sink_ptr->locked_backend( )->set_formatter ( fmt::format( "%1% : [%2%] [%3%] [%4%] [%5%] %6%" ) % fmt::attr< boost::uint32_t > ( "LineID" ) % fmt::attr< std::string > ( "Channel", std::nothrow ) % fmt::date_time< boost::posix_time::ptime > ( "Date_time", keywords::format = "%Y.%m.%d %H:%M:%S.%f" ) % fmt::attr< severity_level >( "Severity", std::nothrow ) % fmt::named_scope( "Scope", keywords::iteration = fmt::reverse, keywords::delimiter = " | " ) % fmt::message( ) ); That is how I do this. That what my question was about. How to use boost.log to have both char and wchar_t for an output to in file backend? -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-log-set-channel-name-dynamically-fo... Sent from the Boost - Dev mailing list archive at Nabble.com.