Re: deprecated: MPL, foreach, typeof, ratio, chrono, assign, more?

From: Vinnie Falco (vinnie.falco_at_[hidden])
Date: 2024-10-05 22:47:34

On Sat, Oct 5, 2024 at 2:43 PM Andrey Semashev via Boost <
boost_at_[hidden]> wrote:

> IMHO, a library either is part of Boost or isn't. There is no middle
> ground.
>

Well, that is true today but there is no rule that says it needs to be this
way forever. We managed to say "C++03 is no longer supported." Or something
similar to that. I'm sure Peter would be able to jump in and explain to me
why my statement regarding C++03 is wrong, yet Boost has moved on from C++
in some fashion and for the first time. Why can't we do the same for old
libraries?

std::move appeared in 2011, which was 13 years ago; for how long should we
keep Boost.Move?

> You could consider removing leaf libraries from Boost (i.e. those on
> which no other Boost libraries depend), so that at least a Boost release
> is working.
> ...
> But I don't think any of the libraries you mentioned
> qualify as leaf libraries, which makes their deprecation rather dubious.

Yes, and the concise proposal is:

1. Boost libraries which use the obsolete libraries are modified to no
longer use the obsolete libraries
2. An obsolete library which is no longer depended on by Boost libraries is
removed from the release
3. The obsolete library repository is still kept in the Boost GitHub
organization
4.  The guidance for users who need to continue using obsolete libraries
becomes "stay on an old release of Boost, or install the obsolete library
using a package manager or manually from the repository."

Thanks