Linked-list assignment operator

I'm trying to figure out if i have the general idea behind the assignment operator for Doubly Linked Lists using a current node (no front or back). This is my pseudo code. I need to get this concept down. If anyone can help, that would be sweet.

Loop to start
    temp = temp->back
loop to count
    if 0
        receiver->back = null
        receiver->entry = temp->entry
        receiver->next = temp->next
    if > 0
        receiver->back = temp->back
        receiver->entry = temp->entry
        receiver->next = temp->next
    if == count-1
        receiver->bac开发者_如何学JAVAk = temp->back
        receiver->entry = temp->entry
        receiver->next = null

This is my Node structure:

struct Node {
    // data members
    Node_entry entry;
    Node<Node_entry> *next;
    Node<Node_entry> *back;
    // constructors
    Node();
    Node(Node_entry, Node<Node_entry> *link_back = nullptr, 
        Node<Node_entry> *link_next = nullptr);

}

I'm not looking for a code answer, but an algorithm (actually code that is well commented and written is good as example). I just need to understand how the copying works.

struct Node {
  Node *prev, *next;
  int entry;

  explicit Node(int entry) : prev (0), next (0), entry (entry) {}
};

Node* copy_list(Node *node) {
  assert(node);  // require a non-null pointer

  // copy "current" node
  Node *new_list = new Node(node->entry);

  // copy backward from node to beginning
  Node *dest = new_list;
  for (Node *x = node->prev; x; x = x->prev) {
    dest->prev = new Node(x->entry);
    dest->prev->next = dest;
    dest = dest->prev;
  }

  // copy forward from node to end
  dest = new_list;
  for (Node *x = node->next; x; x = x->next) {
    dest->next = new Node(x->entry);
    dest->next->prev = dest;
    dest = dest->next;
  }

  return new_list;
}