Question

I have ancestor abstact class called Figure

class Figure {
public:
   string style, color, name;


   virtual void printInfo() = 0;
   /*
   different methods here
   */
   virtual Figure operator * (int prod) = 0;

};

And I have Line class (and few others) that inherites Figure.

class Line : public Figure {
     /* .... */
     Line operator*(int prod);
};

Line Line::operator *(int prod) {
    Line temp = *this ;
    Point p = getPoint2();
    p.setXYZ(p.getX() * prod, p.getY() * prod, p.getZ() * prod);
    temp.setPoint2(p);
    return temp;
}

The point is that I want to have such virtual operator, but if I write code as above I get dozen of mistakes.
What have I done wrong?

Answer 1

Figure is an abstract class, so you can’t return it by value. It is abstract because it has pure virtual methods. Abstract classes cannot be instantiated.