C++ Operator Overload '+=' assignment operator (compound plus assignment)

#include <iostream>
using namespace std;
class Measure//  ww  w  .  j  ava 2 s . co m
{
   private:
   int feet;
   float inches;
   public:
   Measure() : feet(0), inches(0.0)
   {  }
   Measure(int ft, float in) : feet(ft), inches(in)
   {  }
   void getdist()               //get length from user
   {
      cout << "\nEnter feet: ";  cin >> feet;
      cout << "Enter inches: ";  cin >> inches;
   }
   void showdist() const
   { cout << feet << "\'-" << inches << '\"'; }
   void operator += ( Measure );
};
//add distance to this one
void Measure::operator += (Measure d2)
{
   feet += d2.feet;                //add the feet
   inches += d2.inches;            //add the inches
   if(inches >= 12.0)              //if total exceeds 12.0,
   {                            //then decrease inches
       inches -= 12.0;              //by 12.0 and
       feet++;                      //increase feet
    }                            //by 1
}
int main()
{
    Measure dist1;                 //define dist1
    dist1.getdist();                //get dist1 from user
    cout << "\ndist1 = ";  dist1.showdist();
    Measure dist2(11, 6.25);       //define, initialize dist2
    cout << "\ndist2 = ";  dist2.showdist();
    dist1 += dist2;                 //dist1 = dist1 + dist2
    cout << "\nAfter addition,";
    cout << "\ndist1 = ";  dist1.showdist();
    cout << endl;
    return 0;
}