// In header: <boost/log/sinks/basic_sink_backend.hpp>

template<typename CharT, typename ThreadingModelTagT> 
struct basic_sink_backend : public noncopyable {
  // types
  typedef CharT                                    char_type;         // Character type. 
  typedef std::basic_string< char_type >           string_type;       // String type to be used as a message text holder. 
  typedef basic_attribute_values_view< char_type > values_view_type;  // Attribute values view type. 
  typedef basic_record< char_type >                record_type;       // Log record type. 
  typedef ThreadingModelTagT                       threading_model;   // Threading model tag. 
};