[fooker]

You can just generate the 'vtable' as code :)

  switch (animal.type)
    case Cat: return cat_speak()
    case Dog: return dog_speak()

The generated code has the functions resolved in compile time, there's no function pointer lookup in a table happening. I don't know if this is how this project does it, but this is the commonly used technique when you want to do this.

[jeswin]

Hmm yeah good point. I didn't think of it. It might even be cheaper to do this when the list of possible types are closed and few.

I am still inclined to believe AI just made up the documentation though, because this has its own tradeoffs.

[fooker]

> might even be cheaper to do this

Oh yeah, very often. Especially if it's a loop and resolves the same way very often.

Modern CPUs just blaze through code like this, after three decades optimizing for object oriented and dynamic languages.