C++ 77 之 异常的多态

#include <iostream>
#include <string>
using namespace std;

// 异常基类
class BaseException{
public:
    virtual void printError() = 0; // 纯虚函数
};

// 空指针的异常
class NullPointerException : public BaseException{
public:
    virtual void printError(){
        cout << "空指针异常" << endl;
    }
};

// 地址越界异常
class OutOfRangeException : public BaseException{
public:
    virtual void printError(){
        cout << "地址越界异常" << endl;
    }
};

void doThrow(){
    throw NullPointerException();
}


int main()
{
    try{
        doThrow();
    }
    // 父类的指针或引用指向子类对象
    // BaseException &e = NullPointerException();
    catch(BaseException &e){ 
        e.printError();
    }
    return 0;
}