Re: [boost] Yap's formal review is starting now!

Subject: Re: [boost] Yap's formal review is starting now!
From: Zach Laine (whatwasthataddress_at_[hidden])
Date: 2018-02-17 01:16:14

On Fri, Feb 16, 2018 at 6:27 PM, Peter Dimov via Boost <
boost_at_[hidden]> wrote:

> Zach Laine wrote:
>
> If someone else wants to navigate MSVC's limitations and submit patches,
>> I'll switch over to std::tuple in the interface, and maintain that work.
>>
>
> There's the option of stating everything in terms of boost::yap::tuple
> instead, which today would be an alias to hana::tuple. It's questionable
> exactly how much this will help users in the event of moving to std::tuple,
> but it might be possible for at least some user code to not need changes.
>

That's reasonable, but I think in the current state of things I'd like the
user to know as soon as possible that Hana is in play.  If std::tuple is
the tuple of choice, I'd probably want the user to know that up-front as
well.

> On a completely unrelated note, have you considered the use case in which
> an expression supports two separate modes of evaluation? yap::evaluate
> doesn't take a "mode" parameter, and the way it's specified makes it hard
> to extend it with one.

More than that, it's effectively impossible.  The idiomatic way to
accomplish the same end is to transform() your expression differently for
each case, instead of evaluating it differently.

Zach