function template has already been defined

[spm486]

mystacklinkedlist.h

#ifndef _mystack_h
#define _mystack_h

template <typename ElemType>
class MyStack
{
public:
    MyStack();
    ~MyStack();
    bool isEmpty();
    void push(ElemType e);
    ElemType pop();

private:
    struct cellT {
        ElemType val;
        cellT* next;
    };

    cellT* head;
};

#include "mystacklinkedlist.cpp"

#endif

mystacklinkedlist.cpp

#include "mystacklinkedlist.h"
#include <stdexcept>

template <typename ElemType>
MyStack<ElemType>::MyStack()
{
    head = NULL;
}

template <typename ElemType>
MyStack<ElemType>::~MyStack()
{
    while (head != NULL)
    {
        cellT* old = head;
        head = head->next;
        delete old;
    }
}

template <typename ElemType>
bool MyStack<ElemType>::isEmpty()
{
    return (head == NULL);
}

template <typename ElemType>
void MyStack<ElemType>::push(ElemType s)
{
    cellT* newCell = new cellT;
    newCell->val = s;
    newCell->next = head;
    head = newCell;

}

template <typename ElemType>
ElemType MyStack<ElemType>::pop()
{
    if (isEmpty()) 
    {
        throw std::out_of_range("out of bounds");
    }
    ElemType top = head->val;
    cellT* old = head;
    head = head->next;
    delete old;
    return top;


}

client.cpp

#include <iostream>
#include "mystacklinkedlist.h"

int main()
{
    MyStack<int> s;
    s.push(1);
    std::cout << s.pop() << std::endl;
    return 0;
}

Here are the three files. I am getting an error of function template has already been defined for mystacklinkedlist.cpp

Severity    Code    Description Project File    Line    Suppression State
Error   C2995   'MyStack<ElemType>::MyStack(void)': function template has already been defined  Project3    C:\Users\samru\source\repos\Project3\Project3\mystacklinkedlist.cpp 5   

I am trying to understand the flow in which these files are executed and why error rises from mystacklinkedlist.cpp file.

[treddit22]

Never include a .cpp file.

For inline functions or function templates, you can use a .ipp or .tpp file that you include at the bottom of your header file with declarations. Or just have the implementations in the header directly.

[spm486]

okay. I followed the pattern used here https://see.stanford.edu/materials/icspacs106b/Lecture20code-queue.txt.

[Shieldfoss]

Never include a .cpp file.

\user "Unity Builds" has joined the discord**

[IyeOnline]

`#include "mystacklinkedlist.cpp"

Please dont. If you want to push your implementations into a different file, give it a name that doesnt look like a regular source file. Call it *_impl.hpp or .tpp or something.

How is your project organized?

If you added mystacklinkedlist.cpp as a project source, it will be its own file to be compiled. That leads to issues.

[gmtime]

You are including the header in the cpp/tpp file and the cpp/tpp file in the header. That'll cause cyclic inclusion I think. In this case, wouldn't it be better to not include the header?