Re: [ublas] Proposed change: use BOOST_TYPEOF

Subject: Re: [ublas] Proposed change: use BOOST_TYPEOF
From: Gunter Winkler (guwi17_at_[hidden])
Date: 2009-10-09 14:05:44

Neal Becker schrieb:
> Since we have BOOST_TYPEOF, use it in type_traits.hpp:
>
>     template<class X, class Y>
>     struct promote_traits {
>         typedef type_deduction_detail::base_result_of<X, Y> base_type;
>         static typename base_type::x_type x;
>         static typename base_type::y_type y;
> //         static const std::size_t size = sizeof (
> //                 type_deduction_detail::test<
> //                     typename base_type::x_type
> //                   , typename base_type::y_type
> //                 >(x + y)     // Use x+y to stand of all the arithmetic 
> actions
> //             );
>
> //         static const std::size_t index = (size / sizeof (char)) - 1;
> //         typedef typename mpl::at_c<
> //             typename base_type::types, index>::type id;
>       //        typedef typename id::type promote_type;
>       //      typedef typeof (X() + Y()) promote_type;
>       typedef BOOST_TYPEOF (X() + Y()) promote_type;
>     };
>
>
>   
This sounds very useful. The provided return type deduction was only
introduced because BOOST_TYPEOF was not available at this time.

mfg
Gunter