diff -r 03e4d2128efe -r f30867b359a8 lemon/bits/traits.h
--- a/lemon/bits/traits.h	Fri Nov 03 14:14:05 2006 +0000
+++ b/lemon/bits/traits.h	Fri Nov 03 14:20:24 2006 +0000
@@ -323,7 +323,18 @@
     static const bool value = true;
   };
 
+  template <typename Graph, typename Enable = void>
+  struct CloneableTagIndicator {
+    static const bool value = false;
+  };
 
+  template <typename Graph>
+  struct CloneableTagIndicator<
+    Graph, 
+    typename enable_if<typename Graph::CloneableTag, void>::type
+  > {
+    static const bool value = true;
+  };
 
 }