Yes, but that would be an "inside out object" with or without the closure. Using an "inside out object" isn't preventing direct access, using the closure is. A small, but non-trivial difference.

To-may-to. To-mah-to. Personally I think it is a trivial distinction.

Any use of lexically scoped hashes by classes implemented using inside out objects create closures - whether block or file scoped. So it's not using a closure that's making the difference, it's using a particular lexical scope for the attribute hash.

The point is that classes implemented in an inside-out style allow you to scope object attributes at a finer level of detail than the whole class. Something that the traditional approach of sticking the attributes in a blessed hash does not.