Re: [boost] [MPL.Math] ratio

14 Nov 2008

      --- On Fri, 11/14/08, Cromwell Enage wrote:
...
Sections: 20.4.1 [Class template ratio], 20.4.2 [Arithmetic
on ratio types]
Also 20.4.3 [Comparison of ratio types]

[snip rest of report]
...
We should also require that each of the arithmetic
metafunctions inherit from std::ratio if we want to allow
the following usage (note the change from R::type::num to
R::num).
template <typename R>
    struct absolute_ratio
      : boost::mpl::eval_if<
            R::num < 0
          , boost::mpl::negate<R>
          , R
        >
    {
    };
For the sake of completeness, if the arithmetic metafunctions are to inherit from std::ratio, so should the comparison metafunctions.

Cheers,
Cromwell D. Enage