On 9/24/07, Tim Hunter <TimHunter / nc.rr.com> wrote:
> SpringFlowers AutumnMoon wrote:
> > Fixnum   object_id
> > 0            1
> > 1            3
> > 2            5
> >
> > -1          -1
> > -2          -3
> >
> >
> > so the question is...  which objects have the object_id 2, 4, 6, and -2,
> > -4, etc?
> >
>
> ex$ irb
> irb(main):001:0> x = true
> => true
> irb(main):002:0> x.object_id
> => 2
> irb(main):003:0> x = false
> => false
> irb(main):004:0> x.object_id
> => 0
> irb(main):005:0> x = nil
> => nil
> irb(main):006:0> x.object_id
> => 4
>
> In other words, very small even values of object_id are reserved for
> special values.

One should keep in mind that these are interesting implementation
artifacts.  I don't believe that there's any guarantee that such ids
would be the same in an arbitrary ruby implementation or even between
versions of the same implementation.

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/