November 2015 - 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

[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

[Interprocess] Communication between x86 and x64 issue
by Toni Neubert 19 Feb '16

19 Feb '16

I want to communicate between different platforms using boost interprocess. I am using vc12 and boost 1.58 on windows 7. My code below is a very simple example, that should work. But it doesn't for communications between different platforms... If I create it in x64 and open in win32, the process stuck at a lock at function try_based_lock in boost/int/sync/detail/common_algorithms.hpp In the other way around: win32 create, x64 open: the process crashes at name_length in segment_manager_helper.hpp while trying to find the name in index (priv_generic_find in segment_manager). #include <iostream> #include <boost/interprocess/managed_shared_memory.hpp> int main() { namespace bip = boost::interprocess; // open in WIN32, create in x64 #ifdef _WIN32 bip::managed_shared_memory msm(bip::open_only, "TestIPC"); #elsif X64 bip::shared_memory_object::remove("TestIPC"); bip::managed_shared_memory msm(bip::create_only, "TestIPC", 4096); msm.construct<uint32_t>("Data")[1](10); #endif // Get Data and print it auto data = msm.find<uint32_t>("Data"); if (data.second == 1) { std::cout << *data.first << std::endl; } std::cin.ignore(); return 0; } Does anybody have experience in this? Thank you in advance!

3 2

Re: [Boost-users] Using Coroutines in the Visitor Pattern (use-case: BGL event visitor)
by alex 20 Jan '16

20 Jan '16

>-----Original Message----- >From: Boost-users [mailto:boost-users-bounces@lists.boost.org] On Behalf Of >Daniel Hofmann >Sent: 17 November 2015 15:55 >To: boost-users(a)lists.boost.org >Subject: [Boost-users] Using Coroutines in the Visitor Pattern (use-case: BGL >event visitor) > >(Disclaimer: this is not only specific to BGL, I can think of similar >use-cases where the visitor pattern is used --- I will still explain it >in the BGL context, as it is probably easier to understand) > > >Suppose you have a BGL graph and want to implement s-t shortest path >queries. It is possible to do this by using a bi-directional approach, >that is starting a Dijkstra search [1] from the start and starting a >additional Dijkstra search from the target. As soon as they "meet in the >middle", you can unpack the two sub-paths. > >[snip] > >It then came to my mind that I could use Coroutines for cooperative >multitasking, without the downsides that come with threading. > >My idea was to invert the callbacks using Coroutines as it is shown in >the SAX parsing example [3], in order to get a lazy range of vertices >each visitor examines. I then could simply walk the two ranges, >terminating as soon as there is the same element in both. Jeremiah Willcock gave a good description of how this could work: http://lists.boost.org/Archives/boost/2012/07/195300.php The way he describes it is really using coroutines instead of the visitor pattern. > > >But due to way the dijkstra_shortest_path function adds an additional >level of indirection I failed to implement this, and I have strong >doubts that it is possible with Coroutines at all. I> >I'm mainly struggling with wrapping my head around stopping and resuming >the dijkstra_shortest_path function, when all I can modify is the >visitor it takes. That is, the reason I can not make it work is that I >can not launch two dijkstra_shortest_path functions asynchronously with >just Coroutines. > I think there are two options: 1. Let your visitor throw an exception to get out of the dijkstra shortest path function; use some version of the function that skips initialization to resume again (the existing dijkstra_shortest_path_no_init is not good enough, so you would have to make one). 2. Reimplement the dijkstra function as a coroutine. I have implemented both, but have only really used option 1; whereas option 2 remained a toy experiment. In both cases the tricky part was to properly initialize and keep track of(and not re-initialize on resume) all parameters that are input to the dijkstra function, i.e. color_map, queue, distance_map, etc. https://github.com/ahhz/resumable_dijkstra I used the lightweight stackless coroutine of Boost ASIO. http://www.boost.org/doc/libs/1_59_0/doc/html/boost_asio/reference/coroutine .html >The control flow I need would probably look like this: start the first >Dijkstra search, on its first vertex it visits, "jump back out" and >start the second Dijkstra visitor. From there on ping-pong between the >two visitors exclusively. And I'm not sure this is possible with the >Coroutine approach. > It depends how much you are willing to re-implement. It is possible in principle >I appreciate any tips in this regard, even if it's a "just use your 15 >lines of threading code instead of trying to be fancy" :) > I think it would be great to have a fancy solution for this in BGL.

3 14

Using Coroutines in the Visitor Pattern (use-case: BGL event visitor)
by Daniel Hofmann 19 Jan '16

19 Jan '16

(Disclaimer: this is not only specific to BGL, I can think of similar use-cases where the visitor pattern is used --- I will still explain it in the BGL context, as it is probably easier to understand) Suppose you have a BGL graph and want to implement s-t shortest path queries. It is possible to do this by using a bi-directional approach, that is starting a Dijkstra search [1] from the start and starting a additional Dijkstra search from the target. As soon as they "meet in the middle", you can unpack the two sub-paths. In terms of the BGL this would roughly look like the following (simplified, with synchronization and visitor omitted): Vertex middle; async(dijkstra_shortest_paths(g, start, visitor(v{middle}))); async(dijkstra_shortest_paths(g, target, visitor(v{middle}))); where the visitors single-step all vertices in their examine_vertex callback [2] and check if they met in the middle. While this is quite easy to implement with threading, is has its downsides, mainly in synchronization for this ping-pong play between the two visitors, resulting in contention on the synchronization locks. But also the overhead of using threads might be too high for smaller graphs. It then came to my mind that I could use Coroutines for cooperative multitasking, without the downsides that come with threading. My idea was to invert the callbacks using Coroutines as it is shown in the SAX parsing example [3], in order to get a lazy range of vertices each visitor examines. I then could simply walk the two ranges, terminating as soon as there is the same element in both. But due to way the dijkstra_shortest_path function adds an additional level of indirection I failed to implement this, and I have strong doubts that it is possible with Coroutines at all. I'm mainly struggling with wrapping my head around stopping and resuming the dijkstra_shortest_path function, when all I can modify is the visitor it takes. That is, the reason I can not make it work is that I can not launch two dijkstra_shortest_path functions asynchronously with just Coroutines. The control flow I need would probably look like this: start the first Dijkstra search, on its first vertex it visits, "jump back out" and start the second Dijkstra visitor. From there on ping-pong between the two visitors exclusively. And I'm not sure this is possible with the Coroutine approach. I appreciate any tips in this regard, even if it's a "just use your 15 lines of threading code instead of trying to be fancy" :) Cheers, Daniel J H [1] http://www.boost.org/doc/libs/1_59_0/libs/graph/doc/dijkstra_shortest_paths… [2] http://www.boost.org/doc/libs/1_59_0/libs/graph/doc/DijkstraVisitor.html [3] http://www.boost.org/doc/libs/1_59_0/libs/coroutine/doc/html/coroutine/moti…

2 4

multi_index::composite_key with char[]
by leyiliu 16 Dec '15

16 Dec '15

Hi,All: When I use the multi_index::composite_key with char[],I meet a error,when find a element。It seems to the make_tuple can't support the char[].Because the char[] more faster the std::string。So our project choose char[] as the column instead of std::string.So How should I do -- View this message in context: http://boost.2283326.n4.nabble.com/multi-index-composite-key-with-char-tp46… Sent from the Boost - Users mailing list archive at Nabble.com.

3 7

[BGL] k-shortest path
by Ireneusz Szcześniak 11 Dec '15

11 Dec '15

Hi, I need to find k-shortest paths, but there is no such algorithm in BGL. I can get edge-disjoint k-shortest paths with a max-flow algorithm, but I don't need the k-shortest path to be edge-disjoint -- that's too strict for me. I would appreciate it if someone could share an implementation of the Yen or Eppstein algorithms using BGL. I found some implementations on the Internet, but they don't use BGL. Thanks & best, Irek

3 10

[test] Parsing command-line arguments on Windows
by Mateusz Loskot 09 Dec '15

09 Dec '15

Hi, Here is table with four example of command-line input on Windows and expected values of 'argv' elements, according to the rules when interpreting arguments, escape sequences etc.: https://msdn.microsoft.com/en-us/library/17w5ykft.aspx Double-checking this actually works: ///////// Windows console program ////////////////////////////////// #include <cstdio> int main(int argc, char* argv[]) { for (int i = 0; i < argc; ++i) std::printf("%d: %s\n", i, argv[i]); } F:\test_cpp2015\Debug>test_cpp2015.exe "abc" d e 0: test_cpp2015.exe 1: abc 2: d 3: e F:\test_cpp2015\Debug>test_cpp2015.exe a\\b d"e f"g h 0: test_cpp2015.exe 1: a\\b 2: de fg 3: h F:\test_cpp2015\Debug>test_cpp2015.exe a\\\"b c d 0: test_cpp2015.exe 1: a\"b 2: c 3: d F:\test_cpp2015\Debug>test_cpp2015.exe a\\\\"b c" d e 0: test_cpp2015.exe 1: a\\b c 2: d 3: e ////////////////////////////////// Now, the same test but with values of framework::master_test_suite().argv ///////// Boost.Test program /////////////////////////////////////// #define BOOST_TEST_MAIN #include <boost/test/unit_test.hpp> BOOST_AUTO_TEST_CASE(argv_parsing) { auto argc = boost::unit_test::framework::master_test_suite().argc; auto argv = boost::unit_test::framework::master_test_suite().argv; for (int i = 0; i < argc; ++i) std::printf("%d: %s\n", i, argv[i]); } F:\workshop\test_boost\Debug>test_boost.exe "abc" d e Running 1 test case... 0: test_boost.exe 1: abc 2: d 3: e F:\workshop\test_boost\Debug>test_boost.exe a\\b d"e f"g h Running 1 test case... 0: test_boost.exe 1: a\\b 2: de 3: fg 4: h F:\workshop\test_boost\Debug>test_boost.exe a\\\"b c d Running 1 test case... 0: test_boost.exe 1: a\"b 2: c 3: d F:\workshop\test_boost\Debug>test_boost.exe a\\\\"b c" d e Running 1 test case... 0: test_boost.exe 1: a\\b 2: c 3: d 4: e ////////////////////////////////// Why Boost test gives different arguments in the runs #2 (input: a\\b d"e f"g h) and #4 (input: a\\\\"b c" d e) ? I can't see any caveats mentioned in the documentation http://www.boost.org/doc/libs/1_59_0/libs/test/doc/html/boost_test/tests_or… Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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Boost 1.60.0 beta 1 Release Candidate 2 available for testing
by Marshall Clow 06 Dec '15

06 Dec '15

Release candidate files for 1.60.0 beta 1 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. Changes since rc1: * Boost.Sprit has been updated and Boost.Log now builds. * Boost.Math has been updated and now builds. Known issues: * Errors when building libraries for visual studio: test and type_erasure. * Boost.Test fails when building on Darwin with gcc 4.9.2 The files (and associated md5s) are: MD5 (boost_1_60_0_b1_rc2.7z) = dd38daa9378a6002fc12da0cab695511 MD5 (boost_1_60_0_b1_rc2.tar.bz2) = f3c9ffc14db3b2e55c7c5c703e69883d MD5 (boost_1_60_0_b1_rc2.tar.gz) = 89365262443cc16990b69f8e4b8b47ab MD5 (boost_1_60_0_b1_rc2.zip) = 3389bd4595a989fe95966440cbe45ca9 Thanks! -- The release managers

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[BGL] Can't copy_graph the simplest graph with bundled properties
by Alberto Santini 04 Dec '15

04 Dec '15

The following code fails. Is it intended? If it is, how to copy a graph with bundled properties? http://coliru.stacked-crooked.com/a/b1017359126ab6f6 Thanks, AS

2 3

[Boost.Container] Need map supporting incomplete type and heterogeneous lookup
by dariomt＠gmail.com 30 Nov '15

30 Nov '15

Hi, I see that boost::container::map has support for incomplete types. However, it does not seem to support heterogeneous lookup. Is this correct? Are there plans to implement it? Is there anywhere in Boost a std::map-like associative container that supports incomplete types *and* heterogeneous lookup? Thanks!

5 4

[statechart]
by Ernesto Rodriguez Reina 30 Nov '15

30 Nov '15

Hi everyone, The statechart search for an event handler in post-order (children first then parent), however when we have orthogonal states involved then the behaviour I am experiencing is different. Let say we have an state X with two children [orthogonal] states Y and W. Assuming none of the handlers discard (or defer) an event, the handler for that event is called in the following order: Y, X, W, X. Note that the handler of X is called twice. The code in the following link shows that behaviour: http://coliru.stacked-crooked.com/a/14cb35ca23e586a5 If there something that I am missing? Best, Ernesto Rodriguez Reina

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[Ublas] Bug in 1.59 in file boost/numeric/ublas/detail/concepts.hpp
by dariomt＠gmail.com 30 Nov '15

30 Nov '15

In the migration from Boost 1.55.0 to 1.59.0 I found a bug in Ublas. For instance, in 1.55.0 function OneElement() declared in boost/numeric/ublas/detail/concepts.hpp line 716 looks like this: template<> double OneElement (double) { return 1.; } However, in 1.59.0 I think there is a copy'n'paste typo, because the corresponding function (which has been refactored) looks like this: template<class T> T OneElement (T) { return T(0.0); } Please note that the latter version returns a *zero*, instead of a *one*. This same bug affects the vector overload of the function, but the matrix version looks correct (it returns identity_matrix). This looks like a copy'n'paste typo, from a similar function called ZeroElement(), that, of course, returns a zero. I'm not sure if there is time to get a fix for this in the 1.60 release... Regards!

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New to Boost
by Gagan Kumar 30 Nov '15

30 Nov '15

I want to contribute to Boost, can you please give me a small task to start contributing.

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variant has non-trivial destructor even when all constituents have trivial destructor
by ☂Josh Chia (谢任中) 28 Nov '15

28 Nov '15

It seems that boost::variant has non-trivial destructor even for something like boost::variant<int32_t, int64_t>. Thus, It cannot be used in situations that call for a POD where calling the destructor is trivial. Particularly, I can't have a boost::lock_free::queue<boost::variant<X, Y>> even both X and Y are trivially destructible. How about making boost::variant trivially-destructible when everything in it is trivially-destructible?

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[BGL] metric_tsp_approx.cpp Error
by Vicky Vergara 28 Nov '15

28 Nov '15

Hello, I am trying to run the metric_tsp_approx.cpp example, but I get an error, I am using the suggested data 3 vertices data, I don't know what I am doing wrong, please help. Vicky. http://www.boost.org/doc/libs/1_58_0/libs/graph/test/metric_tsp_approx.cpp $more graph.txt 1,2 20,4 15,7 I get this error: terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::negative_edge> >' what(): The graph may not contain an edge with negative weight. Aborted (core dumped) Its after all the graph is connected: we can parse the given file Opened file 1,2 20,4 15,7 Closed file (1,2) -> (20,4) = 19.105 (1,2) -> (15,7) = 14.8661 (20,4) -> (15,7) = 5.83095 Conected all terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::negative_edge> >' what(): The graph may not contain an edge with negative weight. Aborted (core dumped) This is what I get when doing a backtrace: (shortened) (gdb) bt #0 0x00007ffff722bcc9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56 #1 0x00007ffff722f0d8 in __GI_abort () at abort.c:89 #2 0x00007ffff7b36535 in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6 #3 0x00007ffff7b346d6 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6 #4 0x00007ffff7b34703 in std::terminate() () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6 #5 0x00007ffff7b34922 in __cxa_throw () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6 #6 0x00000000004085c8 in boost::throw_exception<boost::negative_edge> (e=...) at /usr/include/boost/throw_exception.hpp:67 #7 0x0000000000408b0f in examine_edge<boost... #8 boost::breadth_first_visit<boost... vis=..., color=...) at /usr/include/boost/graph/breadth_first_search.hpp:82 #9 0x00000000004038ec in breadth_first_visit<boost... at /usr/include/boost/graph/breadth_first_search.hpp:105 #10 dijkstra_shortest_paths_no_init<... (color=..., vis=..., zero=0, combine=..., compare=..., index_map=..., weight=..., distance=..., predecessor=..., s=0, g=...) at /usr/include/boost/graph/dijkstra_shortest_paths.hpp:337 #11 dijkstra_shortest_paths<boost... (color=..., vis=..., zero=0, inf=1.7976931348623157e+308, combine=..., compare=..., index_map=..., weight=..., distance=..., predecessor=..., s=0, g=...) at /usr/include/boost/graph/dijkstra_shortest_paths.hpp:388 #12 dijkstra_shortest_paths<boost... at /usr/include/boost/graph/dijkstra_shortest_paths.hpp:358 #13 dijkstra_dispatch2<boost... at /usr/include/boost/graph/dijkstra_shortest_paths.hpp:431 #14 dijkstra_dispatch1<boost: at /usr/include/boost/graph/dijkstra_shortest_paths.hpp:462 #15 dijkstra_shortest_paths<boost... params=..., s=0, g=...) at /usr/include/boost/graph/dijkstra_shortest_paths.hpp:480 #16 prim_mst_impl<boost at /usr/include/boost/graph/prim_minimum_spanning_tree.hpp:41 #17 boost::prim_minimum_spanning_tree<boost... at /usr/include/boost/graph/prim_minimum_spanning_tree.hpp:72 #18 0x0000000000408bb3 in boost::metric_tsp_approx_from_vertex<boost::... at /usr/include/boost/graph/metric_tsp_approx.hpp:193 #19 0x0000000000402320 in metric_tsp_approx_tour<boost::... o=..., g=...) at /usr/include/boost/graph/metric_tsp_approx.hpp:89 #20 main (argc=<optimized out>, argv=<optimized out>) at metric_tsp_approximation.cpp:249

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Re: [Boost-users] [BGL]Using a function for weightmap to dijkstra_shortest_path
by alex 27 Nov '15

27 Nov '15

>-----Original Message----- >From: Boost-users [mailto:boost-users-bounces@lists.boost.org] On Behalf Of >Amit Prakash Ambasta >Sent: 23 November 2015 08:20 >To: boost-users(a)lists.boost.org >Subject: [Boost-users] [BGL]Using a function for weightmap to >dijkstra_shortest_path > >Hi, > > >I am trying to write use BGL.dijkstra to calculate a shortest path in a time >dependent network where edge.cost C(u, v) is a function of >distance(a)edge.source and a variable wait time dependent on Edge.departure >i.e. > Are you confident that you can use Dijkstra Shortest Paths for this? To me it seems that would only be possible if you knew that delay times are increasing over time, but not when they are fluctuating up and down. The code might be simpler if you put the dynamic part in the combine functor instead of the weight map. using Time = double; using Money = double; struct Distance { Time time; Money cost; }; struct Weight { Time duration; Money cost; Time delay(cost Time& start) const { // delay as a function of start time } }; struct Combine { Distance operator()(const Distance& start, const Weight& weight) const { Distance finish; finish.time = start.time + weight.delay(start.time) + weight.duration; finish.cost = start.cost + weight.cost; return finish; } };

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Boost.Type_erasure: member function return _self
by Yuan Yao 26 Nov '15

26 Nov '15

2 1

[1.60] Beta date?
by Joaquin M López Muñoz 26 Nov '15

26 Nov '15

Hi, Is there a planned date for Boost 1.60 beta (we have beta RC3 so far) or do we intend to jump directly to 1.60 RC? I'm asking because I've got a couple of fairly minimal commits that run succesfully in develop and I'd like to merge to release before it's too late: https://github.com/boostorg/multi_index/commit/ 1f4d33012bb0537d6bd5667aed8a02d29eb1ed26 https://github.com/boostorg/flyweight/commit/ adda32bfa9af8a4427affc41c64b792660ffffae Thank you, Joaquín M López Muñoz Telefónica

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[Statechart] question about event processing rules in orthogonal states.
by Ernesto Rodriguez Reina 25 Nov '15

25 Nov '15

Hi everyone, The event processing order of a normal (non-orthogonal) state is first the innermost and if not handled (or forwarded) then it parent, and that behaviour is repeated upward until the event is discarded (or deferred). But when we are in the presence of orthogonal states, then the behaviour I am getting is a bit different, for example given the following statechart: <code> struct EvTest : sc::event< EvTest > {}; struct Test; struct Inner1; struct Inner2; struct Machine : sc::state_machine< Machine, Test > {}; struct Test : sc::simple_state<Test, Machine, mpl::list<Inner1, Inner2> >{ typedef sc::custom_reaction< EvTest > reactions; sc::result react( const EvTest){ std::cout << "Test" << std::endl; // return discard_event(); return forward_event(); } }; struct Inner1 : sc::simple_state<Inner1, Test::orthogonal< 0 > >{}; struct Inner2 : sc::simple_state<Inner2, Test::orthogonal< 1 > >{ typedef sc::custom_reaction< EvTest > reactions; sc::result react( const EvTest){ std::cout << "Inner2" << std::endl; return forward_event(); } }; </code> When received the event "EvTest" the output I am getting is: <output> Test Inner2 Test </output> That means that the handler in the state "Test" is called twice. If in the handler at test we discard instead of forwarding then we get that only the handler of "Test" is called. I thought that without taking into account if the children are orthogonal or not, the event will be processed first by the children (all of them in the case of orthogonal state until one discard or defer the event), and event is not discarded (or deferred) then the parent process the event. It is that OK? If so why I am getting that weird behaviour in my example? Any thoughts and comments are more than welcome. Best, Ernesto Rodriguez Reina

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boostboost::filesystem::detail::copy_file undefined when using c++14
by ken 25 Nov '15

25 Nov '15

Hello I am building an application that uses boost libraries that I also complied. This is on a mac os x 10.9 system using gnu gcc 5.2 installed with mac ports. I built the boost 1.59.0 libraries as instructed and built the application without any problems (after a few tries). Then I changed the c++ language standard for the build of the application to -std=gnu++14 (the default is gnu++11). However, I now get the following error during the linking phase: g++ -std=gnu++14 -U_WIN32 -Dunix -DNDEBUG -O3 -DTIXML_USE_STL -DBOOST_FILESYSTEM_VERSION=3 -fmessage-length=0 -I[...] -lboost_date_time-mt -lboost_filesystem-mt -lboost_regex-mt -lboost_system-mt -lboost_locale-mt -lboost_thread-mt -lboost_chrono-mt [...] Undefined symbols for architecture x86_64: "boost::filesystem::detail::copy_file(boost::filesystem::path const&, boost::filesystem::path const&, boost::filesystem::copy_option, boost::system::error_code*)", referenced from: [...] ... ld: symbol(s) not found for architecture x86_64 collect2: error: ld returned 1 exit status [...] I rebuilt the boost libraries with the -std=gnu++14 option and verified that they are using the same std library, but I still got the same error when linking those libraries to my application. I removed the c++14 option from the application build and the error went away. So next I took a look at the functions in libboost_filesystem-mt.a and for lib/libboost_filesystem-mt.a(operations.o) I found this function: 0000000000007720 T __ZN5boost10filesystem6detail9copy_fileERKNS0_4pathES4_NS1_11copy_optionEPNS_6system10error_codeE or boost::filesystem::detail::copy_file(boost::filesystem::path const&, boost::filesystem::path const&, boost::filesystem::detail::copy_option, boost::system::error_code*) I see that this differs from what the linker is looking for in that copy_option (third parameter) is in the detail name space. Any ideas on where to go from here? Thanks

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Iterating "root" vertices with boost::graph
by Isaac Lascasas 25 Nov '15

25 Nov '15

Hello I want to enumerate all vertices with zero input edge count in a graph, I am using DFS right now: struct vertex_visitor : public boost::default_dfs_visitor { std::vector<vertex_t> Output; void discover_vertex(vertex_t v, graph_t const& g) { graph_t::in_edge_iterator edgeIt, edgeEnd; tie(edgeIt, edgeEnd) = boost::in_edges(v, g); if (edgeIt==edgeEnd) Output.push_back(v); } }; vertex_visitor vis; boost::depth_first_search(g, boost::visitor(v)); However I don't know how to cleanly stop execution after depth 0 inside my visitor and I can't figure out a better way to archieve this. Since I am fairly new to boost graph I supose that I'm missing something. Thanks.

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Extend boost binary serialization with varints encoding
by Ernest Zaslavsky 24 Nov '15

24 Nov '15

Is it feasible to provide boost binary serialization with varint encoding capabilities? How does one achieve that? Can one just create template overload of "save" and "load" for unsigned integrals? anything else should be changed? [Read More]<http://feeds.feedburner.com/~r/sizmek-blog/~6/1> [http://www.sizmek.com/Sizmek.png]<http://www.sizmek.com/>

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