I don't kernel, but: Empty structures are useful, but behave weirdly. Structures containing a zero-size `char` array are much more portable. Although `__built

I don't kernel, but: Empty structures are useful, but behave weirdly. Structures containing a zero-size `char` array are much more portable. Although `__builtin_choose_expr` isn't available in C++, it's trivial to implement using templates. Actually a lot of these are a reminder that GNU C exists for people who refuse to use C++ for political reasons. `__builtin_types_compatible_p` is mostly not needed now that C11 `_Generic` exists.