title: What is the use of the 'protected' keyword inside a union?
body: <p>I checked that the <code>protected</code> access specifier can be used inside <code>class</code>, <code>struct</code> as well as <code>union</code>. I know that the <code>protected</code> access specifier means that members will be private, but visible to derived class. I am not able to think of a reasonable use case where the <code>protected</code> keyword inside a union would be useful, because a union can't be part of an inheritance hierarchy. Since in a union <code>private</code> and <code>protected</code> would make no difference, why allow <code>protected</code> inside unions too?</p>