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
45
use super::assert_stream;
use core::marker;
use core::pin::Pin;
use futures_core::stream::{FusedStream, Stream};
use futures_core::task::{Context, Poll};
#[derive(Debug)]
#[must_use = "streams do nothing unless polled"]
pub struct Pending<T> {
_data: marker::PhantomData<T>,
}
pub fn pending<T>() -> Pending<T> {
assert_stream::<T, _>(Pending { _data: marker::PhantomData })
}
impl<T> Unpin for Pending<T> {}
impl<T> FusedStream for Pending<T> {
fn is_terminated(&self) -> bool {
true
}
}
impl<T> Stream for Pending<T> {
type Item = T;
fn poll_next(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Option<Self::Item>> {
Poll::Pending
}
fn size_hint(&self) -> (usize, Option<usize>) {
(0, Some(0))
}
}
impl<T> Clone for Pending<T> {
fn clone(&self) -> Self {
pending()
}
}