Re: Future of C++ and Boost

From: James E. King III (jking_at_[hidden])
Date: 2022-05-06 13:57:42

On Fri, May 6, 2022 at 4:36 AM Niall Douglas via Boost
<boost_at_[hidden]> wrote:
>
>
> On 06/05/2022 09:10, John Maddock via Boost wrote:
>
> > Personally, there's little in C++14 that makes that move attractive for
> > me.  C++17 yes (for if constexpr).  There may be a few libraries which
> > could use the enhanced constexpr support in C++14, but otherwise I'm not
> > sure how much practical difference this makes.  On the other hand, C++14
> > is the current baseline for current compilers, so I have no objection to
> > making this the current Boost baseline as well!
>
> C++ 14 has a *lot* of bugfixes over C++ 11.
>
> These won't matter to you until they do, and when they do, they are most
> frustrating.
>
> I note that when GCC and clang changed their default C++ standard they
> jumped from 03 to 14. They did not choose 11 at any point. I find that
> revealing.
>
> Looking around at other compilers, the only one which ever stopped at 11
> as the default was hipcc.
>
> https://gist.github.com/ax3l/53db9fa8a4f4c21ecc5c4100c0d93c94
>
> 17 is also a fine default, which it is for GCC 11 onwards. Our work
> codebase was 17 right up until this week, when we expect to transition
> to 20 as the minimum. And I can then rip out lots of preprocessor
> macros, woohoo!
>
> Niall

It would still be useful to have a plan going forward, where Boost
as a whole follows a predictable pattern.  It sounds like people
would be more amenable to saying Boost will support the current
and previous two language levels at a given release.  In particular
this means those will be the language levels that are tested for
viability.  I was originally recommending 3, but it's possible there
is a consensus around 2.  That means today, C++20, 17, 14 would
be supported in whatever release adopted this strategy.  Do we
have an online tool for voting on proposals to assist?

- Jim