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[Matrix iterators] Beginner problem
by Regis Behmo 19 Jul '07

19 Jul '07

Hello everyone, I don't understand how to use iterators with matrices; how can I scan all the elements of a matrix? The only thing I have managed to do until now is to read/write the elements of the first row or the first column: ublas::matrix<int> M(3,3); int i = 0; for( ublas::matrix<int>::iterator1 Mit1 = M.begin1(); Mit1 != M.end1(); Mit1++ ) { *Mit1 = i; i++; } Are there such things as row iterators, column iterators, or iterators ocver all the elements of the matrix? Thanks Régis B.

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[program_options] add_options method hangs on Linux
by Farberov, Inga 19 Jul '07

19 Jul '07

Hi, I have a piece of code that runs both on Windows and Linux. I am using program_options library to read a settings file. This seems to work fine on windows, but on Linux the same code hangs when I call add_options method. I am using Boost 1.34 on both machines. Any suggestions on what may be causing this problem are greatly appreciated. Inga

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boost::mpi + boost::shared_ptr
by Andras Joo 19 Jul '07

19 Jul '07

Dear All, I have encountered a problem I cannot go through regarding boost::mpi and shared_ptr. Please consider the following code: class Foo { friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) { //... } }; //... mpi::communicator world; boost::shared_ptr<Foo> pFoo; if (world.rank() == 0) pFoo = boost::shared_ptr<Foo>(new Foo); mpi::broadcast(world, pFoo, 0); //... Now unfortunately this doesn't compile, I get the following error message: /home/jooam/usr/include/boost-1_35/boost/serialization/shared_ptr.hpp: In function 'void boost::serialization::load(Archive&, boost::shared_ptr<U>&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = Foo]': /home/jooam/usr/include/boost-1_35/boost/serialization/split_free.hpp:58: instantiated from 'static void boost::serialization::free_loader<Archive, T>::invoke(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = boost::shared_ptr<Foo>]' /home/jooam/usr/include/boost-1_35/boost/serialization/split_free.hpp:74: instantiated from 'void boost::serialization::split_free(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = boost::shared_ptr<Foo>]' /home/jooam/usr/include/boost-1_35/boost/serialization/shared_ptr.hpp:152: instantiated from 'void boost::serialization::serialize(Archive&, boost::shared_ptr<U>&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = Foo]' /home/jooam/usr/include/boost-1_35/boost/serialization/serialization.hpp:140: instantiated from 'void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = boost::shared_ptr<Foo>]' /home/jooam/usr/include/boost-1_35/boost/archive/detail/iserializer.hpp:161: instantiated from 'void boost::archive::detail::iserializer<Archive, T>::load_object_data(boost::archive::detail::basic_iarchive&, void*, unsigned int) const [with Archive = boost::mpi::packed_iarchive, T = boost::shared_ptr<Foo>]' /home/jooam/evolearn/src/evolearn.cpp:75: instantiated from here /home/jooam/usr/include/boost-1_35/boost/serialization/shared_ptr.hpp:137: error: 'class boost::mpi::packed_iarchive' has no member named 'reset' Could you tell me please, what I'm doing wrong? I would appreciate any help. Have a nice day, Andras ____________________________________________________________________________________ Don't get soaked. Take a quick peak at the forecast with the Yahoo! Search weather shortcut. http://tools.search.yahoo.com/shortcuts/#loc_weather

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[python] unresolved docstring_options symbols with 1.34.0 using msvc 8 and 9
by Johan Johansson 19 Jul '07

19 Jul '07

Hi I'm having some problems moving from boost 1.33.1 to 1.34.0. More specifically my python extension isn't linking anymore: > Searching W:\boost_1_34_0\stage\lib\boost_python-vc80-mt.lib: >Finished searching libraries >MagicMarker.obj : error LNK2001: unresolved external symbol "private: >static bool volatile boost::python::docstring_options::show_user_defined_" >(?show_user_defined_@docstring_options@python@boost@@0_NC) >MagicMarker.obj : error LNK2001: unresolved external symbol "private: >static bool volatile boost::python::docstring_options::show_signatures_" >(?show_signatures_@docstring_options@python@boost@@0_NC) That seems to be statistics however: W:\boost_1_34_0\bin.v2\libs\python\build\msvc-8.0\debug>dumpbin /symbols function.obj | findstr docstring ... 1B4 00000004 SECT7 notype External | ?show_user_defined_@docstring_options@python@boost@@0_NC (private: static bool volatile boost::python::docstring_options::show_user_defined_) 1B5 00000005 SECT7 notype External | ?show_signatures_@docstring_options@python@boost@@0_NC (private: static bool volatile boost::python::docstring_options::show_signatures_) ... W:\boost_1_34_0\stage\lib>dumpbin /exports boost_python-vc80-mt.lib | findstr docstring_options ... ?show_signatures_@docstring_options@python@boost@@0_NC (private: static bool volatile boost::python::docstring_options::show_signatures_) ?show_user_defined_@docstring_options@python@boost@@0_NC (private: static bool volatile boost::python::docstring_options::show_user_defined_) ... Any ideas? j

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boost::mpi + serialization of polimorphic pointers
by Andras Joo 19 Jul '07

19 Jul '07

Dear All, I'm facing the following problem. I have the following class hierarchy: AbstractBase <--- AbstractDerived <---- ConcreteDerived I managed to make the serialization of AbstractBase using text and binary archives (text_[i/o]archive, binary_[i/o]archive), tested, and works fine. However when AbstractBase pointers are sent with MPI functions a runtime exception occurs: /usr/include/boost-1_35/boost/archive/detail/oserializer.hpp:413: static void boost::archive::detail::save_pointer_type<Archive, TPtr>::polymorphic<T>::save(Archive&, const T&, const boost::archive::detail::basic_pointer_oserializer*) [with T = AbstractBase, Archive = boost::mpi::packed_oarchive, TPtr = AbstractBase*]: Assertion `__null != bpos_ptr' failed. I appreciate any help. Thank you, and have a nice weekend. Andras ____________________________________________________________________________________ Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games. http://sims.yahoo.com/

2 1

scoped_ptr, shared_ptr and pimpl
by Noah Roberts 19 Jul '07

19 Jul '07

I have an object that uses scoped_ptr to point to it's impl...an incomplete type forward declared in the header and implemented in the cpp file. This object *does have a user defined destructor*! This user defined destructor is defined after the opaque type has been fully defined in the same cpp file. In another cpp file I have a function that lives in the same namespace as the object in question, which creates a shared_ptr to this object. I'm getting the "undefined type" error in checked_delete for the impl object. I've run into this problem before but it was because I did not have a user defined destructor for the outer object...now I do. I even created a blank destructor for the impl, something I've never had to do before. What gives? Any ideas where to look for the problem? My simplest program that exhibits the problem doesn't exhibit the problem...I find this frustrating.

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Question about from_time_t implementation
by Gerardo Lamastra 18 Jul '07

18 Jul '07

Hello everybody, I've seen that boost::posix_time supports a conversion function time_t from_time_t(ptime t) I've also seen on the mailing list, that something related to this issue has already been discussed. However, I've not found enough information (browsing ML and bug support) to understand if this issue is considered closed, or if anyone has never run into similar problems: We're using this function, and a counterpart ptime to_time_t(time_t) function because our application interacts with a MySQL db where date information is stored as unix timestamp. While processing the data, we run in a problem (I won't say 'bug') because MySQL and boost give different meaning to unix timestamp. For example, timestamp 1184795149 is 2007-Jul-18 23:45:49 (local time) for MySQL and it is 2007-Jul-18 21:45:49 (local time) for boost. The correct value is the first one. My current timezone offset is 2 hours, so you can see that we are missing UTC here. Checking the code, I've seen that the function basically converts by adding the number of second to 1/1/1970 0:0:0; however, it should be 1/1/1970 0:0:0 UTC, which is not. Jeff Garland touches this issue in this post: http://aspn.activestate.com/ASPN/Mail/Message/1758411 where he encourages C++ developer to move away from the time_t interface; however, often, for legacy reason, this may not be possible (as in our application). In order to comply with other implementation, we suggest to modify the function as follows: // The Boost Actual Implementation ptime boost_from_time_t(std::time_t t) { ptime start(boost::gregorian::date(1970,1,1)); return start + seconds(static_cast<long>(t)); } // Our 'old' function, written to match the previous one time_t boost_to_time_t(ptime t) { static const ptime THE_EPOCH(boost::gregorian::date(1970,1,1)); return time_period(THE_EPOCH, t).length().total_seconds(); } // The implementations that takes into account UTC ptime my_from_time_t(std::time_t t) { static const time_duration OFFSET = second_clock::local_time() - second_clock::universal_time(); static const ptime THE_EPOCH(boost::gregorian::date(1970,1,1), OFFSET); return THE_EPOCH + seconds(static_cast<long>(t)); } time_t my_to_time_t(ptime t) { static const time_duration OFFSET = second_clock::local_time() - second_clock::universal_time(); static const ptime THE_EPOCH(boost::gregorian::date(1970,1,1), OFFSET); return time_period(THE_EPOCH, t).length().total_seconds(); } That's all. Thanks a lot for any response. -Gerardo -------------------------------------------------------------------- CONFIDENTIALITY NOTICE This message and its attachments are addressed solely to the persons above and may contain confidential information. If you have received the message in error, be informed that any use of the content hereof is prohibited. Please return it immediately to the sender and delete the message. Should you have any questions, please contact us by replying to webmaster(a)telecomitalia.it. Thank you www.telecomitalia.it --------------------------------------------------------------------

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Question about from_time_t implementation
by Gerardo Lamastra 18 Jul '07

18 Jul '07

Hello everybody, I've seen that boost::posix_time supports a conversion function time_t from_time_t(ptime t) I've also seen on the mailing list, that something related to this issue has already been discussed. However, I've not found enough information (browsing ML and bug support) to understand if this issue is considered closed, or if anyone has never run into similar problems: We're using this function, and a counterpart ptime to_time_t(time_t) function because our application interacts with a MySQL db where date information is stored as unix timestamp. While processing the data, we run in a problem (I won't say 'bug') because MySQL and boost give different meaning to unix timestamp. For example, timestamp 1184795149 is 2007-Jul-18 23:45:49 (local time) for MySQL and it is 2007-Jul-18 21:45:49 (local time) for boost. The correct value is the first one. My current timezone offset is 2 hours, so you can see that we are missing UTC here. Checking the code, I've seen that the function basically converts by adding the number of second to 1/1/1970 0:0:0; however, it should be 1/1/1970 0:0:0 UTC, which is not. Jeff Garland touches this issue in this post: http://aspn.activestate.com/ASPN/Mail/Message/1758411 where he encourages C++ developer to move away from the time_t interface; however, often, for legacy reason, this may not be possible (as in our application). In order to comply with other implementation, we suggest to modify the function as follows: // The Boost Actual Implementation ptime boost_from_time_t(std::time_t t) { ptime start(boost::gregorian::date(1970,1,1)); return start + seconds(static_cast<long>(t)); } // Our 'old' function, written to match the previous one time_t boost_to_time_t(ptime t) { static const ptime THE_EPOCH(boost::gregorian::date(1970,1,1)); return time_period(THE_EPOCH, t).length().total_seconds(); } // The implementations that takes into account UTC ptime my_from_time_t(std::time_t t) { static const time_duration OFFSET = second_clock::local_time() - second_clock::universal_time(); static const ptime THE_EPOCH(boost::gregorian::date(1970,1,1), OFFSET); return THE_EPOCH + seconds(static_cast<long>(t)); } time_t my_to_time_t(ptime t) { static const time_duration OFFSET = second_clock::local_time() - second_clock::universal_time(); static const ptime THE_EPOCH(boost::gregorian::date(1970,1,1), OFFSET); return time_period(THE_EPOCH, t).length().total_seconds(); } That's all. Thanks a lot for any response. -Gerardo -------------------------------------------------------------------- CONFIDENTIALITY NOTICE This message and its attachments are addressed solely to the persons above and may contain confidential information. If you have received the message in error, be informed that any use of the content hereof is prohibited. Please return it immediately to the sender and delete the message. Should you have any questions, please contact us by replying to webmaster(a)telecomitalia.it. Thank you www.telecomitalia.it --------------------------------------------------------------------

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[multi_index][ann][rfc] Preview of Boost.MultiIndex 1.35 release
by Joaquín Mª López Muñoz 18 Jul '07

18 Jul '07

Hello, I've uploaded a preview version of Boost.MultiIndex as planned for shipping with Boost 1.35 --I don't think there'll be time to include more major features. Download at the Vault: http://www.boost-consulting.com/vault/index.php?&direction=0&order=&directo… (file multi_index.zip) You can try the preview with Boost 1.34.x; if you want to test the newly added interoperability with Boost.Interprocess, you'll have to use a snapshot of Boost CVS, where this library currently lies. The new important features: * New global_fun predefined key extractor. * Added iterator_to facility. * Included support for non-standard allocators such as those of Boost.Interprocess, which makes multi_index_containers placeable in shared memory. Don't miss example #12 at the examples section, which fully exercises this new capacity. * New versions of modify and modify_key with rollback, as described in the tutorial. * Indices provide the new cbegin, cend and, when applicable, crbegin and crend member functions, in accordance with the latest drafts of the next revision of the C++ standard. A longer list of changes can be consulted at the release notes page. I'd be extremely grateful if you can try this preview version and report any problems you find. As we're still in time to discuss the new features, do not hesitate to comment on these and bring forward your proposals for improvement. Thank you very much for your interest in Boost.MultiIndex, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Problem linking Boost Signals 1.34.0
by Craig Sanders 18 Jul '07

18 Jul '07

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