节点类成员函数在链接列表包中不起作用

Question

我似乎很难激活一个节点类的类成员函数，我试图在数组类中为链表实现。在指出问题时，我将不胜感激。这些是相关的代码块：

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对于实施文件：

    #ifndef LINK_H
    #define LINK_H
    #include <iostream>
    #include <cstdlib>


    namespace linkedlist{

    class node {

    typedef size_t value_type;

    private:
        value_type m_data;
        node *m_link;

public: 
        //Constructor
        node(const value_type& i_data = value_type(), node* i_link = NULL){
            m_data = i_data;
            m_link = i_link;
        }
    void list_copy (const node* source_ptr, node*& head_ptr, node*& tail_ptr);

链接列出的包

#include <iostream>
#include "Link.h"
#include <cassert>
#include <cstdlib>

using namespace linkedlist;

void node::list_copy (const node* source_ptr, node*& head_ptr, node*& tail_ptr){
    head_ptr = NULL;
    tail_ptr = NULL;
    // Handle the case of the empty list.
    if (source_ptr == NULL) return;
    // Make the head node for the newly created list, and put data in it.
    list_head_insert(head_ptr, source_ptr->data( ));
    tail_ptr = head_ptr;
    // Copy the rest of the nodes one at a time, adding at the tail of new list.
    source_ptr = source_ptr->link( );
    while (source_ptr != NULL) {
    list_insert(tail_ptr, source_ptr->data( ));
    tail_ptr = tail_ptr->link( );
    source_ptr = source_ptr->link( );
    }
}

node :: list_copy无法识别