I was looking for a way to make a LogStream from a level and a LogHandle, and there doesn't appear to be a way to do so. LogStream has a constructor for LogTargetHandle, and another for level and LogTagSet*. But there doesn't seem to be a way to convert level + LogHandle to LogTargetHandle, nor is there a way to obtain the tagset of a LogHandle.

To allow these kinds of conversions and constructions, the simple and general solution is to provide a getter for LogHandle::_tagset.

(There might be a reason to provide accessors for the level and tagset of a LogTargetHandle, but I haven't encountered any yet, so not proposing that even though it is consistent with the proposed change.)