26. Possible alternative: Faking it

class Shape {
public:
    enum EnumType {
        Circle, Square
    };

    Shape( EnumType type );
    void draw();

private:
    EnumType m_shape_type;

};//class Shape


void Shape::draw()
{
    switch ( m_shape_type ) {
    case Circle:
        //draw a circle...

    case Square:
        //draw a square...
    }
}

So why not fake it?

1. Can't extend hierarchy without disturbing the base class.

   • This makes maintenance difficult.

2. All functionality is in one type, so specific functionality has no home:

   • e.g. where do we put the radius( ) function?

3. Faking is almost guaranteed to be slower!