Struct futures::stream::TakeUntil

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#[must_use = "streams do nothing unless polled"]pub struct TakeUntil<St, Fut> where
    Fut: Future,
    St: Stream,  { /* fields omitted */ }

[−] Expand description

Stream for the take_until method.

Implementations

impl<St, Fut> TakeUntil<St, Fut> where
    Fut: Future,
    St: Stream, [−]

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 TakeUntil<St, Fut>>) -> 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 as Future>::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 resovled 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
    Fut: Future + Debug,
    St: Stream + Debug,
    <St as Stream>::Item: Debug, [+]

[+] Show hidden undocumented items

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

Formats the value using the given formatter.

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

[+] Show hidden undocumented items

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
    Fut: Future,
    S: Stream + Sink<Item>, [+]

[+] Show hidden undocumented items

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 TakeUntil<S, Fut>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), <TakeUntil<S, Fut> as Sink<Item>>::Error>>[−]

Attempts to prepare the Sink to receive a value.

fn start_send(
    self: Pin<&mut TakeUntil<S, Fut>>,
    item: Item
) -> Result<(), <TakeUntil<S, Fut> as Sink<Item>>::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 TakeUntil<S, Fut>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), <TakeUntil<S, Fut> as Sink<Item>>::Error>>[−]

Flush any remaining output from this sink.

fn poll_close(
    self: Pin<&mut TakeUntil<S, Fut>>,
    cx: &mut Context<'_>
) -> Poll<Result<(), <TakeUntil<S, Fut> as Sink<Item>>::Error>>[−]

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

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

[+] Show hidden undocumented items

type Item = <St as Stream>::Item

Values yielded by the stream.

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

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

Returns the bounds on the remaining length of the stream.

impl<'pin, St, Fut> Unpin for TakeUntil<St, Fut> where
    Fut: Future,
    St: Stream,
    __TakeUntil<'pin, St, Fut>: Unpin,