This was quite a fight; at least it compiles now... (no idea if works)

Ugh, the type system in C++ is bad. It's hard to fit these things
together.

I'll have a ton of cleanup to do when done.

server.py

@@ -76,7 +76,7 @@ async def server(websocket, path):
             #await websocket.send("Got message: {}".format(msg))
             
             print('enqueuing websocket message', flush=True)
-            queue.put_nowait(msg)
+            queue.put_nowait("{}|{}".format(channel, msg))
 
     asyncio.ensure_future(reader(mpsc))
 
@@ -98,7 +98,7 @@ async def server(websocket, path):
             await websocket.send("Websocket ping")
 
             if not queue.empty():
-                msg = queue.get_nowait() # TODO THROWS EXCEPTION
+                msg = queue.get_nowait() # TODO THROWS EXCEPTION IF EMPTY (data race?)
 
                 print('sending pubsub msg over websocket: {}'.format(msg), flush=True)
                 await websocket.send(msg)