Differential D1564 Diff 7328 ps/trunk/source/ps/Singleton.h

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ps/trunk/source/ps/Singleton.h

	/* Copyright (C) 2009 Wildfire Games.			/* Copyright (C) 2019 Wildfire Games.
	* This file is part of 0 A.D.			* This file is part of 0 A.D.
	*			*
	* 0 A.D. is free software: you can redistribute it and/or modify			* 0 A.D. is free software: you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by			* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation, either version 2 of the License, or			* the Free Software Foundation, either version 2 of the License, or
	* (at your option) any later version.			* (at your option) any later version.
	*			*
	* 0 A.D. is distributed in the hope that it will be useful,			* 0 A.D. is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of			* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.			* GNU General Public License for more details.
	*			*
	* You should have received a copy of the GNU General Public License			* You should have received a copy of the GNU General Public License
	* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.			* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
	*/			*/

	/*
	* template base class for Singletons
	*/

	/*
	USAGE: class myClass : Singleton<myClass>{};

	Modified from http://gamedev.net/reference/articles/article1954.asp
	*/

	#ifndef INCLUDED_SINGLETON			#ifndef INCLUDED_SINGLETON
	#define INCLUDED_SINGLETON			#define INCLUDED_SINGLETON

	#include "lib/debug.h"			#include "lib/debug.h"

				/**
				* Template base class for singletons.
				*
				* Usage:
				* class MyClass : public Singleton<MyClass> {};
				* MyClass::GetSingleton().MyMethod();
				*
				* Modified from http://gamedev.net/reference/articles/article1954.asp
				*/
	template<typename T>			template<typename T>
	class Singleton			class Singleton
	{			{
	static T* ms_singleton;			NONCOPYABLE(Singleton);

	public:			public:
	Singleton()			Singleton()
	{			{
	ENSURE( !ms_singleton );			ENSURE(!ms_singleton);
	ms_singleton = static_cast<T*>(this);			ms_singleton = static_cast<T*>(this);
	}			}

	~Singleton()			~Singleton()
	{			{
	ENSURE( ms_singleton );			ENSURE(ms_singleton);
	ms_singleton = 0;			ms_singleton = nullptr;
	}			}

	static T& GetSingleton()			static T& GetSingleton()
	{			{
	ENSURE( ms_singleton );			ENSURE(ms_singleton);
	return *ms_singleton;			return *ms_singleton;
	}			}

	static T* GetSingletonPtr()			static T* GetSingletonPtr()
	{			{
	ENSURE( ms_singleton );			ENSURE(ms_singleton);
	return ms_singleton;			return ms_singleton;
	}			}

	static bool IsInitialised()			static bool IsInitialised()
	{			{
	return (ms_singleton != 0);			return ms_singleton != nullptr;
	}			}

				private:
				static T* ms_singleton;
	};			};

	template <typename T>			template <typename T>
	T* Singleton<T>::ms_singleton = 0;			T* Singleton<T>::ms_singleton = nullptr;

	#endif			#endif // INCLUDED_SINGLETON