singleton.hpp

/*
 * singleton.hpp
 *
 * Created on: 9 May 2012
 * Author: Holger Schmitz
 * Email: holger@notjustphysics.com
 *
 * Copyright 2012 Holger Schmitz
 *
 * This file is part of Schnek.
 *
 * Schnek 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 3 of the License, or
 * (at your option) any later version.
 *
 * Schnek 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 Schnek.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef SCHNEK_SINGLETON_HPP_
#define SCHNEK_SINGLETON_HPP_

namespace schnek
{

template<class TYPE>
struct CreateUsingNew
{
  static TYPE* create()
  {
    return new TYPE();
  }
};


template<
  class TYPE,
  template<class> class CreationPolicy = CreateUsingNew
>
class Singleton
{
  public:

    static TYPE& instance()
    {
      if (!pInstance)
      {
        pInstance = CreationPolicy<TYPE>::create();
      }
      return *pInstance;
    }

  protected:
    Singleton() {}
    ~Singleton() {}
  private:
    Singleton(const Singleton&);
    Singleton& operator=(const Singleton&);


    static TYPE* pInstance;
};

template<
  class TYPE,
  template<class> class CreationPolicy
>
TYPE* Singleton<TYPE,CreationPolicy>::pInstance = 0;


}

#endif // SCHNEK_SINGLETON_HPP_