Richard Day wrote:
Michael Lacher wrote:
Maybe optional log information (channel, type, loglevel, ...) could all be passed similar to manipulators in std::stream. This would keep the basic interface clean (just << operator) and extensible. There would be no need to anticipate numbers/types of function arguments.
If people prefer a functional interface, then they could go for either
#define MYLOG1(LEVEL,CHANNEL,MESSAGE) logger << setLevel(LEVEL) << setChannel(CHANNEL) << MESSAGE << endl
MYLOG1(WARNING,"Debug","Caught Exception: " << e.what());
or
#define MYLOG2(LEVEL,CHANNEL) logger << setLevel(LEVEL) << setChannel(CHANNEL)
MYLOG2(WARNING,"Debug") << "Caught Exception: " << e.what() << endl;
Of course a commonly used subset of such macros could be provided.
Michael
My thinking is that macros are really just for trace during debugging for the most part. Basically so you have a way to turn them off in a release build if/when desired. Stream statements are much nicer for regular logging. No need to know arguments ahead of time and setup macros for every possibility.
Well, my idea was basically that stream statements are the "canonical" way of writing any log message, and that convenience macros ar eprovided to provide a functional style interface for common and quick cases. Depending on the lazy evaluation and the "no global object" requirement the thing you actually stream your message into (the variable 'logger' in the example) might actually be a macro evaluating to a stream object. Michael