diff -r 2da3de1c0ebe -r 08712a8c3afe lemon/concept_check.h
--- a/lemon/concept_check.h	Wed Sep 12 17:29:50 2012 +0200
+++ b/lemon/concept_check.h	Thu Sep 13 12:05:34 2012 +0200
@@ -35,6 +35,22 @@
   */
 
   template <class T> inline void ignore_unused_variable_warning(const T&) { }
+  template <class T1, class T2>
+  inline void ignore_unused_variable_warning(const T1&, const T2&) { }
+  template <class T1, class T2, class T3>
+  inline void ignore_unused_variable_warning(const T1&, const T2&,
+                                             const T3&) { }
+  template <class T1, class T2, class T3, class T4>
+  inline void ignore_unused_variable_warning(const T1&, const T2&,
+                                             const T3&, const T4&) { }
+  template <class T1, class T2, class T3, class T4, class T5>
+  inline void ignore_unused_variable_warning(const T1&, const T2&,
+                                             const T3&, const T4&,
+                                             const T5&) { }
+  template <class T1, class T2, class T3, class T4, class T5, class T6>
+  inline void ignore_unused_variable_warning(const T1&, const T2&,
+                                             const T3&, const T4&,
+                                             const T5&, const T6&) { }
 
   ///\e
   template <class Concept>