【c++】智能指针

// vc下的智能指针，重点在于拥有权的转移

#include <iostream>
using namespace std;

template<class Type>
class Autoptr
{
public:
	Autoptr(int *p = NULL) :ptr(p), owns(ptr != NULL)
	{}
	Autoptr(const Autoptr<Type> &t) :ptr(t.release()), owns(t.owns)
	{}
	Autoptr<Type>& operator=(const Autoptr<Type> &t)
	{
		if (this != &t)// 推断是否给自己赋值
		{
			if (ptr != t.ptr)// 推断是否指向同一个空间
			{
				if (owns)// 假设有拥有权。则释放当前空间
				{
					delete ptr;
				}
				else
				{
					owns = t.owns;// 反之，得到拥有权
				}
				ptr = t.release();// 让t失去拥有权
			}
		}
		return *this;
	}
	~Autoptr()
	{
		if (owns)
			delete ptr;
	}
public:
	Type& operator*()const
	{
		return (*get());
	}
	Type* operator->()const
	{
		return get();
	}
	Type* get()const
	{
		return ptr;
	}
	Type* release()const
	{
		((Autoptr<Type> *const)this)->owns = false;
		return ptr;
	}
private:
	bool owns;
	Type *ptr;
};

int main()
{
	int *p = new int(10);
	Autoptr<int> pa(p);
	cout << *pa << endl;
	Autoptr<int> pa1(pa);
	cout << *pa1 << endl;
	int *p1 = new int(100);
	Autoptr<int> pa2(p1);
	Autoptr<int> pa3;
	pa3 = pa2;
	cout << *pa3 << endl;
	return 0;
}