Access modifiers on properties; why doesn't the following work?

Question

I've run into a compiler error that doesn't quite make sense to me. I have an internal property and I want to restrict its set block such that it is only available through inheritance. I thought this would work:

internal bool MyProperty {
    get { return someValue; }
    protected internal set { someValue = value; }
}

But the compiler says that the access modifier on the set block needs to be more restrictive than internal - am I missing something, or is protected internal not more restrictive than internal?

Answer 1

protected internal is less restrictive; it is protected or internal (not and) - which therefore additionally allows subclasses from other assemblies to access it. You would need to invert:

protected internal bool MyProperty {
    get { return someValue; }
    internal set { someValue = value; }
}

This will allow code in your assembly, plus subclasses from other assemblies, get it (read) - but only code in your assembly can set it (write).