Re: Dropping C++03 support (again)

From: Boris Kolpackov (boris_at_[hidden])
Date: 2023-02-06 09:37:10

Peter Dimov via Boost <boost_at_[hidden]> writes:

> I have a novel idea, let's drop C++03 support.

I think it's a great idea.

I would also be in favor of bumping the major version to 2 and
potentially dropping unmaintained/obsolete libraries though I
also appreciate that this is a more drastic change that may
sink the whole idea.

Also, one benefit of 2.0.0 that I believe was not mentioned is
outside perception. If it's 1.83.0 then I don't think it will
be easy to convince the wider audience that it's anything other
than the "same old" Boost even if there are drastic changes like
dropping of unmaintained/obsolete libraries or better modularity.
(And if anyone here wonders, the perception in the wider audience
is not very good, at least IME).

> Boost release 1.83.0 is announced to require C++11
> at minimum. This means compilers that have all the
> C++11 standard headers, and support all the C++11
> syntactic constructs and keywords without issuing
> errors. (E.g. VS2013 doesn't qualify because it doesn't
> support the `constexpr` or `noexcept` keywords.)

IME, this is an unreliable criterion. For example, based on this
MSVC 14.3 (VS2015) would be a fair game but in practice its
constexpr support is so buggy/incomplete that it's pretty much
unusable.

I believe a better approach would be to name the minimum supported
versions for the main three C++ compilers (GCC, Clang, and MSVC)
which then determines the practically usable set of C++ features.