On Thu, 6 Jul 2000, Yukihiro Matsumoto wrote:

> In message "[ruby-talk:03825] Re: Array.uniq! returning nil"
>     on 00/07/05, "NAKAMURA, Hiroshi" <nahi / keynauts.com> writes:
	[...] 
> |Aleksi, how do you think 'String#gsub?'.  Seeing 'String#gsub?',
> |how do people think?
> 
> I don't vote for them, if they actually substitute strings.
> Predicates should not have any side effect.
> 
> 							matz.

I read this as suggesting test before substituting, but I'm not
sure if you would gain much over

    if astring.sub(this, that) != astring
        ....

	Hugh