text: /*
   *
   * Copyright 2015 gRPC authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  #include <iostream>
  #include <memory>
  #include <string>
  
  #include <grpcpp/grpcpp.h>
  
  #ifdef BAZEL_BUILD
  #include "examples/protos/helloworld.grpc.pb.h"
  #else
  #include "helloworld.grpc.pb.h"
  #endif
  
  using grpc::Channel;
  using grpc::ClientContext;
  using grpc::Status;
  using helloworld::HelloRequest;
  using helloworld::HelloReply;
  using helloworld::Greeter;
  
  class GreeterClient {
   public:
    GreeterClient(std::shared_ptr<Channel> channel)
        : stub_(Greeter::NewStub(channel)) {}
  
    // Assembles the client's payload, sends it and presents the response back
    // from the server.
    std::string SayHello(const std::string& user) {
      // Data we are sending to the server.
      HelloRequest request;
      request.set_name(user);
  
      // Container for the data we expect from the server.
      HelloReply reply;
  
      // Context for the client. It could be used to convey extra information to
      // the server and/or tweak certain RPC behaviors.
      ClientContext context;
  
      // The actual RPC.
      Status status = stub_->SayHello(&context, request, &reply);
  
      // Act upon its status.
      if (status.ok()) {
        return reply.message();
      } else {
        std::cout << status.error_code() << ": " << status.error_message()
                  << std::endl;
        return "RPC failed";
      }
    }
  
   private:
    std::unique_ptr<Greeter::Stub> stub_;
  };
  
  int main(int argc, char** argv) {
    // Instantiate the client. It requires a channel, out of which the actual RPCs
    // are created. This channel models a connection to an endpoint (in this case,
    // localhost at port 50051). We indicate that the channel isn't authenticated
    // (use of InsecureChannelCredentials()).
    GreeterClient greeter(grpc::CreateChannel(
        "localhost:50051", grpc::InsecureChannelCredentials()));
    std::string user("world");
    std::string reply = greeter.SayHello(user);
    std::cout << "Greeter received: " << reply << std::endl;
  
    return 0;
  }
  