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

CMake Announcement from Boost Steering Committee
by Jon Kalb 13 Aug '24

13 Aug '24

The libraries produced by the Boost community have had a greater impact on the way that the C++ community writes code than any other library implementation. The focus of the Boost community will always be on the libraries, but it is undeniable that we are dependent on and often limited by the infrastructure of our trade. Years ago, the move to Git was contentious; yet, it was required to improve development. In a similar vein our build system has become an impediment for many developers and users, existing and prospective. Therefore, we, the Steering Committee, announce to the Boost community our desire and intent to move Boost’s build system to CMake for users and developers alike. We are soliciting comments and proposals from the community to guide the process and the goals. Our desire is that the community can come to consensus by the end of the calendar year with a vision of supporting users and developers. We understand that the actual process of achieving the end goal will be long, time consuming, and not without its share of conflict. We also recognize that the Boost community is comprised of bright and passionate individuals that are eager to get involved and help get work done. The members of the Steering Committee have been encouraged by the discussions and activity surrounding CMake on the mailing lists over the years and know that many people have voiced visions. We hope that each of you rejoins the discussion to support this initiative and contributes to the common goal of improving Boost’s integration into the broader C++ ecosystem. For the Boost Steering Committee, Jon Kalb, Chair jonkalb(a)boost.org

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Boost Governance?
by René Ferdinand Rivera Morell 09 Aug '24

09 Aug '24

A disclaimer: I write this solely as a Boost Library author. And not in any other capacity or representing any other interest. It's now been at least a year since Boost switched from the Software Freedom Conservancy to the Boost Foundation for its governance organization. But have people noticed any difference? Did you know that switch happened? Did you know that they held an election for the Board of Directors and for the Officers? Do you know when that election happened? Do you know who got elected? Do you know how they were selected? Do you know what their responsibilities are? Do you know what their bylaws are? Do you know their financials? More importantly: Did you answer "no" to any of those questions? As a library author, I can say I definitely answered no to many of those questions. This is a problem. As authors, without asking, we should know those answers from the organization that governs our work. We should have input into how that organization governs. In other words, we deserve open and transparent governance; not the closed and opaque status quo. -- -- René Ferdinand Rivera Morell -- Don't Assume Anything -- No Supone Nada -- Robot Dreams - http://robot-dreams.net

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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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Boost.Text is looking for a (mini-)review manager
by Zach Laine 07 Dec '22

07 Dec '22

I've made all the recommended changes to Boost.Text that came up in the review. Glen, the previous review manager, recommended a mini review of Boost.Text once I'd made those changes. If you'd like to manage the mini-review, please let me know. For everyone, including potential reviewers and review managers, here are the major changes: * All the specific review feedback issues have been addressed. * The string layer is now gone. * The text layer got a major re-work. It is now a set of template-based adaptors (basic_text<>, vs. a text typedef. etc.), which lets everyone get what they want. You can change the underlying storage type (including whatever allocator you prefer), select UTF-8 or UTF-16, and change the normalization form. Glen recommended I drop this layer, but the library is way less useful without this stuff, and these changes address all the concerns raised about the text layer in the review. The updated docs can be found here: https://tzlaine.github.io/text/doc/html/index.html Oh yeah, and I added concept constraints to the whole library when you build in C++20 mode. Zach

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Boost.URL review planned for 13-22 August 2022
by Mateusz Loskot 22 Aug '22

22 Aug '22

Folks, Klemens Morgenstern kindly volunteered [1] as the Review Manager (thanks Klemens!) for the Boost.URL [2], so we have planned the review shortly after the upcoming release of the Boost 1.80. Check the Review Schedule [3] for details! [1] https://lists.boost.org/Archives/boost/2022/06/253225.php [2] https://lists.boost.org/Archives/boost/2022/04/252814.php [3] https://www.boost.org/community/review_schedule.html Best regards, -- The Boost Review Wizards Mateusz Loskot

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Questions about incorporating my library into a new library within Boost
by Jooseong Lee 11 Aug '22

11 Aug '22

I recently wrote a general-purpose STL-like ordered associative B-Tree based container in C++. . Its API and usage is very similar to std::set, std::map, std::multiset, std::multimap, and when the number of elements is relatively large, my benchmark shows that it is 2.5~3 times faster than std::set and its friends. Repo link: https://github.com/frozenca/BTree This was better than I thought, so I'd like to contribute to the Boost community by incorporating it within the list of Boost libraries. I'd like to know if it's possible or if you think it's worth it. Best Regards, Jooseong Lee

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[review][JSON] Review of JSON starts today: Sept 14 - Sept 23
by Pranam Lashkari 09 Aug '22

09 Aug '22

Boost formal review of Vinnie Falco and Krystian Stasiowski's library JSON starts today and will run for 10 days ending on 23 Sept 2020. Both of these authors have already developed a couple of libraries which are accepted in Boost(boost beast and Static String) This library focuses on a common and popular use-case for JSON. It provides a container to hold parsed and serialised JSON types. It provides more flexibility and better benchmark performance than its competitors. JSON highlights the following features in the documentation: - Fast compilation - Require only C++11 - Fast streaming parser and serializer - Easy and safe API with allocator support - Constant-time key lookup for objects - Options to allow non-standard JSON - Compile without Boost, define BOOST_JSON_STANDALONE - Optional header-only, without linking to a library (a point I would like to add in highlight: it has cool Jason logo 😝) To quickly understand and get the flavour of the library take a look at "Quick Look" <http://master.json.cpp.al/json/usage/quick_look.html> You can find the source code to be reviewed here: <https://github.com/CPPAlliance/json/tree/master> You can find the latest documentation here: <http://master.json.cpp.al/> Benchmarks are also given in the document which can be found here: <http://master.json.cpp.al/json/benchmarks.html> Some people have also given the early reviews, the thread can be found here: <https://lists.boost.org/Archives/boost/2020/09/249745.php> Please provide in your review information you think is valuable to understand your choice to ACCEPT or REJECT including JSON as a Boost library. Please be explicit about your decision (ACCEPT or REJECT). Some other questions you might want to consider answering: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - 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 here: <http://www.boost.org/community/reviews.html> Thank you for your effort in the Boost community. -- Thank you, Pranam Lashkari, https://lpranam.github.io/

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Boost 1.80.0 master open for bug fixes
by Glen Fernandes 03 Aug '22

03 Aug '22

Now open for bug fixes and documentation changes. Other changes by release manager permission. The next deadline: On August 3rd, master closes for all changes. Glen

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Re: [boost] Boost Digest, Vol 6764, Issue 1
by Benedict Bede McNamara 29 Jul '22

29 Jul '22

I++ Binary Serialization I++ binary serialization just got twice as fast by using linked lists rather than binary trees as before. Sent from Mail for Windows From: boost-request(a)lists.boost.org Sent: Friday, 29 July 2022 10:00 PM To: boost(a)lists.boost.org Subject: Boost Digest, Vol 6764, Issue 1 Send Boost mailing list submissions to boost(a)lists.boost.org To subscribe or unsubscribe via the World Wide Web, visit https://lists.boost.org/mailman/listinfo.cgi/boost or, via email, send a message with subject or body 'help' to boost-request(a)lists.boost.org You can reach the person managing the list at boost-owner(a)lists.boost.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Boost digest..." The boost archives may be found at: http://lists.boost.org/Archives/boost/ Today's Topics: 1. Re: Questions about incorporating my library into a new library within Boost (Phil Endecott) 2. Re: Questions about incorporating my library into a new library within Boost (Jooseong Lee) ---------------------------------------------------------------------- Message: 1 Date: Thu, 28 Jul 2022 13:57:50 +0100 From: "Phil Endecott" <spam_from_boost_dev(a)chezphil.org> To: <boost(a)lists.boost.org> Subject: Re: [boost] Questions about incorporating my library into a new library within Boost Message-ID: <1659013070554(a)dmwebmail.dmwebmail.chezphil.org> Content-Type: text/plain; format="flowed"; charset="UTF-8" Jooseong Lee wrote: >> What is not stored contiguously is child, this is stored in >> std::vector<std::unique_ptr>. >> But when N keys are erased, the number of children erased is not O(N), >> because a node can have #(fanout) keys. > > I have to correct this sentence, the number of children erased is O(N). > But the coefficient is small, because practically B-Trees use large fanouts. > > Most technically, a call for erase_range(a, b) would be O(log N) + O(K) > where N is the number of whole keys and K is the number of keys being > erased. > I've updated the repo description, thanks for the catch. Good, I'm glad I don't have to give the CS101 complexity lecture :-) One other comment - how do you deal with strings? To get the locality benefits of the B-Tree you can't store variable-size data totally out-of-band. Regarding the general "how do I get this in Boost?" question, I encourage you to look back through the mailing list archive at the last few "Is Boost interested in my XYZ libary?" threads. Some people post useful replies about what to do next which. Cynically, what happens most often is that there are one or two emails and then the library author and any replies disappear. Some persistence is required to make anything happen. One hint: put something more descriptive (i.e. "B-Tree") in your subject line! Regards, Phil. ------------------------------ Message: 2 Date: Thu, 28 Jul 2022 22:18:33 +0900 From: Jooseong Lee <frozenca91(a)gmail.com> To: boost(a)lists.boost.org Subject: Re: [boost] Questions about incorporating my library into a new library within Boost Message-ID: <CAPPJyCuKa8mRMzhKhwaVWXbyuECQDVjXCs_m8kcM_EtDz8dZvg(a)mail.gmail.com> Content-Type: text/plain; charset="UTF-8" > One other comment - how do you deal with strings? To get the locality > benefits of the B-Tree you can't store variable-size data totally out-of-band. For std::string and its friends (i.e. not trivially copyable types) it is stored as something like std::vector<std::string>, so it is not *that* good (but still better than std::set<std::string>). Google Abseil's B-Tree implementation use similar approach. When I personally use my B-Tree for strings, I use raw char arrays like std::array<char, 16> > Regarding the general "how do I get this in Boost?" question, I > encourage you to look back through the mailing list archive at the > last few "Is Boost interested in my XYZ libary?" threads. Thanks, I'll have a look. Best, Jooseong On Thu, Jul 28, 2022, 9:58 PM Phil Endecott via Boost <boost(a)lists.boost.org> wrote: > Jooseong Lee wrote: > >> What is not stored contiguously is child, this is stored in > >> std::vector<std::unique_ptr>. > >> But when N keys are erased, the number of children erased is not O(N), > >> because a node can have #(fanout) keys. > > > > I have to correct this sentence, the number of children erased is O(N). > > But the coefficient is small, because practically B-Trees use large > fanouts. > > > > Most technically, a call for erase_range(a, b) would be O(log N) + O(K) > > where N is the number of whole keys and K is the number of keys being > > erased. > > I've updated the repo description, thanks for the catch. > > Good, I'm glad I don't have to give the CS101 complexity lecture :-) > > One other comment - how do you deal with strings? To get the locality > benefits of the B-Tree you can't store variable-size data totally > out-of-band. > > Regarding the general "how do I get this in Boost?" question, I > encourage you to look back through the mailing list archive at the > last few "Is Boost interested in my XYZ libary?" threads. Some people > post useful replies about what to do next which. Cynically, what > happens most often is that there are one or two emails and then > the library author and any replies disappear. Some persistence is > required to make anything happen. One hint: put something more > descriptive (i.e. "B-Tree") in your subject line! > > > Regards, Phil. > > > > > > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost > ------------------------------ Subject: Digest Footer _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost ------------------------------ End of Boost Digest, Vol 6764, Issue 1 **************************************

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Is there any interest in a library that solves genetic simulations?
by Arnaud Becheler 27 Jul '22

27 Jul '22

Hi, I am Arnaud, software engineer in genetics, always eager to learn more about C++! Happy to be on this mailing list :) Is there any interest in a library that solves genetic simulations? A proof of concept library that focuses on a particular simulation framework (spatial coalescence) can be found here: https://github.com/Quetzal-framework/quetzal-CoaTL It lacks many basics including genetic code, mutations, sequences, recombination etc. Such algorithms and data structures are constantly re-implemented in the scientific community, and providing a generic implementation could help significantly. Best, Arnaud Becheler

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C++11 or C++14?
by Vinnie Falco 25 Jul '22

25 Jul '22

I'm considering bumping up the C++ language requirement for Boost.URL from C++11 to C++14. I have concerns about doing this, because it affects all my downstream libraries (HTTP.Proto, HTTP.IO, Websocket.Proto, Websocket.IO, and any examples or complete clients/servers that I write). My main fear is that there are still a considerable number of individuals or corporations who, for whatever reason, cannot build with -std=c++14 or later despite having access to newer compilers. I don't mind if there is a small percentage of loss but I do mind if 20% or more of potential users will be locked out. The questions are: 1. Would you or your company be prevented from using Boost.URL if it required C++14? 2. Do you know any other organizations who cannot use C++14 or later? 3. Do you know of any regional or global metrics on who _cannot_ use libraries which require C++14? See also, this reddit thread on r/cpp: <https://www.reddit.com/r/cpp/comments/w6zuo5/c11_or_require_c14/> -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

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xproc: get process information from foreign processes
by Samuel Venable 20 Jul '22

20 Jul '22

Hi all. The main developer of the boost process library liked what he saw when I showed him my xproc API. He recommended me to send it to the boost mailing list and see what the other developers at boost think of it and whether it could be modified and adjusted into making it worthy of becoming an official part of the boost libraries. The Windows build currently only works with MSYS2/MinGW, see the open issue here for the full details on what works and what doesn't on the Windows platform and why: currently known Windows-related bugs · Issue #1 · time-killer-games/xproc (github.com)<https://github.com/time-killer-games/xproc/issues/1> The build.sh to build and example.sh to test is all you need to test all features, the only thing that isn't verified by the scripts is whether any memory leaks exist, and afaik in my testing Windows might be the only platform whith memory leaks, but its very unclear to me how to debug the source of them, because the code looks very correct, as I'm freeing memory everywhere online Microsoft documentation tells me to. Also supports Mac, Linux, FreeBSD, DragonFly BSD, NetBSD, and OpenBSD. If I ever find hardware that will work with an Illumos-based Operating System, then that will be added to the mix, (I refuse to use a VM, my personal hang-up). If the libprocps library the linux version depends on were ported to Android, that is another potential platform, but the "Enable Windowing Macro" will need to not be defined as that is more of a desktop-related thing. iOS can work with windowing disabled as well, but some sysctl() with KERN_PROCARGS2 may only work when running in developer/debug mode due to Apple's publishing restrictions. Linux and android are the only platforms with the third party library dependency. All other platforms only rely on dependencies already provided by the OS base and/or kernel. Here's everything you need for the API to work on most platforms, source & header... * xproc/process.cpp at main · time-killer-games/xproc (github.com)<https://github.com/time-killer-games/xproc/blob/main/apiprocess/process.cpp> * xproc/process.h at main · time-killer-games/xproc (github.com)<https://github.com/time-killer-games/xproc/blob/main/apiprocess/process.h> And only on Windows you will need these helper blobs generated by the build script... * xproc/process32.h at main · time-killer-games/xproc (github.com)<https://github.com/time-killer-games/xproc/blob/main/apiprocess/process32.h> * xproc/process64.h at main · time-killer-games/xproc (github.com)<https://github.com/time-killer-games/xproc/blob/main/apiprocess/process64.h> Here's an example of how to use the library and repository source tree... * xproc/main.cpp at main · time-killer-games/xproc (github.com)<https://github.com/time-killer-games/xproc/blob/main/main.cpp> * time-killer-games/xproc (github.com)<https://github.com/time-killer-games/xproc> * You guys have my permission to relicense this code under any version of the Boost license we can agree on if this work gets accepted at any point in time. All functions get process information in their current state at the time the functions are called expect on macOS KERN_PROCARGS2 gets the cmdline and environ of the process in its initial state when the process first launched, so if the cmdline or environ get modified after initialization or process lanch, you will have no way to get the updated values (OS-level limitation of macOS). Lastly, I have helper functions to optionally suspend and resume foreign processes to avoid race conditions where applicable. Let me know what you think and if you have any critiques or questions regarding my code do not hesitate to address that with me in a reply to this email! Thanks! Samuel

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[Spirit] '_' parsed as '\0' with qi::phrase_parse
by Olaf van der Spek 19 Jul '22

19 Jul '22

Hi, The underscore is parsed as a null character. Is this expected. A bug? If a full repro is needed I can create one. qi::rule<iterator_t, std::string(), Skip> identifier; identifier %= lexeme[alpha >> *(alnum | '.' | '_')]; typedef boost::spirit::classic::position_iterator<const char*> iterator_t; std::string s = "a_b blah"; iterator_t is(s.c_str(), s.c_str() + s.size(), "<name>"); std::string out; bool res = qi::phrase_parse(is, iterator_t(), identifier, skip, out); if (!res && is != iterator_t()) error_handler_::err(is); cout << out.size() << "|" << out << "|\n"; cout << int(out[0]) << " " << int(out[1]) << " " << int(out[2]) << "\n"; Output: // 3|ab| // 97 0 98 Greetings, -- Olaf

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[release] Boost 1.80.0 beta 1 released
by Glen Fernandes 14 Jul '22

14 Jul '22

Boost release 1.80.0 beta 1 is now available at: https://boostorg.jfrog.io/artifactory/main/beta/1.80.0.beta1/source/ The SHA256 checksums are: boost_1_80_0_b1.tar.bz2 - b29191c1bd4504511f9b1155c6f79f06cc7044444780392ed7358f5778ac7d16 boost_1_80_0_b1.tar.gz - ad3df9f63acd667dcf13375fa0e90e7303f851251e91d1505974bdbbf1f94907 boost_1_80_0_b1.7z - 7bfdf705b1d058c3525be90ed5cb47aacf919cd74aa7d5752d55e78aa60880ba boost_1_80_0_b1.zip - 1b509ed848f153086984658d4d4a57af6230f496a53bf88aba805bb49039012d Release notes (still need updates): https://www.boost.org/users/history/version_1_80_0.html Please try the beta and report any problems you encounter. Thanks, -- Boost Release Team

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[release] Boost 1.80.0 Beta 1 Release Candidate 1 is available
by Marshall Clow 14 Jul '22

14 Jul '22

Available at: <https://boostorg.jfrog.io/ui/native/main/beta/1.80.0.beta1/source> The SHA256 checksums are as follows: b29191c1bd4504511f9b1155c6f79f06cc7044444780392ed7358f5778ac7d16 boost_1_80_0_b1.tar.bz2 7bfdf705b1d058c3525be90ed5cb47aacf919cd74aa7d5752d55e78aa60880ba boost_1_80_0_b1.7z ad3df9f63acd667dcf13375fa0e90e7303f851251e91d1505974bdbbf1f94907 boost_1_80_0_b1.tar.gz 1b509ed848f153086984658d4d4a57af6230f496a53bf88aba805bb49039012d boost_1_80_0_b1.zip 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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[Graph] Can users on Xcode 7-10 help out?
by Jeremy Murphy 12 Jul '22

12 Jul '22

Dear Boost.Graph users, Is anyone that uses old Xcode 7-10 able to help out with some curious compilation errors? https://github.com/boostorg/graph/issues/298 We'll do our best to fix them but I assume it might be easier for someone that actually uses these particular platforms. Thanks, cheers. Jeremy

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static_string
by Gero Peterhoff 10 Jul '22

10 Jul '22

Hello, if i include <boost/static_string.hpp> i get errors in std::variant: /usr/include/c++/12/variant:774:72: Fehler: Templateargument 4 ist ungültig 774 | void_t<decltype(_Arr<_Ti>{{std::declval<_Tp>()}})>> | ^~ /usr/include/c++/12/variant:804:76: Fehler: Templateargument 3 ist ungültig 804 | struct __accepted_index<_Tp, _Variant, void_t<_FUN_type<_Tp, _Variant>>> | ^ Can you retrace that? boost 1.79 gcc 12.1 -std=gnu++2b openSuse Tumbleweed thx Gero

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[process] Process.Spawn leaves the child in zombie state on posix
by Benedek Tass 08 Jul '22

08 Jul '22

Hi, everyone! This bug was observed in 2022.07.05, using boost version 1.79.0. Similar behaviour was commented on before on online messageboards. Bug description When starting a new, detached process with Process.Spawn in a posix system, if the parent process outlives the child, the child process remains in zombie state for the parent process' lifetime. The bug described above is demonstrated in the CMake project attached to this document. Analysis The spawn function injects the syscall "signal(SIGCHLD, SIG_IGN)" with a functor of type boost::process::detail::posix::sig_init_. This is done to the forked child process, to no avail. And this is not done (and should not be done) in the parent process being too intrusive. Possible mitigation Introducing an in-between forked process that serves as the parent of the to-be-spawned process with SIGCHLD set to SIG_IGN would prevent the spawned process to become zombie, and simultaneously does not disturb the parent process' signal handlers. Introducing another class alternative to sig_init_ with the functionality described above would be a reasonable approach. An implementation sketch of the double fork method can be found in the attached project. System used OS: Ubuntu 18.04.6 LTS arch: x86_64 compiler: gcc-7.5.0 libc: libc-2.27 boost: 1.79.0 (built from source) Best regards, Benedek Tass

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Boost 1.80.0 closed for beta
by Glen Fernandes 07 Jul '22

07 Jul '22

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

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Boost 1.80 closed for all major changes
by Glen Fernandes 05 Jul '22

05 Jul '22

The next deadlines: - On 2022-07-06 master is closed for all changes. - On 2022-07-13 the beta is published -- Release Managers

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