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[release] Deadline for MAJOR changes for boost 1.89.0 is tomorrow.
by Marshall Clow 01 Jul '25

01 Jul '25

The calendar is at: https://www.boost.org/calendar/ — Marshall

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[review] [sqlite]
by Richard Hodges 29 Jun '25

29 Jun '25

Dear All, Surprise! The Boost formal review of the Boost SQLITE library starts *TODAY*, taking place from November 13th, 2024 to November 22nd, 2024 (inclusive). I apologise profusely for springing this on you without prior warning. The error is entirely mine. I am extending the period by one day to compensate. The library is authored by Klemens Morgenstern (@klemens-morgenstern in the CppLang slack). Documentation: https://klemens.dev/sqlite/ <https://anarthal.github.io/mysql/index.html> Source: https://github.com/klemens-morgenstern/sqlite <https://github.com/anarthal/mysql/> >From the documentation: boost.sqlite is a simple to use C++ sqlite library. It provides a modern interface using facilities like error_code, views (e.g. for blobs) and the ability to use boost.describe or boost.pfr for parameterised queries. Supported features include: - typed queries - prepared statements - json support - custom functions (scalar, aggregate, windows) - event hooks - virtual tables SQLite provides an excellent C-API, so this library does not attempt to hide, but to augment it. Please provide in your review information you think is valuable to explain your choice to ACCEPT or REJECT including SQLITE as a Boost library. Please be explicit about your decision (ACCEPT or REJECT). Some other questions you might want to consider answering: - Will the library bring additional out-of-the-box utility to Boost? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - Will the choice of API abstraction model ease the development of software that must talk to a SQLITE database? - Are there any immediate improvements that could be made after acceptance, if acceptance should happen? - Did you try to use the library? With which compiler(s)? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? More information about the Boost Formal Review Process can be found at: http://www.boost.org/community/reviews.html The review is open to anyone who is prepared to put in the work of evaluating and reviewing the library. Prior experience in contributing to Boost reviews is not a requirement. Thank you for your efforts in the Boost community. They are very much appreciated. Richard Hodges - review manager of the proposed Boost.SQLITE library Klemens is often available on CppLang Slack and of course by email should you require any clarification not covered by the documentation, as am I.

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[bloom] Post-review changes
by Joaquin M López Muñoz 25 Jun '25

25 Jun '25

Hi, For those interested, I've just merged a branch incorporating most of the feedback received during the review of Boost.Bloom. Arnauld Becheler has once again been tremendously helpful with the process. More details here: https://github.com/boostorg/bloom/pull/32 https://github.com/boostorg/bloom/issues?q=is%3Aissue%20state%3Aclosed%20au… Revised documentation here: https://32.bloom.prtest3.cppalliance.org/libs/bloom/doc/html/index.html Boost.Bloom will be released with Boost 1.89. Thanks to all the people who have contributed to its improvement! Joaquin M Lopez Munoz PS. List of changes: * removed superfluous inline (Alexander Grund) * made hasher equivalence a precondition for &=/|= (Andrzej Krzemienski) * documented exception safety guarantees (Andrzej Krzemienski) * mentioned Bloom filters are called so after Burton H Bloom (Dmitry Arkhipov) * added warning about OOM for very small FPR (Ivan Matek) * stressed config chart x axis is capacity/num elements rather than plain capacity (Ivan Matek) * s/[SIMD] is available/is enabled at compile time (Ivan Matek) * shut down clang-tidy warnings (Ivan Matek) * used "set union" for more clarity (Andrzej Krzemienski) * stressed early on that boost::bloom::filter is _not_ a container (Claudio DeSouza) * added bulk operations to roadmap (Dmitry Arkhipov) * added try_insert to roadmap (Konstantin Savvidy) * added estimated_size to roadmap (Konstantin Savvidy) * added alternative filters to roadmap (Konstantin Savvidy) * used <cstdint> instead of <boost/cstdint.hpp> (Rubén Pérez) * mentioned endianness when serializing filters (Rubén Pérez) * corrected sloppiness about optimum k determination (Tomer Vromen) * added run-time specification of k to roadmap (Tomer Vromen) * added test/CMakeLists.txt (Rubén Pérez) * added CMake-based testing to GHA (Rubén Pérez) (#8) * added <boost/bloom.hpp> (Rubén Pérez) * added Codecov reporting (Rubén Pérez) (#9) * moved from boost::unordered::hash_is_avalanching to ContainerHash's boost::hash_is_avalanching (Ivan Matek/Peter Dimov) * added syntax highlighting to code snippets (Rubén Pérez) * avoided C-style casts in examples (Rubén Pérez) * added acknowledgements section (Peter Turcan) * added Getting Started section (Peter Turcan) * fixed example Jamfile and added example building to CI (Rubén Pérez) (#10) * added diagram about overlapping vs. non-overlapping subarrays (Rubén Pérez/Ivan Matek/Vinnie Falco) * made first code snippet self-contained (Rubén Pérez/Peter Turcan) * added more comments to genome.cpp (Rubén Pérez) * added support for arrays as blocks (Tomer Vromen) (#24) * removed emplace (Seth Heeren/Peter Dimov) (#25) * required the allocator to be of unsigned char (Seth Heeren/Peter Dimov) (#26) * added compile-time validation of Block types (Rubén Pérez) (#27) * added value type to displayed filter names in tables (Tomer Vromen) (#28) * used -march=native rather than -mavx2 (Ivan Matek) * adopted hash strategy with fastrange plus a separate MCG (Kostas Savvidis/Peter Dimov) (#30) * made doc improvements (Peter Turcan/Arnaud Becheler) (#29) * several maintenance commits

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Is it possible to use SVN for develop library, which may be applyed by Boost?
by Leonid . 24 Jun '25

24 Jun '25

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[DynamicBitset] Write access to the repository
by Gennaro Prota 20 Jun '25

20 Jun '25

Hi everyone, I'd like to do some maintenance work on my library, DynamicBitset. Could you please give me write access to the repository? Thanks. -- Gennaro Prota <https://prota.dev>

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[bloom] Benchmarks with Knuth multiplier-based hash production
by Joaquin M López Muñoz 17 Jun '25

17 Jun '25

Hi, As per feedback given here: https://lists.boost.org/Archives/boost//2025/05/259548.php I've experimented with the hash production scheme suggested by Kostas, where h_{i+1} is calculated as h_i * 6364136223846793005 mod 2^64: https://github.com/joaquintides/bloom/blob/refs/heads/feature/alternative-h… These benchmarks show the performance of each filter configuration with the original mechanism and, on the next row, the new mechanism (filter names marked with *): https://github.com/joaquintides/boost_bloom_benchmarks/blob/alternative-has… I can't draw any definitive conclusion as to whether the new mechanism affects performance, probably because the GHA-run benchmarks have a good deal of noise and variations in CPU speed. Maybe a keener eye than mine can tell, or if you're interested in trying the benchmark locally please tell me so and I can instruct you on how to do it. Feedback welcome, Joaquin M Lopez Munoz

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mailman upgrade
by Sam Darwin 17 Jun '25

17 Jun '25

Hi, As discussed earlier, mailman2 is end-of-life and no longer supported. We are planning to upgrade the mailing lists from mailman2 to mailman3. This will be done in-place, importing the previous archives and user list into a mm3 instance hosted at the same URL lists.boost.org. An example staging instance can be viewed at https://lists.preview.boost.org Mailman3 is more complex than Mailman2 with multiple components including "web" and "core". After the upgrade your account should still exist in the core backend, which means you will continue to receive messages and be able to send emails. However, to interact with the web frontend (optional) you must register an account using the same email address at https://lists.boost.org. Registering in the web portal will require setting up a new password, and confirming the email address. Be sure to use your existing email from before. Any previous passwords will not be valid. If you don't create an account in the web UI, your email subscriptions to the lists continue. But you can't yet log in to configure the account. No action is needed right now. Wait until after the upgrade. All previous messages will be imported to the new system. Additionally, the earlier archives in the form of static plain html pages will be available at https://listarchives.boost.org/ The imported lists are Boost, Boost Announce, and Boost Users. Activity on any other lists is remarkably low such as 1-2 emails per year. Please migrate other discussions to Github Issues, Slack, or one of the main mailing lists. Let us know any concerns. Report issues in the github repository cppalliance/boost-mailman. The tentative schedule is Tuesday June 17. Plan on not using the list for one day, or perhaps a few days. Roll back to mailman2 if something unusual is discovered soon after going live. Chat out-of-band in cpplang slack boost channel.

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[fsc] Boost presence in WG21 meeting at Sofia, Bulgaria
by Joaquin M López Muñoz 16 Jun '25

16 Jun '25

Hi everyone, We have brought some Boost advertising material to the ongoing WG21 meeting at Sofia, Bulgaria, and several Boost people are also participating there. Let me share a poster of Boost.Hash2 introduced by one of its authors, and long-time Boost contributor, Peter Dimov. Using a link to the X post so as to not burden the mailing list with a large image: https://x.com/Boost_Libraries/status/1934649592403939668 We'll be posting some other pics of the meeting during the week. Hope you like it! Joaquin M Lopez Munoz Boost Fiscal Sponsorship Committee

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[atomic] RFC: Bitwise operations for enums
by Andrey Semashev 15 Jun '25

15 Jun '25

Hi, There were quite a few times when I wanted to use bitwise operations on atomic<enum>, where the enum lists a number of flags that could be combined with bitwise AND, OR and XOR. Neither std::atomic nor Boost.Atomic enables bitwise operations for enums, so I had to resort to workarounds, such as using atomic<underlying_type_t<enum>> with explicit casts to and from the underlying type of the enum. Obviously, this is rather tedious, and I would prefer not to have to do this. I'm not sure what was the original rationale for not allowing bitwise operations for std::atomic<enum>, but I would guess these points were a part of it: 1. Not all enums represent bit masks, so for some enums the bitwise operations wouldn't make sense. 2. There may be user-defined bitwise operators defined for an enum, and presumably atomic<enum> would not invoke them to implement atomic bitwise operations. (Because it is generally not possible to make an arbitrary user's operator implementation atomic, other than to wrap it in a CAS loop, which defeats the point of having a dedicated atomic operation.) Some users may find this surprising. 3. For some operations, there may be multiple reasonable implementations. For example, bitwise complement (operator~) may be inverting all bits in the enum representation or only those bits, for which there are named values. An atomic<enum> could possibly implement the former, but the user's operator~ could implement the latter, which would introduce a discrepancy in behavior. Also, ironically, if atomic<enum> attempted to solve the problem #1 by detecting presence of user-defined bitwise operators for the enum and took it as a sign that the enum is a bit mask, this would only emphasize the problems #2 and #3. So, clearly, on one hand the functionality could be useful in practice, and on the other hand there may be pitfalls and confusion coming from it. I wonder what people think about this. Would you prefer to have the support and deal with the consequences or the status quo? Perhaps, you had your own solutions to this problem? Maybe there are other strong reasons to not have it? Personally, I'm leaning towards having the functionality rather than not. You can always not use what you don't want or need, but not the other way around. Thanks.

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Modular build progress.
by René Ferdinand Rivera Morell 10 Jun '25

10 Jun '25

It's been some time since the last update on B2 modular build support.. so here it is. Having accumulated more than 170 PRs to make the minimal needed changes to the libraries we are now down to only 13 needing, and ready, to be merged (https://github.com/users/grafikrobot/projects/1/views/2) And except for the MultiPrecision PR for John Maddock, the other 12 are in the hands of the Boost owners to merge. In other words.. We are almost done. I'm crossing fingers that this can get done before the next Boost release! -- -- René Ferdinand Rivera Morell -- Don't Assume Anything -- No Supongas Nada -- Robot Dreams - http://robot-dreams.net

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