Vincent Fourmond wrote:
>   No: is_a? also returns true when the @my_obj is an instance of a
> subclass of Klass.
>
>   
I realize that, but that's beyond the scope of the issue I'm having.
That's why my original post explicitly said to ignore the superclass and
module stuff it does (twice).
>   If you do
>
> ri is_a?
>
>   on command-line, you'll get immediate answer.
>
> 	
Nope, all I get is the exact same API stuff I've already looked at
before asking, and quoted in my original post.

To clarify, I'm interested in *how*, not *if*,  is_a? determines whether
@my_obj.is_a?(Klass) with no concern for superclasses or modules.  I'm
fairly confident it's going to take somebody familiar with Ruby's source
code, not just the API, to answer this one.