#include<iostream>
class base
{
public:
virtual ~base(){std::cout << "base\n";}
};
class derived : public base
{
private:
~derived(){std::cout << "derived\n";} /* destructor is private */
};
int main()
{
base *pt= new derived;
delete pt;
}
上述程序编译并运行正常.
派生类析构函数如何被调用是私有的？
解决方法
这不仅会发生在析构函数中.
您可以使用私有功能覆盖任何虚拟公共功能.
#include<iostream>
class base
{
public:
virtual void x(){std::cout << "base\n";}
};
class derived : public base
{
private:
void x(){std::cout << "derived\n"; base::x();}
};
int main()
{
base *pt= new derived;
pt->x(); //OK
//((derived *)pt)->x(); //error: ‘virtual void derived::x()’ is private
derived *pt2= new derived;
//pt2->x(); //error: ‘virtual void derived::x()’ is private
((base *)pt2)->x(); //OK
}
这个上升/下降是你必须使用指针到基础来访问这个方法.
此功能是将公共API与自定义实现分离的方法之一.
所以,换句话说,你的析构函数被调用,因为它在基地被声明为public,你通过指向base的指针来调用它.