July 2009 - Boost-users - lists.preview.boost.org

serialization std::map
by Adam Szeliga 17 Jul '09

17 Jul '09

Why I can not input from archive std::map ? line: inputArchive >> inputContainer causes compile error: Thanks Adam #include <string> #include <iostream> #include <fstream> #include <sstream> #include <map> #include <boost/serialization/map.hpp> #include <boost/serialization/serialization.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/level.hpp> #include <boost/serialization/tracking.hpp> #include <boost/serialization/split_free.hpp> #include <boost/serialization/base_object.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_wiarchive.hpp> #include <boost/archive/text_woarchive.hpp> class A { public: A() {}; A(std::string const & s): s(s) { } virtual ~A() {}; private: std::string s; friend std::ostream & operator<<(std::ostream & os, A const & a); friend class boost::serialization::access; template<class Archive> void serialize(Archive & archive, unsigned int const version) { archive & s; } }; std::ostream & operator<<(std::ostream & os, A const & a) { return os << a.s; } typedef std::map<unsigned int const, A * const> Container; BOOST_CLASS_TRACKING(Container, boost::serialization::track_never); std::ostream & operator<<(std::ostream & os, Container const & container) { Container::const_iterator end = container.end(); for (Container::const_iterator i = container.begin(); i != end; ++i) { os << "(" << i->first << "," << *i->second << ")" << std::endl; } return os; } int _tmain(int argc, _TCHAR* argv[]) { std::cout << "serialization map test starts" << std::endl; Container outputContainer; outputContainer.insert(std::make_pair(1, new A("one"))); outputContainer.insert(std::make_pair(4, new A("four"))); outputContainer.insert(std::make_pair(2, new A("two"))); std::cout << outputContainer << std::endl; { std::wofstream outputFile("data.txt"); boost::archive::text_woarchive outputArchive(outputFile); outputArchive << outputContainer; } std::cout << "---------------------------" << std::endl; Container inputContainer; { std::wifstream inputFile("data.txt"); boost::archive::text_wiarchive inputArchive(inputFile); inputArchive >> inputContainer; // this line causes compile error } std::cout << inputContainer << std::endl; std::cout << "serialization map test ends" << std::endl; return 0; }

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Re: [Boost-users] [Regex] regex_search
by Etienne Philip Pretorius 16 Jul '09

16 Jul '09

Never mind, I worked around the problem. Thank you, Etienne

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[Regex] regex_search
by Etienne Philip Pretorius 16 Jul '09

16 Jul '09

Hello List, I am having an issue compiling the my code - I get the following error: xml.hpp:43: error: no matching function for call to ‘regex_search(boost::asio::buffers_iterator<boost::asio::const_buffers_1, char>&, boost::asio::buffers_iterator<boost::asio::const_buffers_1, char>&, boost::match_results<boost::asio::buffers_iterator<boost::asio::const_buffers_1, char>, std::allocator<boost::sub_match<boost::asio::buffers_iterator<boost::asio::const_buffers_1, char> > > >&, boost::_bi::bind_t<boost::regex&, boost::_mfi::mf0<boost::regex&, xmpp::xml::parser>, boost::_bi::list1<boost::_bi::value<const xmpp::xml::parser*> > >, boost::regex_constants::match_flags)’ Here is the related code snippet: template <typename iterator> std::pair<iterator, bool> operator()( iterator begin, iterator end ) const { if(begin == end) { return std::make_pair(end,false); } boost::match_results<iterator> match_results; //Compiler Error Start if(boost::regex_search( begin, end, match_results, boost::bind( &parser::regex, this ), boost::match_default | boost::match_partial)) { //Compiler Error End if(match_results[0].matched) { //test return std::make_pair(match_results[0].second,true); }else{ //test return std::make_pair(match_results[0].first,false); } } return std::make_pair(end,false); }; private: boost::regex regex( ){ return XMLDecl_; }; static boost::regex S_, Eq_, EncName_, VersionInfo_, EncodingDecl_, SDDecl_, XMLDecl_, UTF8_, Char_, NameStartChar_, NameChar_, Name_, Names_, Comment_, PITarget_, PI_, Misc_, prolog_; Could someone please shed some light on this problem for me. I want to be able to change the regular expression based on a state variable so that operator() can advance to the next xml type that it should/could encounter. Thank you. Etienne

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(newbie) boost thread compile problems on Fedora 8
by Kishalay Kundu 16 Jul '09

16 Jul '09

Hi, I am having trouble compiling a correct version of the boost thread library on a x86_64 Fedora Core 8 and was wondering if anyone can help me out. I've tried both version 1.37 and 1.39. I describe below what I do and what happens after that. I am on an AMD64 Fedora Core 8 platform (with gcc 4.1.2 and glibc 2.7) that already had boost 1.34 on it at /usr/lib level. I erased that version by deleting all the libraries and moving 'boost' directory in /usr/include to 'boost_1-34' directory. I download the .gz tarball, bootstrap it, make it (with make for 1.37 and bjam for 1.39) and install it to /usr/local/lib. The compilation goes without a hitch (except for some warnings for boost serialization and others, but not for thread). I have both .a and .so files generated and residing in /usr/local/lib and boost include files in /usr/local/include. I add the links libboost_thread-mt.a and libboost_thread-mt.so to point to libboost_thread-gcc41-mt_1.3x.* libs. Now, I write a small test program (given below). It gives me linker errors with undefined references to pretty much every pthread symbol. If anyone wants I can paste all the errors in the next message. When I add the -lpthread flag to the compile, it gives me an undefined reference error with regards to __vdso_clock_gettime from /lib64/libpthread.a. I'm not sure where exactly the problem lies and would greatly appreciate if someone could point me in the right direction. Thank you. regards, Kishalay My test program: compiled with: gcc -o testk test.cpp -lboost_thread-mt #include <cstdio> #include <cstdlib> #include <boost/thread.hpp> using namespace std; using namespace boost; static void somefunc( ) { printf( "thread calling this\n" ); } int main( int argc, char** argv ) { boost::thread* t = new thread( somefunc ); delete t; }

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boost 1.39 hp-ux support dropped ?
by Avi Bahra 16 Jul '09

16 Jul '09

It appears that boost 1.37, 1.38 all support HP-UX as a primary compiler. However 1.39 release notes, make no mention of HP-UX at all? is this deliberate or an oversight? Best regards, Ta, Avi

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[serialization][python] (ab)using serialization to read/write object attribute values from python
by Václav Šmilauer 16 Jul '09

16 Jul '09

Hello boosters, I am working on http://yade.wikia.com project and we plan to switch to boost::serialization. boost::python is already used (many thanks for that fantastic piece of code). Let me explain the current state first. We use custom serialization interface: each class registers various attributes of objects; at serialization, archive of pointers to the attributes associated with attribute names is created and serialized to XML (and vice versa for deserialization). Boost.python is used to wrap c++ objects in python. Each wrapper class defined __getattr__ and __setattr__; if called, the wrapper: 1. Checks that the underlying c++ object has an associated archive of attributes created. 2. Gets/sets the value of the attribute based on its registered name (because of current limitations, the value is passed to the archive as string) The advantage is that there is no need to wrap every single class in python, just a few top-level classes; and access to all other attributes of the derived types is automatically provided by the serialization framework. My questions are: 1. Do boost::serialization archives keep pointers to attributes, in such way that it is possible to keep one archive instance per object and use it to write an attribute continuously, with the change being immediately propagated to the c++ objects, and ask the archive for attribute value based on its name? 2. Is it possible (or has it even been done) to define python_iarchive and python_oarchive that would (de)serialize between python and c++ types (such as std::map to dicitonary, [] to vector etc.)? I am sorry if those questions are trivial or nonsensical... I am trying to foresee problems that we could have with boost::serialization. If you have some proposition how to solve this xml+python attribute access in a better unified way, don't hesitate to post, please. (Switching the wrapper to py++ doesn't seem very practical at the moment, as it works quite nicely the current way; (frequent) adding of a class or adding/removing attributes doesn't require the wrapper to be regenerated/recompiled at all) Regards, Václav Šmilauer

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Building boost faster: /MP
by Robert Dailey 16 Jul '09

16 Jul '09

Hello, I'm sure most of you are aware of the /MP flag introduced in MSVC9. I know this flag works fine when set through Visual Studio 9, however, I'm not sure if it works when calling cl.exe directly. Since it's just a compiler flag I imagine it does. It would be great to see support for this flag in CMake and/or bjam to help build boost faster when using this particular compiler. Any thoughts on this? Sincerely, Robert Dailey

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A question on C++ DLL making in Dev-C++.Can anyone with kindness help me?
by fmingu 16 Jul '09

16 Jul '09

I am using Dev-C++ 4.9.8.0. I tried to make DLLs in Dev-C++. Can anyone with kindness tell me where can I get the help materials on making classes in a DLL and use the member functions in my executables? I found many materials spoke on the functions in DLL but few of them spoke on the member functions and classes in DLL. Although the platform gives the skeleton of a C++ DLL,i.e. dllmain.cpp, dll.h,I can not understand it. The help files in Dev-C++ did not explain it explicitly. Maybe a step_by_step turial is useful. I know that is not quite appropriate to ask such question in this area. But after several days of asking problems, I found there are lots of experts here. And I am just a new comer in programing. Does someone know the format of DLL made from Dev-C++ ? Coff or omf ? Can the DLL be applied by Borland C++ builder 2009? If not, how can I handle it? Can the DLL be compatible with Visual C++? Thanks a lot.

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Re: [Boost-users] Unable to catch exception using boost::asio
by Alex Black 15 Jul '09

15 Jul '09

> > Message: 3 > Date: Wed, 15 Jul 2009 10:56:22 -0500 > From: Zachary Turner <divisortheory(a)gmail.com> > Subject: Re: [Boost-users] Unable to catch exception using boost::asio > To: boost-users(a)lists.boost.org > Message-ID: > <478231340907150856x12c9fd92w3b06630d349eef36(a)mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > > I wrapped my call to run() in a try-catch, no luck, no exception > > appears to be being thrown by io_service.run(). > > > > void CBaseWebServer::RunIoService() > > { > > ? ? ? ?try > > ? ? ? ?{ > > ? ? ? ? ? ? ? ?m_IoService.run(); > > ? ? ? ?} > > ? ? ? ?catch ( ... ) > > ? ? ? ?{ > > ? ? ? ? ? ? ? ?cout << "Unhandled exception in > RunIoService"; ? ? ? ?} > > } _______________________________________________ > > Boost-users mailing list > > Boost-users(a)lists.boost.org > > http://lists.boost.org/mailman/listinfo.cgi/boost-users > > > > > That probably won't help. Notice that > CBaseWebServer::RunIoService() is not in the call stack at > the point you're seeing the exception. > After looking at your callstack again, I believe you're > throwing from a destructor. In particular, notice in your > callstack that you have > this: > > 26 ~ProtoBufStreamAdaptor() /home/noirs/workspace/myfile2.cpp:10 > 0x000000000042c6e5 > 25 CWebServer::HandleGetNeighbors() > /home/noirs/workspace/myfile3.cpp:215 0x000000000041d2d8 > > > These appear to both be in your own code. My suspicion is > that an exception occurs in CWebServer::HandleGetNeighbors(), > which causes it to unwind the stack and execute destructors. > In particular a destructor for an object of type > ProtoBufStreamAdaptor() is called, and this destructor then > throws another exception. At this point your program will > definitely terminate immediately. > > First check the destructor of ProtoBufStreamAdaptor() to see > why it's throwing (destructors should _never_ throw under any > circumstances), and then check the code of > CWebServer::HandleGetNeighbors() to find the original error. Thanks for continuing to help with this. I had the same thoughts as you, and I've looked into that with no luck. For example, here is the code for ~ProtoBufStreamAdaptor(): ProtoBufStreamAdaptor::~ProtoBufStreamAdaptor(void) {} The original error is related to the client (on the other end of the socket) being interrupted. Presumably some socket operation is throwing an exception, e.g. I'm writing to the socket after the client has disconnected. You mentioned never throwing exceptions in destructors - sounds like good advice, thx. Two points though: 1. If an exception is thrown in a destructor can it not be caught with a try catch( ... )? 2. I'll look over the code more closely and see if there are any destructors throwing.

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Serialization on boost::dynamic bitset
by Gokulakannan Somasundaram 15 Jul '09

15 Jul '09

Hi, I have to write code for serialization of dynamic bitset. I could well write the code by iterating through the bitset, but i was just wondering, why it is not provided as part of the library. Thanks, Gokul.

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