Deprecation of poll(std::vector<zmq_pollitem_t> &items)

[yuyichao]

In #415 (b0e7243) poll(std::vector<zmq_pollitem_t> &items, long timeout_) is deprecated. I think this is fine but it also cause a deprecation warning if no timeout is given.

Is this deprecation intentional? If so, what will be the new way of specifying no timeout? It seems that the way to do it right now is either to call poll(zmq_pollitem_t *items_, size_t nitems_, long timeout_ = -1) (or zmq_poll) manually, or to pass an exactly -1ms timeout. Both of these solutions feels very wrong.

If this deprecation isn't intentional, a separate function poll(std::vector<zmq_pollitem_t> &items) should be added to suppress the warning.

[gummif]

Yes this is unfortunate. The timeout parameters should probably have a default value of milliseconds{-1}, and change the long timeout version to not have a default value.

[gummif]

See #497 for proposed change