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[Serialization] serialize from and to an already instantiated object.
by nico 22 May '11

22 May '11

Hello. I use boost.serialization to perform save and load to files. If a class is serializable through the boost mechanism, I'd like to easily add the "savable" feature (through serialization and boost archives). Here how I do, and then I've got 2 questions. I don't post all the #include statements. Let's have a serializable class (I only use text archive for this example) ---------MyClass.h--------- class MyClass { friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version); int data_; public: MyClass(); virtual ~MyClass(); }; BOOST_CLASS_EXPORT_KEY(MyClass) ---------MyClass.cpp--------- MyClass::MyClass() : data_(123) {} MyClass::~MyClass() {} template<class Archive> void MyClass::serialize(Archive & ar, const unsigned int version) { ar & data_; } // instanciate the serialize function for text archives #include "boost/archive/text_iarchive.hpp" #include "boost/archive/text_oarchive.hpp" template void MyClass::serialize(boost::archive::text_iarchive & ar, const unsigned int version); template void MyClass::serialize(boost::archive::text_oarchive & ar, const unsigned int version); BOOST_CLASS_EXPORT_IMPLEMENT(MyClass) --------- Now I define a FileSavable class. Its purpose is to add the "save-to-file" feature to a class that can be serialized in a text archive, making the latter inherting from FileSavable, and adding a line in its serialize function, I write it below). ---------FileSavable.h--------- class FileSavable { friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version); public: virtual ~FileSavable() {} void SaveToFile(std::string path); void LoadFromFile(std::string path); }; BOOST_CLASS_EXPORT_KEY(FileSavable) ---------FileSavable.cpp--------- template<class Archive> void FileSavable::serialize(Archive & ar, const unsigned int version) {} void FileSavable::SaveToFile(std::string path) { std::ofstream ofs(path.c_str()); assert(ofs.good()); boost::archive::text_oarchive oa(ofs); oa & this; } void FileSavable::LoadFromFile(std::string path) { std::ifstream ifs(path.c_str()); assert(ifs.good()); boost::archive::text_iarchive ia(ifs); FileSavable* p; ia & p; *this = *p; delete p; } // instanciate the serialize function for text archives #include "boost/archive/text_iarchive.hpp" #include "boost/archive/text_oarchive.hpp" template void FileSavable::serialize(boost::archive::text_iarchive & ar, const unsigned int version); template void FileSavable::serialize(boost::archive::text_oarchive & ar, const unsigned int version); BOOST_CLASS_EXPORT_IMPLEMENT(FileSavable) ---------Modification to MyClass--------- It now inherit from FileSavable: class MyClass : public FileSavable The serialize function call the base class: template<class Archive> void MyClass::serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<FileSavable>(*this); ar & data_; } --------- Thanks if you read me until here, now my questions: 1) I don't care the FileSavable part of MyClass being serialized, but if I don't call it with boost::serialization::base_object, I have a runtime error: terminate called after throwing an instance of 'boost::archive::archive_exception' what(): unregistered void cast 7MyClass<-11FileSavable Do you see a way to avoid having to add this line in MyClass? Ideally, just having to inheriting from FileSavable would be great: a simple way to add a feature. 2) As you can see, my LoadFromFile function first creates a new MyClass object in p, by de-serializing an archive, and then copies this newly created object into "*this", and finally deletes the object created by the archive d-eserialization. I didn't find a way to avoid this temporary and de-serialize directly in this. Moreover, my solution is not exception-safe, but I didn't manage to de-serialize in a temporary auto_ptr nor boost::shared_ptr. Thanks in advance for replies. Nicolas.

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[BGL] Problems with planar_face_traversal
by "Ulrich Küttler" 22 May '11

22 May '11

Hi all, I'm new to BGL and I already like it a lot. Right now I'm searching for faces in a planar graph. I use boost::planar_face_traversal, however the results I get are confusing. The example I tested consists of 10 faces of 4 vertices each. See side-graph.dot: dot side-graph.dot -Tps > side-graph.ps My test code reads that file and calls both boyer_myrvold_planarity_test and planar_face_traversal. The graph itself seems to be fine, the face traversal fails. Is there anything I do wrong here? Thanks a lot for your help. Ulrich ___________________________________________________________ Schon gehört? WEB.DE hat einen genialen Phishing-Filter in die Toolbar eingebaut! http://produkte.web.de/go/toolbar

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[icl] interval_map<> and overlapping intervals at boundaries
by sguazt 22 May '11

22 May '11

Hello, I don't understand the behavior of icl::interval_map<,> on the following scenario: 1. Before adding a new segment: {([0.179494,0.679494)->0.333333)([2.51847,3.01847)->0.333333)([3.24221,3.74221)->0.333333)} 2. Add segment: ([3.74221,4.24221)->0.333333) 3. After adding the segment: {([0.179494,0.679494)->0.333333)([2.51847,3.01847)->0.333333)([3.24221,4.24221)->0.333333)} What I would expect at step #3 is: {([0.179494,0.679494)->0.333333)([2.51847,3.01847)->0.333333)([3.24221,4.24221)->0.666667)} For the sake of clarity I provide a sample code below: --- [code] --- #include <boost/icl/interval.hpp> #include <boost/icl/interval_map.hpp> #include <iostream> #include <utility> namespace icl = ::boost::icl; int main() { typedef double time_type; typedef double value_type; typedef icl::interval<time_type> interval_type; icl::interval_map<time_type,value_type> intervals; intervals += ::std::make_pair(interval_type::right_open(0.1794936069088625, 0.6794936069088625), 0.3333333333333333); intervals += ::std::make_pair(interval_type::right_open(2.518467327901063, 3.018467327901063), 0.3333333333333333); intervals += ::std::make_pair(interval_type::right_open(3.242205294874485, 3.742205294874485), 0.3333333333333333); std::cout << "Intervals:\n" << intervals << std::endl; intervals += ::std::make_pair(interval_type::right_open(3.742205294874485, 4.242205294874486), 0.3333333333333333); std::cout << "Updated Intervals:\n" << intervals << std::endl; } --- [/code] --- What kind of interval container should I use in order to obtain the wanted result? I'm using the SVN trunk version of boost with GCC 4.5.1 (linux x86_64) Thank you very much for helping me! Best, -- Marco

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program_options: pointer being freed was not allocated
by Matan Nassau 21 May '11

21 May '11

Hi! When I run the following program, #include <boost/program_options.hpp> int main() { boost::program_options::positional_options_description positional; return 0; } the program aborts with the error sandbox(1791) malloc: *** error for object 0x7fff70506500: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug My platform is Mac OS X 10.6.7. I installed Boost 1.46.1 on my own, like so: ./bootstrap --prefix=/usr/local ./bjam memory-model=64 ./bjam install The toolset bjam chose was darwin, which uses gcc-4.0 if I understood the build correctly. I also tried rebuilding boost with ./bjam memory-model=64 toolset=darwin-4.2 but the issue persisted. Any idea what causes this crash? Matan

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Re: [Boost-users] [boost][msm] std::vector<MyStateMachine> generate stack overflow
by Christophe Henry 20 May '11

20 May '11

> [Christophe Henry] >> Maybe Stephan is aware of this problem? > > I haven't heard of this problem before. (Is a templated constructor involved? They can be squirrely.) There are quite a few ones, yes. But I'd suspect a problem with inheriting. I got quite a few problems with getting a wrong type when inheriting from state_machine. Specifically, the compiler saw the derived type (we call it Derived) sometimes as Derived, sometimes as state_machine<Derived...>. Regards, Christophe > Stephan T. Lavavej > Visual C++ Libraries Developer

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[hash] hash returning fixed width integer instead of size_t?
by Frédéric Bron 20 May '11

20 May '11

I would like this code return the same hash on different machines: #include <iostream> #include <boost/functional/hash.hpp> int main() { boost::hash<std::string> hasher; std::cout<<hasher("abcd"); return 0; } But I get 1244709680 when size_t is 32 bits and 706246339511088 when size_t is 64 bits. Is it possible to have hash work with fixed width uint32_t instead of size_t? Frédéric

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[Bind] Binding a sequence of operations.
by Robert Jones 20 May '11

20 May '11

Hi All Is it possible to write this code as a for_each/bind combination? I know I could do this with Boost.Lambda or Boost.Phoenix, which is my solution of last resort, but can it be done with plain Boost.Bind? What I think I'm missing is a bindable sequence operator - is there any such thing? Thanks, Rob #include <vector> #include <boost/bind.hpp> #include <boost/range.hpp> struct X { }; void do_this( const X & ); void do_that( const X & ); typedef std::vector<X> Xs; int main( ) { Xs xs; for( Xs::const_iterator x = boost::begin(xs); x != boost::end(xs); ++x ) { do_this( * x ); do_that( * x ); } }

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Asio unhandled exception
by Łukasz Majewski 20 May '11

20 May '11

Hello, I created a server single thread async (linux) and clinet (win). Every time client is close while server is writing to the socket connected to this client exception appears: terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error>>' what(): Transport endpoint is not connected Aborted and server is terminated. I dont know why this exception is unhandled. int main( int argc, char** argv ) { try { boost::asio::io_service io_service; quotation_server server( io_service ); while ( true ) { try { io_service.run(); } catch( ... ){} } } catch ( std::exception& e ) { LOG << e.what() << std::endl; } catch( ... ) { LOG << "Unexpected exception" << std::endl; } return 0; }

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Which version can I use for my old compiler?
by spam-receiver＠web.de 20 May '11

20 May '11

I am forced to use the old Sun Workshop 6 toolset in my project. Where do I find a summary of which Boost version to which degree supports this toolset? Thanks in advance, Thomas

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[PropertyTree] Using with std algorithms
by Robert Jones 20 May '11

20 May '11

Hi All Is it possible and practical to use the put and get methods of Boost.PropertyTree with std algorithms? I've written this snippet, which doesn't compile, which I think is because I have not correctly expressed the return type of "put()". Is it possible to do this? Thanks, - Rob. #include <algorithm> #include <vector> #include <boost/range.hpp> #include <boost/bind.hpp> #include <boost/property_tree/ptree.hpp> int main( ) { using boost::property_tree::ptree; std::vector<unsigned> v; ptree tree; for_each( boost::begin( v ), boost::end( v ), bind( static_cast<void (ptree::*)( const std::string &, unsigned )>( & ptree::put ), boost::ref( tree ), "Values.value", _1 ) ); } > g++ ptree.cpp ptree.cpp: In function ‘int main()’: ptree.cpp:15: error: invalid static_cast from type ‘<unresolved overloaded function type>’ to type ‘boost::property_tree::ptree& (boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >::*)(const std::string&, unsigned int)’

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