- Boost-users - lists.boost.org

[filesystem] basic_path as paramter
by Alexander Lamaison 09 Mar '10

09 Mar '10

I'd like to use basic_path as a function parameter so that it works correctly whether a wide or narrow string is passed. template<typename T> void func(basic_path<T> file) { do thing to file } func("myfile"); func(L"myfile"); However I can't do this becuase basic_path has a second Traits template paramter which is not itself a template. So I tried the following workaround: template<typename T> struct traits_chooser; template<> struct traits_chooser<char*> { typedef boost::filesystem::path_traits traits; }; template<> struct traits_chooser<wchar_t*> { typedef boost::filesystem::wpath_traits traits; }; template<typename T> void func(basic_path<T, typename traits_chooser<T>::traits> file) {...} But my compiler (MSVC 2005) still can't deduce the paramter type. Does anyone know how I can get this to work? Many thanks. Alex Lamaison

1 0

BOOST_ALL_DYN_LINK
by Paul 09 Mar '10

09 Mar '10

Hi all, I'm confused about boost dynamic linking on windows MSVC90 I always define: BOOST_ALL_NO_LIB So that I directly control which DLLs I link to. I add the signals dll for linking. Then, if I define BOOST_ALL_DYN_LINK, I get lots of these messages: boost_1_42_0\boost/signals/detail/signal_base.hpp(113) : warning C4251: 'boost::signals::detail::signal_base_impl::combiner_' : class 'boost::any' needs to have dll-interface to be used by clients of class 'boost::signals::detail::signal_base_impl' 39> boost_1_42_0\boost/any.hpp(36) : see declaration of 'boost::any' I've read up on this and understand why the warnings are shown. BUT, I don't understand why I am able to still link my program if I do NOT define BOOST_ALL_DYN_LINK. Without the flag, it compiles without warnings, it links without problems, AND the executable requires the signals DLL to be available, so clearly it IS dynamically linked. Right? Any ideas? Thanks, Paul

4 4

[serialization] Sets of shared pointers won't load
by John Pallister 09 Mar '10

09 Mar '10

Hello list, I'm using Visual C++ Express 2008 and Boost 1.42. I have a graph of classes I'm trying to serialise, and I'm using shared_ptrs to manage multiple references to the same object, but I can't deserialise my graph corectly. I get errors like: First-chance exception at 0x7c812afb in sams-6.exe: Microsoft C++ exception: std::basic_string<char,std::char_traits<char>,std::allocator<char> > at memory location 0x03d7f28c.. HEAP[sams-6.exe]: Invalid allocation size - AC1051B4 (exceeded 7ffdefff) First-chance exception at 0x7c812afb in sams-6.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x03c7dc5c.. HEAP[sams-6.exe]: Invalid allocation size - AC1051A8 (exceeded 7ffdefff) Here are my classes: struct stats_t { friend class boost::serialization::access; typedef int ts_t; size_t bytes, packets; ts_t firstPacketTs, lastPacketTs; stats_t() : bytes(0), packets(0), firstPacketTs(0), lastPacketTs(0) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & bytes & packets & firstPacketTs & lastPacketTs; } }; struct dest_port_t { friend class boost::serialization::access; endpoint_t endpoint; shp_socket_t socket; bool inUse; stats_t stats; std::string name; boost::asio::ip::udp::endpoint baue; dest_port_t(const endpoint_t &e, const std::string &n=std::string()) : endpoint(e), inUse(false), name(n), baue(boost::asio::ip::address_v4(e.first), e.second) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & endpoint & name & inUse & stats; } }; typedef boost::shared_ptr<dest_port_t> shp_dest_port_t; typedef std::set<shp_dest_port_t> dest_port_shpset_t; BOOST_SERIALIZATION_SHARED_PTR( dest_port_t ) namespace boost { namespace serialization { template<class Archive> inline void load_construct_data(Archive &ar, dest_port_t *dpp, unsigned int /* file_version */) { endpoint_t endpoint; std::string name; ar >> endpoint; ar >> name; ::new(dpp) dest_port_t(endpoint, name); ar >> dpp->inUse; ar >> dpp->stats; } } } struct dest_t { friend class boost::serialization::access; endpoint_t endpoint; dest_port_shpset_t ports; size_t connections; std::string name; dest_t(const endpoint_t &e=endpoint_t(), const std::string &n=std::string()) : endpoint(e), connections(0), name(n) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & endpoint & ports & connections & name; } }; typedef boost::shared_ptr<dest_t> shp_dest_t; typedef std::set<shp_dest_t> dest_shpset_t; BOOST_SERIALIZATION_SHARED_PTR( dest_t ) struct source_t { friend class boost::serialization::access; endpoint_t endpoint; size_t connections; stats_t stats; const bool foreign; // True for 'unrecognised' sources. std::string name; source_t(const endpoint_t &e=endpoint_t(), bool f=false, const std::string &n=std::string()) : endpoint(e), connections(0), foreign(f), name(n) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & endpoint & connections & stats & const_cast<bool &>(foreign) & name; } }; typedef boost::shared_ptr<source_t> shp_source_t; typedef std::set<shp_source_t> source_shpset_t; BOOST_SERIALIZATION_SHARED_PTR( source_t ) struct connection_t { friend class boost::serialization::access; shp_source_t source; shp_dest_port_t dest_port; shp_dest_t dest; stats_t stats; connection_t(const shp_source_t &s, const shp_dest_port_t &dp, const shp_dest_t &d=shp_dest_t()) : source(s), dest_port(dp), dest(d) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & source & dest_port & dest & stats; } }; typedef std::set<connection_t> connection_set_t; typedef std::map<endpoint_t, connection_set_t> talkspurt_map_t; namespace boost { namespace serialization { template<class Archive> inline void load_construct_data(Archive &ar, connection_t *cp, unsigned int /* file_version */) { shp_source_t src; shp_dest_port_t dest_port; shp_dest_t dest; ar >> src; ar >> dest_port; ar >> dest; ::new(cp) connection_t(src, dest_port, dest); ar >> cp->stats; } } } class UdpWorker : public syn::Thread { protected: size_t errors_; stats_t total_, invalid_, ignored_; dest_shpset_t dests_; source_shpset_t sources_; talkspurt_map_t talkspurtMap_; }; So it's UdpWorker -> dest_shpset_t -> dest_t -> dest_port_shpset_t -> stats_t, UdpWorker -> source_shpset_t -> source_t -> stats_t, UdpWorker -> talkspurt_map_t -> connection_set_t -> shp_source_t etc. The code to save is: void UdpWorker::save() { try { ofstream os(stateFile_.c_str()); boost::archive::text_oarchive oa(os); oa << errors_; oa << total_; oa << invalid_; oa << ignored_; oa << sources_; oa << dests_; oa << talkspurtMap_; } catch (boost::archive::archive_exception &ae) { log("UdpWorker::save(): Error - caught archive_exception \"%s\" while saving to text archive \"%s\".", ae.what(), stateFile_.c_str()); } catch (...) { log("UdpWorker::save(): Error - caught unknown exception while saving to text archive \"%s\".", stateFile_.c_str()); } } And the loading code is very similar: void UdpWorker::load() { try { ifstream is(stateFile_.c_str()); boost::archive::text_iarchive ia(is); ia >> errors_; ia >> total_; ia >> invalid_; ia >> ignored_; ia >> sources_; ia >> dests_; ia >> talkspurtMap_; } catch (boost::archive::archive_exception &ae) { log("UdpWorker::load(): Error - caught archive_exception \"%s\" while loading from text archive \"%s\".", ae.what(), stateFile_.c_str()); } catch (...) { log("UdpWorker::load(): Error - caught unknown exception while loading from text archive \"%s\".", stateFile_.c_str()); } } The archive seems to be written OK, but when loading it seems to load the sources_ set OK and then die on the dests_ set, with the bad_alloc exceptions given above. So the talkspurt_map_t hasn't been tested yet... I've tried the binary archive, but I get pretty much the same error. I'd really appreciate it if someone with a more experienced eye could have a look at my classes and tell me if there's anything suspicious. Is BOOST_SERIALIZATION_SHARED_PTR still required in 1.42? I couldn't find any mention of it in the documentation, but many examples seem to use it. It looks like it's a no-op anyway on this compiler. Thanks very much, John :^P -- John Pallister john(a)johnp.net john(a)synchromesh.com

1 0

Using Boost.Atomic for thread-safe reference counting with strong exception guarantee
by Narcoleptic Electron 08 Mar '10

08 Mar '10

I'm trying to create a thread-safe, strong-exception-guaranteed "intrusive_pte" (intrusive pointee) class that represents a drop-in reference-counted base class for a pointee of intrusive_ptr. I'm using the pending Boost.Atomic library (http://www.chaoticmind.net/~hcb/projects/boost.atomic/) and am basing my code on the example given (http://www.chaoticmind.net/~hcb/projects/boost.atomic/doc/atomic/usage_exam…) but not yet having a sound understanding of memory barriers, I am unsure if my code for the overflow exception is correct or ideal. The relevant code snippet is below. Any feedback would be greatly appreciated. Thanks! --- mutable atomic< IntegralType > ref_count; mutable mutex add_ref_mutex; void add_ref() const { mutex::scoped_lock add_ref_lock( add_ref_mutex ); if ( integer_traits< IntegralType >::const_max == ref_count.load( memory_order_relaxed ) ) { throw_exception( std::overflow_error( "Reference count overflow." ) ); } ref_count.fetch_add( 1, memory_order_relaxed ); } friend void intrusive_ptr_add_ref ( intrusive_pte const * const p ) { BOOST_ASSERT( p && "The argument cannot be null." ); p->add_ref(); } friend void intrusive_ptr_release ( intrusive_pte * const p ) { BOOST_ASSERT( p && "The argument cannot be null." ); BOOST_ASSERT( ( 0 < p->ref_count.load( memory_order_acquire ) ) && "Reference count underflow." ); if ( p->ref_count.fetch_sub( 1, memory_order_release ) == 1 ) { atomic_thread_fence( memory_order_acquire ); checked_delete( p ); } }

1 0

[Serialization] Strange giant warning
by David 08 Mar '10

08 Mar '10

For a short while now I've been using boost serialization. It works perfectly... except... it keeps coming up one massive warning (that takes up ~100 lines). (see below) Whenever I get annoyed, I try to experiment and then search for answers online, but no luck. I'm probably using the library incorrectly somewhere. So I made a small program that generates the problem. Any advice on what I could be doing wrong would be appreciated. I use vc++ 2008 btw. Thanks. Code: -------------------------------------------- /* demonstration of problem. The program asks the user for a number, and then saves this number to a file. When the user returns, the number is remembered. */ #include <iostream> #include <fstream> #include <boost/serialization/shared_ptr.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> // save and load methods void save (const char * fname); bool load (const char * fname); // returns if successful // I know this is way too simple to put in a class, but bare with me class Game { public: Game () { number = 0; } void getNumberFromUser () { std::cin >> number; } int getNumber () { return number; } private: int number; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & number; } }; typedef boost::shared_ptr< Game > Game_ptr; Game_ptr game; // entry int main () { game = Game_ptr( new Game ); // welcome std::cout << "Hello\n"; // if file exists, recall the number if (load ("save.txt")) std::cout << "You're number is " << game->getNumber() << ".\n"; // ask user for number std::cout << "Enter a number: \n"; game->getNumberFromUser (); // memorise number save ("save.txt"); // exit return 0; } void save (const char * fname) { std::ofstream ofs( fname ); boost::archive::text_oarchive oa( ofs ); // save oa << game; } bool load (const char * fname) { std::ifstream ifs( fname ); if (!ifs) return false; // file doesn't already exist boost::archive::text_iarchive ia( ifs ); // load ia >> game; // <------ Removing this line makes the warning go away return true; } Warning: -------------------------------------------- 1>main.cpp 1>d:\dev\boostpro\boost\boost_1_40\boost\serialization\extended_type_info_typeid.hpp(88) : warning C4099: 'boost::serialization::static_warning_impl<false>::STATIC_WARNING' : type name first seen using 'struct' now seen using 'class' 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\static_warning.hpp(115) : see declaration of 'boost::serialization::static_warning_impl<false>::STATIC_WARNING' 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\extended_type_info_typeid.hpp(85) : while compiling class template member function 'const boost::serialization::extended_type_info *boost::serialization::extended_type_info_typeid<T>::get_derived_extended_type_info(const T &) const' 1> with 1> [ 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\shared_ptr_helper.hpp(105) : see reference to class template instantiation 'boost::serialization::extended_type_info_typeid<T>' being compiled 1> with 1> [ 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\shared_ptr.hpp(138) : see reference to function template instantiation 'void boost::archive::detail::shared_ptr_helper::reset<Game>(boost::shared_ptr<T> &,T *)' being compiled 1> with 1> [ 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\split_free.hpp(58) : see reference to function template instantiation 'void boost::serialization::load<Archive,Game>(Archive &,boost::shared_ptr<T> &,const unsigned int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\split_free.hpp(54) : while compiling class template member function 'void boost::serialization::free_loader<Archive,T>::invoke(Archive &,T &,const unsigned int)' 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=boost::shared_ptr<Game> 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\split_free.hpp(74) : see reference to class template instantiation 'boost::serialization::free_loader<Archive,T>' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=boost::shared_ptr<Game> 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\shared_ptr.hpp(153) : see reference to function template instantiation 'void boost::serialization::split_free<Archive,boost::shared_ptr<T>>(Archive &,boost::shared_ptr<T> &,const unsigned int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\serialization.hpp(133) : see reference to function template instantiation 'void boost::serialization::serialize<Archive,Game>(Archive &,boost::shared_ptr<T> &,const unsigned int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(174) : see reference to function template instantiation 'void boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const unsigned int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(161) : while compiling class template member function 'void boost::archive::detail::iserializer<Archive,T>::load_object_data(boost::archive::detail::basic_iarchive &,void *,const unsigned int) const' 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(362) : see reference to class template instantiation 'boost::archive::detail::iserializer<Archive,T>' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(351) : while compiling class template member function 'void boost::archive::detail::load_non_pointer_type<Archive,T>::load_standard::invoke(Archive &,T &)' 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(417) : see reference to class template instantiation 'boost::archive::detail::load_non_pointer_type<Archive,T>::load_standard' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(405) : while compiling class template member function 'void boost::archive::detail::load_non_pointer_type<Archive,T>::invoke(Archive &,T &)' 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(542) : see reference to class template instantiation 'boost::archive::detail::load_non_pointer_type<Archive,T>' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\common_iarchive.hpp(61) : see reference to function template instantiation 'void boost::archive::load<Archive,T>(Archive &,T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\basic_text_iarchive.hpp(62) : see reference to function template instantiation 'void boost::archive::detail::common_iarchive<Archive>::load_override<T>(T &,int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\text_iarchive.hpp(66) : see reference to function template instantiation 'void boost::archive::basic_text_iarchive<Archive>::load_override<T>(T &,int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\interface_iarchive.hpp(61) : see reference to function template instantiation 'void boost::archive::text_iarchive_impl<Archive>::load_override<T>(T &,int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\visual studio 2008\projects\boostserialisation\boostserialisation\main.cpp(82) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_iarchive<Archive>::operator >><Game_ptr>(T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ]

3 4

[graph][spirit] Boost.Graph and Boost.Spirit incompatible ?
by Maxime van Noppen 08 Mar '10

08 Mar '10

Hi, After my very big disappointment when I discovered that Boost.Graph and Boost.Variant where incompatible[1], now it seems that Boost.Graph and Boost.Spirit (and more precisely Qi) are incompatible... :( Minimal test case : -------- test.cc ----------- #include <boost/graph/dijkstra_shortest_paths.hpp> #include <boost/spirit/include/qi.hpp> ---------------------------- > $ g++ -c test.cc > In file included from /usr/include/boost/graph/properties.hpp:19, > from /usr/include/boost/graph/named_function_params.hpp:13, > from /usr/include/boost/graph/dijkstra_shortest_paths.hpp:20, > from inc_test.cc:1: > /usr/include/boost/property_map/property_map.hpp: In instantiation of ‘boost::property_traits<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >’: > /usr/include/boost/graph/two_bit_color_map.hpp:47: instantiated from ‘boost::two_bit_color_map<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >’ > /usr/include/boost/spirit/home/qi/char/char.hpp:206: instantiated from here > /usr/include/boost/property_map/property_map.hpp:31: error: no type named ‘key_type’ in ‘struct std::basic_string<char, std::char_traits<char>, std::allocator<char> >’ > /usr/include/boost/property_map/property_map.hpp:34: error: no type named ‘category’ in ‘struct std::basic_string<char, std::char_traits<char>, std::allocator<char> >’ > /usr/include/boost/property_map/property_map.hpp: In instantiation of ‘boost::property_traits<std::list<boost::spirit::info, std::allocator<boost::spirit::info> > >’: > /usr/include/boost/graph/two_bit_color_map.hpp:47: instantiated from ‘boost::two_bit_color_map<std::list<boost::spirit::info, std::allocator<boost::spirit::info> > >’ > /usr/include/boost/spirit/home/support/detail/what_function.hpp:35: instantiated from here > /usr/include/boost/property_map/property_map.hpp:31: error: no type named ‘key_type’ in ‘class std::list<boost::spirit::info, std::allocator<boost::spirit::info> >’ > /usr/include/boost/property_map/property_map.hpp:34: error: no type named ‘category’ in ‘class std::list<boost::spirit::info, std::allocator<boost::spirit::info> >’ I have g++ 4.4.3 on Linux amd64 and Boost 1.42.0. Maybe there should be some documentation about such incompatibilities between boost libraries. [1] http://lists.boost.org/boost-users/2010/01/55317.php -- Maxime

4 21

[Review] ITL review starts today, February 18th
by Hartmut Kaiser 08 Mar '10

08 Mar '10

Hi all, The formal review of the Interval Template Library (ITL) starts today, February 18th, 2010 and will end February 27th, 2010. ITL is being developed by Joachim Faulhaber. ------------------------------------------------ About the library: The Interval Template Library (ITL) is a library of interval containers that facilitates computations on collections of intervals and associated values. Use cases of such computations typically occur in the date and time problem domain, when collections of time intervals with associated data are analyzed, combined and aggregated. But the scope of applications for interval containers is more general and not limited to date and time problems. Interval containers allow to access and manipulate collections of intervals on an abstract level as sets and maps (of elements), but also to exploit segmental information that is given by the interval borders. Interval containers are fairly generic. They can be instantiated with discrete domain (or key) types like integral numeric types or boost::date or time types. But they also work with continuous domain types like double, rational or string. Using the latter allows to represent infinite sets and maps. The interface of the interval containers strives to be very intuitive and in line with the stl and other boost libraries. * The set theoretic operations union, difference, intersection and symmetric difference are available as operators for all interval containers and for many useful overloads between them. * There is iterator support on the level of segments and interval containers can be combined with stl containers of intervals via stl algorithms. * For discrete domain types, element iterators are available which makes interval sets and maps models of SortedAssociative Containers so they can be used with many stl algorithms. All interval containers are addable and subtractable. The addability and subtractability concept of the ITL leads to a general mechanism of aggregation on interval_maps which is called 'aggregate on overlap'. Exploiting 'aggregate on overlap' allows to compute many useful aggregation results in a simple and abstract manner. The ITL's Set and Map concepts are defined by a signature and collections of laws or axioms. Those semantical constraints have been validated using automatic law based tests. This gives the library both a well founded formal specification and an unusual thorough test base. The ITL emerged out of real world use cases and is successfully used at Cortex Software GmbH since a couple of years in the production code of various applications. On the boost developer's list it has been proposed in four previews and a review request since May 2008 and has been refactored and refined according to boost standards and suggestions from the list. The ITL is available from the boost vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=itl_3_2 _0.zip&directory=Containers Documentation is online available at: http://www.herold-faulhaber.de/boost_itl/doc/libs/itl/doc/html/index.html The current sources are in the sandbox: https://svn.boost.org/svn/boost/sandbox/itl/ ------------------------------------------------ Everybody on this list is invited to participate in this formal review. I hope to see your review of this library, including your vote, and I welcome your participation in the discussions on the Boost mailing list. 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? 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? Regards Hartmut Review Manager --------------- Meet me at BoostCon www.boostcon.com

5 5

Random number generation
by David Kaplan 08 Mar '10

08 Mar '10

I'm using the following code to generate a random 64 bit value: boost::mt19937 rng; boost::uniform_int<uint64_t> r(0,0xffffffffffffffff); boost::variate_generator<boost::mt19937&, boost::uniform_int<uint64_t> > gen(rng, r); uint64_t id = gen(); However it seems it's not random on each execution of the program? (rather I get the same value again). How do I randomise this properly?

3 4

how to share information about a open socket?
by pedro chaparro 08 Mar '10

08 Mar '10

Hi, based on the example http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/tutorial/tutdaytim…, i wanna to separate the part of the code that open de connection , and the part of the code that write a string over the socket, the problem is , that i have no clear how to share the information of the socket between the both fuctions. In this code below i suppose that listen fucion must to return the socket information, but what data type must the function listen() return??? thanks so much in advance void Agent::listen() { try { printf("SERVER A STARTED UDPsk \n"); boost::asio::io_service io_service; tcp::acceptor acceptor(io_service, tcp::endpoint(tcp::v4(), 7777)); //for (;;) { tcp::socket socket(io_service); acceptor.accept(socket); } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } } void Agent::write() { try { std::string message = "mymsg"; boost::system::error_code ignored_error; boost::asio::write(socket, boost::asio::buffer(message), boost::asio::transfer_all(), ignored_error); sleep(1); socket.close(); return; } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } } -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

3 2

[Review] The review of the ITL library ends today, March 7th
by Hartmut Kaiser 08 Mar '10

08 Mar '10

Hey all, The review of Joachim Faulhabers ITL library ends today, March 7th 2010. Please get your reviews in today or get in contact with me to agree on some offline schedule. Regards Hartmut Review Manager --------------- Meet me at BoostCon www.boostcon.com

4 4