about override private virtual fucntions in C++

See this usage in MySQL’s handler class. Find it really weird when you got knowledge of C++ & Java.

About private virtual functions: C++ FAQs

‘private’ doesn’t stop you from override a virtual function. And as it means, derived class cannot call base class’s private function as usual. Private virtual function is useful implementing template pattern.

In short, if you wanna a custom method in derived class and do not want it to show up in class interface and you do not want to provide a reusable base code, mark it private pure virtual.