December 2007 - Boost-users - lists.preview.boost.org

problem with boost/ublas/storage
by nksallem＠laas.fr 26 Dec '07

26 Dec '07

Hi, First Merry Christmas Second, I'm facing the same issue that the one described here : http://lists.boost.org/MailArchives/ublas/2007/08/2247.php As I didn't found a reply, I'm posting new one. I'm runnig version 10.34.01 and using ublas for a linear least square resolution problem. the error was : -------------------------------------------------------------------- ...ublas/storage.hpp at line 196: i < size ** std:exception ** bad index ------------------------------------------------------------ It seems to be a resize() problem on matrixes, any suggestions? Thanks

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Re: [Boost-users] [review] Fast track formal review of Forward library begins today
by Kirit Sælensminde 26 Dec '07

26 Dec '07

Joel de Guzman wrote: > David Abrahams wrote: >> on Fri Dec 07 2007, shunsuke <pstade.mb-AT-gmail.com> wrote: >>> FWIW, starting from Abrahams' callable and functionN, I've been implementing a similar library: >>> http://tinyurl.com/vd4r5 , which regards Boost.Functional/Forward facility >>> as one of higher-order functions, `perfect`. >> Hmm. Did anyone reply to this? I think if someone points to an >> alternative library with that level of maturity during a review, it >> shouldn't be ignored. We should at least have a discussion of the >> relative merits of the two approaches before taking a vote. > > I think the Egg library is awesome. Is it in the review queue yet? > If not, it should be. My opinion here is that it can co-exist with > the Forward library just as boost.bind can coexist with boost.lambda. > It's not always a matter of which is more sophisticated. Certainly, > bind is a subset of lambda. Yet, even with the simplicity of bind, > it is sufficiently useful in many applications. I'd say the same for > Egg and Boost.Functional. > > Let's have more FP in C++! :-) I've got to agree. The egg library looks like an incredible bit of work. I'd love to see this in Boost too. I for one though do find it confusing when there is overlap between libraries because normally the documentation of the libraries don't discus each other's strengths and weaknesses and why you might want to choose one over the other. That isn't to say that there shouldn't be overlap between libraries, but it would be nice if the documentation of the libraries cross tied a bit more. K -- http://www.kirit.com/

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Re: [Boost-users] [review] Fast track formal review of Forward library begins today
by David Abrahams 26 Dec '07

26 Dec '07

on Fri Dec 07 2007, shunsuke <pstade.mb-AT-gmail.com> wrote: > John Torjo wrote: >> Hi all, >> >> The formal review of the Boost.Functional/Forward library, proposed by >> Tobias Schwinger, begins today : >> >> Boost.Functional/Forward provides decorator function objects to have an >> n-ary, >> generic function object accept both RValues and mutable LValues. > > Sorry, this is not a review. Ignore this if irrelevant. > > Was boost::detail::functionN family in Boost.Accumulators considered? > That seems more advanced than Boost.Functional/Forward. > > FWIW, starting from Abrahams' callable and functionN, I've been implementing a similar library: > http://tinyurl.com/vd4r5 , which regards Boost.Functional/Forward facility > as one of higher-order functions, `perfect`. Hmm. Did anyone reply to this? I think if someone points to an alternative library with that level of maturity during a review, it shouldn't be ignored. We should at least have a discussion of the relative merits of the two approaches before taking a vote. -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

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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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