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Spirit guidance needed
by Arkadiy and Marina Vertleyb 04 Dec '12

04 Dec '12

Hi all, Can somebody direct me to a part/facility inside the Spirit library to do the following: I need to pre-parce a boolean expression (once) and save it somewhere. Then I need to evaluate this expression (many times, performance important) based on different values of tokens. Will Spirit.Classic do? Or do I need to use any of the newer libraries inside Spirit? Thanks for any help. Arkadiy

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[boost][polygon]Errors with minkowski sum
by renaud lepere 04 Dec '12

04 Dec '12

I need to implement robust minkowski sum operations on polygons. I have seen that this could be implemented easily using boost::polygon, the tutorial is here http://www.boost.org/doc/libs/1_52_0/libs/polygon/doc/gtl_minkowski_tutoria… The example works fine, however i need more precision than "int" (32 bits on my plateform win32-msvc10-32bits). I tried to replace to replace int -> double typedef boost::polygon::point_data< int > point; with typedef boost::polygon::point_data< double > point; But this leads to strange errors deep into the code (operator< is "bad") if (!_Pred(_Left, _Right)) return (false); else if (_Pred(_Right, _Left)) _DEBUG_ERROR2("invalid operator<", _File, _Line); called after scan_data_.insert(*insert_itr); // line 1197 in scan_arbitrary.hpp What can i do to avoid it, if i use "long long" type it works but it sends a lot of warning at compile time. Any idea of what i should do ? Is "double" type supported ?

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Asio and software interrupts
by Joseph Sulewski 03 Dec '12

03 Dec '12

Hello, I’m use the Boost::Asio libraries to read data from multicast sockets. This is a high rate application that needs to listen to data coming on a large number of multicast addresses (up to 500 different addresses). I would like to funnel all the multicast traffic to a single class where the data can get handled very quickly. I have the code working now using the socket->async_receive_from() method but the system is getting bogged down handling a large number of software interrupts. 51% of the CPU time is spent handling software interrupts. I create each multicast socket (up to 500 of them) like so: socket = new udp::socket(io_service); socket->open(listenEndPoint.protocol()); socket->set_option(boost::asio::ip::udp::socket::resuse_address(true)); socket->bind(listenEndPoint); socket->set_option(boost::asio::ip::multicast::join_group(multicastAddress.to_v4())); Slightly after that I register for data like so: socket->async_receive_from(buffer,senderEndPoint,boost::bind(&EthernetCapture::receiveData,this,boost::asio::placeholders::bytes_transferred)); Is there a more efficient way to receive multicast data without incurring so many software interrupts? By the way this is for an application to run on 32 bit Linux for an embedded application. Thanks

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[serialization] versioning for class nested within template class
by Gabriel Redner 03 Dec '12

03 Dec '12

Hi folks, I am having trouble incrementing the serialization version of a regular class nested within a template class. I'm not sure if the problem is with boost or with my own understanding of the issue. My code looks like: ============================== template <typename A, typename B> struct Foo { struct Bar { int data1; int data2; private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, unsigned int version) { ar & data1; if (version >= 2) { ar & data2; } else { data2 = 0; } } }; }; ============================== My attempt at setting the version looks like: ============================== namespace boost { namespace serialization { template <typename A, typename B> struct version<typename Foo<A, B>::Bar> { BOOST_STATIC_CONSTANT(unsigned int, value = 2); }; } // namespace serialization } // namespace boost ============================== However, g++ gives an error: ============================== main.cpp:31:8: error: template parameters not used in partial specialization: main.cpp:31:8: error: ‘A’ main.cpp:31:8: error: ‘B’ ============================== Strangely, clang 3.0 compiles the code but issues some warnings: ============================== main.cpp:31:8: warning: class template partial specialization contains template parameters that can not be deduced; this partial specialization will never be used struct version<typename Foo<A, B>::Bar> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:30:20: note: non-deducible template parameter 'A' template <typename A, typename B> ^ main.cpp:30:32: note: non-deducible template parameter 'B' template <typename A, typename B> ^ 1 warning generated. ============================== I'd appreciate any pointers! Thanks, -Gabe

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Re: [Boost-users] boost msm - Multiple differed events
by Kamel Zaarouri, Mr 03 Dec '12

03 Dec '12

Hi Guys, Let's say that we have 2 states, S1 and S2. with this transition table: S1 -> S2 on event Es2 S2 -> S1 on event Es1 also let's say that S1 can also accept Ev1 and Ev2 but S2 cannot accept them so it differs them. Now when let's say that S2 receives 2 events Ev1 and Ev2 and differs them. Now, when S2 goes back to S1 would S1 handle both events in order? or how does it work? Thanks,

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Boost 1.49.0 compilation issue
by Shcherbina Vladimir 03 Dec '12

03 Dec '12

2down votefavorite<http://stackoverflow.com/questions/13628685/boost-1-49-0-compilation-issue> I tried to compile this boost dependent class with VS2008 and VS2010 (error lines are in bold) #include <boost/interprocess/ipc/message_queue.hpp> #include <boost/interprocess/sync/scoped_lock.hpp> #include <boost/interprocess/sync/named_mutex.hpp> #include <boost/interprocess/sync/named_condition.hpp> struct SafeShardQueue { typedef boost::interprocess::scoped_lock<boost::interprocess::named_mutex> scoped_mutex; SafeShardQueue()//: { } ~SafeShardQueue() { remove(); } void wait_msg() { scoped_mutex locker(*mu); data_avail_condition->wait(locker); } void wait_space() { scoped_mutex locker(*mu); queue_empty_condition->wait(locker); } boost::shared_ptr<boost::interprocess::message_queue> msgs; boost::shared_ptr<boost::interprocess::named_condition> data_avail_condition; boost::shared_ptr<boost::interprocess::named_mutex> mu; boost::shared_ptr<boost::interprocess::named_condition> queue_empty_condition; static SafeShardQueue* open() { SafeShardQueue* tmp = new SafeShardQueue(); boost::interprocess::open_only_t open_create_type; tmp->msgs.reset(new boost::interprocess::message_queue (open_create_type, "message_queue")); tmp->mu.reset(new boost::interprocess::named_mutex(open_create_type, "shared_queue_mutex")); tmp->data_avail_condition .reset(new boost::interprocess::named_condition(open_create_type, "data_avail_condition")); tmp->queue_empty_condition .reset(new boost::interprocess::named_condition(open_create_type, "queue_empty_condition")); return tmp; } static SafeShardQueue* create() { remove(); SafeShardQueue* tmp = new SafeShardQueue(); boost::interprocess::create_only_t open_create_type; std::stringstream ss; try { tmp->msgs.reset(new boost::interprocess::message_queue(open_create_type, "message_queue", 256, 1024)); tmp->mu.reset(new boost::interprocess::named_mutex(open_create_type, "shared_queue_mutex")); tmp->data_avail_condition .reset(new boost::interprocess::named_condition(open_create_type, "data_avail_condition")); tmp->queue_empty_condition .reset(new boost::interprocess::named_condition(open_create_type, "queue_empty_condition")); } catch (const boost::interprocess::interprocess_exception& e) { ss << e.what(); } return tmp; } static void remove() { boost::interprocess::message_queue::remove("message_queue"); boost::interprocess::named_mutex::remove("shared_queue_mutex"); boost::interprocess::named_condition::remove("data_avail_condition"); boost::interprocess::named_condition::remove("queue_empty_condition"); } }; I got the following error message: 1>\boost\boost\interprocess\ipc\message_queue.hpp(254) : error C2039: 'priority_functor' : is not a member of 'boost::interprocess::ipcdetail::ipcdetail' 1>\boost\boost\interprocess\ipc\message_queue.hpp(425) : see reference to class template instantiation 'boost::interprocess::ipcdetail::mq_hdr_t<VoidPointer>' being compiled 1> with 1> [ 1> VoidPointer=boost::interprocess::offset_ptr<void> 1> ] 1>\boost\boost\interprocess\ipc\message_queue.hpp(425) : while compiling class template member function 'unsigned int boost::interprocess::message_queue_t<VoidPointer>::get_mem_size(unsigned int,unsigned int)' 1> with 1> [ 1> VoidPointer=boost::interprocess::offset_ptr<void> 1> ] 1>\boost\boost\interprocess\ipc\message_queue.hpp(465) : while compiling class template member function 'boost::interprocess::message_queue_t<VoidPointer>::message_queue_t(boost::interprocess::open_only_t,const char *)' 1> with 1> [ 1> VoidPointer=boost::interprocess::offset_ptr<void> 1> ] 1>\**sharedqueue.h(42)** : see reference to class template instantiation 'boost::interprocess::message_queue_t<VoidPointer>' being compiled 1> with 1> [ 1> VoidPointer=boost::interprocess::offset_ptr<void> 1> ] 1>\boost\boost\interprocess\ipc\message_queue.hpp(254) : error C2955: 'boost::interprocess::ipcdetail::priority_functor' : use of class template requires template argument list 1>\boost\boost\interprocess\ipc\message_queue.hpp(209) : see declaration of 'boost::interprocess::ipcdetail::priority_functor' 1>\boost\boost\interprocess\ipc\message_queue.hpp(254) : error C2143: syntax error : missing ',' before '<' It seems that you cannot use both interprocess::message_queue and interprocess:named_condition in the same class. Any ideas? I would greatly appreciate your help in this issue. Best Regards, Vladimir The information in this e-mail transmission contains proprietary and business sensitive information. Unauthorized interception of this e-mail may constitute a violation of law. If you are not the intended recipient, you are hereby notified that any review, dissemination, distribution or duplication of this communication is strictly prohibited. You are also asked to contact the sender by reply email and immediately destroy all copies of the original message.

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[Who's using boost?] Algocoders : books on c++11, Boost and Beyond
by Algocoders . 03 Dec '12

03 Dec '12

Algocoders <http://www.algocoders.com> Algocoders has been using boost since last 6+ years with a mission to help people build a better software eco-system by standing on the shoulder of giants. If it wasn't not for boost, then it could have been really difficult for us to build our framework based on sound mathematical foundation of computer science using modern C++. It is the pioneering efforts at boost towards "Using and Extending C++11, Boost and Beyond" which has motivated us to devote ourself in developing bullet-size capsules in the form of tiny booklets with industrial-set framework to lift the thin veil with initial focus on practical usage of C++11 vis-a-vis mathematical foundation behind it. Web Page : http://www.algocoders.com Enthused by boost, we are working tirelessly towards *publishing a series of books(or booklets) which will bridge the gap between esoteric and street-side ones. Initial focus will be on C++11, Boost, Loki, STL, Algorithms, Data Structures, Multi-threading, Design Patterns, gcc, clang, valgrind.* *First book in this series is :*(will be available by end of November 2012) *Foundation of Algorithms in C++11, Volume 1* Using and Extending C++11, Boost and BeyondList of books(in progress): - *C++11 Algorithms : *Using and Extending C++11, Boost and Beyond - *Smart Pointers** : Tips and Techniques in C++ :* Using and Extending C++11, Boost and Beyond - *C++11 FAQs :* Using and Extending C++11, Boost and Beyond - *Concepts & Traits C++ **:* Using and Extending C++11, Boost and Beyond and so on. We use almost all the libraries under boost including trunk and branches, especially Spirit, Phoenix, Proto, MPL, Fusion to mention a few. Thanks, Algocoders www.algocoders.com

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boost managed shared memory: RUN FAILED
by Olivier Austina 03 Dec '12

03 Dec '12

Hello, I try to run an example from this online book( http://en.highscore.de/cpp/boost/interprocesscommunication.html) and I got "RUN FAILED (exit value 1, total time: 938ms) ". I am using Netbeans. This is the example: #include <boost/interprocess/managed_shared_memory.hpp> #include <iostream> int main() { boost::interprocess::shared_memory_object::remove("Highscore"); boost::interprocess::managed_shared_memory managed_shm(boost::interprocess::open_or_create, "Highscore", 1024); int *i = managed_shm.construct<int>("Integer")(99); std::cout << *i << std::endl; std::pair<int*, std::size_t> p = managed_shm.find<int>("Integer"); if (p.first) std::cout << *p.first << std::endl; } Thanks very much. -- Regards Austina

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Serialization newbie, memory being overwritten?
by Lasse Laursen 03 Dec '12

03 Dec '12

Hello to you, I wonder if you might be able to solve this conundrum I've been pondering. The boost (1.51) serialization library is giving me some trouble. I've been battling back and forth with the library, and I'm beginning to think I'm missing some key element. At first, I had issues to just getting things written out to a file without crashes. As far as I could tell, this particular problem was compounded by the fact, that I tried to simplify my code by just writing a single primitive referenced by a pointer to an object containing said primitive. As I've since come to learn, serializing pointed-to primitives is apparently not trivial. I have since, gotten the serialization class to properly write out a few simple member primitives from my class, but when I read them back using the exact same function, it seems as though a lot - if not all - of the pre-existing data in the object, which I am not serializing, gets overwritten. As far as I have been able to tell from the tutorials, I am doing everything exactly by the book. I was also concerned that maybe boost doesn't allow partial serialization, but this shouldn't be an issue either as far as I can tell. I must be making some sort of colossal mistake that I just cannot see. My in and out code is fairly straight forward: std::string streamPath = PTMFilePath.string(); std::ifstream ifs(streamPath); boost::archive::xml_iarchive ia(ifs); ia >> BOOST_SERIALIZATION_NVP(aStream); ----- std::string streamPath = PTMFilePath.string(); std::ofstream ofs(streamPath); boost::archive::xml_oarchive oa(ofs); oa << BOOST_SERIALIZATION_NVP(aStream); ------ My serialization function: template<class Archive> void serialize(Archive &ar, const unsigned int file_version) { ar & BOOST_SERIALIZATION_NVP(nrOfSamples); } ------ aStream is a pointer to a custom class, where I have allowed boost access. I am really confused as to what is causing this. Both pointed to data and regular primitives in the aStream class are wiped/altered as soon as the program enteres the serialize function, and even before the actual data seems to be read. I must be overlooking something really basic here. I hope someone can whack me with the solution stick... Thanks, Lasse

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Incorrect assertion in Boost.Exception?
by Thorsten Dahlheimer 02 Dec '12

02 Dec '12

Hello, we want to use Boost.Exception (1.47.0) with MS Visual Studio 2010 in a project that consists of several DLLs and a main executable. We have situations where we store an error_info into an exception from inside a DLL and access it again from another DLL/the EXE, e.g.: dll.cpp: void func() { BOOST_THROW_EXCEPTION(my_exception() << my_info(42)); } exe.cpp: try { func(); } catch (boost::exception& e) { std::cout << *boost::get_error_info<my_info>(e) << std::endl; } Now at runtime, when the error info is accessed, the following assertion in boost::exception_detail::error_info_container_impl::get() fails: BOOST_ASSERT( BOOST_EXCEPTION_DYNAMIC_TYPEID(*p).type_==ti.type_ ); As far as we can see, this happens because MSVC++ uses seperate type_info objects in each dll/exe, and the above assertion compares pointers to type_infos instead of the objects themselves. We believe this is a bug on the Boost side, since type_info objects for the same type are generally not guaranteed to be unique. Are we correct with that? Thanks, Thorsten

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