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

Boost summer of formal reviews
by Borislav Stanimirov 12 Mar '14

12 Mar '14

Hello, This is a (half-)joke suggestion. There are currently 19 libraries in the review schedule ( http://www.boost.org/community/review_schedule.html ) which need a review manager (yes, including mine). Some of them have been there for years. Instead of focusing on getting people to write new libraries, which could potentially end up stuck in the review schedule (like AFIO), why don't we focus on getting the reviews for the ones that are already there. Or at least revising the review process. For example, I would be willing to review some of these libraries, but I am not qualified to be a review manager (since I am not very active in the community). I am not saying that most (or any) of the libraries stuck in review limbo, should pass the process, but some of them at least deserve a look (again, like AFIO). -- Borislav

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[GSoC 2014] [ Hypergeometric functions ] [ Complex Numbers Calculations ]
by Cosmin Boaca 11 Mar '14

11 Mar '14

Hello, I am Cosmin Boaca and I want to work during GSoC 2014 at the hypergeometric functions project. The project aims to approximate some hypergeometric functions for real values of their parameters. Even though the final result of the computation will be a real floating point number, some intermediate results would require complex numbers calculations such as the real power of a negative number, the square root of a negative number and also basic operations with complex numbers. My first question is : is there a way to do this operations using boost::multiprecision types such as cpp_dec_float and cpp_bin_float in order to store the real and the imaginary part of the complex number ? The second question is : Can I use the complex functions from the cstdfloat branch of Boost.math ? Thank you, Cosmin Boaca

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Boost.Align review manager approved
by Glen Fernandes 11 Mar '14

11 Mar '14

On February 25, 2014 Glen Fernandes wrote: >Ahmed, many thanks. :-) > >Some information about the role of a review manager: >http://www.boost.org/community/reviews.html#Review_Manager > >The next step, after you verify the submission code/documentation is >complete, would be to get in touch with the review wizard, Ron, > and finalize a date for the review. Ahmed, Ron just listed you as the review manager for Align. :-) Thanks again for volunteering. Glen

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Fwd: Regarding GSoc'14 Boost.odeint idea
by Rishav Agrawal 11 Mar '14

11 Mar '14

Sir/Mam, I, Rishav Agarwal, am a sophomore studing at the Indian Institute of Technology, Kanpur, India. I am interested in the working on implementing implicit routine for solving ODEs. I have done a semeser long on Numerical Methods in my third semester and am quite familiar with the algorithms used. Although I do not have much experience working with the Boost library, I am well aquaited with C++ and Python and can pick up the libraries easily. I would appreciate if the probable mentor could guide me through the application process and tell me about any pre-requisite/tests that I need to clear which could strengthen my proposal. A list of my previous projects can be found here <http://github.com/rra94>. Sincerely, Rishav Raj Agarwal I.I.T.Kanpur

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Standard C++ [Boost.Document] API
by pritesh vikram 11 Mar '14

11 Mar '14

Hello guys, As of having interested in Participating this year's Google Summer of Code Program. I am interested in developing Library which allow integration with spreadsheet application. Situation: As there is need for an API which understands all currently available formats of office applications running in different platforms. So API has to be aware of all formats available to all the platforms. There will be support for interconversion between these document formats.As well as classes and functions supporting to these operations.Conversion to portable formats like PDF. Proposed Solution: Separate components withing the library would be needed for Word processor, Spreadsheet, Presentation application.And also conversion code for each of these components with respect to different formats. Steps Involved: 1. Design all necessary components needed for the proposed solution. 2. Keeping informed to the mentor for the proposed design. 3. Implement using C/C++ as a language for the integration with the existing boost library. 4. Testing the Implemented model. 5. Getting the implemented code approved with the mentor. 6. Proceeding with the full implementation of the API. Benefits: 1. Help existing boost library users to take advantage of the creation, modification,conversion features for office documents. 2. No need for the users to look for another API for getting support for manipulation with office documents. As there is no existing work going on relating to this API.I am aware that all the libraries and components must be developed from scratch. I will move foreword with my above specified proposal for the project. If there is any more details to be included in the API i would like to informed for the additional details needed for this project to be fully integrated with all necessary components. If my proposal is effective then i would like to be appreciated that i am good to go for proposed layout with google summer of code program. Thanks, Pritesh Vikram

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boost::iterator_range does not work in boost::variant in boost 1.55
by Jon Biggar 11 Mar '14

11 Mar '14

If I try to put a boost::iterator_range into a boost::variant, it breaks the variant, because something in boost::iterator_range doesn't allow variant to use SFINAE deduction. My best guess at the problem is the declarations in boost/range/iterator_range_core.hpp that have a 'class ForwardRange' template argument are insufficiently constrained and accept almost anything as a possible ForwardRange type. I'm guessing that putting the correct enable_if<> template constraints on the templates that use 'ForwardRange' will fix the issue, but I'm having trouble identifing the correct metafunction test to use, since concept FowardRange concept doesn't have too many good targets. I'd like to test a candidate FowardRange type to see if boost::begin() and boost::end() can be successfully called on it, but I haven't figured out how to do that yet. Any suggestions? Known fixes or workarounds? I know about the has_range_iterator metafunction, but it can't be used here due to circular definition issues... Exmaple: #include <boost/variant.hpp> #include <boost/range.hpp> #include <boost/mpl/vector.hpp> using namespace boost; enum E { e1, e2, e3 }; typedef mpl::vector<E, std::string > args; typedef boost::make_variant_over<args>::type OkVariant; typedef mpl::vector<boost::iterator_range<std::string::iterator>, args> args1; typedef boost::make_variant_over<args1>::type BrokenVariant; int main(int argc, char **argv) { OkVariant ok; ok = e1; ok = ""; BrokenVariant broken; std::string s; broken = boost::iterator_range<std::string::iterator>(s.begin(), s.end()); broken = e2; broken = ""; } Yields errors on the last two assignments to 'broken' in g++4.8.2: test.cpp:27:12: required from here ./boost/mpl/eval_if.hpp:60:31: error: no type named 'type' in 'boost::mpl::eval_if_c<true, boost::range_const_iterator<E>, boost::range_mutable_iterator<const E> >::f_ {aka struct boost::range_const_iterator<E>}' typedef typename f_::type type; I've attached the full error log and my project-config.jam. -- Jon Biggar jon(a)floorboard.com jon(a)biggar.org jonbiggar(a)gmail.com

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Boost.Thread project for GSoC 2014
by Haoyue Wang 11 Mar '14

11 Mar '14

Hi, I am Haoyue, a PhD student in geophysics at MIT. I used C++11 to write parallel finite element codes in my research and had some coursework on concurrent programming. Boost is such a powerful and efficient library. I sincerely hope I could contribute to it this summer and beyond. I am interested in the standalone GSoC Projects under Boost.Thread. Particularly, the Work-Stealing-Thread-Pool project is a great one that I expect to learn a lot from. I understand that there could be much more to discuss once I have a preliminary proposal. Here I just want to ask if I am heading in the right direction. I think a good point to start is chapter 6, 7, and 9 of the book C++ Concurrency in Action: Practical Multithreading and the Executors and Schedulers revision 3 from http://www.open-std.org/. I haven't used Executor before but I am ware of its existence in Java for a while. Maybe I could go through some Executor and fork/join Java examples to see how they are used in practice. Finally, I will read and understand the executors codes on GitHub. I hope I could put up a good first draft proposal next Monday. If there is any advice, please let me know. Haoyue Wang

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Review Request: Convert V2
by Vladimir Batov 11 Mar '14

11 Mar '14

I think I've addressed all comments/suggestions received so far. So, to keep things moving I would like to request a formal review of the library. Location: https://github.com/yet-another-user/boost.convert.git Short Description: The main purpose of the framework is to unify and to deploy various conversion facilities through one consistent interface, to provide generic consistent behavior -- one of the factors in improving productivity and code-correctness in commercial s/w development environment. / Boost.Convert/ builds on the /boost::lexical_cast/ experience and takes those conversion/transformation-related ideas further * to be applicable to a wider range of conversion-related deployment scenarios, * to provide a more flexible, extensible and configurable type-conversion framework. Thank you.

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speed of light from universal_constants Boost.Units
by Roger Martin 10 Mar '14

10 Mar '14

Hi, I've tried and tried and just not understanding or can't muddle my way through the boost units(looks powerful though). For a start, just trying to get at the speed of light in boost/units/systems/si/codata/universal_constants.hpp boost::units::si::constants::codata::c boost::units<boost::units::si>::constants::codata::c.value() and massive errors; especially if I try to multiplying with something. I use boost::math::constants::pi<double>() from #include "boost/math/constants/constants.hpp" But the universals allude me; and example? where is my brain stuck?

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Regression test failures on the develop branch
by Neil Groves 10 Mar '14

10 Mar '14

Hi! I've been doing some work on Boost.Range and have been ignoring complete failures from the following machines: teeks99* *jc-bell jasonr-Ubuntu13.04-intel-13.0.1 I'm concerned that the errors have been present for a couple of weeks. We are almost without MSVC coverage on the develop branch. I have taken to going off-process and after cycling the other platforms pushing to master to get coverage of MSVC. Of course I completely understand the difficulties balancing our busy schedules to devote time to Boost. This isn't a complaint. I wondered if there was already a plan to fix these and if there was anything I could do to help. Do we need more machines covering Microsoft compilers and platforms? Should we be approaching companies that use Boost with Microsoft that might be willing to donate some equipment and/or time? I don't think the risk is unacceptable at present since the new branching model means that at this stage of the schedule a hiccup on master can be quickly reverted without a total train wreck. I think we should probably get on top of this before we reach the final phase of the next release. Please let me know if I can help in any way. Regards, Neil Groves

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