Re: Thoughts on Special Functions sinc_pi and sinhc_pi

From: Daryle Walker (darylew_at_[hidden])
Date: 2001-05-22 17:24:40

on 5/21/01 10:39 PM, Hubert HOLIN at Hubert.Holin_at_[hidden] wrote:

> paris (U.E.), le 21/05/2001
> 
> --- In boost_at_y..., Daryle Walker <darylew_at_m...> wrote:
>> on 5/19/01 10:28 PM, Hubert HOLIN at Hubert.Holin_at_B... wrote:
>> 
>>> Paris (U.E.), le 20/05/2001
>>> 
>>> --- In boost_at_y..., Daryle Walker <darylew_at_m...> wrote:
>>>> These are from the Special Function library currently under review.
>>>> 
>>>> First Issue: Template-based Template Parameters
[SNIP]
>> But how many other compilers will it work on?  I think that this library is
>> the first one with template-based template parameters, so we're going to
>> discover now how that feature's implementations turn out.
> 
> Be it as it may.
> 
>> Removing them and using custom versions also solves the more serious problem
>> below.
>> 
>>>> Second Issue: Too General?
>>>> 
>>>> These problematic versions are supposed to be shortcuts for defining
>>>> sinc_pi and sinhc_pi for complex, quaterions, octonions, and the like.
>>>> They assume that any kind of U<T> defines a numeric type with a vector-like
>>>> algebra of components T.  Some templates violate that, like
>>>> boost::rational.  I know that's not the kind of type you expect to use with
>>>> sinc_pi, but another numeric template may come along that defines a
>>>> floating type, but doesn't define a vector algebra.  That (hypothetical)
>>>> class would have to take the
> 
> Well, let them incarnate and then only see if there actually is a problem.
[TRUNCATE]

The review process should let us find and fix potential problems in advance
of them coming up.  We don't want to redesign this part (the only real
problem) of the package after someone else gets "screwed over" by it.

-- 
Daryle Walker
Mac, Internet, and Video Game Junkie
darylew AT mac DOT com