source: vbox/trunk/src/VBox/NetworkServices/NetLib/shared_ptr.h@ 49339

#ifndef __SHARED_PTR_H__
#define __SHARED_PTR_H__

#ifdef __cplusplus
template<typename T> 
class SharedPtr
{
    struct imp 
    {
        imp(T *pTrg = NULL, int cnt = 1): ptr(pTrg),refcnt(cnt){}
        ~imp() { if (ptr) delete ptr;}

        T *ptr;
        int refcnt;
    };

    
    public:
    SharedPtr(T *t = NULL):p(NULL)
    {
        p = new imp(t);
    }
    
    ~SharedPtr()
    {
        p->refcnt--;

        if (p->refcnt == 0)
            delete p;
    }


    SharedPtr(const SharedPtr& rhs)
    {
        p = rhs.p;
        p->refcnt++;
    }

    const SharedPtr& operator= (const SharedPtr& rhs)
    {
        if (p == rhs.p) return *this;
        
        p->refcnt--;
        if (p->refcnt == 0) 
            delete p;

        p = rhs.p;
        p->refcnt++;

        return *this;
    }


    T *get() const
    {
        return p->ptr;
    }

    
    T *operator->()
    {
        return p->ptr;
    }

    
    const T*operator->() const
    {
        return p->ptr;
    }


    int use_count()
    {
        return p->refcnt;
    }

    private:
    imp *p;
};
#endif
#endif