stream: expose Elapsed error (#4502)

tokio-stream/src/lib.rs

@@ -77,6 +77,9 @@ pub mod wrappers;
 
 mod stream_ext;
 pub use stream_ext::{collect::FromStream, StreamExt};
+cfg_time! {
+    pub use stream_ext::timeout::Elapsed;
+}
 
 mod empty;
 pub use empty::{empty, Empty};

tokio-stream/src/stream_ext.rs

@@ -56,7 +56,7 @@ mod try_next;
 use try_next::TryNext;
 
 cfg_time! {
-    mod timeout;
+    pub(crate) mod timeout;
     use timeout::Timeout;
     use tokio::time::Duration;
     mod throttle;