Yukihiro Matsumoto wrote:

> Hi,
> 
> In message "Re: #collect with block modifying receiver"
>     on 03/08/29, Hal Fulton <hal9000 / hypermetrics.com> writes:
> 
> |OK, so this *really* makes me wonder what the "theoretically correct"
> |behavior is.
> 
> |Matz, are you listening?? Enlighten us, please...
> 
> Ah, listen, it's undefined behavior. ;-)
> 
> To be serious, I don't want to slow down performance by defining any
> exact behavior.  Don't modify the receiver while you are iterating
> over it.

I have to assert my support of this position; modifying a receiver while 
in a block would be VERY tedious to anticipate, and would be an endless 
source for wonderful new bugs, if the defined behavior were to allow it.

	Sean O'Dell