eepp/include/eepp/system/singleton.hpp

#ifndef EE_SYSTEMSINGLETON_H
#define EE_SYSTEMSINGLETON_H

#include <eepp/core.hpp>

/** Internally we gonna use the macro singleton because it works with the engine compiled as dynamic libraries */

#define SINGLETON_DECLARE_HEADERS( T ) \
public: \
\
		static T * createSingleton(); \
\
		static T * existsSingleton(); \
\
		static T * instance(); \
\
		static void destroySingleton();

#define SINGLETON_DECLARE_IMPLEMENTATION( T ) \
\
static T* ms_singleton = NULL; \
\
T* T::createSingleton() { \
	if ( NULL == ms_singleton ) { \
		ms_singleton = eeNew( T, () ); \
	} \
\
	return ms_singleton; \
} \
\
T * T::existsSingleton() { \
	return ms_singleton; \
} \
\
T * T::instance() { \
	return createSingleton(); \
} \
\
void T::destroySingleton() { \
	eeSAFE_DELETE(ms_singleton) ; \
}

namespace EE { namespace System {

/** @brief Template class for only one instance classes. */
template<typename T>
class Singleton {
	protected:
		static T* ms_singleton;

	public:
		/** Get the singleton pointer */
		static T* createSingleton() {
			if ( NULL == ms_singleton ) {
				ms_singleton = eeNew( T, () );
			}
			
			return ms_singleton;
		}

		/** Get the singleton pointer (without instance verification) */
		static T* existsSingleton() {
			return ms_singleton;
		}

		/** Get the singleton pointer */
		static T* instance() {
			return createSingleton();
		}

		/** Destroy the singleton instance */
		static void destroySingleton() {
			eeSAFE_DELETE(ms_singleton);
		}
};

}}
#endif