[boost] Re: Re: Adding Loki to Boost (reprise)

From: Fernando Cacciola (fcacciola_at_[hidden])
Date: 2002-04-10 18:00:10

"Andrei Alexandrescu" <andrewalex_at_[hidden]> wrote in message
news:a92dbh$e6i$1_at_main.gmane.org...
> [snip]
> > If I wouldn't have to code for a living, I wouldn't try to think in
> > non-functional terms while writing template metacode; but I can afford
> that
> > luxury, so in the meantime I need a tool that allows me to do my job in
> the
> > context of my non-functional experience. Even if it means making a hole
> with
> > a pencil :-)
> >
> > I agree that we need to start mastering more suitable ways to use the
> > template engine, but that's not the goal of a 'boost' library.
>
> It's funny. I thought practicality is an important argument in loki
> typelists' favor. Someone please paste loki length and mpl length (I don't
> have them handy). My point is that loki's typelists are much easier to
> explain, and much simpler for what it does.
>
> Gee, I really didn't mean to start a war here. Again, all I said wasn't
> meant personally. I'd love if I could take out my mpl example from my
> original message. It completely masked the gist of what I was trying to
say.
> Everybody now is talking only about it, and only one person actually
offered
> help about porting loki to boost.
>
I was refering to your comment about mpl as a whole (because you did make a
comment about mpl as a whole).

As for type lists, I agree with you that a pair-based, recursive type-list
is fundamental and a great addition to boost .
It is extremely easy to understand and to use for a lot of straight-forward
metaprogramming tasks.

I do think, however, that a pair-based type-list and its recursive nature
WILL fall short as soon as one get enthusiastic about metaprogramming, and
it is then when mpl would come to the rescue.

As Aleksey already stated, a pair-based recursive type-list can easily be
integrated into mpl, so that when the head fails to see how to use recursion
to achieve a given side-effect (well, a pseudo side-effect); I can turn to
mpl and pretend is C++.

So, I can't offer to help you because I don't have the time, but I would
like to see both a primitive Loki-style type-list and the mpl-style
type-list. I'm pretty sure both can coexist just as a 'goto' and 'while'
can.

(P.S: Do notice that you got back to the loki-mpl debate with the comment
from you that I quoted in my message. Since this is not your intention, make
sure you don't let the issue slip through again)

--
Fernando Cacciola
Sierra s.r.l.
fcacciola_at_[hidden]
www.gosierra.com