>> I haven't tested these changes exhaustively, but it passes the 
>> "rubytest".
>> I am not sure of the procedure for further testing. I hope I haven't
>> broken anything!
>
>  make install
>  make test
>  make test-all
>
> It seems to break rdoc and several tests.
Thanks for this, I'll check it out over the weekend. Perhaps I ran the tests 
wrongly and accidentally picked up the old ruby binary or something.

I also wanted to say that the patch is *not* a silver bullet which suddenly 
makes Ruby's string handling much faster. In fact it probably will only have 
a noticible effect if you are processing long strings. One of the apps that 
I use Ruby for handles quite a bit of TAB separated UTF-8 strings (mainly 
ascii, but not necessarilly), which does run faster with this patch. the 
"count_words" benchmark is an extreme example.

Mike