|
|
Boost : |
From: Ullrich Koethe (koethe_at_[hidden])
Date: 2001-03-29 12:09:59
Jeremy Siek wrote:
>
> I agree, we certainly do need result type traits, however I think the
> requirements on the result type produced should remain what I've stated,
> convertible to X and models ...
>
I don't see why the result traits shouldn't be part of the algebraic
concept definitions. After all, you always need them together.
> To allow for expression templates, the result type will not only
> depend on the operands but also on the operator. Therefore we
> need a tag for each operator.
>
> struct add_tag { };
> struct multiply_tag { };
> ...
>
> and then make the operator tag a parameter to the traits class
>
> result_traits<OpTag,A,B>::type
>
Can you give examples where this would be necessary? I've contemplated
this in my application domain, but it looked like an
over-generalization.
Ulli
-- ________________________________________________________________ | | | Ullrich Koethe Universität Hamburg / University of Hamburg | | FB Informatik / Dept. of Computer Science | | AB Kognitive Systeme / Cognitive Systems Group | | | | Phone: +49 (0)40 42883-2573 Vogt-Koelln-Str. 30 | | Fax: +49 (0)40 42883-2572 D - 22527 Hamburg | | Email: u.koethe_at_[hidden] Germany | | koethe_at_[hidden] | | WWW: http://kogs-www.informatik.uni-hamburg.de/~koethe/ | |________________________________________________________________|
Boost list run by bdawes at acm.org, gregod at cs.rpi.edu, cpdaniel at pacbell.net, john at johnmaddock.co.uk