设计模式，简单工厂模式，为了去switch，类申明前后两难问题

[oN5GrzoN]

原文C#
我用C++写的

class Employee
{
protected:
	double m_basicSalary;
public:
	Employee(double base = 1800):m_basicSalary(base)
	{

	}
	virtual double PayAmount() const = 0;
	static Employee* CreateEmployee(EmployeeType et)
	{
		switch(et)
		{
		case  ENGINEER:
			return new Engineer();
		case SALESMAN:
			return new SalesMan();
		default:
			throw "no such employee type!";
		}
	}
};
class Engineer : public Employee
{
public:
	double PayAmount() const
	{
		return m_basicSalary;
	}
};
class SalesMan : public Employee
{
	double m_commission;
public:
	SalesMan(double commission = 1000):m_commission(commission)
	{

	}
	double PayAmount() const
	{
		return m_basicSalary+m_commission;
	}
};

编译的时候Employee类里用到了new Engineer()，engineer现在在后边，所以编译通过不了
如果使用前置申明，把class Engineer申明到Employee之前，说Engineer没有合适的构造函数。

如果把class Employee放到class Engineer，也不可能。
怎么做呢？

[IranCyberArmy]

CreateEmployee需要放在EmployeeFactory类里