Re: [boost] [MPL.Math] ratio

Subject: Re: [boost] [MPL.Math] ratio
From: Beman Dawes (bdawes_at_[hidden])
Date: 2008-11-13 15:55:27

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.

--Beman