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Boost 1.65.2 Release Candidate 2
by Daniel James 03 Sep '17

03 Sep '17

The second release candidates for the 1.65.1 release are now available at: <https://dl.bintray.com/boostorg/release/1.65.1/> The SHA256 checksums are as follows: df7bea4ce58076bd8e9cd63966562d8cf969b431e1c587969e6aa408e51de606 boost_1_65_1_rc2.7z 9807a5d16566c57fd74fb522764e0b134a8bbe6b6e8967b83afefd30dcd3be81 boost_1_65_1_rc2.tar.bz2 a13de2c8fbad635e6ba9c8f8714a0e6b4264b60a29b964b940a22554705b6b60 boost_1_65_1_rc2.tar.gz d1775aef807bd6a14077b450cce2950d8eacd86aaf51015f79e712917f8cc3c2 boost_1_65_1_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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[release] Boost 1.65.1 Release Candidate 1
by Daniel James 01 Sep '17

01 Sep '17

The release candidates for the 1.65.1 release are now available at: <https://dl.bintray.com/boostorg/release/1.65.1/> The SHA256 checksums are as follows: 9b440d8167043c8d70326d8a5d4df98a59abb40be7d68f51e75ea95ea24d84f3 boost_1_65_1_rc1.7z fbd5663c748a88479adb4106c8a12009b149e602dec4b40a4a778381a33cf3ce boost_1_65_1_rc1.tar.bz2 b1b18d658cc0ff8a5030b29f4ed41de1826281fcb52fc1073b106c5802a570bd boost_1_65_1_rc1.tar.gz 542624352b2c3fd6a76c98624f90d2c0e62dd810ec6cc9fdae831677c7aa1fbf boost_1_65_1_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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Help on boost::iostreams::gzip_compressor: Linker error
by Uthpal Urubail 31 Aug '17

31 Aug '17

Experts, I am getting below linker error on gzip compressor usage. Any help is highly appreciated. I have already tried linking boost_iostreams.lib & zlib.lib Code Description LNK2001 unresolved external symbol "int const boost::iostreams::zlib::default_compression" (?default_compression@zlib@iostreams@boost@@3HB) & Code Description LNK2019 unresolved external symbol "protected: __cdecl boost::iostreams::detail::zlib_base::~zlib_base(void)" (??1zlib_base@detail@iostreams@boost@@IEAA@XZ) referenced in function "int `public: __cdecl boost::iostreams::detail::zlib_compressor_impl<class std::allocator<char> >::zlib_compressor_impl<class std::allocator<char> >(struct iostreams::detail::zlib_params const &)'::`1'::dtor$0" (?dtor$0@?0???0?$zlib_compressor_impl@V?$allocator@D@std@@@detail@iostreams@boost@@QEAA@AEBUzlib_params@23@@Z@4HA) Regards, UJ

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UDP Echo Server
by Mark Hieber 25 Aug '17

25 Aug '17

Hi,

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[fiber][asio] Problem running http://www.boost.org/doc/libs/1_65_0/libs/fiber/examples/asio/autoecho.cpp
by Mark Hieber 24 Aug '17

24 Aug '17

Hi, I am using cmake 3.9.1 and Boost 1.65.0. I have downloaded the autoecho.cpp file and the corresponding yield.hpp, detail/yield.hpp and round_robin.hpp from http://www.boost.org/doc/libs/1_65_0/libs/fiber/examples/asio. When I run my program (just these 4 files, with no modifications), I get this output: Thread A: started Thread A: A0: echo-server started Segmentation fault Using print statements the seg-fault happens in the io_svc->run(); call. If anyone can help me with this, I would appreciate it. BTW, I am running on Ubuntu 16.04.3 LTS Thanks, Mark

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Portable file I/O with system error codes support
by Oleg Andriyanov 23 Aug '17

23 Aug '17

Hi, I'm looking for a portable way to open a file, read some data from it, and do a proper error reporting in case of error. Apparently std::fstream is not suitable for this task because it does not provide means to retrieve original error code or even some human readable description of what went wrong (checking errno does not count since the standard does not guarantee it is set by any functions in std::fstream). I'm wondering if boost::iostreams can do that, but I've found nothing this far that could help in getting the error code. I've also tried boost::filesystem::fstream, but no luck. Users of large frameworks like Qt have advantage of their portable wrappers for file I/O like QFile. Are there any means in Boost which provide similar functionality? Related StackOverflow question: https://stackoverflow.com/questions/45840686/portable-way-to-read-a-file-in… Thanks.

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[release] Boost 1.65.0
by Daniel James 21 Aug '17

21 Aug '17

Release 1.65.0 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 two new libraries and numerous enhancements and bug fixes for existing libraries. For details, including download links, see <http://www.boost.org/users/history/version_1_65_0.html> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.65.0/> To install this release on your system, see <http://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team Vladimir Prus, Rene Rivera, Marshall Clow, Eric Niebler, Daniel James, Beman Dawes

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Is there a C++ implementation for numerical quadrature/cubature?
by Easior Lars 20 Aug '17

20 Aug '17

Hi, all in the list! I need some functions to handle numerical quadrature/cubature in C++. I found that only few packages, e.g. GSL, could do this end. However, those ones are not pure C++ implementations. Although, odeint package in Boost can partially satisfy my need. I want to know whether there is a C++ implementation for numerical quadrature/cubature in Boost. Any suggestion? -- Best wishes, Easior ------ "It was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to heaven, we were all going direct the other way - in short, the period was so far like the present period, that some of its noisiest authorities insisted on its being received, for good or for evil, in the superlative degree of comparison only." TALES OF TWO CITIES, by Charles Dickens

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[Boost][Container] Why is flat_set default constructor explicit?
by dariomt＠gmail.com 17 Aug '17

17 Aug '17

Hi all, I just found out that all Boost.Container default constructors are implicit (just as I would expect) except for flat_set. Quoting from [1]: explicit flat_set() noexcept(/*snip*/); Effects: Default constructs an empty container. Why is flat_set different than the other containers? Is this an oversight? FWIW this issue is breaking my C++14 code (for both clang and gcc) when switching from std::set to boost::container::flat_set, minimal repro follows: #include <boost/container/flat_set.hpp> #include <set> #ifndef USE_STD_SET using S = boost::container::flat_set<int>; #else using S = std::set<int>; #endif struct A { int i; S s; }; int main() { A a1; // OK A a2 {0, {{}} }; // OK A b1 {}; // FAILS A b2 {0}; // FAILS A b3 {0, {}}; // FAILS } A f() { return {}; // FAILS } Using Bost 1.64.0 in case that matters. Any help appreciated. [1] http://www.boost.org/doc/libs/1_64_0/doc/html/boost/container/flat_set.html…

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Re: [Boost-users] Boost 1.65.0 Release Candidate 4
by Marshall Clow 17 Aug '17

17 Aug '17

On Wed, Aug 16, 2017 at 8:33 PM, Marshall Clow <mclow.lists(a)gmail.com> wrote: > The fourth (and hopefully final) release candidates for the 1.65.0 release > are now available at: > > https://dl.bintray.com/boostorg/release/1.65.0/source/ > [snippage] 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. * Builds successfully with Apple Clang [Apple LLVM version 8.0.0 (clang-800.0.42.1)] with C++03/11/14/1z * Builds successfully with Clang Trunk [clang version 6.0.0 (trunk 310587)] with C++03/11/14 * Built successfully with Clang Trunk [clang version 6.0.0 (trunk 310587)] with C++1z except for Boost.Locale. -- Marshall

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Boost 1.65.0 Release Candidate 4
by Marshall Clow 17 Aug '17

17 Aug '17

The fourth (and hopefully final) release candidates for the 1.65.0 release are now available at: https://dl.bintray.com/boostorg/release/1.65.0/source/ [ Note: The RC1s/RC2s/RC3s are in that directory, too - make sure you get the right files! ] Changes since RC3: * Fix a bug in Boost.Thread where timed waits were waiting for a very long time. Changes since RC2: * Fix a crashing bug in Boost.ASIO * Fix a compilation error when including both <boost/math_fwd.hpp> and <boost/math/common_factor_ct.hpp> * An update to Boost.Spirit to fix compilation errors on Mac OS with -std=c++17 Changes since RC1: * An update to Boost.Config so that the flags BOOST_NO_CXX98_RANDOM_SHUFFLE and BOOST_NO_CXX98_BINDERS are now set appropriately for libc++. (This fixes the compilation errors for Boost.Test) * An update to Boost.Fiber to fix compilation errors * An update to Boost.Wave to fix compilation errors on Mac OS with -std=c++17 The SHA256 checksums are as follows: 5d255d1ff8460d52dffcf9a9b55d908ae704027a66c590ec774096effaea26c1 boost_1_65_0_rc4.7z 911602d830ea5d16483d1e565b9859d120d03f2e5176017226ef391eb9d17fc8 boost_1_65_0_rc4.tar.bz2 369e06dc787d32b0fbaae020f33d814c9e7b77263acb859776968e623035f760 boost_1_65_0_rc4.tar.gz a9c6b8346b05ea43ac4278e80036a9e956ea99fc61f0b7f55469471af2df934c boost_1_65_0_rc4.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. Thanks! -- The release managers

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Where we are 1.65.0
by Marshall Clow 16 Aug '17

16 Aug '17

RC1 came out on Monday, and it had some problems. Specifically: * Some libraries didn't build with ToT clang/libc++ (Locale, Wave and Test) This is because in C++17, some deprecated library features have been removed. [bind1st, mem_fun, auto_ptr, random_shuffle, etc ] Boost.Config has support for these removals, but this was ... incomplete. [ This is on me; I did the partial job of adding these to Config's libc++ support a while back ] Normally, I would be tempted to say "Well, clang 5 is not shipping yet, and so we can put this off until 1.66.0". But both clang 5 and C++17 are imminent (they will both happen well before the 1.66 release, and so I think we should fix this now. Also, a future version of MSVC will have the same library issues. So I have committed a fix for Boost.Config that fixes the Boost.Test issues. Hartmut has fixed most of the Boost.Wave issues. Artymom has a fix for Boost.Locale. Windows/MSVC builds look good across the board. * Boost.Fiber fails to build on Mac OS with anything other than -std=c++03. There is a fix in develop for this; but there's still a bunch of tests failing. * There's a problem from the beta in Boost.Math. The regression regarding boost/math/common_factor_ct.hpp (vs > math_fwd.hpp) seems to be still there. (For details please see the > original mail and replies: > https://lists.boost.org/Archives/boost/2017/07/237452.php) > What I presume is the fix (https://github.com/boostorg/math/pull/75) was > merged into develop about 12 hours ago, some automatic CI tests still > running. * There's a problem with ScopeExit and Visual C++ 2017 With Visual C++ 2017 and /permissive-, ScopeExit is still broken, for which > there's an open PR: > https://github.com/boostorg/scope_exit/pull/3 > Looks good otherwise on MSVC 14.11, tested with /std=cpplatest and > _HAS_AUTO_PTR_ETC=1, targeting Windows 10 and XP, 32 bit and 64 bit, built > as static libraries. >

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constructing rationals from mpfr_floats [multiprecision]
by Dani Brake 15 Aug '17

15 Aug '17

Hi, 1) I am getting signaling due to division by 0. The following lines are faulty: mpfr_float p("1.1"); mpq_rational q(p); signal: integer divide by zero; whereas this succeeds: mpq_rational q(1.1); any one seen this before? i'm on compiler Apple LLVM version 8.0.0 (clang-800.0.38) ,with homebrew-provided boost 1.64, mpfr 3.1.5, gmp 6.1.2. -- 2) I also expected to be able to construct rationals as mpq_rational q("1.1") but it fails to parse using the built-in constructor. i mean, i understand why (1.1 isn't a rational), but given that i can construct a rational from a double, i figured that i'd get something reasonable from "1.1", namely 11/10. -- thanks! dani brake university of wisconsin eau claire ps i am not disabling mixed double-multiprecision arithmetic in this scenario, in case you have been reading my other questions this last week

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Re: [Boost-users] deleting operators to forbid mixed arithmetic? [multiprecision]
by Dani Brake 15 Aug '17

15 Aug '17

Paul and John, Putting a macro bracket around this might make it generally useful, perhaps > something like: > > #ifdef BOOST_MULTIPRECISION_NO_DOUBLE_OPS (BUILTIN_OPS would include > float and long double?) > > … > > template <class Backend> > struct is_compatible_arithmetic_type<double, number<Backend> > : public > mpl::false_ {}; > > say > #endif > > If you find this useful, you could create a GIT Pull Request, or just > email the file changed. You won’t be the only one J. Defining the macro > BOOST_MULTIPRECISION_NO_DOUBLE_OPS could be a way to detect dodgy > conversions that need to be changed to keep full precision. I implemented this in my codebase, and had few ill effects. Some unexpected conversions, but I did find this disabling very useful. Wrapping it in a macro bracket and making it officially supported would be fabulous. I think it should go in number_base.hpp at line 110 or so. If we wanted to make it robust and thorough, I think we need to consider turning off implicit constructors from disabled types, too. I believe that what we have so far only disables arithmetic. Dani

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Re: [Boost-users] Problem building Boost 1.64.0 with Oracle Developer Studio 12.6
by Leo Carreon 15 Aug '17

15 Aug '17

It’s now nearly a week since I sent this email and I have not received a comment from anyone from Boost. Does this mean we have no experience building on Developer Studio 12.6 or Boost doesn’t care whether it works on Solaris or not. I suspect Problem #2 may be a Solaris issue but I’m not sure about Problem #1 because even the guys from Oracle have no comment about it. I would appreciate a comment from the maintainer of Boost.Optional. From: Leo Carreon Sent: Wednesday, August 9, 2017 10:52 AM To: Boost Users Mailing List Subject: Problem building Boost 1.64.0 with Oracle Developer Studio 12.6 Hi Boosters, I have been trying to build Boost 1.64.0 with Oracle Developer Studio 12.6 on Oracle Solaris 11.3 x86_64. There are two errors encountered during the build. They are: 1. Problem with Boost.Optional with this error messages: "libs/log/src/named_scope.cpp", line 118: Error: Use of overloaded binary operator '=' is ambiguous. "./boost/optional/optional.hpp", line 900: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. "./boost/optional/optional.hpp", line 962: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. 2. Problem with Boost.Python with this error message: "libs/python/src/numpy/dtype.cpp", line 61: Error: NPY_FLOAT16 is not defined. Note that these two errors are the cause of 9 Boost shared libraries to not be generated. I would appreciate it very much if someone could give me some pointers on how to resolve the above issues. Kind regards, Leo

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[Log][Optional][Python] Problem building Boost 1.64.0 with Oracle Developer Studio 12.6
by Leo Carreon 15 Aug '17

15 Aug '17

Hi, This is a resend with the suggested change on the subject line. I have been trying to build Boost 1.64.0 with Oracle Developer Studio 12.6 on Oracle Solaris 11.3 x86_64 in C++14 mode. There are three errors encountered during the build. They are: 1. Problem with Boost.Log with this error message: >> Assertion: (../lnk/initializer.cc, line 1865) while processing ./boost/log/expressions/message.hpp at line 98. My comment: Acknowledged by Oracle as a compiler issue. 2. Problem with Boost.Optional with this error messages: "libs/log/src/named_scope.cpp", line 118: Error: Use of overloaded binary operator '=' is ambiguous. "./boost/optional/optional.hpp", line 900: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. "./boost/optional/optional.hpp", line 962: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. My comment: Ambiguous boost::optional<>::operator=(), possibly a Boost configuration issue or compiler SFINAE issue. I’m not that fluent with SFINAE to be able to figure this out. 3. Problem with Boost.Python with this error message: "libs/python/src/numpy/dtype.cpp", line 61: Error: NPY_FLOAT16 is not defined. My comment: Possibly a Solaris package installation issue due to no support contract. (numpy package fails to install) I would appreciate it very much if someone could give me some pointers on how to resolve the above issues. Kind regards, Leo

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Boost 1.65.0 Release Candidate 3
by Marshall Clow 14 Aug '17

14 Aug '17

The third (and hopefully final) release candidates for the 1.65.0 release are now available at: https://dl.bintray.com/boostorg/release/1.65.0/source/ [ Note: The RC1s and RC2s are in that directory, too - make sure you get the right files! ] Changes since RC2: * Fix a crashing bug in Boost.ASIO * Fix a compilation error when including both <boost/math_fwd.hpp> <boost/math/common_factor_ct.hpp> * An update to Boost.Spirit to fix compilation errors on Mac OS with -std=c++17 Changes since RC1: * An update to Boost.Config so that the flags BOOST_NO_CXX98_RANDOM_SHUFFLE and BOOST_NO_CXX98_BINDERS are now set appropriately for libc++. (This fixes the compilation errors for Boost.Test) * An update to Boost.Fiber to fix compilation errors * An update to Boost.Wave to fix compilation errors on Mac OS with -std=c++17 The SHA256 checksums are as follows: 1d844a958656e76b140292ec1cbfe770d9916166c16e13b59d3dac1df3b7ef40 boost_1_65_0_rc3.7z 3fc2877cf5da4bbb0c91eab058d2e6764155e705e9c3e2dce2a0248936079675 boost_1_65_0_rc3.tar.bz2 e065b53d7f5326cc20d246b518facedb4407391aaf9fd4a1c90001e0c85accab boost_1_65_0_rc3.tar.gz 96b2ba69c6045060d1dfe012218457870200c2c22af60eb855bab5ffb75c13a2 boost_1_65_0_rc3.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. Thanks! -- The release managers

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Re: [Boost-users] deleting operators to forbid mixed arithmetic? [multiprecision]
by Dani Brake 14 Aug '17

14 Aug '17

> > So in principle you just define a full or partial specialization, for > example: > template <class Backend> > struct is_compatible_arithmetic_type<double, number<Backend> > : public > mpl::false_ {}; > and then cross your fingers and hope for the best ;) Thanks for the suggestion, i'll give it a try. \e crosses fingers ~dani

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Re: [Boost-users] deleting operators to forbid mixed arithmetic? [multiprecision]
by Dani Brake 13 Aug '17

13 Aug '17

> > Been there, done that – fallen into the big pit awaiting the unwary mixing > double and multiprecision – again and again… L > I am being bit by this one hard. Converted a bunch of multipliers and tolerances from mpfr_floats to doubles in an effort to simplify some code, and now mixed precision is introducing error. > I think that you don’t really want to delete a family of operator*s – what > you DO want to get a warning when there is loss of significance, similar to > the warning when you fit a double into a float. > > It’s OK to multiply (or other ops) with a double as long as this doesn’t > lose any bits or digits of precision. > > So multiplying by 0.5 is OK, but not by multiplying 0.1 (the > multiprecision type needs FP_type(1)/10 to represent 0.1 as accurately as > possible for the FP type). > Multiplying by 0.1 is a common desire in my household (adaptive precision solving of polynomials). If only the compiler provided a trait bool is_exactly_representable(double) > so that a warning could be issued… > This is a bit tricky, because any double is by definition exactly representable by a double, right?. You would want is_exactly_representable to get the value before being transformed into a double? Another issue I foresee having to deal with is runtime parsing. Forbid the runtime user from feeding doubles problematic numbers. Thanks for the help, Dani

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Re: [Boost-users] Problem building Boost 1.64.0 with Oracle Developer Studio 12.6
by Leo Carreon 12 Aug '17

12 Aug '17

It appears that Problem #1 is possibly a Boost configuration issue but may also be an issue with the compiler to do with enable_if. Two Boost.Optional member functions using enable_if are showing up in the lookup. Can anyone else comment? Problem #2 is possibly a Python package issue which can only be resolved by having a Solaris support contract because I’m unable to install the required packages to resolve the problem. From: Leo Carreon Sent: Wednesday, August 9, 2017 10:52 AM To: Boost Users Mailing List Subject: Problem building Boost 1.64.0 with Oracle Developer Studio 12.6 Hi Boosters, I have been trying to build Boost 1.64.0 with Oracle Developer Studio 12.6 on Oracle Solaris 11.3 x86_64. There are two errors encountered during the build. They are: 1. Problem with Boost.Optional with this error messages: "libs/log/src/named_scope.cpp", line 118: Error: Use of overloaded binary operator '=' is ambiguous. "./boost/optional/optional.hpp", line 900: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. "./boost/optional/optional.hpp", line 962: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. 2. Problem with Boost.Python with this error message: "libs/python/src/numpy/dtype.cpp", line 61: Error: NPY_FLOAT16 is not defined. Note that these two errors are the cause of 9 Boost shared libraries to not be generated. I would appreciate it very much if someone could give me some pointers on how to resolve the above issues. Kind regards, Leo

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Re: [Boost-users] Problem building Boost 1.64.0 with Oracle Developer Studio 12.6
by Leo Carreon 12 Aug '17

12 Aug '17

BTW, I forgot to mention a third issue which has been acknowledged by Oracle as a problem with the compiler: 3. Problem with Boost.Log with this error message: >> Assertion: (../lnk/initializer.cc, line 1865) while processing ./boost/log/expressions/message.hpp at line 98. From: Leo Carreon Sent: Wednesday, August 9, 2017 10:52 AM To: Boost Users Mailing List Subject: Problem building Boost 1.64.0 with Oracle Developer Studio 12.6 Hi Boosters, I have been trying to build Boost 1.64.0 with Oracle Developer Studio 12.6 on Oracle Solaris 11.3 x86_64. There are two errors encountered during the build. They are: 1. Problem with Boost.Optional with this error messages: "libs/log/src/named_scope.cpp", line 118: Error: Use of overloaded binary operator '=' is ambiguous. "./boost/optional/optional.hpp", line 900: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. "./boost/optional/optional.hpp", line 962: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. 2. Problem with Boost.Python with this error message: "libs/python/src/numpy/dtype.cpp", line 61: Error: NPY_FLOAT16 is not defined. Note that these two errors are the cause of 9 Boost shared libraries to not be generated. I would appreciate it very much if someone could give me some pointers on how to resolve the above issues. Kind regards, Leo

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deleting operators to forbid mixed arithmetic? [multiprecision]
by Dani Brake 12 Aug '17

12 Aug '17

Hi, I'd like to forbid multiplication of Boost.Multiprecision floating point numbers by doubles. Any tips? I think I want to delete a family of operator*s, but am having a hard time coming up with which ones. Thanks, Dani Brake University of Wisconsin Eau Claire

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Boost 1.65.0 Release Candidate 2
by Marshall Clow 12 Aug '17

12 Aug '17

The second release candidates for the 1.65.0 release are now available at: https://dl.bintray.com/boostorg/release/1.65.0/source/ [ Note: The RC1's are in that directory, too - make sure you get the right files! ] Changes from RC1: * An update to Boost.Config so that the flags BOOST_NO_CXX98_RANDOM_SHUFFLE and BOOST_NO_CXX98_BINDERS are now set appropriately for libc++. (This fixes the compilation errors for Boost.Test) * An update to Boost.Fiber to fix compilation errors * An update to Boost.Wave to fix compilation errors on Mac OS with -std=c++17 The SHA256 checksums are as follows: 786ccb478a82ef526fb8649841d2e863af90d7ea31217bb2e938d87aff06cf23 boost_1_65_0_rc2.7z 83dbc7179271825c55a59c26f30cf9de53bb8b42006d920948bad709f5372af9 boost_1_65_0_rc2.tar.bz2 493cbf33a8837b44f87e3ac8a37ec32b9a0a27b8cdb03eac6237a16027a03809 boost_1_65_0_rc2.tar.gz 40e4ccbd52322f9a8cb6e1829075c810d8aad8851f3efb2b3da7fcff6963e14d boost_1_65_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. Thanks! -- The release managers

2 4

[serialization] archive testing
by Sergey Spiridonov 09 Aug '17

09 Aug '17

Hi, 1. The following works with xml_archive: cd boost_1_64_0/libs/serialization/test bjam -sBOOST_ARCHIVE_LIST=xml_archive.hpp 2. Example from documentation[1] does not work for me. Documentation tells[1]: -------------------------- To test a new archive, for example, portable binary archives, with the gcc compiler, make a header file portable_binary_archive.hpp and invoke bjam with -sBOOST_ARCHIVE_LIST=portable_binary_archive.hpp This process in encapsulated in the shell or cmd script library_test whose command line is library_test --toolset=gcc -sBOOST_ARCHIVE_LIST=portable_binary_archive.hpp ------------------------- [1] http://www.boost.org/doc/libs/1_64_0/libs/serialization/doc/archive_referen… I created boost_1_64_0/libs/serialization/test/portable_binary_archive.hpp with following lines: #include <libs/serialization/example/portable_binary_oarchive.hpp> typedef portable_binary_oarchive test_oarchive; typedef std::ofstream test_ostream; #include <libs/serialization/example/portable_binary_iarchive.hpp> typedef portable_binary_iarchive test_iarchive; typedef std::ifstream test_istream; #define TEST_STREAM_FLAGS (std::ios_base::openmode)0 1. There is no "library_test" script in boost_1_64_0.tar.bz2. 2. cd boost_1_64_0/libs/serialization/test bjam -sBOOST_ARCHIVE_LIST=portable_binary_archive.hpp fails with many linking errors like that: ../../../bin.v2/libs/serialization/test/test_array_portable_binary_archive.test/gcc-6.3.0/debug/test_array.o: In function `portable_binary_oarchive::save(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': /home/ss/src/boost_1_64_0/libs/serialization/test/../../../libs/serialization/example/portable_binary_oarchive.hpp:105: undefined reference to `boost::archive::basic_binary_oprimitive<portable_binary_oarchive, char, std::char_traits<char> >::save(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)' What am i doing wrong? -- Best regards, Sergey Spiridonov GAMIC mbH, Roermonder Str. 151, 52072 Aachen, Germany Phone +49 241 889110 CEO Paul Malkomes Amtsgericht Aachen HRB 4029 VAT-ID: DE 121 677 540 Please use support(a)gamic.com for support requests and bug reports

1 0

[heap] Singular handle issue with MSVC iterator debug facilities
by Mateusz Loskot 09 Aug '17

09 Aug '17

Hi, Using VS2017 and Boost 1.64, I'm compiling a program which uses boost::heap::d_ary_heap. In debug configuration (with default _ITERATOR_DEBUG_LEVEL), I'm observing issues at run-time when a handle of item on the heap is compared against default-constructed instance of handle_type. BTW, the handle_type compiled in is based on std::list::iterator as defined in boost::heap::detail::priority_queue_mutable_wrapper. The issue is that MSVC iterator debug facilities break execution with File: c:\program files (x86)\microsoft visual studio\2017\professional\vc\tools\msvc\14.10.25017\include\list Line: 290 Expression: list iterators incompatible AFAIU, handle_type{}; seems to yield handle h object wrapping singular iterator. Below, minimal example to reproduces the problem is included. While debugging the sample, Visual C++ debugger does not show the iterator wrapped by the handle as default-constructed with null node pointer. Instead, it displays garbage: ((???, ???), ???) // ------------------------------------------------------------------ #include <cstdint> #include <functional> #include <boost/heap/d_ary_heap.hpp> using NodeID = std::uint32_t; using EdgeWeight = std::int32_t; using HeapData = std::pair<EdgeWeight, NodeID>; using HeapContainer = boost::heap::d_ary_heap< HeapData, boost::heap::arity<4>, boost::heap::mutable_<true>, boost::heap::compare<std::greater<HeapData>>>; using HandleType = HeapContainer::handle_type; int main() { HeapContainer heap; auto const handle = heap.push(std::make_pair(100, 1)); handle == HandleType{}; // _DEBUG_ERROR("list iterators incompatible"); return 0; } // ------------------------------------------------------------------ Is this a known MSVC drawback while working with boost::heap::d_ary_heap or above the handle_type is actually misused? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

1 0

Boost 1.65.0 Release Candidate 1
by Marshall Clow 09 Aug '17

09 Aug '17

The release candidates for the 1.65.0 release are now available at: https://dl.bintray.com/boostorg/release/1.65.0/source/ The SHA256 checksums are as follows: 0f1352a7738f24b39b564263b66a8c38bc7d984b57406396400474602e961ad3 boost_1_65_0_rc1.7z c2a022d4d6706668ea94b8e799a76e38929e0e34db884ef451fa9d5db6103238 boost_1_65_0_rc1.tar.bz2 7e84a27276792209d48357a0671348768dbf4dd1d4eadbf01b855274208f148d boost_1_65_0_rc1.tar.gz 537c42771b2351b4ea3eb8e9a13a3423edcd155323d2c14c4606cd23fc22d09f boost_1_65_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. Thanks! -- The release managers

4 5

[filesystem] Pull request needs attention
by Robert Dailey 09 Aug '17

09 Aug '17

I have fixed a crash I found due to static initialization ordering in boost filesystem. I have a proposed fix here: https://github.com/boostorg/filesystem/pull/47 It hasn't gotten any attention yet, so I'm hoping someone can offer some advice and/or merge the PR for me. Thanks in advance.

2 1

Problem building Boost 1.64.0 with Oracle Developer Studio 12.6
by Leo Carreon 09 Aug '17

09 Aug '17

Hi Boosters, I have been trying to build Boost 1.64.0 with Oracle Developer Studio 12.6 on Oracle Solaris 11.3 x86_64. There are two errors encountered during the build. They are: 1. Problem with Boost.Optional with this error messages: "libs/log/src/named_scope.cpp", line 118: Error: Use of overloaded binary operator '=' is ambiguous. "./boost/optional/optional.hpp", line 900: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. "./boost/optional/optional.hpp", line 962: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. 2. Problem with Boost.Python with this error message: "libs/python/src/numpy/dtype.cpp", line 61: Error: NPY_FLOAT16 is not defined. Note that these two errors are the cause of 9 Boost shared libraries to not be generated. I would appreciate it very much if someone could give me some pointers on how to resolve the above issues. Kind regards, Leo

1 0

Re: [Boost-users] [filesystem] Pull request needs attention
by Robert Dailey 08 Aug '17

08 Aug '17

On Tue, Aug 8, 2017 at 12:07 PM, Daniela Engert <dani(a)ngrt.de> wrote: > Am 08.08.2017 um 18:20 schrieb Robert Dailey via Boost-users: >> I have fixed a crash I found due to static initialization ordering in >> boost filesystem. I have a proposed fix here: >> https://github.com/boostorg/filesystem/pull/47 > > There is actually an even older (from april) pull request > https://github.com/boostorg/filesystem/pull/43 (by me) open on the very > same subject. > > Ciao > Dani Ah I didn't realize someone else had solved this problem. I will close mine in favor of yours. I don't quite understand why they're trying to share globals/statics between threads without some synchronization, but it's not my battle to deal with. I just want the code to work and not crash my application. Thanks for the reply.

1 0

make file starting out
by Peter Koukoulis 08 Aug '17

08 Aug '17

Hi I am new to setting up make files, and even newer to Boost. I've been using Geany on Ubuntu to learn Boost. When I compile and link using a single file with the following : g++ -g -Wall -std=c++14 -o "%e" "%f" -lboost_thread -DBOOST_THREAD_VERSION=5 -lboost_system -ldl then everything works as expected, for the following that is: #include <iostream> #include <boost/thread.hpp> #include <boost/thread/mutex.hpp> #include <boost/bind.hpp> #include <boost/asio.hpp> class t { private: boost::asio::io_service ios; std::unique_ptr<boost::asio::io_service::work> work_ios; boost::thread_group tg; int f; boost::mutex mx; public: // Constructor t( int p ) : work_ios{std::make_unique<boost::asio::io_service::work>(ios)}, f{p} { if(p>0) p = boost::thread::hardware_concurrency()*2; for ( int i = 0; i < p; ++i ) tg.create_thread( boost::bind( &boost::asio::io_service::run, &ios ) ); } // Destructor ~t () { work_ios.reset(); tg.join_all(); ios.stop(); } template <typename Job> void run_job( Job job ) { boost::unique_lock< boost::mutex > lock( mx ); if ( 0 == f ) return; --f; ios.dispatch( boost::bind( &t::wrap_job, this, boost::function< void() >(job) )); } private: void wrap_job( boost::function< void() > job ) { try { job(); } catch ( const std::exception& ) {} boost::unique_lock< boost::mutex > lock( mx ); ++f; } }; int main() { t tp{2}; tp.run_job( [] () { std::cout << "some work \n"; } ); return 0; } But when I attempt to split "t" into a .h and .cpp file with a separate file for main to test with, my linking does not work. The make output is: g++ test_t.o t.o -o test_t test_t.o: In function `__static_initialization_and_destruction_0(int, int)': test_t.cpp:(.text+0x6e9): undefined reference to `boost::system::generic_category()' test_t.cpp:(.text+0x6f5): undefined reference to `boost::system::generic_category()' The files look as follows: # the makefile: CC=g++ CFLAGS=-c -Wall -std=gnu++14 -lboost_system -lboost_thread -DBOOST_THREAD_VERSION=5 -ldl -lpq all: test_t test_t: t.o test_t.o $(CC) test_t.o t.o -o test_t t.o: t.cpp $(CC) $(CFLAGS) t.cpp test_t.o: test_t.cpp $(CC) $(CFLAGS) test_t.cpp clean: rm *o test_t.o test_t // .h file #ifndef T_H_ #define T_H_ #include <boost/thread.hpp> #include <boost/thread/mutex.hpp> #include <boost/bind.hpp> #include <boost/asio.hpp> class t { private: boost::asio::io_service ios; std::unique_ptr<boost::asio::io_service::work> work_ios; boost::thread_group tg; int f; boost::mutex mx; public: t( int p = 0 ); ~t(); template <typename Job> void run_job( Job job ) { boost::unique_lock< boost::mutex > lock( mx ); if ( 0 == f ) return; --f; ios.dispatch( boost::bind( &t::wrap_job, this, boost::function< void() >(job) )); } private: void wrap_job( boost::function< void() > job ) { try { job(); } catch ( const std::exception& ) {} boost::unique_lock< boost::mutex > lock( mx ); ++f; } }; #endif // .cpp file #include "t.h" // Constructor t::t( int p ) : work_ios{std::make_unique<boost::asio::io_service::work>(ios)}, f{p} { if(p>0) p = boost::thread::hardware_concurrency()*2; for ( int i = 0; i < p; ++i ) tg.create_thread( boost::bind( &boost::asio::io_service::run, &ios ) ); } // Destructor t::~t () { work_ios.reset(); tg.join_all(); ios.stop(); } // main file #include <iostream> #include "t.h" int main() { t tp{4}; tp.run_job( [] () { std::cout << "some work \n"; } ); return 0; } Could somebody point out how the make file should look like ? thanks pkl

4 3

boost::asio::async_read Error Operation canceled
by jupiter 07 Aug '17

07 Aug '17

Hi, I have a client program written by someone who is no longer available. The client program can send a message via async_write to server, but when the server responded back, the client boost::asio::async_read got an error of Operation cancelled. Searching from the Internet, it said the program was caused mostly by using this which should be fixed by using shared_from_this(). But in my client program it does not use this or shared_from_this, could someone explains if it uses some default format implies to this or shared_from_this in following example? (What (=) means, some kind of lambda function?) boost::asio::async_read(this->socket, boost::asio::buffer(this->messageHeader), [=](const boost::system::error_code &error, const uint32_t length) {this->readMessageHeader(error, length);}); Thank you. Kind regards.

1 0

Boost.Test change between 1.56 and 1.64
by Dominique Devienne 06 Aug '17

06 Aug '17

1.56 class BOOST_TEST_DECL test_tree_visitor { public: // test tree visitor interface virtual void visit( test_case const& ) {} virtual bool test_suite_start( test_suite const& ) { return true; } virtual void test_suite_finish( test_suite const& ) {} protected: BOOST_TEST_PROTECTED_VIRTUAL ~test_tree_visitor() {} }; 1.64 class BOOST_TEST_DECL test_tree_visitor { public: // test tree visitor interface virtual bool visit( test_unit const& ) { return true; } virtual void visit( test_case const& tc ) { visit( (test_unit const&)tc ); } virtual bool test_suite_start( test_suite const& ts ){ return visit( (test_unit const&)ts ); } virtual void test_suite_finish( test_suite const& ) {} protected: BOOST_TEST_PROTECTED_VIRTUAL ~test_tree_visitor() {} }; To list test suites and test cases of our test exes, I implemented a custom visitor in Boost 1.56 and simply did const auto& master_ts = but::framework::master_test_suite(); but::traverse_test_tree(master_ts, visitor); This is broken in 1.64, none of the old methods from the visitor are called, and thus no suites or cases are discovered. Two out of 3 of the old methods are forwards to the new visit() method, and obviously the implementation only calls the new visit(). The forwarding should be in the other direction for backward-compatibility. Looking for visit/visitor in http://www.boost.org/doc/libs/1_64_0/libs/test/doc/html/boost_test/change_l… yield nothing. Can someone please shed some light on this incompatible change? Thanks, --DD

2 2

Boost statechart
by Georg Gast 02 Aug '17

02 Aug '17

Hi, as the last changelog entry in statechart is from 1.46. Is it still maintained? Greetings Georg

1 0

[review][mp11] Review report
by Bjorn Reese 02 Aug '17

02 Aug '17

I. VERDICT Mp11 is accepted unconditionally into Boost. There were 14 accept votes and 1 conditional accept vote. See list at end of this report. II. DESIGN Reviewers evaluated the design as very good. Many agreed with the design principle of using template aliases on type lists, which means that Mp11 can be used on std, boost, and custom type lists. Integration with MPL was discussed. This resulted in a new header file <boost/mp11/mpl.hpp> that enables the conversion between mp_list (and std::tuple) and MPL sequences. A version of mp_eval_if that can apply a metafunction to type lists in both the true and false branch was requested. This is not possible due to C++ limitations (template parameter pack must be at the end.) Instead two alternatives were suggested: (1) use a nested mp_eval_if in the true branch, or (2) use mp_if<>::type with mp_defer in both branches. Extra metafunctions were added for working with map and sets: mp_is_set, mp_is_map, and mp_map_keys which returns a list of all keys. No review without a discussion about names. The mp_ prefix received most comments. The prefix is used to avoid collision between mp11 names and C++ keywords. The argument against the mp_ prefix was that MPL and other Boost libraries already have established trailing underscore as the naming convention. The argument in favor is that the mp_ prefix is better suited for later C++ standardization. Other names that deviate from MPL, such as apply versus fn, were also pointed out, and the names of tuple operations were also discussed. III. IMPLEMENTATION The reviewers who looked at the implementation were generally pleased with its quality and simplicity. A faster version of mp_find was proposed during review. On reviewer pointed out that const lists causes obscure compilation errors. IV. DOCUMENTATION The evaluation of the documentation was more mixed. Some found it good, while others found it too terse. A recurring comment was that the documentation is missing beginner-level explanations and examples. For instance, the tuple_cat example was mentioned as being too advanced for an introduction. More examples with higher-order metafunctions (e.g. mp_bind) was requested. The reference documentation does not state the pre-conditions of the metafunctions. For example, what happens when indices are out of bounds? The description of map (list of lists) lead to confusion. Mp11 map entries have one unique key-type, and zero or more value-types. The ability to have multiple value-types per key-type makes it possible to emulate multi-maps. Some where unsure whether C++11 or C++14 was required for the library. There were plenty of other useful comments that I will omit from the review report for the sake of brevity. V. USEFULNESS The library was generally deemed useful. It was discussed if C++11 (and later) makes it too easy to write our own metaprogramming utilities, and thus not needing a metaprogramming library. This was not directed at Mp11 in particular. Some of the arguments in favor of a metaprogramming library were better performance and portability. I would like to add another advantage of a metaprogramming library, namely that it gives us a common vocabulary. VI. CONCLUSION The library fulfills the quality and usefulness criteria without major outstanding issues. The library is therefore cleared to be included into Boost. My main recommendation as review manager is to make the documentation more beginner-friendly before the library is added to Boost. This is a recommendation, not a requirement. VII. PARTICIPANTS The following formal reviews were posted: * Barrett Adair : Accept * Brook Milligan : Accept * Edward Diener : Accept * Glen Fernandes : Accept * Jason Rice : Accept * Joaquin M López Muñoz : Conditional accept * John P Fletcher : Accept * Lee Clagett : Accept * Paul Fultz : Accept * Peter Koch Larsen : Accept * Robert Ramey : Accept * Roberto Hinz : Accept * Vijayan : Accept * Vinnie Falco : Accept * Zach Laine : Accept I would like to thank all participants for their efforts. I would also like to thank Peter Dimov for bringing such a high-quality library to Boost.

2 1

boost-users@lists.boost.org
by phillip mobley 02 Aug '17

02 Aug '17

Hello all, I am a new user to boost. I am currently using the serialization library to save my data structures to a file. However, I am currently running into a few issues. At first, I was getting a lot of undefined errors. After reading on multiple forums, I realized that I forgot to link the serialization library to the project. Once done, all of the errors went away. Except for one. I am getting this error: /usr/local/boost_1_64_0/boost/serialization/throw_exception.hpp:36: undefined reference to `boost::archive::archive_exception::archive_exception(boost::archive::archive_exception const&)' I have been spinng my head around this for a few days. Did I forget to add in another referene somewhere? My code is setup in the same manner as the simple tutorial found on the boost::serialization page. This error only pops up when I have the line: boost::archive::text_oarchive oa(ofs); When I have this line commented out, I do not get the above error. Again, I am wondering if I forgot to reference something in my program but I am not sure. Any help will be greatly appreciated. <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

1 0

Which socket read get first when both asio::async_read and asio::read are active?
by jupiter 02 Aug '17

02 Aug '17

Hi, I have a socket server program to activate in asio::async_read for receive any messages initiated from client. But when the server sends a message to the client, it uses sync write and flowing a sync read (asio::read) to immediately receive the response. The issue I can think of is who will get first read when both asio::async_read and asio::read are active? Thank you. Kind regards.

2 2

Boost.Fusion macro expansion
by Robert Jones 01 Aug '17

01 Aug '17

Hi Peeps Can anyone tell me what's wrong with this? I think macro expansion is going awry, but I'm not sure why. Do I really have to typedef the map<...> type to keep Fusion happy? Thx. #include<string> #include<map> #include <boost/fusion/adapted/struct/define_struct.hpp> #include <boost/fusion/include/define_struct.hpp> BOOST_FUSION_DEFINE_STRUCT( (demo), curves, ((std::map<std::string, std::string>), futures) ((std::map<std::string, std::string>), credit_curves) ) int main( ) { return 0; } > make fusion.cpp|9 col 39| error: invalid declarator before ‘)’ token || ((std::map<std::string, std::string>), futures) Kind Regards Rob.

3 3

Ranges
by Robert Jones 29 Jul '17

29 Jul '17

I realise this isn't strictly about Boost, but I'd appreciate if someone could say a few words about the current state of ranges in the standard, Boost or elsewhere. I'm familiar with the current Boost.Range, but thought there was a newer and rather different range library from Eric Neibler which was Boost compatible but not formally part of Boost, is that right? Are either of these part of the C++ standard, either now or planned, or is there anything else planned for the standard? Thx. Kind Regards Rob.

2 1

[filesystem] Strange "Function not implemented" exception from directory_iterator
by Robert Dailey 28 Jul '17

28 Jul '17

I'm using a recursive_directory_iterator on an Android ARM device (armeabi-v7a, clang compiler, API 15, LLVM STL). The exception I get comes from directory_iterator_increment in operations.cpp (when it does the dir_itr_increment() call and checks the `temp_ec` variable, there is a throw below that). The what() of the exception says: boost::filesystem::directory_iterator::operator++: Function not implemented: "/data/ziosk/content/Common/DemoMode/font" I doubt this is a permissions issue. Which function is not implemented? Is this a POSIX / LIBC issue? I have no idea at this point...

2 4

Boost.ProgramOptions issues porting from 1.56 to 1.64
by Dominique Devienne 28 Jul '17

28 Jul '17

I have an SVN-like "multi-command" single executable, i.e. exe [global-options] command [command-options] It uses two levels of option parsing. First level: typedef std::vector<std::string> UnparsedArgs; inline boost::program_options::typed_value<UnparsedArgs>* anyArgs() { return boost::program_options::value<UnparsedArgs>(); } options_description global_all_desc("Global Options", columns); global_all_desc.add_options() ("command", txtArg(), "Command to execute") ("cmdargs", anyArgs(), "Arguments for command") ...; // from http://stackoverflow.com/questions/15541498 // see also https://gist.github.com/randomphrase/10801888 po::positional_options_description pos; pos .add("command", 1) .add("cmdargs", -1); variables_map global_args; parsed_options parsed = po::command_line_parser(argc, argv) .options(global_all_desc) .positional(pos) // for implicit command and cmdargs above .allow_unregistered() // for command-specific arguments. .run(); po::store(parsed, global_args); std::vector<std::string> cmd_args = po::collect_unrecognized( parsed.options, po::include_positional ); Second level parsed_options reparsed = po::command_line_parser(cmd_args) .options(cmd_all_desc) .run(); po::store(reparsed, args_); // JIRA FOO-426 for (const auto& option : reparsed.options) { if (option.position_key >= 0) { std::ostringstream oss; for (const auto& token : option.original_tokens) { oss << token << ' '; } auto s = oss.str(); s.resize(s.size() - 1); err() << "Error: Too many commands: " << command() << ' ' << s << endl; return 1; } } in this particular case, the option that fails is ( "new", txtArgOpt(), "Creates a new group" ), with txtArgOpt() as below: inline boost::program_options::typed_value<std::string>* txtArg() { return boost::program_options::value<std::string>(); } inline boost::program_options::typed_value<std::string>* txtArgOpt(const std::string& implicit_value = "") { return txtArg()->implicit_value(implicit_value); } in the case that fails, the first parsing works fine, and remains ["--new", "groupA"] as cmd_args. in 1.56, reparsed.options contains 1 element: - [0] {string_key="new" position_key=-1 value={ size=1 } ...} boost::program_options::basic_option<char> + string_key "new" std::basic_string<char,std::char_traits<char>,std::allocator<char> > position_key -1 int - value { size=1 } std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > [size] 1 __int64 [capacity] 1 __int64 + [0] "GroupA" std::basic_string<char,std::char_traits<char>,std::allocator<char> > + [Raw View] 0x0000000009fae6c0 {...} std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > * - original_tokens { size=2 } std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > [size] 2 __int64 [capacity] 2 __int64 + [0] "--new" std::basic_string<char,std::char_traits<char>,std::allocator<char> > + [1] "GroupA" std::basic_string<char,std::char_traits<char>,std::allocator<char> > + [Raw View] 0x0000000009fae6e0 {...} std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > * unregistered false bool case_insensitive false bool but in 1.64, it contains 2 elements: - [0] {string_key="new" position_key=-1 value={ size=0 } ...} boost::program_options::basic_option<char> + string_key "new" std::basic_string<char,std::char_traits<char>,std::allocator<char> > position_key -1 int - value { size=0 } std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > [capacity] 0 __int64 + [allocator] allocator std::_Compressed_pair<std::_Wrap_alloc<std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >,std::_Vector_val<std::_Simple_types<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >,1> + [Raw View] {...} std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > - original_tokens { size=1 } std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > [capacity] 1 __int64 + [allocator] allocator std::_Compressed_pair<std::_Wrap_alloc<std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >,std::_Vector_val<std::_Simple_types<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >,1> + [0] "--new" std::basic_string<char,std::char_traits<char>,std::allocator<char> > + [Raw View] {...} std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > unregistered false bool case_insensitive false bool - [1] {string_key="" position_key=0 value={ size=1 } ...} boost::program_options::basic_option<char> + string_key "" std::basic_string<char,std::char_traits<char>,std::allocator<char> > position_key 0 int - value { size=1 } std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > [capacity] 1 __int64 + [allocator] allocator std::_Compressed_pair<std::_Wrap_alloc<std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >,std::_Vector_val<std::_Simple_types<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >,1> + [0] "GroupA" std::basic_string<char,std::char_traits<char>,std::allocator<char> > + [Raw View] {...} std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > - original_tokens { size=1 } std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > [capacity] 1 __int64 + [allocator] allocator std::_Compressed_pair<std::_Wrap_alloc<std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >,std::_Vector_val<std::_Simple_types<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > >,1> + [0] "GroupA" std::basic_string<char,std::char_traits<char>,std::allocator<char> > + [Raw View] {...} std::vector<std::basic_string<char,std::char_traits<char>,std::allocator<char> >,std::allocator<std::basic_string<char,std::char_traits<char>,std::allocator<char> > > > unregistered false bool case_insensitive false bool This is copy/pasted from VS, sorry, a little hard to read, but basically 1.56 has #0 string_key = "new" position_key = -1 value = ["groupA"] original_tokens = ["--new", "groupA"] unregistered = false case_insensitive = false while 1.64 has 2 items: #0 string_key = "new" position_key = -1 value = [] original_tokens = ["--new"] unregistered = false case_insensitive = false #1 string_key = "" position_key = 0 value = ["groupA"] original_tokens = ["groupA"] unregistered = false case_insensitive = false as-if the arg to --new was now a positional parameter, instead of an optional arg to --new. And this triggers the work-around code that errors out I had put in place to catch cases when the old 1.56 code wouldn't complain about extra arguments (e.g. "exe ... cmd1 cmd1_args cmd2" would be silently accepted, despite the extra cmd2, or "exe ... cmd --arg1 read-only" was accepted, when "exe ... cmd --arg1 --read-only" was expected), and this even though the second parsing doesn't have .allow_unregistered(). I'm trying to understand what's going on; obviously there's some kind of semantic change with optional argument to switches. Could anyone shed some light on this please? I'm not sure how to proceed now. TIA, -DD

2 4

error: 'function' in namespace 'boost' does not name a template type
by jupiter 28 Jul '17

28 Jul '17

Hi, Cannot I define a following boost function? Any workarounds? typedef boost::function<bool (const uint32_t, const std::shared_ptr<boost::asio::streambuf> &)> Subscriber_t; Thank you. Kind regards,

2 2

using ssl::context in boost 1.53 versions
by dipti Burli 27 Jul '17

27 Jul '17

Hi , I am currently using boost 1.53 version. cannot upgrade to latest version. Using ssl asio. Here is my requirement. I need to support tls1.1.and tls1.2 protocol in the server, but not tls1.0 . As there are no options for tls1.1. and tls1.2 ,and context is not present with relevant tls1.1 and tls1.2 versions, I created the ssl::context with tlsv1 method and used long ssl_disallowed = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | SSL_OP_NO_TLSv1 | SSL_OP_NO_TLSv1_1 | SSL_OP_NO_TLSv1_2; ssl_disallowed &= ~SSL_OP_NO_TLSv1_2; ssl_disallowed &= ~SSL_OP_NO_TLSv1_1; SSL_CTX_set_options(myBoostSslcontext.native_handle(), ssl_disallowed|SSL_OP_SINGLE_DH_USE); But handshake seems to be failing for any other versions other than tlsv1. Can you please let me know how to I set the options so that my sserver can accept tls connections on tls1.1 and tls1.2 with boost version 1.53. Thanks in advance. Dipti

1 0

[mpl] [msm] wrong number of template arguments (120, should be at least 0)
by Alessandro Marzialetti 27 Jul '17

27 Jul '17

Hello, I'm working on a msm with a big transition table (120 elements) I already tried with #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS then #define BOOST_MPL_LIMIT_LIST_SIZE <custom value> But I can't go over a size of 50 (including "boost/mpl/vector/vector50.hpp") Any idea on how I can make a bigger table? Thanks, Alessandro <http://www.boost.org/doc/libs/1_63_0/libs/mpl/doc/refmanual/cfg-no-preproce…>

3 2

[Boost Graph Dijkstra Shortest Path]: Could not deduce template argument
by Choppin, Simon 26 Jul '17

26 Jul '17

Hello all, I use boost graph library for some point cloud processing and have had great success. However, I'm struggling to compile Dijkstra shorted path on MSVC v140. I am using boost library 1.53 and compiling in 64 bit. I used the example as a starting point but when I try to compile I get the error: Error C2784 'E boost::detail::get(boost::detail::underlying_edge_desc_map_type<E>,const boost::detail::reverse_graph_edge_descriptor<EdgeDesc> &)': could not deduce template argument for 'boost::detail::underlying_edge_desc_map_type<E>' from 'double *' I understand the fundamental problem that the template can't deduce type, however I'm struggling to source the problem. My graph type is: typedef adjacency_list < vecS, vecS, undirectedS, no_property, property <edge_weight_t, double> > WeightedGraph; Because I'm using MSVC I use the suggested non parameter name version: property_map<WeightedGraph, vertex_index_t>::type indexmap = get(vertex_index, GraphW); property_map<WeightedGraph, edge_weight_t>::type weightmap; std::vector<Vertex> p(num_vertices(GraphW)); std::vector<double> d(num_vertices(GraphW)); Vertex s = vertex(indices.first, GraphW); Vertex s_end = vertex(indices.second, GraphW); dijkstra_shortest_paths (GraphW, s, &p[0], &d[0], weightmap, indexmap, std::less<double>(), closed_plus<double>(), (double)(std::numeric_limits<double>::max)(), (double)0, Custom_visitor(s_end) ); I'm using a custom visitor to stop processing early as in this stackoverflow post: https://stackoverflow.com/questions/32047840/make-boost-dijkstra-algorithm-… Any ideas? All help greatly appreciated. Simon C

1 0

how to generate PDF formate documentations of Boost?
by easior 23 Jul '17

23 Jul '17

Hi, all in the list. I plan to build boost documentation in pdf format for latest version of boost. However, it's no luck to me even following the link: http://www.boost.org/doc/libs/1_40_0/doc/html/boostbook/getting/started.html. I can only find HTML formatted documentation for boost. I don't know what about the relationship between boost and doxygen. I also have no idea about the mechanism of the boostbook. Any suggection? Thanks in advance, Easior Lars

4 4

Boost Regex - Alternation documentation example
by Nick 21 Jul '17

21 Jul '17

According to the Boost Regex documentation for Alternation (http://www.boost.org/doc/libs/1_64_0/libs/regex/doc/html/boost_regex/syntax…) Quoting a piece of the documentation: ----- |abc is not a valid expression, but (?:)|abc is and is equivalent, also the expression: (?:abc)?? has exactly the same effect. ----- Is the last expression: (?:abc)?? correct? Why does it need two '?' operators instead of only one? If I try this expression with the input "abc" the Boost engine does not match "abc" as I'd have expected. However the expression: (?:abc)? matches as expected. Nick

2 2

MS controlled email domains - not going to work
by Michael Caisse 20 Jul '17

20 Jul '17

The irony in sending this message is that the people who need to see it probably wont get it. We are having trouble with hotmail.com, live.com, msn.com, and outlook.com. Microsoft is filtering the dedicated IP address used by the mail lists and most recently has responded with: Not qualified for mitigation [ip address] Our investigation has determined that the above IP(s) do not qualify for mitigation. These IP(s) have previously received mitigations from deliverability support, and have failed to maintain patterns within our guidelines, so they are ineligible for additional mitigation at this time. We have tried to explain multiple times that the IP address has a new owner but we seem to be stuck in almost an auto-response loop. We will continue to try and get service unblocked; however, I would recommend that you dump your MS controlled accounts for Boost mail lists and use another service. michael -- Michael Caisse Ciere Consulting ciere.com

2 1

[review][beast] Beast Review Results
by Michael Caisse 20 Jul '17

20 Jul '17

In an effort to get you all to just read this announcement sequentially, I will start with the result: Beast is ACCEPTED into Boost without conditions The entire community is served when the Boost review process works well and I would like to personally thank each of you who took your valuable time and worked to make Boost better. We had 21 formal reviews submitted from a demographic that included both seasoned participants and first-time reviewers. It is gratifying to have such participation for what some might see as a niche library. * Thank you Vinnie for your effort to assemble a high-quality package for review and for your responsiveness on the mail-lists. GitHub, and Slack. * Thank you to the individuals that submitted their first Boost review. * Thank you to the veteran contributors and authors for continuing to devote energy to the community. I found the discussion surrounding the library beneficial and I know that Vinnie walked away with actionable items to improve Beast. -------------------- The Stats: -------------------- While the review process is not exactly tallying up votes and casting a verdict, we can gain some insight of the general, gross-scale opinion of the library. Official reviews were received from: Reviewer Accept | Reject ------------------------------------------ * Zach Laine : X * Nik Bougalis : X * Artyom Beilis : X * Peter Dimov : X * Klemens Morgenstern : X * Glen Fernades : X * Marcel Ebmer : X * Scott Determan : X * Stanislav Karchebnyy : X * Michael Larson : X * Vadim Zeitlin : X * Jared Wyles : X * Niall Douglas : X * Barrett Adair : X * Gyorgy Szekely : X * Daniela Engert : X * Jens Weller : X * Phil Endecott : X * Bjorn Reese : X * Rüdiger Berlich : X * Christopher Kohlhoff : X Most of the reviewers agreed on the inclusion of Beast into Boost and at the same time that Beast isn't a great name for the library. (Just say Boost.Beast 10-times-fast). Vinnie has a FAQ item discussing the name and his continuing use is deliberate. He has heard the petitions to change and weighed them. -------------------- Concerns: -------------------- A variety of concerns and comments were made during the review. An impressive number of items were addressed in code or documentation during the review period itself. Some of the stated concern for rejection included: * Too many templates * Run-time polymorphism / OO would be better. * Library scope is too small and provides no real value to users - This is clearly one of those value judgements and for some users the not-in-scope nature of Beast made the feature set not compelling enough to use or have as a Boost library. Other users spent time converting existing projects to use Beast. This included projects previously running POCO, libcurl, and homegrown solutions. Beast has existing commercial and open-source users. The library clearly meets the needs of some users. * Premature optimization * Security concerns * Poor support for HTTP chunking - Vinnie proposed and then later made changes addressing the chunking concerns. Unfortunately, the reviewer with the complaint did not respond to multiple requests for feedback. * Licensing - Four files have dual licenses (BSL and another). Boost's legal counsel is reviewing the situation and we hope to have guidance by the end of this week. I have not placed a condition on the acceptance of Beast based on the legal feedback because Vinnie knows licensing issues must be remedied before the repository is merged into Boost. -------------------- The Upsides: -------------------- There were lots of great things said about the Beast package. Some of these include: * Great documentation * High quality implementation. * Thorough test suites * Already being used by commercial entities and others * Lots of successful real-life conversions of existing clients/servers * Extremely responsive developer (do you sleep Vinnie?) -------------------- An Author as much as a Library: -------------------- Accepting a library into Boost is also accepting an author. Boost authors have enormous latitude in the control and modifications of their libraries. Vinnie has shown dedication to addressing issues, listening to constructive input, making changes when appropriate, and protecting his vision of what the Beast is. I believe Vinnie will serve the community well as a contributor. -------------------- Final Thoughts: -------------------- Reviews are hard. It is hard to have your work torn apart and remain considerate. It is hard to repeat answers to previously asked questions. It is hard to explain specific use-cases and why it is important a library supports them. It is difficult to critique a large body of work. It is hard to stick with conversations to make overall improvements. I was impressed with the participants in the review. We are all opinionated and passionate -- likely a prerequisite to being part of the Boost community. Thank you all for making Boost better. I'm looking forward to seeing additional libraries and application built with Beast. -- Michael Caisse Ciere Consulting ciere.com

2 2

Re: [Boost-users] CMake Announcement from Boost Steering Committee
by Oliver Kowalke 20 Jul '17

20 Jul '17

I'm one of the maintainers of the CMake Boost support ( https://gitlab.kitware.com/cmake/cmake/blob/master/Modules/FindBoost.cmake Roger, can Cmake be used for boost.context? Especially this library required to know the architecture, ABI, binary format, address model ... in order to select the right assembler?

3 3

Boost 1.65.0 Beta 1 Release Candidate 2
by Marshall Clow 19 Jul '17

19 Jul '17

The second release candidates for the 1.65.0 beta release are now available at: https://dl.bintray.com/boostorg/beta/1.65.0.beta.1/source/boost_1_65_0_beta… https://dl.bintray.com/boostorg/beta/1.65.0.beta.1/source/boost_1_65_0_beta… https://dl.bintray.com/boostorg/beta/1.65.0.beta.1/source/boost_1_65_0_beta… https://dl.bintray.com/boostorg/beta/1.65.0.beta.1/source/boost_1_65_0_beta… The SHA256 checksums are as follows: d54d29568c4e4933cbfe40a292b6cb84a7f68121e34f6a83f7d0f7c652b6b2d8 boost_1_65_0_beta1_rc2.7z 092676557513e992347d30dd0cd058fb8af2a401e5da4f4413f5b577852d726b boost_1_65_0_beta1_rc2.tar.bz2 31fa3c807e2205e18f7d5c74f77f540677f7b0937af1e37f595c137e1e87bf84 boost_1_65_0_beta1_rc2.tar.gz 83c8d8b76fa9591572226a1a49fd191d76db3011b52b907cbbc8d37d46213bd2 boost_1_65_0_beta1_rc2.zip This RC contains a single fix to the stacktrace library. 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. Thanks! -- The release managers

7 10

CMake Announcement from Boost Steering Committee
by Jon Kalb 18 Jul '17

18 Jul '17

The libraries produced by the Boost community have had a greater impact on the way that the C++ community writes code than any other library implementation. The focus of the Boost community will always be on the libraries, but it is undeniable that we are dependent on and often limited by the infrastructure of our trade. Years ago, the move to Git was contentious; yet, it was required to improve development. In a similar vein our build system has become an impediment for many developers and users, existing and prospective. Therefore, we, the Steering Committee, announce to the Boost community our desire and intent to move Boost’s build system to CMake for users and developers alike. We are soliciting comments and proposals from the community to guide the process and the goals. Our desire is that the community can come to consensus by the end of the calendar year with a vision of supporting users and developers. We understand that the actual process of achieving the end goal will be long, time consuming, and not without its share of conflict. We also recognize that the Boost community is comprised of bright and passionate individuals that are eager to get involved and help get work done. The members of the Steering Committee have been encouraged by the discussions and activity surrounding CMake on the mailing lists over the years and know that many people have voiced visions. We hope that each of you rejoins the discussion to support this initiative and contributes to the common goal of improving Boost’s integration into the broader C++ ecosystem. For the Boost Steering Committee, Jon Kalb, Chair jonkalb(a)boost.org

8 7

Re: [Boost-users] CMake Announcement from Boost Steering Committee
by Oliver Kowalke 18 Jul '17

18 Jul '17

Cmake file for boost.context is missing support for segmented stack (split-stack), valgrind ...? Is the Cmake port is not complete?

1 0

Boost 1.65.0 Beta 1
by Marshall Clow 16 Jul '17

16 Jul '17

Boost release 1.65.0 beta 1 is now available at: <https://dl.bintray.com/boostorg/beta/1.65.0.beta.1/source/> The SHA256 checksums are as follows: d54d29568c4e4933cbfe40a292b6cb84a7f68121e34f6a83f7d0f7c652b6b2d8 boost_1_65_0_beta1.7z 092676557513e992347d30dd0cd058fb8af2a401e5da4f4413f5b577852d726b boost_1_65_0_beta1.tar.bz2 31fa3c807e2205e18f7d5c74f77f540677f7b0937af1e37f595c137e1e87bf84 boost_1_65_0_beta1.tar.gz 83c8d8b76fa9591572226a1a49fd191d76db3011b52b907cbbc8d37d46213bd2 boost_1_65_0_beta1.zip Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

5 5

Boost Regex Back Reference Issue
by Nick 14 Jul '17

14 Jul '17

According to the Boost documentation for Back references (http://www.boost.org/doc/libs/1_64_0/libs/regex/doc/html/boost_regex/syntax…) which seems to be the same at least from 1.37 - 1.64. Quoting a piece of the documentation: ----- For example the expression: ^(a*).*\1$ Will match the string: aaabbaaa But not the string: aaabba ----- I'm finding two issues with the example cited. 1. It seems to me that the example of the string which should not match, should actually match. Ultimately, shouldn't the engine match the marked sub-expression with the first 'a' in order to satisfy the backreference? I tested this example with Oniguruma and with PHP's PCRE and they both matched the string noted here to not match. But also, since the marked sub-expression is (a*) then I wonder what the behavior would be if it couldn't make a match on 'a', since the '*' will allow for zero matches. In fact, it seems like everything in the pattern is effectively "optional" due to the '*' operator. I'm a novice with Perl, but unless I made a mistake, it will match unconditionally: print "It matches\n" if "aaabba" =~ /^(a*).*\1$/; It matches print "It matches\n" if "aaabbac" =~ /^(a*).*\1$/; It matches print "It matches\n" if "" =~ /^(a*).*\1$/; It matches print "It matches\n" if "x" =~ /^(a*).*\1$/; It matches print "It matches\n" if "xyz" =~ /^(a*).*\1$/; It matches print "It matches\n" if "123" =~ /^(a*).*\1$/; It matches 2. The other issue is that when I try this example with the string which is posted to not match, the Boost regex engine runs for a while and ultimately crashes with a memory error. (seems like it might be an endless loop of some sort). Is that a bug? Nick

3 4

boost::unordered_map takes too long when I have only two elements in it
by Ram 14 Jul '17

14 Jul '17

Hi, I am using a boost::unordered_set but I sometimes have just two elements in it. It takes a long time then. Is it wrong if I have too few elements? Thanks, Ram

3 3

rational - 1.64 version shear?
by Nicholas Devenish 14 Jul '17

14 Jul '17

With boost/rational.hpp, the code: boost::rational<int> a{1}; long b{1}; auto c{a * b}; Works fine up to 1.63.0, but fails to compile in 1.64+ on the multiplication with "error: invalid operands to binary expression". This seems to be due to some restructuring that changed the way multiplications are declared, which (as far as I can tell), meant the operation declaration became conditional on number of representable digits. This breaking change isn't listed on the release notes or the ::rational documentation, so I'm wondering if it was accidental and therefore a bug (whose behaviour might change), or a deliberate change to prevent downcasting and just undocumented? Nick (I've come onto a project stuck on 1.56 and trying to update it)

2 1

⁨[process] problem with boost::process::on_exit
by Sandy Martel 14 Jul '17

14 Jul '17

The code below outputs: 1- child about to sleep for 2s 2- child about to sleep for 4s 3- child finish sleeping for 2s 6- sleep 4s child finished 5- child finish sleeping for 4s 4- sleep 2s child finished in a posix environment. I would expect the output to be in-order, looks like I get the wrong on_exit notification for the child processes I launch. Q: is this a bug or am I doing something wrong ? What is the correct way to get notified of specific process termination ? Regards, Sandy. code: #include <boost/process.hpp> #include <boost/asio.hpp> #include <thread> #include <iostream> int main( int argc, char **argv ) { if ( argc > 2 && strcmp( argv[1], "sleep" ) == 0 ) { auto s = atoi(argv[2]); std::cout << (s/2) << "- child about to sleep for " << s << "s" << std::endl; std::this_thread::sleep_for( std::chrono::seconds(s) ); std::cout << (s+1) << "- child finish sleeping for " << s << "s" << std::endl; return 0; } namespace bp = boost::process; boost::asio::io_service ios; // launch a child that will sleep for 2s auto c1 = bp::child( argv[0], "sleep", "2", ios, bp::on_exit( [](int, const std::error_code&) { std::cout << "4- sleep 2s child finished" << std::endl; }) ); // wait a bit, make sure the child startup for my test std::this_thread::sleep_for( std::chrono::milliseconds(10) ); // launch a child that will sleep for 4s auto c2 = bp::child( argv[0], "sleep", "4", ios, bp::on_exit( [](int, const std::error_code&) { std::cout << "6- sleep 4s child finished" << std::endl; }) ); // wait for the notifications ios.run(); }

1 0

[serialization] "Archive" type turns into abstract class during save/load!
by r＠primef.actor 13 Jul '17

13 Jul '17

In a member load function function I call a static method that loads another archive file, i.e. something like this: ```c++ struct Bar; struct Foo { std::shared_ptr<Bar> data; template <class Archive> void load(Archive& archive, const unsigned /*version*/) { std::string key; archive >> key; data = Bar::loadSomewhere<Archive>(std::move(key)); } }; struct Bar { template <class Archive> std::shared_ptr<Bar> loadSomewhere(std::string key) { std::ifstream input(key); Archive ar(input); std::shared_ptr<Bar> bar(new Bar()); ar >> *bar; return bar; } }; ``` The problem is that `Bar::loadSomewhere` is passed a `boost::archive::polymorphic_iarchive`, while I invoke the serialization library with a `boost::archive::xml_iarchive`. This is an abstract class, so I can't instantiate it! So somewhere down the road the `xml_iarchive` is turned into a `polymorphic_iarchive`. I would like to prevent this from happening, because I instantiate an `Archive` object in the `Bar::loadSomewhere` function. How can I get around this problem?

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Re: [Boost-users] Boost 1.65.0 Beta 1 Release Candidate 2
by Matthieu Brucher 11 Jul '17

11 Jul '17

This happens a lot when people develop on gcc or visual studio and then try building with clang. Having a function and a class with the same name is bound to generate errors. So properly should be tagged as a bug. Le 11 juil. 2017 11:14 AM, "Raffi Enficiaud via Boost-users" < boost-users(a)lists.boost.org> a écrit : Le 11.07.17 à 02:14, Marshall Clow via Boost-users a écrit : The second release candidates for the 1.65.0 beta release are now > available at: > > > https://dl.bintray.com/boostorg/beta/1.65.0.beta.1/source/ > boost_1_65_0_beta1_rc2.7z > > https://dl.bintray.com/boostorg/beta/1.65.0.beta.1/source/ > boost_1_65_0_beta1_rc2.tar.bz2 > > https://dl.bintray.com/boostorg/beta/1.65.0.beta.1/source/ > boost_1_65_0_beta1_rc2.tar.gz > > https://dl.bintray.com/boostorg/beta/1.65.0.beta.1/source/ > boost_1_65_0_beta1_rc2.zip > > The SHA256 checksums are as follows: > > d54d29568c4e4933cbfe40a292b6cb84a7f68121e34f6a83f7d0f7c652b6b2d8 > boost_1_65_0_beta1_rc2.7z > 092676557513e992347d30dd0cd058fb8af2a401e5da4f4413f5b577852d726b > boost_1_65_0_beta1_rc2.tar.bz2 > 31fa3c807e2205e18f7d5c74f77f540677f7b0937af1e37f595c137e1e87bf84 > boost_1_65_0_beta1_rc2.tar.gz > 83c8d8b76fa9591572226a1a49fd191d76db3011b52b907cbbc8d37d46213bd2 > boost_1_65_0_beta1_rc2.zip > > > This RC contains a single fix to the stacktrace library. > > 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. > > Thanks! > > -- The release managers > Hi, I have this error during the build on OSX. Built with: ./b2 cxxflags="-std=c++11 -stdlib=libc++" linkflags="-stdlib=libc++" --without-log --layout=versioned install ...on 14200th target... common.mkdir bin.v2/libs/fiber/build/darwin-4.2.1/release/threading-multi common.mkdir bin.v2/libs/fiber/build/darwin-4.2.1/release/threading- multi/numa darwin.compile.c++ bin.v2/libs/fiber/build/darwin-4.2.1/release/threading- multi/numa/pin_thread.o libs/fiber/src/numa/pin_thread.cpp:23:10: warning: pin_thread() not supported [-W#pragma-messages] # pragma message "pin_thread() not supported" ^ 1 warning generated. darwin.compile.c++ bin.v2/libs/fiber/build/darwin-4.2.1/release/threading- multi/numa/topology.o libs/fiber/src/numa/topology.cpp:23:10: warning: topology() not supported [-W#pragma-messages] # pragma message "topology() not supported" ^ libs/fiber/src/numa/topology.cpp:27:14: error: use of undeclared identifier 'topology'; did you mean 'fibers::numa::topology'? std::vector< topology > topology() { ^~~~~~~~ fibers::numa::topology ./boost/fiber/numa/topology.hpp:38:21: note: 'fibers::numa::topology' declared here std::vector< node > topology(); ^ libs/fiber/src/numa/topology.cpp:27:14: error: template argument for template type parameter must be a type std::vector< topology > topology() { ^~~~~~~~ /Applications/Xcode8.1.app/Contents/Developer/Toolchains/Xco deDefault.xctoolchain/usr/bin/../include/c++/v1/vector:456:17: note: template parameter is declared here template <class _Tp, class _Allocator = allocator<_Tp> > ^ 1 warning and 2 errors generated. "g++" -ftemplate-depth-128 -O3 -Wall -dynamic -gdwarf-2 -fexceptions -Wno-inline -fPIC -arch x86_64 -std=c++11 -stdlib=libc++ -DBOOST_ALL_NO_LIB=1 -DBOOST_CONTEXT_DYN_LINK=1 -DBOOST_DISABLE_ASSERTS -DBOOST_FIBERS_DYN_LINK=1 -DBOOST_FIBERS_SOURCE -DBOOST_FILESYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_DYN_LINK=1 -DNDEBUG -I"." -c -o "bin.v2/libs/fiber/build/darwin-4.2.1/release/threading-multi/numa/topology.o" "libs/fiber/src/numa/topology.cpp" ...failed darwin.compile.c++ bin.v2/libs/fiber/build/darwin -4.2.1/release/threading-multi/numa/topology.o... _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org https://lists.boost.org/mailman/listinfo.cgi/boost-users

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Boost 1.65.0 Beta 1 Release Candidate 1
by Marshall Clow 09 Jul '17

09 Jul '17

The release candidates for the 1.61.0 release are now available at: https://dl.bintray.com/boostorg/beta/boost_1_65_0_beta1_rc1.7z https://dl.bintray.com/boostorg/beta/boost_1_65_0_beta1_rc1.tar.bz2 https://dl.bintray.com/boostorg/beta/boost_1_65_0_beta1_rc1.tar.gz https://dl.bintray.com/boostorg/beta/boost_1_65_0_beta1_rc1.zip The SHA256 checksums are as follows: cd7429340bb4aae38e0ad2e9f59c39e66335302c41577956123e55fc1e2a28ee boost_1_65_0_beta1_rc1.7z fda076f7b3c994524d9cd41926c72f4a9b7c017bef310a055956fdd0bed7c358 boost_1_65_0_beta1_rc1.tar.bz2 0d1473041f7a9fa9ce1e256c870cc52af6f98abf723cf4f1ac61c2b45f45d38a boost_1_65_0_beta1_rc1.tar.gz f45bbb75b84cdc0c66f8a571d77c518cfbac076d7a6fc7937c4812f0f242a792 boost_1_65_0_beta1_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. Thanks! -- The release managers

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building for msvc-14.1
by Isaac Lascasas 09 Jul '17

09 Jul '17

Hello I have serious problems building boost for vs2017. My win10 install has just visual studio community 2017 installed right now, with windows SDK 10.0.15063.0 and 8.1. I run the vs2017 x64 native prompt and then I do something like this: b2 -j12 toolset=msvc-14.1 address-model=64 architecture=x86 link=static threading=multi runtime-link=shared --build-type=minimal stage --stagedir=stage/x64 some headers give weird stl container errors: c:\libs\boost_1_64_0__64\boost/archive/detail/basic_serializer_map.hpp(47): error C2039: 'set': is not a member of 'std' Thanks, Isaac.

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[review] Mp11 review starts in one week
by Bjorn Reese 08 Jul '17

08 Jul '17

The formal review of Peter Dimov's Mp11 library is scheduled for July 15 - July 24, 2017 [1]. Mp11 is a C++11 metaprogramming library for compile-time manipulation of data structures that contain types. It’s based on template aliases and variadic templates and implements the approach outlined in the article "Simple C++ metaprogramming" [2] and its sequel [3]. These articles are useful background information for the review. * Mp11 aims to make simple usage simple, and to support complex usage without complicating the simple use cases. * Mp11 works on any type-list, whether its own type-list mp_list, or standard type-lists such as std::tuple and std::variant, or user-defined type-lists. * Mp11 works with any meta-function, such as C++11 or Boost type-traits, or user-defined type-traits. Mp11 can be found here: * Documentation: https://rawgit.com/pdimov/mp11/master/doc/html/mp11.html * Source code: https://github.com/pdimov/mp11/tree/master [1] http://www.boost.org/community/review_schedule.html [2] http://pdimov.com/cpp2/simple_cxx11_metaprogramming.html [3] http://pdimov.com/cpp2/simple_cxx11_metaprogramming_2.html

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Serialization support for small_vector
by Brian Wood 07 Jul '17

07 Jul '17

Shalom I've added support for small_vector to the C++ Middleware Writer. While testing the support, I got a warning about dereferencing a type-punned pointer breaking strict-aliasing rules. That was on line 340 of small_vector.hpp. I was using g++ 7.1 on FreeBSD/ TrueOS. I used the following "Middle" code for testing: message-lengths variable example_messages -out (message_id_8, ::boost::container::small_vector<int32_t,30>) -in (::boost::container::small_vector<int32_t,30>) } >From what I could tell the serialization/deserialization worked fine. If small_vector were broken out into a separate library that would be helpful from my perspective. It would make it easier for me to add small_vector to my example code. Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

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[serialization] unable to link on OS X when MACOSX_DEPLOYMENT_TARGET=10.7
by Pavol Juhas 06 Jul '17

06 Jul '17

Hello, I'd like to build the boost_serialization library with a compatibility setup for Mac OS X version 10.7, because I need to use it with Anaconda Python binaries, which are built for OS X 10.7. The OS X compatibility version can be set either by passing `-mmacosx-version-min=10.7` as a compile and link option or by setting environment variable MACOSX_DEPLOYMENT_TARGET=10.7. If I do so, the boost_serialization library builds without complaints, however I am not able to link it with my test program. Here are the steps I take to compile boost_serialization and the test program starting from a fresh boost 1.64.0 tree: # -------------------------------------------------------------- $ export MACOSX_DEPLOYMENT_TARGET=10.7 $ ./bootstrap.sh $ ./b2 -j4 variant=release link=shared --with-serialization stage # The stage/lib directory now contains libboost_serialization.dylib. # Use it to build a test program from tarchive.cpp: $ c++ tarchive.cpp -I. -Lstage/lib -lboost_serialization Undefined symbols for architecture x86_64: "boost::archive::basic_binary_oprimitive<boost::archive::binary_oarchive, char, std::char_traits<char> >::init()", referenced from: boost::archive::binary_oarchive_impl<boost::archive::binary_oarchive, char, std::char_traits<char> >::init(unsigned int) in tarchive-5e24a9.o "boost::archive::basic_binary_oprimitive<boost::archive::binary_oarchive, char, std::char_traits<char> >::save(std::string const&)", referenced from: void boost::archive::save_access::save_primitive<boost::archive::binary_oarchive, std::string>(boost::archive::binary_oarchive&, std::string const&) in tarchive-5e24a9.o ... # -------------------------------------------------------------- The only thing the test program (attached) does is to instantiate the boost::archive::binary_oarchive class. The procedure above works fine when MACOSX_DEPLOYMENT_TARGET is set to 10.9 or higher. Am I missing some option that would fix the failed linking when building for OS X 10.7? I suppose this could be related to object visibility options as the serialization library is compiled with "-fvisibility=hidden" and "-fvisibility-inlines-hidden" options. Thank you, Pavol

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[review][beast] Five-days Remaining
by Michael Caisse 06 Jul '17

06 Jul '17

Hi all - We are half-way through the review and have some great involvement and exchanges and a few reviews already. I hope if you haven't written a review yet that you still will. Please provide whatever effort you can afford toward the review process. Boost depends on community involvement. You might have noticed that I have solicited input from you regardless of your experience with the domain. I personally think it is a mistake to have input only from domain experts. True innovation often comes from "outsiders". If you have no experience with Asio or with HTTP, how approachable is this library? Were you able to understand the documents? Could you use the examples? Were you able to build something of your own? Domain experts -- you know the dark corners of the domain. The hard parts that have caused you hours of lost sleep and the need to hack around an existing library or to write your own. How does Beast address your concerns and the problems you have experienced in the past? Is it flexible enough to be put into your tool chest? So far we have reviews from: * Marcel Ebmer * Peter Dimov * Artyom Beilis * Zach Lain * Nik Bougalis * Klemens Morgenstern * Glen Fernandes If I missed a review from you, please let me know! Happy Coding! michael -- Michael Caisse Ciere Consulting ciere.com

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performance tuning on boost version 1_64_0
by Connie Zhang 05 Jul '17

05 Jul '17

Hello, I recently upgrade boost version of a visual C++ program from an old version of 1_58_0 to 1_64_0. Compared to the original executable, the newly upgraded one runs very slow (more than 6 times longer) even I disable the debug mode and set the optimization to /ox in visual environment. The other difference between the old and the upgrade ones is the visual studio version. The old one is on 2010 and the new one 2013. Anyone has any idea for why it behaves like this? Which kind of performance tuning I need to look into? Thank you so much for your help! Connie Sent from Yahoo Mail. Get the app

4 4

[serialization]Nans and infinity in wide xml archive
by Elizabeta 04 Jul '17

04 Jul '17

Hi I am using wide xml boost serialization archive. Because of the problem with loading of nans and infinities I tried the nonfinite facet as in the code snippet. This works, expect it messes with the encoding of the xml arhive which is no longer UTF-8 like before the using the facet, and I believe it is because of the no_codecvt flag which is passed to the archive. But without this flag the loading of nans/infinity does not work. How to use the facet and keep the wanted UTF-8 encoding ? float d = std::numeric_limits<float>::quiet_NaN; { std::wofstream oss("C:\\test.xml"); std::locale locale1(oss.getloc(), new boost::math::nonfinite_num_put<wchar_t>); oss.imbue(locale1); xml_woarchive oar(oss, no_codecvt); oar << BOOST_SERIALIZATION_NVP(d); } { float d; std::wifstream iss("C:\\test.xml"); std::locale locale1(iss.getloc(), new boost::math::nonfinite_num_get<wchar_t>); iss.imbue(locale1); xml_wiarchive iar(iss, no_codecvt); iar >> BOOST_SERIALIZATION_NVP(d); std::cout << d << std::endl; } -- View this message in context: http://boost.2283326.n4.nabble.com/serialization-Nans-and-infinity-in-wide-… Sent from the Boost - Users mailing list archive at Nabble.com.

3 5

Log: Coloring logging output
by Florian Lindner 04 Jul '17

04 Jul '17

Hello, I try to create a formatter that can display logging messages (or just prints the severity level in different colors). Given a format string like: default_formatter = "%SeverityFormat% %Message%"; /// A custom formatter that handles the Severity formatting class severity_formatter_factory : public boost::log::formatter_factory<char> { public: formatter_type create_formatter(boost::log::attribute_name const& name, args_map const& args) { namespace expr = boost::log::expressions; return expr::stream << "|" << "\033[32m" << expr::attr<boost::log::trivial::severity_level >("Severity") << "|"; } }; and register with bl::register_formatter_factory("SeverityFormat", boost::make_shared<severity_formatter_factory>()); it basically works, i.e. the output is colored (all green) and the severity name is printed. But how can I get the actual severity of the message that is about to be formatted inside the formatter? So I can act on that and color warn messages red and info messages green? What I found on the internets, e.g. https://stackoverflow.com/questions/38309479/how-to-add-color-coding-to-boo… http://www.boost.org/doc/libs/1_64_0/libs/log/doc/html/log/tutorial/formatt… was using the sink->set_formatter method, which gives me, afaik, no possbility to configure using a format string. But I'm open to any ideas... Thanks, Florian

1 0

Why cannot asio tcp socket server detect TCP disconnection when the client device lost power?
by jupiter 03 Jul '17

03 Jul '17

Hi, The asio tcp server can detect the disconnection when the client program stop. But I have small device when it lost power, the server won't be able to detect the TCP disconnection. Does the boost socket has TCP timeout? What is an effective way to handle this situation other than running heartbeat in user level? Thank you. Kind regards, - j

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[review][beast] Review of Beast starts today : July 1 - July 10
by Michael Caisse 01 Jul '17

01 Jul '17

The formal review of Vinnie Falco’s Beast library will take place from July 1 through July 10, 2017. Please consider participating in this review. The success of Boost is partially a result of the quality review process which is conducted by the community. You are part of the Boost community. I will be grateful to receive a review based on whatever level of effort or time you can devote. Beast is a C++ header-only library serving as a foundation for writing interoperable networking libraries by providing low-level HTTP/1, WebSocket, and networking protocol vocabulary types and algorithms using the consistent asynchronous model of Boost.Asio. Beast is designed for: * Symmetry: Algorithms are role-agnostic; build clients, servers, or both. * Ease of Use: Boost.Asio users will immediately understand Beast. * Flexibility: Users make the important decisions such as buffer or thread management. * Performance: Build applications handling thousands of connections or more. * Basis for Further Abstraction: Components are well-suited for building upon. A branch has been made for the review. You can find Beast for review at these links: * Documentation : <http://vinniefalco.github.io/stage/beast/review/> * Source code : <https://github.com/vinniefalco/Beast/tree/review> * The FAQ answers real questions that come up : <http://vinniefalco.github.io/stage/beast/review/beast/design_choices/faq.ht…> A lightning talk from CppCon 2016 introducing Beast can be found here: <https://www.youtube.com/watch?v=uJZgRcvPFwI> Please provide in your review whatever information you think is valuable to understand your final choice of ACCEPT or REJECT including Beast as a Boost library. Please be explicit about your decision. Some other questions you might want to consider answering: - 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 which compiler(s)? 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? More information about the Boost Formal Review Process can be found here: <http://www.boost.org/community/reviews.html> Thank you for your effort in the Boost community. Happy coding - michael -- Michael Caisse Ciere Consulting ciere.com

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Boost_1_64_0 compile errors - gcc 5.3.0
by Michael Miller 30 Jun '17

30 Jun '17

Hello, Qt Creator 4.3.1 Based on Qt 5.9.1 gcc version 5.3.0 Trying to use Boost in my program. I’m getting the following compile errors. Any suggestions, Please. Regards In file included from C:\boost\boost_1_64_0/boost/numeric/ublas/vector.hpp:21:0, from C:\boost\boost_1_64_0/boost/numeric/ublas/matrix.hpp:18, from lib\math/lc_quadratic.h:30, from lib\engine\rs_arc.cpp:37: C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp: In member function 'void boost::numeric::ublas::unbounded_array<T, ALLOC>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp:299:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp: In member function 'void boost::numeric::ublas::bounded_array<T, N, ALLOC>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp:494:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ In file included from C:\boost\boost_1_64_0/boost/numeric/ublas/vector.hpp:21:0, from C:\boost\boost_1_64_0/boost/numeric/ublas/matrix.hpp:18, from lib\math/lc_quadratic.h:30, from lib\engine\rs_circle.cpp:42: C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp: In member function 'void boost::numeric::ublas::unbounded_array<T, ALLOC>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp:299:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp: In member function 'void boost::numeric::ublas::bounded_array<T, N, ALLOC>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp:494:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ In file included from lib\math/lc_quadratic.h:30:0, from lib\engine\rs_circle.cpp:42: C:\boost\boost_1_64_0/boost/numeric/ublas/matrix.hpp: In member function 'void boost::numeric::ublas::c_matrix<T, M, N>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/matrix.hpp:5977:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, N); ^

1 0

[poly_collection] Boost.PolyCollection release version ready
by Joaquin M López Muñoz 29 Jun '17

29 Jun '17

Hello, For those who are following the development of this lib, I'd like to announce that the release version of Boost.PolyCollection for Boost 1.65 is already committed to the master branch of Boost. Much of the to-do list prepared by Ion at the end of the review has been implemented. The main features left as roadmap are listed at: http://www.boost.org/doc/libs/master/doc/html/poly_collection/future_work.h… As for the improvements already included, let me comment on what I feel are the most important: * The implementation has been refactored to avoid internal virtual calls at places where the type of the segment involved is known at compile time. Also, segment lookup (the process to get to the segment for U from typeid(U)) has been greatly sped up by means of a std::type_info* cache. These two improvements result in a combined reduction of around 25-30% in insertion times. There's an API breaking change though: no longer is std::type_index used and const std::type_info &'s have to be directly provided instead --this is likely to go unnoticed by those of you already using the lib. * Polymorphic collections now satisfy standard requirements on allocator use as stated in [container.requirements.general]/3 (or, more precisely, the natural interpretation for polymorhpic containers of this clause). This is explicitly described in the reference. As a result, polymorphic collections can now use std::scoped_allocator_adaptor without any problem. * Added segment(typeid(U))/segment<U>() convenience funtions returning a range object over the selected segment. This allows us to write: for(const auto& x:c.segment(typeid(warrior))){ ... } * Collection-level max_size() and capacity() have been removed as I didn't seem to find sensible semantics for them. Segment-level max_size() and capacity() are kept, of course. * Hopefully the tutorial section on boost::function_collection is a bit clearer now. The library works OK for MSVC>=14.0,GCC>=5.0,Clang>=3.7. Unfortunately, Intel fails for test_algorithm: https://lists.boost.org/Archives/boost/2017/06/236016.php If someone's interested in helping fix that, please step up. Thank you, Joaquín M López Muñoz

4 4

C++11 ABI stability
by Marek Skalický 29 Jun '17

29 Jun '17

Hi, mongo-cxx-driver notices this: "Important note about C++11/C++14: The boost libraries do not offer a stable ABI across different versions of the C++ standard. As a result, you must ensure that your application, the C++ driver, and boost are all built with the same language standard. In particular, if you are building the C++ driver with C++11 enabled, you must also build your application with C++11 enabled, and link against a C++11 compiled boost. " [1] Is it true? What changes with new standard? (or is this only related to ABI change in gcc introduced by c++11?) I'm interested mainly in libraries: filesystem, chrono, thread, system and regex Thanks, Marek [1] http://mongodb.github.io/mongo-cxx-driver/legacy-v1/installation/#s cons-options-when-compiling-the-c-driver

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[boost] [beast] Formal "review" branch frozen
by Vinnie Falco 29 Jun '17

29 Jun '17

The "review" branch of Beast is now available and frozen for modifications. It contains the snapshot of the repository which will undergo the Boost formal review starting on July 1 and lasting for 10 days. Currently the review branch is even with the master branch, at version 70. The review branch repository is here: https://github.com/vinniefalco/Beast/tree/review The review documentation snapshot: http://vinniefalco.github.io/stage/beast/review/ Autobahn WebSocket Implementation Test Report: http://vinniefalco.github.io/autobahn/index.html Beast is a C++ header-only library serving as a foundation for writing interoperable networking libraries by providing low-level HTTP/1, WebSocket, and networking protocolvocabulary types and algorithms using the consistent asynchronous model of Boost.Asio. Beast empowers users to create their own libraries, clients, and servers using HTTP/1 and WebSocket. Code will be easier and faster to implement, understand, and maintain, because Beast takes care of the low-level protocol details. Please don't forget to "star" the repository on GitHub, the increased exposure will vitalize Beast and Boost with the new generation of programmers! Thanks! -- Follow me on Github: https://github.com/vinniefalco

1 0

Regression in Boost.Variant with gcc6.3 in C++03 mode
by dariomt＠gmail.com 28 Jun '17

28 Jun '17

Hi, This is the simplest possible repro I could get: #include <boost/variant.hpp> class A {}; class B : private A {}; typedef boost::variant<A, B> variant_t; int main() { B b; variant_t v (b); } This used to work with Boost 1.59.0 but fails with 1.64.0 Using wandbox I've found that: - it started failing in 1.62.0 - clang does not have this problem - newer and older versions of gcc do have the same problem The error is miles long. I think the important parts are: boost/type_traits/is_convertible.hpp:149:53: error: 'A' is an inaccessible base of 'B' error: no matching function for call to 'boost::variant<A, B>::variant(B&)' It seems the metaprogramming messes up due to the private inheritance, and decides that the variant<A,B> is *not* constructible from B Workarounds are very welcome! Switching to C++14 is not an option (yet). Regards

3 8

Compiling Boost_1_6_0 under linux.
by Michael Miller 27 Jun '17

27 Jun '17

Hello, I’m trying to compile Boost_1_64_0 under linux, without success. Debian 9 gcc version 6.3.0 Terminal commands:- cd tools/build ./bootstrap.sh ./b2 install --prefix=~/boost/boost_1_64_0 No Boost (executable) appears. Am I missing something? Regards

2 2

Build error C3083
by James 26 Jun '17

26 Jun '17

Hi, I am trying to build an application that uses the boost libraries. I am seeing build error C3083 in bind_mf_cc.hpp. The error states: Error C3083 'core': the symbol to the left of a '::' must be a type This is the offending code section : template<class Rt2, class R, class T, class A1> typename boost::enable_if_c<!boost::core::is_same<Rt2,R>::value, _bi::bind_t<Rt2, _mfi::BOOST_BIND_MF_NAME(mf0)<R,T>, typename _bi::list_av_1<A1>::type>>::type BOOST_BIND(R(BOOST_BIND_MF_CC T::*f) (), A1 a1) { typedef _mfi::BOOST_BIND_MF_NAME(mf0)<R, T> F; typedef typename _bi::list_av_1<A1>::type list_type; return _bi::bind_t<Rt2, F, list_type>(F(f), list_type(a1)); } And the line giving the trouble is the line beginning: typename boost::enable_if_c<!boost::core::is_same<Rt2,R>::value, Can anyone help me correct the line to fix this issue please? Thanks.

5 11

[Fiber] Boost 1.63 buffered_channel failed to compile with g++ 4.8 on Ubuntu
by lin li 23 Jun '17

23 Jun '17

Hi, guys. I was trying to compile the example code from Boost website for the buffered_channel in Boost 1.63, but it failed with the following error: In file included from /opt/third_party/include/boost/fiber/all.hpp:15:0, from /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudWorkerJob.h:19, from /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudEndpointWorker.h:16, from /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudEndpointWorker.cpp:7: /opt/third_party/include/boost/fiber/buffered_channel.hpp: In instantiation of ‘boost::fibers::buffered_channel<T>::buffered_channel(std::size_t) [with T = HAUD::SS7Wrapper*; std::size_t = long unsigned int]’: /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudEndpointWorker.cpp:23:25: required from here /opt/third_party/include/boost/fiber/buffered_channel.hpp:49:9: error: use of deleted function ‘std::atomic<long unsigned int>::atomic(const std::atomic<long unsigned int>&)’ slot() = default; ^ In file included from /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudWorkerJob.h:11:0, from /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudEndpointWorker.h:16, from /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudEndpointWorker.cpp:7: /usr/include/c++/4.8/atomic:658:7: error: declared here atomic(const atomic&) = delete; ^ In file included from /opt/third_party/include/boost/fiber/all.hpp:15:0, from /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudWorkerJob.h:19, from /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudEndpointWorker.h:16, from /home/ak70/HaudDevelopment/HaudCore/HaudCore/Services/HaudSMSService/HaudEndpointWorker.cpp:7: /opt/third_party/include/boost/fiber/buffered_channel.hpp:138:16: note: synthesized method ‘boost::fibers::buffered_channel<T>::slot::slot() [with T = HAUD::SS7Wrapper*]’ first required here slots_ = new slot[capacity_](); ^ make[2]: *** [cpm-bin/gitfortytwolocal_haudbackend_haudcore_origin_master/bin/CMakeFiles/HaudCore.dir/HaudCore/Services/HaudSMSService/HaudEndpointWorker.cpp.o] Error 1 make[1]: *** [cpm-bin/gitfortytwolocal_haudbackend_haudcore_origin_master/bin/CMakeFiles/HaudCore.dir/all] Error 2 make: *** [all] Error 2 Any ideas?

1 0

compiling error C1001 for common_type.hpp on boost_1_64_0
by Connie Zhang 20 Jun '17

20 Jun '17

Hi, there, I am getting internal error C1001 on one of the library header file. it points to the line inside the code: template<class T1, class T2, class... T> using common_type_fold = common_type_t<common_type_t<T1, T2>, T...>; Do anyone has some idea for how to fix it? The program is on Visual Studio 2013. Thank you for your input. WZ Sent from Yahoo Mail. Get the app

2 2

Compiling Boost with Qt & gcc ver. 5.3.0
by Michael Miller 20 Jun '17

20 Jun '17

Hello, I've got Boost 1_53_0 & 1_64_0 working with Qt 5.9 (gcc version 5.3.0) and c++ on Windows 10 - 32 bit. Compiling (without warnings) and running from within Qt Creator. In each version of Boost change "std:auto" to "std::unique". That’s it. What this does with MSVC, I don’t know Regards

2 1

Process extension compile issue.
by dinesh kumar 15 Jun '17

15 Jun '17

Hi Team, Greetings for the day. I am currently facing the problem with process extension as documented here <http://www.boost.org/doc/libs/1_64_0/doc/html/boost_process/design.html#boo…> . I am testing the boost 1.64 version macOS, and unable to use the below functionality. void test() { cout << "On Setup" << endl; } int main() { std::function<void(void)> on_st = test; bp::child c2("ls", boost::process::extend::on_setup(on_st)); } *Error: * /usr/local/include/boost/process/detail/handler.hpp:33:9: No matching function for call to object of type 'std::__1::function<void ()>' Would somebody guide me here, please? -- Regards, Dinesh manojadinesh.blogspot.com

2 4

[Boost.Program_options] String options parser
by Belcourt, Kenneth 14 Jun '17

14 Jun '17

Hi, We have an executable that uses the program_options library to process command line options like this: $ ./hilbert.x -h -b [ --hilbert ] arg (=1) enable hilbert matrix -e [ --epsilon ] arg (=0.001) roundoff epsilon -h [ --help ] help message -i [ --input-file ] arg process input file -r [ --rank ] arg rank of matrix to construct -t [ --tolerance ] arg (=1e-13) linear tolerance -v [ --inverse ] arg (=0) enable inverse hilbert matrix -w [ --wordsize ] arg (=8) floating-point word size (bytes) and it works great. Now we’re trying to automate some testing and we test our executable with an input file that has hundreds of lines like this: --inverse 1 --tolerance 1e-15 --rank 2 --inverse 1 --tolerance 1e-15 --rank 3 --inverse 1 --tolerance 1e-15 --rank 4 where each line is a separate test case that we run with the specified options. I was looking for a program options parser that can parse a string, so I can read one line of input from this file into a string, and run that test case, that is something like this: // read one line of input from file ifstream ifp; string buffer; while (!ifp.eof() && ifp.good()) { getline(ifp, buffer); // load a set of command line options from this string po::parse_config_file<char>(buffer.c_str(), desc); } The only program option parsers I see are parse_command_line, parse_config_file, and parse_environment. Is there an easy way (without having to construct an argc/argv data structure) to parse a file of program options? — Noel Belcourt

3 4

Compile errors with Booost_1_64_0
by Michael Miller 13 Jun '17

13 Jun '17

Hello, Windows 10 gcc version 5.3.0 My program compiles OK with Boost_1_53_0. I get a compile failure (3 errors) when including Boost_1_64_0. \boost\boost_1_64_0\boost\numeric\ublas\storage.hpp:299: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ private: friend class boost::serialization::access; // Serialization template<class Archive> void serialize(Archive & ar, const unsigned int /*version*/) { serialization::collection_size_type s(size_); ar & serialization::make_nvp("size",s); if ( Archive::is_loading::value ) { resize(s); } line 299 ar & serialization::make_array(data_, s); } \boost\boost_1_64_0\boost\numeric\ublas\storage.hpp:494: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ private: // Serialization friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int /*version*/) { serialization::collection_size_type s(size_); ar & serialization::make_nvp("size", s); if ( Archive::is_loading::value ) { if (s > N) bad_size("too large size in bounded_array::load()\n").raise(); resize(s); } line 494 ar & serialization::make_array(data_, s); } \boost\boost_1_64_0\boost\numeric\ublas\matrix.hpp:5977: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, N); ^ void serialize(Archive & ar, const unsigned int /* file_version */) { // we need to copy to a collection_size_type to get a portable // and efficient serialization serialization::collection_size_type s1 (size1_); serialization::collection_size_type s2 (size2_); // serialize the sizes ar & serialization::make_nvp("size1",s1) & serialization::make_nvp("size2",s2); // copy the values back if loading if (Archive::is_loading::value) { size1_ = s1; size2_ = s2; } // could probably use make_array( &(data[0][0]), N*M ) line 5977 ar & serialization::make_array(data_, N); } Regards

1 0

How do I build x64 binaries with Boost source?
by Osman Zakir 12 Jun '17

12 Jun '17

Hi, How do I specify that I want to build 64-bit binaries when I run bootstrap and then invoke b2? I had a linker error saying, “1>libboost_thread-vc141-mt-gd-1_64.lib(thread.obj) : fatal error LNK1112: module machine type 'X86' conflicts with target machine type 'x64'” when I tried to build an ISAPI extension DLL with Wt (just a simple app using the same code as in the “Hello world” example). [Note: I’m just trying out the wtispai.lib/wisapid.lib connector libraries to see how to use them.] Any help would be appreciated. Thanks in advance. Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10

3 2

Semantic Compiler Errors (general question)
by James Stortz 12 Jun '17

12 Jun '17

I have included and linked the latest Boost C++ library into my build. I tested the library beforehand. However, when simply including the header files in a C++ actor class in my Unreal game project, I get errors like: Warning Example: Error boost/config/stdlib/dinkumware.hpp(99) : warning C4668: '_HAS_NAMESPACE' is not defined as a preprocessor macro, replacing with '0' for '#if/#elif' Error Examples: Error boost/intrusive/slist.hpp(1926) : error C4003: not enough actual parameters for macro 'check' Error boost/intrusive/slist.hpp(1926) : error C2062: type 'void' unexpected It looks like there is some strict/unsupported semantic issues with the compiler that is being used. How do I fix this? I am on Windows with VS 2017. Sample programs compile fine with just cl /EHsc /I boost_1_64_0 test_game.cpp /link /LIBPATH:"F:\boost_1_64_0\stage\lib" Why would the compiler not work from within Unreal? Thanks, Regards, James

4 3

Re: [Boost-users] Beginner Question (Windows MSVC)
by James Stortz 11 Jun '17

11 Jun '17

So I got it to work by simply renaming the library, but I don't know if that's the proper solution or why. I'm wary that I'll have other issues or that something is off about my installation. (And I do have the LIBPATH correctly typed in the console -- sorry. :D) On Fri, Jun 9, 2017 at 8:26 PM, James Stortz <james.ryan.stortz(a)gmail.com> wrote: > So I got it to work by simply renaming the library, but I don't know if > that's the proper solution or why. I'm wary that I'll have other issues or > that something is off about my installation. (And I do have the LIBPATH > correctly typed in the console -- sorry. :D) > > On Fri, Jun 9, 2017 at 7:30 PM, stathis <stathis(a)npcglib.org> wrote: > >> Look at the path you're using with LIBPATH, it seems wrong, it should >> probably be >> >> /LIBPATH:F:\src\boost_1_64_0\stage\lib >> >> --st >> >> >> >> On 10/06/2017 02:04, James Stortz via Boost-users wrote: >> >> correction, the error was: >> >> LINK : fatal error LNK1104: cannot open file >> 'libboost_date_time-vc141-mt-s-1_64.lib' >> >> On Fri, Jun 9, 2017 at 7:00 PM, James Stortz <james.ryan.stortz(a)gmail.com >> > wrote: >> >>> I can't seem to include/link and compile properly. I am using boost 1.64 >>> and Visual Studio 2017 (Community). >>> >>> I can successfully include the headers and compile the example program >>> on the Getting Started page[1]. But when trying to simply compile the mutex >>> example from interprocess docs[2], I get this error: >>> >>> >>> LINK : fatal error LNK1104: cannot open file >>> `libboost_date_time-vc141-mt-2-1_64.lib` >>> >>> >>> From the Getting Started page on linking, I have been trying the >>> following: >>> >>> cl /EHsc /I boost_1_64_0 doc_memtest1.cpp ^ >>> /link /LIBPATH:F\src\boost_1_64_0\stage\lib >>> >>> >>> I have even tried a solution from Stackoverflow[3], multiple times with >>> various configurations, x64/x86, but nothing. I don't even have that >>> particular library. I have "libboost_date_time-vc141-mt-gd-1_64.lib" >>> and "libboost_date_time-vc141-mt-1_64.lib". >>> >>> I assume I am doing something wrong, as I am new to programming on >>> Windows/MSVC. >>> >>> Any help? Thanks! >>> James >>> >>> >>> [1] http://www.boost.org/doc/libs/1_64_0/more/getting_started/wi >>> ndows.html >>> >>> [2] http://www.boost.org/doc/libs/1_64_0/doc/html/interprocess/s >>> ynchronization_mechanisms.html#interprocess.synchronization_ >>> mechanisms.mutexes.mutexes_anonymous_example >>> >>> [3] https://stackoverflow.com/questions/41464356/build-boost-wit >>> h-msvc-14-1-vs2017-rc >>> >> >> >> >> _______________________________________________ >> Boost-users mailing listBoost-users@lists.boost.orghttps://lists.boost.org/mailman/listinfo.cgi/boost-users >> >> >> >

2 3

[MSM] exception_caught question
by Christophe Henry 10 Jun '17

10 Jun '17

Hi, > I found that answer for exceptions which can occur during the processing: > >https://lists.boost.org/boost-users/2012/03/73904.php > >Here is handled the case that exception is derived from std::exception. >What happens if not? >Can the parameter be changed to std::exception_ptr or just a > template Parameter? only std::exception are caught. Others just go through and interrupt the transition, which might leave the state machine in a dirty state, where an entry or exit action would not have been called. Cheers, Christophe

1 0

Beginner Question (Windows MSVC)
by James Stortz 09 Jun '17

09 Jun '17

I can't seem to include/link and compile properly. I am using boost 1.64 and Visual Studio 2017 (Community). I can successfully include the headers and compile the example program on the Getting Started page[1]. But when trying to simply compile the mutex example from interprocess docs[2], I get this error: LINK : fatal error LNK1104: cannot open file `libboost_date_time-vc141-mt-2-1_64.lib` >From the Getting Started page on linking, I have been trying the following: cl /EHsc /I boost_1_64_0 doc_memtest1.cpp ^ /link /LIBPATH:F\src\boost_1_64_0\stage\lib I have even tried a solution from Stackoverflow[3], multiple times with various configurations, x64/x86, but nothing. I don't even have that particular library. I have "libboost_date_time-vc141-mt-gd-1_64.lib" and "libboost_date_time-vc141-mt-1_64.lib". I assume I am doing something wrong, as I am new to programming on Windows/MSVC. Any help? Thanks! James [1] http://www.boost.org/doc/libs/1_64_0/more/getting_started/windows.html [2] http://www.boost.org/doc/libs/1_64_0/doc/html/interprocess/synchronization_… [3] https://stackoverflow.com/questions/41464356/build-boost-with-msvc-14-1-vs2…

2 2

[ Boost.Units ] Invert a quantity_type
by Belcourt, Kenneth 09 Jun '17

09 Jun '17

Hi, I have a structure that is passed some type from which I can extract a units quantity type: template <typename Field> struct field { Field f; typedef typename Field::quantity_type quantity_type; // access typed data off Field quantity_type operator[](int i) { return f[i]; } }; Is there a way to invert a quantity type so I can compute and return, say, the inverse of the passed quantity_type? So, for example, is there any Boost.Units inverse meta like function that might let me say something like this: template <typename Field> struct field_inverse { Field f; typedef typename Field::quantity_type quantity_type; typedef typename bu::inverse<quantity_type>::type inverse_quantity_type; // access typed data off field, return inverse of quantity_type inverse_quantity_type operator[](int i) { return one / f[i]; } }; I’m hoping for something more general than partially specializing the bu::inverse method for each quantity I may want to invert. Any ideas? — Noel Belcourt

2 2

[Boost.Heap] Possible bug with ordered iterator and boost::heap::binomial_heap
by Kudo, Jun 08 Jun '17

08 Jun '17

Hi all, I'm observing a weird phenomenon when iterating over a binomial heap after pushing two values with the same priority. Instead of printing the expected values twice, the ordered iterator seems to print three values. I do not observe this behavior when using a Fibonacci heap or a binary heap. I've attached sample code that demonstrates this behavior. Can anyone help explain what's going on? Boost Version : Boost 1.64 Compiler : GCC 5.3.0 #include <iostream> #include "boost/heap/fibonacci_heap.hpp" #include "boost/heap/binomial_heap.hpp" #include "boost/heap/d_ary_heap.hpp" template <class HeapType> void PrintHeap(HeapType const & heap) { std::cout << "Printing out heap : "; for (auto it = heap.begin(); it != heap.end(); ++it) { std::cout << *it << " "; } std::cout << "\n Printing out heap in order : "; for (auto it = heap.ordered_begin(); it != heap.ordered_end(); ++it) { std::cout << *it << " "; } std::cout << "\n\n"; } int main(int /* argc */, char** /* argv */) { typedef boost::heap::binomial_heap<int> BinomialHeap; BinomialHeap binomial_heap; binomial_heap.push(1); binomial_heap.push(1); // Prints {1,1} and {1,1,1} PrintHeap(binomial_heap); typedef boost::heap::fibonacci_heap<int> FibonacciHeap; FibonacciHeap fibonacci_heap; fibonacci_heap.push(1); fibonacci_heap.push(1); // Prints {1,1} and {1,1} PrintHeap(fibonacci_heap); typedef boost::heap::d_ary_heap<int, boost::heap::arity<2>, boost::heap::mutable_<true>> BinaryHeap; BinaryHeap binary_heap; binary_heap.push(1); binary_heap.push(1); // Prints {1,1} and {1,1} PrintHeap(binary_heap); } Thanks! Jun

1 0

svn.boost.org schedule maintenance - DOWN TIME
by Michael Caisse 07 Jun '17

07 Jun '17

Hi all - svn.boost.org is scheduled for maintenance on June 8 from 1700 - 1900 UTC. Expect outages for Trac during this time. Happy coding! michael -- Michael Caisse Ciere Consulting ciere.com

1 0

[MSM] What happens to MSM if guard returns `false`, mutable events and error recovery?
by Ovanes Markarian 05 Jun '17

05 Jun '17

Hi *, I am currently reading through the MSM docs and have one question, what happens to MSM if guard returns `false`. Does the MSM enter an error state in orthogonal region (http://www.boost.org/doc/ libs/1_64_0/libs/msm/doc/HTML/ch03s02.html#d0e577)? Even internals page describes, what happens if guard returns `true`, but not a single word on `false` case. Regarding the const events: I am programming an MSM to proxy network traffic and once a message with data was received it'll be analysed and moved between different states. Message instances implement move semantics. Currently, the MSM has an initial state `ready` where the `message_in` event is handled. This event contains the message to be analysed. From my current understanding I either have to make message field in `message_in` event mutable or MSM needs to to support r-value references. Can somebody tell me what's going to happen if the action only accepts r-value reference to an event instance? Currently, it seems to work, but would like to understand the implications. struct some_action_impl { template<class Fsm, class Event, class SourceState, class TargetState> void operator()(Event&& ev, Fsm& fsm, SourceState& source, TargetState& target) { ... } } My last question relates to multi-threading. I understand that MSM manages internal states, would it be safe to create MSM as a thread-local storage and restart the thread-local MSM if the new request comes in? It's more about, what happens to MSM after an error state? Is calling stop(), start() members enough? Many thanks for help, Ovanes

2 1

[MSM] exception_caught question
by Ovanes Markarian 05 Jun '17

05 Jun '17

Hi *, I found that answer for exceptions which can occur during the processing: https://lists.boost.org/boost-users/2012/03/73904.php Here is handled the case that exception is derived from std::exception. What happens if not? Can the parameter be changed to std::exception_ptr or just a template parameter? Thanks for help, Ovanes

1 0

[Units] What is the correct/recommended way to handle different ratios in the same unit
by Carel Combrink 05 Jun '17

05 Jun '17

Hi All, I have recently started looking at Boost.Units to use in my applications where unit conversions happens regularly. The conversions are mostly within the same unit, but different ratios, like hertz to killohertz and back (also distances). I have asked for some advice on StackOverflow, but still waiting for an answer to either indicate the correct way or confirm that what I am doing is correct. The mentioned question can be seen here: https://stackoverflow.com/q/44300549/991000 Is there someone that can perhaps look at my question on SO and offer some assistance or advice please? Regards, Carel

1 0

Boost.Parameter python and lazy evaluation of default arguments
by Philipp.Buettgenbach＠gmail.com 05 Jun '17

05 Jun '17

Hello all, I have a question concerning the Boost.Parameter library and the python binding provided by this library. When I try to compile the attached code with clang I get: ------------------------------- /tmp$ clang -I/usr/include/python2.7/ -std=c++14 -c python_test.cpp In file included from python_test.cpp:7: In file included from /usr/include/boost/parameter/preprocessor.hpp:8: In file included from /usr/include/boost/parameter/parameters.hpp:40: /usr/include/boost/parameter/aux_/arg_list.hpp:361:16: error: no viable conversion from 'boost::parameter::aux::maybe<std::basic_string<char> >' to 'const std::basic_string<char>' return arg.value; ^~~~~~~~~ ------------------------------- If I just compile main or use standard default arguments everything compiles fine. Can anybody explain to me what's wrong with using lazy default argument evaluation when exporting to python? Thanks a lot, Philipp

1 0

Source incompatible changes in Boost.Test
by Dominique Devienne 03 Jun '17

03 Jun '17

What's the point of changing a public symbol's case like this, leading to a hard build error? Seems a bit gratuitous, no? And not up to Boost's standards I might add. --DD if (BOOST_VERSION < 106000) boost::unit_test::tut_suite #else boost::unit_test::TUT_SUITE #endif

2 1

[MSM] What happens to MSM if guard returns `false`, mutable events and error recovery?
by Christophe Henry 02 Jun '17

02 Jun '17

Hi, >I am currently reading through the MSM docs and have one question, > what happens to MSM if guard returns `false`. Does the MSM enter an error state > in orthogonal region (http://www.boost.org/doc/libs/1_64_0/libs/msm/doc/HTML/ch03s02.html#d0e577)? >Even internals page describes, what happens if guard returns `true`, >but not a single word on `false` case. What happens is described in http://www.boost.org/doc/libs/1_64_0/libs/msm/doc/HTML/ch02s02.html#d0e226 and in http://www.boost.org/doc/libs/1_64_0/libs/msm/doc/HTML/ch06.html#d0e3013 To sum up, in this case the next guard is tried and the next until no more is left. If all return false, processing in this region is finished. Each region processes independently from others but if one guard rejected the event, this event is seen as processed. >Regarding the const events: I am programming an MSM to proxy network >traffic and once a message with data was received it'll be analysed and >moved between different states. Message instances implement move semantics. >Currently, the MSM has an initial state `ready` where the `message_in` >event is handled. This event contains the message to be analysed. From my >current understanding I either have to make message field in `message_in` >event mutable or MSM needs to to support r-value references. Can somebody >tell me what's going to happen if the action only accepts r-value reference >to an event instance? Currently, it seems to work, but would like to >understand the implications. MSM is still C++98. const& were necessary to pass temporary objects. You can simply const_cast. I'm unsure about the r-value reference action. >My last question relates to multi-threading. I understand that MSM >manages internal states, would it be safe to create MSM as a >thread-local storage and restart the thread-local MSM if the new >request comes in? It's more about, what happens to MSM after an error >state? Is calling stop(), start() members enough? I don't get where there is multithreading in your question. Using TLS it is thread-safe to restart whatever you want. start() calls the first on_entry, stop(), the last on_exit, nothing else. HTH, Christophe

1 0

[Intrusive] Call custom function after tree rotations
by Lukas Barth 31 May '17

31 May '17

Hi, I'm trying to implement an interval tree based on boost::intrusive::rbtree. For such an interval tree, certain fixup operations must be run after a node rotation. Now, as far as I can see from the code (looking at rotate_* in bstree_algorithms), there is no way of "hooking into"[0] these methods, right? Am I missing something? What I need: After every operation that changes the parent-child-relationship of nodes I need to touch all involved nodes. At this point, I'm considering monkey-patching bstree_algorithms using some preprocessor directives, but that is bound to fail spectacularly. Any better ideas? Kind regards, and thanks for any help, Lukas [0] I know the term "hook" is overloaded differently with intrusive, but I can't think of a better term.

2 1

[Interprocess] uint64 atomic
by dnj0496 31 May '17

31 May '17

Hi, I am new to boost-interprocess. I am trying to store some of my data structures in shared memory using boost::interprocess. Each of my data structure(s) contain a bunch of counters (basically size_t values) updated atomically. In the traditional world, std::atomic supports atomic update for size_t. However, I came to know that boost::interprocess doesn't support atomic update for uint64. I've looked at pairing my counter with a lock for synchronization purposes. I've implemented it and it seems to work. However, the upgradable_mutex is consuming 144bytes while my counter is 8bytes(size_t) making it cost prohibitive. Alternatively, I could use one lock for all the counters of a class to spread the cost but that'd affect the performance and affect parallelism. I'd appreciate it if someone could offer any alternate suggestions. Thanks. Dk. -- View this message in context: http://boost.2283326.n4.nabble.com/Interprocess-uint64-atomic-tp4695000.html Sent from the Boost - Users mailing list archive at Nabble.com.

3 3

[type_erasure] any holding a ref to any
by Joaquin M López Muñoz 31 May '17

31 May '17

Say I have an object a of type any<mpl::vector<Concept1,typeid_<>>,_self&> and an object b of type any<Concept2,T> where Concept1 is a subconcept of Concept2. Is it possible to make a refer to b rather than the object wrapped by b? I mean: any_cast<void*>(&a)==&b typeid_of(a)==typeid(b) A solution involving wrapping/copying b into some auxiliary entity would be acceptable too. This questin is obviously connected to the implementation of boost::any_collection, as Steven will undoubtedly have guessed. Thank you, Joaquín M López Muñoz

2 1