Re: [Boost-users] boost.proto optimization on MSVC (2005/2008)

From: AJD (n.outpost_at_[hidden])
Date: 2007-12-08 13:23:48

"Eric Niebler" <eric_at_[hidden]> wrote in message 
news:<475A0ED4.1010307_at_[hidden]>...
> template< typename T, typename U = proto::is_proto_expr >
> struct vector2;
>
> template< typename T >
> struct vector2<T[3]>
> {
>      BOOST_PROTO_EXTENDS(typename proto::terminal<T[3]>::type,
> vector2<T[3]>, VectorDomain)
>
>      typedef T value_type;
>
>      T & operator [](std::size_t i)
>      {
>          return proto::arg(*this)[i];
>      }
>
>      T const & operator [](std::size_t i) const
>      {
>          return proto::arg(*this)[i];
>      }
> };
>
> // Tell proto that in the VectorDomain, all
> // expressions should be wrapped in vector_expr<>
> struct VectorDomain
>    : proto::domain<
>          proto::pod_generator< vector_expr >
>        , VectorGrammar
>      >
> {
> };

Thanks, this works great. The only problem is that vector<> is intended as a 
wrapper class, and I just implemented it as an array for convenience in this 
example. It could have any underlying type, not necessarily an array. Is 
there a proper way to do this without exposing vector<>'s underlying type?