Re: [boost] [metal] Feature Complete - Request for Feedback

Subject: Re: [boost] [metal] Feature Complete - Request for Feedback
From: Peter Dimov (lists_at_[hidden])
Date: 2017-02-21 15:32:43

Klemens Morgenstern wrote:
> Am 21.02.2017 um 14:11 schrieb Bruno Dutra via Boost:
>
> > This is by the way another advantage of Metal, since all of its types 
> > are precisely defined and friendly to pattern matching.
>
> I think that's your main selling point. Afaik Hana also relys on concepts 
> more than on actual types; i.e. the result types are not completely 
> specified.

This is a false dilemma; it's possible to take 'concepts' and return 
completely specified types.

There are other legitimate reasons to prefer strictness in the arguments 
though - SFINAE friendliness is one. And there are reasons to prefer 
concept-ness. Such as for instance

    mp_transform<std::add_const_t, std::shared_ptr<X>> // std::shared_ptr<X 
const>