December 2009 - Boost-users

[preprocessor]
by Christian Henning 14 Dec '09

14 Dec '09

Hi there, let's assume I have a structure which takes 5 ints as template parameters. template< int NumChannel , int FirstChannelBits = 0 , int SecondChannelBits = 0 , int ThirdChannelBits = 0 , int FourthChannelBits = 0 , int FifthChannelBits = 0 > struct pixel_type_generator { /* omitted*/ } The first parameter is different as it defines how many of the other parameters are actually used. How can I use boost::preprocessor to get this kind of code repetition: // one channel test pixel_pixel_test< pixel_type_generator< 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 2 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 3 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 4 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 5 >::type >(); pixel_pixel_test< pixel_type_generator< 1, 6 >::type >(); // up to 64 // two channels test pixel_pixel_test< pixel_type_generator< 2, 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 1, 2 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 1, 3 >::type >(); // ... pixel_pixel_test< pixel_type_generator< 2, 1, 32 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 2, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 2, 2 >::type >(); pixel_pixel_test< pixel_type_generator< 2, 2, 3 >::type >(); // ... // ... pixel_pixel_test< pixel_type_generator< 2, 32, 32 >::type >(); // last two parameters up to 32 - which means there are 32 x 32 calls // three channels test pixel_pixel_test< pixel_type_generator< 3, 1, 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 3, 1, 1, 2 >::type >(); // ... // last three parameters up to 21 - which means there are 21 x 21 x 21 calls // four channels test pixel_pixel_test< pixel_type_generator< 4, 1, 1, 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 4, 1, 1, 1, 2 >::type >(); // ... // last four parameters up to 16 - which means there are 16 x 16 x 16 x 16 calls // five channels test pixel_pixel_test< pixel_type_generator< 5, 1, 1, 1, 1, 1 >::type >(); pixel_pixel_test< pixel_type_generator< 5, 1, 1, 1, 1, 2 >::type >(); // ... // last four parameters up to 12 - which means there are 12 x 12 x 12 x 12 x 12 calls As you might realize, I try to test every combination until the sum of all channels hits 64. Thanks, Christian

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regex
by Dejan 14 Dec '09

14 Dec '09

Hi all, I have a question regarding boost::regex. I have one regex which should identify my string AND cut it into pieces. I've tried with regex_token_iterator and cmatch and failed. code: #include <string> #include <iostream> #include <boost/regex.hpp> int main() { std::string s("s0,s1,s2"); boost::regex re("^(s[0-9])(,s[0-9])*$"); // 1. attempt boost::sregex_token_iterator i(s.begin(), s.end(), re), j; while(i!=j) { std::cout << *i++ << std::endl; } // 2. attempt boost::cmatch matches; if(boost::regex_search(s.c_str(), matches, re)) { for(int p=0, q=matches.size(); p<q; p++) { std::string match(matches[p].first, matches[p].second); std::cout << match << std::endl; } } } output: s0,s1,s2 s0,s1,s2 s0 ,s2 desired output: s0,s1,s2 s0 ,s1 ,s2 Any hints how to do this in one step? Thanks!

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Re: [Boost-users] BOOST_FOREACH with Index
by pete＠pcbartlett.com 14 Dec '09

14 Dec '09

> Nat Goodspeed wrote: > > Maybe this shouldn't be a BOOST_FOREACH feature at all. As with > Python's > > builtin enumerate() function, maybe what we want here is an > iterator > > adapter that dereferences to a std::pair > original_iterator_value_type>? > Couldn't you just do a BOOST_FOREACH over combine(count_range(), > foos) > for that? > (uses zip_iterator) Yup, Nat's idea is a nice one and easy to implement. As Eric alluded to with his reference to the ticket on FOREACH_FIELD, the heart of the matter really though is getting a syntactically convenient version. We've seen this situation - where we have the neat iterators/ranges but not the syntactic convenience - a few times (REVERSE_FOREACH, FOREACH_FIELD, this "FOREACH_WITHINDEX" spring to mind) - I wonder if there is an opportunity to expose a lower level API in the FOREACH mini-library that would enable advanced users to build such macros themselves.

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Hello Everyone
by Rick Eyre 14 Dec '09

14 Dec '09

I have a problem with installing boost. I downloaded the installer 1.40 for VC 2008 and followed all the instructions in the manual but I'm getting the error 1>LINK : fatal error LNK1104: cannot open file 'libboost_thread-vc90-mt-gd-1_40.lib'. This is from the header #include <boost/thread/thread.hpp> in my code. Does anyone know what I can possible do to resolve this? Thanks

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Compilation error Boost lambda function (Boost 1.40)
by Joost Kraaijeveld 14 Dec '09

14 Dec '09

Hi, What is wrong in my syntax in the std::for_each call (the BOOST_FOREACH works fine): ... class Session { virtual void stopSession(); } class ServerSession : public Sessoon { } typedef std::map<unsigned long, ServerSession*> ServerSessions; ServerSessions serverSessions; ... ... typedef std::pair<unsigned long, ServerSession*> ServerSessionsIterator; BOOST_FOREACH(ServerSessionsIterator session,serverSessions) { session.second->stopSession(); } std::for_each( serverSessions.begin(), serverSessions.end(), boost::lambda::bind( &ServerSession::stopSession, // function boost::bind(&ServerSessions::value_type::second, boost::lambda::_1))); // object The actual error is: make -k -j6 all /bin/bash ../libtool --tag=CXX --mode=compile g++ -DHAVE_CONFIG_H -I. -I/home/jkr/Programming/C++/Dagda/library/DagdaCom -I../../include/Dagda/DagdaConfig -DDEVELOPMENT -DDANUEXE=1 -I/home/jkr/Programming/C++/Danu/include/Danu -DDAGDADLL=1 -I /home/jkr/Programming/C++/Dagda/library/../include/Dagda -pipe -Wall -Wextra -Wundef -Wshadow -Wconversion -I/usr/include -I/usr/lib/wx/include/gtk2-unicode-release-2.8 -I/usr/include/wx-2.8 -D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D__WXGTK__ -pthread -g -O2 -MT libdagdacom_la-Server.lo -MD -MP -MF .deps/libdagdacom_la-Server.Tpo -c -o libdagdacom_la-Server.lo `test -f 'Server.cpp' || echo '/home/jkr/Programming/C++/Dagda/library/DagdaCom/'`Server.cpp libtool: compile: g++ -DHAVE_CONFIG_H -I. -I/home/jkr/Programming/C++/Dagda/library/DagdaCom -I../../include/Dagda/DagdaConfig -DDEVELOPMENT -DDANUEXE=1 -I/home/jkr/Programming/C++/Danu/include/Danu -DDAGDADLL=1 -I /home/jkr/Programming/C++/Dagda/library/../include/Dagda -pipe -Wall -Wextra -Wundef -Wshadow -Wconversion -I/usr/include -I/usr/lib/wx/include/gtk2-unicode-release-2.8 -I/usr/include/wx-2.8 -D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D__WXGTK__ -pthread -g -O2 -MT libdagdacom_la-Server.lo -MD -MP -MF .deps/libdagdacom_la-Server.Tpo -c /home/jkr/Programming/C++/Dagda/library/DagdaCom/Server.cpp -fPIC -DPIC -o .libs/libdagdacom_la-Server.o /usr/include/boost/lambda/detail/actions.hpp: In static member function ‘static RET boost::lambda::function_action<2, T>::apply(A1&, A2&) [with RET = void, A1 = void (DagdaCom::Session::* const)(), A2 = const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >, T = boost::lambda::detail::unspecified]’: /usr/include/boost/lambda/detail/lambda_functor_base.hpp:418: instantiated from ‘RET boost::lambda::lambda_functor_base<boost::lambda::action<2, Act>, Args>::call(A&, B&, C&, Env&) const [with RET = void, A = std::pair<const long unsigned int, DagdaCom::ServerSession*>, B = const boost::tuples::null_type, C = const boost::tuples::null_type, Env = const boost::tuples::null_type, Act = boost::lambda::function_action<2, boost::lambda::detail::unspecified>, Args = boost::tuples::tuple<void (DagdaCom::Session::* const)(), const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>]’ /usr/include/boost/lambda/detail/lambda_functors.hpp:175: instantiated from ‘typename T::sig<boost::tuples::tuple<A&, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >::type boost::lambda::lambda_functor<Base>::operator()(A&) const [with A = std::pair<const long unsigned int, DagdaCom::ServerSession*>, T = boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<void (DagdaCom::Session::* const)(), const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >]’ /usr/include/c++/4.3/bits/stl_algo.h:3791: instantiated from ‘_Funct std::for_each(_IIter, _IIter, _Funct) [with _IIter = std::_Rb_tree_iterator<std::pair<const long unsigned int, DagdaCom::ServerSession*> >, _Funct = boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<void (DagdaCom::Session::* const)(), const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >]’ /home/jkr/Programming/C++/Dagda/library/DagdaCom/Server.cpp:204: instantiated from here /usr/include/boost/lambda/detail/actions.hpp:87: error: no matching function for call to ‘boost::lambda::function_adaptor<void (DagdaCom::Session::*)()>::apply(void (DagdaCom::Session::* const&)(), const boost::_bi::bind_t<DagdaCom::ServerSession* const&, boost::_mfi::dm<DagdaCom::ServerSession*, std::pair<const long unsigned int, DagdaCom::ServerSession*> >, boost::_bi::list1<boost::arg<1> > >&)’ /usr/include/boost/lambda/detail/actions.hpp:87: error: return-statement with a value, in function returning 'void' make: *** [libdagdacom_la-Server.lo] Error 1 make: Target `all' not remade because of errors. TIA -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

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Bundled properties with boyer_myrvold_planarity_test
by Nick Wiggill 13 Dec '09

13 Dec '09

Can't seem to get this working. I'm not sure if there was something I missed in the docs, but as soon as I use bundled properties boyer_myrvold_planarity_test falls over. void SomeClass::create() { typedef adjacency_list<listS, listS, undirectedS, property <vertex_index_t, int>, property <edge_index_t, int> > Graph; typedef graph_traits<Graph>::vertex_descriptor Vertex; typedef graph_traits<Graph>::edge_descriptor Edge; typedef graph_traits<Graph>::vertex_iterator VertexIterator; BOOST_CONCEPT_ASSERT ((boost::concepts::VertexAndEdgeListGraph<Graph>)); BOOST_CONCEPT_ASSERT ((boost::concepts::IncidenceGraph<Graph>)); //Create graph const int NUM_VERTICES = 5; Graph graph(NUM_VERTICES); //Create vertices and edges Vertex u, v; u = vertex(0, graph); v = vertex(4, graph); //add_edge(u, v, graph); //BAD line! //Other attempted/failed way of adding edges //Edge e; //e = edge(u, v, graph); //Another attempt, doesn't seem to work with //bundled props, unsurprisingly. //add_edge(0, 4, graph); cout << "Vertex and edge additions complete." << endl; //iterate through vertices VertexIterator vItr, vItrEnd; for (tie(vItr, vItrEnd) = vertices(graph); vItr != vItrEnd; ++vItr) { cout << "#"<< endl; //<< graph[*vItr] << endl; } cout << "Vertex iteration complete." << endl; if (boyer_myrvold_planarity_test(graph)) cout << "Test claims graph is planar" << endl; else cout << "Test claims graph is non-planar" << endl; cout << "Planarity testing complete." << endl; } The line commented "BAD line!" causes an exit on calling boyer_myrvold_planarity_test. With the test commented out, the program will run to its normal completion. What am I failing to grasp? TIA -Nick

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Unable to access graph concepts
by Nick Wiggill 13 Dec '09

13 Dec '09

Hi I'm new to Boost (using 1.41.0) and specifcally the BGL and am having a small problem with accessing graph concepts. My IDE (Eclipse/CDT) and compiler (GCC 3.4.5) are having trouble seeing definitions of graph concepts, although I have included boost/graph/graph_concepts.hpp. When I type the boost namespace specifier, autocomplete can find e.g. EqualityComparable, but it cannot find VertexAndEdgeListGraph (among others... but this the one I need). I can see the basic BCCL concepts from boost/concept_check.hpp just fine, making this all the more confusing. My paths are correct, as for example adjacency_list (residing in the same path) works fine. PS. Try to have mercy on me, I'm not only returning to C++ after a number of years but I'm also in the process of reacquainting myself fully with generic programming (and the STL), something I was never too great at... so a lot of things still meet with a blank stare from me. I've just been learning these things slowly by example and by trial-and-error so far. TIA, -- Nick Wiggill skype: nickwiggill nick.wiggill(a)gmail.com www.handcraftedgames.net -- "He uses statistics as a drunken man uses lamp-posts... for support rather than illumination." -Andrew Lang (1844-1912)

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Asio io_service::work destructor throwing mutex exception
by Florian Turck 13 Dec '09

13 Dec '09

Hi, I am using asio´s io_service::work class to prevent io_service.run() from returning. Unfortunatly on deletion of my object the destructor of io_service::work throws an exception: terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >' what(): mutex: Invalid argument Thread 0 Crashed: Dispatch queue: com.apple.main-thread 0 libSystem.B.dylib 0x9578c732 __kill + 10 1 libSystem.B.dylib 0x9578c724 kill$UNIX2003 + 32 2 libSystem.B.dylib 0x9581f98d raise + 26 3 libSystem.B.dylib 0x95835a44 abort + 93 4 libstdc++.6.dylib 0x9122afda __gnu_cxx::__verbose_terminate_handler() + 433 5 libstdc++.6.dylib 0x9122917a __cxxabiv1::__terminate(void (*)()) + 10 6 libstdc++.6.dylib 0x9122851d __cxa_call_terminate + 53 7 libstdc++.6.dylib 0x9122909d __gxx_personality_v0 + 911 8 libSystem.B.dylib 0x9579aa9d unwind_phase2 + 205 9 libSystem.B.dylib 0x957b1fd9 _Unwind_Resume + 73 10 com.yourcompany.ReclaimR 0x00026ed3 boost::asio::detail::scoped_lock<boost::asio::detail::posix_mutex>::scoped_lock(boost::asio::detail::posix_mutex&) + 79 (scoped_lock.hpp:37) 11 com.yourcompany.ReclaimR 0x00027dfa boost::asio::detail::task_io_service<boost::asio::detail::kqueue_reactor<false> >::work_finished() + 28 (task_io_service.hpp:171) 12 com.yourcompany.ReclaimR 0x00027e72 boost::asio::io_service::work::~work() + 22 (io_service.ipp:155) The asio related objects are all members of my class: [...] private: io_service ioService; io_service::work ioWork; thread ioThread; tcp::socket controlSocket; tcp::acceptor acceptor; [...] This is how I initialize everything: [...] MyClass() : ioService(), ioWork(ioService), ioThread(bind(&io_service::run, &ioService)), controlSocket(ioService), acceptor(ioService), [...] Finally this is what happens in the destructor: [...] if (connected) disconnect(); ioService.stop(); ioThread.join(); [...] Anyone knows how to deal with this? Regards, Florian

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can't build an official example on eclipse
by loveley 13 Dec '09

13 Dec '09

hello, I have an issue while trying to run boost for the first time. I downloaded boost on my mac snow leopard, with eclipse. I compiled the sources(with bjam, without options), and I added the "include" directory (ie boost_1_41_0/boost)and the "libs" one (ie boost_1_41_0/libs) in eclipse. the example I used is the one provided by the official tutorial : ****************************************************** #define BOOST_TEST_MODULE MyTest #include <boost/test/unit_test.hpp> int add( int i, int j ) { return i+j; } BOOST_AUTO_TEST_CASE( my_test ) { // seven ways to detect and report the same error: BOOST_CHECK( add( 2,2 ) == 4 ); // #1 continues on error BOOST_REQUIRE( add( 2,2 ) == 4 ); // #2 throws on error if( add( 2,2 ) != 4 ) BOOST_ERROR( "Ouch..." ); // #3 continues on error if( add( 2,2 ) != 4 ) BOOST_FAIL( "Ouch..." ); // #4 throws on error if( add( 2,2 ) != 4 ) throw "Ouch..."; // #5 throws on error BOOST_CHECK_MESSAGE( add( 2,2 ) == 4, // #6 continues on error "add(..) result: " << add( 2,2 ) ); BOOST_CHECK_EQUAL( add( 2,2 ), 4 ); // #7 continues on error } ****************************************************** and the error is: http://pastebin.com/m4c85af13 . can you help me? thank you, olivier. ****************************************************** ___________________________________________________________________________ Yahoo! Mail réinvente le mail ! Découvrez le nouveau Yahoo! Mail et son interface révolutionnaire. http://fr.mail.yahoo.com

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[Serialization] Saving non-const values
by Patrick Moran 12 Dec '09

12 Dec '09

Hello all, I noticed in the documentation of Boost.Serialization in 1.41.0 that under the "Rationale" section the link for "Compile time trap when saving a non-const value" still appears at the top of the page, but the section it points to is now missing. Is this just an error in the documentation, or has this restriction been removed in 1.41.0. No such change is mentioned in the release notes, but I read somewhere a while ago that they were considering removing the saving-const restriction. In case it helps, the context I'm using this in is using Boost.Serialization to serialize polymorphic classes and polymorphic containers from Boost.PointerContainer. Thanks, Patrick Moran

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