title: -Wextra how useful is it really?
body: <p>I'm reading the gcc manual at the moment, especially the part about warning/error flags. After reading the part about the -Wextra flag, I wonder if it is useful at all. It seems that it complains about things which seem to be rather subjective or a matter of taste. I'm not that experienced with gcc, I only use it from time to time for some small projects at university, so to all experienced C/C++ (or for whatever language you use gcc), what's the deal with -Wextra?</p>