Hi Tomislav,

I have a question regarding the Ring model. How come it inherits from a
(STL) Sequence?
Inheriting from STL containers is said to be a problem because of the
lack of a virtual destructor.
However, this is only dangerous if you try to use dynamic polymorphism
with a container, accessing
the derived container member functions using a base class container

Exactly, and that's not the intended use here. Inheritance is used for aliasing in this situation, as a convenient way to pull the public interface of the STL container. It's not intended to be used polymorphically. The documentation implicitly incurs that by not mentioning this implementation detail.

, but
why would anyone use
pointers to containers?

Outside of Boost.Geometry there's plenty of reasons to do that, but you are right to say that doing it with STL classes would be plain wrong. They are not intended to be extended this way.

Bruno