투포인터(?) 덱 구현

2ptrdeque.cpp

#include<iostream>
using namespace std;

template<class T>
struct ptrDeque
{
	using iterator=T*;
	iterator l,r;
	ptrDeque():l(new T),r(l){}
	void push_back(T a){*r=a;r++;}
	void push_front(T a){l--;*l=a;}
	void pop_back(){r--; delete r;}
	void pop_front(){iterator t=l;l++; delete t;}
	T& operator[](size_t s){return *(l+s);}
	iterator begin(){return l;}
	iterator end(){return r;}
	T& front(){return *l;}
	T& back(){return *(r-1);}
};

namespace std
{
	template<class T>
	T* begin(ptrDeque<T>&p){return p.l;}
	template<class T>
	T* end(ptrDeque<T>&p){return p.r;}
}

int main()
{
	ptrDeque<int> deq;
	deq.push_back(100);
	deq.push_back(200);
	deq.push_back(300);
	deq.push_back(400);
	deq.push_back(500);
	deq.push_front(100);
	deq.push_front(200);
	deq.push_front(300);
	deq.push_front(400);
	deq.push_front(500);
	deq.pop_back();
	for(auto i:deq)cout << i << endl;
}