Thanks for the reply, Mr. Gor. Your proposal has two obvious advantages: more refined in real-world workloads and implementations available to test them.

That said, what I would like to see maybe it is something that mixes the easy understanding of function objects with other things. I am not sure whether resumable functions can be done less heavy-weight or if there is any inherent limitation. But, and I say this from the POV of a person familiar with C++ idioms, I understand function objects, shared_ptrs, and many other things and know how they can be optimized.

That said, I am not sure how far it could go the performance of resumable functions compared to Coroutines as implemented now, and my understanding is that something close to max performance is essential, so if Coroutines are superior in that sense, that would be a big point for them.

As for all the compiler-generated hooks, I think it would be good if part of that in one way or another could be moved to a more library-based solution, since once this is added into the language... you know, there is no easy way back.