[boost] [hana] some notes, not a review

Subject: [boost] [hana] some notes, not a review
From: Phil Endecott (spam_from_boost_dev_at_[hidden])
Date: 2015-06-18 10:50:24

Dear All,

I have just a couple of notes about Hana; this does not
constitute a review:

Firstly, as I understand it Hana believes that it can replace
much or all of what Fusion and MPL provide with a superior
alternative.  If that is the case, I suggest that the docs
should not start out by describing Hana with reference to
those libraries.  At present, it would seem that in order to
understand what Hana can do for me, I need to first learn at
least a little about those other libraries - and then the
Hana docs tell me how it compares to them.  This might not
be a bad thing in the context of docs for this review, but
for "end user" documentation it should stand alone.

Secondly, we're moving towards a future where a lot of what
previously required TMP can now be done using "regular" C++
code qualified with constexpr.  I've just replaced a fair
chunk of my crufty old TMP code with constexpr and it is
like a breath of fresh air.  Against that background, it
might be worthwhile to structure your examples by showing
what Hana (and TMP in general, perhaps) can do that
constexpr cannot do, i.e. start with an example using
constexpr and extend it to add features not possible with
constexpr.

Regards,  Phil.