Sha256: ed7e3d15e7b1adec5ad5789b0d3186b5995a3353cc974fb7f41a72f6d8ad4cbb
Contents?: true
Size: 1.57 KB
Versions: 22
Compression:
Stored size: 1.57 KB
Contents
use core::pin::Pin;
use core::usize;
use futures_core::ready;
use futures_core::stream::{FusedStream, Stream};
use futures_core::task::{Context, Poll};
use pin_project_lite::pin_project;
pin_project! {
/// Stream for the [`cycle`](super::StreamExt::cycle) method.
#[derive(Debug)]
#[must_use = "streams do nothing unless polled"]
pub struct Cycle<St> {
orig: St,
#[pin]
stream: St,
}
}
impl<St> Cycle<St>
where
St: Clone + Stream,
{
pub(super) fn new(stream: St) -> Self {
Self { orig: stream.clone(), stream }
}
}
impl<St> Stream for Cycle<St>
where
St: Clone + Stream,
{
type Item = St::Item;
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
let mut this = self.project();
match ready!(this.stream.as_mut().poll_next(cx)) {
None => {
this.stream.set(this.orig.clone());
this.stream.poll_next(cx)
}
item => Poll::Ready(item),
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
// the cycle stream is either empty or infinite
match self.orig.size_hint() {
size @ (0, Some(0)) => size,
(0, _) => (0, None),
_ => (usize::max_value(), None),
}
}
}
impl<St> FusedStream for Cycle<St>
where
St: Clone + Stream,
{
fn is_terminated(&self) -> bool {
// the cycle stream is either empty or infinite
if let (0, Some(0)) = self.size_hint() {
true
} else {
false
}
}
}
Version data entries
22 entries across 22 versions & 1 rubygems