diff -r 1309a803a057 -r a30455cd0107 lemon/concepts/heap.h
--- a/lemon/concepts/heap.h	Wed Jan 11 13:58:30 2012 +0100
+++ b/lemon/concepts/heap.h	Fri Jan 20 19:16:43 2012 +0100
@@ -252,6 +252,7 @@
 
         _Heap& heap;
         ItemIntMap& map;
+        Constraints() {}
       };
     };