diff -r 012cd0ca3254 -r 66d160810c0a lemon/bits/array_map.h
--- a/lemon/bits/array_map.h	Thu Apr 13 17:22:17 2006 +0000
+++ b/lemon/bits/array_map.h	Thu Apr 13 17:57:03 2006 +0000
@@ -78,7 +78,7 @@
     /// \brief Graph initialized map constructor.
     ///
     /// Graph initialized map constructor.
-    ArrayMap(const Graph& graph) {
+    explicit ArrayMap(const Graph& graph) {
       Parent::attach(graph.getNotifier(Item()));
       allocate_memory();
       Notifier* notifier = Parent::getNotifier();