ublas-bounces@lists.boost.org wrote on 11/07/2005 05:22:50 PM:
> > #include <limits>
> > #include <boost/call_traits.hpp>
>
> Your email got me thinking.  I certainly dislike the ublas type_traits, and
> using a boost/call_traits would be nice. Sadly the norms are always a
> sticking point. We need some way to define these.

> I think there is a logical reason to include abs etc, but not
> because they are
> 'needed'. I think the logic goes as follows:
>   We need a definition of the norms. There is no generic solution tothis, it
> requires some type specific information. We therefore have a traits class.
> Since we must have this class, we can provide and interface so the user can
> specify specific implementations for all higher functions.
>
> Interestingly for interval types there is the definition
>         real_type abs (const_reference t) {
>             return boost::numeric::abs (t);
>         }
>
> to make sure the abs of the interval is used.

Function templates would naturally solve this issue and stop you having to duplicate calls.  In this way, the compiler is doing all the hard work.  
A traits class should not have any member functions which do actual work.

Kind regards,
Andrew

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