blob: 706069fa6ec1a50fe591e52063bbc32c65691f3c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
use crate::Stream;
use core::future::Future;
use core::marker::PhantomPinned;
use core::pin::Pin;
use core::task::{Context, Poll};
use pin_project_lite::pin_project;
pin_project! {
/// Future for the [`next`](super::StreamExt::next) method.
///
/// # Cancel safety
///
/// This method is cancel safe. It only
/// holds onto a reference to the underlying stream,
/// so dropping it will never lose a value.
///
#[derive(Debug)]
#[must_use = "futures do nothing unless you `.await` or poll them"]
pub struct Next<'a, St: ?Sized> {
stream: &'a mut St,
// Make this future `!Unpin` for compatibility with async trait methods.
#[pin]
_pin: PhantomPinned,
}
}
impl<'a, St: ?Sized> Next<'a, St> {
pub(super) fn new(stream: &'a mut St) -> Self {
Next {
stream,
_pin: PhantomPinned,
}
}
}
impl<St: ?Sized + Stream + Unpin> Future for Next<'_, St> {
type Output = Option<St::Item>;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let me = self.project();
Pin::new(me.stream).poll_next(cx)
}
}
|
