Virtual Base Classes

Inheritance Conflicts

• Member Conflicts
  • Name conflicts can occur - same member name from more than one base class
  • Derived class can overshadow base class members name
  • Use scope resolution operator to resolve conflicts
• Multiple Inheritance Conflicts
  • Derived class may combine more than one copy of a member
  • Base class may combine more than one copy of a member

Virtual Base Classes

• Prevents inheriting multiple copies of same base class members
• Keyword virtual in inheritance link
  • Base classes made virtual class B { // base class protected: int X,Y;}; class D1 : public virtual B {protected: int Z;} ;class D2 : public virtual B {protected: int Z;}; class D3 : public D1, public D2 { …};
• All base classes used in multiple inheritance