Re: [boost] [optional] Safe optional

Subject: Re: [boost] [optional] Safe optional
From: Gottlob Frege (gottlobfrege_at_[hidden])
Date: 2014-11-24 13:03:21

On Wed, Nov 19, 2014 at 2:42 PM, Andrey Semashev
<andrey.semashev_at_[hidden]> wrote:
> On Wed, Nov 19, 2014 at 10:02 PM, Nevin Liber <nevin_at_[hidden]> wrote:
>> On 19 November 2014 02:37, Andrzej Krzemienski <akrzemi1_at_[hidden]> wrote:
>>
>>> We would have people
>>> experiment with an alternative and decide which they find better, and they
>>> could deliver their opinion to the Standardization committee.
>>>
>>
>> This can be taken to mean that you, the proposer of optional for the
>> standard (and hence a domain expert), do not believe the design space has
>> been sufficiently explored and the committee might be better off waiting
>> and not putting std::experimental::optional into C++17.
>
> I think you're taking it too negatively. It's very good that Andrzej
> is open to new ideas, especially since he's behind std::optional
> proposal. Exploring new approaches doesn't mean that the current
> optional is not well designed or not useful.
>

The thing with optional is that it is the first in a series of
"wrapper" types: optional, expected, variant, any, clone_ptr, ...

It would be wonderful to get it as "right" as the container +
algorithm approach of STL.

If it was just optional, I wouldn't care so much.  But it is a much
bigger class of, uh, classes.

So, yes, someone, particularly a proposer, saying "maybe this is a
better way", is a good thing, but does exactly say the design space
has not been sufficiently explored.

Stepanov had years, and a number of tries (with a number of languages)
to get STL right.

Tony