1 use tokio_stream::{self as stream, Stream, StreamExt}; 2 3 #[tokio::test] basic_usage()4async fn basic_usage() { 5 let mut one = stream::once(1); 6 7 assert_eq!(one.size_hint(), (1, Some(1))); 8 assert_eq!(Some(1), one.next().await); 9 10 assert_eq!(one.size_hint(), (0, Some(0))); 11 assert_eq!(None, one.next().await); 12 } 13