Observer.h

#ifndef UTIL_OBSERVER_H
#define UTIL_OBSERVER_H 
 
/*
* Util Package - C++ Utilities for Scientific Computation
*
* Copyright 2010 - 2017, The Regents of the University of Minnesota
* Distributed under the terms of the GNU General Public License.
*/
 
namespace Util
{
 
   template <typename Event>
   class Observer
   {
 
   public:
 
      // Default constructor.
 
      virtual ~Observer();
   
      virtual void update(const Event& event) = 0;
 
   };
   class Observer {…};
 
   // Destructor
   template <typename Event>
   Observer<Event>::~Observer()
   {}
   Observer<Event>::~Observer() {…}
 
}
 
#endif