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/***************************************************************************
* Copyright (C) 2005-2019 by the FIFE team *
* http://www.fifengine.net *
* This file is part of FIFE. *
* *
* FIFE is free software; you can redistribute it and/or *
* modify it under the terms of the GNU Lesser General Public *
* License as published by the Free Software Foundation; either *
* version 2.1 of the License, or (at your option) any later version. *
* *
* This 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 *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this library; if not, write to the *
* Free Software Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA *
***************************************************************************/
#ifndef FIFE_SINGLETON_H
#define FIFE_SINGLETON_H
#define SINGLEFRIEND(classname) friend class FIFE::StaticSingleton<classname>; classname(); virtual ~classname();
// Standard C++ library includes
#include <cassert>
// 3rd party library includes
// FIFE includes
// These includes are split up in two parts, separated by one empty line
// First block: files included from the FIFE root src directory
// Second block: files included from the same folder
#include "fifeclass.h"
namespace FIFE {
/** The "classic" Singleton.
*
* @see DynamicSingleton
*/
template <typename T> class StaticSingleton {
public:
static T* instance() {
static T inst;
return &inst;
}
protected:
StaticSingleton() {
}
virtual ~StaticSingleton() {
}
private:
StaticSingleton(const StaticSingleton<T>&) {}
StaticSingleton<T>& operator=(const StaticSingleton<T>&) {
return this;
}
};
/** Another Singleton.
*
* This implementations needs to be created and destroyed explicitly.
* That way the order of construction and destruction is well defined, so we don't
* get those nasty static initialization/destruction order problems.
*
* Engine will create all standard FIFE Singletons when created (just call Engine::instance())
* and destroy them on exit.
*
* Maybe we'll change this one day to use one of those funny NiftyCounter implementations.
*
* @see StaticSingleton
* @see Engine
*/
template <typename T> class DynamicSingleton {
public:
static T* instance() {
assert(m_instance);
return m_instance;
}
DynamicSingleton() {
assert(!m_instance);
m_instance = static_cast<T*>(this);
}
virtual ~DynamicSingleton() {
m_instance = 0;
}
private:
static T* m_instance;
DynamicSingleton(const DynamicSingleton<T>&) {};
DynamicSingleton<T&> operator=(const DynamicSingleton<T>&) {};
};
template <typename T> T* DynamicSingleton<T>::m_instance = 0;
}//FIFE
#endif
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