C++之list容器模拟实现方式

template<class T>
struct Listnode
{
	ListNode<T>* prev;
	ListNode<T>* next;
	T data;//要在链表中保存的数据类型

	ListNode(const T& value = T())
		:prev(nullptr)
		, next(nullptr)
		, data(value)
	{ }
};

ListNode<变量类型>*变量名=new ListNode(value)；

Node* _pNode;//成员变量，节点类型指针

ListIterator(Node* pNode = nullptr)
	:_pNode(pNode)
{}

Ref operator*()
{
	return _pNode->data;
}

Ptr operator->()
{
	return &_pNode->data;
}

Self& operator++()
{
	_pNode = _pNode->next;
	return *this;
}

Self operator++(int)
{
	Self temp(*this);
	_pNode = _pNode->next;
	return temp;
}

Self& operator--()
{
	_pNode = _pNode->prev;
	return (*this);
}
Self operator--(int)
{
	Self temp(*this);
	_pNode = _pNode->prev;
	return temp;
}

bool operator!=(const Self& it)
{
	return _pNode != it._pNode;
}
bool operator==(const Self& it)
{
	return _pNode == it._pNode;
}

private:
	Iterator _it;//正向迭代器

Reference operator*()
{
	/
		    //复用insert
			insert(begin(), value);
		}
		void pop_front()
		{
			erase(begin());
		}

		//⭐insert
		// iterator是ListIterator<T, T&, T*>
		iterator insert(iterator Insertpos, const T& value)
		{
			Node* newnode = new Node(value);
			Node* pos = Insertpos._pNode;//_pNode是节点类型的指针
			newnode->next = pos;
			newnode->prev = pos->prev;
			newnode->prev->next = newnode;
			pos->prev = newnode;
			//return newnode;
			//⭐迭代器是封装的Node*指针，此时不能再返回newnode
			return iterator(newnode);//构造匿名对象返回
		}
		//⭐erase
		iterator erase(iterator Erasepos)
		{
			Node* pos = Erasepos._pNode;
			Node* ret = pos->next;
			pos->prev->next = pos->next;
			pos->next->prev = pos->prev;
			delete pos;
			return iterator(ret);
		}
		iterator erase(iterator first, iterator last)
		{
			auto it = first;
			while (it != last)
			{
				//it=erase(it);
				erase(it++);
			}
			return it;
		}

		void clear()
		{
			erase(begin(), end());
		}
		void swap(list<T>& l)
		{
			std::swap(head, l.head);
		}

	private:
		//提供一个创造头结点的方法
		void CreatHead()
		{
			//调用节点类的构造方法
			head = new Node();
			head->next = head;
			head->prev = head;
		}
	private:
		Node* head;

	};

	template<class T>
	void PrintList(const list<T>& l)
	{
		auto it = l.cbegin();
		while (it != l.cend())
		{
			cout << *it << " ";
			++it;
		}
		cout << endl;
	}
}

void Test1()
{
	ZH::list<int> l1;
	ZH::list<int> l2(3, 1);
	PrintList(l2);
	ZH::list<int> l3(l2.begin(), l2.end());
	PrintList(l3);
	vector<int> v{ 0,1,2,3,4 };
	ZH::list<int> l4(v.begin(), v.end());
	PrintList(l4);
}

void Test2()
{
	vector<int> v{ 1,2,3,4 };
	ZH::list<int> L1(v.begin(), v.end());
	L1.push_back(5);
	L1.push_back(6);
	L1.push_front(0);
	PrintList(L1);
	L1.pop_back();
	L1.pop_front();
	PrintList(L1);
	L1.erase(--L1.end());
	PrintList(L1);
}

void Test3()
{
	ZH::list<int> L1;
	L1.push_back(1);
	L1.push_back(2);
	L1.push_back(3);
	L1.push_front(0);
	PrintList(L1);
	L1.resize(6, 5);
	PrintList(L1);
}

struct A
{
	int a;
	int b;
	int c;
};

void Test4()
{
	A aa{ 1,2,3 };
	A bb{ 4,5,6 };
	A cc{ 7,8,9 };
	ZH::list<A> L;
	L.push_back(aa);
	L.push_back(bb);
	L.push_back(cc);
	auto it = L.begin();
	while (it != L.end())
	{
		//⭐it->得到的是节点的地址
		//本应是it->->a，编译器做了特殊处理
		cout << it->a << " ";
		it++;
	}
	cout << endl;
}

void Test5()
{
	ZH::list<int> L1;
	L1.push_back(0);
	L1.push_back(1);
	L1.push_back(2);
	L1.push_back(3);
	PrintList(L1);
	cout << L1.back() << endl;
	cout << L1.front() << endl;
	cout << L1.size() << endl;
	L1.clear();
	cout << L1.size() << endl;
}
 void Test6()
 {
	 ZH::list<int> L1;
	 L1.push_back(0);
	 L1.push_back(1);
	 L1.push_back(2);
	 L1.push_back(3);
	 PrintList(L1);
	 //区间删除
	 

	 ZH::list<int> L2;
	 L2.push_back(1);
	 L2.push_back(2);
	 L2.push_back(3);
	 L2.push_back(4);
	 L2.push_back(5);
	 PrintList(L2);
	 L1.swap(L2);
	 PrintList(L1);
	 PrintList(L2);
 }

int main()
{
	Test6();
	system("pause");
	return 0;
}