模板类编译错误

Question

When I compile I keep getting errors about my template in my linked list class. For a project I'm doing we have to make a linked list and basically just modify it with different functions but I have no idea how to get it to work with my template and to run the functions in my main(). So here is the code.

#pragma once

template <typename ItemType>

class LinkedList {

private:

    struct Node {
    ItemType info;
    Node* next;
    Node* prev;
  };


  Node* head;
  Node* tail;
  int size;

public:
  LinkedList() :

    size(0),
    head(NULL),
    tail(NULL)

  { }
  ~List() 
   {
        clear();
   }
  void clear()
  {
    Node* n = tail;
    while(n != NULL)
    {
        Node *temp = n;
        n = n->prev;
        delete temp;
    }
    head = NULL;
    tail = NULL;
  }
  void print()
  {
      int count = 0;
      Node* temp = head;
      while(temp != NULL)
      {
         cout << "node " << count << ": " << temp->info << endl;
         temp = temp->N;
         count++;
      }
  }
  void insert(int index, const ItemType& item) 
  {
     int count = 0;
     Node* n = head;
     while(n != NULL)
    {
        if(count == index)
        {
            break;
        }
        n = n->next;
        count++;
    }
    if(n == NULL)
    {
        return;
    }

    Node* p = new Node;
    p->info = item;
    p->next = n->next;
    p->prev = n;
    n->next = p;

  }

so I have all my functions in the header file because that's the format they asked us to do it in. My main is as follows:

#include <iostream>
#include <string>
#include <fstream>

#include "LinkedList.h"

using namespace std;


int main(int argc, char* argv[])
{
    string cmd;
    int index;
    string item;
    LinkedList<string> list; // I don't know if this is how its suppose to be done.


    while(cin >> cmd)
    {
        if (cmd == "clear")
        {
            cout << "clear" << endl;        
        }
        if (cmd == "insert")
        {
            cin >> index;
            cin >> item;
            list.insert(index, item);       
        }           
        if (cmd == "print")
        {
            cout << "print" << endl;
        }
    }



    system("pause");
    return 0;

}

So basically I don't know how to run the functions in my header file in my main and it compile correctly. The errors its giving me are related to the LinkedList part with the std::string. So I'm just not sure how to initialize that the correct way to get the functions to work. I'm not so worried now if the code for the functions are right, I will do the debugging and figure that out I just want to be able to test my code but it won't compile! If anyone could steer me in the right direction that would be awesome. Thanks.

ERRORS:

1>  project5.cpp
1>c:\users\marsh\documents\cs\project5\project5\linkedlist.h(28): error C2523: 'LinkedList<ItemType>::~List' : destructor tag mismatch
1>          c:\users\marsh\documents\cs\project5\project5\linkedlist.h(133) : see reference to class template instantiation 'LinkedList<ItemType>' being compiled
1>c:\users\marsh\documents\cs\project5\project5\linkedlist.h(28): error C2523: 'LinkedList<ItemType>::~List' : destructor tag mismatch
1>          with
1>          [
1>              ItemType=std::string
1>          ]
1>          c:\users\marsh\documents\cs\project5\project5\project5.cpp(15) : see reference to class template instantiation 'LinkedList<ItemType>' being compiled
1>          with
1>          [
1>              ItemType=std::string
1>          ]

Answer 1

~List() 
{
    clear();
}

should be:

~LinkedList() 
{
    clear();
}

Answer 2

The compiler errors pretty clearly point you to the problem:

~List() 
{
    clear();
}

Your type is named LinkedList , not List .