// In header: <boost/unicode/utf_codecs.hpp>


struct u16_encoder {
  // types
  typedef char32         input_type; 
  typedef char16         output_type;
  typedef mpl::int_< 2 > max_output; 

  // public member functions
  template<typename OutputIterator> 
    OutputIterator operator()(char32, OutputIterator);
};