John Torjo wrote:

Boost Logging v2 - new version (v0.13.6)

[list of features snipped]

All in all, I've added quite a few features - so, take a look! Look forward to your feedback!

John, I've just started looking at this new version of your logging library. I have used a modified version of your earlier review candidate for some time now in a production system and all in all it's been quite good. However in both that version and this newer version I see (at least for me) a very important use case overlooked. Simply I would like to be able to use logging in library code. For example, imagine I have a header based library that is somewhat complex and therefore I would like to embed logging statements in the library for possible future exposure in a production system. I'd want to be able to write something like this (using a syntax similar to that from your fist library). <code> #include <other_stuff> #include <boost/logging.hpp> BOOST_DEFINE_LOG(persitence_synchroniser, "persitence.synchroniser") namespace persistence { template< class PersistableContainer, class DatabaseInstance > class synchroniser : private boost::noncopyable { ... }; ... template< class PersistableContainer, class DatabaseInstance > void synchroniser< PersistableContainer, DatabaseInstance >:: run() { BOOST_LOGL(persitence_synchroniser,dbg) << BOOST_LOG_FILE_AND_LINE << "synchroniser::run() - Started" << std::endl; ... } ... } </code> Note that the idea here would be to use a naming strategy for the log that would minimise clashes. A couple of points then, 1. Writing BOOST_DEFINE_LOG() or something like that is all that is required to make the log available for writing to (no separate declare and define). 2. I would hope that if the log was never enabled by a client of the library, the BOOST_LOG() calls would be optimised away. I recall there being some discussion about this during the last review but I don't have a reference to hand. If this is possible then the logging library would be capable of providing a generally useful logging facility which could be used in library code also (with a single dependency on the boost logging library but I do not see that as a bad thing if logging could be generally useful). Incidentally this is how we used a modified version of your original log library submission. It allowed us to get log statements into the parts of our libraries where they were needed most and when necessary we switched them on. I hope what I describe makes sense. Thanks, Jamie

http://www.torjo.com/log2/ http://torjo.blogspot.com/2008/01/boost-logging-v2-new-version-v0136.html

Best, John