Remove #[derive(Debug)] from library structs (#327)

* Remove `#[derive(Debug)]` from library structs
* Add manual debug impl for backward compatibility

tarpc/src/rpc/client.rs

@@ -8,6 +8,7 @@
 
 use crate::context;
 use futures::prelude::*;
+use std::fmt;
 use std::io;
 
 /// Provides a [`Client`] backed by a transport.
@@ -127,7 +128,6 @@ impl Default for Config {
 
 /// A channel and dispatch pair. The dispatch drives the sending and receiving of requests
 /// and must be polled continuously or spawned.
-#[derive(Debug)]
 pub struct NewClient<C, D> {
     /// The new client.
     pub client: C,
@@ -153,3 +153,9 @@ where
         Ok(self.client)
     }
 }
+
+impl<C, D> fmt::Debug for NewClient<C, D> {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(fmt, "NewClient")
+    }
+}

tarpc/src/rpc/server.rs

@@ -36,7 +36,6 @@ pub use self::{
 };
 
 /// Manages clients, serving multiplexed requests over each connection.
-#[derive(Debug)]
 pub struct Server<Req, Resp> {
     config: Config,
     ghost: PhantomData<(Req, Resp)>,
@@ -48,6 +47,12 @@ impl<Req, Resp> Default for Server<Req, Resp> {
     }
 }
 
+impl<Req, Resp> fmt::Debug for Server<Req, Resp> {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(fmt, "Server")
+    }
+}
+
 /// Settings that control the behavior of the server.
 #[derive(Clone, Debug)]
 pub struct Config {
@@ -167,7 +172,6 @@ where
 
 /// BaseChannel lifts a Transport to a Channel by tracking in-flight requests.
 #[pin_project]
-#[derive(Debug)]
 pub struct BaseChannel<Req, Resp, T> {
     config: Config,
     /// Writes responses to the wire and reads requests off the wire.
@@ -236,6 +240,12 @@ where
     }
 }
 
+impl<Req, Resp, T> fmt::Debug for BaseChannel<Req, Resp, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "BaseChannel")
+    }
+}
+
 /// The server end of an open connection with a client, streaming in requests from, and sinking
 /// responses to, the client.
 ///
@@ -384,7 +394,6 @@ where
 
 /// A running handler serving all requests coming over a channel.
 #[pin_project]
-#[derive(Debug)]
 pub struct ClientHandler<C, S>
 where
     C: Channel,
@@ -508,9 +517,17 @@ where
     }
 }
 
+impl<C, S> fmt::Debug for ClientHandler<C, S>
+where
+    C: Channel,
+{
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(fmt, "ClientHandler")
+    }
+}
+
 /// A future fulfilling a single client request.
 #[pin_project]
-#[derive(Debug)]
 pub struct RequestHandler<F, R> {
     #[pin]
     resp: Abortable<Resp<F, R>>,
@@ -528,8 +545,13 @@ where
     }
 }
 
+impl<F, R> fmt::Debug for RequestHandler<F, R> {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(fmt, "RequestHandler")
+    }
+}
+
 #[pin_project]
-#[derive(Debug)]
 struct Resp<F, R> {
     state: RespState,
     request_id: u64,
@@ -614,6 +636,12 @@ where
     }
 }
 
+impl<F, R> fmt::Debug for Resp<F, R> {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(fmt, "Resp")
+    }
+}
+
 impl<C, S> Stream for ClientHandler<C, S>
 where
     C: Channel,