Fix R/W template argument order in prototypes

In some cases, the prototype argument order was different
than the declaration order.

Based on a patch from Sam Leffler.

include/grpc++/channel.h

@@ -54,13 +54,13 @@ template <class R>
 class ClientReader;
 template <class W>
 class ClientWriter;
-template <class R, class W>
+template <class W, class R>
 class ClientReaderWriter;
 template <class R>
 class ClientAsyncReader;
 template <class W>
 class ClientAsyncWriter;
-template <class R, class W>
+template <class W, class R>
 class ClientAsyncReaderWriter;
 template <class R>
 class ClientAsyncResponseReader;
@@ -98,13 +98,13 @@ class Channel GRPC_FINAL : public GrpcLibrary,
   friend class ::grpc::ClientReader;
   template <class W>
   friend class ::grpc::ClientWriter;
-  template <class R, class W>
+  template <class W, class R>
   friend class ::grpc::ClientReaderWriter;
   template <class R>
   friend class ::grpc::ClientAsyncReader;
   template <class W>
   friend class ::grpc::ClientAsyncWriter;
-  template <class R, class W>
+  template <class W, class R>
   friend class ::grpc::ClientAsyncReaderWriter;
   template <class R>
   friend class ::grpc::ClientAsyncResponseReader;

include/grpc++/client_context.h

@@ -76,13 +76,13 @@ template <class R>
 class ClientReader;
 template <class W>
 class ClientWriter;
-template <class R, class W>
+template <class W, class R>
 class ClientReaderWriter;
 template <class R>
 class ClientAsyncReader;
 template <class W>
 class ClientAsyncWriter;
-template <class R, class W>
+template <class W, class R>
 class ClientAsyncReaderWriter;
 template <class R>
 class ClientAsyncResponseReader;
@@ -304,13 +304,13 @@ class ClientContext {
   friend class ::grpc::ClientReader;
   template <class W>
   friend class ::grpc::ClientWriter;
-  template <class R, class W>
+  template <class W, class R>
   friend class ::grpc::ClientReaderWriter;
   template <class R>
   friend class ::grpc::ClientAsyncReader;
   template <class W>
   friend class ::grpc::ClientAsyncWriter;
-  template <class R, class W>
+  template <class W, class R>
   friend class ::grpc::ClientAsyncReaderWriter;
   template <class R>
   friend class ::grpc::ClientAsyncResponseReader;

include/grpc++/completion_queue.h

@@ -49,13 +49,13 @@ template <class R>
 class ClientReader;
 template <class W>
 class ClientWriter;
-template <class R, class W>
+template <class W, class R>
 class ClientReaderWriter;
 template <class R>
 class ServerReader;
 template <class W>
 class ServerWriter;
-template <class R, class W>
+template <class W, class R>
 class ServerReaderWriter;
 template <class ServiceType, class RequestType, class ResponseType>
 class RpcMethodHandler;
@@ -151,13 +151,13 @@ class CompletionQueue : public GrpcLibrary {
   friend class ::grpc::ClientReader;
   template <class W>
   friend class ::grpc::ClientWriter;
-  template <class R, class W>
+  template <class W, class R>
   friend class ::grpc::ClientReaderWriter;
   template <class R>
   friend class ::grpc::ServerReader;
   template <class W>
   friend class ::grpc::ServerWriter;
-  template <class R, class W>
+  template <class W, class R>
   friend class ::grpc::ServerReaderWriter;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class RpcMethodHandler;

include/grpc++/server_context.h

@@ -58,13 +58,13 @@ template <class W>
 class ServerAsyncWriter;
 template <class W>
 class ServerAsyncResponseWriter;
-template <class R, class W>
+template <class W, class R>
 class ServerAsyncReaderWriter;
 template <class R>
 class ServerReader;
 template <class W>
 class ServerWriter;
-template <class R, class W>
+template <class W, class R>
 class ServerReaderWriter;
 template <class ServiceType, class RequestType, class ResponseType>
 class RpcMethodHandler;
@@ -145,13 +145,13 @@ class ServerContext {
   friend class ::grpc::ServerAsyncWriter;
   template <class W>
   friend class ::grpc::ServerAsyncResponseWriter;
-  template <class R, class W>
+  template <class W, class R>
   friend class ::grpc::ServerAsyncReaderWriter;
   template <class R>
   friend class ::grpc::ServerReader;
   template <class W>
   friend class ::grpc::ServerWriter;
-  template <class R, class W>
+  template <class W, class R>
   friend class ::grpc::ServerReaderWriter;
   template <class ServiceType, class RequestType, class ResponseType>
   friend class RpcMethodHandler;