Re: [boost] Re: [MPL] Compile-time math metafunctions.

From: Aleksey Gurtovoy (agurtovoy_at_[hidden])
Date: 2004-05-17 21:18:35

Alexander Nasonov writes:
> David Abrahams wrote:
> 
> > is an illegal program (try comeau online to see some reasons why).
> > 
> > Also, it's not very mpl-ish.  Nothing seems to follow the
> > metafunction protocol of operating on and returning types.
> > 
> > I hate to be discouraging; it's probably a really interesting idea.  I
> > am only looking as far as some details of the implementation, here.
> 
> What happened to fixed_c? 

Nothing; the stub is still there, waiting for somebody to implement it in 
full.

> It's used here
> http://www.boost.org/libs/mpl/doc/paper/html/codegeneration.html
> in a form mpl::fixed_c<9,0001> (he-he).
                           ^^^^

This one is actually kind of nasty -- ignoring the fact that 0001 is an 
octal constant, there is no way you can detect the number of leading zeros
here, which renders this particular representation unusable. I guess we 
can go with something like

    float_<0,90001,e<+1> >

or something along these lines.

> Any plans to redesign it and to put into MPL?

Well, somebody who needs it needs to tackle it. It would be a welcome 
contribution.

--
Aleksey Gurtovoy
MetaCommunications Engineering