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[stl_interfaces] Ok to merge small fix to C++20-mode builds before release?
by Zach Laine 09 Jul '20

09 Jul '20

I have just committed a fix to develop that addresses compilation errors in C++20 builds. Is it too late to merge this to master? The change is here: https://github.com/boostorg/stl_interfaces/commit/6d31433af0b7cb8c7f9140ce4… Zach

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[Boost][Outcome] Compile error?
by Emil Dotchevski 07 Jul '20

07 Jul '20

When exceptions are disabled, I get: In file included from ../../../../boost/outcome/result.hpp:34: In file included from ../../../../boost/outcome/boost_result.hpp:36: In file included from ../../../../boost/exception_ptr.hpp:9: In file included from ../../../../boost/exception/detail/exception_ptr.hpp:17: ../../../../boost/exception/detail/clone_current_exception.hpp:22:6: error: This header requires exception handling to be enabled. Is there a way to configure Outcome so it does not use (boost) exception_ptr?

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[random] pull requests stacking up
by Jeff Garland 06 Jul '20

06 Jul '20

Just submitted a pull request for boost.random to remove dependence on system library. There's 17 open requests -- some of which are pretty easy maintenance items. Can someone give these some a look?

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Boost.Beast state of play
by Richard Hodges 06 Jul '20

06 Jul '20

Dear all, As you know, Boost.Beast has a strong dependency on Boost.Asio. At the present time, Chris is working to finalise some significant changes to Asio. These changes have required some refactoring of Boost.Beast at short notice in order to continue to provide a functioning library. Boost.Asio has two significant customisation macros: BOOST_ASIO_NO_DEPRECATED and BOOST_ASIO_NO_TS_EXECTORS. The 1.74 release of Asio deprecates some classes and interfaces relevant to net.ts-style executors. In addition, it introduces execution-style executors. *There is no combination of the above flags (save for none of them) that will allow an unmodified dependent library or program to compile as of boost.asio 1.74.* As of this moment, Beast is correctly compiling all examples and passing all tests with the exception of tests relevant to c++20 coroutines, where the latest Asio commit on develop branch has one (it would appear) remaining bug. Chris has been contacted and we are awaiting a fix. Once I have this, I will be in a position to rebase Beast PR1999 onto develop/master in readiness for the 1.74. Thank you for bearing with me during my time as an unwilling hostage to fortune. -- Richard Hodges hodges.r(a)gmail.com office: +442032898513 home: +376841522 mobile: +376380212

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Fixed Boost.CallableTraits is_invocable_v
by Barrett Adair 03 Jul '20

03 Jul '20

It was recently brought to my attention that the variable template version of boost::callable_traits::is_invocable was always broken. A fix has been merged to match the non-variable version of the trait. I This is a minor change. Can this be included in 1.74? https://github.com/boostorg/callable_traits/commit/6da8b5a9b8b439f8e751191a…

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[thread] Release critical bug (optimized away hooks)
by Nikita Kniazev 02 Jul '20

02 Jul '20

I am informing release managers that there is a severe bug in Boost.Thread that will affect static library users built with MSVC in the next release. The bug report: https://github.com/boostorg/thread/issues/316 (TLDR: thread_specific_ptr data destructor is not called in non-Boost.Thread threads) I have opened a PR that fixes the issue https://github.com/boostorg/thread/pull/320, but got no response in weeks.

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How good to use dynamic_bitset?
by Jupiter 02 Jul '20

02 Jul '20

Hi, I am working on an embedded system where I read hardware 32-bit register values represented variables in bits. Currently I am using bit shift to extract values, it is too vague to represent variables. I have been thinking to make overhaul of using dynamic bitset, is it a good idea or bad idea? Thank you. Kind regards, jupiter -- "A man can fail many times, but he isn't a failure until he begins to blame somebody else." -- John Burroughs

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Boost, not LEWG
by Glen Fernandes 01 Jul '20

01 Jul '20

(A new subject, since the thread has evolved past the Text review result). I spend part of my time in the C++ standards committee. I spend part of my time in Boost. I would prefer that my time spent in Boost, and that Boost itself, be focused on its goals of serving the C++ community and Boost users (existing ones, and growing to new ones). If there is benefit of Boost to any other entity, be it the LEWG of the committee, or some organization, that's great. i.e. When Boost is adopted by some organization, or when Boost components go into the standard, that's just a bonus. But Boost itself shouldn't compromise on quality - in its review process or what it ships in a Boost distribution, to serve any of those other interests. Putting a bunch of experimental libraries into a Boost release just because people have proposed them for standardization is not something we should do. If someone wants to, they can should just start their own project full of libraries that have not undergone any kind of formal review, and convince OS distributions to start including that as part of their packages based on its own merits. In case there was any misunderstanding on this point: Zach's goals of standardization are his own, and in Boost we don't have to be concerned with them. Because we're not changing the review process because of them, and he's not asking us to. Glen

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[containers] Addition of a dense map implementation
by Jeremy Junac 29 Jun '20

29 Jun '20

Hi, While working on different projects in which performance is key, I came to realize that the efficiency of the associative containers that are available in the STL can be improved. For instance, it is well know that neither std::unordered_map nor std::map are cache-friendly. It isn't that hard to find implementations that are faster, for instance flat_map, already in Boost.Containers. However, I would be interested in another implementation, a "Dense Map", similar to the one we can find in SparseHash (https://github.com/sparsehash/sparsehash) or in LLVM's ADT (https://llvm.org/doxygen/DenseMap_8h.html) For sure I am not the only one attracted to such implementation, as we can find several ones in the internet, although, it really lacks of "one true generic implementation". SparseHash doesn't seem that maintained anymore and, well, LLVM is LLVM. Hence, instead of having yet another implementation of my own, I would rather have one in Boost, to ensure long-term maintainability. I know that this particular subject was kind of already discussed in this thread from 2016 (https://lists.boost.org/Archives/boost//2016/01/227076.php) and some very good points were made. But in the end, years have passed, and we still don't have an alternative, so in my opinion an implementation in Boost would actually be something to consider. Please let me know what you think about that. I am open to any other ideas, and in case we agree on the addition of a new implementation, I would actually be pleased to contribute. Best regards, Jeremy Junac

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Re: [boost] Boost, not LEWG
by pbristow＠hetp.u-net.com 29 Jun '20

29 Jun '20

> -----Original Message----- > From: Boost <boost-bounces(a)lists.boost.org> On Behalf Of Vinnie Falco via Boost > Sent: 29 June 2020 06:40 > To: boost(a)lists.boost.org List <boost(a)lists.boost.org> > Cc: Vinnie Falco <vinnie.falco(a)gmail.com> > Subject: Re: [boost] [OT] Re: Boost, not LEWG > > On Sun, Jun 28, 2020 at 10:22 PM Schrom, Brian T via Boost <boost(a)lists.boost.org> wrote: > > My suggestion is.... > > Yeah mailing lists are nice for the monotonically decreasing set of older engineers used to the > anachronism but they are not in any way shape or form attractive for bringing in new, young blood. As one no longer in the first flush of youth (and I suspect a target of this barb 😉 ), I'm not sure that this is the most important issue. We seem to have shifted to CVS, SVN and now GIT and GitHub a little ahead of the curve (and I note that GitHub gives you an email interface as well as a web one). I suspect that 'If it ain't broke, don't fix it." applies to the mailing list/forum issue. I think that the key problem with reviews in finding people who are knowledgeable enough to make useful comments. Often users are best-informed we can get. Too many reviews are theoretical analyses, not based on any 'real-life' use that would expose strengths and weaknesses. There has long been a chicken and egg issue, you don't get many users until a library is in Boost, and so you don't get much informed feedback. I still favor some sort of 'Candidate' status, formalizing the current 'Acceptance subject to changes' status, but giving wider visibility on the Boost GitHub site. Boost has spawned several standards, but also provided many libraries that are entirely unsuitable for standardization. I hope this will continue. Paul Bristow PS I have always been impressed by the overwhelmingly politeness of interchanges on Boost and WG21 etc, in contrast to the internet in general. I believe that Boost is also entirely gender and color-blind.

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