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[regex] character sets
by Detlef Meyer-Eltz 09 Feb '09

09 Feb '09

I'm working with CBuilder6 and boost boost_1_34_1 and found, that regex expression1("[[:print:]]+"); matches with regex_search the whole string: testtext = "ab\r\ncd ef"; including the linebreak and the white space. I had assumed, that the print-class would consist exactly in the set of characters for which the standard function isprint returns true but isprint returns false for the space characters. Is there there any documentation with the exact enumerations of the different character sets? With Kind Regards, Detlef Meyer-Eltz

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[Smart Ptr] make_shared for arrays
by Alexander 09 Feb '09

09 Feb '09

Why isn't there ? It looks easier to implement than for single objects as there would be only unary version which would take array size.

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boost serialization not working unless you have at least one virtual function in base
by Martin Seiler 09 Feb '09

09 Feb '09

Hi all, Does anybody know why this is the case? Is there a way to make a class "polymorphic" without adding a dummy virtual function? Is this some "silly" optimization done by C++ compilers? Not generating vtables? It took me quite some time to figure this one out. It is mentioned in the documentation (2 lines, easily missed). http://www.boost.org/doc/libs/1_37_0/libs/serialization/doc/serialization.h… Maybe add a big huge WARNING? Also please mention this fact in the examples! (like in demo.cpp?) regards M. Seiler #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> #include <boost/serialization/nvp.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/type_info_implementation.hpp> #include <boost/serialization/export.hpp> #include <boost/archive/archive_exception.hpp> #include <boost/archive/basic_xml_archive.hpp> class A { public: A() : test(33) { } int test; virtual void dummy(){} // if you comment this line it won't work }; class B : public A { public: B() : test_b(52) { } int test_b; virtual void foo(){}; }; namespace boost { namespace serialization { template<class Archive> void serialize(Archive & ar, A & o, const unsigned int version) { ar & make_nvp("test", o.test); } template<class Archive> void serialize(Archive & ar, B & o, const unsigned int version) { ar & boost::serialization::make_nvp("A", boost::serialization::base_object<A>(o)); ar & make_nvp("test_b", o.test_b); } } } BOOST_CLASS_EXPORT(B); // Should register B for all archives such that it can be serialized of the basepointers void main() { A* a = new B(); boost::archive::xml_oarchive archive(std::cout); archive.template register_type<B>(); // Should register B for this archive archive & boost::serialization::make_nvp ("a", a); // If you check the output, you see that `{B}.test_b' was not serialized int i; std::cin >> i; }

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Need boost_regex_vc7_mssd.lib
by Dyuti Barma 09 Feb '09

09 Feb '09

Hi, I'm not sure where to find boost_regex_vc7_mssd.lib and the corresponding library for VC8. Can anyone let me know where to get the above libs from ? Thanks Dyuti

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Boost.lambda: how to sort this vector with function?
by Joost Kraaijeveld 09 Feb '09

09 Feb '09

I want to sort a vector of Edges according to their remaining estimated distance to the finish point (an own implementation of a graph algorithm). How do I sort this vector with edges: // Returns the cost between start and finish, given a graph int CostEstimate( const Graph& aGraph, const Vertex& start, const Vertex& finish) ... // Member function of a graph std::vector< Edge > v = ...; // Sort them according to the cost std::sort( v.begin(), v.end(), boost::lambda::bind( CostEstimate( (*this), boost::lambda::bind( &Edge::otherSide, &start, boost::lambda::_1), finish)) < boost::lambda::bind( CostEstimate( (*this), boost::lambda::bind( &Edge::otherSide, &start, boost::lambda::_2), finish))); where otherSide is a const function of the class Edge which returns a "const Vertex&" Compiling this results in an error: error: invalid initialization of reference of type ‘const Vertex&’ from expression of type ‘const boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<3, boost::lambda::function_action<3, boost::lambda::detail::unspecified> >, boost::tuples::tuple<const Vertex& (Edge::* const)(const Vertex&)const, const Vertex* const, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >’ TIA -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

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[Graph] is it possible to define my own edge_descriptor
by George Slavov 09 Feb '09

09 Feb '09

Hello, I have a graph which corresponds to an n by m grid of vertices. Edges in this graph are only allowed to point from one vertex to an adjacent vertex. In this situation, it would be wonderful if I could define an edge, so that its target is not a vertex_descriptor but some other construct which would allow me to store the target in just one byte or less instead of the full unsigned int which I use to describe my vertices. That is, the edge could go from vertex 102 to a descriptor in the range [0,8] which would give you enough information to compute which vertex you're talking about. The graph I'm working with is rather large. It could have millions of vertices and saving this kind of space would be fantastic. If it's important at all, mostly I'll be doing topological sort on these graphs. Is this possible? Best, George Slavov

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NURBS curves/surfaces
by Peter Barker 09 Feb '09

09 Feb '09

Hello, Is there anything in Boost current or planned to deal with NURBS curves/surfaces? Regards, Pete

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[boost-users][asio] why boost::thread thread1(boost::bind(...)) doesn't start io_service on multicore machine?
by tomasz jankowski 09 Feb '09

09 Feb '09

I would like to test my class which implements shared data. because of it I have written test code which use boost::thread & boost asio (please see below). the problem is that threads are NOT started... on multicore machine. one one core machine it runs fine. any idea why? tom #include <iostream> #include <istream> #include <ostream> #include <string> #include <boost/asio.hpp> #include <boost/date_time/posix_time/posix_time.hpp> #include <boost/bind.hpp> #include <boost/thread.hpp> #include "shared.hpp" #include <boost/random/linear_congruential.hpp> #include <boost/random/uniform_real.hpp> #include <boost/random/variate_generator.hpp> SharedData replyToClients; void handle_timeout1(const boost::system::error_code&) { boost::minstd_rand generator(42u); boost::uniform_real<> uni_dist(0,1); boost::variate_generator<boost::minstd_rand, boost::uniform_real<> >uni(generator, uni_dist); std::string key = "ello";std::cout<<key<<std::endl; std::string value1 = "see you later aligator"; std::string value2 = "what do you want to eat today?"; double cond = 0.500000; while(true){ if(uni() >= cond){ replyToClients.set(key,value1); }else{ replyToClients.set(key,value2); } } } void handle_timeout2(const boost::system::error_code&) { std::string key = "ello"; while(true){ std::cout<<replyToClients.get(key); } } int main(int argc, char* argv[]) { try{ boost::asio::io_service io_service; boost::system::error_code error; //boost::asio::io_service::work work(io_service); io_service.post(boost::bind(handle_timeout1,error)); io_service.post(boost::bind(handle_timeout2,error)); io_service.post(boost::bind(handle_timeout2,error)); io_service.post(boost::bind(handle_timeout2,error)); boost::thread thread1(boost::bind(&boost::asio::io_service::run, &io_service)); boost::thread thread2(boost::bind(&boost::asio::io_service::run, &io_service)); boost::thread thread3(boost::bind(&boost::asio::io_service::run, &io_service)); boost::thread thread4(boost::bind(&boost::asio::io_service::run, &io_service)); //io_service.run(); std::cout<<"the end\n"; io_service.stop(); thread1.join(); thread2.join(); thread3.join(); thread4.join(); } catch (boost::system::system_error& er) {std::cout << "Exception er: " << er.what() << "\n"; } catch (std::exception& e) { std::cout << "Exception e: " << e.what() << "\n"; } return 0; } ---------------------------------------------------- Nużą Cię utarte scenariusze? Wymyśl własną grę flashową i wygraj główną nagrodę 5.500 Euro: http://klik.wp.pl/?adr=http%3A%2F%2Fwhosegame.pl%2Fcontestcard.php%3Fcontes…

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[program_options] VM object unable to store the values of options
by Wenjing Jia 09 Feb '09

09 Feb '09

(Apologies if this message has come out for more than once, as I had problem with authorization and is unsure when the message is able to be seen by boost users!) Hi, I'm met a very weird thing when using the “Boost.Program_options” library. Somehow, the variable-map(VM) object is unable to store values of options which are fed in from the command line. I've been stuck in this stupid problem for two days and cannot find any clue about it. Can someone please give me a hint? I'm using the Visual Studio 2005 on Windows XP SP3 to compile some examples provided in Boost.Program_options Tutorial. The boost library was installed using the boost_1_34_1 installer. However, no matter what value I input to any option, the variable-map object "vm" I defined is unable to store it and output it correctly. For instance, I followed the instructions in the Tutorial of the Boost.Program_options and compiled the first simplest possible example "example/first.cpp". I then went to "start" of Windows XP and Run "cmd", then run: "first --compression 10". The output is always "Compression level was set to -858993460." regardless of what value I type after the "--compression". Below is the full codes of the program (copied from the "example/first.cpp"): ------------------------------------------------------------------------------- #include <boost/program_options.hpp> namespace po = boost::program_options; #include <iostream> #include <iterator> using namespace std; int main(int ac, char* av[]) { try { po::options_description desc("Allowed options"); desc.add_options() ("help", "produce help message") ("compression", po::value<int>(), "set compression level") ; po::variables_map vm; po::store(po::parse_command_line(ac, av, desc), vm); po::notify(vm); if (vm.count("help")) { cout << desc << "\n"; return 1; } if (vm.count("compression")) { cout << "Compression level was set to " << vm["compression"].as<int>() << ".\n"; } else { cout << "Compression level was not set.\n"; } } catch(exception& e) { cerr << "error: " << e.what() << "\n"; return 1; } catch(...) { cerr << "Exception of unknown type!\n"; } return 0; } ------------------------------------------------------------------------------- I also tried on the other examples mentioned on that web page, such as "example/options_description.cpp". When I type: "options_description --optimization 4 -I foo a.cpp", the output is: "Include paths are: Input files are: Optimization level is -858993460". That is the input values are not taken and stored by the vm object. Why such a simple example won't work on my machine!? Your suggestion would be most appreciated! Many thanks in advance! Wenjing

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boost graph compiling problem with vc7.1
by liulewes 08 Feb '09

08 Feb '09

Dear there: I recently started to use the boost graph library and I got the following problem. I'v 2 projects A and B in my vc 7.1 solution. A uses boost graph lib while B is dependent on A. I'v no problem compiling A but got some errors in B like this: C:\Program Files\boost\boost_1_35_0\boost\graph\detail\adjacency_list.hpp(2292): error C2039: 'size_type' : is not a member of 'boost::vec_adj_list_impl<Graph,Config,Base>' with [ Graph=boost::adjacency_list<boost::vecS,boost::vecS,boost::undirectedS,boost::property<vmap_id_t,int,boost::property<boost::vertex_color_t,RGBColor,boost::property<vertex_feature_t,FeatureVector2D<double> *>>>,boost::property<boost::edge_weight_t,double>>, Config=boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::undirectedS,boost::property<vmap_id_t,int,boost::property<boost::vertex_color_t,RGBColor,boost::property<vertex_feature_t,FeatureVector2D<double> *>>>,boost::property<boost::edge_weight_t,double>>,boost::vecS,boost::vecS,boost::undirectedS,boost::detail::retag_property_list<boost::vertex_bundle_t,boost::property<vmap_id_t,int,boost::property<boost::vertex_color_t,RGBColor,boost::property<vertex_feature_t,FeatureVector2D<double> *>>>>::type,boost::detail::retag_property_list<boost::edge_bundle_t,boost::property<boost::edge_weight_t,double>>::type,boost::no_property,boost::listS>::config, Base=boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::undirectedS,boost::property<vmap_id_t,int,boost::property<boost::vertex_color_t,RGBColor,boost::property<vertex_feature_t,FeatureVector2D<double> *>>>,boost::property<boost::edge_weight_t,double>>,boost::vecS,boost::vecS,boost::undirectedS,boost::detail::retag_property_list<boost::vertex_bundle_t,boost::property<vmap_id_t,int,boost::property<boost::vertex_color_t,RGBColor,boost::property<vertex_feature_t,FeatureVector2D<double> *>>>>::type,boost::detail::retag_property_list<boost::edge_bundle_t,boost::property<boost::edge_weight_t,double>>::type,boost::no_property,boost::listS>::DirectedHelper ] and even like this: C:\Program Files\boost\boost_1_35_0\boost\pending\container_traits.hpp(150): error C2065: 'list' : undeclared identifier I think that I have all the standard headers included. Where mush I have been wrong? Thanks _________________________________________________________________ MSN资讯快递，帮助你第一时间了解最新资讯！ http://im.live.cn/newsexpress

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