Inheritance


Let's extend the class Point from the previous tutorial to handle Complex numbers. The real and imaginary numbers will be defined as private integer references to coordinates of the Point object.

#include <iostream>
using namespace std;

class Point;
std::ostream& operator<<(std::ostream& out, const Point& c);

template<typename T>
void Swap(T &a, T &b) { T temp = a; a = b; b = temp; }

class Point {
public:
    int x, y;

    Point (int c1, int c2) { x = c1; y = c2;}
    Point& operator=(Point rhs) {
        x = rhs.x; y = rhs.y;
        return *this;
    }
};

class Complex : public Point {
  private: 
    int &real, &imag;
  public: 
    Complex(int r, int i) : Point (r, i), real (x), imag (y) 
    { cout << "Forming..." << *this; }

};

int main()
{

    Complex c1(15, 15), c2 (100, 100); 
    return 0;
}

std::ostream& operator<<(std::ostream& out, const Point& c)
{
  out<< "x:" << c.x << " ";
  out<< "y:" << c.y << "\n";
  return out;
}

We All Need Friends

Exercise

Form two Complex objects. Use the Swap function to swap the Complex objects as Point types. Reset the code area, and take the opportunity to write everything from scratch.

Print the swapped objects as Point objects. Subsequently, also print the swapped objects as Complex objects.