February 2007 - Boost-users

serialization stream error
by pwm 09 Feb '07

09 Feb '07

I am trying to use the boost serialization library to save an objects from a class heiarchy. I keep running into a stream error when deserializing a pointer from an xml archive. I have everything registered (that took a while, but I have that problem figured out, I think), and the serialization to an xml archive seems to work just fine. I have stepped through the deep nesting of calls to the exception and it is being thrown because the stream says it is bad when trying to read the end tag. I also tried it with text archives, and I get the same problem. I have done the obvious (to me at least) things such as class export/registration, us std::ios::binary for output/input stream instances. Any advice on how to track down this problem with a stream error? I have gone back to first principles with a simple example and that all seems to work. So it is obviously user error. I am trying to understand what is wrong with my more involved case. I appreciate any advice someone could give me.) Thanks, Phil

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[Python] Bug when exporting function overloaded on base and derived classes
by Edson Tadeu 09 Feb '07

09 Feb '07

Hi, I've found a bug where Boost.Python calls the wrong function overload. Here is a small unit test: ===== The C++ module "_test.cpp": ===== #include <boost/python.hpp> #include <string> class Base { }; class Derived : public Base { }; std::string f(Base& b) { return "Base"; } std::string f(Derived& d) { return "Derived"; } BOOST_PYTHON_MODULE( _test ) { using namespace boost::python; class_<Base>("Base"); class_<Derived, bases<Base> >("Derived"); def("f", static_cast<std::string (*)(Derived&)>(&f)); def("f", static_cast<std::string (*)(Base&)>(&f)); } ===== The small test in python: ===== >>> from _test import * >>> f(Base()) 'Base' >>> f(Derived()) 'Base' ===== Interestingly enough, if the function overloads are exported in the inverse order, it actually works, i.e., if using this code: ===== BOOST_PYTHON_MODULE( _test ) { using namespace boost::python; class_<Base>("Base"); class_<Derived, bases<Base> >("Derived"); def("f", static_cast<std::string (*)(Base&)>(&f)); def("f", static_cast<std::string (*)(Derived&)>(&f)); } ===== I do not know very well how does the boost.python registry works, but it seems that it is selecting the first match instead of testing all matches and selecting the "best one".

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[asio].[hp-ux].[1_33_1] Build related issue
by Gaurav.Jain＠iflexsolutions.com 09 Feb '07

09 Feb '07

Hi, I have tried using boost 1_33_1 on HP UX machine, while compiling the program I am getting some errors. Can anybody help me out? The detail of the compilation is as follows: Boost Version: 1_33_1 bjam install -sTOOLS=acc --prefix="/home/pthakre/boost" --builddir="/tmp" \ "-sBUILD=release <runtime-link>dynamic/static <threading>multi <cxxflags>+DD64 <cflags>+DD64 <linkflags>+DD64" --without-python Jamfile Compiler Details: aCC: HP C/aC++ B3910B A.06.13 [Nov 27 2006] OS Details: HP-UX B.11.23 ia64 While compiling "daytime_server.cpp" with -D_HPUX_SOURCE -D_XOPEN_SOURCE_EXTENDED, I am getting the following error: "boost-1_33_1/include/boost/asio/detail/socket_types.hpp", line 136: error #2020: identifier "ip_mreq" is undefined typedef ip_mreq in4_mreq_type; Also, from /usr/include/netinet/in.h #ifndef _XOPEN_SOURCE_EXTENDED /* * Argument structure for IP_ADD_MEMBERSHIP and IP_DROP_MEMBERSHIP. */ struct ip_mreq { struct in_addr imr_multiaddr; /* IP multicast address of group */ struct in_addr imr_interface; /* local IP address of interface */ }; #endif /* ! _XOPEN_SOURCE_EXTENDED */ Compiling "daytime_server.cpp" without -D_HPUX_SOURCE -D_XOPEN_SOURCE_EXTENDED, I m getting 22 errors. I have done the following changes: Line 575 ./asio/detail/socket_ops.hpp: #if defined(BOOST_WINDOWS) || defined(__CYGWIN__) || defined(__hpux) Line 611 ./asio/detail/socket_ops.hpp: #if defined(BOOST_WINDOWS) || defined(__CYGWIN__) || defined(__hpux) Line 274 ./asio/error.hpp: #if defined(__sun) || defined(__QNX__) || defined(__hpux) Line 109 ./asio/system_exception.hpp: #elif defined(__sun) || defined(__QNX__) || defined(__hpux) Regards, Gaurav

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easy serialization question
by Mark Wyszomierski 09 Feb '07

09 Feb '07

Hi, I'm using the boost serialization methods, they're great. I'm using some 3rd party classes that I don't have access to, so I can't add a serialize() member function to them. It's something like: class CMyClass { int m_nWhatever; CSomeClass m_sc; // I am just using this from someone else's library.... void serialize(Archive &ar, const unsigned int version) { ar & version; ar & m_nWhatever; ar & m_sc; // fails!!! } } how can I get around this? Thanks, Mark

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[signals] thread-safe combiner()
by Frank Mori Hess 09 Feb '07

09 Feb '07

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 In implementing some of the missing parts of thread_safe_signals, I noticed that boost::signal provides a non-const combiner() function. In it's current form, it can't be made thread-safe against signal invocation. Is it worth changing the prototype from combiner_type& combiner(); to void set_combiner(const combiner_type &); so the combiner can only be modified while holding the appropriate lock? - -- Frank -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQFFy55q5vihyNWuA4URAiHbAJ45kSHJDeBOCKy+s5Yc6TwzqoclkACgx7PY vLAMNIfrlNQWu1jXFppxOj4= =9yLn -----END PGP SIGNATURE-----

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Boost.Numeric.Interval: Please specify rounding control mechanism.
by Andreas Fabri 09 Feb '07

09 Feb '07

Hello, I use boost_1_33_1 with VC8 on a XP64 Turion system, and get an error message C:/cygwin/usr/include/boost-1_33_1\boost/numeric/interval/hw_rounding.hpp(34) : fatal error C1189: #error : Boost.Numeric.Interval: Please specify rounding control mechanism. What shall I do? Any help would be appreciated. andreas

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[boost-users] [interprocess] Using semaphores to synchronize startup
by Lars Hagström 09 Feb '07

09 Feb '07

Hi, I am trying to use Boost.Interprocess to get N processes (senders) to send data to one receiver through shared memory. The receiver has to be the one that initializes the shared memory, so no senders can be "let in" before the receiver has completed initialization. I can't guarantee the order that the processes are starting in. To do this I have both the receiver and the senders create_or_open a named_semaphore with 0 as initial value. The senders then immediately do a wait on the semaphore, but the receiver goes ahead and initializes the memory and then does a post on the semaphore. This lets the first sender in, which can then initialize itself and then do a post on the semaphore and start running. The second sender is then let in (because of the post) and it can get going and so on. This approach works very well if the semaphore has been manually deleted from /dev/shm/ or c:\temp\boost_interprocess\, but will not work if there is an old semaphore around. I can get around this on Windows by doing a named_semaphore::remove, since that will fail if a process has got it loaded. But this same code will not work on linux, since the semaphore will be unlinked and then all the processes will be able to delete the semaphore and will then be using different semaphores! I am used to semaphores working so that if it is opened when noone has it loaded it will be initialized to some known value, but this does not appear to be the case with Boost.Interprocess semaphores? Is there something obvious that I've missed, or some other way of accomplishing the same thing? Cheers Lars

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Serialization of pointers with custom allocators
by Anders Sundman 09 Feb '07

09 Feb '07

Hi! Is it possible to serialize a class A by pointer using a custom allocator? (Not the custom in-place allocator approach). I'm trying to serialize the (OpenCV) class IplImage. The class is used like this: IplImage* img = cvCreateImage(...); ... cvReleaseImage(&img); I've tried the following: template<class Archive> inline void load_construct_data(Archive & ar, IplImage * img, const unsigned int file_version){ ... IplImage* tmpImg = cvCreateImage(...); memcpy(img, tmpImg, sizeof(IplImage)); } But I get exceptions later, when releasing the loaded image. As far as I can tell, the image class data is identical before and after serialization, so I guess that the cvCreateImage/cvReleaseImage keep track of pointers somehow and things go bad when the ReleaseImage is called by a pointer not returned by the CreateImage function? Can the allocation of the IplImage used as input to load_construct_data be customized somehow? I also tried using an IplImage * & as input to load_construct_data: template<class Archive> inline void load_construct_data(Archive & ar, _IplImage * & img, const unsigned int file_version){ _IplImage* tmpImg = cvCreateImage(...); delete img; img = tmpImg; } But that screws up the (de)serialization. Any suggestions or thoughts anyone? // Anders Sundman

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Re: [Boost-users] [Serialization] Linking Error in the Latest CVS
by Wu Yinghui, Freddie 09 Feb '07

09 Feb '07

> OK - I checked in a small change in Jamfile.v2 of the build directory which > I believe my address this. > > Robert Ramey Thanks, Robert, for checking in the update. But I don't think that fixes the problem. (Indeed, rebuilding Boost with the update still gave me exactly the same errors.) The problems, I think, is that codecvt_null.cpp was compiled, and linked to produce boost_serialization_....dll/.lib. But I found that the codecvt_null class's methods are mysteriously missing from the resulting .dll/.lib. So when boost_wserialization_....dll/.lib links with boost_serialization....lib, all codecvt_null-related symbols are not found. I don't understand why, but turning /VERBOSE on for the linker showed that the linker somehow discarded the codecvt_null-related symbols when producing the boost_serialization....dll. > Wu Yinghui, Freddie wrote: >> Hi all, >> >> I posted a question regarding usage of BJam V2 in building the latest >> Boost checked out from the CVS >> (http://lists.boost.org/boost-users/2007/02/25201.php) But there >> seems to be no interest in explaining that at all so far. >> >> But I've sort of worked out most of the solution so far (though mostly >> hacking around in the .jam files, which I suppose could have been >> done a lot easier by someone more familiar with the building system). >> Still I failed to build the Boost.Serialization library out-of-box. >> >>> My system: Windows XP Pro SP2 >>> Compiler: MSVC 7.1 >> The errors I met was something like this: >> =====snip===== >> Creating library >> bin.v2\libs\serialization\build\msvc-7.1\release\instruction >> -set-pentium4\qt3support-on\stdlib-stlport\threading-multi\boost_wserialization- >> vc71-mt-p-1_35.lib and object >> bin.v2\libs\serialization\build\msvc-7.1\release\i >> nstruction-set-pentium4\qt3support-on\stdlib-stlport\threading-multi\boost_wseri >> alization-vc71-mt-p-1_35.exp >> basic_text_wiprimitive.obj : error LNK2001: unresolved external symbol >> "private: >> virtual enum stlp_std::codecvt_base::result __thiscall >> boost::archive::codecvt_ >> null<wchar_t>::do_in(int &,char const *,char const *,char const * >> &,wchar_t *,wc >> har_t *,wchar_t * &)const " >> (?do_in@?$codecvt_null@_W@archive@boost@@EBE?AW4resu >> lt@codecvt_base@stlp_std@@AAHPBD1AAPBDPA_W3AAPA_W@Z) >> basic_text_woprimitive.obj : error LNK2001: unresolved external symbol >> "private: >> virtual enum stlp_std::codecvt_base::result __thiscall >> boost::archive::codecvt_ >> null<wchar_t>::do_in(int &,char const *,char const *,char const * >> &,wchar_t *,wc >> har_t *,wchar_t * &)const " >> (?do_in@?$codecvt_null@_W@archive@boost@@EBE?AW4resu >> lt@codecvt_base@stlp_std@@AAHPBD1AAPBDPA_W3AAPA_W@Z) >> binary_wiarchive.obj : error LNK2001: unresolved external symbol >> "private: virtu >> al enum stlp_std::codecvt_base::result __thiscall >> boost::archive::codecvt_null<w >> char_t>::do_in(int &,char const *,char const *,char const * &,wchar_t >> *,wchar_t >> *,wchar_t * &)const " >> (?do_in@?$codecvt_null@_W@archive@boost@@EBE?AW4result@cod >> ecvt_base@stlp_std@@AAHPBD1AAPBDPA_W3AAPA_W@Z) >> binary_woarchive.obj : error LNK2001: unresolved external symbol >> "private: virtu >> al enum stlp_std::codecvt_base::result __thiscall >> boost::archive::codecvt_null<w >> char_t>::do_in(int &,char const *,char const *,char const * &,wchar_t >> *,wchar_t >> *,wchar_t * &)const " >> (?do_in@?$codecvt_null@_W@archive@boost@@EBE?AW4result@cod >> ecvt_base@stlp_std@@AAHPBD1AAPBDPA_W3AAPA_W@Z) >> =====snip===== >> >> I tried >> dumpbin /all >> bin.v2\libs\serialization\...\boost_serialization-vc71-mt-p-1_35.lib >> >> And indeed, it seems that codecvt_null object's methods were missing >> from the library. Any hints on how I can fix this problem? >> >> Cheers, >> >> Freddie -- Wu Yinghui, Freddie Senior Software Engineer Advanced Technology Research and Development Group Volume Interactions Pte Ltd 1 Kim Seng Promenade #12-01 Great World City East Tower Singapore 237994 Tel: +65 62226962 (Ext 216) Fax: +65 62226215 Email: yhwu(a)volumeinteractions.com URL: http://www.volumeinteractions.com http://www.dextroscope.com Important: This message is intended for the recipient(s) addressed above. It contains privileged and confidential information. If you are not the intended recipient, please notify the sender immediately by replying to this message and then delete it from your system. You must not read, copy, use, or disseminate this communication in any form. Thank you.

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[Serialization] Linking Error in the Latest CVS
by Wu Yinghui, Freddie 09 Feb '07

09 Feb '07

Hi all, I posted a question regarding usage of BJam V2 in building the latest Boost checked out from the CVS (http://lists.boost.org/boost-users/2007/02/25201.php) But there seems to be no interest in explaining that at all so far. But I've sort of worked out most of the solution so far (though mostly hacking around in the .jam files, which I suppose could have been done a lot easier by someone more familiar with the building system). Still I failed to build the Boost.Serialization library out-of-box. > My system: Windows XP Pro SP2 > Compiler: MSVC 7.1 The errors I met was something like this: =====snip===== Creating library bin.v2\libs\serialization\build\msvc-7.1\release\instruction -set-pentium4\qt3support-on\stdlib-stlport\threading-multi\boost_wserialization- vc71-mt-p-1_35.lib and object bin.v2\libs\serialization\build\msvc-7.1\release\i nstruction-set-pentium4\qt3support-on\stdlib-stlport\threading-multi\boost_wseri alization-vc71-mt-p-1_35.exp basic_text_wiprimitive.obj : error LNK2001: unresolved external symbol "private: virtual enum stlp_std::codecvt_base::result __thiscall boost::archive::codecvt_ null<wchar_t>::do_in(int &,char const *,char const *,char const * &,wchar_t *,wc har_t *,wchar_t * &)const " (?do_in@?$codecvt_null@_W@archive@boost@@EBE?AW4resu lt@codecvt_base@stlp_std@@AAHPBD1AAPBDPA_W3AAPA_W@Z) basic_text_woprimitive.obj : error LNK2001: unresolved external symbol "private: virtual enum stlp_std::codecvt_base::result __thiscall boost::archive::codecvt_ null<wchar_t>::do_in(int &,char const *,char const *,char const * &,wchar_t *,wc har_t *,wchar_t * &)const " (?do_in@?$codecvt_null@_W@archive@boost@@EBE?AW4resu lt@codecvt_base@stlp_std@@AAHPBD1AAPBDPA_W3AAPA_W@Z) binary_wiarchive.obj : error LNK2001: unresolved external symbol "private: virtu al enum stlp_std::codecvt_base::result __thiscall boost::archive::codecvt_null<w char_t>::do_in(int &,char const *,char const *,char const * &,wchar_t *,wchar_t *,wchar_t * &)const " (?do_in@?$codecvt_null@_W@archive@boost@@EBE?AW4result@cod ecvt_base@stlp_std@@AAHPBD1AAPBDPA_W3AAPA_W@Z) binary_woarchive.obj : error LNK2001: unresolved external symbol "private: virtu al enum stlp_std::codecvt_base::result __thiscall boost::archive::codecvt_null<w char_t>::do_in(int &,char const *,char const *,char const * &,wchar_t *,wchar_t *,wchar_t * &)const " (?do_in@?$codecvt_null@_W@archive@boost@@EBE?AW4result@cod ecvt_base@stlp_std@@AAHPBD1AAPBDPA_W3AAPA_W@Z) =====snip===== I tried dumpbin /all bin.v2\libs\serialization\...\boost_serialization-vc71-mt-p-1_35.lib And indeed, it seems that codecvt_null object's methods were missing from the library. Any hints on how I can fix this problem? Cheers, Freddie -- Wu Yinghui, Freddie Senior Software Engineer Advanced Technology Research and Development Group Volume Interactions Pte Ltd 1 Kim Seng Promenade #12-01 Great World City East Tower Singapore 237994 Tel: +65 62226962 (Ext 216) Fax: +65 62226215 Email: yhwu(a)volumeinteractions.com URL: http://www.volumeinteractions.com http://www.dextroscope.com Important: This message is intended for the recipient(s) addressed above. It contains privileged and confidential information. If you are not the intended recipient, please notify the sender immediately by replying to this message and then delete it from your system. You must not read, copy, use, or disseminate this communication in any form. Thank you.

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