feat: add downcast on Sleep trait

This commit adds `as_any` downcast method for the `Sleep` trait.

BREAKING CHANGE: `Sleep` trait now needs `as_any` implementation

Author: dswij

src/rt.rs

@@ -9,6 +9,7 @@ use std::{
     future::Future,
     pin::Pin,
     time::{Duration, Instant},
+    any::Any,
 };
 
 /// An executor of futures.
@@ -32,4 +33,7 @@ pub trait Timer {
 }
 
 /// A future returned by a `Timer`.
-pub trait Sleep: Send + Sync + Future<Output = ()> {}
+pub trait Sleep: Send + Sync + Future<Output = ()> {
+    /// Downcast API
+    fn as_any(&self) -> &dyn Any;
+}