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Subject: Re: [boost] boost.test regression or behavior change (was Re: Boost.lockfree)
From: Gennadiy Rozental (rogeeff_at_[hidden])
Date: 2015-10-05 15:53:16

Bjorn Reese <breese <at>> writes:

> On 10/04/2015 12:18 PM, Gennadiy Rozental wrote:
> > Sooner rather than later we should have this discussion and setup
> > IMO it had very little sense to continue to maintain c++03 workarounds.
> > Boost code should be an example how modern c++ libraries should look
> > And c++03 compatibility is directly in a way of this goal.
> You appear to have missed the many discussions on this topic.

Can you please give me some references?
> While Boost started out to design cutting-edge libraries, it has been
> caught by its own success. Today there is a large user-base that still
> uses C++03, and that are unlikely to upgrade in the foreseeable future.

1. Without data backing this fact, this statement as good as "Most of our
users already moved to c++11". If we measure by the compilers used by our
test runners, 80% of them are running c++11 enabled compilers.

2. Those who are not ready to upgrade to new version of the compiler, are
very likely not going to upgrade to new version of boost, so this
discussion is irrelevant for them.

> Therefore, the current consensus is that existing libraries should not
> increase their standards requirements. New libraries are free to decide
> their standards requirements (although it will probably be questioned
> during a formal review.)

1. There also libraries which are actively maintained and extended and
those which are not.

2. If new libraries have c++11 requirement, what is the reason for anyone
restricted to c++03 to upgrade to new version of boost?

3. In general, what is the formal criteria for changing the decision? At
which point we'll be ready to say: no - we do not test against c++03
anymore? The presence of at least one c++03 test runner can't be a

Realistically your concern only applies to users, restricted to c++03, who
found an issue in old release (let's say 1.55) in specific library I am pretty sure (I was in similar position few years ago) they
would be much more happy with patch release for specific library or at the
very least a patch release to boost 1.55. instead of requiring them to
upgrade to 1.6x, which brings who knows how many changes.

I wish we have some formal regulations for this decisions, instead of some
hand waving. Our personal backgrounds can't play into this.


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