Source Files for DLLArith

//DLLArith - These are all the Source Files for DLLArith
//Add.cpp

#include "Add.h"

// Defining a member function outside of class
int Add::Calc(int v1, int v2)
{
    return v1+v2;
}
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//DLLArith.cpp
#include <iostream>
using namespace std;

// IMPORTANT: DLLTEST_API will perform an export of the exposed functions
#define DLL_EXPORT

// Include the header, must come after #define DLL_EXPORT
#include "DLLArith.h"
#include "Add.h"
#include "Subtract.h"

extern "C"
{
    DLLTEST_API IArith* NewObject(int operation)
    {
        if(operation == 0){

            return new Add();
        }
        else if(operation == 1){
            return new Subtract();
        }
        else{
            return NULL;
        }
    }

    DLLTEST_API void DelObject(IArith *pObject)
    {
        delete pObject;
    }
}
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// Subtract.cpp
#include "Subtract.h"

// Defining a member function outside of class
int Subtract::Calc(int v1, int v2)
{
    return v1-v2;
}