RStruct           409 gc.c           	struct RStruct rstruct;
RStruct          1225 include/ruby/ruby.h #define RSTRUCT(obj) (R_CAST(RStruct)(obj))
RStruct           574 struct.c           NEWOBJ_OF(st, struct RStruct, klass, T_STRUCT | (RGENGC_WB_PROTECTED_STRUCT ? FL_WB_PROTECTED : 0));