Polymorphism, Virtual Functions and Dynamic Binding "Under the Hood"

• Polymorphism has overhead
  • Not used in STL (Standard Template Library) to optimize performance
• virtual function table (vtable)
  • Every class with a virtual function has a vtable
  • For every virtual function, vtable has pointer to the proper function
  • If derived class has same function as base class; function pointer aims at base-class function
  • Detailed explanation in Fig. 10.21 (in book) (will not be covered)