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Subject: Re: [boost] [GSoC, MPL11] Community probe
From: Gonzalo Brito Gadeschi (g.brito_at_[hidden])
Date: 2014-04-23 07:45:38

I have a question: the proposal and library are called MPL11.

In my experience, relaxed constexpr allows for beautiful metaprogramming
with respect to C++11, in particular when combined with Boost.Fusion, and I
think that it is really a game changer with respect to C++11 constexpr,
since it allows not only "functional" metaprogramming but also "imperative"
metaprogramming, significantly lowering the learning curve of
metaprogramming for C++ programmers.

Have you consider the influence of relaxed constexpr (C++14) in your

Could it simplify the design/implementation/usage of the MPL?

Would a rewrite of MPL11 be necessary afterwards (MPL14)?

On Wed, Apr 23, 2014 at 11:51 AM, Niall Douglas

> On 22 Apr 2014 at 23:33, Vicente J. Botet Escriba wrote:
> > I'm not concerned with MPL-backward compatibility or the learning curve
> > for users coming from MPL. You have an opportunity to build a new TMP
> > library, the work will be long and hard, but adding more constraints
> > than needed wouldn't help. TMP should be a basic library and other
> > inter-operable libraries must be build on top of it.
> >
> > Of course, the new TMP should perform better and be easier to learn than
> > MPL. This must be possible as C++14 provides more features and so you
> > will be able to choose the ones that go towards this goal.
> >
> > What I would like is something that can be proposed to the C++ standard.
> > A little bit more of TMP in the standard would be much better than much
> > more in Boost but outside the C++ standard.
> +1 on Vicente's opinion. I see no problem with your current plan
> Louis, and besides everyone here is a backseat driver and doesn't
> really have the domain experience that you do. I'd present on the
> options you've discovered so far at C++ Now as you're already doing,
> and listen to Joel's opinion, he's very experienced on the topic, and
> I'm sure he'll make sure you go the right way.
> Maybe this time next year once you have the TMP14 engine in place and
> well tested, then would be the time to think about MPL98
> compatibility and all that jazz as a second GSoC. Between now and
> then you'll need to decide on Concepts, sadly Andrew won't be at C++
> Now this year as he's the right person to talk to, but I may try to
> very poorly fill Andrew's place and talk to you myself after your
> talk.
> Niall
> --
> Currently unemployed and looking for work in Ireland.
> Work Portfolio:
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Dipl.-Ing. Gonzalo Brito Gadeschi
Institute of Aerodynamics and Chair of Fluid Mechanics
RWTH Aachen University
Wuellnerstraße 5a
D-52062 Aachen
Phone: ++49-(0)241-80-94821
Fax: ++49-(0)241-80-92257
E-mail:  g.brito_at_[hidden]

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