boost::log::operator<<
// In header: <boost/log/utility/manipulators/auto_newline.hpp> template<typename CharT, typename TraitsT, typename AllocatorT> basic_formatting_ostream< CharT, TraitsT, AllocatorT > & operator<<(basic_formatting_ostream< CharT, TraitsT, AllocatorT > & strm, auto_newline_manip);