diff -r ca8d98289ff9 -r 67d8b07bac22 stage3/datatype_functions.hh
--- a/stage3/datatype_functions.hh	Mon Feb 27 11:28:51 2012 +0000
+++ b/stage3/datatype_functions.hh	Mon Feb 27 11:44:03 2012 +0000
@@ -146,6 +146,13 @@
  */
 void copy_candidate_datatype_list(symbol_c *from, symbol_c *to);
 
+/* Intersect two candidate_datatype_lists.
+ * Remove from list1 (origin, dest.) all elements that are not found in list2 (with).
+ * In essence, list1 will contain the result of the intersection of list1 with list2.
+ * In other words, modify list1 so it only contains the elelements that are simultaneously in list1 and list2!
+ */
+void intersect_candidate_datatype_list(symbol_c *list1 /*origin, dest.*/, symbol_c *list2 /*with*/);
+
 
 /* A helper function... */
 bool is_ANY_ELEMENTARY_type         (symbol_c *type_symbol);