Re: [boost] [optional] rebinding references

From: Joel de Guzman (joel_at_[hidden])
Date: 2005-10-18 13:34:53

Fernando Cacciola wrote:
> Rob Stewart wrote:
> 
>>From: "Fernando Cacciola" <fernando_cacciola_at_[hidden]>
>>
>>>I wonder what would be the result of the following thought
>>>experiment: Please, answer the questions _without_ looking at the
>>>answers, and if possible post your initial results; then compare
>>>with the answers.
>>
>>IANAOU either (yet!), but I'll give my answers.
>>
>>First, I'll describe what I think the right behavior is; this may
>>be exactly how optional works now or it may not be.  I haven't
>>compared this description to optional's documentation.
>>
> 
> OK. You just described Joel's proposed behaviour, and, from your test 
> results, it's clear that at least you wouldn't be confused about the fact 
> that in one case it binds while in the other it doesn't.
> Now I wonder how would that be in real code... I mean, in my example you 
> could infer from the context that 'o' was null in one of the cases... but 
> what if you can't tell that? you wouldn't be able from context alone to know 
> the expected effect of assignment. That's real problem don't you agree?

For the record, that is not exactly my proposed behaviour.
I am objecting to *any* form of bind/rebind *from assignment*.
Maybe that was not clear (as I noticed from Peter Dimov's
reply) but what I am advocating is bind only at construction
time (see my reply to Peter Dimov).

Anyway, I like the new direction this is heading into (i.e.
no assigment from T and the reset(), reset(nil), reset(T)
syntax).

Regards,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net