Hands-On Design Patterns with C++

Destructors and polymorphic deletion

So far, we have willfully avoided tackling the issue of deleting objects implemented with CRTP in some sort of polymorphic fashion. In fact, if you go back and re-read the examples that presented complete code, such as the benchmark fixture, BM_static, in the Introducing CRTP section, we either avoided deleting the object altogether or constructed a derived object on the stack. This is because polymorphic deletion presents an additional complication that we are finally ready to deal with.

First of all, let's note that, in many cases, polymorphic deletion is not a concern. All objects are created with their actual types known. If the code that constructs the objects also owns and eventually deletes them, ...