Struct futures_util::stream::Once

#[must_use = "streams do nothing unless polled"]pub struct Once<Fut> { /* fields omitted */ }

A stream which emits single element and then EOF.

Trait Implementations

impl<Fut: Debug> Debug for Once<Fut>

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

Formats the value using the given formatter.

impl<Fut: Future> FusedStream for Once<Fut>

pub fn is_terminated(&self) -> bool

Returns true if the stream should no longer be polled.

impl<Fut: Future> Stream for Once<Fut>

type Item = Fut::Output

Values yielded by the stream.

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

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

Returns the bounds on the remaining length of the stream.

impl<'pin, Fut> Unpin for Once<Fut> where
    __Once<'pin, Fut>: Unpin,