November 2007 - Boost-users

boost program options positional arguments in config file?
by Zachary 12 Nov '07

12 Nov '07

I've been using program_options quite happily and successfully for a short while now and would like to take this opportunity to express my gratitude. Is there a way to extract postional args from config file, though? The headers seem to indicate that it's possible include_positional flag, but I haven't been able to find something workable in the documentation or mailing lists. Thanks, Zak

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Problem with shared version of Boost.Regex library
by ancode tran 12 Nov '07

12 Nov '07

Hi all, I compiled a shared version (DLL) of Boost.Regex on Windows2000 Pro with gcc 3.4.5, mingw 3.13, STLport 5.1.4 and IBM's ICU 3.8. Details are as below: 1. Open file "boost/config/platform/win32.hpp", change the line: #if !defined(__GNUC__) && !defined(BOOST_HAS_DECLSPEC) to: #if (!defined(__GNUC__) || defined(__MINGW32__)) && !defined(BOOST_HAS_DECLSPEC) I did this because mingw (at least with my version) supports both __declspec(dllexport) and __declspec(dllimport), and __GNUC__ is also defined. 2. Open file "boost/regex/user.hpp" and uncomment 2 lines: "#define BOOST_HAS_DLL_RUNTIME 1" and "#define BOOST_REGEX_DYN_LINK 1". 3. Edit file "libs/regex/build/gcc-shared.mak" and then use it to build Boost.Regex from MSYS shell with GNU Make. After the building process completed, I wrote a small program to test the output. It ran nicely but I got the following warning when linking against Boost.Regex: ../../include/boost/regex/pending/static_mutex.hpp:116: warning: 'bool boost::scoped_static_mutex_lock::locked() const' defined locally after being referenced with dllimport linkage It seems my compiler doesn't like to see "inline" and "__declspec(dllimport)" in the same place. So I have some questions: 1. Should I remove "inline" and rebuild Boost.Regex to skip this warning ? 2. Should I continue to use my own shared version of Boost.Regex ? May it result in such thing like undefined behavior, especially in multithread world ? Can anyone give me a hint, please ? Thanks in advance. P.S: STLport and ICU were built as shared libraries, I therefore dont like a static build of Boost.Regex at all. --------------------------------- Thức ăn hữu cơ - thức ăn lành mạnh có lợi cho sức khỏe như thế nào? Khám phá tại Yahoo! Hỏi & Đáp

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Boost::test unknown location(0): fatal error in "...": memory access violation
by Yann Golanski 12 Nov '07

12 Nov '07

I get the following message from one of my test case. Clearly, I have some pointer wrong. Can you tell me how I can generate core files and thus use gdb to find out which pointer is causing the problem? Thanks. -- yann(a)kierun.org -= H+ =- www.kierun.org PGP: 009D 7287 C4A7 FD4F 1680 06E4 F751 7006 9DE2 6318

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linking trouble
by brad 12 Nov '07

12 Nov '07

I am trying to make a package called visual python, but I keep getting this error. I am using fedora 8 and have Linking cvisualmodule.la ... make[1]: *** [cvisualmodule.la] Error 1 make[1]: Leaving directory `/home/brad/Download/visual-4.beta16/src' make: *** [all-recursive] Error 1 The key reason I get this error is this line right here... /usr/bin/ld: cannot find -lboost_thread I looked online saw that I could try --LDFLAGS-L[path], where path is the path to libboost_thread.so and libboost_thread.a. Those files don't exist on my computer and I have boost-1.34.1-5.fc8 and boost-devel-1.34.1-5.fc8. I did however find /usr/lib/libboost_thread-mt.so, /usr/lib/libboost_thread-mt.so.1.34.1, and /usr/lib/libboost_thread-mt.so.3. Brad Longo

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Monitors like Java's Object.wait() / Object.notify() in boost ?
by Yves Dessertine 12 Nov '07

12 Nov '07

Hello, I am a new Boost user (and especialy boost::thread for a school project), I haven't found in Boost a feature like minotors in java, with the methods Object.wait() / Object.notify() / Object.notifyAll(). I have the problem of having one thread that produces information, and several threads that extract infos when available... but all the reader threads needs to be woken up only when more data is available (with an equivalent to nofityAll()). Does such features exists in Boost::thread ??? Thank you for any tip. Have a nice day. Yves Dessertine IT student

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[serialization] portable binary archive first release
by Pfligersdorffer, Christian 12 Nov '07

12 Nov '07

Dear all, I am proud to announce the very first release of our portable_binary_[io]archive which we use here at EOS to move data between different platforms. It really is a conglomerate of pieces that already were there - as is most often the case in oo world - we simply put them together in a way that seemed to make sense. I know a lot of people were interested in portable binary archives, so here you are - give it a try and let me know what you think about it! We rely heavily on boost::serialization and really appreciate the amount of time and knowledge that flew into it. By publishing this small missing piece we hope to contribute our mite to this great library. The work extends the portable binary example which was done by Robert Ramey and uses Beman Dawes' endian library plus the fp_utilities by Johan Rade. You will need to get those two libraries in order to use our classes - look for them at the boost vault (http://www.boost-consulting.com/vault/) in categories 'integer' and 'math - numerics'. Finally you will find the portable binary archive in category 'serialization' as well. Regards, Christian Pfligersdorffer -- christian.pfligersdorffer(a)eos.info http://www.eos.info

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The Calling of Bjam on the Command Line - Problem
by chandra_india＠webdunia.com 12 Nov '07

12 Nov '07

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[Serialization] Compiler warnings from binary_iarchive
by Mahesh Venkitachalam 11 Nov '07

11 Nov '07

Hello, I am getting the compiler warnings below when I include the following in a source file. #include <boost/archive/binary_iarchive.hpp> Everything works fine, but I was wondering if there's any way to get rid of the warnings. I am using boost 1.34.0 on windows XP, and building using Visual Studio 8. Best Regards Mahesh C:\boost_1_34_0\boost/archive/basic_binary_iprimitive.hpp(148) : warning C4996: 'std::basic_streambuf<_Elem,_Traits>::sgetn' was declared deprecated with [ _Elem=char, _Traits=std::char_traits<char> ] C:\Program Files\Microsoft Visual Studio 8\VC\INCLUDE\streambuf(122) : s ee declaration of 'std::basic_streambuf<_Elem,_Traits>::sgetn' with [ _Elem=char, _Traits=std::char_traits<char> ] Message: 'You have used a std:: construct that is not safe. See document ation on how to use the Safe Standard C++ Library' C:\boost_1_34_0\boost/archive/basic_binary_iprimitive.hpp(120) : while c ompiling class template member function 'void boost::archive::basic_binary_iprim itive<Archive,Elem,Tr>::load_binary(void *,size_t)' with [ Archive=boost::archive::binary_iarchive, Elem=char, Tr=std::char_traits<char> ] C:\boost_1_34_0\boost/archive/detail/iserializer.hpp(94) : see reference to function template instantiation 'void boost::archive::basic_binary_iprimitiv e<Archive,Elem,Tr>::load<T>(T &)' being compiled with [ Archive=boost::archive::binary_iarchive, Elem=char, Tr=std::char_traits<char>, T=unsigned char ] C:\boost_1_34_0\boost/archive/detail/iserializer.hpp(348) : see referenc e to function template instantiation 'void boost::archive::load_access::load_pri mitive<Archive,T>(Archive &,T &)' being compiled with [ Archive=boost::archive::binary_iarchive, T=unsigned char ] C:\boost_1_34_0\boost/archive/detail/iserializer.hpp(347) : while compil ing class template member function 'void boost::archive::detail::load_non_pointe r_type<Archive,T>::load_primitive::invoke(Archive &,T &)' with [ Archive=boost::archive::binary_iarchive, T=unsigned char ] C:\boost_1_34_0\boost/archive/detail/iserializer.hpp(423) : see referenc e to class template instantiation 'boost::archive::detail::load_non_pointer_type <Archive,T>::load_primitive' being compiled with [ Archive=boost::archive::binary_iarchive, T=unsigned char ] C:\boost_1_34_0\boost/archive/detail/iserializer.hpp(416) : while compil ing class template member function 'void boost::archive::detail::load_non_pointe r_type<Archive,T>::invoke(Archive &,T &)' with [ Archive=boost::archive::binary_iarchive, T=unsigned char ] C:\boost_1_34_0\boost/archive/detail/iserializer.hpp(570) : see referenc e to class template instantiation 'boost::archive::detail::load_non_pointer_type <Archive,T>' being compiled with [ Archive=boost::archive::binary_iarchive, T=unsigned char ] C:\boost_1_34_0\boost/archive/detail/common_iarchive.hpp(57) : see refer ence to function template instantiation 'void boost::archive::load<Archive,T>(Ar chive &,T &)' being compiled with [ Archive=boost::archive::binary_iarchive, T=unsigned char ] C:\boost_1_34_0\boost/archive/basic_binary_iarchive.hpp(63) : see refere nce to function template instantiation 'void boost::archive::detail::common_iarc hive<Archive>::load_override<T>(T &,int)' being compiled with [ Archive=boost::archive::binary_iarchive, T=unsigned char ] C:\boost_1_34_0\boost/archive/binary_iarchive_impl.hpp(45) : see referen ce to function template instantiation 'void boost::archive::basic_binary_iarchiv e<Archive>::load_override<T>(T &,int)' being compiled with [ Archive=boost::archive::binary_iarchive, T=unsigned char ] C:\boost_1_34_0\boost/archive/detail/interface_iarchive.hpp(77) : see re ference to function template instantiation 'void boost::archive::binary_iarchive _impl<Archive,Elem,Tr>::load_override<T>(T &,int)' being compiled with [ Archive=boost::archive::binary_iarchive, Elem=char, Tr=std::char_traits<char>, T=unsigned char ] C:\boost_1_34_0\boost/archive/basic_binary_iarchive.hpp(73) : see refere nce to function template instantiation 'Archive &boost::archive::detail::interfa ce_iarchive<Archive>::operator >><unsigned char>(T &)' being compiled with [ Archive=boost::archive::binary_iarchive, T=unsigned char ] C:\boost_1_34_0\boost/archive/basic_binary_iarchive.hpp(70) : while comp iling class template member function 'void boost::archive::basic_binary_iarchive <Archive>::load_override(boost::archive::version_type &,int)' with [ Archive=boost::archive::binary_iarchive ] C:\boost_1_34_0\boost/archive/binary_iarchive_impl.hpp(31) : see referen ce to class template instantiation 'boost::archive::basic_binary_iarchive<Archiv e>' being compiled with [ Archive=boost::archive::binary_iarchive ] C:\boost_1_34_0\boost/archive/binary_iarchive.hpp(34) : see reference to class template instantiation 'boost::archive::binary_iarchive_impl<Archive,Elem ,Tr>' being compiled with [ Archive=boost::archive::binary_iarchive, Elem=char, Tr=std::char_traits<char> ] C:\boost_1_34_0\boost/archive/basic_binary_iprimitive.hpp(159) : warning C4996: 'std::basic_streambuf<_Elem,_Traits>::sgetn' was declared deprecated with [ _Elem=char, _Traits=std::char_traits<char> ] C:\Program Files\Microsoft Visual Studio 8\VC\INCLUDE\streambuf(122) : s ee declaration of 'std::basic_streambuf<_Elem,_Traits>::sgetn' with [ _Elem=char, _Traits=std::char_traits<char> ] Message: 'You have used a std:: construct that is not safe. See document ation on how to use the Safe Standard C++ Library'

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Boost serialization: Problem reading strings from binary archive
by Mahesh Venkitachalam 11 Nov '07

11 Nov '07

Hello, I am having a strange problem with std::string as I am trying to read from a binary archive using Boost serialization. I am new to this, and it is possible that I have not understood the usage. In the code below, the string "faultblock" seems to be causing the problem. The code crashes in the ia & tst line which is reading back the archive - the stack indicates that it is trying to read an invalid string. I have tried to minimize the code I need to post, but sorry if this is still too much. I'd appreciate any help with this. I am using Boost 1.34.0 on windows XP. Best Regards Mahesh // // test.cpp // #include <iomanip> #include <iostream> #include <fstream> #include <string> #include <vector> #include <boost/archive/text_iarchive .hpp> #include <boost/archive/text_oarchive.hpp #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/list.hpp> #include "Attribute4dv.h" using namespace std; class Test { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar.template register_type<AttrDouble4dv>(); ar.template register_type<AttrString4dv>(); ar & _attrs; } public: vector<Attribute4dv*> _attrs; Test() {} ~Test() {} }; int main(int argc, char* arv[]) { // save data to archive { Test* tst = new Test; vector<double> dVals; dVals.push_back(1.1); dVals.push_back(2.2); AttrDouble4dv* attr1 = new AttrDouble4dv; attr1->_name = "attr1"; attr1->_vals = dVals; tst->_attrs.push_back(attr1); vector<string> lut; lut.push_back("2001"); lut.push_back("2002"); vector<int> lutIndices; lutIndices.push_back (0); lutIndices.push_back(1); AttrString4dv* attr2 = new AttrString4dv; attr2->_name = "faultblock"; attr2->_indices = lutIndices; attr2->_lut = lut; tst->_attrs.push_back(attr2); const Test* tst2 = tst; std::ofstream ofs("test.bin"); boost::archive::binary_oarchive oa(ofs); oa & tst2; } // read data from archive { Test* tst; std::ifstream ifs("test.bin", std::ios::binary); boost::archive::binary_iarchive ia(ifs); ia & tst; int j = 0; } return 0; } // // Attribute4dv.h // #ifndef _ATTRIBUTE4DV_H #define _ATTRIBUTE4DV_H #include <vector> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/vector.hpp> // Base class class Attribute4dv { public: Attribute4dv() {} virtual ~Attribute4dv() {} // name of attribute std::string _name; private: // for serialization friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & _name; } }; // double attributes class AttrDouble4dv : public Attribute4dv { public: AttrDouble4dv() {} ~AttrDouble4dv() {} std::vector<double> _vals; private: // for serialization friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) { // save/load base class info ar & boost::serialization::base_object<Attribute4dv>(*this); ar & _vals; } }; // string attributes class AttrString4dv : public Attribute4dv { public: AttrString4dv() {} ~AttrString4dv() {} // a lookup table (LUT) of strings std::vector<std::string> _lut; // indices to the LUT std::vector<int> _indices; private: // for serialization friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) { // save/load base class info ar & boost::serialization::base_object<Attribute4dv>(*this); ar & _lut; ar & _indices; } }; #endif // _ATTRIBUTE4DV_H

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[Date_Time]: efficient use, fuzzy formats and a valgrind error
by Christoph 10 Nov '07

10 Nov '07

I today made first (hands on) contact with the Boost.Date_Time library and it really is quite intuitive to use and I'd like to see if it fits our needs. I want to replace some rather heavily used C functions with something Boost.Date_Time based as the old code is rather ugly and unintellegible whereas the Boost lib is tested, well documented and so on. i) As I have mentioned before, one important aspect is efficient parsing of dates. Our old function is configurable through format strings. Is the following code (esp. the function parse_date) efficient? #define ID_INP_NORMDAT "%d.%m.%Y" static MDATUM date_to_mdatum(const date &d); static MDATUM parse_date(const char * const sDate, const char * const sFormat) { string s(sDate); // stringstream needs a std::string? stringstream ss(s); date_input_facet* facet(new date_input_facet(sFormat)); // expensive? ss.imbue(locale(ss.getloc(), facet)); date d; ss >> d; // yes, I need to do error checking here // I need to produce our internal date format again return date_to_mdatum(d); } What I wonder are: * Esp. (as I am new to facets and imbueing etc as well): is the construction of facets etc expensive? * I need to support some twenty input/output formats. Should I construct (and cache) facets in advance, or is it ok to construct these every time they are needed? * valgrind tells me I do not have a memory leak. Who owns facets? * Do I have to unimbue a stream (assuming I had imbued cout)? * Can I avoid constructing the std::string? It would be great if you could point out flaws and inefficiencies (or just best practices in this case) in the above code to me. I'd like to say in advance thanks for looking into this. ii) 'Fuzzy formats' I need to allow the user some degree of freedom (lazyness) when entering dates. It is required that (German dates) 01.10.2007 01102007 011007 (and more) all produce the same date (Oct 1st 2007). Is this possible with Boost.Date_Time's format strings? (I don't think so.) Is there a(n efficient) way to achieve that (ideally not trying the different possible formats one by one ;-) iii) When I ran the attached program through valgrind (with options --tool=memcheck --leak-check=full -v) I got the following error report: ==7762== Conditional jump or move depends on uninitialised value(s) ==7762== at 0xC9FAC99: strftime_l (in /lib64/libc-2.6.1.so) ==7762== by 0xC2C63DB: std::__timepunct<char>::_M_put(char*, unsigned long, char const*, tm const*) const (in /usr/lib64/libstdc++.so.6.0.9) ==7762== by 0xC2874DE: std::time_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::do_put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, tm const*, char, char) const (in /usr/lib64/libstdc++.so.6.0.9) ==7762== by 0xC285A7F: std::time_put<char, std::ostreambuf_iterator<char, std::char_traits<char> > >::put(std::ostreambuf_iterator<char, std::char_traits<char> >, std::ios_base&, char, tm const*, char const*, char const*) const (in /usr/lib64/libstdc++.so.6.0.9) ==7762== by 0x40CFBD: std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > boost::date_time::gather_month_strings<char>(std::locale const&, bool) (strings_from_facet.hpp:57) ==7762== by 0x40E991: boost::date_time::format_date_parser<boost::gregorian::date, char>::format_date_parser(std::string const&, std::locale const&) (format_date_parser.hpp:175) ==7762== by 0x40F6DC: boost::date_time::date_input_facet<boost::gregorian::date, char, std::istreambuf_iterator<char, std::char_traits<char> > >::date_input_facet(std::string const&, unsigned long) (date_facet.hpp:474) ==7762== by 0x409539: parse_date(char const*, char const*) (datum_test.cpp:29) ==7762== by 0x40976C: main (datum_test.cpp:40) --7762-- REDIR: 0xC9E1C70 (index) redirected to 0x4C22A20 (index) Just in case I am doing something wrong here. Am I? Thank you for producing a great library and best regards Christoph

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