muti-part message functionality available via API

include/zmq.h

@@ -181,6 +181,7 @@ ZMQ_EXPORT int zmq_term (void *context);
 #define ZMQ_RCVBUF 12
 
 #define ZMQ_NOBLOCK 1
+#define ZMQ_TBC 2
 
 ZMQ_EXPORT void *zmq_socket (void *context, int type);
 ZMQ_EXPORT int zmq_close (void *s);

src/socket_base.cpp

@@ -311,6 +311,11 @@ int zmq::socket_base_t::connect (const char *addr_)
 
 int zmq::socket_base_t::send (::zmq_msg_t *msg_, int flags_)
 {
+    //  ZMQ_TBC is actually a message flag, not a real send-flag
+    //  such as ZMQ_NOBLOCK. At this point we impose it on the message.
+    if (flags_ & ZMQ_TBC)
+        msg_->flags |= ZMQ_MSG_TBC;
+
     //  Process pending commands, if any.
     app_thread->process_commands (false, true);