Re: [eigen] Re: meeting in February?

[Benoit Jacob <jacob.benoit.1@xxxxxxxxx>]

2010/1/11 Hauke Heibel <hauke.heibel@xxxxxxxxxxxxxx>:
> On Mon, Jan 11, 2010 at 7:42 PM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
> wrote:
>>
>> 2010/1/11 Hauke Heibel <hauke.heibel@xxxxxxxxxxxxxx>:
>>
>> > The point c) ... well, it's related to a) and b). Unifying the access to
>> > class properties (traits) has the chance of improving readability and
>> > navigability.
>>
>> The biggest purpose of ei_traits<...> is forward-declarations.
>> Actually, at some point, I named it ForwardDecl<...>. The idea is that
>> with our CRTPs, when we want to access Derived::SomeTypedef from
>> MatrixBase<Derived>, we can't, because Derived isn't fully declared at
>> that point, so we put SomeTypedef instead in ei_traits<Derived>. Does
>> that help? Should ei_traits be renamed?
>
> It wasn't primarily about the understanding. I think the naming ei_traits is
> perfect. I was wondering about things as this here (found e.g. in
> ProductBase)
>
>   typedef typename Lhs::Nested LhsNested;
>   typedef typename ei_cleantype<LhsNested>::type _LhsNested;
>   ...
>
> Sometimes, expression helpers are used explicitly and sometimes they are
> just indirectly. For the sake of clarity I would have preferred something
> like
>
>   typedef typename ei_nested<Lhs>::type LhsNested;
>   typedef typename ei_cleantype<LhsNested>::type _LhsNested;
>   ...
>
> Here, I know right away where to look for the type behind LhsNested. For the
> other case, I first have to browse to the file corresponding to the 'Lhs'
> type, then I have to search for the 'Nested' typedef, which might be again
> redirecting to another class. Since I am lacking the possibility to create
> the pre-compiled code with MSVC, it would just allow me faster navigation..

Ah OK, I understand your point. On the other hand, Lhs::Nested looks
nicer than ei_nested<Lhs>::type, which I think is the reason why we
tended to use that notation, although as you note this is
non-uniform... yes, that can be discussed at the meeting!

Benoit