Thanks for the example! I'm doing it slightly differently but using your basic technique.
Next roadblock is that `FlowVar` doesn't seem compatible with ORC (which I need so I can pass object graphs across threads): `nim-1.2.2/lib/pure/concurrency/threadpool.nim(214, 6) Error: cannot bind another '=destroy' to: FlowVarObj; previous declaration was constructed here implicitly: nim-1.2.2/lib/pure/concurrency/threadpool.nim(211, 48)`
