November 2018 - Boost-users

Trouble building boost
by Vipin Verma 13 Nov '18

13 Nov '18

Hello I have tried building boost on my Windows as well as Ubuntu system, but I am not able to make it work. Could you please help me? Here is a post with details about Windows - https://stackoverflow.com/questions/53273860/opennero-windows-could-not-fin… Here is a post about Ubuntu - https://stackoverflow.com/questions/53151130/opennero-ubuntu-process-finish… -- Regards Vipin Verma <https://www.linkedin.com/in/vipin8169> BlueSapling Technologies Pvt Ltd. <https://bluesapling.com/> +1-480-410-1673

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[Variant] Minimum implementation to be variant friendly
by Michael Powell 13 Nov '18

13 Nov '18

Hello, What's the minimum implementation a struct needs to fulfill in order to be boost::variant friendly? Things like, does it need to support perfect forwarding? An assignment operator? And so on. Thanks! Michael Powell

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[Spirit] Qi int_parser rejecting a negative signed std::intmax_t
by Michael Powell 12 Nov '18

12 Nov '18

Hello, qi::int_parser works fine for a positive signed hex radix integer, but is failing for a negative signed hex radix integer. My integer type is std::intmax_t, which on this platform I think is long long. Is there an integer width constraint? And/or a signage problem? Do I need to enable BOOST_HAS_LONG_LONG? Or is that enabled by default? Cheers, thanks! Michael Powell

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Boost 1.68.0 contains only python 3.7 library, no python 2.7 library?
by Heng Zhou 10 Nov '18

10 Nov '18

Hi, I installed Boost 1.68.0 recently from Windows x64 pre-compiled binary "boost_1_68_0-msvc-14.0-64.exe" downloaded from https://urldefense.proofpoint.com/v2/url?u=https-3A__sourceforge.net_projec…. Then, I noticed that this version of Boost contains only python 3.7 library because the filenames under C:\local\boost_1_68_0\lib64-msvc-14.0 are only boost_python37-vc140-mt-.... This caused errors from building a third-party library which tries to link Boost python 2.7 library (i.e., tries to find file boost_python27-vc140-mt-...) . So what is matter? Does Boost decide to stop supporting python 2.7 since version 1.68.0, or is Boost python 2.7 library located somewhere else using some hard-to-recognize filename? I'm using Windows 10, VS2015 and have only python 2.7 installed. Thank you for your help with this issue.

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[Format] Possible to format numeric values using radix?
by Michael Powell 09 Nov '18

09 Nov '18

Hello, For instance, given a numerical value, I'd like to specify the Radix, whether to format octal or hex. Thanks in advance! Best regards, Michael Powell

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[DLL] BOOST_DLL_ALIAS not working on MinGW-w64
by David Demelier 09 Nov '18

09 Nov '18

Hello, I'm using boost 1.68 on MinGW-w64 (Windows 10). I'm trying a simple plugin that works fine under Linux and FreeBSD However, on Windows boost::dll::import_alias triggers an exception: terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >' what(): boost::dll::shared_library::get() failed: The specified procedure could not be found This is the plugin (plugin.cpp) #include <iostream> #include <boost/dll.hpp> namespace custom { void my_function() { puts("CALLED"); } } // !custom BOOST_DLL_ALIAS(custom::my_function, my_function) I compile using: g++ -std=c++17 -shared -o plugin.dll plugin.cpp -lboost_system-mt And the simple main.cpp file: #include <boost/dll.hpp> int main() { using my_function = void (); auto f = boost::dll::import_alias<my_function>("./plugin.dll", "my_function"); } What's strange, nm does not report any kind of unmangled symbols related to "my_function": $ nm plugin.dll | grep my_function 0000000067e81422 t _GLOBAL__sub_I__ZN6custom11my_functionEv 0000000067e813b0 T _ZN6custom11my_functionEv It should contains something starting with boostdll_ isn't it? What's happening there? Do I miss something? -- David

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[Spirit] Qi lexeme only taking the first word
by Michael Powell 08 Nov '18

08 Nov '18

Hello, I've got a couple of rules that are perplexing to me. First, rule<It, std::string(), St> id %= lexeme[qi::alpha >> *char_("A-Za-z0-9_")]; In and of itself, id is working fine. Then I've got a "full id": rule<It, full_id_t(), St> full_id %= id >> *(char_('.') >> id); Where: struct full_id_t { std::string val; }; full_id_t::val is quite intentional for reasons elsewhere in the grammar. The perplexity comes in, it seems lexeme is only shaving off the first word as the val. For instance, parsing "two.oranges.red.test", I receive back "two" in the AST. Perhaps I should defer specifying the lexeme part of id until later? Thoughts? Suggestions? Thank you! Best regards, Michael Powell

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Build/use Boost without ICU
by braden 08 Nov '18

08 Nov '18

How does one build (and use) Boost without ICU when ICU is installed (i.e., visible to b2)? I am am bootstrapping with: ...which shows: Seems reasonable so far. Building happens with: ...which shows: In spite of passing "--disable-icu -sboost.locale.icu=off" to b2, I still see Boost.Locale getting built with -DBOOST_LOCALE_WITH_ICU=1; e.g.: What's the correct way to do this? ----- Braden McDaniel braden(a)endoframe.com -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Users-f2553780.html

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Newby help with Boost::Log
by Davies, John 08 Nov '18

08 Nov '18

I'm using Boost Log to capture all keypresses in my embedded device. I want to be able to store at most 3 files of a certain size and rotate them. That's working. My problem is a scenario like this: The device is inserting data into Log_009.log which is in the base folder. In the log folder are Log_006.log, Log_007.log, and Log_008.log. The program stops and restarts. This may be due to some keypress that was logged in Log_009.log. When it restarts, it clears out Log_009.log and starts it over - losing the last logged keypresses Ideally, I'd like Boost Log to just keep appending to Log_009.log, but my reading online says that this isn't possible. My second favorite solution would be that Log_009 gets rotated and Log_010.log is started. Anything so I don't lose data. Here is my configuration: logging::add_common_attributes(); logging::add_file_log ( keywords::file_name = "KeyLog_%3N.log", keywords::target = "./Logs", keywords::rotation_size = 500, // 10 * 1024 * 1024, keywords::format = "[%TimeStamp%]: %Message%", keywords::auto_flush = true, keywords::min_free_space = 30 * 1024 * 1024, boost::log::keywords::max_size = 20 * 1024, keywords::enable_final_rotation = true, keywords::scan_method = sinks::file::scan_matching, keywords::max_files = 3 ); Can you see what I'm missing? If a program exits via a crash, does final rotation occur? Maybe I need something like enable_initial_rotation. Thanks for the help, John ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

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Deadline for 1.69.0 beta extended
by Marshall Clow 07 Nov '18

07 Nov '18

The deadline for closing the master branch for the 1.69.0 beta has been extended until Friday, November 9th. The final release date has not been changed. -- Marshall (who is at a WG21 meeting all week)

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