模拟 C++11 的shared_ptr

最新推荐文章于 2025-06-16 21:04:45 发布

king1076

最新推荐文章于 2025-06-16 21:04:45 发布

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分类专栏： c/c++ 文章标签： c++11 智能指针

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本文探讨了仿照C++11中shared_ptr原理的智能指针实现，并对其功能进行了详细解析，包括构造、赋值操作、析构及引用计数管理等关键点。

仿照C++11 中的shared_ptr 写的智能指针，不像源码那么好，自己还需要努力

	template<class T>
	class RefCount
	{
	private:
		long refcount;
		T* Ptr;
	public:
		~RefCount()
		{
			cout<<"delete"<<endl;
		}
		virtual bool DeletePtr()
		{
			if(refcount==0)
			{
				delete Ptr;
				return true;
			}
			else
			{
				refcount--;
				return false;
			}
		}
		virtual void DeleteThis()
		{
			if(DeletePtr())
			{
				delete this;
			}
		}
		RefCount(T* _ptr):Ptr(_ptr),refcount(0){}
		inline bool Empty()
		{
			return refcount ==0;
		}

		inline void AddRef(){
			refcount++;
		}
		inline void DeRef()  
		{
			refcount --;
		}
	};
	template<class T>
	class JShare_Ptr
	{
	public:
		typedef JShare_Ptr<T > MyPtr;
		JShare_Ptr()
		{
			refcount = 0;
		}
		JShare_Ptr& operator=(const JShare_Ptr<T>& _Ptr)
		{
			if(this->ptr == _Ptr.ptr)
			{
				return *this;
			}else
			{
				delete refcount;
				this->ptr = _Ptr.ptr;
				this->refcount = _Ptr.refcount;
				refcount->AddRef();
			}
		}
		JShare_Ptr& operator=(JShare_Ptr<T>& _Ptr)
		{
			if(this->ptr == _Ptr.ptr)
			{
				return *this;
			}else
			{
				delete refcount;
				this->ptr = _Ptr.ptr;
				this->refcount = _Ptr.refcount;
				refcount->AddRef();
			}
		}
		JShare_Ptr(T* _ptr)
		{
			refcount = new RefCount<T>(_ptr);
			ptr = _ptr;

		}

		JShare_Ptr(const JShare_Ptr<T >& _Ptr)
		{
			Assign(_Ptr);
		}
		~JShare_Ptr()
		{
			(refcount)->DeleteThis();
		}
		T* operator ->(){return ptr;}
		T* operator*(){return ptr;}
	private:
		void Assign(const MyPtr& _Ptr)
		{
			ptr = _Ptr.ptr;
			refcount = _Ptr.refcount;
			(refcount) ->AddRef();
		}
	private:
		T* ptr;
		RefCount<T>* refcount;
	};
}