On Sun, Oct 16, 2005 at 01:34:13PM +0900, Charles Mills wrote:
> On Oct 14, 2005, at 12:43 PM, Charles E. Thornton wrote:
> >>>Can someone provide a short fragment that induces this behavior  
> >>>(Shared!).
>
> substring:
> a = "ab"[1,1]

Not all substring #[] operations cause the underlying string to be shared (the
above doesn't).
Take a look at rb_str_substr.

-- 
Mauricio Fernandez