Overloading streams

/***********************************************************************************************************
	This program illustrates overloading of streams i.e., 
	programmer need not to worry about which stream his object 
	is being inserted of from which stream his object extracted.	
			
			Author: Prasad Kulkarni
			Created date: Sep-27-2003
			
	All	rights reserved to SUBEX SYSTEMS Ltd.
************************************************************************************************************/
#include <iostream>
#include <fstream>
#include <sstream>

using namespace std ;

class SomeClass 
{
public:
	explicit SomeClass(int x) // Constructor
	{
		this->x = x ;
	}
	
	int getx() const { return x; }    // Getter and
	
	void setx(int x) { this->x = x; } // Setter methods
	
	template<class T>
	friend T& operator<<(T& os, const SomeClass &d) // Overloading operator <<
	{
		os<<d.x;
		return os;
	}
	
	template<class T>
	friend T& operator>>(T& os, SomeClass &d) // Overloading operator >>
	{
		cout<<"Enter an integer: ";
		os>>d.x;
		return os;
	}
	
private:
	int x;
};


int main()
{
	SomeClass d(10); 
	cout<<d<<endl; // Output to stdout
	
	d.setx(20);
	ofstream out("hello");
	out<<d<<endl; // Output to file "hello"
	out.close(); 
	
	d.setx(30);
	ostringstream oss (ostringstream::out);
	oss<<d<<endl; // Output to string stream
	cout<<oss.str();
	return 0;
}