Overloading Inserters

Provides specialized output mechanisms for an object.

  Overloading 
  inserter prototype
  basic_ostream &oerator<<
  (basic_ostream &stream,const omanip<T>&){
        // procedures;
        return stream;
  } 
  

You may overload the inserter operator to tailor it to the specific needs of a particular class.

The this pointer is returned.

#include <iostream>
#include <string.h>

#include <iomanip>

class phonebook {

   friend ostream &operator<<

      (ostream &stream, phonebook o);

protected:                        

   char *name;

   int areacode;

   int exchange;

   int num;

public:

   phonebook(char *n, int a, int p, int nm) :

      areacode(a), 

      exchange(p), 

      num(nm), 

      name(n) {}

};

int main()

{

using namespace std;

   phonebook a("Sales", 800, 377, 5416);

   phonebook b("Voice", 512, 873, 4700);

   phonebook c("Fax",    512, 873, 4900);

   cout << a << b << c;

   return 0; 

}

       

std::ostream &operator<<(std::ostream &stream, phonebook o)

{

   stream << o.name << " ";

   stream << "(" << o.areacode << ") ";

   stream << o.exchange << "-";

   stream << setfill('0') << setw(4) 

      << o.num << "\n";

   return stream;

}

Result:

  Sales (800) 377-5416
  Voice (512) 873-4700
  Fax (512) 873-4900