C ++ OOP仅授予对某些类的访问权限 [英] C++ OOP Only grant access to certain classes

问题描述

我想实现一个 Container 类，只能按照我想要的类访问，类似于下面的

I would like to implement a Containerclass that can only be accessed by the classes I want, in a way similar to the following

class ContainerAccess {
    // empty 
};

class Container{
  private:
    static void _do_stuff();
    static int _value;

    friend class ContainerAccess;
};

现在我想要访问 Container 数据如下：

Now I want to have access to the Container data as follows:

class Processor: public ContainerAccess {
  public:
    void proccess() {
      Container::_do_stuff();
      Container::_value++;
    }
};

但是，这不起作用。这是为什么？

However, this does not work. Why is that? And how could that be done?

推荐答案

你的做法是错误的，因为友谊不是继承的。但是，有一个很好的方法来解决你要解决的问题，这是私人继承。

Your approach is wrong as friendship is not inherited. However, there is a good way to solve what you are trying to solve and that's private inheritance.

class Container
{
  protected:
    static void _do_stuff();
    static int _value;
};


class ContainerAccess : private Container 
{
    //using _do_stuff();
};

这样你就可以选择任何需要使用的类 class Container 同时您也阻止其他用户使用您的课程。

This way you can chose whatever classes need to use class Container at the same time you also prevent other users from using your class.

这篇关于C ++ OOP仅授予对某些类的访问权限的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！