template<typename time_period_type, typename charT = char> 
class ostream_time_period_formatter {
public:
  // types
  typedef std::basic_ostream< charT >                ostream_type;  
  typedef time_period_type::point_type               time_type;     
  typedef ostream_time_formatter< time_type, charT > time_formatter;

  // public static functions
  void period_put(const time_period_type &, ostream_type &) ;
};