Hi, AFAICS you can't use unconstify()/unvolatize() in a static inline function in a .h file, or in a .cpp file, because __builtin_types_compatible_p is only available in C, not C++. Seems like a reasonable thing to want to be able to do, no? I'm not immediately sure what the right fix is; would #if defined(HAVE__BUILTIN_TYPES_COMPATIBLE_P) && !defined(__cplusplus) around the relevant versions of constify()/unvolatize() be too easy?
HAVE__BUILTIN_TYPES_COMPATIBLE_P is also tested in relptr.h, but only for further preprocessor stuff, not in functions that the compiler will see, so cpluspluscheck doesn't have anything to reject, and nothing will break unless someone writing C++ code actually tries to use relptr_access(). I think we can live with that one?
