October 2016 - Boost-users - lists.preview.boost.org

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

12 Oct '19

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

3 2

Weird compilation error when using boost::geometry
by 邓尧 16 Nov '17

16 Nov '17

Hi, I have implemented my own "point" as specified by the point concept http://www.boost.org/doc/libs/1_59_0/libs/geometry/doc/html/geometry/refere… When I use it along with boost::geometry::model::polygon/multi_polygon, GCC refuses to compile, tested on GCC 4.9/5.2. What's even more weird is that CLANG 3.6 would happy accept my code. BTW, the Point implementation is part of a large project, it difficult to replace it with boost::geometry::model::point. Here is my code: Point.hpp > #ifndef RAPTOR_POINT_HPP_INCLUDED_ > > #define RAPTOR_POINT_HPP_INCLUDED_ > > >> #include <boost/mpl/int.hpp> > > #include <boost/geometry/core/access.hpp> > > #include <boost/geometry/core/cs.hpp> > > #include <boost/geometry/core/coordinate_type.hpp> > > #include <boost/geometry/core/coordinate_system.hpp> > > #include <boost/geometry/core/coordinate_dimension.hpp> > > #include <boost/geometry/geometries/polygon.hpp> > > #include <boost/geometry/multi/geometries/multi_polygon.hpp> > > >> namespace raptor { > > >> template<typename T, int tDimension = 2> > > class Point { > > public: > > Point() = default; > > >> Point(T a, T b) { > > data[0] = a; > > data[1] = b; > > } > > >> Point(T a, T b, T c) { > > data[0] = a; > > data[1] = b; > > data[2] = c; > > } > > >> T& operator [] (long index) { > > return data[index]; > > } > > >> const T& operator [] (long index) const { > > return data[index]; > > } > > >> private: > > T data[tDimension]; > > }; > > >> using CubicPoint = Point<long, 3>; > > using PlanarPoint = Point<long>; > > using SphericalPoint = Point<double>; > > >> template<typename T> > > using Polygon = boost::geometry::model::polygon<T>; > > >> template<typename T> > > using PolySet = boost::geometry::model::multi_polygon<Polygon<T>>; > > >> } // namespace raptor > > >> namespace boost { namespace geometry { namespace traits { > > >> template<typename Type, std::size_t tDimension> > > struct tag<::raptor::Point<Type, tDimension>> { > > typedef point_tag type; > > }; > > >> template<typename Type, std::size_t tDimension> > > struct coordinate_type<::raptor::Point<Type, tDimension>> { > > typedef Type type; > > }; > > >> template<typename Type, std::size_t tDimension> > > struct coordinate_system<::raptor::Point<Type, tDimension>> { > > typedef boost::geometry::cs::cartesian type; > > }; > > >> template<typename Type, std::size_t tDimension> > > struct dimension<::raptor::Point<Type, tDimension>> > > : public boost::mpl::int_<tDimension> { > > // EMPTY > > }; > > >> template<typename Type, std::size_t tDimension, std::size_t tIndex> > > struct access<::raptor::Point<Type, tDimension>, tIndex> { > > static Type get(const ::raptor::Point<Type, tDimension>& p) { > > return p[tIndex]; > > } > > >> static void set(::raptor::Point<Type, tDimension>& p, > > const Type& value) { > > p[tIndex] = value; > > } > > }; > > >> }}} // namespace boost::geometry::traits > > >> #endif // RAPTOR_POINT_HPP_INCLUDED_ > > A real simple main.cpp: > #include "Point.hpp" > > >> int main() { > > raptor::Polygon<raptor::SphericalPoint> pl; > > raptor::PolySet<raptor::SphericalPoint> set; > > return sizeof(pl) + sizeof(set); > > } > > > GCC compilation error: g++ main.cpp -std=c++14 > In file included from /usr/include/boost/geometry/core/access.hpp:20:0, from Point.hpp:5, from main.cpp:1: /usr/include/boost/geometry/core/point_type.hpp: In instantiation of > 'struct boost::geometry::traits::point_type<raptor::Point<double> >': /usr/include/boost/geometry/core/point_type.hpp:66:17: required from > 'struct boost::geometry::core_dispatch::point_type<void, > raptor::Point<double> >' /usr/include/boost/geometry/core/coordinate_type.hpp:58:62: required from > 'struct boost::geometry::core_dispatch::coordinate_type<void, > raptor::Point<double> >' /usr/include/boost/geometry/core/coordinate_type.hpp:92:25: required from > 'struct boost::geometry::coordinate_type<raptor::Point<double> >' /usr/include/boost/geometry/geometries/concepts/point_concept.hpp:90:54: > required from 'class boost::geometry::concept::Point<raptor::Point<double> > >' /usr/include/boost/concept/detail/has_constraints.hpp:32:62: required by > substitution of 'template<class Model> boost::concepts::detail::yes > boost::concepts::detail::has_constraints_(Model*, > boost::concepts::detail::wrap_constraints<Model, (& Model:: constraints)>*) > [with Model = boost::geometry::concept::Point<raptor::Point<double> >]' /usr/include/boost/concept/detail/has_constraints.hpp:42:5: required from > 'const bool > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >::value' /usr/include/boost/concept/detail/has_constraints.hpp:45:31: required > from 'struct > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >' /usr/include/boost/mpl/if.hpp:67:11: required from 'struct > boost::mpl::if_<boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >, > boost::concepts::constraint<boost::geometry::concept::Point<raptor::Point<double> > > >, boost::concepts::requirement<boost::concepts::failed************ > boost::geometry::concept::Point<raptor::Point<double> >::************> >' /usr/include/boost/concept/detail/general.hpp:50:8: required from 'struct > boost::concepts::requirement_<void > (*)(boost::geometry::concept::Point<raptor::Point<double> >)>' /usr/include/boost/geometry/geometries/ring.hpp:60:5: required from > 'class boost::geometry::model::polygon<raptor::Point<double>, true, true, > std::vector, std::vector, std::allocator, std::allocator>' main.cpp:4:42: required from here /usr/include/boost/geometry/core/point_type.hpp:45:5: error: no matching > function for call to 'assertion_failed(mpl_::failed************ > (boost::geometry::traits::point_type<raptor::Point<double> > >::NOT_IMPLEMENTED_FOR_THIS_POINT_TYPE::************)(mpl_::assert_::types<raptor::Point<double>, > mpl_::na, mpl_::na, mpl_::na>))' BOOST_MPL_ASSERT_MSG ^ /usr/include/boost/mpl/assert.hpp:82:5: note: candidate: template<bool C> > int mpl_::assertion_failed(typename mpl_::assert<C>::type) int assertion_failed( typename assert<C>::type ); ^ /usr/include/boost/mpl/assert.hpp:82:5: note: template argument > deduction/substitution failed: /usr/include/boost/geometry/core/point_type.hpp:45:5: note: cannot > convert > 'boost::geometry::traits::point_type<Geometry>::NOT_IMPLEMENTED_FOR_THIS_POINT_TYPE48::assert_arg<raptor::Point<double> > >()' (type 'mpl_::failed************ > (boost::geometry::traits::point_type<raptor::Point<double> > >::NOT_IMPLEMENTED_FOR_THIS_POINT_TYPE::************)(mpl_::assert_::types<raptor::Point<double>, > mpl_::na, mpl_::na, mpl_::na>)') to type 'mpl_::assert<false>::type {aka > mpl_::assert<false>}' BOOST_MPL_ASSERT_MSG ^ In file included from > /usr/include/boost/geometry/core/coordinate_type.hpp:21:0, from /usr/include/boost/geometry/core/access.hpp:24, from Point.hpp:5, from main.cpp:1: /usr/include/boost/geometry/core/point_type.hpp: In instantiation of > 'struct boost::geometry::core_dispatch::point_type<void, > raptor::Point<double> >': /usr/include/boost/geometry/core/coordinate_type.hpp:58:62: required from > 'struct boost::geometry::core_dispatch::coordinate_type<void, > raptor::Point<double> >' /usr/include/boost/geometry/core/coordinate_type.hpp:92:25: required from > 'struct boost::geometry::coordinate_type<raptor::Point<double> >' /usr/include/boost/geometry/geometries/concepts/point_concept.hpp:90:54: > required from 'class boost::geometry::concept::Point<raptor::Point<double> > >' /usr/include/boost/concept/detail/has_constraints.hpp:32:62: required by > substitution of 'template<class Model> boost::concepts::detail::yes > boost::concepts::detail::has_constraints_(Model*, > boost::concepts::detail::wrap_constraints<Model, (& Model:: constraints)>*) > [with Model = boost::geometry::concept::Point<raptor::Point<double> >]' /usr/include/boost/concept/detail/has_constraints.hpp:42:5: required from > 'const bool > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >::value' /usr/include/boost/concept/detail/has_constraints.hpp:45:31: required > from 'struct > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >' /usr/include/boost/mpl/if.hpp:67:11: required from 'struct > boost::mpl::if_<boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >, > boost::concepts::constraint<boost::geometry::concept::Point<raptor::Point<double> > > >, boost::concepts::requirement<boost::concepts::failed************ > boost::geometry::concept::Point<raptor::Point<double> >::************> >' /usr/include/boost/concept/detail/general.hpp:50:8: required from 'struct > boost::concepts::requirement_<void > (*)(boost::geometry::concept::Point<raptor::Point<double> >)>' /usr/include/boost/geometry/geometries/ring.hpp:60:5: required from > 'class boost::geometry::model::polygon<raptor::Point<double>, true, true, > std::vector, std::vector, std::allocator, std::allocator>' main.cpp:4:42: required from here /usr/include/boost/geometry/core/point_type.hpp:66:17: error: no type named > 'type' in 'struct boost::geometry::traits::point_type<raptor::Point<double> > >' >::type type; ^ In file included from > /usr/include/boost/geometry/geometries/polygon.hpp:26:0, from Point.hpp:10, from main.cpp:1: /usr/include/boost/geometry/geometries/concepts/point_concept.hpp: In > instantiation of 'class > boost::geometry::concept::Point<raptor::Point<double> >': /usr/include/boost/concept/detail/has_constraints.hpp:32:62: required by > substitution of 'template<class Model> boost::concepts::detail::yes > boost::concepts::detail::has_constraints_(Model*, > boost::concepts::detail::wrap_constraints<Model, (& Model:: constraints)>*) > [with Model = boost::geometry::concept::Point<raptor::Point<double> >]' /usr/include/boost/concept/detail/has_constraints.hpp:42:5: required from > 'const bool > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >::value' /usr/include/boost/concept/detail/has_constraints.hpp:45:31: required > from 'struct > boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >' /usr/include/boost/mpl/if.hpp:67:11: required from 'struct > boost::mpl::if_<boost::concepts::not_satisfied<boost::geometry::concept::Point<raptor::Point<double> > > >, > boost::concepts::constraint<boost::geometry::concept::Point<raptor::Point<double> > > >, boost::concepts::requirement<boost::concepts::failed************ > boost::geometry::concept::Point<raptor::Point<double> >::************> >' /usr/include/boost/concept/detail/general.hpp:50:8: required from 'struct > boost::concepts::requirement_<void > (*)(boost::geometry::concept::Point<raptor::Point<double> >)>' /usr/include/boost/geometry/geometries/ring.hpp:60:5: required from > 'class boost::geometry::model::polygon<raptor::Point<double>, true, true, > std::vector, std::vector, std::allocator, std::allocator>' main.cpp:4:42: required from here /usr/include/boost/geometry/geometries/concepts/point_concept.hpp:93:10: > error: 'value' is not a member of > 'boost::geometry::dimension<raptor::Point<double> >' enum { ccount = dimension<Geometry>::value }; ^ Where is the problem ? or it's a GCC bug ? Thanks

3 4

[Range, Phoenix] What am I missing...
by Robert Jones 25 Apr '17

25 Apr '17

Hi Folks Can anyone explain the output of this program... #include <iostream> #include <boost/range/algorithm/copy.hpp> #include <boost/range/counting_range.hpp> #include <boost/range/adaptor/reversed.hpp> #include <boost/range/adaptor/transformed.hpp> #include <boost/phoenix/bind/bind_function.hpp> #include <boost/phoenix/core/argument.hpp> int f( int i ) { return i * 2; } int main( ) { using boost::adaptors::reversed; using boost::adaptors::transformed; using boost::counting_range; using boost::copy; using boost::phoenix::arg_names::_1; copy( counting_range( 1, 5 ) | reversed | transformed( f ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; copy( counting_range( 1, 5 ) | reversed | transformed( bind( f, _1 ) ), std::ostream_iterator<int>( std::cout, " " ) ); std::cout << std::endl; } Which is... 8 6 4 2 1768406272 1768406272 1768406272 1768406272 I'm using Gcc 4.6.2 & Boost 1.53 Thx All.

3 4

[serialize] using virtual inheritance causes compiler error
by Douwe Gelling 02 Mar '17

02 Mar '17

Hi all, When trying to serialize a class with a virtual base class, I'm getting compilation errors. It seems to be part of a bug in type_traits, but I'm wondering if anyone knows a workaround for making it work anyhow. ultimately, the error boils down to "error: virtual function 'A::foo' has more than one final overrider in 'boost_type_traits_internal_struct_X'", using the code listing below.. It's simplified as much as possible, but obviously I need virtual inheritance due to using diamond inheritance. #include <boost/archive/text_oarchive.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/export.hpp> #include <boost/serialization/serialization.hpp> struct A { virtual ~A(){}; virtual void foo() = 0; template <class Archive> void serialize(Archive& ar, const unsigned int version) { } }; struct B : public virtual A { virtual void foo() { } template <class Archive> void serialize(Archive& ar, const unsigned int version) { ar& boost::serialization::base_object<A>(*this); } }; struct C : public B { template <class Archive> void serialize(Archive& ar, const unsigned int version) { ar& boost::serialization::base_object<B>(*this); } }; BOOST_CLASS_EXPORT(C); int main() { C c; return 0; }

4 7

[Log] Random "double free or corruption" in dtor of attribute_value_set
by robin.lorke＠jenoptik.com 01 Dec '16

01 Dec '16

Hi Gentlemen, I have an application that is using Boost.Log. The application is long-term running (days, weeks, maybe months). Currently I am experiencing random crashes in my application that seem related to Boost.Log. I dont't say that is is a bug in Boost.Log, but probably I am doing something wrong. I am using version 1.55.0 but I also tried upgrading to version 1.61.0 but it is still happening there. I am currently able to reproduce the crash by forcing logs at a pace of 3 records per second. Then it takes up to 3 days for the crash to happen. The application is multi-threaded and therefore several threads may be logging at the same time. For that reason I chose "severity_logger_mt". It seems related to the destruction of objects of type attribute_value_set. This is a gdb stacktrace of the crash (gcc O0 build): (gdb) bt #0 0xb6bdbed8 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:66 #1 0xb6bdf960 in __GI_abort () at abort.c:90 #2 0xb6c139fc in __libc_message (do_abort=2, fmt=0xb6cc8c44 "*** glibc detected *** %s: %s: 0x%s ***\n") at ../sysdeps/unix/sysv/linux/libc_fatal.c:200 #3 0xb6c1e17c in malloc_printerr (action=3, str=0xb6cc8d80 "double free or corruption (!prev)", ptr=<optimized out>) at malloc.c:4949 #4 0xb6b3fcb8 in boost::log::v2_mt_posix::attribute_value_set::~attribute_value_set() () from /usr/lib/libboost_log.so.1.55.0 #5 0xb6b42688 in boost::log::v2_mt_posix::record_view::public_data::destroy (boost::log::v2_mt_posix::record_view::public_data const*) () from /usr/lib/libboost_log.so.1.55.0 #6 0xb6b44c7c in boost::log::v2_mt_posix::core::push_record_move (boost::log::v2_mt_posix::record&) () from /usr/lib/libboost_log.so.1.55.0 #7 0xb6e66814 in Logger::addLog(Logger::LEVEL, char const*, char const*, int) () from /usr/lib/libtslog.so.1 #8 0x0005ba50 in addLogRusp (iMessageId=2, sMessage=<optimized out>, sProcess=0x8dee8 "Application", eLevel=Logger::LEVEL_INFO) at ../src/RLS-V/Platform/System.inl.h:303 #9 RLS::Application::fnThreadRuspOut (thread=...) at ../src/RLS-V/Application.cpp:1447 #10 0xb6e7aa4c in Thread::startFunction(void*) () from /usr/lib/libtscommon.so.1 #11 0xb6edae38 in start_thread (arg=0xb3eff460) at pthread_create.c:313 #12 0xb6c7c318 in ?? () from /lib/libc.so.6 Backtrace stopped: previous frame inner to this frame (corrupt stack?) This is the global logger initialization (using some custom attributes): BOOST_LOG_GLOBAL_LOGGER_INIT(appLogger, boost::log::sources::severity_logger_mt< robot::log::Severity >) { core::get()->add_global_attribute("TimeStamp", attributes::local_clock()); core::get()->add_global_attribute("ProcessID", AttrProcessId()); core::get()->add_global_attribute("LineCounter", attributes::counter< unsigned int >()); core::get()->add_global_attribute("Process", attributes::current_process_name()); core::get()->add_global_attribute("Scopes", attributes::named_scope ()); core::get()->add_global_attribute("LineID", attributes::counter< unsigned int >(1)); core::get()->add_global_attribute("SimpleTimeStamp", AttrSimpleTime ()); Logger::init(); sources::severity_logger_mt< Severity > lg; return lg; } These are are my macros for logging: //these are needed to convert a macro into a string #define STRINGIFY(x) #x #define TOSTRING(x) STRINGIFY(x) /* NOTE: * __FUNCTION__ is not a macro. It's a char pointer. So we use an empty std::string as basis to concatenate the char* to it */ #define R_LOG_ID(x,y) BOOST_LOG_SEV (robot::log::appLogger::get(), y) << boost::log::add_value("LogID", x) << boost::log::add_value("FLF", ROBOT_FLF) #define R_LOG(x) R_LOG_ID(0, x) #define ROBOT_FLF std::string() + TOSTRING(__FILE__) + ":" + TOSTRING (__LINE__) + " (" + __FUNCTION__ + ")" While "R_LOG_ID" is the only one that is used currently. There are currently three sinks active: syslog, console and a custom sink sending log records via an IPC mechanism (http://www.cs.cmu.edu/~./IPC/) I am currently testing if it will still happen if I deactivate one or more of those sinks. I imagine it will be hard to tell the exact problem from the information above but maybe you guys could point me in the right direction where to dig deeper. I will happily provide any missing information and/or code snippets that could help. Possibly there are well-known common mistakes that can lead to that memory corruption in attribute_value_set? Maybe something like lazy evaluation of log expressions or multi-threading issues? Many thanks in advance for any help! Robin Lorke

2 1

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

16 Nov '16

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

5 6

Microsoft and hana
by Dan Bloomquist 31 Oct '16

31 Oct '16

I'm sorry, I take it back. Things were fine until I included <boost/hana.hpp> I had been testing with <boost/hana/core/when.hpp> and the likes of: template<class T> constexpr T pi = T(3.1415926535897932385); // variable template which would not work until I patched. And to quote: In this release, we've updated the C++ compiler and standard library with enhanced support for C++11 and C++14 features, as well as preliminary support for certain features expected to be in the C++17 standard. The most notable compiler changes include complete support for generalized constexpr. Maybe next time.... Best, Dan.

5 4

Microsoft and hana
by Dan Bloomquist 29 Oct '16

29 Oct '16

I did a quick search here and didn't find anything on this. But I just patched up VS2015 with 'Visual Studio "15" Preview 5' <https://www.visualstudio.com/news/releasenotes/vs15-relnotes> and downloaded boost_1_62_0 The compiler now handles variable templates and I've compiled and run some simple hana tests. I did have to comment line 74 in "..\boost\hana\config.hpp". I just thought I'd drop a heads up for those, like me, that wanted to use hana with the Microsoft compiler. Best, Dan.

1 0

Re: [Boost-users] Boost Coroutine
by Emile Cormier 29 Oct '16

29 Oct '16

On 16-10-19 02:57 AM, Oliver Kowalke wrote: > > I'm not the maintainer of boost.asio, so I don't know if an upgrade is > planed - you might ask Christopher Kohlhoff. > This is a bit worrisome to me. We are using the Boost.Asio + Boost.Coroutine integration _extensively_ in our project. Did the API change from Coroutine1 to Coroutine2? Is it simply a matter of including from boost/coroutine2/xxx instead of boost/coroutine/xxx based on some preprocessor macro being defined?

2 1

boost 1.50 unable to make regex_match to work
by MAURICE Jean 27 Oct '16

27 Oct '16

1) Hi Kai, I wrote const_iterator BOOST_REGEX_CALL end()const { // JME 27/10/16 pour savoir si on passe là, je crée une division par 0 en // esperant que le compilateur ne la détecte pas int ijme1, ijme2; ijme2 = 1; ijme1 = 2; --ijme2; ijme1 = ijme1 / ijme2; return (!this->m_status ? 0 : this->m_expression + this->m_expression_len); // return (this->m_status ? 0 : this->m_expression + this->m_expression_len); JME 26/10/16 } Hoping the divide by 0 error would be thrown but it never appears. So I don't think this bug is annoying me. 2) As I am new to boost and regex I tried a simple test : string pattern = "GHI+"; string chaineatester = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; boost::regex boost_pattern( pattern ); boost::smatch what; int errjme = boost::regex_match( chaineatester, what, boost_pattern ); if (errjme == 1) { *outputLog << "test 1: GHI+ a été trouvé" << endl; } else { *outputLog << "test 1: GHI+ n'a pas été trouvé" << endl; // what[0] contains the whole string // what[1] contains the response code // what[2] contains the separator character // what[3] contains the text message. *outputLog << " what[0]:" << what[0] << endl \ << " what[1]:" << what[1] << endl \ << " what[2]:" << what[2] << endl \ << " what[3]:" << what[3] << endl; } string pattern2 = "GHI"; boost::regex boost_pattern2( pattern2 ); errjme = boost::regex_match( chaineatester, what, boost_pattern2 ); if (errjme == 1) { *outputLog << "test 1bis: GHI a été trouvé" << endl; } else { *outputLog << "test 1bis: GHI n'a pas été trouvé" << endl; *outputLog << " what[0]:" << what[0] << endl \ << " what[1]:" << what[1] << endl \ << " what[2]:" << what[2] << endl \ << " what[3]:" << what[3] << endl; } And here is what I get : test 1: GHI+ n'a pas été trouvé what[0]: what[1]: what[2]: what[3]: test 1bis: GHI n'a pas été trouvé what[0]: what[1]: what[2]: what[3]: What am I doing wrong ? Jean

2 4

[geometry] Stable and fast rtree serialize/de-serialize
by 邓尧 27 Oct '16

27 Oct '16

Hi all, How can I serialize/deserialize a Boost.Geometry rtree reliably and efficiently ? I tried the experimental rtree serialization support built-in (-DBOOST_GEOMETRY_INDEX_DETAIL_EXPERIMENTAL=1), I found that the implementation was unstable and failed to deserialize sometimes. I don't even know whether it corrupted any of the tree nodes. I also implemented a slow hack: save all tree nodes during serialization and rebuild the rtree during deserialization. I want something faster. Serialization time isn't important to me, I just need a faster deserialization (as fast as the experimental implementation) Thanks

1 0

Building Boost with VS15 Preview 5
by Trueman, Chris 26 Oct '16

26 Oct '16

2 2

Can't catch Boost.Asio exceptions inside coroutines
by Sergey Shpikin 25 Oct '16

25 Oct '16

I have this little example of Boost.Asio code: http://codepad.org/tuQedXI7 It works as expected on Linux producing 1 2 Caught Host not found (authoritative) but on Windows it crashes with: 1 2 terminate called after throwing an instance of 'boost::system::system_error' what(): Unknown error Tested on Windows Server 2008, Windows 7 and Wine, everything is the same. I'm compiling on Linux for Windows with MXE ( http://mxe.cc/ ) on GCC 4.9.4, Boost version is 1.60.0. I'm really stuck at this point as nothing in Google looks a valid solution for the case and I already have a working application on Linux but it crashes on any network error on Windows. On Windows coroutines prevent any exceptions from being caught when the program is compiled with -O1/2/3 but they're caught with -O0 or -Os (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54267 — this is about GCC on FreeBSD but the same seemingly applies to MinGW). However, boost's own exceptions, like the aforementioned boost::system::system_error, still can't be caught.

1 0

boost @ Meeting C++ 2016
by Jens Weller 24 Oct '16

24 Oct '16

Hello boost community, a short and final reminder, that the Meeting C++ conference is just a few weeks away! A few tickets are still available, here is the schedule: https://meetingcpp.com/index.php/schedule16.html The schedule also has the link to the student program and diversity tickets! Also there is still a few places available in the boost workshop with Boris Schäling and Michael Caisse. I plan to have a meetup for boost users in one of the breaks in the upper lounge, so that the boost communtiy is able to actually meet at Meeting C++! thanks, Jens Weller

1 0

boost asio ssl read issue
by Ananth 24 Oct '16

24 Oct '16

Hi, I have posted the question here at StackForge with all the details. http://stackoverflow.com/questions/40163626/boost-asio- ssl-not-working-as-expected-when-used-with-null-buffers Basically, http://www.boost.org/doc/libs/1_40_0/doc/html/ boost_asio/overview/core/reactor.html did not work when used with ssl. With plain-tcp steam socket, it works fine. o If we do ssl_socket->lowest_layer().async_read_some(null_buffers(), read_cb), then we do get all data in read_cb, but read_cb keep getting called endlessly (and read_some then returns 0, with error 11 resource unavailable) (This causes cpu remain over-utilized for ever) If we do ssl_socket->async_read_some(null_buffers(), read_cb), then it works fine with small amounts of data. When larger data is to be received (~20MB or so), then not all data is received. around 1% of data towards the end is never received by the application. My guess is that data is sitting in openssl library some where I tried with latest ssl and boost code, but that did not help either. Can some one please help ? Thanks, Ananth

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Filesystem recursive iterator issues
by mlimber 24 Oct '16

24 Oct '16

I have this code, which does a simple recursive directory iteration and prints each directory entry and then does it again ( http://coliru.stacked-crooked.com/a/0bfab95a513ebed8 ): #include <boost/filesystem.hpp> #include <boost/range/iterator_range.hpp> #include <iostream> namespace fs = boost::filesystem; int main() { try { const auto iter = fs::recursive_directory_iterator{ "." }; for( const auto& entry : boost::make_iterator_range( iter, {} ) ) { std::cout << entry << "\n"; } // Rinse and repeat std::cout << "\n"; for( const auto& entry : boost::make_iterator_range( iter, {} ) ) // CRASH -- Replace 'iter' with 'fs::recursive_directory_iterator{"."}' and it will work. //for( const auto& entry : boost::make_iterator_range( fs::recursive_directory_iterator{"."}, {} ) ) { std::cout << entry << "\n"; } } catch( const std::exception& e ) { std::cerr << e.what() << "\n"; } catch( ... ) { std::cerr << "Unknown exception.\n"; } } As you can see at Coliru, it crashes. (It also crashes on Visual Studio 2012 and with Boost 1.55.0 and on Coliru with <experimental/filesystem> instead of Boost.) Similarly, using a filesystem iterator with std::distance() fails when the iterator passed in is used again later (with boost: http://coliru.stacked-crooked.com/a/1b06dca057872762 and with experimental/filesystem: http://coliru.stacked-crooked.com/a/7bd5e73f1444619d ). It seems that something in the state of the *constant* iterator gets confused or corrupted after it is advanced to the end. I have a workaround for it commented out in the code. I found this possibly related issue: https://svn.boost.org/trac/boost/ticket/11910 Am I missing something? Should I file a new bug report? Cheers! M

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When to use BOOST_ALL_DYN_LINK?
by Florian Lindner 24 Oct '16

24 Oct '16

Hello, http://www.boost.org/doc/libs/1_62_0/libs/log/doc/html/log/installation/con… says: BOOST_LOG_DYN_LINK If defined in user code, the library will assume the binary is built as a dynamically loaded library ("dll" or "so"). Otherwise it is assumed that the library is built in static mode. This macro must be either defined or not defined for all translation units of user application that uses logging. This macro can help with auto-linking on platforms that support it. BOOST_ALL_DYN_LINK Same as BOOST_LOG_DYN_LINK but also affects other Boost libraries the same way. We build our library in a dynamic and a static version using SCons: staticlib = env.StaticLibrary ( target = buildpath + '/libprecice', source = [sourcesPreCICE] ) env.Alias("staticlib", staticlib) solib = env.SharedLibrary ( target = buildpath + '/libprecice', source = [sourcesPreCICE] ) env.Alias("solib", solib) Both have BOOST_LOG_DYN_LINK set: env.Append(CPPDEFINES=["BOOST_LOG_DYN_LINK"]) However, I wonder if this is correct. Should DYN_LINK only be set when building the dynamically linked lib? Thanks, Florian

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Update the index of a hashed_non_unique entry in boost::multiindex
by Ram 24 Oct '16

24 Oct '16

I have a boost::multiindex container which has an index as follows : boost::multi_index::hashed_non_unique< boost::multi_index::tag<IndexByNonUniqueId>, boost::multi_index::const_mem_fun<StoredObj, std::string, &StoredObj::getNonUniqueIdString> > This ID comes in as ""(empty string) when I initially get the object. I add it to the multiindex at this point. But later in the course of the program the ID gets populated using its "setNonUniqueId" method. At this point of time inside "setNonUniqueId" I would like to update the index to the object(in the multiindex) as well(while the ID is being updated from "" to something concrete). How do I do this? How do I locate the specific object and update the index? -R

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upgrade from boost 1.39 to boost 1.50. Issue with regex_match
by MAURICE Jean 21 Oct '16

21 Oct '16

Hi, I am 'upgrading' a huge C++ app from VS2005 (32bits) to VS2010 (64 bits) and boost 1.39 to boost 1.50. This app runs both under Windows and Linux. In a function that searchs subdirectories and files of a given directory, we get the list of all the elements and then this list is filtered by : if(true==boost::regex_match(sAdaptation, what, childNode.infoNode.rFullPathFilePattern)) sAdaptation is ".\TEST\un_noeud" (this subdirectory exists) childNode.infoNode.rFullPathFilePattern is something like {m_pimpl={...}} And regex_match always returns false. If you can give me information about what is happening ... Jean

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build boost 1.58 failed on centos 7.2
by Glenn WANG 20 Oct '16

20 Oct '16

hi, I try to build boost 1.58 on CentOS, but it cannot be done, there're many errors. could anybody help? thanks. ============================== ./b2 --with-log -q gcc.compile.c++ bin.v2/libs/system/build/gcc-4.8.5/release/threading-multi/error_code.o In file included from libs/system/src/error_code.cpp:19:0: ./boost/system/detail/error_code.ipp:48:27: error: expected ‘;’ at end of member declaration const char * name() const BOOST_SYSTEM_NOEXCEPT; ^ ./boost/system/detail/error_code.ipp:48:33: error: ‘BOOST_SYSTEM_NOEXCEPT’ does not name a type const char * name() const BOOST_SYSTEM_NOEXCEPT; ^ ./boost/system/detail/error_code.ipp:56:32: error: expected ‘;’ at end of member declaration const char * name() const BOOST_SYSTEM_NOEXCEPT; ^ ./boost/system/detail/error_code.ipp:56:38: error: ‘BOOST_SYSTEM_NOEXCEPT’ does not name a type const char * name() const BOOST_SYSTEM_NOEXCEPT;

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Boost Coroutine
by Miguel Portilla 19 Oct '16

19 Oct '16

Hello, Using Boost 1.62, I am seeing the following warning when I build my project. warning : Boost.Coroutine is now deprecated. Please switch to Boost.Coroutine2. To disable this warning message, define BOOST_COROUTINE_NO_DEPRECATION_WARNING. I haven't found any documentation on what exactly this means or how to 'switch'. Can someone please point me to some docs or explain what 'switching' entails? Thanks, -M

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Re: [Boost-users] [Boost-build] [System] Link issues using BOOST_ERROR_CODE_HEADER_ONLY
by Matthias Seemann 17 Oct '16

17 Oct '16

Hi, > We decided to fix these by defining the macro BOOST_ERROR_CODE_HEADER_ONLY > according to this link: > > http://www.boost.org/doc/libs/1_56_0/libs/system/doc/reference.html#Header-… > > However, when building Boost itself with this macro defined, we're > encountering several problems: > ... > 2) We get multiple definitions of "boost::system::throws" > Defining the macro BOOST_SYSTEM_NO_DEPRECATED (see that doc page above) resolved the issue of multiple definitions of "boost::system::throws". Matthias

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boost graph pruning vertices (nodes)
by Brian Davis 14 Oct '16

14 Oct '16

In reading http://www.boost.org/doc/libs/1_62_0/libs/graph/doc/adjacency_list.html regarding Iterator and Descriptor Stability/Invalidation it leaves the impression that when using vecS there is no real good way to remove nodes. as example: typedef adjacency_list<listS, vecS> Graph; // VertexList=vecS all cases are wrong and typedef adjacency_list<listS, listS> Graph; // VertexList=listS where only one case is correct which leave the programmer walking the mine field. Of course same can be said for stl. My goal to remove graph vertices based on the value of the connected components. I currently have a method which uses connected components to generate a connected components list. I then generate a histogram of the connected components values thus giving me how many vertices are connected and what the connection property value is... assuming I understand connected components however I have thought I understood portions of boost only to find through some brain warp and folding my thought process back on itself like an origami master that I came to understand how certain parts work. vertid, component 0 0 1 0 2 0 3 0 4 1 5 1 6 2 7 2 8 2 9 2 10 2 11 2 12 3 13 3 so in this simple example vert ids [0-3] are connected in subnet 0 with a total of 4, [4-5] are connected in sub net 1 with a total of 2, [6-11] are connected in subnet 2 with a total of 6, and [12-13] is connected in subnet 3 with a total of 2. Histogram yields connected component value and number of vertices that have that value in the bin component : bin counts 0: #### 1: ## 2: ###### 3: ## etc for say subnet/subgraph less than 4 would yield the filtered histogram: 1: ## 3: ## using values 1, and 3 from filtered histogram I can then find the vertex ids to filter. Yielding vertices 4,5,12, and 15 to be removed which would remove subnets 1 and 3. 4 1 5 1 12 3 13 3 I tried to use boost::accumulators::density and maybe I have a different idea of what a histogram really is, but for a typical histogram density is just plane broken due to the seemingly use of count for number of bins (seems to ignore tag::density::num_bins) and associated logic. accumulator_t acc( tag::density::num_bins = n_bins, tag::density::cache_size = n_bins/2 ); Sure wish there was a boost::accumulators::histogram that just did what we need as programmers. I am unsure as to how much boost coolaid to drink before finding any use for density. I did find this relating to the seemingly not as advertised implementation of density http://lists.boost.org/Archives/boost/2008/01/132801.php. From http://www.boost.org/doc/libs/1_62_0/doc/html/accumulators/user_s_guide.html "The tag::density feature returns a histogram of the sample distribution. For more implementation details, see density_impl." err huh no it does not... at least in my testing. It would also be great if the abcicissas (intervals) were some how obtainable to compare to the ordinates (bin counts) . Note the histogram.hpp attached there. So I write by own histogram code using stl. I digress on that. So as I said I then filter the vertex vs connected components data based on a threshold say 4 to remove all vertices that are not connected to 4 or more vertices in a subnet/subgraph So I then have a list of vertices (subnets/subgraphs) that I wish to prune from the graph thus these questions: Question 1: if finding a list of vertices to erase, sorting them, and then using, a reverse iterator to remove(*itr, g) would this also not work? If this works why is it now shown as an example of vecS vertex removal working? Question 2: Should there not be a boost graph-ish way of doing this such as coloring vertices to be pruned by possibly adding property prune = true. then maybe a future call to prune(g) Question 3: Possibly there is a way to get filtered_graph to do the trick? Statement: it is unfortunate the use of the term vertex/vertices in stead of node(s) in boost graph. As some graphs have a vertex (euclidean geometry) such as a graph of the center-lines of the vascular network of a brain while other graphs do not. It is very confusing in this instance to keep the two strait in code. Ugh!

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Re: [Boost-users] [Serialization] Free-standing serialize function for "enum class"
by Bjorn Reese 13 Oct '16

13 Oct '16

On 10/13/2016 06:56 PM, Rüdiger Berlich wrote: > I have for a while suspected a problem with the serialization of an „enum class“ item (currently with Boost 1.61 on Ubuntu 16.04), and have written a small test program to further examine any potential problems. While the generated XML looks fine and I cannot see any problems with the enum class, my custom, free-standing „serialize“ function does not get called. Boost.Serialization automatically converts an enum into an int before it is serialized.

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[Serialization] Free-standing serialize function for "enum class"
by Rüdiger Berlich 13 Oct '16

13 Oct '16

Hi there, I have for a while suspected a problem with the serialization of an „enum class“ item (currently with Boost 1.61 on Ubuntu 16.04), and have written a small test program to further examine any potential problems. While the generated XML looks fine and I cannot see any problems with the enum class, my custom, free-standing „serialize“ function does not get called. It is modelled after the examples for non-intrusive serialization, so I do not understand the reason behind this. Any idea ? /*************************************/ // Compile with g++ --std=c++14 -o enum_ser -I/opt/boost/include/ -L/opt/boost/lib enum_ser.cpp -lboost_serialization #include <boost/serialization/nvp.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> #include <iostream> #include <sstream> enum class test_enum : int {a=5,b=6}; namespace boost { namespace serialization { //----------------------------------------- template<typename Archive> void serialize(Archive &ar , test_enum &x, const unsigned int){ std::cout << "Serializing via custom serialize function" << std::endl; int t = 0; if (Archive::is_saving::value) { t = static_cast<int>(x); ar & t; } else { ar & t; x = static_cast<test_enum>(t); } } //----------------------------------------- } } int main(int argc, char **argv){ std::ostringstream oss; test_enum x = test_enum::a; { boost::archive::xml_oarchive oa(oss); oa << BOOST_SERIALIZATION_NVP(x); } std::cout << oss.str() << std::endl; } /*************************************/ Output of the program (note: the „Serializing via custom serialize function“ does not appear) : /*************************************/ <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <!DOCTYPE boost_serialization> <boost_serialization signature="serialization::archive" version="14"> <x>5</x> </boost_serialization> /*************************************/ Thanks and Kind Regards, Beet

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