Simplify the mailbox code

src/mailbox.rs

@@ -28,21 +28,17 @@ impl<'a, T> Future for MailboxPut<'a, T> {
 
 	fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
 		let mut mb = self.0 .0.lock().unwrap();
-		match mb.value {
-			None => {
-				let waker = mb.waker.take();
-				mb.value = self.1.take();
-				drop(mb);
-				if let Some(waker) = waker {
-					waker.wake();
-				}
-				Poll::Ready(())
-			}
-			Some(_) => {
-				mb.waker = Some(cx.waker().clone());
-				Poll::Pending
-			}
+		let None = mb.value else {
+			mb.waker = Some(cx.waker().clone());
+			return Poll::Pending;
+		};
+		mb.value = self.1.take();
+		let waker = mb.waker.take();
+		drop(mb);
+		if let Some(waker) = waker {
+			waker.wake();
 		}
+		Poll::Ready(())
 	}
 }
 
@@ -52,20 +48,16 @@ impl<'a, T> Future for MailboxGet<'a, T> {
 
 	fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
 		let mut mb = self.0 .0.lock().unwrap();
-		match mb.value.take() {
-			None => {
-				mb.waker = Some(cx.waker().clone());
-				Poll::Pending
-			}
-			Some(value) => {
-				let waker = mb.waker.take();
-				drop(mb);
-				if let Some(waker) = waker {
-					waker.wake();
-				}
-				Poll::Ready(value)
-			}
+		let Some(value) = mb.value.take() else {
+			mb.waker = Some(cx.waker().clone());
+			return Poll::Pending;
+		};
+		let waker = mb.waker.take();
+		drop(mb);
+		if let Some(waker) = waker {
+			waker.wake();
 		}
+		Poll::Ready(value)
 	}
 }