Hi myself,

further testing revealed that delegation works (singleton methods didn't):

-----------------8<---------------------------
$ cat meta.rb
require 'pp'
require 'set'

require 'delegate'
class MyStr < SimpleDelegator
     attr_accessor :src
end

def test_delegation

     set = Set.new
     set.add('foo')
     s = MyStr.new('bar')
     s.src = 'source'
     set.add(s)

     set.each { |e|
         if e.respond_to?(:src)
             pp e.src
         end
     }
end

test_delegation
-----------------8<---------------------------
$ ruby meta.rb
"source"
-----------------8<---------------------------

It didn't worked in my "App" so I initially didn't care about writing a 
smaller test -> was I wrong.

I'll dig further, thank you (Brian, not me) :)

- Markus