YYYH

// Inside file A.h
#pragma once

#define NAMESPACE_NAME            TruYobaEngine
#define NS_BEGIN                namespace NAMESPACE_NAME {
#define NS_END                  }
#define NS_USING                using namespace NAMESPACE_NAME;

typedef long MY_LONG;
typdef MY_LONG MY_RESULT;

// Inside file B.h
#pragma once

#include "A.h"

NS_BEGIN

class IInterface
{
public:
    virtual MY_RESULT methodOne() = 0; // <= error: "MY_RESULT"
};

NS_END;

// end