Re: [boost] Interest in dimension/unit-checking library?

From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2005-12-19 22:54:31

"Andy Little" <andy_at_[hidden]> wrote

> Hi Arkadiy,
>
> "Arkadiy Vertleyb"  wrote
> > Hi Andy,
> > If every library author uses his/her own typeof emulation mechanism, not
> > only the effort will be repeated every time, but also types composed
from
> > different libraries, such as liba::x<libb::y>, would not be handled...
> >
> > Or did I misinterpret your statement?  Maybe you implied that you will
use
> > typeof for your library interface, while avoiding it in the
implementation?
>
> I guess it was misleading. I am currently wrapping Typeof in a class
template
>
> template <typename Lhs, typename Op, typename Rhs>
> struct binary_operation;
>
> template <typename Lhs,typename Rhs>
> struct binary_operation<Lhs, plus, Rhs>
> // arithmetic types but allowing customisation
> where  is_value_type<Lhs> && is_value_type<Rhs>
> {
>     typedef BOOST_TYPEOF_TPL( Lhs() + Rhs()) type;
> };
>
> Now its also possible to use typeof or not as I please via a macro. (It
might be
> useful to find the difference in cvompile times anyawy) Note that its not
> actually required to use typeof in my own definitions, IOW the interface,
but
> other libraries can use typeof  and will work Ok with  my library ( types
are
> registered).
>
> template <typename Lhs, typename Rhs>
> where is_quantity<Lhs> && is_quantity<Rhs>
> typename binary_operation<Lhs,plus,Rhs>::type
> operator +( Lhs const & lhs, Rhs const & rhs);
>
>
> IOW its not really an interface versus implementation thing really.  Does
that
> make any sense?

OK, it does.

Regards,
Arkadiy