Why does this even compile? (Circular self-initialisation).

After doing some "Find & Replace" in some code I was working on I wound up with code like this:

```vb
Public Class TestClass
Private ReadOnly SomeFoo As SomeOtherClass = Me.SomeFoo
End Class
```

Strangely enough, that code compiles without a problem and when you try to access the `SomeFoo` field at run-time you get a null reference exception. It's a little hard to spot at first, but the problem is `SomeFoo` is being initialised to the value of `SomeFoo`. **It is being initialised with its own value** which makes no sense logically because it is circular.

The compiler already rejects other circular scenarios such as a class inheriting from itself:


...so is there any reason why circular initialisation of a field is allowed (or even useful)?