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Boost.url review reminder
by Klemens Morgenstern 21 Aug '22

21 Aug '22

Hi all, this is a reminder that the boost.url review is currently going on, and we only got one review so far. Any review is appreciated. The Review ends on the 22nd, i.e. next Monday. Thanks in advance, Klemens

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Is there an analogue of `boost::reference_wrapper`, that can also work with rvalue references?
by Денис Михайлов 20 Aug '22

20 Aug '22

I find an wrapper like `boost::reference_wrapper`, but with more abilities, like this: ``` int value = 0; auto rref = boost::ref(std::move(value)); auto prref = boost::ref(int{}); f(rref); // pass rref into f by ordinary reference f(std::move(rref)); // move rref into f f(std::move(prref)); // move prref into f ``` Is there such functionality on the Boost side? If not, is it allowed to discuss the possibility of contributing it?

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Is there a way to get ctype facet with boost::locale::generator?
by Gleb Igumnov 19 Aug '22

19 Aug '22

Hello. I have a problem. I need to get std::locale object for my locale (ru_RU.UTF-8) on a systems that don't have one. I decided to take a look at boost::locale::generator, as it has ICU as a backend and there must be full locale info in it. But to my surprise generator do not generate only locale facet that I really need - ctype one. For example following code will go "oops" branch: #include <iostream> #include <boost/locale.hpp> #include <boost/locale/localization_backend.hpp> using namespace std; int main() { using namespace boost::locale; localization_backend_manager my = localization_backend_manager::global(); my.select("icu"); // I know that icu is default backend but I select it explicitly to be sure. boost::locale::generator gen(my); std::locale loc( gen.generate( "ru_RU.UTF-8" ) ); if( !std::isalpha( L'ф', loc ) ) std::cout<< "Oops\n"; else std::cout << "Ok\n"; return 0; } But if I will do std::locale loc( gen.generate( std::locale( "en_US.UTF-8" ), "ru_RU.UTF-8" ) ); It will work, as it will have ctype facet from en_US.UTF-8 locale, but that is not a solution as I may not have en_US.UTF-8 locale either, and on some systems, (for example iOS) I won't have any UTF-8 locale available for std::locale constructor. So I'm curious, why generator won't generate ctype locale? Is there any reason behind it? Or maybe I'm doing something wrong? Is there any way to generate locale with proper ctype facet from ICU using boost::locale::generator? -- -- With respect Gleb "Crazy Sage" Igumnov mailto:crazy.sage@gmail.com

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TSAN SEGFAULT in Boost.Beast CI
by Richard Hodges 16 Aug '22

16 Aug '22

Dear all, You may have noticed that one of the Beast CI checks fails on the master and develop branches. The failure is a segfault in thread sanitizer. Running on my local machine I get the stack trace embedded below. This does not happen if Asio is reverted back to version 1.79.0 Chris has confirmed that the change in Asio that caused this is in asio::spawn. Note that at this stage there is no reason to suspect that Asio is actually at fault. I believe it to be a false positive. However, I am an absolute noob when it comes to the Dark Arts of thread sanitizer. I have no idea what to blacklist. This email has two aims: 1. To prevent multiple people wasting their time trying to get to the bottom of this, 2. To encourage some sage TSAN-maester to emerge who may guide me to enlightenment. Here is the error and stack trace: testing.capture-output bin.v2/libs/beast/test/beast/http/read.test/gcc-12/debug/link-static/thread-sanitizer-norecover/threading-multi/visibility-hidden/read.run ====== BEGIN OUTPUT ====== beast.http.read ThreadSanitizer:DEADLYSIGNAL ==1761540==ERROR: ThreadSanitizer: SEGV on unknown address 0x7f6ea78ff000 (pc 0x7f6eaaaba0d0 bp 0x000000000000 sp 0x7f6ea783d910 T1761542) ==1761540==The signal is caused by a READ memory access. #0 __sanitizer::StackDepotBase<__sanitizer::StackDepotNode, 1, 20>::Put(__sanitizer::StackTrace, bool*) <null> (libtsan.so.2+0xba0d0) #1 __tsan::CurrentStackId(__tsan::ThreadState*, unsigned long) <null> (libtsan.so.2+0x8c48f) #2 __sanitizer::DD::MutexInit(__sanitizer::DDCallback*, __sanitizer::DDMutex*) <null> (libtsan.so.2+0xac534) #3 __tsan::DDMutexInit(__tsan::ThreadState*, unsigned long, __tsan::SyncVar*) <null> (libtsan.so.2+0x9a3f8) #4 __tsan::MetaMap::GetSync(__tsan::ThreadState*, unsigned long, unsigned long, bool, bool) <null> (libtsan.so.2+0xa85dc) #5 __tsan_atomic32_fetch_add <null> (libtsan.so.2+0x783e9) #6 __gnu_cxx::__exchange_and_add(int volatile*, int) /usr/include/c++/12/ext/atomicity.h:66 (read+0x41ad46) #7 __gnu_cxx::__exchange_and_add_dispatch(int*, int) /usr/include/c++/12/ext/atomicity.h:101 (read+0x41ad46) #8 std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release_last_use() /usr/include/c++/12/bits/shared_ptr_base.h:187 (read+0x41ad46) #9 std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release() /usr/include/c++/12/bits/shared_ptr_base.h:361 (read+0x40d87c) #10 std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count() /usr/include/c++/12/bits/shared_ptr_base.h:1071 (read+0x41b43c) #11 std::__shared_ptr<boost::asio::detail::strand_executor_service::strand_impl, (__gnu_cxx::_Lock_policy)2>::~__shared_ptr() /usr/include/c++/12/bits/shared_ptr_base.h:1524 (read+0x424db7) #12 std::shared_ptr<boost::asio::detail::strand_executor_service::strand_impl>::~shared_ptr() /usr/include/c++/12/bits/shared_ptr.h:175 (read+0x424de3) #13 boost::asio::detail::strand_executor_service::invoker<boost::asio::io_context::basic_executor_type<std::allocator<void>, 0ul> const, void>::~invoker() <null> (read+0x486f4d) #14 boost::asio::detail::executor_op<boost::asio::detail::strand_executor_service::invoker<boost::asio::io_context::basic_executor_type<std::allocator<void>, 0ul> const, void>, boost::asio::detail::recycling_allocator<void, boost::asio::detail::thread_info_base::default_tag>, boost::asio::detail::scheduler_operation>::do_complete(void*, boost::asio::detail::scheduler_operation*, boost::system::error_code const&, unsigned long) <null> (read+0x49ff36) #15 boost::asio::detail::scheduler_operation::complete(void*, boost::system::error_code const&, unsigned long) boost/asio/detail/scheduler_operation.hpp:40 (read+0x513742) #16 boost::asio::detail::scheduler::do_run_one(boost::asio::detail::conditionally_enabled_mutex::scoped_lock&, boost::asio::detail::scheduler_thread_info&, boost::system::error_code const&) boost/asio/detail/impl/scheduler.ipp:492 (read+0x501be9) #17 boost::asio::detail::scheduler::run(boost::system::error_code&) boost/asio/detail/impl/scheduler.ipp:210 (read+0x5008af) #18 boost::asio::io_context::run() boost/asio/impl/io_context.ipp:63 (read+0x4f54d6) #19 boost::beast::test::enable_yield_to::enable_yield_to(unsigned long)::{lambda()#1}::operator()() const <null> (read+0x41480d) #20 void std::__invoke_impl<void, boost::beast::test::enable_yield_to::enable_yield_to(unsigned long)::{lambda()#1}>(std::__invoke_other, boost::beast::test::enable_yield_to::enable_yield_to(unsigned long)::{lambda()#1}&&) <null> (read+0x4bb4bc) #21 std::__invoke_result<boost::beast::test::enable_yield_to::enable_yield_to(unsigned long)::{lambda()#1}>::type std::__invoke<boost::beast::test::enable_yield_to::enable_yield_to(unsigned long)::{lambda()#1}>(boost::beast::test::enable_yield_to::enable_yield_to(unsigned long)::{lambda()#1}&&) <null> (read+0x4b8c78) #22 void std::thread::_Invoker<std::tuple<boost::beast::test::enable_yield_to::enable_yield_to(unsigned long)::{lambda()#1}> >::_M_invoke<0ul>(std::_Index_tuple<0ul>) <null> (read+0x4b5b00) #23 std::thread::_Invoker<std::tuple<boost::beast::test::enable_yield_to::enable_yield_to(unsigned long)::{lambda()#1}> >::operator()() <null> (read+0x4b1f74) #24 std::thread::_State_impl<std::thread::_Invoker<std::tuple<boost::beast::test::enable_yield_to::enable_yield_to(unsigned long)::{lambda()#1}> > >::_M_run() <null> (read+0x4ab02e) #25 execute_native_thread_routine <null> (libstdc++.so.6+0xdbb72) #26 __tsan_thread_start_func <null> (libtsan.so.2+0x393ef) #27 start_thread <null> (libc.so.6+0x8ce2c) #28 clone3 <null> (libc.so.6+0x1121af) ThreadSanitizer can not provide additional info. SUMMARY: ThreadSanitizer: SEGV (/lib64/libtsan.so.2+0xba0d0) in __sanitizer::StackDepotBase<__sanitizer::StackDepotNode, 1, 20>::Put(__sanitizer::StackTrace, bool*) ==1761540==ABORTING EXIT STATUS: 66 ====== END OUTPUT ====== -- Richard Hodges hodges.r(a)gmail.com office: +44 2032 898 513 home: +376 861 195 mobile: +376 380 212

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stream operators for number
by Gero Peterhoff 15 Aug '22

15 Aug '22

Hello, can you please provide the << and >> operators for boost::multiprecision::number as a stream template? currently (fixed ostream) template <class Backend, expression_template_option ExpressionTemplates> std::ostream& operator<<(std::ostream& os, const number<Backend, ExpressionTemplates>&) useful template <typename Char, typename Traits, typename Backend, expression_template_option ExpressionTemplates> std::basic_ostream<Char, Traits>& operator<<(std::basic_ostream<Char, Traits>& stream, const number<Backend, ExpressionTemplates>&) thx Gero

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Tested Compilers
by Eduardo Quintana 15 Aug '22

15 Aug '22

Hi! I would like to suggest that Boost is also tested on compilers like Intel OneAPI 2022 and Visual Studio 2022. Regards, Eduardo Quintana SFTWY CDI Ltda. 5511-2157-6800 / 5511-2251-8181- / 5511-95025-3705

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numeric_cast
by Gero Peterhoff 15 Aug '22

15 Aug '22

Hallo, can you improve numeric_cast 1) constexpr 2) vectorisable The problem is that the compilers on x86 without hardware support (AVX512DQ) do not vectorize the conversions u/int64_t -> float64/32_t. This may also apply to other architectures. But that can be solved manually. My patch requires C++20 (std::bit_cast), but you can probably work around that. Modifications: - add #include <boost/predef.h> - improve raw_converter For a better understanding see https://godbolt.org/z/j58rW411s regards Gero

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Boostbook doesn't not work with libxslt 1.1.35
by Giovanni Mascellani 13 Aug '22

13 Aug '22

Hi, it seems that Boost fails building boostbook docs if xsltproc and libxslt1 version 1.1.35 is installed (it works with version up to 1.1.34). Specifically, I can reproduce the failure following these steps: * recursively clone git@github.com:boostorg/boost.git * ./bootstrap.sh * echo "using boostbook ;" > user-config-doc.jam * ./b2 -j32 -q -d2 --ignore-site-config --enable-index --user-config=user-config-doc.jam --build-dir=build-doc * ./b2 -j32 -q -d2 --ignore-site-config --enable-index --user-config=user-config-doc.jam --build-dir=build-doc doc On my Debian unstable system this works when xsltproc and libxslt1.1 version 1.1.34 are installed, but fails when 1.1.35 is installed, with the following error: "xsltproc" --stringparam boost.defaults "Boost" --stringparam boost.root "../../../.." --path "build-doc/boost/bin.v2/libs/logic/doc/docbook" --xinclude -o "build-doc/boost/bin.v2/libs/logic/doc/docbook/tribool.docbook" "/<<PKGBUILDDIR>>/tools/boostbook/xsl/docbook.xsl" "/<<PKGBUILDDIR>>/libs/logic/doc/tribool.boostbook" runtime error: file /<<PKGBUILDDIR>>/tools/boostbook/xsl/annotation.xsl line 432 element element xsl:element: The effective name '' is not a valid QName. runtime error: file /<<PKGBUILDDIR>>/tools/boostbook/xsl/annotation.xsl line 432 element element xsl:element: The effective name '' is not a valid QName.runtime error: file /<<PKGBUILDDIR>>/tools/boostbook/xsl/annotation.xsl line 432 element element xsl:element: The effective name '' is not a valid QName. [repeated many times] Many different libraries are failing in the same way, so I guess that the real problem is in boostbook. However I don't know enough of XSLT and xsltproc to give a proper diagnosis. For the context, this bug was discovered during a test rebuild of the Debian package for Boost[1]. However it can be reproduced with master doing the steps above. [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1016321 Thanks in advance for any help you can provide, Giovanni.

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Superproject is taking a nap
by Vinnie Falco 12 Aug '22

12 Aug '22

The Boost superproject is not updating submodules on master, that switch needs to be flipped back on if Boost.URL is going to work. -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

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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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