Re: [boost] [chrono] type_traits/common_type and integer/ratio

Subject: Re: [boost] [chrono] type_traits/common_type and integer/ratio
From: vicente.botet (vicente.botet_at_[hidden])
Date: 2009-12-06 13:05:31

----- Original Message ----- 
From: "joel falcou" <joel.falcou_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Sunday, December 06, 2009 10:57 AM
Subject: Re: [boost] [chrono] type_traits/common_type and integer/ratio

> 
> joel falcou wrote:
>> could be nice if they used mpl::integral_c so it can be used easily as 
>> MPL meta-functions
> forgot the code obv. :
> 
> namespace mpl
> {
>  template<class X> struct abs : integral_c< typename X::value_type, (X 
> < 0 ? -X : X)> {};
> }
> 
> etc
> 
> -- 

Hi Joel,

even if 

  template <boost::intmax_t X>
  struct static_abs
  {
      static const boost::intmax_t value = X < 0 ? -X : X;
  };

don't use mpl::integral_c, it is a valid mpl metafunction. I don't think it is worth adding a dependency to Boost.MPL.

Best,
Vicente