Struct futures_util::stream::Once

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

[−] Expand description

A stream which emits single element and then EOF.

Trait Implementations

impl<Fut: Debug> Debug for Once<Fut>[+]

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

Formats the value using the given formatter.

impl<Fut: Future> FusedStream for Once<Fut>[+]

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fn is_terminated(&self) -> bool[−]

Returns true if the stream should no longer be polled.

impl<Fut: Future> Stream for Once<Fut>[+]

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type Item = Fut::Output

Values yielded by the stream.

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.

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
    __Origin<'__pin, Fut>: Unpin,