C/C++ Users Group Library 1996 July/C-C++ Users Group Library July 1996.iso/listings/v_12_01/saks/derived.h

C/C++ Source or Header | 1993-11-07 | 442 b | 28 lines

Listing 8 - Derived class that doesn't override all pure virtual
functions is still abstract

class B
    {
public:
    virtual void f();
    virtual void g() = 0;
    };

void B::f() { ... }

class D : public B
    {
public:
    void f();   // virtual
                // g is still pure virtual
    };

void D::f() { ... }

int main()
    {
    B b;        // error, B is abstract class
      D d;        // error, D is abstract class
    ...
    }