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From: Zhihao Yuan <lichray@gmail.com>
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Subject: Re: optional<T>, one more value or two states
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On Thu, Jan 24, 2013 at 7:38 AM, Ville Voutilainen
<ville.voutilainen@gmail.com> wrote:
> I have since cured that problem in my head, there's no 'danger' involved in
> it.

The danger already shows up.

Quoting from the proposal:

  "Such implicit conversions impose some risk of introducing bugs,
   and in fact in order to avoid one such possible bug we had to 'poison'
   comparisons between optional<T> and T."

And a carefully specified comparison logic is under discussion.

> boost::optional has such implicit conversions, and I see no reason
> to do it differently for std::optional.

This is convincible to some (or many) people, but not me.
Not all Boost practices are good.  They are not good just because
they exists for several years.

--
Zhihao Yuan, ID lichray
The best way to predict the future is to invent it.
___________________________________________________
4BSD -- http://4bsd.biz/

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