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[release] Boost 1.84.0
by Marshall Clow 14 Dec '23

14 Dec '23

Release 1.84.0 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 contain two new libraries, numerous enhancements and bug fixes for existing libraries. For details, including download links, see <http://www.boost.org/users/news/version_1.84.0> You can also download directly from: <https://boostorg.jfrog.io/artifactory/main/release/1.84.0/source> 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

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Re: [Boost-users] Could sprintf be replaced with snprintf?
by McGrath, Justin M 13 Dec '23

13 Dec '23

Has there been any movement on having someone else maintain ODEINT? I don't know that I would be of much use, but I'm willing to help where I can. There is one other issue that isn't critical, but it would save our group from having to do some hand editing of ODEINT for use with our project. Some of the paths are long enough that after they're included in our project they have nonportable lengths, requiring use to rename them. I made an issue last year: https://github.com/boostorg/odeint/issues/54. Changing the names would surely break code, and I don't know if this is a feasible change. Given that it's pretty easy for people to update include directives though, maybe it's not too intrusive. If it's a welcome change, I can submit a PR on GitHub. Best wishes, Justin ________________________________________ From: McGrath, Justin M <jmcgrath(a)illinois.edu> Sent: Monday, December 4, 2023 11:53 AM To: Matt Borland; Karsten Ahnert Cc: mario.mulansky(a)gmx.net; Nick Thompson Subject: Re: [Boost-users] Could sprintf be replaced with snprintf? Thank you everyone. It would be great if someone could continue managing the package. It's a great resource. Best wishes, Justin ________________________________________ From: Matt Borland <matt(a)mattborland.com> Sent: Friday, December 1, 2023 2:04 AM To: Karsten Ahnert Cc: McGrath, Justin M; mario.mulansky(a)gmx.net; Nick Thompson Subject: Re: [Boost-users] Could sprintf be replaced with snprintf? > On Nov 30, 2023, at 9:27 PM, Karsten Ahnert <karsten.ahnert(a)gmx.de> wrote: > > Merged the pull request. We are not actively maintaining the library anymore. > > But I will keep an eye on any upcoming changes. > Karsten, Thanks. Would you be interested in new maintainers stepping in for the library? Nick Thompson (cced) and I are maintainers on several other Boost libraries (math, multiprecision, random, and test), and we would be interested in helping out. He’s a mathematician, and I am a full-time Boost developer. If you would like to schedule a call or anything to discuss we can do that. Matt

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coroutine condition_variable
by Keith Bennett 07 Dec '23

07 Dec '23

I'm using asio's awaitable. Couroutines are pretty neat. One of the things that keeps cropping up in the ability to notify another function that something has finished. In the past, I would use condition_variable and wait on that. Is there a better way to do that with coroutines? eg, I want to do something like: asio::awaitable<void> function(std::mutex& mtx, condition_variable& cv) { std::unique_lock lock{mtx}; // suspend this function until notified or 30 seconds expired auto expired = co_await cv.wait_until(lock, std::chrono::seconds(30)); if (expired) { // or something log("expired"); co_return; } do_some_work(); } then somewhere else I might do: asio::awaitable<void> somewhere_else(condition_variable& cv) { do_other_work(); cv.notify_one(); } I understand that it's a bad idea to hold a lock during co_await. What other problems prevent something like this from being created? Does something like this already exist? It's not clear from asio reference. I'm using boost 1.81.0 but I can upgrade if that is a problem -- Keith Bennett

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[python] to_python_converter , is by value needed?
by MM 04 Dec '23

04 Dec '23

Hello, I have posted a question here some time ago, I thought to try here as well https://stackoverflow.com/questions/77552946/to-python-converter-is-by-valu… The community of experts in boost.python seems to have moved off to other concerns? Rds,

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Could sprintf be replaced with snprintf?
by McGrath, Justin M 30 Nov '23

30 Nov '23

I am using some Boost libraries in a code base that does not want any use of sprintf. An automatic test flags any calls to it or vsprintf. Is it possible to replace all uses of sprintf with snprintf? I really doubt there are actually any security issues here, but I'm hoping this wouldn't be too difficult or cause any problems other than the effort to do it. Cheers, Justin

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[Boost.Test] Saving Context Information for Failed Test Cases
by Bingtao Yin 16 Nov '23

16 Nov '23

I am a user of Boost.Test, and I am currently looking for a way to record some context information when dealing with failed test cases. Specifically, I would like to save certain variables to a file to facilitate debugging Could you please advise on any methods or recommendations within Boost.Test to fulfill this requirement? Are there any best practices or example code snippets that you could share? Thank you very much for your assistance! Best regards,

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Re: [Boost-users] Problem with named_mutex on Windows
by David C. Partridge 15 Nov '23

15 Nov '23

I just realised it's not hanging - it's thrown an interprocess exception. I have revised my code to capture and report on that. I will let you know what it says. David From: David C. Partridge <david.partridge(a)perdrix.co.uk> Sent: 13 November 2023 14:16 To: 'boost-users(a)lists.boost.org' <boost-users(a)lists.boost.org> Subject: Problem with named_mutex on Windows I have a user reporting that the following code in my application's main() hangs unless he uses "Run as Adminstrator": ZTRACE_RUNTIME("Checking Mutex"); bip::named_mutex dssMutex{ bip::open_or_create, "DeepSkyStacker.Mutex.UniqueID.12354687" }; bip::scoped_lock<bip::named_mutex> lk(dssMutex, bip::defer_lock); const bool firstInstance{ lk.try_lock() }; ZTRACE_RUNTIME(" firstInstance: %s", firstInstance ? "true" : "false"); The trace shows "Checking mutex" and then it all stops. Is my code in error and if so what do I need to change? If not, how can I determine what the problem is? On a related issue: I think that this is C++ Exception safe, as the mutex will be unlocked and deleted. However, if a C exception occurs then how should I clean up? Is the named_mutex persistent over reboots? If so, where is it held (in case I need to do a manual cleanup). Many thanks David

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Problem with named_mutex on Windows
by David C. Partridge 13 Nov '23

13 Nov '23

I have a user reporting that the following code in my application's main() hangs unless he uses "Run as Adminstrator": ZTRACE_RUNTIME("Checking Mutex"); bip::named_mutex dssMutex{ bip::open_or_create, "DeepSkyStacker.Mutex.UniqueID.12354687" }; bip::scoped_lock<bip::named_mutex> lk(dssMutex, bip::defer_lock); const bool firstInstance{ lk.try_lock() }; ZTRACE_RUNTIME(" firstInstance: %s", firstInstance ? "true" : "false"); The trace shows "Checking mutex" and then it all stops. Is my code in error and if so what do I need to change? If not, how can I determine what the problem is? On a related issue: I think that this is C++ Exception safe, as the mutex will be unlocked and deleted. However, if a C exception occurs then how should I clean up? Is the named_mutex persistent over reboots? If so, where is it held (in case I need to do a manual cleanup). Many thanks David

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Optimizing serialization of std containers
by Gidi Gal 05 Nov '23

05 Nov '23

Hello, Are there any settings or additional code required to optimize the serialization of std containers ? I serialize a nested container: std::vector<std::deque<int>>. The max size of each deque entry is 20. I include boost/serialization/deque.hpp and boost/serialization/vector.hpp and I serialize the container in the following way: std::ofstream ofs(outFileName); boost::archive::binary_oarchive oa(ofs); oa << data; I created data with 10600 integers in the deque. The size of the serialized output file is 54493. Now, I test an alternate serialization. I serialized the size of the vector and then per each entry I serialize its size, which cannot be more than 20, so char is enough for that, next I serialize the integers in this entry. The size of the serialized output file is 43484. Is there a way to achieve better results for the default serialization ? Thanks, Gidi

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why diagnostic_information is std::exception::what: Unknown exception
by Bernard 30 Oct '23

30 Oct '23

greetings kind regards may i please inquire how not to obtain "std::exception::what: Unknown exception" from diagnosic_inforumation() . my meaning is to inquire how to obtain as per example on boost web page https://www.boost.org/doc/libs/1_83_0/libs/exception/doc/tutorial_diagnosti… output : "std::exception::what: example_io error" id est where did "example_io error" come from as neither boost::exception nor std:::exception accept constructor string arguments . please my code below . thank you kindly #include "stl" // #includes all stl #include files #include "boost\exception\all.hpp" using namespace std; struct ceXception : virtual boost::exception, virtual std::exception { using this_type = ceXception; ceXception() {} auto what() { cerr << __FUNCSIG__ << endl; return string("return from " + string(__FUNCSIG__)); } template<typename charType> friend std::basic_ostream<charType>& operator<<(std::basic_ostream<charType>& _ostream, const this_type&) { cerr << "to cerr from " << __FUNCSIG__ << endl; _ostream << "to ostream from " << __FUNCSIG__ << endl; return _ostream; } }; void foo() { try { BOOST_THROW_EXCEPTION(ceXception()); } catch (ceXception& e) { cerr << boost::diagnostic_information(e); } } int main() { foo(); return 0; }

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