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

Subject: Re: [boost] [review][mp11] Formal review of Mp11
From: Peter Dimov (lists_at_[hidden])
Date: 2017-07-17 09:50:30

Brook Milligan wrote:
> >> - mp_is_map: type trait to determine whether a type is a map, i.e., has 
> >> a unique set of keys
> >
> > This is mp_is_set<mp_map_keys<M>>, although not quite if M has an 
> > element that is not a list.
>
> Yes, that was also my implementation.  I just punted on the question of 
> whether or not mp_map_keys would always work.  Given that it might not, 
> this could be motivation for a more robust implementation in the library.

This also raises the question of what mp_is_set should do when passed 
something that is not a list - return false or cause a substitution failure 
(which in turn hints at the lack of mp_is_list as well).

Thank you for you suggestions. They make sense and I'll probably add them.