diff -r 551ffd3bcbb7 -r bdbb9144a49e src/lemon/xy.h
--- a/src/lemon/xy.h	Thu Apr 14 12:09:35 2005 +0000
+++ b/src/lemon/xy.h	Thu Apr 14 12:30:18 2005 +0000
@@ -339,7 +339,7 @@
     ///\e
     XMap(M &map) : _map(map) {}
     Value operator[](Key k) const {return _map[k].x;}
-    Value set(Key k,Value v) {_map.set(k,typename M::Value(v,_map[k].y));}
+    void set(Key k,Value v) {_map.set(k,typename M::Value(v,_map[k].y));}
   };
     
   ///Returns an \ref XMap class
@@ -396,7 +396,7 @@
     ///\e
     YMap(M &map) : _map(map) {}
     Value operator[](Key k) const {return _map[k].y;}
-    Value set(Key k,Value v) {_map.set(k,typename M::Value(_map[k].x,v));}
+    void set(Key k,Value v) {_map.set(k,typename M::Value(_map[k].x,v));}
   };
 
   ///Returns an \ref YMap class
@@ -440,6 +440,35 @@
   }
 
 
+  ///Map of the \ref xy::normSquare() "normSquare()" of an \ref xy "xy"-map
+
+  ///Map of the \ref xy::normSquare() "normSquare()" of an \ref xy "xy"-map
+  ///\ingroup maps
+  ///
+  template<class M>
+  class NormSquareMap 
+  {
+    const M &_map;
+  public:
+    typedef typename M::Value::Value Value;
+    typedef typename M::Key Key;
+    ///\e
+    NormSquareMap(const M &map) : _map(map) {}
+    Value operator[](Key k) const {return _map[k].normSquare();}
+  };
+    
+  ///Returns a \ref NormSquareMap class
+
+  ///This function just returns an \ref NormSquareMap class.
+  ///
+  ///\ingroup maps
+  ///\relates NormSquareMap
+  template<class M> 
+  inline NormSquareMap<M> normSquareMap(const M &m) 
+  {
+    return NormSquareMap<M>(m);
+  }
+
   /// @}