136.异常的多态,父类对象,传递子类的引用或指针(地址)

#include <iostream>
using namespace std;

//纯虚类
class error
{
public:
    //纯虚函数
    virtual void showerror() = 0;
};

class big :public error
{
public:
    void showerror()
    {
        cout << "big error" << endl;
    }
    
};

class small :public error
{
public:
    void showerror()
    {
        cout << "small error" << endl;
    }

};

class zero :public error
{
public:
    void showerror()
    {
        cout << "zero error" << endl;
    }

};

//抛出一个引用对象
class print3d
{
public:
    print3d(double size)
    {
        if (size == 0)
        {
            throw &zero();
        }
        else if (size > 1000)
        {
            throw &big();
        }
        else if (size < 1)
        {
            throw &small();
        }
    }
};

void main()
{
    try
    {
        print3d dg(0);
    }
    catch (error *p)
    {
        p->showerror();
    }
    cin.get();
}