Inclusion compilation Model and separate compilation Model in Qt?

[cwxfly]

Hello all;
Recently , I write a link list project using c++ template .But it's does work well.
Firstly , I use Inclusion compilation model so I add a sentence "#include "LinkList.cpp"" in head file, but it comes out an error " error: redefinition of 'LinkList<T>::LinkList()' ";
Secondly , I use seperate compilation model so I add a sentence "export template <class T> class LinkList;" in source file . However, there comes an error "error: undefined reference to `LinkList<char>::LinkList()' " too.
Thirdly , I add a sentence "#include "LinkList.cpp"; ". It's worked and the results are easy to understand!
But , how to use Inclusion compilation Model and separate compilation Model in Qt?
Thank for you reply!!!

//head file LinkList.h
#ifndef LINKLIST_H
#define LINKLIST_H
#include<iostream>
 
template <class T>
struct ListNode
{
   T data;
   ListNode<T> *next;
};
 
template <class T>
class LinkList
{
public:
    LinkList();
    virtual ~LinkList();
 
    bool GetElem(int loca,T &elem);
    bool ListInsert(int loca,T elem);
    bool ListDelete(int loca,T &elem);
    void ListAppending(T item);
    int ListLens();
 
private:
    ListNode<T> *p_head;
    int i_listlen;
};
 
#endif // LINKLIST_H
 
//source file LinkList.cpp
#include<iostream>
#include "LinkList.h"
 
template <class T> 
...
 
//test file main.cpp
#include <iostream>
#include "LinkList.h"
int main()
{
    LinkList<char> c_list;
    c_list.ListAppending('a');
    c_list.ListAppending('b');
    c_list.ListAppending('c');
    int lens = c_list.ListLens();
    std::cout<<"lens = "<<lens<<std::endl;
    return 0;
}

//head file LinkList.h
#ifndef LINKLIST_H
#define LINKLIST_H
#include<iostream>

template <class T>
struct ListNode
{
   T data;
   ListNode<T> *next;
};

template <class T>
class LinkList
{
public:
    LinkList();
    virtual ~LinkList();

    bool GetElem(int loca,T &elem);
    bool ListInsert(int loca,T elem);
    bool ListDelete(int loca,T &elem);
    void ListAppending(T item);
    int ListLens();

private:
    ListNode<T> *p_head;
    int i_listlen;
};

#endif // LINKLIST_H

//source file LinkList.cpp
#include<iostream>
#include "LinkList.h"

template <class T> 
...

//test file main.cpp
#include <iostream>
#include "LinkList.h"
int main()
{
    LinkList<char> c_list;
    c_list.ListAppending('a');
    c_list.ListAppending('b');
    c_list.ListAppending('c');
    int lens = c_list.ListLens();
    std::cout<<"lens = "<<lens<<std::endl;
    return 0;
}

To copy to clipboard, switch view to plain text mode 

[wysota]

Why are you including a cpp file? That's almost never a good idea.

[cwxfly]

Because I saw a blog which tells some tips to fix this error by adding source code into head file , so try including the cpp file in main.cpp and indeed it's work well. However , how can I use Inclusion compilation Model and separate compilation Model in Qt?
thank you!

[stampede]

Use qmake and project files.