diff --git a/src/libcore/task/poll.rs b/src/libcore/task/poll.rs index 3db70d5e7645f..fec17c4d1a4df 100644 --- a/src/libcore/task/poll.rs +++ b/src/libcore/task/poll.rs @@ -81,6 +81,34 @@ impl Poll> { } } +impl Poll>> { + /// Changes the success value of this `Poll` with the closure provided. + #[unstable(feature = "poll_map", issue = "63514")] + pub fn map_ok(self, f: F) -> Poll>> + where F: FnOnce(T) -> U + { + match self { + Poll::Ready(Some(Ok(t))) => Poll::Ready(Some(Ok(f(t)))), + Poll::Ready(Some(Err(e))) => Poll::Ready(Some(Err(e))), + Poll::Ready(None) => Poll::Ready(None), + Poll::Pending => Poll::Pending, + } + } + + /// Changes the error value of this `Poll` with the closure provided. + #[unstable(feature = "poll_map", issue = "63514")] + pub fn map_err(self, f: F) -> Poll>> + where F: FnOnce(E) -> U + { + match self { + Poll::Ready(Some(Ok(t))) => Poll::Ready(Some(Ok(t))), + Poll::Ready(Some(Err(e))) => Poll::Ready(Some(Err(f(e)))), + Poll::Ready(None) => Poll::Ready(None), + Poll::Pending => Poll::Pending, + } + } +} + #[stable(feature = "futures_api", since = "1.36.0")] impl From for Poll { fn from(t: T) -> Poll {