简单工厂模式

把实例化对象的过程放在工厂类中

code

#include <string>
#include <memory>

class Opearation
{
public:
	virtual double getResult(double numA, double numB) = 0;
	virtual ~Opearation() = default; // 虚析构函数，避免内存泄漏
private:
};

class Add : public Opearation
{
public:
	double getResult(double numA, double numB) override
	{
		return numA + numB;
	}
private:
};
class Sub : public Opearation
{
public:
	double getResult(double numA, double numB) override
	{
		return numA - numB;
	}
private:
};
class Mul : public Opearation
{

public:
	double getResult(double numA, double numB) override
	{
		return numA * numB;
	}
private:
};
class Div : public Opearation
{
public:
	double getResult(double numA, double numB) override
	{
		return numA / numB;
	}
private:
};

// 定义枚举类型来表示操作符
enum class OperationType
{
	Add,
	Sub,
	Mul,
	Div,
	Invalid // 无效操作
};

class OperationSimpleFactory
{
public:
	static std::shared_ptr<Opearation> createOperate(const OperationType& operate)
	{
		switch (operate)
		{
		case OperationType::Add:
		{
			return std::make_shared<Add>();
		}
		case OperationType::Sub:
		{
			return std::make_shared<Sub>();
		}
		case OperationType::Mul:
		{
			return std::make_shared<Mul>();
		}
		case OperationType::Div:
		{
			return std::make_shared<Div>();
		}
		}
	}
};

#include <iostream>
#include "SimpleFactory.h"

using namespace std;

double cal(std::shared_ptr<Opearation> baseOpearate)
{
	return baseOpearate->getResult(10, 2);
}

int main()
{
	cout << cal(OperationSimpleFactory::createOperate(OperationType::Add)) << endl;
	cout << cal(OperationSimpleFactory::createOperate(OperationType::Sub)) << endl;
	cout << cal(OperationSimpleFactory::createOperate(OperationType::Mul)) << endl;
	cout << cal(OperationSimpleFactory::createOperate(OperationType::Div)) << endl;
	return 0;
}