C++ Dynamic Binding

* C++ Dynamic Binding
- Implemented by public inheritance and virtual functions
- Base and derived classes: general and special
- Base class must have one virtual function at least and it is the destructor. This affects the following two points.
- Virtual pointer to the virtual function table and its implementation in the derivation.
- Conversion/casting between base class object and derived class object.
- Public inheritance preferred. Use composite instead of private inheritance. No protected inheritance.
- Distinguish function overload, override, and hidden.

* Inheritance
- Base class consists of public interface (public accessibility) and private interface for derived classes (public and protected accessibility)
- Pure virtual function allows only interface without implementation for derived class.
- Virtual function allows interface with default implementation for derived class.
- Non-virtual function allows interface with mandatory implementation for derived class.

* Virtual Function
- Virtual function can not be static
- Redefine all the overloaded virtual functions
- No default arguments for virtual functions
- No virtual copy and assignment operator
- No virtual function calling in the constructor and destructor

* Abstract Class and Virtual Base Class