diff -r 6a958ab38386 -r 674182524bd9 lemon/concept/maps.h
--- a/lemon/concept/maps.h	Fri Oct 14 10:44:49 2005 +0000
+++ b/lemon/concept/maps.h	Fri Oct 14 10:48:34 2005 +0000
@@ -17,6 +17,7 @@
 #ifndef LEMON_CONCEPT_MAPS_H
 #define LEMON_CONCEPT_MAPS_H
 
+#include <lemon/utility.h>
 #include <lemon/concept_check.h>
 
 ///\ingroup concept
@@ -97,7 +98,7 @@
 	typename _WriteMap::Value own_val;
 	Key& key;
 	typename _WriteMap::Key& own_key;
-	WriteMap& m;
+	_WriteMap& m;
 
       };
     };
@@ -122,7 +123,7 @@
       struct Constraints {
 	void constraints() {
 	  checkConcept<ReadMap<K, T>, _ReadWriteMap >();
-	  checkConcept<ReadMap<K, T>, _ReadWriteMap >();
+	  checkConcept<WriteMap<K, T>, _ReadWriteMap >();
 	}
       };
     };
@@ -133,6 +134,8 @@
     class ReferenceMap : public ReadWriteMap<K,T>
     {
     public:
+      /// Tag for reference maps.
+      typedef True ReferenceMapTag;
       /// Map's key type.
       typedef K Key;    
       /// Map's value type. (The type of objects associated with the keys).
@@ -176,7 +179,7 @@
 	Key& key;
 	Value& val;
 	Reference& ref;
-	ReferenceMap& m;
+	_ReferenceMap& m;
       };
     };