Re: [boost] About all these metaprogramming libraries

Subject: Re: [boost] About all these metaprogramming libraries
From: Paul Fultz II (pfultz2_at_[hidden])
Date: 2017-03-19 20:07:27

> On Mar 18, 2017, at 7:02 PM, Peter Dimov via Boost <boost_at_[hidden]> wrote:
> 
> Paul Fultz II wrote:
> 
>> It would be nice to see better collaboration between authors to build an unifying metaprogramming library, rather than competing against each other. Of course, this can be somewhat difficult as they have different fundamental concepts.
> 
> As I see it, it's the fundamental concepts competing against each other, and that's how it should be; how else we'll find out which approach is best? 

Well brigand and mpl11 seem very similar conceptually. There is a conceptual difference with Metal where everything is explicit. However, I don’t think we have to choose between a implicit and explicit API. Rather a library could provide both APIs, much like Boost.PP provides an API for both explicit and implicit(ie deduced) re-entrance. 

Furthermore, the simple API of mpl11 very likely could be implemented using Metal underneath. Perhaps instead of providing two different libraries we provide one library with metal::explicit_ and metal::implicit where the implicit API could follow mpl11 very closely(if thats what seems to be the best approach to the implicit part considering other APIs).

Paul