Simple exported callback from a DLL

Exports.cpp

#include <iostream>

#define LIBAPI __declspec(dllexport)
#define LIBSTDCALL __stdcall

struct SimpleStruct
{
	SimpleStruct() : Value(0) {}

	operator int ()
	{
		return Value;
	}

	int Value;
};

typedef SimpleStruct ReturnType;

typedef ReturnType (LIBSTDCALL *MyCallback)(int, int);

static MyCallback g_MyCallback = nullptr;

extern "C"
{

LIBAPI void LIBSTDCALL InstallCallback(MyCallback callback)
{
	g_MyCallback = callback;
}

LIBAPI void LIBSTDCALL FireCallback(int x, int y)
{
	if (g_MyCallback)
	{
		ReturnType retVal = g_MyCallback(x, y);

		SimpleStruct* simple = (SimpleStruct*)&retVal;
		std::cout << *simple << std::endl;
	}
}

};