How to use zmq_msg_more correctly?

The API reference for zmq_msg_more () and zmq_msg_recv () (ZeroMQ 3.2.2 Stable) contains examples to show that zmq_msg_close () is called after zmq_msg_more. As far as I know, there is nothing in the API docs that contradicts this, so the example from the Connected code seems to be wrong. The documentation for zmq_msg_close()

specifies that the actual release of memory can be delayed by layers of the subclass, implying that the operation zmq_msg_more()

may succeed but still looks wrong to invoke after the message is closed.

Example from zmq_msg_more () API documentation (3.2.2) (slightly edited for reading):

zmq_msg_t part;
while (true) 
{
    //  Create an empty ØMQ message to hold the message part
    int rc = zmq_msg_init (&part);
    assert (rc == 0);

    //  Block until a message is available to be received from socket
    rc = zmq_recvmsg (socket, &part, 0);
    assert (rc != -1);

    if (zmq_msg_more (&part))
        fprintf (stderr, "more\n");
    else 
    {
        fprintf (stderr, "end\n");
        break;
    }
    zmq_msg_close (part); 
}

      

        
        
        
      

    

However, looking at the ZeroMq Manual regarding multi-part messages , this example actually checks for more messages after the message is closed, but this is achieved by checking the socket using zmq_getsockopt () , without using any reference to the message, I suspect code related examples , just used this example and changed from zmq_getsockopt()

to zmq_msg_more()

(maybe not so).

Example from The ZeroMq Manual (multipart posts) :

while (1) 
{
    zmq_msg_t message;
    zmq_msg_init (&message);
    zmq_msg_recv (&message, socket, 0);
    //  Process the message frame
    zmq_msg_close (&message);
    int more;
    size_t more_size = sizeof (more);
    zmq_getsockopt (socket, ZMQ_RCVMORE, &more, &more_size);
    if (!more)
        break;      //  Last message frame
}