auto_ptr实现代码两种方法

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template<class T>
class auto_ptr {
public:
    explict auto_ptr(T *p = 0);
    template<class U>
    auto_ptr(auto_ptr<U>& rhs);

    ~auto_ptr();
    template<class U>
    auto_ptr<T>& operator=(auto_ptr<U>& rhs);
    T& operator*() const;
    T* operator->() const;
    T* get() const;
    T* release();

    void reset(T *p = 0);
private:
    T *pointee;
    template<class U>
    friend class auto_ptr<U>;
};

template<class T>
template<class U>
    inline auto_ptr<T>::auto_ptr(auto_ptr<U>& rhs) : pointee(rhs.release()) {}

template<class T>
    inline auto_ptr<T>::~auto_ptr() { delete pointee; }

template<class T>
template<class U>
    inline auto_ptr<T>& auto_ptr<T>::operator=(auto_ptr<T>& rhs)
    {
        if(this != &rhs) reset(rhs.release());
        return *this;
    }

template<class T>
    inline T& auto_ptr<T>::operator*() const { return pointee; }

template<class T>
    inline T* auto_ptr<T>::operator->() const { return pointee; }

template<class T>
    inline T* auto_ptr<T>::get() const { return pointee; }

template<class T>
    inline T* auto_ptr<T>::release()
    {
        T* oldPointee = pointee;
        pointee = 0;
        return oldPointee;
    }

template<class T>
    inline void auto_ptr<T>::reset(T*p)
    {
        if(pointee != p) {
            delete pointee;
            pointee = p;
        }
    }

//所有函数都定义在class定义区内：
template<class T>
class auto_ptr {
public:
    explicit auto_ptr(T *p = 0) : pointee(p) {}

template<class U>
    auto_ptr(auto_ptr<U>& rhs) : pointee(rhs.release()) { }
    ~auto_ptr() { delete pointee: }

template<class U>
    auto_ptr<T>& operator=(auto_ptr<U>& rhs)
    {
        if(this != &rhs) reset(rhs.release());
        return *this;
    }

    T& operator*() const { return *pointee; }
    T* operator->()const { return pointee; }
    T* get() cosnt { return pointee; }
    T* release() 
    {
        T *oldPointee = pointee;
        pointee = 0;
        return oldPointee;
    }

    void reset(T *p = 0)
    {
        if(pointee != p) {
        delete pointee;
        pointee = p;
        }
    }

private:
    T* pointee;
    template<class U> friend class auto_ptr<U>;
};