C preprocessor, MACRO必要之惡

// file macroAid.hpp

#ifndef MACRO_AID_HPP

#define MACRO_AID_HPP

#define MACRO_SETTER_DECL( type, VarName)\

int Set##VarName(type v);

#define MACRO_SETTER_IMPL( cls, type, VarName, var)\

int cls::Set##VarName(type v) {\

this->var = v;\

return 0;\

}

#define MACRO_GETTER_DECL(type, VarName)\

type Get##VarName();

#define MACRO_GETTER_IMPL( cls, type, VarName, var)\

type cls::Get##VarName() {\

return this->var ;\

}

#define MACRO_VARIABLE_ACCESS_DECL( type, VarName, var )\

private:\

type var;\

public:\

MACRO_GETTER_DECL(type,VarName);\

MACRO_SETTER_DECL(type,VarName);

#define MACRO_VARIABLE_ACCESS_IMPL( cls, type, VarName, var)\

MACRO_SETTER_IMPL(cls, type, VarName, var);

MACRO_GETTER_IMPL(cls, type, VarName, var);

#endif

// a.hpp

#include "macroAid.hpp"

#ifndef A_HPP

#define A_HPP

class A {

MACRO_VARIABLE_ACCESS_DECL(int, Size, size);

MACRO_VARIABLE_ACCESS_DECL(int, Age, age);

};

#endif

// aSetFunc.cpp

#include "a.hpp"

MACRO_VARIABLE_ACCESS_IMPL(A, int,Size, size);

MACRO_VARIABLE_ACCESS_IMPL(A, int,Age, age);

雖然 MACRO會讓程式碼不易讓程式碼分析器 例如：SOURCE INSIGHT 解析,

但它真的很方便可以減少打錯字的危機, 用簡單的幾行就可以完成原本複雜的工作