链接列表深层复制问题

Question

我在重载operator =时遇到问题。

template <class T>
class Node
{
public:
  T m_data;                  // Data to be stored
  Node<T>* m_next;     // Pointer to the next element in the list


  // Purpose: Default constructor
  // Postconditions: next pointer set to NULL
  // ---INLINE---
  Node() : m_next(NULL) {}

  // Purpose: Auxiliaty constructor, construct from parameters
  // Postconditions: data and next pointer set to parameters
  // ---INLINE---
  Node(const T& x, Node<T>* p) 
             : m_data(x), m_next(p) {}

};

template <class T>
class LinkedList
{
 
public:

  Node<T>* head;     // Pointer to the head of the list

    // Purpose: Default constructor
    // Postconditions: head pointer set to NULL
    // ---INLINE---
  LinkedList() : head(NULL) {}

// --------
// ---- Big 3 Member Functions ---
// --------

// Purpose: Destructor
// IMPORTANT:: For didactic purposes, the destructor is left empty.
// YOU are expected to implement function clear() to de-allocate the list
	// --INLINE
  ~LinkedList() {}

// Purpose: performs a deep copy of the data from rhs into this linked list
// Parameters: rhs is linked list to be copied
// Returns: *this
// Postconditions: this list contains same data values (in the same order)
//     as are in rhs; any memory previously used by this list has been
//     deallocated.
  const LinkedList<T>&  operator= (const LinkedList<T>& rhs);

// Purpose: copy constructor
// Parameters: rhs is the LinkedList that is to be copied
// Postconditions: this list contains same data values (in same order) 
//      as in rhs.
  LinkedList(const LinkedList<T>& rhs);

以上是给出的。我当前的实现不提供深层复制。

template<class T>
const LinkedList<T>& LinkedList<T>::operator =(const LinkedList<T>& rhs)
{
	if(this != &rhs)
	{
	  if(head != NULL)
	  {
	    clear();
	  }
	  Node<T>* current = rhs.head;
	  while (current != NULL)
	  {
	    insert_front(current -> m_data);
	    current = current -> m_next;
	  }
	  head = current;
	}  
	return(*this);
}