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boost::ptr_vector::sort with c++11 lambdas
by qplace 12 Nov '11

12 Nov '11

I am trying to figure out if c++11 lambda can be used instead of the straight preducates. say, I have class A : public boost::noncopyable { ... } and boost::ptr_vector<A> lst; I'd like to use something like: lst.sort([&] (const A& v1, const A& v2) ->bool {return v1 < v2;}); Tutorial for ptr_vector says that predicates are wrapped in indirect_fun. May be this is the reason the sort fails to compile?

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Re: [Boost-users] [Spirit-general] Pattern matching with boost
by Anthony Foiani 12 Nov '11

12 Nov '11

Anthony Foiani <tkil(a)scrye.com> wrote: > Have you even tried my code? > > http://article.gmane.org/gmane.comp.lib.boost.user/71262 Seth Heeren <bugs(a)sehe.nl> writes: > FYI: that mail never seems to have arrived at my MUA... Perhaps it > got lost for Alec too? FWIW, the webinterface I sometimes use > doesn't seem to list your post either. I don't know the why's there, > just thought I'd mention. Drat. Thanks for the heads-up. And it seems that your message didn't go out over the boost-users list, either, although it did make it to spirit-general. Weird. Alec, I apologize for the snark in my latest message. When you replied to my later messages, but not to my original reply, I just assumed you had seen it and were ignoring it for some reason. Sorry about that. > Some corner cases to think about: > > 1. ... > B. ... > > +1 many good points! Only a side effect of fixing my own stupid mistakes for many years! Best regards, Tony

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Re: [Boost-users] dynamic_bitset: request for new functions
by David Hochstuhl 12 Nov '11

12 Nov '11

> My apologies if my tone was not friendly, this was not my intention. Hey, there is absolutely no reason why you should apologize... your tone is very friendly...and thank you again for your answer. >Given the current interface I find your requests quite reasonable. >I'm sure that if you provide a patch for the functions you are >suggesting, with documentation and test, the author/maintainer will >accept them. My hope was that the maintainer himself will do it. Writing the code for the find functions and other "easy" ones (like setting a range of bits to true, setting trailing zeros to true, etc) will probably take a few minutes. For me, it will at least take several days, as I first would have to study the source code of the class (although it is not all too long). btw, who is the maintainer of dynamic_bitset? best, David ___________________________________________________________ SMS schreiben mit WEB.DE FreeMail - einfach, schnell und kostenguenstig. Jetzt gleich testen! http://f.web.de/?mc=021192

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[smart_ptr] weak_ptr pointer semantics
by Szymon Gatner 12 Nov '11

12 Nov '11

Hi, Why weak_ptr does not have (smart) pointer semantics? No * or -> or even get(). I often need a pointer type that is a listener to shared_ptr<> (does not affect refcount) but is still usable as a regular pointer type. If providing * and -> operators is for some reason undesirable then just a get() member would be nice as it would allow to implement own wrapper with pointer semantics. get() would return raw pointer from shared counter (so is fast) and not shared_ptr<> as lock() does. -- Szymon Gatner The Lordz Games Studio www.thelordzgamesstudio.com

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[fusion] trouble with transform
by Gennadiy Rozental 12 Nov '11

12 Nov '11

Hi, I have code similar to the following snippet: #include <boost/fusion/container/list/list.hpp> #include <boost/fusion/container/list/convert.hpp> #include <boost/fusion/container/generation/make_list.hpp> #include <boost/fusion/algorithm/transformation/transform.hpp> namespace fusion=boost::fusion; template<typename T> class A { public: struct B {}; B make_b() const { return B(); } }; template<typename T> A<T> make_a( T const& ) { return A<T>(); } struct make_b { template<typename Sig> struct result; template <typename DS> struct result<make_b(DS const&)> { typedef typename DS::B type; }; template <typename T> typename T::B operator()(T const& t) const { return t.make_b(); } }; int main() { namespace fusion=boost::fusion; fusion::as_list( fusion::transform( fusion::make_list( make_a( 1. ), make_a( 1 ) ), make_b() ) ); return 0; } it fails to compile with an error like this: ... rather long context here ..\..\../boost/utility/result_of.hpp:83:1: error: invalid use of incomplete type ‘struct make_b::result<make_b(A<double>)>’ test.cpp:27:35: error: declaration of ‘struct make_b::result<make_b(A<double>)>’ What am I doing wrong? Any help appreciated, Gennadiy

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Re: [Boost-users] dynamic_bitset: request for new functions
by David Hochstuhl 11 Nov '11

11 Nov '11

Hey, thank you for your answer. >For the find features, I would consider to provide a view of a bitset >that behaves as standard set, with iterators. Even if the complexity of >these operations could not conform to the standard one, the advantages >are evident. In the same way you can associate a view of the >complementary set. I don't understand exactly what mean by this. Do you mean one should set up a std::set or something similar from a range of the bitset? >For the bit-twiddling hacks algorithm, the interface is almost ready. >Currently there is the data() function given access to the storage, and >a constructor from it. The problem is that the access is read-only and >the constructor will make a copy. Adding some move functions to extract >the storage and to take an external storage would permit to build every >algorithm you want on top of them in an efficient way. Can you tell me where to find this function. I searched the documentation and the source code, but couldn't find it. >As you said this is a lot and even if this is not complex, this will >need a considerable time to make something with the expected quality. Do >you think that you could contribute in some way? Sure I could, but I don't know whether I could provide the "expected quality". I anyway planned to code at least the LSB/MSB search functions for myself. best, David ___________________________________________________________ SMS schreiben mit WEB.DE FreeMail - einfach, schnell und kostenguenstig. Jetzt gleich testen! http://f.web.de/?mc=021192

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[mpi/serialization] Potential bug or just library misunderstanding?
by Tim Jacobs 10 Nov '11

10 Nov '11

I'm not sure why the following test-class produces this error: "MPI_Recv: MPI_ERR_TRUNCATE: message truncated" If the std::map has only a single element (ie I remove one of the test[].push_back() lines) the error does not occur. Can someone verify that this is indeed a bug and not just novice misuse of the library? Thanks, Tim #include <boost/mpi.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/vector.hpp> #include <boost/serialization/map.hpp> int main( int argc, char * argv [] ) { boost::mpi::environment env(argc, argv); boost::mpi::communicator world; if(world.rank()==0){ std::map<int, std::vector<std::string> > test; test[1].push_back("FOO"); test[50].push_back("BAR"); world.send(1, 1, boost::mpi::skeleton(test)); world.send(1, 1, boost::mpi::get_content(test)); std::cout << "sent" << std::endl; } else{ std::map<int, std::vector<std::string> > test; world.recv(0,1,boost::mpi::skeleton(test)); world.recv(0,1,boost::mpi::get_content(test)); } }

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dynamic_bitset: request for new functions
by David Hochstuhl 10 Nov '11

10 Nov '11

Hi everybody, is it planned to extend the dynamic_bitset in the near future? I would consider the implementations of the following functions to be particularly useful: find_last(); // position of most significant bit find_previous(size_t pos); // like find next, but in the other direction find_first_not(); // position of first unset bit find_next_not(); //... find_last_not(); //... find_previous_not(); //... further, views would be nice, so that one could act with bitwise operation only on a certain subset of the bitset. and last but not least -- I know that might be beyond the scope of this class -- arithmetics would be nice, so that one could directly copy e.g. the algorithms form bit-twiddling hacks. ( *of course* they should also work on views ^^ ) I know thats a lot, but it would certainly be helpful. Thanks in advance and best regards, David ___________________________________________________________ SMS schreiben mit WEB.DE FreeMail - einfach, schnell und kostenguenstig. Jetzt gleich testen! http://f.web.de/?mc=021192

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[C++ Now! 2012] Call for Submissions
by Hartmut Kaiser 10 Nov '11

10 Nov '11

INAUGURAL C++ NOW! CONFERENCE 2012 Aspen CO, USA, May 14-18, 2012, www.cppnow.org CALL FOR SUBMISSIONS We invite you to submit session proposals to the Inaugural C++ Now! Conference: C++Now! 2012 (Aspen CO, USA, May 14 - 18, 2012). Based on the successful traditions of 5 years of BoostCon, which was the main face-to-face event for all things C++ and Boost (www.boost.org) C++Now! 2012 will present leading speakers from the whole C++ community. The conference name is changing to C++ Now! to reflect the current value of the language, the focus on its new state (from the new Standard), and the need to continually look to the future so the language remains useful to the C++ community. The focus of this conference will be the new C++11 language Standard and as usual Boost: what's new in C++, its Standard library, and in the Boost libraries, how to write and maintain them, how to evangelize or to deploy Boost within your organization. The new C++ Standard, but also the infrastructure and process of Boost, its vision and mission - no matter what you are interested in, it all comes together in the C++Now! sessions. Meet the colleagues, and feel the inspiration to support your work with C++ and Boost for the next year. 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. IMPORTANT DATES New proposal submissions due: January 10th, 2012. Proposals decisions sent (tentative program available): February 17th, 2012. Fully scheduled program available: February 25th, 2012. Session materials due: April 15th, 2012. 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 and how it changes life for users and library writers * General tutorial sessions on C++11, the C++11 Standardslibrary, and one or more Boost libraries * 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 Boost 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, Boost and users. Panels Panels feature three or four people presenting their ideas and experiences relating to C++11 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 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 These were introduced at BoostCon 2008, and were a great Presentations 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 We actively encourage tool vendors and ISP's to submit Presentations 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 60 minutes. You may submit a proposal for fractions or multiples of 90-minutes. Fractional proposals will be grouped into 60 minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned 90 minute, 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=cppnow2012. 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! 2012 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 cppnow2012(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) Dave Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

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Can't run Library Status tests
by Tim Musson 10 Nov '11

10 Nov '11

Hello, I installed boost 1.47.0 and wanted to run the Library Status tests but tools/regression/library_test does not exist and was not created when I built tools/regression/build (according to instructions at http://www.boost.org/doc/libs/1_47_0/tools/regression/doc/library_status.ht…) It doesn't seem like this question belongs on the Regression list, but if it does just let me know and I'll post over there. Thanks in advance! Tim

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