December 2022 - Boost - lists.preview.boost.org

Library proposal - indexed_array
by Julien Blanc 12 Oct '23

12 Oct '23

Hi, I've written and released a (rather small) library which allows defining arrays with arbitrary index mechanisms (hence the name, indexed_array). This especially allows indexing with scoped enums, use non zero-starting indexes, or use sparse indexes. This is not a view, but an array in the sense that it owns the data, and provides the same guarantees and functionalities as std::array, such as triviality propagation, being able to reside in read-only program sections, etc. It also supports multidimensional indexing, and provides an indexed_span template class to access lower dimension content (which can be used outside indexed_array). Finally, it provides an opt-in safer way to initialize the array content, which is especially useful when using complex and/or changing indexing schemes (like based on externally generated files). The library is available here: https://github.com/Julien-Blanc-tgcm/indexed_array And the doc is here: https://julien-blanc-tgcm.github.io/indexed_array/ It requires C++17 and mp11, and has first-class support for describe-d enums. If there is some interest, i'd like to propose it for inclusion in boost. So i'm looking for people who would endorse it. Thanks and best regards, Julien

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Decommissioning Trac (svn.boost.org)
by Glen Fernandes 31 Jan '23

31 Jan '23

We have Trac in read-only mode after we migrated to Git, but we're still paying for the server. Do people still want to preserve any part of the content in some way? The wiki aside, there are old issues, with comments, and some of them have patches attached. Peter had the idea of generating static HTML content from Trac and hosting that on an archive section on boost.org. (I don't know how difficult this is to do). Thoughts? Suggestions? Glen

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Regression Results Not Updating
by Tom Kent 15 Jan '23

15 Jan '23

The results from the pages at: https://www.boost.org/development/tests/develop/developer/summary.html https://www.boost.org/development/tests/master/developer/summary.html Have not updated in almost a month. Can someone check on the process that manages this? Thanks, Tom

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Paul Bristow
by John Maddock 30 Dec '22

30 Dec '22

I've just heard that Paul Bristow who helped so much with the development of Boost.Math and indeed many other libraries, passed away peacefully last week. RIP Paul. Much missed. John.

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New Boost library proposal, Mustache
by Peter Dimov 30 Dec '22

30 Dec '22

I'm looking for endorsements and a review manager volunteer for a new library, Boost.Mustache. It's an implementation of Mustache templates (http://mustache.github.io/) in C++11 and at the moment supports the mandatory portions of the Mustache spec (https://github.com/mustache/spec). The repository is https://github.com/pdimov/mustache. Mustache is a simple templating language in which tags of the form {{something}} are replaced with the value of the entity `something`, which typically means with the member "something" of the JSON object passed when rendering the template. Boost.Mustache can take a Boost.JSON object as the context against which data references are resolved, but it can also take arbitrary values that can be converted to boost::json::value by using boost::json::value_from. This allows, for instance, described classes (structs and classes annotated with Boost.Describe) to be passed as the data context, such that references to e.g. {{title}} in the template are resolved to the corresponding `title` member of the class. A simple usage example demonstrating the above is: ``` #include <boost/mustache.hpp> #include <boost/describe.hpp> #include <iostream> struct item { std::string title; std::string author; std::string link; }; BOOST_DESCRIBE_STRUCT(item, (), (title, author, link)) struct reference { std::string heading; std::vector<item> items; }; BOOST_DESCRIBE_STRUCT(reference, (), (heading, items)) int main() { reference ref = { "Reference", { { "Better Bit Mixing - Improving on MurmurHash3's 64-bit Finalizer", "David Stafford", "https://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html" }, { "Stronger, better, morer, Moremur; a better Murmur3-type mixer", "Pelle Evensen", "https://mostlymangling.blogspot.com/2019/12/stronger-better-morer-moremur-b…" }, { "Improved mx3 and the RRC test", "Jon Maiga", "http://jonkagstrom.com/mx3/mx3_rev2.html" } } }; std::string tmpl = R"(<html> <body> <h1>{{heading}}</h1> <ul> {{#items}} <li> {{title}} {{author}} <a href="{{link}}">{{link}}</a> {{/items}} </ul> </body> </html>)"; boost::mustache::render( tmpl, std::cout, ref, {} ); } ``` The resulting output is <html> <body> <h1>Reference</h1> <ul> <li> Better Bit Mixing - Improving on MurmurHash3's 64-bit Finalizer David Stafford <a href="https://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html">https://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html</a> <li> Stronger, better, morer, Moremur; a better Murmur3-type mixer Pelle Evensen <a href="https://mostlymangling.blogspot.com/2019/12/stronger-better-morer-moremur-b…">https://mostlymangling.blogspot.com/2019/12/stronger-better-morer-moremur-b…</a> <li> Improved mx3 and the RRC test Jon Maiga <a href="http://jonkagstrom.com/mx3/mx3_rev2.html">http://jonkagstrom.com/mx3/mx3_rev2.html</a> </ul> </body> </html>

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Tribute to John Kalb
by Robert Ramey 27 Dec '22

27 Dec '22

It's the end of 2022. I wanted to take a moment to recognize the contributions to Boost over the last dozen years or so by Jon Kalb. I first met Jon at a Microsoft Meeting named "Going Native" which was promoting a "resurgence" of C++ over Languages like Java and C#. It seems that this was related to the C++ committee incorporating large parts of Boost into the standard library and Microsofts renewed commitment to C++. This is my take, I'm sure someone else could provide more details on this. My view that was that there wasn't much more for Boost to do. Dave Abrahams was moving on to bigger things which reinforced this impression. Jon was enthusiastic about taking the lead on Boost. It was clear that he and I had a different visions. I sort of cringed - it looked to me like he got suckered. He asked me if I planned to attend C++Now - I weaseled out of actually answering. Of course he turned out to be right and I was wrong. The C++ committee hasn't really been able to replace Boost. It's too slow and cumbersome. Working as a design committee isolated from actual implementation doesn't seem to conducive to designing good, clean, elegant software. And it takes forever. It's odd to me that the committee adopted a large part of Boost software, but failed to learn anything from Boost about how to make this kind of stuff. So in this environment Jon led Boost. He worked from top to bottom on all the stuff that needs to be done - finances, legal, C++Now planning, recruitment of collaborators, etcetra . Very successful and, like many successful people, made it look easy. Hence he has not been appreciated to the extent he should be. Now he as moved on from Boost - he will be missed. Apparently this was in the works for some time but was pushed along by complaint about his handling about an alleged code of conduct violation which in my view was blown way out of proportion. I think the Boost BOD has treated Jon shabbily regarding this incident. My aim here is to correct that. Boost has had a large role in saving C++ from decline into obscurity. David Abrahams and Beman Dawes were the primary promoters at Boost at it's start. I don't think it's too much to say that these two persons saved C++. To this list, I'd like to add the name of Jon Kalb, without whom Boost would likely have wound down with C++11. -- Robert Ramey www.rrsd.com (805)569-3793

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Why do Predef and Config exist?
by Hans Dembinski 27 Dec '22

27 Dec '22

Hi all, since there were concerns that the email list is so quiet, here is some noise. Is someone willing to explain to me why we have Predef and Config? It looks like these two libraries have a strong overlap in scope. Shouldn’t they be merged? Best regards, Hans

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Proposing a Redis client library for inclusion in Boost
by Marcelo Zimbres Silva 22 Dec '22

22 Dec '22

Hi, I would like to propose my Redis client library for inclusion in Boost Github: https://github.com/mzimbres/aedis Homepage: https://mzimbres.github.io/aedis Redis: https://redis.io Aedis implements asynchronous communication with a Redis server using the RESP3 protocol [1] and is built on top of Boost.Asio, which makes it similar to Boost.Beast and Boost.MySql. For more information, please, refer to the project homepage. I am looking for someone who would like to endorse the library and also for a review manager. Thanks, Marcelo [1] https://github.com/redis/redis-specifications/blob/master/protocol/RESP3.md

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[Test] How to make test framework create Core dump in case of any unhandled exceptions?
by Sergey P 21 Dec '22

21 Dec '22

Dear developers, Is it possible to force Boost.Test framework to create Core dump in case of catching any kind of unhandled exception from code that is being tested? We tried to use parameter: *--catch_system_error=no* but it creates core dump for system signals only, while we need core dump for any exceptions, even custom ones. We would appreciate any suggestions or hints. Thank you very much! Best regards, Sergey Podolyan

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[release] Boost 1.81.0
by Marshall Clow 17 Dec '22

17 Dec '22

Release 1.81.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains one new library and numerous enhancements and bug fixes for existing libraries. * URL: A library for parsing, modifying, and printing URLs using only C++11, from Vinnie Falco and Alan de Freitas. For details, including download links, see <http://www.boost.org/users/news/version_1.81.0> You can also download directly from: <https://boostorg.jfrog.io/artifactory/main/release/1.81.0/> To install this release on your system, see <http://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. -- The Boost Release Team Marshall Clow, Glen Fernandes, Michael Caisse

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