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Re: [Boost-users] [Tokenizer] Compile error with lots of missing binary operator statments
by Collin Day 31 Oct '11

31 Oct '11

Previously, I had posted what I thought was a bug. I did not think to do this originally, but I just tried a simple Hello World program that included boost/tokenizer.hpp. It compiled fine. I then looked at where the sample code was pulling headers from, and it appears that the download included old boost headers it was including instead of 1.47.0. I completley missed this. I apologize - and take back the error - there is none :) Thanks!

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boost random uniform real infinite loop
by Peter Man 31 Oct '11

31 Oct '11

Hi, Recently, I've encountered a problem with the generate_uniform_real function (the is_integral version) in boost/random/uniform_real_distribution.hpp. A bug in my code meant that I was trying to generate a uniform random number where the min and max bounds were exactly equal. However, this meant that when on entering the function stated earlier, an infinite loop is never exited from! Is this a bug in boost::random, or have I missed something? Thanks Peter

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sending large serialized objects over network using MPI
by Jonathan Bishop 31 Oct '11

31 Oct '11

HI, I am involved in a project which requires the transport of large C++ instances over MPI communication channels. I am using boost serialization to pack and unpack the objects into a buffer. The whole buffer is sent in one shot. Of course for large objects this can be problematic. I have two questions... 1) is there any way to tell beforehand how large the buffer needs to be? In other words, can you run serialization in a counting only mode? 2) is there an archive implemented which streams across MPI communication channels (not sure this is the right terminology.)? Seems like it might be useful. This might be a better question for the boost MPI team, though. Thanks, Jon

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[Signals] trackable detection for user defined callabcks
by Szymon Gatner 30 Oct '11

30 Oct '11

Hi, Signals docs say: "Warning: User-defined function objects and function objects from other libraries (e.g., Boost.Function or Boost.Lambda) do not implement the required interfaces for trackable object detection, and will silently ignore any bound trackable objects. Future versions of the Boost libraries will address this limitation." My questions: 1) What is the required interface for user-defined callbacks? 2) Is it still true that it will be addressed in future versions of Boost.Function? Regards, Simon -- Szymon Gatner The Lordz Games Studio www.thelordzgamesstudio.com

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[boost] [C++ Now! 2012] Call for Submissions
by Brian Wood 30 Oct '11

30 Oct '11

Hartmut Kaiser: > The C++ Now! Conference is dedicated to discussion and education > about C++, an open and free language and standard. It costs a lot to buy a copy of the standard now! Hope conference goes well and maybe I can attend someday. -- Brian Wood Ebenezer Enterprises http://webEbenezer.net

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Re: [Boost-users] sending large serialized objects over network
by Brian Wood 30 Oct '11

30 Oct '11

Jonathan Bishop: > HI, > I am involved in a project which requires the transport of large C++ > instances over MPI communication channels. I am using boost serialization to > pack and unpack the objects into a buffer. The whole buffer is sent in one > shot. > > Of course for large objects this can be problematic. I have two questions... > > 1) is there any way to tell beforehand how large the buffer needs to be? In > other words, can you run serialization in a counting only mode? I'm not sure about the Boost Serialization library, but the C++ Middleware Writer counts the number of bytes in a message before any is marshalled. Here's an example void remote_messages::Marshal (SendCompressedBuffer& buf , marshalling_integer const& abt1 , marshalling_integer const& abt2 , cmw_user_input const& abt3 ) { Counter cntr(msg_length_max); abt1.CalculateMarshallingSize(cntr); abt2.CalculateMarshallingSize(cntr); abt3.CalculateMarshallingSize(cntr); cntr.Add(sizeof(msg_id_direct)); buf.Receive(&msg_id_direct, sizeof(msg_id_direct)); abt1.Marshal(buf, false); abt2.Marshal(buf, false); abt3.Marshal(buf, false); } -- Brian Wood Ebenezer Enterprises http://webEbenezer.net <http://webebenezer.net/>

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split() and MSVS .NET 2003
by Larry 30 Oct '11

30 Oct '11

I have found using Boost 1.47 with MSVS .Net 2003 that if I include split() that it tends to kill the Intellisense function in the editor for a current method or function. I usually have something like typedef vector<string> Splits; Splits sv; string input_string; split(sv,input_string,is_any_of("|")); I was curious if anyone else had run across this and better yet if there was a way around it. I think I may have seen it in earlier Boost versions but my memory is fuzzy about that. There was a time when this behavior did not exist but I am not certain when and what MSVS changes may have been applied since it did work. The code compiles OK and works correctly. Larry

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Build error with boost-1.45.0 in ptree_implementation.hpp
by Sunil Thomas 29 Oct '11

29 Oct '11

Hi all! I am getting the following error with boost-1.45.0 using MS VS 2010 Profession, Win64 (Windows Vista 64 bit). Appreciate if anyone knows a fix. This error was seen with older versions like 1.41 and so on; hence, it must've been fixed by now. <path\to>\boost/property_tree/detail/ptree_implementation.hpp(30) : error C2440: 'specialization' : cannot convert from 'const std::string std::_Pair_base<_Ty1,_Ty2>::* ' to 'const std::basic_string<_Elem,_Traits,_Ax> std::pair<_Ty1,_Ty2>::* ' with [ _Ty1=const std::string, _Ty2=boost::property_tree::basic_ptree<std::string,std::string> ] and [ _Elem=char, _Traits=std::char_traits<char>, _Ax=std::allocator<char>, _Ty1=const std::string, _Ty2=boost::property_tree::basic_ptree<std::string,std::string> ] Standard conversion from pointer-to-member of base to pointer-to-member of derived is not applied for template arguments <path\to>\boost/property_tree/detail/ptree_implementation.hpp(78) : see reference to class template instantiation 'boost::property_tree::basic_ptree<Key,Data>::subs' being compiled with [ Key=std::string, Data=std::string ] <path\to>\boost/foreach.hpp(265) : see reference to class template instantiation 'boost::property_tree::basic_ptree<Key,Data>::const_iterator' being compiled with [ Key=std::string, Data=std::string ] libs\graph\src\graphml.cpp(36) : see reference to class template instantiation 'boost::foreach_detail_::auto_any<T>' being compiled with [ T=boost::property_tree::basic_ptree<std::string,std::string>::const_iterator ] Appreciate any help! Thanks, --Sunil.

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How efficient is the boost::regex library?
by Alec Taylor 29 Oct '11

29 Oct '11

Good afternoon, I am looking for the most efficient open-source C++ regex library. Reading this article: http://swtch.com/~rsc/regexp/regexp1.html - It seems that GNU awk is the best overall: http://pdos.csail.mit.edu/~rsc/regexp-img/grep1p.png How does the boost::regex library compare? Would you recommend boost::regex as the most efficient one, or would you suggest another? Thanks for all information, Alec Taylor

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[serialization] tracking objects
by Matthias Brantner 29 Oct '11

29 Oct '11

Hello, I have n objects sharing common (sub)objects in a pool (i.e. via pointers). I would like to save (serialize) these n objects separately. Each result should contain one copy of the shared object and can be used stand alone. However, when loading (deserializing) multiple of those n objects, I would like to recreate the original state, i.e. subobjects previously pooled are again shared and contained in the pool. For example, object O1 contains a pointer to object P1. Object O2 also contains a pointer to object P1. O1 and O2 are separately serialized and each serialization will contain a copy of P1. After deserializing, the deserialized versions of O1 and O2 should both contain pointers to the same object P1. My current idea is to deserialize P1 (in the process of deserializing O1 or O2) by implementing the load function for P1's class. In this function, I would like to check if an object equal to P1 already exists in the pool. If it exists, I would like to return a pointer to the existing object. Otherwise, I would like to insert it into the pool and return the newly created object. However, I have not found a way to return a pointer that was not created by boost. Is there such a way or is there a better way to do what I'm trying to do? Thanks in advance. Best regards Matthias

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Boost 1.47 and exception_ptr
by Travis Gockel 29 Oct '11

29 Oct '11

I'm working on upgrading from Boost 1.46.1 to 1.47 and having one tiny little problem with exception_ptr. Currently, some of my systems keep an exception_ptr around to denote if they have a "current exception" or not. At times, we need to "clear" the current exception (it was resolved or whatever), which we used to do by calling ex->reset(). However, as of 1.47, excecption_ptr is no longer just a shared_ptr, so reset() has gone away. What is the new preferred way of getting this old functionality? I can't seem to find the way in the source. -- Travis Gockel C++ Pirate

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Event system using signals2
by Chris Cranford 29 Oct '11

29 Oct '11

In the past, I have typically seen a lot of event systems leverage an abstract base listener class that all classes were derived from if they wanted to wire themselves up to a particular system, such as an event dispatcher. This lead to giant switch statements inside the listener's handle event method. I've used this methodology in the past and it has worked. But noticing that a number of articles have suggested using a signal/slot mechanism rather than the above approach, I started trying to implement a simple event dispatcher based on boost signals2; however I cannot seem to make it work as I would like. See code below: // holds relationship of type and signal object struct event_signal { int type; boost::signals2::signal<void(void)> sig; }; typedef struct event_signal event_signal_t; class EventDispatcher { // other stuff left out public: void addListener(int type, boost::function<void(void)> pFunction) { std::map<int,even_signal_t*>::iterator i = m_events.begin(); if(i == m_events.end()) { event_signal_t* p = new event_signal_t; p->type = type; p->sig.connect(p); m_events.insert(std::make_pair(type, p)); } else { m_events[type]->sig.connect(pFunction); } } private: std::map<int, event_signal_t*> m_events; }; Since signals are not copyable, I had to store a pointer to a signal. I chose a struct in case I want to add more information later; however I could have easily used the signal directly. The classes that I want to wire to my event dispatcher must derive from boost::signals2::trackable because I want their connection to be automatically deleted upon the tracked object's destruction; so here is my tracked object: // base class for event system tracking class EventTrackedObject : public boost::signal2::trackable { public: EventTrackedObject() { } ~EventTrackedObject() { } }; class MyObject : public EventTrackedObject { public: MyObject(EventDispatcher* pDispatcher) { pDispatcher->addListener(E_MY_EVENT, boost::bind(&MyObject::OnMyEvent, this)); } ~MyObject() { } void OnMyEvent(void) { } }; The problem with this I found is that the tracked object appears to be getting copied at the time the boost::bind is passing itself to the addListener() method. Is there a way to avoid this so that the tracked object's disconnect happens as expected? Secondly, I would prefer not to have to reference this and use the bind call at all in my base objects and rather simply have a call that looks like: pDispatcher->addListener(E_MY_EVENT, &MyObject::OnMyEvent); Or is there a more ideal approach to my problem that I am missing? Chris

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Problem compiling
by Matteo 28 Oct '11

28 Oct '11

Hi guys, I am writing a class that include gboy's libraries ( http://gobysoft.com/#/software/goby) but I have a problem with boost libraries. The code is: (from gobymodule.cc) void GobyModule::start() { // // 1. Create and initialize MMDriver // // goby::acomms::ModemDriverBase* driver = 0; goby::acomms::protobuf::DriverConfig cfg; // set the serial port given on the command line cfg.set_serial_port(serial_path); using google::protobuf::uint32; // set the source id of this modem // uint32 our_id = goby::util::as<uint32>(argv[2]); cfg.set_modem_id(ID); goby::glog.set_name("WHIO Micromodem"); goby::glog.add_stream(goby::util::logger::DEBUG1, &std::clog); // default to WHOI MicroModem // if (!driver) // { std::cout << "Starting WHOI Micro-Modem MMDriver" << std::endl; driver = new goby::acomms::MMDriver; // turn data quality factor message on // (example of setting NVRAM configuration) cfg.AddExtension(micromodem::protobuf::Config::nvram_cfg, "DQF,1"); // } /////////////////////////////////////// // THE PROBLEM IS HERE ///////////////////////////////////// function_pointer = &handle_data_receive; goby::acomms::connect(&driver->signal_receive, function_pointer); // // 2. Startup the driver // driver->startup(cfg); } (from gobyModule.h) class GobyModule: { public: void function(str::string); } void (*function_pointer)(const goby::acomms::protobuf::ModemTransmission & data_msg, GobyModule* foo); void handle_data_receive(const goby::acomms::protobuf::ModemTransmission & data_msg, GobyModule* foo) { foo->payload_parser(str.str()); } The problem, compiling, is: In file included from /usr/include/boost/function/detail/maybe_include.hpp:18:0, from /usr/include/boost/function/detail/function_iterate.hpp:14, from /usr/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:52, from /usr/include/boost/function.hpp:64, from /usr/include/boost/thread/future.hpp:20, from /usr/include/boost/thread.hpp:24, from /usr/local/include/goby/acomms/modemdriver/driver_base.h:23, from /usr/local/include/goby/acomms/modem_driver.h:23, from gobyModule.h:10, from gobyModule.cc:1: /usr/include/boost/function/function_template.hpp:913:60: instantiated from ‘void boost::function1<R, T1>::assign_to(Functor) [with Functor = void (*)(const goby::acomms::protobuf::ModemTransmission&, GobyModule*), R = void, T0 = const goby::acomms::protobuf::ModemTransmission&]’ /usr/include/boost/function/function_template.hpp:722:7: instantiated from ‘boost::function1<R, T1>::function1(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = void (*)(const goby::acomms::protobuf::ModemTransmission&, GobyModule*), R = void, T0 = const goby::acomms::protobuf::ModemTransmission&, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ /usr/include/boost/function/function_template.hpp:1064:16: instantiated from ‘boost::function<R(T0)>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = void (*)(const goby::acomms::protobuf::ModemTransmission&, GobyModule*), R = void, T0 = const goby::acomms::protobuf::ModemTransmission&, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]’ /usr/include/boost/signals/slot.hpp:111:122: instantiated from ‘boost::slot<SlotFunction>::slot(const F&) [with F = void (*)(const goby::acomms::protobuf::ModemTransmission&, GobyModule*), SlotFunction = boost::function<void(const goby::acomms::protobuf::ModemTransmission&)>]’ /usr/local/include/goby/acomms/connect.h:35:11: instantiated from ‘void goby::acomms::connect(Signal*, Slot) [with Signal = boost::signal<void(const goby::acomms::protobuf::ModemTransmission&)>, Slot = void (*)(const goby::acomms::protobuf::ModemTransmission&, GobyModule*)]’ gobyModule.cc:404:66: instantiated from here /usr/include/boost/function/function_template.hpp:112:11: error: too few arguments to function Thank you so much, Matteo

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Serializing handles to opaque objects
by James Amundson 28 Oct '11

28 Oct '11

I am trying to use Boost Serialization with a set of classes which contain handles to opaque objects written in C. (Specifically, the objects are MPI communicator objects and the handles are of the MPI_Comm type, but I don't think that's important for the problem.) Now, I can easily extract the information from the objects necessary to serialize and de-serialize them; that is not the problem. The problem is that several classes have handles to the *same* object. When I restore the objects I need to make certain that all the identical handles end up pointing to the same object. I don't see an easy way to do that. The problem seems to me to be highly analogous to the (solved) problem of serializing pointers, except that the handles are not literally pointers. I'd be grateful for any advice Thanks, Jim Amundson

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[graph] how do i test at compile time if a Graph is directed or undirected?
by Christoph 28 Oct '11

28 Oct '11

Hi, ist it possible to test at compile time if a graph is directed or undirected? I would like the compiler to give an error message if the graph is directed. best regards Christoph

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[boost-users] Cartesian product
by Christoph Heindl 28 Oct '11

28 Oct '11

Hi, I'm on search for an algorithm that produces the cartesian product for n-dimension. The coordinates of each dimension are not limited to numbers. Ideally I'd like to write something along the lines of std::vector<int> d0; // (assume d0 = [0, 3, 2]); std::vector<bool> d1; // (assume d1 = [true]); std::vector<std::string> d2; // (assume d2 = ["hello", "world"]) typedef boost::fusion::vector< std::vector<int>, std::vector<bool>, std::vector<std::string> > tt; tt space(d0, d1, d2); boost::cartesian_product<tt> cp(space); BOOST_FOREACH(const boost::cartesian_product<tt>::value_type &t, cp) { // Invoked for every possible combination of the three dimension. // t is boost::tuple<int, bool, std::string> or similar } I think that something similar can be accomplished using boost.fusion, but I cannot derive the algorithm. What I have found so far is a meta cartesian product [1]. Has anyone such an algorithm lying around? Any help would be greatly appreciated. Best regards, Christoph [1] http://organicvectory.com/index.php?option=com_content&view=article&id=75:b…

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[Tokenizer] Error - Missing Binary operator
by Collin Day 28 Oct '11

28 Oct '11

Hi all, I have been trying to compile some example source code that uses the tokenizer. I am using GCC 4.5.3 with boost 1.47. I get the following compile error: In file included from ../../include/boost/mpl/apply.hpp:23:0, from ../../include/boost/iterator/iterator_facade.hpp:34, from ../../include/boost/iterator/iterator_adaptor.hpp:15, from ../../include/boost/token_iterator.hpp:21, from ../../include/boost/tokenizer.hpp:20, from Path.cpp:4: ../../include/boost/mpl/apply_wrap.hpp:81:31: error: missing binary operator before token "(" ../../include/boost/mpl/apply_wrap.hpp:173:31: error: missing binary operator before token "( I looked on the web, and everything that looks remotley like this said it was a problem with GCC > 4.4, but was fixed in boost 1.37. I have tried with both gcc 4.4.6 and 4.5.3. I don't think I am missing anything since it is just an include file, but I could be wrong. any help would be appreciated. Thanks!

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dijkstra_shortest_paths with a graph with bundled edge properties
by David Doria 27 Oct '11

27 Oct '11

This example works fine: http://programmingexamples.net/index.php?title=CPP/Boost/BGL/DijkstraUndire… However, if I change typedef boost::property<boost::edge_weight_t, float> EdgeWeightProperty; to struct EdgeWeightProperty{float weight;}; (and of course remove the lines adding the weights as properties: boost::add_edge(v1, v2, weight1, g); ) I get crazy template errors: /usr/include/boost/graph/dijkstra_shortest_paths.hpp: In member function ‘void boost::detail::dijkstra_bfs_visitor<UniformCostVisitor, UpdatableQueue, WeightMap, PredecessorMap, DistanceMap, BinaryFunction, BinaryPredicate>::examine_edge(Edge, Graph&) [with Edge = boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, Graph = const boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty>, UniformCostVisitor = boost::dijkstra_visitor<>, UpdatableQueue = boost::d_ary_heap_indirect<unsigned int, 4u, boost::iterator_property_map<unsigned int*, boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int>, unsigned int, unsigned int&>, int*, std::less<int>, std::vector<unsigned int> >, WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, boost::detail::error_property_not_found, const boost::detail::error_property_not_found&, unsigned int, const boost::property<boost::edge_bundle_t, EdgeWeightProperty, boost::no_property>, boost::edge_weight_t>, PredecessorMap = unsigned int*, DistanceMap = int*, BinaryFunction = boost::closed_plus<int>, BinaryPredicate = std::less<int>]’: /usr/include/boost/graph/breadth_first_search.hpp:77:47: instantiated from ‘void boost::breadth_first_visit(const IncidenceGraph&, typename boost::graph_traits<IncidenceGraph>::vertex_descriptor, Buffer&, BFSVisitor, ColorMap) [with IncidenceGraph = boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty>, Buffer = boost::d_ary_heap_indirect<unsigned int, 4u, boost::iterator_property_map<unsigned int*, boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int>, unsigned int, unsigned int&>, int*, std::less<int>, std::vector<unsigned int> >, BFSVisitor = boost::detail::dijkstra_bfs_visitor<boost::dijkstra_visitor<>, boost::d_ary_heap_indirect<unsigned int, 4u, boost::iterator_property_map<unsigned int*, boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int>, unsigned int, unsigned int&>, int*, std::less<int>, std::vector<unsigned int> >, boost::adj_list_edge_property_map<boost::undirected_tag, boost::detail::error_property_not_found, const boost::detail::error_property_not_found&, unsigned int, const boost::property<boost::edge_bundle_t, EdgeWeightProperty, boost::no_property>, boost::edge_weight_t>, unsigned int*, int*, boost::closed_plus<int>, std::less<int> >, ColorMap = boost::two_bit_color_map<boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int> >, typename boost::graph_traits<IncidenceGraph>::vertex_descriptor = unsigned int]’ /usr/include/boost/graph/dijkstra_shortest_paths.hpp:332:5: instantiated from ‘void boost::dijkstra_shortest_paths_no_init(const Graph&, typename boost::graph_traits<Graph>::vertex_descriptor, PredecessorMap, DistanceMap, WeightMap, IndexMap, Compare, Combine, DistZero, DijkstraVisitor, ColorMap) [with Graph = boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty>, DijkstraVisitor = boost::dijkstra_visitor<>, PredecessorMap = unsigned int*, DistanceMap = int*, WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, boost::detail::error_property_not_found, const boost::detail::error_property_not_found&, unsigned int, const boost::property<boost::edge_bundle_t, EdgeWeightProperty, boost::no_property>, boost::edge_weight_t>, IndexMap = boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int>, Compare = std::less<int>, Combine = boost::closed_plus<int>, DistZero = int, ColorMap = boost::two_bit_color_map<boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int> >, typename boost::graph_traits<Graph>::vertex_descriptor = unsigned int]’ /usr/include/boost/graph/dijkstra_shortest_paths.hpp:383:5: instantiated from ‘void boost::dijkstra_shortest_paths(const VertexListGraph&, typename boost::graph_traits<VertexListGraph>::vertex_descriptor, PredecessorMap, DistanceMap, WeightMap, IndexMap, Compare, Combine, DistInf, DistZero, DijkstraVisitor, ColorMap) [with VertexListGraph = boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty>, DijkstraVisitor = boost::dijkstra_visitor<>, PredecessorMap = unsigned int*, DistanceMap = int*, WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, boost::detail::error_property_not_found, const boost::detail::error_property_not_found&, unsigned int, const boost::property<boost::edge_bundle_t, EdgeWeightProperty, boost::no_property>, boost::edge_weight_t>, IndexMap = boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int>, Compare = std::less<int>, Combine = boost::closed_plus<int>, DistInf = int, DistZero = int, ColorMap = boost::two_bit_color_map<boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int> >, typename boost::graph_traits<VertexListGraph>::vertex_descriptor = unsigned int]’ /usr/include/boost/graph/dijkstra_shortest_paths.hpp:353:5: instantiated from ‘void boost::dijkstra_shortest_paths(const VertexListGraph&, typename boost::graph_traits<VertexListGraph>::vertex_descriptor, PredecessorMap, DistanceMap, WeightMap, IndexMap, Compare, Combine, DistInf, DistZero, DijkstraVisitor, const boost::bgl_named_params<T, Tag, Base>&, typename boost::enable_if_c<boost::is_base_and_derived<boost::vertex_list_graph_tag, typename boost::graph_traits<VertexListGraph>::traversal_category>::value, boost::graph::detail::no_parameter>::type) [with VertexListGraph = boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty>, DijkstraVisitor = boost::dijkstra_visitor<>, PredecessorMap = unsigned int*, DistanceMap = int*, WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, boost::detail::error_property_not_found, const boost::detail::error_property_not_found&, unsigned int, const boost::property<boost::edge_bundle_t, EdgeWeightProperty, boost::no_property>, boost::edge_weight_t>, IndexMap = boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int>, Compare = std::less<int>, Combine = boost::closed_plus<int>, DistInf = int, DistZero = int, T = int*, Tag = boost::vertex_distance_t, Base = boost::bgl_named_params<unsigned int*, boost::vertex_predecessor_t, boost::no_property>, typename boost::graph_traits<VertexListGraph>::vertex_descriptor = unsigned int, typename boost::enable_if_c<boost::is_base_and_derived<boost::vertex_list_graph_tag, typename boost::graph_traits<VertexListGraph>::traversal_category>::value, boost::graph::detail::no_parameter>::type = boost::graph::detail::no_parameter]’ /usr/include/boost/graph/dijkstra_shortest_paths.hpp:423:7: instantiated from ‘void boost::detail::dijkstra_dispatch2(const VertexListGraph&, typename boost::graph_traits<VertexListGraph>::vertex_descriptor, DistanceMap, WeightMap, IndexMap, const Params&) [with VertexListGraph = boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty>, DistanceMap = int*, WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, boost::detail::error_property_not_found, const boost::detail::error_property_not_found&, unsigned int, const boost::property<boost::edge_bundle_t, EdgeWeightProperty, boost::no_property>, boost::edge_weight_t>, IndexMap = boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int>, Params = boost::bgl_named_params<int*, boost::vertex_distance_t, boost::bgl_named_params<unsigned int*, boost::vertex_predecessor_t, boost::no_property> >, typename boost::graph_traits<VertexListGraph>::vertex_descriptor = unsigned int]’ /usr/include/boost/graph/dijkstra_shortest_paths.hpp:455:7: instantiated from ‘void boost::detail::dijkstra_dispatch1(const VertexListGraph&, typename boost::graph_traits<VertexListGraph>::vertex_descriptor, DistanceMap, WeightMap, IndexMap, const Params&) [with VertexListGraph = boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty>, DistanceMap = int*, WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, boost::detail::error_property_not_found, const boost::detail::error_property_not_found&, unsigned int, const boost::property<boost::edge_bundle_t, EdgeWeightProperty, boost::no_property>, boost::edge_weight_t>, IndexMap = boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int>, Params = boost::bgl_named_params<int*, boost::vertex_distance_t, boost::bgl_named_params<unsigned int*, boost::vertex_predecessor_t, boost::no_property> >, typename boost::graph_traits<VertexListGraph>::vertex_descriptor = unsigned int]’ /usr/include/boost/graph/dijkstra_shortest_paths.hpp:473:5: instantiated from ‘void boost::dijkstra_shortest_paths(const VertexListGraph&, typename boost::graph_traits<IncidenceGraph>::vertex_descriptor, const boost::bgl_named_params<P, T, R>&) [with VertexListGraph = boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty>, Param = int*, Tag = boost::vertex_distance_t, Rest = boost::bgl_named_params<unsigned int*, boost::vertex_predecessor_t, boost::no_property>, typename boost::graph_traits<IncidenceGraph>::vertex_descriptor = unsigned int]’ Any chance anyone can interpret these? Thanks, David

2 2

"Cannot Open Shared Object File" only present when run as cron
by Russ Jones 27 Oct '11

27 Oct '11

Hey folks, I'm currently using Boost to hold a statistical model in memory but am running into a problem. When run directly from the command line (as root), there are no issues, but when the same is run as a cron job, the following error is present... "/root/pylda/src/infer: error while loading shared libraries: libboost_program_options.so.1.46.1: cannot open shared object file: No such file or directory" Not quite sure what would change between running the same script as root user vs cron (I believe the cron is running as root, anyway). Have any of you experienced a similar problem? Thanks in advance, Russ Jones

2 1

[1.48.0] Beta 1 is now available from SourceForge
by Beman Dawes 27 Oct '11

27 Oct '11

Boost release 1.48.0 beta 1 is now available from SourceForge See http://sourceforge.net/projects/boost/files/boost/1.48.0.beta.1/ This release includes 3 new libraries (Container, Locale and Move), an extension to TypeTraits to support operator detection as well as updates to many existing libraries. For partial details of what's in the release, see http://beta.boost.org/users/history/version_1_48_0.html. This page is still in process of being updated, and there are some known issues with links. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team Beman Dawes Daniel James Eric Niebler Rene Rivera Vladimir Prus

1 0

Cross Compiling Boost.serialisation
by David.Allen＠generaldynamics.uk.com 27 Oct '11

27 Oct '11

Hello, Has anyone experienced the multiple link errors when trying to cross compile boost serialisation to the ARM platform ? The version of boost I am trying to build is 1.38. A copy of the output is attached. I am using the arm-angstrom compiler and linker. I believe I have captured all the correct compiler and linker flags and settings from inspection of other boost builds for Ubuntu. Any help gratefully received. Regards, Dave This email and any files attached are intended for the addressee and may contain information of a confidential nature. If you are not the intended recipient, be aware that this email was sent to you in error and you should not disclose, distribute, print, copy or make other use of this email or its attachments. Such actions, in fact, may be unlawful. In compliance with the various Regulations and Acts, General Dynamics United Kingdom Limited reserves the right to monitor (and examine for viruses) all emails and email attachments, both inbound and outbound. Email communications and their attachments may not be secure or error- or virus-free and the company does not accept liability or responsibility for such matters or the consequences thereof. General Dynamics United Kingdom Limited, Registered Office: 21 Holborn Viaduct, London EC1A 2DY. Registered in England and Wales No: 1911653.

1 0

[graph] std::priority_queue of vertex_descriptors with extended comparison object will not initialize
by Christoph 27 Oct '11

27 Oct '11

Hi List, as the Subject states. I would like to initialize a std::priority_queue with vertex_descriptors and a comparison object as a template parameter but the compiler tells me: ... /usr/include/c++/4.5/bits/stl_heap.h:303:4: error: invalid conversion from ‘unsigned int’ to ‘void*’ /usr/include/c++/4.5/bits/stl_heap.h:303:4: error: initializing argument 1 of ‘bool degree_compare::operator()(void* const&, void* const&)’ ... if i try to initialize the queue and i just don't know why 'bool degree_compare::operator()(void* const&, void* const&)' comes up. Could you please help me to initialize my priority_queue? best regards Christoph // begin code #include <iostream> #include <map> #include <queue> #include <boost/graph/adjacency_list.hpp> #include <boost/smart_ptr.hpp> typedef boost::adjacency_list_traits<boost::listS, boost::vecS, boost::bidirectionalS> link_adjacency_list_traits; struct vertex_properties; struct edge_properties; struct graph_properties; struct vertex_properties { std::map <int, link_adjacency_list_traits::edge_descriptor > used_colors; // this one works fine, i can use a traits::edge_descriptor }; struct edge_properties { int color; }; struct degree_compare; typedef std::priority_queue < link_adjacency_list_traits::vertex_descriptor, std::vector <link_adjacency_list_traits::vertex_descriptor>, degree_compare> VERTEX_DEGREE_PQ; struct graph_properties { int delta; boost::shared_ptr <VERTEX_DEGREE_PQ> pq; }; typedef boost::adjacency_list < boost::listS, boost::listS, boost::bidirectionalS, vertex_properties, edge_properties, graph_properties> link_graph; class degree_compare { private: link_graph g; public: degree_compare(const link_graph &g): g(g) {std::cout << "Num Vertices: " << num_vertices(g) << std::endl;} bool operator()(const boost::graph_traits<link_graph>::vertex_descriptor &a, const boost::graph_traits<link_graph>::vertex_descriptor &b) { return out_degree(a, g) < out_degree(b, g); } }; int main () { link_graph g; boost::graph_traits<link_graph>::vertex_descriptor a = add_vertex (g); degree_compare dc(g); // init the comparison object VERTEX_DEGREE_PQ pq(dc);// init the p_queue with comparison // object fails //pq.push(a); //pq.top(); } // end code

1 1

[Preprocessor] documentation link broken
by Belcourt, K. Noel 27 Oct '11

27 Oct '11

Hi, There's a web page misdirect for the MPL library. If you go here: http://www.boost.org/doc/libs/1_47_0/libs/preprocessor/doc/index.html and click Introduction, it will attempt to go here: http://boost-consulting.com/tmpbook/preprocessor.html and be redirected here: http://www.boostpro.com/tmpbook/preprocessor.html where you get an Internal Server Error message. The other links seem okay, it's only the Introduction link that's broken. -- Noel

4 5

[Graph] redefinition of hash<void*> clashes with boost/functional/hash.hpp
by Ioannis Papadopoulos 27 Oct '11

27 Oct '11

Hi, In graph/detail/adjacency_list.hpp:2766 there is a specialization of struct hash for void*. Isn't the generic pointer specialization in functional/hash/extensions.hpp:172 enough? The problem I am facing is the following (which I couldn't reproduce in a trivial example): 1. I include <boost/functional/hash.hpp> and <boost/tr1/unordered_map.hpp> 2. I create an std::tr1::unordered_map<void*, int> and typedef std::tr1::unordered_map<void*, int>::iterator iterator_type; 3. In some test file that includes <boost/graph/adjacency_list.hpp> and uses it, I get the following error (gcc 4.4.5/4.6.1): /usr/local/include/boost/graph/detail/adjacency_list.hpp:2766: error: specialization of ‘boost::hash<void*>’ after instantiation /usr/local/include/boost/graph/detail/adjacency_list.hpp:2766: error: redefinition of ‘struct boost::hash<void*>’ /usr/local/usr/include/boost/functional/hash/extensions.hpp:172: error: previous definition of ‘struct boost::hash<void*>’ I can resolve it by providing my own hash functor to the unordered_map (which causes hash<void*> not to be instantiated). I will keep trying to provide a trivial example. Thanks

2 2

[graph] Graph type needed in Graph Proptery, cyclic definition problem
by Christoph 26 Oct '11

26 Oct '11

Hi List, id like to use a std::priority_queue as a property of my graph. In the priority queue i store some vertices by the vertex degree. I have to Problems i think: First i have to define the priority_queue in a struct graph_properties. Within this priority_queue definition i use a comparison object as the 3rd template parameter. Now the problem is, that the class vertex_degree_compare needs to know the graph type, because of the use of out_degree(u, g) but the graph type depends on the graph_struct and this depends on the priority_queue definition. For the edge descriptors and vertex descriptors i used the traits_class http://www.boost.org/doc/libs/1_47_0/libs/graph/doc/adjacency_list_traits.h… but for the graph itself i don't know how to proceed. Any help is highly appreciated. // begin code #include <iostream> #include <queue> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graph_utility.hpp> typedef boost::adjacency_list_traits<boost::listS, boost::vecS, boost::bidirectionalS> link_adjacency_list_traits; struct vertex_properties { vertex_properties () : color (-1) {} unsigned int vertex_index; unsigned int vertex_index_t; int color; std::list <int> free_colors; std::map <int, link_adjacency_list_traits::edge_descriptor > used_colors; }; struct edge_properties { edge_properties () : color (-1) {} int color; }; struct graph_properties { int delta; std::priority_queue < link_adjacency_list_traits::vertex_descriptor, vertex_degree_compare> A; std::priority_queue < link_adjacency_list_traits::vertex_descriptor, vertex_degree_compare> B; }; typedef boost::adjacency_list < boost::listS, boost::listS, boost::bidirectionalS, vertex_properties, edge_properties, graph_properties> link_graph; typedef boost::graph_traits <link_graph> lgt; class vertex_degree_compare { private: link_graph g; public: vertex_degree_compare (const link_graph &g) : g(g) {} bool operator() (link_adjacency_list_traits::vertex_descriptor& u, link_adjacency_list_traits::vertex_descriptor& v) const { return out_degree (u, g) < out_degree (v, g); } }; int main(int argc, char** argv) { return 0; } // end code best regards Christoph

2 6

Accessing the edge through edge descriptor with bundled properties
by giridhar 26 Oct '11

26 Oct '11

Hello All, I have to access an edge in a vector called border_edge through an edge descriptor. For example for( vector<Edge>::iterator j=border_edge.begin();j!=border_edge.end();++j) { Edge e = t1[*j]; // I am getting error saying that No suitable conversion for Edge to Edgep exits } *Details*: border_edge is of type std::vector<Edge> border_edge(10); Graph as: typedef subgraph< adjacency_list<vecS, vecS, undirectedS, Vertexp, property< edge_index_t, unsigned int, Edgep > > > Graph; typedef Graph::edge_descriptor Edge; I have exterior Edge property defined as struct Edgep { int edge_index; int edge_w; std::string edge_name; int capacity; int residual_capcity; int bandwidth_used; }; Whenever I am adding edges into graph I am updating this border_edge vector. Say I am adding an edge from vertex 0 to 4 then I am doing this border_edge[i] = (add_edge(0,4,t)).first; //i is an example index. It is actually running in the loop. Can anyone please give some suggestions regarding this. How to access this edge which is inside vector? or what descriptor type should I use? -- Regards, Giridhar

3 4

[graph] VertexList type boost::vecS and boost::listS
by Christoph 26 Oct '11

26 Oct '11

Hi, I have some Questions concerning the Boost Graph Library graph template selector VertexList type. In the docs at http://www.boost.org/doc/libs/1_47_0/libs/graph/doc/using_adjacency_list.ht… I just found the two types documented. 1. How do i use the printed_graph (...) with a graph type that uses boost::listS instead of boost::vecS? I read that by using boost::vecS there is automatically an internal property for each Vertex created, which is the index of the vertex. I assume this is the reason why 'add_edge (1,2,g);' and 'print_graph (g,get(boost::vertex_index, g));' work for a graph g with a boost::vecS VertexList. However i cannot simply do 'add_edge (1,2,g);' or 'print_graph (g,get(boost::vertex_index, g));' vor a graph g with a VertexList type listS. How do i specify a vertex_index property for VertexList listS graph type, so that i can somehow use print_graph (g,something);? How are vertices internally identified when using listS? Are there any documentations about the function 'vertex()'? I think it is missing in Table 1: Summary of boost graph concepts in http://www.boost.org/doc/libs/1_47_0/libs/graph/doc/graph_concepts.html Look at the difference in using add_edge for the two different graph types and what happens if i try to insert an edge with one vertex not yet being part of the vertex set. Here is an example: //begin code #include <iostream> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graph_utility.hpp> typedef boost::adjacency_list < boost::listS, boost::vecS, boost::bidirectionalS> link_graph_vertex_vec; typedef boost::adjacency_list < boost::listS, boost::listS, boost::bidirectionalS> link_graph_vertex_list; int main(int argc, char** argv) { link_graph_vertex_vec g1(3); std::cout << "Number of vertices in g1: " << num_vertices (g1) << std::endl; add_edge (0,1,g1); std::cout << "Number of vertices in g1: " << num_vertices (g1) << std::endl; add_edge (1,2,g1); std::cout << "Number of vertices in g1: " << num_vertices (g1) << std::endl; add_edge (2,10,g1); std::cout << "Number of vertices in g1: " << num_vertices (g1) << std::endl; print_graph (g1, get(boost::vertex_index, g1)); link_graph_vertex_list g2(3); std::cout << "Number of vertices in g2: " << num_vertices (g2) << std::endl; add_edge (vertex(0,g2), vertex(1,g2), g2);//add_edge (0,1,g2); std::cout << "Number of vertices in g2: " << num_vertices (g2) << std::endl; add_edge (vertex(1,g2), vertex(2,g2), g2);//add_edge (1,2,g2); std::cout << "Number of vertices in g2: " << num_vertices (g2) << std::endl; //add_edge (vertex(2,g2), vertex(3,g2), g2);//add_edge (2,3,g2); //vertex(3,g2) // what is the return type, why does the program exit? std::cout << "Number of vertices in g2: " << num_vertices (g2) << std::endl; return 0; } //end code I have to decide whether to use boost::listS or boost::vecS for the VertexList type. The 'interface' of the vecS type graph operations are much easier for me to understand and to use. But on the other hand the listS type has the faster remove and insert operations. best regards Christoph

1 1

odeint feedback request
by Karsten Ahnert 25 Oct '11

25 Oct '11

Dear community, odeint is a library for solving ordinary differential equations and has been discussed several times on this list. After successfully fulfilling the GSOC 2011 we continued working on odeint and we published two papers which are available at the arxiv: http://arxiv.org/abs/1110.3397 http://arxiv.org/abs/1110.3233 We would like to request feedback and/or comments on the implementation and the current status of odeint. The library and the documentation are available at the github: https://github.com/headmyshoulder/odeint-v2 http://headmyshoulder.github.com/odeint-v2/doc/index.html Thank you, Mario and Karsten

2 2

[regex] /g
by Andrey Moshbear 25 Oct '11

25 Oct '11

I have a few questions regarding implementing /g when using boost.regex. Firstly, is the iterator-pair form of match equivalent to /g? I.e. { sregex_iterator m1(str.begin(), str.end(), regex); sregex_iterator m2; for (; m1 != m2; ++m1) { // do something with *m1 } } Secondly, does regex_replace() loop internally in a /g fashion? 001100 Andrey "m05hbear" Vul 010010 011110 andrey at moshbear dot net 100001 andrey dot vul at gmail 101101 110011

2 1

[fusion] push_back / pop_back
by Daniel Bradburn 25 Oct '11

25 Oct '11

Hi, I am trying to do the following: #include <string>#include <boost/fusion/tuple.hpp>#include <boost/fusion/include/push_back.hpp>#include <boost/fusion/include/pop_back.hpp> int main(int argc, char* argv[]) { typedef boost::fusion::tuple<int> T1; typedef boost::fusion::result_of::push_back<const T1, std::string>::type T2; T1 a(0); T2 b(boost::fusion::push_back(a, std::string(""))); boost::fusion::get<0>(); T1 c(boost::fusion::pop_back(b)); return 0; } However I get the following compilation errors: error C4430: missing type specifier - int assumed. Note: C++ does not support default-int error C2868: 'boost::lazy_disable_if_c<B,T>::type' : illegal syntax for using-declaration; expected qualified-name error C2602: 'boost::lazy_disable_if_c<B,T>::type' is not a member of a base class of 'boost::lazy_disable_if_c<B,T>' error C2504: 'boost::fusion::extension::at_impl<Tag>::apply<Sequence,N>' : base class undefined error C2504: 'boost::fusion::extension::at_impl<Tag>::apply<Sequence,N>' : base class undefined error C2146: syntax error : missing ';' before identifier 'type' error C2039: 'type' : is not a member of 'boost::fusion::result_of::at_c<Sequence,N>' error C2664: 'boost::fusion::tuple<T0>::tuple(const boost::fusion::tuple<T0> &)' : cannot convert parameter 1 from 'boost::fusion::iterator_range' to 'const boost::fusion::tuple<T0> &' error C2146: syntax error : missing ',' before identifier 'type' error C2065: 'type' : undeclared identifier error C2039: 'type' : is not a member of 'boost::fusion::result_of::prior<Iterator>' Having read the topic here : http://lists.boost.org/Archives/boost/2011/08/184624.php it looks like this is partly due to a bug in the pop_back implementation. Is there a fix for this? However I would like to know if it is also possible to use boost::fusion::get on the result of push_back? Best regards Daniel Bradburn

2 2

throw and catch exception
by Christer Borgqvist 25 Oct '11

25 Oct '11

I have a code like this when execute the IdHTTPServDataEMVObj.Exequte(); it will throw a std::runtime_error if running one thread all is fine, the catch is excequted, but if running two threads then the application crash. What is the problem, have i miss something appreciate any help. huvcbo.. void server(boost::asio::io_service& io_service, short port) { tcp::acceptor a(io_service, tcp::endpoint(tcp::v4(), port)); for (;;) { socket_ptr sock(new tcp::socket(io_service)); a.accept(*sock); boost::thread t(boost::bind(socketclientEMVthread, sock, logFunc, mygetFunc, mybackFunc, statusUpdateFunc)); } } the client thread void socketclientEMVthread( socket_ptr sock) { cout << "connect on port " << sock->remote_endpoint().port() << endl; for (;;) { char data[max_length]; boost::system::error_code error; size_t length = sock->read_some(boost::asio::buffer(data), error); if (error == boost::asio::error::eof) break; // Connection closed cleanly by peer. else if (error) throw boost::system::system_error(error); // Some other error. std::string trans_in(data), trans_out; CIdHTTPServDataEMVObj IdHTTPServDataEMVObj(trans_in); try { // this is thrown IdHTTPServDataEMVObj.Exequte(); if ( IdHTTPServDataEMVObj.txBufferlen > 0 && IdHTTPServDataEMVObj.txBufferlen != std::string::npos) { trans_out = IdHTTPServDataEMVObj.txBuffer; } else { trans_out = trans_in; } } catch(trans_error &te) { trans_out = te.what(); boost::asio::write(*sock, boost::asio::buffer(trans_out, trans_out.size())); break; } boost::asio::write(*sock, boost::asio::buffer(trans_out, trans_out.size())); break; } }

3 5

[date time] How to get "10" and not "Oct"
by Ken Murphy 24 Oct '11

24 Oct '11

I have the following code: std::string db_time() { typedef boost::posix_time::ptime TimeT; TimeT ct = boost::posix_time::microsec_clock::local_time(); std::stringstream ss; boost::local_time::local_time_facet* output_facet = new boost::local_time::local_time_facet("%Y-%m-%d %h:%m:%s"); ss.imbue(std::locale(std::locale::classic(), output_facet)); ss << ct; return ss.str(); } Currently, the following string is returned: 2011-Oct-24 12:43:05.476990 How do I get the month as "10" and not as "Oct"? Ken Murphy

2 1

asio. documentation errors.
by niXman 24 Oct '11

24 Oct '11

Hi list! In the documentation for upd::socket::bind(): http://www.boost.org/doc/libs/1_47_0/doc/html/boost_asio/reference/basic_da… examples are shown from the tcp::socket::bind() Thanks. niXman.

1 0

Problems with (de)serialization from/through pointer to base class
by Rafael Arco Arredondo 24 Oct '11

24 Oct '11

Hello: I am encountering problems with boost::serialization, particularly when objects are sent with boost::mpi and contain pointers to a base class. I am getting segmentation faults, but not always, only when the transmitted objects exceed a particular size. I have two abstract classes, A and B, two instantiable classes, D and E, and a fifth class C, which is the class eventually serialized and contains one pointer to an object of class A and another to an object of class B. In the example attached, when n (which determines the size of E objects) is 1000, everything works fine. If, for instance, n=2000, the segmentation fault appears when the object is deserialized after calling comm.recv. The output for this last case is also attached in file output.log. I am also using boost::shared_ptr as well to wrap class C objects, but the error is also thrown when no shared pointers are used. When types and object sizes are known a priori there are no problems, but I would need something more general and dynamic right now. It is possible to do this, isn't it? Any ideas of what is happening? Am I doing something wrong? Did I miss something in the documentation? Is there any size limitation for serializing/deserializing objects? I imagine MPI_Unpack, which appears in the stack trace, is restricted by the size of the input buffer, indicated by an int, but I believe this is not the problem here. Is it perhaps a bug? Any help or comments will be appreciated. Thank you in advance, Rafa

1 2

[optional] Working around gcc 4.6 bug which produces error "‘*((void*)& aNewItem +8)’ may be used uninitialized in this function"
by Rob Desbois 24 Oct '11

24 Oct '11

I've just begun having issues with some use of boost::optional producing the error shown in the subject. This is a gcc bug, filed at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47679 The corresponding downstream bug for RedHat/Fedora is at https://bugzilla.redhat.com/show_bug.cgi?id=676361 and has a code listing to reproduce. Sending this partially as an FYI, and also to ask if anyone has any workaround? Altering client code to construct with boost::none or a false condition, then assigning a value if required, still yields the error on the assign operation. My current workaround is to initialize the optional<T> in question with a dummy T instance, then call reset() with no params if I want an 'uninitialized' optional. It looks rather bizarre, but if it must be then it must be. -- Rob Desbois Eml: rob.desbois(a)gmail.com Blog: http://theotherbranch.wordpress.com/

1 0

[regex] Grouping behaviour
by U.Mutlu 24 Oct '11

24 Oct '11

Hi, I need to split a regex pattern into two groups like from this blafoo to (bla)(foo) But the second variant matches also input like this one: blaABCfoo There is no .* between the groups, so I wonder why it still matches. How to fix this?

2 2

Re: [Boost-users] [locale] IOStream encoding conversions?
by Artyom Beilis 24 Oct '11

24 Oct '11

> Currently I'm messing about with Boost.Locale, I'm intending to use it > for my project, but I don't know how to do something along the lines of > specifying the external encoding (usually the user's locale, en_US.UTF-8 > in my case), and the internal coding of my program (UTF-16), > to have input and output converted, possibly using a codecvt. A possible example > would be translating UTF-16-≥POSIX UTF-8 paths, or UTF-8-≥Windows UTF-16 > paths. I assume you use Windows and wide characters. It is enough to imbue the locale to the output **wide** stream and write to it. boost::locale::generator gen; // stdout std::wcout.imbue(gen("")); std::wcout << L"שלום" << std::endl; // UTF-8 file I/O std::wfstream stream; stream.imbue(gen("")); stream.open(name,std::wfstream::out); stream << L"שלום" << std::endl; Would actually output the text in narrow encoding. Also there is an example how to create custom wide streams that would convert wide to narrow encoding http://svn.boost.org/svn/boost/trunk/libs/locale/doc/html/charset_handling.… Also for converting things like path UTF-8/UTF-16 you can use utf_to_utf functions that work just on chunks of text. http://svn.boost.org/svn/boost/trunk/libs/locale/doc/html/group__codepage.h… Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.sf.net/ CppDB - C++ SQL Connectivity: http://cppcms.sf.net/sql/cppdb/

1 0

Portable stack trace mechanism?
by Chris Cleeland 24 Oct '11

24 Oct '11

I've written this code several times and thought boost might have something. No, it doesn't, but I found this old bit thread: http://lists.boost.org/Archives/boost/2010/10/172303.php >From the evidence I can conclude that it never made it in, but the thread gives no indication as to why. I don't want to resurrect something that's already been fully hashed and excluded, but if it never made it in simply because nobody carried the torch forward, perhaps I could be the new bearer.

6 5

[Review] Boost.Atomic review period extended
by Tim Blechmann 24 Oct '11

24 Oct '11

Hi all, Since there has been only rather limited discussion about the Boost.Atomic library and only one full review, the review period will be extended until next Sunday, October 30th. I encourage everyone with an interest in this library to participate in the remaining days of the review. If someone wants to do a review, but won't find the time during the review period, please let me know how much time you need. Cheers, Tim Review Manager

1 0

[serialization] how can load the nth element using binary_archive?
by gongyiling 24 Oct '11

24 Oct '11

Hello, Everyone: boost::serialization is a cool library. I use it in my project. I encounter a problem now. I serialized a array of objects to file as following: std::ofstream ofs(filename, std::ios_base::binary); boost::binary_oarchive oar(ofs); oar << obj[0] << obj[1] << ... << obj[n-1]; Now I want to load the obj[i] (i>=0 && i<n) from file. I tried recording obj[i]'s position in file, then set file stream's pointer to that position and trying to load it, but failed with exception input_stream_error, can I by any means doing that? here is my minimun code segments: struct word_block { std::string word; template<typename Archive> void serialize(Archive & ar, const unsigned int file_version ) { ar & word; } }; int main(int argc, char* argv[]) { const char* filename = "words.idx"; word_block wb1, wb2, wb2_r; std::ofstream ofs(filename, std::ios_base::binary); boost::archive::binary_oarchive oar(ofs); oar << wb1; size_t wb2_pos = ofs.tellp(); //record the position of wb2. oar << wb2; ofs.close(); std::ifstream ifs(filename, std::ios_base::binary); boost::archive::binary_iarchive iar(ifs); ifs.seekg(wb2_pos); //set file pointer to wb2. iar >> wb2_r; //failed with exception input_stream_error. return 0; } Any idea is appreciated!

4 3

ublas speed and multi-core processors
by petros 23 Oct '11

23 Oct '11

Hi, Is there any way to use ublas taking advantage of the multi-core facility of current processors? Even naive “strategies”, like breaking the number of rows of a targeted matrix expression across different threads would improve performance significantly, even if not optimally. It would be nice to be able to use the matrix expression templates to perform operations in a multi-threaded way. Is there any provision for this? Thank you for your help, Petros

3 4

ublas matrix_range resize
by petros 22 Oct '11

22 Oct '11

HI, I wanted to ask how I can resize a matrix_range object. I understand that is is a very light/disposable object but here is the problem I want to solve: I need to wrap some Lapack functions (Linear equation solvers) using ublas. The package I am using (mkl) asks for specific memory requirements that translate to having a –possibly- larger lda (basically the hosting matrix number of rows). So my way to address this was to contain a general matrix (ublas::matrix) and derive from a matrix_range which references it. Alas, I cannot resize! Is there a way? – Yes I could contain a pointer to the matrix_range and reconstruct, but this is rather silly. There should be a way to assign a matrix_range to an existing one, overwriting its contents. Thank you, in advance, for your help, Petros

1 0

boost serialization- handle endianness
by ohad barta 22 Oct '11

22 Oct '11

Hi I am serializing my data in a one computer, transfer it to another computer and desirialize the data there,.Does the data can get messed because of the 2 endian option, or is boost lobrary take care of it automatically? If I do need to handle this myself, are there any functions/MACROS in the boost serialization library that will help me? Many Thanks Ohad Barta

2 1

[iostreams] Apply a filter temporarily - base64_encoder
by Fernando Pelliccioni 21 Oct '11

21 Oct '11

Is there any way to apply a filter temporarily ? I want to do this... io::filtering_ostream out; out.push_back(file_sink("my_file.txt")); out << "Authentication: "; out.push_front ( base64_encoder() ); // pseudo-code... see *push_front* instead of *push* out << make_ntlm_auth_from_system(); // this have to be base64 encoded out.pop_front(); // removes the base64_encoder out << "......"; // *NO* base64 encoded I don't want to do this... io::filtering_ostream out; out.push(file_sink("my_file.txt")); out << "Authentication: "; out.pop(); out.push(base64_encoder()); out.push(file_sink("my_file.txt")); out << make_ntlm_auth_from_system(); out.pop(); out.pop(); out.push(file_sink("my_file.txt")); out << "......"; The function make_ntlm_auth_from_system() creates an object that is *OStreamable*. Any other suggestions are welcome. :) Thanks and regards, Fernando.

1 0

[Boost.Units] Trouble with I/O and specific scaled units
by Michael J Iatauro 21 Oct '11

21 Oct '11

I have the following declarations (reduced from a much larger problem): typedef make_system<si::second_base_unit>::type system; typedef unit<time_dimension, system> second; BOOST_UNITS_STATIC_CONSTANT(seconds, second); typedef make_scaled_unit<second, scale<60, static_rational<1> > >::type minute; BOOST_UNITS_STATIC_CONSTANT(minutes, minute); Unfortunately, if I try this: quantity<minute, double> t = 33.3 * minutes; std::cout << t << std::endl; I get, ultimately, a pair of compile errors: io.hpp:392: error: ‘name’ is not a member of ‘boost::units::scale_list_dim<boost::units::scale<60l, boost::units::static_rational<1l, 1l> > >’ io.hpp:326: error: ‘symbol’ is not a member of ‘boost::units::scale_list_dim<boost::units::scale<60l, boost::units::static_rational<1l, 1l> > >’ I tried adding std::string name_string(const minute&) { return "min"; } std::string symbol_string(const minute&) { return "min"; } but that didn't change anything. Interestingly, if I change the scale from 60 to 10, it compiles and runs fine. What am I missing? Thanks! ~MJI ------------------ Michael J. Iatauro Software Engineer Dell | Services, Federal Government NASA Ames Research Center Office: 650-604-0662 Mail stop: 269-2 P.O. Box 1 Moffett Field, CA 94035-0001 www.dell.com/perotsystems

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Serializing the same Objekt several times
by Fabian Weiss 21 Oct '11

21 Oct '11

At the moment I am working with XML serialization of Boost. I am serializing my own classes which works well. But my objects are changing often, for example: class Modul { public: setValue(int); private: int Value; } Modul* M = new Modul(); Now I wanna serialize M every time Value changes, so that I can save a complete history of changes on M. But M is serialized only once, after that I get this in my XML, although Value has changed: <Modul class_id_reference="1" object_id_reference="_2"></Modul> This is unusable for my purpose, so how can I stop that kind of "linking" and serialize the Objekt every time completely?

2 1

[locale] IOStream encoding conversions?
by Jookia 21 Oct '11

21 Oct '11

Currently I'm messing about with Boost.Locale, I'm intending to use it for my project, but I don't know how to do something along the lines of specifying the external encoding (usually the user's locale, en_US.UTF-8 in my case), and the internal coding of my program (UTF-16), to have input and output converted, possibly using a codecvt. A possible example would be translating UTF-16->POSIX UTF-8 paths, or UTF-8->Windows UTF-16 paths. I've read the examples and 'Using Boost.Locale' documentation, but I can't figure out how to do it. In fact, the closest to this is in the 'Character Set Conversions' documentation, where somehow a generator is the boost::locale::conv namespace, but that doesn't work with streams. I tried to pry open the test code only to not understand much. I've searched the web for solutions, but since there's only limited use and documentation of this, I'm starting to wonder if I'm using the right tool for the job.

1 0

unit_test compile error under MSVC10
by Marc de Kamps 21 Oct '11

21 Oct '11

Hi, I'm trying to emulate the following example using Visual Studio 10. In one file I have: --------- #ifndef QW #define QW #ifdef WIN32 #define BOOST_ALL_DYN_LINK // Force boost to use shared libraries #endif #define BOOST_TEST_MAIN #include <boost/test/unit_test.hpp> #endif // include guard -------------- By itself this compiles and runs, correctly reporting that there is an empty test tree. In a second file, Test1.cpp , I have: ----------------- #include <boost/test/unit_test.hpp> #ifdef WIN32 #define BOOST_ALL_DYN_LINK // Force boost to use shared libraries #endif BOOST_AUTO_TEST_CASE(Test1) { BOOST_REQUIRE(true); } -------------------------- Compiling now leads to the error below(I use multithreaded debug ddl for the project). Is there anything obvious I'm doing wrong? Thx, Marc boost_unit_test_framework-vc100-mt-gd-1_47.lib(boost_unit_test_framework-vc100-mt-gd-1_47.dll) : error LNK2005: "public: static class boost::unit_test::unit_test_log_t & __cdecl boost::unit_test::singleton<class boost::unit_test::unit_test_log_t>::instance(void)" (?instance@?$singleton@Vunit_test_log_t@unit_test@boost@@@unit_test@boost@@SAAAVunit_test_log_t@23@XZ) already defined in Test1.obj 5

1 0

[Bind?] Returning generators instead of evaluating.
by Robert Jones 21 Oct '11

21 Oct '11

Hi All Does this functionality exist anywhere in Boost? If so can someone point me to it, and if not does it seem like a useful thing? Thx, - Rob. using boost::function; using boost::bind; template <typename T, typename T1> function<T( )> function<T( )> make_generator( function<T(T1)> f, T1 t1 ) { return bind( f, t1 ); } template <typename T, typename T1, typename T2> function<T( )> function<T( )> make_generator( function<T(T1, T2)> f, T1 t1, T2 t2 ) { return bind( f, t1, t2 ); } template <typename T, typename T1, typename T2, typename T3> function<T( )> function<T( )> make_generator( function<T(T1, T2, T3)> f, T1 t1, T2 t2, T3 t3 ) { return bind( f, t1, t2, t3 ); } // ...etc...

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Re: [Boost-users] Proposal mpl::switch_case
by Hite, Christopher 21 Oct '11

21 Oct '11

> Is this what you want? > http://dancinghacker.com/switch/ Yes! That is exactly what I want. I read some of the reviews. The input seems ok. I really don't care about return types. I wouldn't use a fall through, but I can see the point in doing it. Why did the project die? Does it just need a little bit of help? I'd be willing to offer a day or so. I was only testing gcc. Does this happen on other platforms as well? I would have hoped gcc would have detected a swtich/case. I posted on their list a while back. Chris

1 0

[asio] virtual/emulated serial ports?
by Michael Powell 21 Oct '11

21 Oct '11

Hello, Does asio, or another boost API, allow developers to create a virtual or emulated serial port? By virtual or emulated, I mean, creating a software serial port that looks and feels just like the physical hardware, with device protocol to boot. Or something like a serial-tcp/ip bridge might be satisfactory as well. Oh, free, or not as expensive, is preferred, of course... :) Thank you... Best regards, Michael

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Re: [Boost-users] [asio] virtual/emulated serial ports
by Marat Abrarov 21 Oct '11

21 Oct '11

> Or something like a serial-tcp/ip bridge might be satisfactory as well. > Oh, free, or not as expensive, is preferred, of course... :) I use VSPE: http://www.eterlogic.com/Products.VSPE.html Regards, Marat Abrarov.

1 0

MSM <-> UML Conversion
by asif saeed 21 Oct '11

21 Oct '11

Hi, I haven't yet looked at MSM. However, I do wonder if the activity/state diagrams generated from MSM based code would be convertible to equivalent sequence diagrams. In other words, I want to know if MSM does indeed create object instance and whether it creates those instances on heap, etc. In short, I am interested in the performance aspect. I have a scenario where I have two state machines - basically, protocols for the trading domain - and I am supposed to map one protocol to another and vice versa - that is, develop a message broker. I am thinking about designing a generic solution that could be used to map any protocol (all messages along with their behavior) to any protocol based on the grammar - the message strings, their sequences, etc. Can I use MSM for this kind of a problem? I did write something like this for a client a long time back but it would take me quite some time if I jump into doing that again. That does make think if Boost MSM (or StateChart?) offers a faster solution. Thanks in advance, -Asif

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[Boost-Interest][General] Will Boost C++ work for my device control software
by Boost lzw 20 Oct '11

20 Oct '11

Hi everyone, I am soon to start a project and am wondering if I can use Boost C++ for it. Basically, I am going to develop software to control a variety of devices. The "Big Picture" of it is this: the software will "talk" to each of these devices via their drivers from different "interfaces" - USB port, serial port, etc., and collecting measurement data from these devices and controlling them. My "Big Picture" questions are: is it possible for me to use Boost C++ for these tasks. If so, how? Any links to where I should look at in the Boost documentation would be welcomed. Are there any specific Boost library that I should study before starting the project. Thanks in advance. Best Robert

2 1

serialization of STL containers with non-default allocator
by Jonathan Bishop 20 Oct '11

20 Oct '11

In my code I have used a non-default allocator MyAlloc for the STL classes. For instance, typedef std::basic_string< char, std::char_traits<char>, MyAlloc<char> > string ; Archive ar; ar & s; // compile error Is there a way to make this work. I know there is a builtin serialization for std::string which I would like to use. Thanks

1 0

[Boost.Thread] thread started after constructor
by gast128 20 Oct '11

20 Oct '11

Hello all, I have a basic question about threads: can one assume that the thread is started after the constructor call (or when using create_thread in thread groups) or does one has to use an extra synchronization primitive (e.g. a barrier)? Example (real world is more complex): void g(int* x) { int x1 = *x; } void f() { int x = 0; boost::thread thd(&g, &x); //<-- thread is started or not? }

1 1

[thread]N of args for thread::thread with args
by Marcello Puligheddu 20 Oct '11

20 Oct '11

In http://www.boost.org/doc/libs/1_47_0/doc/html/thread/thread_management.html Thread Constructor with arguments<http://www.boost.org/doc/libs/1_47_0/doc/html/thread/thread_management.html…> [...] Note: Currently up to nine additional arguments a1 to a9 can be specified in addition to the function f. But in Launching threads<http://www.boost.org/doc/libs/1_47_0/doc/html/thread/thread_management.html…>is clearly stated "There is an unspecified limit on the number of additional arguments that can be passed." -- marcello puligheddu Cagliari ,Sardegna, Italia +393203090251

3 4

boost-python stringifying
by immanuel litzroth 20 Oct '11

20 Oct '11

Hello, I've got a object and I need to stringify it in boost-pyton bridge.... actually just the equivalent of calling str(obj) in python. I have a hard time finding out how to do this from the documentation. Thanks in advance for any pointers, Immanuel

1 0

Is there Text Diff in Boost Unit Testing?
by Alexander Feldman 19 Oct '11

19 Oct '11

Hi Guys, I am now using Boost Unit Testing as well and I am quite happy. I am writing, among other things, a compiler and I would benefit if in BOOST_CHECK_EQUAL there is some kind of a text diff... Is there such a facility? Thanks, -- Alex

2 1

Proposal mpl::switch_case
by Hite, Christopher 19 Oct '11

19 Oct '11

My use case is a fast protocol decoder. I've described the protocol in mpl and generate the instructions I need to decode/encode/store packets. During decoding I have to be able to take a run time id and map it to the correct compile time generated code. Traditionally such code was written as a switch/case. The obvious solution is to use metaprogramatic recursion, for example mpl::for_each to check the id against each value. You would hope the compiler would inline all the recursion, detect the ifs on an id, and do general switch/case optimization. Unfortunately the code generated by gcc and it's not as good as I hoped. They actually generate a function for every ~6 levels of recursion and just do a bunch of if/equal/else. boost::variant has this same problem. They use BOOST_PP_REPEAT to generate an actual switch/case statement(visitation_impl.hpp). The compiler does a good job with the swich/case. It removes redundant cases and then optimizes using array lookups and binary searches depending on size. Good job! 1) Could we factor this logic out into a utility like mpl::switch_case? 2) What would the best interface look like? 3) What other bits of code could benefit from it? phoenix::switch_? Meta State Machine? Chris

2 1

[serialization] unregistered_class exception that wasn't occurring before
by Igor R 19 Oct '11

19 Oct '11

Hello, I'm serializing the following type: (pseudo-definition) multi_index_container< variant< shared_ptr<template1<arg1> >, shared_ptr<template2<arg2> >, etc... > > It works well when I make and load archives with the current version of my app, but when I try to open an archive made by the pervious version it throws unregistered_class for one of my classes. The both versions use boost 1.47, and the differences between them seem to me absolutely unrelated to serialization (as far as I can see). Unfortunately I can't provide here code snippets, so my question is theoretical: what could break the backward compatibility in such a way? What should I look into? Thanks.

2 4

[shared_ptr] implicit conversion to bool problem
by Steckmann, Sven 19 Oct '11

19 Oct '11

Dear list, I have a problem with the implicit conversion to bool in the shared_ptr class. I want to use operator overloading for an easy to use interface. I have 2 Instances of a class with a common Interface and I want to define an operator-class (OpAnd of type K) which can handle the operator. By compiling this little test below, I got: g++ -I/home/steckmann/proj/libs/boost -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"test.d" -MT"test.d" -o "test.o" "../test.cpp" ../test.cpp: In function 'int main()': ../test.cpp:49: error: ambiguous overload for 'operator&&' in 'a && b' ../test.cpp:49: note: candidates are: operator&&(bool, bool) <built-in> ../test.cpp:40: note: boost::shared_ptr<K> operator&&(boost::shared_ptr<K>, boost::shared_ptr<K>) This is quite clear to me, but how can I avoid this without touching the shared_ptr? Thanks for any comments, Sven #include <boost/shared_ptr.hpp> using namespace boost; class K { public: virtual bool value() = 0; }; class Value :public K { public: Value( bool i ) : var( i ) {} bool value() { return var; } bool var; }; class OpAnd : public K { public: OpAnd( boost::shared_ptr<K> l, boost::shared_ptr<K> r ) :l(l), r(r) {} bool value() { return l->value() && r->value(); } boost::shared_ptr<K> l; boost::shared_ptr<K> r; }; boost::shared_ptr<K> operator&&( boost::shared_ptr<K> l, boost::shared_ptr<K> r) { return shared_ptr<K>( new OpAnd(l, r ) ); } int main() { boost::shared_ptr<Value> a( new Value(true) ); boost::shared_ptr<Value> b( new Value(false) ); boost::shared_ptr<K> c = a && b; // Now use c here for some stuff c->value(); // returns false b->var = true; c->value(); // returns true return 0; }

2 1

Why does the creating of distributed adjacency list cost so much time?
by Yan 19 Oct '11

19 Oct '11

Hi all, I'm learning to use the distributed adjacency list and distributed dijkstra SP-algorithm. I use some test data contains about 3,800,000 edges and 2,800,000 vertices. I use a pair of iterators to pass the data to the distributed adjacency list, like that: Graph g(reader.begin(), reader.end(), reader.weight_begin(), reader.num_vertices(), pg, dist); "reader" is an user-defined class which supplys required data (edges, vertices, weights). "pg" is defined like that "mpi_process_group pg;" "dist" is supplied by the reader like that "graph::metis_distribution dist = reader.distribution();". It is based on a metis partition file coordinating the test data. I run 2 processes on my notebook computer(Intel core2 2.0G, Ram 2G, WinXPsp3). I also test the same data using a sequential bgl dijkstra SP-algorithm on this computer. The result is that: Parallel bgl: Creating of Graph g costs *10080 seconds*; dijkstra computing costs 28.281 seconds. Sequential bgl: Creating of Graph g costs *4.563 seconds*; dijkstra computing costs 1.703 seconds. As you see, when using distributed adjacency list, it costs so much time to create the graph. Is it nomal? I have done some more comparison between 2-processes parallel dijkstra on one core2 computer and sequential dijkstra on the same computer, using different scale data set. Always, the sequential bgl dijkstra costs less time than the 2-processes parallel dijkstra. What's the problem? I have read the boost document on "boost_1_46_1\libs\graph_parallel\doc\html\dijkstra_shortest_paths.html", which shows a good performance and speedup in the charts. Doesn't that mean less time costing than the sequential program? Any advice would be appreciated. Thanks, Yan -- View this message in context: http://boost.2283326.n4.nabble.com/Why-does-the-creating-of-distributed-adj… Sent from the Boost - Users mailing list archive at Nabble.com.

2 2

condition variable predicate and lambda
by Christopher Pisz 19 Oct '11

19 Oct '11

I want to do something simple, but implementing it seems awefully complex. All I want to do is wait for a specified amount of time for a member variable of my class to equal a certain value. Can someone please help me with an example? I've tried several that came from Googling and read the documentation, but I get compile errors no matter what I try. Currently the compiler is complainging "term does not evaluate to a function taking 0 arguments" Here is the problem in all its simplicity: class A { public: enum STATE { HAPPY = 0, SAD, ANGRY, NUM_STATES }; Foo(boost::posix_time::millisec & timeout) { // I need to wait to return from this until the state is HAPPY } private: STATE state_; };

3 4

Wave doesn't recognize c++0x keywords ?
by 邓尧 19 Oct '11

19 Oct '11

Hi, I'm new to Boost.Wave. I followed the "quick start", but found that wave take the C++0x keyword "decltype" as an identifier instead of a keyword. The macro "BOOST_WAVE_SUPPORT_CPP0X" is defined as "1". Boost version: 1.47.0 Any suggestions ? Thanks. -Yao

2 2

Re: [Boost-users] Building boost with stlport?
by Brian Vandenberg 18 Oct '11

18 Oct '11

> STLport is not used much nowadays. Used to use it with msvc-6 and 7.1, but > those are loooong gone here. Keep in mind that msvc is not the only place someone might consider using a more portable STL implementation. Where I work we're using Sun Studio; at least in old implementations their support for STL was anything but standards compliant -- in particular, people were doing god-awful things that never should have passed peer review; stuff that stlport or gcc puke on. Using stlport in older versions of Sun Studio is all but necessary if you want to use boost. More recent releases of Sun Studio are less troublesome, but in our case we're porting between Solaris and Linux; the implementations of STL between SS for Solaris & SS for Linux appeared to have different behaviors for some things, and if we port to gcc there'll no doubt be issues with poorly written code that worked in SS that doesn't work under gcc. In short, I wouldn't discount stlport as an ancient, no-longer-used piece of software; for those of us trying to port/improve older and more fragile code, stlport is a boon. -Brian

2 1

Chrono System time Conversion to Since Epoch not working
by Michael Chrostowski 18 Oct '11

18 Oct '11

Hi, I'm using boost 1.47 on Visual Studio 2008 and cannot seem to get the time since epoch from the Chrono library. At first I noticed that boost::chrono::system_time::now() does not have to be represented in time since epoch format so I don't believe that's an issue. However, I tried calling boost::chrono::system_time::now().time_since_epoch() and I get the same return result as if I was only referencing now(). That is, it is not time since epoch. Calling the static method to_time_t() DOES return proper time since epoch but it is in seconds (as time_t generally is) and is not what I'm looking for. Michael Chrostowski

2 1

boost atomic query
by Sean Farrow 18 Oct '11

18 Oct '11

Hi: I'm just starting to use boost atomic. I need to protect an std::map. If I had: boost::atomic<std;:map<int, int> > test; Would I need to protect this with a mutex, or is the fact that the variable is atomic enough? Cheers SEean.

2 1

[BGL] problem using subgraph
by Avishay Ben Shabtai 18 Oct '11

18 Oct '11

Hey i am trying to use subgraph but i am having troubles one of them is the following scenario typedef adjacency_list_traits< vecS, vecS, directedS > Traits; typedef subgraph< adjacency_list< vecS, vecS, directedS, no_property, property< edge_index_t, int > > > Graph; Graph G0(6); boost::add_edge(0,1,G0); Graph G1 = G0.create_subgraph(); boost::add_vertex(0,G1); boost::add_vertex(1,G1); boost::remove_edge(boost::edge(0,1,G1).first,G1); My Analysis is that since the edge is added to G0 before creation of G1 it does not add the edge (0,1) to its m_local_edge is there a way to overcome it? or i need to create all my subgraphs upfront Thanks

1 0

[Bind] Finding the right syntax.
by Robert Jones 18 Oct '11

18 Oct '11

Hi All In the code below my objective is pass a nullary function object to apply, and for that nullary function object to be 'my_function()' called with each member of the vector. How can I recode the call to apply as a unary bind expression such that I can write the for loop as a for_each loop? Thx, - Rob. #include <vector> #include "boost/function.hpp" #include "boost/bind.hpp" void apply( boost::function<void()> f ) { f( ); } int main( ) { static boost::function<void(int)> my_function = 0; std::vector<int> v; for ( std::vector<int>::iterator i = v.begin( ); i != v.end( ); ++ i ) { apply( bind( my_function, * i ) ); } }

2 1

svn name / password?
by Benson Limketkai 17 Oct '11

17 Oct '11

SVN keeps asking me for a name and password. I'm not sure what to do about this, because it's not supposed to do that. Who should I ask to look into this? thanks, Benson

1 0

[boost::polygon::operators] Boolean operations compiler error
by Dimitris Dakopoulos 17 Oct '11

17 Oct '11

Hello all, I'm using a custom polygon set (PolygonCollection) according to the guidelines here: http://www.boost.org/doc/libs/1_47_0/libs/polygon/doc/gtl_custom_polygon_se… There is one case that I don't get any compiler error: PolygonCollection p1, p2; p1 & p2; There is this case that I do have an error: PolygonCollection p1, p2; PolygonCollection p3 = p1 & p2; The error is: error: conversion from 'boost::polygon::polygon_set_view<PolygonCollection, PolygonCollection, 1>' to non-scalar type 'PolygonCollection' requested There is also this case that I have a compiler error: PolygonCollection p1,p2,p3; p3 = p1 & p2; The error is:error: no match for 'operator=' in 'p3 = boost::polygon::operators::operator&(const geometry_type_1&, const geometry_type_2&) [with geometry_type_1 = PolygonCollection, geometry_type_2 = PolygonCollection](((const PolygonCollection&)((const PolygonCollection*)(& p1))))' /xxx/Polygon.hpp:182: note: candidates are: PolygonCollection& PolygonCollection::operator=(const PolygonCollection&) (You can notice that I have overloaded the operator= for my custom polygon set but I got the same error without the suggestion before my implementation) Any ideas are welcomed! Dimitris

3 2

Storing a Huge Graph
by Nouf M. 17 Oct '11

17 Oct '11

Hi, Regarding the Boost Graph Library, Will I be able to convert a huge text file to a graph with millions of nodes and edges? Can I store the graph somewhere in the hard disk and then upload it whenever I test my code (i.e. I don't have to convert the text file into a graph each time I run my program).

4 3

Re: [Boost-users] [boost] [Review] Boost.Atomic review starts today, October 17th 2011
by Tim Blechmann 17 Oct '11

17 Oct '11

> > The review of Helge Bahmann's Boost.Atomic library starts today, October > > 17th 2011. It will end on October 26th. > > > > I encourage everyone to participate the the discussion on the Boost > > mailing > > > list about this very important library. In addition the code can be > > reviewed > > > line-by-line in code collaborator (http://demo.smartbear.com/boost/) > > Is there some explanation on how this works? I have created an account on > that site for myself and see this Boost.Atomic review as being in progress, > but it also tells me I'm not a participant. not really .. you can simply browse the files, select files and add per-line comments. not sure, if you have get the `reviewer' role or if you can add yourself to the project (iac, i've just made your a `reviewer'). from my experience, code collaborator is better for code reviews, while the lists are better to discuss the architecture, documentation, concepts etc ... cheers, tim

1 0

[BGL] using subgraph and SCC in algorithm
by Avishay Ben Shabtai 17 Oct '11

17 Oct '11

hi i am trying to figure out how is the best way to use the capabilities of subgraph. i am using the following declarations typedef boost::adjacency_list<boost::listS ,boost::vecS ,boost::bidirectionalS // ,GVertexProp // ,CFGEdgeProp> // GBase; typedef GBase::vertex_descriptor G_v_id; class Graph : public GraphBase { public: remove(const std::string& vName){ G_v_id vToRemove = findVertexByName(vName); boost::remove_vertex(vToRemove,*this); } } now my algorithm uses SCCs and works and modify each component separately and the idea of subgraph charmed me so i performed the following change typedef boost::subgraph<boost::adjacency_list<boost::listS ,boost::vecS ,boost::bidirectionalS // ,GVertexProp // ,CFGEdgeProp> > // GBase; typedef GBase::vertex_descriptor G_v_id; and now it stops to compile on boost::remove_vertex. is there an elegant way to use subgraph instead of copying it to separate graph and working from there.

1 0

[Review] Boost.Atomic review starts today, October 17th 2011
by Tim Blechmann 16 Oct '11

16 Oct '11

Hi all, The review of Helge Bahmann's Boost.Atomic library starts today, October 17th 2011. It will end on October 26th. I encourage everyone to participate the the discussion on the Boost mailing list about this very important library. In addition the code can be reviewed line-by-line in code collaborator (http://demo.smartbear.com/boost/) About Boost.Atomic: Boost.Atomic is a library that provides atomic data types and operations on these data types, as well as memory ordering constraints required for coordinating multiple threads through atomic variables. It implements the interface as defined by the C++11 standard, but makes this feature available for platforms lacking system/compiler support for this particular C++11 feature. Tarball: http://www.chaoticmind.net/~hcb/projects/boost.atomic/boost.atomic.tar.gz Documentation: http://www.chaoticmind.net/~hcb/projects/boost.atomic/doc/index.html Please always state in your review, whether you think the library should be accepted as a boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? On which platform? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Cheers, Tim Review Manager

1 0

building bjam vc9 troubles...
by Dan Bloomquist 16 Oct '11

16 Oct '11

I'm trying to figure out what is wrong with my system, lots of google searching and everything seems to check. My |%VS90COMNTOOLS% is good and my VS works fine in every respect I use it. But when I try a 'build' in ../v2/engine even with 'msvc' or 'vc9' as an argument it just loops like: C:\cpp\boost_1_47\tools\build\v2\engine>build ### ### "Could not find a suitable toolset." ### ### You can specify the toolset as the argument, i.e.: ### .\build.bat msvc ### ### Toolsets supported by this script are: borland, como, gcc, gcc-nocygwin, ### intel-win32, metrowerks, mingw, msvc, vc7, vc8, vc9, vc10 ### ### ### "Could not find a suitable toolset." ### ### You can specify the toolset as the argument, i.e.: ### .\build.bat msvc ### Over and over until I control c it. No, I have yet to dig into the workings of build.bat for a better answer. I was hoping someone knew of the top of their head what may be my problem. I had last built 1_42 without a hitch back when it was released. But I've started using boost::geometry and need the lib for boost::filesystem. I tried to mix 1.42 filesystem and 1.47 geometry headers, but it bumps the filesystem lib needed to 1.47, I can't seem to cheat. ~~ cannot open file 'libboost_filesystem-vc90-mt-gd-1_47.lib' Thanks, Dan. |

2 2

Locale on Mac OS X
by Alberto Simões 16 Oct '11

16 Oct '11

Hello, friends I am kind of desesperate. I am trying to use a Natural Language Processing application written in C++ that uses libboost on my Mac OS X. The problem is that locales seem to be broken for C++ in darwin. I know that is is (as far as I can tell) libboost fault. If you run the c++ program in attach under Leopard, you get the behavior I paste below. My question is: anybody found a way to make locale working on darwin? Couldn't libboost try to implement an indirection level for mac os X using the C locale API? (not sure if you are interested, just an idea). Please let me know if there is a solution to this problem. Kindest regards, Alberto [ambs@rachmaninoff tmp]$ ./a.out Trying c locales... Succeeded in calling setlocale(LC_ALL, "C") Succeeded in calling setlocale(LC_ALL, "POSIX") Succeeded in calling setlocale(LC_ALL, "en_US") Succeeded in calling setlocale(LC_ALL, "en_US.UTF-8") Succeeded in calling setlocale(LC_ALL, "pl_PL") Succeeded in calling setlocale(LC_ALL, "pl_PL.ISO8859-2") Trying C++ locales... Succeeded ctor for std::locale with "C" Succeeded ctor for std::locale with "POSIX" Failed ctor for std::locale with "en_US": locale::facet::_S_create_c_locale name not valid Failed ctor for std::locale with "en_US.UTF-8": locale::facet::_S_create_c_locale name not valid Failed ctor for std::locale with "pl_PL": locale::facet::_S_create_c_locale name not valid Failed ctor for std::locale with "pl_PL.ISO8859-2": locale::facet::_S_create_c_locale name not valid -- Alberto Simões

2 2

[Objective-C++] Specializing boost::lexical_cast
by Kelvin Chung 16 Oct '11

16 Oct '11

I'm trying to specialize boost::lexical_cast to convert Objective-C objects into various standard C++ classes (for example, leveraging NSNumber::-intValue to create lexical_cast<int>(NSNumber*)). However, as Objective-C objects exist as pointers, I would imagine that they would fail the requirements of needing well-defined streaming operator<<() in order to use the stock boost::lexical_cast. Any words of advice on how to do this in a way that will do as little damage as possible?

2 2

[threadpool] Using with Boost.Bind
by Robert Jones 15 Oct '11

15 Oct '11

Hi All I'm making use of a threadpool implementation from sourceforge, which I know is not properly part of Boost, but I'm hoping someone has some experience which can help me. I'm trying to use one of the functions from pool_adaptors.hpp, which I've reproduced below. I think this contains an error in the first template as the parameter passed as a Pool is used as a pointer to Pool, and I'm guessing there should four functions in here, not three, as the set seems incomplete. On either count I might be missing something. Stripped down my code says approximately this... #include "threadpool.hpp" #include "boost/threadpool/pool_adaptors.hpp" using namespace boost::threadpool; void task( int ); vector<int> v; v += 1,2,3,4,5,6,7,8,9; pool my_pool; for_each( v.begin( ), v.end( ), bind( schedule, my_pool, _1 ) ); ...and of course the problem is that 'schedule' is both templated and overloaded, so the compiler complains it can't find/resolve 'schedule'. The usual solution is to express the exact type of 'schedule' required, but it's huge, and uses types internal the the threadpool library. Is there a better solution? Thanks - Rob. namespace boost { namespace threadpool { // TODO convenience scheduling function /*! Schedules a Runnable for asynchronous execution. A Runnable is an arbitrary class with a run() * member function. This a convenience shorthand for pool->schedule(bind(&Runnable::run, task_object)). * \param * \param obj The Runnable object. The member function run() will be exectued and should not throw execeptions. * \return true, if the task could be scheduled and false otherwise. */ template<typename Pool, typename Runnable> bool schedule(Pool& pool, shared_ptr<Runnable> const & obj) { return pool->schedule(bind(&Runnable::run, obj)); } /*! Schedules a task for asynchronous execution. The task will be executed once only. * \param task The task function object. */ template<typename Pool> typename enable_if < is_void< typename result_of< typename Pool::task_type() >::type >, bool >::type schedule(Pool& pool, typename Pool::task_type const & task) { return pool.schedule(task); } template<typename Pool> typename enable_if < is_void< typename result_of< typename Pool::task_type() >::type >, bool >::type schedule(shared_ptr<Pool> const pool, typename Pool::task_type const & task) { return pool->schedule(task); } } } // namespace boost::threadpool

2 2

Using boost::signal2 for generic event handling with overloaded methods
by Alessandro Giulianelli 15 Oct '11

15 Oct '11

Hi People, I'm studying boost to understand if I can remove from a project a homemade event-dispatcher with boost::signal2 but I found a lot of troubles and I cannot solve it. My actual code which I would migrate to boost is made by a "Sender" and "Multiple Receiver" The sender has the ability to register many "signals" (I use a map for do this" ) and each listener has a map of "slots" connected to the sender of the sender. The sender code is: struct Event {}; struct ID {}; struct OneSecondElapsedEvent : public Event { static ID id; }; struct UpdatePresentationTracksReqEvent : public Event { UpdatePresentationTracksReqEvent() {}; static ID id; }; typedef boost::signals2::signal<void (Event*)> signal_t; typedef signal_t::slot_type slot_t; class MainTask: public Elt::Thread , public Sender { boost::ptr_map<ID*, signal_t> signals_map; public: sig; MainTask(char* taskName); virtual ~MainTask(); void Main(); void registerListener(IListener* listener) { if(listener != NULL) { SlotMap::const_iterator it = listener->slots_map.begin(); for(;it != listener->slots_map.end();it++) { ID *id = it->first; const slot_t *handler = it->second; signals_map[id].connect(*handler); } } else printf("Listener NULLO!!!!\n"); } }; now my generic "listener" or Receiver should be able to register to sender and the code is: #include "SpActiveContext.h" #include <cassert> #include "ActiveObject.h" #include "GenericMessageHandler/ActiveMessage.h" #include "boost/bind.hpp" #include "boost/function.hpp" #include <stdio.h> #include "EventDefinitions.h" #include "MainTask.h" SpActiveContext::SpActiveContext(SpContext * component): _ActiveObject("SpActiveContext"), _Component(component){ assert(_Component); * //boost::function<void (OneSecondElapsedEvent*)> g = boost::bind(&SpActiveContext::Handle, this, _1);* * * * //const slot_t& t = static_cast<void (SpActiveContext::*)(OneSecondElapsedEvent* )>(&SpActiveContext::Handle);* * //registerEvent(OneSecondElapsedEvent::id, t);* * * * //typedef boost::signals2::signal<void (Event*)> signal_t;* * //typedef signal_t::slot_type slot_t;* * * * //boost::bind(&SpActiveContext::Handle(OneSecondElapsedEvent*), this, _1); * * * * //void (SpActiveContext::*Handle) (OneSecondElapsedEvent*) = &SpActiveContext::Handle;* * * * //boost::bind( static_cast<void (SpActiveContext::*)( int )>(&Foo::Bar) , foo, _1);* * * * * * //const slot_t1& t = boost::bind( static_cast<void (SpActiveContext::*)(OneSecondElapsedEvent*)>(&SpActiveContext::Handle) , this, _1);* * //registerEvent(OneSecondElapsedEvent::id, t );* * * * //const slot_t1& t = boost::bind( static_cast<void (SpActiveContext::*)( UpdatePresentationTracksReqEvent *)>(&SpActiveContext::Handle) , this, _1); ** //registerEvent(UpdatePresentationTracksReqEvent ::id, t ); * } void SpActiveContext::Handle(OneSecondElapsedEvent* msg) { printf("OneSecondElapsedEvent 2\n"); } void SpActiveContext::Handle(UpdatePresentationTracksReqEvent* msg) { printf("UpdatePresentationTracksReqEvent\n"); } In the constructor I tried to "connect" the function "Handle(*OneSecondElapsedEvent*)" to the slot but I cannot to this..the compiler write errors sayng that cannot connvert from "Event*" to "OneSecondElapsedEvent*".* * * *Is there any solution to make it working?* * * *Thanks in advance,* *AlexGiul* * *

2 1

serialization basic question
by Luis A. Montes 15 Oct '11

15 Oct '11

Hi, I'm trying to use the serialization library and was having a compile error using MSVC 2005. So I decided to try and compile "A Very Simple Case" from the tutorial, and that of course works. But then I noticed that the example serializes a const object, that sort of is rather useless, so I removed the const specifier, and I got the same error that I was getting with my program, namely: warning C4099: 'boost::serialization::static_warning_impl<false>::STATIC_WARNING' : type name first seen using 'struct' now seen using 'class' I went googling for an answer and I found that I should look at the rationale on the docs, but the rationale (http://www.boost.org/doc/libs/1_47_0/libs/serialization/doc/rationale.html) doesn't seem at all relevant. I finally sort of guessed that I wanted was probably to modify the tracking behavior on my program (looking at the thread http://lists.boost.org/boost-users/2010/05/59107.php ). But my objects are not on the stack, so I'm not really sure. My class structure is a bit more complicated than the simple example, but my question basically is, what changes would be appropriate on the simple example so that it would compile for non-const objects? Thanks

4 6

Boost Object Pool Ticket #3789
by Gokulakannan Somasundaram 15 Oct '11

15 Oct '11

Hi, I just want to know, when the patch will get applied for this bug. We want to use Boost object Pool, but we find this bug very disturbing. Thanks, Gokul.

1 1

[chrono] Compilation with MinGW/gcc 4.4.0
by Richard Hazlewood 14 Oct '11

14 Oct '11

I've been trying to compile the chrono "hello world" example with MinGW/GCC 4.4.0, but it fails. I then tried to compile the tests, and saw similar errors. The docs say this compiler is supported, has anyone else tried this? Here's the error chain: .\boost_1_47_0/boost/type_traits/common_type.hpp: At global scope: .\boost_1_47_0/boost/type_traits/common_type.hpp: In instantiation of 'boost::common_type<double, long long int, long long int>': .\boost_1_47_0/boost/chrono/duration.hpp:252: instantiated from 'ToDuration boost::chrono::detail::duration_cast_aux<FromDuration, ToDuration, Period, true, false>::operator()(const FromDuration&) const [with FromDuration = boost::chrono::duration<long long int, boost::ratio<1ll, 10000000ll> >, ToDuration = boost::chrono::duration<double, boost::ratio<1ll, 1ll> >, Period = boost::ratio<1ll, 10000000ll>]' .\boost_1_47_0/boost/chrono/duration.hpp:311: instantiated from 'ToDuration boost::chrono::detail::duration_cast<FromDuration, ToDuration>::operator() (const FromDuration&) const [with FromDuration = boost::chrono::duration<long long int, boost::ratio<1ll, 10000000ll> >, ToDuration = boost::chrono::duration<double, boost::ratio<1ll, 1ll> >]' .\boost_1_47_0/boost/chrono/duration.hpp:472: instantiated from 'boost::chrono::duration<Rep, Period>::duration(const boost::chrono::duration<Rep2, Period2>&, typename boost::enable_if<boost::mpl::or_<boost::chrono::treat_as_floating_point<Rep>, boost::mpl::and_<boost::chrono::chrono_detail::is_evenly_divisible_by<Period2, Period>, boost::mpl::not_<boost::chrono::treat_as_floating_point<Rep2> >, mpl_::bool_<true>, mpl_::bool_<true>, mpl_::bool_<true> >, mpl_::bool_<false>, mpl_::bool_<false>, mpl_::bool_<false> >, void>::type*) [with Rep2 = long long int, Period2 = boost::ratio<1ll, 10000000ll>, Rep = double, Period = boost::ratio<1ll, 1ll>]' ...\test.cpp:96: instantiated from here .\boost_1_47_0/boost/type_traits/common_type.hpp:77: error: no type named 'type' in 'struct boost::common_type<double, long long int, void>'

3 4

Problem with Spirit Qi and inherited attributes reference
by Anand kumar 14 Oct '11

14 Oct '11

Hello, This is my first time using boost and spirit. I am trying to find construct a tree from a string input. While parsing I am trying to assign each created node a number. For this purpose I am using a inherited attribute, an integer reference. But when I check on the values assigned. It is not the value of the integer reference rather some other value (some consistent value). I am sure this must be something that I am overlooking. But I am not sure what exactly. Thanks for your help, Anand Kumar. Code: struct node; struct term { bool visited; int cnt; int val; term(bool b = false, int cn = -1, int v = numeric_limits<int>::min()) { visited = b; cnt = cn; val = v; } }; BOOST_FUSION_ADAPT_STRUCT( ::term, (bool, visited) (int, cnt) (int, val) ) typedef boost::variant<term, boost::recursive_wrapper<node>> node_impl; struct node { bool visited; int cnt; vector<node_impl> children; }; BOOST_FUSION_ADAPT_STRUCT( ::node, (bool, visited) (int, cnt) (std::vector<::node_impl>, children) ) template<typename Iterator> struct node_parser : qi::grammar<Iterator, node(), ascii::space_type> { qi::rule<Iterator, node(), ascii::space_type> start_r; qi::rule<Iterator, node(int&), ascii::space_type> node_r; qi::rule<Iterator, node_impl(int&), ascii::space_type> node_impl_r; node_parser() : node_parser::base_type(start_r) { using qi::int_; using qi::lexeme; using namespace qi::labels; using phoenix::ref; int cnt = 990; start_r %= node_r(phoenix::ref(cnt)); node_r = ('{' >> +node_impl_r(_r1) >> '}') [at_c<0>(_val) = false, at_c<1>(_val) = _r1++, at_c<2>(_val) = _1]; node_impl_r = ((lexeme['(' >> int_ >> ')'])[_val = phoenix::construct<term>(phoenix::val(false), _r1++, _1)]) | (node_r(_r1)[_val = _1]); } };

1 0

Regarding building of boost1.38.0 with aCC ( Hp compiler)
by Pravar 14 Oct '11

14 Oct '11

Hi *, I am trying to build *boost1.38.0* with *aCC A.0.17* ( HP compiler). I need to understand a few details: - Does in older boost versions, *build process* is a bit different ? I think it is as I can not found any bootstrap.sh in boost root directory. - Does $BOOST_ROOT./configure is equivalent to $BOOST_ROOT./bootstrap.sh in latest versions ? I executed following commands during building of boost 1.38.0 : - From boost root directory, ./configure --prefix=/opt/boost, I get following output, ----------------------------------------------------------------------- -n Building Boost.Jam with toolset acc... tools/jam/src/bin.hpuxia64/bjam ----------------------------------------------------------------------- - Then, I changed directory to tools/jam/src/bin.hpuxia64/bjam. I tried to build by executing ./bjam /some build options/ I get below error, *------------------------------------------------------- notice: could not find main target install notice: assuming it is a name of file to create. don't know how to make <e>install ...found 1 target... ...can't find 1 target... --------------------------------------------------------* Is there something i am missing ? Any inputs would be helpful. Best Regards, Pravar DISCLAIMER: ----------------------------------------------------------------------------------------------------------------------- The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. It shall not attach any liability on the originator or NECHCL or its affiliates. Any views or opinions presented in this email are solely those of the author and may not necessarily reflect the opinions of NECHCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. . -----------------------------------------------------------------------------------------------------------------------

1 0

[thread] UpgradeLockable Concept & Writer Starvation
by Ovanes Markarian 14 Oct '11

14 Oct '11

Hello *, I was reading through the docs of boost::thread lib and I can't find any guarantees that when using upgrade_lock the writer (upgrader) starvation is prevented. Are there any ordering guarantees, that if some thread is going to upgrade the lock the threads which acquire the shared lock after the upgrade request will not be able to acquire the lock until the upgrade request was accomplished and released the lock? Many thanks for help, Ovanes

1 0

Problem using special mathematical function in Visual C++
by Keith Fraser 13 Oct '11

13 Oct '11

Hello, I downloaded Boost in order to use the expint function: http://www.boost.org/doc/libs/1_37_0/libs/math/doc/sf_and_dist/html/math_to… I copied the /boost folder into the /include folder in Visual C++ where the other library files (stdio.h, etc.) are kept. In the .cpp file for the program I wanted to use expint in, I inserted the following line, taken from the description: #include <boost/math/special_functions/expint.hpp> When compiling, Visual C++ appears to be able to open expint.hpp, but it doesn't recognize the function: error C3861: 'expint': identifier not found Is there something else I need to add to the .cpp file so that expint will be recognized? I am using Visual C++ 2010 Express. Thanks, Keith

2 2

[lexical_cast] Fast conversion from boost::iterator_range<std::string::iterator>?
by Michel Morin 13 Oct '11

13 Oct '11

lexical_cast made optimizations for some types (such as `std::string`) to achieve better performance. But, from my experience, it seems that lexical_cast does not make any optimization for `boost::iterator_range<std::string::iterator>`. Is there any plan to add optimization for such iterator ranges? Currently, - `lexical_cast<int>(std::string(iter_rng.begin(), iter_rng.end()))` is faster than `lexical_cast<int>(iter_rng)`. - Assuming it is safe to use `std::atoi`, `std::atoi(&iter_rng.front())` is faster than both of the above two methods. (`iter_rng` is an instance of `boost::iterator_range<std::string::iterator>`.) Regards, Michel

1 0

[xpressive] treating special literals as non-regex
by Ovanes Markarian 13 Oct '11

13 Oct '11

Hello *, I ran into a problem, that I use some regex to split a string by some delimiters. My interface to the outer world is non-regex. A user can pass anything like delimiter. E.g. $d$ can be a valid delimiter. If I use sregex_token_iterator with regex created as: as_xpr("$d$") are $ treated as regex special characters and I have to escape them or can I safely use them in this context? If I have to escape the special characters is there any helper function like protect("$d$"). Many thanks for help, Ovanes

1 1

help with boost::spirit:parsing out a list of menuitems
by Littlefield, Tyler 13 Oct '11

13 Oct '11

Hello: I have a client I'm writing, where the server sends data to the client to display as a menu in one instance. I wanted to use boost::spirit to parse this out. So, here's the code. I have three questions: 1) What can I do better/differently? 2) When I parse out my menuitem, if there's no flag, can it be set to 0 by default somehow? 3) Where is menuitem returned? Is there a way I can push it to a queue since I'll have more? My actual parser will look something like: pstart >> item >> *(delem >> item) >> pend; Here is the code I have currently: struct menuitem { std::string name; int flag; int choice; }; BOOST_FUSION_ADAPT_STRUCT( menuitem, (std::string, name) (int, flag) (int, choice)) namespace ascii = boost::spirit::ascii; namespace qi = boost::spirit::qi; //I'd like to just take a char* here, since that's my payload. copying the char* to a std::string will take extra time, is there a way to do that? BOOL Menu::Parse(const std::string &data, int length) { std::string::const_iterator it, itEnd; it = data.begin(); itEnd = data.end(); //we construct a few parsers to make things easier. qi::rule<std::string::const_iterator, char, ascii::space_type> pstart = qi::char_('['); qi::rule<std::string::const_iterator, char, ascii::space_type> pend = qi::char_(']'); qi::rule<std::string::const_iterator, char, ascii::space_type>delem = qi::char_('|'); qi::rule<std::string::const_iterator, menuitem(), ascii::space_type>item = qi::char_("a-zA-Z0-9 -.?!$@") >> qi::char_('(') >> -qi::int_ >> qi::char_(':') >> qi::int_ >> qi::char_(')'); if (!qi::phrase_parse(it, itEnd, pstart >> item >> pend, ascii::space)) { return false; } return true; } -- Take care, Ty Web: http://tds-solutions.net The Aspen project: a light-weight barebones mud engine http://code.google.com/p/aspenmud Sent from my toaster.

3 3

Boost message_queue: when I receive an object, how can I remove it from the queue?
by pietro 13 Oct '11

13 Oct '11

I noticed that, when I get an object from a Boost message_queue with the *receive() member functions, that object remains in the queue. So if I read the same message_queue multiple times, I keep getting copies of the same objects, even if nothing has been inserted from the producer's side. Is there a way to remove an object from the queue once it has been read? In message_queue I found no member function that allows to do it. E.g.: (this is pseudo code; the consumer is shown and the producer would be in a separate process) boost::scoped_ptr<boost::interprocess::message_queue> pMQueue; message_queue::remove("myQueue"); pMQueue.reset(new message_queue(open_or_create, "myQueue", 100, sizeof(MyClass))); MyClass token; std::vector<MyClass> tokens; size_t recvdSize = 0; float timeDelay = 100; // milliseconds bool dataAvailable = true; // If I do this block twice, I receive the same tokens twice while(dataAvailable) { ptime t = microsec_clock::universal_time() + milliseconds(timeDelay); dataAvailable = pMQueue->timed_receive(&token, sizeof(token), recvdSize, 0, t); if(dataAvailable && recvdSize > 0) tokens.push_back(token); else ... } Note: in this example, MyClass' objects are fixed sized POD member variable objects only. -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-message-queue-when-I-receive-an-ob… Sent from the Boost - Users mailing list archive at Nabble.com.

1 1

[graph] vertex property Graph type cyclic definition problem. forward declaration not possible.
by Christoph 13 Oct '11

13 Oct '11

Hi, i would like to use the bundled properties feature of the boost graph library to specify the vertex properties of my graph. The problem is that i would like to have some graph type dependent descriptor type map defined within these vertex properties. Here is the example: // begin code #include <iostream> #include <boost/graph/adjacency_list.hpp> struct vertex_properties { vertex_properties () : color (-1) {} int color; std::list <int> free_colors; std::map<int,link_graph_traits::edge_descriptor> used_colors; // this is a cycle def problem }; struct edge_properties { edge_properties () : color (-1) {} int color; }; struct graph_properties { int delta; }; typedef boost::adjacency_list < boost::listS, boost::vecS, boost::bidirectionalS, vertex_properties,// this is a cycle problem edge_properties, graph_properties> link_graph; typedef boost::graph_traits <link_graph> link_graph_traits; int main(int argc, char** argv) { link_graph g; return 0; } // end code This example won't compile because the 'struct vertex_properties' contains a variable declaration of a std::map which contains the type ('link_graph_traits::edge_descriptor') as a template parameter that is not defined yet. I tried to forward declare the 'struct vertex_properties;' and move the definition of 'struct vertex_properties {...};' behind the graph type definition but then the compiler complained about. The forward declaration code, that does not compile, too follows: // begin code #include <iostream> #include <boost/graph/adjacency_list.hpp> struct vertex_properties; struct edge_properties { edge_properties () : color (-1) {} int color; }; struct graph_properties { int delta; }; typedef boost::adjacency_list < boost::listS, boost::vecS, boost::bidirectionalS, vertex_properties, edge_properties, graph_properties> link_graph; typedef boost::graph_traits <link_graph> link_graph_traits; struct vertex_properties { vertex_properties () : color (-1) {} int color; std::list <int> free_colors; std::map <int, link_graph_traits::edge_descriptor> used_colors; }; int main(int argc, char** argv) { link_graph g; return 0; } // end code I do not want to use (void*) and std::reinterpret_cast to work around this problem. I hope that you can help me with a technique not using casts. I assume that there may be a possibility to first declare the graph type without the vertex_properties struct and then 'adding' the vertex_propterties struct after defining the graph. best regards Christoph

2 2

Quaternions and SLERP
by Yves Rogez 13 Oct '11

13 Oct '11

Hello, I'm currently searching for a BLAS and geometrical library in C++ for ray-tracing simulation. I would like to know if Boost provides an implementation of the SLERP (Spherical Linear Interpolation) with Quaternions. As far as I could read in the Boost::Quaternions docs, it is not integrated, maybe it is elsewhere in boost ? I also found QVM which is not integrated with boost but extensively uses it. Is that in your mind a reliable solution ? (I have to compute a huge set of quaternion interpolations and compositions during my simulation steps). Thanks in advance for your replies, Regards, Yves

2 4

Boost asio deadline_timer, bug?
by Allan Nielsen 13 Oct '11

13 Oct '11

Hi Is this a bug, or am I doing something wrong? #include <iostream> #include <boost/asio.hpp> #include <boost/bind.hpp> using namespace std; using namespace boost::asio; struct A { A(io_service & service) : timer1(service), timer2(service) { timer1.expires_from_now( boost::posix_time::seconds(5) ); timer1.async_wait(boost::bind(&A::handler, this, _1)); timer2.expires_from_now( boost::posix_time::seconds(2) ); timer2.async_wait(boost::bind(&A::interrupt, this, _1)); } void handler(const boost::system::error_code &ec) { cout << "Forbidden handler" << endl; assert(0); } void handler_interrupted(const boost::system::error_code &ec) { cout << "Hello world" << endl; } void interrupt(const boost::system::error_code &ec) { cout << "Interrupted" << endl; int res = timer1.cancel(); assert(res > 0); timer1.expires_from_now( boost::posix_time::milliseconds(0) ); timer1.async_wait(boost::bind(&A::handler_interrupted, this, _1)); } int count, max, timeout1, timeout2; deadline_timer timer1; deadline_timer timer2; }; int main() { io_service service; A a(service); service.run(); return 0; }

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[Accumulators] Calling extractors on empty accumulator_set
by Dylan Klomparens 12 Oct '11

12 Oct '11

Hello all, I am curious, what mean is obtained from this code snippet? boost::accumulators::accumulator_set<int, boost::accumulators::features<boost::accumulators::tag::mean> > Accumulator; int Mean = boost::accumulators::mean(Accumulator); It appears to be non-zero when I test it. Is there some way I can tell that the average was taken for an empty data set? I was looking around in the documentation for the accumulator library, but was unable to find an answer to this question. Thanks in advance! -- Dylan

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using numpy instead of numeric
by Leila Baghdadi 12 Oct '11

12 Oct '11

Hello, I am very new to boost, I had a few files which build and run fine with boost , but return a numeric array, I now need to change my code to return a numpy array as I am sending it in another python package for further processing, I have been searching the web trying to find a simple example to do this conversion but so far was unsuccessful, The sample of my code is attached, any help is greatly appreciated! Leila

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boost::iterator_facade and assignment operation
by Arun Ramasamy 12 Oct '11

12 Oct '11

HI, I'm using the boost iterator_facade class to implement a random access iterator for my class. When I try to assign the iterators to one another, the compiler fails saying 'operator =' function is unavailable". Sample code from my implementation below: |class MyClass{ class Iterator : public boost::iterator_facade<Iterator, T, boost::bidirectional_traversal_tag>{ protected: void increment(); bool equal(const Iterator& rhs)const; //etc || //... Note - no method implemented to support assignment | | } }| I'd assumed that it'll be possible to assign iterators to each other. Why is the assignment operator not supported by iterator_facade. It implements other operations (like ++ and ==)by making the derived version implement private methods (like increment and equal). Am I missing something. The boost documentation doesn't mention why this is not supported. Thanks AR

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Does Boost suit me?
by Nouf M. 12 Oct '11

12 Oct '11

Hello, I'm a phd student. I'm working in the graph mining field. I have a huge text file that I would like to convert to a graph. Then, I will write some code to implement my algorithm (something similar to shortest paths algorithms). I'm planning to write my code in C++. Do you think Boost will suit me? Best regards, Nouf

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Re: [Boost-users] Compiling version 1.43 of boost/graph with SunCC 5.8
by Rob Riggs 12 Oct '11

12 Oct '11

You won't get far with that compiler. Your only hope is SS12 (CC 5.10), but even that's a stretch. The Solaris compiler was not exactly standard compliant. Rob Renaud Kauffmann <renaud(a)ekauffmann.net> wrote: >#include <boost/graph/adjacency_list.hpp> > >using namespace boost; > >typedef adjacency_list <vecS, vecS, undirectedS> BoostGraph; >typedef graph_traits < BoostGraph >::vertex_descriptor vertex_t; > >int main() { > > BoostGraph g; > vertex_t v1 = add_vertex(g); > vertex_t v2 = add_vertex(g); > vertex_t v3 = add_vertex(g); > > return 0; >} > >The above code doesn't seem to compile with Sun Studio 11, that is Sun C++ >compiler 5.8 and boost 1.43 >Here is the error: > >"/home/renaudk/boost/boost_1_43_0/boost/unordered/detail/table.hpp", line >38: Error: Could not find a match for >boost::unordered_detail::hash_table<boost::unordered_detail::T>::find_iterator<boost::unordered_detail::hash_table<boost::unordered_detail::T>::Key, >boost::unordered_detail::hash_table<boost::unordered_detail::T>::Pred>(bucket_ptr, >const boost::unordered_detail::Key&, const boost::unordered_detail::Pred&) >const. >"/home/renaudk/boost/boost_1_43_0/boost/unordered/detail/table.hpp", line >38: Error: Too many args in template, from boost::unordered_detail::Pred on >ignored. >"/home/renaudk/boost/boost_1_43_0/boost/unordered/detail/table.hpp", line >595: Error: Could not find a match for >boost::unordered_detail::hash_table<boost::unordered_detail::T>::find(const >boost::unordered_detail::Key&, const boost::unordered_detail::Hash&, const >boost::unordered_detail::Pred&) const. >"/home/renaudk/boost/boost_1_43_0/boost/unordered/detail/table.hpp", line >595: Error: Too many args in template, from boost::unordered_detail::Hash on >ignored. >4 Error(s) detected. > >I have tried some of the switch I found in the forums such as >-library=stlport4 >-features=tmplife -features=tmplrefstatic > >But no luck. > >Does anybody know the trick ? > >Thanks. > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

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