May 2017 - 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

[MSM] What happens to MSM if guard returns `false`, mutable events and error recovery?
by Ovanes Markarian 05 Jun '17

05 Jun '17

Hi *, I am currently reading through the MSM docs and have one question, what happens to MSM if guard returns `false`. Does the MSM enter an error state in orthogonal region (http://www.boost.org/doc/ libs/1_64_0/libs/msm/doc/HTML/ch03s02.html#d0e577)? Even internals page describes, what happens if guard returns `true`, but not a single word on `false` case. Regarding the const events: I am programming an MSM to proxy network traffic and once a message with data was received it'll be analysed and moved between different states. Message instances implement move semantics. Currently, the MSM has an initial state `ready` where the `message_in` event is handled. This event contains the message to be analysed. From my current understanding I either have to make message field in `message_in` event mutable or MSM needs to to support r-value references. Can somebody tell me what's going to happen if the action only accepts r-value reference to an event instance? Currently, it seems to work, but would like to understand the implications. struct some_action_impl { template<class Fsm, class Event, class SourceState, class TargetState> void operator()(Event&& ev, Fsm& fsm, SourceState& source, TargetState& target) { ... } } My last question relates to multi-threading. I understand that MSM manages internal states, would it be safe to create MSM as a thread-local storage and restart the thread-local MSM if the new request comes in? It's more about, what happens to MSM after an error state? Is calling stop(), start() members enough? Many thanks for help, Ovanes

2 1

[Intrusive] Call custom function after tree rotations
by Lukas Barth 31 May '17

31 May '17

Hi, I'm trying to implement an interval tree based on boost::intrusive::rbtree. For such an interval tree, certain fixup operations must be run after a node rotation. Now, as far as I can see from the code (looking at rotate_* in bstree_algorithms), there is no way of "hooking into"[0] these methods, right? Am I missing something? What I need: After every operation that changes the parent-child-relationship of nodes I need to touch all involved nodes. At this point, I'm considering monkey-patching bstree_algorithms using some preprocessor directives, but that is bound to fail spectacularly. Any better ideas? Kind regards, and thanks for any help, Lukas [0] I know the term "hook" is overloaded differently with intrusive, but I can't think of a better term.

2 1

[Interprocess] uint64 atomic
by dnj0496 31 May '17

31 May '17

Hi, I am new to boost-interprocess. I am trying to store some of my data structures in shared memory using boost::interprocess. Each of my data structure(s) contain a bunch of counters (basically size_t values) updated atomically. In the traditional world, std::atomic supports atomic update for size_t. However, I came to know that boost::interprocess doesn't support atomic update for uint64. I've looked at pairing my counter with a lock for synchronization purposes. I've implemented it and it seems to work. However, the upgradable_mutex is consuming 144bytes while my counter is 8bytes(size_t) making it cost prohibitive. Alternatively, I could use one lock for all the counters of a class to spread the cost but that'd affect the performance and affect parallelism. I'd appreciate it if someone could offer any alternate suggestions. Thanks. Dk. -- View this message in context: http://boost.2283326.n4.nabble.com/Interprocess-uint64-atomic-tp4695000.html Sent from the Boost - Users mailing list archive at Nabble.com.

3 3

[type_erasure] any holding a ref to any
by Joaquin M López Muñoz 31 May '17

31 May '17

Say I have an object a of type any<mpl::vector<Concept1,typeid_<>>,_self&> and an object b of type any<Concept2,T> where Concept1 is a subconcept of Concept2. Is it possible to make a refer to b rather than the object wrapped by b? I mean: any_cast<void*>(&a)==&b typeid_of(a)==typeid(b) A solution involving wrapping/copying b into some auxiliary entity would be acceptable too. This questin is obviously connected to the implementation of boost::any_collection, as Steven will undoubtedly have guessed. Thank you, Joaquín M López Muñoz

2 1

Compiling Boost 1.64.0 with Visual Studio 2017
by Leo Carreon 31 May '17

31 May '17

Hi, Has anyone tried building Boost 1.64.0 with Visual Studio 2017 in “/std:c++latest” mode? I’m asking because I tried and the build generated a lot of errors and some of them are to do with things that have been removed in C++17, e.g. std::auto_ptr, etc. It seems that these need to be resolved soon especially when a lot of the compilers become C++17 compliant. If anyone is curios, I’m attaching a ZIP file containing my complete build log. Kind regards, Leo

1 0

Boost.Python can't link using downloaded pre-compiled binaries
by Heng Zhou 30 May '17

30 May '17

Following are the environment: - Windows 7 Enterprise SP1 64 bit - Python 2.7.13 - Visual Studio 2015 (v14.0) Following are the steps to the problem: (1) I downloaded boost_1_64_0-msvc-14.0-64.exe from https://urldefense.proofpoint.com/v2/url?u=https-3A__sourceforge.net_projec… . Since it is pre-compiled binary, I think there is no need to build Boost.Python manually. Note that it is for 64 bit build in VS2015 if I understand correctly. (2) Install the pre-compiled binary to C:\local\boost_1_64_0 (3) Follow the Boost.Python's QuickStart here: https://urldefense.proofpoint.com/v2/url?u=http-3A__www.boost.org_doc_libs_… . The source code are the same as shown therein. (4) Set in VS2015 Property Pages->C/C++->Additional Include Directories: C:\local\boost_1_64_0;C:\Python27\include Set in VS2015 Property Pages->Linker->Additional Library Directories: C:\local\boost_1_64_0\lib64-msvc-14.0;C:\Python27\libs Set in VS2015 Property Pages->Linker->Input->Additional Dependencies: boost_python-vc140-mt-1_64.lib;boost_python-vc140-mt-gd-1_64.lib;%(AdditionalDependencies) Set in VS2015 Property Pages->General->Configuration Type: Dynamic Library (.dll) (5) Build under x64 configuration and got errors: 1>Source.obj : error LNK2001: unresolved external symbol __imp_PyString_Type 1>Source.obj : error LNK2001: unresolved external symbol __imp__Py_NoneStruct 1>C:\...\ConsoleApplication1\x64\Release\ConsoleApplication1.dll : fatal error LNK1120: 2 unresolved externals I have no idea what the matter is. I will greatly appreciate it if you can help me out.

3 2

NEWBIE: Undefined references: How do I find the library that resolves an undefined reference
by JENNINGS, LYNN M NH-03 USAF AFMC 517 SMXS/MXDPB 30 May '17

30 May '17

NEWBIE question: Undefined references: How do I find the library that resolves an undefined reference. For example, the output for the gcc linker running in MinGW shows: C:/boost/boost/asio/detail/impl/winsock_init.ipp:39: Undefined reference to `WSAStartup@8' I have googled the documentation a number of ways, but I cannot find the library that will resolve this error. I am sure that this is a common problem. Please point me to the documentation so I can fix this and the undefined references. Thanks!

4 3

boost::process async io and reading stdout line by line
by niXman 29 May '17

29 May '17

Hi, Is it possible to use boost::process async io and reading the stdout line by line? Thanks. -- Regards, niXman ___________________________________________________ Dual-target(32 & 64-bit) MinGW-W64 compilers for 32 and 64-bit Windows: https://sf.net/p/mingw-w64/

2 1