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

Subject: Re: [boost] [review][mp11] Formal review of Mp11
From: Brook Milligan (brook_at_[hidden])
Date: 2017-07-17 00:32:33

Before I write a review, I have a couple of questions that are the outgrowth of having been using mp11 since some time after the first two articles of Peter’s.  That should suggest I generally like the library, which I do.

Nevertheless, in my code, I have found need for the following additional metafunctions:

- mp_map_keys: creates a list of keys from a map

- mp_is_map: type trait to determine whether a type is a map, i.e., has a unique set of keys

- mp_is_set: type trait to determine whether a type is a set, i.e., has unique elements

Is there a reason that support for such functions should not be in the library?

I have also found need for a metafunction that takes a map and a set of keys and returns a map with only elements with the selected keys.  This is perhaps more specialized, but I can also see a general use case.

I would appreciate your thoughts on these functions.

Thanks.

Cheers,
Brook