SmartPointer.h

#pragma once
namespace cyh {
	template<class T>
	class SmartPtr;
	template <typename T>
	class U_Ptr;

	template <typename T>
	class U_Ptr    
	{
	private:

		friend class SmartPtr<T>;

		U_Ptr(T *ptr) :p(ptr), count(1) { }

		~U_Ptr() { delete p; }

		int count;

		T *p;
	};

	template<class T>
	class SmartPtr
	{
	public:
		typedef  SmartPtr<T> _Myt;
		SmartPtr() = delete;
		constexpr SmartPtr(std::nullptr_t)
		{}

		SmartPtr(_Myt& Value) : pointer(Value.pointer)
		{
			Value.pointer->count++;
		}
		SmartPtr(T *p) : pointer(new U_Ptr<T>(p))
		{
		}
		SmartPtr& operator=(_Myt& _Right)
		{
			reduce();
			this->pointer = _Right.pointer;
			this->pointer->count++;
			return *this;
		}
		T* operator->()
		{
			return pointer;
		}
		T& operator*()
		{
			return *pointer;
		}
		int use_count() const
		{
			return this->pointer->count;
		}
		T* get()
		{
			return pointer;
		}
		~SmartPtr()
		{
			reduce();
		}

	private:
		void reduce() {
			if (--this->pointer->count == 0) {
				delete this->pointer;
			}
		}
		U_Ptr<T> *pointer; 
	};
}