add #[must_use] to more futures and streams (#1309)

tokio-udp/src/recv.rs

@@ -7,7 +7,7 @@ use std::task::{Context, Poll};
 /// A future that receives a datagram from the connected address.
 ///
 /// This `struct` is created by [`recv`](super::UdpSocket::recv).
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 #[derive(Debug)]
 pub struct Recv<'a, 'b> {
     socket: &'a UdpSocket,

tokio-udp/src/recv_from.rs

@@ -8,7 +8,7 @@ use std::task::{Context, Poll};
 /// A future that receives a datagram.
 ///
 /// This `struct` is created by [`recv_from`](super::UdpSocket::recv_from).
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 #[derive(Debug)]
 pub struct RecvFrom<'a, 'b> {
     socket: &'a UdpSocket,

tokio-udp/src/send.rs

@@ -7,7 +7,7 @@ use std::task::{Context, Poll};
 /// A future that sends a datagram to the connected address.
 ///
 /// This `struct` is created by [`send`](super::UdpSocket::send).
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 #[derive(Debug)]
 pub struct Send<'a, 'b> {
     socket: &'a UdpSocket,

tokio-udp/src/send_to.rs

@@ -8,7 +8,7 @@ use std::task::{Context, Poll};
 /// A future that sends a datagram to a given address.
 ///
 /// This `struct` is created by [`send_to`](super::UdpSocket::send_to).
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 #[derive(Debug)]
 pub struct SendTo<'a, 'b> {
     socket: &'a UdpSocket,