From: Lars Westergren <lars.westergren@...>
Date: 2007-07-25T20:47:52+09:00
Subject: Re: Detecting singletons

Robert Dober skrev:
> On 7/25/07, Robert Dober <robert.dober@gmail.com> wrote:
> Did I do something stupid?
Oh, good, so it wasn't just me then.
:)

It doesn't seem to work for me either. I get false, and then the
exception anyway.

I think that test only works if the class in question used the Singleton
module mixin, I believe the problematic class probably uses some form of
  sing = class << self; self end
magic.

I tried looking at the code for marshalling, but alas, it was C, and
therefore not much help to me...

if (FL_TEST(klass, FL_SINGLETON)) {
        if (check && RCLASS(klass)->m_tbl->num_entries ||
            (RCLASS(klass)->iv_tbl && RCLASS(klass)->iv_tbl->num_entries
> 1)) {
            rb_raise(rb_eTypeError, "singleton can't be dumped");
        }



Thanks,
Lars