improved error message for unused futures (#32)

Author: ibaryshnikov

src/net/tcp.rs

@@ -217,7 +217,7 @@ impl AsyncWrite for TcpStream {
 ///
 /// [`TcpStream::connect`]: struct.TcpStream.html#method.connect
 /// [`TcpStream`]: struct.TcpStream.html
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Connect {
     addrs: Option<io::Result<VecDeque<SocketAddr>>>,
     last_err: Option<io::Error>,
@@ -453,7 +453,7 @@ impl TcpListener {
 ///
 /// [`TcpStream::accept`]: struct.TcpStream.html#method.accept
 /// [`TcpStream`]: struct.TcpStream.html
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 #[derive(Debug)]
 pub struct Accept<'stream> {
     inner: Incoming<'stream>,

src/net/udp.rs

@@ -358,7 +358,7 @@ impl UdpSocket {
 /// On success, returns the number of bytes written.
 ///
 /// [`UdpSocket::send_to`]: struct.UdpSocket.html#method.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<'socket, 'buf> {
     /// The open socket we use to send the message from.
@@ -393,7 +393,7 @@ impl<'socket, 'buf> Future for SendTo<'socket, 'buf> {
 /// On success, returns the number of bytes read and the origin.
 ///
 /// [`UdpSocket::recv_from`]: struct.UdpSocket.html#method.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<'socket, 'buf> {
     socket: &'socket mut UdpSocket,

src/task.rs

@@ -45,7 +45,7 @@ where
 /// A handle that awaits the result of a [`spawn`]ed future.
 ///
 /// [`spawn`]: fn.spawn.html
-#[must_use = "futures do nothing unless polled"]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 #[derive(Debug)]
 pub struct JoinHandle<T> {
     pub(crate) rx: futures::channel::oneshot::Receiver<T>,