Re: [boost] [review][mp11] Formal review of Mp11

Subject: Re: [boost] [review][mp11] Formal review of Mp11
From: Joaquin M López Muñoz (joaquinlopezmunoz_at_[hidden])
Date: 2017-07-17 08:17:09

El 17/07/2017 a las 1:24, Peter Dimov via Boost escribió:
> Joaquin M López Muñoz wrote:
>
>> 1.7 mp_eval[_xx] functions should accept metafunctions in both their 
>> true and
>> false branches.
>
> I can't make this work. [...]

This is most unfortunate. My original concern remains though that there's no
reason why one of the two branches of mp_eval_if should not accept a 
metafunction
(and note the irony that mp_eval_if<B,...> precisely does not eval when 
B holds). If
syntax can't be made to work, it could be advisable to drop mp_eval_if
altogether and provide for instance mp_apply_if:

   mp_apply_if<B,F,mp_list<T...>,G,mp_list<U...>>

Joaquín M López Muñoz