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Re: [Boost-users] tuples with more than 10 template parameters.
by Mauricio Gomes 12 Feb '09

12 Feb '09

Hi Joel, Thank you for your response. Joel Facou wrote: >Aren't Fusion::tuples extendable by using some macros already ? I don't know, could you please point me to an example ? How can I do that ? I searched for a solution and I could not find any so I started to change the header files myself. I am stuck on a compiler error right now but I want to give it another try before posting a question. Anyway, a macro to extend it would be much better. If some one could point me in the right direction it would be great. Thanks again, Mauricio. >> 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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Inline functions in boost/utility
by Timenkov Yuri 12 Feb '09

12 Feb '09

Hi Looking through assembly code of simple test produced by gcc with optimization, I've noticed that free functions in utility/value_init.hpp (get and set) are not declared as inline, though its body consist only of prologue and epilogue. Is there any reason for this or just a bug?

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Inverval timer.
by Alexei Sergeev 12 Feb '09

12 Feb '09

Hello, I want some function / functor to run every n seconds, is there right timer in boost for that? I tried to loop deadline_timer but wasn't able to get it work more than one time. Here is part of code I tryied: //bool _isOnline; // status of internet connection. //boost::asio::io_service _ioService; // need for boost timers. //boost::asio::deadline_timer _internetConnectionTimer; void Logic::InitializeInternetConnectionChecking( long secondsInterval ) { _internetConnectionTimer.expires_from_now( boost::posix_time::seconds( secondsInterval ) ); _internetConnectionTimer.async_wait( boost::bind( &Logic::CheckInternetConnection, this ) ); _ioService.poll(); } void Logic::InitializeInternetConnectionChecking() { InitializeInternetConnectionChecking( 5 ); } void Logic::CheckInternetConnection() { if ( _isOnline = IsLanOrRasInetConnect() ) onOnline(); else onOffline(); _ioService.reset(); InitializeInternetConnectionChecking(); }

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Re: [Boost-users] [multi_index] Problem of scope with the replace in static data structure
by Rodrigo Dias Ferreira 12 Feb '09

12 Feb '09

Hi Joaquim, I saw what you meant, and I have changed... But still if I use the same graph_h, still I got the same problem: Here it is my solution for the Graph constructor: Graph(const Graph &g) : _rangeBegin(g._rangeBegin), _rangeEnd(g._rangeEnd), _nodeRep(g._nodeRep), _nodeNameRep(g._nodeNameRep), _localPropRep(g._localPropRep), _globalPropRep(g._globalPropRep){ //_nodeRep::_uniqueName* Initialization pair<nodeMapIt,nodeMapIt> rangeNodeIt; nodeMapIt tmpNodeIt; rangeNodeIt.first = g._nodeRep.begin(); rangeNodeIt.second = g._nodeRep.end(); while (rangeNodeIt.first != rangeNodeIt.second){ _nodeRep.insert(nodeMap( &*(_nodeNameRep.find(rangeNodeIt.first->_uniqueName->_name)), rangeNodeIt.first->_timestamp, rangeNodeIt.first->_node)); ++rangeNodeIt.first; } } I've debugged, but I didn't see anything suspicious anymore... Did you see something else? thanks, Rodrigo -------- Original-Nachricht -------- > Datum: Wed, 11 Feb 2009 18:26:33 +0100 > Von: joaquin(a)tid.es > An: Rodrigo Dias Ferreira <rodrigodias(a)gmx.de> > Betreff: Re: [multi_index] Problem of scope with the replace in static data structure > Rodrigo Dias Ferreira escribió: > > Hi Joaquim, > > > > > > > >> Can you please test the following? In your //Test of the > >> commit section, rather than reuse graph_h please use a different > >> variable to do the after-commitChanges check: > >> > >> [...] > >> > >> Does this make any difference? > >> > > Yes, it worked, if I instantiate another object (like graph_h2). > > After that I have done some more Debug to try to find the reason, > > but I still don't understand, because inside the constructor it > > finds the Nodes, when I use the same object (graph_h)... > > Inside the overloaded operator-> does not work anymore, even I > > am using the _localGraph in both stretch of codes. > > So if it was the assignment of the _localGraph, it should not > > work with the constructor also, isn't true? > > > > What happens when you do *not* use graph_h2 is that, upon reassigning > graph_h in > > graph_h = Graph_h(it); > > the previous value of graph_h is destroyed, and presumably this leaves > some dangling pointer/iterator when it shouldn't. > > I've examined your code in search for candidates to potential dangling > pointers/iterators and found something a little suspicious: Graph contains > the following two member variables: > > uniqueNameTable _nodeNameRep; > nodeIndex _nodeRep; > > where uniqueNameTable is a container of uniqueNodeNameStruct's and > nodeIndex is a container of nodeMaps pointing to > uniqueNodeNameStruct's in _nodeRep, right? If so, default copy semantics > of Graph is flawed; consider: > > Graph g2; > { > Graph g1; // g1._nodeRep elements point into g1._nodeNameRep > g2=g1; // g2._nodeRep elements point into g1._nodeNameRep > } // g1 is destroyed > // g2._nodeRep elements point to destroyed objects > > See what I mean? Pointers inside _nodeRep are not reassigned on > copy. Does the copy constructor of Graph take this issue into > account? > > If this leads nowhere, you can always try setting up Boost.MultiIndex > safe mode: > > http://boost.org/libs/multi_index/doc/tutorial/debug.html#safe_mode > > and see if some safe mode assertion is triggered. > > Joaquín M López Muñoz > Telefónica, Investigación y Desarrollo -- ************************************************* Rodrigo Dias Ferreira Master Student of Computational Engineering Technische Universität Dresden - Germany E-mail: rodrigodias(a)gmx.de ************************************************* Jetzt 1 Monat kostenlos! GMX FreeDSL - Telefonanschluss + DSL für nur 17,95 Euro/mtl.!* http://dsl.gmx.de/?ac=OM.AD.PD003K11308T4569a

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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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