future<Output = Option<B>>,
Self: Sized,
fn scan<S, B, Fut, F>(self, initial_state: S, f: F) -> Scan<Self, S, Fut, F>where F: FnMut(&mut S, Self::Item) -> Fut, Fut: Future<Output = Option<B>>, Self: Sized,
Combinator similar to
StreamExt::fold
that holds internal state
and produces a new stream. Read moresource§fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F>where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
Self: Sized,
fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F>where F: FnMut(&Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,
Skip elements on this stream while the provided asynchronous predicate
resolves to
true
. Read moresource§fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F>where
F: FnMut(&Self::Item) -> Fut,
Fut: Future<Output = bool>,
Self: Sized,
fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F>where F: FnMut(&Self::Item) -> Fut, Fut: Future<Output = bool>, Self: Sized,
Take elements from this stream while the provided asynchronous predicate
resolves to
true
. Read moresource§fn take_until<Fut>(self, fut: Fut) -> TakeUntil<Self, Fut>where
Fut: Future,
Self: Sized,
fn take_until<Fut>(self, fut: Fut) -> TakeUntil<Self, Fut>where Fut: Future, Self: Sized,
Take elements from this stream until the provided future resolves. Read more
source§fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F> ⓘwhere
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
Self: Sized,
fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F> ⓘwhere F: FnMut(Self::Item) -> Fut, Fut: Future<Output = ()>, Self: Sized,
Runs this stream to completion, executing the provided asynchronous
closure for each element on the stream. Read more
source§fn for_each_concurrent<Fut, F>(
self,
limit: impl Into<Option<usize>>,
f: F
) -> ForEachConcurrent<Self, Fut, F> ⓘwhere
F: FnMut(Self::Item) -> Fut,
Fut: Future<Output = ()>,
Self: Sized,
fn for_each_concurrent<Fut, F>( self, limit: impl Into<Option<usize>>, f: F ) -> ForEachConcurrent<Self, Fut, F> ⓘwhere F: FnMut(Self::Item) -> Fut, Fut: Future<Output = ()>, Self: Sized,
Runs this stream to completion, executing the provided asynchronous
closure for each element on the stream concurrently as elements become
available. Read more
source§fn take(self, n: usize) -> Take<Self>where
Self: Sized,
fn take(self, n: usize) -> Take<Self>where Self: Sized,
Creates a new stream of at most
n
items of the underlying stream. Read moresource§fn skip(self, n: usize) -> Skip<Self>where
Self: Sized,
fn skip(self, n: usize) -> Skip<Self>where Self: Sized,
Creates a new stream which skips
n
items of the underlying stream. Read moresource§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 stream. Read more
source§fn boxed<'a>(
self
) -> Pin<Box<dyn Stream<Item = Self::Item> + Send + 'a, Global>>where
Self: Sized + Send + 'a,
fn boxed<'a>( self ) -> Pin<Box<dyn Stream<Item = Self::Item> + Send + 'a, Global>>where Self: Sized + Send + 'a,
Wrap the stream in a Box, pinning it. Read more
source§fn boxed_local<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a, Global>>where
Self: Sized + 'a,
fn boxed_local<'a>(self) -> Pin<Box<dyn Stream<Item = Self::Item> + 'a, Global>>where Self: Sized + 'a,
Wrap the stream in a Box, pinning it. Read more
source§fn buffered(self, n: usize) -> Buffered<Self>where
Self::Item: Future,
Self: Sized,
fn buffered(self, n: usize) -> Buffered<Self>where Self::Item: Future, Self: Sized,
An adaptor for creating a buffered list of pending futures. Read more
source§fn buffer_unordered(self, n: usize) -> BufferUnordered<Self>where
Self::Item: Future,
Self: Sized,
fn buffer_unordered(self, n: usize) -> BufferUnordered<Self>where Self::Item: Future, Self: Sized,
An adaptor for creating a buffered list of pending futures (unordered). Read more
source§fn zip<St>(self, other: St) -> Zip<Self, St>where
St: Stream,
Self: Sized,
fn zip<St>(self, other: St) -> Zip<Self, St>where St: Stream, Self: Sized,
An adapter for zipping two streams together. Read more
source§fn chain<St>(self, other: St) -> Chain<Self, St>where
St: Stream<Item = Self::Item>,
Self: Sized,
fn chain<St>(self, other: St) -> Chain<Self, St>where St: Stream<Item = Self::Item>, Self: Sized,
Adapter for chaining two streams. Read more
source§fn peekable(self) -> Peekable<Self>where
Self: Sized,
fn peekable(self) -> Peekable<Self>where Self: Sized,
Creates a new stream which exposes a
peek
method. Read moresource§fn chunks(self, capacity: usize) -> Chunks<Self>where
Self: Sized,
fn chunks(self, capacity: usize) -> Chunks<Self>where Self: Sized,
An adaptor for chunking up items of the stream inside a vector. Read more
source§fn ready_chunks(self, capacity: usize) -> ReadyChunks<Self>where
Self: Sized,
fn ready_chunks(self, capacity: usize) -> ReadyChunks<Self>where Self: Sized,
An adaptor for chunking up ready items of the stream inside a vector. Read more
source§fn forward<S>(self, sink: S) -> Forward<Self, S> ⓘwhere
S: Sink<Self::Ok, Error = Self::Error>,
Self: TryStream + Sized,
fn forward<S>(self, sink: S) -> Forward<Self, S> ⓘwhere S: Sink<Self::Ok, Error = Self::Error>, Self: TryStream + Sized,
A future that completes after the given stream has been fully processed
into the sink and the sink has been flushed and closed. Read more
source§fn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>)where
Self: Sink<Item> + Sized,
fn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>)where Self: Sink<Item> + Sized,
source§fn inspect<F>(self, f: F) -> Inspect<Self, F>where
F: FnMut(&Self::Item),
Self: Sized,
fn inspect<F>(self, f: F) -> Inspect<Self, F>where F: FnMut(&Self::Item), Self: Sized,
Do something with each item of this stream, afterwards passing it on. Read more
source§fn right_stream<B>(self) -> Either<B, Self> ⓘwhere
B: Stream<Item = Self::Item>,
Self: Sized,
fn right_stream<B>(self) -> Either<B, Self> ⓘwhere B: Stream<Item = Self::Item>, Self: Sized,
source§fn poll_next_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Option<Self::Item>>where
Self: Unpin,
fn poll_next_unpin(&mut self, cx: &mut Context<'_>) -> Poll<Option<Self::Item>>where Self: Unpin,
A convenience method for calling
Stream::poll_next
on Unpin
stream types.