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tuples with more than 10 template parameters.
by Mauricio Gomes 12 Feb '09

12 Feb '09

Hi, Has anybody extended the 10 template parameters in boost::tuples ? I've written a class named FixedColumnsParser that parses files with fixed columns sizes but now I've got a file with more than 10 columns. In case nobody has done it before I am willing to do it myself and I just need to confirm if these are the only files I need to change to accomplish that: tuple_basic.hpp tuple_basic_no_partial_spec.hpp Thank you for your attention ! P.S.: Will the coming variadic templates in C++0x solve this in a more elegant way ? C++ Builder 2009 promisses C++0x support but I have downloaded the trial and it is not supporting variadic templates yet. -- Mauricio Gomes Pensar Digital 55-11-8319-9610 (Brazil - mobile)

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Unit test framework and environment initialization/finalization
by Vinokurov, Aleksandr 12 Feb '09

12 Feb '09

Hello all, My name is Aleksandr Vinokurov, I've just read the site docs on Boost.Tests and now I start writing tests. And realized that there were nothing told about initialization and finalization of the environment of the test suite. I mean some kind of solid calling my finalization function to properly stop the environment, like a try {} final {} in Java -- even if the test fails by BOOST_REQUIRE or BOOST_FAIL. Any suggestions or recommendations from gurus? Oh, just remembered: I use 1.33 version of Boost. With best wishes, Aleksandr Vinokurov Senior Software engineer CJSC "PETER-SERVICE" ========================== Work tel:+7(812)326-12-99 ext. 5039 Fax tel:+7(812)326-12-98 E-mail: mailto:aleksandr.vinokurov@billing.ru URL: http://www.billing.ru

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[xpressive] static expression adding
by Jan Boehme 12 Feb '09

12 Feb '09

Hi, is it possible to add an expression to an already existing expression object? Something like: sregex re = '$' >> +_d >> '.' >> _d >> _d; replace by: sregex re = '$'; re += +_d; re += '.' >> _d >> _d; My attempts did result in compile time troubles. Thanks for helping, Jan.

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boost::serialize stream error
by ppatel＠efs-us.com 12 Feb '09

12 Feb '09

Hi all, I am having following problem while reading the data out of the file using one of the sample program provided in boost serialization example online. I am trying to read the file having multiple gps_position objects but getting following exception. Can someone please let me know what might be the problem here. Let me know if you need any more information: #include <fstream> #include <string> // include headers that implement a archive in simple text format #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/list.hpp> #include <boost/serialization/vector.hpp> #include <boost/serialization/base_object.hpp> ///////////////////////////////////////////////////////////// // gps coordinate // // illustrates serialization for a simple type // class gps_position { private: friend class boost::serialization::access; // When the class Archive corresponds to an output archive, the // & operator is defined similar to <<. Likewise, when the class Archive // is a type of input archive the & operator is defined similar to >>. template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & degrees; ar & minutes; ar & seconds; ar & day; } public: int degrees; int minutes; float seconds; std::string day; gps_position(){}; gps_position(int d, int m, float s, std::string inDay) : degrees(d), minutes(m), seconds(s), day(inDay) {} }; int main() { // create and open a character archive for output std::ofstream ofs("filename"); // create class instance const gps_position g(35, 59, 24.567f, "Monday_Pointer"); const gps_position g1(45, 69, 34.567f, "Tuesday_Pointer"); const gps_position * g2 = new gps_position(1,2,3.3, "WEDNESDAY_PTR"); { boost::archive::text_oarchive oa(ofs); oa << g; oa << g1; oa << (*g2); } { /**gps_position g; std::vector<gps_position> vec; std::ifstream ifs("filename"); boost::archive::text_iarchive ia(ifs); while (!ifs.eof()) { std::cout << " ++++++++++++++++ " << std::endl; ia >> g; std::cout << g.degrees << " : " << g.minutes << " : " << g.seconds << " : " << g.day <<std::endl; std::cout << " **************** " << std::endl; }*/ } { // Using boost vector std::vector<gps_position> gps; std::ifstream ifs("filename"); boost::archive::text_iarchive ia(ifs); ia >> gps; for (int i = 0; i < gps.size(); ++i) { std::cout << gps[i].degrees << " : " << gps[i].minutes << " : " << gps[i].seconds << " : " << gps[i].day <<std::endl; } } return 0; } // File data that is being read $ cat filename 22 serialization::archive 4 0 0 35 59 24.566999 14 Monday_Pointer 45 69 34.567001 15 Tuesday_Pointer 1 2 3.3 13 WEDNESDAY_PTR // Output of program with while loop, don't know why eof is not being detected after reading three gps position objects ++++++++++++++++ 35 : 59 : 24.567 : Monday_Pointer **************** ++++++++++++++++ 45 : 69 : 34.567 : Tuesday_Pointer **************** ++++++++++++++++ 1 : 2 : 3.3 : WEDNESDAY_PTR **************** ++++++++++++++++ terminate called after throwing an instance of 'boost::archive::archive_exception' what(): stream error Aborted (core dumped) //Output of program with using vector terminate called after throwing an instance of 'boost::archive::archive_exception' what(): stream error Aborted (core dumped) Thanks Priyank

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[test] BOOST_CHECK_EQUAL and wchar_t
by Alexander 12 Feb '09

12 Feb '09

The following code: BOOST_CHECK_EQUAL("boo", "boo"); BOOST_CHECK_EQUAL("boo", "bar"); BOOST_CHECK_EQUAL(L"boo", L"boo"); BOOST_CHECK_EQUAL(L"boo", L"bar"); Gives the following results test.cpp(368): error in "Strings": check "boo" == "bar" failed [boo != bar] test.cpp(370): error in "Strings": check L"boo" == L"bar" failed [00B6FAA4 != 00B6FA90] Can this be fixed ?

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[asio] Poll without read
by Oleg Malashenko 12 Feb '09

12 Feb '09

Hi everyone, I am trying to get video stream from Video4Linux2 device (/dev/video*) and faced with a interesting boost::asio usecase. V4L2 device implements poll calls, so one can poll() on specific device file to wait for next portion of data, but read itself is made via ioctl. I suppose, boost::asio is a natural choice in this situation and I am wondering if there is a method to run my callback when "the data is ready to read", but without calling read()? (on the same manner as ACE::Reactor does)? Thank you.

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[serialization] problem using BOOST_CLASS_EXPORT macro in a static library
by Renaud Lepere 12 Feb '09

12 Feb '09

I have some problems with BOOST_CLASS_EXPORT macro, it seems that this macro have no effect if i put it in a separate .cpp file of a static library. I have a simple class Element that contains a pointer to a curve that can be of different types (geom2d.hpp). struct Curve { Curve() {}; virtual ~Curve() {}; }; struct Line : public Curve { Line(int y = 0): m_y(y) {}; int m_y; }; typedef boost::shared_ptr< Curve > CurvePtr; struct Element { Element(const CurvePtr & curve): m_curve(curve) {} boost::shared_ptr< Curve > m_curve; }; I would like to be able to serialize Element, so i wrote a serialize.hpp file (attached) containing code for serializing those structures. I also wrote export.cpp using #include "geom2d.hpp" #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include "serialize.hpp" #include <boost/serialization/export.hpp> #include <iostream> BOOST_CLASS_EXPORT(Curve); BOOST_CLASS_EXPORT(Line); I put the export.cpp file in a library named geom2d, but when trying to serialize my structures using something (attached main.cpp). CurvePtr c(new Line(10)); const Element e(c); std::ofstream ofs("filename"); { boost::archive::text_oarchive oa(ofs); oa << e; } I received an exception "unregistered class". If i dont put export.cpp in a library but in the same compilation unit as main.cpp, the error disappear (visual studio 8.0 and 9.0). What is the good way of doing this, should i wrote an export.hpp file containing the macros and include this file in a .cpp of the main compilation unit ? Thanks, Renaud

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Re: [Boost-users] how to make a vector to derivedClass::create() methods
by Victor Whiskey Yankee 12 Feb '09

12 Feb '09

Victor.Whiskey.Yankee wrote: > > > > Thank you for your patience. > > I am really wanting to make a factory that holds a > > std::map where the pair.first is a std::string and > > the pair.second is somehow a pointer to a constructor or create() > > method to any of several derived classes>. > > > > I thought expressing in terms of vector might be simplified and enough > > for my understanding. > > > > I see. How about using Boost.Function like this: > > std::map<std::string, boost::function<Base*()> > factory_impl; > > //... > > factory_impl["Derived1"] = boost::lambda::new_ptr<Derived1>(); > > // ... > > Base* b = factory_impl["Derived1"]() Thank you Steve for your solution, it is working fine. I have a nice thread-safe singleton factory now, and it is generic using templates. I am now trying to make my derived classes register with the factory automatically, but cannot figure it out. I basically have this: template<typename BaseType, typename keyType> class GenericFactory { public: GenericFactory(); boost::shared_ptr<BaseType> create(const keyType& typeName); template<typeName DerivedType> void registrate(const keyType& _key); }; As said, I can register my derived classes with the above just fnie. I have tried writing a help class like I've seened "RegisterInFactory", but it escapes me. Thanks, Vic

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Gomory Hu algorithm (another time)
by Gianni Loiacono 11 Feb '09

11 Feb '09

Hi all, sorry for my english. I'm desperate :(.... From about 15 days I'm trying to make the Gomory-Hu algorithm: http://www.corelab.ntua.gr/~syrganis/sources/Gomory-Hu.pdf I'm using succesfully the Boost library to manage and build the graph but unfortunately the Gomory-Hu algorithm was not implemented :( Into the boost library there is only the mincut function and I have trying to use it (edmunds_karp_max_flow) for to make the Go-Hu function but the result was disastrous (the code is very long and I have lost the "control" of the program so at the and the program works only with some examples :(.....It's unusable) On the net there isn't any source code :( I have found only a pseudo-code here: http://www.prefield.com/algorithm/graph/gomory_hu.html But honestly I don't know how to convert it in c++ for to use with boost library. Please, somebody can help me? I'm very very desperate :( . Thanks a lot all for the help. Bye :) Passa a Yahoo! Mail. La webmail che ti offre GRATIS spazio illimitato, antispam e messenger integrato. http://it.mail.yahoo.com/

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boost::thread performance questions
by Alfonso Urdaneta 11 Feb '09

11 Feb '09

I'm looking for information about boost::thread switch time and mutex lock/release times (trying to track down a performance issue). If someone could point me in the right direction it would be greatly appreciated. -- alfonso e. urdaneta _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ This e-mail and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this e-mail in error please notify the originator of the message. This footer also confirms that this e-mail message has been scanned for the presence of computer viruses. Any views expressed in this message are those of the individual sender, except where the sender specifies and with authority, states them to be the views of Indra Systems, Inc.

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