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Boost Pub/Sub message service model Implementation
by Rakshita Parihar 15 Dec '20

15 Dec '20

Hello, Currently, I am working on an IoT project where I need to send data from client to server. To transfer data, I need to setup a Pub/Sub message service model. Presently, I am using MQTT Paho C libraries to transmit data to server over TCP IP protocol but I want to switch to boost C++ library for the publish/subscribe model. I am a newbie to this library and have some queries: *1) Is there any boost C++ library for pub/sub model? If yes, please give me the details or link for the tutorial.* *2) If no library is present, please tell me how to implement a message pub/sub <https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern> service to communicate using boost C++ library?* Please, help me to solve these issues. Thanks & Regards, Rakshita Parihar

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[release] Boost 1.75.0 Release Candidate 1
by Marshall Clow 13 Dec '20

13 Dec '20

[release] Boost 1.75.0 Release Candidate 1 The first release candidates for the 1.75.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.75.0/source/> The SHA256 checksums are as follows: caf36d7c13b3d8ce62282a64a695113945a13b0f1796a45160726d04295f95ed boost_1_75_0_rc1.zip aeb26f80e80945e82ee93e5939baebdca47b9dee80a07d3144be1e1a6a66dd6a boost_1_75_0_rc1.tar.gz 953db31e016db7bb207f11432bef7df100516eeb746843fa0486a222e3fd49cb boost_1_75_0_rc1.tar.bz2 3a8b314871646e7404886736273c053278ba71b11347f72d4751411d65d6d1a5 boost_1_75_0_rc1.7z 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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bootstrap was broken since 1.74
by Neo Anderson 12 Dec '20

12 Dec '20

Hi List, I am a casual user of boost library. I usually build boost for use to build CodeBlocks IDE on Windows platform. But since version 1.74, I found that bootstrap.bat was broken. So I skipped 1.74 and stuck to the old version 1.73. Today I am happy to see that 1.75 was out and I thought this problem would have been fixed since it’s a small problem. But I am wrong. I think line 15 lacks command line parameter: call .\build.bat %1. After adding that %1, I successfully built b2 with bootstrap.cmd gcc. But when I run .\b2, I get very confusing error messages (which are the same ones in 1.74): C:\Build\src\boost_1_75_0>.\b2 Performing configuration checks - default address-model : 32-bit - default architecture : x86 Building the Boost C++ Libraries. - compiler supports SSE2 : yes - compiler supports SSE4.1 : yes - has synchronization.lib : yes - C++11 mutex : yes - has BCrypt API : yes - has stat::st_mtim : no - has stat::st_mtimensec : no - has stat::st_mtimespec : no - has stat::st_birthtim : no - has stat::st_birthtimensec : no - has stat::st_birthtimespec : no - has statx : no - has statx syscall : no - cxx11_auto_declarations : yes - cxx11_constexpr : yes - cxx11_defaulted_functions : yes - cxx11_final : yes - cxx11_hdr_mutex : yes - cxx11_hdr_tuple : yes - cxx11_lambdas : yes - cxx11_noexcept : yes - cxx11_nullptr : yes - cxx11_rvalue_references : yes - cxx11_template_aliases : yes - cxx11_thread_local : no - cxx11_variadic_templates : yes - has_icu builds : no warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam. note: to suppress this message, pass "--without-graph_parallel" to bjam. - zlib : yes - bzip2 : no - lzma : no - zstd : yes - lzma : no - has_lzma_cputhreads builds : no - cxx11_alignas : yes - cxx11_decltype : yes - iconv (libc) : no - iconv (separate) : yes - icu : no - icu (lib64) : no - native atomic int32 supported : yes - has message compiler : no - native syslog supported : no - pthread supports robust mutexes : no - compiler supports SSSE3 : yes - compiler supports AVX2 : yes - gcc visibility : yes - long double support : yes warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. - cxx11_static_assert : yes - std::fstream is moveable and swappable : yes - Has Large File Support : yes warning: No python installation configured and autoconfiguration note: failed. See http://www.boost.org/libs/python/doc/building.html note: for configuration instructions or pass --without-python to note: suppress this message and silently skip all Boost.Python targets - libbacktrace builds : no - addr2line builds : no - WinDbg builds : yes - WinDbgCached builds : no - BOOST_COMP_GNUC >= 4.3.0 : yes - zlib : yes (cached) - bzip2 : no (cached) - lzma : no (cached) - zstd : yes (cached) - compiler supports SSE2 : no - compiler supports SSE4.1 : no - has synchronization.lib : no - C++11 mutex : no - has BCrypt API : no - is Windows CE : no - has stat::st_mtim : no - has stat::st_mtimensec : no - has stat::st_mtimespec : no - has stat::st_birthtim : no - has stat::st_birthtimensec : no - has stat::st_birthtimespec : no - has statx : no - has statx syscall : no - cxx11_auto_declarations : no - cxx11_constexpr : no - cxx11_defaulted_functions : no - cxx11_final : no - cxx11_hdr_mutex : no - cxx11_hdr_tuple : no - cxx11_lambdas : no - cxx11_noexcept : no - cxx11_nullptr : no - cxx11_rvalue_references : no - cxx11_template_aliases : no - cxx11_thread_local : no - cxx11_variadic_templates : no - native atomic int32 supported : no - has message compiler : no - native syslog supported : no - pthread supports robust mutexes : no - has_icu builds : no - compiler supports SSSE3 : no - compiler supports AVX2 : no C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:609: in start-building from module targe ts error: Recursion in main target references error: the following target are being built currently: error: ./forward ./stage ./stage-proper libs/filesystem/build/stage libs/filesystem/build/stage-depe ndencies libs/log/build/stage libs/log/build/stage-dependencies libs/filesystem/build/stage C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:776: in class(a)main-target.generate from module object(main-target)@7282 C:/Build/src/boost_1_75_0/tools/boost_install\boost-install.jam:1176: in generate-dependencies from module boost-install C:/Build/src/boost_1_75_0/tools/build/src/kernel\modules.jam:107: in modules.call-in from module boo st-install C:/Build/src/boost_1_75_0/tools/build/src/util\indirect.jam:105: in indirect.call from module indire ct C:/Build/src/boost_1_75_0/tools/build/src/tools\generate.jam:59: in construct from module object(gen erated-target-class)@2809 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1364: in class(a)basic-target.generate fro m module object(generated-target-class)@2809 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:812: in generate-really from module obje ct(main-target)@11221 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:784: in class(a)main-target.generate from module object(main-target)@11221 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:934: in targets.generate-from-reference from module targets C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1277: in generate-dependencies from modu le object(alias-target-class)@2810 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1334: in class(a)basic-target.generate fro m module object(alias-target-class)@2810 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:812: in generate-really from module obje ct(main-target)@11222 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:784: in class(a)main-target.generate from module object(main-target)@11222 C:/Build/src/boost_1_75_0/tools/boost_install\boost-install.jam:1176: in generate-dependencies from module boost-install C:/Build/src/boost_1_75_0/tools/build/src/kernel\modules.jam:107: in modules.call-in from module boo st-install C:/Build/src/boost_1_75_0/tools/build/src/util\indirect.jam:105: in indirect.call from module indire ct C:/Build/src/boost_1_75_0/tools/build/src/tools\generate.jam:59: in construct from module object(gen erated-target-class)@1817 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1364: in class(a)basic-target.generate fro m module object(generated-target-class)@1817 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:812: in generate-really from module obje ct(main-target)@7281 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:784: in class(a)main-target.generate from module object(main-target)@7281 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:934: in targets.generate-from-reference from module targets C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1277: in generate-dependencies from modu le object(alias-target-class)@1818 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1334: in class(a)basic-target.generate fro m module object(alias-target-class)@1818 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:812: in generate-really from module obje ct(main-target)@7282 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:784: in class(a)main-target.generate from module object(main-target)@7282 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:934: in targets.generate-from-reference from module targets C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1277: in generate-dependencies from modu le object(alias-target-class)@184 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1334: in class(a)basic-target.generate fro m module object(alias-target-class)@184 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:812: in generate-really from module obje ct(main-target)@5196 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:784: in class(a)main-target.generate from module object(main-target)@5196 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:934: in targets.generate-from-reference from module targets C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1277: in generate-dependencies from modu le object(top-level-target)@190 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1334: in alias-target-class.generate fro m module object(top-level-target)@190 C:/Build/src/boost_1_75_0\boostcpp.jam:403: in build-multiple from module object(top-level-target)@1 90 C:/Build/src/boost_1_75_0\boostcpp.jam:393: in class(a)top-level-target.generate from module object(to p-level-target)@190 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:812: in generate-really from module obje ct(main-target)@5198 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:784: in class(a)main-target.generate from module object(main-target)@5198 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:934: in targets.generate-from-reference from module targets C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1277: in generate-dependencies from modu le object(top-level-target)@191 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:1334: in alias-target-class.generate fro m module object(top-level-target)@191 C:/Build/src/boost_1_75_0\boostcpp.jam:403: in build-multiple from module object(top-level-target)@1 91 C:/Build/src/boost_1_75_0\boostcpp.jam:393: in class(a)top-level-target.generate from module object(to p-level-target)@191 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:812: in generate-really from module obje ct(main-target)@5199 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:784: in class(a)main-target.generate from module object(main-target)@5199 C:/Build/src/boost_1_75_0/tools/build/src/build\targets.jam:273: in class(a)project-target.generate fr om module object(project-target)@134 C:/Build/src/boost_1_75_0/tools/build/src\build-system.jam:797: in load from module build-system C:/Build/src/boost_1_75_0/tools/build/src/kernel\modules.jam:295: in import from module modules C:/Build/src/boost_1_75_0/tools/build/src/kernel/bootstrap.jam:139: in boost-build from module C:/Build/src/boost_1_75_0/boost-build.jam:17: in module scope from module

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[release] Boost 1.75.0
by Marshall Clow 11 Dec '20

11 Dec '20

Release 1.54.0 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 1 new library and numerous enhancements and bug fixes for existing libraries. For details, including download links, see <http://www.boost.org/users/news/version_1.75.0> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.75.0/> 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. Thanks, -- The Boost Release Team Marshall Clow, Glen Fernandes, Michael Caisse

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[release] 1.76.0 open for merging
by Marshall Clow 11 Dec '20

11 Dec '20

The master branch is open for merging all stable changes from develop, including bug fixes and major upgrades to existing libraries. Breaking changes should be coordinated via the mailing list with the developers of the other libraries affected. New libraries may be added, but require permission of a release manager. In other words, merging does not require permission from a release manager, except for new libraries. Boost Calendar with the release schedule: http://www.boost.org/development/index.html <http://www.boost.org/development/index.html> Release schedule explanation: https://github.com/boostorg/wiki/wiki/Releases%3A-Schedule <https://github.com/boostorg/wiki/wiki/Releases%3A-Schedule> Release practices for developers: http://svn.boost.org/trac/boost/wiki/ImprovingPractices <http://svn.boost.org/trac/boost/wiki/ImprovingPractices> -- The Boost Release Team

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The new Boost 17.0.0
by Antony Polukhin 10 Dec '20

10 Dec '20

Hi, == The problem. TL;DR: we are having huge troubles with usability and popularity! Quite a lot of companies forbid using Boost because: * it provides vocabulary types, that should be the same across the whole project (like shared_ptr, filesystem::path or optional). Otherwise it's hard to combine different APIs * it is huge, in consists of legacy on more than a half, with a lot of dependencies between libraries. This is extremely painful for big companies, because there's no efficient distributed build system. Each company invents it's own and/or tries to minimize headers by all means. New companies (startups) also avoid Boost: * "We are using C++17, we do not want legacy libraries with C++98 support" * Junior developers are confused by multiple vocabulary types. "Should we use boost::optional or std::optional?" * hard to upgrade, because symbols are not versioned ISO C++ WG21 community not willing to push prototypes into Boost. "We aim to establish "existing practice" and provide reference implementations so that Boost libraries are suitable for eventual standardization." - that's not really true any more. == The Solution TL;DR: we need a C++17 fork of Boost with close to 0 dependencies between libraries and namespace versioning. С++17 provides many vocabulary types, feature test macro and a bunch of features for variadic templates. All of that allows us to drop a lot of weight and fix majority of popularity and usability problems. Rule of a thumb should be: "If the C++17 provides that functionality - use the standard version". That approach would allow to loose a lot of weight, do not mess with vocabulary types and significantly reduce dependencies https://pdimov.github.io/boostdep-report/master/module-levels.html By levels: config 0 -> we probably would not need it any more assert 1 -> 0 core 2 -> 1 (or 0 if we merge it with asser) smart_ptr 4 -> 2 exception 5 -> 2 stacktrace 5 -> 2 intrusive 5 -> 2 outcome 6 -> 3 container 6 -> 3 gil 11 -> 2? context 16 -> 2? dll 17 -> 1 asio 18 -> 3? beast 19 -> 4? == The Path TL;DR: we should start the Boost17 now and ship it as we are ready. Old Boost should be still available. The new approach requires quite a lot of effort and not all the maintainers have enough time to do the migration. We should keep releasing the existing Boost, while migrating the libraries to the Boost17. The migration is not as hard as it seems. It took 2 or 3 days to make Boost.DLL work with either boost or std filesystem. It could be done in less than a day, if I do not have to support the Boost filesystem. == Action points 0) Discuss 1) Bury the idea, wait for a few years, goto 0); or make a boost17 repo with the same layout as the existing one, but without submodules 2) start the migration -- Best regards, Antony Polukhin

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[release] Master branch now closed for 1.75.0 release
by Marshall Clow 09 Dec '20

09 Dec '20

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qvm: return type for mixed scalar type vector operations
by Kai Szuttor 09 Dec '20

09 Dec '20

Hey all, concerning vector operations in boost qvm, is it possible to somehow specify the return type of a binary operator with mixed scalar input data, e.g. operator+(vec<double, 3>, vec<int, 3>) ? Could not find the customisation point to do this depending on the involved operation. Thanks in advance, Kai

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Re: [boost] Boost Digest, Vol 6513, Issue 3
by Brian Wood 07 Dec '20

07 Dec '20

Peter Dimov writes: > Marshall Clow wrote: > > > I must concur with Ville here; I have had several people tell me they > won?t > > use Boost because ?it changes with every release?. > > Boost does change with every release, and I still keep using 1.38 in > several > projects of mine, but these changes are not limited to ABI at all. > Everything changes, you have to retest the whole lot, for correctness as > well as performance. > > And in general, expecting ABI stability from a collection of predominantly > header-only libraries is setting one up for severe disappointment. > > The standardized libraries are more header-only than Boost so am not sure how this isn't a rap on them also. Somehow C++ has become successful in spite of this. Brian Ebenezer Enterprises - In G-d we trust. https://github.com/Ebenezer-group/onwards

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[SmartPtr] intrusive_ref_counter CounterPolicyT requirements API?
by Billy 05 Dec '20

05 Dec '20

Hi Boost, We're considering implementing our own atomic ref count for `intrusive_ref_count` [*]. A question came up. Is the `CounterPolicyT` template parameter a stable extension hook, or are users expected to strictly stick to the two provided policies of `thread_unsafe_counter` and `thread_safe_counter`? I can see that under the hood, these policy structs are trivially simple and we can just do it, but the question is really about whether the lack of documentation implies that it's a private boost detail. From https://www.boost.org/doc/libs/1_74_0/libs/smart_ptr/doc/html/smart_ptr.htm… "The second parameter is a policy that defines the nature of the reference counter. The library provides two such policies: thread_unsafe_counter and thread_safe_counter." Thanks for your time, Billy Donahue [*] Incidentally we want to increment with memory order relaxed instead of acq_rel. -- ǝnɥɐuop ʎllıq

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