Why is internal protected not more restrictive than internal?

Question

I'd like to create an internal auto-property:

internal bool IP { get; protected internal set; } 

I thought it would be possible to make the setter protected or protected internal - but I always get the error accessibility modifier must be more restrictive than the property. Isn't that the case? Private does not help me, here.

EDIT:
The question is: How do I implement an auto-property with a internal getter and a protected setter?

Answer 1

It's effectively protected or internal, not and. It's accessible both by derived classes and types in the same assembly. It's a common misconception to think protected internal means accessible only to derived classes in the same assembly.

Answer 2

At the .NET level, there are two similar but distinct access levels:

• FamilyAndAssembly: more restrictive than either protected or internal
• FamilyOrAssembly: less restrictive than either protected or internal

"protected internal" in C# means FamilyOrAssembly; there's no modifier for FamilyAndAssembly.

So, your protected internal setter is less restrictive than the internal overall property. What you could do is:

protected internal bool IP { internal get; set; } 

But then your setter is less restricted than your getter, which is odd...

Another (somewhat equivalent) alternative is:

internal bool IP { get; set; }  protected void SetIP(bool ip) {     this.IP = ip; }