June 2013 - Boost-users - lists.preview.boost.org

Comparison boost spirit and ANTLR
by Olivier Austina 17 Jun '13

17 Jun '13

Hi, I would like to choose a parser. I would like to use a parser for text processing (natural language text). Which parser is suited in this case. In general which are the benefit to use boost spirit instead of ANTLR or ANTLR instead of boost spirit. Thank you. -- Regards Austina

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[statechart] state_machine send_event assertion fails
by Gooding, Dustin R. (JSC-ER411) 17 Jun '13

17 Jun '13

Hello, I'm a new user of statechart and for the most part am enjoying it very much. I've implemented a state machine with about 30 states (9 orthogonal regions) and over 50 events. It works very well and as expected, except for this one issue. Every once in a while, and in a way I've been unable to consistently repeat, I get an assertion failure resulting in a core dump. /usr/include/boost/statechart/state_machine.hpp:873: boost::statechart::detail::reaction_result boost::statechart::state_machine<MostDerived, InitialState, Allocator, ExceptionTranslator>::send_event(const event_base_type&) [with MostDerived = GripperPosition, InitialState = Container, Allocator = std::allocator<void>, ExceptionTranslator = boost::statechart::null_exception_translator, boost::statechart::state_machine<MostDerived, InitialState, Allocator, ExceptionTranslator>::event_base_type = boost::statechart::event_base]: Assertion `get_pointer( pOutermostUnstableState_ ) == 0' failed. "GripperPosition" is my state_machine. "Container" is the simple_state the state machine initially enters. Container has no transitions, but many sub states (it's the owner of the 9 orthogonal regions). (As far as I can tell, if the state machine is alive, then "Container" is an active state.) "Container" has a handful of custom_reactions that essentially listen for user-supplied events, "forward" those events in to the appropriate orthogonal regions using internal-only events, and then discard the user-supplied events. The intention here is to have a single event propagate to multiple orthogonal regions, allowing them all to react. For example: boost::statechart::result Container::react(const e_still&) { post_event(i_still_action()); post_event(i_still_moving()); return discard_event(); } I am unsure if these reactions are the cause of the assertion failure, but given that the error message says "Container" is the InitialState, I have to assume so. Given that, I don't see how either Container or GripperPosition are inactive and don't know how to interpret this error. I'd appreciate some guidance. I'm running Ubuntu 12.04, GCC 4.6.3, and Boost 1.46.1. -- Dustin Gooding NASA/JSC Robotics

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[multiprecision] noexcept() usage in gmp int
by Francesco Biscani 16 Jun '13

16 Jun '13

Hello, I was trying out the new multiprecision library (kudos!), and I ran into a problem. In order to make certain guarantees in my code regarding exception safety, I am mandating that types being used in generic containers are marked noexcept() for certain basic operations (namely, destruction and move operations). It seems like this is generally guaranteed in the multiprecision library (tried with cpp_int and the mpfr adaptor), with the important exception of the gmp integer class. A glance at the headers reveals that (gmp.hpp): // // Within this file, the only functions we mark as noexcept are those that manipulate // (but don't create) an mpf_t. All other types may allocate at pretty much any time // via a user-supplied allocator, and therefore throw. // Additionally, browsing the gmp documentation yields this snippet ( http://gmplib.org/manual/Custom-Allocation.html): """ There's currently no defined way for the allocation functions to recover from an error such as out of memory, they must terminate program execution. A longjmp or throwing a C++ exception will have undefined results. This may change in the future. """ Would it be possible then for the mp library authors to consider adding basic noexcept() guarantees to the gmp adaptor class in future versions? Cheers and thanks for the great library, Francesco.

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Building a large graph using Parallel Boost Graph Library
by William Shipman 15 Jun '13

15 Jun '13

Hi all, I'm working with a graph that has about 16 million vertices and 320 million edges. Currently, I'm using graph-tool in Python but building the graph is far too slow. Before I start porting to C++ I starting reading up on the Parallel Boost Graph Library. From the examples in the documentation, it seems that one must build the graph on one node in the cluster, then call synchronize to send that graph to all nodes. Is there a way to build parts of the graph on each node and then synchronize those parts? Some background: the graph actually comes from a CT scan. The vertices are voxels, the edges are relationships between adjacent voxels. At the moment I'm working on a very small test volume - 256^3 voxels - but later volumes will have billions of vertices and edges. Thanks for the help.

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Regarding boost interval library package.
by Pranjal vyas 15 Jun '13

15 Jun '13

Hello, I have written a program in boost which simply calculates the exponent in an interval, but for some interval inputs it is giving the wrong output such as for [1,3] or [-1,3]...but for some values it is giving correct o/p such as [1,9]. Please help in solving this query. The program is appended below.... ********************************************************************************************************************************************************* #include </boost/numeric/interval.hpp> #include <vector> #include <algorithm> #include <utility> #include <iostream> #include <iomanip> #include <math.h> using namespace boost; using namespace numeric; using namespace interval_lib; template<class T, class Policies> std::ostream &operator<<(std::ostream &os, const boost::numeric::interval<T, Policies> &x) { os << "[" << x.lower() << ", " << x.upper() << "]"; return os; } int main() { typedef interval<double,policies<save_state<rounded_transc_opp<double> >,checking_base<double> > > I; //typedef interval<double> I; I a(1,3.2); std::cout << exp(a) << std::endl; } ********************************************************************************************************************************************************** Thanks in Advance. Regards, PV

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http://www.boost.org/doc/libs/1_53_0/libs/serialization/example/demo.cpp does not work properly when using polymorphic xml archive
by Fadhel 14 Jun '13

14 Jun '13

Hi all, I used http://www.boost.org/doc/libs/1_53_0/libs/serialization/example/demo.cpp file as a first introduction to boost serialization. I would like to use polymorphic archives with XML serilialization format (to avoid having the templatized version). I edited this example and run it. Writing the data has worked fine -- except for the base_class serialization which needed an nvp -- but reading it causes a memory/segmentation fault problem. The same error happens with a binary archive. Using a text archive works fine. I'm new to boost serialization and debugging the code did not help me a lot. Is there anything specific to the serialization of base classes or abstract classes with the polymorphic XML format which needs to be handled? Or is this related to the serialization of pointers to the base class. Thanks for your help. Best Regards, Fadhel BA Here is the code I'm using: ( I removed some comments to make the code shorter) /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8 // demo.cpp #include <cstddef> // NULL #include <iomanip> #include <iostream> #include <fstream> #include <string> #include <boost/archive/polymorphic_iarchive.hpp> #include <boost/archive/polymorphic_oarchive.hpp> #include <boost/archive/polymorphic_xml_iarchive.hpp> #include <boost/archive/polymorphic_xml_oarchive.hpp> #include <boost/archive/polymorphic_binary_iarchive.hpp> #include <boost/archive/polymorphic_binary_oarchive.hpp> #include <boost/archive/polymorphic_text_iarchive.hpp> #include <boost/archive/polymorphic_text_oarchive.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/list.hpp> #include <boost/serialization/assume_abstract.hpp> #include <boost/serialization/nvp.hpp> ///////////////////////////////////////////////////////////// // gps coordinate // // llustrates serialization for a simple type // class gps_position { friend std::ostream & operator<<(std::ostream &os, const gps_position &gp); friend class boost::serialization::access; int degrees; int minutes; float seconds; void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int /* file_version */) const { ar << BOOST_SERIALIZATION_NVP(degrees); ar << BOOST_SERIALIZATION_NVP(minutes); ar << BOOST_SERIALIZATION_NVP(seconds); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int /* file_version */) { ar >> BOOST_SERIALIZATION_NVP(degrees); ar >> BOOST_SERIALIZATION_NVP(minutes); ar >> BOOST_SERIALIZATION_NVP(seconds); } public: // every serializable class needs a constructor gps_position(){}; gps_position(int _d, int _m, float _s) : degrees(_d), minutes(_m), seconds(_s) {} }; std::ostream & operator<<(std::ostream &os, const gps_position &gp) { return os << ' ' << gp.degrees << (unsigned char)186 << gp.minutes << '\'' << gp.seconds << '"'; } ///////////////////////////////////////////////////////////// // One bus stop // // illustrates serialization of serializable members // class bus_stop { friend class boost::serialization::access; friend std::ostream & operator<<(std::ostream &os, const bus_stop &gp); virtual std::string description() const = 0; gps_position latitude; gps_position longitude; void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { ar << BOOST_SERIALIZATION_NVP(latitude); ar << BOOST_SERIALIZATION_NVP(longitude); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { ar >> BOOST_SERIALIZATION_NVP(latitude); ar >> BOOST_SERIALIZATION_NVP(longitude); } protected: bus_stop(const gps_position & _lat, const gps_position & _long) : latitude(_lat), longitude(_long) {} public: bus_stop(){} virtual ~bus_stop(){} }; BOOST_SERIALIZATION_ASSUME_ABSTRACT(bus_stop) std::ostream & operator<<(std::ostream &os, const bus_stop &bs) { return os << bs.latitude << bs.longitude << ' ' << bs.description(); } ///////////////////////////////////////////////////////////// // Several kinds of bus stops // // illustrates serialization of derived types // class bus_stop_corner : public bus_stop { friend class boost::serialization::access; std::string street1; std::string street2; virtual std::string description() const { return street1 + " and " + street2; } void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { // save/load base class information ar << boost::serialization::make_nvp("base", boost::serialization::base_object<bus_stop>(*this)); ar << BOOST_SERIALIZATION_NVP(street1); ar << BOOST_SERIALIZATION_NVP(street2);; } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { // save/load base class information ar >> boost::serialization::make_nvp("base", boost::serialization::base_object<bus_stop>(*this)); ar >> BOOST_SERIALIZATION_NVP(street1); ar >> BOOST_SERIALIZATION_NVP(street2); } public: bus_stop_corner(){} bus_stop_corner(const gps_position & _lat, const gps_position & _long, const std::string & _s1, const std::string & _s2 ) : bus_stop(_lat, _long), street1(_s1), street2(_s2) { } }; class bus_stop_destination : public bus_stop { friend class boost::serialization::access; std::string name; virtual std::string description() const { return name; } void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { ar << boost::serialization::make_nvp("base", boost::serialization::base_object<bus_stop>(*this)); ar << BOOST_SERIALIZATION_NVP(name); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { ar >> boost::serialization::make_nvp("base", boost::serialization::base_object<bus_stop>(*this)); ar >> BOOST_SERIALIZATION_NVP(name); } public: bus_stop_destination(){} bus_stop_destination( const gps_position & _lat, const gps_position & _long, const std::string & _name ) : bus_stop(_lat, _long), name(_name) { } }; ///////////////////////////////////////////////////////////// // a bus route is a collection of bus stops // // illustrates serialization of STL collection templates. // // illustrates serialzation of polymorphic pointer (bus stop *); // class bus_route { friend class boost::serialization::access; friend std::ostream & operator<<(std::ostream &os, const bus_route &br); typedef bus_stop * bus_stop_pointer; std::list<bus_stop_pointer> stops; void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { // in this program, these classes are never serialized directly but rather // through a pointer to the base class bus_stop. So we need a way to be // sure that the archive contains information about these derived classes. //ar.template register_type<bus_stop_corner>(); ar.register_type(static_cast<bus_stop_corner *>(NULL)); //ar.template register_type<bus_stop_destination>(); ar.register_type(static_cast<bus_stop_destination *>(NULL)); // serialization of stl collections is already defined // in the header ar << BOOST_SERIALIZATION_NVP(stops); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { ar.register_type(static_cast<bus_stop_corner *>(NULL)); ar.register_type(static_cast<bus_stop_destination *>(NULL)); // in the header ar >> BOOST_SERIALIZATION_NVP(stops); } public: bus_route(){} void append(bus_stop *_bs) { stops.insert(stops.end(), _bs); } }; std::ostream & operator<<(std::ostream &os, const bus_route &br) { std::list<bus_stop *>::const_iterator it; // note: we're displaying the pointer to permit verification // that duplicated pointers are properly restored. for(it = br.stops.begin(); it != br.stops.end(); it++){ os << '\n' << std::hex << "0x" << *it << std::dec << ' ' << **it; } return os; } ///////////////////////////////////////////////////////////// // a bus schedule is a collection of routes each with a starting time class bus_schedule { public: // note: this structure was made public. because the friend declarations // didn't seem to work as expected. struct trip_info { void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int file_version) const { // in versions 2 or later if(file_version >= 2) // read the drivers name ar << BOOST_SERIALIZATION_NVP(driver); // all versions have the follwing info ar << BOOST_SERIALIZATION_NVP(hour); ar << BOOST_SERIALIZATION_NVP(minute); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int file_version) { // in versions 2 or later if(file_version >= 2) // read the drivers name ar >> BOOST_SERIALIZATION_NVP(driver); // all versions have the follwing info ar >> BOOST_SERIALIZATION_NVP(hour); ar >> BOOST_SERIALIZATION_NVP(minute); } // starting time int hour; int minute; // only after system shipped was the driver's name added to the class std::string driver; trip_info(){} trip_info(int _h, int _m, const std::string &_d) : hour(_h), minute(_m), driver(_d) {} }; private: friend class boost::serialization::access; friend std::ostream & operator<<(std::ostream &os, const bus_schedule &bs); friend std::ostream & operator<<(std::ostream &os, const bus_schedule::trip_info &ti); std::list<std::pair<trip_info, bus_route *> > schedule; void serialize(boost::archive::polymorphic_oarchive &ar, const unsigned int version) const { ar << BOOST_SERIALIZATION_NVP(schedule); } void serialize(boost::archive::polymorphic_iarchive &ar, const unsigned int version) { ar >> BOOST_SERIALIZATION_NVP(schedule); } public: void append(const std::string &_d, int _h, int _m, bus_route *_br) { schedule.insert(schedule.end(), std::make_pair(trip_info(_h, _m, _d), _br)); } bus_schedule(){} }; BOOST_CLASS_VERSION(bus_schedule, 2) std::ostream & operator<<(std::ostream &os, const bus_schedule::trip_info &ti) { return os << '\n' << ti.hour << ':' << ti.minute << ' ' << ti.driver << ' '; } std::ostream & operator<<(std::ostream &os, const bus_schedule &bs) { std::list<std::pair<bus_schedule::trip_info, bus_route *> >::const_iterator it; for(it = bs.schedule.begin(); it != bs.schedule.end(); it++){ os << it->first << *(it->second); } return os; } void save_schedule(const bus_schedule &s, const char * filename){ // make an archive std::ofstream ofs(filename); boost::archive::polymorphic_xml_oarchive oa(ofs); oa << s; } void restore_schedule(bus_schedule &s, const char * filename) { // open the archive std::ifstream ifs(filename); boost::archive::polymorphic_xml_iarchive ia(ifs); // restore the schedule from the archive ia >> s; } int main(int argc, char *argv[]) { // make the schedule bus_schedule original_schedule; // fill in the data // make a few stops bus_stop *bs0 = new bus_stop_corner( gps_position(34, 135, 52.560f), gps_position(134, 22, 78.30f), "24th Street", "10th Avenue" ); bus_stop *bs1 = new bus_stop_corner( gps_position(35, 137, 23.456f), gps_position(133, 35, 54.12f), "State street", "Cathedral Vista Lane" ); bus_stop *bs2 = new bus_stop_destination( gps_position(35, 136, 15.456f), gps_position(133, 32, 15.300f), "White House" ); bus_stop *bs3 = new bus_stop_destination( gps_position(35, 134, 48.789f), gps_position(133, 32, 16.230f), "Lincoln Memorial" ); // make a routes bus_route route0; route0.append(bs0); route0.append(bs1); route0.append(bs2); // add trips to schedule original_schedule.append("bob", 6, 24, &route0); original_schedule.append("bob", 9, 57, &route0); original_schedule.append("alice", 11, 02, &route0); // make aother routes bus_route route1; route1.append(bs3); route1.append(bs2); route1.append(bs1); // add trips to schedule original_schedule.append("ted", 7, 17, &route1); original_schedule.append("ted", 9, 38, &route1); original_schedule.append("alice", 11, 47, &route1); // display the complete schedule std::cout << "original schedule"; std::cout << original_schedule; std::string filename("C:/Dev/XML"); filename += "/demofile.xml"; // save the schedule save_schedule(original_schedule, filename.c_str()); // ... some time later // make a new schedule bus_schedule new_schedule; std::cout << "\n\nstarting restored schedule"; restore_schedule(new_schedule, filename.c_str()); // and display std::cout << "\nrestored schedule"; std::cout << new_schedule; // should be the same as the old one. (except for the pointer values) delete bs0; delete bs1; delete bs2; delete bs3; return 0; }

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Boost 32-64
by Dave Dyer 14 Jun '13

14 Jun '13

This is sort of a final report to thank the list for several good pieces of advice. I'm just completing a project which uses boost libraries to assist a project which uses shared memory to communicate between a 64 bit process and a separate 32 bit Application. Trying to use the managed version of shared memory proved to be too unreliable. Doing so is advertized as "experimental" and it proved not ready for prime time. I succeeded by using only the very simplest, unmanaged versions of boost shared memory and managing my own memory, very carefully, to be sure the shared structures were identical on the 32 and 64 bit sides of the divide.

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[unordered] order in container
by gast128 14 Jun '13

14 Jun '13

Hello all, although it's called 'unordered_set', it surprised me that an unordered container could have a different ordering although its contents are the same: void f() { boost::unordered_set<int> uset1; uset1.insert(10); uset1.insert(9); uset1.insert(8); boost::unordered_set<int> uset2; uset2.insert(8); uset2.insert(9); uset2.insert(10); //uset1: 8, 9, 10 //uset2: 10, 9, 8 bool b = uset1 == uset2; //ok, they are the same } Maybe it is somewhere in the documentation, otherwise maybe add a documentation note.

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[accumulator] compiler error with quantil
by Philipp Kraus 14 Jun '13

14 Jun '13

Hello, I try to create a complex accumulator. I would like to use an accumulator for a box plot with the whisker data ( http://en.wikipedia.org/wiki/Box_plot ). My typedef shows at the momen like this: typedef boost::accumulators::accumulator_set<double, boost::accumulators::stats< boost::accumulators::tag::count, boost::accumulators::tag::sum, //boost::accumulators::tag::median, boost::accumulators::tag::mean, boost::accumulators::tag::variance, boost::accumulators::tag::min, boost::accumulators::tag::max, boost::accumulators::tag::extended_p_square > > Accumulator; I would like to create the 25% & 75% quantil and replace the median with the 50% quantil, so I have defined the ctor accumulator call like this: boost::array<double, 3> probs = {0.25, 0.5, 0.75}; m_times[p_name] = Accumulator( boost::accumulators::extended_p_square_probabilities = probs ); (the median is disabled and m_times is a std::map<std::string, Accumulator>). At this point I get a compiler errors: /Developer/opt/Boost/1.53.0/include/boost/accumulators/statistics/extended_p_square.hpp: In constructor 'boost::accumulators::impl::extended_p_square_impl<Sample>::extended_p_square_impl(const Args&) [with Args = boost::parameter::aux::arg_list<boost::parameter::aux::tagged_argument<boost::accumulators::tag::accumulator, boost::accumulators::accumulator_set<double, boost::accumulators::stats<boost::accumulators::tag::count, boost::accumulators::tag::sum, boost::accumulators::tag::mean, boost::accumulators::tag::variance, boost::accumulators::tag::min, boost::accumulators::tag::max, boost::accumulators::tag::extended_p_square, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, void> >, boost::parameter::aux::empty_arg_list>, Sample = double]': /Developer/opt/Boost/1.53.0/include/boost/accumulators/framework/depends_on.hpp:319: instantiated from 'boost::accumulators::detail::accumulator_wrapper<Accumulator, Feature>::accumulator_wrapper(const Args&) [with Args = boost::parameter::aux::arg_list<boost::parameter::aux::tagged_argument<boost::accumulators::tag::accumulator, boost::accumulators::accumulator_set<double, boost::accumulators::stats<boost::accumulators::tag::count, boost::accumulators::tag::sum, boost::accumulators::tag::mean, boost::accumulators::tag::variance, boost::accumulators::tag::min, boost::accumulators::tag::max, boost::accumulators::tag::extended_p_square, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, void> >, boost::parameter::aux::empty_arg_list>, Accumulator = boost::accumulators::impl::extended_p_square_impl<double>, Feature = boost::accumulators::tag::extended_p_square]' .... I need one accumulator for all the data. I'm using Boost 1.53. How can I create working code? Thanks for help Phil

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Any debugging tips for Boost Interprocess shared memory crashes?
by Warren Postma 14 Jun '13

14 Jun '13

I am a newly humbled mediocre C++ programmer, who is completely unable to figure out why Boost interprocess shared memory classes frequently freeze or crash both at creation and deletion of the manager objects, both with the persistent and the windows-only non persistent versions of the classes. Do you ever debug things and it all just gets worse and worse the longer you try to fix it? http://stackoverflow.com/questions/17100597/does-boostinterprocesswindows-s… Today I am getting crashes in the boost shared memory manager object destructor, or deadlocks in WMI calls. It's in Boost 1.53, on Visual C++ 2008, and involves DLLs. I am unable to reproduce the insanity at a top level EXE demo, and I tried to build a exe-loads DLL1, which loads DLL2, which creates boost objects, which fail when you destroy them, but I am unable to extricate it from my project. So it could be one of the lovely compiler or linker or project settings in my Visual C++ project, something about Multithreaded Debug DLL and MFC and ATL and all the billion varieties of weird RTL and heap bugs that lurk in Visual C++ runtime libraries. I am not blaming boost, but I am at wits end here. I have about 80 hours into debugging this and it's only getting worse the more I look at it. After this I promise to go away, perhaps drink myself silly, and never ever again try to use C++ or boost. Or Windows. Because for all I know this could be a windows SxS issue with Visual Studio 2008 and its lovely assortment of DLLs and runtime SxS insanity. Warren

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