Found cpc https://github.com/kerneis/cpc from your comment stream. Looks super interesting. http://felix-lang.org/share/src/web/tut/fibres_index.fdoc might pique your interest. It also compiles coroutines portably and efficiently (to a C++ runtime library). Felix tries to do for C++ what F# does to C# (in case there is any confusion, I am just a new user)