Re: [Boost-users] [serialization] Multiply defined symbol:guid_initializer

Subject: Re: [Boost-users] [serialization] Multiply defined symbol:guid_initializer
From: Robert Dailey (rcdailey_at_[hidden])
Date: 2009-04-03 12:44:56

Besides, it doesn't make sense to have the global function in the first
place. I'm already creating instances of the very class I'm exporting via
the macro. That alone should be enough to keep the compiler from stripping
out the class specializations created by the boost class macros, right? This
whole thing is just so confusing... why can't it just work like it is
supposed to? I am doing things exactly as they are being done in the
test_no_rtti unit test...

On Fri, Apr 3, 2009 at 11:26 AM, Robert Dailey <rcdailey_at_[hidden]> wrote:

> What?? I see you have a force_serialize_export() function, but how can you
> guys expect me to mangle my interfaces to get boost::serialization to do its
> job? So I have to now call arbitrary global functions all over the place?
> This is unreasonable and unacceptable. There has to be a better way!
>
>
> On Fri, Apr 3, 2009 at 11:05 AM, Renaud Lepere <Renaud.Lepere_at_[hidden]>wrote:
>
>> Hello,
>>
>> I had a similar problem, you must call a function in the compilation
>> unit if you put only the macros in the .cpp if will not work.
>>
>> BOOST_CLASS_EXPORT(Curve2);
>> BOOST_CLASS_EXPORT(Line2);
>> BOOST_CLASS_EXPORT(Circle2);
>>
>> /**
>>  * DO NOT REMOVE THIS FUNCTION
>>  * The C++ standard guarantees that all global objects contained
>>  * in a compilation unit (a CPP file) are initialized by the time
>>  * execution enters a function from that compilation unit. So, if
>>  * execution never enters a function from that compilation unit,
>>  * the compiler is allowed to deadstrip it.
>>  *
>>  * BOOST_CLASS_EXPORT is based upon global objects.
>>  */
>> void force_serialize_export();
>>
>>
>>
>> ________________________________
>>
>>        De : boost-users-bounces_at_[hidden] [mailto:
>> boost-users-bounces_at_[hidden]] De la part de Robert Dailey
>>        Envoyé : vendredi 3 avril 2009 16:56
>>        À : boost-users_at_[hidden]
>>        Objet : Re: [Boost-users] [serialization] Multiply defined
>> symbol:guid_initializer
>>
>>
>>        But I've already tried that, as I said. It fails at runtime with an
>> exception saying "unregistered void cast". I'll test it once more, but I
>> don't expect different results.
>>
>>
>>        On Thu, Apr 2, 2009 at 10:07 PM, Robert Ramey <ramey_at_[hidden]>
>> wrote:
>>
>>
>>                Look at the pimple demo in the examples or test directory.
>>  Basically you're getting some things defined twiice.
>>
>>                Move the implementation of template< class Archive >
>>                        void serialize( Archive& archive, unsigned int
>> version ) to the *.cpp
>>                and move
>>                BOOST_CLASS_EXPORT( rs::StaticText )
>>
>>                to the *.cpp file as well.  compile that/those *.cpp files
>> and include in the library. This is touched upon in the manual in the part
>> describing EXPORT.
>>
>>                Robert Ramey
>>
>>                        "Robert Dailey" <rcdailey_at_[hidden]> wrote in
>> message news:496954360904021720o79c9c17cs18b1cf3f53da08c_at_mail.gmail.com.
>> ..
>>                        Hi,
>>
>>                        I'm currently trying to polymorphically serialize a
>> class without using RTTI. I'm doing this currently in a file called
>> StaticText.hpp:
>>
>>                        #ifndef RS_GUI_WIDGETS_STATICTEXT_HPP
>>                        #define RS_GUI_WIDGETS_STATICTEXT_HPP
>>
>>
>>                        #include <boost/scoped_ptr.hpp>
>>                        #include <boost/serialization/access.hpp>
>>                        #include <boost/serialization/base_object.hpp>
>>                        #include <boost/serialization/string.hpp>
>>                        #include
>> <boost/serialization/extended_type_info_no_rtti.hpp>
>>                        #include <boost/serialization/export.hpp>
>>
>>
>>                        #include <rs/gui/widgets/Widget.hpp>
>>                        #include <rs/gui/Text.hpp>
>>
>>
>>
>>
>>                        namespace rs
>>                        {
>>                            class StaticText : public Widget
>>                            {
>>                            public:
>>                                StaticText( std::string const& text );
>>
>>
>>                                void Update();
>>                                void Render( RenderSystem& renderer,
>> Camera& camera );
>>                                char const* get_key() const;
>>
>>
>>                            private:
>>                                StaticText() {}
>>
>>
>>                                template< class Archive >
>>                                void serialize( Archive& archive, unsigned
>> int version )
>>                                {
>>                                    archive &
>> boost::serialization::base_object<Widget>( *this );
>>
>>
>>                                    std::string text;
>>                                    archive & text;
>>                                    m_text.reset( new Text( text ) );
>>                                }
>>
>>
>>                                boost::scoped_ptr<Text> m_text;
>>
>>
>>                                friend class boost::serialization::access;
>>                            };
>>                        }
>>
>>
>>                        BOOST_CLASS_TYPE_INFO(
>>                            rs::StaticText,
>>                            extended_type_info_no_rtti<rs::StaticText>
>>                            )
>>
>>
>>                        BOOST_CLASS_EXPORT( rs::StaticText )
>>
>>
>>                        #endif // RS_GUI_WIDGETS_STATICTEXT_HPP
>>
>>                        When I compile this into a LIB first, and then link
>> the lib into an EXE, the linker says this (Visual Studio 2008):
>>                        gui.lib(StaticText.obj) : error LNK2005: "public:
>> static struct boost::archive::detail::guid_initializer<class rs::StaticText>
>> const & const boost::archive::detail::init_guid<class
>> rs::StaticText>::guid_initializer" (?guid_initializer@
>> ?$init_guid_at_VStaticText@rs@@@detail_at_archive@boost@
>> @2ABU?$guid_initializer_at_VStaticText@rs@@@234_at_B) already defined in
>> main.obj
>>
>>
>>                        If I move the 2 macro calls into the StaticText.cpp
>> file, everything compiles/links just fine but I end up getting an exception
>> thrown at runtime that says "unregistered void cast".
>>
>>                        ________________________________
>>
>>
>>  _______________________________________________
>>                        Boost-users mailing list
>>                        Boost-users_at_[hidden]
>>
>> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>>
>>
>>                _______________________________________________
>>                Boost-users mailing list
>>                Boost-users_at_[hidden]
>>                http://lists.boost.org/mailman/listinfo.cgi/boost-users
>>
>>
>>
>> _______________________________________________
>> Boost-users mailing list
>> Boost-users_at_[hidden]
>> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>>
>
>