singleton.h

/*
 * sysjt - SYStray Job Tracker
 * Copyright (C) 2011  Tieto Corp., Martin Kampas <martin.kampas@tieto.com>
 *
 * This program 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.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#pragma once

template<class T>
class Singleton
{
public:
  static void singletonInit()
  {
    Q_ASSERT(m_instance == 0);
    m_instance = new T;
  }

  static void singletonDestroy()
  {
    Q_ASSERT(m_instance != 0);
    delete m_instance;
    m_instance = 0;
  }

  static T *instance()
  {
    Q_ASSERT(m_instance != 0);
    return m_instance;
  }

private:
  static T *m_instance;
};

#if defined(Q_CC_MSVC)
# define SINGLETON_DEFINE_INSTANCE(CLASS) \
    template<> CLASS *Singleton<CLASS>::m_instance = 0;
#else
# define SINGLETON_DEFINE_INSTANCE(CLASS) \
    template<> Q_DECL_EXPORT CLASS *Singleton<CLASS>::m_instance = 0;
#endif