error[E0599]: no method named `poll` found for struct `Sleep` in the current scope --> $DIR/pin-needed-to-poll.rs:42:20 | LL | struct Sleep; | ------------ method `poll` not found for this struct ... LL | self.sleep.poll(cx) | ^^^^ method not found in `Sleep` | help: consider pinning the expression | LL ~ let mut pinned = std::pin::pin!(self.sleep); LL ~ pinned.as_mut().poll(cx) | error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0599`.