Function tokio::prelude::stream::once [−] [src]

pub fn once<T, E>(item: Result<T, E>) -> Once<T, E>

Creates a stream of single element

use futures::*;

let mut stream = stream::once::<(), _>(Err(17));
assert_eq!(Err(17), stream.poll());
assert_eq!(Ok(Async::Ready(None)), stream.poll());