/home/vlg/develop/libASSA/libassa/assa/Singleton.h

Go to the documentation of this file.

// -*- c++ -*-
//------------------------------------------------------------------------------
//                            Singleton.h
//------------------------------------------------------------------------------
//  Copyright (C) 1997-2002,2005  Vladislav Grinchenko
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Library General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//------------------------------------------------------------------------------
//  Created: 02/22/99
//------------------------------------------------------------------------------
#ifndef _Singleton_h
#define _Singleton_h

#include "Destroyer.h"

namespace ASSA {

template <class T>
class Singleton
{
public:

    static T* get_instance () {
        if (m_instance == 0) {
            m_instance = new T;
            m_destroyer.setGuard (m_instance);
        }
        return m_instance;
    }

protected:
    Singleton() {}
    
    friend class Destroyer<T>;
    
    virtual ~Singleton () {}
    
private:
    static T* m_instance;
    
    static Destroyer<T> m_destroyer;
};

} // end namespace ASSA


#define ASSA_DECL_SINGLETON(K)  \
template <> K* ASSA::Singleton<K>::m_instance = NULL;  \
template <class T> ASSA::Destroyer<T> ASSA::Singleton<T>::m_destroyer; \
template ASSA::Destroyer<K> ASSA::Singleton<K>::m_destroyer;

#endif

---