I had a C++ actor model which required an Api like the following (std::function):

child->Async(&ChildActor::Method, child, args);

Refactored it to use small buffer optimisation and std::move_only_function)

child<&ChildActor::Method>(args);

And saw a performance jump since no more malloc in std::function.

It also helped me decipher an animation bug in gtlf importer.

Productivity is x4 or higher.