adding some virtual dtors

git-svn-id: http://svn.berlios.de/svnroot/repos/sems/trunk@1639 8eb893ce-cfd4-0310-b710-fb5ebe64c474

core/AmAudio.h

@@ -66,6 +66,7 @@ public:
   };
 
   AmAudioEvent(int id):AmEvent(id){}
+  virtual ~AmAudioEvent() { }
 };
 
 

core/AmB2ABSession.h

@@ -177,7 +177,7 @@ class AmB2ABSession: public AmSession
 
   AmB2ABSession();
   AmB2ABSession(const string& other_local_tag);
-  ~AmB2ABSession();
+  virtual ~AmB2ABSession();
 
   void onBye(const AmSipRequest& req);
 

core/AmStats.h

@@ -48,6 +48,8 @@ class MeanValue
     n_val(0)
     {}
 
+  virtual ~MeanValue() { }
+
   void push(double val){
     cum_val += val;
     n_val++;