RBignum          2982 bignum.c           NEWOBJ_OF(big, struct RBignum, klass, T_BIGNUM | (RGENGC_WB_PROTECTED_BIGNUM ? FL_WB_PROTECTED : 0));
RBignum           410 gc.c           	struct RBignum bignum;
RBignum           522 internal.h     #define RBIGNUM(obj) (R_CAST(RBignum)(obj))