diff -r 7fe378247fea -r 630a5e16dc12 lemon/maps.h
--- a/lemon/maps.h	Fri May 12 09:56:14 2006 +0000
+++ b/lemon/maps.h	Fri May 12 09:57:03 2006 +0000
@@ -381,7 +381,7 @@
     ///Constructor
     ///\param _m is the undelying map
     ///\param _v is the shift value
-    ShiftWriteMap(const M &_m, const C &_v ) : m(_m), v(_v) {};
+    ShiftWriteMap(M &_m, const C &_v ) : m(_m), v(_v) {};
     Value operator[](Key k) const {return m[k] + v;}
     void set(Key k, const Value& c) { m.set(k, c - v); }
   };