C++ 反射机制的简单实现

 #ifndef __CLASSFACTORY_

 #define __CLASSFACTORY_

 #include <iostream>

 #include<string>

 #include<map>

 //定义函数指针

 typedef void* (*create_fun)();

 class ClassFactory{

 public:

     ~ClassFactory() {}; 

     //根据类注册时的名字, 创建类实例, 并返回

     void* getClassByName(std::string name){

         std::map<std::string, create_fun>::iterator it = my_map.find(name);

         if (it == my_map.end()) { return NULL; }

         create_fun fun = it->second;

         if (!fun) { return NULL; }

         return fun();

     }   

     //注册类名称与指针函数到映射关系

     void registClass(std::string name, create_fun fun){

         my_map[name] = fun;

     }   

     //单例模式

     static ClassFactory& getInstance(){

         static ClassFactory fac;

         return fac;

     }   

 private:

     ClassFactory() {};  //私有

     std::map<std::string, create_fun> my_map;

 }; 

 #endif

 #ifndef __TEST_H

 #define __TEST_H

 #include <iostream>

 class Test{

 public:

     Test(){ std::cout << "call Test Constructor fun" << std::endl; }

     ~Test(){ std::cout << "call Test Destructor fun" << std::endl; }

     void print(){ std::cout << "call Test print fun" << std::endl; }

 };

 void* create_Test(){

     Test *t = new Test;

     return (t == NULL)? NULL:t;

 }

 #endif

 #include "test.h"

 #include "class_factory.h"

 int main(){

     //注册

     ClassFactory::getInstance().registClass("Test", create_Test);

     //获取类对象

     Test *t = (Test*)ClassFactory::getInstance().getClassByName("Test");

     if (!t){

         std::cout << "get instnce Test err;" << std::endl;

         return ;

     }   

     t->print();

     delete t;

     return ;

 }