- Add unified Singleton support

git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@643 3ecf2c5c-341e-0410-92b4-d18e462d057c

src/backend/history.hh

@@ -32,6 +32,8 @@
 #include "dynamic_schedulable.hh"
 #include "../templates/smartp.hh"
 
+#include "singleton.hh"
+
 namespace sgpem
 {
 
@@ -47,8 +49,10 @@ namespace sgpem
   */
   class History;
 	
-  class SG_DLLEXPORT History : public ObservedSubject 
+  class SG_DLLEXPORT History : public Singleton<History>, public ObservedSubject 
   {
+    friend class Singleton<History>;
+
   public:
 	/**
 	 Gets the \ref Schedulable object running at the specified time.
@@ -82,16 +86,9 @@ namespace sgpem
 	 */	
 	virtual void	truncate_at(int instant);
 	
-	
-	/**
-	 Gets the only instance of History.
-	 \return The Singleton instance of this object.
-	 */	
-	static History&	get_instance();
-			
+		
   protected:
-	History();			//private constructor. The parameter is discarded
-	static History*  _instance;
+	History();			//private constructor.
 
   private:
 	int             _total_time_elapsed;