Random_access_iterator

구현은 거의 비슷하다.

1. pubilic member

public:
	typedef	std::random_access_iterator_tag		iterator_category;
	typedef	T									value_type;
	typedef	T*									pointer;
	typedef	T&									reference;
	typedef	std::ptrdiff_t						difference_type;
	typedef random_access_iterator<T>			iterator;
	typedef random_access_iterator<const T>		const_iterator;

2. protected member

protected: 
    pointer	_ptr;

3. canonical, constructor

random_access_iterator(void) : _ptr(NULL) {}

random_access_iterator(pointer ptr) : _ptr(ptr) {}

random_access_iterator(const random_access_iterator &x)
{
	*this = x;
}

// 변환연산자
operator const_iterator() const
{
	return const_iterator(_ptr);
}

random_access_iterator &operator=(const random_access_iterator &x)
{
	if (this != &x)
		_ptr = x._ptr;
	return (*this);
}

~random_access_iterator(void) {}

4. 나머지는 reverse_iterator와 비슷함.

참고)
https://github.com/hyungyoo/42_Cursus/blob/main/Circle_06/ft_containers/inc/random_access_iterator.hpp