clemensv

/*
Example use (from an email I sent)

I’m using WhenAny to either register for a callback on any of the pending operations and to use 
the IO thread that comes up with their respective completion or to execute handling of completed 
work on the current thread (‘borrowing’ the IO thread). 

So if I read from a socket and from a queue, first both ops hang. Queue read completes and I get 
called back on an IO thread which continues the await. I process that completion in the loop. 
Meanwhile the socket read completes. That IO thread pops up and just registers the fact that it’s