There is a performance problem in the simplified implement of std::function we have talked about at the former post, that is a dynamic allocation is called for no matter what wrapped in the function object, and when the copy-constructor is called, which often happens when the function object is saved into a container, another dynamic allocation is fired again. This probably results in heavy performance problem.
So we are now going to see if there are some approaches to avoid dynamic allocations.
We want to get rid of new but we also need polymorphism, so the solution is to maintenance a set of "virtual function" by ourselves. Well this is where we need function pointers.