Singleton.h

/*
 * Singleton - template base class for singleton pattern.
 *
 * This file is part of the Rulbus Device Class Library (RDCL).
 *
 * Copyright (C) 2003-2004, Leiden University.
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * The library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with mngdriver; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * $Id: Singleton.h 2 2004-10-12 11:54:15Z moene $
 */

#ifndef __SINGLETON_H
#define __SINGLETON_H

namespace Rulbus
{
   template <typename T>
   class Singleton
   {
   public:
      static T& instance();

   protected:
      static T* theInstance;

   };

   template <typename T>
   T* Singleton<T>::theInstance = 0;

   template <typename T>
   T& Singleton<T>::instance()
   {
      if ( 0 == theInstance )
      {
         theInstance = new T;
      }

      return *theInstance;
   }

} // namespace Rulbus

#endif  // __SINGLETON_H

/*
 * end of file
 */

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