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[multi_index] passing 'const TYPE' as 'this' argument discards qualifiers
by damny＠web.de 26 Dec '07

26 Dec '07

merry xmas everyone, and maybe santa claus or anyone of you have a helping surprise for me :o) after became acquainted with boost and boost.python i have to learn boost.multi_index now. the goal is to build a 'map' with two individual keys (a name and an identifier) per value (object of user class); nme1-idf1-valu1, nme2-idf2-valu2, nme3-idf3-valu3, ... any value should be 'directly' accessible by name or by identifier; valu1:=map[nme1], valu1:=map[idf1]. although i don't understand the documentation perfectly and i'm not familiar with templates i recognise that boost.multi_index is the perfect way :o) and i did the following: //--- cclass.hpp ----------- #ifndef _CCLASS_HPP_ #define _CCLASS_HPP_ class cClass { private: int att1; public: std::string nme; // name int idf; // identifier cClass(); cClass(std::string nme, int idf); int get_attribute(); }; typedef boost::multi_index_container < cClass, boost::multi_index::indexed_by < boost::multi_index::hashed_unique < BOOST_MULTI_INDEX_MEMBER(cMessage,std::string,nme) >, boost::multi_index::ordered_unique < BOOST_MULTI_INDEX_MEMBER(cMessage,int, idf) > > > mMap; typedef mMap::nth_index<0>::type mMapByNme; typedef mMap::nth_index<1>::type mMapByIdf; #endif //--- cclass.cpp ----------- #include <boost/multi_index_container.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/hashed_index.hpp> #include "cclass.hpp" cClass::cClass() { this->att1=0xFF; } cClass::cClass(std::string nme, int idf) : nme(nme), idf(idf) { this->att1=idf+1; } int cClass::get_attribute() {return this->att1; } //--- main.cpp ------------- #include <boost/multi_index_container.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/hashed_index.hpp> #include "cclass.hpp" int main() { mapMsg locMsg; locMsg.insert( cClass("name1", 123) ); locMsg.insert( cClass("name2", 456) ); mMapByNme::iterator itrNme = locMsg.get<0>().find("name1"); mMapByIdf::iterator itrIdf = locMsg.get<1>().find(456); printf( "att1 = %d\n", itrNme->get_attribute() ); // <<<<< printf statement } //-------------------------- compiling (mingw/gcc3.4.5) this code without the printf statement works. but if i compile the whole code i get this error message: main.cpp: In function `int main()': main.cpp:33: error: passing 'const cClass' as 'this' argument of 'int cClass::get_attribute()' discards qualifiers Process terminated with status 1 (0 minutes, 20 seconds) any hints how to solve the problem? how to encapsulate this special multi_index into a class, that fits the above description of the needed 'map'. are there possibilities to avoid the 'std::string' for the 'name' key? where are the more easier examples for C++-templates/boost newbies like me :o) ? many, many thnx, daniel _______________________________________________________________________ Jetzt neu! Schützen Sie Ihren PC mit McAfee und WEB.DE. 30 Tage kostenlos testen. http://www.pc-sicherheit.web.de/startseite/?mc=022220

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[serialization] get rid from rtti
by Yan Drugalya 26 Dec '07

26 Dec '07

Folks, I have class some class Circle which is derived from Shape class. I want to get rid from RTTI. In order that I did following: BOOST_CLASS_TYPE_INFO( Circle, extended_type_info_no_rtti<Circle> ) BOOST_CLASS_EXPORT(Circle) const char * Circle::get_key() const { const boost::serialization::extended_type_info *eti = boost::serialization::type_info_implementation<Circle> ::type::get_instance(); return eti->get_key(); } But even after that, if I try to compile project a lot of waring appear: warning C4541: 'dynamic_cast' used on polymorphic type 'boost::archive::detail::basic_oarchive' with /GR-; unpredictable behavior may result it also fails with exception during runtime. What also need to be done to completely get rid form RTTI

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MPL: flatten implementation not working
by Andreas Klöckner 25 Dec '07

25 Dec '07

Hi all, I came up with the following implementation of a "flatten" operation that turns a sequence of sequences into a flat list: 8< ------------------------------------------------------------------- #include <iostream> #include <boost/mpl/vector.hpp> #include <boost/mpl/vector_c.hpp> #include <boost/mpl/clear.hpp> #include <boost/mpl/fold.hpp> #include <boost/mpl/copy.hpp> #include <boost/mpl/placeholders.hpp> #include <boost/mpl/back_inserter.hpp> #include <boost/mpl/size.hpp> template<class Sequence> struct flatten { typedef typename boost::mpl::fold< Sequence, typename boost::mpl::clear<Sequence>::type, typename boost::mpl::copy< boost::mpl::_2, boost::mpl::back_inserter<boost::mpl::_1> >::type >::type type; }; typedef flatten< boost::mpl::vector< boost::mpl::vector_c<int, 0, 1, 2, 3>, boost::mpl::vector_c<int, 4, 5, 6> > >::type flatvec; int main() { std::cout << boost::mpl::size<flatvec>::value << std::endl; } 8< ------------------------------------------------------------------- It compiles (using gcc 4.2.1), but prints 0 instead of the expected 7. What am I doing wrong? Thanks for your help Andreas

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[boost-users] [iterator_range construct new iterator_range of arbitary size_type]
by chun ping wang 25 Dec '07

25 Dec '07

Hi I have two questions. How would I go about using iterator_range to construct a new boost iterator_range of specific size_type ? 1.) Like std::vector<int> v(40); // constructs 40 int objects but instead your giving only std::vector<int>::iterator beg(v.begin()), end(v.end()); // the range 2.) How would with combination of iterator_range modify an existing sequence. Like BOOST_FOREACH(int& x, v) but using boost iterator_range concept instead. Thanks.

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[serialization] understanding of track_always serialization trait
by Yan Drugalya 24 Dec '07

24 Dec '07

Folks , I feel a lack of understanding what actually track_always trait does. I expect that boost does not allow me to save/load twice object with the same address? But it reports BOOST_STATIC_ASSERT even in following case: Question 1 Class A { // serialization support }; BOOST_CLASS_TRACKING (A, track_always) BOOST_CLASS_EXPORT( A) … A* a = new A; oa << a ; assert in oserializer.hpp // if your program traps here, it indicates taht your doing one of the following: // a) serializing an object of a type marked "track_never" through a pointer. // b) saving an non-const object of a type not markd "track_never) // Either of these conditions may be an indicator of an error usage of the // serialization library and should be double checked. See documentation on // object tracking. Qurstion 2 Above code with using of xml_oarchive compliles and works: oa << BOOST_SERIALIZATION_NVP(a); oa << BOOST_SERIALIZATION_NVP(a); I expect that it should raise above BOOST_STATIC_ASSERT because I trying to store the same object twice? Question 3 Also I can't understand how track_always serialization trait works in case of Diamond inheritance Quataion from documentation "In a diamond hesitance structure with a virtual base class, object tracking will prevent redundant save/load invocations" How boost knows that this is virtual base class and prevents redundant save/load invocations? Please help me to find the way to understanding of object tracking trait :) Thank you

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Help needed on time date
by tonyaim83 24 Dec '07

24 Dec '07

Hi I'm using Date time library for the first time so no idea how best make use of it. My primary target is to check if the first timestamp and second timestamp entered by the user are in a span of one hour. Format of input string is as follows YYYYDDMM-HH:MM:SS(20071015-17:47:10) Now if the second string is also in the an hour span it should return true otherwise false. I m thinking of doing this like std::string to_iso_string(date d1) ptime p1(d1, time_duration("17:21:23")); std::string to_iso_string(date d2) ptime p2(d2, time_duration("17:22:23")); ptime p3=p2-p1; if (p3>1) { return false; } I could also find a function which has a separator T std::string to_iso_extended_string(ptime); How can i make use of this function as in my case the separtor of date- time is "-" Or a better way to perform the same task. -- View this message in context: http://www.nabble.com/Help-needed-on-time-date-tp14486644p14486644.html Sent from the Boost - Users mailing list archive at Nabble.com.

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[interprocess][intrusive][mpi] Latest SVN head documentation
by Edward Diener 24 Dec '07

24 Dec '07

In the latest SVN head, the documentation for interprocess and intrusive offo of the main Boost documentation page eventually points to an HTTP metacomm address where no documentation exists rather than to the documentation in the corresponding boost/libs/interprocess/doc/html and boost/libs/intrusive/doc/html where documentation does exist after bjam is used to build it. For MPI in the latest SVN head, the documentation off of the main Boost documentation page points to boost/doc/html/mpi.html but no file exists here even after building the MPI docs with bjam. Instead it should eventually point to boost/libs/mpi/doc/html where docs do exist for MPI after one builds them.

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BGL: Finding all simple cycles in an undirected graph
by Torsten Sadowski 23 Dec '07

23 Dec '07

Hello, I am looking for a way to find all simple cycles in an undirected graph. I need it to reconstruct a 3D mesh from a graph containing the mesh vertices and edges. Any hints? Cheers, Torsten

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Cygwin compilation problem
by Kent Holsinger 23 Dec '07

23 Dec '07

I've used various earlier versions of Boost with Cygwin in the past, and I am finally getting around to trying version 1.34.1. Unfortunately, I can't get it to build. Here's the string of error messages I get when I try: ***** Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more information (don't panic: this is a strictly optional feature). /c/development/boost_1_34_1/tools/build/v2/tools/stage.jam:424: in object(installed-shared-lib-generator)(a)4.run *** argument error * rule virtual-target.register ( target ) * called with: ( object(file-target)@1391 object(file-target)@1392 ) * extra argument object(file-target)@1392 /c/development/boost_1_34_1/tools/build/v2/build/virtual-target.jam:880:see definition of rule 'register' being called /c/development/boost_1_34_1/tools/build/v2/build/generators.jam:840: in try-one-generator-really /c/development/boost_1_34_1/tools/build/v2/build/generators.jam:902: in try-one-generator /c/development/boost_1_34_1/tools/build/v2/build/generators.jam:1110: in construct-really /c/development/boost_1_34_1/tools/build/v2/build/generators.jam:1186: in generators.construct /c/development/boost_1_34_1/tools/build/v2/tools/stage.jam:160: in construct /c/development/boost_1_34_1/tools/build/v2/build/targets.jam:1242: in object(install-target-class)(a)65.generate /c/development/boost_1_34_1/tools/build/v2/build/targets.jam:765: in generate-really /c/development/boost_1_34_1/tools/build/v2/build/targets.jam:738: in object(main-target)(a)249.generate /c/development/boost_1_34_1/tools/build/v2/build/targets.jam:895: in targets.generate-from-reference /c/development/boost_1_34_1/tools/build/v2/build/targets.jam:1169: in generate-dependencies /c/development/boost_1_34_1/tools/build/v2/build/targets.jam:1214: in object(alias-target-class)(a)71.generate /c/development/boost_1_34_1/tools/build/v2/build/targets.jam:765: in generate-really /c/development/boost_1_34_1/tools/build/v2/build/targets.jam:738: in object(main-target)(a)253.generate /c/development/boost_1_34_1/tools/build/v2/build-system.jam:402: in load /c/development/boost_1_34_1/tools/build/v2/kernel/modules.jam:261: in import /c/development/boost_1_34_1/tools/build/v2/kernel/bootstrap.jam:132: in boost-build /c/development/boost_1_34_1/boost-build.jam:9: in module scope ***** If it makes any difference bjam --version reports: Boost.Build V2 (Milestone 11) Boost.Jam 03.1.16 and gcc --version reports gcc (GCC) 3.4.4 (cygming special, gdc 0.12, using dmd 0.125) Do I need to figure out how to compile gcc 4.x under Cygwin, or is there a simpler way to get things to work? Kent -- Kent E. Holsinger kent(a)darwin.eeb.uconn.edu http://darwin.eeb.uconn.edu -- Department of Ecology & Evolutionary Biology -- University of Connecticut, U-3043 -- Storrs, CT 06269-3043

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VS2005 threads with clr option not working
by Jason McGuidwin 23 Dec '07

23 Dec '07

hello, I am trying to compile a simple proragm with the thread headers included and the clr option in VS2005 When i include the thread headers and set the to compile with the /clr option the app will not execute and give the error below: "The application failed to initialize properly (0xc000007b). Click on OK to terminate the application." this sample program works fine without the clr option, however I am writing a managed c++ app that needs this option on. also I have used the lib installer from http://www.boost-consulting.com/products/free the 1.34.1 installer for vs8.0, I have selected all options and still does not work. I have tried defining BOOST_THREAD_USE_DLL and BOOST_THREAD_USE_LIB, still fails. BOOST_THREAD_USE_LIB error message is the same as if I did not have this define. BOOST_THREAD_USE_DLL error message: "This application has failed to start because boost_threads-vc80-mt-gd-1_34_1.dll was not found. Re-Installing the application may fix this problem." my project prefs have the following settings: c/c++ - additional include directories= "C:\Program Files\Boost\boost_1_34_1\" linker - additional include directories= "C:\Program Files\Boost\boost_1_34_1\lib" [code] #include "stdafx.h" #include <iostream> #include <boost/timer.hpp> //#define BOOST_THREAD_USE_DLL //#define BOOST_THREAD_USE_LIB #include <boost/thread/thread.hpp> #include <boost/thread/xtime.hpp> int main(int argc, char* argv[]) { boost::xtime expiration; boost::timer the_timer; //starts the timer std::cout<<"Welcome to the sample program!"<<std::endl; for(int i = 0;i <1000000; i++) { if(i%100000 == 0) { std::cout<<"."; boost::xtime_get(&expiration, boost::TIME_UTC); expiration.nsec +=int(5 * 1e08);// half second; boost::thread::sleep(expiration); } } std::cout<<std::endl<<"This program has been running for: "<< the_timer.elapsed() <<" second(s)." << std::endl; std::cout<< std::endl<<"Press any key then enter to exit. "<< std::endl; char buff[100]; std::cin>>buff; } [/code] Jason McGuidwin Gnostech Inc. San Diego, Ca

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