October 2010 - Boost-users - lists.preview.boost.org

VS Debugging Filter [WAS: boost.foreach overhead]
by Dominique Devienne 18 Oct '10

18 Oct '10

On Sun, Oct 17, 2010 at 6:29 PM, OvermindDL1 <overminddl1(a)gmail.com> wrote: > On Sun, Oct 17, 2010 at 3:47 PM, Eric Niebler <eric(a)boostpro.com> wrote: >> What debugger do you use? Visual Studio doesn't give me this grief. > > Ditto, but even if it did I could setup a debugging filter in it to > ignore the extra steps in the VS debugger, can you not do that in GDB? Would someone be kind enough to provide pointers or expand on these debugging filters? I've used in the past a registry key to avoid stepping into some functions/methods. Is this it? Thanks, --DD

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How to improve property_tree performance
by Bo Jensen 18 Oct '10

18 Oct '10

Hi, I have a fairly easy record structure which I am writing to xml using property_tree. I am trying to figure out how to do it better, since the current time spend building the tree is too high. I do the following : wiptree pt; wiptree &tvars = pt.add(L"some.recordname",L""); for( int i = 0; i < somenumber /*say 60K*/; ++i ) { wiptree &curtree = tvars.add(L"someitem",L""); curtree.add(L"<xmlattr>.name",L"some_attribute"); ... } To me this seems reasonable. Is there a faster way to do this ? Since I just want to write it out and it's quite simple, I could avoid using property_tree and write the xml file manually. But since I read it in later with property_tree, then for maintainability I would like to read and write with the same method. Thanks Bo

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Re: [Boost-users] [serialization] can I serialize concrete types that are not acessible where the archive is created
by Massaro Alessio 18 Oct '10

18 Oct '10

I eventually managed to get everything to work nicely Just one essential bit that seems to be missing in the docuemntation...at least I missed it :-) **** Use the ***DLL version*** of boost serialization (#define BOOST_ALL_DYN_LINK or BOOST_SERIALIZATION_DYN_LINK in your build) Otherwise, afaict, every DLL gets a separate static extended type-info singleton container. **** And, to anwer my own question, the documentation does say explicitly that non-rtti and rtti implementations of extended type-info can coexist. Hopefully, this will help other newbies!

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Set time boost::date_time
by Lloyd 18 Oct '10

18 Oct '10

Hi, How can I set the system time using boost? I have gone through boost date_time, but could not find a method to set the time. The time is in UTC. Thanks, Lloyd ______________________________________ Scanned and protected by Email scanner

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[Test] Seeking advice for writing effective performance tests
by Bryce Lelbach 18 Oct '10

18 Oct '10

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 How do I write accurate, empirical and reproducible performance tests? I realize this is a very broad question, but my knowledge on this subject is lacking, so I'd appreciate a comprehensive answer (e.g. I'm not looking to benchmark a particular program/library, just looking for a strategy for designing good performance tests). I have read up on the subject, but I'm interested in what you guys (e.g. Boost users/developers) do. - -- Bryce Lelbach aka wash http://groups.google.com/group/ariel_devel -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAky4yvsACgkQO/fqqIuE2t4WFQCcDXQWdg2Dr4WXialrZWMnSnii 2PAAoK8BbHS42t6utnzjSWxlMWYKXh+O =qJFv -----END PGP SIGNATURE-----

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[OT] Calling Overmind
by John Phillips 18 Oct '10

18 Oct '10

Overmind, Would you please contact either me (John Phillips) or Ron Garcia off list? Thanks. John

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boost asio: repeated reading to delimiter
by Cattus Cerebrum 17 Oct '10

17 Oct '10

A very newbie question from a beginner user of boost::asio. I have used BSD socket interface a lot in the past, and would like to start using boost::asio for my networking code. I have a server that is providing data through a network socket. The data is a continuous stream of bytes, with different data elements separated from each other by a zero byte. Would reading into a streambuf with the help of async_read_until() be a good way of handling this situation? The code I am thinking of replacing uses select() to wait for arriving data, and then reads it into a circular buffer. Thanks.

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Forward declarations and iterator_facade<>
by Phil Endecott 17 Oct '10

17 Oct '10

Dear Experts, I have code something like this: struct S; class iter: public boost::iterator_facade<iter,S,......> { ... }; struct S { ... }; This used to work, but stopped recently; I believe it may have been after upgrading gcc, not after upgrading Boost itself, but I'm uncertain about that. The problem is that something inside iterator_facade calls boost::is_POD<S>, which (not unreasonably) doesn't seem to work for the forward-declared S. I've never been entirely sure what you're allowed to do with forward-declared types like that. Was I just lucky that it worked before, or is this a regression? Re-ordering the code to remove the circular dependencies will be painful, so if anyone has any other hints I would love to hear them. Thanks, Phil.

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link error on serialization demo.cpp
by jiryih.tsaur＠nomura.com 16 Oct '10

16 Oct '10

Tried to compile demo.cpp and getting link error below. Any suggestions? g++ -c -I. -I/usr/include -I/usr/include/c++/4.1.2 -I/usr/include/boost -I/home/jitsaur/usr/include -g -D_DEBUG -o demo.o demo.cpp g++ -I. -I/usr/include -I/usr/include/c++/4.1.2 -I/usr/include/boost -I/home/jitsaur/usr/include -g -D_DEBUG -o demo demo.o demo.o: In function `archive_exception': /home/jitsaur/usr/include/boost/archive/archive_exception.hpp:45: undefined reference to `vtable for boost::archive::archive_exception' ... PLEASE READ: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please delete it and all copies from your system, destroy any hard copies and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Nomura Holding America Inc., Nomura Securities International, Inc, and their respective subsidiaries each reserve the right to monitor all e-mail communications through its networks. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorized to state the views of such entity. Unless otherwise stated, any pricing information in this message is indicative only, is subject to change and does not constitute an offer to deal at any price quoted. Any reference to the terms of executed transactions should be treated as preliminary only and subject to our formal written confirmation.

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[CfP] 5th Annual BoostCon, Aspen (CO, USA), May 15-20, 2011
by Hartmut Kaiser 16 Oct '10

16 Oct '10

Please distribute. ------------------ 5TH ANNUAL BOOST CONFERENCE 2011 Aspen CO, USA, May 15 - 20, 2011, www.boostcon.com CALL FOR PARTICIPATION We invite you to submit session proposals to the 5th Annual Boost Conference: BoostCon 2011 (Aspen CO, USA, May 15 - 20, 2011). Traditionally the main face-to-face event for all things Boost (www.boost.org) BoostCon 2011 will present leading speakers from the whole C++ community. >From using the Boost libraries to writing and maintaining them, from evangelizing to deploying Boost within your organization, from infrastructure and process to vision and mission, and the new C++ Standard, BoostCon brings together the sessions, the colleagues, and the inspiration to support your work with C++ and Boost in particular for the next year. To reflect the breadth of the Boost community, the conference includes sessions aimed at three constituencies: Boost end-users, hard-core Boost library and tool developers, and academics focusing on researcher. The program fosters interaction and engagement within and across those groups, with an emphasis on hands-on, participatory sessions. SESSION TOPICS Topics of interest include, but are not restricted to, the following: * General tutorial sessions introducing 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 * C++0x and how it changes life for users and library writers * 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 nature of both the on-line Boost community and 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 Boost and Boost users. Panels ------------- Panels feature three or four people presenting their ideas and experiences relating to 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 Boost-relevant skills. 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 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 have to be done through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=boostcon2011. 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 BoostCon website and will be available to attendees. For general information on the BoostCon 2011 paper submission or the scope of technical papers solicited, please refer to the conference website at www.boostcon.com. For any other questions about the submission process or paper format, please contact the Program Committee at boostcon2011(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 BoostCon. IMPORTANT DATES Proposal submissions due: December 10th, 2011. Proposals decisions sent (tentative program available): January 17th, 2011. Fully scheduled program available: February 7th, 2011. Session materials due: April 15th, 2011. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) David Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

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[Boost.MPI] question about serializing custom object
by Cristobal Navarro 16 Oct '10

16 Oct '10

hello everybody, this is first post i have some questions after reading the Boost documentation of serialization and MPI, is it possible to serialize my custom objects with Boost.serialize and then send/receive them using plain openMPI as MPI_BYTE type?? the other question is on the tutorials i only found examples of serializing objects to archive and saving to file, but i didnt find any example where they serialize it to a binary form and send them through mpi, is there any example of this type on the documentation? best regards Cristobal

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[MPI, serialization] Segmentation fault in heterogeneous cluster
by Francesco Biscani 16 Oct '10

16 Oct '10

Hello, I'm getting a segfault when using Boost.MPI on a cluster of heterogeneous machines (x86_64 and ppc64). The problem arises when the "slave" machine, ppc64, receives its payload from the "master" machine, x86_64, and tries to unpack the archive. Tracing down the issue with valgrind and in debug mode, the problem arises here: ==28632== Invalid write of size 8 ==28632== at 0x10429DDC: boost::archive::detail::basic_iarchive_impl::load_pointer(boost::archive::detail::basic_iarchive&, void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (basic_iarchive.cpp:453) ==28632== by 0x1042772F: boost::archive::detail::basic_iarchive::load_pointer(void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (basic_iarchive.cpp:564) ==28632== by 0x10468707: void boost::archive::detail::load_pointer_type<boost::mpi::packed_iarchive>::invoke<pagmo::population*>(boost::mpi::packed_iarchive&, pagmo::population*&) (iserializer.hpp:518) ==28632== by 0x104683EF: void boost::archive::load<boost::mpi::packed_iarchive, pagmo::population*>(boost::mpi::packed_iarchive&, pagmo::population*&) (iserializer.hpp:586) ==28632== by 0x10468223: void boost::archive::detail::common_iarchive<boost::mpi::packed_iarchive>::load_override<pagmo::population*>(pagmo::population*&, int) (common_iarchive.hpp:68) ==28632== by 0x10468023: void boost::archive::basic_binary_iarchive<boost::mpi::packed_iarchive>::load_override<pagmo::population*>(pagmo::population*&, int) (basic_binary_iarchive.hpp:67) ==28632== by 0x10467E27: void boost::mpi::packed_iarchive::load_override<pagmo::population*>(pagmo::population*&, int, mpl_::bool_<false>) (packed_iarchive.hpp:98) ==28632== by 0x10467C27: void boost::mpi::packed_iarchive::load_override<pagmo::population*>(pagmo::population*&, int) (packed_iarchive.hpp:115) ==28632== by 0x1046798F: boost::mpi::packed_iarchive& boost::archive::detail::interface_iarchive<boost::mpi::packed_iarchive>::operator>><pagmo::population*>(pagmo::population*&) (interface_iarchive.hpp:60) ==28632== by 0x104676BB: void boost::serialization::nvp<pagmo::population*>::load<boost::mpi::packed_iarchive>(boost::mpi::packed_iarchive&, unsigned int) (nvp.hpp:87) ==28632== by 0x104674AF: void boost::serialization::access::member_load<boost::mpi::packed_iarchive, boost::serialization::nvp<pagmo::population*> >(boost::mpi::packed_iarchive&, boost::serialization::nvp<pagmo::population*>&, unsigned int) (access.hpp:101) ==28632== by 0x104672CF: boost::serialization::detail::member_loader<boost::mpi::packed_iarchive, boost::serialization::nvp<pagmo::population*> >::invoke(boost::mpi::packed_iarchive&, boost::serialization::nvp<pagmo::population*>&, unsigned int) (split_member.hpp:54) ==28632== Address 0x4b65d98 is not stack'd, malloc'd or (recently) free'd The issue is in the method basic_iarchive_impl::load_pointer, around line 450: int i = cid; cobject_id_vector[i].bpis_ptr = bpis_ptr; Indeed, a printf confirms that i == 512 while cobject_id_vector.size() == 3. This also provokes the assertion new_cid == cid to fail one line below (where new_cid == 2). The same code, run locally on the ppc64 acting both as slave and master with mpirun -np 2, runs ok. Boost version is 1.42.0, MPI implementation is openMPI 1.4.2. Can this be related to some endianness issue? Is Boost.MPI expected to work on heterogeneous clusters? Thanks, Francesco.

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[serialization] check_object_versioning(), STATIC_ASSERTION_FAILURE
by Витя Истомин 15 Oct '10

15 Oct '10

Please help, or point me where should i read about it. What is this versioning and why my code was compiled with boost 1.39 will get compilation errors in 1.43? Code: #include <list> #include <boost/serialization/access.hpp> #include <boost/serialization/level.hpp> #include <boost/serialization/split_member.hpp> #include <boost/serialization/tracking.hpp> #include <boost/serialization/list.hpp> #include <boost/serialization/variant.hpp> #include <boost/serialization/version.hpp> ... typedef boost::variant <__int32, unsigned __int32, std::string, std::wstring > param_t; // note: I've tried to use boost::int32_t and others, result is the same typedef std::list< param_t > params_list_t; ... class instruction { public: ... private: friend class boost::serialization::access; /**< Make accessible private members for boost serialization */ void save (boost::archive::xml_oarchive& ar, unsigned int version) const; void load (boost::archive::xml_iarchive& ar, unsigned int version); BOOST_SERIALIZATION_SPLIT_MEMBER() private: ... params_list_t m_params; /**< List of parameters */ }; BOOST_CLASS_IMPLEMENTATION(instruction, boost::serialization::object_serializable); BOOST_CLASS_TRACKING(instruction, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(nvp<instruction>, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(nvp<instruction>, boost::serialization::track_never) BOOST_CLASS_VERSION(instruction, 1); BOOST_CLASS_IMPLEMENTATION(param_t, boost::serialization::object_serializable); BOOST_CLASS_TRACKING(param_t, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(nvp<param_t>, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(nvp<param_t>, boost::serialization::track_never) BOOST_CLASS_VERSION(param_t, 1) BOOST_CLASS_VERSION(params_list_t, 1) BOOST_CLASS_IMPLEMENTATION(nvp<params_list_t>, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(nvp<params_list_t>, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(params_list_t, boost::serialization::object_serializable); BOOST_CLASS_TRACKING(params_list_t, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(nvp<instructions_list_t>, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(nvp<instructions_list_t>, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(instructions_list_t, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(instructions_list_t, boost::serialization::track_never) CPP file: void instruction::save (boost::archive::xml_oarchive& ar, unsigned int version) const { // ... ar << BOOST_SERIALIZATION_NVP(m_params); // error is here, all other lines commented // ... } Error (MS VS2008): 1>d:\Work\manager\third_party\boost\include\boost/archive/detail/check.hpp(78) : error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' 1> with 1> [ 1> x=false 1> ] 1> d:\Work\manager\third_party\boost\include\boost/archive/detail/oserializer.hpp(307) : see reference to function template instantiation 'void boost::archive::detail::check_object_versioning<T>(void)' being compiled 1> with 1> [ 1> T=const params_list_t 1> ] 1> d:\Work\manager\third_party\boost\include\boost/archive/detail/oserializer.hpp(525) : see reference to function template instantiation 'void boost::archive::detail::save_non_pointer_type<Archive>::invoke<const T>(Archive &,const T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::xml_oarchive, 1> T=const params_list_t 1> ] 1> d:\Work\manager\third_party\boost\include\boost/archive/detail/common_oarchive.hpp(69) : see reference to function template instantiation 'void boost::archive::save<Archive,T>(Archive &,T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::xml_oarchive, 1> T=const params_list_t 1> ] ... This is a first error message place: template<class T> inline void check_object_versioning(){ typedef BOOST_DEDUCED_TYPENAME mpl::or_< BOOST_DEDUCED_TYPENAME mpl::greater< serialization::implementation_level<T>, mpl::int_<serialization::object_serializable> >, BOOST_DEDUCED_TYPENAME mpl::equal_to< serialization::version<T>, mpl::int_<0> > > typex; // trap attempts to serialize with objects that don't // save class information in the archive with versioning. BOOST_STATIC_ASSERT(typex::value); } I have understanding about what is BOOST_STATIC_ASSERT, but I haven't any ideas about what I'm doing wrong. Changelog reading between 1.39 and 1.43 hasn't clarified anything. -- реклама ----------------------------------------------------------- Три новые линейки хостинг-планов - всё что нужно Вашему сайту! 6 месяцев хостинга бесплатно и домен в подарок. http://Hvosting.ua

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[fusion] proposal BOOST_FUSION_ADAPT_FUNCTION, BOOST_FUSION_DEFINE_FUNCTION, etc
by alfC 15 Oct '10

15 Oct '10

Hi, I am using Boost.Fusion lately. Sometimes one has a function with several parameters, int f(double d , int i , std::string s){ ...bla bla ... } the logic of the program says that sometimes that same funcion will be called by generic code and in such case it is better if "f" where defined as taking a fusion::vector as argument. int f(fusion::vector<double, int, std::string>) // another function, could be an overload even since there is only one why to define this adaptor function, e.g. int f(fusion::vector<double, int, std::string> x){ return f(at_c<0>(x), at_c<1>(x), at_c<2>(x));\ } and it is pretty mechanical. I was wondering if it would be a good idea to have, with consistency with the BOOST_FUSION_ADAPT_STRUCT, something called BOOST_FUSION_ADAPT_FUNCTION BOOST_FUSION_ADAPT_FUNCTION( int, f, double, int, std::string ) (or something like that) that defines the second / fusion-compatible version of f. It could be even a BOOST_FUSION_DEFINE_FUNCTION( int, f, (double, d), (int, i), (std::string, s), ( ... code using variables d, i, s or at_key<d_>, at_key<i_>, at_key<s_> ... ) ) that defines simultaneously the raw-C function, f(double, int, string) *and* the fusion friendly version f(vector<...>). I could probably program these macro for specific cases but not a general one since I don't know enough macro syntax to make it work. Do you think it is a good idea or it is already doable with existing Fusion features? Thank you, Alfredo

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[iostreams] changing char_type of bzip2_compressor
by Matthias Vallentin 15 Oct '10

15 Oct '10

I am having trouble with typedef'ing a custom bzip2_compressor that works with unsigned char instead of plain char. This is the pipeline: typedef boost::uint8_t uint8 typedef boost::iostreams::filtering_stream< boost::iostreams::input, uint8> filtering_istream; typedef boost::iostreams::filtering_stream< boost::iostreams::output, uint8> filtering_ostream; typedef boost::iostreams::basic_bzip2_compressor< std::allocator<uint8>> bzip2_compressor; // FIXME: The bzip2_compressor as defined above does not fit in // the pipeline, what is the correct way to typedef it? std::vector<uint8> raw; auto range = boost::make_iterator_range(start, end); // args of type uint8*. filtering_istream in(range); filtering_ostream out; -> out.push(bzip2_compressor()); out.push(boost::iostreams::back_inserter(raw)); boost::iostreams::copy(in, out); The line with the arrow causes the following errors below, presumable due to an incorrect typedef of the basic_bzip2_compressor. I could not find the correct way to typedef it by crawling through the bzip2.hpp header file of the iostreams library. Any ideas? I am using g++ 4.6 with -std=gnu++0x for C++0x support. Matthias Error subset: [..] ../boost/iostreams/chain.hpp:258: error: no matching function for call to 'std::list<boost::iostreams::detail::linked_streambuf<unsigned char, std::char_traits<unsigned char> >*, std::allocator<boost::iostreams::detail::linked_streambuf<unsigned char, std::char_traits<unsigned char> >*> >::push_back(std::auto_ptr<boost::iostreams::stream_buffer<boost::iostreams::basic_bzip2_compressor<std::allocator<unsigned char> >, std::char_traits<unsigned char>, std::allocator<unsigned char>, boost::iostreams::output> >::element_type*)' [..] /opt/local/include/gcc46/c++/bits/streambuf.tcc:89: error: invalid conversion from 'std::basic_streambuf<char, std::char_traits<unsigned char> >::char_type*' to '__gnu_cxx::char_traits<unsigned char>::char_type*' [-fpermissive] /opt/local/include/gcc46/c++/bits/char_traits.h:188: error: initializing argument 1 of 'static __gnu_cxx::char_traits<_CharT>::char_type* __gnu_cxx::char_traits<_CharT>::copy(__gnu_cxx::char_traits<_CharT>::char_type*, const char_type*, std::size_t) [with _CharT = unsigned char, __gnu_cxx::char_traits<_CharT>::char_type = unsigned char, std::size_t = long unsigned int]' [-fpermissive] /opt/local/include/gcc46/c++/bits/streambuf.tcc:89: error: invalid conversion from 'const char_type*' to 'const char_type*' [-fpermissive] /opt/local/include/gcc46/c++/bits/char_traits.h:188: error: initializing argument 2 of 'static __gnu_cxx::char_traits<_CharT>::char_type* __gnu_cxx::char_traits<_CharT>::copy(__gnu_cxx::char_traits<_CharT>::char_type*, const char_type*, std::size_t) [with _CharT = unsigned char, __gnu_cxx::char_traits<_CharT>::char_type = unsigned char, std::size_t = long unsigned int]' [-fpermissive] /opt/local/include/gcc46/c++/bits/streambuf.tcc: In member function 'std::streamsize std::basic_streambuf<_CharT, _Traits>::xsgetn(std::basic_streambuf<_CharT, _Traits>::char_type*, std::streamsize) [with _CharT = char, _Traits = std::char_traits<unsigned char>, std::streamsize = long int, std::basic_streambuf<_CharT, _Traits>::char_type = char]': [..] .._client.cc:170: instantiated from here /opt/local/include/gcc46/c++/bits/streambuf.tcc:55: error: invalid conversion from 'std::basic_streambuf<char, std::char_traits<unsigned char> >::char_type*' to '__gnu_cxx::char_traits<unsigned char>::char_type*' [-fpermissive] /opt/local/include/gcc46/c++/bits/char_traits.h:188: error: initializing argument 1 of 'static __gnu_cxx::char_traits<_CharT>::char_type* __gnu_cxx::char_traits<_CharT>::copy(__gnu_cxx::char_traits<_CharT>::char_type*, const char_type*, std::size_t) [with _CharT = unsigned char, __gnu_cxx::char_traits<_CharT>::char_type = unsigned char, std::size_t = long unsigned int]' [-fpermissive] /opt/local/include/gcc46/c++/bits/streambuf.tcc:55: error: invalid conversion from 'std::basic_streambuf<char, std::char_traits<unsigned char> >::char_type*' to 'const char_type*' [-fpermissive] /opt/local/include/gcc46/c++/bits/char_traits.h:188: error: initializing argument 2 of 'static __gnu_cxx::char_traits<_CharT>::char_type* __gnu_cxx::char_traits<_CharT>::copy(__gnu_cxx::char_traits<_CharT>::char_type*, const char_type*, std::size_t) [with _CharT = unsigned char, __gnu_cxx::char_traits<_CharT>::char_type = unsigned char, std::size_t = long unsigned int]' [-fpermissive]

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math: combinations of i amongst n elements
by Hicham Mouline 15 Oct '10

15 Oct '10

Hi, Is there an available function to generate all the i-tuples among a sequence of size n (runtime) and 1<= i <=n For e.g. in a vector of 3 ints 1 2 and 3 we want to get all of the singletons: 1 2 3 all the pairs 1 2 1 3 2 3 and all the triplets 1 2 3 If not and I were to write one (n known at runtime only), what signature should I use? template <typename iterator> .... combinations(iterator begin, iterator end) { } what return type would hold all of the singletons, pairs, triplets, ... n-tuples Perhaps a better signature is template <typename iterator> .... combinations(iterator begin, iterator end, int i) { } but then the return type is still not easy to define. I'm thinking a 2D multi_array where not all the space is used (dim1 size is 2^n and dim2 size is n), and pass it by ref template <typename iterator> void combinations(multi_array& out, iterator begin, iterator end) { } regards,

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Determine 32 vs 64 architecture
by Ryan McConnehey 15 Oct '10

15 Oct '10

Is there a library that lets me determine on what architecture my code is compiled? I needed to redefine a couple of typedef for fundamental types. Ryan

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build failed for mpi on homogeneous platform
by Alain Miniussi 14 Oct '10

14 Oct '10

Hi, I am trying to build 1.44 on linux systems and the MPI component fails when I uncomment the #define BOOST_MPI_HOMOGENEOUS line in boost/mpi/config.hpp It is failing with both intel 11 and g++ compilers, here is the first error message for gcc 4.4.3: gcc.compile.c++ bin.v2/libs/mpi/build/gcc-4.4.3/release/threading-multi/broadcast.o In file included from ./boost/mpi/packed_iarchive.hpp:26, from ./boost/mpi/communicator.hpp:27, from ./boost/mpi/collectives.hpp:21, from ./boost/mpi/collectives_fwd.hpp:19, from ./boost/mpi/collectives/broadcast.hpp:11, from libs/mpi/src/broadcast.cpp:9: ./boost/mpi/detail/binary_buffer_iprimitive.hpp: In member function ‘void boost::mpi::binary_buffer_iprimitive::load(T&) [with T = boost::archive::version_type]’: ./boost/archive/detail/iserializer.hpp:107: instantiated from ‘static void boost::archive::load_access::load_primitive(Archive&, T&) [with Archive = boost::mpi::packed_iarchive, T = boost::archive::version_type]’ ./boost/archive/detail/iserializer.hpp:356: instantiated from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::load_primitive::invoke(Archive&, T&) [with T = boost::archive::version_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/iserializer.hpp:433: instantiated from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::invoke(Archive&, T&) [with T = boost::archive::version_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/iserializer.hpp:586: instantiated from ‘void boost::archive::load(Archive&, T&) [with Archive = boost::mpi::packed_iarchive, T = boost::archive::version_type]’ ./boost/archive/detail/common_iarchive.hpp:66: instantiated from ‘void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = boost::archive::version_type, Archive = boost::mpi::packed_iarchive]’ ./boost/mpi/packed_iarchive.hpp:101: instantiated from ‘void boost::mpi::packed_iarchive::load_override(T&, int, mpl_::false_) [with T = boost::archive::version_type]’ ./boost/mpi/packed_iarchive.hpp:118: instantiated from ‘void boost::mpi::packed_iarchive::load_override(T&, int) [with T = boost::archive::version_type]’ ./boost/archive/detail/interface_iarchive.hpp:60: instantiated from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = boost::archive::version_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/common_iarchive.hpp:45: instantiated from ‘void boost::archive::detail::common_iarchive<Archive>::vload(boost::archive::version_type&) [with Archive = boost::mpi::packed_iarchive]’ libs/mpi/src/broadcast.cpp:151: instantiated from here ./boost/mpi/detail/binary_buffer_iprimitive.hpp:87: error: no matching function for call to ‘assertion_failed(mpl_::failed************ boost::serialization::is_bitwise_serializable<boost::archive::version_type>::************)’ ./boost/mpi/detail/binary_buffer_iprimitive.hpp: In member function ‘void boost::mpi::binary_buffer_iprimitive::load(T&) [with T = boost::archive::object_id_type]’: Regards, -- Alain Miniussi ---- mail: alain.miniussi(a)oca.eu SIT https://sitweb.oca.eu tel: +33 4 92 00 30 09 CRIMSON https://crimson.oca.eu web: http://www.oca.eu/alainm

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[Pool] Problems using Boost.Pool with the Eigen matrix library
by lfrfly＠icqmail.com 14 Oct '10

14 Oct '10

Since Eigen matrices and vectors use SSE and therefore require a particular alignment, Eigen requires that when these types (specifically, the compile-time sized versions) are within a struct or class, that struct be given the EIGEN_MAKE_ALIGNED_OPERATOR_NEW macro. But here's the problem. What if that struct is allocated by a boost::pool_allocator<T>? Is there any way to enforce alignment then? I'm trying it and it just isn't working. I keep getting breakpoints hit inside of Eigen calls, presumably due to unaligned accesses. Has anyone investigated this, and are there any reasonable options? Perhaps a way to force the pool's start to be aligned, and a way to make sure the sizeof() my type as a whole is aligned? (But what about allocator conversion, eg, std::allocate_shared<T> may take an allocator<T> but it converts it internally to an allocator<somewrapper<T>>?)

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bzip2_compressor help
by Bryan S 14 Oct '10

14 Oct '10

I know that I'm doing something stupid but it isn't obvious to me what. I'm trying to write a compressed file using: namespace BI = boost::iostreams; BI::filtering_ostream out; std::fstream mfile("test.gz", std::ios::binary|std::ios::out); out.push(BI::bzip2_compressor()); out.push(mfile); out << "This is a gz file" << endl; but when I do so, the file is always empty. Commenting out the push of the bzip2_compressor works like I'd expect. Any help for a newbie? Thanks B

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Re: [Boost-users] [Boost.Spirit] Synthesised attributes and sub-rules
by Hartmut Kaiser 14 Oct '10

14 Oct '10

> On 14 October 2010 22:36, Hartmut Kaiser <hartmut.kaiser(a)gmail.com> wrote: > > That should be easy, see below. > > > > start = a_rule | b_rule | c_rule; > > > > qi::rule<Iterator, std::vector<int>()> a_rule; > > qi::rule<Iterator, std::vector<int>()> b_rule; > > qi::rule<Iterator, std::vector<int>()> c_rule; > > > I think I tried something like that, but it didn't work. Unless I'm > mistaken, each of those rules will create their own std::vector<int> > instance, so the values will not end up inserted into the vector specified > in the grammar parameter. No, it should work. The vector attribute is propagated to the alternatives, where it is filled. > I was able to eventually achieve my goal by specifying each of the rules > like so: > > qi::rule<Iterator, std::vector<int> &> a_rule; > > and in the main grammar I passed the _val into them. > > start = a_rule(_val) | b_rule(_val) | c_rule(_val) > > Then I referenced the arguments with _r1 in the sub-rules. > > Does that look correct? Is there a better way? That should work as well. This might be a tick better in terms of performance, even. But I'm guessing here, I have not done any measurements. Regards Hartmut --------------- http://boost-spirit.com

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where is lexical_cast.hpp?
by alapex0310＠gmail.com 14 Oct '10

14 Oct '10

Hi, I want to use boost::lexical_cast but cannot find lexical_cast.hpp in the boost tree. I am using VS2008. Has it been moved somewhere? I am trying to use boost 1.44. Thanks a lot in advance, -Al

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[fusion] memory layout of fusion::vector vs boost::tuple/boost::array
by alfC 14 Oct '10

14 Oct '10

Hi, I am trying to convert a boost::array into a fusion::vector. reinterpreting the memory from boost::array. It works for tuples but not fusion::vector, why is that. Is there a way to make it work? ( I was hoping that the memory layout is the same to make conversion from one to the other very easy.) #include <boost/fusion/container.hpp> #include <boost/fusion/include/container.hpp> #include<boost/array.hpp> #include<iostream> #include<boost/tuple/tuple.hpp> using std::clog; using std::endl; int main(){ boost::array<double, 3> ba={{1.0, 2.1, 3.2}}; clog << "ba: " << ba[0] << ", " << ba[1] << ", " << ba[2] << endl; using namespace boost::fusion; vector<double, double, double> bfv( reinterpret_cast<vector<double, double, double>&>(ba) ); //doesn't work as expected clog << "bfv: " << at_c<0>(bfv) << ", "<< at_c<1>(bfv) << ", " << at_c<2>(bfv) << endl; using boost::tuple; tuple<double, double, double> btt(reinterpret_cast<tuple<double, double, double>&>(ba) ); // works! clog << "btt: " << btt.get<0>() << ", "<< (btt).get<1>() << ", " << (btt).get<2>() << endl; return 0; } outputs: ba: 1, 2.1, 3.2 //original data bfv: -9.25597e+61, -2.35344e-185, 4.87507e-270 //not expected btt: 1, 2.1, 3.2 //works! Let me give some context, the reason I am doing this is that I need to interface fusion::vector of boost::quantities (all have the sizeof double) and adimensionalize the list of quantities into an array of doubles and vise-versa In reality, the final goal is to get this to work: boost::array<double, 3> ba={{1.0, 2.1, 3.2}}; vector<quantity<si::length>, quantity<si::time> , quantity<si::mass> > bfv( reinterpret_cast<vector<quantity<si::length>, quantity<si::time> , quantity<si::mass> >&>(ba) ); (or other generic option to go from array<double, N> to vector<quantity<T1>, quantity<T2>, ... quantity<TN> >) but since I can't make it work with simple 'doubles' I am asking why this could be done. Thank you again, Alfredo

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Re: [Boost-users] [serialization] Deserialize by pointer withoutcalling new/constructor
by averigin 14 Oct '10

14 Oct '10

> It's not the most common scenario. It can be addressed, but requires > some more complete understanding of the library. The library "just works" > for the common cases. > > Think about why you have a base class pointer in your class which will > "never change". That is, if you recover it with out re-creating it, > you're > assuming that in the meantime the following statement has not been > executed. > > my_base_ptr = some_derived_ptr; > > That is, you're writing code on an assumption which you can't enforce. > If someday, in some other code module, far, far, away .. someone > executes the above, you'll have some unrecoverable mess to deal with > with no clear idea of what the source of the problem is. > > Sooo - my suggestion is to replace > > struct my_thing { > Base *m_ptr > ... > }; > > with > > struct my_thing > Base &m_b > ... > }; > > This will "just work" as far as serialization is concerned. > > Now if making the above change in your program is hard to do, you should > think about it a little bit more before you insert a booby trap into your > program. > Usually, this will entail some refactoring to get things back together > again. > But the result will be something more robust, less likely to contain bugs, > easier to test and aintain. Here's an attempt to further explain and (hopefully) clarify what's happening and why. 4 pieces of background to start, then I'll try to tie it all together. 1. In OMNeT, there are two main components to a simulation: Simple Modules, which have associated functionality (i.e., code), and Compound Modules, which are containers for simple modules and have no associated code. Note, for reference, the module types are termed cSimpleModule and cCompoundModule, both derived from cModule. All simple modules are derived from cSimpleModule and all compound modules are derived from cCompoundModule. 2. In a simulation it's possible to lookup another module (M_i) from the active module (M_a) and invoke methods on M_i. The lookup functions return a cModule pointer to M_i, which then must be dynamically cast to M_i's most-derived type to invoke its methods. However, that cast requires including M_i's header file in the code for M_a, which can result in ugly dependency trees. Thus, serializing by a looked-up cModule (base-class) pointer keeps things 'nice'. 3. When dynamically generating modules, they are created using a module factory which configures some internal state information which is not publicly accessible. Also, note that the factory method returns a cModule pointer. 4. When I run simulations, serialization and deserialization never occur during the same simulation; either the simulation starts fully configured and eventually serializes its state immediately before terminating, or it starts with a minimal skeleton and constructs the rest of the modules based upon a previously stored state. Now to put all the pieces together. When saving a simulation state, it's necessary to serialize a number of compound modules. So far, I've done this by adding a simple "archiver" module to them. I lookup the "archiver" module using the lookup functions and try to serialize the resulting cModule pointer. This causes the "archiver" module to save what information is publicly accessible (i.e., there is some internal state information it cannot access). When loading a saved state, the minimal skeleton includes one of the above mentioned "archiver" modules. It creates the input archive and then tries to create the other modules in the simulation. This is where I run into problems. What I wanted to do was have the "archiver" module create the other modules using their associated factories and then deserialize the rest of their state via the cModule pointers returned by the factories. This way the factory configures the module's private internal state information and the everything else is loaded from the archive, and this minimizes file dependencies (i.e., including header files for derived types). (I realize this isn't true (de)serialization, so I refer to it as partial-serialization.) However, this conflicts with the normal method for pointer deserialization, which would allocate memory for a new module, initialize it and then deserialize the information from the archive into that new object, which (in my case) is then promptly deleted or leaked. The only alternative I can see would be to dynamically cast the cModule pointers and directly call their serialize() or save()/load() methods directly. However, this seems like an ugly hack since that requires making the serialization methods public and including derived-class headers all over the place. Thus, I would like to stick with my partial-serialization method. I'm just not sure if it's possible to "easily" implement what I need for the loading portion. > > Of course if you're working in an environment whose controlling principle > is "just make it work right now", you're out of luck. You'll just have to > bury the bomb in your program and hope you're not in the immediate > vicinity when it blows up. > While I don't quite see it as a bomb, I know that probably just indicates short-sightedness on my part. Regardless, I am in the "just make it work right now" boat, so any help you can offer would be much appreciated. Regards, Adam Verigin P.S.: I did manage a temporary hack of archive/detail/iserializer.hpp pointer_iserializer::load_object_ptr() that (badly) assumed that if the passed pointer is not NULL, then it is a pointer to an allocated object so there's no need to create a new object. Coupled with a do-nothing load_construct_data() method this worked great for partial-deserialization, but causes memory corruption for normal deserialization since the assumption is not always true (nor is it a good assumption to try an force on other users).

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[Smart Ptr] Why is weak_ptr a _ptr?
by Szymon Gatner 13 Oct '10

13 Oct '10

Hi, Is it just me or is it really the worse naming in whole boost library? It is nothing like any other smart pointer. No initialization / construction from raw pointer. No operator * or -> (the very least one would expect from _ptr class). No get(). And many more which I now forgot. My point is that is is not a pointer at all, not even a bit. It only happens to have a member variable returning one and that is hardly a reason to call type pointer-like. It should rather be called shared_tracker or shared_listener or something in that taste ;) Regards, Szymon

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