Re: [boost] [MPL.Math] ratio

Subject: Re: [boost] [MPL.Math] ratio
From: Howard Hinnant (hinnant_at_[hidden])
Date: 2008-11-13 15:58:20

On Nov 13, 2008, at 3:55 PM, Beman Dawes wrote:

> On Thu, Nov 13, 2008 at 3:18 PM, Cromwell Enage <sponage_at_[hidden]>  
> wrote:
>> --- On Thu, 11/13/08, Beman Dawes <bdawes_at_[hidden]> wrote:
>>> The latest WP is N2798. See
>>> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf
>>
>> Got it.
>>
>>>> I just noticed section 20.3, called "compile-time rational
>>>> arithmetic", and I'm wondering how stable that specification is.
>>>
>>> 20.3 in N2798 is very stable, since except for the diff markup it is
>>> the same as the Committee Draft that is currently being reviewed by
>>> national bodies, and there are no outstanding issues in the LWG  
>>> active
>>> issues list.
>>
>> Hmmm.  I see that the ratio class template is neither required nor  
>> implemented as a nullary metafunction, as std::integral_constant  
>> is.  (There is no "typedef ratio<N,D> type;" statement.)  Is there  
>> any particular reason?  I ask because this may cause problems if I  
>> try to have the ratio interact with other MPL metafunctions.
>
> Howard would have to comment on that; I've pinged him to make him
> aware of this thread.
>
> The Boost implementation can add extensions, and we can submit a
> comment on the CD. If it is as simple as a typedef, it stands a good
> chance of being accepted. If you write it up, with a proposed
> resolution, I'll submit it.

My only comment so far is that these look like good suggestions.  A  
defect report should show a motivating code sample for best chances.

-Howard