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Boost.Filesystem with MSVC8 & STLPort linker errors
by Craig Henderson 12 Jun '09

12 Jun '09

Hi, I have an application using Boost.Filesystem, Boost.Thread and others, that I am building on Windows XP using MSVC8, STLPort and Boost 1.39.0. I have built Boost using Boost Jam 3.1.17 and STLPort. Using the MSVC native STL I get no errors and everything runs well, but with the STL version, I have four linker errors; all from Boost.Filesystem. Has anyone come across this problem before and found a solution, or give me a clue what might be wrong? Many thanks -- Craig 1>fsdatasource.obj : error LNK2019: unresolved external symbol "class boost::filesystem::file_status __cdecl boost::filesystem::detail::status_api(class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> > const &,class boost::system::error_code &)" (?status_api@detail@filesystem@boost@@YA?AVfile_status@23@ABV?$basic_string@ DV?$char_traits@D@stlpd_std@@V?$allocator@D@2@@stlpd_std@@AAVerror_code@syst em@3@@Z) referenced in function "bool __cdecl boost::filesystem::is_directory<class boost::filesystem::basic_path<class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> >,struct boost::filesystem::path_traits> >(class boost::filesystem::basic_path<class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> >,struct boost::filesystem::path_traits> const &)" (??$is_directory@V?$basic_path@V?$basic_string@DV?$char_traits@D@stlpd_std@@ V?$allocator@D@2@@stlpd_std@@Upath_traits@filesystem@boost@@@filesystem@boos t@@@filesystem@boost@@YA_NABV?$basic_path@V?$basic_string@DV?$char_traits@D@ stlpd_std@@V?$allocator@D@2@@stlpd_std@@Upath_traits@filesystem@boost@@@01@@ Z) 1>fsdatasource.obj : error LNK2019: unresolved external symbol "class boost::system::error_code __cdecl boost::filesystem::detail::dir_itr_increment(void * &,class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> > &,class boost::filesystem::file_status &,class boost::filesystem::file_status &)" (?dir_itr_increment@detail@filesystem@boost@@YA?AVerror_code@system@3@AAPAXA AV?$basic_string@DV?$char_traits@D@stlpd_std@@V?$allocator@D@2@@stlpd_std@@A AVfile_status@23@2@Z) referenced in function "private: void __thiscall boost::filesystem::basic_directory_iterator<class boost::filesystem::basic_path<class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> >,struct boost::filesystem::path_traits> >::increment(void)" (?increment@?$basic_directory_iterator@V?$basic_path@V?$basic_string@DV?$cha r_traits@D@stlpd_std@@V?$allocator@D@2@@stlpd_std@@Upath_traits@filesystem@b oost@@@filesystem@boost@@@filesystem@boost@@AAEXXZ) 1>fsdatasource.obj : error LNK2019: unresolved external symbol "class boost::system::error_code __cdecl boost::filesystem::detail::dir_itr_first(void * &,class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> > const &,class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> > &,class boost::filesystem::file_status &,class boost::filesystem::file_status &)" (?dir_itr_first@detail@filesystem@boost@@YA?AVerror_code@system@3@AAPAXABV?$ basic_string@DV?$char_traits@D@stlpd_std@@V?$allocator@D@2@@stlpd_std@@AAV67 @AAVfile_status@23@3@Z) referenced in function "private: class boost::system::error_code __thiscall boost::filesystem::basic_directory_iterator<class boost::filesystem::basic_path<class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> >,struct boost::filesystem::path_traits> >::m_init(class boost::filesystem::basic_path<class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> >,struct boost::filesystem::path_traits> const &)" (?m_init@?$basic_directory_iterator@V?$basic_path@V?$basic_string@DV?$char_t raits@D@stlpd_std@@V?$allocator@D@2@@stlpd_std@@Upath_traits@filesystem@boos t@@@filesystem@boost@@@filesystem@boost@@AAE?AVerror_code@system@3@ABV?$basi c_path@V?$basic_string@DV?$char_traits@D@stlpd_std@@V?$allocator@D@2@@stlpd_ std@@Upath_traits@filesystem@boost@@@23@@Z) 1>fsdatasource.obj : error LNK2019: unresolved external symbol "class boost::system::error_code __cdecl boost::filesystem::detail::remove_api(class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> > const &)" (?remove_api@detail@filesystem@boost@@YA?AVerror_code@system@3@ABV?$basic_st ring@DV?$char_traits@D@stlpd_std@@V?$allocator@D@2@@stlpd_std@@@Z) referenced in function "bool __cdecl boost::filesystem::detail::remove_aux<class boost::filesystem::basic_path<class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> >,struct boost::filesystem::path_traits> >(class boost::filesystem::basic_path<class stlpd_std::basic_string<char,class stlpd_std::char_traits<char>,class stlpd_std::allocator<char> >,struct boost::filesystem::path_traits> const &,class boost::filesystem::file_status)" (??$remove_aux@V?$basic_path@V?$basic_string@DV?$char_traits@D@stlpd_std@@V? $allocator@D@2@@stlpd_std@@Upath_traits@filesystem@boost@@@filesystem@boost@ @@detail@filesystem@boost@@YA_NABV?$basic_path@V?$basic_string@DV?$char_trai ts@D@stlpd_std@@V?$allocator@D@2@@stlpd_std@@Upath_traits@filesystem@boost@@ @12@Vfile_status@12@@Z)

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Re: [Boost-users] C++ Framework Libraries for Programming Populardatabases
by biolaser 12 Jun '09

12 Jun '09

Thanks all for your help in pointing me to solutions for database programming framework libraries. Please let me know if additional prospects become available.

1 0

[Multi-Index] Get container view of a non-unique-index equal_range?
by Dominique Devienne 12 Jun '09

12 Jun '09

Given for example class Ident : public noncopyable { .. .}; class VehicleIdent : public Ident { ... }; struct ByUid {}; struct ByType {}; struct ByNKey {}; struct VehicleIdentHash { ... }; struct VehicleIdentPred { ... }; typedef boost::multi_index_container< shared_ptr<VehicleIdent>, indexed_by< hashed_unique< // primary (surrogate) key tag<ByUid>, BOOST_MULTI_INDEX_CONST_MEM_FUN( Ident, const Uid&, uid ) >, hashed_unique< // natural key (logical primary key) tag<ByNKey>, identity< shared_ptr<VehicleIdent> >, VehicleIdentHash, VehicleIdentPred >, // additional index to iterate on a type range (e.g. all Cars) hashed_non_unique< tag<ByType>, BOOST_MULTI_INDEX_CONST_MEM_FUN( VehicleIdent, const string&, type ) > > > VehicleIndex; typedef VehicleIndex::index<ByUid>::type VehicleByUid; typedef VehicleIndex::index<ByType>::type VehicleByType; typedef VehicleIndex::index<ByNKey>::type VehicleByNKey; I'd like to be able to have a "view" of VehicleIndex, for example compatible with unordered_set in this case since using a hashed index, for a given vehicle type ("Audi" for example), and going further have this view allow inserts which would go into the "master" vehicle index under the cover, validated by its unique indexes. In pseudo-code, something a bit like this: struct VehicleMake { VehicleByType::EqualRangeView& models_; VehicleMake(const string& name) : models_(get<ByType>(get_vehicle_index()).equal_range_view(name)) {} }; With models_ behaving has a normal container one can iterate on (begin, end), query (empty, find, count), modify (insert, erase, clear, etc...), those operations only affecting the VehicleIndex elements matching the VehicleByType given range, and possibly asserting all inserts are valid for the range (the vehicles added via the "range view" have the type matching the range's type). Can this be done? Has it been considered as a possible extension, and is it even feasible given the current B.MI design? Any input on how to achieve or emulate the above would be appreciated. Thanks, --DD PS: The above design is synthetic of course. We have a parent-child hierarchy of C++ objects where parents have lists of their children, but now there's a list of all children, from all parents, in a B.MI, indexed (non-unique) on the parent instance, and I'd like the "concrete" list maintained by each parent to become the kind of "view" I'm describing above. Right now I'm manually maintaining the sync of the existing and the new "master" list (the B.MI index), having to "sprinkle" the code to keep them in sync, but the "view" approach above would be cleaner IMHO, and avoid many potential bugs from forgetting to "sprinkle" in all the right places.

2 4

Help needed to implement D_shortest_path
by Amanullah Yasin 12 Jun '09

12 Jun '09

Hi Dear all, Sorry for disturbing, i hope you can help me because i am facing one problem i tried a lot but i can not succeeded. To find the directed path between two nodes. First i tried to implement Depth First Search but it is searching the verteces even there is no edge exist. so, now i want to implement dijkstra_shortest_path , it is giving errors. Please guide me how i can implement this method. code is : slGraph& graph = this->pBN->get_graph(); slNode n = vertex(2, graph); std::vector<slNode> p(num_vertices(graph)); std::vector<int> d(num_vertices(graph)); boost::property_map<slGraph, edge_weight_t>::type weightMap = get(edge_weight, graph); boost::property_map<slGraph, vertex_index_t>::type indexmap = get(vertex_index, graph); dijkstra_shortest_paths(graph, n, predecessor_map(&p[0]).distance_map(&d[0])); // First pattern to implement //dijkstra_shortest_paths(graph, n, &p[0], &d[0], weightMap, indexmap, // std::less<int>(), closed_plus<int>(), // second pattern // (std::numeric_limits<int>::max)(), 0, // default_dijkstra_visitor()); ============================================ errors ============================================================== 1>c:\probt_slp\boost\include\boost\graph\dijkstra_shortest_paths.hpp(251) : error C2664: 'void put<int,DistInf>(T *,ptrdiff_t,const V &)' : cannot convert parameter 2 from 'void *' to 'ptrdiff_t' 1> with 1> [ 1> DistInf=int, 1> T=int, 1> V=int 1> ] 1> There is no context in which this conversion is possible 1> c:\probt_slp\boost\include\boost\graph\dijkstra_shortest_paths.hpp(292) : see reference to function template instantiation 'void boost::dijkstra_shortest_paths<VertexListGraph,boost::dijkstra_visitor<>,void**__w64 ,DistanceMap,WeightMap,IndexMap,std::less<_Ty>,boost::closed_plus<T>,int,int,ColorMap>(const VertexListGraph &,void *,PredecessorMap,DistanceMap,WeightMap,IndexMap,Compare,Combine,DistInf,DistZero,DijkstraVisitor,ColorMap)' being compiled 1> with 1> [ 1> VertexListGraph=slGraph, 1> DistanceMap=int *__w64 , 1> WeightMap=boost::adj_list_edge_property_map<boost::bidirectional_tag,long double,const long double &,void *,const boost::property<boost::edge_weight_t,slScoreValueType>,boost::edge_weight_t>, 1> IndexMap=boost::adj_list_vertex_property_map<slGraph,unsigned int,const unsigned int &,boost::vertex_index_t>, 1> _Ty=D, 1> T=D, 1> ColorMap=boost::iterator_property_map<std::_Vector_iterator<boost::default_color_type,std::allocator<boost::default_color_type>>,boost::adj_list_vertex_property_map<slGraph,unsigned int,const unsigned int &,boost::vertex_index_t>,boost::default_color_type,boost::default_color_type &>, 1> PredecessorMap=void **__w64 , 1> Compare=std::less<D>, 1> Combine=boost::closed_plus<D>, 1> DistInf=int, 1> DistZero=int, 1> DijkstraVisitor=boost::dijkstra_visitor<> 1> ] 1> c:\probt_slp\boost\include\boost\graph\dijkstra_shortest_paths.hpp(322) : see reference to function template instantiation 'void boost::detail::dijkstra_dispatch2<VertexListGraph,int*__w64 ,WeightMap,IndexMap,Params,boost::iterator_property_map<RandomAccessIterator,IndexMap,T,R>>(const VertexListGraph &,void *,DistanceMap,WeightMap,IndexMap,const Params &,ColorMap)' being compiled 1> with 1> [ 1> VertexListGraph=slGraph, 1> WeightMap=boost::adj_list_edge_property_map<boost::bidirectional_tag,long double,const long double &,void *,const boost::property<boost::edge_weight_t,slScoreValueType>,boost::edge_weight_t>, 1> IndexMap=boost::adj_list_vertex_property_map<slGraph,unsigned int,const unsigned int &,boost::vertex_index_t>, 1> Params=boost::bgl_named_params<int *__w64 ,boost::vertex_distance_t,boost::bgl_named_params<void **__w64 ,boost::vertex_predecessor_t,boost::no_property>>, 1> RandomAccessIterator=std::_Vector_iterator<boost::default_color_type,std::allocator<boost::default_color_type>>, 1> T=boost::default_color_type, 1> R=boost::default_color_type &, 1> DistanceMap=int *__w64 , 1> ColorMap=boost::iterator_property_map<std::_Vector_iterator<boost::default_color_type,std::allocator<boost::default_color_type>>,boost::adj_list_vertex_property_map<slGraph,unsigned int,const unsigned int &,boost::vertex_index_t>,boost::default_color_type,boost::default_color_type &> 1> ] 1> c:\probt_slp\boost\include\boost\graph\dijkstra_shortest_paths.hpp(342) : see reference to function template instantiation 'void boost::detail::dijkstra_dispatch1<VertexListGraph,int*__w64 ,boost::adj_list_edge_property_map<Directed,Value,Ref,Vertex,Property,Tag>,boost::adj_list_vertex_property_map<Graph,ValueType,Reference,boost::vertex_index_t>,boost::bgl_named_params<T,boost::vertex_distance_t,Base>,boost::detail::error_property_not_found>(const VertexListGraph &,void *,DistanceMap,WeightMap,IndexMap,const Params &,ColorMap)' being compiled 1> with 1> [ 1> VertexListGraph=slGraph, 1> Directed=boost::bidirectional_tag, 1> Value=long double, 1> Ref=const long double &, 1> Vertex=void *, 1> Property=const boost::property<boost::edge_weight_t,slScoreValueType>, 1> Tag=boost::edge_weight_t, 1> Graph=slGraph, 1> ValueType=unsigned int, 1> Reference=const unsigned int &, 1> T=int *__w64 , 1> Base=boost::bgl_named_params<void **__w64 ,boost::vertex_predecessor_t,boost::no_property>, 1> DistanceMap=int *__w64 , 1> WeightMap=boost::adj_list_edge_property_map<boost::bidirectional_tag,long double,const long double &,void *,const boost::property<boost::edge_weight_t,slScoreValueType>,boost::edge_weight_t>, 1> IndexMap=boost::adj_list_vertex_property_map<slGraph,unsigned int,const unsigned int &,boost::vertex_index_t>, 1> Params=boost::bgl_named_params<int *__w64 ,boost::vertex_distance_t,boost::bgl_named_params<void **__w64 ,boost::vertex_predecessor_t,boost::no_property>>, 1> ColorMap=boost::detail::error_property_not_found 1> ] 1> c:\probt_slp\work\yasin\test\pc\algopc.cpp(251) : see reference to function template instantiation 'void boost::dijkstra_shortest_paths<slGraph,int*__w64 ,boost::vertex_distance_t,boost::bgl_named_params<T,Tag,Base>>(const VertexListGraph &,void *,const boost::bgl_named_params<int *__w64 ,boost::vertex_distance_t,boost::bgl_named_params<T,Tag,Base>> &)' being compiled 1> with 1> [ 1> T=void **__w64 , 1> Tag=boost::vertex_predecessor_t, 1> Base=boost::no_property, 1> VertexListGraph=slGraph 1> ] 1>c:\probt_slp\boost\include\boost\graph\dijkstra_shortest_paths.hpp(252) : error C2664: 'void put<void*,void*>(T *,ptrdiff_t,const V &)' : cannot convert parameter 2 from 'void *' to 'ptrdiff_t' 1> with 1> [ 1> T=void *, 1> V=void * 1> ] 1> There is no context in which this conversion is possible 1>c:\probt_slp\boost\include\boost\graph\dijkstra_shortest_paths.hpp(255) : error C2664: 'void put<int,DistInf>(T *,ptrdiff_t,const V &)' : cannot convert parameter 2 from 'void *' to 'ptrdiff_t' 1> with 1> [ 1> DistInf=int, 1> T=int, 1> V=int 1> ] 1> There is no context in which this conversion is possible 1>Build log was saved at "file://c:\ProBT_SLP\work\yasin\test\Debug\BuildLog.htm" 1>testPC - 3 error(s), 75 warning(s) ============================================================================================================== I will be thankful to you for your guidance. Regards Amanullah YASIN Master2 (ECD) Ecole Polytechnique Université de Nantes, France. Mob# 06 47 62 89 96 Fix # 02 72 00 26 45 amanyasin(a)gmail.com

2 4

Mixing shared_ptr and regular pointers in containers
by Remko Tronçon 12 Jun '09

12 Jun '09

Hi, This feels like a stupid question, but is there an easy/clean way of mixing shared_ptr<A> and regular A* pointers in one STL container? Boost.Variant comes to mind, but I somehow have the idea that there's a more obvious way and that I'm missing it. thanks, Remko

3 3

C++ Framework Libraries for Programming Popular databases
by biolaser 12 Jun '09

12 Jun '09

I am interested in your recommendation of any open source, cross-platform C++ libraries designed for programming the major databases (Oracle, MySql, Postgres, MS Access, Sybase, etc). Boost does not provide any such database/sql library framework for C++. If you can point me toward a source or sources that do offer such a framework, and possibly one(s) the Boost people favor, it would be very much appreciated. Primarily, I am developing code for Windows and Unix/Linux.

9 8

Spirit: Chset base uint32_t
by Etienne Philip Pretorius 11 Jun '09

11 Jun '09

Hello List, I am trying to define the Char definition in the XML specification and I receive this compiler error: hex escape sequence out of range Here is the relvent code: const static boost::spirit::chset<uint32_t> Char( "\x9\xA\xD\x20-\xD7FF\xE000-\xFFFD\x10000-\x10FFFF" ); Can someone please point me in the right direction to get this working. Thank you, Etienne Pretorius

2 1

shared_ptr binary compatibility
by pcayouette 11 Jun '09

11 Jun '09

Are shared_ptr binary compatible through boost versions? Example: Imagine a "Producer" class that sends shared_ptr to a "Consumer" class. Now imagine an executable that instanciate a Producer and a shared library (.dll or .so) that instanciate a Consumer. The executable is built with boost v1.xx. The shared library is built with boost v1.yy. If xx == yy, obviously there will be no problem since the version of the shared_ptr is the same. However if xx != yy, there might be a problem since the version of the shared_ptr might be binary imcompatible. Thanks, Philippe Cayouette -- View this message in context: http://www.nabble.com/shared_ptr-binary-compatibility-tp23985635p23985635.h… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

Am I doing something wrong here? Boost threads & intrusive_ptr crash
by Space Ship Traveller 11 Jun '09

11 Jun '09

Hi, I'm using an event loop type system which I've implemented myself. This is due to specific needs. Event loop is fairly simple, it has several types of events: - Timer based events (relative or exact, repeating, etc) - IO based events - Notification based events Notifications are events which can come from any thread, and get processed on in the main loop. Here is the function which is used to post a notification. REF(t) is simply a macro for boost::intrusive_ptr<t>. void Loop::postNotification (REF(INotificationSource) note, bool urgent) { using namespace boost; typedef boost::mutex::scoped_lock scoped_lock; // Lock the event loop notification queue // Add note to the end of the queue // Interrupt event loop thread if urgent // We should probably lock around m_currentThread, it might not be set before we read it..? if (this_thread::get_id() == m_currentThread) { note->processEvents(this, NOTIFICATION); } else { { // Enqueue the notification to be processed scoped_lock lock(m_notifications.lock); m_notifications.sources->push(note); (*) } if (urgent) { // Interrupt event loop thread so that it processes notifications more quickly m_urgentNotificationPipe->notifyEventLoop(); } } } I'm experiencing a very infrequent crash at the line marked with (*). The note is a reference counted pointer (boost::intrusive_ptr), but by the time we get here, this pointer is invalid, even though there are still references to it in the system. The odd thing is, further up the chain (and on the same thread), I'm checking to ensure that note is valid, i.e. //... display update system, separate thread from event-loop. ensure(ctx->notificationSource); loop->postNotification(ctx->notificationSource); //... After writing this far in the email, I'm starting to see something where there could be an error. Is it possible that the object reference count is being messed up due to multi-threading issues? I.e. if the object is being passed around on two separate threads, having the reference count incremented and decremented at the same time? Actually, it seems obvious that this could be a problem... Are there any "patterns" for using reference counted objects across different threads? Any feedback is appreciated. Kind regards, Samuel

3 4

troubles building 1.39.0 with intel compiler under linux
by Frédéric Bron 11 Jun '09

11 Jun '09

Hi, I try to upgrade from 1.38 to 1.39 and have to rewrite my building scripts. For gcc I had no particular issue. But for the intel compiler, it does not work: $ ./bootstrap.sh --without-icu --without-libraries=python --prefix=/soft/bal/usr/icc/boost --with-toolset=intel-linux $ ./bjam --layout=system --libdir=/soft/bal/usr/icc/boost/lib link=static threading=multi runtime-link=shared address-model=64 instruction-set=nocona release install However, I obtain the following error from bjam: error: at /soft/bal/usr/builds/icc/boost_1_39_0/tools/build/v2/build/project.jam:874 error: intel-linux initialization: parameter 'version' inconsistent error: an explicit value was specified in an earlier initialization error: no value is specified now Any clue? Frédéric PS: the content of the automatically generated project-config.jam: import option ; import feature ; if ! intel-linux in [ feature.values <toolset> ] { using intel-linux ; } project : default-build <toolset>intel-linux ; libraries = --without-python ; option.set prefix : /soft/bal/usr/icc/boost ; option.set exec-prefix : /soft/bal/usr/icc/boost ; option.set libdir : /lib ; option.set includedir : /soft/bal/usr/icc/boost/include ;

3 3

Problem with throwing exceptions in async handler functions of ASIO library
by J.W.F. Thirion 11 Jun '09

11 Jun '09

Dear Boost community, We're having a problem using the ASIO class with multiple IO service threads and throwing exceptions inside the handle_xxx functions, as used by the async_xxx functions of the ASIO library. It seems that when any error is thrown in a normal/non-handler function, the try/catch block of the main program is able to catch the error. However, when the handler functions are called (I would assume by the io service, now running in a separate thread), the main function's try/catch blocks never receive the execeptions, and a std::terminate() is called automatically. To demonstrate this, we've taken the HTTP Server 2 example from the ASIO examples page and reduced its complexity. Below are the sources of the example. Basically, to duplicate the problem, run the main executable and then in another terminal, simply "telnet 127.0.0.1 60000" to see the std::terminate() being called, even though there are try/catch blocks in the main function (main.cpp). Here is an output: $ ./main terminate called after throwing an instance of 'int' Aborted $ We've also taken the HTTP Server 2 example "as is" and added a "throw 123;" at the top of handle_accept in server.cpp and a "catch (...)" block in posix_main.cpp. The same issue occurred here, which indicates that the exceptions are not propagated through all the way (maybe because the io service runs in a separate thread). Does anyone have a suggestion on how we can throw exceptions inside the handler functions of the async functions used? We'd like to handle all our errors with custom exception classes (e.g. ExceptionAccept is thrown if there is an error detected in handle_accept, which can then be handled inside the main function of main.cpp). We've compiled the sources below by typing: g++ -I/usr/local/boost/include/boost-1_38 -L/usr/local/boost/lib -lboost_thread-gcc41-mt-1_38 -lboost_system-gcc41-mt-1_38 io_service_pool.cpp server.cpp main.cpp -o main where /usr/local/boost is the local boost installation path. Many thanks in advance! Kind regards, Derik Thirion main.cpp -------- #include <iostream> #include <string> #include <boost/asio.hpp> #include <boost/thread.hpp> #include <boost/bind.hpp> #include <boost/lexical_cast.hpp> #include "server.hpp" #include <pthread.h> #include <signal.h> int main(int argc, char* argv[]) { try { // Block all signals for background thread. sigset_t new_mask; sigfillset(&new_mask); sigset_t old_mask; pthread_sigmask(SIG_BLOCK, &new_mask, &old_mask); server s("127.0.0.1", "60000", 2); // 2 threads boost::thread t(boost::bind(&server::run, &s)); // 2 threads // Restore previous signals. pthread_sigmask(SIG_SETMASK, &old_mask, 0); // Wait for signal indicating time to shut down. sigset_t wait_mask; sigemptyset(&wait_mask); sigaddset(&wait_mask, SIGINT); sigaddset(&wait_mask, SIGQUIT); sigaddset(&wait_mask, SIGTERM); pthread_sigmask(SIG_BLOCK, &wait_mask, 0); int sig = 0; sigwait(&wait_mask, &sig); s.stop(); t.join(); } catch (std::exception& e) { std::cerr << "exception: " << e.what() << "\n"; } catch (...) { std::cerr << "all exception" << "\n"; } return 0; } server.hpp ---------- #ifndef SERVER_HPP #define SERVER_HPP #include <boost/asio.hpp> #include <string> #include <vector> #include <boost/noncopyable.hpp> #include <boost/shared_ptr.hpp> #include "io_service_pool.hpp" /// The top-level class of the HTTP server. class server : private boost::noncopyable { public: /// Construct the server to listen on the specified TCP address and port, and /// serve up files from the given directory. explicit server(const std::string& address, const std::string& port, std::size_t io_service_pool_size); /// Run the server's io_service loop. void run(); /// Stop the server. void stop(); private: /// Handle completion of an asynchronous accept operation. void handle_accept(const boost::system::error_code& e); /// The pool of io_service objects used to perform asynchronous operations. io_service_pool io_service_pool_; /// Acceptor used to listen for incoming connections. boost::asio::ip::tcp::acceptor acceptor_; }; #endif // SERVER_HPP server.cpp ---------- #include "server.hpp" #include <boost/bind.hpp> server::server(const std::string& address, const std::string& port, std::size_t io_service_pool_size) : io_service_pool_(io_service_pool_size), acceptor_(io_service_pool_.get_io_service()) { // Open the acceptor with the option to reuse the address (i.e. SO_REUSEADDR). boost::asio::ip::tcp::resolver resolver(acceptor_.io_service()); boost::asio::ip::tcp::resolver::query query(address, port); boost::asio::ip::tcp::endpoint endpoint = *resolver.resolve(query); acceptor_.open(endpoint.protocol()); acceptor_.set_option(boost::asio::ip::tcp::acceptor::reuse_address(true)); acceptor_.bind(endpoint); acceptor_.listen(); acceptor_.async_accept(*(new boost::asio::ip::tcp::socket(io_service_pool_.get_io_service())), boost::bind(&server::handle_accept, this, boost::asio::placeholders::error)); } void server::run() { io_service_pool_.run(); } void server::stop() { io_service_pool_.stop(); } void server::handle_accept(const boost::system::error_code& e) { throw 123; // this one never gets caught in main // instead std::terminate() gets called } io_service_pool.cpp ------------------- #include <stdexcept> #include <boost/thread.hpp> #include <boost/bind.hpp> #include <boost/shared_ptr.hpp> #include "io_service_pool.hpp" io_service_pool::io_service_pool(std::size_t pool_size) : next_io_service_(0) { if (pool_size == 0) throw std::runtime_error("io_service_pool size is 0"); // Give all the io_services work to do so that their run() functions will not // exit until they are explicitly stopped. for (std::size_t i = 0; i < pool_size; ++i) { io_service_ptr io_service(new boost::asio::io_service); work_ptr work(new boost::asio::io_service::work(*io_service)); io_services_.push_back(io_service); work_.push_back(work); } } void io_service_pool::run() { // Create a pool of threads to run all of the io_services. std::vector<boost::shared_ptr<boost::thread> > threads; for (std::size_t i = 0; i < io_services_.size(); ++i) { boost::shared_ptr<boost::thread> thread(new boost::thread( boost::bind(&boost::asio::io_service::run, io_services_[i]))); threads.push_back(thread); } // Wait for all threads in the pool to exit. for (std::size_t i = 0; i < threads.size(); ++i) threads[i]->join(); } void io_service_pool::stop() { // Explicitly stop all io_services. for (std::size_t i = 0; i < io_services_.size(); ++i) io_services_[i]->stop(); } boost::asio::io_service& io_service_pool::get_io_service() { // Use a round-robin scheme to choose the next io_service to use. boost::asio::io_service& io_service = *io_services_[next_io_service_]; ++next_io_service_; if (next_io_service_ == io_services_.size()) next_io_service_ = 0; return io_service; } io_service_pool.hpp: -------------------- #ifndef IO_SERVICE_POOL_HPP #define IO_SERVICE_POOL_HPP #include <boost/asio.hpp> #include <vector> #include <boost/noncopyable.hpp> #include <boost/shared_ptr.hpp> /// A pool of io_service objects. class io_service_pool : private boost::noncopyable { public: /// Construct the io_service pool. explicit io_service_pool(std::size_t pool_size); /// Run all io_service objects in the pool. void run(); /// Stop all io_service objects in the pool. void stop(); /// Get an io_service to use. boost::asio::io_service& get_io_service(); private: typedef boost::shared_ptr<boost::asio::io_service> io_service_ptr; typedef boost::shared_ptr<boost::asio::io_service::work> work_ptr; /// The pool of io_services. std::vector<io_service_ptr> io_services_; /// The work that keeps the io_services running. std::vector<work_ptr> work_; /// The next io_service to use for a connection. std::size_t next_io_service_; }; #endif // IO_SERVICE_POOL_HPP

3 4

boost::test test case levels
by Anatoli Sakhnik 11 Jun '09

11 Jun '09

Hi there! Our automatic tests are of two kinds: short (just like BOOST_CHECK_EQUAL(2*2, 4);), and complicated, which process bulks of random data (for instance, to check if a map with random numbers is always sorted). So we’d like to select which test cases to run: either simple ones or all. I see two ways: 1. Default variants release, debug build and run only simple test cases. We define another feature (or even a build variant) that builds and runs all the tests. This will require additional build efforts, and we’d like to select test cases in run-time. 2. We try to get use of --run_test=??? and test case name mangling. This is a hack, of course. Is there another way to select test cases in run-time? — Anatoli

2 1

[Boost.Thread] Join not waiting?
by James Auger 11 Jun '09

11 Jun '09

This is my first time working with Boost.Thread and I'm having some difficulty in that Join does not seem to work (obviously I'm doing something wrong). In a nutshell what I'm doing is: Instantiating the Example class (which has a boost::thread as a member variable) calling Example::run() (which starts the thread) do some stuff (both in main and in the thread) calling Example::terminate() (which sets the condition for the thread function to stop, and calls Join) end. The problem is that Join returns instantly, before the thread has finished. In the code below I've commented out the stop condition (making the thread run an infinite loop) to demonstrate that it keeps running after join returns. By my understanding of how boost threads and join works, this is not the correct behavior; my understanding is that the call to join should not return until the thread has stopped running. Either my understanding is wrong, or my code to make that happen is wrong. Can you guys help me? The example is stripped down/simplified code that I wrote to demonstrate and test what was going on in my actual program. Example Output: --- thread: main: 00 thread: main: 11 thread: main: 22 thread: main: 33 main: thread: 44 main: After Terminate thread: 5 thread: 6 thread: 7 thread: 8 --- Note the interleaved output 0 - 4, that's expected and fine. The problem is the thread is still running (as evidenced by writing to cout) after terminate() (and thus join()) has been called on that thread. Example Code: --- #include <iostream> #include <boost/thread/thread.hpp> #include <boost/thread/mutex.hpp> #include <boost/bind.hpp> class Example { public: Example() { flag = 0; }; void run() { flag = 1; boost::thread _myThread(boost::bind(&Example::threadLoop, this)); }; void terminate() { //flag = 3; //commented out stop condition _myThread.join(); }; private: void threadLoop() { flag = 2; for(int i = 0; flag == 2; i++) { boost::this_thread::sleep(boost::posix_time::seconds(1)); std::cout<<"thread: "<<i<<std::endl; } flag = 4; }; boost::thread _myThread; int flag; }; int main() { Example anExample; anExample.run(); for(int i = 0; i < 5; i++) { boost::this_thread::sleep(boost::posix_time::seconds(1)); std::cout<<"main: "<<i<<std::endl; } anExample.terminate(); std::cout<<"main: After Terminate"<<std::endl; boost::this_thread::sleep(boost::posix_time::seconds(5)); //sleep so we can see the thread still outputing return 0; } --- Thanks!

3 3

size of serialized ptime object?
by Archie14 11 Jun '09

11 Jun '09

when serializing ptime without using any custom facets, just by using >> or << : how to find the size of the serialized data? Seems to me that sizeof(ptime) should not return the proper value of serialized object size.

1 0

serializing ptr_map results in compiler error C2039
by Faheemullah Memon 11 Jun '09

11 Jun '09

I have some code that I want to build. The code uses boost::ptr_map class to serialize certain objects. I have Visual Studio 2008 with boost1.38 and I am getting following error from compiler. I wonder if any one else has seen any thing like this. C2039: 'serialize' : is not a member of 'boost::ptr_map<Key,T>' Looks like some reference is missing and I wonder what it is, I don't see any boost/serialization/ptr_map. I have Googled a lot and nothing has proved to be viable. I have created a sample code that generates the same error below #include <fstream> #include <iostream> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/config.hpp> #include <boost/shared_ptr.hpp> #include <boost/ptr_container/ptr_map.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/version.hpp> #include <boost/serialization/split_member.hpp> using namespace std; class User { boost::ptr_map<std::string, string> ptrmap; public: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & ptrmap; } bool save(const std::string& filename) { ofstream ofs(filename.c_str()); if(ofs.good() == false) { return false; } try { boost::archive::text_oarchive oa(ofs); oa << (*this); } catch(...) { throw; } return true; } }; int main() { User user; user.save("C:\\test.db"); return EXIT_SUCCESS; } Any help is appreciated. faheemitian

2 1

Re: [Boost-users] [Boost.CircularBuffer] begin()/end() arithmetic not working out quite right
by Jan Gaspar 11 Jun '09

11 Jun '09

Hi David, you just cannot rely on this. I don't think standard says anything about begin() moving forward after push_back(). Correct me if I'm wrong. The way how it is implemented is that if the circular_buffer is empty begin() returns the same iterator as end(). There is also a note about iterator invalidation for push_back(): "Does not invalidate any iterators with the exception of iterators pointing to the overwritten element." It means iterator 'a' in your first example will point to the same element as it was before calling push_back() - which is end(). This explains the behaviour you are describing. Regards, Jan ----- Original Message ---- From: David Baird <dhbaird(a)gmail.com> To: Jan Gaspar <jano_gaspar(a)yahoo.com>; boost-users(a)lists.boost.org Sent: Thursday, 11 June, 2009 1:01:54 Subject: [Boost.CircularBuffer] begin()/end() arithmetic not working out quite right Hi, Firstly, thanks for the work on a circular buffer. This is very useful since many of my applications require it. I am having a problem though... I am using Boost 1.38.0. When I call push_back(), the iterator math makes it appear that begin() moves backwards and end() remains constant. (Based on other STL libraries, I expect that begin() will remain constant and end() will keep advancing as I call push_back()). In other words, this assertion fails (but I expect it to succeed): circular_buffer<int> buf(8); circular_buffer<int>::iterator a; circular_buffer<int>::iterator b; a = buf.begin(); buf.push_back(1); b = buf.begin(); assert(a == b); // Fails!! Also, this code fails too (but I expect it to succeed): circular_buffer<int> buf(8); circular_buffer<int>::iterator a; circular_buffer<int>::iterator b; a = buf.end(); buf.push_back(1); b = buf.end(); assert(a != b); // Also fails! Below is a full example that you can compile and try out: #include <boost/circular_buffer.hpp> #include <stdio.h> int main () { typedef boost::circular_buffer<int> buf_type; // Instead of "end" moving ahead, "begin" is moving backwards when // // using "push_back". { buf_type buf1(1024); buf_type::iterator a; buf_type::iterator b; a = buf1.end(); buf1.push_back(1); buf1.push_back(2); b = buf1.end(); printf ("%d\n", a == b); // >>> // got: 1 // expected: 0 printf ("%d, %d\n", a-buf1.begin(), b-buf1.begin()); // >>> // got: 2, 2 // expected: 0, 2 } { buf_type buf2(1024); buf_type::iterator c; buf_type::iterator d; c = buf2.begin(); buf2.push_back(1); buf2.push_back(2); d = buf2.begin(); printf ("%d\n", c == d); // >>> // got: 0 // expected: 1 // (i.e. "begin()" is not still pointing to first item!! // This is incorrect, isn't it?) printf ("%d, %d\n", buf2.end()-c, buf2.end()-d); // >>> // got: 0, 2 // expected: 2, 2 } return 0; } Thanks, David

1 0

[MPI] Derived class not properly registered, even if it is.
by Mathieu Larose 11 Jun '09

11 Jun '09

Hi, I'm using MPI and I've come to an strange assertion fail from the library and I was wondering if it was "normal". Here is the code. I've got three files: header.hpp main.cpp other.cpp - - - - - - - - header.cpp - - - - - - - - #ifndef HEADER_HPP #define HEADER_HPP #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> // Abstract class A { friend class boost::serialization::access; template <class Archive> void serialize(Archive & ar, const unsigned int version) {} public: virtual void foo() = 0; }; class B : public A { friend class boost::serialization::access; template <class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<A>(*this); } public: void foo() {} }; #endif - - - - - - - - main.cpp - - - - - - - - #include <iostream> #include <boost/mpi.hpp> #include "header.hpp" // #include <boost/serialization/export.hpp> // BOOST_CLASS_EXPORT(B); int main(int argc, char * argv[]) { boost::mpi::environment env(argc, argv); boost::mpi::communicator world; if (world.rank() == 0) { A * a = new B; world.send(1,0,a); std::cout << "sent" << std::endl; } } - - - - - - - - other.cpp - - - - - - - - #include "header.hpp" #include <boost/serialization/export.hpp> BOOST_CLASS_EXPORT(B); If I run this code I've got this assertion fail: a.out: ./boost/archive/impl/archive_pointer_oserializer.ipp:64: static const boost::archive::detail::basic_pointer_oserializer* boost::archive::detail::archive_pointer_oserializer<Archive>::find(const boost::serialization::extended_type_info&) [with Archive = boost::mpi::packed_oarchive]: Assertion `it != boost::serialization::singleton< oserializer_map<Archive> >::get_const_instance().end()' failed. I realized that if I uncomment these lines in main.cpp: #include <boost/serialization/export.hpp> BOOST_CLASS_EXPORT(B); My code runs correctly. It seems that BOOST_CLASS_EXPORT needs to be in the same .cpp file (i.e main.cpp) where MPI is used. When using serialization only, BOOST_CLASS_EXPORT could be in any .cpp files. Is this normal? Also, if A is no more an abstract class, BOOST_CLASS_EXPORT(B); could be called from other.cpp and the code runs correctly. I'm using version 1.39.0. Thank you, Mathieu Larose

2 2

[conversion] Using Lexical_cast to convert string to float
by Ryan McConnehey 11 Jun '09

11 Jun '09

In writing some unit tests to convert strings to floats I've come across a puzzling situation. I was trying to test that a std::bad_cast was thrown if a number was too large to fit into a float. The error wasn't thrown but the float was given 1.#INF000. The work around I used was to cast to a double and then do a numeric_cast on the result. This provided an exception for values larger than could fit in a float. Lexical_cast on a double though works as I would have expected. If a value is too large to fit into a double then a std::bad_cast is called. float test = boost::lexical_cast<float>("3.4e050"); //test will have the value of 1.#INF000 float test = boost::numeric_cast<float>( boost::lexical_cast<double>("3.4e50"); //std::bad_cast is thrown double test = boost::lexical_cast<double>("3.4e350"); //std::bad_cast is thrown Is the lexical_cast for float behaving correctly? Ryan P.S. This code is using boost 1.38.0

2 4

[Boost.CircularBuffer] begin()/end() arithmetic not working out quite right
by David Baird 10 Jun '09

10 Jun '09

Hi, Firstly, thanks for the work on a circular buffer. This is very useful since many of my applications require it. I am having a problem though... I am using Boost 1.38.0. When I call push_back(), the iterator math makes it appear that begin() moves backwards and end() remains constant. (Based on other STL libraries, I expect that begin() will remain constant and end() will keep advancing as I call push_back()). In other words, this assertion fails (but I expect it to succeed): circular_buffer<int> buf(8); circular_buffer<int>::iterator a; circular_buffer<int>::iterator b; a = buf.begin(); buf.push_back(1); b = buf.begin(); assert(a == b); // Fails!! Also, this code fails too (but I expect it to succeed): circular_buffer<int> buf(8); circular_buffer<int>::iterator a; circular_buffer<int>::iterator b; a = buf.end(); buf.push_back(1); b = buf.end(); assert(a != b); // Also fails! Below is a full example that you can compile and try out: #include <boost/circular_buffer.hpp> #include <stdio.h> int main () { typedef boost::circular_buffer<int> buf_type; // Instead of "end" moving ahead, "begin" is moving backwards when // // using "push_back". { buf_type buf1(1024); buf_type::iterator a; buf_type::iterator b; a = buf1.end(); buf1.push_back(1); buf1.push_back(2); b = buf1.end(); printf ("%d\n", a == b); // >>> // got: 1 // expected: 0 printf ("%d, %d\n", a-buf1.begin(), b-buf1.begin()); // >>> // got: 2, 2 // expected: 0, 2 } { buf_type buf2(1024); buf_type::iterator c; buf_type::iterator d; c = buf2.begin(); buf2.push_back(1); buf2.push_back(2); d = buf2.begin(); printf ("%d\n", c == d); // >>> // got: 0 // expected: 1 // (i.e. "begin()" is not still pointing to first item!! // This is incorrect, isn't it?) printf ("%d, %d\n", buf2.end()-c, buf2.end()-d); // >>> // got: 0, 2 // expected: 2, 2 } return 0; } Thanks, David

1 0

boost::multi_array SWIG binding
by NJ Duncan 10 Jun '09

10 Jun '09

Hi all, I'm fairly new to C++ and learning as I go, but there is very little info out there on my particular problem. I am trying to turn a model I've written in C++ into a python module using SWIG. The main problems I'm having are initializing Boost multiarray containers then getting data into and out of them. Here is some sample code: #include <iostream> #include <vector> #include <algorithm> #include "boost/multi_array.hpp" typedef boost::multi_array<double,2> array_typef; typedef boost::multi_array<int,2> array_typei; class G2G_hydro_model { public: array_typei A; array_typef S; G2G_hydro_model(int A_ncols,int A_nrows,int S_ncols,int S_nrows):, A(boost::extents[A_ncols][A_nrows]), S(boost::extents[S_ncols][S_nrows]) {}; ~G2G_hydro_model(void) {}; void read_floating(int x, int y, array_typef& data, double& element); void write_floating(int x, int y, array_typef& data, double& element); void write_integer(int x, int y, array_typei& data, int& element); void functions_to_do_stuff(array_typef&,array_typei&) }; void G2G_hydro_model::read_floating(int x, int y, array_typef data, double element) {element = data[x][y];} void G2G_hydro_model::write_floating(int x, int y, double element, array_typef data) {data[x][y] = element;} void G2G_hydro_model::write_integer(int x, int y, int element, array_typei data) {data[x][y] = element;} Code is pushed through SWIG to create bindings, then compiled as a linked library. Compiles ok with no warnings and Python accepts the module. But when I try to use with Python code like this: import sys import numpy as np import G2G h = G2G4.G2G_hydro_model(A.cols,A.nrows,S.cols,S.rows) element = 9 for x in range(0,A.cols) for y in range(0,A.rows) h.write_integer(x, y, element, h.A) Unfortunately I get the following error message: python: /usr/include/boost/multi_array/multi_array_ref.hpp:481: boost::multi_array_ref<T, NumDims>& boost::multi_array_ref<T, NumDims>::operator=(const ConstMultiArray&) [with ConstMultiArray = boost::multi_array<double, 2ul, std::allocator<double> >, T = double, long unsigned int NumDims = 2ul]: Assertion `std::equal(other.shape(), other.shape()+this->num_dimensions(), this->shape())' failed. I think I have assigned the array extents incorrectly, but I'm not sure of the proper way to do this as part of a C++ class. Any ideas, I'm starting to pull my hair out, I hope there is a simple answer. Many Thanks Niall -- __________________________________________________________________ Niall Duncan, Postgraduate Student Institute for Energy Systems, School of Engineering and Electronics The University of Edinburgh www.see.ed.ac.uk -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.

2 1

[Intrusive] safe_link assertion with list
by Pearl Rothman 10 Jun '09

10 Jun '09

I am using Fedora 9, gcc 4.3.0, and boost 1.38.0. I get the following error when calling the destroyMessage function. boost/intrusive/detail/utilities.hpp:421: void boost::intrusive::detail::destructor_impl(Hook&, boost::intrusive::detail::link_dispatch<safe_link>) [with Hook = boost::intrusive::detail::generic_hook<boost::intrusive::get_list_node_algo<void*>, boost::intrusive::default_tag, safe_link, 1>]: Assertion `!hook.is_linked()' failed. class MessageHook : public boost::intrusive::list_base_hook<>{ public: MessageHook(Message* msg) : m_msg(msg) {}; Message* GetMsg() { return m_msg; } private: Message* m_msg; }; class MessageFactory { public: MessageFactory() { } ~MessageFactory() { } ... virtual void destroyMessage( Message* msg ) { MessageHook hook(msg); m_message_list.push_back( hook ); } private: boost::intrusive::list<stockTraderMessageHook> m_message_list; }; Thanks

3 3

[Boost.Graph]: read_graphviz into std::vector
by Sascha Winter 10 Jun '09

10 Jun '09

Hi, I have graphes in the .dot format, with 24 vertex labels d1-d24, each storing one double. I want to use struct Vertex_p { std::string node_id; std::vector<double> d; } as the bundled property for my graph in boost and use read_graphviz to load the graph. How do I have to construct the property_map and the dynamic_properties? This property_map<graph_t, vector<double> Vertex_p::*>::type g_d = get(&Vertex_p::d, graph); g_dp.property("d",g_d); does not work. Is it even possible to do something like this? Thanks for any help, Sascha

2 1

Problem in returning value from DFS vistor class.
by Amanullah Yasin 10 Jun '09

10 Jun '09

Bonjour,Dear all I am facing general programming related logical error. I want to access bolean variable of the class by using get method. but it is not giving the right result. When i read the counter and boolean variable by getcount() and isPathExist() methods. Each time it returns "0" for counter and false for boolean. My code is below #include "AlgoPC.h"#include <boost/graph/depth_first_search.hpp> //=============================Depth First Search===========================class DFSVisitor: public default_dfs_visitor {protected: slBayesianNetwork *pBN; int nodeA, nodeC; bool exist; int counter; public: DFSVisitor(slBayesianNetwork *pBN, int nodeA, int nodeC); ~DFSVisitor(); void discover_vertex(slNode u, const slGraph &g); void resetCounter(); bool isPathExist(); int getCounter(); };//-------------------------------------------------------------------------- DFSVisitor::DFSVisitor(slBayesianNetwork *pBN, int nodeA, int nodeC) { this->pBN = pBN; this->nodeA = nodeA; this->nodeC = nodeC; this->exist = false; this->resetCounter(); }//-------------------------------------------------------------------------- DFSVisitor::~DFSVisitor() { }//--------------------------------------------------------------------------void DFSVisitor::resetCounter() { this->counter = 0; }//-------------------------------------------------------------------------- //--------------------------------------------------------------------------void DFSVisitor::discover_vertex(slNode u, const slGraph &g) { this->counter++; unsigned int varIdx = this->pBN->getVariableIndex(u); if ((varIdx == this->nodeC ) && ((this->counter) > 2)) { this->exist = true; cout<<"\n "<<counter<<" node = "<< varIdx+1; } }//--------------------------------------------------------------------------int DFSVisitor::getCounter() { return this->counter; }//--------------------------------------------------------------------------bool DFSVisitor::isPathExist() { return this->exist; } ====================== main program ======================= cout<< "\n a = "<<a<<" c = "<<c; DFSVisitor vis(this->pBN, a , c); depth_first_search((slGraph&)this->pBN->get_graph(),visitor(vis).root_vertex(vertex(a, this->pBN->get_graph()))); cout<<"\n counter is = "<<vis.getCounter()<<" Path exist = "<< vis.isPathExist(); ======================== out put ========================= counter is = 0 path exist = 0 (false) ------------------------------------------------------- I will be thankful to you for guiding me. Best Regards Amanullah YASIN Master2 (ECD) Ecole Polytechnique Université de Nantes, France. Mob# 06 47 62 89 96 Fix # 02 72 00 26 45 amanyasin(a)gmail.com

2 1

Obtaining base class type
by Robert Dailey 09 Jun '09

09 Jun '09

Hey everyone, I'm using wxWidgets, and as you all may know they have a silly macro used to define an event table... BEGIN_EVENT_TABLE( MainWindow, wxFrame ) EVT_CLOSE( MainWindow::OnClose ) END_EVENT_TABLE() I spend a few hours finding out that wxFrame is the incorrect parameter for parameter #2. This is not the base class that MainWindow derives from. There was no compiler error or warning, nor any errors during runtime. Only weird behavior because events were getting skipped. Because of this error-proneness, I'm looking for a way to have boost help me out with this. I'm looking for a metafunction in Boost that can be used to obtain (at compile time) the base type of MainWindow. For example: BEGIN_EVENT_TABLE( MainWindow, boost::get_base_of<MainWindow>::type ) EVT_CLOSE( MainWindow::OnClose ) END_EVENT_TABLE() Something like that above. I know that type traits has is_base_of, and I'm hoping there is a get version of that too. I've browsed through the reference but I've found nothing helpful.

3 4

assignment operator could not be generated
by Zachary Turner 09 Jun '09

09 Jun '09

When building a project that uses boost on Windows under MSVC 9.0 (VS 2008), I get _tons_ of warnings for "assignment operator could not be generated" all throughout the code. Is this going to cause subtle errors when I run the code, or are the warnings harmless ones that can be disabled with pragmas? One example where I get lots of "assignment operator could not be generated" spam is in boost::detail::addr_impl_ref<T> when I try to use boost::bind. But there are many other places as well. I can produce an explicit sample if requested, but since it happens so frequently and I haven't done anything special AFAIK to make it happen, I suspect someone else will immediately know what I'm talking about.

2 1