Replace _non_exhaustive fields with #[non_exhaustive] attribute.

The attribute landed on stable rust (1.40.0) today.

Fixes https://github.com/google/tarpc/issues/275

tarpc/src/rpc/client/channel.rs

@@ -385,9 +385,7 @@ where
             context: context::Context {
                 deadline: dispatch_request.ctx.deadline,
                 trace_context: dispatch_request.ctx.trace_context,
-                _non_exhaustive: (),
             },
-            _non_exhaustive: (),
         });
         self.as_mut().project().transport.start_send(request)?;
         self.as_mut().project().in_flight_requests.insert(
@@ -768,7 +766,6 @@ mod tests {
             Response {
                 request_id: 0,
                 message: Ok("hello".into()),
-                _non_exhaustive: (),
             },
         )
         .await;

tarpc/src/rpc/client/mod.rs

@@ -104,6 +104,7 @@ where
 
 /// Settings that control the behavior of the client.
 #[derive(Clone, Debug)]
+#[non_exhaustive]
 pub struct Config {
     /// The number of requests that can be in flight at once.
     /// `max_in_flight_requests` controls the size of the map used by the client
@@ -113,8 +114,6 @@ pub struct Config {
     /// `pending_requests_buffer` controls the size of the channel clients use
     /// to communicate with the request dispatch task.
     pub pending_request_buffer: usize,
-    #[doc(hidden)]
-    _non_exhaustive: (),
 }
 
 impl Default for Config {
@@ -122,7 +121,6 @@ impl Default for Config {
         Config {
             max_in_flight_requests: 1_000,
             pending_request_buffer: 100,
-            _non_exhaustive: (),
         }
     }
 }

tarpc/src/rpc/context.rs

@@ -16,6 +16,7 @@ use std::time::{Duration, SystemTime};
 /// The context should not be stored directly in a server implementation, because the context will
 /// be different for each request in scope.
 #[derive(Clone, Copy, Debug)]
+#[non_exhaustive]
 #[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
 pub struct Context {
     /// When the client expects the request to be complete by. The server should cancel the request
@@ -35,9 +36,6 @@ pub struct Context {
     /// include the same `trace_id` as that included on the original request. This way,
     /// users can trace related actions across a distributed system.
     pub trace_context: trace::Context,
-    #[doc(hidden)]
-    #[cfg_attr(feature = "serde1", serde(skip_serializing, default))]
-    pub(crate) _non_exhaustive: (),
 }
 
 #[cfg(feature = "serde1")]
@@ -51,7 +49,6 @@ pub fn current() -> Context {
     Context {
         deadline: SystemTime::now() + Duration::from_secs(10),
         trace_context: trace::Context::new_root(),
-        _non_exhaustive: (),
     }
 }
 

tarpc/src/rpc/mod.rs

@@ -64,6 +64,7 @@ pub enum ClientMessage<T> {
 
 /// A request from a client to a server.
 #[derive(Clone, Copy, Debug)]
+#[non_exhaustive]
 #[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
 pub struct Request<T> {
     /// Trace context, deadline, and other cross-cutting concerns.
@@ -72,26 +73,22 @@ pub struct Request<T> {
     pub id: u64,
     /// The request body.
     pub message: T,
-    #[doc(hidden)]
-    #[cfg_attr(feature = "serde1", serde(skip_serializing, default))]
-    _non_exhaustive: (),
 }
 
 /// A response from a server to a client.
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
+#[non_exhaustive]
 #[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
 pub struct Response<T> {
     /// The ID of the request being responded to.
     pub request_id: u64,
     /// The response body, or an error if the request failed.
     pub message: Result<T, ServerError>,
-    #[doc(hidden)]
-    #[cfg_attr(feature = "serde1", serde(skip_serializing, default))]
-    _non_exhaustive: (),
 }
 
 /// An error response from a server to a client.
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
+#[non_exhaustive]
 #[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
 pub struct ServerError {
     #[cfg_attr(
@@ -106,9 +103,6 @@ pub struct ServerError {
     pub kind: io::ErrorKind,
     /// A message describing more detail about the error that occurred.
     pub detail: Option<String>,
-    #[doc(hidden)]
-    #[cfg_attr(feature = "serde1", serde(skip_serializing, default))]
-    _non_exhaustive: (),
 }
 
 impl From<ServerError> for io::Error {

tarpc/src/rpc/server/mod.rs

@@ -569,11 +569,9 @@ where
                                         "Response did not complete before deadline of {}s.",
                                         format_rfc3339(self.deadline)
                                     )),
-                                    _non_exhaustive: (),
                                 })
                             }
                         },
-                        _non_exhaustive: (),
                     });
                     *self.as_mut().project().state = RespState::PollReady;
                 }

tarpc/src/rpc/server/testing.rs

@@ -87,11 +87,9 @@ impl<Req, Resp> FakeChannel<io::Result<Request<Req>>, Response<Resp>> {
             context: context::Context {
                 deadline: SystemTime::UNIX_EPOCH,
                 trace_context: Default::default(),
-                _non_exhaustive: (),
             },
             id,
             message,
-            _non_exhaustive: (),
         }));
     }
 }

tarpc/src/rpc/server/throttle.rs

@@ -61,9 +61,7 @@ where
                         message: Err(ServerError {
                             kind: io::ErrorKind::WouldBlock,
                             detail: Some("Server throttled the request.".into()),
-                            _non_exhaustive: (),
                         }),
-                        _non_exhaustive: (),
                     })?;
                 }
                 None => return Poll::Ready(None),
@@ -311,7 +309,6 @@ fn throttler_start_send() {
         .start_send(Response {
             request_id: 0,
             message: Ok(1),
-            _non_exhaustive: (),
         })
         .unwrap();
     assert!(throttler.inner.in_flight_requests.is_empty());
@@ -320,7 +317,6 @@ fn throttler_start_send() {
         Some(&Response {
             request_id: 0,
             message: Ok(1),
-            _non_exhaustive: ()
         })
     );
 }