Re: [boost] Compile-time power of a run-time base

From: Bruno Lalande (bruno.lalande_at_[hidden])
Date: 2008-02-05 04:17:00

>
> * The result type is not necessarily going to be the same as the arguments
>   so it would need to use Boost.Typeof or some such.

Yep, I had already thought about this improvement.

>
> * Rational exponents need to work, so I would need a way to specialize
>   the function to work with boost::units::static_rational.  I would expect
>   the customization mechanism to look something like this:
>
> struct default_value_tag;
>
> template<class T>
> struct pow_value_tag {
>    typedef default_value_tag tag;
> };
>
> template<class Exp>
> struct pow_exponent_tag {
>    typedef typename Exp::tag type;
> };
>
> template<class ValueTag, class ExponentTag>
> struct pow_impl;
>
> template<class Value, class Exponent>
> struct pow {
>    typedef typename pow_impl<
>        typename pow_value_tag<Value>::type,
>        typename pow_exponent_tag<Exponent>::type
>    >::template apply<Value, Exponent> impl;
>    typedef typename impl::type type;
>    static type call(const Value& v) {
>        return(impl::call(v));
>    }
> };
>

OK I will consider this need and find a way to satisfy it.

I'm going to write a first version of tests and docs with the implementation
we have for now, and then I'll add those additional functionalities.

Thanks
Bruno