在C ++中的联合中“受保护”的意义是什么 [英] What is the point of 'protected' in a union in C++

问题描述

有什么可以使用受保护的成员或函数吗？

Is there anything that protected members or functions can be used for?

您不能继承一个联合，所以没有孩子可以访问它。

You cannot inherit from a union so there are no children that can access it. Does it provide a functional use or is just there because removing it was hassle?

推荐答案

protected 在联合中完全等同于 private ，但此容限没有任何损害， union 和 struct / 之间的额外差异 （在标准中一起描述）。

protected in a union becomes completely equivalent to private, but this allowance does no harm and avoids extra special case handling and extra differences between union and struct/class (which are described all together in the standard).

老实说，我认为可以使用 protected union 只是为了将第十五个特殊情况添加到标准中来;也许它没有想到标准委员会来区分这种行为，因为它是一个奇怪的角落情况，但没有伤害，因为它目前的规定。

Honestly, I think it's possible to use protected in a union just not to add the umteenth special case to the standard for the sake of it; maybe it didn't even come to mind to the standard committee to differentiate this behavior, since it's quite a bizarre corner case but does no harm as it's currently specified.

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