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[Library idea] Type-safe Flagsets
by Julien Vernay 27 Jun '18

27 Jun '18

Hello everybody, I want to know if some people are interested in a type-safe flagsets. I define flagsets as a container similar to a bitset, but where each bit has a meaning. For example, we could have in some game : enum Direction : unsigned { UP = 0b0001, DOWN = 0b0010, LEFT = 0b0100, RIGHT = 0b1000 }; ... unsigned player_dir = UP | RIGHT; if ((player_dir & (UP|LEFT)) == (UP|LEFT)) player.setAnim("up_left"); player_dir &= ~UP; //removing UP from player_dir I think there are some issues with this kind of flagset : - you need to think about power-of-twos when attributing values to your flags. - you need to use bitwise operations which can be non-trivial, even for removing only one flag. - it is not safe: for example with another flagset using the flag INIT_VIDEO (in a window library like SDL), you can do " UP | INIT_VIDEO " even if the two flagsets have nothing in common With a type-safe flagset library, this code would become : namespace Direction { struct UP; struct DOWN; struct LEFT; struct RIGHT; using Type = flagset<unsigned, UP, DOWN, LEFT, RIGHT>; //unsigned is the underlying type }; ... auto player_dir = Direction::Type::Value<Direction::UP, Direction::RIGHT>(); if (player_dir.allOf<Direction::UP,Direction::LEFT>()) player.setAnim("up_left"); player_dir.reset<Direction::UP>(); It is more verbose but also more safe and easy to use. I actually have a partial implementation on GitHub, supporting read, write and conversions to strings : https://github.com/J-Vernay/flagset I would like to know if some people are interested in this kind of library, and if yes, what they think about the current syntax/implementation. Thanks for reading !

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Re: [boost] On Boost's logo copyright
by Mateusz Loskot 25 Jun '18

25 Jun '18

(CC to boost(a)lists.boost.org) On 25 June 2018 at 22:03, Giovanni Mascellani <gio(a)debian.org> wrote: > Il 25/06/2018 14:33, Mateusz Loskot via Boost ha scritto: >> AFAICT, the logo design was established around Boost 1.33. >> Here is related note from the release notes [1] >> >> ``` >> Rene Rivera for the new Boost web page design; and Zoltan >> "cad" Juhasz for the new Boost logo. >> ``` > > This is very useful, thank you! You're welcome. I hope I've pulled the actual facts. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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On Boost's logo copyright
by Giovanni Mascellani 25 Jun '18

25 Jun '18

Dear Boost developers, I am preparing the next upload of Boost package in Debian. I would appreciate your help on a little detail, which is however very important for Debian (if this is not the right place to ask, please accept my apologies and direct me to a more appropriate one): who is the copyright holder of Boost's logo? I understand that it is licensed under the BSL license, but it seems to me that the name of the rights holder is not listed anywhere. Thanks for your help and for the great library, Giovanni. -- Giovanni Mascellani <g.mascellani(a)gmail.com> Postdoc researcher - Université Libre de Bruxelles

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[release][yap] Master archive builds broken.. for a long time.
by Rene Rivera 24 Jun '18

24 Jun '18

While checking to see that the master PRs I did yesterday to master where not causing problems I noticed something unrelated. Looks like the master archive build has been failing for a long time now. Seems the addition of YAP is broken. It appears there's some documentation files missing: /home/ubuntu/build/boost/bin.v2/doc/gcc-4.8/debug/auto-index-on/threadapi-pthread/src/boost.auto_index.docbook:65535: element include: XInclude error : could not load /home/ubuntu/build/boost/bin.v2/doc/gcc-4.8/debug/auto-index-on/threadapi-pthread/home/ubuntu/boost/libs/yap/doc/yap_reference.xml, and no fallback was found >From any of the builds in < https://circleci.com/gh/boostorg/boost/tree/master>. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net

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[math] policy<discrete_quantile<real> > test's fail because multiple matches for 'real'
by Brian Kuhl 24 Jun '18

24 Jun '18

When I compile with VxWorks 7/Clang v5/ Dinkum 700 there is an inline real() function in global scope. Leading to a few errors like this: ----------------------------------------------------------------------- clang-vxworks.compile.c++ ../bin.v2/libs/math/test/test_poisson_float.test/clang-vxworks-4.2.1/debug/cross-compile-vxworks/static-only-on/test_poisson.o "/yow-build40-lx1/bkuhl/vx7/compilers/llvm-5.0.0.3/LINUX386/bin/clang" -x c++ --target=x86_64 -m64 -mcmodel=large -fno-omit-frame-pointer -fno-strict-aliasing -mno-implicit-float -fno-builtin -nostdlibinc -nostdinc++ -fno-use-init-array -ftls-model=local-exec -ansi -std=c++14 -O2 -Wall -Wno-missing-braces -Wreturn-type -Wconversion -Wformat -Wno-sign-conversion -Wno-c++11-narrowing -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/system -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public -O0 -fno-inline -Wall -g -include/yow-build40-lx1/bkuhl/workspace/VSB/3pp/BOOST/boost_1_67_0/autoconf_vsbConfig_quote.h -D_C99 -D_HAS_C9X -D__vxworks -D__VXWORKS__ -D__RTP__ -D__ELF__ -D__WRS_NO_DIRECT_TLS_ACCESS_FROM_RTP_TO_SHARED_LIB -I/yow-build40-lx1/bkuhl/workspace/VSB/3pp/BOOST/boost_1_67_0 @/yow-build40-lx1/bkuhl/workspace/VSB/mk/_vsbuinc_cmdllvmBOOST -D_VX_CPU=_VX_SIMLINUX -D_VX_TOOL_FAMILY=llvm -D_VX_TOOL=llvm -D_nq_VSB_CONFIG_FILE=/yow-build40-lx1/bkuhl/workspace/VSB/h/config/vsbConfig.h -I/yow-build40-lx1/bkuhl/workspace/VSB/share/h -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/system -isystem/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public -D_VSB_PUBLIC_HDR_DIR=/yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public -I. -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_STATIC_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_SYSTEM_STATIC_LINK=1 -DBOOST_TEST_NO_AUTO_LINK=1 -DBOOST_TIMER_STATIC_LINK=1 -DBOOST_UBLAS_UNSUPPORTED_COMPILER=0 -DTEST_FLOAT -I".." -I"../libs/math/include_private" -I"../libs/math/test" -c -o "../bin.v2/libs/math/test/test_poisson_float.test/clang-vxworks-4.2.1/debug/cross-compile-vxworks/static-only-on/test_poisson.o" "../libs/math/test/test_poisson.cpp" ../libs/math/test/test_poisson.cpp:454:39: error: reference to 'real' is ambiguous typedef policy<discrete_quantile<real> > P1; ^ /yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public/complex.h:689:21: note: candidate found by name lookup is 'real' inline long double real(_Lcomplex _Left) ^ /yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public/complex.h:543:14: note: candidate found by name lookup is 'real' inline float real(_Fcomplex _Left) ^ /yow-build40-lx1/bkuhl/workspace/VSB/usr/h/public/complex.h:397:15: note: candidate found by name lookup is 'real' inline double real(_Dcomplex _Left) ^ /yow-build40-lx1/bkuhl/workspace/VSB/3pp/BOOST/boost_1_67_0/boost/math/policies/policy.hpp:225:4: note: candidate found by name lookup is 'boost::math::policies::discrete_quantile_policy_type::real' real, ^ ../libs/math/test/test_poisson.cpp:454:39: error: unknown type name 'real' typedef policy<discrete_quantile<real> > P1; ^ ../libs/math/test/test_poisson.cpp:454:45: error: expected a type typedef policy<discrete_quantile<real> > P1; ^ 3 errors generated. ...failed clang-vxworks.compile.c++ ../bin.v2/libs/math/test/test_poisson_float.test/clang-vxworks-4.2.1/debug/cross-compile-vxworks/static-only-on/test_poisson.o... -------------------------------------------------------- I'd like to contribute a pull request to resolve this. But I'd like some guidance; is a simple change that qualifies real acceptable. using namespace boost::math::policies; - typedef policy<discrete_quantile<real> > P1; + typedef policy<discrete_quantile<boost::math::policies::real> > P1; typedef policy<discrete_quantile<integer_round_down> > P2; Or is this something that should be added with #ifdef __VXWORKS__

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Re: [boost] Boost.Signals deprecation and removal
by Mike 22 Jun '18

22 Jun '18

> Isn't deprecation the warning? That depends on what deprecation means. Currently the warning message just says: > [1]Boost.Signals is no longer being maintained and is now deprecated. [...] No mention of removal. The documentation even says > If you have existing [2]Boost.Signals-based code, it **will continue to work**, but consider moving to Boost.Signals2.Â Best Mike References 1. http://Boost.Signals/ 2. http://Boost.Signals/

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[release] 1.68.0 closing for major changes next week
by Marshall Clow 21 Jun '18

21 Jun '18

One week from tomorrow master will closed for major changes. Upcoming dates: * 27-Jun: Boost 1.68.0 closed for major code changes * 4-Jul: Boost 1.68.0 closed for beta * 11-Jul: Boost 1.68.0 beta 1 * 1-Aug: Boost 1.68.0 closed for release * 4-Aug: Boost 1.68.0 release -- The Boost Release Team

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[Build] Create test with shared library linked against current Boost link-variant
by Alexander Grund 18 Jun '18

18 Jun '18

Hi, I discovered a severe bug in Boost.Serialization and am trying to contribute a test to the test suite to reproduce that behavior. I have a minimum example which runs into this (see also https://stackoverflow.com/questions/50064617/order-of-destruction-for-stati…) but I'm having trouble getting that into the Jamfile. What I need: 2 shared libraries linked against the currently tested Boost link-variant and link those into an executable not linked against Boost. So testcase a) would be against Boost-Shared and b) against Boost-Static. But in all cases the libraries itself must be shared. What I have: lib multi_shared_1 : multi_shared1.cpp ../build//boost_serialization : <link>shared ; lib multi_shared_2 : multi_shared2.cpp ../build//boost_serialization : <link>shared ; ... [ test-bsl-run test_multi_shared_lib : : multi_shared_1 multi_shared_2 ] Problem: This links against Boost-Shared even with "./b2 link=static" My best approach so far is to change "../build//boost_serialization" to "../build//boost_serialization/<link>static" but then I cannot test testcase a) (Boost-Shared) anymore. Also it does link other Boost-Libraries (filesystem, system) shared, not static. Furthermore I'd need to add `-fPIC` to the cxxflags of the boost libraries. This is minor as it can be done in the `.travis` file but I'd rather have it in the Jamfile so it is not missed in other test-environments. How can I achieve this? I'm not to familiar with the Jamfiles so this is basically all I could find so far. Thanks, Alexander Grund

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[container] [flat_map] Sub-optimal behavior when utilized with std::less<>
by Viktor Sehr 16 Jun '18

16 Jun '18

It seems to me that neither boost::flat_map nor boost:flat_set with a custom comparator such as std::less<> behaves like std::set/std::map. This results in unnecessary allocation, in difference from std::map/set when used with a std::string as key for example Example: // Please note that I pretend that "dummy" is large enough to make the std::string utilize the heap. auto set = std::set<std::string, std::less<> >{}; auto n = set.count("dummy"); // No conversion from const char* to std::string auto flatset = boost::container::flat_set<std::string, std::less<> >{}; auto n = flatset.count("dummy"); // const char* is converted to a std::string before comparison, thus resulting in an unnecessary allocation. Is this a known issue intended to be resolved? Looking at the code of STL (which ever version ships with Visual Studio), find, count etc has been extended with template key types in addition to the regular key_type using an "is_transparent" trait: template<class _Other, class _Mycomp = key_compare, class = typename _Mycomp::is_transparent> size_type count(const _Other& _Keyval) const { _Keyval _Paircc _Ans = equal_range(_Keyval); return (_STD distance(_Ans.first, _Ans.second)); } Best regards /Viktor Sehr

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Interest in (parts of) type_safe, e.g. Boost.StrongTypedef?
by Jonathan Müller 15 Jun '18

15 Jun '18

I've been working on https://github.com/foonathan/type_safe for the past 20 months or so. What started as an experimenting ground for type safe programming facilities quickly turned into a general mix bag of utilities. However, it became my most popular project, so there is something in there people find really useful. And with that multiple approached me wanting to have it added to Boost, so here I am. I do realize that not all of it is suited for Boost: some of it has overlap with existing libraries (e.g. optional/variant), some of it has better implementations elsewhere (e.g. improved integer types) and some of it is to novel/experimental (e.g. stuff like constrained_type). But there are some things that could be useful for Boost. I'm mainly thinking of the strong typedef facility. I plan on splitting the library up into multiple parts anyway (see also https://github.com/foonathan/type_safe/issues/82) so please let me know whether there is anything you'd like to see being prepared for Boost. Thanks, Jonathan

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