#include <fstream>
#include <iostream>
using namespace std;

template <class T>
class Node {
public:
  T value;
  Node* next;
};

template <class T>
void print_list( Node<T> * head, ostream & out_str )
{
  if ( !head )
    out_str << "  <empty>" << endl;
  else
    {
      //  Since head was passed by value, this code does not change
      //  the value of the pointer passed to this function. 
      while ( head )
	{
	  out_str << "  " << head->value << endl;
	  head = head->next;
	}
    }
}