/* Variable auxiliary data. */
void *var_get_aux (const struct variable *);
-void *var_attach_aux (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 *);
/* Observed categorical values. */
struct cat_vals *var_get_obs_vals (const struct variable *);
-void var_set_obs_vals (struct variable *, struct cat_vals *);
+void var_set_obs_vals (const struct variable *, struct cat_vals *);
bool var_has_obs_vals (const struct variable *);
/* Classes of variables. */