+ /* If types is NULL, read exactly one element */
+ if (!types) {
+ struct bus_container *c;
+ size_t l;
+
+ if (message_end_of_signature(m))
+ return -ENXIO;
+
+ if (message_end_of_array(m, m->rindex))
+ return 0;
+
+ c = message_get_container(m);
+
+ r = signature_element_length(c->signature + c->index, &l);
+ if (r < 0)
+ return r;
+
+ types = strndupa(c->signature + c->index, l);
+ }