-/* Variable auxiliary data. */
-void *var_get_aux (const struct variable *);
-void *var_attach_aux (const struct variable *,
- void *aux, void (*aux_dtor) (struct variable *));
-void var_clear_aux (struct variable *);
-void *var_detach_aux (struct variable *);
-void var_dtor_free (struct variable *);
-
-/* Observed categorical values. */
-struct cat_vals *var_get_obs_vals (const struct variable *);
-void var_set_obs_vals (const struct variable *, struct cat_vals *);
-bool var_has_obs_vals (const struct variable *);
-