August 2008 - Boost-users - lists.preview.boost.org

BGL: Unable to compile graphviz.cpp
by Rajesh 06 Aug '08

06 Aug '08

Hi, I downloaded boost_1_35_0 and tried to compile graphviz.cpp using the new spirit parser. Any suggestions? Here is the error I got: g++-4.1.2 -I../../../ -fpermissive -ftemplate-depth-128 -DBOOST_GRAPH_READ_GRAPHVIZ_ITERATORS graphviz.cpp /tmp/ccfGYuqq.o: In function `bool boost::read_graphviz<boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::property<boost::vertex_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::property<boost::edge_weight_t, double, boost::no_property>, boost::no_property, boost::listS> >(std::basic_istream<char, std::char_traits<char> >&, boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::property<boost::vertex_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::property<boost::edge_weight_t, double, boost::no_property>, boost::no_property, boost::listS>&, boost::dynamic_properties&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': graphviz.cpp:(.text._ZN5boost13read_graphvizINS_14adjacency_listINS_4vecSES2_NS_11undirectedSENS_8propertyINS_13vertex_name_tESsNS_11no_propertyEEENS4_INS_13edge_weight_tEdS6_EES6_NS_5listSEEEEEbRSiRT_RNS_18dynamic_propertiesERKSs[bool boost::read_graphviz<boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::property<boost::vertex_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::property<boost::edge_weight_t, double, boost::no_property>, boost::no_property, boost::listS> >(std::basic_istream<char, std::char_traits<char> >&, boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::property<boost::vertex_name_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::no_property>, boost::property<boost::edge_weight_t, double, boost::no_property>, boost::no_property, boost::listS>&, boost::dynamic_properties&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)]+0x52): undefined reference to `boost::detail::graph::read_graphviz(std::basic_istream<char, std::char_traits<char> >&, boost::detail::graph::mutate_graph&)' collect2: ld returned 1 exit status -- Regards Rajesh

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statechart: Constructors for initial state can't access outermost_context
by Tim Crews 06 Aug '08

06 Aug '08

Hello: I posted last week about a project in which I am creating two instances of the same state machine class, with the two instances running in separate boost threads. I have the threading issues resolved, but now I am having some other trouble. The two instances of the state machine class are differentiated by slightly different constructor parameter values, which are then stored in some state machine member variables. The contained states then access these member variables. Unfortunately, at least for the initial state, the state constructor is unable to access these member variables. (This may also be true of states other than the initial state, but I haven't been able to get that far yet.) Here is some example code that demonstrates the problem: ################################################################ #include <iostream> using namespace std; #include <boost/statechart/state_machine.hpp> #include <boost/statechart/simple_state.hpp> using boost::statechart::state_machine; using boost::statechart::simple_state; struct TopState; struct Machine : state_machine< Machine, TopState > { Machine (int u): unique(u) {} int unique; }; struct TopState : simple_state< TopState, Machine > { TopState(void) { int z = outermost_context().unique; cout << z << endl; } }; int main (int argc, char *argv[]) { Machine machine1(1); Machine machine2(2); machine1.initiate(); } ################################################################ When I run this code, I get the following error message when machine1 is initiated: app: /usr/include/boost/statechart/simple_state.hpp:217: typename Context::inner_context_type::outermost_context_type& boost::statechart::simple_state<MostDerived, Context, InnerInitial, historyMode>::outermost_context() [with MostDerived = TopState, Context = Machine, InnerInitial = boost::mpl::list<mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na, mpl_::na>, boost::statechart::history_mode historyMode = has_no_history]: Assertion `get_pointer( pContext_ ) != 0' failed. It is as if the outermost context doesn't exist yet (or hasn't been fully initialized yet?) when the initial state is entered. Am I doing something wrong? Thank you for your time, Tim Crews GECO, Inc.

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dynamic allocation of boost/numeric/ublas/matrix?
by Ed 06 Aug '08

06 Aug '08

From an example on teh Boost website, I can use matrix as follows: #include <boost/numeric/ublas/matrix.hpp> #include <boost/numeric/ublas/io.hpp> int main () { using namespace boost::numeric::ublas; matrix<double> m (3, 3); for (unsigned i = 0; i < m.size1 (); ++ i) for (unsigned j = 0; j < m.size2 (); ++ j) m (i, j) = 3 * i + j; std::cout << m << std::endl; } But I want to use Boost matrix where I don't know the size at the time the matrix is declared. I want to do something like matrix<double> *m; then later m=new matrix<double> How do I do this? Ed

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Re: [Boost-users] boost 1.35 code completion under Visual Studio 2008
by Roma.. 06 Aug '08

06 Aug '08

> Hmm, seems to work OK for me with VC8-Express, at the risk of stating the > obvious you may need to build the file once and then wait for Intellisense > to update before it becomes available however. > HTH, John. thanks, John! I want to add one more fact - Code completion (Intellisense) does not work properly also under VS2005 (not express). Some boost modules used in code block Intellisense fully. Some other blocks block Intellisense partially (in the current {block}). Hope, somebody knows the solution of this. Currently workaround is to wrap calls to boost library into BoostFuncCallWrapper.h and BoostFuncCallWrapper.cpp module.

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how to know if a type supports comparison operators
by frederic.bron＠alcan.com 06 Aug '08

06 Aug '08

I am looking for a means to know if a type supports comparison operators (<, >, <=, >=). I have looked in Boost.TypeTraits but could not find what I need. F. Bron Avis : Ce message et toute pièce jointe sont la propriété d'Alcan et sont destinés seulement aux personnes ou à l'entité à qui le message est adressé. Si vous avez reçu ce message par erreur, veuillez le détruire et en aviser l'expéditeur par courriel. Si vous n'êtes pas le destinataire du message, vous n'êtes pas autorisé à utiliser, à copier ou à divulguer le contenu du message ou ses pièces jointes en tout ou en partie. Notice: This message and any attachments are the property of Alcan and are intended solely for the named recipients or entity to whom this message is addressed. If you have received this message in error please inform the sender via e-mail and destroy the message. If you are not the intended recipient you are not allowed to use, copy or disclose the contents or attachments in whole or in part.

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Maemo?
by Pau Garcia i Quiles 06 Aug '08

06 Aug '08

Hello, Is Boost available on Maemo (ARM)? -- Pau Garcia i Quiles http://www.elpauer.org (Due to my workload, I may need 10 days to answer)

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Problems with Boost::Python Embedding Tutorials
by Kripken 06 Aug '08

06 Aug '08

Hello, I am unable to get the boost:python embedding tutorials to work. I have the exact same problems as in this unanswered post: http://www.nabble.com/boost.python-embedding-tutorial-doesn%27t-work---td17… Basically, commands like this python::object ignore = python::exec("print len([1,2,3])", main_namespace); fail with Traceback (most recent call last): File "<string>", line 1, in <module> TypeError: 'NoneType' object is unsubscriptable whereas simpler commands like this do work: python::object ignoreme = python::exec(python::str("print 5"), main_namespace); Similar problems occur with eval instead of exec, for some uses the error is instead TypeError: 'NoneType' object does not support item assignment If it's important, I am running Ubuntu 8.04, Python is 2.5.2, Boost is 1.34.1. Thanks in advance for any tips. - Kripken

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boost::asio::read: Is it possible to read directly into a string?
by Jean-Sebastien Stoezel 06 Aug '08

06 Aug '08

Hello, Is it possible to directly read into a string using boost::asio::read? Or do I have to first read into an array of char, then assign it to the string? Thanks! Jean

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[program_options]
by Marcio Paim de Aquino 06 Aug '08

06 Aug '08

Hi, here is the output of one of the example programs from program_options library: paim@notebook:~$ ./first --help Allowed options: --help produce help message --compression arg set compression level I would like to know if there is a way to change "arg" for something else? Thanks Marcio

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[mpi] Any plan for mpi2 IO support ?
by Alain Miniussi 06 Aug '08

06 Aug '08

Hi, I have a code based on MPI uising MPI2 IO to read/writte its data on disk (all mpi procces perform concurrent read/writte on the same file). Boost::mpi does not seems to include whose functionnalities (parralllel IO, views, async ios, basically the stuff described in http://www.mpi-forum.org/docs/mpi-20-html/node171.htm#Node171 ). Is there a plan to support that in the near future ? I had a looks a boost serialization libraries but they do not seems provide whose functionnalities (or did I missed something ?). Thanks, -- Alain Miniussi Equipe CRIMSON Mesocentre de Calcul SIGAMM +33 492 00 30 09 https://crimson.oca.eu

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