非议MFC（一）宏和类型定义的困惑

关键字：C++,MFC,宏,macro,define,typedef

有感于MFC库代码之去简就繁、之故弄玄虚，作下文，聊博一笑。

请看一段常见的代码：

//in user.h
class CTest
{
private:
        int x;
public:
        void SetX(int setX);
        int GetX() const;
        operator int *();
        operator const int *() const;
        void * GetSafeHandle() const;
};

//in user.cpp
#include "user.h"
void CTest::SetX(int setX)
{
        x=setX;
}
//...

我们（MFC的作者）认为这样的代码太浅显，不够深沉，缺少内涵，没有嚼劲。赶快include我们的头文件吧，它可以提高代码的整体形象。我们的口号是：让蓝色关键字在屏幕上消失。

//in minimfc.h
#define USER_CLASS class
#define BEGIN_CLASS_DECLARATION {
#define END_CLASS_DECLARATION };
#define PRIVATE_MEMBER private:
#define PROTECTED_MEMBER protected:
#define PUBLIC_MEMBER public:
#define OPERATOR_OVERLOAD operator
#define CONSTANT_MEMBER_FUNTION const
#define BEGIN_FUNCTION_DEFINITION {
#define END_FUNCTION_DEFINITION }
typedef void AFX_RETURN_VOID_FUNCTION;
typedef int INT;
typedef int * LPINT;
typedef const int * LPCINT;
typedef void * HOBJ;

看！我们做到了。从此，我们的客户代码将这样写：

//in user.h
#include "minimfc.h"
USER_CLASS CTest
BEGIN_CLASS_DECLARATION
PRIVATE_MEMBER
        INT x;
PUBLIC_MEMBER
        AFX_RETURN_VOID_FUNCTION SetX(INT setX);
        INT GetX() CONSTANT_MEMBER_FUNTION;
        OPERATOR_OVERLOAD LPINT();
        OPERATOR_OVERLOAD LPCINT() CONSTANT_MEMBER_FUNTION;
        HOBJ GetSafeHandle() CONSTANT_MEMBER_FUNTION;
END_CLASS_DECLARATION

//in user.cpp
#include "user.h"
AFX_RETURN_VOID_FUNCTION CTest::SetX(INT setX)
BEGIN_FUNCTION_DEFINITION
        x=setX;
END_FUNCTION_DEFINITION
//...