Something interesting.I know that D has C++ SFML bindings, although they are unmaintained.
I was interested to see how they would 'implement' the C++ namespaces of SFML, and - boy was I surprised.
Reading through `DSFML`, I see `final abstract class` getting used to implement SFML's `Keyboard` namespace:
`final abstract class Keyboard` at https://github.com/Jebbs/DSFML/blob/master/src/dsfml/window/keyboard.d
It seems like using `final abstract` is the best solution.
