What do you think of the proposal that is simply a hint? The one where you tell the compiler you expect given object classes and metaclasses? There are two ways it could go:

- At runtime, if we don't have the expected classes & metaclasses, ignore the hint and do what you would have done anyway. This way, the semantics aren't changed, but if the types are as expected the call is much faster. If not, it's a little slower.

- At runtime, if things don't match, signal an error. This turns it into an assertion mechanism. This might be helpful in tracking down bugs and making the programmer's intention clearer, as well as performance.