RRegexp           405 gc.c           	struct RRegexp regexp;
RRegexp          1221 include/ruby/ruby.h #define RREGEXP(obj) (R_CAST(RRegexp)(obj))
RRegexp          2688 re.c               struct RRegexp *re = RREGEXP(obj);
RRegexp          2776 re.c               NEWOBJ_OF(re, struct RRegexp, klass, T_REGEXP | (RGENGC_WB_PROTECTED_REGEXP ? FL_WB_PROTECTED : 0));