设计模式——简单工厂模式（C++实现）

#include <iostream>
#include <string>

using namespace std;


class COperator
{
public:
        virtual double GetResult()=0;

public:
        COperator()
        {
        }
        COperator(double number_a, double number_b): m_numberA(number_a), m_numberB(number_b)
        {
        }
        double m_numberA;
        double m_numberB;
};


class CSub: public COperator
{
public:
        CSub()
        {
        }
        CSub(double number_a, double number_b): COperator(number_a, number_b)
        {
        }
        virtual double GetResult();
};

double CSub::GetResult()
{
        return this->m_numberA - this->m_numberB;
}


class CAdd: public COperator
{
public:
        CAdd()
        {
        }
        CAdd(double number_a, double number_b): COperator(number_a, number_b)
        {
        }
        virtual double GetResult();
};

double CAdd::GetResult()
{
        return m_numberA + m_numberB;
}


class CFactory
{
public:
        static COperator* CreateOperation(char sOpeType);
};

COperator* CFactory::CreateOperation(char sOpeType)
{
        switch(sOpeType)
        {
                case '-':
                        return new CSub();
                        break;
                case '+':
                        return new CAdd();
                        break;
                default:
                        break;
        }
}


int main(void)
{
        COperator* oper = CFactory::CreateOperation('-');
        oper->m_numberA = 10;
        oper->m_numberB = 20;
        cout<< "oper->m_numberA: "<< oper->m_numberA<< endl;
        cout<< "oper->m_numberB: "<< oper->m_numberB<< endl;
        cout<< oper->GetResult()<< endl;

        return 0;
}
////////////////////////
[root]$ ./2_simple_factory
oper->m_numberA: 10
oper->m_numberB: 20
-10