ControllerRootViewContainer could be typed.

[matoushybl]

The implementation could be like this:

public final class TypedControllerRootViewContainer<CONTROLLER>: ControllerRootViewContainer

public class ControllerRootViewContainer: UIView, Configurable

It would allow switching in styles in Configuration like this:

controllerRoot = { view in
    if view is TypedControllerRootViewContainer<LoginController> { ... }
}