April 2013 - Boost - lists.preview.boost.org

About
by Hasit Bhatt 17 Apr '13

17 Apr '13

I am 3rd year student of Computer Science and Engineering from Institute Of Technology, Nirma University, Ahmedabad, one of the best Engineering colleges in Gujarat. I was going through GSoC ideas page and, as I like algorithms, I wish to work on algorithms. So, I just wanted to ask, how can I start working on it. ~ Hasit Bhatt

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[gsoc-2013] Boost.uBLAS
by Jignesh Jain 17 Apr '13

17 Apr '13

I am interested in this project for Gsoc, which involves unification of vector and matrix libraries. I have been browsing boost ublas code, but have no idea about how should I begin as I am totally new to Boost. Can Someone please guide me some approach for getting started in this project. Thank you.

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[log] Segfault in "rotating_file" example
by Jason 16 Apr '13

16 Apr '13

I'm working from SVN trunk revision 83923. I've been experiencing segfaults when trying to set up a file sink that has date/time format specifiers in its file name. I thought I was doing something wrong, but I found that the "rotating_file" example also illustrates the same behavior. Here is a sample backtrace: #0 0x000000000077c0b8 in ?? () #1 0x0000000000415d25 in boost::date_time::microsec_clock<boost::posix_time::ptime>::create_time (converter=0x77c0b8) at /code/env/include/boost/date_time/microsec_time_clock.hpp:100 #2 0x00000000004d628b in boost::log::v2s_mt_posix::sinks::(anonymous namespace)::date_and_time_formatter::operator()(std::string const&, unsigned int) const [clone .isra.401] () #3 0x00000000004d639a in boost::log::v2s_mt_posix::aux::light_function<std::string (unsigned int)>::impl<boost::_bi::bind_t<boost::_bi::unspecified, boost::log::v2s_mt_posix::sinks::(anonymous namespace)::date_and_time_formatter, boost::_bi::list2<boost::_bi::bind_t<boost::_bi::unspecified, boost::log::v2s_mt_posix::sinks::(anonymous namespace)::file_counter_formatter, boost::_bi::list2<boost::_bi::value<std::string>, boost::arg<1> > >, boost::arg<1> > > >::invoke_impl(boost::log::v2s_mt_posix::aux::light_function<std::string (unsigned int)>::impl_base*, unsigned int) () #4 0x00000000004d3c90 in boost::log::v2s_mt_posix::sinks::text_file_backend::consume(boost::log::v2s_mt_posix::record_view const&, std::string const&) () #5 0x00000000004206c6 in boost::log::v2s_mt_posix::sinks::basic_formatting_sink_frontend<char>::feed_record<boost::log::v2s_mt_posix::aux::fake_mutex, boost::log::v2s_mt_posix::sinks::text_file_backend> (this=this@entry=0x783600, rec=..., backend_mutex=..., backend=...) at /code/env/include/boost/log/sinks/basic_sink_frontend.hpp:445 #6 0x000000000042082f in boost::log::v2s_mt_posix::sinks::basic_formatting_sink_frontend<char>::try_feed_record<boost::mutex, boost::log::v2s_mt_posix::sinks::text_file_backend> (this=0x783600, rec=..., backend_mutex=..., backend=...) at /code/env/include/boost/log/sinks/basic_sink_frontend.hpp:489 #7 0x00000000004c1475 in boost::log::v2s_mt_posix::core::push_record_move(boost::log::v2s_mt_posix::record&) () #8 0x000000000040dff1 in push_record (this=<optimized out>, rec=...) at /code/env/include/boost/log/core/core.hpp:308 #9 push_record_unlocked (rec=..., this=<optimized out>) at /code/env/include/boost/log/sources/basic_logger.hpp:268 #10 push_record (rec=..., this=<optimized out>) at /code/env/include/boost/log/sources/basic_logger.hpp:582 #11 ~record_pump (this=0x7fffffffddc0, __in_chrg=<optimized out>) at /code/env/include/boost/log/sources/record_ostream.hpp:279 #12 main (argc=<optimized out>, argv=<optimized out>) at main.cpp:84 Looking at the disassembly of where the segfault happens, it seems to have gone off the rails and is executing invalid code. Specifically, the function pointer "converter" inside the date_time::microsec_clock<>:create_time() function seems to be invalid. Any ideas? I'm using gcc 4.7.2 on Ubuntu 12.10. Jason -- View this message in context: http://boost.2283326.n4.nabble.com/log-Segfault-in-rotating-file-example-tp… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[smart_ptr] No more shared_ptr<T>::value_type?
by Andrew Hundt 16 Apr '13

16 Apr '13

I updated from boost 1.52 to 1.53 and it appears that the typedefs have been removed, I couldn't find any mention of it in the release notes, and I searched the list for shared_ptr value_type and saw no mention of the change there. Was this a deliberate change? This breaks a *lot* of code for me, and will make more difficult for me to convince my team to continue to use boost or upgrade in the future because they are very apprehensive of breaking changes. I understand if it has been removed to be C++11 compliant but I expected some warning before breaking changes like this. boost::thread and boost::filesystem are good examples of changes that were made with solid advance notice. This caught me completely by surprise, did I miss something obvious? Could someone point me to the recommended alternative as well? 1.52 has typedef T value_type: http://www.boost.org/doc/libs/1_52_0/boost/smart_ptr/shared_ptr.hpp 1.53 does not: http://www.boost.org/doc/libs/1_53_0/boost/smart_ptr/shared_ptr.hpp Thanks for your help! Cheers! Andrew Hundt

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Windows Binary Builds
by Tom Kent 16 Apr '13

16 Apr '13

A couple months ago some of us got an e-mail from Dave Abrams saying that since BoostPro was going to be shutting down, there wouldn't be anyone maintaining the windows binary installer that they had been offering. Since I have been making windows binaries available on my site for the last several releases [http://boost.teeks99.com] he suggested that I take this over. I currently have a simple zip file (self extracting though) that just grabs all the 32 bit or 64 bit binaries...and they're huge, 6-8GB installed. So going forward I've built a system to make one installer for each tool/architecture: msvc-8.0-32, msvc-9.0-32, msvc-10.0-32, msvc-11.0-32, msvc-8.0-64, msvc-9.0-64, msvc-10.0-64, msvc-11.0-64. In addition to the binaries for that architecture, I would also include the boost release inside the installer. This way it is a single download/single install for everything an end-user developer would need (for each architecture). If a user wants multiple architectures, he/she can run multiple installers and they will instill on top of each other (with seperate lib directories for each set of binaries...for example: boost_1_53_0/lib_32-msvc-8.0 and boost_1_53_0/lib_64-msvc-11.0). All the scripts I use to build these (assume visual studio pro 8.0, 9.0, 10.0, and 11.0) are on my github account at: https://github.com/teeks99/boost-build If you want to see for yourself, I have the 1.53 installers on my website at: http://boost.teeks99.com/bin/boost_1_53_0-msvc-8.0-32.exe http://boost.teeks99.com/bin/boost_1_53_0-msvc-9.0-32.exe http://boost.teeks99.com/bin/boost_1_53_0-msvc-10.0-32.exe http://boost.teeks99.com/bin/boost_1_53_0-msvc-11.0-32.exe http://boost.teeks99.com/bin/boost_1_53_0-msvc-8.0-64.exe http://boost.teeks99.com/bin/boost_1_53_0-msvc-9.0-64.exe http://boost.teeks99.com/bin/boost_1_53_0-msvc-10.0-64.exe http://boost.teeks99.com/bin/boost_1_53_0-msvc-11.0-64.exe If we like this going forward, I'd be happy to upload these to sourceforge for each release, instead of having to go to my site for them. Thoughts? Tom Kent

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Reading uBLAS Documentation
by Yosef Hamza 16 Apr '13

16 Apr '13

i'm little confused here ... should i read the documentation in the same sequence they are written ?(i started that way and i'm having a hard time but still on it) or should i start from (Storage and Special Containers) and down? Thanks in advance!

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Google Summer of Code 2013 - Boost.org - Boost.Multiprecision
by Saurav 16 Apr '13

16 Apr '13

Hi! I am a CS undergraduate student and I really want to work on Boost.Multiprecision<https://svn.boost.org/trac/boost/wiki/SoC2013#Boost.Multiprecision>. C++ has been my favorite programming language and I find GSoC 2013 a wonderful opportunity to create something valuable with it, while getting some 'value' out of it for myself. I like learning new things and trying to find out better ways of doing existing things. I like coding and listening to music (sometimes simultaneously too). Greetings to the entire Boost community. And Thank you! I really appreciate the great work Boost is doing for the rest of us, and I want to be on the other side now, and do something for the rest of them. That's all from my side. I wish to get through to Christopher Kormanyo, the mentor for the project I am interested in, to discuss more specifically about the further steps. Thanking you all once again, Best regards, Saurav

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What Should we do About Boost.Test?
by Dave Abrahams 16 Apr '13

16 Apr '13

Hi All, I was just going through Boost.Test to try to figure out how to teach it, and while it looks to have substantial value, it is also in quite a mess. It contains loads of features that are exercised in the examples/ directory but neither included in any of the tests nor documented. There are facilities for command-line argument parsing! There are "decorators" that turn on/off features for test cases. There is support for mock objects! These are cool and sometimes necessary features, but who knew? The third tutorial page (http://www.boost.org/doc/libs/1_51_0/libs/test/doc/html/tutorials/new-year-…) has a glaring typo in the code examples: "BOOST_AUTO_EST_CASE". There's no reference manual at all. There are nearly-identical files in the examples/ directory called "est_example1.cpp" and "test_example1.cpp" (Did the "t" key on someone's keyboard break?) I could go on, but where would I stop? I don't know what to do about this. Because of the lack of redundancy (i.e. tests and documentation), it's hard to tell whether this library is correct or even to define what "correct" should mean. It seems like, as long as the code is incompletely / incorrectly documented and tested, it's just someone's personal coding project that we happen to keep shipping with Boost, and not really a library for general use. This situation reflects poorly on Boost as a whole and the fact that it centers around a _testing_ library, which is concerned with robustness... well, let's just say that the irony isn't lost on me. I don't mean this posting as an attack on Gennadiy in any way, but I think the situation is unacceptable and therefore am opening a discussion about what should happen. As a straw man, I'll make this suggestion: - Boost.Test is officially deprecated in the next release - Its documentation, such as it is, is removed from the release after that - Meanwhile, other tests in Boost that use this library are rewritten to use a different mechanism - The code is removed from Boost thereafter I am not at all attached to removing Boost.Test from Boost, but IMO rescuing it would require a significant new investment of time and energy from people who are committed to bringing the library up to par with the rest of what we do. (I seriously thought about volunteering for this myself, but realistically speaking, I don't have the time, and volunteering for something you can't actually do is worse than not volunteering at all.) Even if volunteers show up, I'd suggest proceeding with the plan above, subject to reversal at any time the work actually gets done. Thoughts? -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

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[any] last commit breaks program_options
by Jürgen Hunold 15 Apr '13

15 Apr '13

Hi! It seems that introducing move semantics to Boot.Any in r 83901 breaks compilation of program_options. /home/hunold/src/devel/boost/boost/program_options/variables_map.hpp:58:38: note: no known conversion for argument 1 from ‘boost::program_options::variable_value’ to ‘boost::program_options::variable_value&’ Full build log attached. Any Ideas? Yours, Jürgen -- * Dipl.-Math. Jürgen Hunold ! * voice: ++49 4257 300 ! Fährstraße 1 * fax : ++49 4257 300 ! 31609 Balge/Sebbenhausen * jhunold(a)gmx.eu ! Germany

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GSOC 2013 Parallelized Backend
by Muhammad Junaid Muzammil 15 Apr '13

15 Apr '13

Hello, This is Junaid form National University of Sciences and Technology. I have gone through the GSOC 2013 idea listing. I am pretty much interested in extension of odeint. I am more interested for the parallelization over the GPUs preferably NVIDIA. From the details listed there, it seems that Boost community is more interested in parallelization over the CPUs i.e. much preference is given to OpenMP and MPI. Is that the case here? Regards, Junaid.

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