operator-overloading.cc

#include <iostream>
using namespace std;

class Distance {
    int feet;
    int inches;
public:
    Distance(): feet(0), inches(0){}
    Distance(int f, int i): feet(f), inches(i){
      if (feet < 0 && inches < 0) {
          inches = 0 - inches;
      }
    }
    void displayDistance () {
        cout << feet << "\' " << inches << "\"" << endl;
    }
    bool operator < (Distance const& d) {
        int m = (feet * 12) + inches;
        int n = (d.feet * 12) + d.inches;
        return (m < n);
    }
    Distance operator + (Distance const& d) {
        int dist = ((feet * 12) + inches) + ((d.feet * 12) + d.inches);
        Distance nd(dist / 12, dist % 12);
        return nd;
    }
    Distance operator - (Distance const& d) {
        int dist = ((feet * 12) + inches) - ((d.feet * 12) + d.inches);
        Distance nd(dist / 12, dist % 12);
        return nd;
    }
    Distance operator ++ () {
        if(++inches > 11) {
          inches = 0;
          ++feet;
        }
        return *this;
    }
};


int main (void) {
    Distance D1(2, 6), D2(3, 6);

    D1.displayDistance();
    cout << "+" << endl;
    D2.displayDistance();
    cout << "=" << endl;

    Distance D3 = D1 + D2;
    D3.displayDistance();
    
    cout << endl << endl << "++";
    D1.displayDistance();
    //++D1;
    D1.displayDistance();
    
    
    cout << endl << endl;
    D1.displayDistance();
    cout << "-" << endl;
    D2.displayDistance();
    cout << "=" << endl;

    Distance D5 = D1 - D2;
    D5.displayDistance();

    return 0;
}