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Templates in shared libraries
by Hughes, James 21 Jun '06

21 Jun '06

Hello all, I didn't get an answer to my question about a good C++/Templates mailing list (I am sure there is one, or maybe our c**p email system has culled any replies), so, since I am sure that the problem I am encountering must have been solved/avoided in the Boost libs I will ask here. I have a template, solely defined in a header file header.h. This template has a static factory function in case that's important. This is used by code in a shared library, shared.cpp->shared.so The main application (app) also uses the template. When I link my app without including the shared library, all is fine. When I start to use the shared library, I get a seg fault on app startup (doesn't even get to main()). I think this is a translation unit problem (Hope term is correct). When the shared.so is compiled, it must create instances/functions based on the template. When app is compiled, it also must be instantiating the same functions, since I don't think it can know about the ones in shared.so. So, when system attempts to start up there is some sort of conflict between the template instances in the shared lib and the ones in the app itself - there are effectively two sets of template code do the same thing with the same name. I have done some checking on the net, and have not yet seen how to avoid this problem, but of course it's quite possible I have got hold of completely the wrong end of the stick! I think I may be in the right track with -frepo and -fno-implicit-templates compiler flags, but I am not sure. Any help gratefully received. James This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately.

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warning C4561: '__fastcall' incompatible with the '/clr' option:, converting to '__stdcall'
by Andreas Fabri 20 Jun '06

20 Jun '06

Hello, When using the /clr option for generating managed code with Visual C++ one gets the warning C4561: '__fastcall' incompatible with the '/clr' option:,converting to '__stdcall' Is there a way to compile files that include boost header files such that __stdcall is the default, or is ignorng or switching off the warning the "solution"? Thanks in advance, andreas

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[serialization] link problem
by picca＠synchrotron-soleil.fr 20 Jun '06

20 Jun '06

Hello My post is closely related to this one. http://lists.boost.org/boost-users/2004/12/8768.php I am trying to build a library. so I put a serialize template in most of my classes. I have no problem to create the static library. Now I have a test suit for my library. if I build it with the the serialization test. diffractometer::twoC::Vertical d_ref, d; stringstream flux; diffractometer::twoC::Vertical const & work_around = d_ref; boost::archive::text_oarchive oa(flux); oa << work_around; boost::archive::text_iarchive ia(flux); ia >> d; Everything is ok but when I comment the oa << work_around and the the ia >> d The compilation fail with tone of error like this: debug/linux2/src/libhkl.a(affinement_simplex.o): In function `boost::archive::detail::load_non_pointer_type<boost::archive::text_iarchive, hkl::affinement::Simplex>::load_standard::invoke(boost::archive::text_iarchive&, hkl::affinement::Simplex&)': /usr/include/boost/archive/detail/iserializer.hpp:375: undefined reference to `boost::archive::detail::basic_iarchive::load_object(void*, boost::archive::detail::basic_iserializer const&)' debug/linux2/src/libhkl.a(affinement_simplex.o): In function `boost::archive::detail::pointer_iserializer<hkl::affinement::Simplex, boost::archive::text_iarchive>::load_object_ptr(boost::archive::detail::basic_iarchive&, void*&, unsigned int) const': /usr/include/boost/archive/detail/iserializer.hpp:309: undefined reference to `boost::archive::detail::basic_iarchive::next_object_pointer(void*)' debug/linux2/src/libhkl.a(affinement_simplex.o): In function `~void_caster_primitive': /usr/include/boost/serialization/void_cast.hpp:132: undefined reference to `boost::serialization::void_cast_detail::void_caster::~void_caster()' /usr/include/boost/serialization/void_cast.hpp:132: undefined reference to `boost::serialization::void_cast_detail::void_caster::~void_caster()' debug/linux2/src/libhkl.a(geometry_kappa.o): In function `boost::serialization::detail::extended_type_info_typeid_1<hkl::geometry::Kappa const>::export_register(char const*)': /usr/include/boost/serialization/extended_type_info_typeid.hpp:101: undefined reference to `boost::serialization::extended_type_info::key_register(char const*)' debug/linux2/src/libhkl.a(geometry_kappa.o): In function `pointer_oserializer': /usr/include/boost/archive/detail/oserializer.hpp:226: undefined reference to `boost::archive::detail::archive_pointer_oserializer<boost::archive::text_oarchive>::archive_pointer_oserializer(boost::serialization::extended_type_info const&)' /usr/include/boost/archive/detail/oserializer.hpp:236: undefined reference to `boost::archive::detail::archive_pointer_oserializer<boost::archive::text_oarchive>::~archive_pointer_oserializer()' /usr/include/boost/archive/detail/oserializer.hpp:226: undefined reference to `boost::archive::detail::archive_pointer_oserializer<boost::archive::text_oarchive>::archive_pointer_oserializer(boost::serialization::extended_type_info const&)' /usr/include/boost/archive/detail/oserializer.hpp:236: undefined reference to `boost::archive::detail::archive_pointer_oserializer<boost::archive::text_oarchive>::~archive_pointer_oserializer()' debug/linux2/src/libhkl.a(geometry_kappa.o): In function `pointer_iserializer': /usr/include/boost/archive/detail/iserializer.hpp:332: undefined reference to `boost::archive::detail::archive_pointer_iserializer<boost::archive::text_iarchive>::archive_pointer_iserializer(boost::serialization::extended_type_info const&)' /usr/include/boost/archive/detail/iserializer.hpp:341: undefined reference to `boost::archive::detail::archive_pointer_iserializer<boost::archive::text_iarchive>::~archive_pointer_iserializer()' /usr/include/boost/archive/detail/iserializer.hpp:332: undefined reference to `boost::archive::detail::archive_pointer_iserializer<boost::archive::text_iarchive>::archive_pointer_iserializer(boost::serialization::extended_type_info const&)' /usr/include/boost/archive/detail/iserializer.hpp:341: undefined reference to `boost::archive::detail::archive_pointer_iserializer<boost::archive::text_iarchive>::~archive_pointer_iserializer()' debug/linux2/src/libhkl.a(geometry_kappa.o): In function `~pointer_oserializer': /usr/include/boost/archive/detail/oserializer.hpp:184: undefined reference to `boost::archive::detail::archive_pointer_oserializer<boost::archive::text_oarchive>::~archive_pointer_oserializer()' debug/linux2/src/libhkl.a(geometry_kappa.o): In function `~pointer_iserializer': /usr/include/boost/archive/detail/iserializer.hpp:197: undefined reference to `boost::archive::detail::archive_pointer_iserializer<boost::archive::text_iarchive>::~archive_pointer_iserializer()' /usr/include/boost/archive/detail/iserializer.hpp:197: undefined reference to `boost::archive::detail::archive_pointer_iserializer<boost::archive::text_iarchive>::~archive_pointer_iserializer()' debug/linux2/src/libhkl.a(geometry_kappa.o): In function `~pointer_oserializer': /usr/include/boost/archive/detail/oserializer.hpp:184: undefined reference to `boost::archive::detail::archive_pointer_oserializer<boost::archive::text_oarchive>::~archive_pointer_oserializer()' debug/linux2/src/libhkl.a(geometry_kappa.o): In function `boost::archive::detail::pointer_iserializer<hkl::geometry::Kappa, boost::archive::text_iarchive>::load_object_ptr(boost::archive::detail::basic_iarchive&, void*&, unsigned int) const': /usr/include/boost/archive/detail/iserializer.hpp:309: undefined reference to `boost::archive::detail::basic_iarchive::next_object_pointer(void*)' collect2: ld returned 1 exit status So the question is how can I avoid all this ? Have a nice day.

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boost::serialization unregistered_class exceptions with DLL.
by Arjuna Balasingham 20 Jun '06

20 Jun '06

Re: unregistered_class exceptions are thrown when the derived class are in an explicitly loaded DLL. Hello, In a nutshell, the problem that I have is that an "unregistered_class" exception is thrown when the derived class is defined/declared in a DLL that is explicitly loaded. The problem as far as I can tell is that the derived class in dll and the derived class in the framework are being "registered" in two different instances (m_self->m_map.insert(eti); in "extended_type_info.cpp"). Exception is thrown when trying to serialize the foobar_derived_dll. It looks for "foobar_derived_dll" in the wrong instance of the m_map defined in the extened_type_info.cpp and then throws an exception. Can anybody please help The Application Structure is more or less as follows. Common Framework Library Contains. class foobar_base : public foobar_base { protected: bool m_attr0; public: foobar_base() {} template<class Archive> void serialize(Archive & ar, const unsigned int /* file_version */){ std::cout << "serialize foobar_base\n"; ar & BOOST_SERIALIZATION_NVP(m_attr0); } } class foobar_derived : public foobar_base { protected: bool m_attr1; public: foobar_derived() {} template<class Archive> void serialize(Archive & ar, const unsigned int /* file_version */){ std::cout << "serialize foobar_derived_dll\n"; ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(foobar_base); ar & BOOST_SERIALIZATION_NVP(m_attr1); } } BOOST_CLASS_EXPORT_GUID(foobar_derived, "foobar_derived") Dynamic Link Library Contains (Includes Common Framework Library) class foobar_derived_dll { protected: bool m_attr2; public: foobar_derived_dll() {} template<class Archive> void serialize(Archive & ar, const unsigned int /* file_version */){ std::cout << "serialize foobar_derived_dll\n"; ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(foobar_base); ar & BOOST_SERIALIZATION_NVP(m_attr2); } } BOOST_CLASS_EXPORT_GUID(foobar_derived_dll, "foobar_derived_dll") Main Application (includes Common framework library & explictly lods Dynamic Link Library) class foo { public: std::list<boost::shared_ptr<foobar_base> > m_foovec; public: foo ( ) { }; ~foo ( ) { }; template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(m_foovec); } }; (..Include Framwork..) int main() { // load the DLL.. LoadLibrary(... DLL)" foo f; f.m_foovec.push_back( boost::shared_ptr<foobar_base>(new foobar_derived(.... f.m_foovec.push_back( boost::shared_ptr<foobar_base>(new foobar_derived_dll(.... std::string filename("c:\\tmp.txt"); try { // write to file std::ofstream ofs(filename.c_str()); assert(ofs.good()); boost::archive::text_oarchive oa(ofs); oa << BOOST_SERIALIZATION_NVP(f); ofs.close(); } catch (std::exception &e) { std::cout << e.what() << std::endl; } }

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Boost.Thread locking across two functions
by Peteris Krumins [Newsgroups] 20 Jun '06

20 Jun '06

Hello! I am using a library which itself internally does not use any thread sync mechanisms but it provides callback functions lib_lock() and lib_unlock() which I can specify if the lib is used in multithread environment. lib_lock() would get called before critical segment and after it lib_unlock() would get called. I read Boost.Thread documentation and I understand that lock concept is not thread-safe itself and should be used only at block scope. This makes me think that I have no way to use locking provided by Boost to acquire a lock in lib_lock() function and release it in lib_unlock()? But I am not sure. Do you have any suggestions if this can be done using Boost? Thanks! P.Krumins

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portable way to get present time and date
by Stephen Torri 20 Jun '06

20 Jun '06

What is a portable way to get the present time and date? Stephen

2 2

[statechart] - templated asynchronous_state_machine compilation problem
by Oliver.Kowalke＠qimonda.com 19 Jun '06

19 Jun '06

Hello, I've a problem to compile (gcc- 4.1.2) a templated asynchronous state machine. error: expected `)' before 'ctx' template< typename streamT > struct proto; template< typename streamT > class presentation : public sc::asynchronous_state_machine< presentation< streamT >, proto< streamT >, sc::fifo_scheduler<> > { public: typedef streamT stream_type; presentation( my_context ctx) : my_base( ctx) // error: expected `)' before 'ctx' {} }; Thanks, Oliver

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C++ Template Metaprogramming Book - Chapter 4
by Eduardo Bezerra 19 Jun '06

19 Jun '06

Hi, In C++ Template Metaprogramming chapter 4, item 4.1.2. Lazy Type Selection typename is_scalar<T>::type and is_scalar<T> can be used interchangeably as in the example below: template <class T> struct param_type : mpl::eval_if< typename boost::is_scalar<T>::type , mpl::identity<T> , boost::add_reference<T const> > // no ::type here {}; template <class T> struct param_type : mpl::eval_if< boost::is_scalar<T> , mpl::identity<T> , boost::add_reference<T const> > {}; I'm still trying to figure out the reason why. I understand that to invoke a metafunction you have to reach into its nested ::type member and I also know that integral constant wrappers have a ::value member. Any help would be greatly appreciated Regards, Eduardo

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mpl::transform question
by Ovanes Markarian 19 Jun '06

19 Jun '06

Hello all, somehow I have extreme difficulties to use mpl. Please do not understand this as any kind of blaming. I find the library really great and the possiblities it offers are tremendous. Currently I have some sort of problem, where I stuck at: I have an mpl::vector instance of form (mpl namespace was left out for better readability): class A; class B; class C; typedef vector< pair<int_<0>, A>, pair<int_<1>, B>, pair<int_<2>, C> > types_vector; Now I would like to use the mpl::transform algorithm to transform this vector into the mpl::map. I try to do it in the following way: typedef mpl::transform<type_vector, mpl::insert<mpl::map<>, mpl::_1 >::type type_map; And I also understand that _1 has no embedded typedefs for first and second, what a pair should have, so I am stuck here. David pointed me to the MPL Book, which I ordered, but unfortunately it is on the way to me... So if someone could help I would be really thankful. With Kind Regards, Ovanes Markarian

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Re: [Boost-users] [Interprocess] How to Get Started?
by Wu Yinghui, Freddie 19 Jun '06

19 Jun '06

boost-users-request(a)lists.boost.org wrote: > From: > Ion Gaztañaga <igaztanaga(a)gmail.com> > Date: > Mon, 19 Jun 2006 16:17:45 +0200 > > Hi, > >> I can see that Boost.Interprocess (former Shmem) is now in the CVS. But >> is there any documentation on it to get one started? > > There is no documentation for the moment. The CVS was intended for > advanced Shmem users that wanted to start testing the code based on tests. > > I've started writing the documentation, but still a few introductory > pages, but I will need some time to have something useful, since I'm > quite busy for the moment. > > Regards, > > Ion Thanks for your efforts! I think I can wait for a little while for the moment. Or... can I make use of the shmem docs in the sandbox instead? Any brief summary on the difference between that shmem version and the cvs interprocess version? Cheers, Freddie

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