Log levels "debug" and maybe also "trace" would be useful, but I see
that vlog(n)() is meant for that purpose. I would just prefer explicit
names instead of just numbers.
Is there a compelling reason why formatted logging is not the default? I
find that most logging calls in practice use formatted output, and the
only overhead would be searching once through the format string in the
case of format placeholders.
A predefined logger for OutputDebugString on Windows would be useful -
or maybe it could be used instead of stdout at least for non-console
applications.
One kind of log writer that I have in my code is one that outputs a
nicely formatted HTML file with built-in JavaScript to be able to filter
messages by priority or module. Maybe this is too much for a standard
library implementation though.
Support for multiple log writers can be useful (e.g. logging to a file +
logging to stdout or to a log control inside of the running
application). Of course, one can also simply write a
"MultiDispatchLogger"...
A format option to log the thread name instead of just the ID.
