diff -r cd72eae05bdf -r 3c00344f49c9 lemon/concept_check.h
--- a/lemon/concept_check.h	Mon Jul 16 16:21:40 2018 +0200
+++ b/lemon/concept_check.h	Wed Oct 17 19:14:07 2018 +0200
@@ -2,7 +2,7 @@
  *
  * This file is a part of LEMON, a generic C++ optimization library.
  *
- * Copyright (C) 2003-2009
+ * Copyright (C) 2003-2013
  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
  * (Egervary Research Group on Combinatorial Optimization, EGRES).
  *
@@ -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
   }