fbzmq publisher unable to publish on topic

[marktam264]

Please use this template for reporting suspected bugs or requests for help.

Issue Description

From the current documentation and examples, it is unclear to me whether the API supports publishing a message on a specific topic. Is this possible using the fbzmq API?

Environment

• tag or commit hash on which this occured
• OS version: <e.g. ubuntu-16.04>
  Mint 18.3 (Ubuntu 16.04)

Minimal test code / Steps to reproduce the issue

What's the actual result?

Current send*() methods on the API do not seem to support publishing on a topic for a ZMQ_PUB socket.

What's the expected result?

send*() methods on the API have a parameter to publish on a topic.

[saifhhasan]

Yes it is possible. Use sendMultiple method. Something on the lines of

socket.sendMultiple(
  fbzmq::Message::from(std::string("topic")),
  fbzmq::Message::from(std::string("data")));

[marktam264]

@saihhasan, thank you, yes that would work.

Although, I still think it would be ideal if we could put the responsibility of routing into fbzmq (via topics) rather than putting it on the client to do so.

[saifhhasan]

@marktam264 hmm. I would dis-agree here. We tried to keep fbzmq as a C++ wrapper over libzmq (C version). So things like migrating existing code, or just getting started with fbzmq with understanding of libzmq is straight forward :)

[marktam264]

@saifhhasan no problem. Yes, it is straight forward if you know libzmq. Thank you, again.