January 2009 - Boost-users - lists.preview.boost.org

[typeof] fails with Intel Compiler v11.0 on windows
by Mikko Vainio 10 Jan '09

10 Jan '09

Dear boosters, Could someone out there verify that the following piece of code fails with Intel Compiler v11.0.066 on Windows (Microsoft SDK v6.1): --------------------- #include <boost/typeof/typeof.hpp> #include <vector> using namespace std; int main(int argc, char* argv[]) { vector< int > testvec; BOOST_TYPEOF( testvec.begin() ) i = testvec.begin(); return 0; } --------------------- The compiler output is: --------------------- using typeof emulation C:\boost\include\boost-1_37\boost/typeof/encode_decode.hpp(50): error: incomplete type is not allowed struct encode_type : BOOST_TYPEOF_ENCODE_NS_QUALIFIER::encode_type_impl<V, T> ^ detected during instantiation of class "boost::type_of::encode_type<V, T> [with V=boost::type_of::vector0<void>, T=std::_Vector_iterator<int, std::allocator<int>>]" at line 9 of "typeoftest.cpp" ... --------------------- Preprocessor output shows that encode_type_impl is indeed just forward-declared before encode_type: --------------------- #line 30 "C:\\boost\\include\\boost-1_37\\boost/typeof/encode_decode.hpp" namespace { namespace boost_typeof { template<class V, class Type_Not_Registered_With_Typeof_System> struct encode_type_impl; <snip> }} namespace boost { namespace type_of { template<class V, class T> struct encode_type : boost_typeof::encode_type_impl<V, T> {}; template<class Iter> struct decode_type : boost_typeof::decode_type_impl< typename Iter::type, typename Iter::next > {}; }} --------------------- Is this a bug? Should a header containing the implementation of encode_type_impl be included prior to encode_decode.hpp? Any help appreciated. Cheers, Mikko

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Units: adding quantities
by Mark Volkmann 09 Jan '09

09 Jan '09

I have a method that takes a parameter of type quantity<feet> where feet is defined by the following typedef: typedef boost::units::us::foot_base_unit::unit_type feet; I also have this typedef: typedef bu::us::inch_base_unit::unit_type inches; Do I really need to define a typedef like this for every measurement type I want to use? I certainly don't want to specify all those namespaces every time I use one of the measurement types, but this approach seems a bit tedious. I'd like to do something like this: a.setWingspan(195*feet() + 8*inches()); but that doesn't work because there is no match for operator+. What's a good way to add inches to a feet quantity? --- Mark Volkmann

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getting started with Boost::Units
by Mark Volkmann 09 Jan '09

09 Jan '09

The first thing I'm trying to do is determine how to represent a velocity in miles per hour. I haven't been able to figure it out from the documentation. Any hints would be appreciated. I also need to figure out the best way to get string representations of quantities that include their units for output. --- Mark Volkmann

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forward declared class serialization
by niranjan bangera 09 Jan '09

09 Jan '09

hi all, I am in learning stage of the boost serialization concept. I have one small problem in my project again. Here i have to serialize a pointer of a forward declared class. i dont how to do this. Pls help me to do this. May be the solutuion is too tough, it seems to tough for me, coz i have less knowledge about the c++. I am using, Version:1.36.0 compiler: gnu-gcc-4.1.1-binutils-2.16.1/x86_64-pc-linux2.4/bin/g++ my code looks like. class fd; class base: class derived { ..... fd *ptr; ..... }; i have done it like serialization method is class fd; class base: class derived { ..... fd *ptr; ..... friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int file_version) { (void) file_version; ar & ps_core_; ar & boost::serialization::base_object<derived>(*this); } }; //end of class base Thanks in advance, Thanks for your time. Niranjan

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Boost and Intel Compiler 11
by Matthieu Brucher 09 Jan '09

09 Jan '09

Hi, I've read on the archive that some work needed to be done to support Intel Compiler 11 (Linux). Was progress made in that matter ? Matthieu -- Information System Engineer, Ph.D. Website: http://matthieu-brucher.developpez.com/ Blogs: http://matt.eifelle.com and http://blog.developpez.com/?blog=92 LinkedIn: http://www.linkedin.com/in/matthieubrucher

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[Thread] order of shared_lock and unique_lock acquisitions
by Roland Bock 09 Jan '09

09 Jan '09

Hi, I am trying to use shared_lock and unique_lock on a shared_mutex to allow read-functions to access a certain resource in parallel, but write functions use the resource exclusively. Is there a way to determine the order in which the (shared) locks are acquired? I tried testing with the attached program and got rather weird and (seemingly) non-deterministic results. In the test program (see attachment), I start 9 threads of readers(r) and writers(w). Before doing anything else, the sleep and wake up in groups. rrww rr w rr There is one second delay between the groups I would expect to see them working in this order: rr w w rr w rr The first group could be scrambled of course since they race for the lock. But at least I would expect the order of groups to be maintained. I get quite different results, though, and the results differ from run to run. The weirdest result I saw until now is attached. rr rrr (these do not start before the first group is finished) w w w (the last writer is handled in second position btw) r This I do not understand at all. The readers are using the shared mutex. Why is the second group waiting for the first to be finished? And how can the last writer be handled in second place? I am at a total loss here... System information: ------------------- boost-1.36 Ubuntu-8.04 gcc-4.2.4 Intel Quad Core processor Thanks in advance, Roland reader(0) at 0 sleeping 5 reader(1) at 0 sleeping 5 writer(2) at 0 sleeping 5 writer(3) at 0 sleeping 5 reader(4) at 0 sleeping 6 reader(5) at 0 sleeping 6 writer(6) at 0 sleeping 7 reader(7) at 0 sleeping 8 reader(8) at 0 sleeping 8 reader(0) at 5 trying to acquire lock reader(0) at 5 got lock reader(1) at 5 trying to acquire lock reader(1) at 5 got lock writer(2) at 5 trying to acquire lock writer(3) at 5 trying to acquire lock reader(4) at 6 trying to acquire lock reader(5) at 6 trying to acquire lock writer(6) at 7 trying to acquire lock reader(7) at 8 trying to acquire lock reader(8) at 8 trying to acquire lock reader(0) at 10 finished reader(1) at 10 finished reader(4) at 10 got lock reader(5) at 10 got lock reader(7) at 10 got lock reader(4) at 15 finished reader(5) at 15 finished reader(7) at 15 finished writer(3) at 15 got lock writer(3) at 20 finished writer(6) at 20 got lock writer(6) at 25 finished writer(2) at 25 got lock writer(2) at 30 finished reader(8) at 30 got lock reader(8) at 35 finished

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[BGL] max-flow/min-cut value of G for every pair of nodes s, t
by Rui Carvalho 09 Jan '09

09 Jan '09

Hi, Are there any optimized algorithms in the BGL to compute max-flow for every pair of nodes in a graph? Many thanks, R.

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What help can Boost offer?
by Robert Jones 09 Jan '09

09 Jan '09

I often want to express intent of this sort... struct X {...}; void f( X & ); X my_array[3][6][11]; for (unsigned i=0;i!=3;++i) for(unsigned j=0;j!=6;++j) for(unsigned k=0;k!=11;++k) f( my_array[i][j][k] ); Apart from all the grottiness on hardcoded sizes and loop indices, which is just for exposition, is there a nice idiom in boost to do traversals over multiple indices in this way, or perhaps multiple ranges? Thanks, Rob.

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boost-test with wxWidgets
by Matěj Týč 09 Jan '09

09 Jan '09

Hello all, is there anyone, who knows the Boost Unit Testing Framework (UTF)? I am developing a project that uses wxWidgets library and I would like to test some aspects where wxWidgets stuff is involved. The problem is that wxWidgets like to implement the main() function via IMPLEMENT_APP macro and I have found quite troublesome to work around that. When one lets UTF to generate the main() function, everything is very easy. The question is: There must be some sane way how to initialize UTF and launch a testsuite when wxWidgets are ready. I also know that I should supply the framework with argc and argv since the verbosity of the test module output can be tweaked. I have learned so far that I have to implement function init_unit_test_suite( int argc, char* argv[] (but I don't have an idea how), and that I have to register test cases (that should be OK) and to create some master test suite. Am I missing something here as well? I haven't found anything in the documentation that would lead me to the result, could you help me and possibly extend the documentation a little bit so wxWidgets users could start using UTF massively? :-) Regards, Matej

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Boost.Function in 1.37.0
by Amit Sonawane 09 Jan '09

09 Jan '09

Environment: WinXP SP2/Visual Studio Team System 2005/Boost 1.37.0 32-bit Using boost.function in Boost 1.37.0 generates several errors. Compiler extract : 28>c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_t emplate.hpp(80) : error C2143: syntax error : missing ';' before 'namespace' 28>c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_t emplate.hpp(980) : error C2838: '()' : illegal qualified name in member declaration 28> c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_temp late.hpp(80) : see reference to class template instantiation 'boost::function0<R>' being compiled 28>c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_t emplate.hpp(995) : error C2804: binary 'operator ==' has too many parameters 28>c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_t emplate.hpp(1002) : error C2804: binary 'operator !=' has too many parameters 28>c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_t emplate.hpp(1098) : error C2764: 'R' : template parameter not used or deducible in partial specialization 'boost::function<R(void)>' 28>c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_t emplate.hpp(1098) : error C3412: 'boost::function<R(void)>' : cannot specialize template in current scope 28>c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_t emplate.hpp(90) : error C2061: syntax error : identifier 'function_buffer' 28> c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_temp late.hpp(96) : see reference to class template instantiation 'boost::boost::detail::function::function_invoker1<FunctionPtr,R,T0>' being compiled 28>c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_t emplate.hpp(106) : error C2061: syntax error : identifier 'function_buffer' 28> c:\software\boost\boost_1_37_0\boost_1_37_0\boost\function\function_temp late.hpp(113) : see reference to class template instantiation 'boost::boost::detail::function::void_function_invoker1<FunctionPtr,R,T0 >' being compiled In Boost 1.36.0 the code complies ok. Is it boost function or my code. Esta mensagem pode conter informação confidencial e/ou privilegiada. Se você não for o destinatário ou a pessoa autorizada a receber esta mensagem, não deverá utilizar, copiar, alterar, divulgar a informação nela contida ou tomar qualquer ação baseada nessas informações. Se você recebeu esta mensagem por engano, por favor avise imediatamente o remetente, respondendo o e-mail e em seguida apague-o. Agradecemos sua cooperação. This message may contain confidential and/or privileged information. If you are not the addressee or authorized to receive this for the addressee, you must not use, copy, disclose, change, take any action based on this message or any information herein. If you have received this message in error, please advise the sender immediately by reply e-mail and delete this message. Thank you for your cooperation.

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