使用智能指针的一个示例

使用智能指针的一个示例

class U_Ptr
{
        friend class HasPtr;
        int *ip;
        size_t use;
        U_Ptr(int *p):ip(p),use(1){}
        ~U_Ptr() { delete ip;}
};

class HasPtr
{
private:
        U_Ptr *ptr;
        int val;
public:
        int *get_ptr() const{ return ptr->ip;}
        int get_ptr_val() const{ return *ptr->ip;}
        int get_val() const { return val;}
        void set_int(int i) {val = i;}
        void set_ptr(int *p) { ptr->ip = p;}
        void set_ptr_val(int i){ *ptr->ip=i; }
        HasPtr(int *p,int i):ptr(new U_Ptr(p)),val(i){}
        HasPtr(const HasPtr &orig):ptr(orig.ptr),val(orig.val){++ptr->use;}
        HasPtr& operator=(const HasPtr?
        ~HasPtr(){if(--ptr->use==0) delete ptr;}        
};

HasPtr& HasPtr::operator=(const HasPtr &rhs)
{
        ++rhs.ptr->use;
        if(--ptr->use==0)
                delete ptr;
        ptr=rhs.ptr;
        val=rhs.val;
        return *this;
}

转自：http://blog.youkuaiyun.com/weiyuweizhi/article/details/5266160