char *cached_label;
};
-struct output_item *output_item_ref (const struct output_item *);
+struct output_item *output_item_ref (const struct output_item *) WARN_UNUSED_RESULT;
void output_item_unref (struct output_item *);
bool output_item_is_shared (const struct output_item *);
struct output_item *output_item_unshare (struct output_item *);