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Library for await and stackless coroutine emulation
by TONGARI J 10 Mar '15

10 Mar '15

Hi there, I just want to announce my recent work on a small library called `CO2`, which intend to emulate await/yield and stackless coroutine. https://github.com/jamboree/co2 This library depends on Boost.Preprocessor, while I'm not proposing this library to Boost at this moment, if there's much interest in this library, I'd think about it. The idea is based on N4286: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4286.pdf The library is still work in progress, but the core features are complete, so if you're interested in the resumable function proposal and don't have a tool to experiment with, this library may serve the purpose. You can find a more detailed description on the github page, if you want to know some number about performance, from a rough test borrowed from Boost.Coroutine (symmetric/performance_switch.cpp), the avg cpu cycles for context-switch are: Boost.Coroutine: 40 cycles CO2: 16 cycles built-in await: 9 cycles (compiled with MSVC14, x64) Feedbacks will be appreciated. Thanks

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Release 1.58. - Permission to merge Boost.Integer
by Vicente J. Botet Escriba 09 Mar '15

09 Mar '15

Hi, I forget to do the merge to master of the last 5 commits in https://github.com/boostorg/integer/commits/develop Please, let me know if I can do the merge? Best, Vicente

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[interprocess] BOOST_NO_SWPRINTF not honored...
by Joseph Van Riper 09 Mar '15

09 Mar '15

This might seem pedantic, but with Microsoft's compilers magnify this issue a bit. boost/interprocess/detail/win32_api.hpp, line 2255 (as of boost 1.57) uses std::sprintf even when BOOST_NO_SWPRINTF is defined. This causes a problem for some folks (like me), as VC++ 2013 (and possibly other Microsoft compilers) have set a pragma deprecating this function, which leads to outright compiler errors when compiled with #pragma strict_gs_check(on), as is required in some environments who are picky about security. I confess, I have not checked to see if interprocess still does this in the latest code, but if it doesn't, I wonder if it could use an alternative (Microsoft recommends sprintf_s, but you might know of something better). - Trey

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[1.58.0] Release Notes
by Daniel James 09 Mar '15

09 Mar '15

Hi, The beta release is coming up soon, so please can you add your release notes as necessary. Easiest way is probably to create a pull request at: https://github.com/boostorg/website/blob/master/feed/history/boost_1_58_0.q… thanks, Daniel

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[gsoc15]Request for feedback: Enhanced vector and deque containers proposal
by Sandilya Jandhyala 08 Mar '15

08 Mar '15

Hello Boost, My name is Sandilya Jandhyala, and I'm interested in the 'Enhanced vector and deque containers' project idea. I've prepared a first draft of my proposal. It can be viewed here: https://github.com/jysandy/boost-gsoc-proposal/blob/master/README.md I haven't included my solution to the programming competency test, since I don't want it to be copied. I'd appreciate feedback/suggestions/criticisms, since I feel that the proposal still has some room for improvement. I'd also appreciate suggestions for additional features. Thanks, Sandilya

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GSoC project " Enhanced vector and deque containers "
by ahmad samir 08 Mar '15

08 Mar '15

Good morning guys I'm Ahmad, I want to contribute in " Enhanced vector and deque containers ", I'm working on the programming competency test, but I have a question about the main idea * The idea is " Write full-fledged and enhanced C++11 versions of std::deque and std::vector with extra functionality that gives the programmer more control over buffers, segments and iteration " . * Is there specific features or new functionality you want to add or I should search for some new features in other languages like " java & python " which isn't in C++ vector and deque containers, or search for what can give the programmer more control on these containers ?.

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GSoC 2015 Paritipation
by vladiksonic＠mail.ru 07 Mar '15

07 Mar '15

Dear Boost, I am eager to participate in GSoC 2015 in one of the two projects (from this page: https://svn.boost.org/trac/boost/wiki/SoC2015 , 1 or 5). As far as I understood - the first one is tougher, and (as for me) conditions are clearer, and the second one is (seemingly) simpler. I am totally new to Boost (never used it, actually, but that is because I mostly used C++ in programming contests). I am familiar with algorithms (from contests), and testing (manual, both for stability and performance), but I am not very familiar with C++11 (but I can compensate for that, because I have knowledge of other languages (C#, Javascript (nodejs)) and older C++ versions), and automated tests. At first, I'd like to ask - what should I choose? My main goals are: 1) To enter the community 2) Learn C++11 new features (I will start early on that, obviously) 3) And to learn how to code open-source programs (up till now I only have closed-source ones, apart from one project, which has not-so-good code quality - see here: https://github.com/hotab/OpticalBuilder ) 4) Plus understand better how to maintain library code (I already have some understanding of that, but I want to sharpen it). Both can give me that. I'm looking forward to hearing from you, Vladislav Babkin

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[dynamic_bitset] Maintainer available?
by Riccardo Marcangelo 07 Mar '15

07 Mar '15

Hi Boost developers, Does anybody know if the maintainer of dynamic_bitset is available? I made some contributions to dynamic_bitset on GitHub last year but there doesn't appear to have been any activity in the repository for many months. My pop_back() commit was accepted into the 'develop' branch over 5 months ago and, despite passing tests, has yet to be merged to 'master'. I also implemented capacity(), reserve(), and shrink_to_fit() which have been sitting in a pull request waiting to go into 'develop' since November. It would be nice to get these into 1.58.0 if possible. Kind regards, Riccardo -- View this message in context: http://boost.2283326.n4.nabble.com/dynamic-bitset-Maintainer-available-tp46… Sent from the Boost - Dev mailing list archive at Nabble.com.

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GSoC project " Enhanced vector and deque containers "
by ahmad samir 07 Mar '15

07 Mar '15

Good morning guys I'm Ahmad, I want to contribute in " Enhanced vector and deque containers ", I'm working on the programming competency test, but I have a question about the main idea * The idea is " Write full-fledged and enhanced C++11 versions of std::deque and std::vector with extra functionality that gives the programmer more control over buffers, segments and iteration " . * Is there specific features or new functionality you want to add or I should search for some new features in other languages like " java & python " which isn't in C++ vector and deque containers, or search for what can give the programmer more control on these containers ?.

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[GSOC2015] uBLAS Matrix Solver Project
by Rajaditya Mukherjee 07 Mar '15

07 Mar '15

Hi, My name is Raj and I am Phd student in Computer Graphics. I am interested in tackling the problem of uBLAS Matrix Solver and in order to write my proposal, I am looking for inputs for which of the following algorithms will be most useful for prospective users in boost-numeric library. Here is a categorical list of all the prospective ones which will bring uBLAS updated to other commercial libraries like Eigen/Armadillo. Please let me know your preferences.... *David Bellot* : As a potential mentor, do you have any specific additions or deletions for this list? This could also be useful for other candidates pursuing this project. *DENSE SOLVERS AND DECOMPOSITION* : 1) *QR Decomposition* - *(Must have)* For orthogonalization of column spaces and solutions to linear systems. (Bonus : Also rank revealing..) 2) *Cholesky Decomposition* - *(Must have)* For symmetric Positive Definite systems often encountered in PDE for FEM Systems... 3) *Householder Method* - Conversion to tridiagonal form for eigen solvers. *SPARSE SOLVERS AND PRECONDITIONERS* : 1) *Conjugate Gradient* - *(Must have)* For symmetric Positive Definite systems, this is the kryvlov space method of choice. Both general and preconditioned variants need to be implemented for convergence issues. 2) *BiCGSTAB* *(Needs introspection)* - For non symmetric systems.. 3) *Incomplete Cholesky Decomposition* *(Good to have)* - For symmetric Positive definite sparse matrices, to be used as preconditioner as extension to (1) for preconditioned CG Methods ... 4) *Jacobi Preconditioner* *(Must have)* - As prerequisite for step(1). *EIGEN DECOMPOSITION MODULES (ONLY FOR DENSE MODULES)**:* 1) *Symmetric Eigen Values* - *(Must have)* Like SSYEV Module in Lapack - That is first reduction to a tridiagonal form using Householder then using QR Algorithm for Eigen Value computation. 2) *NonSymmetric Eigen Values* - *(Good to have)* Like SGEEV module in Lapack - using Schur decompositions as an intermediate step in the above algorithm. 3) *Generalized Eigen Values* - *(needs introspection)* I use this in my research a lot and its a good thing to have.. ** Computing Eigen Decomposition of sparse modules needs special robust numerical treatment using implicitly restarted arnoldi iterations and may be treated as optional extensions.

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[MPL lite or MPL 2] A modest proposal
by Robert Ramey 07 Mar '15

07 Mar '15

I've been looking at another thread which address the problems of maintaining and/or finding a maintainer for MPL. I've come up with an idea for a proposal which I've laid out here: Library Idea MPL lite or MPL2 <http://rrsd.com/blincubator.com/bi_suggestion/mpl-lite-or-mpl2/> -- View this message in context: http://boost.2283326.n4.nabble.com/MPL-lite-or-MPL-2-A-modest-proposal-tp46… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[asio] Massive regression failures
by Aparna Kumta 06 Mar '15

06 Mar '15

I am running the regression tests on the develop branch with Oracle Solaris Studio12.4 on Solaris 11.2 OS. Tests for asio fail as follows: ../boost/system/config.hpp", line 34: Error: #error Must not define both BOOST_SYSTEM_DYN_LINK and BOOST_SYSTEM_STATIC_LINK. I looked at the developer issues on http://www.boost.org/development/tests/develop/developer/issues.html and see that asio tests fail similarly. I'm not sure what causes both BOOST_SYSTEM_DYN_LINK and BOOST_SYSTEM_STATIC_LINK. to be defined on the command line. Any idea on how this can be fixed? Thanks, Aparna

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[move] unique_ptr: problems with move-assign constructor when used with base/derived classes in C++03
by Adam Romanek 06 Mar '15

06 Mar '15

Hi, There is a problem with move-assignment constructor in boost::movelib::unique_ptr when used with a pair of base/derived classes in C++98/03 mode [1] (uncomment the code to see the compiler error). Is it a known issue? Or a limitation of the emulation? I discovered the issue when I wanted to use boost::movelib::make_shared in an answer to a question on StackOverflow [2], i.e. return boost::movelib::make_shared<Derived>(); Where the return value is boost::movelib::unique_ptr<Base>, but unfortunately because of this issue, in C++03 we need to use: return unique_ptr<Base> x(new Derived()); I can create a ticket if that is desired. Nevertheles, thanks for boost::movelib::unique_ptr anyway! BTW, note how the appearance of boost::movelib::unique_ptr makes the most voted answer on the question [3] invalid. This is where my answer comes in. Best regards, Adam Romanek [1] http://melpon.org/wandbox/permlink/8Rvk2g7LJ0Ey0BQL [2] http://stackoverflow.com/a/28193068/1776942 [3] http://stackoverflow.com/q/2953530/1776942

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GSoC 2015 project " Enhanced vector and deque containers "
by ahmad samir 06 Mar '15

06 Mar '15

Good morning I wish to contribute in this project, now I am working on programming competency test. I want to ask about Is there specific or preferable method to show you my work or just upload my code in any online compiler or Github?.

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[random] Quantization effects in generating floating point values
by John Maddock 05 Mar '15

05 Mar '15

First off, I notice there are no examples for generating floating point values in Boost.Random, so maybe what follows is based on a misunderstanding, or maybe not... Lets say I generate values in [0,1] like so: boost::random::mt19937 engine; boost::random::uniform_01<boost::random::mt19937, FPT> d(engine); FPT d = d(); //etc Where FPT is some floating point type. Now my concern is that we're taking a 32-bit random integer and "stretching" it to a floating point type with rather more bits (53 for a double, maybe 113 for a long double, even more in the multi-precision world). So quantization effects will mean that there are many values which can never be generated. It's true that I could use independent_bits_engine to gang together multiple random values and then pass that to uniform_01, however that supposes we have an unsigned integer type available with enough bits. cpp_int from boost.multiprecision would do it, and this does work, but the conversions involved aren't particularly cheap. It occurs to me that an equivalent to independent_bit_engine but for floating point types could be much more efficient - especially in the binary floating point case. So I guess my questions are: Am I worrying unnecessarily? and What is best practice in this area anyway? Thanks, John.

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[build] adding a rquirement for Cygwin only?
by Peter Dimov 05 Mar '15

05 Mar '15

Is it possible to add, for example, <threadapi>pthread to a project's requirements, but only for Cygwin? This works: <toolset>gcc,<target-os>windows:<threadapi>pthread but it also applies to MinGW. This only applies to MinGW: <toolset-gcc:flavor>mingw:<threadapi>pthread but Cygwin has no <flavor>. This: <toolset>gcc,<target-os>windows:<threadapi>pthread <toolset-gcc:flavor>mingw:-<threadapi>pthread doesn't work. There are references to <target-os>cygwin in gcc.jam, but <target-os> is actually 'windows'.

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Call for Papers Meeting C++ 2015
by Jens Weller 05 Mar '15

05 Mar '15

Hello boost community! I'd like to inform you that the call for papers for this years Meeting C++ conference is running! It will end at April 5th, boost related talks are very welcome! This years conference will be again at the Andels Hotel in Berlin, on the 4th and 5th december. It will feature 2 keynotes and 4 Tracks a 7 Talks, this years theme track is "embedded and IoT". There is again also a student program, which will be announced later. Call for Papers: http://meetingcpp.com/index.php/newsreader/items/call-for-papers-for-meetin… Announcement: http://meetingcpp.com/index.php/newsreader/items/announcing-meeting-c-2015.… kind regards, Jens Weller

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GSOC 2015 : Introduction
by roopal nahar 05 Mar '15

05 Mar '15

Hi, I am Roopal, an undergraduate student from IIIT, Hyderabad, India. I would like to express my candidature as an applicant for GSOC, 2015. This is my first time contributing to an open source organization. I have been studying the list of ideas proposed so far and "Boost.uBLAS a library for matrix computations" has caught my attention. Before contacting you, the following is the spade work I have done so far : 1.) The Panda Libraries <http://pandas.pydata.org/pandas-docs/dev/generated/pandas.DataFrame.html> 2.) R package <http://cran.r-project.org/web/packages/data.table/index.html> Apart from the competency test(which I believe, will be submitted at the proposal time), what are your expectations from me and what can I do to prove my seriousness for the candidature before the proposal deadline? I will be joining the IRC channel as soon as my college proxy starts to work(A good time to invest in VPN! :P ) Cheers, Roopal

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GSoc 2015 libraries
by Ágota Horváth 05 Mar '15

05 Mar '15

Hello, I'm Ágota Horváth and I'd like to choose one of the Boost C++ Libraries project this year, because of the language and the interesting projects. However, I haven't really worked with libraries yet, so I'd appreciate if you could tell me how to get started. Thanks, Ágota

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[release 1.58] additional example
by Oliver Kowalke 05 Mar '15

05 Mar '15

Hello, I'd like to add an additional example to boost.context - do I get the permission? best regards, Oliver

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New to open source
by Brian Wood 04 Mar '15

04 Mar '15

Pranjal Rai writes: > Hi, > I am new to open source and would like to contribute to it. > Can someone please guide me what to do next? Hi, Pranjal, I have an archive of serialization and messaging code available here: http://webEbenezer.net/build_integration.html . My software has serialization support for some Boost types and I'm open to adding support for more Boost types. That is one way I contribute to Boost. -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

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New to the List?
by Rob Stewart 04 Mar '15

04 Mar '15

It seems that each newcomer to this mailing list manages to sign up without reading about our policies[1]. If you're one of them, please read them, paying particular attention to [2] and [3], before your next post. [1] http://www.boost.org/community/policy.html [2] http://www.boost.org/community/policy.html#subject-line [3] http://www.boost.org/community/policy.html#quoting ___ Rob (Sent from my portable computation engine)

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boost.ublas gsoc 2015
by Dhruv Kohli 04 Mar '15

04 Mar '15

Hello, I am Dhruv, majoring in Mathematics & Computing from Indian Institute of Technology, Guwahati. After doing a bit of research over the project ideas, I found the idea of further developing boost.ublas library interesting and have started writing the programming competency code. Here is the link to the code I've written yet: https://github.com/chiggum/boost.ublas/blob/master/gaussian_elimination.hpp. Though the code is not yet complete, but a naive version of algorithm is implemented and is integrated into ublas. To me, the code seems to be running properly. I need a little help to proceed further. 1. Can someone please direct me to some code snippet that shows how the error handling code is written in boost library. To be specific, the gaussian elimination doesn't work on singular matrices. So, I would like to set the errno and display appropriate message to the user whenever a singular matrix is given as an input. 2. What sort of test code is required? Do we need to have a test case with hard-coded output to be checked against the results obtained when the test case is passed to the algo. Or there's some other predefined format for testing codes in boost library. Sorry, I haven't yet gone through most of the code in boost library. Any further helpful links/resources are welcomed. Thanks & Best regards, Dhruv https://github.com/chiggum

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An invalid XML character (Unicode: 0x8) problem because of property_tree::xml_parser::write_xml
by Rohan Shetty 04 Mar '15

04 Mar '15

Hi, I have used the following C++ code to generate the xml boost::property_tree::ptree ptResponse; // Populate the tree from the Microsoft Outlook contactsstd::stringstream buf; const std::string enc("utf-8"); boost::property_tree::xml_writer_settings<char> settings(' ', 0, enc); boost::property_tree::xml_parser::write_xml(buf, ptResponse, settings); This works fine. But in one of the customer's machine, when reading the this(xml content) in a JAVA program. I get the following error An invalid XML character (Unicode: 0x8) was found in the element content of the document. Any help in solving this is appreciated. Regards,Rohan

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[foreach] Errors using foreach
by Edward Diener 04 Mar '15

04 Mar '15

When trying to use the foreach library, whether running it tests or trying to build quickbook which uses the foreach macro, I am seeing from different compilers: gcc-4.9.2 > In file included from stl_byval.cpp:15:0: > ./utility.hpp: In function 'bool sequence_equal_byval_n(foreach_container_type&, const char*)': > ..\..\../boost/foreach.hpp:906:96: error: no matching function for call to 'encode_type(foreach_container_type&, boost::is_const<std::list<int> >*)' > (true ? 0 : boost::foreach_detail_::encode_type(COL, boost::foreach_detail_::is_const_(COL))) > ^ > ..\..\../boost/foreach.hpp:1013:9: note: in expansion of macro 'BOOST_FOREACH_TYPEOF' > , BOOST_FOREACH_TYPEOF(COL) \ > ^ > ..\..\../boost/foreach.hpp:1095:77: note: in expansion of macro 'BOOST_FOREACH_BEGIN' > if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_cur) = BOOST_FOREACH_BEGIN(COL)) {} else \ > ^ > ./utility.hpp:20:5: note: in expansion of macro 'BOOST_FOREACH' > BOOST_FOREACH( foreach_value_type i, rng ) > ^ clang > In file included from stl_byval.cpp:25: > ././utility.hpp:20:5: error: no matching function for call to 'encode_type' > BOOST_FOREACH( foreach_value_type i, rng ) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > ..\..\..\boost/foreach.hpp:1095:77: note: expanded from macro 'BOOST_FOREACH' > if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_cur) = BOOST_FOREACH_BEGIN(COL)) {} else \ > ^~~~~~~~~~~~~~~~~~~~~~~~ > ..\..\..\boost/foreach.hpp:1013:9: note: expanded from macro 'BOOST_FOREACH_BEGIN' > , BOOST_FOREACH_TYPEOF(COL) \ > ^~~~~~~~~~~~~~~~~~~~~~~~~ > ..\..\..\boost/foreach.hpp:906:17: note: expanded from macro 'BOOST_FOREACH_TYPEOF' > (true ? 0 : boost::foreach_detail_::encode_type(COL, boost::foreach_detail_::is_const_(COL))) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > ..\..\..\boost/foreach.hpp:401:22: note: candidate function [with T = std::list<int, std::allocator<int> >] not viable: no known conversion from 'boost::is_const<list<int, allocator<int> > > *' to 'boost::mpl::false_ *' (aka 'bool_<false> *') for 2nd argument > inline type2type<T> *encode_type(T &, boost::mpl::false_ *) { return 0; } > ^ > ..\..\..\boost/foreach.hpp:404:30: note: candidate function [with T = std::list<int, std::allocator<int> >] not viable: no known conversion from 'boost::is_const<list<int, allocator<int> > > *' to 'boost::mpl::true_ *' (aka 'bool_<true> *') for 2nd argument > inline type2type<T, const_> *encode_type(T const &, boost::mpl::true_ *) { return 0; } > ^ > In file included from stl_byval.cpp:25: > ././utility.hpp:20:5: error: no matching function for call to 'encode_type' > BOOST_FOREACH( foreach_value_type i, rng ) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Does anybody know what is causing this error ? I can't seem to proceed in building documentation with quickbook until I can get foreach working. I pulled the latest foreach from the master branch and ran b2 headers but still the problem occurs.

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