c++ factory

factory.h

#ifndef FACTORY_H
#define FACTORY_H
#include "operate.h"
//    virtual double operate(double, double) = 0;
class Factory
{
public:
    virtual void Create(void) = 0;
protected:
    Operate *op;
private:
};
class AddFactory: public Factory
{
public:
    void create(void )
    {
        op = new AddOperate;
    }

private:

};
class SubFactory: public Factory
{
public:

    Operate* create(void )
    {
        op = new SubOperate;
    }

    private:

};



#endif

　　operate.h

#ifndef OPERATE_H
#define OPERATE_H

class Operate
{
public:
    virtual double operate(double, double) = 0;

private:
    double m_num1;
    double m_num2;

};

class AddOperate: public Operate
{
    double operate(double a, double b)
    {
        return a+b;
    }
};

class SubOperate: public Operate
{
    double operate(double a, double b)
    {
        return a-b;
    }
};
#endif

　　main.cpp

#include <iostream>
#include "operate.h"
#include <string>
#include "factory.h"
int main()
{
    char s1;
    std::cout << "input" << std::endl;
    std::cin >> s1 ;
//    Operate *oper ;//= new AddOperate;
//    Factory *fact = new AddFactory;

    Operate *oper = new AddOperate; 
    switch(s1)
    {
    case '+' :
    //    Factory *fact = new AddFactory;
        break;
    case '-':
//        Factory fact = new SubFactory;
        break;
    default :
//        Factory fact = new AddFactory;
        break;
    }

/*
    Operate *oper = fact.Create();
    std::cout << oper->operate(2,3) << std::endl;
*/    return 0;
}