pub struct PollImmediate<T> { /* private fields */ }
Expand description

Future for the poll_immediate function.

It will never return Poll::Pending

Trait Implementations§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Returns true if the underlying future should no longer be polled.
The type of value produced on completion.
Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more

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);
Values yielded by the stream.
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 more
Returns the bounds on the remaining length of the stream. Read more

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Map this future’s output to a different type, returning a new future of the resulting type. Read more
Map this future’s output to a different type, returning a new future of the resulting type. Read more
Chain on a computation for when a future finished, passing the result of the future to the provided closure f. Read more
Wrap this future in an Either future, making it the left-hand variant of that Either. Read more
Wrap this future in an Either future, making it the right-hand variant of that Either. Read more
Convert this future into a single element stream. Read more
Flatten the execution of this future when the output of this future is itself another future. Read more
Flatten the execution of this future when the successful result of this future is a stream. Read more
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 more
Do something with the output of a future before passing it on. Read more
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
Turn this future into a future that yields () on completion and sends its output to another future on a separate task. Read more
Wrap the future in a Box, pinning it. Read more
Wrap the future in a Box, pinning it. Read more
A convenience for calling Future::poll on Unpin future types.
Evaluates and consumes the future, returning the resulting output if the future is ready after the first call to Future::poll. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The output that the future will produce on completion.
Which kind of future are we turning this into?
Creates a future from a value. Read more
Creates a future that resolves to the next item in the stream. Read more
Converts this stream into a future of (next_item, tail_of_stream). If the stream terminates, then the next item is None. Read more
Maps this stream’s items to a different type, returning a new stream of the resulting type. Read more
Creates a stream which gives the current iteration count as well as the next value. Read more
Filters the values produced by this stream according to the provided asynchronous predicate. Read more
Filters the values produced by this stream while simultaneously mapping them to a different type according to the provided asynchronous closure. Read more
Computes from this stream’s items new items of a different type using an asynchronous closure. Read more
Transforms a stream into a collection, returning a future representing the result of that computation. Read more
Converts a stream of pairs into a future, which resolves to pair of containers. Read more
Concatenate all items of a stream into a single extendable destination, returning a future representing the end result. Read more
Drives the stream to completion, counting the number of items. Read more
Repeats a stream endlessly. Read more
Execute an accumulating asynchronous computation over a stream, collecting all the values into one final result. Read more
Execute predicate over asynchronous stream, and return true if any element in stream satisfied a predicate. Read more
Execute predicate over asynchronous stream, and return true if all element in stream satisfied a predicate. Read more
Flattens a stream of streams into just one continuous stream. Read more
Flattens a stream of streams into just one continuous stream. Polls inner streams produced by the base stream concurrently. Read more
Maps a stream like StreamExt::map but flattens nested Streams. Read more
Maps a stream like StreamExt::map but flattens nested Streams and polls them concurrently, yielding items in any order, as they made available. Read more
Combinator similar to StreamExt::fold that holds internal state and produces a new stream. Read more
Skip elements on this stream while the provided asynchronous predicate resolves to true. Read more
Take elements from this stream while the provided asynchronous predicate resolves to true. Read more
Take elements from this stream until the provided future resolves. Read more
Runs this stream to completion, executing the provided asynchronous closure for each element on the stream. Read more
Runs this stream to completion, executing the provided asynchronous closure for each element on the stream concurrently as elements become available. Read more
Creates a new stream of at most n items of the underlying stream. Read more
Creates a new stream which skips n items of the underlying stream. Read more
Fuse a stream such that poll_next will never again be called once it has finished. This method can be used to turn any Stream into a FusedStream. Read more
Borrows a stream, rather than consuming it. Read more
Catches unwinding panics while polling the stream. Read more
Wrap the stream in a Box, pinning it. Read more
Wrap the stream in a Box, pinning it. Read more
An adaptor for creating a buffered list of pending futures. Read more
An adaptor for creating a buffered list of pending futures (unordered). Read more
An adapter for zipping two streams together. Read more
Adapter for chaining two streams. Read more
Creates a new stream which exposes a peek method. Read more
An adaptor for chunking up items of the stream inside a vector. Read more
An adaptor for chunking up ready items of the stream inside a vector. Read more
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
Splits this Stream + Sink object into separate Sink and Stream objects. Read more
Do something with each item of this stream, afterwards passing it on. Read more
Wrap this stream in an Either stream, making it the left-hand variant of that Either. Read more
Wrap this stream in an Either stream, making it the right-hand variant of that Either. Read more
A convenience method for calling Stream::poll_next on Unpin stream types.
Returns a Future that resolves when the next item in this stream is ready. Read more
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.