Struct futures_util::stream::TakeUntil

pub struct TakeUntil<St: Stream, Fut: Future> { /* private fields */ }

Stream for the take_until method.

Implementations

impl<St, Fut> TakeUntil<St, Fut>where St: Stream, Fut: Future,

pub fn get_ref(&self) -> &St

Acquires a reference to the underlying sink or stream that this combinator is pulling from.

pub fn get_mut(&mut self) -> &mut St

Acquires a mutable reference to the underlying sink or stream that this combinator is pulling from.

Note that care must be taken to avoid tampering with the state of the sink or stream which may otherwise confuse this combinator.

pub fn get_pin_mut(self: Pin<&mut Self>) -> Pin<&mut St>

Acquires a pinned mutable reference to the underlying sink or stream that this combinator is pulling from.

Note that care must be taken to avoid tampering with the state of the sink or stream which may otherwise confuse this combinator.

pub fn into_inner(self) -> St

Consumes this combinator, returning the underlying sink or stream.

Note that this may discard intermediate state of this combinator, so care should be taken to avoid losing resources when this is called.

pub fn take_future(&mut self) -> Option<Fut>

Extract the stopping future out of the combinator. The future is returned only if it isn’t resolved yet, ie. if the stream isn’t stopped yet. Taking out the future means the combinator will be yielding elements from the wrapped stream without ever stopping it.

pub fn take_result(&mut self) -> Option<Fut::Output>

Once the stopping future is resolved, this method can be used to extract the value returned by the stopping future.

This may be used to retrieve arbitrary data from the stopping future, for example a reason why the stream was stopped.

This method will return None if the future isn’t resolved yet, or if the result was already taken out.

Examples

use futures::future;
use futures::stream::{self, StreamExt};
use futures::task::Poll;

let stream = stream::iter(1..=10);

let mut i = 0;
let stop_fut = future::poll_fn(|_cx| {
    i += 1;
    if i <= 5 {
        Poll::Pending
    } else {
        Poll::Ready("reason")
    }
});

let mut stream = stream.take_until(stop_fut);
let _ = stream.by_ref().collect::<Vec<_>>().await;

let result = stream.take_result().unwrap();
assert_eq!(result, "reason");

pub fn is_stopped(&self) -> bool

Whether the stream was stopped yet by the stopping future being resolved.

Trait Implementations

impl<St, Fut> Debug for TakeUntil<St, Fut>where St: Stream + Debug, St::Item: Debug, Fut: Future + Debug,

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

Formats the value using the given formatter.

impl<St, Fut> FusedStream for TakeUntil<St, Fut>where St: Stream, Fut: Future,

fn is_terminated(&self) -> bool

Returns true if the stream should no longer be polled.

impl<S, Fut, Item> Sink<Item> for TakeUntil<S, Fut>where S: Stream + Sink<Item>, Fut: Future,

type Error = <S as Sink<Item>>::Error

The type of value produced by the sink when an error occurs.

fn poll_ready( self: Pin<&mut Self>, cx: &mut Context<'_> ) -> Poll<Result<(), Self::Error>>

Attempts to prepare the Sink to receive a value.

fn start_send(self: Pin<&mut Self>, item: Item) -> Result<(), Self::Error>

Begin the process of sending a value to the sink. Each call to this function must be preceded by a successful call to poll_ready which returned Poll::Ready(Ok(())).

fn poll_flush( self: Pin<&mut Self>, cx: &mut Context<'_> ) -> Poll<Result<(), Self::Error>>

Flush any remaining output from this sink.

fn poll_close( self: Pin<&mut Self>, cx: &mut Context<'_> ) -> Poll<Result<(), Self::Error>>

Flush any remaining output and close this sink, if necessary.

impl<St, Fut> Stream for TakeUntil<St, Fut>where St: Stream, Fut: Future,

type Item = <St as Stream>::Item

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_> ) -> Poll<Option<St::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.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.

impl<'__pin, St: Stream, Fut: Future> Unpin for TakeUntil<St, Fut>where __Origin<'__pin, St, Fut>: Unpin,