What I"ve just done is define a logger with an attribute in each class: #define DECLARE_LOGGER(name) static ::youtils::Logger::logger_type& getLogger__() \ { \ static youtils::SeverityLoggerWithAttribute logger(name); \ return logger.get(); \ } Where: class SeverityLoggerWithAttribute { public: SeverityLoggerWithAttribute(const std::string& name, const std::string& /*subsystem*/ = "no subsystem") { logger_.add_attribute(LOGGER_ATTRIBUTE_ID, boost::log::attributes::constant<LOGGER_ATTRIBUTE_ID_TYPE>(name)); // logger_.add_attribute(LOGGER_ATTRIBUTE_SUBSYSTEM, // boost::log::attributes::constant<LOGGER_ATTRIBUTE_SUBSYSTEM_TYPE>(subsystem)); } inline Logger::logger_type& get() { return logger_; } private: Logger::logger_type logger_; }; Then I wrote some macros: #define LOG_TYPE(type, message) \ BOOST_LOG_SEV(getLogger__(), type) << __FUNCTION__ << ": " << message #define LOG_NOTIFY(message) LOG_TYPE(youtils::Severity::notification, message) So long as getLogger__ is in scope and returns the correct logger you can just LOG_XXX(whatever). You add DECLARE_LOGGER("xxx") to the class and all the member functions will do the correct logging. A mixin class that contains a logger would work equally well -- or better -- but i had to stay close to an existing architecture. So the idea is * use different loggers * make sure the LOG statements find the correct logger * Add the attribute to the logger once, and each log record will see it automatically. Regards, i On Mon, Sep 2, 2013 at 11:10 PM, Timo Schmiade <the_isz@gmx.de> wrote:

Hi all,

I want to use boost's log library to output messages to the console which feature a per-message severity and a per-file channel.

I already tried two approaches, none of which was satisfying:

=== 1. approach ===

The class boost::log::sources::severity_channel_logger supports both severity and channel and I could define it in each source file like so:

--- 8< ---

BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT( log, boost::log::sources::severity_channel_logger< boost::log::trivial::severity_level, std::string > )

--- >8 ---

Unfortunately, using it like this requires me to redundantly add the channel to each log message, which is very inconvenient because it is the same for all logs in the file.

--- 8< ---

// Message.cpp

BOOST_LOG_CHANNEL_SEV(log, Message, trace) << "Hello, world";

--- >8 ---

=== 2. approach ===

I defined my logger like this:

--- 8< ---

BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT( log, boost::log::sources::severity_logger< boost::log::trivial::severity_level > )

--- >8 ---

Then, in each file, I manually set the "Channel" attribute for the logger, like so:

--- 8< ---

// Message.cpp

log::get().add_attribute( "Channel", boost::log::attributes::make_constant("Message"));

--- >8 ---

This works, but as the "log" object seems to be stored globally, I would have to "invent" new names for the logger object in each file. This is both insecure and prevents the usage of macros (I think).

So here's the question:

What would be the recommended / a convenient way to add a per-file constant channel to log messages?

Thanks in advance!

Timo _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users