public static class ExportClass
    {
        [DllExport(ExportName = "SimpleFunction", CallingConvention = CallingConvention.StdCall)]
        public static int SimpleFunction(int a, int b)
        {
            return a + b;
        }

        [DllExport(ExportName = "CPPObjectMethodCall", CallingConvention = CallingConvention.StdCall)]
        public static bool CPPObjectMethodCall(IntPtr cppObject)
        {
            // How to make call of c++ object method here?
        }

    }

class CPPClass
{
    public :
        CPPClass() {}

        ~CPPClass() {}

        void CPPClassMethodCall(std :: string text)
        {
            MessageBoxA(NULL, text.c_str(), "Message", 0);
        }
};


void TestFunction()
{
    HMODULE hDLL = LoadLibraryA("LibCS.dll");

    typedef int (*SIMPLEFUNCTION)(int a, int b);
    typedef bool (*CPPOBJECTMETHODCALL)(void * cppObject);

    SIMPLEFUNCTION SimpleFunction = (SIMPLEFUNCTION)GetProcAddress(hDLL, "SimpleFunction");
    CPPOBJECTMETHODCALL CPPObjectMethodCall = (CPPOBJECTMETHODCALL)GetProcAddress(hDLL, "CPPObjectMethodCall");

    int x = SimpleFunction(1, 2);

    CPPClass * cppObject = new CPPClass();

    // Pass pointer to C++ object
    CPPObjectMethodCall(cppObject);

    delete cppObject;

    FreeLibrary(hDLL);
}