C++反射类和成员函数的实现

来源：互联网发布：全国高校名单数据库编辑：程序博客网时间：2024/06/08 12:03

原文地址：http://blog.wangziliang.com/2012/12/28/c%E5%8F%8D%E5%B0%84%E5%87%BD%E6%95%B0%E5%92%8C%E7%B1%BB%E7%9A%84%E5%AE%9E%E7%8E%B0/

C++反射类和成员函数的实现，需要用到STL标准模板库

//定义反射工厂类以及基类NSObject#ifndef __NS_OBJECT_FACTORYE_H__#define __NS_OBJECT_FACTORYE_H__ #include <map>#include <string>  typedef void* (*SEL)(void);typedef SEL (*callFuc)(void); class NSObject{public:    Base(){};    ~Base(){};}; struct NSObjectFactory {     typedef std::map<std::string, NSObject*(*)()> map_type;    typedef std::map<std::string, callFuc> fuc_map_type; private:     static map_type * m_map;    static fuc_map_type * fuc_map; protected: public:     static NSObject * createInstance(std::string const& s){        map_type::iterator it = getMap()->find(s);        if(it == getMap()->end())            return 0;        return it->second();    }      static SEL callFaction(std::string const& s) {        fuc_map_type::iterator it = getFunctionMap()->find(s);        if(it == getFunctionMap()->end())            return 0;        return it->second();      }     static map_type * getMap(){        // never delete'ed. (exist until program termination)        // because we can't guarantee correct destruction order         if(!m_map) { m_map = new map_type; }         return m_map;    }     static fuc_map_type* getFunctionMap() {          if(!fuc_map) { fuc_map = new fuc_map_type(); }           return fuc_map;       }     }; NSObjectFactory::map_type * NSObjectFactory::m_map = 0; NSObjectFactory::fuc_map_type * NSObjectFactory::fuc_map = 0; template<typename T> NSObject * createT() { return (NSObject *)(new T); }  template<typename T>struct NSObjectRegister : NSObjectFactory {     NSObjectRegister(std::string const& s) {         getMap()->insert(std::make_pair(s, &createT<T>));    }}; #define REFECTION_CLASS_IMPLEMENT_DEFINE(NAME) \    virtual string toString(){return #NAME;}; \    static NSObjectRegister<NAME> registerNSObject #define REFECTION_CLASS_IMPLEMENT(NAME) \    NSObjectRegister<NAME> NAME::registerNSObject(#NAME) #define NSClassFromString(NAME) \    NSObjectFactory::createInstance(NAME) struct FuctionRegister : NSObjectFactory {     FuctionRegister(std::string const& s, callFuc f) {         getFunctionMap()->insert(std::make_pair(s, f));    }  };  #define REFECTION_FUNCTION_IMPLEMENT(NAME) \    static FuctionRegister* f_reg_##NAME = new FuctionRegister(#NAME, (callFuc)NAME) #define NSSelectorFromString(NAME) \    NSObjectFactory::callFaction(NAME) #endif // __NS_OBJECT_FACTORYE_H__

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//示例封装成员函数反射方法定义一个base类#define __EJ_GET_POINTER_TO(NAME) \    SEL _ptr_to_##NAME() { \        return (SEL)NAME; \    } \    REFECTION_FUNCTION_IMPLEMENT(_ptr_to_##NAME); #define EJ_BIND_FUNCTION_DEFINE(NAME, ARGC_NAME, ARGV_NAME) \    int _func_##NAME(size_t ARGC_NAME, const char* ARGV_NAME) #define EJ_BIND_FUNCTION(CLASS, NAME, ARGC_NAME, ARGV_NAME) \    \    static int _##CLASS##_func_##NAME( \        Base* object, \        size_t argc, \        const char argv[] \    ) { \        CLASS* instance = (CLASS*)object; \        int ret = instance->_func_##NAME(argc, argv); \        return ret; \    } \    __EJ_GET_POINTER_TO(_##CLASS##_func_##NAME)\    \    /* The actual implementation for this method */ \    int CLASS::_func_##NAME(size_t ARGC_NAME, const char* ARGV_NAME) class Base: public NSObject {public:    Base();    ~Base();    REFECTION_CLASS_IMPLEMENT_DEFINE(Base);//反射类申明     EJ_BIND_FUNCTION(EJBindingEjectaCore,include, argc, argv )//反射成员函数申明}; REFECTION_CLASS_IMPLEMENT(Base);//反射类实现 //反射成员函数类申明EJ_BIND_FUNCTION(EJBindingEjectaCore,include, argc, argv ) {    if( argc < 1 ) { return -1; }    return 1;}

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//使用方法typedef int (*CALL_BACK)( Base* object,  size_t argc,  const char argv[] ); int main(){      NSObject* object = NSClassFromString("Base");//获得反射对象    SEL callback = NSSelectorFromString("_ptr_to__Base_func_include");//获得函数指针    ((CALL_BACK)callback)((Base*)object, 0, NULL);//调用静态函数使其调用object对象的成员函数    return 0;  }

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