Struct futures_util::future::PollImmediate
source · pub struct PollImmediate<T> {
future: Option<T>,
}
Expand description
Future for the poll_immediate
function.
It will never return Poll::Pending
Fields§
§future: Option<T>
Trait Implementations§
source§impl<T: Clone> Clone for PollImmediate<T>
impl<T: Clone> Clone for PollImmediate<T>
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from
source
. Read moresource§impl<T: Debug> Debug for PollImmediate<T>
impl<T: Debug> Debug for PollImmediate<T>
source§impl<T: Future> FusedFuture for PollImmediate<T>
impl<T: Future> FusedFuture for PollImmediate<T>
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);
impl<'__pin, T> Unpin for PollImmediate<T>where
PinnedFieldsOf<__Origin<'__pin, T>>: Unpin,
Auto Trait Implementations§
impl<T> Freeze for PollImmediate<T>where
T: Freeze,
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> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§unsafe fn clone_to_uninit(&self, dst: *mut T)
unsafe fn clone_to_uninit(&self, dst: *mut T)
🔬This is a nightly-only experimental API. (
clone_to_uninit
)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<T> StreamExt for T
impl<T> StreamExt for T
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> ⓘ
fn into_future(self) -> StreamFuture<Self> ⓘ
source§fn map<T, F>(self, f: F) -> Map<Self, F>
fn map<T, F>(self, f: F) -> Map<Self, F>
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>
fn filter<Fut, F>(self, f: F) -> Filter<Self, Fut, F>
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>
fn filter_map<Fut, T, F>(self, f: F) -> FilterMap<Self, Fut, F>
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>
fn then<Fut, F>(self, f: F) -> Then<Self, Fut, F>
Computes from this stream’s items new items of a different type using
an asynchronous closure. Read more
source§fn collect<C: Default + Extend<Self::Item>>(self) -> Collect<Self, C> ⓘwhere
Self: Sized,
fn collect<C: Default + Extend<Self::Item>>(self) -> Collect<Self, C> ⓘwhere
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> ⓘ
fn unzip<A, B, FromA, FromB>(self) -> Unzip<Self, FromA, FromB> ⓘ
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 as Stream>::Item as IntoIterator>::Item> + IntoIterator + Default,
fn concat(self) -> Concat<Self> ⓘwhere
Self: Sized,
Self::Item: Extend<<<Self as Stream>::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> ⓘ
fn fold<T, Fut, F>(self, init: T, f: F) -> Fold<Self, Fut, T, F> ⓘ
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> ⓘ
fn any<Fut, F>(self, f: F) -> Any<Self, Fut, F> ⓘ
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> ⓘ
fn all<Fut, F>(self, f: F) -> All<Self, Fut, F> ⓘ
Execute predicate over asynchronous stream, and return
true
if all element in stream satisfied a predicate. Read moresource§fn flatten(self) -> Flatten<Self>
fn flatten(self) -> Flatten<Self>
Flattens a stream of streams into just one continuous stream. Read more
source§fn flatten_unordered(
self,
limit: impl Into<Option<usize>>,
) -> FlattenUnordered<Self>
fn flatten_unordered( self, limit: impl Into<Option<usize>>, ) -> FlattenUnordered<Self>
Flattens a stream of streams into just one continuous stream. Polls
inner streams produced by the base stream concurrently. Read more
source§fn flat_map_unordered<U, F>(
self,
limit: impl Into<Option<usize>>,
f: F,
) -> FlatMapUnordered<Self, U, F>
fn flat_map_unordered<U, F>( self, limit: impl Into<Option<usize>>, f: F, ) -> FlatMapUnordered<Self, U, F>
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>
fn scan<S, B, Fut, F>(self, initial_state: S, f: F) -> Scan<Self, S, Fut, F>
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>
fn skip_while<Fut, F>(self, f: F) -> SkipWhile<Self, Fut, F>
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>
fn take_while<Fut, F>(self, f: F) -> TakeWhile<Self, Fut, F>
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>
fn take_until<Fut>(self, fut: Fut) -> TakeUntil<Self, Fut>
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> ⓘ
fn for_each<Fut, F>(self, f: F) -> ForEach<Self, Fut, F> ⓘ
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> ⓘ
fn for_each_concurrent<Fut, F>( self, limit: impl Into<Option<usize>>, f: F, ) -> ForEachConcurrent<Self, Fut, F> ⓘ
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) -> BoxStream<'a, Self::Item>
fn boxed<'a>(self) -> BoxStream<'a, Self::Item>
Wrap the stream in a Box, pinning it. Read more
source§fn boxed_local<'a>(self) -> LocalBoxStream<'a, Self::Item>where
Self: Sized + 'a,
fn boxed_local<'a>(self) -> LocalBoxStream<'a, Self::Item>where
Self: Sized + 'a,
Wrap the stream in a Box, pinning it. Read more
source§fn buffered(self, n: usize) -> Buffered<Self>
fn buffered(self, n: usize) -> Buffered<Self>
An adaptor for creating a buffered list of pending futures. Read more
source§fn buffer_unordered(self, n: usize) -> BufferUnordered<Self>
fn buffer_unordered(self, n: usize) -> BufferUnordered<Self>
An adaptor for creating a buffered list of pending futures (unordered). Read more
source§fn zip<St>(self, other: St) -> Zip<Self, St>
fn zip<St>(self, other: St) -> Zip<Self, St>
An adapter for zipping two streams together. 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> ⓘ
fn forward<S>(self, sink: S) -> Forward<Self, S> ⓘ
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>)
fn split<Item>(self) -> (SplitSink<Self, Item>, SplitStream<Self>)
source§fn inspect<F>(self, f: F) -> Inspect<Self, F>
fn inspect<F>(self, f: F) -> Inspect<Self, F>
Do something with each item of this stream, afterwards passing it on. Read more
source§fn left_stream<B>(self) -> Either<Self, B> ⓘ
fn left_stream<B>(self) -> Either<Self, B> ⓘ
source§fn right_stream<B>(self) -> Either<B, Self> ⓘ
fn right_stream<B>(self) -> Either<B, Self> ⓘ
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.