Visual Studio 2012

#ifdef MATHFUNCSDLL_EXPORTS
#define MATHFUNCSDLL_API __declspec(dllexport) 
#else
#define MATHFUNCSDLL_API __declspec(dllimport) 
#endif
 
namespace MathFuncs
{
    class MyMathFuncs
    {
    public: 
        
        static MATHFUNCSDLL_API double Add(double a, double b); 
 
        static MATHFUNCSDLL_API double Subtract(double a, double b); 
 
        static MATHFUNCSDLL_API double Multiply(double a, double b); 
 
        static MATHFUNCSDLL_API double Divide(double a, double b); 
    };
}

#include "pch.h"
#include <iostream>
#include "dll_klim.h"
#include <stdexcept>
 
using namespace std;
 
namespace MathFuncs
{
    double MyMathFuncs::Add(double a, double b)
    {
        return a + b;
    }
 
    double MyMathFuncs::Subtract(double a, double b)
    {
        return a - b;
    }
 
    double MyMathFuncs::Multiply(double a, double b)
    {
        return a * b;
    }
 
    double MyMathFuncs::Divide(double a, double b)
    {
        if (b == 0)
        {
            throw invalid_argument("b cannot be zero!");
        }
 
        return a / b;
    }
}

#include "stdafx.h"
#include "dll_klim.h"
#include <iostream>
using namespace std;
 
int main()
{
 
    double a = 7.4;
    int b = 99;
 
    /*cout << "Type number 1: " << endl;
    cin >> a;
    cout << "Type number 2: " << endl;
    cin >>b;*/
 
    cout << "a + b = " <<
        MathFuncs::MyMathFuncs::Add(a, b) << endl;
    cout << "a - b = " <<
        MathFuncs::MyMathFuncs::Subtract(a, b) << endl;
    cout << "a * b = " <<
        MathFuncs::MyMathFuncs::Multiply(a, b) << endl;
    cout << "a / b = " <<
        MathFuncs::MyMathFuncs::Divide(a, b) << endl;
 
    try
    {
        cout << "a / 0 = " <<
            MathFuncs::MyMathFuncs::Divide(a, 0) << endl; 
    }
    catch (const invalid_argument &e) 
    {
        cout << "Caught exception: " << e.what() << endl; 
    }
 
    cin.get();
    cin.get();
    return 0;
}

#ifdef DLL_KLIM_EXPORTS
#define DLL_KLIM_API __declspec(dllexport) 
#else
#define DLL_KLIM_API __declspec(dllimport) 
#endif