[boost] [log] Default logging configuration for trivial logger

Hi, I'm using the trivial logging interface, but I need to tweak the default configuration. I want to be able to flush after every log entry, and I also want to be able to do file rolling. As far as I can tell, in order to configure it this way, I pretty much need to configure the whole thing from scratch including formatters, but I can't find the code that sets up the default logger to replicate it. Any pointers? Cheers, Ben