大话设计模式学习之简单工厂模式

下面是简单工厂的那个例子的C++实现，参考了网上的一个Word文档，vs2005测试，留作备份

#include <iostream>
using namespace std;
//运算类
class COperation
{
public:
	int m_nFirst;
	int m_nSecond;
	virtual double GetResult()
	{
		double result=0;
		return result;
	}
};
//加法
class CAddOperation:public COperation
{
public:
	virtual double GetResult()
	{
		return m_nFirst+m_nSecond;
	}
};
//减法
class CSubOperation:public COperation
{
public:
	virtual double GetResult()
	{
		return m_nFirst-m_nSecond;
	}
};
//简单工厂类
class CCaculatorFactory
{
public:
	static COperation *Create(char cOperation);
};
//客户端
int main()
{
	int a,b;
	cin>>a>>b;
	COperation *op=CCaculatorFactory::Create('+');
	op->m_nFirst=a;
	op->m_nSecond=b;
	cout<<op->GetResult()<<endl;
	return 0;
}
//类的函数实现
COperation * CCaculatorFactory::Create( char cOperation )
{
	COperation *oper;
	switch(cOperation)
	{
	case '+':
		oper=new CAddOperation();
		break;
	case '-':
		oper=new CSubOperation();
		break;
	default:
		cout<<"没有合适的操作！程序终止"<<endl;
		exit(1);
		break;
	}
	return oper;
}