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problem with serialization of pure virtual
by Tobias Combe 28 Feb '06

28 Feb '06

Hello I read the documention and some prior postings to related topics. But none of the proposed solutions seems to work for me. My problem: I have an abstarct base class(with pure vitual function) and several derived from that. All are written in the same source/header -file. I want to serialize an object via a pointer to the base-class. When i use "ar.register<derived>();" in the template of the base-class to register the derived classes, i get a syntax error. When i export them with "BOOST_CLASS_EXPORT(derived);" or BOOST_CLASS_EXPORT_GUID(derived,"derived") it doesn't work (i think because they are all in the same file). I'm also using "BOOST_IS_ABSTRACT(base);" When i comment "oa << object;" ervything compiles fine. Uncommented i get a: boost/archive/detail/oserializer.hpp:567: error: incomplete type ` boost::STATIC_ASSERTION_FAILURE<false>' does not have member `value' error... So is there a solution (without seperating the derived classes into different files) for this problem?

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Re: [Boost-users] problem with serialization of pure virtual
by RIVASSEAU Jean Noel 28 Feb '06

28 Feb '06

>From the code snippet, I can say that you are not serializing via a pointer to base class, since you serialize tmp which is an object, not a pointer (by the way, tmp is just an object of the base class... you would lose the information of *event if event pointed to a derived class). Try changing: SENSOR_Event tmp = *event; oa << tmp; to just: oa << event; And also, include the BOOST_CLASS_EXPORT macro for the base class. Or, you can try doing (to see what it does): const SENSOR_Event tmp = *event; oa << tmp; but there, you are serializing a pointer, not an object. Jean-Noël -----Message d'origine----- De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de Tobias Combe Envoyé : mardi 28 février 2006 16:51 À : boost-users(a)lists.boost.org Objet : Re: [Boost-users] problem with serialization of pure virtual Jean Noel wrote: >You should send a code snippet. > Event.h: #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/vector.hpp> #include <boost/serialization/shared_ptr.hpp> #include <boost/serialization/export.hpp> #include <fstream> class SENSOR_Event{ friend class Sensor; friend class AODVRTSensor; friend class OLSRRTSensor; private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar.register<NodeEvent>(); ""// for each derived class ar & time; ar & sourceId; ar & sourceType; ar & eventType; ar & *data; } protected: double time; int sourceId; std::string sourceType; std::string eventType; DataNode *data; public: ... }; class NodeEvent : public SENSOR_Event{ private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<SENSOR_Event>(*this); } public: NodeEvent(); NodeEvent(double nodeId, double x, double y, double z, double speed); }; ...//other derived Events BOOST_CLASS_EXPORT(NodeEvent); ""// for each derived class BOOST_IS_ABSTRACT(SENSOR_Event); Sensor.cc: #include "Event.h" void Sensor::send(const SENSOR_Event *event){ ... // serialize to string std::stringstream s; boost::archive::text_oarchive oa(s); SENSOR_Event tmp = *event; oa << tmp; std::string p = s.str(); ... } Error: ... boost/archive/detail/oserializer.hpp: In function `void boost::archive::save(Archive&, T&) [with Archive = boost::archive::text_oarchive, T = SENSOR_Event]': boost/archive/basic_text_oarchive.hpp:78: instantiated from `void boost::archive::basic_text_oarchive<Archive>::save_override(T&, int) [with T = SENSOR_Event, Archive = boost::archive::text_oarchive]' boost/archive/detail/interface_oarchive.hpp:78: instantiated from `Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(T&) [with T = SENSOR_Event, Archive = boost::archive::text_oarchive]' IDSNet/Sensor.cc:24: instantiated from here boost/archive/detail/oserializer.hpp:567: error: incomplete type ` boost::STATIC_ASSERTION_FAILURE<false>' does not have member `value' >What are the syntax error you get, and the error you get when doing a "BOOST_CLASS_EXPORT(derived);" ? > "syntax error before `;' token" for that line >I also have a problem with an abstract base class (although at link time, not compile time). Try removing the pure virtual function (just to see if it works). > this doesn't help >Another hint too would be to try to serialize a constant member; sometimes I had strange ASSERTION_FAILURE related to serialization of non-constants (this is also explained in the docs) > I'm serializing a constant member... _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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serialization: errata: even manual instantiation is impossible
by RIVASSEAU Jean Noel 28 Feb '06

28 Feb '06

Hello : Regarding my last post : Even a manual template instantiation is in fact impossible since it would require including the necessary archive headers (else, the boost ::archive ::xml_iarchive is not recognized). Since you forbid to include any archive headers in the classes, I do not understand how you can follow your own advice. This seems impossible to me. Would you have code to illustrate ? Jean-Noël

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Re: [Boost-users] Serialization : unregistered_cast & otherquestions
by RIVASSEAU Jean Noel 28 Feb '06

28 Feb '06

Hello, CommonSerialize.h - remove the following #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> and add the following: #include <boost/serialization/export.hpp> test_independent.cc - change the top to look like the following: // INDEPENDENT TEST #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> #include <MObject.h> #include <MObject_serialization.hh> #include <MemberVariableSpecification.h> #include <MemberVariableSpecification_serialization.hh> #include <fstream> This won't work. Since you now have the archive headers in only one place, there is no multiple definition problem. However serialization code is *not* instantiated for MObject or MemberVariableSpecification. This is normal since when compiling the .cc that contains this code, there is no archive header included and so the export.hpp has no effect. The code is here but is not instantiated. So in order to follow this advice: a) include all boost/serialization/.. headers in each class file. b) include NO boost/archive/... headers in any class file c) make a "template instantiation module" which instanticiates code for all archives I plan to use. This can be either in the app or in a library. d) lihk and execute without problem. I have to explicitly instantiate the serialization code for the needed archive in the .cc files. That is, do: template void save<boost::archive::xml_oarchive>( boost::archive::text_oarchive & ar, const MObject & m, const unsigned int file_version ); And same for load. This is what you do in demo_pimpl.cpp. Is that what you usually do and recommend to do? This has the advantage to avoid big compilations (these code instantiations will only occur when the class to serialize has indeed changed). However this has the inconvenience of manually instantiating every template (and if you want to change your archive format , eg from text to xml for example, everything needs to be changed). Jean-Noël

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[BGL] graph without parallel edges
by Alejandro Aragón 28 Feb '06

28 Feb '06

Hi everyboty, Can someone point to a concrete example of a graph without parallel edges??? I am using setS as my container for the edges but I still insert edges twice in my graph algorithm. Thank you, aa

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Re: [Boost-users] [graph] [python] Python vertex vs. C++ Vertex
by Nat Goodspeed 28 Feb '06

28 Feb '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of David E. Konerding > Sent: Monday, February 27, 2006 5:09 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [graph] [python] > > Doug Gregor wrote: > > > > Your guess is correct. We don't cache the Python objects corresponding > > to vertex and edge descriptors. > > my idea was to keep the > mapping between on-screen widgets and the graph vertices they corresponded > to in a dictionary: > > self._widgetmap[vertex] = widget > > However, since Vertex objects aren't cached, placing the vertex object I > get back from add_vertex obviously isn't going to work. [Nat] Maybe twiddle the hash function of the Python vertex object so that it derives its return value from the underlying C++ Vertex?

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[program_options]Iterator decremented past begin of container
by Peter Gerell 28 Feb '06

28 Feb '06

Hi, I have filed the following bug in the SF tracker. In format_paragraph the following code appears: string::const_iterator line_begin = par.begin(); <snip> string::const_iterator last_space = find(reverse_iterator<string::const_iterator>(line_end - 1), reverse_iterator<string::const_iterator>(line_begin - 1), ' ') .base(); This generates a run-time assertion if compiled with VC8 and debug/checked iterators. /Peter

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Re: [Boost-users] serialization: again a problem, failing to serialize a std::vector of pointers
by RIVASSEAU Jean Noel 28 Feb '06

28 Feb '06

I added this into the ClassSpecification_serialization.cc : typedef std::vector< MemberVariableSpecification * , std::allocator<MemberVariableSpecification*> > my_vector; BOOST_CLASS_IMPLEMENTATION(my_vector, boost::serialization::object_serializable) But I still get the same error... help! Jean-Noël Ps: the typedef was necessary, else gcc parsing would recognize 3 arguments to the macro BOOST_CLASS_IMPLEMENTATION -----Message d'origine----- De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de Robert Ramey Envoyé : lundi 27 février 2006 18:25 À : boost-users(a)lists.boost.org Objet : Re: [Boost-users] serialization: again a problem,failing to serialize a std::vector of pointers "RIVASSEAU Jean Noel" <JN.RIVASSEAU(a)oberthurcs.com> wrote in message news:87F60F7FA02FF749AFB02BD9FCAA6B04DA7ABF@naserv31.nanterre.oberthurcs.com... Hello This is my last problem with the BSL but the most important one (because there is no workaround). I am trying to serialize a class (whose name is "ClassSpecification") which has a std::vector of pointers. The code for serializing the class the pointer refer to (MemberVariableSpecification) is written and instantiated correctly. However I cannot correctly serialize the std::vector. It fails with a message complaining about: C:/Boost/include/boost-1_33_1/boost/archive/detail/iserializer.hpp:115: error: incomplete type `boost::serialization::extended_type_info_null<std::vector<MemberVariableSpecification*, std::allocator<MemberVariableSpecification*> > >' used in nested name specifier I do not understand why I need an extended_type_info for this vector. I sure need it for the class the pointers refer to (and I did specify it), but the std::vector itself is serialized as such, not as a pointer. *** hmmm - can sympathise with you here. I suspect that this is a mistake. It might be an accidental side effect of the fact that the default serialization trait for any class is tracked with class information. You might try the following: BOOST_CLASS_IMPLEMENTATION( std::vector<MemberVariableSpecification*, std::allocator<MemberVariableSpecification*>, boost::serialization::object_serializable ) Why do I get this error ??? I would have to look into it. Can you please check the attached code and help me? Thanks Jean-Noël Ps: using gcc 3.4.2 _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Re: [Boost-users] Serialization : unregistered_cast & otherquestions
by RIVASSEAU Jean Noel 28 Feb '06

28 Feb '06

Hello I agree with you, and currently have the same comprehension of the problem than you. I am currently also including BOOST_EXPORT_CLASS in only one implementation file *per class*. This seems to work. Robert is saying however, that even that can cause problem, but as written on a previous message, I cannot manage to follow his advice on including the archive headers in only one instantiation module (except putting all serialization code into that module, which I did previously: this is a maintenance nightmare, to the point that I ended up trying to break my code into smaller places). I'll chime in, as I'm having exactly the same issue, but on darwin/ gcc-4 with code in multiple dynamically loaded libraries... (I have other issues too, I get to those later) The problem is that although export.hpp is only included once per generated .o file, there are multiple .o files all including the same headers - and each therefore generates the same template instantiations, thereby causing the multiple definitions during linking. Also - the same headers may be included in multiple shared libraries, exacerbating the problem with the same code instantiated into multiple libraries - a serious problem if there are singletons. I may not be understanding this correctly - here's what >I< think needs to happen - please correct me. For any derived class, there is a set of code (templates) that need to be instantiated for each archive type (specifically, the list boost::archive::detail::known_archive_types::type, for the templates guid_initializer<T> and export_instantiate<T, archive_list>) From what I see, these are NOT declarations required by the other serialization code, but singletons that, during construction, register the serializers to the derived classes with the extended_type_info class registry. Is that incorrect? If the above is correct, then the BOOST_EXPORT_CLASS should only be in exactly one implementation file (.cpp, .C, .cc, whatever). And also, THAT implementation file should ONLY be linked into one shared library. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Re: [Boost-users] serialization: problem with abstract base class
by RIVASSEAU Jean Noel 28 Feb '06

28 Feb '06

I have included <boost/serialization/base_object.hpp> where it should be, it did not change anything... Anyway what is "implementing is_abstract for your compiler" ?? Jean-Noël *** its hard for me to follow what's going on here. One thing I did notice is that the I didn't see <boost/serialization/base_object.hpp> included in the places where it is used. I'm not sure if that's significant. Robert Ramey _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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