Problem B: 一切皆对象

Description

一切都是对象 —— Everything is an object。 所以，现在定义一个类Thing，来描述世界上所有有名字的事物。该类只有构造函数、拷贝构造函数和析构函数，并具有一个字符串数据成员来存储其名字。

Input

输入只有1行，是一个没有空白符的字符串。

Output

见样例。

Sample Input

NAME

Sample Output

A thing without name is created! A thing without name is copied! A thing named by NAME is created! A thing named by NAME is copied! A thing named by NAME is erased! A thing named by NAME is erased! A thing without name is erased! A thing without name is erased!

HINT

Append Code

append.cc,

int main()

{

    string name;

    Thing Thing1, Thing2(Thing1);

    cin>>name;

    Thing Thing3(name);

    Thing Thing4(Thing3);

    return 0;

}

代码

#include<iostream>

#include<string>

using namespace std;

class Thing

{

    string s;

public:

    Thing (string t = "without name"):s(t)

    {

 

        if(s=="without name")

        cout <<"A thing without name is created!"<<endl;

        else

            cout<<"A thing named by "<<s<<" is created!"<<endl;

    }

    Thing(const Thing&p)

    {

        s = p.s;

        if(s=="without name")

        cout <<"A thing without name is copied!"<<endl;

        else

            cout<<"A thing named by "<<s<<" is copied!"<<endl;

 

    }

    ~Thing ()

    {

        if(s=="without name")

        cout <<"A thing without name is erased!"<<endl;

        else

            cout<<"A thing named by "<<s<<" is erased!"<<endl;

    }

};

int main()

{

    string name;

    Thing Thing1, Thing2(Thing1);

    cin>>name;

    Thing Thing3(name);

    Thing Thing4(Thing3);

    return 0;

}