Singleton.hpp

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#ifndef _BASE_SINGLETON_H_
#define _BASE_SINGLETON_H_

namespace base {

template<class Derived>
class Singleton
{

private:
        static Derived* msInstance;

protected:
        Singleton() {}

public:
        static Derived* getInstance()
        {
                static CGuard g;

                if(msInstance == 0)
                {
                        msInstance = new Derived(); 
                }
        
                return msInstance;
        }

        virtual ~Singleton()
        {
        }


        // Nested singleton helper class
        class CGuard
        {
                public: 
                        ~CGuard()
                        {
                                if(msInstance != 0)
                                {
                                        delete msInstance;
                                        msInstance = 0;
                                }
                        }

        };

        friend class CGuard;

};

template<typename Derived> Derived* Singleton<Derived>::msInstance = 0;

} // end namespace base;


#endif // _BASE_SINGLETON_H_