June 2014 - Boost - lists.preview.boost.org

[random] new threefry random engine
by Thijs van den Berg 13 Jun '14

13 Jun '14

Hi all, I've completed a nice new random engine that I would like to propose for addition to boost/random. The engine is called "threefry" and it's based on the paper "Parallel random numbers: as easy as 1, 2, 3" by Salmon, John K. and Moraes, Mark A. and Dror, Ron O. and Shaw, David E. I've been using it myself a lot for the last couple of years, and now I've rewritten it so that it will fit in the boost random framework and adhere to the concepts. It has some really nice properties, in particular for large scale parallel computing: * High quality randomness (according to the BigCrush tests) with a cycle length of 2^258 * Fast (comparable to Mersenne Twister) & little memory usage (13x 64 bit integers) * O(1) discard and guarantees for non-overlapping sequences when the (up to 256 bit) seeds are unequal I've uploaded the code, description and tests to https://github.com/sitmo/threefry The actual engine is at https://github.com/sitmo/threefry/blob/master/random/include/boost/random/t… I would really appreciate any feedback about the idea for inclusion and of course comments about the quality of the code,tests,docs kind regards, Thijs Sitmo Consultancy B.V. Financial Modelling & Data Science + 31 6 24110061 thijs(a)sitmo.com P.O. Box 1059, 2600BB, Delft, The Netherlands

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Errors Compiling in AIX 7.1 with gcc
by Axel Ismirlian 13 Jun '14

13 Jun '14

Hello, I am trying to compile boost on AIX 7.1 with gcc, but I am getting several errors. The configuration checks report that zlib support is disabled even though I do have that package installed. I also don't have icu support. Is there a package for that in AIX? I was not able to find one. Performing configuration checks - symlinks supported : yes - 32-bit : yes - arm : no - mips1 : no - power : yes - lockfree boost::atomic_flag : yes - has_icu builds : no warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - zlib : no - iconv (libc) : no - iconv (separate) : yes - icu : no - icu (lib64) : no - x86 : no - gcc visibility : no - long double support : yes warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. - zlib : no I also tried adding a user-config.jam in the boost/ (the same place as the project-config.jam) in order to add some flags to my gcc compilation and to use mpi, but my jam was soundly ignored. However, the most concerning of these errors is some apparent assembler error. gcc.compile.asm bin.v2/libs/context/build/gcc-4.8.1/release/link-static/threading-multi/asm/make_ ppc32_sysv_xcoff_gas.o Assembler: /tmp//cc0uhEhf.s: line 5: 1252-016 The specified opcode or pseudo-op is not valid. Use supported instructions or pseudo-ops only. /tmp//cc0uhEhf.s: line 8: 1252-016 The specified opcode or pseudo-op is not valid. Use supported instructions or pseudo-ops only. /tmp//cc0uhEhf.s: line 8: 1252-016 The specified opcode or pseudo-op is not valid. Use supported instructions or pseudo-ops only. /tmp//cc0uhEhf.s: line 8: 1252-016 The specified opcode or pseudo-op is not valid. Use supported instructions or pseudo-ops only. /tmp//cc0uhEhf.s: line 8: 1252-016 The specified opcode or pseudo-op is not valid. Use supported instructions or pseudo-ops only. /tmp//cc0uhEhf.s: line 11: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 15: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 19: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 22: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 25: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 27: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 28: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 30: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 32: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 34: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 37: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 40: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 46: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 48: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 50: 1252-142 Syntax error. /tmp//cc0uhEhf.s: line 53: 1252-142 Syntax error. I'm not sure how to go about fixing that. When I go to my /tmp/ directory ccvhH2Fc.s is not an assembler file present. Right after this message another error appears. ...failed gcc.compile.asm bin.v2/libs/context/build/gcc-4.8.1/release/link-static/threading-multi /asm/jump_ppc32_sysv_xcoff_gas.o... gcc.compile.c++ bin.v2/libs/context/build/gcc-4.8.1/release/link-static/threading-multi/untested. o libs/context/src/untested.cpp:7:2: error: #error "! code for this platform is untested - please r emove this file from build/Jamfile.v2 and report the test-result on boost-track !" #error "! code for this platform is untested - please remove this file from build/Jamfile.v2 and report the test-result on boost-track !" What is the complete path for the Jamfile.v2 that this error refers to? Any advice the community can offer would be greatly appreciated. Sincerely, -Axel

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[thread] Mass test failures on clang
by Andrey Semashev 13 Jun '14

13 Jun '14

Hi, I'm seeing mass test failures in Atomic and Log both in develop and master. E.g.: http://www.boost.org/development/tests/develop/developer/atomic.html http://www.boost.org/development/tests/master/developer/atomic.html The logs are not descriptive (as usual) but point to Thread compilation: http://www.boost.org/development/tests/develop/developer/output/teeks99-04b… Could this be resolved? The freeze deadline is nearing, so I'd like to see my test results at least once before it is reached.

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Code review for bug no. 7396
by ullas srinivas 13 Jun '14

13 Jun '14

Hi, I have fixed bug no. 7396 Bug # 7396 :filesystem::path::remove_all(path, error_code) throws filesystem_error exception Description : Several methods in filesystem::path, including remove_all, have an overload in which an extra error_code& argument is taken. According to the docs, this is supposed to cause failure (other than failure to allocate storage) to be reported in the error_code rather than as a thrown filesystem_error exception. However, remove_all can still throw filesystem_error exceptions because it uses a directory_iterator internally but makes no attempt to catch exceptions thrown by it. For example, if a subdirectory is deleted by another thread or process just before remove_all tries to list its contents, directory_iterator_construct will throw a filesystem_error that propagates up to remove_all's caller. As a side note, I think path and directory_iterator are both excessively exception-happy. It makes them painful to use. Root Cause : The exceptions thrown by fs::directory_iterator were not handled in remove_all_aux function of operations.cpp file. Fix: The exceptions thrown by fs::directory_iterator are handled by catching the exception and proper ly assigning error values . Try-catch statement has been put inside remove_all_aux function of operations.cpp file. I kindly request you to please find the patch file attached and review the bug Regards Ullas

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[test] Compilation errors on MinGW 4.8.1
by Adam Wulkiewicz 12 Jun '14

12 Jun '14

Hi, When I try to compile Boost.Test (develop) tests or any other tests using execution_monitor on MinGW-GCC 4.8.1 I get the following errors: ..\..\../boost/test/execution_monitor.hpp:364:27: error: 'FE_DIVBYZERO' was not declared in this scope BOOST_FPE_DIVBYZERO = FE_DIVBYZERO, ^ ..\..\../boost/test/execution_monitor.hpp:365:27: error: 'FE_INEXACT' was not declared in this scope BOOST_FPE_INEXACT = FE_INEXACT, ^ ..\..\../boost/test/execution_monitor.hpp:366:27: error: 'FE_INVALID' was not declared in this scope BOOST_FPE_INVALID = FE_INVALID, ^ ..\..\../boost/test/execution_monitor.hpp:367:27: error: 'FE_OVERFLOW' was not declared in this scope BOOST_FPE_OVERFLOW = FE_OVERFLOW, ^ ..\..\../boost/test/execution_monitor.hpp:368:27: error: 'FE_UNDERFLOW' was not declared in this scope BOOST_FPE_UNDERFLOW = FE_UNDERFLOW, ^ ..\..\../boost/test/execution_monitor.hpp:370:27: error: 'FE_ALL_EXCEPT' was not declared in this scope BOOST_FPE_ALL = FE_ALL_EXCEPT, ^ When I use MinGW-GCC 4.8.0 shipped with Qt5 everything is ok. I though I'll let you know since AFAIS this toolset isn't tested. If you decided to take a look at this and needed a guinea pig I'd be here. Regards, Adam

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Building Boost on Haiku
by Andrew Hudson 12 Jun '14

12 Jun '14

Hi, New booster here. I am building Boost 1.55 on Haiku X86 and have a build issue: -pthreads is not recognized by GCC 4.8 on Haiku X86 and gives an error. pthreads are supported by Haiku by default, so I need to suppress the compiler option but enable pthreads in the build. I used ./bootstrap.sh -PREFIX to set the default lib path as /usr is not used in Haiku Then I started the build with ./b2 install Where and how can I make this config change? I have little jam experience. I also need to suppress use of MPI as this is not ported yet. Many thanks!

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Meeting C++ Schedule released
by Jens Weller 12 Jun '14

12 Jun '14

Hello C++ & Boost Community, since last week the schedule for Meeting C++ is released: http://meetingcpp.com/index.php/schedule14.html Like last year Meeting C++ will feature 21 Talks in 3 Tracks, the conference will be opened by Scott Meyers, the closing Keynote will be given by Hartmut Kaiser. This years Theme Track is "Scientific Programming with C++". Also, if your are a student, you have the chance to participate in our student program which will give 50 Students access to the conference: http://meetingcpp.com/index.php/newsreader/items/meeting-cpp-2014-the-stude… kind regards, Jens Weller

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[config] config_test fails on g++ 4.8/4.9
by Peter Dimov 12 Jun '14

12 Jun '14

... due to In file included from ../libs/config/test/config_test.cpp:376:0: ../libs/config/test/boost_no_lambdas.ipp: In function ???int boost_no_cxx11_lambdas::test()???: ../libs/config/test/boost_no_lambdas.ipp:21:4: error: expected primary-expression before ???void??? (void)[](){}; ^ ../libs/config/test/boost_no_lambdas.ipp:21:4: error: expected ???)??? before ???void??? I'm not sure why.

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[review] Convert library
by Jeroen Habraken 12 Jun '14

12 Jun '14

Hi, As promised my review of the boost::convert library. Note that the questions were answered in a seemingly random order, thus I hope it all comes together. Secondly, being the author of the boost::coerce library [2][3] I may be a little biased at times, please forgive me. -- What is your evaluation of the design? There are two parts to this, the design of the backend and the design of the interface that the user predominantly sees. I have little to say on the first, the notion of multiple backend converters is a big step forwards and their interface is sane. I'm far less convinced when it comes to the user-facing interface as I believe the simple tasks should be simple and intuitive, whereas the harder tasks may be harder. The most trivial use of boost::convert, and boost::lexical_cast and boost::coerce simply don't compare in my opinion. boost::cstringstream_converter cnv; int i = boost::convert<int>::from("23", cnv).value(); versus int i = boost::lexical_cast<int>("23"); int j = boost::coerce::as<int>("23"); When the convert library makes it into boost I'd want to mentally deprecate lexical_cast as a library I should use, and always use convert instead. This means convert should have a default converter, which may well be backed by lexical_cast with an interface such as: int i = boost::convert<int>::from("23").value(); This still doesn't completely satisfy me as I'd like to write int i = boost::convert<int>::from("23"); but it'd be an improvement in my opinion. Now I'm aware lexical_cast doesn't have a non-throwing interface, and it probably never will, but I've solved the problem as follows in boost::coerce: int i = boost::coerce::as_default<int>("XXX"); int j = boost::coerce::as_default<int>("XXX", tag::hex()); int k = boost::coerce::as_default<int>("XXX", 23); int l = boost::coerce::as_default<int>("XXX", tag::hex(), 23); The former two returning the default-constructed int, 0, the latter two returning 23. That said, I'll be the first to admit the coerce interface isn't perfect, the fact that I need SFINAE to distinguish between as_default calls with two parameters, the second either being a tag (somewhat similar to your converters but not quite) or the default value goes to show just that. However I'd prefer int i = boost::convert<int>::from("23", cnv); int i = boost::convert<int>::from_default("23", cnv, 0); to the current interface using value_or(0). This is subjective though, and quite possibly a matter of taste. In summary, before this turns into too long a rant, I think the current user-facing interface can be improved substantially, but I'm well aware this is subjective. -- What is your evaluation of the implementation? I've only had a quick glance at the code and it still looks fine. The gripe I had two years ago regarding the use of reserved names (include guards prefixed with "__") has been fixed. A few comments though: In the boost::lexical_cast based converter there is a try { } catch (...) { } which I believe to be an overly broad catch as lexical_cast explicitly throws a boost::bad_lexical_cast. If in an unlikely event a std::bad_alloc were to be thrown for example I'd rather not have boost::convert hide it from me. In the std::strtol based converter errno isn't checked, and it must be noted that strtol accepts leading whitespace which may or may not be wanted. I've implemented what I believe to be a correct converter using strtol which checks for the leading whitespace in [0], but it comes with no guarantees as it's quite tricky indeed. The new C++11 wrapper std::stol and friends in [1] may be of use here, but unfortunately they only have a throwing interface. All converters are added to the main boost namespace which is crowded enough as it is -- hi boost::_1 --, and libraries should add their functionality to their own namespaces in my opinion. With the current design it's not possible to add them in the boost::convert namespace but I believe they should be in their own namespace, may I suggest boost::converter. It must be said that the first two comments are minor at best, the last regarding the namespace is more important but potentially quite trivial to fix. -- What is your evaluation of the documentation? I've found it to be very hard to write documentation as the library author as at some point you're so intimately familiar with your library that it's hard to get a feel for what the user needs. Whilst there are some rough edges I think the current documentation is decent enough for it not to pose a problem. Again a few comments: The motivation should probably be addressed first, not near the end. The printf and std::strtol based converters aren't documented, and the converters should probably be grouped into a sub-section along with an explanation of how to write your own. Last of all I'd like to see an examples directory showing the examples from the documentation, you already have a test/encryption.hpp which probably belongs there. -- What is your evaluation of the potential usefulness of the library? In the previous review I've argued the library its functionality should be added to boost::lexical_cast. Whilst I still hold that position for the previous version of the library I believe this is no longer the case for the present version, largely due to the added support for multiple backends. There would be no practical way for lexical_cast to add this, and I believe it to be very useful indeed. -- Did you try to use the library? With what compiler? Did you have any problems? I've tried the library with Clang 3.2 and 3.4, and GCC 4.6 and 4.8 on Mac OS X 10.9.3 and the examples from the documentation using the sstream converter compile and run fine. When I tried the printf_converter something as simple as: #include <boost/convert/api.hpp> #include <boost/convert/converter/printf.hpp> int main(int, char *[]) { return boost::convert<int>::from("23", boost::printf_converter()).value(); } failed to compile. It's missing includes as adding the following to converter/printf.hpp fixes the problem: #include <boost/mpl/find.hpp> #include <boost/mpl/vector.hpp> This probably indicates that you're trying to test too much in a single file, and had the includes included via a different boost library. In the previous review I noticed that boost::convert<int>::from('1', cnv).value() spew a rather long error message. This has since been fixed, the error message is now considerably shorter making it easier -- will it ever be easy with C++ -- to figure out what's going on. I must note here that the error message the latest versions of GCC produced is actually easier to figure out than the one Clang produced. -- How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? Something between a quick reading and an in-depth study, now probably leaning towards the latter. -- Are you knowledgeable about the problem domain? As the author of boost::coerce, which I've admittedly ignored for far too long, I'm familiar with the conversion domain. Consequently I've seen the pitfalls and endured the hardships in designing and implementing such a library, my utmost respect for having it reviewed not once, but twice! And finally: -- Do you think the library should be accepted as a Boost library? In my previous review this was a straight no, stating that the functionality should be added to boost::lexical_cast. With the current design supporting multiple backends this no longer holds true as I've stated in the evaluation of the potential usefulness of the library. Again, the library is quite useful, but, I so strongly disagree with the current user-facing interface that I can't straight-out accept it. Once the library is accepted this interface is set in stone and like marriage it's "speak now or forever hold your peace". As such I'm voting YES, CONDITIONALLY on the interface being simplified for the seemingly simple cases as most of my other comments were minor or quite trivial to fix. With that out of the way I'd like to propose the following if you're interested. Let's have a look at whether it may be possible to merge the functionally of boost::convert and boost::coerce, as they seem to have grown towards each other with the possibility to support multiple backends. Two years ago I'd never have proposed this, but I've mellowed a bit since then. You seem to have focussed on backends primarily backed by std::stringstream and friends whereas I have focussed on a backend backed by boost::spirit. These may end up complementing leading to a single library capable of supporting both, being more generic and powerful to the user when done right. Regardless of whether we end up going this way I'd love to have a discussion on the interface, either on the mailing list or offline as this is currently a major stumbling block for me. Jeroen [0] https://github.com/VeXocide/coerce/blob/master/libs/coerce/example/backend.… [1] http://en.cppreference.com/w/cpp/string/basic_string/stol [2] https://github.com/VeXocide/coerce/ [3] http://vexocide.org/coerce/

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Even newer dependency report
by Peter Dimov 12 Jun '14

12 Jun '14

Shows significant progress. http://www.pdimov.com/tmp/report-d6c23cf/module-overview.html http://www.pdimov.com/tmp/report-d6c23cf/module-levels.html

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