py: Allow hashing of functions and tuples.
diff --git a/py/obj.h b/py/obj.h
index dd80b3f..1daa943 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -330,6 +330,7 @@
 extern const mp_obj_type_t tuple_type;
 void mp_obj_tuple_get(mp_obj_t self_in, uint *len, mp_obj_t **items);
 void mp_obj_tuple_del(mp_obj_t self_in);
+machine_int_t mp_obj_tuple_hash(mp_obj_t self_in);
 
 // list
 extern const mp_obj_type_t list_type;