July 2020 - Boost - lists.preview.boost.org

Adding my sorting algorithm, ska_sort, to boost, attempt 2
by Malte Skarupke 24 Nov '21

24 Nov '21

Hi everyone, I started a discussion about this in October, but at the time the maintainer of the sort library was busy, then I was busy, so now it's January... I wrote a generalized version of radix sort a couple years ago and gave a talk about it here: https://www.youtube.com/watch?v=zqs87a_7zxw I would like to get a new version of that sorting algorithm into boost. It's faster than what I showed several years ago. It's also even more general and has a new interface that should be easier to extend. I uploaded the code here: https://github.com/skarupke/sort/tree/master The documentation is also already updated with new benchmark results. Let me know what's required to get this into boost. Would you like this in the form of a pull request? One of the big things that probably needs review is the interface, since radix sorting works differently than comparison based sorting. For most normal uses you just need to provide a sort key, but more complicated cases can get more complicated. I tried very hard to make everything easy, but I'd also be curious if others can come up with better ways of doing the interface. Thanks, Malte -- Malte Skarupke malteskarupke(a)fastmail.fm

8 10

[Core] gdb/VS Pretty-printers for Boost
by Jeff Trull 21 Aug '20

21 Aug '20

There's been a number of independent efforts to produce pretty-printers (or "visualizers") for different popular Boost libraries. The one I like most due to its thoughtful execution is probably this one <https://github.com/ruediger/Boost-Pretty-Printer>. But maintaining a set of pretty-printers out of tree is a challenge for all the usual reasons. Having libraries optionally supply and maintain them is much more sustainable. Would it be possible to define a small set of standard ways (file locations, build steps) for a library to store and install pretty-printers for gdb and/or Visual Studio? Thanks, Jeff

7 10

[release] Boost 1.74.0 beta 1 released
by Marshall Clow 09 Aug '20

09 Aug '20

Boost release 1.74.0 beta 1 is now available at: <https://dl.bintray.com/boostorg/beta/1.74.0.beta.1/source/> The SHA256 checksums are as follows: 577a6b575ff2c227e14cce1b929c73d969475e58f3d2ab2901ad234f773bbd12 boost_1_74_0_b1.7z ba09c72dc848e7c0904922967014d853897b5a634926c910cc3b1fd627c31605 boost_1_74_0_b1.tar.bz2 2ccdc39efa076822cf1b359f9449f9d07707f3e27a18b393297b25885a9ff45b boost_1_74_0_b1.tar.gz c267c450166e040a374eaddab5e583cef09f6c3fe96a4db826172d0315c38dd5 boost_1_74_0_b1.zip For details of what's in the release, see < https://www.boost.org/users/history/version_1_74_0.html>. Please download the beta, give it a try, and report any problems you encounter. Issues that were found during the beta release process and will be fixed for the final 1.74.0 release: * The Boost.STLInterfaces documentation was left out of the beta. * Some of the Boost.Geometry documentation files have very long names; this could cause problems on platforms (like Windows) with shorter limits on path lengths. * There is a compile error in Boost.ASIO when compiling with 32-bit MSVC-14.2 with BOOST_BEAST_NO_TS_EXECUTORS. Thanks, -- The Boost Release Team

2 3

[release] 1.74.0 post-beta merges
by Marshall Clow 03 Aug '20

03 Aug '20

The master branch is is now open for post-beta merges, but only as described in the Post-Beta Merge Policy. See <https://github.com/boostorg/wiki/wiki/Releases%3A-Beta-Merge-Policy> Reminder: The master branch closes for the release on August 5th. -- The release managers

13 52

Hello everybody, I have something to share about the shared_ptr class
by 逸霖杨 02 Aug '20

02 Aug '20

Hello dear boost members, I’m quite honored to join this mail list for the first time! As I was told that the boost project is where the shared_ptr class originated, so I think it should be OK to talk about it here. Here I have some ideas and code on my version of shared_ptr class. The aim is to remove the usage of weak_ptr and fix the circular reference problem. Please check code on https://github.com/yyl-20020115/RCGC That’s the idea and primitive implementation. I don’t know exactly how to test it more widely among situations, please help me to find the very situations that this solution would fail, and I’ll try to fix it ASAP. READM.md is a good start and README_ZHCN.md is better if you can read Chinese. However, I don’t think I can illustrate the algorithm very well both in English and Chinese. Well the code speaks for itself, and please read the code and run the program. Please generate a makefile and build with CMakeLists.txt on *nix platforms if Visual Studio 2019 (where I code the project) is not available. All ideas and discussions and help from you are all very welcome! Best Regards, Yilin

6 18

Re: [boost] About rcgc_shared_ptr
by 逸霖杨 31 Jul '20

31 Jul '20

A downgrade implementation can be like this (which is actually my former implementation during the experiments) We define an interface: struct IDIsposable { virtual void Dispose() = 0; }; And implement this interface with class A class A : public IDisposable { Public; A():disposed(false){} public: virtual void Dispose(){ if(!this->disposed){ this->_pb.Dispose();//this Dispose belongs to rcgc_shared_ptr this->_pc.Dispose(); //this Dispose belongs to rcgc_shared_ptr this->disposed = true; } } bool disposed; rcgc_shared_ptr<B> _pb; rcgc_shared_ptr<C> _pc; }; And we don’t care about ~A() and let the rcgc_shared_ptr call Dispose method of the IDisposable. This would avoid the dtors definition. However, this is not as elegant as the previous given solution in C++, having to write more code which we don’t like to do, although no difference in other languages or platforms. I’m sorry that I have to call it a day now and have to get some sleep (4:06am here) Waiting for your kindly response and suggestions. Best Regards, Yilin

1 0

Re: [boost] About rcgc_shared_ptr
by 逸霖杨 31 Jul '20

31 Jul '20

Hi, I finally understand what is Top-Post. And feel very sorry for the Top-Posted emails, please pardon me. My email writer is the default one with Win10, and it replies with Chinese RE, not English, and embedding Chinese characters. Also sorry for the inconvenience when you’re reading the replies. My aim is not to replace shared_ptr or weak_ptr, I’m trying to provide another choice. Personally, I don’t like to decide when to use shared_ptr or weak_ptr and also don’t like the IUnknown way of manually memory or object allocation management, just personally. I like GC when I code in C# or Java for I don’t have to remember the trivial things beyond my design, BUT not its performance. I code this in C++ because it would be too complicated if I insert code into JavaVM or C#’s native support platform. As we have great flexibility coding whatever we want in C++ on the infrastructure level. So this is what I’m going to do with this rcgc_shared_ptr: 1. use it in my projects, and make it go through tests to see If its capable of doing things.2. Trying to make this a part of a GC based language or platform to see any performance increasing. And if possible, just as I did in emails, contribute to communities and let other coders to decide if the work Is helpful or even harmful. Please forgive me to be such a rude guy for the first time to talk so much. However, I do hope you can debug the code and hope this can be any help. Best Regards, Yilin

1 0

Still about rcgc_shared_ptr, to Andrey
by 逸霖杨 31 Jul '20

31 Jul '20

Hi Andrey, I just put Case 1 into main function and updated the GitHub project, please pull and run. I don’t have reset function for rcgc_shared_ptr, so case 2 can not work for now. Best Regards, Yilin

1 0

[gil] Can I merge one fix for regression in 1.74?
by Mateusz Loskot 27 Jul '20

27 Jul '20

Dear Release Manager, We've received bug report about regression and have just fixed it in the develop branch of GIL: https://github.com/boostorg/gil/commit/8555ba08cd53c2ec5d65ea60bae9578ad586… Can I merge this fix to master? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

2 2

[gil] Can I merge two minor fixes to header dependencies and tests for 1.7.4?
by Mateusz Loskot 26 Jul '20

26 Jul '20

Dear Release Manager, I'd like to request permission to merge these two minor fixes into GIL's master for release with 1.74 1. Fix dynamic_image extension header dependencies https://github.com/boostorg/gil/pull/508 This basically removes all-in-one #include <boost/gil.hpp from GIL's own headers. 2. Re-enable self containing header tests in CMake https://github.com/boostorg/gil/pull/509 Minor correction to an incidental disabling of headers tests in CMake. May I? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

2 4

Two Graphs Common Spanning Trees Issue [GSoC]
by Prakash Tiwari 24 Jul '20

24 Jul '20

Hello, Community Members and developers, I'm student of Google Summer Of Code and contributing to the pgRouting <https://github.com/pgRouting/pgrouting/>[1]. I need to use boost algorithm boost::two_graphs_common_spanning_trees. I have gone through the documentation and try to use it (with help of example.cpp) But I found that this algorithm is not returning the expected results. I have mentioned the example that I have used and explained the expected and given results <https://github.com/prakashupes/ProposalCodes/issues/1>.[2] So, please try to figure out that is it a bug implemented algorithm or It might be possible that I'm using the algorithm in the wrong way. Thanks Prakash Tiwari [1].https://github.com/pgRouting/pgrouting/ [2]. https://github.com/prakashupes/ProposalCodes/issues/1

1 0

[release] Boost 1.74.0 Beta 1 Release Candidate 1
by Marshall Clow 15 Jul '20

15 Jul '20

The release candidates for the first 1.74.0 beta release are now available at: https://dl.bintray.com/boostorg/beta/1.74.0.beta.1/source/ The release notes are not yet available. The SHA256 checksums are as follows: 577a6b575ff2c227e14cce1b929c73d969475e58f3d2ab2901ad234f773bbd12 boost_1_74_0_b1_rc1.7z ba09c72dc848e7c0904922967014d853897b5a634926c910cc3b1fd627c31605 boost_1_74_0_b1_rc1.tar.bz2 2ccdc39efa076822cf1b359f9449f9d07707f3e27a18b393297b25885a9ff45b boost_1_74_0_b1_rc1.tar.gz c267c450166e040a374eaddab5e583cef09f6c3fe96a4db826172d0315c38dd5 boost_1_74_0_b1_rc1.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 Boost Release Managers

4 7

[release] Master branch now closed for 1.74.0 beta release
by Marshall Clow 12 Jul '20

12 Jul '20

1 0

[Release] master branch will be closed for the 1/74/0 beta release TODAY
by Marshall Clow 11 Jul '20

11 Jul '20

Later today the master branch will be closed for all changes. See the calendar here for more dates: https://www.boost.org/development/ <https://www.boost.org/development/> The master branch will be re-opened after the beta release. Thanks, — The Boost Release Team

1 0

CI errors in [serialization] windows cygwin, mingw builds
by Jeff Garland 11 Jul '20

11 Jul '20

I've been seeing a bunch of CI errors related to serialization that seem to be new. Not seeing this so much on the test dashboard however. https://ci.appveyor.com/project/jeking3/date-time-1evbf/builds/33988388 gcc.compile.c++ bin.v2\libs\serialization\build\gcc-mngw6\rls\cxstd-11-iso\thrd-mlt\vsblt-hdn\xml_iarchive.o gcc.compile.c++ bin.v2\libs\serialization\build\gcc-mngw6\rls\cxstd-11-iso\thrd-mlt\vsblt-hdn\xml_oarchive.o In file included from ./boost/archive/iterators/mb_from_wchar.hpp:31, from ./boost/archive/impl/xml_oarchive_impl.ipp:28, from libs\serialization\src\xml_oarchive.cpp:23: ./boost/archive/detail/utf8_codecvt_facet.hpp:20: warning: "BOOST_ARCHIVE_DECL" redefined 20 | #define BOOST_ARCHIVE_DECL | In file included from ./boost/archive/detail/auto_link_archive.hpp:26, from ./boost/archive/xml_oarchive.hpp:29, from libs\serialization\src\xml_oarchive.cpp:17: ./boost/archive/detail/decl.hpp:28: note: this is the location of the previous definition 28 | #define BOOST_ARCHIVE_DECL BOOST_SYMBOL_EXPORT | gcc.compile.c++ bin.v2\libs\serialization\build\gcc-mngw6\rls\cxstd-11-iso\thrd-mlt\vsblt-hdn\xml_archive_exception.o gcc.compile.c++ bin.v2\libs\serialization\build\gcc-mngw6\rls\cxs

3 7

Build Errors for ASIO on msvc-10.0 and -11.0
by Tom Kent 10 Jul '20

10 Jul '20

After seeing the announcement that library freeze is coming, I just tried building the master snapshot with the build scripts I use for building the windows releases. I encountered failures in msvc-10.0 and msvc-11.0 for ASIO. .\boost/asio/execution/any_executor.hpp(940) : error C2668: 'boost::asio::execution::detail::any_executor_base::query_fn_impl' : ambiguous call to overloaded function .\boost/asio/execution/any_executor.hpp(915): could be 'void boost::asio::execution::detail::any_executor_base::query_fn_impl<Ex,Prop>(void *,const void *,const void *,boost::type *)' with [ Ex=void, Prop=boost::asio::execution::context_as_t<boost::asio::execution_context &> ] .\boost/asio/execution/any_executor.hpp(902): or 'void boost::asio::execution::detail::any_executor_base::query_fn_impl<Ex,Prop>(void *,const void *,const void *,boost::type *)' with [ Ex=void, Prop=boost::asio::execution::context_as_t<boost::asio::execution_context &> ] .\boost/asio/execution/any_executor.hpp(887): or 'void boost::asio::execution::detail::any_executor_base::query_fn_impl<Ex,Prop>(void *,const void *,const void *,boost::type *)' with [ Ex=void, Prop=boost::asio::execution::context_as_t<boost::asio::execution_context &> ] .\boost/asio/execution/any_executor.hpp(875): or 'void boost::asio::execution::detail::any_executor_base::query_fn_impl<Ex,Prop>(void *,const void *,const void *,boost::type *)' with [ Ex=void, Prop=boost::asio::execution::context_as_t<boost::asio::execution_context &> ] .\boost/asio/execution/any_executor.hpp(859): or 'void boost::asio::execution::detail::any_executor_base::query_fn_impl<Ex,Prop>(void *,const void *,const void *,boost::type *)' with [ Ex=void, Prop=boost::asio::execution::context_as_t<boost::asio::execution_context &> ] .\boost/asio/execution/any_executor.hpp(849): or 'void boost::asio::execution::detail::any_executor_base::query_fn_impl<Ex,Prop>(void *,const void *,const void *,boost::type *)' with [ Ex=void, Prop=boost::asio::execution::context_as_t<boost::asio::execution_context &> ] .\boost/asio/execution/any_executor.hpp(837): or 'void boost::asio::execution::detail::any_executor_base::query_fn_impl<Ex,Prop>(void *,const void *,const void *,boost::type *)' with [ Ex=void, Prop=boost::asio::execution::context_as_t<boost::asio::execution_context &> ] .\boost/asio/execution/any_executor.hpp(827): or 'void boost::asio::execution::detail::any_executor_base::query_fn_impl<Ex,Prop>(void *,const void *,const void *,void *)' with [ Ex=void, Prop=boost::asio::execution::context_as_t<boost::asio::execution_context &> ] while trying to match the argument list '(void *, const void *, const void *, int)' .\boost/asio/execution/any_executor.hpp(1782) : see reference to function template instantiation 'void boost::asio::execution::detail::any_executor_base::query_fn<Ex,T1>(void *,const void *,const void *)' being compiled with [ Ex=void, T1=boost::asio::execution::context_as_t<boost::asio::execution_context &> ] .\boost/asio/execution/any_executor.hpp(1782) : see reference to function template instantiation 'const boost::asio::execution::detail::any_executor_base::prop_fns<Poly> *boost::asio::execution::any_executor<<unnamed-symbol>,boost::asio::execution::detail::blocking::never_t<I>,boost::asio::execution::prefer_only<InnerProperty>,boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::tracked_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::untracked_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::fork_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::continuation_t<0>>>::prop_fns_table<void>(void)' being compiled with [ Poly=boost::asio::execution::any_executor<boost::asio::execution::context_as_t<boost::asio::execution_context &>,boost::asio::execution::detail::blocking::never_t<0>,boost::asio::execution::prefer_only<boost::asio::execution::detail::blocking::possibly_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::tracked_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::untracked_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::fork_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::continuation_t<0>>>, <unnamed-symbol>=boost::asio::execution::context_as_t<boost::asio::execution_context &>, I=0, InnerProperty=boost::asio::execution::detail::blocking::possibly_t<0> ] .\boost/asio/execution/any_executor.hpp(1782) : while compiling class template member function 'boost::asio::execution::any_executor<<unnamed-symbol>,boost::asio::execution::detail::blocking::never_t<I>,boost::asio::execution::prefer_only<InnerProperty>,boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::tracked_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::untracked_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::fork_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::continuation_t<0>>>::any_executor(void)' with [ <unnamed-symbol>=boost::asio::execution::context_as_t<boost::asio::execution_context &>, I=0, InnerProperty=boost::asio::execution::detail::blocking::possibly_t<0> ] .\boost/asio/detail/io_object_impl.hpp(168) : see reference to class template instantiation 'boost::asio::execution::any_executor<<unnamed-symbol>,boost::asio::execution::detail::blocking::never_t<I>,boost::asio::execution::prefer_only<InnerProperty>,boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::tracked_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::untracked_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::fork_t<0>>,boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::continuation_t<0>>>' being compiled with [ <unnamed-symbol>=boost::asio::execution::context_as_t<boost::asio::execution_context &>, I=0, InnerProperty=boost::asio::execution::detail::blocking::possibly_t<0> ] .\boost/asio/basic_socket.hpp(1804) : see reference to class template instantiation 'boost::asio::detail::io_object_impl<IoObjectService,Executor>' being compiled with [ IoObjectService=boost::asio::detail::win_iocp_socket_service<boost::asio::ip::udp>, Executor=boost::asio::any_io_executor ] .\boost/asio/basic_datagram_socket.hpp(53) : see reference to class template instantiation 'boost::asio::basic_socket<Protocol,Executor>' being compiled with [ Protocol=boost::asio::ip::udp, Executor=boost::asio::any_io_executor ] libs\log\src\syslog_backend.cpp(315) : see reference to class template instantiation 'boost::asio::basic_datagram_socket<Protocol>' being compiled with [ Protocol=boost::asio::ip::udp ] Hopefully this can be cleared up before the beta. Thanks, Tom

3 3

[stl_interfaces] Ok to merge small fix to C++20-mode builds before release?
by Zach Laine 09 Jul '20

09 Jul '20

I have just committed a fix to develop that addresses compilation errors in C++20 builds. Is it too late to merge this to master? The change is here: https://github.com/boostorg/stl_interfaces/commit/6d31433af0b7cb8c7f9140ce4… Zach

2 2

[Boost][Outcome] Compile error?
by Emil Dotchevski 07 Jul '20

07 Jul '20

When exceptions are disabled, I get: In file included from ../../../../boost/outcome/result.hpp:34: In file included from ../../../../boost/outcome/boost_result.hpp:36: In file included from ../../../../boost/exception_ptr.hpp:9: In file included from ../../../../boost/exception/detail/exception_ptr.hpp:17: ../../../../boost/exception/detail/clone_current_exception.hpp:22:6: error: This header requires exception handling to be enabled. Is there a way to configure Outcome so it does not use (boost) exception_ptr?

5 20

[random] pull requests stacking up
by Jeff Garland 06 Jul '20

06 Jul '20

Just submitted a pull request for boost.random to remove dependence on system library. There's 17 open requests -- some of which are pretty easy maintenance items. Can someone give these some a look?

2 1

Boost.Beast state of play
by Richard Hodges 06 Jul '20

06 Jul '20

Dear all, As you know, Boost.Beast has a strong dependency on Boost.Asio. At the present time, Chris is working to finalise some significant changes to Asio. These changes have required some refactoring of Boost.Beast at short notice in order to continue to provide a functioning library. Boost.Asio has two significant customisation macros: BOOST_ASIO_NO_DEPRECATED and BOOST_ASIO_NO_TS_EXECTORS. The 1.74 release of Asio deprecates some classes and interfaces relevant to net.ts-style executors. In addition, it introduces execution-style executors. *There is no combination of the above flags (save for none of them) that will allow an unmodified dependent library or program to compile as of boost.asio 1.74.* As of this moment, Beast is correctly compiling all examples and passing all tests with the exception of tests relevant to c++20 coroutines, where the latest Asio commit on develop branch has one (it would appear) remaining bug. Chris has been contacted and we are awaiting a fix. Once I have this, I will be in a position to rebase Beast PR1999 onto develop/master in readiness for the 1.74. Thank you for bearing with me during my time as an unwilling hostage to fortune. -- Richard Hodges hodges.r(a)gmail.com office: +442032898513 home: +376841522 mobile: +376380212

12 23

Fixed Boost.CallableTraits is_invocable_v
by Barrett Adair 03 Jul '20

03 Jul '20

It was recently brought to my attention that the variable template version of boost::callable_traits::is_invocable was always broken. A fix has been merged to match the non-variable version of the trait. I This is a minor change. Can this be included in 1.74? https://github.com/boostorg/callable_traits/commit/6da8b5a9b8b439f8e751191a…

2 1

[thread] Release critical bug (optimized away hooks)
by Nikita Kniazev 02 Jul '20

02 Jul '20

I am informing release managers that there is a severe bug in Boost.Thread that will affect static library users built with MSVC in the next release. The bug report: https://github.com/boostorg/thread/issues/316 (TLDR: thread_specific_ptr data destructor is not called in non-Boost.Thread threads) I have opened a PR that fixes the issue https://github.com/boostorg/thread/pull/320, but got no response in weeks.

2 1

How good to use dynamic_bitset?
by Jupiter 02 Jul '20

02 Jul '20

Hi, I am working on an embedded system where I read hardware 32-bit register values represented variables in bits. Currently I am using bit shift to extract values, it is too vague to represent variables. I have been thinking to make overhaul of using dynamic bitset, is it a good idea or bad idea? Thank you. Kind regards, jupiter -- "A man can fail many times, but he isn't a failure until he begins to blame somebody else." -- John Burroughs

3 4

Boost, not LEWG
by Glen Fernandes 01 Jul '20

01 Jul '20

(A new subject, since the thread has evolved past the Text review result). I spend part of my time in the C++ standards committee. I spend part of my time in Boost. I would prefer that my time spent in Boost, and that Boost itself, be focused on its goals of serving the C++ community and Boost users (existing ones, and growing to new ones). If there is benefit of Boost to any other entity, be it the LEWG of the committee, or some organization, that's great. i.e. When Boost is adopted by some organization, or when Boost components go into the standard, that's just a bonus. But Boost itself shouldn't compromise on quality - in its review process or what it ships in a Boost distribution, to serve any of those other interests. Putting a bunch of experimental libraries into a Boost release just because people have proposed them for standardization is not something we should do. If someone wants to, they can should just start their own project full of libraries that have not undergone any kind of formal review, and convince OS distributions to start including that as part of their packages based on its own merits. In case there was any misunderstanding on this point: Zach's goals of standardization are his own, and in Boost we don't have to be concerned with them. Because we're not changing the review process because of them, and he's not asking us to. Glen

16 40