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C++Now 2014: Call for Submissions
by Hartmut Kaiser 20 Oct '13

20 Oct '13

============================================== C++ Now Conference 2014 Aspen CO, USA, May 12-17, 2014, www.cppnow.org ============================================== Call for Submissions -------------------- We invite you to submit session proposals to the 2nd annual C++ Now Conference (Aspen CO, USA, May 12-17, 2014). Building upon the resounding success of C++ Now 2013 and five years of BoostCon, C++ Now 2014 will present leading speakers from the whole C++ community. The C++ Now Conference is dedicated to discussion and education about C++, an open and free language and standard. Our Conference will focus on discussion and education about open source software usage and developments in the C++ developer and user community. To reflect the breadth of the C++ and Boost communities, the conference includes sessions aimed at three constituencies: C++ and Boost end-users, hard-core Boost library and tool developers, and researchers pushing the boundaries of computation. The program fosters interaction and engagement within and across those groups, with an emphasis on hands-on, participatory sessions. As a multi-paradigm language, C++ is a melting pot where the most compelling ideas from other programming communities are blended in powerful ways. Historically, some of the most popular sessions at C++ Now have highlighted these concepts, from DSLs to functional programming to transactional memory and more. Bring your C#, Python, Ruby or Haskell influences to bear in an environment that will broaden their exposure. At C++ Now 2014 we would like to focus on the now established C++11 standard and the new, upcoming C++14 and how those standard are and will shape C++'s future. However, by no means this is intended to restrict the topics of proposals we hope to see. Any other topic related to C++ as outlined below is perfectly fine for submission. Important dates --------------- New proposal submissions due: December 8th, 2013. Proposals decisions sent (tentative program available): January 30th, 2014. Fully scheduled program available: February 24th, 2014. Best Presentation Awards ------------------------ We know how much effort it takes to prepare talks for our conference. For this reason we will award the best presentations in the following categories: Best Presentation, Best Short Presentation, Best Tutorial, and Best Workshop. The awards will be given based on the audience's voting. Each award will include the author's name listed on the cover of the C++ Now website for that year and a plaque containing all the C++ Now conference information. Session topics -------------- Topics of interest include, but are not restricted to, the following: * C++11/14 and how it changes life for users and library writers * General tutorial sessions on C++11/14, the C++11/14 Standards library, and one or more Boost libraries * Parallelism in the new C++11/14 standard * Parallel, distributed and GPGPU topics relating to C++ * In-depth sessions on using specific Boost libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * Development workshops to extend or enhance existing Boost libraries * Workshops on design process * Infrastructure workshops such as Build tools, Website, Testing * Concepts and Generic Programming * Hardware and infrastructure presentations focused on how libraries can make better use of the technology * Software development tools and their application to C++ and or Boost * Other topics likely to be of great interest to C++ users and developers Interactive and collaborative sessions are encouraged, as this is the style of learning and participation that has proven most successful at such events. Sessions can be tutorial based, with an emphasis on interaction and participant involvement, or workshop based, whether hands-on programming or paper-based, discussion-driven collaborative work. Session formats --------------- Presentations Presentations focus on a practitioner's ideas and experience with anything relevant to C++11 or C++14, Boost and users. Panels Panels feature three or four people presenting their ideas and experiences relating to C++11 or C++14 and Boost's relevant, controversial, emerging, or unresolved issues. Panels may be conducted in several ways, such as comparative, analytic, or historic. Tutorials Tutorials are sessions at which instructors teach conference participants specific skills relevant to C++11 or C++14 and Boost. Workshops Workshops provide an active arena for advancements in Boost-relevant topics. Workshops provide the opportunity for experienced practitioners to develop new ideas about a topic of common interest and experience. Author's Corner Presentations These were introduced at BoostCon 2008, and were a great success. They are short (30 minute) sessions, focusing on tips on usage and design. In addition, we're looking to uncover the hidden design gems in Boost libraries. Tool Vendors Presentations We actively encourage tool vendors and ISP's to submit proposals for a special Tool Vendors Session Track aimed at products related to Boost and C++ (compilers, libraries, tools, etc.). Other formats may also be of interest. Don't hold back a proposal just because it doesn't fit into a pigeonhole. Submitting a proposal --------------------- Standard Sessions are 90 minutes. You may submit a proposal for fractions or multiples of 90-minutes. Fractional proposals will be grouped into 90 minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned three hour (i.e. half day), or six hour (i.e. full day) time slots. Please include: * The working title. * Type of session: presentation, panel, tutorial, workshop, authors corner, vendor track, other. * A paragraph or two describing the topic covered, suitable for the conference web site. * Proposed length: 10-20 minute short talks, 45 minutes, 90 minutes, half day, full day. * Alternate lengths, if you are willing to make adjustments: 10-20 minute short-talks, 45 minutes, 90 minutes, half-day, full day. * Audience: users, developers, both. * Level: basic, intermediate, advanced. * A biography, suitable for the conference web site. * Your contact information (will not be made public). Submission details ------------------ All submissions should be made through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=cppnow2014. If you have not already registered at EasyChair, you will need to do so in order to submit your proposal. All submissions will go through a peer review process. Authors are invited (but are not required) to submit PDF versions of full papers of up to 10 pages in ACM conference proceedings format (see http://www.acm.org/sigs/publications/proceedings-templates) The full papers are not required unless you want them published in the proceedings. All accepted proposals will be made available in the Association for Computing Machinery (ACM) Digital Library (approval pending). Best papers, after further reviews, will be considered to be book chapters or journal articles in a renowned journal. The session materials go on the C++ Now website and will be available to attendees. For general information on the C++ Now 2014 paper submission or the scope of technical papers solicited; please refer to the conference website at www.cppnow.org. For any other questions about the submission process or paper format, please contact the Program Committee at cppnow2014(a)easychair.com. If you have any technical problems with EasyChair, please contact EasyChair for help. Note: Presenters must agree to grant a non-exclusive perpetual license to publish submitted materials, either electronically or in print, in any media related to C++ Now. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) Joel Falcou, email: joel.falcou(a)lri.fr (Program Committee Chair) Jon Kalb, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

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NT2 and Boost.SIMD beta 2 available
by Joel Falcou 18 Oct '13

18 Oct '13

This following releases updates NT2 and Boost.SIMD libraries.10 months had past and 176 Issues have been closed since last beta release and more than 2000 commits have been issued. Boost.SIMD is heading toward API stability. We want to tackle ons ome more compile time issues before going for an actual Boost Review. Special thanks to Tim Blenchmann and Domagoj Saric for their help and suggestions throughout this development. The release Changelog is here : https://github.com/MetaScale/nt2/releases The files can be download from : http://nt2.metascale.org/downloads/ The Documentation (in progress) is here : http://nt2.metascale.org/doc/html/index.html

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[Voronoi] Trying to figure out proper direction of semi-infinite edges.
by Nicolay P 18 Oct '13

18 Oct '13

Hi, Trying to figure out how to use the Voronoi library in 1.54 Boost (Great stuff BTW, Thanks!) I am using the library to shatter a 2d convex polygon. So I need to generate polygons that are the results of clipping a voronoi cell against my convex poly. I am having hard time figuring out how to properly identify the direction of the semi-infinite edge. I know i can obtain the general direction of the infinite edge from the participating cell points, but I am not clear on how to distinguish between two possible directions in the semi-finite case. Any help would be much appreciated! Thanks! Nick.

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Boost_1_54_0: boost::math::sph_bessel(n, x) crash at x=0 n>0
by JE Campagne 18 Oct '13

18 Oct '13

Dear developpers, I'am running Boost 1_54_0 on Scientific Linux slc-6.1, gcc-4.4.5, 64 bits machine. I face a problem with computation of spherical bessel function, although the problem seems well known here is a test program { int L; try { for(L=100;L<2010;L++) { boost::math::sph_bessel(L, 0.); } } catch (std::exception& sex) { cout << "Error j_"<<L<<"(0): "<< sex.what() << endl; } } And the output Error j_1755(0): Error in function boost::math::tgamma<e>(e): Result of tgamma is too large to represent. which tends to point out that at L=1755 the spherical bessel function get a problem once one ant to estimate at x=0. Of course, I know that j0(0) = 1 and for L>0 jL(0) = 0 but 1) I'm using a program which compute integral of product of bessel function and sometimes it needs to call the function at 0. So I would expect the BOOST library to be protected against that. Am I wrong? Best regards Jean-Eric

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zlib question
by Robert Ramey 18 Oct '13

18 Oct '13

I'm using boost 1.55 - current release branch and now I want to link with libboost_zlib-vc90-mt-sgd-1_55.lib - but of course I don't have this. What is the most expedient way to address this? Robert Ramey

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How to use multi index container?
by yuan 18 Oct '13

18 Oct '13

Hi, I try to use multi index container.I have one problem.Please help me.Thanks struct TOrder { char szDate[9]; //date type int nID; // order id int nProductID; //product id double fPrice;// int nVol;// //other member … } // The unique key of TOrder struct is szDdate and nID. How I can typedef the composite_key and the multi_index_container? Thank you for your help. Best regards. Yuan

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Getting introduced to boost Python world, struck at hello_ext.pyd generation
by Raghu Kalyan Anna 18 Oct '13

18 Oct '13

Hi, Started to explore boost.Python to use C++ classes (.so or .dll) from Python world. I did these, (Windows) downloaded boost 1.54 and unpacked to C:\boost_1_54, Python 3.3 (earlier tried with Python 2.7) installed visuall C++ 2010 Express free edition From Visual studio command prompt, tested example.cpp and got the result. Now struck in getting hellp.cpp and to generate hello_ext.pyd. Looked at posts in stackoverflow and tried similar steps. Still the same. After unpacking boost1.54, I tried these <boost root> C:\boost_1_54>bootstrap.bat C:\boost_1_54>b2 Now it said add C:\boost_1_54 to compiler include path and add c:\boost_1_54\stage\lib to linker paths. Added these two paths to %PATH% environment variable thru advanced settings. Now ran bjam from hello tutorial C:\boost_1_54\libs\python\example\tutorial>bjam hello_ext.pyd is not generated And noted this "LINK : fatal error LNK1104: cannot open file 'boost_python-vc100-mt-gd-1_54.lib' call "C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\vcvarsall.b at" x86 >nul link /NOLOGO /INCREMENTAL:NO /DLL /DEBUG /MACHINE:X86 /MANIFEST /subsystem:conso le /out:"bin\msvc-10.0\debug\hello_ext.pyd" /IMPLIB:"bin\msvc-10.0\debug\hello_e xt.lib" /LIBPATH:"C:\Python33\libs" @"bin\msvc-10.0\debug\hello_ext.pyd.rsp" if %ERRORLEVEL% NEQ 0 EXIT %ERRORLEVEL% ...failed msvc.link.dll bin\msvc-10.0\debug\hello_ext.pyd bin\msvc-10.0\debug\he llo_ext.lib bin\msvc-10.0\debug\hello_ext.pdb bin\msvc-10.0\debug\hello_ext.pdb. .. common.copy boost_python-vc100-gd-1_54.dll ..\..\..\..\bin.v2\libs\python\build\msvc-10.0\debug\boost_python-vc100-gd-1_54. dll 1 file(s) copied. ...skipped <p.>hello_ext.pyd for lack of <pbin\msvc-10.0\debug>hello_ext.pyd... common.mkdir bin\hello.test common.mkdir bin\hello.test\msvc-10.0 common.mkdir bin\hello.test\msvc-10.0\debug ...failed updating 3 targets... ...skipped 1 target... ...updated 41 targets..." If this is basic question, please answer. Or else please direct to appropriate Boost mailing list -- Regards, Ram **

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Re: [Boost-users] Boost_1_54_0: boost::math::sph_bessel(n, x) crash at x=0 n>0
by campagne 17 Oct '13

17 Oct '13

Thanks That's true that for x close to zero but positive there are also problems to the use of power series close to 0 is certainly the best thing to do. I am astonished that this not yet used. Jean Eric Envoyé depuis un mobile Samsung -------- Message d'origine -------- De : John Maddock <john(a)johnmaddock.co.uk> Date : A : boost-users(a)lists.boost.org Objet : Re: [Boost-users] Boost_1_54_0: boost::math::sph_bessel(n, x) crash at x=0 n>0 > I'am running Boost 1_54_0 on Scientific Linux slc-6.1, gcc-4.4.5, 64 > bits machine. > > I face a problem with computation of spherical bessel function, although > the problem seems well known here > is a test program Not well known to me - there are a number of fixes to the (cyclic) Bessel functions due out with 1.55, but I'm afraid this isn't one of them. BTW the issue effects all x < 1, not just x == 0. Here's the patch I'm about to commit to SVN: Index: boost/math/special_functions/bessel.hpp =================================================================== --- boost/math/special_functions/bessel.hpp (revision 86329) +++ boost/math/special_functions/bessel.hpp (working copy) @@ -48,7 +48,16 @@ { BOOST_MATH_STD_USING mult = x / 2; - term = pow(mult, T(v)) / boost::math::tgamma(v+1+T(0.5f), Policy()); + if(v + 3 > max_factorial<T>::value) + { + // term = v * log(mult) - boost::math::lgamma(v+1+T(0.5f), Policy()); + // term = exp(term); + // Denominator increases faster than numerator each time v increases by one, + // so if tgamma would overflow then the result is neceesarily zero. + term = 0; + } + else + term = pow(mult, T(v)) / boost::math::tgamma(v+1+T(0.5f), Policy()); mult *= -mult; } T operator()() @@ -142,6 +151,11 @@ if(n == 0) return boost::math::sinc_pi(x, pol); // + // Special case for x == 0: + // + if(x == 0) + return 0; + // // When x is small we may end up with 0/0, use series evaluation // instead, especially as it converges rapidly: // Index: libs/math/test/test_bessel_j.hpp =================================================================== --- libs/math/test/test_bessel_j.hpp (revision 86329) +++ libs/math/test/test_bessel_j.hpp (working copy) @@ -262,6 +262,13 @@ do_test_sph_bessel_j<T>(sph_bessel_data, name, "Bessel j: Random Data"); // + // Some special cases: + // + BOOST_CHECK_EQUAL(boost::math::sph_bessel(0, T(0)), T(1)); + BOOST_CHECK_EQUAL(boost::math::sph_bessel(1, T(0)), T(0)); + BOOST_CHECK_EQUAL(boost::math::sph_bessel(100000, T(0)), T(0)); + + // // Special cases that are errors: // BOOST_CHECK_THROW(boost::math::cyl_bessel_j(T(-2.5), T(0)), std::domain_error); HTH, John. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[serialization] customizing save/load for a type (pointer)
by Mathieu Champlon 16 Oct '13

16 Oct '13

Hi, I'm using Boost.Serialization on a project where part of the data is not serialized and then loaded separately when unserializing. For instance a class MyThing can have a member data MyThingData* which described some "static" data. There is an application which edits these data and saves them on file for the main application to use latter on. When serializing MyThing we customize save/load in order to serialize MyThingData as a UID (MyThingData has a GetId member function). Upon unserialization the proper MyThingData instance is searched for based on the UID read from the archive. This works OK but is a bit tedious because with class MyThing { ... MyThingData* data_; }; instead of simply doing template< typename Archive > void serialize( Archive& ar, const unsigned int ) { ar & data_; } we have to do something like BOOST_SERIALIZATION_SPLIT_MEMBER() template< typename Archive > void load( Archive& ar, const unsigned int ) { int id; ar >> id; data_ = FindData( id ); // not very important how it is actually retrieved } template< typename Archive > void save( Archive& ar, const unsigned int ) const { ar << data_->GetId(); } Moreover things get even more complicated when serializing for instance a std::vector< MyThingData* > ... So I'm looking for a way to customize the serialization of MyThingData*. Of course I could wrap MyThingData* in a simple object to encapsulate save/load but they're everywhere and the code base is quite massive so this would require a lot of changes. Any idea how I could achieve this ? Thank you ! Regards, MAT.

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bug in boost::date_time::time_facet?
by Jakub Zytka 16 Oct '13

16 Oct '13

Hi all I've run into a problem with *_facet from boost::date_time when compiling for windows and I'm pretty convinced it is a bug in boost (tested 1.49 and 1.54). However, since gcc makes a successful attempt not to trigger it, and I'm not exactly an expert on windows formats/linkers/etc I'd like to have second opinion before I fill a ticket. So, here we go: Consider following code: ------------- setFacet.h -------------------------- #include <iostream> __declspec(dllexport) void setFacet(std::ostream &); -------------- setFacet.cpp ----------------------- #include <boost/date_time/posix_time/posix_time.hpp> #include <locale> #include "setFacet.h" __declspec(dllexport) void setFacet(std::ostream & os) { boost::posix_time::time_facet * dateFormat =new boost::posix_time::time_facet("%Y-%m"); os.imbue(std::locale(os.getloc(), dateFormat)); } ------------------- test.cpp -------------------------- #include <boost/date_time/posix_time/posix_time.hpp> #include <iostream> #include "setFacet.h" using namespace std; int main() { std::string ts("20020131T235959"); boost::posix_time::ptime t(boost::posix_time::from_iso_string(ts)); cerr << t << endl; setFacet(cerr); cerr << t << endl; return 0; } ------------------------------------------------------- The expected result is that facet with "%Y-%m" format is imbued to cerr after calling "setFacet" function and that second print uses specified format. Now, suppose we built it so that we have setFacet.dll exporting function setFacet, and test.exe is linked against this dll. In such setting the code works under linux (gcc 4.1, 4.7), but it doesn't work under mingw-w64 4.6.4 or msvc10 - default format is used both times: linux: 2002-Jan-31 23:59:59 2002-01 windows: 2002-Jan-31 23:59:59 2002-Jan-31 23:59:59 Why? Well, lets look at operator<< for ptime. It does one interesting comparison: if (std::has_facet<custom_ptime_facet>(os.getloc())) this comparison gives different results under linux and windows. The key is static member "id" of a facet class. It is declared in boost/date_time/time_facet.hpp and it is used by has_facet to give answer whether locale has facet for the given class. Since this header is included twice - once in dll and once in exe there are two storages for id of the same facet class. In gcc 4.1 appropriate symbols are weak objects. Apparently only one is selected as the proper one by the linker and used universally. In gcc 4.7 it is even better. Appropriate symbols are "unique global symbol" which explicitly means there should be only one instance in whole process. In mingw both these storages are used independently and the same class (boost::posix_time::time_facet) has different id in dll (in setFacet function) and different in exe file (in operator<<). This is why operator<< believes locale has no facet for posix_time. At this point I was suspecting some incompatibility between windows' linker and mingw's libstdc++ implementation (regarding std::locale::id initialization) However, under msvc10 it doesn't work either, with msvc library. I believe it is a bug in boost, even if some deficiency in mingw/msvc/windows is involved. Also, let me confess I'm far from having learned boost docs by heart. If there is some big red sign somewhere telling I must link statically if using facets from boost::date_time have mercy on me. command lines used to build example: gcc (just get rid of these dllspecs): g++ -fPIC -shared -o libsetFacet.so setFacet.cpp g++ -L. -lsetFacet -Wl,--rpath=. -o test test.cpp mingw: x86_64-w64-mingw32-g++ -isystem pathToBoostIncludes -shared -o libsetFacet.dll -m32 -Wl,--enable-runtime-pseudo-reloc-v2 -Wl,--out-implib,libsetFacet.lib setFacet.cpp x86_64-w64-mingw32-g++ pathToBoostIncludes -o test.exe -m32 -Wl,--enable-runtime-pseudo-reloc-v2 -L. -lsetFacet test.cpp msvc10: cl.exe /I"pathToBoostIncludes" /LD set.cpp /EHsc /link /out:setFacet.dll /LIBPATH:"pathToBoostLibs" cl.exe /I"pathToBoostIncludes" /EHsc setFacet.lib test.cpp /link /LIBPATH:"pathToBoostLibs" regards, Jakub Zytka

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