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
use futures_core::{Async, Poll, Future, Stream};
use futures_core::task;
#[must_use = "futures do nothing unless polled"]
#[derive(Debug)]
pub struct IntoStream<F: Future> {
future: Option<F>
}
pub fn new<F: Future>(future: F) -> IntoStream<F> {
IntoStream {
future: Some(future)
}
}
impl<F: Future> Stream for IntoStream<F> {
type Item = F::Item;
type Error = F::Error;
fn poll_next(&mut self, cx: &mut task::Context) -> Poll<Option<Self::Item>, Self::Error> {
let ret = match self.future {
None => return Ok(Async::Ready(None)),
Some(ref mut future) => {
match future.poll(cx) {
Ok(Async::Pending) => return Ok(Async::Pending),
Err(e) => Err(e),
Ok(Async::Ready(r)) => Ok(r),
}
}
};
self.future = None;
ret.map(|r| Async::Ready(Some(r)))
}
}