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use {Future, Poll, Async};
use stream::Stream;
#[derive(Debug)]
#[must_use = "futures do nothing unless polled"]
pub struct StreamFuture<S> {
stream: Option<S>,
}
pub fn new<S: Stream>(s: S) -> StreamFuture<S> {
StreamFuture { stream: Some(s) }
}
impl<S: Stream> Future for StreamFuture<S> {
type Item = (Option<S::Item>, S);
type Error = (S::Error, S);
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
let item = {
let s = self.stream.as_mut().expect("polling StreamFuture twice");
match s.poll() {
Ok(Async::NotReady) => return Ok(Async::NotReady),
Ok(Async::Ready(e)) => Ok(e),
Err(e) => Err(e),
}
};
let stream = self.stream.take().unwrap();
match item {
Ok(e) => Ok(Async::Ready((e, stream))),
Err(e) => Err((e, stream)),
}
}
}