February 2010 - Boost-users

More problems...
by Daniel Veneros 02 Feb '10

02 Feb '10

Sorry to bother with this questions... What I am trying to do is: Share MAP objects between several process, the map I need to share is something like this: map<string, Employee> myMap; String is the key and the value has to be a custom class or a struct... I tried this but I got lots of errors: struct Employee { std::string name; int age; }; managed_shared_memory segment(create_only, "MySharedMemory", 65536); typedef std::pair<boost::interprocess::basic_string, Employee> ValueType; typedef allocator<ValueType, managed_shared_memory::segment_manager> ShMemAllocator; typedef map<StrAllocator, EmpAllocator, NULL, ShMemAllocator> MyMap; ShMemAllocator alloc_inst (segment.get_segment_manager()); MyMap m*mymap = segment.construct<MyMap>("MyMap")(alloc_inst); //to insert just one value: Employee John; john.name = "Johnny"; john.age = 25; mymap->insert(std::pair<"Hello", john>(boost::interprocess::basic_string, Employee); Actually I don't know what other path should I take on this... Could anyone please help me fix this portion of code? Thank you very much. Dann

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xlC 6.0 building math lib - Errors
by Radha 02 Feb '10

02 Feb '10

Hi Team, I am trying to compile boost math library using xlC version 6 on Aix 5.3. I get the following error: "./boost/fusion/sequence/intrinsic/begin.hpp", line 54.88: 1540-0408 (S) The base class "apply<const boost::fusion::tuple<double,double,double,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_> >" is declared but not defined. "./boost/fusion/container/vector/detail/vector_n.hpp", line 65.41: 1540-0700 (I) The previous message was produced while processing "struct boost::fusion::result_of::begin<const boost::fusion::tuple<double,double,double,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_> >". "./boost/fusion/sequence/intrinsic/at.hpp", line 58.26: 1540-0408 (S) The base class "apply<const boost::fusion::tuple<double,double,double,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>,mpl_::int_<0> >" is declared but not defined. "./boost/fusion/sequence/intrinsic/at.hpp", line 63.15: 1540-0700 (I) The previous message was produced while processing "struct boost::fusion::result_of::at<const boost::fusion::tuple<double,double,double,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>,mpl_::int_<0> >". "./boost/fusion/sequence/intrinsic/at.hpp", line 62.16: 1540-0700 (I) The previous message was produced while processing "struct boost::fusion::result_of::at_c<const boost::fusion::tuple<double,double,double,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>,0>". "./boost/math/tools/roots.hpp", line 41.13: 1540-0700 (I) The previous message was produced while processing "boost::math::tools::detail::unpack_0<boost::fusion::tuple<double,double,double,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>,double>(const tuple<double,double,double,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_> &, double &)". "./boost/math/tools/roots.hpp", line 45.6: 1540-0700 (I) The previous message was produced while processing "boost::math::tools::detail::handle_zero_derivative<boost::math::detail::cbrt_functor<double>,double>(cbrt_functor<double>, double &, const double &, double &, double &, double &, const double &, const double &)". "./boost/math/tools/roots.hpp", line 274.3: 1540-0700 (I) The previous message was produced while processing "boost::math::tools::halley_iterate<boost::math::detail::cbrt_functor<double>,double>(cbrt_functor<double>, double, double, double, int, uintmax_t &)". "./boost/math/tools/roots.hpp", line 418.10: 1540-0700 (I) The previous message was produced while processing "boost::math::tools::halley_iterate<boost::math::detail::cbrt_functor<double>,double>(cbrt_functor<double>, double, double, double, int)". "./boost/math/special_functions/cbrt.hpp", line 52.18: 1540-0700 (I) The previous message was produced while processing "boost::math::detail::cbrt_imp<double,boost::math::policies::policy<boost::math::policies::domain_error<1>,boost::math::policies::pole_error<1>,boost::math::policies::overflow_error<1>,boost::math::policies::evaluation_error<1>,boost::math::policies::rounding_error<1>,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::polici...". "./boost/math/special_functions/cbrt.hpp", line 61.11: 1540-0700 (I) The previous message was produced while processing "boost::math::cbrt<double,boost::math::policies::policy<boost::math::policies::domain_error<1>,boost::math::policies::pole_error<1>,boost::math::policies::overflow_error<1>,boost::math::policies::evaluation_error<1>,boost::math::policies::rounding_error<1>,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_...". "libs/math/build/../src/tr1/c_policy.hpp", line 129.1: 1540-0700 (I) The previous message was produced while processing "c_policies::cbrt<double>(double)". "libs/math/build/../src/tr1/cbrt.cpp", line 16.11: 1540-0700 (I) The previous message was produced while processing "cbrt(double)". "./boost/math/tools/roots.hpp", line 42.9: 1540-0218 (S) The call does not match any parameter list for "std::tr1::get<0>". "./boost/fusion/tuple/tuple.hpp", line 82.5: 1540-1283 (I) "template <int N, class Tuple> boost::fusion::get(const Tuple &)" is not a viable candidate. "./boost/fusion/tuple/tuple.hpp", line 75.5: 1540-1283 (I) "template <int N, class Tuple> boost::fusion::get(Tuple &)" is not a viable candidate. "./boost/math/tools/roots.hpp", line 41.13: 1540-0700 (I) The previous message was produced while processing "boost::math::tools::detail::unpack_0<boost::fusion::tuple<double,double,double,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>,double>(const tuple<double,double,double,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_> &, double &)". "./boost/math/tools/roots.hpp", line 45.6: 1540-0700 (I) The previous message was produced while processing "boost::math::tools::detail::handle_zero_derivative<boost::math::detail::cbrt_functor<double>,double>(cbrt_functor<double>, double &, const double &, double &, double &, double &, const double &, const double &)". "./boost/math/tools/roots.hpp", line 274.3: 1540-0700 (I) The previous message was produced while processing "boost::math::tools::halley_iterate<boost::math::detail::cbrt_functor<double>,double>(cbrt_functor<double>, double, double, double, int, uintmax_t &)". "./boost/math/tools/roots.hpp", line 418.10: 1540-0700 (I) The previous message was produced while processing "boost::math::tools::halley_iterate<boost::math::detail::cbrt_functor<double>,double>(cbrt_functor<double>, double, double, double, int)". "./boost/math/special_functions/cbrt.hpp", line 52.18: 1540-0700 (I) The previous message was produced while processing "boost::math::detail::cbrt_imp<double,boost::math::policies::policy<boost::math::policies::domain_error<1>,boost::math::policies::pole_error<1>,boost::math::policies::overflow_error<1>,boost::math::policies::evaluation_error<1>,boost::math::policies::rounding_error<1>,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::polici...". "./boost/math/special_functions/cbrt.hpp", line 61.11: 1540-0700 (I) The previous message was produced while processing "boost::math::cbrt<double,boost::math::policies::policy<boost::math::policies::domain_error<1>,boost::math::policies::pole_error<1>,boost::math::policies::overflow_error<1>,boost::math::policies::evaluation_error<1>,boost::math::policies::rounding_error<1>,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_policy,boost::math::policies::default_...". "libs/math/build/../src/tr1/c_policy.hpp", line 129.1: 1540-0700 (I) The previous message was produced while processing "c_policies::cbrt<double>(double)". "libs/math/build/../src/tr1/cbrt.cpp", line 16.11: 1540-0700 (I) The previous message was produced while processing "cbrt(double)". Is there any patch i need to apply? Any help would be much appreciated! All my search on this error didn't get me anywhere; if there is prior post on same topic and solution please let me know! Thanks, Radha

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[proto] Manipulating _data
by David A. Greene 01 Feb '10

01 Feb '10

So I've had fun tinkering with my lambda-like language. I moved on to try to introduce scoping, but I'm having some trouble. I've attached a simplified example. Compiling as-is, the test outputs what I would expect. It seems like the LookupSymbol transform works brilliantly, so symbol lookup is a go. However, convincing the grammar to match an expression that invokes the AddScope transform seems more difficult. Commenting the #if clause results in an error about converting a Wrapper<...> to a shared_ptr<Base> which I can only guess means the grammar is not matching the proto expression. I've tried all sorts of different things. I don't think the UnaryPassThrough transform should be neccessary, but maybe it does't hurt either. With or without it, the error is the same. What am I missing here? Thanks! -Dave

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boost::weak_ptr usage in multithreaded environments
by Virgil Palanciuc 01 Feb '10

01 Feb '10

Hello all, [long story short: I'd like to know whether a weak_ptr.lock() counts as a "shared pointer read" or as a "shared pointer write" ] I'm using boost shared pointers in an multi-threaded app. Basically, my app maintains a "forest" of "context trees" - i.e. I have a map from a "file name" to a "global context" that organizes the information for that file. The "global context" in the map is basically the root node of a tree of "local contexts" in that file. The tree is kept with boost:shared_ptr<> on the way down (father-son relations) and boost::weak_ptr<> on the way up (son->father pointers). I have added proper synchronization to the data structure... I think. I use reader/writer locks (only one writer allowed, but arbitrary number of readers) and I'm still getting sporadic crashes, especially when constructing a "global context" (root node) shared_ptr<> from a weak_ptr<> - using lock(). I am assuming in my app. that weak_ptr<>.lock() only requires a "read lock", not a "write lock".. is this true? I've checked out the page at http://www.boost.org/doc/libs/1_41_0/libs/smart_ptr/shared_ptr.htm#ThreadSa…, but there's nothing about weak_ptr there... Thanks, Virgil.

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BoostCon 2010 preliminary program
by Hartmut Kaiser 01 Feb '10

01 Feb '10

Hey all, please find below a list of accepted submissions to BoostCon 2010. A tentative, fully scheduled program will be available soon. The keynote will be held by Maurice Herlihy. Maurice Herlihy is a computer scientist active in the field of multiprocessor synchronization. Herlihy has contributed to the design of concurrent algorithms, and in particular to the exposition and quantification of the properties and uses of hardware synchronization operations. He is currently (2009) a professor of computer science at Brown University and one of the leading visionaries in the field of transactional memory. Following up on this keynote we will have a full day sessions and panel discussion where we plan for 4 different groups to talk about their work on transactional memory (Mark Moir (Sun), Tatiana Shpeisman (Intel), Michael Wong (IBM), Vicente Botet (TBoost.STM)) In addition we have a high quality, distinctive, fully packed, and very diverse list of accepted talks: João P. R. Abecasis: Cross-platform development with Qt and Boost Ruediger Berlich: Distributed parametric optimization with the Geneva library Dean Michael Berris: Techniques in Flexible Header-Only C++ Network Library Implementations Michael Caisse: Using Spirit 2.1: Qi and Karma An Asio Based Flash XML Server Marshall Clow: A (proposed) MIME library for Boost Tony Van Eerd: The Basics of Lock-free Programming Joel Falcou and Jean-Thierry Lapresté: The Numerical Template Toolbox: BOOST'ed Generic Array Library for High Performance Computing Joachim Faulhaber: Boost.Alabaster (proposed): A Law Based Tester Barend Gehrels, Bruno Lalande and Mateusz Loskot: Generic Programming for Geometry Justin Gottschlich: TBoost.STM's Engine: An Efficient Software Transactional Memory Using Commit-Time Invalidatio Douglas Gregor: Clang: An Open-Source C++ Compiler Library C++ Tool-Builders Workshop Christophe Henry: Tutorial: The Meta State Machine Library V2 Ken Joyner: Revisiting Guidelines to Using Exceptions in C++ Hartmut Kaiser and Joel de Guzman: RAD Spirit Spirit History and Evolution Zachary Laine and Matt Calabrese: Instantiations Must Go! Stephan Lavavej: Data Structure Visualizers in Visual Studio 2010 Nevin Liber: Type Erasure Eric Niebler: Practical DSEL Design with Proto Roshan Naik: Logic Paradigm for C++ Stjepan Rajko: Patterns Library: a generic library for modeling, recognition, and synthesis of sequential patterns Gennadiy Rozental: Production use of Boost.Test David Sankel: Functional Programming in C++ Jeremy Siek: Generic Programming and the Boost Graph Library Robert Ramey: Is Boost Broken? Michael Wong: C++0x Update C++0x Concurrency We believe this program is reason enough to come to BoostCon this year (Aspen, CO, USA, May 10-14th)! For registration, accommodation, and more information please visit the conference website at http://www.boostcon.com. Please note the reduced early registration fee! Regards Hartmut Program Chair BoostCon 2010 --------------- Meet me at BoostCon www.boostcon.com

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boost::random: get same number sequences 32/64 bit?
by Sebastian Mach 01 Feb '10

01 Feb '10

Hello list, today I found out that boost::random, at least the combination boost::mt19937 rng(<seed>); typedef boost::uniform_int<int> dist_t; dist_t dist (<min>, <max>); boost::variate_generator< boost::mt19937&, dist_t > rand_ (rng, dist); will give me different results depending on whether I use "g++ (Debian 4.3.2-1.1) 4.3.2" (with sizeof(long)=8) or "g++.exe (TDM-2 mingw32) 4.4.1" (with sizeof(long)=4). This testcase: ++ #include <boost/random.hpp> boost::mt19937 rng(1); typedef boost::uniform_int<int> dist_t; dist_t dist (0, 16); boost::variate_generator< boost::mt19937&, dist_t > rand_ (rng, dist); int main () { for (int i=0; i<6; ++i) { std::cout << rand_() << std::endl; } } -- will print 16 8 1 6 0 12 with the 64bit variant variant, but 7 16 12 15 0 2 with the 32bit variant. Is there a (preferably portable) way to ensure that they will be the same on all 32bit+ machines? Otherwise this would be a real stopper to use boost::random for me, and I'd have to go back to libcoyotl's Mersenne Twister, which gives consistent results, upon which I really depend. Sincerely Sebastian Mach phresnel(a)gmail.com

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PP: how to use automatic recursion
by Hicham Mouline 01 Feb '10

01 Feb '10

Hello, I am trying to generate many types from 1 struct (for full background, please see thread "generate structs with all combinations of members from a given struct"), with the help of Boost.PP #include <boost/preprocessor/control/if.hpp> #include <boost/preprocessor/seq/size.hpp> #include <boost/preprocessor/seq/seq.hpp> #include <boost/preprocessor/seq/elem.hpp> #include <boost/preprocessor/arithmetic/sub.hpp> #include <boost/preprocessor/seq/pop_front.hpp> #include <boost/preprocessor/seq/push_back.hpp> #define STRUCTMEMBERS ((double,m1))((double,m2))((double,m3))((double,m4))((double,m5)) #define SEQ_LAST_ELEM(seq) \ BOOST_PP_SEQ_ELEM( BOOST_PP_SUB(BOOST_PP_SEQ_SIZE(seq), 1), seq) #define UPDATE_MAIN_SEQ(mainseq, globalseq)\ BOOST_PP_IF( BOOST_PP_SEQ_SIZE(mainseq),\ BOOST_PP_SEQ_PUSH_BACK(\ mainseq,\ ((SEQ_LAST_ELEM(mainseq))(BOOST_PP_SEQ_HEAD(globalseq)))\ ),\ ((BOOST_PP_SEQ_HEAD(globalseq)))\ ) #define COMBINATIONS(seq, combseq)\ BOOST_PP_IF( BOOST_PP_SEQ_SIZE(seq),\ COMBINATIONS( UPDATE_MAIN_SEQ(combseq,seq), BOOST_PP_SEQ_POP_FRONT(seq) ), \ combseq\ ) #define COMBOS COMBINATIONS(STRUCTMEMBERS, BOOST_PP_SEQ_NIL) COMBOS Reading PP docs, I just realized that the preprocessor disallows recursion ( the COMBINATIONS macro calls itself in my case), but I didn't understand the reentrancy topic page. How can I change the above code to make the recursive COMBINATIONS possible? regards,

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[range_ex]"Practical" Status of boost::range, boost::range_ex, and associated algorithms
by Jesse Perla 01 Feb '10

01 Feb '10

Hi there, I am excited to start using ranges in user code with standard algorithms (mostly copy, transform, binary_searches). Is it safe for me to start using code with range/range_ex? Since the http://www.boostpro.com/vault/index.php?directory=Algorithms version hasn't been updated for a while, I was worried that there could be interface changes. I am perfectly willing to use a subset of algorithms that are expected to remain stable -Jesse

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mix usage of boost.thread and pthread?
by Hua Su 01 Feb '10

01 Feb '10

Hi all, Is it OK to use both pthread and boost.thread in the same program under linux? E.g., there are two cases: 1. use pthread api to create/join/detach/cancel threads but use boost.thread's mutex/condition_variable etc. to do thread synchronization, and this_thread/sleep/get_id/thread_local_storage etc.. 2. use boost.thread api to create/join/detach/interrupt thread but use pthread api to do thread synchronization. I know boost.thread is a pthread api wrapper under linux, but I'm afraid of that the two cases above aren't safe if boost.thread uses some tricks I don't understand. Would you kindly give any hints? Thanks! Hua

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[property_tree]problem with equal_range
by Ken Murphy 01 Feb '10

01 Feb '10

Hello all, I am getting an error while trying to compile the following program: #include "boost/property_tree/ptree.hpp" int main(int argc, char* argv[]) { boost::property_tree::ptree t; t.equal_range("KEY"); return 0; } Compiler output: 1>c:\hibbettlinux\src\boost-1.41.0\boost\property_tree\detail\ptree_impl 1>emen tation.hpp(448) : error C2039: 'base' : is not a member of 'boost::multi_index::detail::bidir_node_iterator<Node>' 1> with 1> [ 1> Node=boost::multi_index::detail::ordered_index_node<boost::multi_index::deta il::index_node_base<std::pair<const std::string,boost::property_tree::basic_ptree<std::string,std::string>>,std: :allocator<std::pair<const std::string,boost::property_tree::basic_ptree<std::string,std::string>>>>> 1> ] 1> c:\hibbettlinux\src\boost-1.41.0\boost\property_tree\detail\ptree_implementa tion.hpp(444) : while compiling class template member function 'std::pair<_Ty1,_Ty2> boost::property_tree::basic_ptree<Key,Data>::equal_range(const std::basic_string<_Elem,_Traits,_Ax> &)' 1> with 1> [ 1> _Ty1=boost::property_tree::basic_ptree<std::string,std::string>::assoc_itera tor, 1> _Ty2=boost::property_tree::basic_ptree<std::string,std::string>::assoc_itera tor, 1> Key=std::string, 1> Data=std::string, 1> _Elem=char, 1> _Traits=std::char_traits<char>, 1> _Ax=std::allocator<char> 1> ] 1> c:\hibbettlinux\src\platform\vc80\test\test.cpp(9) : see 1> reference to class template instantiation 'boost::property_tree::basic_ptree<Key,Data>' being compiled 1> with 1> [ 1> Key=std::string, 1> Data=std::string 1> ] 1>c:\hibbettlinux\src\boost-1.41.0\boost\property_tree\detail\ptree_impl 1>emen tation.hpp(449) : error C2039: 'base' : is not a member of 'boost::multi_index::detail::bidir_node_iterator<Node>' 1> with 1> [ 1> Node=boost::multi_index::detail::ordered_index_node<boost::multi_index::deta il::index_node_base<std::pair<const std::string,boost::property_tree::basic_ptree<std::string,std::string>>,std: :allocator<std::pair<const std::string,boost::property_tree::basic_ptree<std::string,std::string>>>>> 1> ] I am using boost 1.41 with VC 7.1 Any help is appreciated!!!!!! Ken Murphy

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