Overloaded stream insertion study

I'm trying to convert this simple phone number program into a demonstration of using the overloaded stream-insertion operator as a member function, i.e. I'm trying to use

Code:

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phone << cout

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instead of the typical

Code:

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cout << phone

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Can someone point me in the right direction?

Code:

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#include <iostream>
#include <iomanip>

using namespace std;

class PhoneNumber {
  ostream &operator<<( ostream& ); // defined as a member function
  friend istream &operator>>( istream&, PhoneNumber& );

private:
  char areaCode[ 4 ]; // 3-digit area code and null
  char exchange[ 4 ]; // 3-digit exchange and null
  char line[ 5 ];  // 4-digit line and null

ostream &operator<<( ostream &output ) // defined as a member function
{
  output << "(" << num.areaCode << ")" << num. exchange << "-" << num.line;

  return output; // enables cout << a << b << c;
} // end function operator<<



}; // end class PhoneNumber

istream &operator>>( istream &input, PhoneNumber &num )
{
  input.ignore();
  input >> setw( 4 ) >> num.areaCode;
  input.ignore( 2 ); // skip ( and space
  input >> setw( 4 ) >> num.exchange;
  input.ignore();
  input >> setw( 5 ) >> num.line;  // input line

  return input;
}

int main()
{
  PhoneNumber phone; // create object phone

  cout << "Enter phone number in the form (123) 456-7890:\n";

  cin >> phone; // operator>>(cin, phone)

  cout << "The phone number entered was: ";

  //cout << phone << endl; // operator<<( cout, phone );

    phone << cout << endl;
    phone.operator<<( cout ); // must be defined within the function operator<<

  return 0;
} // end main

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Simply change the order of the parameters in the overloaded operator.

Code:

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#include <iostream>
#include <iomanip>

using namespace std;

class myClass {
  friend ostream &operator<<(const myClass&, ostream&);
  int data;
  public:
    myClass(int d) : data(d) {}
};

ostream &operator<<(const myClass& obj, ostream& file) {
    return file << obj.data;
}

int main()
{
  myClass obj1(5);
 
  obj1 << cout;
  cin.get();
  return 0;
}

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Now keep in mind, there is no way to prevent the right shift operator from reading left to right, so chaining becomes impossible without a reference to the ostream, for instance

Code:

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obj1 << obj1 << cout; // Doesn't work

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You also can't, as you seem to be trying to do, make it a member function. It's simply not allowed in the language to change the number of arguements.