RClass            165 class.c            NEWOBJ_OF(obj, struct RClass, klass, (flags & T_MASK) | FL_PROMOTED1 /* start from age == 2 */ | (RGENGC_WB_PROTECTED_CLASS ? FL_WB_PROTECTED : 0));
RClass            401 gc.c           	struct RClass  klass;
RClass           1218 include/ruby/ruby.h #define RCLASS(obj)  (R_CAST(RClass)(obj))