Struct futures_util::stream::Unfold

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

Stream for the unfold function.

Trait Implementations

impl<T, F, Fut> Debug for Unfold<T, F, Fut> where
    T: Debug,
    Fut: Debug, 

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

Formats the value using the given formatter.

impl<T, F, Fut, Item> FusedStream for Unfold<T, F, Fut> where
    F: FnMut(T) -> Fut,
    Fut: Future<Output = Option<(Item, T)>>, 

fn is_terminated(&self) -> bool

Returns true if the stream should no longer be polled.

impl<T, F, Fut, Item> Stream for Unfold<T, F, Fut> where
    F: FnMut(T) -> Fut,
    Fut: Future<Output = Option<(Item, T)>>, 

type Item = Item

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.

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

Returns the bounds on the remaining length of the stream.

impl<'__pin, T, F, Fut> Unpin for Unfold<T, F, Fut> where
    __Origin<'__pin, T, F, Fut>: Unpin,