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[range] master broken in latest MSVC
by Vinnie Falco 26 Apr '18

26 Apr '18

I'm using the latest release of Visual Studio and I get these errors from the master superproject: 8>c:\users\vinnie\src\boost\boost\range\concepts.hpp(257): error C3646: 'n': unknown override specifier 8>c:\users\vinnie\src\boost\boost\range\concepts.hpp(264): note: see reference to class template instantiation 'boost::range_detail::RandomAccessIteratorConcept<Iterator>' being compiled 8>c:\users\vinnie\src\boost\boost\range\concepts.hpp(257): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int This issue exactly describes the problem: <https://github.com/boostorg/range/issues/68> Thanks

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[lexical_cast] calling virtual function in constructor of `boost::detail::basic_pointerbuf`
by Andrzej Krzemienski 25 Apr '18

25 Apr '18

Hi everyone, Following the recommendation, I am posting a note about the filed issue in lexical_cast: https://svn.boost.org/trac10/ticket/13540#ticket clang-tidy reports (while checking the code that uses boost::lexical_cast) a virtual function is called in the default constructor of class template boost::detail::basic_pointerbuf. (Function setbuf() is declared virtual in base class.) This might be an indication of a bug. If not, I would recommend using a different construct that avoids confusion, for instance declaring the function override final in newer versions of C++, or providing another function with different name but with the same semantics as the overriding setbuf(). Here's the link to the offending call: https://github.com/boostorg/lexical_cast/blob/develop/include/boost/detail/… Regards, &rzej;

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Fornux C++ Superset
by Phil Bouchard 24 Apr '18

24 Apr '18

Greetings, Because there was a conflict of interests in the past then I feel obliged to give an update regarding the status of the "Fornux C++ Superset" (formerly "Fornux C Leak Detector"). This way corporations will not claim ownership of the idea. - Fornux C++ Superset harnesses the power of Clang. - It now supports, as you have guessed, C++98 syntax. - It's deterministic so it will not slow down your application randomly like with Java. - You can see attached examples memory leaks in C & C++ with cyclic references which are correctly handled and the memory usage never increases. Like I mentioned previously, I am working hard on a free version I will be able to share in a month or two. Regards, Phil Bouchard www.fornux.com

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[interprocess] Enhancment for Boost.Interprocess on Windows
by Aliaksandr Zaitsau 23 Apr '18

23 Apr '18

Hello, My colleague at work suggests an enchancement for Boost.Interprocess for detecting unique boot on Windows. Currently in Boost.Interprocess we have 3 implementations: 1. Using COM. It is marked as incorrect in case of hibernation. 2. Current default implementation using system events log is incorrect since lots of computers will not have expected event in system event log. 3. There is some new for me implementation using reading Windows registry. It is disabled by default. Question 1 What Windows versions are expected to be supported by current library version? What about Windows XP? Earlier Windows? Question 2 What is the status of third implementation via registry? Question 3 It seems strange for him third implementation needs 2 registry values for creating unique id. First of them looks enough for this purpose. And another one may be not present on some Windows. Who may he speak to get technical details why this implementation looks like this? He has an idea how to implement unique boot id better than first and second implementations. He tried to email Ion Gaztanaga directly, but without any responce. Is it good idea to create PR on GitHub before getting any details from Ion? Best regards, Alexander Zaitsev

2 1

UUID broken with Boost 1.67 and VS2015?
by rleigh＠codelibre.net 23 Apr '18

23 Apr '18

In a source file including: #include <boost/uuid/uuid.hpp> #include <boost/uuid/uuid_io.hpp> #include <boost/uuid/uuid_generators.hpp> and then calling boost::uuids::to_string(boost::uuids::random_generator()()) I'm getting: [15/26] Linking CXX executable test\ome-files\ometiffwriter.exe FAILED: test/ome-files/ometiffwriter.exe cmd.exe /C "cd . && "C:\Program Files\CMake\bin\cmake.exe" -E vs_link_exe --intdir=test\ome-files\CMakeFiles\ometiffwriter.dir --manifests -- C:\PROGRA~2\MICROS~1.0\VC\bin\amd64\link.exe /nologo test\ome-files\CMakeFiles\ometiffwriter.dir\ometiffwriter.cpp.obj test\ome-files\CMakeFiles\ometiffwriter.dir\tiffsamples.cpp.obj /out:test\ome-files\ometiffwriter.exe /implib:test\ome-files\ometiffwriter.lib /pdb:test\ome-files\ometiffwriter.pdb /version:0.0 /machine:x64 /debug /INCREMENTAL /subsystem:console lib\ome\files\ome-filesd.lib lib\ome\test\ome-testd.lib C:\build\b\stage\lib\ome-xmld.lib C:\build\b\stage\lib\boost_random-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\tiffd.lib C:\build\b\stage\lib\ome-commond.lib C:\build\b\stage\lib\boost_iostreams-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_log-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_filesystem-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_regex-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_log_setup-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_thread-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_date_time-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_chrono-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_system-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_atomic-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\Xalan-C_1D.lib C:\build\b\stage\lib\xerces-c_3D.lib C:\build\b\tools\lib\gtest.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib && cd ." LINK Pass 1: command "C:\PROGRA~2\MICROS~1.0\VC\bin\amd64\link.exe /nologo test\ome-files\CMakeFiles\ometiffwriter.dir\ometiffwriter.cpp.obj test\ome-files\CMakeFiles\ometiffwriter.dir\tiffsamples.cpp.obj /out:test\ome-files\ometiffwriter.exe /implib:test\ome-files\ometiffwriter.lib /pdb:test\ome-files\ometiffwriter.pdb /version:0.0 /machine:x64 /debug /INCREMENTAL /subsystem:console lib\ome\files\ome-filesd.lib lib\ome\test\ome-testd.lib C:\build\b\stage\lib\ome-xmld.lib C:\build\b\stage\lib\boost_random-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\tiffd.lib C:\build\b\stage\lib\ome-commond.lib C:\build\b\stage\lib\boost_iostreams-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_log-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_filesystem-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_regex-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_log_setup-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_thread-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_date_time-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_chrono-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_system-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\boost_atomic-vc140-mt-gd-x64-1_67.lib C:\build\b\stage\lib\Xalan-C_1D.lib C:\build\b\stage\lib\xerces-c_3D.lib C:\build\b\tools\lib\gtest.lib kernel32.lib user32.lib gdi32.lib winspool.lib shell32.lib ole32.lib oleaut32.lib uuid.lib comdlg32.lib advapi32.lib /MANIFEST /MANIFESTFILE:test\ome-files\CMakeFiles\ometiffwriter.dir/intermediate.manifest test\ome-files\CMakeFiles\ometiffwriter.dir/manifest.res" failed (exit code 1120) with the following output: Creating library test\ome-files\ometiffwriter.lib and object test\ome-files\ometiffwriter.exp ome-filesd.lib(OMETIFFWriter.cpp.obj) : error LNK2019: unresolved external symbol BCryptCloseAlgorithmProvider referenced in function "public: __cdecl boost::uuids::detail::random_provider_base::~random_provider_base(void)" (??1random_provider_base@detail@uuids@boost@@QEAA@XZ) ome-filesd.lib(OMETIFFWriter.cpp.obj) : error LNK2019: unresolved external symbol BCryptGenRandom referenced in function "public: void __cdecl boost::uuids::detail::random_provider_base::get_random_bytes(void *,unsigned __int64)" (?get_random_bytes@random_provider_base@detail@uuids@boost@@QEAAXPEAX_K@Z) ome-filesd.lib(OMETIFFWriter.cpp.obj) : error LNK2019: unresolved external symbol BCryptOpenAlgorithmProvider referenced in function "public: __cdecl boost::uuids::detail::random_provider_base::random_provider_base(void)" (??0random_provider_base@detail@uuids@boost@@QEAA@XZ) test\ome-files\ometiffwriter.exe : fatal error LNK1120: 3 unresolved externals Looking at boost/winapi/bcrypt.hpp from the 1.67.0 source tar.bz2, I see these symbols prototyped, but not defined anywhere. Is this header broken, missing the implementation? Thanks, Roger

4 4

Seeking help to build GitHub forks on AppVeyor and Travis
by Cromwell Enage 22 Apr '18

22 Apr '18

Hi, all! 1. Is this the right mailing list to seek help for building forks of Boost library modules on GitHub? If not, which mailing list should I bring the next questions to? 2. On my Boost.Parameter fork, one of the AppVeyor jobs gets cut off after 1 hour. How do I split the job into several jobs, one for each compiler or smaller set of compilers? 3. The Boost.MultiArray project on GitHub doesn't have AppVeyor or Travis configuration files, so I created a couple for my fork based on the ones that exist in Boost.Parameter. The AppVeyor jobs error out because they don't recognize the compile-fail rule when running the Jamfile script. Any clues as to what I'm missing? 4. On my Boost.MultiArray fork, one of the Travis jobs builds fine, but the other fails because <boost/array.hpp> is not found. Has anyone else run into this issue? If so, what was your workaround? My GitHub account is GitHub.com/CromwellEnage, in case anyone wants to peruse. Thanks in advance! Cromwell D. Enage

2 2

[graph][graph_parallel][disjoint_sets] Of dependencies and "pending" libraries.
by Rene Rivera 21 Apr '18

21 Apr '18

In the process of creating Conan packages I ran into the rather strange "disjoint_sets" library. It's a library that has been "pending" for 18 years, AFAICT. I don't know what a pending status means for this. But for creating modular packages it means it's a giant PITA to deal with the the interdependencies of "disjoint_sets", "graph", and "graph_parallel". What I want to know is: 1. What is this hidden "disjoint_sets" library/module that only has two headers? 2. Why isn't "disjoint_sets" in the "graph" library tree, especially given that it's not an official library (AFAICT)? 3. Why is "graph_parallel" not in the "graph" library also? -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net

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[release] Boost 1.67.0 Release Candidate 2
by Daniel James 20 Apr '18

20 Apr '18

The second release candidates for the 1.67.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.67.0/source/> The SHA256 checksums are as follows: 1cd94f03a71334a67d36f5161b57f5931e0cd6ecf726d7aca8bd82a3be720b74 boost_1_67_0_rc2.7z 2684c972994ee57fc5632e03bf044746f6eb45d4920c343937a465fd67a5adba boost_1_67_0_rc2.tar.bz2 8aa4e330c870ef50a896634c931adf468b21f8a69b77007e45c444151229f665 boost_1_67_0_rc2.tar.gz 7e37372d8cedd0fd6b7529e9dd67c2cb1c60e6c607aed721f5894d704945a7ec boost_1_67_0_rc2.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.

11 12

Bug or change behavior in Fusion at_c in boost 1.66 and 1.67
by Pietro Incardona 18 Apr '18

18 Apr '18

Dear boost developers I used to use boost vector container with arrays like in the code below #include <boost/fusion/sequence/intrinsic/at.hpp> #include <boost/fusion/include/at.hpp> #include <boost/fusion/container/vector.hpp> int main() { boost::fusion::vector<int[3], int, int> v; boost::fusion::at_c<1>(v) = 2; boost::fusion::at_c<0>(v)[0] = 1; //// <----- Broken on newer boost version } Compiled with g++ --std=c++11 -I/home/i-bird/BOOST_166/include -o out main.cpp Unfortunately while this code was working under BOOST 1.63, on Boost 1.66 and Boost 1.67 it does not compile and it produce this error below. It seem that include/boost/fusion/container/vector/detail/value_at_impl.hpp went under some "modernization" process that broke the code above Regards Pietro /////////////////////////// Error ///////////////////////////////////////////// In file included from /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/at_impl.hpp:12:0, from /home/i-bird/BOOST_166/include/boost/fusion/container/vector/vector.hpp:29, from /home/i-bird/BOOST_166/include/boost/fusion/container/vector.hpp:12, from main.cpp:3: /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp: In instantiation of ‘struct boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’: /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/at_impl.hpp:45:95: required from ‘struct boost::fusion::extension::at_impl<boost::fusion::vector_tag>::apply<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:66:16: required from ‘struct boost::fusion::detail::at_impl<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0>, boost::fusion::vector_tag>’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:81:16: required from ‘struct boost::fusion::result_of::at<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:86:16: required from ‘struct boost::fusion::result_of::at_c<const boost::fusion::vector<int [3], int, int>, 0>’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: required by substitution of ‘template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) [with int N = 0; Sequence = boost::fusion::vector<int [3], int, int>]’ main.cpp:9:26: required from here /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: error: no matching function for call to ‘value_at_impl<mpl_::int_<0>::value>(boost::fusion::vector<int [3], int, int>*)’ decltype(vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: note: candidate: template<long unsigned int N, class U> U boost::fusion::vector_detail::value_at_impl(const volatile boost::fusion::vector_detail::store<N, U>*) U value_at_impl(store<N, U> const volatile*); ^~~~~~~~~~~~~ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: note: template argument deduction/substitution failed: /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: note: template argument ‘1’ does not match ‘0’ decltype(vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: note: template argument ‘2’ does not match ‘0’ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp: In substitution of ‘template<long unsigned int N, class U> U boost::fusion::vector_detail::value_at_impl(const volatile boost::fusion::vector_detail::store<N, U>*) [with long unsigned int N = 0; U = int [3]]’: /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: required from ‘struct boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/at_impl.hpp:45:95: required from ‘struct boost::fusion::extension::at_impl<boost::fusion::vector_tag>::apply<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:66:16: required from ‘struct boost::fusion::detail::at_impl<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0>, boost::fusion::vector_tag>’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:81:16: required from ‘struct boost::fusion::result_of::at<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:86:16: required from ‘struct boost::fusion::result_of::at_c<const boost::fusion::vector<int [3], int, int>, 0>’ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: required by substitution of ‘template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) [with int N = 0; Sequence = boost::fusion::vector<int [3], int, int>]’ main.cpp:9:26: required from here /home/i-bird/BOOST_166/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: error: function returning an array U value_at_impl(store<N, U> const volatile*); ^~~~~~~~~~~~~ main.cpp: In function ‘int main()’: main.cpp:9:26: error: no matching function for call to ‘at_c<0>(boost::fusion::vector<int [3], int, int>&)’ boost::fusion::at_c<0>(v)[0] = 1; ^ In file included from main.cpp:1:0: /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:119:5: note: candidate: template<int N, class Sequence> constexpr typename boost::lazy_disable_if<boost::is_const<Sequence>, boost::fusion::result_of::at_c<Sequence, N> >::type boost::fusion::at_c(Sequence&) at_c(Sequence& seq) ^~~~ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:119:5: note: template argument deduction/substitution failed: /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: note: candidate: template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) at_c(Sequence const& seq) ^~~~ /home/i-bird/BOOST_166/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: note: substitution of deduced template arguments resulted in errors seen above [i-bird@localhost boost_bug_test]$ [i-bird@localhost boost_bug_test]$ [i-bird@localhost boost_bug_test]$ [i-bird@localhost boost_bug_test]$ g++ --std=c++11 -I/home/i-bird/BOOST_167/include -o out main.cpp In file included from /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/at_impl.hpp:12:0, from /home/i-bird/BOOST_167/include/boost/fusion/container/vector/vector.hpp:29, from /home/i-bird/BOOST_167/include/boost/fusion/container/vector.hpp:12, from main.cpp:3: /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp: In instantiation of ‘struct boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’: /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/at_impl.hpp:45:95: required from ‘struct boost::fusion::extension::at_impl<boost::fusion::vector_tag>::apply<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:66:16: required from ‘struct boost::fusion::detail::at_impl<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0>, boost::fusion::vector_tag>’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:81:16: required from ‘struct boost::fusion::result_of::at<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:86:16: required from ‘struct boost::fusion::result_of::at_c<const boost::fusion::vector<int [3], int, int>, 0>’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: required by substitution of ‘template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) [with int N = 0; Sequence = boost::fusion::vector<int [3], int, int>]’ main.cpp:9:26: required from here /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: error: no matching function for call to ‘value_at_impl<mpl_::int_<0>::value>(boost::fusion::vector<int [3], int, int>*)’ decltype(vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: note: candidate: template<long unsigned int N, class U> U boost::fusion::vector_detail::value_at_impl(const volatile boost::fusion::vector_detail::store<N, U>*) U value_at_impl(store<N, U> const volatile*); ^~~~~~~~~~~~~ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: note: template argument deduction/substitution failed: /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: note: template argument ‘1’ does not match ‘0’ decltype(vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: note: template argument ‘2’ does not match ‘0’ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp: In substitution of ‘template<long unsigned int N, class U> U boost::fusion::vector_detail::value_at_impl(const volatile boost::fusion::vector_detail::store<N, U>*) [with long unsigned int N = 0; U = int [3]]’: /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:53:68: required from ‘struct boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/at_impl.hpp:45:95: required from ‘struct boost::fusion::extension::at_impl<boost::fusion::vector_tag>::apply<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:66:16: required from ‘struct boost::fusion::detail::at_impl<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0>, boost::fusion::vector_tag>’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:81:16: required from ‘struct boost::fusion::result_of::at<const boost::fusion::vector<int [3], int, int>, mpl_::int_<0> >’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:86:16: required from ‘struct boost::fusion::result_of::at_c<const boost::fusion::vector<int [3], int, int>, 0>’ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: required by substitution of ‘template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) [with int N = 0; Sequence = boost::fusion::vector<int [3], int, int>]’ main.cpp:9:26: required from here /home/i-bird/BOOST_167/include/boost/fusion/container/vector/detail/value_at_impl.hpp:38:11: error: function returning an array U value_at_impl(store<N, U> const volatile*); ^~~~~~~~~~~~~ main.cpp: In function ‘int main()’: main.cpp:9:26: error: no matching function for call to ‘at_c<0>(boost::fusion::vector<int [3], int, int>&)’ boost::fusion::at_c<0>(v)[0] = 1; ^ In file included from main.cpp:1:0: /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:119:5: note: candidate: template<int N, class Sequence> constexpr typename boost::lazy_disable_if<boost::is_const<Sequence>, boost::fusion::result_of::at_c<Sequence, N> >::type boost::fusion::at_c(Sequence&) at_c(Sequence& seq) ^~~~ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:119:5: note: template argument deduction/substitution failed: /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: note: candidate: template<int N, class Sequence> constexpr typename boost::fusion::result_of::at_c<const Sequence, N>::type boost::fusion::at_c(const Sequence&) at_c(Sequence const& seq) ^~~~ /home/i-bird/BOOST_167/include/boost/fusion/sequence/intrinsic/at.hpp:127:5: note: substitution of deduced template arguments resulted in errors seen above

3 3

Proposal of a new container
by Vanand Gasparyan 16 Apr '18

16 Apr '18

Hi everyone, First, a short introduction of me. My name is Vanand, I'm from Armenia, 23 yo, C++ software Engineer. I'm new in the community and I've come with a proposal. I've implemented a prefix tree and tried to make it as STL compatible as possible. After a short investigation I found out that boost libraries don't provide one and here I am with a proposal. Here is the link to the repository: https://github.com/vgasparyan1995/prefix_tree It's a header only implementation, all source files are in "include" directory. I also have unit and performance tests. If the proposal (of having prefix tree container in boost) is accepted, I will ask for mentorship and support to make it "boost friendly" , create a proper documentation, meet the coding style and other guidelines. In the end I want to mention that I am new to this, so if I'm already doing something wrong or this is not the proper way to propose something, please kindly let me know and help to do it right. Looking forward to hearing from anyone :) Best Regards, Vanand

2 4

[release] 1.68.0 open for merging
by Daniel James 15 Apr '18

15 Apr '18

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 Release schedule explanation: https://github.com/boostorg/boost/wiki/Release-Schedule Release practices for developers: http://svn.boost.org/trac/boost/wiki/ImprovingPractices -- The Boost Release Team

1 0

[release] Boost 1.67.0
by Daniel James 14 Apr '18

14 Apr '18

Release 1.67.0 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 2 new libraries and numerous enhancements and bug fixes for existing libraries. For details, including download links, see <https://www.boost.org/users/news/version_1.67.0> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.67.0/> To install this release on your system, see <https://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team

2 1

Library for printing STL containers
by Eric Curtin 14 Apr '18

14 Apr '18

Hi Guys, I have tried to contact the developer of this neat little library. It allows you to use streams such as ostringstreams and couts with various STL containers, without the boilerplate of any loops to get all the contents. I will likely fork and maintain it as I have tried (and failed) to contact the developer. https://github.com/louisdx/cxx-prettyprint If I cleaned it up, could we consider it for boost inclusion? It is already under boost open source license.

2 1

MSVC now correctly reports __cplusplus
by degski 12 Apr '18

12 Apr '18

https://blogs.msdn.microsoft.com/vcblog/2018/04/09/msvc-now-correctly-repor… degski

1 0

[release] Boost 1.67.0 Release Candidate 1
by Daniel James 11 Apr '18

11 Apr '18

The release candidates for the 1.67.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.67.0/source/> The SHA256 checksums are as follows: 289d55fc90b637781018c4babe3ba83244175aa539b54bc687529a65e352e713 boost_1_67_0_rc1.7z 0d13e038f8f402ea0d811397876c8e6f2a2352c170f90d0a42bb61dcec3f86fc boost_1_67_0_rc1.tar.bz2 5d25d1cdf6f7061f25463f59ce2e5c9e1cecfece90d86a04513de386c86fbb5e boost_1_67_0_rc1.tar.gz ae8d461a8573d24813c92e3daf1f7832908d1845820d94b77243d6cd06197635 boost_1_67_0_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.

4 5

[build] Broken doc links
by Gavin Lambert 10 Apr '18

10 Apr '18

Prompted by the thread "Toolset version for Visual Studio 2017 15.6.3" over in the user list, I was looking through some Boost.Build documentation when I found some dead links and other weirdness. Boost.Build's github page links to https://www.boost.org/build/, which appears to be fully working. On https://www.boost.org/doc/libs/1_66_0/more/getting_started/windows.html, under "5.2.1 Install Boost.Build" it links to https://www.boost.org/doc/libs/1_66_0/tools/build/index.html, which appears to be a versioned clone of the above. But at that page, the "Documentation" link points at https://www.boost.org/doc/libs/1_66_0/tools/build/doc/html/index.html, which 404s. Back in "Getting Started", in "5.2.2 Identify Your Toolset" it first links directly to https://www.boost.org/build/doc/html/bbv2/reference/tools.html (which is now an unversioned link, but does work), and then to https://www.boost.org/doc/libs/1_66_0/doc/html/bbv2/installation.html (which is a versioned link that also works). So it's not very consistent. Putting these things together, it looks like the "right" root page for the versioned documentation should be https://www.boost.org/doc/libs/1_66_0/doc/html/bbv2.html, although that lacks some user-friendliness. (And it also links to https://www.boost.org/boost-build2 for yet another URL variation... although that does redirect to https://www.boost.org/build/ at least.)

2 2

please integrate patches for Boost.Gil and Boost.Graph
by Brook Milligan 10 Apr '18

10 Apr '18

I am not sure what the correct procedure for this is, but there are at least two old patches that would improve Boost.Gil and Boost.Graph. I would greatly appreciate it if someone integrates these. I have been using these for some time now with no detrimental effects. The patch to Boost.Gil corrects clearly incorrect code. The patch to Boost.Graph solves a problem that should never have been in the original design in the first place. Since it expands the acceptable set of arguments to cover the full range of values any user would expect and has the original semantics for cases that worked before, as far as I can see there can be no effect on existing user code. Thank you very much. Cheers, Brook See the following: - https://lists.boost.org/Archives/boost/2013/02/200721.php - https://svn.boost.org/trac10/ticket/7270 - https://svn.boost.org/trac10/ticket/9517 - https://svn.boost.org/trac10/attachment/ticket/9517/gil_channel_algorithm.p… - https://svn.boost.org/trac10/ticket/13397 --- boost/gil/channel_algorithm.hpp.orig 2018-02-23 22:45:42.000000000 -0700 +++ boost/gil/channel_algorithm.hpp 2018-03-11 22:05:31.000000000 -0600 @@ -25,6 +25,7 @@ #include "gil_config.hpp" #include "channel.hpp" +#include <limits> #include <boost/mpl/less.hpp> #include <boost/mpl/integral_c.hpp> #include <boost/mpl/greater.hpp> @@ -51,7 +52,7 @@ template <typename UnsignedIntegralChannel> -struct unsigned_integral_max_value : public mpl::integral_c<UnsignedIntegralChannel,-1> {}; +struct unsigned_integral_max_value : public mpl::integral_c<UnsignedIntegralChannel,std::numeric_limits<UnsignedIntegralChannel>::max()> {}; template <> struct unsigned_integral_max_value<uint8_t> : public mpl::integral_c<uint32_t,0xFF> {}; Allow dimensions to have length >= 1, rather than > 1. See https://svn.boost.org/trac10/ticket/11735. --- boost/graph/grid_graph.hpp.orig 2017-12-13 16:56:43.000000000 -0700 +++ boost/graph/grid_graph.hpp 2018-04-07 09:33:56.000000000 -0600 @@ -630,15 +630,17 @@ // If the vertex is on the edge of this dimension, then its // number of out edges is dependent upon whether the dimension - // wraps or not. - if ((vertex[dimension_index] == 0) || - (vertex[dimension_index] == (length(dimension_index) - 1))) { - out_edge_count += (wrapped(dimension_index) ? 2 : 1); - } - else { - // Next and previous edges, regardless or wrapping - out_edge_count += 2; - } + // wraps or not, but only if the length is > 1. + if (length(dimension_index) > 1) { + if ((vertex[dimension_index] == 0) || + (vertex[dimension_index] == (length(dimension_index) - 1))) { + out_edge_count += (wrapped(dimension_index) ? 2 : 1); + } + else { + // Next and previous edges, regardless or wrapping + out_edge_count += 2; + } + } } return (out_edge_count);

4 7

[concept_check] Reference page concept links out-of-date
by Spencer Collyer 09 Apr '18

09 Apr '18

Not sure if this has been reported before, but any links on the Reference page of the concept_check library that point to SGI.com now take you to a page that says 'SGI.com Tech Archive Resources now retired'. Regards, Spencer Collyer

5 4

Reducing dependencies
by Antony Polukhin 08 Apr '18

08 Apr '18

Hello, I've noted that many libraries depend on container_hash while it depends only on a single header from Boost.Detail library https://pdimov.github.io/boostdep-report/master/module-levels.html Can we move "boost/detail/container_fwd.hpp" into Boost.Core or into Boost.ContainerHash? This will break the circular dependency, move the Boost.ContainerHash on level 4 and improve levels of Intrusive, Container, CircularBuffer, Unordered, Algorithm, Test, TypeIndex, Any, Function, Functional, ScopeExit, Signals, MultiArray, Variant. -- Best regards, Antony Polukhin

6 12

[release] 1.67.0 mostly closed for release candidate
by Daniel James 07 Apr '18

07 Apr '18

The master branch is now closed for all changes except by permission for the release candidate. We're expecting potential fixes for build, context and a documentation update for ptr_container. Please let us know if there are any other fixes that you want to include in the release. Thanks, -- The Boost Release Team

5 9

mkmakefile
by Ggh 05 Apr '18

05 Apr '18

Hi! is anyone interested in developing this code further? pls have a look at: http://www.multi.fi/~ghaga http://www.multi.fi/~ghaga/mkmakefile/ anyone? Ty, Greg

4 6

[ptr_container] Docs not updated to reflect std::auto_ptr -> std:unique_ptr changes
by Edward Diener 04 Apr '18

04 Apr '18

An issue was recently created that while ptr_container now supports std::unique_ptr where appropriate and no longer supports std::auto_ptr where it has been removed from the C++ standard, the docs were never updated to reflect this change. I thought it would be worthwhile mentioning this as we go to the 1.67 release. A contributo is preparing a PR to correct this issue, and I will review as a member of CMT once the PR is submitted. I don't mean this as a way to delay the new release but I thought I should bring this up in the mailing list so others know this is the case.

2 1

[1.67] Missing include in Boost.Graph
by Denis Davydov 03 Apr '18

03 Apr '18

Dear all, 1.67.0.beta1 has a regression of missing include in Boost.Graph which prevents deal.II https://www.dealii.org <https://www.dealii.org/> project from building. Even though the file was not modified since 2015, it’s a regression as we have not had this issue with previous versions of boost. The one-liner fix is here https://github.com/boostorg/graph/pull/104 <https://github.com/boostorg/graph/pull/104> I would appreciate if you could merge it prior to 1.67.0 release. ps. https://github.com/boostorg/graph/pull/101 <https://github.com/boostorg/graph/pull/101> is a better way to fix it but as suggested in https://svn.boost.org/trac10/ticket/13505#comment:4 <https://svn.boost.org/trac10/ticket/13505#comment:4> this might not get merged into 1.67.0, which would be pity. Regards, Denis

3 2

Build breaking changes
by Antony Polukhin 03 Apr '18

03 Apr '18

Hello, I've just noted that building Boost from master stopped working: [00:16:51] b2.exe -j4 toolset=gcc --layout=system variant=release architecture=x86 link=static --with-program_options --with-filesystem --with-system --with-test --with-atomic --with-thread --with-timer --with-date_time --with-chrono --with-regex --with-random --with-context stage [00:16:52] Performing configuration checks [00:16:52] [00:16:52] - default address-model : 32-bit [00:16:53] - default architecture : x86 [00:16:53] - symlinks supported : yes (cached) [00:16:54] - C++11 mutex : yes [00:16:55] - has_icu builds : no [00:16:55] - BOOST_COMP_GNUC >= 4.3.0 : yes [00:16:55] - C++11 mutex : no [00:16:56] - has_icu builds : no [00:16:56] - BOOST_COMP_GNUC >= 4.3.0 : no [00:16:56] error: Name clash for '<pstage\lib>libboost_atomic.a' [00:16:56] error: [00:16:56] error: Tried to build the target twice, with property sets having [00:16:56] error: these incompatible properties: [00:16:56] error: [00:16:56] error: - <address-model>64 [00:16:56] error: - <address-model>32 [00:16:56] error: [00:16:56] error: Please make sure to have consistent requirements for these [00:16:56] error: properties everywhere in your project, especially for install [00:16:56] error: targets. [00:16:56] [00:16:56] Command exited with code 1 Previously this build command worked fine. Full log available at https://ci.appveyor.com/project/apolukhin/boost-cookbook/branch/second_edit… Is this an intended breaking change?

12 21

Debate until Decision
by James E. King, III 03 Apr '18

03 Apr '18

I'm going to float some thoughts about how the group makes decisions below. I'm not suggesting a specific course of action, but I would like people to think about how these ideas can be used to improve Boost development. Recent discussions about default address-model, and past discussions about issues like cmake and CI build improvements (like whether or not to purchase more build slaves from travis or appveyor), and topics about legal use of code snippets leads me to the following conclusion: 1. We are geographically, culturally, and vertically distributed and have highly varying viewpoints. 2. We are all very good at expressing our viewpoint about various topics. 3. We collectively need to improve our skill at coming to a group decision and moving forward. Folks generally have individual control over their respective maintained repositories in the current structure. There are many topics that generally affect all of the repositories, such as the ones I mentioned previously, that affect all of us. At my most recent startup company we implemented an effective "Debate until Decision" mechanism by which: 1. The issue is discussed. (We do this well) 2. A decision is made and implemented (We do not seem to do this well): Not everyone will be happy with the outcome. Folks should not attempt to undermine the outcome after decision. The issue can be raised again if new information is brought to light. How is a decision made? Typically in a meeting where people vote face-to-face. For a group like this, voting would be done online with a time limit. Who can vote? That's a good question. In this environment it may fall to the group of folks who are maintainers of an affected repository. I don't necessarily have a good answer for that, as I am relatively new to the group. Some folks have been here for 10+ years and may feel differently that seniority should have a say. I don't know. What are the benefits of this? Simply: *Things get done.* Look at the cmake discussion, or the CI build job discussion, or the current address-model discussion. These need to be finished, agreed to, and implemented (or not), and everyone moves forward. The Apache Software Foundation maintains a fairly well documented structure for each project, with a project management committee consisting of a chair and members who have equal voting rights, however said group's primary function is to identify and grow the team of developers who have commit privileges. The committers as a whole vote on issues that are project-wide, like "should we split into multiple repositories", or "should we move to another source code control environment"? This mechanism could also be applied to how folks are brought into maintainer status for a repository, or how a library enters the CMT. If you look at the bug backlog in trac for some one the libraries, it's pretty clear that they are not properly maintained. The issue may be discussed, but then dropped and forgotten, and no action is taken to remedy it. When repositories have pull requests open for years, or a backlog of 100 defects going back 10 years, there's a very unhealthy problem for that project that needs to be addressed. It may be a similar structure that will work well here. Folks may disagree. This will be debated, certainly, as folks probably have varying opinions about how much structure is needed or desired. I simply hope this leads to an effective discussion about how this group identifies deficiencies, solves them, and moves forward. Any group large or small can benefit from examination and improvement of processes, including ours. Thanks, Jim

5 5

[ineterprocess] managed mapped file - recovery from process failure
by Assaf Ben-amitai 02 Apr '18

02 Apr '18

Hi, I have noticed that if a process is killed while it's allocating memory from a managed file, later loading of the managed file may segfault (even in read-only mode). A. What is the expected behaviour in this case? B. Should such a segfault be considered as a bug or is it the case that the user is not supposed to use the managed file after process failure? C. If unsupported, any pointers on efforts to improve this? Thx, Assaf

2 1

[cmake] Where to discuss CMake in Boost?
by Mateusz Loskot 02 Apr '18

02 Apr '18

Hi, TL;TR: Which is the right mailing list to discuss CMake in Boost? Numerous CMake discussions happened here lately which, I think, were mostly about the grand Boost vs CMake strategy, politics. The boost-cmake ml has been quiet for years now, according to its archives. https://lists.boost.org/mailman/listinfo.cgi/boost-cmake Whereas, there has been lots of activity in development of CMake for various aspects: to use CMake inside Boost. to use CMake to build Boost, etc. That is https://github.com/boost-cmake where, in particular, I'm interested in https://github.com/boost-cmake/bcm Where can I ask *technical* questions about those to avoid polluting wrong list? Best regards. -- Mateusz Loskot, http://mateusz.loskot.net

5 10

[gil] Locator bug in MSVC release builds
by Christian Henning 31 Mar '18

31 Mar '18

Hi all, there is this nagging bug (#49) with boost::gil which I have a hard time figuring out. Please consider the following code: #define _CRT_SECURE_NO_WARNINGS 1 #include <boost/gil/gil_all.hpp> #include <boost/gil/extension/io/bmp_all.hpp> using namespace boost::gil; int main() { using ref_t = const bit_aligned_pixel_reference<boost::uint8_t, boost::mpl::vector3_c<int, 1, 2, 1>, bgr_layout_t, true>; using ptr_t = bit_aligned_pixel_iterator<ref_t>; using pixel_t = std::iterator_traits<ptr_t>::value_type; using bgr121_image_t = image<ref_t, false>; ////////////////////// // works ////////////////////// { bgr121_image_t a(10, 10); fill_pixels(view(a), pixel_t(0, 0, 1)); auto loc = view(a).xy_at(0, 0); for (int y = 0; y < view(a).height(); ++y) { *loc = pixel_t(1, 0, 0); ++loc.x(); ++loc.y(); } auto v = color_converted_view<rgb8_pixel_t>(view(a)); write_view("a.bmp", v, bmp_tag()); } ////////////////////// // doesn't work ////////////////////// { bgr121_image_t b(10, 10); fill_pixels(view(b), pixel_t(0, 0, 1)); auto loc = view(b).xy_at(0, view(b).height() - 1); for (int y = 0; y < view(b).height(); ++y) { *loc = pixel_t(1, 0, 0); ++loc.x(); --loc.y(); } auto v = color_converted_view<rgb8_pixel_t>(view(b)); write_view("b.bmp", v, bmp_tag()); } } When running with VS 2017 all is working in Debug but with Release the second image is incorrect. The bug should be in the locator code. Anyone has an idea what is going wrong or what else I should try? Thanks, Christian

2 3

[boost.test] merging minor changes to master
by Raffi Enficiaud 31 Mar '18

31 Mar '18

Hi list, I merged a very minor commit that will make MinGW people happy. Rev of Boost.test on master is now 413b2f660118060db732dbf38a2bdffb527395e3 . Since Beta1: * doc updates * small bugfix PR 134 * include all lower case on windows for MinGW. PR 136 I would be grateful to the release managers if those changes go to the final 1.67 release. Thanks, Raffi

1 0

Maintenance of boostorg on AppVeyor
by Mateusz Loskot 30 Mar '18

30 Mar '18

Hi, I found [1] there is boostorg account on AppVeyor https://ci.appveyor.com/project/boostorg/boost/ There seem to be no sites/URLs per GitHub repo, eg. https://ci.appveyor.com/project/boostorg/hana https://ci.appveyor.com/project/boostorg/gil etc. I'm unclear how this is setup, but boostorg/boost seems to be a sink for all boostorg repos on GitHub. What is the purpose of this AppVeyor boostorg account? Can library maintainers have access to this account and use to build their library repo? If yes, where can I request to set-up AppVeyor roles [2] for Boost.GIL maintainers, so they can cancel/re-run builds? Or, is it that typically maintainers are supposed to create sparate account for builds a library, eg. ci.appveyor.com/project/mloskot/gil Isn't such duplication of builds a waste of resources? [1] https://lists.boost.org/Archives/boost/2015/06/223325.php [2] https://www.appveyor.com/docs/team-setup/#github-integration Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

1 0

Failing to use b2/bjam including libraries with Clang
by Paul A. Bristow 30 Mar '18

30 Mar '18

I am still failing to get Clang on Windows 10 to work with b2/bjam *linking to libraries*. I have a few simple test cases, using Boost.System to display an error code ,using Boost.Test for a 'hello World" use of Boost.Test, and a simple regex example1 linking to Boost.Regex library. All links to libraries are static (to avoid reported problems with DLL and Clang). I have tried to use the LLD linker http://releases.llvm.org/6.0.0/tools/lld/docs/ReleaseNotes.html as some have recommended this, but not successfully with libraries, so far. Things that DO work OK with Clang 6.0.0 are 1 Visual Studio IDE (using Boost prebuilt libraries) Platform Toolset = llvm-2014 and MS linker only. 2 Codeblocks IDE (mingw64 on windows 10) (using normal Boost prebuilt libraries as part of the normal install) and clang++.exe. (But NOT when using the LTO lld.exe linker getting error: Expected a single module ???- but I am not trying to use C++ modules!). 3 Using b2/bjam to run a *single* exe (no libraries). jamfile is just [ run hello_boost.cpp ] with >b2 toolset=gcc-7.2.0,msvc-14.1,clang-6.0.0 4 Using all examples in jamfile b2/bjam with libraries with toolset=gcc-7.2.0,msvc-14.1 (so I am confident that it is not a problem with the C++ or the jamfile). What *doesn't work* is b2/bjam using a library with toolset=clang-6.0.0, neither using clang++ linker nor using LTO llvm-lld.exe. And since I want to write b2 -a -j6 --debug-configuration -d2 toolset=msvc-14.1,gcc-7.2.0,clang-6.0.0 address-model=64 > my.log this is most disappointing :-( My user-config.jam contains using clang : # Version. 6.0.0 : # Location of Clang compiler .exe file(s). "C:/LLVM/clang-600/LLVM/bin/clang++.exe" : # Options. <compileflags>-v <compileflags>-m64 <compileflags>-fmsc-version=1900 <compileflags>--target=i686-pc-windows-msvc <define>_CRT_SECURE_NO_DEPRECATE <define>_CRT_SECURE_NO_WARNINGS <cxxflags>-std=c++17 <cxxflags>-flto=thin <<<<<<< if trying to use LTO lld linker <cxxflags>-Wno-deprecated <cxxflags>-Wno-deprecated-declarations <linkflags>-v <linkflags>-fuse-ld=lld <<<<<<< if trying to use LTO lld linker <linkflags>-flto=thin <<<<<<< if trying to use LTO lld linker <linkflags>--verbose <linkflags>-m64 <linkflags>--target=i686-pc-windows-msvc <linkflags>-lmsvcrt The Boost.Test and Boost.System libraries are built as expected (for Clang) at "..\..\..\bin.v2\libs\system\build\clang-gnu-linux-6.0.0\release\address-model-64\link-static\threadapi-win32\libboost_system-clang6 0-x64-1_66.lib" my jamfile contains lines like [ run hello_boost_system.cpp ../../system/build//boost_system/<link>static ] [ run hello_boost_test.cpp : : : <library>/boost/test//boost_unit_test_framework/<link>static ] After trying a bewildering array of linkers, and many options, I finally always end up with a series of link failures with errors either like error: lto.tmp: undefined symbol: ? system_category@system@boost@@YAAEBVerror_category@12@XZ or a missing entry point: LINK : fatal error LNK1561: entry point must be defined (This appears to be a message from MSVC, not the lld linker?) clang-linux.link ..\..\..\bin.v2\libs\hello_boost_test\test\hello_boost_system.test\clang-gnu-linux-6.0.0\release\address-model-64\threadapi-win32\he llo_boost_system.exe "C:/LLVM/clang-600/LLVM/bin/clang++.exe" -o "..\..\..\bin.v2\libs\hello_boost_test\test\hello_boost_system.test\clang-gnu-linux-6.0.0\release\address-model-64\threadapi-win32\h ello_boost_system.exe" -Wl,--start-group "..\..\..\bin.v2\libs\hello_boost_test\test\hello_boost_system.test\clang-gnu-linux-6.0.0\release\address-model-64\threadapi-win32\h ello_boost_system.obj" "..\..\..\bin.v2\libs\system\build\clang-gnu-linux-6.0.0\release\address-model-64\link-static\threadapi-win32\libboost_system-clang6 0-x64-1_66.lib" -Wl,-Bstatic -Wl,-Bdynamic -Wl,--end-group -v -fuse-ld=lld -flto=thin --verbose -m64 --target=i686-pc-windows-msvc -lmsvcrt -m64 clang version 6.0.0 (tags/RELEASE_600/final) Target: x86_64-pc-windows-msvc Thread model: posix InstalledDir: C:\LLVM\clang-600\LLVM\bin "C:\\LLVM\\clang-600\\LLVM\\bin\\lld-link" "-out:..\\..\\..\\bin.v2\\libs\\hello_boost_test\\test\\hello_boost_system.test\\clang-gnu-linux-6.0.0\\release\\address-model-64\\t hreadapi-win32\\hello_boost_system.exe" -defaultlib:libcmt "-libpath:C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\Professional\\VC\\Tools\\MSVC\\14.13.26128\\lib\\x64" "-libpath:C:\\Program Files (x86)\\Windows Kits\\10\\Lib\\10.0.16299.0\\ucrt\\x64" "-libpath:C:\\Program Files (x86)\\Windows Kits\\10\\Lib\\10.0.16299.0\\um\\x64" -nologo --start-group "..\\..\\..\\bin.v2\\libs\\hello_boost_test\\test\\hello_boost_system.test\\clang-gnu-linux-6.0.0\\release\\address-model-64\\thread api-win32\\hello_boost_system.obj" "..\\..\\..\\bin.v2\\libs\\system\\build\\clang-gnu-linux-6.0.0\\release\\address-model-64\\link-static\\threadapi-win32\\libboost_s ystem-clang60-x64-1_66.lib" -Bstatic -Bdynamic --end-group msvcrt.lib C:\LLVM\clang-600\LLVM\bin\lld-link: warning: ignoring unknown argument: --start-group C:\LLVM\clang-600\LLVM\bin\lld-link: warning: ignoring unknown argument: -Bstatic C:\LLVM\clang-600\LLVM\bin\lld-link: warning: ignoring unknown argument: -Bdynamic C:\LLVM\clang-600\LLVM\bin\lld-link: warning: ignoring unknown argument: --end-group C:\LLVM\clang-600\LLVM\bin\lld-link: error: lto.tmp: undefined symbol: ?system_category@system@boost@@YAAEBVerror_category@12@XZ C:\LLVM\clang-600\LLVM\bin\lld-link: error: lto.tmp: undefined symbol: ?generic_category@system@boost@@YAAEBVerror_category@12@XZ clang++.exe: error: linker command failed with exit code 1 (use -v to see invocation) Which seems to indicate some link problem finding error_category (error_category is found OK with GCC or MSVC)? and for a simple use of Boost.Test library clang version 6.0.0 (tags/RELEASE_600/final) Target: x86_64-pc-windows-msvc Thread model: posix InstalledDir: C:\LLVM\clang-600\LLVM\bin "C:\\LLVM\\clang-600\\LLVM\\bin\\lld-link" "-out:..\\..\\..\\bin.v2\\libs\\hello_boost_test\\test\\hello_boost_test.test\\clang-gnu-linux-6.0.0\\release\\address-model-64\\thr eadapi-win32\\hello_boost_test.exe" -defaultlib:libcmt "-libpath:C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\Professional\\VC\\Tools\\MSVC\\14.13.26128\\lib\\x64" "-libpath:C:\\Program Files (x86)\\Windows Kits\\10\\Lib\\10.0.16299.0\\ucrt\\x64" "-libpath:C:\\Program Files (x86)\\Windows Kits\\10\\Lib\\10.0.16299.0\\um\\x64" -nologo --start-group "..\\..\\..\\bin.v2\\libs\\hello_boost_test\\test\\hello_boost_test.test\\clang-gnu-linux-6.0.0\\release\\address-model-64\\threadap i-win32\\hello_boost_test.obj" "..\\..\\..\\bin.v2\\libs\\test\\build\\clang-gnu-linux-6.0.0\\release\\address-model-64\\link-static\\threadapi-win32\\libboost_uni t_test_framework-clang60-x64-1_66.lib" "..\\..\\..\\bin.v2\\libs\\timer\\build\\clang-gnu-linux-6.0.0\\release\\address-model-64\\link-static\\threadapi-win32\\libboost_ti mer-clang60-x64-1_66.lib" "..\\..\\..\\bin.v2\\libs\\chrono\\build\\clang-gnu-linux-6.0.0\\release\\address-model-64\\link-static\\threadapi-win32\\libboost_c hrono-clang60-x64-1_66.lib" "..\\..\\..\\bin.v2\\libs\\system\\build\\clang-gnu-linux-6.0.0\\release\\address-model-64\\link-static\\threadapi-win32\\libboost_s ystem-clang60-x64-1_66.lib" -Bstatic -Bdynamic --end-group msvcrt.lib C:\LLVM\clang-600\LLVM\bin\lld-link: warning: ignoring unknown argument: --start-group C:\LLVM\clang-600\LLVM\bin\lld-link: warning: ignoring unknown argument: -Bstatic C:\LLVM\clang-600\LLVM\bin\lld-link: warning: ignoring unknown argument: -Bdynamic C:\LLVM\clang-600\LLVM\bin\lld-link: warning: ignoring unknown argument: --end-group C:\LLVM\clang-600\LLVM\bin\lld-link: error: entry point must be defined clang++.exe: error: linker command failed with exit code 1 (use -v to see invocation) Which leaves me baffled. Verbose logs are attached, and I have several others if any kind soul would be willing to pass a more expert eye over them. Ideas on what I am doing wrong most welcome? Thanks. Paul PS I am away for a while, but eagerly await solutions on my return ;-) --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

1 0

Permission to merge bugfix into 1.67 master (geometry)
by Barend Gehrels 29 Mar '18

29 Mar '18

Hi, Can I merge a small bugfix for Boost.Geometry into master? It is about https://github.com/boostorg/geometry/commit/68296965f55d911d74574ae7bbc0652… If allowed, I will cherry-pick this commit into master. Thanks, Barend

3 2

[gil] gcc fail with simple code
by Christian Henning 28 Mar '18

28 Mar '18

Hi all, we are, at the boost::gil corner, investigating a runtime failure when compiling with gcc 5.4. When running in release configuration the following code fails: #include <iostream> #include <boost/gil/gil_all.hpp> using namespace boost::gil; using namespace std; void error_if(bool condition) { if (condition) throw std::exception(); } bits32s c32s_min = channel_traits<bits32s>::min_value(); bits32s c32s_max = channel_traits<bits32s>::max_value(); // For channel values simply initialize the value directly template <typename ChannelValue> struct value_core { typedef ChannelValue channel_t; channel_t _min_v, _max_v; value_core() : _min_v(channel_traits<ChannelValue>::min_value()), _max_v(channel_traits<ChannelValue>::max_value()) {} }; int main(int argc, char *argv[]) { value_core<bits32s> a; bits32s v_min, v_max; v_min = channel_convert<bits32s>(c32s_min); v_max = channel_convert<bits32s>(c32s_max); //std::cout << v_min << std::endl; // std::cout << this->_min_v << std::endl; //std::cout << v_max << std::endl; // std::cout << this->_max_v << std::endl; error_if(v_min != a._min_v || v_max != a._max_v); } The interesting thing is that everything works with the cout's enabled. Has anyone ever dealt with a similar issue? Thanks, Christian

5 8

[optional] get() misses optional r-value overload in contrast to operator* and value()
by Viktor Sehr 28 Mar '18

28 Mar '18

Both *value()* and *operator** has an overload to handle if the *optional<T>* object is an r-value. However *get()* does not have the r-value overload. This leads to undefined behavior using *get()*, but not with *operator** and *value()*, in the following example: auto func0() { return optional<int>{3}; } auto func1() { const auto& x = func0().get(); // Undefined behavior const auto& y = func0().value(); // Correct const auto& z = *func0(); // Correct } Is this intended, I can't see any reason why the r-value overload of .get() would be missing? Otherwise, the following overload of .get() should be added: reference_type_of_temporary_wrapper get() && { BOOST_ASSERT(this->is_initialized()); return boost::move(this->get_impl()); } /Viktor Sehr, Software Developer at Toppluva

5 15

Unescaped special character in argument <cxx, flags>/std:c++nn
by Edward Diener 26 Mar '18

26 Mar '18

When compiling with vc++ and specifying in my user_config.jam file: using msvc : 14.1c14 : : <cxxflags>/std:c++14 ; using msvc : 14.1c17 : : <cxxflags>/std:c++latest ; I am getting the messages: user-config.jam:5: Unescaped special character in argument <cxxflags>/std:c++14 user-config.jam:6: Unescaped special character in argument <cxxflags>/std:c++latest I am using the latest 'develop' branch of Boost Build. What is the workaround for this ?

3 3

Stale branch removal - safe?
by James E. King, III 26 Mar '18

26 Mar '18

There are some stale branches (over 7 years old) from the svn conversion in the Boost.Uuid (and other) repository: https://github.com/boostorg/uuid/branches/stale Is it safe to remove these? example name: svn-branches/units/autoprefix Apart from "master" and "develop" branches and all the version tags, is anything else sacred for branches or tags? Thanks, Jim

1 0

Permission to merge into 1.67.0 (build fix)
by James E. King, III 26 Mar '18

26 Mar '18

Requesting permission to merge into 1.67.0 (build fix) pending successful CI completion of a pull request. Build script issue reported by a consumer of Boost.Uuid: https://github.com/boostorg/uuid/pull/62 Thanks, Jim

1 0

[release] Boost 1.67.0 Beta 1
by Daniel James 26 Mar '18

26 Mar '18

Boost release 1.67.0 beta 1 is now available at: <https://dl.bintray.com/boostorg/beta/1.67.0.beta.1/source/> The SHA256 checksums are as follows: 154cf490da858fd9c2307bb904b07a42cbe8355ecf99d5477f0d843c6d03cdda boost_1_67_0_b1.7z 0d854b208fefaeb5837d6c417f505b189275e32d017f6226001fb165a5ac51ed boost_1_67_0_b1.tar.bz2 6eb3f9ca8db355765f41361e1e26976228f0c2dff400aade8a5e97aec6aa59f4 boost_1_67_0_b1.tar.gz 678a6459f2517932536ec97297be1de46ea073f2e2ee17ec8397b80aa0953f49 boost_1_67_0_b1.zip For details of what's in the release, see <http://www.boost.org/users/history/version_1_67_0.html>. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

6 11

1.67 libraries missing autolink/dependency information
by Roger Leigh 26 Mar '18

26 Mar '18

When updating the CMake FindBoost dependencies for 1.67, it was noted that the stacktrace library wasn't being included. Closer examination showed that it doesn't have any autolink information in the headers: grep -R BOOST_LIB_NAME . | grep stacktrace grep -R BOOST_LIB_NAME . | grep contract (for example). Does this library work on Windows? Is it expected that the autolink information is missing, or is this something which needs adding? The same applies to the "contract" library. Do either of these libraries have any other dependencies on other Boost libraries? Thanks, Roger

4 5

[gsoc18] Regarding GSOC 2018 proposal for Boost.Geometry
by Vissarion Fisikopoulos 26 Mar '18

26 Mar '18

Hi, I am copying to the list. As written in https://github.com/boostorg/boost/wiki/Boost-Google-Summer-of-Code-2018 a student "takes a C++ programming aptitude test or provides links to at least 1,000 lines (excluding comments and whitespace) non-coursework C++ library (not application nor solution) open source code. Note if following the second route, code should have been open sourced at least three months ago, and show a log of commits improving the library over time." It is not clear in which case you belong. Please share your draft on gsoc page. Best, Vissarion. On 26 March 2018 at 11:58, Abhinav Siddharth <abhinavsiddharth8409(a)gmail.com> wrote: > Hello, > > Sorry to disturb you. > > As suggested by you, I have made the changes in my proposal. > > It would be very kind of you if you could share your opinion on my new > proposal. > > I have written this mail as no response came in the Boost mailing list and > GSOC deadline is coming to a close also. > > Thanks in advance. > Regards > Abhinav Siddharth

1 0

[gsoc18] Working on my proposal for Boost.Geometry project.
by Abhinav 26 Mar '18

26 Mar '18

Hi everyone, This is a draft of my proposal for Boost.Geometry. Proposal_upd.pdf <http://boost.2283326.n4.nabble.com/file/t371389/Proposal_upd.pdf> Please take a look at it and share your opinion about how I could improve it. Thanks in advance for your time and effort. Regards. Thanks in advance Abhinav Siddharth -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

1 0

[gsoc]Mentor searching for tensors support
by Jiawei Jiang 26 Mar '18

26 Mar '18

Hi community, I'm Jiawei Jiang, a graduate from Uchicago. I'm trying to find a mentor for GSoC(uBLAS, precanned project2). Here's the rough idea of my proposal: I divide the project to 3 parts. First, completion of class structure. As a extension of n-d array structure, basic lookup and modification functions(size, resize, insert, etc.), operator overloadings(+, *, ==...) and iterator interfaces must be implemented. Second, specialization for special tensors. Take 2-order tensors, matrix as an example. Many useful algorithms are implemented specifically to sparse matrix. So it's even worthy to change storing structures for sparse matrix to fit in those operation and algorithms. Similiar cases occur in high-order tensors. Last part is algorithms. Though after completion of iterator inferfaces, we can already call a lot of stl/boost algorithms, some specializations can be a choice. For examle, if we want to calculate the sum of values in n-order tensors, we need call "accumulate" for n times(well, maybe not a big codeload using generic lambdas but still a repetitive work, right?) And of course, other particular algorithms for high-order tensors is a work to complete, such as lowing/rasing index for tensors. My programming competency test: *https://github.com/awesomejiang/matrix <https://github.com/awesomejiang/matrix>* I shared my proposal draft in GSoC website and post a message in boost-uBLAS yesterday and got no response, is it too late to find mentors now? Or someone still has interest in mentoring me? Glad to hear any feedbacks!:) Best regards, Jiawei Jiang

1 0

GSoC'18 - Search for Mentor for Boost.uBLAS project
by Shivam Choudhary 26 Mar '18

26 Mar '18

Hi there, This is Shivam Choudhary, a third year undergraduate at Indian Institute of Technology Bombay. I *would like to contribute to Boost.uBLAS library's project - Add statistics and Machine Learning functions*. I have already taken Machine Learning course at my institute and am quite good at implementing these. I would be highly grateful if anyone would mentor me for this project. I have *completed the Competency test and also would like to know to whom it needs to be shared *for scrutiny. Regards, Shivam Choudhary Third year Undergraduate Indian Institute of Technology Bombay, India emailid - shivam19j(a)gmail.com ᐧ

1 0

[GSoC 2018][uBLAS] Questions about the proposal guide on GitHub Wiki
by philectron 26 Mar '18

26 Mar '18

Hello, I'm doing my GSoC 2018 proposal for Boost.uBLAS project 1 https://github.com/boostorg/boost/wiki/Boost-Google-Summer-of-Code-2018#pro… The guide suggests implementing some fundamental components like... "many sorts of distributions like histograms, etc." Why do we need to implement those distributions when we've already had all the things we need in <boost/math/distributions>? Here is the documentation page of the <boost/math/distributions> library: http://www.boost.org/doc/libs/1_66_0/libs/math/doc/html/dist.html If I read the documentation and the proposal guide correctly, then we have basically had "many sorts of distributions like histograms, etc." already, haven't we? -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

1 0

[gsoc18] Seeking mentor for Boost.uBLAS Statistics and Machine Learning
by Raul Alfonso Sanchez Cayo 26 Mar '18

26 Mar '18

Hi I'm Raul Sanchez Cayo, a student at The University of Guadalajara and I'm looking for a mentor. The Statistics and Machine Learning project on your ideas list got my attention. I just took the subject of Statistics last semester and I found it really interesting, especially when we got into different kinds of distributions and learned how to analyze them. Of course Statistics is not the only reason I want to work with this project. Since last year, I have been training to compete in the ACM-ICPC using C++. Although C++ is not the only programming language I work with, it is by far the first I have gotten to know deeply. I will be submitting a more detailed proposal at Google today, along with my programming competency test and a couple of libraries of my own. Thanks for your time, I look forward to hear from you.

1 0

[gsoc18] Project Proposal
by Vardhan Shah 25 Mar '18

25 Mar '18

Hello, I have been in touch with my mentor( Rishabh Arora) regarding project Enhancement of Boost.Intrusive library. I'm working on my project proposal. Here is draft of my proposal <https://docs.google.com/document/d/1cFqo94XmM0FE9Hd5kyRylYUoNvkIpcaF4JJQCKp…> . *Please take a look at it and share your opinion about how I could improve it. Thanks in advance for your time and effort. Any kind of help is highly appreciated.* Regards, Vardhan Shah

1 0

[gsoc18] Becoming a mentor
by Adam Wulkiewicz 25 Mar '18

25 Mar '18

Hi, What's the procedure of becoming a mentor? I couldn't find any info at our Wiki regarding this. Do I understand correctly that I should be able to go to gsoc page and agree to mentor a proposed project? I'm unable to log in. Do I need some sort of invitation? Adam

3 4

[boost 18] [gsoc18] Proposal for project 1 of Boost.ublas: Adding statistics and machine learning functions
by pranay gupta 25 Mar '18

25 Mar '18

Hello Community, I have submitted a draft of my proposal to the project 1 of boost.ublas, adding statistics and machine learning functions through the Google website. I have been writing the proposal with the help from both of the mentors. It would be really helpful if you could please review it and suggest me changes which would help me in improving it further. Thank you. Link to the proposal <https://docs.google.com/document/d/17i32MhDKBbM56VQjx7akW_-GDGpKNWhBl1EIrV9…> Sincerely, Pranay Gupta

1 0

Re: [boost] [gsoc18] Project Proposal for uBLAS - Add statistics and machine learning functions
by Arun Ramachandran 25 Mar '18

25 Mar '18

Hello, Just dropping a reminder regarding my proposal. I'd really appreciate any comments and suggestions for improvements anyone might have! I'm unsure of whether I've been specific enough while describing the interfaces to the proposed functionality, so if anyone feels I should flesh out my proposal a bit more, I'll gladly do so. Thank you, Arun Ramachandran On Sun, Mar 25, 2018 at 4:42 AM, Arun Ramachandran <ramachandran.arun(a)outlook.com<mailto:ramachandran.arun@outlook.com>> wrote: Hello, I've written a proposal for precanned idea 1 of uBLAS (add statistics and machine learning functions) and submitted a draft on the GSoC website. I'd greatly appreciate any comments on the proposal. ‌ Thank you, Arun Ramachandran

2 1

[gsoc18] Boost.uBLAS support for tensors: seeking a mentor
by Лясота Костя 25 Mar '18

25 Mar '18

Hello, My name is Konstantin. I would like to add tensor support to boost library. I am an aspirant (1st year) in computer science from Moscow Technological University, Russia (I believe aspirant corresponds to PhD Student in USA), and I have taken extra tensor algebra and differential geometry courses. My motivation, besides my affection towards topology and tensors, comes from the fact that I need C++ tensor library for use in my own project. Since I'm going to implement it, I would like to see it as a part of great open source project like Boost that anyone can use. Â I have completed a competency test: [1]http://coliru.stacked-crooked.com/a/5cf1908494c2da5d Due to some circumstances I had to do that in web ide, but I should be able to send it in separate .h and .cpp files directly via email if needed. Â I'm sorry I applied so late, but I found out about gsoc only yesterday. I should note that I'm willing to implement this even not as gsoc student, so contact me if you're interested. References 1. http://coliru.stacked-crooked.com/a/5cf1908494c2da5d

2 1

[gsoc18] Working on my proposal for Boost.Geometry project.
by Abhinav 25 Mar '18

25 Mar '18

Hi everyone, This is a draft of my proposal for Boost.Geometry. Proposal.pdf <http://boost.2283326.n4.nabble.com/file/t371389/Proposal.pdf> Please take a look at it and share your opinion about how I could improve it. Thanks in advance for your time and effort. Regards. Thanks in advance Abhinav Siddharth -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

2 3

Re: [boost] [gsoc18] Project Proposal for uBLAS - Add statistics and machine learning functions
by Arun Ramachandran 25 Mar '18

25 Mar '18

Hello, Just dropping a reminder regarding my proposal. I'd really appreciate any comments and suggestions for improvements anyone might have! I'm unsure of whether I've been specific enough while describing the interfaces to the proposed functionality, so if anyone feels I should flesh out my proposal a bit more, I'll gladly do so. Thank you, Arun Ramachandran On Sun, Mar 25, 2018 at 4:42 AM, Arun Ramachandran <ramachandran.arun(a)outlook.com<mailto:ramachandran.arun@outlook.com>> wrote: Hello, I've written a proposal for precanned idea 1 of uBLAS (add statistics and machine learning functions) and submitted a draft on the GSoC website. I'd greatly appreciate any comments on the proposal. ‌ Thank you, Arun Ramachandran

1 0

[GSoC18] proposal
by Rajat Miglani 25 Mar '18

25 Mar '18

Hello, I am Rajat Miglani,I had been in contact with my mentor (Damian Vicino) regarding the project Boost.SafeFloat. I have submitted my draft proposal on the Google and would like someone to review it. Thanks, Rajat Miglani

1 0

[GSoC 2018] A question on the wording of a background question of the proposal template
by philectron 25 Mar '18

25 Mar '18

Hello, >From Boost submission template, https://svn.boost.org/trac10/wiki/SoCSubmissionTemplate, I'm a little confused by the wording of the following question: "What are your plans beyond this Summer of Code time frame for your proposed work?" So, does this question ask about how much time I'll spend on my proposed project besides the GSoC expected timeframe, or does it ask about my plans for some projects other than this GSoC project? Thanks, Phi -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

1 0

[gsoc18] Project Proposal for uBLAS - Add statistics and machine learning functions
by Arun Ramachandran 24 Mar '18

24 Mar '18

Hello, I've written a proposal for precanned idea 1 of uBLAS (add statistics and machine learning functions) and submitted a draft on the GSoC website. I'd greatly appreciate any comments on the proposal. ‌ Thank you, Arun Ramachandran

1 0

[gsoc18] Project Proposal for uBLAS - Add statistics and machine learning functions
by Arun Ramachandran 24 Mar '18

24 Mar '18

Hello, I've written a proposal for precanned idea 1 of uBLAS (add statistics and machine learning functions) and submitted a draft on the GSoC website. I'd greatly appreciate any comments on the proposal. ‌ Thank you, Arun Ramachandran

1 0

Re: [boost] [cmake] Where to discuss CMake in Boost?
by Mateusz Loskot 24 Mar '18

24 Mar '18

On 23 March 2018 at 10:37, Paul A. Bristow via Boost <boost(a)lists.boost.org> wrote: >> Mateusz Loskot via Boost >>> On Fri, 23 Mar 2018, 00:13 P F, <pfultz2(a)yahoo.com> wrote: >>> >>> I was completely unaware of the boost-cmake ML >>> >> >> It seems a bit hidden from the front page, one has to browse lists.boost.org >> for full list of MLs. > > A bit of judicious selective cross-posting to the user or developer lists might bring progress (or snags) with Cmake to a wider > public? Valid point. I understand that may be the case indeed. OTOH, I think, the CMake has become a delicate topic in Boost. Every time I want to ask about any kind of use of CMake in Boost, I fear that will make the snowball rolling down the hill, again :) For instance, I wish Boost offered CMake support library, review eg. BCM and let it in. I'm not speaking of building Boost with CMake, no! I mean joint development of support scripts for Modern CMake which are useful for those Boost library developers who wish to add CMake configuration (along the official BB2), for convenience. I think such bunch of Boost for CMake scripts would foster better common practices. Currently, there is bunch of CMake-enabled libraries, each developed in isolation, each using different conventions, techniques, custom macros, modules. Lately, I was adding CMake setup for Boost.GIL. It made me wondering why the BCM thing is not in boost/tools/bcm. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

4 4

[GSOC18] GSOC18 with Boost.Intrusive
by Harsh Jain 24 Mar '18

24 Mar '18

Hi, I have shared a draft of my proposal for "Enhancing Boost.Intrusive library" through the GSOC portal. Someone please review that and reply with the feedbacks. Thanks, Harsh Jain

1 0

[gsoc18]Mentor search for Boost.Geometry project :Similarity between geometries
by Abhinav 24 Mar '18

24 Mar '18

Hello, My name is Abhinav and I am currently a Btech second-year student of IIT Patna, India. Recently, I was going through the project ideas listed on the Wiki page of Boost and I am very interested to work on the project idea- "Similarity between geometries". I am very keen to share my ideas on the project and I would give a detailed description of this very idea in my proposal shortly. I sincerely look forward to your reply. Thanks. Regards, Abhinav Siddharth -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

2 1

Gsoc 18
by Payal . 24 Mar '18

24 Mar '18

Can anyone provide me the contact of Vinícius dos Santos Oliveira . I urgently need it . I wish to work on New Astronomy Library as my gsoc 18 project .But I am unable to find his contact. I tried #boost channel , there they said that here you'll find nothing and when I went to #boost-soc , there noone is there. Your help would be appreciated. Thanks, Payal B.tech 2nd year Nit kurukshetra

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Re: [boost] [GSoC 2018] A Few Questions about Boost.uBLAS
by luucamphi＠gmail.com 23 Mar '18

23 Mar '18

Hello Stefan, Here is my Programming Competency Test repo: https://github.com/philectron/gsoc2018-boost-ublas-competency What are the next steps I need to take to get involved in Boost.uBLAS? Thank you! <quote author='Boost - Dev mailing list'> On 19.03.2018 00:11, philectron via Boost wrote: > Hello, > > I'm interested in working on *Boost.uBLAS* library. *I've fundamentally > finished the Programming Competency Test for this project. I'm currently > improving it.* I need more information on the following: > > *1.* Can multiple people who also apply for GSoC work on this same > project? Note that you are only referring to "Boost.uBLAS" as a whole. As you'll see on https://github.com/boostorg/boost/wiki/Boost-Google-Summer-of-Code-2018, there are actually multiple project proposals for this library. Also, note that these are mere proposals. There is no reason to restrict yourself to those. Feel free to suggest your own. (In fact, taking the initiative to reframe things according to your own expertise and interest demonstrates your ability to work autonomously, which is very valuable.) > > *2.* How will I submit my Programming Competency Test? I suggest you create a (temporary) github repo for it and then us (the potential mentors) the link to it. > > *3.* Has anyone taken this project already? There are a few submissions for the Boost.uBLAS library, yes. None are formally "taken" though. They are all in development, and will further evolve till the deadline. > > *4.* If 3 = yes, do you allow multiple people working on the same project > for GSoC 2018? See my answer to 1). I have no idea how many slots Google will give to Boost, and accordingly, how many slots an individual library (such as Boost.uBLAS) will get. > > *5.* If 5 = no, what project should I work on? I have never used or worked > with Boost Library before, so I don't know what in Boost Library needs to > be > improved. What project do you think would be feasible for > > Thank you! That's very hard to say without knowing a bit more about your programming experience and your interests. I suggest you put together a little "resume" of your education and programming background, then pick one of the competency tests above, just to get started. Then we can iterate over that and see whether there is a possible match. Regards, Stefan -- ...ich hab' noch einen Koffer in Berlin... _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost </quote> Quoted from: http://boost.2283326.n4.nabble.com/GSoC-2018-A-Few-Questions-about-Boost-uB… _____________________________________ Sent from http://boost.2283326.n4.nabble.com

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[GSoC18] Working on my proposal for the Boost.Real project
by Laouen Belloli 23 Mar '18

23 Mar '18

Hi, I have made some modifications to my Google Summer of Code proposal and I have posted the new version here <https://drive.google.com/file/d/1DGlShhVgfo4HXcXOvhDE1s-lv48p3xkt/view?usp=…>. please comment on it if you have some time so I can continue improving my proposal. The modifications in this new version are extensions to the next sections: - Availability - Software development tools - Software documentation tool I have also specified that this project is based on a precanned project but it is not the same as the one posted on the boost Github. Best regards, Laouen. 2018-03-17 13:37 GMT-03:00 Laouen Belloli <laouen.belloli(a)gmail.com>: > Hi, I was in contact with Damián Vicino talking about a proposal for the > Boost Real project. I posted here > <https://drive.google.com/file/d/1KwPUioBYy19HM0X9O1e6X6gigOkmzoqZ/view?usp=…> what > I got so far, please comment on it if you have some time so I can improve > it following your suggestions. > > I would appreciate very much your opinion as I have no experience writing > GSoC proposals. > > Thanks and Best regards to all, > Laouen. > > -- > Laouen Mayal Louan Belloli. > LIAA - DC - FCEyN - UBA. > C.A.B.A. - Buenos Aires - Argentina. > https://liaa.dc.uba.ar > +54 9 11 38675694 > -- Laouen Mayal Louan Belloli. LIAA - DC - FCEyN - UBA. C.A.B.A. - Buenos Aires - Argentina. https://liaa.dc.uba.ar +54 9 11 38675694

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[GSoC18] Astronomy Project Proposal
by Pranam Lashkari 23 Mar '18

23 Mar '18

Hello, Boost community, I was in constant contact with Vinícius dos Santos Oliveira talking about this project. I have made this proposal for the same. Hope you go through the proposal. I will appreciate your feedback to improve proposal and the betterment of the project. Proposal: https://drive.google.com/open?id=1ZdS__MZr6cSJggkK0P_w2jXQQeRWubPk Thank you, Pranam Lashkari

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[gsoc18] Draft proposal for Project 1.1: Add statistics and machine learning functions
by Dattatreya Mohapatra 23 Mar '18

23 Mar '18

Hi, I have submitted a draft proposal for the above-mentioned project on the GSoC website. I have been in contact with the mentors of the project (cc'ed) for the past couple of weeks, working on their feedback and improving the draft. *I request the community to review the draft and suggest any additions/improvements as feedback.* I have put a link to my competency test implementation in the proposal. Thanks and regards, Dattatreya Mohapatra‌

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[gsoc2018]
by Akshay Raut 22 Mar '18

22 Mar '18

Hello Boost community. I had already introduced myself. I am Akshay, computer science undergrad 3rd year. This is my project proposal on Boost.Real project. Please go through this and suggest changes if any required. Thank you all much. https://docs.google.com/document/d/1W4V4tvhl-6ZyK4Jq_NLcd1HAoOP5AWcrIU8dw3Q…

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GSOC 18 Enhancing Boost.Intrusive Library
by Athul Pai 22 Mar '18

22 Mar '18

Hello! I am Athul pai a 3rd year B.TECH student . It would be great if I get some feedback on my proposal. The link for the proposal is below Proposal <https://docs.google.com/document/d/1Rmvzq4nqsu-qEfiTbhWhSxPI31RVHoYGadbMJ7u…> Regards Athul

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[gsoc18]Mentor search for Boost.Geometry project :Similarity between geometries
by Abhinav Siddharth 22 Mar '18

22 Mar '18

*Hello, My name is Abhinav and I am currently a Btech second-year student of IIT Patna, India. Recently, I was going through the project ideas listed on the Wiki page of Boost and I am very interested to work on the project idea- "Similarity between geometries". I am very keen to share my ideas on the project and I would give a detailed description of this very idea in my proposal shortly. I sincerely look forward to your reply. Thanks. Regards, Abhinav Siddharth *

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Fwd: Fwd: [gsoc18] Boost.Detour & Mentor Search
by Michael Kiros 22 Mar '18

22 Mar '18

---------- Forwarded message ---------- From: Michael Kiros <michaelakiros(a)gmail.com> Date: 22 March 2018 at 10:16 Subject: Re: [boost] Fwd: [gsoc18] Boost.Detour & Mentor Search To: Vinícius dos Santos Oliveira <vini.ipsmaker(a)gmail.com> What's the proper interception place then? If the game's main function was called main and your hook function was called _main_hook, then you'd need a way to get your function inside of the same address space of game's process. So that would mean DLL injection, adding your DLL to the list of loaded modules etc. What's the workflow? For software where the source code is available you'd simply compile your executable with the hooks and you wouldn't have to go through the problem of having your shared library/DLL getting loaded by the process. On 21 March 2018 at 23:25, Vinícius dos Santos Oliveira < vini.ipsmaker(a)gmail.com> wrote: > 2018-03-22 1:16 GMT-03:00 Michael Kiros <michaelakiros(a)gmail.com>: > >> That repo represents the last, latest state of the repository [...] >> > > Thanks. > > [...] Like you said, it's easier to work with DLLs because their functions >> are exported so you'd just located the address >> of the function using the export symbol table and the Windows API >> functions/POSIX equivalent. >> > > I was more concerned with the separation of library/application when I > made the question. > > Suppose I want to change Tibia to cheat the game. There is a main function > there on the executable (it's not _your main_). What's the proper > interception place then? What's the workflow? Open the executable using > your executable and transfer control flow once you prepare the hooks? > > The 'hook types' that would be required would be specializations of a >> single type and each type >> would represent a different approach to hooking a function. >> > > Thanks. > > > -- > Vinícius dos Santos Oliveira > https://vinipsmaker.github.io/ >

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Fwd: [gsoc18] Boost.Detour & Mentor Search
by Michael Kiros 22 Mar '18

22 Mar '18

---------- Forwarded message ---------- From: Michael Kiros <michaelakiros(a)gmail.com> Date: 15 March 2018 at 02:30 Subject: Re: [boost] [gsoc18] Boost.Detour & Mentor Search To: David Bellot <david.bellot(a)gmail.com> Hi David, I have written the draft of a proposal to add a new library (or work on it during the Summer of Code 2018). It's a proposal for the addition of Boost.Hook, a function hooking and control flow augmentation library. It's something I've worked on a lot in the past and would like to incorporate into Boost so that both I and others have a centralized, agreed way of taking an approach to function hooking. I also have plans of integrating it with Boost.Process and some memory mapping libraries from Boost so that there are fewer "third-party dependencies". Here's a link to the draft: https://drive.google.com/file/d/1nh436adVvIHC_ AXTAJi6Wr_uLpM4-SSc/view?usp=sharing I would really like to know the feedback to this and if anyone's interesting in mentoring me during the build up of this project. It's a very interesting, useful topic. I can assure anyone that. On 14 March 2018 at 07:01, David Bellot <david.bellot(a)gmail.com> wrote: > an explanation of the idea with examples would be good. > Please follow the instructions on https://github.com/boostorg > /boost/wiki/Boost-Google-Summer-of-Code-2018 > > On Wed, Mar 14, 2018 at 12:50 PM, Michael Kiros <michaelakiros(a)gmail.com> > wrote: > >> Would the proposal be in the form of code or just an explanation of the >> idea? >> >> On Mar 14, 2018 7:41 AM, "David Bellot" <david.bellot(a)gmail.com> wrote: >> >> Hi Michael, >> >> as it is a new project in Boost, ideally you want to write a first draft >> proposal and submit it to this list too (via a link please, do not attach >> document). >> >> I'm sure someone would be interested in mentoring for GSoC especially if >> the idea is brilliantly explained. >> As we have a few days left before submission to Google, I encourage you >> to start working on it right now. >> >> Cheers, >> David >> >> On Wed, Mar 14, 2018 at 8:19 AM, Michael Kiros via Boost < >> boost(a)lists.boost.org> wrote: >> >>> Hello, >>> >>> I'm a C++ developer and have been developing in C++ for over 6 years now >>> in >>> my personal time. I wanted to accomplish two things with this post: >>> >>> 1. Propose the idea of boost::detour >>> 2. Find a mentor in the process >>> >>> Boost.Detour is not something new that I'd like to implement but a >>> concept >>> in programming that I have been using for a very long time now and would >>> love to have it easily accessible with the inclusion of a simple >>> <boost/detour.hpp>. The idea is to have function hooking easily >>> accessible >>> to everyone using C++. Though it may seem like a niche feature, function >>> hooking is more commonly used than most people think (e.g. modifying >>> binaries after compilation for feature addition, reverse engineering >>> proprietary software). It's a beautiful concept when you see it working. >>> >>> In the process I need a mentor to guide me through the process of putting >>> down my ideas to paper and implementing them according to the standards >>> that Boost holds. This includes replacing components from my library with >>> Boost concepts (e.g. boost::process). >>> >>> I'm also a student at Texas Tech University studying Computer Science. >>> >>> Can't wait to hear from someone. >>> >>> Michael >>> >>> _______________________________________________ >>> Unsubscribe & other changes: http://lists.boost.org/mailman >>> /listinfo.cgi/boost >>> >> >> >> >

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[gsoc18] Project proposal for Boost.Geometry (set operations on boxes)
by Tinko Bartels 22 Mar '18

22 Mar '18

Hi, one week ago I posted a mail searching for mentors for a Boost.Geometry idea about implementing the basic set operations (difference, union_, sym_difference) for <box,box,Collection<box> and I was happy to see interest voiced by Vissarion and Adam. I have now completed my proposal with a slightly extended version of that idea and I'd be thankful for any comments: https://docs.google.com/document/d/1gNtqTbkDVXp9dPCRZZut4bBgjvQwJNdoV-EJOrE… I've also improved my proof of concept/self-designed competency test, added a check for correctness and committed it to the github repository: https://github.com/tinko92/boost_geometry_difference_demo It now includes a patch for the boost_1_66_0 source tree, that allows tests of that implementation with the proper call: boost::geometry::difference(box1,box2,box_vector) (hopefully, if I didn't break anything I didn't see) without breaking it for other geometries. This was tested on GCC (main.cpp can be built if the folder tree from the repository is copied to some directory XYZ with the command g++ main.cpp -o main -IXYZ), VC9 and VC15. Thanks in advance for any comments on the proposal or the preliminary implementation of difference. Best, Tinko -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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[GSoC 2018] Want to contribute to Boost.SafeFloat
by Recolic Keghart 21 Mar '18

21 Mar '18

Dear boost community, I'm Bensong Liu, a second year undergraduate student. I'm interested in Boost.SafeFloat and willing to contribute to this project. I've finished all of the `Programming competency test` and I'm still working on the proposal(draft shared). Then how should I contact my mentor, and how should I submit my [solution to tests](https://recolic.net/res/tmp/note-deploy-key-for-gsoc.sh)? Thanks for your guidance. Thanks, Bensong Liu

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[gsoc2018]Project Proposal for Boost.SafeFloat
by Saga _-_ 21 Mar '18

21 Mar '18

Hi everyone, This is a draft of my proposal for Boost.SafeFloat: https://docs.google.com/document/d/1XQRygvTYPXKnWU0MW7XoL5YWJGLpI fIm4VmJVKj1EmY/edit?usp=sharing Please take a look at it and share your opinion about how I could improve it. Thanks in advance for your time and effort. -- Have a nice day Sagar Tewari

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[gsoc18] Seeking a mentor for Boost.Geometry project 2: Nearly antipodal points distance accuracy improvement
by Adeel Ahmad 21 Mar '18

21 Mar '18

Greetings, Congratulations to the Boost community on being selected for GSoC 2018! I recently read through the project ideas listed on the Wiki page, I'm particularly interested in "Boost.Geometry Project 2: Nearly antipodal points distance accuracy improvement". I wanted to know if I should implement a particular algorithm for finding the shortest distance between two points? There are many options, such as the Haversine formula, Equirectangular approximation, and Rhumb line. Or, would any of these be fine? Additionally, could the mentor please let me know on how to share the code? I was thinking of creating a GitHub repository, this would make it easier for the mentor to provide feedback. Would that be alright? I was also a participant in GSoC 2017 with the OpenAstronomy organization. My project was to design and create a Python client for Hierarchical Progressive Surveys. It enabled users to view astronomical figures in an interactive environment. More details of the software package can be found here (https://hips.readthedocs.io/en/latest/getting_started.html) I look forward to your reply. Kind regards, Adeel

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Re: [boost] [Boost-users] [release] Boost 1.67.0 Beta 1
by Daniel James 21 Mar '18

21 Mar '18

On 20 March 2018 at 08:55, Rainer Deyke via Boost-users <boost-users(a)lists.boost.org> wrote: > I see that boost/next_prior.hpp has been removed from boost/utility.hpp. > Since this is a breaking change, maybe it should be added to the release > notes. I've added a note. Thanks.

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[gsoc18] Mentor Search
by Jimmy Beckett 21 Mar '18

21 Mar '18

Hello all, I'm a high school senior out of Texas (I've been accepted into an accredited 4-year college and am therefore eligible for GSOC.) I'm most interested in the uBLAS proposal, but any of the other proposals would be amazing to work on, along with any additional ideas any prospective mentors might have. I've completed the competency test for uBLAS ( https://github.com/jimmybeckett/gsoc18CodeSample) and I also have a lightweight big integer library that I've been working on recently available at https://github.com/jimmybeckett/BigInteger. It doesn't meet the 1000 loc requirement, but it should supplement my competency test. Of course, code reviews are always welcome! If any prospective mentors have project ideas to discuss or any comments to make, I would love to hear them! Thank you, Jimmy Beckett

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[gsoc2018]Project Proposal for Boost.SafeFloat
by Saga _-_ 21 Mar '18

21 Mar '18

Hi everyone, This is a draft of my proposal for Boost.SafeFloat: https://docs.google.com/document/d/1XQRygvTYPXKnWU0MW7XoL5YWJGLpIfIm4VmJVKj… Please take a look at it and share your opinion about how I could improve it. Thanks in advance for your time and effort. Have a nice day Sagar Tewari

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[gsoc2018]Proposal for Boost.SafeFloat
by iaansagar＠gmail.com 20 Mar '18

20 Mar '18

Hi everyone, This is a draft of my proposal for Boost.SafeFloat: https://docs.google.com/document/d/1XQRygvTYPXKnWU0MW7XoL5YWJGLpIfIm4VmJVKj… Please take a look at it and share your opinion about how I could improve it. Thanks in advance for your time and effort. Have a nice day Sagar Tewari _____________________________________ Sent from http://boost.2283326.n4.nabble.com

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[gsoc2018]Proposal for Boost.SafeFloat
by Sagar Tewari 20 Mar '18

20 Mar '18

Hi everyone, This <https://docs.google.com/document/d/1XQRygvTYPXKnWU0MW7XoL5YWJGLpIfIm4VmJVKj…> is a draft of my proposal for Boost.SafeFloat as a gsoc project. I'll be very grateful if you could take out some of your time to take a look at it and provide your opinion. Have a nice day Sagar Tewari -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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[gsoc2018] Boost.Real project proposal
by Akshay Raut 20 Mar '18

20 Mar '18

Hello community, I had introduced myself earlier also. I have made some minor changes to the proposal I am making for the Boost.Real project. Hope you all take out some of you time to go through the proposal and suggest changes or improvements in the proposal. https://drive.google.com/open?id=1f9WYzX1mSigrmnkjbPKGpLP0-Y0-KTfv Sincerely yours, Akshay Kumar Raut

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C++Now 2018 Program Published
by Jon Kalb 19 Mar '18

19 Mar '18

Boosters, The program has (mostly) been published for C++Now 2018: http://cppnow.org/announcements/2018/03/2018-program-announced/ It promises to be an exciting event. It isn’t too late to decide to join us in Aspen this may: http://cppnow.org/registration/ Jon

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[CircleCI] boostorg's plan has 8 days left on its trial
by Mateusz Loskot 19 Mar '18

19 Mar '18

Hi, I've been working on CircleCI configuration for Boost.GIL, temporarily, in my GitHub fork (mloskot/gil). When I go to https://circleci.com/gh/mloskot/gil/edit#parallel-builds, I see this message: "boostorg's plan has 8 days left on its trial. You may want to try increasing parallelism below to get the most value out of your containers." Could anyone help me to understand why I see this message even if I added the project to CircleCI from my fork and not from boostorg/gil? Does it mean, all boostorg repositories and all their forks share the CircleCI allowances? There is also second message saying "These settings are only for 1.0 builds. To define parallelism for 2.0 jobs" and since I'm developing CircleCI 2.0 setup for Boost.GIL, I assume I can ignore this secong message. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[release] 1.67.0 post-beta merges
by Daniel James 19 Mar '18

19 Mar '18

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/boost/wiki/Release-Beta-Merge-Policy>

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[gsoc2018]boost.safefloat and boost.real
by Sagar Tewari 19 Mar '18

19 Mar '18

Hi, I'm interested in working on the Boost.SafeFloat or Boost.Real as a gsoc project. Currently I'm in the process of completing the selection criteria(reading the linked matrial, solving competency test) . I've good experience with coding in C++. I went through the safefloat codebase and documentation and it looks quite interesting. But I'm not sure how I'm supposed to submit the competency test solutions. Do I have to include that with the Gsoc proposal? Can someone inform me about that? Also, the Boost.Real project is under the catagory "GSoC Projects which have been prearranged by students with mentors for 2018". Is this project still open for participent submission? -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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[GSoC 2018] A Few Questions about Boost.uBLAS
by philectron 19 Mar '18

19 Mar '18

Hello, I'm interested in working on *Boost.uBLAS* library. *I've fundamentally finished the Programming Competency Test for this project. I'm currently improving it.* I need more information on the following: *1.* Can multiple people who also apply for GSoC work on this same project? *2.* How will I submit my Programming Competency Test? *3.* Has anyone taken this project already? *4.* If 3 = yes, do you allow multiple people working on the same project for GSoC 2018? *5.* If 5 = no, what project should I work on? I have never used or worked with Boost Library before, so I don't know what in Boost Library needs to be improved. What project do you think would be feasible for Thank you! -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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[GSoC 2018] Want to contributed to Boost.SafeFloat
by Recolic Keghart 19 Mar '18

19 Mar '18

Dear boost community, I'm Bensong Liu, a second year undergraduate student. I'm interested in Boost.SafeFloat and willing to contribute to this project. I've finished all of the `Programming competency test` and I'm still working on tests && proposal. Then how could I contact my mentor, and how should I submit my solution to tests(https://recolic.net/res/note-deploy-key-for-gsoc.sh)? Thanks for your guidance. Bensong Liu

1 0

[gsoc2018]boost.safefloat and boost.real
by iaansagar＠gmail.com 19 Mar '18

19 Mar '18

Hi, I'm interested in working on the Boost.SafeFloat or Boost.Real as a gsoc project. Currently I'm in the process of completing the selection criteria(reading the linked matrial, solving competency test) . I've good experience with coding in C++. I went through the safefloat codebase and documentation and it looks quite interesting. But I'm not sure how I'm supposed to submit the competency test solutions. Do I have to include that with the Gsoc proposal? Can someone inform me about that? Also, the Boost.Real project is under the catagory "GSoC Projects which have been prearranged by students with mentors for 2018". Is this project still open for participent submission? _____________________________________ Sent from http://boost.2283326.n4.nabble.com

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[GSoC18] Working on my proposal for the Boost.Real project
by Laouen Belloli 17 Mar '18

17 Mar '18

Hi, I was in contact with Damián Vicino talking about a proposal for the Boost Real project. I posted here <https://drive.google.com/file/d/1KwPUioBYy19HM0X9O1e6X6gigOkmzoqZ/view?usp=…> what I got so far, please comment on it if you have some time so I can improve it following your suggestions. I would appreciate very much your opinion as I have no experience writing GSoC proposals. Thanks and Best regards to all, Laouen. -- Laouen Mayal Louan Belloli. LIAA - DC - FCEyN - UBA. C.A.B.A. - Buenos Aires - Argentina. https://liaa.dc.uba.ar +54 9 11 38675694

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regarding proposal
by anant agrawal 17 Mar '18

17 Mar '18

I am Anant Agrawal currently pursuing B.E in computer science had posted the proposal but had not received any response regarding it. Had anyone gone through it.

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[gsoc2018]
by Akshay Raut 16 Mar '18

16 Mar '18

Hello everyone I am Akshay Kumar Raut, a 3rd year undergrad student in Computer Science from India. Please provide feedback and comments on my project proposal on Boost.Real basic operators. Thank you. here is the link : https://drive.google.com/open?id=1TrfYxYHRVFREkLKMqn9b23X3i8dtZ2_q warm regards, Akshay Kumar Raut

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[gsoc18] Mentor Search for Boost.Geometry idea
by Tinko Bartels 16 Mar '18

16 Mar '18

Hi, my name is Tinko Bartels, I'm studying to get a Master's degree in Mathematics at TU Berlin. I'm interested to work on Boost Geometry. I'm working at the university for a couple of years on C++ projects that rely on Boost libraries, most notably Boost.Geometry. Our work involves the computation of exact covers of spaces with boxes. This motivated my idea to add support to void union_(Geometry1 const & geometry1, Geometry2 const & geometry2, Collection & output_collection) void sym_difference(Geometry1 const & geometry1, Geometry2 const & geometry2, Collection & output_collection) void difference(Geometry1 const & geometry1, Geometry2 const & geometry2, Collection & output_collection) for Geometry1=Geometry2=box and Collection is a collection of boxes. Since I have no merged contributions to open source projects to refer to, I could, for example, provide an implementation of the difference method for types adhering to the box concept and a collection of boxes as output_collection. Since the results of those operations in terms of exact covers of the resulting space with boxes are not uniquely defined and the implementation should take less than 3 months, additional strategies for these specializations of the above algorithms could be added as future milestones. If this endeavor is considered worthwhile by potential mentors, I would get started on writing a proposal right away. Kind regards, Tinko Bartels -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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Clang on Windows
by Egor Pugin 16 Mar '18

16 Mar '18

Hi, Based on recent news: Clang 6.0.0 is out with very decent support of the latest MSVC STL (15.6). Chrome is built with clang on Windows. So, maybe it is good time to include clang+windows into list of supported configs, setup a CI worker with clang (clang-cl) on Windows? Currently many boost libs already work fine, but some of them require small tweaks like explicit BOOST_USE_WINDOWS_H etc. -- Egor Pugin

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Boost library
by anant agrawal 16 Mar '18

16 Mar '18

I had recently uploaded the draft I would like to make the library more efficient and faster and with a improved functionality. Would like to get the response for a mentor for better guidance

1 0

[release] Boost 1.67.0 Beta 1 Release Candidate 2
by Daniel James 16 Mar '18

16 Mar '18

The second release candidates for the 1.67.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.67.0.beta.1/source/> The release notes can be previewed at: <http://www.boost.org/users/history/in_progress.html> The documentation is available at: <http://www.boost.org/doc/libs/1_67_0_beta1/> The SHA256 checksums are as follows: 154cf490da858fd9c2307bb904b07a42cbe8355ecf99d5477f0d843c6d03cdda boost_1_67_0_b1_rc2.7z 0d854b208fefaeb5837d6c417f505b189275e32d017f6226001fb165a5ac51ed boost_1_67_0_b1_rc2.tar.bz2 6eb3f9ca8db355765f41361e1e26976228f0c2dff400aade8a5e97aec6aa59f4 boost_1_67_0_b1_rc2.tar.gz 678a6459f2517932536ec97297be1de46ea073f2e2ee17ec8397b80aa0953f49 boost_1_67_0_b1_rc2.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.

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[gsoc18] sharing of proposal
by vardhan gupta 15 Mar '18

15 Mar '18

Hi, I have shared the 1st draft of my proposal for "adding multicore and GPU computations to uBLAS" through the gsoc portal, but haven't yet gotten any feedback on it. Do I need to share it again on the mailing list too? Regards, Vardhan Gupta

3 3

[qvm] Tait–Bryan/Euler angles implemented for matrices
by Emil Dotchevski 15 Mar '18

15 Mar '18

See: https://boostorg.github.io/qvm/rot_mat.html https://boostorg.github.io/qvm/set_rot_mat.html https://boostorg.github.io/qvm/rotate_mat.html Emil

1 0

[gsoc18] Student proposal reviewing (Internal process)
by madhur4127 14 Mar '18

14 Mar '18

Hi Boost Community, As per Submission template <https://svn.boost.org/trac10/wiki/SoCSubmissionTemplate> a candidate is required to show competency in C++ and must be "genuinely" interested in the project and also in open-source community. Judging of competency is straight forward, but how can interest be judged? Considering myself as example who had just got in serious open source projects(Sophomore Undergraduate). My coding ablilities <https://github.com/madhur4127/Programming-Competency-Test> are not at expert level but I am improving and learning myself while my university teaches knapsack greedy and automaton. Doesn't this gives an idea of interest in open source of a candidate or am I being a sophomore is a disadvantage with respect to other post graduate candidates? I know boost requires serious level work and it has world's most craftiest libraries but does Boost prefer experienced candidates or take chances with candidates genuinely interested in development and are moderately skilled? As per the division rules "A student must be able to write in C++". Regards, Madhur gsoc18 aspirant [Boost.Intrusive] -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

1 0

Re: [boost] [interprocess] file_mutex class proposal
by mateusz janek 14 Mar '18

14 Mar '18

Hey, any thoughts on that? Thanks, Mateusz 2018-03-04 3:42 GMT-08:00 mateusz janek <stryku2393(a)gmail.com>: > Hello boost::interprocess community, > > During my pet projects development I found that a file access > synchronization is a common problem so, I wrote a class that wraps it and > thought that it can be useful for wider community. I would like to ask you > what do you think about such functionality in boost::interprocess? I'm > aware that class from the repo is not ready to release. Just wanted to show > about what functionality I'm talking about. > > Here you can find the repo: https://github.com/stryku/file_mutex > You can find there the proposed class and a simple usage example. > > If you will find it interesting I will prepare more formal merge proposal, > update docs, maybe more examples etc. > > Looking forward to hearing from you what do you think about it. > > Thank you, > Mateusz Janek > >

2 2

[release] Boost 1.67.0 Beta 1 Release Candidate 1
by Daniel James 14 Mar '18

14 Mar '18

The release candidates for the first 1.67.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.67.0.beta.1/source/> The release notes can be previewed at: <http://www.boost.org/users/history/in_progress.html> The documentation is available at: <http://www.boost.org/doc/libs/1_67_0_beta1/> The SHA256 checksums are as follows: 3d52af11ea6c45c73e18bf9b386056d31dab5092923cc9ed8efa29a083ffb9de boost_1_67_0_b1_rc1.7z 680336bd9a56dccda359061660348c5656cab71cb76713b157ce9a6f840659f0 boost_1_67_0_b1_rc1.tar.bz2 a4608b3ee0b4fadad7b2a2a9efa7c4ad8ce120ee94232e0ee86796f38cced319 boost_1_67_0_b1_rc1.tar.gz 3d1faa96ddda6f0a864f3292c014420457159f0960ff82efcca9feb898d21c1a boost_1_67_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.

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[gsoc18] Boost.Detour & Mentor Search
by Michael Kiros 14 Mar '18

14 Mar '18

Hello, I'm a C++ developer and have been developing in C++ for over 6 years now in my personal time. I wanted to accomplish two things with this post: 1. Propose the idea of boost::detour 2. Find a mentor in the process Boost.Detour is not something new that I'd like to implement but a concept in programming that I have been using for a very long time now and would love to have it easily accessible with the inclusion of a simple <boost/detour.hpp>. The idea is to have function hooking easily accessible to everyone using C++. Though it may seem like a niche feature, function hooking is more commonly used than most people think (e.g. modifying binaries after compilation for feature addition, reverse engineering proprietary software). It's a beautiful concept when you see it working. In the process I need a mentor to guide me through the process of putting down my ideas to paper and implementing them according to the standards that Boost holds. This includes replacing components from my library with Boost concepts (e.g. boost::process). I'm also a student at Texas Tech University studying Computer Science. Can't wait to hear from someone. Michael

2 1

[type_traits] is_list_constructible regression failures
by Lorenzo Caminiti 13 Mar '18

13 Mar '18

Hello all, I noticed the following failure in Boost.TypeTraits regression tests on GCC 4.6 C++11. Any idea why this is failing? http://www.boost.org/development/tests/master/developer/type_traits.html Test output: igaztanaga-master-gcc-4.6c++11 - type_traits - cxx14_aliases_test / gcc-4.6c+ Rev cb62bbf20f4a0000ee6f16835b0c2dc92edea8cd / Sun, 11 Mar 2018 03:16:04 +0000 Compile [2018-03-11 10:15:18 UTC]: fail "C:/Programs/mingw-builds/x32-4.6.4-posix-dwarf-rev0/mingw32/bin/gcc-4.6.bat" -pipe -fmax-errors=1 -std=c++0x -m32 -O0 -fno-inline -Wall -pedantic -Werror -march=i686 -Wextra -Wno-bool-operation -Wno-int-in-bool-context -Wno-uninitialized -DBOOST_ALL_NO_LIB=1 -I".." -I"..\libs\type_traits\test\libs\tt2\light\include" -c -o "c:\boost\master\results\boost\bin.v2\libs\type_traits\test\cxx14_aliases_test.test\gcc-4.6c+\dbg\dbg-symbl-off\cxx14_aliases_test.o" "..\libs\type_traits\test\cxx14_aliases_test.cpp" In file included from ../boost/type_traits.hpp:110:0, from ..\libs\type_traits\test\cxx14_aliases_test.cpp:10: ../boost/type_traits/is_list_constructible.hpp:36:61: error: expected class-name before 'decltype' compilation terminated due to -fmax-errors=1. I am asking because a couple of Boost.Contract tests that #include <boost/type_traits.hpp> fail with the same Boost.TypeTraits error on this compiler. Thanks. --Lorenzo

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Re: [boost] [gsoc18]Boost.SafeFloat
by Rajat Miglani 13 Mar '18

13 Mar '18

Is there any specific template that I should follow for the proposal or I can make it my own way? Thanks, Rajat Miglani On Tue, Feb 27, 2018 at 12:43 AM, Damian Vicino <damian(a)vicino.com.ar> wrote: > Hi, > From the top of my head, the big missing pieces are the safefloat > literals, some pieves of unit testing (copile and runtime), documentation, > implementing some of the policies that are already defined. Maybe a better > way to specify policies could be implemented. > However, the complete list of things being done is what your proposal is > about, you need to define the milestones and goals for the project. > > 2018-02-25 18:57 GMT+00:00 Rajat Miglani <rajatmiglani26(a)gmail.com>: > >> I have read the paper "Goldberg, David. "What every computer scientist >> should know about floating-point arithmetic." ACM Computing Surveys (CSUR) >> 23.1 (1991): 5-48."and documentation and now having a little >> understanding of what this project is about.Presently going through the >> code and concepts, please guide me of what changes I have to do in the >> previous code to make it better. >> >> On Wed, Feb 21, 2018 at 11:52 PM, Damian Vicino <damian(a)vicino.com.ar> >> wrote: >> >>> Hi Rajat, >>> For the Boost.SafeFloat project, I suggest you take a look to the >>> following links: >>> - Repository: https://github.com/sdavtaker/safefloat >>> - Documentation: https://sdavtaker.github.io/safefloat/doc/htm >>> l/index.html >>> >>> Also, try to read this paper if you didn't before: Goldberg, David. >>> "What every computer scientist should know about floating-point >>> arithmetic." ACM Computing Surveys (CSUR) 23.1 (1991): 5-48. >>> From the C++ perspective, key concepts you need to know are: >>> - Templates (a lot of it) >>> - Custom Literals >>> >>> A good proposal would be to take a read to the documentation and code >>> base and describe what is missing to complete the project. >>> Best regards, >>> Damian Vicino >>> >>> >>> >>> >>> 2018-02-21 14:11 GMT-03:00 Rajat Miglani via Boost < >>> boost(a)lists.boost.org>: >>> >>>> Dear boost community, >>>> I am a GSOC aspirant and I'd like to contribute to your organization. >>>> I have read the project ideas and is interested in working on:- >>>> 1)Boost.SafeFloat or >>>> 2)Enhancing Boost.Intrusive Library >>>> Can I get some more info about how to work on these projects and the >>>> basic >>>> requirements so that I can learn them and be able to contribute to my >>>> fullest. >>>> >>>> Thank you, >>>> >>>> _______________________________________________ >>>> Unsubscribe & other changes: http://lists.boost.org/mailman >>>> /listinfo.cgi/boost >>>> >>> >>> >> >

2 1

[gsoc2018]Guidance for Google Summer of code on Project1
by sumit_kumar 12 Mar '18

12 Mar '18

I am a third year undergraduate student. I have a good implementation skills in C++ . I know machine learning algorithms & math required for it very well. So ,I would like to contribute to the Boost.uBLAS by doing project1. Could you please guide me. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

2 1

Re: [boost] [gsoc18] Mentor Request for uBLAS (prefer support for tensors)
by David Bellot 11 Mar '18

11 Mar '18

Hi Karl, you're exactly the kind of people I want to see in GSOC: student with passion for C++ and some already implemented library. Your competency test is good. Best now is to work on the proposal and send it to us directly (no need to go through the main mailing-list from now on). Cheers, David On Wed, Mar 7, 2018 at 9:27 PM, Karl Chen <karl.chen(a)mail.utoronto.ca> wrote: > Hi, > > > Thanks for replying! Here is a link to my competency test: > https://github.com/HiImKarl/GSOC18-uBLAS. > > The link in my first email was to a different library, more of a > basic proof of concept than anything. > > > Cheers! > > Karl > ------------------------------ > *From:* mohammad sharique <1sharique1(a)gmail.com> > *Sent:* Wednesday, March 7, 2018 12:06:05 PM > *To:* boost(a)lists.boost.org; Karl Chen > *Cc:* David Bellot > *Subject:* Re: [boost] [gsoc18] Mentor Request for uBLAS (prefer support > for tensors) > > Hi Karl, > David and I are mentoring this project. Thanks for sending in the source. > We'll have a look at it, and get back to you soon. > You may start writing proposal in the meanwhile. The proposal usually > involves details about what you want to achieve > with the project, the resource required, approach(s) for the same, time division, > class designs and interactions, implementation > details etc. > > Should there be any questions, please feel free to ask. > > Regards, > Sharique > > On Wed, Mar 7, 2018 at 2:36 PM, HiImKarl via Boost <boost(a)lists.boost.org> > wrote: > > Hi, > > I am Karl, a financial engineering student that is very passionate about > C++. I think my background in applied math and stats would make me a great > candidate for writing a tensor library. I would also like to point to this > header-only multi-dimensional array template library with compile time > tensor rank that I've written in the past: > https://github.com/HiImKarl/Tensors, which may be good groundwork. > > It is a little late into March, so I was wondering if there were any > mentors > still looking for students for this project. I have already completed the > competency test. > > > > -- > Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html > > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman > /listinfo.cgi/boost > > >

1 0

[gsoc18] uBLAS competency test
by Arun Ramachandran 11 Mar '18

11 Mar '18

Hello, I'm Arun, a final year computer science undergrad. I'm interested in working on project 1 of the uBLAS library (adding statistics and machine learning functions). I have experience with developing in C++ from working on Code Character (https://github.com/delta/codecharacter-simulator) an online AI programming challenge that some fellow students and I hosted. Since this is an application, I've taken the competency test for uBLAS and have implemented a small matrix library using expression templates along with some unit tests and benchmarks. The repo is currently private, so if a mentor shares their GitHub handle I can add them as a collaborator for reviewing it. Thank you, Arun Ramachandran

3 3

[gsoc18] Request for Guidance
by Mohd Faisal 11 Mar '18

11 Mar '18

Hello, my name is Mohd Faisal. I want to work on Boost.uBLAS: linear algebra and matrix computations. Is there a specific reason that only the listed algorithms have to be implemented. Because there are many good ML algorithms that can also be implemented like SVM.

3 2

[gsoc18] how to share a competency test
by vardhan gupta 11 Mar '18

11 Mar '18

Hi, My name is Vardhan Gupta. I am a 2nd year undergraduate student from IIT Kanpur. I am interested in working on project #3 of Boost.uBLAS on adding multicore and gpu computations to uBLAS. I have created a private repository of it's competency test on gitlab. Now, I am having trouble in sharing the repository with the mentors since I do not have their email address. how do I share it/find their e-mail address? Thank you, Yours sincerely; Vardhan Gupta

6 10

[gsoc2018]Mentor Required
by P.H S 11 Mar '18

11 Mar '18

Hello, my name is Zhixuan Xiao, a student from BUPT, BeiJing China. I am interested to Boost.uBLAS:project 3, Add Multicore and GPU computations to uBLAS and I want to connect with a mentor. Thanks, Zhixuan Xiao

2 1

Google Summer of Code: Potential Applicant
by Christos Maris 10 Mar '18

10 Mar '18

Hey there, My name is Christos (Chris for short) and I would love to work with you via the GSoC program this summer. I am sending this mail because I am in a need for some instructions on how to find a mentor and a project (at first). Can anyone help me with that? Also is there any potential mentor here? Any info helps. Thanks a lot in advance!

2 1

[gsoc18] Regarding Boost uBLAS Google Summer of Code 2018
by Varun Mehrishi 09 Mar '18

09 Mar '18

Hi, I am Varun Mehrishi, a third year engineering student from Manipal University Jaipur (MUJ), India. I am currently pursuing Bachelors of Technology in Computer Science and Engineering. I am most comfortable with C++(STL) and Python, and also follow the new and experimental features introduced in the new standards with additional help of cppcon and BoostCon. I also have interests in Data Science, Machine Learning. I wish to participate and contribute to Boost.uBLAS. I've read the project idea and description from the suggested GSoC project proposals. I am really interested in working on the project "Project 1 : Add statistics and machine learning functions" which is focused on extending Boost.uBLAS functionality towards statistics/ML. I have implemented a basic template version of the mentioned Programming Competency Test (basic-matrix-lib <https://github.com/varunmehrishi/basic-matrix-lib>) and used C++14 generic lambdas wherever necessary. Your feedback and suggestions will be extremely valuable as they will help me improve my implementation and add more functionality. Looking forward to your guidance -- With warm regards, Varun Mehrishi GSoC 2018 Aspirant

1 0

Re: [boost] How to set LDFLAGS in 1.66.0?
by Nana Sakisaka 09 Mar '18

09 Mar '18

> I'm not looking to find an external library, I'm trying to set the RUNPATH on the boost shared libraries There's no need to use an external library. You just pass options to b2. Are you sure that you've tried my suggestion on previous reply? > Ordinarilly, one just adds LDFLAGS to the configure script with the -Wl,rpath ... Using boost libraries does not prevent you to do so. One could either specify RPATH for your boost library files, application executable, or both. BTW, looking at your pasted output of ldd indicates that you've set your RPATH for wrong value, but that should not be boost specific; try googling without 'boost' keyword? 2018-03-09 9:59 GMT+09:00 Dean Anderson <dean(a)av8.com>: > Thanks for the reply. > > I'm not looking to find an external library, I'm trying to set the RUNPATH > on the boost shared libraries. For example: > > The path on libstdc++ is set by the ld, so it finds the right compiler > runtime... > > libboost_wave.so needs a RUNPATH to where its going to be installed. > > Ordinarilly, one just adds LDFLAGS to the configure script with the > -Wl,rpath ... > > --Dean > > ldd libboost_wave.so.1.66.0 > linux-vdso.so.1 => (0x00007ffebf1b6000) > libboost_filesystem.so.1.66.0 => not found > libboost_thread.so.1.66.0 => not found > libboost_date_time.so.1.66.0 => not found > libboost_chrono.so.1.66.0 => not found > libboost_system.so.1.66.0 => not found > librt.so.1 => /lib64/librt.so.1 (0x00007f5082f0a000) > libstdc++.so.6 => /efs/dist/gnu/gcclib/4.9.4/.ex > ec/x86-64.rhel.7/lib/libstdc++.so.6 (0x00007f5082c00000) > libm.so.6 => /lib64/libm.so.6 (0x00007f50828fd000) > libgcc_s.so.1 => /efs/dist/gnu/gcclib/4.9.4/.ex > ec/x86-64.rhel.7/lib/libgcc_s.so.1 (0x00007f50826e6000) > libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f50824ca000) > libc.so.6 => /lib64/libc.so.6 (0x00007f5082108000) > /lib64/ld-linux-x86-64.so.2 (0x00007f508343e000) > > > > On Fri, 9 Mar 2018, Nana Sakisaka via Boost wrote: > > You could try passing this option to b2: >> >> dll-path="'$ORIGIN/../lib'" >> >> Make sure to escape $ and " appropriately for your CI scripts. >> Note that there are actually two types of flags, i.e. >> (1) the flag for your application executable (the RPATH) >> and >> (2) a flag for your build system's sanity check (e.g. the "checking if >> *whatever* works..." internal binary flag for ./configure) >> >> p.s. Invoke command below to check whether the flags are set: >> objdump -p ./a.out|grep RPATH >> >> >> >> 2018-03-09 8:33 GMT+09:00 Dean Anderson via Boost <boost(a)lists.boost.org >> >: >> >> I need to set an rpath on the shared libraries. Any ideas how to do that? >>> >>> Alternatively, is there a fork of boost that use the gnu build system? >>> >>> Thanks! >>> >>> --Dean >>> >>> Av8 Internet Prepared to pay a premium for better service? >>> www.av8.net faster, more reliable, better service >>> 617 256 5494 >>> >>> >>> _______________________________________________ >>> Unsubscribe & other changes: http://lists.boost.org/mailman >>> /listinfo.cgi/boost >>> >>> >> _______________________________________________ >> Unsubscribe & other changes: http://lists.boost.org/mailman >> /listinfo.cgi/boost >> >>

1 0

How to set LDFLAGS in 1.66.0?
by Dean Anderson 09 Mar '18

09 Mar '18

I need to set an rpath on the shared libraries. Any ideas how to do that? Alternatively, is there a fork of boost that use the gnu build system? Thanks! --Dean Av8 Internet Prepared to pay a premium for better service? www.av8.net faster, more reliable, better service 617 256 5494

2 1

[foreach][polygon][xpressive][bimap][ptr_container][gil][assign][typeof][msm] PRs for removing executable attribute for files
by Edward Diener 08 Mar '18

08 Mar '18

The following libraries still have PRs, which I have previously submitted, for removing the executable attribute for one or more files: foreach polygon xpressive bimap ptr_container gil assign typeof msm None of these PRs affect anything other than the file attribute, so no testing is needed AFAICS since no code changes. If the maintainers of the above libraries, or someone else with write access to these libraries, can merge the appropriate PR to 'develop', and then merge 'develop' to 'master', we can get rid of having any files with their executable attribute set in the next release.

5 13

[gsoc18] Boost.Intrusive mentor request
by BogdanCodreanu 08 Mar '18

08 Mar '18

Hello, I've read about the Boost.Intrusive library and it matches my desires of programming. Is there a mentor available for this project? How should I prove myself worthy of this project? -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

2 1

Re: [boost] [system] [teeks99] Mass test failures on MSVC-14.0
by Andrey Semashev 08 Mar '18

08 Mar '18

On 02/26/18 17:20, Tom Kent wrote: > On Mon, Feb 26, 2018 at 6:56 AM, Andrey Semashev via Boost > <boost(a)lists.boost.org <mailto:boost@lists.boost.org>> wrote: > > On 02/26/18 15:43, Tom Kent via Boost wrote: > > On Sat, Feb 24, 2018 at 3:45 PM, Andrey Semashev via Boost < > boost(a)lists.boost.org <mailto:boost@lists.boost.org>> wrote: > > Hi, > > Most of Boost.System tests are failing on the > teeks99-09-f-win2016-64on64 > tester, MSVC-14.0[1]. The test logs don't show any errors > and I can't > reproduce it locally. I'm seeing similar test failures in > other libraries, > like Boost.Atomic for example, and the links point to > Boost.System. > > Is it possible to get the error log from the tester? > > >> > > Here's all 82MB of it: > > http://boost.teeks99.com/temp/teeks99-09-f-results-bjam-2018-02-26.log > <http://boost.teeks99.com/temp/teeks99-09-f-results-bjam-2018-02-26.log> > > > > But be warned, I just moved the -09 runner onto a new (Win 2016) VM about a > > week ago, and there have been some teething issues. If all goes well, the > > -f run should hit again in the next 24-48hrs. > > The link returns 403: Forbidden. > > Try again now. Sorry about that. I got the log now, thanks. The relevant part seems to be this: msvc.link.dll D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.dll call "D:\teeks99-09\run\results\boost\bin.v2\standalone\msvc\msvc-14.0\adrs-mdl-64\archt-x86\msvc-setup.bat" amd64 >nul link /NOLOGO /INCREMENTAL:NO /DLL /DEBUG /MACHINE:X64 /MANIFEST /subsystem:console /out:"D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.dll" /IMPLIB:"D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.lib" @"D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.dll.rsp" if %ERRORLEVEL% NEQ 0 EXIT %ERRORLEVEL% Creating library D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.lib and object D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.exp msvc.manifest.dll D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.dll if exist "D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.dll.manifest" ( call "D:\teeks99-09\run\results\boost\bin.v2\standalone\msvc\msvc-14.0\adrs-mdl-64\archt-x86\msvc-setup.bat" amd64 >nul mt -nologo -manifest "D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.dll.manifest" "-outputresource:D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.dll;2" ) 'mt' is not recognized as an internal or external command, operable program or batch file. ...failed msvc.manifest.dll D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.dll D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.lib D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.pdb D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.pdb D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.pdb D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.pdb D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.pdb... ...removing D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.dll ...removing D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.lib ...removing D:\teeks99-09\run\results\boost\bin.v2\libs\system\build\msvc-14.0\dbg\adrs-mdl-64\thrd-mlt\boost_system-vc140-mt-gd-x64-1_67.pdb I think, this problem has been discussed on the list not long ago - `mt` being not found on the system after some MSVC update: http://boost.2283326.n4.nabble.com/build-msvc-14-linker-step-failing-tc4701… Looks like MSVC needs to be reinstalled or installed on a separate machine. Will you be able to fix this?

3 7

[release] 1.67.0 closed for Beta
by Daniel James 07 Mar '18

07 Mar '18

The master branch is now closed for all changes except by permission for the Beta release. Also, remember to add your libraries' changes to the release notes at: <https://github.com/boostorg/website/blob/master/feed/history/boost_1_67_0.q…> You can preview the release notes at: <http://www.boost.org/users/history/in_progress.html> Thanks, -- The Boost Release Team

1 0

About authorizing CircleCI
by Vicente J. Botet Escriba 07 Mar '18

07 Mar '18

Hi, recently I heard of CircleCI (https://circleci.com/) and it seems much faster than Travis. Is someone using it? What is your feedback? If the feedback is positive, could someone authorize CircleCI to access boostorg? Best, Vicente

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[gsoc18] Mentor Request for uBLAS (prefer support for tensors)
by HiImKarl 07 Mar '18

07 Mar '18

Hi, I am Karl, a financial engineering student that is very passionate about C++. I think my background in applied math and stats would make me a great candidate for writing a tensor library. I would also like to point to this header-only multi-dimensional array template library with compile time tensor rank that I've written in the past: https://github.com/HiImKarl/Tensors, which may be good groundwork. It is a little late into March, so I was wondering if there were any mentors still looking for students for this project. I have already completed the competency test. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

2 1

[gsoc2018] Project 1.1: Add statistics and machine learning functions
by Dattatreya Mohapatra 07 Mar '18

07 Mar '18

Hi, My name is Dattatreya Mohapatra. I am an undergrad at IIIT Delhi, majoring in CS. I am interested in working on extending the Boost.uBLAS library as a project. I have taken courses on Linear Algebra and Machine Learning in the past, so I have a decent basic understanding of the subject. I have used C++11 in several of my course projects, so I have some familiarity with advanced features like lambdas and template programming. I have gone through the earlier threads on the same, and have started working on the core-competency test (CCT). Can the mentors of this project please guide me as to how should I get the CCT reviewed when its ready? Also, is there anything else I should look at apart from the documentation which would be helpful? Thanks and regards, Dattatreya Mohapatra

2 2

VS 2017 15.6 released, _MSC_VER=1913...
by Peter Dimov 07 Mar '18

07 Mar '18

... and Boost.Config once again warns: 1>c:\boost-git\develop\boost\config\compiler\visualc.hpp(349): note: Info: Boost.Config is older than your compiler version - probably nothing bad will happen - but you may wish to look for an updated Boost version. Define BOOST_CONFIG_SUPPRESS_OUTDATED_MESSAGE to suppress this message. Maybe we should display this only on 1920 and above, as I suggested last time? :-)

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[gsoc18] [Boost.Intrusive] Mini version of project
by Rishija Mangla 07 Mar '18

07 Mar '18

Hello, My name is Rishija Mangla. I’m a mathematics graduate and pursuing my MCA (2nd year) from University of Delhi, India. I want to contribute in enhancing Boost.Intrusive library and have implemented a mini library for the same ( as asked for competency test ). Library includes: - Generic segment tree ( support range queries where operation is given by the user over any general class ) - Expression templates for lazy evaluation - Written test programs to check the accuracy ( using Boost.test unit test framework ) - Test cases are generated randomly Link to library implemented https://github.com/Rishija/boost_competency_test <https://github.com/Rishija/boost_competency_test> I plan to implement more complex data structures that have been mentioned in the list. I have already implemented prefix tree, both dynamic and via filesystem ( will provide link to the project in case you want to have a look ). So I’ll be pretty comfortable in developing other similar data structures and algorithms for them. Thanks

1 0

[Boost.Yap] Review results
by Louis Dionne 06 Mar '18

06 Mar '18

Dear Boost, I am pleased to announce that the Yap library is CONDITIONALLY ACCEPTED into Boost. I counted the following formal reviews: - Alex Hagen-Zanker: REJECT / CONDITIONAL ACCEPT - Barrett Adair: ACCEPT - Brook Milligan: CONDITIONAL ACCEPT - John Fletcher: ACCEPT - Paul Fultz II: ACCEPT - Steven Watanabe: ACCEPT I'd like to thank everyone who participated to the review for their feedback, and also Zach Laine for his submission. The following is a summary of the main issues that were raised during the review: - Contextual evaluation of terminals The concern was that there was no way of evaluating an expression tree with a custom context other than to first transform it with a custom transform, and then evaluate it. This, however, requires encoding the recursion into the transform even when we only want to modify terminals. After a lot of discussion, everybody seemed to agree that the following would be desirable (paraphrasing Steven): `transform_evaluate` would behave exactly like `transform`, except that the default behavior for nodes that are not handled by the context is to evaluate the operators instead of building a new expression. Zach fixed that in https://github.com/tzlaine/yap/issues/63 by introducing a new transform called `evaluation()` which evaluates terminals, and the ability to pass multiple transforms `t1`, ..., `tN` to `transform`. The first matching transform is executed, and `transform` will copy-and-recurse if no transforms match. `transform_evaluate(expr, tform)` can then be implemented as `yap::transform(expr, tform, yap::evaluation())`. - Auto-unwrapping of terminals in transform and automatic application of terminal transforms before unwrapping There was a concern that automatically unwrapping terminals in transforms and applying terminal transforms before unwrapping would result in counter intuitive behavior. After some discussion, it was determined that automatic application of transforms before unwrapping could indeed lead to surprising results and was removed. However, unwrapping of terminals is necessary to keep the matching of terminals reasonable, so it was kept. I am comfortable with that decision, as the unwrapping of terminals, which leads to a very intuitive way of matching terminals, was one of the features that sprung to me as being a great usability boost when I first looked at the library. - Positional placeholders should stay or go? Some of the reviewers felt like it was not desirable to provide positional placeholders as part of Yap, because those aren't the primary purpose of the library and C++14 obsoletes them with lambdas. Other reviewers felt like they were in fact very useful and shouldn't be removed. Since no clear consensus could be reached, no acceptance condition is attached to this issue. However, I personally favor the removal of placeholders from the core API on the basis of minimality. I would like to encourage Zach to check whether their removal would result in API simplifications; if so, I would encourage (but not require) their removal, at Zach's discretion. - Documentation The documentation is not sufficiently extensive, and takes too much for granted from the reader. This was raised by a couple of reviewers and it has been my largest problem with the library so far. More on this below. - The eval_xxx customization points. Nobody liked them, and they are already gone. - BOOST_YAP_CONVERSION_OPERATOR_TEMPLATE Nobody liked it, and it is already gone. - Short-circuiting of && and || in evaluate Steven brought up the fact that `yap::evaluate` would not short-circuit the evaluation of && and ||. This issue was mooted when customization points were removed. Also, the new `evaluation()` transform, which could suffer from the same short-circuiting problems, doesn't because it was implemented properly. - Support for Boost.Build is missing. - Hana vs not Hana Full disclosure: I am the author of Boost.Hana. A couple of reviewers raised concerns with Hana being part of the public interface. The main concern seemed to be about MSVC not being able to compile Hana, and hence Yap being unusable on MSVC. While I agree that MSVC is a big player, I believe that should not dictate what all Boost libraries do. Some libraries are meant to bridge gaps with older compilers, some libraries are cutting edge. Yap is the latter, and that's fine. The MSVC folks are working hard on their C++ conformance, and they will eventually get there. Also, it is likely that Hana wouldn't be the barrier anyway: Yap relies a lot on SFINAE and MSVC is known to be poor at it. Many of the features that one would likely want to use when using Yap are also not too well supported by MSVC, so users would probably hit limitations there anyway. Plus, as soon as MSVC is close enough, I'll start working on Hana's side to support it. Taking my review manager hat off for a second, I'd also like to point out that Yap is exactly the kind of use case that Hana was built for. Just like MPL was (and is) used in many libraries' implementation and APIs, I don't see a problem with using Hana in Yap's API, since that is the right tool for the job. That being said, if Zach wishes to explore using Hana's concepts (like hana::Sequence) to conceptify his API, I encourage him to do so. This may make it possible to use any tuple-like sequence for the children of an expression, thereby reducing the coupling between the two libraries. If Zach wants to explore using Fusion instead of Hana, that is also an option that would make MSVC support achievable. - A single macro for symmetric binary operators It was brought up that there's no macro to define both `arg <op> expr` and `expr <op> arg` at once. I believe this was initially done to avoid potential conflicts with the member variants, which already provide `expr <op> arg`. I believe it should still be possible to do it, since, as Steven said, most of the time a user will need symmetric behavior anyway. - External dependencies checked-into the repository The library includes internal copies of some of its dependencies, which is unusual for a Boost library. Zach said it wasn't his intent to put the library into Boost that way if it were accepted. To see all the issues that were raised during the review, you can search for tickets labeled with `Boost Review` on GitHub: https://github.com/tzlaine/yap/issues?q=label%3A%22Boost+Review%22 Based on the concerns above, the following lists the conditions for acceptance: - Documentation In my opinion, this was the biggest concern to be addressed. A lot of progress was made during and after the review, but I still think the documentation can be improved and made more complete. I especially believe that integrating more examples inside the "tutorial" (not just at the end) and introducing new concepts more gradually would help readers that are not already expression template gurus. It is very difficult to set a clear action item for "improving the documentation". For this reason, Brook Milligan and I will work with Zach to define what it means for the documentation to meet this acceptance condition. Brook was kind enough to agree to this when I asked him in a private communication. - A single macro for symmetric binary operators The library must provide a way to define symmetric binary operators in one go. Exactly how this can be achieved and whether we should be able to SFINAE-constrain the arguments is left to Zach's discretion. - External dependencies The external dependencies must not be packaged with the library itself. Another mechanism should be used; I leave that mechanism unspecified, but it should be possible to test the library using the usual Boost.Build workflow (e.g. an ExternalPackage download that would only work in CMake is not acceptable). - Boost.Build Yap needs to support Boost.Build like all the other Boost libraries. I will post an update to this list when the conditions of the review are met. If they wish to do so, reviewers can then verify that the conditions are met in a satisfactory fashion and the library will automatically be accepted unless someone objects. I would like to thank everyone who participated in the review, and congratulations to Zach for his library. Regards, Louis Dionne

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[graph] r_c_shortest_paths writes/reads outside allocated memory
by Mateusz Polnik 06 Mar '18

06 Mar '18

Dear Colleagues, The algorithm for computing resource constrained shortest path writes/reads outside allocated memory which may result in segmentation faults. The finding is confirmed using Valgrind. I fixed the bug and opened a pull request. Could you review the pull request and give feedback if there is something more that should be done to meet quality requirements for the merge? The pull request https://github.com/boostorg/graph/pull/93 explains the issue, fixes it and contains a test for preventing regressions. Thank you in advance for your help. Regards, Mateusz Polnik

1 0

GSoc - Request for guidance
by Fady Saeed 06 Mar '18

06 Mar '18

Hello, I’m Fady Saeed. I’m Studying Computer & System Engineering at Faculty of Engineering (3rd year) at Ain Shams University in Egypt I read GSoc projects idea list and it was really interesting and I want to contribute I’m interested in contributing to Boost Geometry, Boost SafeFloat Project 1 So If it’s possible I’d like to connect to a mentor and know what should I do next and If there’s anything I need to read about so I can contribute Thanks in advance

3 2

[filesystem] Boost 1.66 fails to compile under Android NDK r16b
by Robert Dailey 06 Mar '18

06 Mar '18

I'm following a bug reported against boost filesystem here on github: https://github.com/boostorg/filesystem/issues/65 This issue has gone dead. Early on they asserted it was an NDK issue. However, the NDK developers say it's a filesystem issue. I'm not able to build Boost 1.66 with the following configuration: Android NDK Version: r16b Architecture: armeabi-v7a API: 15 Toolchain: Clang STL: libc++ (LLVM) This is blocking my migration away from GNUSTL. Can anyone confirm that this issue is being looked at? Either I'm the only one seeing this, or my toolchain combination exposes the bug but not many people build boost this way.

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Proposed SG14 <system_error2> ready for feedback
by Niall Douglas 05 Mar '18

05 Mar '18

Back after the Outcome discussion died down, I started a thread discussing making breaking changes to Boost.System to test the feasibility of fixing some of the unfortunate design choices now apparent through hindsight in `<system_error>`. I won one argument - constexprification - the others I lost. I said at the time that I'd go off and make a better mousetrap i.e. a proposed `<system_error2>`. That proposed `<system_error2>` is now ready for feedback: Single file include: https://github.com/ned14/status-code/raw/develop/single-header/system_error… Github: https://github.com/ned14/status-code Docs: https://ned14.github.io/status-code/ Lots of detail about the differences between proposed `<system_error2>` and `<system_error>` is in the front page of the docs and pasted after this email, but essentially it fixes all the problems listed in https://wg21.link/P0824, and a few other problems I considered important as well. It works well in C++ 11, is believed to be freestanding C++ (https://wg21.link/P0829) friendly, and generates really lovely and tight codegen. If SG14 smile upon it in the April meeting, it'll be heading to Rapperswil for standardisation. Boost members should be aware that there will be shortly a push by the WG21 leadership to improve the current state of exception and error handling in the C++ standard as it is becoming increasingly obvious that the current design is no longer sufficient. You may see a paper on that from the leadership at Jacksonville, if not then fairly definitely you will at Rapperswil. This proposed `<system_error2>` *may* have a part to play in the reform proposals, if it is felt that this approach is a wise one by SG14, you guys here, and then WG21. So, as a quick introduction given that there is no documentation, instead of `error_code` we have a `status_code<D>` where `D` is the type of the code's *domain*. The domain provides all of the heavy lifting so status code itself can be trivial. Status codes can be type erased of their domain, you can always erase to `status_code<void>` but at the cost that it cannot be copied, moved nor deleted. If your domain's value type is trivially copyable, it can also be type erased into any `status_code<erased<U>>` where `U` is an integer type, and the size of the erased status code is bigger or equal to its unerased form. There is a special status_code called `generic_code`, which is a typedef for `status_code<_generic_code_domain_impl>`. Its value type is `errc`, which is a slight superset of `std::errc`. The reason it is special is because it is the baseline error code, all other codes must be semantically comparable to it, if that is possible. In current STL speak, `generic_code` is what `std::error_condition` with a `std::generic_category` is. On all POSIX platforms, we provide a `posix_code`. Its value type is `int`, as from `errno`. This maps the local POSIX implementation's error coding. It is *not* necessarily equal to `generic_code`, but usually is a superset, so all codes in `generic_code` can exist in `posix_code`, but not the other way round. On Windows, we have three main system error coding systems, so we have `win32_code`, `nt_code` and `com_code`. Their value types are `DWORD` from GetLastError(), `LONG` from `NTSTATUS`, and `HRESULT` from Microsoft COM. On all systems, there is a typedef `system_code` which is to the erased status code sufficiently large that you are guaranteed that all possible system error coding schemes can be safely erased into it. For POSIX, this is `status_code<erased<int>>`, as `int` can hold all possible error codings. For Windows, this is `status_code<erased<intptr_t>>`, as `intptr_t` can hold any of a `DWORD`, a `LONG` and a `HRESULT`. All comparisons between status codes are *semantic*. As in, `operator==()` returns true if the two types are semantically equal e.g. `win32_code(ERROR_SUCCESS) == generic_code(errc::success) == com_code(S_OK)`. Semantic comparison is the only form of comparison, if you want literal comparison, it can be done by hand by comparing value and domain by hand. There is no boolean testing at all, as it is ambiguous as we learned with `std::error_code`. One always writes: `if(sc.failure()) ...` etc. `status_code` can represent success codes, failure codes, and empty. Empty is there to say "no code was set". Empty is neither a success, nor a failure. It is there for code where a virtual function call to determine success/failure is too expensive and where the domain is known for a fact to only ever represent failure. You should only ever use empty as a local optimisation, and never ever expose empty status codes to code that you don't 100% control. And that's basically it. Idiomatic usage is for extern functions to return type erased status codes or to take one by lvalue reference. Code local to the translation unit uses typed status codes, and lets any implicit conversion into the erased form occur as needed. I've copy and pasted relevant excerpts from the Readme.txt below for those not willing to click on a link. If you have any questions, please do shout. My next step is to start work on preparing Outcome for entry into Boost now a month of settling time has passed since the review. Once the Jacksonville meeting has finished and I've done any post-meeting correspondence, I'll be starting on my (currently five!) papers for Rapperswil where I'll hopefully be attending my very first WG21 meeting! Niall --- Readme.md (excerpt) -- Solves the problems for low latency/large code base users with `<system_error>` as listed by [WG21 P0824](https://wg21.link/P0824). This proposed `<system_error2>` library is EXPERIMENTAL and is subject to change as the committee evolves the design. To fetch a drop-in standalone single file implementation: ``` wget https://github.com/ned14/status-code/raw/develop/single-header/system_error… ``` ## Features: - Portable to any C++ 11 compiler. These are known to work: - >= GCC 5 (due to requiring libstdc++ 5 for sufficient C++ 11 type traits) - >= clang 3.3 with a new enough libstdc++ (previous clangs don't implement inheriting constructors) - >= Visual Studio 2015 (previous MSVC's don't implement inheriting constructors) - Aims to cause zero code generated by the compiler most of the time. - Never calls `malloc()`. - Header-only library friendly. - Type safe yet with type erasure in public interfaces so it can scale across huge codebases. - Minimum compile time load, making it suitable for use in the global headers of multi-million line codebases. ## Problems with `<system_error>` solved: 1. Does not cause `#include <string>`, and thus including the entire STL allocator and algorithm machinery, thus preventing use in freestanding C++ as well as substantially impacting compile times which can be a showstopper for very large C++ projects. Only includes the following headers: - `<atomic>` to reference count localised strings retrieved from the OS. - `<cassert>` to trap when misuse occurs. - `<cerrno>` for the generic POSIX error codes (`errno`) which is required to define `errc`. - `<cstddef>` for the definition of `size_t` and other types. - `<cstring>` for the system call to fetch a localised string and C string functions. - `<exception>` for the basic `std::exception` type so we can optionally throw STL exceptions. - `<initializer_list>` so we can permit in-place construction. - `<new>` so we can perform placement new. - `<type_traits>` as we need to do some very limited metaprogramming. - `<utility>` if on C++ 17 or later for `std::in_place`. These may look like a lot, but in fact just including `<atomic>` on libstdc++ actually brings in most of the others in any case, and a total of 200Kb (8,000 lines) of text is including by `system_error2.hpp` on libstdc++ 7. Compiling a file including `status_code.hpp` takes less than 150 ms with clang 3.3 as according to the `-ftime-report` diagnostic (a completely empty file takes 5 ms). 2. Unlike `std::error_code` which was designed before `constexpr`, this proposed implementation has all-`constexpr` construction and destruction with as many operations as possible being trivial or literal, with only those exact minimum operations which require runtime code generation being non-trivial (note: requires C++ 14 for a complete implementation of this). 3. This in turn means that we solve a long standing problem with `std::error_category` in that it is not possible to define a safe custom C++ 11 error category in a header only library where semantic comparisons would randomly break depending on the direction of wind blowing when the linker ran. This proposed design is 100% safe to use in header only libraries. 4. `std::error_code`'s boolean conversion operator i.e. `if(ec) ...` has become unfortunately ambiguous in real world C++ out there. Its correct meaning is "if `ec` has a non-zero value". Unfortunately, much code out in the wild uses it as if "if `ec` is errored". This is incorrect, though safe most of the time where `ec`'s category is well known i.e. non-zero values are always an error. For unknown categories supplied by third party code however, it is dangerous and leads to unpleasant, hard-to-debug, surprise. The `status_code` proposed here suffers from no such ambiguity. It can be one of exactly three meanings: (i) success (ii) failure (iii) empty (uninitialised). There is no boolean conversion operator, so users must write out exactly what they mean e.g. `if(sc.success()) ...`, `if(sc.failure()) ...`, `if(sc.empty()) ...`. 5. Relatedly, `status_code` can now represent successful (informational) codes as well as failure codes. Unlike `std::error_code` where zero is given special meaning, we impose no requirements at all on the choice of coding. This permits safe usage of more complex C status coding such as the NT kernel's `NTSTATUS`, which is a `LONG` whereby bits 31 and 30 determine which of four categories the status is (success, informational, warning, error), or the very commone case where negative numbers mean failure and positive numbers mean success-with-information. 6. The relationship between `std::error_code` and `std::error_condition` is confusing to many users reading code based on `<system_error>`, specifically when is a comparison between codes *semantic* or *literal*? `status_code` makes all comparisons *semantic*, **always**. If you want a literal comparison, you can do one by hand by comparing domains and values directly. 7. `std::error_code` enforced its value to always be an `int`. This is problematic for coding systems which might use a `long` and implement coding namespaces within the extended number of bits, or for end users wishing to combine a code with a `void *` in order to transmit payload or additional context. As a result, `status_code` is templated to its domain, and the domain sets its type. A type erased edition of `status_code<D>` is available as `status_code<void>`, this is for obvious reasons non-copyable, non-movable and non-destructible. A more useful type erased edition is `status_code<erased<T>>` which is available if `D::value_type` is trivially copyable, `T` is an integral type, and `sizeof(T) >= sizeof(D::value_type)`. This lets you use `status_code<erased<T>>` in all your public interfaces without restrictions. As a pointer to the original category is retained, and trivially copyable types may be legally copied by `memcpy()`, type erased status codes work exactly as normal, except that publicly it does not advertise its type. 8. `std::system_category` assumes that there is only one "system" error coding, something mostly true on POSIX, but not elsewhere. This library defines `system_code` to a type erased status code sufficiently large enough to carry any of the system error codings on the current platform. This allows code to construct the precise error code for the system failure in question, and return it type erased from the function. Depending on the system call which failed, a function may therefore return any one of many system code domains. 9. Too much `<system_error>` code written for POSIX uses `std::generic_category` when they really meant `std::system_category` because the two are interchangeable on POSIX. Further confusion stems from `std::error_condition` also sharing the same coding and type. This causes portability problems. This library's `generic_code` has a value type of `errc` which is a strong enum. This prevents implicit confusion with `posix_code`, whose value type is an `int` same as `errno` returns. There is no distinction between codes and conditions in this library, rather we treat `generic_code` as something special, because it represents `errc`. The cleanup of these ambiguities in `<system_error>` should result in users writing clearer code with fewer unintended portability problems. -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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Trouble getting feedback on a program_option feature PR
by Eyal Rozenberg 05 Mar '18

05 Mar '18

Hello Boosters, Following a (much) earlier suggestion on this list, I've implemented one of the features I'd like to see in program_option, and created Pull Request for initial review/feedback on GitHub: https://github.com/boostorg/program_options/pull/40 I've noticed, however, that there are 4 other unattended PRs, the earliest being from 2016. Some of them have comments such as "Can you please merge or decline?" urging a response. Also, there have been no commits for the past 4 months. I've also emailed Vladimir (Prus) last month - a short message, merely to ensure he's noticed my PR, not to demand anything; but I've gotten no reply. Now, I don't want to sound accusatory - I'm sure there are perfectly good reasons for the lack of responsiveness, and I'm very appreciate of the work of writing the library and maintaining it over the years. Still, given the situation I thought I'd bring this up here on the list. What would you suggest I do? Eyal

1 0

Gsoc2018/mentor required
by nivyatheresa 05 Mar '18

05 Mar '18

Hello, I am Nivya and I am a btech student from IIT Roorkee. I would like to contribute to the Boost.Real project. I need a mentor to help me to proceed further. Thanks in advance, Sincerely, Nivya. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

2 1

[serialization] RTTI issue with non-polymorphic types
by Jorge Lodos 05 Mar '18

05 Mar '18

Hi I am trying to use the serialization library for non-polymorphic types without RTTI. In release mode everything works fine, but in debug mode there are problems because dynamic_cast is used for debugging purposes. The code is in smart_cast.hpp, starting in line 87: #if ! defined(NDEBUG) \ || defined(__MWERKS__) // do a checked dynamic cast return cross::cast(u); #else I believe the first line could be replaced with: #if (! defined(NDEBUG) && ! defined(BOOST_NO_RTTI) ) \ Is this something you are willing to consider? I decided to ask before creating any ticket or pull request because there is a number of previous attempts to make serialization work without RTTI for the general case. But this is specific for non-polymorphic types. Thanks. Jorge

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Re: [boost] Proposed SG14 <system_error2> ready for feedback
by Bjorn Reese 04 Mar '18

04 Mar '18

On 02/28/18 23:10, Niall Douglas via Boost wrote: > 7. `std::error_code` enforced its value to always be an `int`. This is > problematic for coding systems which might use a `long` and implement > coding namespaces within the extended number of bits, or for end users > wishing to combine a code with a `void *` in order to transmit payload > or additional context. As a result, `status_code` is templated to its > domain, and the domain sets its type. A type erased edition of > `status_code<D>` is available as `status_code<void>`, this is for > obvious reasons non-copyable, non-movable and non-destructible. > > A more useful type erased edition is `status_code<erased<T>>` > which is available if `D::value_type` is trivially copyable, `T` is an > integral type, and `sizeof(T) >= sizeof(D::value_type)`. This lets you > use `status_code<erased<T>>` in all your public interfaces without > restrictions. As a pointer to the original category is retained, and > trivially copyable types may be legally copied by `memcpy()`, type > erased status codes work exactly as normal, except that publicly it does > not advertise its type. While I do see the need for providing extensions, I am not sure if status_code<void> is useful given all its "non-" characteristics. Can you elaborate on its use-cases? I propose that the customizable status_code<D> is renamed to basic_status_code<D>. In keeping with the pre-established practices of std::error_code using int, I furthermore suggest that status_code becomes a non-templated alias for basic_status_code<int>.

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Gsoc2018/Mentor required.
by nivyatheresa 04 Mar '18

04 Mar '18

Hi, I am Nivya Theresa Jose, b-tech student from Indian Institute of Technology Roorkee. I would like to contribute to boost.uBLAS project 1, which is to add support for tensors .I would like to connect with a mentor and would like to know about further procedures. Thanks in advance, sincerely, Nivya Theresa Jose. -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

1 0

Help/Mentor required
by Devika Krishnadas 04 Mar '18

04 Mar '18

Hi, I am Devika Krishnadas, an Undergrad Computer Science student from Amrita University. I am interested in contributing to boost.uBLAS project #1, which is to add Statistics and Machine learning functions. It would be great if anyone could help me proceed further. Thanks in advance, Regards, Devika Krishnads.

2 1

gsoc2018 inquiry and mentor seeking
by fady esam 04 Mar '18

04 Mar '18

Hello, I am Fady Esam student at 3rd year of computer engineering in ASU university in Egypt I want to cobtribute the the project of "Adding multicore and gpu computations to uBLAS" As i was the team leader and main contributer in an open source library for complex-numbers matrices that has the same parsing and interface as matlab and supports all operations like computing inverse by gaussian elimination and determinant by LU decomposition and +, - , * ,/ , .* , ./ and computing power of matrix in a very optimized way That's a github link to the library : https://github.com/boostorg/boost/wiki/Boost-Google-Summer-of-Code-2018 I want to know do i have to implement part of the library again in template for the competency test? And is there a mentor that is interested so i can submit a proposal to? Thanks for reading :)

2 2

[interprocess] file_mutex class proposal
by mateusz janek 04 Mar '18

04 Mar '18

Hello boost::interprocess community, During my pet projects development I found that a file access synchronization is a common problem so, I wrote a class that wraps it and thought that it can be useful for wider community. I would like to ask you what do you think about such functionality in boost::interprocess? I'm aware that class from the repo is not ready to release. Just wanted to show about what functionality I'm talking about. Here you can find the repo: https://github.com/stryku/file_mutex You can find there the proposed class and a simple usage example. If you will find it interesting I will prepare more formal merge proposal, update docs, maybe more examples etc. Looking forward to hearing from you what do you think about it. Thank you, Mateusz Janek

1 0

Which headers to include?
by Lakshay Garg 03 Mar '18

03 Mar '18

Hello Boost I am using a few Boost libraries in a project I am working on. I must confess that this is perhaps my first serious use of boost so all this could just be due to lack of familiarity. The one thing that keeps frustrating me about boost is finding out _which headers to include?_ I am not sure if this is a problem with my googling skills or library documentation or maybe I just don't know the proper place to look at but most of the times I need to use a library with lots of headers (I am looking at Boost.Log) I have to go grepping the boost code. Is there something I am missing or is there a better way to go about this problem? Lakshay

3 2

why boost does not have skip list implementation?
by David Frank 03 Mar '18

03 Mar '18

like java concurrentSkipListSet for example. Thanks, David

3 2

past few days coding:=>>makefile generator
by Ggh 03 Mar '18

03 Mar '18

#-------------------------------------------------------------------------------- # # Command Line Options: # # For each argument add a space between the switch and the argument to the switch, # e.g.: # # mkmakefile -tt exe -t targetname # # mkmakefile --help # # -tt <exe|dynamic|objs|static> Target type # -t <targetname> Target name # -i <include directory> Include directory # Include directories can be several. Prepend # each directory with an '-i' # -L <library directory> Library directory # Library directories may also be several, prepend each # directory with an '-L' # -l <library name> Library name, may also be several, prepend each # library with '-l'. # -d <define> Define # May also be several, prepend each define with '-d'. # -hd Header dependencies # This flag makes the generator scan # the source files for header files # included. Creates dependency rules # in the generated makefile. # If a header file is included in a source file # and found in any of the include directories given # it will be listed as a dependency to the source file. # -o <makefile filename> Makefile filename to generate # -c <c compiler> C compiler, the compiler needs to be in the PATH # environment variable. # -cc <c++ compiler> C++ compiler, the C++ compiler needs to be in # the PATH environment variable aswell. # -sl <static library> Link to static library # The number of static libraries can be any. # Prepend each library name with an '-sl' tag. # -wd <target directory> Target directory. The program changes # to the target directory, creates the makefile # and reverts back to the directory it was # started from. The makefile is written # to the target directory. If this argument is # not set then the current directory will be used. # -mk Make the program / library. This option executes # 'make' with the make file given. If no makefile # argument is given it will use 'makefile.mk' by # default # # -help This help information # #--------------------------------------------------------------------------------

1 0

[gsoc18]project1-1: Add statistics and machine learning functions
by SheldonZhang 02 Mar '18

02 Mar '18

Hi, My name is Zhang Bohan(Sheldon Zhang) from China. I am a freshman in Beijing University of Posts and Telecommunications, majoring in Information and Communication Engineering. I want a mentor who can guide me to accomplish the project. I am interested in working for Boost.uBLAS because in my profession there are plenty of calculation about matrix. I believe this will lead me to better understanding about it. And I love machine learning, it is the way to the future. I am taking a machine learning course(taught by Andrew Ng) on coursea. So I know what I am going to do in the project. I do quite well in Linear Algebra. In the exam, I got top 10% in the grade. I have been programming since junior high school. I am familiar to C++-11 and its features(like lambdas and template). I have good command of basic algorithms. I participated in National Olympiad in Informatics and got good grades. Besides, I am a teaching assistant in Program Designing Course. I am googd at English, so there is few difficulty in communicating. I have done the programming competency test https://github.com/ltg001/gsoc18-codeCompetencyTest At last, what should I do in this period? With regard, Sheldon Zhang -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

2 1

[gsoc18] [Boost.Real] Competency Test
by Parth Mittal 02 Mar '18

02 Mar '18

Hi My name is Parth Mittal, and I'm a third year computer science undergraduate. Here is my attempt at the competency test: (wrt the first, second, and third bullet on the project page) 1. I uploaded my code here (https://github.com/parthmittal/boost_competency_test) I'm not sure how much of it is required to be functional but (of course) I can write more code if required. The current code uses an std::pair of the chosen rational type to represent intervals, it is probably more sensible to replace this with a dedicated type for intervals. Also I have two different ideas for dealing with integers in the binary operators: (i) Wrap them into a "real" number (with an approximation function that always returns the exact value and an error term of 0). (ii) Add a facility for additive and multiplicative rational factors to the class. 2. For sure there is no way to be sure two numbers are equal in finite time, so while checking if a and b are equal, we should pass an integer parameter, say K, and then for every pair of integers i, j between 1 and K, we should check if a(i) = b(j) (of course a(i) = b(j) iff the intervals share a point). This feels somewhat inefficient (it would be nice to eliminate the quadratic runtime with K), but since we don't have a guarantee that a(i + 1) is a subset of a(i), I don't see any obvious way to improve this. 3. To be honest, I had to google for "Small String Optimization" - and the analogue I can see is to store as an array the values of a(k) for all k <= K for some small constant K. I'm not sure how to implement this at compile time; it makes sense that the approximation function(s) for the real number involved be constexpr, but I've never written any code which is constexpr. Perhaps my code in (1) already makes this clear, but I'm not very experienced at writing C++; I've written probably 100k+ lines while doing programming contests, but this was rather simple code which was written once and read never. I can fill in the gaps in my knowledge of the language on an ad-hoc basis (or using the time until the SoC officially begins). Thank you for reading Parth Mittal

2 1

Boost Performance
by Ian Kosen 01 Mar '18

01 Mar '18

Hi, I was looking at this benchmark https://github.com/mloskot/spatial_index_benchmark <https://github.com/mloskot/spatial_index_benchmark> which attempts to compare the performance between Boost and LibSpatialIndex. It caught my eye that Boost was magnitudes faster than LibSpatialIndex. Is there an obvious reason for this? Design considerations and trade offs? Thank you :) Regards, Kosen

2 1

[teeks99-09-p-win2016-64on64][poly_collection] Regression with latest MSVC 14.1 in C++17 mode
by Joaquin M López Muñoz 28 Feb '18

28 Feb '18

Hi, MSVC 14.1 (_MSC_FULL_VER=191225834) in C++17 mode (_MSVC_LANG=201704L) is having a regression when compiling Boost.PolyCollection tests: http://www.boost.org/development/tests/develop/developer/output/teeks99-09-… The problem happens in this seemingly innocent context (https://github.com/boostorg/poly_collection/blob/654018c7ce14674a1c0527206a… ): template< typename ForwardIterator1,typename ForwardIterator2,typename Predicate > bool operator()( ForwardIterator1 first1,ForwardIterator1 last1, ForwardIterator2 first2,Predicate pred)const { ... using difference_type= typename std::iterator_traits<ForwardIterator1>::difference_type; difference_type l1=std::distance(first1,last1); // syntax error (wrongly) signalled here Is there some kind soul with access to this compiler who'd like to try the following workarounds and report the results? // workaround 1 using difference_type= typename std::iterator_traits<ForwardIterator1>::difference_type; typename difference_type l1=std::distance(first1,last1); // workaround 2 typedef typename std::iterator_traits<ForwardIterator1>::difference_type difference_type; difference_type l1=std::distance(first1,last1); Thank you! Joaquín M López Muñoz

2 2

request for comments in a new format library
by Roberto Hinz 28 Feb '18

28 Feb '18

Dear boost community, some time ago I announced a format library I'm working on. I think at that time it was still too incipient for one to evaluate whether it looked promising, thought some few but very useful observation were made ( one regarding i18n and other code bloat ) that made me change many things. Now the library is more evolved and I think it will be ready for review somewhere in the second half of this year, if no big change happens. This is a c++14 text format library with some unique features: - designed to be utf8 friendly - easy to extend for new destination types ( like some different string type ) - able to align (justify) a set of sub-arguments as one ( see joins <https://robhz786.github.io/stringify/doc/html/special_input_types/special_i…> ) - it enables the use of translations tools ( like gettext ), yet the formatting is not specified by a format string. And the problem with format strings that they lead to run time errors (instead of compilation error ) when they are incorrect. Hence I much appreciate any comments, especially if can identify any flaw I didn't realize. repo: https://github.com/robhz786/stringify doc: https://robhz786.github.io/stringify/doc/html/ best regards roberto

3 7

Re: [boost] [Boost-bugs] [Boost C++ Libraries] #13458: 'cl' is not recognized as an internal or external command, operable program or batch file. Failed to build Boost.Jam build engine. Please consult bjam.log for furter diagnostics.
by Andrew Depke 28 Feb '18

28 Feb '18

It looks like you're missing "cl.exe" on your system, or have not included it in your PATH. cl.exe, as seen here <https://msdn.microsoft.com/en-us/library/f35ctcxw.aspx>, is Microsoft's C++ compiler, which can be obtained by downloading the latest version of Visual Studio. Downloading and installing MSVS will automatically place it in your PATH. On Tue, Feb 27, 2018 at 2:28 PM, Boost C++ Libraries < noreply(a)lists.boost.org> wrote: > #13458: 'cl' is not recognized as an internal or external command, > operable program > or batch file. Failed to build Boost.Jam build engine. Please consult > bjam.log for furter diagnostics. > ------------------------------+--------------------- > Reporter: anonymous | Owner: (none) > Type: Bugs | Status: new > Milestone: To Be Determined | Component: None > Version: Boost 1.41.0 | Severity: Problem > Keywords: | > ------------------------------+--------------------- > 'cl' is not recognized as an internal or external command, > operable program or batch file. > > Failed to build Boost.Jam build engine. > Please consult bjam.log for furter diagnostics. > > -- > Ticket URL: <https://svn.boost.org/trac10/ticket/13458> > Boost C++ Libraries <http://www.boost.org/> > Boost provides free peer-reviewed portable C++ source libraries. > > _______________________________________________ > Boost-bugs mailing list > Boost-bugs(a)lists.boost.org > https://lists.boost.org/mailman/listinfo.cgi/boost-bugs > >

1 0

[release] 1.67.0 closed for major changes
by Daniel James 28 Feb '18

28 Feb '18

The master branch is now closed for major changes and will be closed for the beta in a week. Also, you can also add your libraries' changes to the release notes at: <https://github.com/boostorg/website/blob/master/feed/history/boost_1_67_0.q…> Remember that after editing the file, you need to submit the form to create a pull request. You can preview the release notes at: <http://www.boost.org/users/history/in_progress.html> Thanks, -- The Boost Release Team

1 0

Boost managed_shared_memory not working with C's mmap call on freeBSD
by vijay sharma 27 Feb '18

27 Feb '18

Hi All, I am having two processes and they are sharing shared-memory. - Process-1 (implemented in c++ and using boost::interprocess::managed_shared_memory interface) - Process-2 (implemented in c and using "she_open" and "mmap" interfaces) This code was working fine on Linux But When I deployed same code on FreeBSD. Process-2 (C lang based) is keep on throwing error in mmap. Error is "Bad file Descriptor". Please let me know: 1. Do I need to change the interface while moving from Linux to FreeBSD. 2. Is there any known issue with this design. Code Snippet: Process-1(c++): obj = new boost::interprocess::managed_shared_memory( boost::interprocess::open_or_create,<shm_name>, <shm_size>); // to create shm obj->allocate(<data_size>) ; // to write in shm Process-2 (c): int fd = shm_open(<shm_name>,O_RDWR, 0666);void * startpoint = mmap(NULL, <shm_size>, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); // using the startpoint to read data written by process-1. Boost version: Boost.1.63.0 I have raised same on stackoverflow.com and below is the link: https://stackoverflow.com/questions/48984703/boost-managed-shared-memory-no… Thanks, Vijay

2 1

[Boost][CMake] Status of cmake support.
by Mike 26 Feb '18

26 Feb '18

Hi everyone, since I couldn't find any official information about that, I wanted to ask if there is any new information about the cmake support in boost (since the initial discussion on the ml after the steering committee's announcement)? Is there some agreement on how to do the transition or at least a popular formal/informal proposal? Is there any place to track which libraries can already be built with cmake? What is the best way for a non library authors like me to help with the transition? IIRC there was talk about a cmake library some time ago, but I haven't heard anything about that in a long time. Is such a library even desired/necessary? Imho getting all of boost to compile with cmake should be pretty simple, but if this is expected to happen in a transparent manner (same output, same workflow including test result upload), a fair bit of boost knowledge, cmake skills and support machinery might be required. Best regards Mike

10 15

[winapi] Bumping default target to Windows 7?
by Andrey Semashev 26 Feb '18

26 Feb '18

Hi, I was thinking about bumping the default target Windows version to 7 in Boost.WinAPI. The current default is Vista, which EOLed in April 2017. There is not much difference from the available API standpoint (in Boost.WinAPI this would enable a few constants related to process management), but there may be some interesting extensions that could be useful to libraries. Note that this will not preclude targeting older Windows versions, just as it doesn't preclude targeting XP or 2000 now. Users will still be able to specify the target Windows version as they can now. Note also that I'm not planning this for 1.67, only 1.68. Any objections/thoughts?

1 0

[gsoc18] Project - Add statistics and machine learning functions
by Anagha G 26 Feb '18

26 Feb '18

Hi, I'm Anagha G. I'm pursuing 2nd year Bachelor of Engineering in Information Science and Engineering in R.V College of Engineering, Bangalore, India. I'm interested to work on a project to add statistics and machine learning functions to Boost.uBLAS. I've a good knowledge in Statistics, data visualization and Machine Learning. I've also learnt C++ and use it everyday for projects and academic assignments. Please let me know further details about finding a mentor and also how I should submit my competency test. Thanks Anagha G

1 0

[system] [teeks99] Mass test failures on MSVC-14.0
by Andrey Semashev 26 Feb '18

26 Feb '18

Hi, Most of Boost.System tests are failing on the teeks99-09-f-win2016-64on64 tester, MSVC-14.0[1]. The test logs don't show any errors and I can't reproduce it locally. I'm seeing similar test failures in other libraries, like Boost.Atomic for example, and the links point to Boost.System. Is it possible to get the error log from the tester? [1]: http://www.boost.org/development/tests/develop/developer/system.html

2 2

Re: [boost] [Boost][CMake] Status of cmake support.
by Mike 26 Feb '18

26 Feb '18

I don't believe in conspiracies. But I've seen enough resistance (me st of it well reasoned) on the ml after the steering committee made their announcement that I wouldn't be surprised if a lot of reviews focus on deficiencies / differences compared to boost build that are inherent to cmake and not the library itself.

6 5

crash during bad_file_descriptor
by VIKRAM LODHI 26 Feb '18

26 Feb '18

Hi, Working Scenario: I have a scenario of single server and multiple client. server is constantly sending update to connected client. all the connection and transmission is async. Problem: lets say i have 3 client connected. which they are receiving update . if one client closed during in middle of transmitting. (killing the process of client ) my server crashes .. socket.async_write_some(buffer, [&](error_code& e, size_t size_) { if(e) { cout << e.message() << endl; } }); the last error i get is bad_file_descriptor . pfa : error thrown by gdb

1 0

make makefile
by Ggh 26 Feb '18

26 Feb '18

Hello all, The past few days I have kept myself busy coding a kind of makefile generator. It can scan directories and generate makefile(s) from what c/c++ files it finds. Is such a program of interest to the boost lib? If so, I'd like to contribute. thank's Greg

2 2

Re: [boost] [gsoc18]Boost.SafeFloat
by Rajat Miglani 25 Feb '18

25 Feb '18

I have read the paper "Goldberg, David. "What every computer scientist should know about floating-point arithmetic." ACM Computing Surveys (CSUR) 23.1 (1991): 5-48."and documentation and now having a little understanding of what this project is about.Presently going through the code and concepts, please guide me of what changes I have to do in the previous code to make it better. On Wed, Feb 21, 2018 at 11:52 PM, Damian Vicino <damian(a)vicino.com.ar> wrote: > Hi Rajat, > For the Boost.SafeFloat project, I suggest you take a look to the > following links: > - Repository: https://github.com/sdavtaker/safefloat > - Documentation: https://sdavtaker.github.io/safefloat/doc/html/index.html > > Also, try to read this paper if you didn't before: Goldberg, David. > "What every computer scientist should know about floating-point > arithmetic." ACM Computing Surveys (CSUR) 23.1 (1991): 5-48. > From the C++ perspective, key concepts you need to know are: > - Templates (a lot of it) > - Custom Literals > > A good proposal would be to take a read to the documentation and code base > and describe what is missing to complete the project. > Best regards, > Damian Vicino > > > > > 2018-02-21 14:11 GMT-03:00 Rajat Miglani via Boost <boost(a)lists.boost.org> > : > >> Dear boost community, >> I am a GSOC aspirant and I'd like to contribute to your organization. >> I have read the project ideas and is interested in working on:- >> 1)Boost.SafeFloat or >> 2)Enhancing Boost.Intrusive Library >> Can I get some more info about how to work on these projects and the basic >> requirements so that I can learn them and be able to contribute to my >> fullest. >> >> Thank you, >> >> _______________________________________________ >> Unsubscribe & other changes: http://lists.boost.org/mailman >> /listinfo.cgi/boost >> > >

1 0

[gsoc18] Project - Add statistics and machine learning functions
by Anagha G 25 Feb '18

25 Feb '18

Hi, I'm Anagha G. I'm pursuing 2nd year Bachelor of Engineering in Information Science and Engineering in R.V College of Engineering, Bangalore, India. I'm interested to work on a project to add statistics and machine learning functions to Boost.uBLAS. I've a good knowledge in Statistics, data visualization and Machine Learning. I've also learnt C++ and use it everyday for projects and academic assignments. Please let me know further details about finding a mentor and also how I should submit my competency test. Thanks Anagha G

1 0

GSoC 2018
by shubham soni 25 Feb '18

25 Feb '18

Hello Boost Community! I'm Shubham Soni, fourth year dual degree student from IIT Kharagpur, India. I have experience in working with C/C++, Python, ruby and good theoretical knowledge in parallel programming. I've gone through the project list and found out* Boost.UBLAS (Add statistics & machine learning function)* to be interesting and i want to contribute in it. I have downloaded the code base and i am trying to understand it. Is there something else that i should read or anything you would suggest? Thanks *shubham soni*

1 0

regarding gsoc 2018
by Akshay Raut 23 Feb '18

23 Feb '18

hello everyone i am from india doing bachelors in computer science. I am very passionate for c++ and hence, I want to contribute to it through this organization in this year's gsoc. can someone please tell me the best way to get started so that i get selected this year??

2 1

[yap] Re-announcing Yap
by Zach Laine 23 Feb '18

23 Feb '18

I posted 2-3 months ago about Yap, an expression template library I've written that I intend to propose for Boost. This is just a reminder that the library exists, and where to find it. I'm giving a talk about it at C++Now 2017, and some time after that I intend to submit it to the queue. Louis Dionne has offered to serve as review manager when the time comes. You can find the main repo on GitHub: https://github.com/tzlaine/yap And online docs are here: https://tzlaine.github.io/yap Zach

4 6

Query for interest in library: reflective enum
by Nir Friedman 23 Feb '18

23 Feb '18

Hello, I recently needed a reflective enum for work (that is an enum where you can programmatically convert to and from strings, know how many enumerators there are, and iterate over all enumerators). I looked online but I didn't find anything that met my requirements. I was surprised that there wasn't one in Boost. So I'd like to see if there is interest; I wrote an implementation that I think has several nice features. The most polished existing smart enum implementation I could find was http://aantron.github.io/better-enums/. However, the enum implemented there is not a true enum; it uses a nested member of a class kind of approach. So for example, the is_enum type trait will not recognize is as an enum. You cannot use it as a non-type template parameter. I strongly think that a good generic smart enum macro should generate the exact "vanilla" enum (or enum class) declaration. My library's syntax looks like this: WISE_ENUM(Foo, BAR, (BAZ, 3)) This generates, among other things, exactly: enum Foo { BAR, BAZ=3}; I intend this as an explicit guarantee of the library that the programmer can count on. That way when Foo is used for things unrelating to reflection, the developer can be confident that there will not be any surprises. Beyond compatability with C++ facilities for enums, and minimizing surprise, another advantage of this approach is that it's guaranteed to be backwards compatible. An existing codebase with an existing enum/enum class can switch to this smart enum with very high confidence that existing code will continue to work as before. The WISE_ENUM macro, beyond generating the vanilla enum, also generates a switch-case function for to-string conversion (for maximal efficiency), and finally it generates a constexpr function that returns a std::array<std::pair<const char*, Foo>> listing all of the arrays and their string descriptions. This constexpr function, which is found via ADL, allows writing a sequence of (constexpr) variables and functions providing the rest of the desired functionality. Usage looks like this: std::cerr << "My enum's size is : " << wise_enum::size<Foo> // this is constexpr template variable auto x = wise_enum::from_string<Foo>("BAR").value(); // from_string returns an optional auto y = wise_enum::to_string(x); // y is string literal, no heap allocation My implementation (POC level) is here: https://github.com/quicknir/wise_enum. I don't yet have separate macros to cover enum/enum class/explicit/implicit backing type combinations. It's only about 100 lines of code, leaning heavily on BOOST_PP to do the heavy lifting. It requires variadic macros, and can probably target C++11 (if it doesn't already). I probably need to "comma harden" the macros for bizarre stuff like WISE_ENUM(Foo, (BAR, my_func<3,4>())). It has the limitation that the macro cannot be used inside a class (this is hard to workaround for reflective macros). It's also unclear how repeated enumeration values would be handled (enum Foo { BAR = 1, BAZ = 1}). As it stands this will cause a compilation failure in the generated switch case of the to_string function. Can discuss more in subsequent emails. One suggested feature is an is_contiguous trait. Another reasonable bit of functionality might be an is_wise_enum trait. Version 2 of this library could target enum sets. Although it's not fancy, I think this nicely covers a piece of functionality I often need, and it does so avoiding any downside compared to using a simple enum (beyond having to use macros). Hope other people will agree! Cheers, Nir

4 5

[Math] Only a fraction of the tests showing up online
by John Maddock 23 Feb '18

23 Feb '18

I assume this is an issue with the test matrix, but only about 1/3 of the Math lib tests are showing up at http://www.boost.org/development/tests/develop/developer/math.html Thanks, John. --- This email has been checked for viruses by AVG. http://www.avg.com

2 4

[gsoc18] - Similarity Between Geometries and Timeframe Question
by Aidan Nyquist 23 Feb '18

23 Feb '18

Hello, My name is Aidan Nyquist, a sophomore at North Park University. I'm currently majoring in Math and Physics, and minoring in computer science. I have been programming for about 4 years now, and have experience with a fair amount of languages (Python, C/C++, Java, LISP, Haskell, SQL, etc.). Sifting through all the GSoC projects, while fun, can be somewhat difficult. I have just found the "Similarity between geometries" project and think I am a great fit. I wish I had found it sooner though, so I could have started the evaluation test done by now. Is there a rough deadline for its submission? I'm applying for one other organization, and they had a Feb. 28 deadline. If there is a similar date, I will reluctantly not attend the Hackathon I was hoping to go to this weekend. However, if there is some buffer time, that would be great to know, so I could be at ease. Any advice is always appreciated. Thanks, Aidan Nyquist

2 1

Yap's formal review is starting now!
by Louis Dionne 23 Feb '18

23 Feb '18

Dear Boost community, The formal review of Zach Laine's Yap library starts Monday, February 5th and ends on Wednesday, February 14th. Yap is a C++14-and-later library to build expression templates. Yap uses new features introduced in C++14/17 to make the library simpler to use and compile faster than existing solutions, such as the well known Boost.Proto library. The documentation is available here: https://tzlaine.github.io/yap/doc/html/index.html The GitHub repository is available here: https://github.com/tzlaine/yap We encourage your participation in this review. At a minimum, please state: - Whether you believe the library should be accepted into Boost - Your name - Your knowledge of the problem domain You are strongly encouraged to also provide additional information: - What is your evaluation of the library's: * Design * Implementation * Documentation * Tests * Usefulness - Did you attempt to use the library? If so: * Which compiler(s)? * What was the experience? Any problems? - How much effort did you put into your evaluation of the review? All issues discussed during this review will be tracked on the library's GitHub issue tracker at https://github.com/tzlaine/yap/issues. Regards, Louis Dionne P.S.: I've been having trouble posting to this list. If this ends up being a duplicate post, let's make this one the official one.

14 107

Re: [boost] New Astronomy Library
by Pranam Lashkari 22 Feb '18

22 Feb '18

These days I was studying already available astronomy libraries in different languages. I found that "Astropy"( http://www.astropy.org/ ) is well established and it is being used in many places. Maybe one of the reasons for its success is that it is for Python. As we all know that python is one of the easiest languages to learn. Not all scientists are programmers and maybe that's why they find python and Astropy easy to use. So what I was thinking is, what if we build a similar structure to the same library? It will make things easier for those scientists who do not have much time to learn a new programming language and this will make the transition easier from python to C++. Is it a good idea? Pranam Lashkari On Mon, Feb 12, 2018 at 7:31 PM, JC Passy <jcpassy(a)gmail.com> wrote: > Dear Pranam, > > Sorry for taking so long to get back to you. > So I talked to some of my former colleagues about potential projects > related to the analysis of astronomical data. They forwarded me the > following paper which gives an example of the amount of data they are > dealing with and some solutions they have found. I think you might find it > interesting: > http://adsabs.harvard.edu/abs/2017PASA...34...38V > > I must say in terms of concrete ideas, they did not have anything specific > to suggest. Most of these large surveys have already teams dedicated to > develop a pipeline to deal with their specific data. However, we will keep > looking and talking to people, may be something will come up in the future. > > In the meantime, you seem to already have ideas for amateur astronomers. I > suggest you start with it (I am happy to help you if you feel like it) and > I will let you know if a potential project for professionals comes up. Does > it sound good to you? > > Cheers, > > Jean-Claude > > > On 26. Jan 2018, at 12:17, JC Passy <jcpassy(a)gmail.com> wrote: > > Dear Pranam, > > Sure, I am waiting for some feedback from two former colleagues of mine on > that matter. I should get something by early next week, I will let you know > as soon as I do. > > Cheers, > > Jean-Claude > > On 25. Jan 2018, at 13:49, Pranam Lashkari <plashkari628(a)gmail.com> wrote: > > Dear Jean-Claude; > > As you mentioned in your emails, you are having some ideas what can be > implemented in this library as per requirement of professionals in this > field. > Can you start discussing those ideas so that we can get a better idea of > how to structure this library? > > On Mon, Jan 22, 2018 at 1:40 AM, JC Passy <jcpassy(a)gmail.com> wrote: > >> Dear Pranam, dear Vinicius, >> >> not sure that my initial email made it to the mailing list. If it did, >> sorry for repeating myself. >> I am working as a computer scientist at the MPI for Intelligent Systems >> in Tübingen. Before that, I did my PhD in astrophysics and a postdoc. In >> general, I am also interested in using boost and developing a library that >> could be used by astronomers and astrophysicists. >> >> Looking at your proposal, I would second Vinicius’ opinion in the sense >> that one should try to make it a bit more specific. In particular, you >> should emphasize the *why* (what do you wish to accomplish? why would >> someone need/use it?) and the *who* (who is your target audience?). >> Regarding the latter, I see two options: >> >> 1) *amateur astronomers*: I personally do not know what their needs are, >> but I could try to find out. There are some open source projects dedicated >> to amateur astronomers (for instance https://openphdguiding.org to which >> we contributed), so that could be an option; >> >> 2) *professional astronomers*: I think a lot can be done, in particular >> regarding observational data analysis. They used *REALLY* old tools >> (IDL, IRAF, …) and given the future and upcoming surveys that will produce >> very large amount of data, they might have serious performance issues. This >> is why I believe they might benefit from using cutting-edge C++ libraries. >> >> I would be quite interested in option 2, and it could impact potentially >> a large audience IMHO. Of course, the “selling” part won’t be easy (people, >> especially astrophysicists :) won’t give up their old methods easily even >> though the new method is 10x faster) but we can facilitate this process by >> pin-pointing features that they really need. I will try to talk to some of >> my former colleagues this week and see what they think about that. In this >> case, this is a project that would need a bit of time to be properly >> defined and the deadline for GSoC18 is coming too soon. As far as I am >> concerned, this is no problem as this project does not need to be tied to >> it. >> >> Cheers, >> >> Jean-Claude >> >> >> On 21. Jan 2018, at 15:00, Vinícius dos Santos Oliveira via Boost < >> boost(a)lists.boost.org> wrote: >> >> 2018-01-21 8:07 GMT-03:00 Pranam Lashkari <plashkari628(a)gmail.com>: >> >> I have made this proposal for this new library(check attachment) >> Suggestions are invited. >> >> >> You need to focus more on "selling your project". Why is it important to >> have such library in C++ specifically? Isn't this one of those projects >> where other languages will do just fine? What market are we missing by not >> having this library? What C++ have to offer to make such library be >> inviting to write in C++? >> >> You mention "gather information from observation data". Does this mean >> you'll include a parser for some format? >> >> Can you compare this library with some non-C++ library and detail a little >> how will scope between the two differ (e.g. your library will focus >> initially only on X given the library is only starting)? >> >> For now, this should be good. When it's time to submit the student form >> through the GSoC platform, you'll also focus on selling yourself. I'll >> give >> more feedback on this when the time comes. Don't worry. >> >> Should I publish this on the wiki page of Boost GSoC 2018? >> >> >> >> Yes, please. You can put my name as a potential mentor. >> >> -- >> Vinícius dos Santos Oliveira >> https://vinipsmaker.github.io/ >> >> _______________________________________________ >> Unsubscribe & other changes: http://lists.boost.org/mailman >> /listinfo.cgi/boost >> >> >> > > >

3 4

[gsoc18] SafeFloat or Real
by Thomas Ferrand 21 Feb '18

21 Feb '18

Hello everyone, I'm a student willing to be part of this year GSoC program and I'd love to work with Boost. Among the proposed projects, I'm interested in two of them, Boost.SafeFloat and Boost.Real. As Damian Vicino is said to be the potential mentor of both, I already send him an email but don't have any answer for now. I've already made the competency test for Boost.SafeFloat but I don't know what to do now, wait for an answer? Seek another mentor? Can you please guide me? Thanks, Thomas Ferrand

2 1

new to the organization
by Rajat Miglani 21 Feb '18

21 Feb '18

Dear boost community, I am a GSOC aspirant and I'd like to contribute to your organization. I have read the project ideas and is interested in working on:- 1)Boost.SafeFloat or 2)Enhancing Boost.Intrusive Library Can I get some more info about how to work on these projects and the basic requirements so that I can learn them and be able to contribute to my fullest. Thank you,

2 1

Legal problem with Stackoverflow contribution under the "Creative Commons Attribution Share Alike 3.0" license
by Dominique CHABAUD 21 Feb '18

21 Feb '18

Hi all, In Boost 1.62.0 we saw in the following header file : boost/thread/win32/thread_primitives.hpp that the function inline ticks_type __stdcall GetTickCount64emulation() is a contribution coming from https://stackoverflow.com /questions/8211820/userland-interrupt-timer-access-such- as-via-kequeryinterrupttime-or-similar Stackoverflow re-lisensing to MIT is told to be in place starting Feb 1, 2016 and only for new contributions. But the StackOverflow contribution that has been borrowed in Boost is Nov 23, 2011 and contributions prior to Feb1, 2016 are under the "Creative Commons Attribution Share Alike 3.0" license which is not permissive. This causes legal problem. Hope somebody can fix this. Thanks Dominique

15 37

Re: [boost] C++03 / C++11 compatibility question for compiled libraries
by Glen Fernandes 21 Feb '18

21 Feb '18

Olaf van der Spek wrote: > > Glen Fernandes wrote: >> Before I became a contributor to Boost, and before I became a Boost >> library author, I was a user of Boost at Microsoft. Even as late as >> 2014 when I left the company, those projects depended on Boost for >> C++03 support. (In fact, at least one of the projects only dropped >> C++03 support as late as 2016). > > Where did the C++03 support requirement come from though, an old compiler? > Even VS 2010 knows some C++11 stuff. Supporting teams that were still on older compilers was the motivation, yes. Boost was upgraded more frequently than upgrading to a newer compiler (even though in this particular case, the compiler was developed within the same company). For that project I referenced which dropped C++03 support in 2016, they also dropped VC10 support in the same year. Those projects came to depend on the reliability of Boost for its implementation of standard library facilities that were otherwise defective in VC that wouldn't be fixed until the next major release of the compiler, while Boost releases were every few months. Even trivial standard library things like std::ref, std::addressof, std::unique_ptr::~unique_ptr (wrong order of operations in VC10, fixed in VC11), std::align (wrong return value in VC11, fixed in VC12), std::call_once (was 1500 times slower than InitOnceExecuteOnce, fixed in VC14), the list went on. After a while, certain projects that dropped compatibility still chose to use Boost instead of the corresponding [now fixed] standard library facilities, just operating under the assumption that Boost would provide a higher quality of implementation, and more rapid rate of maintenance. Glen

2 1

failing accumulators tests
by Yuval Lifshitz 21 Feb '18

21 Feb '18

Dear All,Did anyone seen these failures on p_square_cumul_dist and weighted_median (latest checkout from github and gcc7.3.1/fedora27)? libs/accumulators/test/p_square_cumul_dist.cpp(66): error: in "p_square_cumulative_distribution test/test_stat": difference{0.0331329} between 0.5 * (1.0 + my_erf( histogram[i].first / std::sqrt(2.0) )){0.010331329148570989} and histogram[i].second{0.01} exceeds 3%libs/accumulators/test/p_square_cumul_dist.cpp(66): error: in "p_square_cumulative_distribution test/test_stat": difference{0.0372556} between 0.5 * (1.0 + my_erf( histogram[i].first / std::sqrt(2.0) )){0.020755484496021825} and histogram[i].second{0.02001} exceeds 3% libs/accumulators/test/p_square_cumul_dist.cpp(66): error: in "p_square_cumulative_distribution test/test_stat": difference{0.0326898} between 0.5 * (1.0 + my_erf( histogram[i].first / std::sqrt(2.0) )){0.030980693519017} and histogram[i].second{0.029999999999999999} exceeds 3% libs/accumulators/test/p_square_cumul_dist.cpp(66): error: in "p_square_cumulative_distribution test/test_stat": difference{0.0306804} between 0.5 * (1.0 + my_erf( histogram[i].first / std::sqrt(2.0) )){0.041227215128245343} and histogram[i].second{0.040000000000000001} exceeds 3% libs/accumulators/test/weighted_median.cpp(50): error: in "weighted_median test/test_stat": difference{0.0327894} between 1.{1} and weighted_median(acc_dens){0.96825159071079681} exceeds 3% libs/accumulators/test/weighted_median.cpp(51): error: in "weighted_median test/test_stat": difference{0.0316788} between 1.{1} and weighted_median(acc_cdist){0.96929395242297978} exceeds 3% Best Regards, Yuval

1 0

[release] 1.67.0 closed for major changes
by Daniel James 21 Feb '18

21 Feb '18

The master branch is now closed for new libraries and breaking changes, and will be closing for major changes in a week and closed for the beta in two weeks. Although I'm allowing HOF to merge a little late, as I haven't had much to time to check it for release this week. Also, if you're ready, you can also add your libraries' changes to the release notes at: <https://github.com/boostorg/website/blob/master/feed/history/boost_1_67_0.q…> After editing the release notes, you should get a form to create a pull request, remember to submit it, otherwise I won't see your change. Also, a reminder that there are now templates for linking to github issues and pull requests. To link to a github issue use [github module-name issue-number] and to link to a pull request [github_pr module-name issue-number]. For example, to link to issue 24 from uuid, use [github uuid 24] which generates the text '#24'. Thanks, -- The Boost Release Team

1 0

C++03 / C++11 compatibility question for compiled libraries
by Raffi Enficiaud 20 Feb '18

20 Feb '18

Dear list, I have a technical question I do not know how to address, and I would like to know how people deal with this. To put things in the background: boost.test uses heavily boost::function and boost::bind, however I would like to use in some circumstances std::function and std::bind, which are, for instance, variadic. Boost.test is compiled with b2. I believe if the user does not pass additional parameters to the build, the default is to use whatever is provided in the Jamfile, that compiles the static and shared libraries in C++03 mode. If the user of boost.test compiles in C++03, it is ok if the library is used in a C++11 project. The other way is obviously not true. Now, in the headers of boost.test, I can detect for the compiler version, and depending on the language settings, activate an API that is C++11. OTOH, if I do not want users to be confused, this API should be header only. But this hardly work in practice, as the C++03 and C++11 APIs are usually not separable. Say: struct test_case { // compiled member function test_case(boost::function<void ()> function_to_test); #if Cpp11 // std::function variant to ensure compatibility with std::bind test_case(std::function<void ()> function_to_test); #endif private: boost::function<void ()> m_function_to_test; }; This API is obviously not good at all, and for having the slightest chance to make this work, the 2 APIs C++11 vs C++03 should be mutually exclusive. This also produces 2 different incompatible shared/static libraries, which is even more confusing for the user as the compiler options should be transitively passed to the user's code, or the user should be aware of which library to link with. So, the questions are: * how do other boost developers deal with this? * what is your experience on users in terms of compilation+linking? are usually people aware of this problem and they compile in C++11 all the code including boost? * is there any better option? All the other options I see are even worse. Thanks, Raffi

24 140

C++03 / C++11 compatibility question for compiled libraries
by Mike 20 Feb '18

20 Feb '18

Hello everyone, I hope it is ok, for me as a non-boost-dev, to chime in here. What I generally expect " dropping c++03 support" to mean are the following things: - Any library may start to use c++11 features at any point without prior announcement and/or without having to wait a few releases (I.e. it is no longer considered a breaking change). - c++03 builds are removed from the test matrices - Compilation paths that are c++03 only can be removed (thus simplifying the code base and future refactoring/development) - My hope (obviously no one can or should force a volunteer to do anything) is that - where applicable - libraries start to replace boost types & functions that have been merged into the c++11 standard with their std equivalent or the equivalent c++11 language feature. - In the long run, libraries that have been fully merged into c++11 could be deprecated and removed all together. Just to be clear: Dropping c++03 support doesn't mean a developer is forced to use c++11 constructs (if we ignore the potential future removal of boost libraries) - it primarily means that a user can no longer rely on the lib being usable in c++03 mode. And yes, this could be done on a per library basis, but especially older boost libraries are so tightly coupled that such decisions affect a lot of other libraries anyway. So my guess is that very few maintainers would dare to drop c++03 support as long as that hasn't been deemed acceptable by larger parts of the boost community.j Best regards Mike -- Diese Nachricht wurde von meinem Android Mobiltelefon mit GMX Mail gesendet.

7 8

Review of Yap concluded today
by Louis Dionne 20 Feb '18

20 Feb '18

Dear Boost, The review of Zach Laine's Yap library concluded today, February 19th. I'd like to thank everyone who submitted a review or participated to the discussion in one way or another. The following reviews were submitted: - Barrett Adair (accept): https://lists.boost.org/Archives/boost/2018/02/241284.php - Alex Hagen-Zanker (reject/conditional accept): https://lists.boost.org/Archives/boost/2018/02/241296.php - Paul Fultz II (accept): https://lists.boost.org/Archives/boost/2018/02/241251.php - John Fletcher (accept): https://lists.boost.org/Archives/boost/2018/02/241212.php - Brook Milligan (conditional accept): https://lists.boost.org/Archives/boost/2018/02/241386.php - Steven Watanabe (accept): https://lists.boost.org/Archives/boost/2018/02/241442.php Please let me know if I've missed anyone. Also, for reference purposes, here are other notable general threads in the list archives that are related to the review: - Discussion on contextual evaluation of terminals: https://lists.boost.org/Archives/boost/2018/02/241092.php - Discussion on std::tuple vs hana::tuple: https://lists.boost.org/Archives/boost/2018/02/241351.php - Steven Watanabe on the documentation: https://lists.boost.org/Archives/boost/2018/02/241196.php - Steven Watanabe on the implementation: https://lists.boost.org/Archives/boost/2018/02/241281.php - Kickoff post: https://lists.boost.org/Archives/boost/2018/02/241076.php - Post extending the review until February 19th: https://lists.boost.org/Archives/boost/2018/02/241303.php I will summarize what was discussed during the review and announce the result of the review in a future post. Regards, Louis Dionne

1 0

[gsoc 18] - Enhancing Boost.Intrusive Library
by harisaicharan.challa＠gmail.com 19 Feb '18

19 Feb '18

Hello Boost community, I am Hari sai charan challa, 3rd year undergraduate student from International Institute of Information Technology, Hyderabad (IIIT). I have been working on boost-libraries since 2 months, trying to fix a bug.I can code efficiently in C++ .I have good knowledge in Data structures and Algorithms.I am interested in "Enhancing Boost.Intrusive Library" project so i am looking for a mentor to guide me in this project.

3 3

(no subject)
by karan singh 18 Feb '18

18 Feb '18

hello all , i want to contribute for boost and want to participate in gsoc18. i have c++ knowledge but dont know where to start.

2 1

[gsoc 18] Enhancing Boost.Intrusive Library
by harisaicharan.challa＠gmail.com 18 Feb '18

18 Feb '18

Hello, I am Hari.I am working on competency test of "Enhancing Boost.Intrusive library" project , so can someone please elaborate on the following requirement for the competency test. Requirement:- Test programs for ensuring accuracy and performance benchmark tests against various type of solutions (brute-force, recursive, iterative) Thank-you.

1 0

(no subject)
by karan singh 18 Feb '18

18 Feb '18

hi all , i want to contribute for boost , can anyone help i am a newbie

1 0

Moving Boost.HigherOrderFunctions(formely know as Fit) to boostord
by paul 15 Feb '18

15 Feb '18

Hi All, Can someone with Admin access help me move my repo to boostorg? Thanks, Paul

2 3

[GSoC'18] Project : Add support for tensors
by Manan Sharma 15 Feb '18

15 Feb '18

Hello Boost Community, My name is Manan Sharma. I am a 3rd year undergraduate student pursuing my B.Tech in Computer Science and M.S by research in IIIT Hyderabad, India. I have good understanding of Linear Algebra and Machine Learning. I have a sound background in data structures and algorithms and have qualified twice for ACM ICPC regionals. I have secured good rank in other programming contests too. I have good understanding of C++ having done all my competitive programming and several different projects using it. I am interested in project for adding support for tensors in uBLAS. Since I am new to open source, please let me know as to how can I get started. Thanks Manan Sharma

2 1

Can't build docs in downloaded Boost 1.66 sources
by Zach Laine 15 Feb '18

15 Feb '18

I came across this while trying to build the Yap docs, outside the Boost source tree. It turns out it doesn't work in the Boost source tree either. This: cd ~/boost_1_66_0 ./bootstrap.sh cd libs/units/doc ~/boost_1_66_0/b2 used to work (not sure how long ago). Now it says this: tzlaine@linux-desk:~/boost_1_66_0/libs/units/doc$ ~/boost_1_66_0/b2 Performing configuration checks - 32-bit : no (cached) - 64-bit : yes (cached) - arm : no (cached) - mips1 : no (cached) - power : no (cached) - sparc : no (cached) - x86 : yes (cached) - symlinks supported : yes (cached) BoostBook warning: no DocBook XSL directory specified. If you have the DocBook XSL stylesheets installed, please set DOCBOOK_XSL_DIR to the stylesheet directory on either the command line (via -sDOCBOOK_XSL_DIR=...) or in a Boost.Jam configuration file. The DocBook XSL stylesheets are available here: http://docbook.sourceforge.net/ Stylesheets will be downloaded on-the-fly (very slow!) ...patience... ...patience... ...patience... ...found 2671 targets... ...updating 2 targets... xslt-xsltproc ../../../bin.v2/libs/units/doc/gcc-gnu-7/debug/threadapi-pthread/units.docbook http://docbook.sourceforge.net/release/xsl/current/common/common.xsl:1: parser error : Start ta g expected, '<' not found Project web is currently offline pending the final migration of its data to our ^ compilation error: file /home/tzlaine/boost_1_66_0/tools/boostbook/xsl/docbook.xsl line 12 elem ent import xsl:import : unable to load http://docbook.sourceforge.net/release/xsl/current/common/common.xs l XML_CATALOG_FILES="../../../bin.v2/boostbook_catalog.xml" export XML_CATALOG_FILES "xsltproc" --stringparam boost.defaults "Boost" --stringparam boost.root "../../../.." --strin gparam chunk.section.depth "8" --stringparam toc.max.depth "1" --stringparam toc.section.depth "8" --xinclude -o "../../../bin.v2/libs/units/doc/gcc-gnu-7/debug/threadapi-pthread/units.docbo ok" "/home/tzlaine/boost_1_66_0/tools/boostbook/xsl/docbook.xsl" "../../../bin.v2/libs/units/do c/gcc-gnu-7/debug/threadapi-pthread/units.xml" ...failed xslt-xsltproc ../../../bin.v2/libs/units/doc/gcc-gnu-7/debug/threadapi-pthread/units. docbook... ...skipped <phtml>standalone_HTML.manifest for lack of <p../../../bin.v2/libs/units/doc/gcc-gnu -7/debug/threadapi-pthread>units.docbook... ...failed updating 1 target... ...skipped 1 target... That's the full output from doing the build a second time, FWIW. Some of the steps the first time said the same thing, but it seemed too much to post. Anyone know what's doing on? Zach

2 2

New developer interested in working on the Project 1 of Boost.ublas for GSoC18
by pranay gupta 14 Feb '18

14 Feb '18

Hello everyone, My name is Pranay Gupta I am a second year computer science undergrad at IIIT Hyderabad, Im new here at Boost. I was very much interested in doing the first project of Boot.uBLAS which was about adding statistical and machine learning functions to Boost.uBLAS and have started with the competency test. Can someone please guide me as to how should I share my competency test with the mentors and improve it further. Thank You, Yours Sincerely, Pranay Gupta

2 1

Re: [boost] [yap] Review
by P F 14 Feb '18

14 Feb '18

> On Feb 14, 2018, at 1:38 PM, Zach Laine <whatwasthataddress(a)gmail.com> wrote: > > On Tue, Feb 13, 2018 at 8:24 PM, P F <pfultz2(a)yahoo.com <mailto:pfultz2@yahoo.com>> wrote: > >> On Feb 12, 2018, at 7:57 PM, Zach Laine via Boost <boost(a)lists.boost.org <mailto:boost@lists.boost.org>> wrote: >> >> On Mon, Feb 12, 2018 at 4:15 PM, P F via Boost <boost(a)lists.boost.org <mailto:boost@lists.boost.org>> >> wrote: >> >> I actually experimented with trying to remove the Hana bits for this exact >> reason. The conclusion I came to was that writing the library was quite a >> bit harder in a couple of places, but that's not too bad. The bigger >> problem is that the lack of algorithms over std::tuple for users of the >> library when they write transforms. Maybe we should talk offline about how >> to do things that are done now with Hana, with Fit instead. > > Actually, the main algorithms you use are transform, for_each, and unpack, which is trivial to do with Fit. Doing a `zip` or `filter` is a little more complicated, but grepping the source code, I did not see that. I discuss how thats done here: > > http://pfultz2.com/blog/2015/09/12/power-of-unpack/ <http://pfultz2.com/blog/2015/09/12/power-of-unpack/> > > Which we can discuss more offline. > > I also use Hana constants all over the place. Yes, but it should be simple to move from `0_c` to `c<0>{}`. Ultimately, it really should be moved to a separate library, because even Boost.TypeTraits could use these “enhanced” integral constants(but that is another discussion). >>> by just taking it as a type and using something similiar to `mp_transform` >>> to change the parameters. Or even change `Kind` to be a type of >>> `std::integral_constant<boost::yap::expr_kind, Kind>` so `mp_transform` >>> could be used directly: >>> >>> template <typename Kind, typename Tuple> >>> struct user_expr : logical_not<user_expr> >>> { >>> static const boost::yap::expr_kind kind = Kind{}; >>> >>> Tuple elements; >>> }; >>> >> >> You certainly could. What does this buy, though? > > Being able to use `mp_assign` to change the parameters to `user_expr`. Although, you could write your own version which allows the first parameter to be an integral. > > Ok, but all of the above is still the "what". I want the "why". Why is it better to be able to use mp_assign? >> I'm not getting that >> part yet. One thing this give up is the inability to write functions in >> terms of chained >> >> constexpr if (kind == expr_kind::foo) >> >> statements, which I quite like. You can do this with is_same<> of course, >> but at the cost of 45 extra template instantiations and a lot more noise. > > That should still work. I dont see why it wouldn’t. In fact, you should be able to do all of these: > > template<boost::yap::expr_kind Kind> > using expr_kind_c = std::integral_constant<boost::yap::expr_kind, Kind>; > > constexpr if (kind == expr_kind_c<foo>{}) > constexpr if (Kind{} == expr_kind_c<foo>{}) > constexpr if (kind{} == expr_kind::foo) > > What may not work is doing something like `fit::if_(Kind{} == expr_kind_c<foo>{})`(due to lack of operator overloading for integral_constant), but using `fit::if_c<Kind{} == expr_kind_c<foo>{}>` still does work. > > Right, but all of that is noisier than what I currently have. Not really because `constexpr if (kind == expr_kind::foo)` will still work. > If there are advantages to using mp_assign, maybe this extra noise in a few places is worth it. I still have no idea what the mp_assign advantages are though. The point is to be able to get rid of `::` at the beginning in `BOOST_YAP_USER_UNARY_OPERATOR_MEMBER(logical_not, ::user_expr)`. If the user forgets those, you need to have a clear way to tell the user they need to add them, because it may not be obvious from the compiler error without understanding the implementation details. One way to solve this is to avoid it altogether by not passing a template, which you can try to utilize something like mp_assign. Another possible solution may be to add a static_assert with a message like “you are passing a type instead of template, you may need to prepend :: to the parameter to this macro". I think you can use function overloading to distinguish between a type and a template, but I am not sure. Paul

4 3

We need more mentors for GSoC
by David Bellot 14 Feb '18

14 Feb '18

Hi Boost community, we have already a few mentors, but we need more. If you're interested working with top-level C++ students from all around the world, please contact me and I'll add you to the list of mentors. We need more mentors now ! Best regards, David

2 2

[gsoc-18] enhancing boost.intrusive library
by Anurag Tangri 14 Feb '18

14 Feb '18

Hello Boost Community. My name is Anurag Tangri. I am a 3rd year student at Thapar university patiala. I have good knowledge of C++ programming knowledge because of my competitive programming background. I am interested in “Enhancing Boost.Intrusive Library” project so i am a looking for mentor to guide me.

2 1

Yap review extended until Feb 19th
by Louis Dionne 14 Feb '18

14 Feb '18

Dear Boost community, The review of Zach Laine's Yap library was supposed to conclude today, Wednesday February 14th. To give more people the chance to review the library, and since there's no review scheduled directly after Yap, the review period will be extended until (and including) Monday February 19th. Thanks, Louis Dionne

1 0

[gsoc-18]
by Anurag Tangri 14 Feb '18

14 Feb '18

Hello Boost community ! My name is Anurag Tangri. I am a 3rd year undergrad at Thapar University. I am very much familiar with C++14 because of my competitive programming background.I have decent knowledge of Data structures and algorithms and eagerly want to contribute in open source. I am new to open source and stuff. So it would be very helpful if someone could guide me.

1 0

[release] 1.67.0 deadline for new libraries approaching
by Daniel James 14 Feb '18

14 Feb '18

One week from today master will closed for new libraries and breaking changes. Thanks, -- The Boost Release Team

2 1

[release notes] Linking to github issues/pull requests
by Daniel James 14 Feb '18

14 Feb '18

Hi, I've added templates for linking to github issues and pull requests from the release notes. There are two templates: [github module number] which expands to '#number' [github_pr module number] which expands to 'PR#number'. Both will be linked, they need the name of the module to link to the right place. We only really need the issue template as github redirects to the pull request if appropriate, but existing release notes have been using the PR#3 format, so I thought it should support that. You can see an example in the unordered release notes for 1.67.0: https://github.com/boostorg/website/blob/master/feed/history/boost_1_67_0.q… http://www.boost.org/users/history/in_progress.html Does that look okay? Daniel

5 17

[yap] Review
by P F 14 Feb '18

14 Feb '18

- Whether you believe the library should be accepted into Boost I think it should be Accepted. - Your name Paul Fultz II - What is your evaluation of the library's: The design is very nice and simple to follow. I have found Proto to be a little hard for me to grep, but this seems fairly simple to follow. I think the transform -> evalute workflow is great. Also, with transforms being just function objects, it makes transformations very composable. I think this library is very useful. I would love to use this for some projects at work, but the dependency on Hana prevents that(I need to support gcc 5 and MSVC). Looking at the codebase, it could easily be replaced with Boost.Fit(once its included in the release) in the future. Of course, I dont expect a reimplementation without Hana as a condition for acceptance. However, I think Hana at least can be removed from the "interface". The expression elements could be expressed as a `std::tuple` and the placeholders could be a `std::integral_constant`. This should make it easier to use another backend without breaking API compatibility. Some other notes: - Couldn't the operator macros be provided as base classes? So instead of writing: template <boost::yap::expr_kind Kind, typename Tuple> struct user_expr { static const boost::yap::expr_kind kind = Kind; Tuple elements; // Member operator overloads for operator!(). BOOST_YAP_USER_UNARY_OPERATOR_MEMBER(logical_not, ::user_expr) }; The user could write: template <boost::yap::expr_kind Kind, typename Tuple> struct user_expr : logical_not<::user_expr> { static const boost::yap::expr_kind kind = Kind; Tuple elements; }; You could also get rid of the need for `::user_expr` by just taking it as a type and using something similiar to `mp_transform` to change the parameters. Or even change `Kind` to be a type of `std::integral_constant<boost::yap::expr_kind, Kind>` so `mp_transform` could be used directly: template <typename Kind, typename Tuple> struct user_expr : logical_not<user_expr> { static const boost::yap::expr_kind kind = Kind{}; Tuple elements; }; - The customization points seem unnecessary. Why wouldn't the user just use `transform`? Using `transform` also keeps the customizations local. Also, implicit transformations seems like it would lead to suprises(and not good suprises). Are those on the cutting block? - It would be interesting to provide common transformations, like common subexpression elimination, or dead code elimination, but I guess that is beyond the scope of this library. - The `op_string` function is missing the case for `expr_ref` and `terminal`. Also, the tests only check for plus. - The `make_expr_from_tuple` does a move here: auto make_expr_from_tuple (ExprTemplate<Kind, OldTuple> const & expr, NewTuple && tuple) { return ExprTemplate<Kind, NewTuple>{std::move(tuple)}; } But maybe this should be using `std::forward`? - Did you attempt to use the library? If so: Yes, I ran it on clang 3.8 and gcc 7. - How much effort did you put into your evaluation of the review? Several hours

3 8

Regarding how to get selected for gsoc boost
by Syed Souban 13 Feb '18

13 Feb '18

Hi! I am Syed Souban. I am new to the world of open source and I want to contribute to it. I am a Computer Science And Engineering Undergraduate and I know C, C++, Java, Android App Development, HTML, CSS, JavaScript, PHP. I want some guidance on how should I start preparing to get selected for GSoC in your organisation.

2 1

[system] virtual ~error_category
by Peter Dimov 12 Feb '18

12 Feb '18

The virtual destructor of error_category creates problems for constexpr-ification because it makes the class non-literal. I can't think of a scenario in which we need the destructor to be virtual. It's probably virtual for "guideline" reasons - the class has virtual functions. But does it really need to be? Error categories aren't destroyed via a pointer to base. They are, in fact, static instances, not destroyed at all, except on program exit. Can anyone think of a case in which error_category needs the virtual destructor?

7 16

Boost C++ is a mentoring organization for GSoC'18 !
by David Bellot 12 Feb '18

12 Feb '18

We just received this message from Google. It says it all ! *Congratulations! Boost C++ Libraries has been selected as a Google Summer of Code 2018 mentor organization.* This year again, we will be a mentoring organization for the Google Summer of Code. If you want to be a mentor, please contact me right now and register on the Google Summer of Code website too. Best regards, David

1 0

[yap] Review
by Fletcher, John P 12 Feb '18

12 Feb '18

I have quite a lot to say and I may not get it all down in one go. > - Whether you believe the library should be accepted into Boost Accept. > - Your name John Fletcher > - Your knowledge of the problem domain I have been working on codes doing similar things for a long time. I started with FC++ and have worked with Phoenix (I did some maintenance) and a lot of other codes. I have also worked with Hana around the time of that review. I tend to work by trying things out and extending the examples given, which is what I have been doing with YAP. I suppose you can categorize me as someone working at an intermediate level, attempting to make use of libraries to make results available to users at a higher level in a way which is intuitive. As I have worked in the past with the old C++ I particularly appreciate new codes which take advantage of C++14 to make this work easier. > You are strongly encouraged to also provide additional information: > - What is your evaluation of the library's: > * Design I like the design and have found this grow on me as I worked with the examples and saw how the pieces work together. I have found some of the recent discussion about why things are how they are very helpful. > * Implementation I have encountered quite a lot of the implementation as I have worked on the examples. I appreciate that this library makes extensive use of Boost Hana. There are some places in the examples where the user needs to have an understanding of Boost Hana to work. For example the transform example for arity uses Boost Hana maximum and transform. I will except boost::hana::tuple from the comment as it is used so much and is similar to std::tuple. One issue I have had is with the namespace. I am not clear why some code needs the full name e.g. boost::yap::evaluate and in other places evaluate will do without using being defined. It would be good if that was consistent. > * Documentation I don't think that the documentation at present does full justice to the code. There are several things which I found very useful which are not much mentioned in the code. When I saw that the examples were taken from work with proto I set out to make one which was missing, the mini_lambda example. I have had a lot of success with that while having to dig quite hard to find information. make_expression_function I have found this very useful in moveing to a functional approach. It is not much mentioned. I think what is needed is more examples and some contributions from users as to what help is needed to understand how to get the best use out of YAP. > * Tests I have already mentioned working on a version of the proto mini lambda. I have also built and example of the member call operator as the only example was in a more complicated example. I have also extended the vector example to add some cases which are missing e.g. 3. * v3 and v3 * v . I have made it use v3*v3 to return a scalar product. > * Usefulness I have found this to be useful from the examples. > - Did you attempt to use the library? If so: Yes > * Which compiler(s)? Mainly clang 4.0 C++14 with corresponding libc++. I have run some examples with gcc 7.1 C++14. This work is on ubuntu linux. > * What was the experience? Any problems? Problems encountered have been with my own understanding and wanting to explore the boundaries. > - How much effort did you put into your evaluation of the review? I have spent many hours spread over several weeks. I started before the start of the review. I hope this is helpful. Zach, thank you for your work and please ask if anything is not clear. Best wishes John Fletcher

2 1

[build] msvc-14 linker step failing?
by John Maddock 12 Feb '18

12 Feb '18

I have, and have had for some time: using msvc : 14.0 : "C:/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin/cl.exe" ; In my user-config.jam However, with current develop this leads to the linker step always failing: msvc.manifest ..\..\..\bin.v2\libs\config\test\config_info.test\msvc-14.0s11\debug\address-model-64\link-static\runtime-link-static\config_info.exe 'mt' is not recognized as an internal or external command, operable program or batch file. if exist "..\..\..\bin.v2\libs\config\test\config_info.test\msvc-14.0s11\debug\address-model-64\link-static\runtime-link-static\config_info.exe.manifest" ( call "..\..\..\bin.v2\standalone\msvc\msvc-14.0s11\address-model-64\architecture-x86\msvc-setup.bat" amd64 >nul mt -nologo -manifest "..\..\..\bin.v2\libs\config\test\config_info.test\msvc-14.0s11\debug\address-model-64\link-static\runtime-link-static\config_info.exe.manifest" "-outputresource:..\..\..\bin.v2\libs\config\test\config_info.test\msvc-14.0s11\debug\address-model-64\link-static\runtime-link-static\config_info.exe;1" ) As you can see no tool name is set on the start of the command line. Anyone any ideas? Thanks! John. --- This email has been checked for viruses by AVG. http://www.avg.com

5 14

[Heads up] PR adding guidelines for breaking changes on the website
by Louis Dionne 11 Feb '18

11 Feb '18

Folks, In early December 2017, there was a thread asking for guidelines regarding breaking changes: [1]. The conclusion reached in that thread seemed to be agreed upon [2] and I suggested making it part of the library guidelines. I have finally submitted a PR [3] to add it to the library _guidelines_ (not _requirements_). Feel free to take a look at the PR and chime in as this concerns everyone. Cheers, Louis [1]: https://lists.boost.org/Archives/boost/2017/12/240071.php [2]: https://lists.boost.org/Archives/boost/2017/12/240108.php [3]: https://github.com/boostorg/website/pull/300

4 3

Boost Python library suffix change
by Stefan Seefeld 09 Feb '18

09 Feb '18

Hello, I'm proposing a naming change that affects all libraries that use the `python.jam` build logic, i.e. Boost.Python, as well as libraries providing Python bindings (as far as I can tell, this is only Boost.MPI, but perhaps I'm missing some). At present, the Boost.Python build logic produces a library named "boost_python", if built with Python2, and "boost_python3", if built with Python3. I'd like to change that so the actual Python version suffix (e.g. "27" for Python 2.7) is being used. Not only would this simplify / unify naming conventions, it also allows users to collocate libraries compiled against multiple Python versions more easily. While I could apply this change to Boost.Python only, it seems more natural to patch Boost.Build itself, in which case any library whose build logic uses `python.jam` would also be concerned. Again, as far as I can tell, this only concerns the Boost.MPI Python bindings, but perhaps I'm missing some. So if you are concerned, please speak up, so we can discuss any necessary changes. Thanks, Stefan -- ...ich hab' noch einen Koffer in Berlin...

3 3

[review] Review of Outcome v2 (Fri-19-Jan to Sun-28-Jan, 2018)
by charleyb123 . 09 Feb '18

09 Feb '18

Hi, Everyone, The formal review of Niall Douglas' Outcome (v2) library begins Fri-19-Jan and continues until Sun-28-Jan, 2018. Your participation is encouraged, as the proposed library is uncoupled and focused, and reviewers do not need to be domain experts to appreciate the potential usefulness of the library and to propose improvements. Everyone needs (and has suffered) error handling, and can compose an opinion on that topic. Outcome is a header-only C++14 library providing expressive and very lightweight 'outcome<T>' and 'result<T>' error handling, suitable for low-latency code bases. The library further provides mechanisms for wrapping '<success|error|exception>' state to safely wrap throwing APIs; and poses an idiom of, "islands of exception in a sea of noexcept". Key features: *- Makes using 'std::error_code' from C++11's <system_error> more convenient and safe *- Good focus on low-latency (with tests and benchmarks) *- Error-handling algorithmic composition with-or-without C++ exceptions enabled *- Dependency only on Boost Recall a previous Outcome (v1) Boost Review occurred 19-May to 02-June 2017: *- Outcome (v1) Review Report: *- https://lists.boost.org/Archives/boost/2017/06/235783.php This review for Outcome (v2) includes significant changes as a result of feedback from the Outcome (v1) review. For a list of changes (v1==>v2), see: *- https://github.com/ned14/outcome#changes-since-v1 Reference API docs: *- https://ned14.github.io/outcome/reference/ GitHub: *- https://github.com/ned14/boost-outcome Tarball: *- https://github.com/ned14/boost-outcome/releases/tag/v2. 0-boost-peer-review Online "play-pen" (try it out!): *- https://wandbox.org/permlink/Ji1khzyxoAR0LJQC YOUR REVIEW --------------------- Please post your comments and review to the boost mailing list (preferably), or privately to the Review Manager (to me ;-). Here are some questions you might want to answer in your review: - 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 what compiler? 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? And most importantly: - Do you think the library should be accepted as a Boost library? For more information about Boost Formal Review Process, see: http://www.boost.org/community/reviews.html Thank you very much for your time and efforts. --charley Outcome (v2) Review Manager

24 122

Mailman upgrade
by Sys Admin - Boost 08 Feb '18

08 Feb '18

All, Per https://bugs.launchpad.net/mailman/+bug/1747209, Ciere staff will install 2.1.26 beginning 9-Feb-2018 04:00 UTC. While the maintenance is performed, incoming messages to the mailing lists for Boost will be temporarily blocked. This may result in “temporarily unable to deliver” messages received by senders if a message is delivered during the upgrade. The upgrade is expected to finish by 9-Feb-2018 05:00 UTC. Thanks, Brad Johnson Your Friendly Mailing List Admin

1 0

[review] Boost.Outcome.v2 Review Report
by charleyb123 . 08 Feb '18

08 Feb '18

# Boost.Outcome.v2 REVIEW REPORT In conclusion to the review for Boost.Outcome(v2) (19-Jan to 28-Jan, 2018): The library is ACCEPTED (conditions below). Acceptance is principally based on: (1) Reviewers found the library useful to address a current recognized need (2) New idioms are enabled that reviewers found compelling (3) The submission satisfies all Boost Library Requirements Concerns over accepting the library raised in the review discussion include: (a) New idioms proposed are not compelling (b) Requires C++14 (prefer compatibility with C++11) (c) Library may evolve beyond the current design (d) Library is unnecessarily complex Reviews submitted during the review period: *- Vinícius dos Santos Oliveira -- ACCEPT (Fri-26-Jan-2018) *- Andrzej Krzemienski -- ACCEPT (CONDITIONAL) (Fri-26-Jan-2018) *- Bjorn Reese -- ACCEPT (CONDITIONAL) (Sun-28-Jan-2018) *- Daniela Engart -- ACCEPT (Sun-28-Jan-2018) *- John P Fletcher -- ACCEPT (CONDITIONAL) (Sun-28-Jan-2018) In addition, after the review period concluded (but within the duration had the review period been extended) further reviews were submitted: *- Vinnie Falco -- REJECT (Tue-30-Jan-2018) *- Emil Dotchevski -- REJECT (Tue-30-Jan-2018) *- Glen Fernandes -- REJECT (Tue-30-Jan-2018) *- Paul A Bristow -- WOULD ACCEPT (?not a review?) (Wed-31-Jan-2018) *- Rob Stewart -- NOT ACCEPT (Sat-03-Feb-2018) Conditions for acceptance: It is expected: *- Changes are made to use Boost-standard names for macros and namespaces *- Docs are updated to be clear regarding: *- how library treats default-constructed values *- salient attributes of objects, and how “spare_storage” is treated *- Documentation is integrated into Boost framework and release process *- Library is distributed under the Boost Software License (BSL) The remainder of this report contains context and analysis contributing to this decision, including basis for why acceptance purports to be constructive and beneficial to the Boost community, and broader C++ community. # MOTIVATION: REAL-WORLD USE TODAY The prime motivation for acceptance is: *- Reviewers have real-world use cases _today_ for which they found Outcome to be an effective and best available alternative; and which is consistent with current-need and expectations; and which is consistent with ongoing C++ Standard evolution efforts. >From the Library Author: > <quote> > “Outcome is really an abstraction layer for setting per-namespace > rules for when to throw exceptions. Exception throwing is absolutely at > the heart of Outcome. That's why Outcome != Expected, and why it ICEs > older compilers, and why C++ 14 is needed.” Exhibited behavior is two-fold: (1) Expected errors are handled locally with low overhead (e.g., deterministic / predictable with low-latency) (2) Unexpected errors are type-erased into an 'exception_ptr' and pushed up the call stack (e.g., exception-throw stack-unwind) For example, server-side code that is expected to handle a lot of failures, where “stop-the-world” is never suitable, may always handle errors locally. In contrast, most other system-wide code may 'throw' an error, which should be handled within some caller-context. # AT ISSUE: DESIGN AND IDIOMS What appears to be debated in this review are the Outcome library design and idioms; and not the quality of implementation (although the implementation is criticized as complex -- see below). For example, even reviewers that voted to reject commented that the library seems sound, and seems useful for some cases. This merits repeating: This review has the highly positive characteristic (despite the accompanying discomfort) of debating the idioms that challenge what already exists, and which forces re-evaluation of our historical approaches. Many of these discussions might otherwise be summarized (and which has a fair chance of being agreed upon by all parties) as: *- Error handling can be done with exceptions, or with branch-testing on error instances; and some algorithms or constraints may favor one over the other for technical or compositional reasons. It is this highly pragmatic observation that is at the core of the Outcome library submission. Outcome enables a new idiom consistent with other pattern explorations deemed by the C++ community as useful, as demonstrated through acceptance into the C++ standard for 'std::optional<>' and the pending 'std::expected<>'. Outcome enables value-transport of a multi-modal data object '<T|error|exception>' across API boundaries that provides the benefit of static compile-time type-checking, but places the explicit burden upon the user for 'visit / interrogation' of that multi-modal data object. Outcome is intended for use in program areas with harsh resource constraints, where many inconveniences are expected, and tradeoffs are part of the design decision for creating and handling explicit 'out' values that include failure information. These constraints may include: interaction among one-or-more modules compiled without exception-handling enabled; deterministic or low-latency execution requirements; and use of custom 'error' and/or 'exception' objects that are expected to be populated and tested within the local context (such as to perform explicit conditional branching for error handling or recovery). During the review there was some confusion regarding evaluating Outcome in the context of “generalized use” across an entire codebase, versus “localized use” where the algorithm intends to machine specific cases for statically-bound stateful handling of errors. For example, it is not expected that Outcome might be used across all APIs across all modules within a system. (Recall that current C++ community guidance might otherwise suggest 'std::error_code' or 'exception-throw' might be used across all APIs for all modules within a system, if such consistency is permitted.) Rather, Outcome intends to address that nexus where an algorithm interacts with several modules, each with differing 'error' and 'exception' practices, where the library consistently transfers '<T|error|exception>' with compile-time type enforcement and runtime behavior and performance guarantees. Design decisions within Outcome v2 are well-considered, and faithfully reflect feedback raised during the (quite extensive) v1 review. Indeed, none of the issues raised during the v1 review were again raised within the v2 review. And, it is noted that two reviewers previously voting REJECT on v1 now vote ACCEPT on v2. Further, it should be noted that Outcome v2 has evolved into a collaborative effort with assistance from several contributors, with validation and feedback in multiple real-world codebases with specific engineering constraints. In this review, reviewers found the idioms specifically useful (beyond alternatively available tools / idioms), and consistent with practices in existing codebases and in other languages. Further, the proposed direction appears to be consistent with evolving idiomatic practice within the C++ Standard enabling new idiomatic algorithm expression, as evidenced by multi-mode types such as 'std::optional<>' and the (proposed and evolving) 'std::expected<>'. Idioms provided through Outcome are also demonstrated to be useful / successful in other languages. As noted in the review, Outcome enables handling of failure with idioms similar to those found in Rust, a language which also supports RAII but which does not support exceptions (and reviewers commented that these idioms are sufficiently successful that exceptions are not viewed as an interesting nor desired mechanism in Rust). One reviewer commented that it is not compelling to attempt to replicate Rust error handling idioms, which (as a different language) naturally offers different idioms. And instead, offered that the natural idiom in C++ is to throw (and catch) exceptions. However, it can be noted that the Outcome design approach is somewhat agnostic to the use of 'exceptions', but rather relies upon a multi-modal data object that the user must explicitly unpack (similar to 'std::optional<>' or 'std::expected<>'), and which makes explicit guarantees about unified transport and handling of '<error|exception>'. The core of the dispute seems to be over the value of localized reasoning for handling errors: Exceptions are good for “distant” handling (to seamlessly transfer handling to a parent context), while explicit error/result instances (possibly customized) encourage local reasoning for discrete handling within the local algorithm context. Complicating the issue is that (of course) both are accepted practice in differing environments and with differing engineering constraints: Throwing exceptions may be most expressive to avoid algorithmic edge cases or ensure errors are actually handled; but alternatively it may be more expressive to explicitly handle errors locally when it is not desirable to delegate the failure to an upper level. # DISAGREEMENT: ERROR / EXCEPTION HANDLING Even prior to considering the Outcome library submission, error handling idioms and practices remain contentious and confusing within the C++ community (as well as within the Boost community). Recent threads on the Boost email-list continue to highlight the ongoing confusion and disagreement even over the proper or idiomatic use of 'std::error_code', which boasts a decade of real-world experience and approaches a decade in the C++standard. One might think such discussions should by now be resolved; but no, we observe that even semantic agreement of proper-or-intended behavior for 'std::error_code' was not reached on these recent Boost email discussions. We also observe that discussion regarding 'error' or 'exception' handling can at times be clouded within the evolving C++ Standard itself, with discussions of 'throw'/'no-throw' (e.g., “dual”) APIs, semantics for 'wide' or 'narrow' contracts, and even the occasional (and “over-simplified”) discussion of “for vs. against” exception handling (a topic that alone is worthy of consuming a surprising number of evenings and libations). The Library Author can be congratulated (or scolded) for exploring work or attempting Boost community review in such a contentious space. However, these topics are also fundamental motivations in the creation of Outcome itself: It provides a mechanism to unify 'error' _and_ 'exception' handling to enable unified localized reasoning across third-party modules; and directly exposes the resulting issues for cross-module error handling by charging the user with explicit unpacking of the '<T|error|exception>' object, but with the benefit of static binding (e.g., compile-time type checking). The implication is that in such a library review attempting to address a portion of the C++ landscape already marked with disagreement regarding current-and-alternative approaches, we cannot expect but to see charged commentary where issues of “global reasoning” over a “generalized use case” were inevitably raised to sometimes overshadow the discussion of a library that specifically intends to address “localized reasoning” with specific performance constraints and behavior guarantees. (Although compared to the v1 review, we might consider some threads to have missed opportunity to be yet more colorful.) The beclouded discussion appeared at times to exhibit violent agreement: Quoting reviewer (voting to reject): > However it looks like Outcome provides a solution for most of the practical > cases, while leaving the general case unsolved. Boost.Outcome is a set of > tools (rather than just one) and you are expected to choose one that best > solves your particular problem. Quoting response by library author: > I was just about to say the same thing, but more pointed. <...> Knowing that > a piece of code will never, ever see stack unwinding lets you skip handling > stack unwinding. Hence `noexcept`. > > Furthermore, unlike with exception specifications which were unhelpfully checked > at runtime, Outcome fails at compile time. .... You can't successfully compile code > if your E types don't have interop specified for them. > > Outcome is of particular use in a lower-level layer of code (closer to bare metal, > or in server contexts), where explicit deterministic error handling warrants > increased tedium or inconvenience in explicit checks for success/failure. An observer might note that the reviewer (voting to reject) and library author have a shared view of what the library proposes to do; but the reviewer desires a generalized solution, rather than an interop-solution that provides specific performance constraints and behavioral guarantees. They agree on what it does. They disagree regarding the value and likelihood of a future possible generalized solution to perform a similar function, which is not currently proposed for review. The (perhaps unstated) concept is that no generalized solution may be possible with today's language, or perhaps ever: Both 'error' objects and 'exception' throws fundamentally serve different use cases: (a) 'error / status' instance (i.e., “opt-in”): A discrete object that can be inspected (or ignored), such as to perform conditional processing (b) 'exception' throw (i.e., “opt-out”): A control transfer-to-caller that avoids accidental instruction execution (e.g., stack-unwind) and which cannot be ignored Proponents of (a) talk of contract and execution simplicity, and of determinism / efficiency. Proponents of (b) talk of composition simplicity, and avoidance of edge cases due to liberation from local tedium. A further complication is due to how arbitrary (implementation-specific) data is returned for failure handling: It can be encoded into the type system (increasing coupling across APIs), or may be type-erased (such as done by 'std::error_code'). Noted in the review is that 'exception' throws are a special case of type erasure, as the C++ runtime performs the type erasure without impacting the declared API (thus providing a very large part of the convenience for using exceptions). The Outcome library attempts to unify '<error|exception>' handling for localized reasoning, and (re-)throw only in specific well-defined contexts. It is not a generalized pattern, but a unified mechanism for discrete handling of those scenarios where the design choice is explicitly made to perform localized reasoning of failure from dependence upon heterogeneous modules that may perform surprising (and evolving) behavioral changes for failure-notification. A generalized solution intends to provide uniformly simpler code, or generalized idioms. This might not (ever) be possible when we explicitly talk about localized reasoning of error handling within the local context: By definition, we want to enumerate and handle discrete failure cases specific to the local algorithm; so the best we can do is to utilize (compile-time) type-checks that verify our unwrapping-and-interrogation of our '<T|error|exception>' instance that bubbles up from within some far-away dependency that chooses the most inopportune time to exhibit surprising changes in behavior. Also by definition, localized reasoning requires localized tedium to _handle_ specific error cases, which are also enumerated locally. In such cases, a generalized solution does not apply. Much of the concern over Outcome acceptance appears to be based on concerns of the effects of the library on the ecosystem. It is true that users might wrongly apply localized reasoning tools to (widespread) generalized use. However, that same issue already exists with the C++ community's dichotomous split between 'error' or 'exception' handling, and with our Groundhog-Day revisiting of the same irreconcilable patterns that bring us the “dual-APIs” for “throw/no-throw” in the C++ Networking TS and Filesystem TS (and presumedly, many more Standard libraries to come). Of particular note is the assertion raised during the review that: *- The error being exceptional or not depends upon context, and not the algorithm. For example, connection failure on a game client and a game server are both backed by the same function; but Outcome permits the context to convert an 'error' into an 'exception', or not (based on caller-context). To quote one reviewer (voting to accept): > Boost.Outcome is not to “replace exception handling in your programs”: It is > used to cover those isolated places where exception handling proves inferior > to manual control flows. We might now expand our Matrix Of Confusion for preferring 'error' or 'exception' to include: (a) “Generalized-pattern” vs. “Localized-reasoning” (b) Expected vs. Non-Expected failure (c) Dependency upon subsystem providing 'error' vs. subsystem providing 'exception' While technically a “matrix”, commonly this is (quite) multi-dimensional: Frequently we depend upon many subsystems, each of which make very different decisions for how they relay disappointment, and where each individual subsystem will *change* that decision in surprising ways merely when we perform a version update. This is the brittleness that Outcome intends to address. Outcome is merely a mechanism to enable 3rd party module inter-operation. It does not make the decision for whether 'error' or 'exception' instances are provided by some subsystem, nor does it care. Rather, it is a unification mechanism that enables an algorithm to be _authored_ with specific performance and behavioral guarantees when reliance is upon one-or-more modules that _made_ that 'error' vs. 'exception' decision in a manner your specific use case finds unfortunate. Lastly, reviewers most critical of Outcome point to 'exceptions' as the C++ language mechanism to be leveraged in design, such as to enforce strong guarantees of object invariants (e.g., RAII permits ctors to throw to ensure invariants are not violated), and thus the Outcome library is not needed. However, despite this language feature, alternative idioms such as private ctors and 'make_xxx()' factory functions are not uncommon to also enable successful instantiation with internal state upholding invariant values; and we again must concede that modules employ differing decisions to compile with exception handling enabled. Thus, it seems reasonable that a library such as Outcome might exist to present a unifying interface across 3rd party code with differing design decisions, rather than hope for a simpler world where a single (exception-based) approach is mandated system-wide across modules. # CONCERN: CUSTOMIZATION POINTS (COMPLEXITY) Outcome attempts to bridge vocabulary types for '<error|exception>' handling among subsystems, including: C++ with or without exceptions enabled, C subsystems, and modules providing customized errors and/or customized exceptions. These goals necessarily complicate the design beyond a simple 'variant<>' value-type with no such customization points. This complexity was commented on by reviewers that voted to reject, suggesting: (1) Complexity is too high for the features provided; (2) Additional complexity to support C compatibility is unnecessary; and (3) Complexity is unnecessary if the library required subsystems not using exceptions to be wrapped behind a C-style API and to compile only those wrapped-subsystems with exception handling disabled. Further, other indirect comments suggested: (4) Complexity is lessened if Outcome assumed use of only 'std::error_code' (not user-customized error instances), and the type-erased payload provided through an exception (e.g., 'throw'). In response, the Outcome library premise is that a simpler world does not exist (where such customization is unnecessary): Despite nearly a decade of experience, the C++ community has yet to adopt 'std::error_code' as the ubiquitous mechanism to identify error (where instead bespoke error types remain in widespread use); and even in modern C++ codebases, it is not uncommon to compile with exceptions disabled. A heterogeneous landscape exists, and likely will continue to exist. For both practical and technical reasons, it is expected that domain-specific customization for error and exception handling will continue to be required, such as to address engineering constraints and needs for 'constexpr'; for small-embedded environments with severe restrictions on memory allocation; and for context-specific payload transferred or accumulated into journals / logs as a part of error handling. It is even expected that the C++ Standard itself will adapt to its own evolving idioms exposed through new language features, and (future) standard types that we might assume will be consistently applied across standard library APIs. This underscores the need for such customization points, where proposals such as Outcome attempt to provide an effective mechanism within a rather bleak current landscape with guaranteed future changes. In the face of this (currently-seen and continually expected) evolution, we have today's practical real-world issues: Commonly today's systems are composed of 3rd party modules that must interoperate in a well-behaved and deterministic manner, where '<error|exception>' customization becomes a system requirement. Of particular note is that in large codebase environments, current practice is to adopt customization policies to impose consistent and bespoke rules across the entire codebase, and across modules. Prior to Outcome, this customization is often done with preprocessor macros. In these environments, Outcome is viewed as a positive evolution. Today's Outcome customization points exist “out-of-the-box” to be compatible with existing module-specific 'error' or 'exception' needs, and to provide API/source-compatibility with a possible future-compatible 'std2::error_code'. Reviewers critical of the provided customization points want type-erased error state, but the library author asserts that this is hard to do in a manner that is (1) efficient, and (2) permits evolution (such as to support user-specific error values, or a possible future 'std2::error_code'). Further, the library author asserts that the library is not in fact complex; but that it can be overwhelming to the uninitiated merely because it enables customization of '<E>', and customization enables possibilities (which by definition implies complexity); and that such customization is characteristic of most (all?) vocabulary libraries. Despite concerns over complexity, v2 is greatly simplified over v1 where changes were directed through v1 review feedback; and provides a single-header version with reasonable compile-time overhead. Using (integrating) the library should not be difficult, and explicit efforts to establish ABI stability should make extended use over evolving codebases possible, and not-hard. Because enabling cross-module '<error|exception>' handling is fundamental to the library, it is conceivable that the library offers the minimal interface with the minimal possible complexity to do this job. And, this is a job that is (1) needed by real-world users; and (2) unavailable through alternative mechanisms (and which would not be provided through a simplified value-type composed of 'variant<T,error,exception>'). >From the library author: > As the last section of the tutorial covers, there is a non-source-intrusive mechanism > for externally specifying interoperation rules to handle libraries using one policy > interoperating with libraries with different policies. This lets Eve stitch together the > Alice and Bob libraries without having to modify their source code, and without > affecting any other libraries. I personally think this Outcome's coup de grace and > why it's the only scalable choice for large programs considering using this sort of > error handling. In this context where Outcome may possibly exhibit minimal sufficient complexity to address its intended target of cross-module '<error|exception>' transport, one might recall the Fred Brooks quote: > “The complexity of software is an essential property, not an accidental one. > Hence, descriptions of a software entity that abstract away its complexity > often abstracts away its essence.” -- Fred Brooks, “No Silver Bullet” (1986) # DISAGREEMENT: REQUIRES C++14 (versus C++11) Outcome requires C++14 and is identified as failing on some toolchains exhibiting non-conforming C++ Standard behavior. The review raised concerns that requiring C++14 (rather than C++11) would limit the library's suitability for Boost inclusion. In this context, it might be suggested that an error variant is needed by everyone, so we might reject a C++14 implementation in the hope that a future C++11 compatible library will be proposed. It is noted that Outcome v1 supported old compilers back to clang 3.1 and gcc 4.9, and had many workarounds to suppress non-conforming compiler behavior; and used preprocessor metaprogramming to work around compile-time selected CRTP (because of compile-time costs, and issues on older compilers). However, these approaches were rejected in the v1 review as too complex; and reviewers were not persuaded by concerns raised by the library author that their removal would demand dropping compatibility with older toolchains. Outcome v2 removed these workarounds based on v1 feedback, resulting in a requirement for newer toolchains. Similar discussions have been raised in other contexts regarding Boost distribution packaging, and the possibility of forking “pre/post” C++11 (e.g., “modern C++”) libraries into separate Boost distributions. This is an unfortunately complex issue, as Boost already contains libraries supporting varying levels of “minimum” requirements including varying support for compilers exhibiting non-conforming behavior for C++98, C++03, C++11, C++14, and C++17 (and others). Some libraries such as Boost.Hana or those reliant upon heavy 'constexpr' behavior demand the very-latest C++17 toolchains. Further, it is recognized that in some cases backward-compatibility can be undesirable, or fundamentally limiting to the library's usefulness. For example, at a recent 'BoostCon' / 'C++Now' conference an attempt was made to evolve the 'Boost.Date_Time' API to use the seemingly highly suitable C++17 'structured binding' declaration to decompose 'date / time' objects. Unfortunately, this work was abandoned: Due to use by other Boost libraries restricted to a previous C++ Standard, and the discovery that 'Boost.Date_Time' library semantics fundamentally changed when using this new language feature, it was concluded to not be feasible to support both the legacy API and new API using structured bindings. It appears in this case a new library must be authored without consideration of backward-compatibility to enable this evolution for what appears to be an otherwise obvious or natural expressiveness to decompose 'date / time' objects using 'structured binding' declarations. It is noted that C++11 is already eclipsed by C++14 and C++17, and that current Boost library requirements merely require C++ Standard conforming behavior, whereby the library must clearly document those platforms that are supported. Further, it is noted that a v1 implementation supporting older tool chains was rejected (so v2 now requires C++14). As this is a complex issue that demands consideration of many tradeoffs (including feasibility and behavior fundamental to the library itself), it is expected that the Library Maintainer constantly review and evolve these decisions as the C++ language evolves; toolchains are updated; and users raise issues or provide contributions. # CONCERN: LIBRARY FUTURE EVOLUTION A concern is raised that upon acceptance into Boost, Outcome may evolve beyond the design reviewed for acceptance. Further, a specific concern was raised regarding Outcome exploring evolution of an 'std::error_code' (which we might call a proposed 'std2::error_code'). Within the context of Outcome, the 'error' type exists as a mere customization point by which the user may supply a bespoke definition, or incidentally use the 'std::error_code' provided by the C++11 Standard. Both of these are seen today in common practice. It is expected that users (and perhaps the library author) will continue to explore possible 'error' implementations for specific purposes (such as exploration of an 'error' for small-embedded that does not rely upon allocation machinery). This is viewed as a necessary and healthy advancement of the science, for which the library (by design) conveniently empowers the end-user to parameterize domain-specific 'error' types into 'result<>' or 'outcome<>'. Indeed, it is hoped (and expected) that a greater amount of user-experimentation or flirtation with 'error' value transfer will be performed (not less) in the context of user-specific needs or engineering constraints: This is a fundamental benefit from having Outcome as a design option for authoring interfaces across module boundaries. Regarding a possible future “drift” from its clearly-stated mission, this review considers the library as submitted; and defers to the Boost community regarding policies and procedures for handling libraries included in the Boost distribution (which exist in varying states of evolution and maintenance). # FINAL THOUGHTS The Boost community is stronger for enabling and exploring idioms, and for not shying away from the difficult (and sometimes contentious) effort to discover new approaches that address the dark corners that stress our real-world systems. These are (perhaps) the only noble efforts that someday may lead to new best practices. If experience (otherwise known as, “painful memory of limitation”) is a prime driver for the design and implementation choices made by developers, then it is unreasonable in a review such as this to expect agreement on all fronts. Indeed, our systems have differing constraints and evolutionary / scaling prospects, and we fear different things. However, it seems important to keep in mind that this disagreement continues to be necessary and expected: Rather than pretending to hide within an echo chamber, the Boost Community does the “hard work” of challenging perspectives, pushing the envelope, and questioning assertions in the face of a constantly shifting technological landscape and evolving C++ language. Dissenting or critical reviews are essential, and desired. The long Boost history includes many examples of speculative and risky approaches, which in hindsight are now considered common and "best" practice. Few C++ developers today can practice professionally without at least passing knowledge of template-metaprogramming, which used to be an esoteric ritual only within the confines of Boost. Outcome was designed under the proposition that cross-module 'error' / 'exception' handling in today's systems is unnecessarily brittle and problematic. Reviewers found Outcome to effectively address a serious concern of transporting different '<error|exception>' instances across modules. It attempts to solve a hard problem, which spans 3rd-party module composition, while adhering to specific performance constraints and behavioral guarantees. Its use is demonstrated to be effective in some environments exhibiting severe engineering restrictions. As such, it is not expected that all users everywhere will have direct need for Outcome. However, it is hoped that evolution of similar idioms will eventually permit the broader C++ community to consider this domain of cross-module stateful control transfer to be a “solved problem” (or certainly “less-brittle” or “less-problematic”). Great thanks to the Boost Community for their tremendous efforts, disciplined review, and detailed exploration of topics in considering this library submission. Sincerest appreciation to Niall Douglas (Author of the Outcome Library) and other contributors for pushing the boundary for '<error|exception>' handling and for submitting this work to the Boost Review process. --charley Boost.Outcome (v2) Review Manager

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Fwd: Changes to __PRETTY_FUNCTION__ in clang
by Mikhail Ramalho 05 Feb '18

05 Feb '18

Hi all, I recently send an email to the clang mailing list, to change how clang prints __PRETTY_FUNCTION__ [0], and one person raised a question if it would break boost. Honestly, I don't know boost's code and I could only find a few places where it's used, mainly for diagnostics, but also in CTTI and hanna; that's why I'm sending this email to ask for some help. Does boost relies on the format of these macros? The main idea is to just change how templates are printed, from: X<void>::X() [T = void] to a gcc-like style: X<T>::X() [with T = void] Thank you, [0] http://lists.llvm.org/pipermail/cfe-dev/2018-February/056766.html -- Mikhail Ramalho.

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[gsoc18][boost.intrusive]
by Rishabh Arora 05 Feb '18

05 Feb '18

Hello Boost Community, I have proposed a project as a mentor for Google Summer of Code '18, as a new addition to the Boost.Intrusive library. The details about the project proposal and the competency test can be found here: https://github.com/ boostorg/boost/wiki/Boost-Google-Summer-of-Code-2018 (Project-5). All the interested candidates can contact me and send me their competency test on the following e-mail: rishabharora1997(a)gmail.com Best Regards, Rishabh

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Re: [boost] [CppCMS] What can be contributed to Boost?
by Bjorn Reese 04 Feb '18

04 Feb '18

On 02/02/18 19:30, Artyom Beilis via Boost wrote: > Once I can think of is cppcms::json > > http://cppcms.com/wikipp/en/page/cppcms_1x_json > http://cppcms.com/cppcms_ref/latest/classcppcms_1_1json_1_1value.html > > Also it should be updated to C++11 and probably do some small features > updates. it is one of the fastest JSON parsers around (and yes it is > way faster and convenient than one in property tree) > > What do you think? If the Boost community wants a JSON library, then I would like to suggest another, more versatile ibrary: https://github.com/breese/trial.protocol Documentation can be found here: http://breese.github.io/trial/protocol/ This library consists of two (well, three) parts: 1. A dynamic variable which is a variant type that can contain fundamental types, arrays, and associative arrays. This can be used as a parse tree for JSON and similar binary formats like MsgPack, UBJSON, BinToken, and CBOR. But it can also be used as a data container for, say, configuration data. The dynamic variable has iterators so it works with std algorithms. It also comes with a visitor. 2. A JSON parser/generator framework. This contains an incremental pull parser (json::reader) as the basic building-block. The incremental parser is used by a Boost.Serialization archive to enable serialization directly between JSON and C++ data structures. The incremental parser is also used by a tree parser that converts JSON into the before-mentioned dynamic variable. 3. A BinToken parser/generator framework. Like the JSON framework, but for the binary BinToken format. Currently undocumented.

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[CppCMS] What can be contributed to Boost?
by Artyom Beilis 02 Feb '18

02 Feb '18

Hello Dear Boost Developers, Recently I had released CppCMS - C++ Web Framework 1.2 under MIT license instead of LGPLv3 See: http://cppcms.com Since CppCMS project had already contributed some of its parts for Boost: Boost.Locale - in Boost for long time Boost.Nowide (passed review still need some my time to integrate to release) I wanted to renew the discussions of what parts may interest the community Boost outside CppCMS. Some samples I thought of: -------------------------------------------- Once I can think of is cppcms::json http://cppcms.com/wikipp/en/page/cppcms_1x_json http://cppcms.com/cppcms_ref/latest/classcppcms_1_1json_1_1value.html Also it should be updated to C++11 and probably do some small features updates. it is one of the fastest JSON parsers around (and yes it is way faster and convenient than one in property tree) What do you think? -------------------------------------- Another one that was already discussed once is CppDB: http://cppcms.com/sql/cppdb/ It also needs C++11 updates in general and is already under dual Boost/MIT License. It was discussed before but nothing moved further. ---------------------------------- Some smart pointers I find very useful especially for Pimpl implementation: hold_ptr -> similar to scope ptr but object constness is same as the pointer copy_ptr-> copies underlying object upon copy (very useful for pimpl) clone_ptr->clones objects. Regards, Artyom Beilis

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