c++ - Why do linked lists use pointers instead of storing nodes inside of nodes

Question

I've worked with linked lists before extensively in Java, but I'm very new to C++. I was using this node class that was given to me in a project just fine

class Node
{
  public:
   Node(int data);

   int m_data;
   Node *m_next;
};

but I had one question that wasn't answered very well. Why is it necessary to use

Node *m_next;

to point to the next node in the list instead of

Node m_next;

I understand that it is better to use the pointer version; I'm not going to argue facts, but I don't know why it's better. I got a not so clear answer about how the pointer is better for memory allocation, and I was wondering if anyone here could help me understand that better.

Answer 1

It's not just better, it's the only possible way.

If you stored a Node object inside itself, what would sizeof(Node) be? It would be sizeof(int) + sizeof(Node), which would be equal to sizeof(int) + (sizeof(int) + sizeof(Node)), which would be equal to sizeof(int) + (sizeof(int) + (sizeof(int) + sizeof(Node))), etc. to infinity.

An object like that can't exist. It's impossible.