diff --git a/trunk/paradiseo-moeo/src/archive/moeoArchive.h b/trunk/paradiseo-moeo/src/archive/moeoArchive.h
index d5e23da1c..edc1492c0 100644
--- a/trunk/paradiseo-moeo/src/archive/moeoArchive.h
+++ b/trunk/paradiseo-moeo/src/archive/moeoArchive.h
@@ -42,12 +42,17 @@
 #include <comparator/moeoObjectiveVectorComparator.h>
 #include <comparator/moeoParetoObjectiveVectorComparator.h>
 
+//template < class MOEOT >
+//class ufMOEOT : public eoUF < const MOEOT &, bool> {};
+//template < class MOEOT >
+//class ufPop : eoUF < const eoPop < MOEOT > &, bool> {};
+
 /**
  * Abstract class for representing an archive ;
  * an archive is a secondary population that stores non-dominated solutions.
  */
 template < class MOEOT >
-class moeoArchive : public eoPop < MOEOT >
+class moeoArchive : public eoPop < MOEOT >, public eoUF < const MOEOT &, bool>, public eoUF < const eoPop < MOEOT > &, bool>
 {
 public:
 
@@ -112,22 +117,24 @@ public:
         }
         return false;
     }
-    
-    
+
+
 
 
     /**
      * Updates the archive with a given individual _moeo
      * @param _moeo the given individual
+     * @return if the _moeo is added to the archive
      */
-    virtual void operator()(const MOEOT & _moeo) = 0;
+    virtual bool operator()(const MOEOT & _moeo) = 0;
 
 
     /**
      * Updates the archive with a given population _pop
      * @param _pop the given population
+     * @return if at least one _pop[i] is added to the archive
      */
-    virtual void operator()(const eoPop < MOEOT > & _pop) = 0;
+    virtual bool operator()(const eoPop < MOEOT > & _pop) = 0;
 
 
     /**
@@ -152,13 +159,13 @@ public:
         }
         return true;
     }
-    
+
 protected:
 	/**
      * Updates the archive with a given individual _moeo
      * @param _moeo the given individual
      */
-    void update(const MOEOT & _moeo)
+    bool update(const MOEOT & _moeo)
     {
         // first step: removing the dominated solutions from the archive
         for (unsigned int j=0; j<size();)
@@ -194,6 +201,7 @@ protected:
         {
             push_back(_moeo);
         }
+        return !dom;
     }
 
 
@@ -201,14 +209,16 @@ protected:
      * Updates the archive with a given population _pop
      * @param _pop the given population
      */
-    void update(const eoPop < MOEOT > & _pop)
+    bool update(const eoPop < MOEOT > & _pop)
     {
+    	bool res = false;
         for (unsigned int i=0; i<_pop.size(); i++)
         {
-            (*this).update(_pop[i]);
+            res = (*this).update(_pop[i]) || res;
         }
+        return res;
     }
-    
+
 
 private:
 
diff --git a/trunk/paradiseo-moeo/src/archive/moeoBoundedArchive.h b/trunk/paradiseo-moeo/src/archive/moeoBoundedArchive.h
index 45e1e92d2..f442464c0 100644
--- a/trunk/paradiseo-moeo/src/archive/moeoBoundedArchive.h
+++ b/trunk/paradiseo-moeo/src/archive/moeoBoundedArchive.h
@@ -99,10 +99,12 @@ public:
     /**
      * Updates the archive with a given individual _moeo
      * @param _moeo the given individual
+     * @return true if _moeo is non-dominated (and not if it is added to the archive)
      */
-    void operator()(const MOEOT & _moeo)
+    bool operator()(const MOEOT & _moeo)
     {
-    	update(_moeo);
+		bool res;
+    	res = update(_moeo);
 
     	if(size() > maxSize){
     		fitness(*this);
@@ -110,16 +112,19 @@ public:
     		std::sort(begin(), end(), indiComparator);
     		resize(maxSize);
     	}
+    	return res;
     }
 
 
     /**
      * Updates the archive with a given population _pop
      * @param _pop the given population
+     * @return true if a _pop[i] is non-dominated (and not if it is added to the archive)
      */
-    void operator()(const eoPop < MOEOT > & _pop)
+    bool operator()(const eoPop < MOEOT > & _pop)
     {
-    	update(_pop);
+    	bool res;
+    	res = update(_pop);
 
     	if(size() > maxSize){
     		fitness(*this);
@@ -127,6 +132,7 @@ public:
     		std::sort(begin(), end(), indiComparator);
     		resize(maxSize);
     	}
+    	return res;
     }
 
 private:
diff --git a/trunk/paradiseo-moeo/src/archive/moeoFixedSizeArchive.h b/trunk/paradiseo-moeo/src/archive/moeoFixedSizeArchive.h
index e87c4385f..cef1493ae 100644
--- a/trunk/paradiseo-moeo/src/archive/moeoFixedSizeArchive.h
+++ b/trunk/paradiseo-moeo/src/archive/moeoFixedSizeArchive.h
@@ -73,20 +73,6 @@ public:
      */
     moeoFixedSizeArchive(moeoObjectiveVectorComparator < ObjectiveVector > & _comparator) : moeoArchive < MOEOT >( _comparator) {}
 
-
-    /**
-     * Updates the archive with a given individual _moeo
-     * @param _moeo the given individual
-     */
-    virtual void operator()(const MOEOT & _moeo)=0;
-
-
-    /**
-     * Updates the archive with a given population _pop
-     * @param _pop the given population
-     */
-    virtual void operator()(const eoPop < MOEOT > & _pop)=0;
-
 };
 
 #endif /*MOEOFIXEDSIZEARCHIVE_H_*/
diff --git a/trunk/paradiseo-moeo/src/archive/moeoSPEA2Archive.h b/trunk/paradiseo-moeo/src/archive/moeoSPEA2Archive.h
index af3678e1f..a39304be2 100644
--- a/trunk/paradiseo-moeo/src/archive/moeoSPEA2Archive.h
+++ b/trunk/paradiseo-moeo/src/archive/moeoSPEA2Archive.h
@@ -126,20 +126,23 @@ public:
     /**
      * Updates the archive with a given individual _moeo
      * @param _moeo the given individual
+     * @return true (TODO)
      */
-    void operator()(const MOEOT & _moeo)
+    bool operator()(const MOEOT & _moeo)
     {
         eoPop < MOEOT > pop_tmp;
         pop_tmp.push_back(_moeo);
         operator()(pop_tmp);
+        return true;
     }
 
 
     /**
      * Updates the archive with a given population _pop
      * @param _pop the given population
+     * @return true (TODO)
      */
-    void operator()(const eoPop < MOEOT > & _pop)
+    bool operator()(const eoPop < MOEOT > & _pop)
     {
         unsigned int i;
         unsigned int foo=0;
@@ -275,7 +278,7 @@ public:
                 }
             }
         }
-
+        return true;
     }//endoperator()
 
 
diff --git a/trunk/paradiseo-moeo/src/archive/moeoUnboundedArchive.h b/trunk/paradiseo-moeo/src/archive/moeoUnboundedArchive.h
index bae417896..6fc9998f2 100644
--- a/trunk/paradiseo-moeo/src/archive/moeoUnboundedArchive.h
+++ b/trunk/paradiseo-moeo/src/archive/moeoUnboundedArchive.h
@@ -75,20 +75,22 @@ public:
     /**
      * Updates the archive with a given individual _moeo
      * @param _moeo the given individual
+     * @return true if _moeo is added to the archive
      */
-    void operator()(const MOEOT & _moeo)
+    bool operator()(const MOEOT & _moeo)
     {
-        update(_moeo);
+    	return update(_moeo);
     }
 
 
     /**
      * Updates the archive with a given population _pop
      * @param _pop the given population
+     * @return true if a _pop[i] is added to the archive
      */
-    void operator()(const eoPop < MOEOT > & _pop)
+    bool operator()(const eoPop < MOEOT > & _pop)
     {
-    	update(_pop);
+    	return update(_pop);
     }
 
 };