On Sat, Dec 27, 2008 at 12:18 PM, Jason Wagner <jason@nialscorva.net> wrote:
-------Original Message------- I'm differentiating macros from simple defines.
#define LOG_LINE filename(__FILE__) << line(__LINE__) << function(__FUNCTION__)
will be in the library in some form in the future.
That would work when the user explicitly wants to log __FILE__ or __LINE__ but I meant that it's desirable to log them implicitly, automatically. To make this work, you need the logging itself to use macros, which I think is quite fine.
if( logging::warnings ) log << "Warning";
where log simply implements std::ostream.
You could put the if in a macro but frankly, I personally don't mind typing it every time; compared to the rest of the junk I have to type to format a meaningful logging message, the if is not an issue. As a bonus, you don't have to worry about functions referenced by a logging expression being executed when logging is not enabled.
I'm not a fan of the macros, either. What's really the difference between what you wrote and:
LOG_DEBUG(log) << "Warning";
other than the latter being ugly.
I don't find LOG_DEBUG(log)<<"Warning" ugly at all, my point was that the reason you'd use something like LOG_DEBUG(log)<<"foo" or log<<severity::info()<<"foo" is so that the logging expression could compile to nothing depending on how the logging is configured. My point was that I think it's better to leave it up to the user to deal with the condition "manually", as in if( logging::warnings ) log << "Warning"; or if( logging::warnings && logging::severity>10 ) log << "Severe warning"; or even if( logging::warnings ) { log << "Warning"; if( logging::severity>10 ) log << "Severe warning"; } That way the logging library only needs to expose two independent interfaces, one that provides the "log" object (which is just a std::ostream &) and another that provides convenient compile-time or run-time flags for users to type in if statements as above. Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode