diff -r 1b6d8e3df1b2 -r fe5cb87610fa stage3/visit_expression_type.hh
--- a/stage3/visit_expression_type.hh	Mon May 30 17:52:15 2011 +0100
+++ b/stage3/visit_expression_type.hh	Mon May 30 17:54:15 2011 +0100
@@ -214,6 +214,11 @@
 
     /* a helper function... */
     void *verify_null(symbol_c *symbol);
+    
+    /********************************/
+    /* B 1.3.3 - Derived data types */
+    /********************************/
+    void *visit(data_type_declaration_c *symbol);
 
     /*********************/
     /* B 1.4 - Variables */