Виртуальные деструкторы

#include <iostream>
using namespace std;
 
class first
{
public:
    first();
    virtual ~first(){delete pointer;}
    virtual void text(){cout<<"text"<<endl;}
    void text2(){cout<<"text2"<<endl;}  
};
 
class second:public first
{
public:
    second();
    virtual ~second(){delete pointer;}
    virtual void text(){cout<<"text"<<endl;}        
    void text2(){cout<<"text2"<<endl;}
};
 
int main()
{   first *pointer=new second;
    pointer->text();
    pointer->text2();
    system("pause");
}

virtual ~first(){delete pointer;}

///
delete pointer;
system("pause");
//

#include <iostream>
using namespace std;
 
class first
{
public:
    first(){cout<<"ConstrBase"<<endl;}
    virtual ~first(){cout<<"DestrBase"<<endl;}
    virtual void text(){cout<<"text"<<endl;}
    void text2(){cout<<"text2"<<endl;}  
};
 
class second:public first
{
public:
    second(){cout<<"ConstDeriv"<<endl;}
    virtual ~second(){cout<<"DestrDerive"<<endl;}
    virtual void text(){cout<<"text"<<endl;}        
    void text2(){cout<<"text2"<<endl;}
};
 
int main()
{   first *pointer=new second;
    pointer->text();
    pointer->text2();
    delete pointer;
    system("pause");
}