Listing 6

class rational
   {
public:
   rational() :num(0), denom(1) { }
   ...
   friend ostream &operator<<(ostream &, rational)
private:
   long num, denom;
   void simplify();
   };

...

ostream &operator<<(ostream &os, rational r)
   {
   return os << '(' << r.num << '/' << r.denom << ')';
   }

// End of File