Singleton.hpp

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/*
    Copyright (c) 2009-2010 Christopher A. Taylor.  All rights reserved.

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    modification, are permitted provided that the following conditions are met:

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#ifndef CAT_SINGLETON_HPP
#define CAT_SINGLETON_HPP

#include <cat/Platform.hpp>

namespace cat {


// Derived class should define the constructor using this macro:
#define CAT_SINGLETON(subclass) \
    private: \
        friend class Singleton<subclass>; \
        subclass()



template<class T> class Singleton
{
protected:
    Singleton<T>() {}
    Singleton<T>(Singleton<T> &) {}
    Singleton<T> &operator=(Singleton<T> &) {}

public:
    static T *ii;

public:
    CAT_INLINE static T *ref()
    {
        if (ii) return ii;
        return ii = new T;
    }
    CAT_INLINE static void deallocate()
    {
        if (ii)
        {
            delete ii;
            ii = 0;
        }
    }

    virtual ~Singleton() {}
};

// TODO: I'm actually not 100% sure this always works
template<class T> T *Singleton<T>::ii = 0;


} // namespace cat

#endif // CAT_SINGLETON_HPP