Zeromq: How to access tcp message in c++ -

i new-by zeromq , make way through c++ hello-world example of echo client-server pattern (request-reply). server looks like:

// // hello world server in c++ // binds rep socket tcp://*:5555 // expects "hello" client, replies "world" // #include <zmq.hpp> #include <string> #include <iostream> #include <unistd.h>  int main () {     // prepare our context , socket     zmq::context_t context (1);     zmq::socket_t socket (context, zmq_rep);     socket.bind ("tcp://*:5555");      while (true) {         zmq::message_t request;          // wait next request client         socket.recv (&request);         std::cout << "received hello" << std::endl;          // 'work'         sleep (1);          // send reply client         zmq::message_t reply (5);         memcpy ((void *) reply.data (), "world", 5);         socket.send (reply);     }     return 0; } 

now question: how can access / read real data socket.recv() ? trying:

 std::cout << request << std::endl; 

resulted in error message:

 error: no match ‘operator<<’ in ‘std::operator<< [with _traits =   std::char_traits<char>](((std::basic_ostream<char, std::char_traits<char> >&)  (& std::cout)), ((const char*)"received hello")) << request’ 

the same goes client side sending message. don't find way display real message...

the hello world example goes half way , outputs hard-coded values:

std::cout << "received hello" << std::endl; 

printing actual response can done follows:

zmq::message_t reply; socket.recv (&reply);  std::string rpl = std::string(static_cast<char*>(reply.data()), reply.size());  std::cout << rpl << std::endl; 

there other useful examples in zhelpers.hpp.