template<typename Incrementable> 
class counting_output_iterator {
public:
  // types
  typedef void                     value_type;       
  typedef void                     reference;        
  typedef void                     pointer;          
  typedef void                     difference_type;  
  typedef std::output_iterator_tag iterator_category;

  // construct/copy/destruct
  counting_output_iterator();
  counting_output_iterator(const Incrementable&);

  // operators
  implementation defined operator*() const;
  counting_output_iterator<Incrementable>& operator++();

  // queries
  const Incrementable& base() const;

  private: Incrementable current;
};

// creation
counting_output_iterator<Incrementable> 
make_counting_output_iterator(Incrementable);