- Boost-users - lists.boost.org

boost::asio::read: Is it possible to read directly into a string?
by Jean-Sebastien Stoezel 06 Aug '08

06 Aug '08

Hello, Is it possible to directly read into a string using boost::asio::read? Or do I have to first read into an array of char, then assign it to the string? Thanks! Jean

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[program_options]
by Marcio Paim de Aquino 06 Aug '08

06 Aug '08

Hi, here is the output of one of the example programs from program_options library: paim@notebook:~$ ./first --help Allowed options: --help produce help message --compression arg set compression level I would like to know if there is a way to change "arg" for something else? Thanks Marcio

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[mpi] Any plan for mpi2 IO support ?
by Alain Miniussi 06 Aug '08

06 Aug '08

Hi, I have a code based on MPI uising MPI2 IO to read/writte its data on disk (all mpi procces perform concurrent read/writte on the same file). Boost::mpi does not seems to include whose functionnalities (parralllel IO, views, async ios, basically the stuff described in http://www.mpi-forum.org/docs/mpi-20-html/node171.htm#Node171 ). Is there a plan to support that in the near future ? I had a looks a boost serialization libraries but they do not seems provide whose functionnalities (or did I missed something ?). Thanks, -- Alain Miniussi Equipe CRIMSON Mesocentre de Calcul SIGAMM +33 492 00 30 09 https://crimson.oca.eu

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Error when using the strstr function, help required
by Sean Farrow 06 Aug '08

06 Aug '08

Hi: When using the strstr function I get the following error: error C2440: 'initializing' : cannot convert from 'const char *' to 'char *' What have I do? Can I fix this with a const_cast, if not what is the fix, I'm sure it must be simple! Chers Sean. __________ Information from ESET NOD32 Antivirus, version of virus signature database 3331 (20080806) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

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serialization of vectors somehow odd
by Sebastian Weber 06 Aug '08

06 Aug '08

Hi! I just switched to the new 1.36.0 beta release and was very confused by the new scheme how optimized arrays are handled within archives as I have implemented an HDF5 archive by myself. After a while I found out how to fix it by browsing SVN changesets - is there some documentation about it I overlooked? Well, now I even see that I have to include serialization/vector_135.hpp to avoid this strange item_version tag to appear which distracts my archives. This is fine, but this is a meta-information, wouldn't it be possible to use some BOOST_STRONG_TYPEDEF to inject this item_version variable as some specific meta-type which I can then filter in my archive? Greetings, Sebastian

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boost 1.35 code completion under Visual Studio 2008
by Roma.. 06 Aug '08

06 Aug '08

Hi! I've compiled and now using Boost 1.35 under XpSp2 VS2008 Regex example from "Getting started" was successfully launched. Another example was not launched: http://www.boost.org/doc/libs/1_35_0/libs/regex/doc/html/boost_regex/captur… Error 1 error C2039: 'captures' : is not a member of 'boost::match_results<BidiIterator>' Error 2 error C2228: left of '.size' must have class/struct/union Error 3 error C2039: 'captures' : is not a member of 'boost::match_results<BidiIterator>' Moreover, code completion seems to not work (I mean list of variants does not appear after typing "pat.", where pat is boost::regex) Are there any ideas? Thanks!

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[Boost.Serialization] shared_ptr compile-time error.
by Vjekoslav Brajkovic 06 Aug '08

06 Aug '08

Hi, I receive a compile time error when I try to serialize shared_ptr<string> in my class. Here are the relevant parts of this class: /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8 #include <boost/serialization/base_object.hpp> #include <boost/serialization/shared_ptr.hpp> #include <boost/serialization/string.hpp> class chunk_data : public chunk_metadata { public: chunk_data(std::string s); chunk_data( chunk_metadata metadata, boost::shared_ptr<std::string> data_ptr); chunk_data( boost::filesystem::path path, chunk_metadata::cuid_type chunk_id); chunk_data( boost::filesystem::path path, chunk_metadata::cuid_type chunk_id, boost::shared_ptr<std::string> data_ptr); virtual ~chunk_data(); template <typename Archive> void serialize(Archive& ar, const unsigned int version) { boost::serialization::base_object<chunk_metadata>(*this); ar & data_ptr_; } boost::shared_ptr<std::string> data_ptr_; }; /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8 And here are the relevant parts from compilation error. invalid application of âsizeofâ to incomplete type âboost::STATIC_ASSERTION_FAILURE<false>â error: âstruct std::basic_string<char, std::char_traits<char>, std::allocator<char> >â has no member named âserializeâ I haven't found any relevant hints about this error neither in the documentation or on the boost mailing list. Also I've attached the compilation log. I would really appreciate any help. -Vjeko

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Re: [Boost-users] MS SDK 2003 Compiler Configuration
by Bob Monat 06 Aug '08

06 Aug '08

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O(1) free in boost::object_pool ?
by Domagoj Babic 05 Aug '08

05 Aug '08

Hi all, I'm considering using boost::object_pool for my project. Reading the code, I found something that is seemingly suboptimal for my application: destroy in boost::object_pool calls object_pool::free, which calls (eventually) simple_segregated_storage::ordered_free. From the code (and documentation), it seems to me that only simple_segregated_storage::malloc_n uses that ordering. In my application, I don't need malloc_n, so the ordering is redundant. My question is: How can I change the default behavior of object_pool so as to use the simple, unordered O(1) free, which just adds the chunk to the beginning of the list of free chunks? I've (of course) read the documentation, but the only relevant sentences are not very clear: "Memory deallocation may be as simple as adding that chunk to the front of the free list, a O(1) operation. However, more complicated uses of Simple Segregated Storage may require a sorted free list, which makes deallocation O(N)." I.e., since I don't need more complicated uses (I guess that's just malloc_n, please correct me if I'm wrong), I'd like O(1) deallocation. Thank you in advance. Kind regards, -- Domagoj Babic http://www.domagoj.info/ http://www.calysto.org/

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Serialization. On to its binary archive format.
by Alejandro Martinez 05 Aug '08

05 Aug '08

Im sorry to bother with this, but im having lots of trouble with this. I was able to serialize and deserialize flawlessly in c++ in the binary archive. But now i need to be able to construct binary payloads from php, and then deserialize them in c++ in the same way. But i have been hex-viewing the binary output of boost::serialization and wasn't able to understand it completely. Is there any guide or general idea to understand such format? Im not sure if i understand the library enough so as to make my own archive format. for example, when i try to serialize something like this: BOOST_CLASS_IMPLEMENTATION(std::vector<std::string>, boost::serialization::object_serializable) void save(const std::vector<std::string>& a) { std::ofstream ofs("caca.txt", std::ios::binary); boost::archive::binary_oarchive oa(ofs, boost::archive::no_header); oa << a; ofs.close(); } int main() { std::vector<std::string> sarr; sarr.push_back("Uno"); sarr.push_back("Dos"); sarr.push_back("Tres"); save(sarr); return 0; } i get: 00000000 03 00 00 00 00 00 00 00 03 00 00 00 55 6E 6F 03 ············Uno· 00000010 00 00 00 44 6F 73 04 00 00 00 54 72 65 73 ···Dos····Tres So that is: 03 00 00 00 means the vector has 3 elements. then 00 00 00 00 i don't know what it is for and then i have 3 times 4 bytes for the length of the string, and then the string. that weird 00 00 00 00 does not happen if i had (for example) a std::vector<int>. and more of that kind of things happen when i try to use derived types. like... class Request { public: virtual void run() = 0; template<class Archive> void serialize(Archive & ar, const unsigned int) { } }; BOOST_CLASS_IMPLEMENTATION(Request, boost::serialization::object_serializable) class Request1 : public Request { public: void run() { std::cout << " | " << ia << " | " << ib << " | " << sname << " | "; for(int i = 0; i < iarr.size(); ++i) std::cout << iarr[i] << " | "; std::cout << std::endl; } template<class Archive> void serialize(Archive & ar, const unsigned int) { ar & boost::serialization::base_object<Request>(*this); ar & ia & ib & sname & iarr; } public: int ia; int ib; std::string sname; std::vector<int> iarr; }; BOOST_CLASS_EXPORT(Request1) BOOST_CLASS_TRACKING(Request1, boost::serialization::track_never) BOOST_CLASS_VERSION(Request1, 0xff) void arrrg(const Request* a) { std::ofstream ofs("caca.txt", std::ios::binary); boost::archive::binary_oarchive oa(ofs, boost::archive::no_header); oa << a; ofs.close(); } int main() { Request1* temp(new Request1); temp->ia = 1; temp->ib = 2; temp->sname = "Omg!"; temp->iarr.push_back(3); temp->iarr.push_back(4); temp->iarr.push_back(5); Request* a(temp); arrrg(a); return 0; } i get: 00000000 00 00 08 00 00 00 52 65 71 75 65 73 74 31 00 FF ··?···Request1·· 00000010 01 00 00 00 02 00 00 00 04 00 00 00 4F 6D 67 21 ?···?···?···Omg! 00000020 03 00 00 00 03 00 00 00 04 00 00 00 05 00 00 00 ?···?···?···?··· So what are the first 2 bytes in zero? Then 08 00 00 00 is the length of the derived type. then 52 65 71 75 65 73 74 31 is the string. then i get another 00 which i don't know what it is. then FF is the version and the rest is just as expected. so it is also weird. but even weirdest if (for example) i make the arrrg function do oa << a; oa << a; instead of just oa << a; then i get: 00000000 00 00 08 00 00 00 52 65 71 75 65 73 74 31 00 FF ··?···Request1·· 00000010 01 00 00 00 02 00 00 00 04 00 00 00 4F 6D 67 21 ?···?···?···Omg! 00000020 03 00 00 00 03 00 00 00 04 00 00 00 05 00 00 00 ?···?···?···?··· 00000030 00 00 01 00 00 00 02 00 00 00 04 00 00 00 4F 6D ··?···?···?···Om 00000040 67 21 03 00 00 00 03 00 00 00 04 00 00 00 05 00 g!?···?···?···?· 00000050 00 00 ·· after the first 05 00 00 00, i would suspect it should come the same object again (as tracking is off!) but i get that 00 00 again first. and then just the data but with no "derived type signature". so how would the deserialization know what is the derived type for the data that follows? Im a little lost here. Id apreciate any help. Thanks a lot in advance. I'll be trying to hack this thing... :S

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