c++ - 使用 protected 析构函数删除对象

Question

我对 C++ 内存管理还很陌生。我读了Should every class have a virtual destructor?并找到了这个答案:

Every abstract class should either have a

• protected destructor or
• virtual destructor

If you've got a public non-virtual destructor, that's no good, since it allows users to delete through that pointer a derived object. Since as we all know, that's undefined behavior.

For a class not intended to delete through a pointer to it, there is no reason whatsoever to have a virtual destructor. It would not only waste resources, but more importantly it would give users a wrong hint. Just think about what crappy sense it would make to give std::iterator a virtual destructor.

所以我现在有一个 protected 析构函数(我不是从类派生的)。

虽然我有一个指向这个对象的指针，但在另一个类中。在我的构造函数中，我为指针提供了该类的"new"对象，在我的析构函数中，我想销毁它。

我该怎么做？如果析构函数不 protected ，我会遇到段错误(我不完全理解，但我意识到无论如何都是糟糕的编程)。如果析构函数受到保护，我不知道如何删除该对象。

Answer 1

您在上面的 block 中遗漏了术语“抽象”。 “抽象”意味着您不应该/拥有/该类的对象。如果你有一个类的对象，它几乎应该总是有一个公共(public)析构函数。