Re: [Boost-users] [mpl] compile time integer power

From: Sami (randomaccessiterator_at_[hidden])
Date: 2007-01-22 18:30:52

Hi Tony,

Thx for your reply first of all.

On 1/22/07, Gottlob Frege <gottlobfrege_at_[hidden]> wrote:
>
>
>
> On 1/22/07, Sami <randomaccessiterator_at_[hidden]> wrote:
> >
> > Hi All,
> >
> >     if (Pow == 0) return 1; // to do argue about the value of '0 to the
> > 0'.
> >     if (Pow == 1) return r;
> >     return pow<Pow - 1>(r) * r;
> >
>
>  }
> >
> >
> Now, why do you want it - I doubt that it will buy you anything in terms
> of performance.

The issue is not particularly about performance,  it is about being able to
do this at compile time; other than, well, trying out MPL. Your resolution
to the problem is quite nice, though that's not what I am asking. My
question is about MPL, not "how to do this with C++"...

There should be a way of doing this using MPL with a single line of code.
Or, even compute integer power of integers and get a compile time result.
This is useful for many metaprograms and again, not a performance concern.

Any ideas?