diff -r 2b45f64f6377 -r 5c7f270f8e25 lemon/graph_utils.h
--- a/lemon/graph_utils.h	Tue Jul 12 21:45:39 2005 +0000
+++ b/lemon/graph_utils.h	Wed Jul 13 13:16:57 2005 +0000
@@ -749,6 +749,18 @@
 
   public:
 
+    /// \brief Swaps the position of the two items in the map.
+    ///
+    /// Swaps the position of the two items in the map.
+    void swap(const Item& p, const Item& q) {
+      int pi = Map::operator[](p);
+      int qi = Map::operator[](q);
+      Map::set(p, qi);
+      invMap[qi] = p;
+      Map::set(q, pi);
+      invMap[pi] = q;
+    }
+
     /// \brief Gives back the \e descriptor of the item.
     ///
     /// Gives back the mutable and unique \e descriptor of the map.
@@ -790,7 +802,7 @@
       /// \brief Size of the map.
       ///
       /// Returns the size of the map.
-      unsigned size() const {
+      int size() const {
 	return inverted.invMap.size();
       }