February 2007 - Boost-users

read_graphviz question
by Jeffrey Holle 26 Apr '07

26 Apr '07

I'm using the post 1.31.1 version of boost, which has a much nicer read_graphviz function. I'm wondering if there is a way to "ignore" unwanted properties, something akin to sending them to /dev/null. My present experience is that if an unexpected property is found, an exception is thrown. Is there a way to express that a given property is to be ignored? Better yet, is there a way to say that all unexpected properties are to be ignored?

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[boost::wave] MSVC 8 warning
by Ovanes Markarian 27 Mar '07

27 Mar '07

Hello, I would like to address this issue to boost::wave authors. First of all great lib! Many thanks! During the compilation with MSVC8 Express Edition I get a warning: c:\boost\include\boost-1_33_1\boost\wave\cpp_context.hpp(112) : warning C4355: 'this' : used in base member initializer list c:\boost\include\boost-1_33_1\boost\wave\cpp_context.hpp(106) : while compiling class template member function 'boost::wave::context<IteratorT,LexIteratorT>::context(const std::_String_iterator<_Elem,_Traits,_Alloc> &,const std::_String_iterator<_Elem,_Traits,_Alloc> &,const char *,const TraceT &)' with [ IteratorT=token_groups::str_iter_type, LexIteratorT=token_groups::lex_iter_type, _Elem=char, _Traits=std::char_traits<char>, _Alloc=std::allocator<char>, TraceT=boost::wave::context_policies::default_preprocessing_hooks ] My typedefs look like: typedef wave::cpplexer::lex_token<> token_type; typedef wave::cpplexer::lex_iterator<token_type> lex_iter_type; typedef std::string::iterator str_iter_type; typedef wave::context<str_iter_type, lex_iter_type> context_type; typedef context_type::iterator_type ctx_iter_type; Is there any chance that this warning will be suppressed in the next release, since it is a little bit annoying. I can't do anything about it as a user of wave and I also try to follow the rule to compile clean without warnings. Many thanks and With Kind Regards, Ovanes Markarian

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[BGL] Reading GraphML
by Jens Müller 24 Mar '07

24 Mar '07

I tried to read a GraphML file using Douglas' code and the following: std::auto_ptr<boost::dynamic_property_map> string2string_gen(const std::string& name, const boost::any&, const boost::any&) { typedef std::map<std::string,std::string> map_t; typedef boost::associative_property_map< std::map<std::string, std::string> > property_t; map_t* mymap = new map_t(); // hint: leaky memory here! property_t property_map(*mymap); std::auto_ptr<boost::dynamic_property_map> pm( new boost::detail::dynamic_property_map_adaptor<property_t>(property_map)); return pm; } int main(int argc, char* argv[]){ // create a typedef for the Graph type using namespace boost; typedef boost::adjacency_list<vecS, vecS, directedS> Graph; Graph g; std::ifstream input(argv[1]); boost::dynamic_properties properties(&string2string_gen); typedef graph_traits<Graph>::vertex_descriptor Node; typedef property_map<Graph, vertex_index_t>::type NodeID_Map; NodeID_Map node_id = get(vertex_index, g); boost::read_graphml(input, g, properties); } but when running it I get: Unrecognized attribute `xmlns' of element `graphml'. Ignoring... Unrecognized attribute `xmlns:y' of element `graphml'. Ignoring... Unrecognized attribute `xmlns:xsi' of element `graphml'. Ignoring... Unrecognized attribute `xsi:schemaLocation' of element `graphml'. Ignoring... Unrecognized attribute `yfiles.type' of element `key'. Ignoring... Unrecognized attribute `yfiles.type' of element `key'. Ignoring... Unrecognized element `y:ShapeNode' Unrecognized element `y:Geometry' Unrecognized element `y:Fill' Unrecognized element `y:BorderStyle' Unrecognized element `y:NodeLabel' Unrecognized element `y:Shape' terminate called after throwing an instance of 'boost::bad_any_cast' what(): boost::bad_any_cast: failed conversion using boost::any_cast /bin/sh: line 1: 31380 Abgebrochen ./src/graphml2 Core0bis10_1000.graphml The file contains nodes like this (what a bloat ...): <node id="n1"> <data key="d0" > <y:ShapeNode > <y:Geometry x="2.457598996954175" y="498.06375265283157" width="10.0" height="10.0"/> <y:Fill color="#FF0000" transparent="false"/> <y:BorderStyle type="line" width="1.0" color="#000000" /> <y:NodeLabel x="3.0" y="3.0" width="4.0" height="4.0" visible="true" alignment="center" fontFamily="Dialog" fontSize="12" fontStyle="plain" textC olor="#000000" hasBackgroundColor="false" hasLineColor="false" modelName="internal" modelPosition="c" autoSizePolicy="content"></y:NodeLabel> <y:Shape type="rectangle"/> </y:ShapeNode> </data> </node> I am not even really interested in the d0 properties ... What can I do?

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[Serialization] issue with portable_binary_oarchive
by Dan Leibovich 16 Mar '07

16 Mar '07

Hi, I am trying to use the portable binary archive example. I need to serialize only integers and strings. I tried it on linux and solaris5.8. The result binary stream is not the same and deserialization fails. I used hex viewer and notice that the files are very similar except for some few differences which results from endienness issues. Can it be that the metadata is written differently on each platform. This is happens when I serialize derived class through a pointer to base class. (I used BOOS_CLASS_EXPORT) Below you will find a test case. It produce differ output on linux and solaris. Am I missing something? Thanks in advance Dan Leibovich #include <fstream> #include "portable_binary_oarchive.hpp" #include <boost/serialization/base_object.hpp> #include <boost/serialization/export.hpp> class Base { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & x; } protected: int x; public: Base() {} ; Base(int x_) : x(x_) {} ; virtual void foo() {} ; }; class Derived1 : public Base { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<Base>(*this); ar & y; } protected: int y; public: Derived1() {} ; Derived1(int x_, int y_) : Base(x_), y(y_) {} ; virtual void foo() {x++;} }; class Derived2 : public Base { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<Base>(*this); ar & z; } protected: bool z; public: Derived2() {} ; Derived2(int x_) : Base(x_), z(true) {} ; virtual void foo() {x--;} }; class Container { Base* b1 ; Base* b2 ; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & b1; ar & b2 ; } public: Container() {} ; Container(int x, int y) { b1 = new Derived1(x,y) ; b2 = new Derived2(x) ; } }; BOOST_CLASS_EXPORT(Derived1) ; BOOST_CLASS_EXPORT(Derived2) ; int main() { std::ofstream ofs("filename"); const Container c(1,2) ; portable_binary_oarchive oa(ofs); oa << c; }

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[statechart] - problem with sc::transition<> -> invalid use of 'boost::statechart::detail::no_context::no_function [with Event = jm::ffcp::ev_init]' to form a pointer-to-member-func
by Oliver.Kowalke＠qimonda.com 15 Mar '07

15 Mar '07

Hello, I get following error: /opt/boost/include/boost-1_33_1/boost/statechart/transition.hpp:33: error: invalid use of 'boost::statechart::detail::no_context::no_function [with Event = jm::ffcp::ev_init]' to form a pointer-to-member-function /opt/boost/include/boost-1_33_1/boost/statechart/transition.hpp:33: note: a qualified-id is required if I try to compile: #ifndef JM_FFCP_UNINITIALIZED_H #define JM_FFCP_UNINITIALIZED_H #include <boost/mpl/list.hpp> //#include <boost/statechart/custom_reaction.hpp> #include <boost/statechart/simple_state.hpp> #include <boost/statechart/transition.hpp> #include <jm/ffcp/events.h> #include <jm/ffcp/proto.h> namespace jm { namespace ffcp { namespace mpl = boost::mpl; namespace sc = boost::statechart; template< typename SocketDeviceT > struct initialized; template< typename SocketDeviceT > struct uninitialized : public sc::simple_state< uninitialized< SocketDeviceT >, proto< SocketDeviceT > > { typedef mpl::list< // sc::custom_reaction< ev_init > sc::transition< ev_init, initialized< SocketDeviceT > > > reactions; uninitialized() { uninitialized< SocketDeviceT >::custom_static_type_ptr("uninitialized"); } // sc::result react( ev_init const& ev) // { return this->template transit< initialized< SocketDeviceT > >(); } }; } } #endif // JM_FFCP_UNINITIALIZED_H Any hints? regards, Oliver

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[Threads] Conditions and avoiding lengthy mutex locks (background loading for a game)
by Peter Mackay 11 Mar '07

11 Mar '07

Hello, I'm trying to use the Boost Threads library to help me implement a background loading system for a game I'm writing. I want to enqueue load requests while the main game thread is running, and have a separate thread load the data and pass back the appropriate objects. Currently when I enqueue a new request, I notify a 'something to do' condition, which my loading thread waits on. The trouble is, when I notify it, the loader could be loading in the background, and has a lock on the mutex connected with the condition. Would anyone be able to offer me any advice on how to solve this? Many thanks, Peter P.S. Please find attached my current implementation. begin 666 loader.cpp M(VEN8VQU9&4@(FQO861E<BYH<' B#0H-"B-I;F-L=61E(#QB;V]S="]B:6YD M+FAP<#X-"@T*;&]A9&5R.CIL;V%D97(H*0T*.B!T:')E861?<VAO=6QD7V5X M:70H9F%L<V4I#0I[#0H)=&AR96%D+G)E<V5T*&YE=R!B;V]S=#HZ=&AR96%D M*&)O;W-T.CIB:6YD*"9L;V%D97(Z.G1H<F5A9%]P<F]C+"!T:&ES*2DI.PT* M?0T*#0IL;V%D97(Z.GYL;V%D97(H*0T*>PT*"2\O(%-I9VYA;"!T:&4@=&AR M96%D('1O(&5X:70N#0H)>PT*"0EB;V]S=#HZ;75T97(a)Z.G-C;W!E9%]L;V-K M(&QO8VLH;75T97(a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` ` end begin 666 loader.hpp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`` ` end

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[fusion2/phoenix2] polymorphic function objects return type
by Chris Weed 05 Mar '07

05 Mar '07

Hi, I have been looking at fusion2 and phoenix2, and I noticed fusion2 suggests using "result" as polymorphic function objects return type, but the phoenix2 documentation suggests "apply" in the examples. Are these two different things, will they be merged, or am I missing something? Thanks, Chris

2 1

[Iterator, MSV8] iterator_adaptor fails with undefined class
by Kris Braun 04 Mar '07

04 Mar '07

Hi there, I'm using Boost 1.33.1. The following code compiles with MSVC7.1, but not with MSVC8: class Path { private: typedef std::vector< Path > PathList; public: class iterator : public boost::iterator_adaptor< iterator, PathList::const_iterator > { ... } MSVC8 gives this error: boost/type_traits/is_pod.hpp(34) : error C2139: 'fledge::Path' : an undefined class is not allowed as an argument to compiler intrinsic type trait '__is_pod' Any recommendations on a solution? Thanks, Kris --------------------------------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful.

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[BGL] - filesystem graph
by Shams 03 Mar '07

03 Mar '07

Hi, I would like to know how to "best" represent a filesystem using BGL. In this case the filesystem I want to describe is the unix/linux filesystem and its various paths from the root node "/". My questions: 1. What kind of graph is this filesystem and what is best to use in BGL to describe this? 2. How can I also best describe symbolic links (symlinks) and what kind of graph would this be, does this graph defer from the above? 3. How can I describe the metadata of a file (including symlinks) using BGL eg. given a path /usr/bin/ls I also want to stores its creation date, acl etc in BGL, how can I best describe this, is there where properties come in handy? 4. Are there any examples on this anywhere and/or does the BGL book describe any examples on this? Thanks Shams

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(no subject)
by gzahl＠arcor.de 01 Mar '07

01 Mar '07

Hi, > Hello Manuel, >> Hi, >> >> Im defining a class with a multi_index_container as base. >> When i construct a instance of this class, and the >> multi_index_container is called, the program crashes. It even >> crashes, when i dont use it as a base class. > [...] >> This compiles just fine, but if i run the code i get the >> following backtrace after a Sigmentation Abort. It happens, >> when the queue::queue() is called. Someone a idee whats it >> about? Im new to boost::multi_index, so maybe i misunderstud >> something? Thank you > > Well, what you're doing is AFAICS correct, so you shouldn't > be getting this crash. You haven't provided a complete > test program showing producing the crash, so I wrote one > myself after what you've shown and tried it locally, no > problems here. Could you please try the attached jung.cpp > file? Does it crash also? If it doesn't then there's more > to your program than you have described, maybe you can > send compilable program showing the issue. If jung.cpp > crashes, then could you please provide the following info? The Testprogramm jung.cpp does not crash on my machines (im testing on a ubuntu 6.10 and a debian 3.1 system, both working with g++ 4.0.2) I will try to get a example which reproduces my error, but in the meantime i was thinking about the libc stuff. Maybe this is the real problem thing? i changed to 4.0.2 from a 3.x version just some weeks ago, so maybe here is the problem, because some lib im using is not compiled with 4.0.2? is there a way i can get the compiler version a library was compiled with? > > 1. What system are you running this on? > 2. The stacktrace mentions a failed assertion in libc.so. Can > you see the source code that's causing the assertion? Maybe > it sheds some light. Im not sure about, where to see this sourcecode? scoped_lock(lightweight_mutex & m): m_(m.m_) { pthread_mutex_lock(&m_); } these are the lines alst mentioned in the backtrace "/usr/local/include/boost/detail/lwm_pthreads.hpp:72" from #5. But this is not what you meant, right? > 3. Can you try the attached lock.cpp file? Crash/no crash? > I didnt tried, because example worked fine. > Looking forward to your response, Thanks for help so far. I hope we can fix it soon. Ill go on, cut some working code out, which reproduces the error. > Joaquín M López Muñoz > Telefónica, Investigación y Desarrollo Manuel Jung Viel oder wenig? Schnell oder langsam? Unbegrenzt surfen + telefonieren ohne Zeit- und Volumenbegrenzung? DAS TOP ANGEBOT JETZT bei Arcor: günstig und schnell mit DSL - das All-Inclusive-Paket für clevere Doppel-Sparer, nur 44,85 inkl. DSL- und ISDN-Grundgebühr! http://www.arcor.de/rd/emf-dsl-2

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