The symbolic operators (+ - * / ...) can be defined for new data types

NOTE : -

THIS CONTENT IS NOT ORIGINAL

14. The symbolic operators (+ - * / ...) can be defined for new data types

OPERATOR OVERLOADING can be used to redefine the basic symbolic operators for new kinds of parameters:

using namespace std;
#include 

struct vector
{
  double x;
  double y;
};

vector operator * (double a, vector b)
{
  vector r;

  r.x = a * b.x;
  r.y = a * b.y;

  return r;
}

int main ()
{
  vector k, m;              // No need to type "struct vector"

  k.x =  2;                 // To be able to write
  k.y = -1;                 // k = vector (2, -1)
                            // see chapter 19.

  m = 3.1415927 * k;        // Magic!

  cout << "(" << m.x << ", " << m.y << ")" << endl;

  return 0;
}

Output

(6.28319, -3.14159)

Besides multiplication, 43 other basic C++ operators can be overloaded, including +=, ++, the array [], and so on...

The << operator, normally used for binary shifting of integers, can be overloaded to give output to a stream instead (e.g., cout <<). It is possible to overload the <<operator further for the output of new data types, like vectors:

using namespace std;
#include 

struct vector
{
  double x;
  double y;
};

ostream& operator << (ostream& o, vector a)
{
  o << "(" << a.x << ", " << a.y << ")";
  return o;
}

int main ()
{
  vector a;

  a.x = 35;
  a.y = 23;

  cout << a << endl;     // Displays (35, 23)

  return 0;
}

Output

(35, 23)

BIBILOGRAPHY / REFERENCE : - http://www.4p8.com/eric.brasseur/cppcen.html