June 2012 - Boost-users - lists.preview.boost.org

[interprocess] Determine size of managed_shared_memory
by Kai Benndorf 12 Oct '19

12 Oct '19

Hi all, I want to create a managed_shared_memory in exactly the size I needed. Therefore I do something like this: size = sizeof( common_managed_shared_memory ); size += sizeof( MyClassInSharedMem ); managed_shared_memory segment(create_only, "name", size ); MyClassInSharedMem allocates itself some memory by segment->allocate(). I added this also to the size, but get a boost::interprocess::bad_alloc exception on allocating this additional memory. Are there some magic bytes I forgot to add? Many thanks in advance Kai

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[statechart] Passing parameters from event to State Local Storage
by Christophe Bourez 16 Nov '16

16 Nov '16

I need to maintain a parameter into the state local storage. This parameter is initially contained in the event that causes the transition to the target state. I give hereafter a small illustrative example. typename sc = boost::statechart; class EvTest : public sc::event<EvTest> { public: EvTest(std::size_t val) : value(val) {} std::size_t getValue() const { return this->value; } private: std::size_t value; }; class MyStateMachine; class StSource; class StTarget; class StSource : public sc::simple_state<StSource, MyStateMachine> { public: typedef sc::custom_reaction<EvTest> reactions; sc::result react(const EvTest &event) { // How to pass event.getValue() to the target state ? transit<StTarget>(); } }; class StTarget : public sc::simple_state<StTarget, MyStateMachine> { public: StTarget(std::size_t val) : val(value) {} private: std::size_t value; }; Thanks, Christophe

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Statechart serialization
by mbrodeur65 04 Mar '15

04 Mar '15

Hi, I'm looking for a solution to serialize boost::statechart objects. I'm aware that this feature is on the statechart library todo list but was wondering if there are any workaround to achieve this with the latest boost release (1.34) ? thanks for your help ! mbrodeur65 -- View this message in context: http://www.nabble.com/Statechart-serialization-tf4131326.html#a11749139 Sent from the Boost - Users mailing list archive at Nabble.com.

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[Thread] Read-write locks
by lfrfly＠icqmail.com 18 Sep '14

18 Sep '14

I'm trying to create a standard read/write lock using Boost Threads, and I'm having a bit of difficulty mapping the Boost concepts onto the usual ones. A read/write lock should have several states: Locked for reading (multiple threads may lock at once), locked for writing (only one thread may lock, and no threads may be locked for reading at the same time), and unlocked. Ideally it would be nice if an RWL which is locked for reading may temporarily upgrade to locked for writing, then return to the locked for reading state. Boost supports several relevant notions of locking: shared locking, upgrade locking, and exclusive locking. This to me is a confusing distinction. In particular, a shared_mutex seems appropriate as the basis for a RWL, but is lock_upgrade() the equivalent of a write lock and lock_shared the equivalent of a read lock? This is unclear. If "upgrade locking" is not the same as "exclusive locking", then is an upgrade lock actually exclusive? Could someone please clarify this.

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[Statechart] How to decide between post_event and process_event atrun time ?
by Philippe DAVID 22 Jul '14

22 Jul '14

Hi, I have a method in which I want to post/process an event. The thing is, this method can be called from outside the state machine (so I need to call process_event), or indirectly by a reaction of the state machine (in this case I must call post_event since process_event is not reentrant). I don't want to write 2 distinct methods to do this (one that calls post, and the other process), I would much rather prefer adding a 'if' in my method that tells me if I have to call process_event or post_event (if I'm being called indirectly by the state machine or not). Is there a way to do this with statechart ? regards, Philippe

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[asio] resolver::cancel() problem
by Matthew Edwards 14 Mar '14

14 Mar '14

In my application (and a separate test program) it seems as though the cancel() function on the resolver does not work as intended. For async resolves, the cancel functionality should abort them immediately and pass an 'operation aborted' error code to the callback handler. In my tests, I will resolve an invalid domain (this causes the resolve to take a few seconds, to demonstrate the problem), sleep for 100ms, then call cancel on the resolver object. No cancelling actually occurs, and the callback is simply triggered after a few seconds with a "No host found" error code, not the expected operation aborted. Has anyone experienced this before, or know how I might be using the resolver incorrectly?

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[BGL] Having a cost function as weight map
by Maxime van Noppen 06 Sep '13

06 Sep '13

Hi, I can't find how to do this pretty basic thing : having a function instead of a field to compute the cost of edges for various path finding algorithms. I couldn't find the answer in the documentation and Google was of no help. Did I miss something obvious ? Example : ------------------- #include <boost/graph/dijkstra_shortest_paths.hpp> #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> struct my_edge { double cost() const { return cost_ * 2; } double cost_; }; struct my_node { }; int main() { typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::directedS, my_node, my_edge > graph_t; typedef boost::graph_traits<graph_t>::vertex_descriptor vertex_t; graph_t graph; vertex_t v /*= ... */; using boost::weight_map; // Works : boost::dijkstra_shortest_paths(graph, v, weight_map(boost::get(&my_edge::cost_, graph))); // Doesn't compile : //boost::dijkstra_shortest_paths(graph, v, // weight_map(boost::get(&my_edge::cost, graph))); } ------------------- Thanks ! -- Maxime

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Identify cycles in a undirected graph
by NsPx 20 Aug '13

20 Aug '13

Hi all, I use undirected_dfs to detect all cycles in a undirected graph. I detect a cycle with DFSVisitor.back_edge(e,g) but how can I get the list of vertices defining this cycle ? Thanks by advance

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can't get first example in boost tutorial to work
by 7stud 11 Mar '13

11 Mar '13

I'm trying to install boost on mac osx 10.4.7. I followed the tutorial "Getting Started on Unix Variants" found here: http://www.boost.org/doc/libs/1_35_0/ more/getting_started/unix-variants.html Following the instructions in the tutorial, I installed boost in /usr/local as instructed, so my directory structure is: /usr/local/boost_1_34_1/boost But when I run the first example in the tutorial: #include <boost/lambda/lambda.hpp> #include <iostream> #include <iterator> #include <algorithm> int main() { using namespace boost::lambda; typedef std::istream_iterator<int> in; std::for_each(in(std::cin), in(), std::cout << (_1 * 3) << " " ); } I get the error(among others): error: boost/lambda/lambda.hpp: No such file or directory If I change the include path to: #include </user/local/boost_1_34_1/boost/lambda/lambda.hpp> I get the error(among others): error: boost/lambda/core.hpp: No such file or directory But core.hpp is in the lambda directory: /usr/local/boost_1_34_1/boost/lambda$ ls algorithm.hpp control_structures.hpp lambda.hpp bind.hpp core.hpp loops.hpp casts.hpp detail numeric.hpp closures.hpp exceptions.hpp switch.hpp construct.hpp if.hpp I'm using the Xcode 2.4 IDE to run my C++ programs. I also tried to execute the program from the command line with the original include path: #include <boost/lambda/lambda.hpp> but I get the same error: ~/2testing/dir1$ g++ prog1.cpp prog1.cpp:1:35: error: boost/lambda/lambda.hpp: No such file or directory prog1.cpp: In function 'int main()': prog1.cpp:8: error: 'boost' has not been declared prog1.cpp:8: error: expected namespace-name before ';' token prog1.cpp:8: error: '<type error>' is not a namespace prog1.cpp:11: error: '_1' was not declared in this scope I get the same errors again with the full include path: #include </user/local/boost_1_34_1/boost/lambda/lambda.hpp> $ g++ prog1.cpp In file included from prog1.cpp:1: /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:14:33: error: boost/lambda/core.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:21:52: error: boost/lambda/detail/operator_actions.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:22:61: error: boost/lambda/detail/operator_lambda_func_base.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:23:63: error: boost/lambda/detail/operator_return_type_traits.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:26:45: error: boost/lambda/detail/operators.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:30:46: error: boost/lambda/detail/member_ptr.hpp: No such file or directory prog1.cpp: In function 'int main()': prog1.cpp:8: error: 'boost' has not been declared prog1.cpp:8: error: expected namespace-name before ';' token prog1.cpp:8: error: '<type error>' is not a namespace prog1.cpp:11: error: '_1' was not declared in this scope What path should I be using? Or, should I set an environment variable somewhere?

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[units] Missing quantity operator++, operator%
by Nathan Crookston 25 Oct '12

25 Oct '12

All, I'm in the process of switching my homegrown units system over to boost units. Some operators which I'm missing are the modulus and the pre and post increment operators. Looking through the archives I note an original review[1] which mentioned the absence of those operators. One response claimed that quantity<si::length, int> t = 5. ...; t++; was nonsensical as writing 5 m + 1, and the reviewer eventually agreed, citing possible confusion if the quantity type converted the initializer. Matthias Schabel seemed to respond favorably: 'I debated this for a while - the only problem is that there will be some value types with heterogeneous operator+ / operator- for which q + 1 is not the same type as q, but I guess that it is just OK for it to just give a compile error in those cases.' And Steven Watanabe said 'Will do.' I haven't found anything regarding the modulus operator. My question is, would a patch adding those operators be accepted? Thanks, Nate [1] http://lists.boost.org/Archives/boost/2007/03/119001.php

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Asio and ZeroMQ
by Matthias Vallentin 11 Oct '12

11 Oct '12

A while ago, Maciej Gajewski started an effort to use Asio to observe a ZeroMQ socket [1]. Based on his code, I put together a thin library that wraps the implementation details. Since other have requested a working example, here it is now at github: https://github.com/mavam/bmq Any feedback is highly appreciated. A basic usage example looks like this: #include <boost/asio/io_service.hpp> #include <bmq.h> int main() { boost::asio::io_service io; bmq::context ctx(1); bmq::component c(ctx, io); auto sink = c.add_sink(ZMQ_PAIR, "inproc://x"); c.subscribe(sink, [](bmq::message&& msg) { std::string str(static_cast<char*>(msg.data()), msg.size()); std::cout << str << std::endl; }); auto source = c.add_source(ZMQ_PAIR, "inproc://x"); bmq::message msg(const_cast<char*>("foo"), 3, nullptr); source->send(msg); // Execute message handler. io.poll(); return 0; } At this point, the library is really thin and only provides very rudimentary wrapping of ZeroMQ. In the future, I plan to extend it in order to facilitate applications that build on message-passing. The dataflow abstraction I envision is essentially a directed graph, where nodes represent components and edges communication links. 0mq provides the edges and the Asio handles asynchronous event processing at the component level. The motiviation is that this model lends itself well for scaling out distributed systems over large clusters. Matthias [1] http://permalink.gmane.org/gmane.network.zeromq.devel/9538

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[Sandbox - endian] Why is endian still in sandbox?
by Nathaniel J Fries 07 Oct '12

07 Oct '12

A fairly novel (at least when put up against more intricate labours like asio, filesystem, and their like) project which appears to be finished and would be a very useful companion to existing libraries sits in the sandbox. Is there a reason for this?

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[BGL] vecS for vertex container and vertex index adjustments
by Sergey Mitsyn 03 Oct '12

03 Oct '12

Hi all, I know that while using vecS for vertices one has no vertex iterator stability upon removing vertices. But I have a question if there exists something like vertex _index_ stability. The documentation says that indices for vertices are automatically adjusted so that they are still in contiguous range, but it is not specified how it is done. Is it okay to assume that if a vertex with an index I is removed, then vertices with indices < I have their indices unchanged, while vertices with indices > I have their indices decreased by one? The actual problem is removing all vertices meeting some condition. Is the following code ok? // traverse all vertices and remove those for which predicate // condition_to_remove_vertex returns true. // graph is adjacency_list<.., vecS, ...> vertex_iterator vi = vertices(graph).first, vi_end = vertices(graph).second; while (vi != vi_end) { if (condition_to_remove_vertex(vi, graph)) { vertices_size_type end_index = vertex_index[*vi_end] , vi_index = vertex_index[*vi]; remove_vertex_f(*vi, graph); // vi and vi_end are invalid --end_index; vi = vertices(graph).first + vi_index; vi_end = vertices(graph).first + end_index; // now vi and vi_end are valid again } else ++vi; } This way seems to be more effective than to start iteration again every time a vertex is removed. ------------ Sergey Mitsyn.

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[Range] insert algorithm fails if target is a map
by Robert Jones 11 Sep '12

11 Sep '12

The title says it all really. The failure occurs because the insert algorithm expects the container to provide a 3-arg insert of the form container.insert( position, begin, end ); whereas map's, multimap's and set's insert method only takes two arguments... map.insert( begin, end ); Is this limitation by design? It would be easy to provide specialisations for maps, mmaps and sets, but that would not be a completely general solution. - Rob.

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filesystem directory_iterator run-time error during construction after upgrading to OSX Lion
by Martin Searancke 04 Sep '12

04 Sep '12

I have just upgraded my Mac to Lion and code that worked fine under snow leopard is giving me a run-time exception when constructing a directory_iterator. The error I am getting is "malloc: pointer being freed was not allocated" The line in question that raises this error is: for ( directory_iterator itr( my_path ); itr != end_itr; ++itr ) taken directly from the example and working fine under windows. This is version 1.49 installed with MacPorts. Is this a known problem? I found some vague references to a similar problem in an earlier version of boost but no solution. I have confirmed that I only have 1 copy of the headers and libs on the system and in the correct path. The date stamp on the files matches the last time I did a macports update so this should be the matching library for the header. Please note that I am a real novice to Mac development and have only just started porting code from windows for less than a month. Thanks in advance, Martin

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[Graph] compilation error under Windows but not under Linux
by Gaël de Chalendar 29 Aug '12

29 Aug '12

Hello, I have a compilation error under Windows (Visual C++ 2008) with a code that works well under Linux (gcc 4.6.1 and before). The compilation error is: =========== /FsaAccess16.tcc(833) : error C2784: 'std::pair<graph_traits<G>::in_edge_iterator,graph_traits<G>::in_edge_iterator> boost::in_edges(graph_traits<G>::vertex_descriptor,const boost::subgraph<Graph> &)'ÿ: impossible de d‚duire l'argument modŠle pour 'const boost::subgraph<Graph> &' … partir de 'FrCeaLic2m::Common::FsaAccess::selected_graph_types16::spareGraphType' C:\PROGRA~1\boost\BOOST_~1\boost/graph/subgraph.hpp(432)ÿ: voir la d‚claration de 'boost::in_edges' Z: \Projets\MoteurMultimedia\mm_common\src\common/FsaAccess/FsaAccess16.tcc(778)ÿ: lors de la compilation de la fonction membre '<Inconnu>' de la classe <Inconnu> z: \projets\moteurmultimedia\mm_common\src\common\fsaaccess\FsaAccessReader16.h(118)ÿ: voir la r‚f‚rence … l'instanciation de la classe modŠle 'FrCeaLic2m::Common::FsaAccess::FsaAccess16<graphType>' en cours de compilation with [ graphType=FrCeaLic2m::Common::FsaAccess::selected_graph_types16::spareGraphType ] z: \projets\moteurmultimedia\mm_common\src\common\fsaaccess\FsaAccessSpare16.h(35)ÿ: voir la r‚f‚rence … l'instanciation de la classe modŠle 'FrCeaLic2m::Common::FsaAccess::FsaAccessReader16<graphType>' en cours de compilation with [ graphType=FrCeaLic2m::Common::FsaAccess::selected_graph_types16::spareGraphType ] =========== The line that does not compile is boost::tie(iei,ie_end) = boost::in_edges(commonTarget,m_graph); The function being compiled is declared like that: template <typename graphType > std::pair< const typename boost::graph_traits<graphType>::vertex_descriptor, bool > FsaAccess16<graphType>::findEquivalentInRegister( dicoVertexType tempState ){ ... And here graphType, the type of m_graph is spareGraphType defined by: struct selected_graph_types16 { ... typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, dicoVertexCountProperty> spareGraphType; ... This is a cmake based project that I compile using qtcreator. I'm a Linux developer and I'm a little bit lost with VC outputs and tools under Windows... Regards, Gaêl -- Gael de Chalendar CEA LIST Centre de Fontenay-aux-Roses Laboratoire Vision et Ingénierie des Contenus (Vision and Content Engineering Laboratory) Bat. 38-2 ; 18, rue du Panorama ; BP 6 92265 Fontenay aux Roses Cedex ; France Tél.:01.46.54.80.18 ; Fax.:01.46.54.75.80 Email : Gael.D.O.T.de-Chalendar.A(a)T.cea.D.O.T.fr

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Re: [Boost-users] asio HTTP Server 3 example memory leak
by admin＠thefireflyproject.us 25 Aug '12

25 Aug '12

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eos_portable_archive for 1.49
by Paul Harris 13 Jul '12

13 Jul '12

Hi all, Does anyone know if eos_portable_archive is still actively used and maintained? It doesn't compile with boost 1.49, and before I try to fix it up, I was wondering if anyone else has fixed it up. cheers Paul

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[bgl] depth_first_search does not compile. color_map howto?
by Joachim Faulhaber 04 Jul '12

04 Jul '12

Hi, When using visitors with the depth_first_search algorithm I can successfully compile and run this code: //========================================================= template<class Graph> class Visitor: public default_dfs_visitor { public: typedef typename graph_traits<Graph>::vertex_descriptor Vertex; void discover_vertex(Vertex v, const Graph& g)const {cout << v << " "; return;} }; void GLV_visit() { typedef adjacency_list<listS, vecS, directedS> GraphLV; GraphLV g; add_edge(0, 1, g); add_edge(0, 2, g); add_edge(1, 2, g); add_edge(1, 3, g); Visitor<GraphLV> vis; boost::depth_first_search(g, visitor(vis)); cout << endl; } BOOST_AUTO_TEST_CASE(graph_test) { GLV_visit(); } //========================================================= With a slightly different graph (listS instead of vecS for vertices) the same call of depth_first_search fails to compile with msvc-10. //========================================================= struct Int{ Int(): _value(0){} Int(int val): _value(val){} int _value; }; void GLL_visit() { typedef adjacency_list<listS, listS, directedS, Int> GraphLL; typedef graph_traits<GraphLL>::vertex_descriptor VertexLL; GraphLL g; Int val(42); VertexLL v0 = boost::add_vertex(g); VertexLL v1 = boost::add_vertex(g); g[v0] = Int(0); g[v1] = Int(1); add_edge(v0, v1, g); Visitor<GraphLL> vis; boost::depth_first_search(g, visitor(vis)); //compile errors } //========================================================= >From the tiny error message of 108 long verbose lines of internal graph template instantiations (see attachment) it seems that the compiler is unable to create a default color_map (but I might be wrong with this interpretation of the template jungle). 1. Do I need to provide a color_map parameter here? 2. If so, what is the simplest way to do that and provide an object of the appropriate type? I'd greatly appreciate a working code example. Examples and best practices for defining and handling external propery maps in general would be helpful. TIA, Joachim -- Interval Container Library [Boost.Icl] http://www.joachim-faulhaber.de

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[statechart] history in the different state hierarchies
by Vlad Orlov 02 Jul '12

02 Jul '12

Hello everybody. I have a problem similar to the one described in the Statechart tutorial, but a little different. My state machine has two states (let's call them A and B) in the different state hierarchies and a third state C that can be transited to from either A or B. The transition from C must be done to either A or B, depending on where we came to C from. So I've decided to use the history. The difference between this problem and what's described in the tutorial is that A and B don't belong to the same composite state (they only belong to the same state machine). I can't simply declare "has_xxx_history" in the outer state like it's done in the tutorial. Here's what I've tried to do: #include <iostream> #include <boost/statechart/shallow_history.hpp> #include <boost/statechart/simple_state.hpp> #include <boost/statechart/state_machine.hpp> #include <boost/statechart/transition.hpp> namespace sc = boost::statechart; // events struct transfer_to_B : sc::event<transfer_to_B> {}; struct visit_C : sc::event<visit_C> {}; struct exit_to_history : sc::event<exit_to_history> {}; // forward declarations struct state_A; struct substate_A; struct substate_B; struct state_C; // state machine struct test_fsm : sc::state_machine<test_fsm, state_A> {}; // composite state A struct state_A : sc::simple_state<state_A, test_fsm, substate_A, sc::has_shallow_history> {}; struct substate_A : sc::simple_state<substate_A, state_A> { typedef boost::mpl::list < sc::transition<transfer_to_B, substate_B> , sc::transition<visit_C, state_C> > reactions; substate_A() { std::cout << "Entered A" << std::endl; } ~substate_A() { std::cout << "Exited A" << std::endl; } }; // composite state B struct state_B : sc::simple_state<state_B, test_fsm, substate_B, sc::has_shallow_history> {}; struct substate_B : sc::simple_state<substate_B, state_B> { typedef sc::transition<visit_C, state_C> reactions; substate_B() { std::cout << "Entered B" << std::endl; } ~substate_B() { std::cout << "Exited B" << std::endl; } }; // simple state C struct state_C : sc::simple_state<state_C, test_fsm> { typedef sc::transition < exit_to_history, sc::shallow_history<substate_A> > reactions; state_C() { std::cout << "Entered C" << std::endl; } ~state_C() { std::cout << "Exited C" << std::endl; } }; int main() { test_fsm fsm; fsm.initiate(); fsm.process_event(visit_C()); fsm.process_event(exit_to_history()); fsm.process_event(transfer_to_B()); fsm.process_event(visit_C()); fsm.process_event(exit_to_history()); } Unfortunately, this doesn't work as intended. The transition to history always leads to substate_A and never to substate_B: Entered A Exited A Entered C Exited C Entered A Exited A Entered B Exited B Entered C Exited C Entered A Exited A Can anyone please clarify if I've got something wrong or made a mistake somewhere? Is history supposed to work in the different state hierarchies?

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Program Options: What would be involved in implementing add_options()(optionNameWork, po::value<std::pair<int, float>>() ?
by Charles Mills 30 Jun '12

30 Jun '12

I really like Boost Program Options. I came up with this wild hare of being able to handle something like foo= int float Obviously, I could do it by instead using foo_int= int foo_float= float But what would be involved in being able to do something like add_options()(optionNameWork, po::value<std::pair<int, float>>() ? I would have to derive a class from boost::program_options::value_semantic? I would have to implement all of the abstract methods? The other classes also like abstract_variables_map? Or just variable_value? Volodya wrote in response to an earlier question "I would imagine this to be not hard. Either define operator>> for the class you use to represent rectangles, over override 'validate'" Is that what I should? Define operator>> for pair<int, float> ? Where is an example of a boost::program_options >> operator? Where is validate() declared? Sorry to be such a newbie at this level of C++ programming. You have to start somewhere. Charles

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Re: [Boost-users] [boost] Meeting C++ - Call for Papers
by Jens Weller 30 Jun '12

30 Jun '12

Hi, small update on this: As some people haved asked: The session length will be 45 minutes, some talks might extend to 90 min. There is now a form to submit your talk: http://meetingcpp.com/index.php/submit-your-talk.html Call for Papers should end at 15. July 2012 Tickets will also be available in July. regards, Jens Weller -------- Original-Nachricht -------- > Datum: Wed, 27 Jun 2012 16:45:54 +0200 > Von: Matus Chochlik <chochlik(a)gmail.com> > An: boost(a)lists.boost.org > Betreff: [boost] Meeting C++ - Call for Papers > On Wed, Jun 27, 2012 at 4:08 PM, Jens Weller <JensWeller(a)gmx.de> wrote: > > Dear C++/boost community! > > > > I'm proud to announce the call for papers for the Meeting C++ > conference! > > After having talked to some people in Aspen about the plans for a C++ > conference in Germany, I've decided to give it a try. > > Meeting C++ will take place in November in Germany, as a 2 Day C++ > conference. > > > > Thank You for organizing this conference! -- Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de

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[1.50.0] Boost release 1.50.0 available
by Beman Dawes 29 Jun '12

29 Jun '12

Release 1.50.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains four new libraries (Algorithm, Functional/OverloadedFunction, LocalFunction and Utility/IdentityType) and numerous enhancements and bug fixes for existing libraries. For details, including download links, see http://www.boost.org/users/news/version_1_50_0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.50.0/ To install this release on your system, see http://www.boost.org/doc/libs/release/more/getting_started/index.html Thanks, --The Boost release team Beman Dawes Daniel James Eric Niebler Marshall Clow Rene Rivera Vladimir Prus

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[Boost.Python] Is it possible classes X Y returned each other?
by Sergiy Nazarenko 29 Jun '12

29 Jun '12

Hi, all! I'm writing python module and run into obstacle. I need a couple of classes which can return instance of each other. This is part of my module: /// mysupermodule.cpp ... struct X { X():s("default") {} X(std::string s):s(s) {} Y getY() const { return Y(); } }; struct Y { Y():s("default") {} Y(std::string s):s(s) {} X getX() const { return X(); } }; ... /// And I got obvious error: mysupermodule.cpp:45:5: error: ‘Y’ does not name a type. How can I solve this task? Regards Sergiy

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boost 1.50 different libraray naming?
by Szymon Gatner 29 Jun '12

29 Jun '12

Hi, I just build v 1.50 on Win 7 / Visual Studio 2008 SP1 (msvc9) and I am getting linker errors like: Error 21 fatal error LNK1104: cannot open file 'libboost_filesystem-vc90-mt-gd-1_50.lib' test test because in this release files are named without "90" part: libboost_filesystem-vc-mt-gd-1_50 while in 1.49 (and below): libboost_exception-vc90-mt-gd-1_49 Regards, Szymon Gatner

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