
	class Inc {
	public:
		Inc( int n = 0)		{ val = n; }
		void increment()	{ val++; }
	private:
		friend void print( Inc);
		int val;
	};

	void print( Inc i) { printf( "%d ", i.val); }
	
	...
	Inc i(3);
	i.increment();
	print( i);

