One issue with static polymorphism is that without using a general base class like "Shape"<code>AbstractShape</code> from the above example, derived classes cannot be stored homogeneously--that is, putting different types derived from the same base class in the same container. For example, a container defined as <code>std::vector<Shape*></code> does not work because <code>Shape</code> is not a class, but a template needing specialization. A container defined as <code>std::vector<Shape<Circle>*></code> can only store <code>Circle</code>s, not <code>Square</code>s. This is because each of the classes derived from the CRTP base class <code>Shape</code> is a unique type. ForA thiscommon reason,solution itto isthis moreproblem commonis to inherit from a shared base class with a virtual destructor, like the <code>AbstractShape</code> example above, allowing for the creation of a <code>std::vector<AbstractShape*></code>.
