Add example use of poll_zsock wrapper.

examples/forward_poll.lua

@@ -0,0 +1,28 @@
+local zmq = require'zmq'
+local poller = require"examples.poller"
+local poll_zsock = require"examples.poll_zsock"
+
+local poll = poller.new()
+poll_zsock.set_poller(poll)
+
+local c = zmq.init(1)
+local xreq = poll_zsock(c:socket(zmq.XREQ))
+xreq:bind('tcp://127.0.0.1:13333')
+local xrep = poll_zsock(c:socket(zmq.XREP))
+xrep:bind('tcp://127.0.0.1:13334')
+
+local function forward_io(src,dst)
+   src.on_data = function()
+      repeat
+         local data = assert(src:recv(zmq.NOBLOCK))
+         local more = src:getopt(zmq.RCVMORE) > 0
+         dst:send(data,more and zmq.SNDMORE or 0)
+      until not more
+   end
+end
+
+forward_io(xrep,xreq)
+forward_io(xreq,xrep)
+
+poll:start()
+