Re: [boost] [ratio][mpl] static metafunctions

Subject: Re: [boost] [ratio][mpl] static metafunctions
From: vicente.botet (vicente.botet_at_[hidden])
Date: 2011-01-01 15:27:57

----- Original Message ----- 
From: "Aleksey Gurtovoy" <agurtovoy_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Friday, December 31, 2010 7:06 AM
Subject: Re: [boost] [ratio][mpl] static metafunctions

> On Thu, 30 Dec 2010 15:52:58 -0600, Dave Abrahams <dave_at_[hidden]>  
> wrote:
> 
>> At Thu, 30 Dec 2010 22:45:12 +0100,
>> vicente.botet wrote:
>>>
>>> [1  <text/plain; iso-8859-1 (quoted-printable)>]
>>> Hi,
>>>
>>> during the Boost.Ratio review as requested to push some of the static  
>>> integer metafunctions as static_abs, static_sign, static_gcd,  
>>> static_lcm to a public library.
>>>
>>> At the begining I has the impression that these functions should be  
>>> added to Boost.Integer or Boost.Math, but after reflexion I think that  
>>> these static metafunctions could be better integrated into Boost.MPL  
>>> with the existing integral functions. I have prepared a patch for 3 of  
>>> them.
>>>
>>> Do you think that these can be added to Boost.MPL if I provide the  
>>> needed documentation and tests?
>>>
>>
>> Looks good to me.  Aleksey?
> 
> I'd drop BOOST_MPL_CFG_MSVC_ETI_BUG workarounds since they are only  
> relevant for MSVC < 7.1, otherwise yes, I will be happy to accept this  
> (with tests and docs :).

I have added the modified files on https://svn.boost.org/svn/boost/sandbox/chrono/boost/mpl/ and  https://svn.boost.org/svn/boost/sandbox/chrono/libs/mpl/

I've found useful to add the associated _c meta-functions, so we can request for gcd_c<int, 10, 6, 4> instead of gcd<int_<10>,int_<6>, int_<4>>. Let me know if you agree with this addition and if it is good to add them in the same file.

For the moment I have documented variadic metafunctions for gcd and lcm, but I have not yet take the time to understand how the variadic part is done for other arithmetic operations and if I can use it. I'm sure some of the maintainers could make the needed modifications quite quikly. If this is not the case I will change the documentation until I get the variadic implementation.
Best,

Vicente