Virtual Function Return Type
Generally, the redefined version of a virtual function must have the same return type as in the initial declaration. However, for certain virtual functions in a base class, their overriding version in a derived class can have a return type that is different from the overridden function. This is possible only if the derived class ( say, D ) function's return type is D * or D &, and base class ( say, B ) function's return type is B* or B &, respectively, and B is an accessible base class of D.
For example,
class B
{
public :
virtual B * F ( ) ;
// . . . .
} ;
class D : public B
{
public :
virtual D * F ( ) ;
// . . . .
} ;
