November 2024 - Boost - lists.preview.boost.org

Pretty printer module
by Дмитрий Архипов 14 Apr '25

14 Apr '25

Recently Niall Douglas posted about his idea to embed GDB pretty printers into binaries using a header. At the time I was thinking about a good way to deploy pretty printers for JSON that facilitates their autoloading. After Niall's post I experimented a little bit more, and I came to the conclusion that indeed nothing beats embedding via a C++ header in terms of convenience. At the same time I was also thinking about testing that pretty printers do in fact work. Given that pretty printers (usually) are implemented as a Python module, it initially looked like one could just run a Python program and import GDB Python modules. But actually you cannot. It turns out, though, you can run a Python script with GDB as the interpreter. After several iterations I arrived at this setup: https://github.com/boostorg/json/blob/develop/test/printers.cpp. A script converts this file into a Python script that uses GDB to break on certain lines and check if a particular expression produces a particular output when printed. While doing all this I thought that most of this work can be useful to other libraries. So, I moved the reusable parts into a separate directory (https://github.com/boostorg/json/tree/develop/pretty_printers) and added both a b2 module, and a CMake module. For B2. Importing: https://github.com/boostorg/json/blob/develop/build.jam#L8-L9 https://github.com/boostorg/json/blob/develop/build/Jamfile#L13 (Re)generating the header: https://github.com/boostorg/json/blob/develop/build/Jamfile#L88-L95 Testing: https://github.com/boostorg/json/blob/develop/test/Jamfile#L96-L101 For CMake: Importing: https://github.com/boostorg/json/blob/develop/CMakeLists.txt#L54-L55 (Re)generating the header: https://github.com/boostorg/json/blob/develop/CMakeLists.txt#L56-L63 Testing: https://github.com/boostorg/json/blob/develop/test/CMakeLists.txt#L80-L88 My questions to the community: do you find this useful? Would you use it in your Boost or non-Boost library? If you do, the module should be moved to tools rather than stay in libs/json.

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[review] [sqlite]
by Richard Hodges 04 Feb '25

04 Feb '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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Any interest in a faster "any" type alternative?
by Marcus Tomlinson 06 Dec '24

06 Dec '24

I’m aware that the current implementation of any intentionally avoids copy assignments and uses only copy construction for all value updates. I believe this is due to the fact that copy assignment isn’t always available for all types - understandable. My proposal is what if we had a separate “fast-any” type that does utilise copy assignment when types match. In my own usage of this new type, I’ve found massive (roughly 2x) performance improvement on consecutive assignments of the same type. I’d like to gauge whether there would be any interest in adding such a type to the Boost library. Source code: https://github.com/cross-platform/fast_any Regards, Marcus Tomlinson

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[release] Master branch is now open for bug fixes
by Ion Gaztañaga 04 Dec '24

04 Dec '24

Hi, The master branch is now open for bug fixes, test and documentation changes, but please follow the policy described in: https://github.com/boostorg/wiki/wiki/Releases%3A-Beta-Merge-Policy The next deadline: On December 4th, master closes for all changes. As always, the calendar is at https://www.boost.org/development/ — The release managers

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Boost 1.87-beta1 still has sha1 failure in boost.compute
by Benjamin Redelings 02 Dec '24

02 Dec '24

Hi, It looks like boost 1.87-beta1 still has the compile failures from version 1.86 in boost::compute::detail::sha1. I see that there are patches from Aug 21, 2024 to address this in the `develop` branch of `boost.compute`. Are these likely to make it into boost 1.87? -BenRI

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[release] Boost 1.87.0 beta 1 released
by Marshall Clow 19 Nov '24

19 Nov '24

Boost release 1.86.0 beta 1 is now available at: https://archives.boost.io/beta/1.87.0.beta1/source/ The SHA256 checksums are: 2e7cdf358526e8937b36b93fc96c501b8d6a0c8436e95e65440de31c48ec3086 boost_1_87_0_b1.tar.bz2 98a86940c13509dfd0288a3075280f46a76c9a3faeb8a9bf49ca7f9e6a271995 boost_1_87_0_b1.tar.gz 2ca4c019d0c96fd160dec5292a7a6bfcf7b4e592cd238a2207e17084f8021d08 boost_1_87_0_b1.zip 5ea32facd963dbb79ceb5bda7ef7546017ea5da854158f8933bbad74d6bbe622 boost_1_87_0_b1.7z This is slightly different than the RC3. Someone committed a documentation fix to master after we had started the release process, and rather than re-do the whole thing (and re-tag everything), we decided to go with the release that we prepared. The person who did this has been informed of the problems that he caused, and I don’t think he’ll do it again. Release notes (still need updates): https://www.boost.org/users/history/version_1_87_x.html Please try the beta and report any problems you encounter. Thanks to everyone who contributed to the release. -- Boost Release Team

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Re: [boost] [review] [sqlite]
by Дмитрий Архипов 19 Nov '24

19 Nov '24

пт, 15 нояб. 2024 г. в 15:58, Klemens Morgenstern <klemensdavidmorgenstern(a)gmail.com>: > Would you also suggest automatic conversions or just stick to sqlite::value ? To be honest, I'm not sure. Automatic conversions would also have to rely on deduction, which would again inhibit the use of templates and overloaded functions. > I think you're right. I didn't really like the context idea in your > previous code example, but I think this can be rectified: instead of a > context object, you can pass in a tuple that gets forwarded to the > constructor of the function. > ... > create_aggregate_function<collect_libs, 1>("my-prefix", 42); First, I realised that there's no need to put any additional shared data into SQLite-managed memory, as you can always just add a reference member to the callable and store that shared data on your side. Second, I assume the point of this approach is to avoid copying the callable object, and also support non-default constructible callables. My approach uses the original callable as a kind of prototype, from which it copies new objects for every operation. To be honest, I don't think there should be any difference in performance between my approach with copying and yours with constructing. Ergonomically, I think mine is better. Yours may be looking more straightforward to users. One idea came to my mind. It's sometimes hard to determine which parts of the SQLite C API are supported by your library, and what specific components do it. So, I think you need a dedicated list of all SQLite C functions with comments like "supported via sqlite::backup", "supported via sqlite::mutex", "not supported because an analogous function X is supported ", "not supported because deprecated by SQLite", etc.

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[graph] Temporary maintenance delays until the new year
by Jeremy Murphy 18 Nov '24

18 Nov '24

Dear Boost.Graph users, I'm in the process of moving to another country and changing jobs at the moment, so apologies that there has been and will continue to be a period of slow responses to (some) pull requests, etc until I get settled into a new routine. Regards, Jeremy

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Re: [boost] [review] [sqlite]
by Ruben Perez 16 Nov '24

16 Nov '24

(CC-ing the list) On Sat, 16 Nov 2024 at 12:11, Klemens Morgenstern <klemensdavidmorgenstern(a)gmail.com> wrote: > > On Sat, Nov 16, 2024 at 7:07 PM Ruben Perez <rubenperez038(a)gmail.com> wrote: > > > > > > 3. What's the rationale behind BOOST_SQLITE_NO_VIRTUAL? Wouldn't > > > > setting it cause trouble, being a compiled library? > > > > > > It would. The idea is that you can use that for constrained (i.e. > > > embedded environments) to avoid the unnecessary vtable and to enforce > > > devirtualization if your compiler misses this. > > > > If I have read the code correctly, these functions seem to only be > > used in headers. Why do they need to be virtual? It looks like it > > could have been made a compile-time interface (i.e. a concept), > > completely avoiding the need for the macro. What's the rationale > > behind this? > > That's correct, that's also what it was originally. But the error > messages were horrendous. > By creating a base class you get good error messages (purely virtual > because method X is missing) and the compiler is still compelled to > devirtualize by the way it's used. > And because it's effectively unused, you can disable it. Couldn't you achieve a similar effect (scoped to C++20 and later) by conditionally using concepts? In a way similar to what Asio does to diagnose completion tokens (i.e. BOOST_ASIO_COMPLETION_TOKEN_FOR).

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Re: [boost] [review] [sqlite]
by Ruben Perez 16 Nov '24

16 Nov '24

(CC-ing the list) On Sat, 16 Nov 2024 at 11:55, Klemens Morgenstern <klemensdavidmorgenstern(a)gmail.com> wrote: > > On Sat, Nov 16, 2024 at 6:47 PM Ruben Perez <rubenperez038(a)gmail.com> wrote: > > > > What's the current recommended way to consume the library? Installing > > it with CMake seems to only install the binaries (and not the > > headers/cmake find_package scripts), and I haven't found a Jamfile to > > build the library as part of the Boost superproject. > > FetchContent + add_subdirectory is what I do. > > There also is a Jamfile in /build, but it's going to just to sqlite3, > because there's no `using sqlite ;` available at the moment. That's > probably only going to work on linux as of now. > Thanks, I completely missed out the Jamfile because of an unfortunate IDE setting.

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[release] Boost 1.87.0 Release Candidate 3 is available
by Marshall Clow 15 Nov '24

15 Nov '24

The third release candidates for the 1.87.0 release are now available at: <https://boostorg.jfrog.io/artifactory/main/release/1.87.0/source/> The SHA256 checksums are as follows: 10ea784394be84794ed8981643ea0f05fae38de6aa595353115f85c79e4c1cd7 boost_1_87_0_b1_rc3.tar.gz 56db0fc204e6e0e40e1764800ef82475c96916e86112bc9627d1b94102cb786a boost_1_87_0_b1_rc3.7z 45fcc8f7f63e023cdafc1d88b3b915f3feac6bc7aab52a91d5766b5a2248af6d boost_1_87_0_b1_rc3.zip e0c971e3b92aa8ab781fe8239e050078600a446bd26c4509001037872974c4c2 boost_1_87_0_b1_rc3.tar.bz2 Changes since RC2: * The Boost.Parser library is included * A bug that caused compile failures in stl_interfaces with recent versions of clang has been fixed. * A bug that caused compile failures on Boost.Proces with gcc has been fixed. As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. -- The Release managers

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Status of the 1.87.0 Beta Release
by Marshall Clow 12 Nov '24

12 Nov '24

There have been a couple of minor problems reported against RC2. However, yesterday we noticed that Boost.Parser was not part of the RC. We will be issuing an RC3 later today to rectify this. Unfortunately, this means that the beta release will be delayed by a couple of days — The Release Managers

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[fsa] Current status of Fiscal Sponsor Agreement (repost)
by Joaquin M López Muñoz 12 Nov '24

12 Nov '24

(Reposting as PDF) Hi everyone, From the Fiscal Sponsorship Committee, we'd like to share with you the current status of the creation of the new Fiscal Sponsor Agreement for Boost: https://drive.google.com/file/d/1jVggIrQsl4FPrh3H3n-qmy60BclXSILS/view?usp=… We'll be sending periodic updates on this issue. Don't hesitate to ask about any doubt you may have. Best, Joaquin M Lopez Munoz The Fiscal Sponsorship Committee

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[release] Boost 1.87.0 Beta 2 Release Candidate is available
by Marshall Clow 11 Nov '24

11 Nov '24

RC1 had some build issues which have been corrected. Available at: https://archives.boost.io/beta/1.87.0.beta1/source/ The SHA256 checksums are as follows: d24c351fdeaeefa4f25ce5e9365e9d69b86d342570eaac649e3b12f244a6eef7 boost_1_87_0_b1_rc2.7z 98090d258e1d50db30b549072a5db04210350fa7a5ede47d2c71a78af6724e55 boost_1_87_0_b1_rc2.zip 85075e27e6f866cbe3a00f1d5a57e801ce313119dcfd8327babf554c84af9ec3 boost_1_87_0_b1_rc2.tar.bz2 48e51ddfb67eace9181be87f2f25a06dace5e0eb4a84ab803ebfcd8d98e4aab1 boost_1_87_0_b1_rc2.tar.gz As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. -- The Release Managers

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Formal Review Retrospective
by Vinnie Falco 11 Nov '24

11 Nov '24

Ironically, a robust discussion regarding the review process and the usage of Slack is now taking place... on Slack. Arnaud made this suggestion which I am reposting here: "... formalizing a "Retrospective" phase as an actual part of the Formal Review could be key in avoiding criticism against the process to leak into criticism against the proposed library." I think this is a great idea. After each formal review result is announced, there is a new "retrospective" thread started which allows the community to reply and weigh in on how they thought the review was conducted. This actually happened organically in the last review of async-mqtt5 and I think it could be enhanced if the review wizard or review manager had pre-emptively started a retrospective thread where the replies could be accumulated. The subject line could for example be "[async-mqtt5] Review Retrospective" What do you think? Thanks

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[fsa] Current status of Fiscal Sponsor Agreement
by Joaquin M López Muñoz 11 Nov '24

11 Nov '24

Hi everyone, From the Fiscal Sponsorship Committee, we'd like to share with you the current status of the creation of the new Fiscal Sponsor Agreement for Boost: https://docs.google.com/document/d/1fMvWJi0guPCVI_YSD86FTgTMpf69lGiwRs0lgAa… We'll be sending periodic updates on this issue. Don't hesitate to ask about any doubt you may have. Best, Joaquin M Lopez Munoz The Fiscal Sponsorship Committee

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async-mqtt5 is CONDITIONALLY ACCEPTED
by Klemens Morgenstern 09 Nov '24

09 Nov '24

Hi all, thanks to everyone participating in the review! I really want to express my appreciation to the reviewers, especially those who invested multiple hours if not days to review this library: thank you Vinnie, Ruben, Mohammad and Marcelo. I interpreted Darylls review as a "weak rejection", but since that doesn't exist in the formal review process I'll count it as a rejection. Leaving the recommendations at 1 ACCEPT 3 CONDITIONAL ACCEPT 2 REJECT The actual conditions for acceptance are: 1. Correct usage of the executor. It is an asio contract that the async operation always completes on the associated executor and mqtt5 should follow this. 2. Add logging/reporting facilities. A user should be able to follow what is happening internally and ideally react to it, especially concerning reconnects. I also recommend the authors to review all the comments, including the rejections (Daryll's review had interesting details) and non-review comments such as from Peter Turcan. I would also advise that inclusion in boost is usually a time to change the name, because the library now gains the boost. prefix. I.e. boost.async-mqtt5 might be a bit cumbersome. Also note that there is no time requirement to include this library in boost in the next release. Thanks again to everyone participating in the review and to Ivica & Mireo for their submission.

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Slack and Formal Reviews
by Vinnie Falco 09 Nov '24

09 Nov '24

We need to solve the problem of review conversations taking place on Slack instead of the list. I would ultimately love a technical solution that allows discussions to also happen on Slack in a way that preserves the integrity of the review, and that might not be practical right this second. Therefore, I propose the following: 1. Formal review announcement will remind participants that conversations should happen on the list (and specifically mention that Slack should not be used) 2. If a Slack conversation is initiated during the review period, the review manager and library submitter will politely remind folks to move the discussion to the list. Perhaps some copy and pasting will be needed. 3. Periodic reminder from the review manager during the review process, if things get out of hand. 4. We explore ideas for how to incorporate other platforms into the review process. Mailing list participation is down, yet Slack participation is up. Ideally we figure out how to harness change instead of taking on losing battles. -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

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Shared memory path to custom path
by Murali Kishore 08 Nov '24

08 Nov '24

Hi all, Is it possible to change the shared memory segment path from /dev/shm to other directory ex. /tmp/shm_file instead of /dev/shm/shm_file. Regards, Murali Kishore

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[release] Boost 1.87.0 Beta 1 Release Candidate is available
by Marshall Clow 08 Nov '24

08 Nov '24

Available at: https://archives.boost.io/beta/1.87.0.beta1/source/ The SHA256 checksums are as follows: 26f987635320854a141a8c9c3750eb6f01edb6eb75df9454726c4a03724b2472 boost_1_87_0_b1_rc1.tar.gz 3712ead87a26ae5b8ee7dcf0c180e4c27f58e50bd32f14d77e8e04bf6a13ae51 boost_1_87_0_b1_rc1.zip e6b047e06369392241f8574a5cc1b6aa493819aa498276654477e3a08bc94167 boost_1_87_0_b1_rc1.7z deff255d96e11760f728f5f90785b138fff93f6c9a3ab24664710211a41614ad boost_1_87_0_b1_rc1.tar.bz2 As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. -- The Release Managers

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[Release] Master branch is now closed for the beta release
by Marshall Clow 07 Nov '24

07 Nov '24

Master is closed for all changes. See the release schedule at: https://www.boost.org/development/index.html -- Release managers

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[release] Master branch closes for the 1.87.0 beta release on WEDNESDAY
by Ion Gaztañaga 05 Nov '24

05 Nov '24

Calendar is here: https://www.boost.org/development/ — The Release Managers

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Bringing Boost.Array up to date?
by Peter Dimov 05 Nov '24

05 Nov '24

I recently needed to make use of std::array in a constexpr context, and was rudely informed by the compilers that a lot of its features are only constexpr in C++17 (non-const access) or even C++20 (operator==). This makes the standard std::array not very useful in C++14 constexpr code. Ordinarily, the way we deal with such problems is to shadow the standard component in Boost.Compat and backport all features introduced in later standards. But in this specific case, we already have boost::array, and it makes no sense to introduce another one. boost::array, however, looks mostly abandoned. The thinking there was probably that it's rendered entirely obsolete by std::array, and that no further development is warranted or required. But as outlined above, this is not the case; there's still value in maintaining boost::array and keeping it up to date. I'd like to do something about that. If Array's current maintainer, Marshall, agrees, I'd like to take over the maintenance of Boost.Array and do the usual thing - port the documentation to AsciiDoc, expand the test suite, add the necessary BOOST_CONSTEXPR/BOOST_CXX14_CONSTEXPR annotations, add the features introduced by later standards such as deduction guides and to_array, deprecate/remove the nonstandard parts of boost::array that are no longer relevant in 2024, and so on. Comments?

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[release] The 1.87.0 release will close for major changes WEDNESDAY
by Ion Gaztañaga 05 Nov '24

05 Nov '24

Calendar here: https://www.boost.org/development/ Next deadline: The master branch will close for the beta next Wednesday. — The release managers

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