+SCM_API SCM scm_c_array_ref_1 (SCM v, ssize_t idx0);
+SCM_API SCM scm_c_array_ref_2 (SCM v, ssize_t idx0, ssize_t idx1);
+
+SCM_API void scm_c_array_set_1_x (SCM v, SCM obj, ssize_t idx0);
+SCM_API void scm_c_array_set_2_x (SCM v, SCM obj, ssize_t idx0, ssize_t idx1);
+