sorry I could read that a few ways. Are you saying will this line throw an exception of monitoring is disabled or are you suggesting I show ad a "Throw" in an else on this if say throw new Error('Callbacks are not supported when broadcasting'); 

Line 338 won't throw an exception regardless if its disabled in the cc file I made sure it is a valid variable regardless of compiler flags and ifdefs.

I don't mind at all adding a throw but if I do then a few others should be changed as well such as ZMQ_CAN_DISCONNECT. If you want me to start the ball rolling by adding it to my function or I would be happy to submit another patch for all of them. 

Just let me know.