diff -r 2c2e8df67ddc -r b9887ae63df0 lemon/concept_check.h
--- a/lemon/concept_check.h	Tue Aug 06 12:21:06 2013 +0200
+++ b/lemon/concept_check.h	Wed Aug 07 07:09:31 2013 +0200
@@ -58,7 +58,7 @@
   {
 #if !defined(NDEBUG)
     void (Concept::*x)() = & Concept::constraints;
-    ignore_unused_variable_warning(x);
+    ::lemon::ignore_unused_variable_warning(x);
 #endif
   }
 
@@ -68,7 +68,7 @@
 #if !defined(NDEBUG)
     typedef typename Concept::template Constraints<Type> ConceptCheck;
     void (ConceptCheck::*x)() = & ConceptCheck::constraints;
-    ignore_unused_variable_warning(x);
+    ::lemon::ignore_unused_variable_warning(x);
 #endif
   }