Pre-RFC: Explicit overload sets for mixed-arity function calls

chrefr:

unless you argue that it's not possible to create a good API with overloads.

I actually do argue that the costs of ad-hoc overloads are always too high, especially when those ad-hoc overloads are used as extension points.

A variadic trait method that thus can take different arities? Sure, that's fine, because it's not ad-hoc.