January 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

[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

[graph] Search algorithm using quality metric rather than distance
by rleigh＠codelibre.net 19 Feb '16

19 Feb '16

I have an adjacency_list graph (shown in attached dot file). Each edge has an attached "quality metric" as a bundled property. Similar to the dijkstra_shortest_paths algorithm, I'd like to determine the optimal path. However, this algorithm sums the distance along each edge, and finds the shortest path. What I'd like to do is *multiply* the quality metric for each edge in the path, and find the largest one. A perfect path will have a quality metric of 1.0, while suboptimal paths will have values tending towards zero, and the more "bad" edges the smaller the number. I'll likely then look at the number of edges and then select the shortest of the candidates. It seems like a simple algorithm that might already be included, but I just haven't found it yet not knowing its formal name. If anyone has any suggestions, I'd be very grateful. Many thanks, Roger

5 4

Building Boost 1.60 with VS2015 - 32 bit compiler is always selected
by Tiago Gehring 01 Feb '16

01 Feb '16

Hi, I'm trying to build Boost 1.60 with Visual Studio 2015 Update 1 in 64-bit mode but it seems to be ignoring the address-model=64 parameter and always builds a 32-bit version (I called b2 from the VS2015 Native tools for x64 command prompt): -- C:\Users\Tiago\code\boost_1_60_0>*b2 --toolset=msvc-14.0 variant=release link=static threading=multi address-model=64 architecture=x86* Performing configuration checks *- 32-bit : yes* - arm : no - mips1 : no - power : no - sparc : no - x86 : yes .... C:\Users\Tiago\code\boost_1_60_0>*cl* Microsoft (R) C/C++ Optimizing Compiler *Version 19.00.23506 for x64* Copyright (C) Microsoft Corporation. All rights reserved. usage: cl [ option... ] filename... [ /link linkoption... ] --- I saw in some ond discussion mentions to explicitly select the compiler version (I also have VS2010 and VS2012 installed) and environment variables batch file (in the project-config.jam file) but this didn't help either. Any help is really appreciated. Best regards, Tiago Gehring

4 4

Re: [Boost-users] asio: implementing sock->receive like behavior eith async_read_some
by Bjorn Reese 01 Feb '16

01 Feb '16

On 01/28/2016 01:56 PM, Lloyd wrote: > I am using asio to read some data from SSL socket. asio tcp socket > implements a "receive" function, but ssl socket doesn't have an > implementation for "receive". In the code sample given below I wish to > implement this kind of behavior. > > eg > > { > ... > sock.async_read_some(...); > //continue the execution only after the above call finishes. > } Why are you using an asynchronous operation instead of simply calling ssl::stream::read_some()?

2 1

C++Now 2016 Registration is Open
by Jon Kalb 28 Jan '16

28 Jan '16

Boost Users, Registration is now open for this year¹s C++Now (put on by Boost). http://cppnow.org/2016-conference/announcements/2016/01/28/registration-is-o pen.html The conference has sold out the last three years and is expect to do say again this year. Do not put off registering. Note that session submitters should not register until they receive instructions from Marshall Clow, our conference registrar. See you in Aspen! Jon

1 0

asio: implementing sock->receive like behavior eith async_read_some
by Lloyd 28 Jan '16

28 Jan '16

Hi, I am using asio to read some data from SSL socket. asio tcp socket implements a "receive" function, but ssl socket doesn't have an implementation for "receive". In the code sample given below I wish to implement this kind of behavior. eg { ... sock.async_read_some(...); //continue the execution only after the above call finishes. } Whats the best way to do this? I tried "future" but the code blocks/dead locks some how, The I tried "spawn", but in this case also I don't know the method to wait for the coroutine to finish. Some tips are greatly appreciated. Thanks, Lloyd

1 0

[Boost.LexicalCast] problem with 1.59 in Solaris
by dariomt＠gmail.com 28 Jan '16

28 Jan '16

Trying to compile file libs/date_time/src/gregorian/greg_month.cpp I get an error related to Boost.LexicalCast. I have reduced the problem to a minimal test case: #include <string> #include <boost/lexical_cast.hpp> void f(const char* s) { std::string s1(boost::lexical_cast<std::string>(s)); } My feeling is that this compiler has problems in the specializations for boost::detail::is_stdstring and boost::detail::is_char_array_to_stdstring. If I remove all those specializations the error goes away. I assume this is not the perfect solution because I guess this will miss some optimization of lexical_cast, but at least I can compile it this way :( Is there a better solution for this? Has this problem been fixed in 1.60? Error message (full instantiation stack available if needed): "/ThirdPartyLibs/boost/1_59_0/boost/lexical_cast/try_lexical_convert.hpp", line 146: Error: Ambiguous partial specialization for boost::detail::is_char_array_to_stdstring<std::string, const char*>, boost::detail::is_char_array_to_stdstring<boost::container::basic_string<boost::detail::CharT, boost::detail::Traits, boost::detail::Alloc>, const boost::detail::CharT*> and boost::detail::is_char_array_to_stdstring<std::basic_string<boost::detail::CharT, boost::detail::Traits, boost::detail::Alloc>, const boost::detail::CharT*>. "/ThirdPartyLibs/boost/1_59_0/boost/lexical_cast.hpp", line 42: Where: While instantiating "boost::conversion::detail::try_lexical_convert<std::string, const char*>(const char*const&, std::string &)". "/ThirdPartyLibs/boost/1_59_0/boost/lexical_cast/try_lexical_convert.hpp", line 134: Error: Ambiguous partial specialization for boost::detail::is_stdstring<std::string>, boost::detail::is_stdstring<boost::container::basic_string<boost::detail::CharT, boost::detail::Traits, boost::detail::Alloc>> and boost::detail::is_stdstring<std::basic_string<boost::detail::CharT, boost::detail::Traits, boost::detail::Alloc>>. "/ThirdPartyLibs/boost/1_59_0/boost/lexical_cast.hpp", line 42: Where: While instantiating "boost::conversion::detail::try_lexical_convert<std::string, const char*>(const char*const&, std::string &)".

5 9

Regression with boost::python 1.60
by Emmanuel 28 Jan '16

28 Jan '16

Hello, I am not sure if this is the right place to do it, but I will try :-). I am having a regression in boost 1.60, I documented a small reproducer here: http://stackoverflow.com/questions/35056398/typeerror-when-iterating-over-a… Does anyone have a clue ? Cheers, Emmanuel

1 0

[Odeint] Stiff System of differential equations
by jules 25 Jan '16

25 Jan '16

Hi all, I am currently working with a very large set of differential equations; it is a disease model with 20160 classes depending on which vaccine has been admnistered, history of infection, and age. To solve this I have been using the runge_kutta_fehlber78 controlled stepper with the integrate_const function. There I need to set the absolute_error, relative_error and the step_size. My issue is that the results from the solver seems to depend highly on the step_size and whether or not an observer is provided. Since the solver is adaptive I feel like the results should not depend on step_size and they should definitely not depend on the presence of an observer. My question is why would the results be related to the step_size or the observer? How would it be possible to get the same results regardless of the step_size and the presence of an observer? Could this be related to the system being stiff and if so how would it be possible to solve it (The jacobian is too complicated to calculate because of the population dynamics)? Any help would be appreciated. Many thanks, Jules

3 5

BGL, shortest path between two nearby nodes in a huge graph
by Paolo Bolzoni 25 Jan '16

25 Jan '16

Dear list, I am a happy user of BGL, but recently I got stuck in a strange problem. I think I am missing the obvious, so I'll be happy to read the fine manual if it's the case. Just point me to the right direction. I need to find the shortest path between two nodes, for doing so I am using dijkstra with a custom visitor that stops the search (throwing an exception) when examine_vertex is called on the destination node. It worked fine, but it run strangely slow. After some profiling, it is clear that most of the time is used in the initialize_vertex function. The graph is fairly large, but the path I am looking for are fairly small (10 edges tops usually). It is possible to skip the initialize phase? Cheers, Paolo

3 5

Some help for betweenness centrality for undirected weighted graph
by Xinran Wang 25 Jan '16

25 Jan '16

Hi everyone, this is from Jason. I am a new user of Boost library. Nowadays, I am doing a research about betweenness centrality measure. I am very confused about how to use boost to calculate the betweenness centrality. I need to calculate the centrality score based on a undirected and weighted graph. The following code is what I tried to do. But this block of code can only be used for calculated for unweighted graph. Could anyone here can offer me examples? Thanks for any reply. #include <boost/graph/betweenness_centrality.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graphviz.hpp> typedef boost::property<boost::edge_weight_t, float> EdgeWeightProperty; typedef boost::adjacency_list < boost::listS, boost::vecS, boost::undirectedS, boost::no_property, EdgeWeightProperty > Graph; typedef boost::graph_traits < Graph >::vertex_descriptor vertex_descriptor; typedef boost::graph_traits < Graph >::edge_descriptor edge_descriptor; typedef std::pair<int, int> Edge; typedef std::map<Edge, int> StdEdgeIndexMap; void betweennessCentrality() { Graph g; Graph::vertex_descriptor a1 = boost::add_vertex(g); Graph::vertex_descriptor a2 = boost::add_vertex(g); Graph::vertex_descriptor a3 = boost::add_vertex(g); Graph::vertex_descriptor a4 = boost::add_vertex(g); Graph::vertex_descriptor a5 = boost::add_vertex(g); Graph::vertex_descriptor a6 = boost::add_vertex(g); Graph::vertex_descriptor a7 = boost::add_vertex(g); EdgeWeightProperty weight0 = 1; boost::add_edge(a1, a2, weight0, g); EdgeWeightProperty weight1 = 1; boost::add_edge(a1, a3, weight1, g); EdgeWeightProperty weight2 = 1; boost::add_edge(a2, a3, weight2, g); EdgeWeightProperty weight3 = 1; boost::add_edge(a3, a4, weight3, g); EdgeWeightProperty weight4 = 1; boost::add_edge(a4, a5, weight4, g); EdgeWeightProperty weight5 = 1; boost::add_edge(a5, a6, weight5, g); EdgeWeightProperty weight6 = 1; boost::add_edge(a5, a7, weight6, g); EdgeWeightProperty weight7 = 1; boost::add_edge(a6, a7, weight7, g); typedef boost::property_map< Graph, boost::vertex_index_t>::type VertexIndexMap; VertexIndexMap v_index = get(boost::vertex_index, g); std::vector< double > v_centrality_vec(boost::num_vertices(g), 0.0); boost::iterator_property_map< std::vector< double >::iterator, VertexIndexMap > v_centrality_map(v_centrality_vec.begin(), v_index); brandes_betweenness_centrality( g, v_centrality_map); }

1 0

[math/stat] generating t-distributed random numbers
by U.Mutlu 22 Jan '16

22 Jan '16

Hi, I've an old code that creates a normal-distributed random number between 0 and 1 (by using the polar method). Is it possible to convert this number to a t-distributed number (with v=5) using boost? Or, alternatively: how to generate t-distributed random numbers in the range 0 to 1 with v=5 (ie. degrees of freedom = 5) in boost?

1 1

[fusion] [mpl] binary MPL transform on empty fusion vectors
by Nathan Ridge 22 Jan '16

22 Jan '16

Hi, I've run into an error in code involving MPL and Fusion which I've reduced to the following: #include <boost/mpl/transform.hpp> #include <boost/fusion/container/vector.hpp> #include <boost/fusion/mpl.hpp> struct predicate { template <typename T, typename U> struct apply { typedef T type; }; }; typedef boost::mpl::transform< boost::fusion::vector<>, boost::fusion::vector<>, predicate> ::type Result; This simple piece of code tries to perform a binary MPL transform on two fusion vectors of size 0. It produces the error reproduced below, with both gcc 5.1 and clang 3.7. My boost version is 1.60. I'm quite sure that this used to work with an older boost and compiler version combination, though I don't recall which exactly (something in the vicinity of boost 1.54 / gcc 4.8). Did I run into a regression, or should I not be expecting this to work in the first place? Should I be special-casing zero-length vectors? Thanks, Nate In file included from test.cpp:2: In file included from boost/include/boost/fusion/container/vector.hpp:12: In file included from boost/include/boost/fusion/container/vector/vector.hpp:28: In file included from boost/include/boost/fusion/container/vector/detail/at_impl.hpp:12: boost/include/boost/fusion/container/vector/detail/value_at_impl.hpp:50:57: error: no matching function for call to 'value_at_impl' typedef typename mpl::identity<decltype(seq::template value_at_impl<N::value>(boost::declval<seq*>()))>::type::type type; ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ boost/include/boost/fusion/container/vector/detail/value_of_impl.hpp:30:61: note: in instantiation of template class 'boost::fusion::extension::value_at_impl<boost::fusion::vector_tag>::apply<boost::fusion::vector<>, mpl_::int_<0>>' requested here typedef typename value_at_impl<vector_tag>::template apply<vector, index>::type type; ^ boost/include/boost/fusion/iterator/value_of.hpp:52:15: note: in instantiation of template class 'boost::fusion::extension::value_of_impl<boost::fusion::vector_iterator_tag>::apply<boost::fusion::vector_iterator<boost::fusion::vector<>, 0>>' requested here : extension::value_of_impl<typename detail::tag_of<Iterator>::type>:: ^ boost/include/boost/fusion/iterator/mpl/fusion_iterator.hpp:47:45: note: in instantiation of template class 'boost::fusion::result_of::value_of<boost::fusion::vector_iterator<boost::fusion::vector<>, 0>>' requested here typedef typename fusion::result_of::value_of<Iterator>::type type; ^ boost/include/boost/mpl/iterator_category.hpp:27:22: note: in instantiation of template class 'boost::mpl::fusion_iterator<boost::fusion::vector_iterator<boost::fusion::vector<>, 0>>' requested here typedef typename Iterator::category type; ^ boost/include/boost/mpl/pair_view.hpp:152:20: note: in instantiation of template class 'boost::mpl::iterator_category<boost::mpl::fusion_iterator<boost::fusion::vector_iterator<boost::fusion::vector<>, 0>>>' requested here typename iterator_category<iter1_>::type ^ boost/include/boost/mpl/aux_/has_tag.hpp:20:1: note: in instantiation of template class 'boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>' requested here BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_tag, tag, false) ^ boost/include/boost/mpl/has_xxx.hpp:245:65: note: expanded from macro 'BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF' , boost::mpl::aux::type_wrapper<BOOST_MSVC_TYPENAME U::name>* = 0 \ ^ boost/include/boost/mpl/aux_/has_tag.hpp:20:1: note: while substituting deduced template arguments into function template 'test' [with U = boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>] BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_tag, tag, false) ^ boost/include/boost/mpl/has_xxx.hpp:253:18: note: expanded from macro 'BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF' sizeof(gcc_3_2_wknd::test(static_cast<t_*>(0))) \ ^ boost/include/boost/config/suffix.hpp:394:72: note: expanded from macro 'BOOST_STATIC_CONSTANT' # define BOOST_STATIC_CONSTANT(type, assignment) static const type assignment ^ boost/include/boost/mpl/sequence_tag.hpp:112:30: note: in instantiation of template class 'boost::mpl::aux::has_tag<boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>, mpl_::bool_<false>>' requested here ::boost::mpl::aux::has_tag<Sequence>::value ^ boost/include/boost/mpl/O1_size.hpp:30:30: note: in instantiation of template class 'boost::mpl::sequence_tag<boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>>' requested here : O1_size_impl< typename sequence_tag<Sequence>::type> ^ boost/include/boost/mpl/fold.hpp:34:25: note: in instantiation of template class 'boost::mpl::O1_size<boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>>' requested here ::boost::mpl::O1_size<Sequence>::value ^ boost/include/boost/mpl/transform.hpp:75:7: note: in instantiation of template class 'boost::mpl::fold<boost::mpl::pair_view<boost::fusion::vector<>, boost::fusion::vector<>>, boost::fusion::vector<>, boost::mpl::bind2<boost::mpl::push_back<mpl_::na, mpl_::na>, mpl_::arg<1>, boost::mpl::bind2<predicate, boost::mpl::bind1<boost::mpl::first<mpl_::na>, mpl_::arg<2>>, boost::mpl::bind1<boost::mpl::second<mpl_::na>, mpl_::arg<2>>>>>' requested here : fold< ^ boost/include/boost/mpl/transform.hpp:114:1: note: in instantiation of template class 'boost::mpl::aux::transform2_impl<boost::fusion::vector<>, boost::fusion::vector<>, predicate, boost::mpl::back_inserter<boost::fusion::vector<>>>' requested here BOOST_MPL_AUX_INSERTER_ALGORITHM_DEF(4, transform2) ^ boost/include/boost/mpl/aux_/inserter_algorithm.hpp:52:7: note: expanded from macro 'BOOST_MPL_AUX_INSERTER_ALGORITHM_DEF' : if_< has_push_back< typename clear<P1>::type> \ ^ boost/include/boost/mpl/eval_if.hpp:38:22: note: in instantiation of template class 'boost::mpl::transform2<boost::fusion::vector<>, boost::fusion::vector<>, predicate, mpl_::na>' requested here typedef typename f_::type type; ^ boost/include/boost/mpl/transform.hpp:138:1: note: in instantiation of template class 'boost::mpl::eval_if<boost::mpl::or_<boost::mpl::is_na<predicate>, boost::mpl::is_lambda_expression<boost::fusion::vector<>>, boost::mpl::not_<boost::mpl::is_sequence<boost::fusion::vector<>>>, mpl_::bool_<false>, mpl_::bool_<false>>, boost::mpl::transform1<boost::fusion::vector<>, boost::fusion::vector<>, predicate>, boost::mpl::transform2<boost::fusion::vector<>, boost::fusion::vector<>, predicate, mpl_::na>>' requested here AUX778076_TRANSFORM_DEF(transform) ^ boost/include/boost/mpl/transform.hpp:125:22: note: expanded from macro 'AUX778076_TRANSFORM_DEF' typedef typename eval_if< \ ^ test.cpp:13:17: note: in instantiation of template class 'boost::mpl::transform<boost::fusion::vector<>, boost::fusion::vector<>, predicate, mpl_::na>' requested here boost::mpl::transform< ^ boost/include/boost/fusion/container/vector/vector.hpp:275:30: note: candidate template ignored: could not match 'store' against 'vector' mpl::identity<U> value_at_impl(store<N, U>*); ^

2 2

Boost Log: Use of operator<<
by Florian Lindner 21 Jan '16

21 Jan '16

Hello, I want to put a custom object called DynamicVector on the BOOG_LOG_SEV stream. For that I defined an operator<< template<typename Vector> typename std::enable_if<tarch::la::IsVector<Vector>::value, std::ostream&>::Type operator<< (std::ostream & os, const Vector & vector); IsVector<Vector> will be true, since template<typename Scalar> struct IsVector<DynamicVector<Scalar> > { static const int value = true; }; The operator itself is working: // getCoords returns a DynamicVector<double> std::cout << inMesh->vertices()[j].getCoords(); // compiles just fine. but BOOST_LOG_SEV(_log, boost::log::trivial::severity_level::error) << inMesh->vertices()[j].getCoords(); gives an compile error: /usr/include/boost/log/utility/formatting_ostream.hpp:799:19: error: invalid operands to binary expression ('ostream_type' (aka 'basic_ostream<char_type, traits_type>') and 'const tarch::la::DynamicVector<double>') strm.stream() << value; str.stream() seems to be an ostream_type which is an basic_ostream<char_type, traits_type>. I wonder why this isn't convertible to std::ostream, like http://stackoverflow.com/questions/17269499/overloading-operator-for-boost-… and the comment at http://www.boost.org/doc/libs/1_54_0/boost/log/utility/formatting_ostream.h… suggest. Any help appreciated! Thanks, Florian

1 0

Re: [Boost-users] [boost] Boost.Operators issue: polluting namespace of caller through argument-dependent lookup
by John M. Dlugosz 21 Jan '16

21 Jan '16

On 1/20/2016 10:41 AM, Daniel Frey wrote: > In a way it makes library collections like Boost harder and I still think you should use > qualified lookup in your specific case, No, I specifically don't want to qualify every use, as explained originally. The code needs compatibility with some configurations that require the tr1 namespace and others that prohibit it. Qualifying every reference is bad; rather, import them in one place. You are basically saying that `using N::foo;` is never right because someone may happen to use the name foo in an unrelated library and ADL is a misfeature? I think that doesn't scale. It should be SOP to isolate classes that are meant to be used as base classes by library consumers, and treat unqualified lookup of names pulled in to the local scope via `using` as something that is a useful feature that ought to work. > but as I already said in another mail I’m willing to fix it. I just need to figure out > where to commit and merge stuff as the last time I worked on it we were still using svn > and the branching model was different. I hope to be able to find the time somewhere in > the next days. Regards, Daniel Looking forward to it in 1.62 or whatever. Thanks! —John

1 0

[locale] boost::locale::format number formatting on OS X and Windows
by Michael Smith 21 Jan '16

21 Jan '16

Using Boost.Locale from Boost 1.60.0 (installed via homebrew, so it uses icu) on Mac OS X 10.11.2, I seem to be getting unexpected behavior for some of the boost::format number formatting. A short example program #include <boost/locale.hpp> int main(int argc, char** argv) { boost::locale::format fmt("{1,number} should be 1,25."); fmt % 1.25; boost::locale::generator gen; std::cout << fmt.str(gen("fr-fr.UTF-8")) << std::endl; return 0; } That produces 1,25 on Linux, and 1.25 on Windows (using mingw-w64) and Mac. Any idea why they'd represent it differently?

1 0

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

boost serialization
by Виктория Доможакова 20 Jan '16

20 Jan '16

I use boost serialization in my project. I I conducted f an experiment: 1) I removed one line with the data in the boost archive file. 2) I started my project. 3) All variables initialized in the constructor. 4) Value of variables loaded from boost archive in order . 5) When queue comes to removing values , I get exeption (I handle exeption with try-catch ) and file didn't read to end and close. 6) But this variable is equal to the value next after removal . My question: why this variable is equal to the value next after removal . if this variable has value from constructor than it is more logic. -- Виктория Доможакова

1 0

[gsoc16] Attn: We need 2016 mentors and project ideas for Boost!
by Niall Douglas 20 Jan '16

20 Jan '16

Dear Boost community, We are now within one month of the beginning of Google Summer of Code 2016! Last year's GSoC was a particularly momentus one as we witnessed the approval by the community for Boost.Hana to enter Boost - congratulations to Louis and his mentor Joel for bringing to Boost a very exciting new C++ library which pushes C++ compilers to their limits. We have also seen greatly improved retention of GSoC students in the community thanks to the improved student selection procedures introduced last year, and the fresh blood brought into Boost has been very evident on the mailing list this year. As part of filling in our application for 2016, we must supply to Google a list of potential GSoC mentors and potential GSoC projects for summer 2016 in order to be approved as an organisation this year. Therefore a lengthy page of awesome project ideas at https://svn.boost.org/trac/boost/wiki/SoC2016 before *February 8th* would be an enormous help to getting us approved again this year and bringing to Boost another US$35,000 of Google funding. If you think yourself able to mentor a student doing some work on Boost this summer, *please* consider adding a description of the proposed work item and your name to the list. Last year we had more slots awarded to us by Google than we had good combinations of student and mentor, so we had to return slots which I believe has not happened here at Boost GSoC in at least a decade. That means that your project ideas have a better chance than ever of receiving funding if you can find a good student, and that is best done by getting project ideas floated *early*. If you want to know more about mentoring a Google Summer of Code funded student work before you nominate yourself, please feel free to ask on the main Boost developers mailing list boost(a)lists.boost.org or via gsoc-admin(a)boost.org. Thank you in advance for your time. --- Boost C++ Libraries Google Summer of Code 2016 admin https://svn.boost.org/trac/boost/wiki/SoC2016

2 1

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

Re: [Boost-users] boost.dll winapi compile error
by Elod G 18 Jan '16

18 Jan '16

I was missing the latest winapi module, duh. ElodG On 1/18/2016 19:00, boost-users-request(a)lists.boost.org wrote: > Message: 1 > Date: Sun, 17 Jan 2016 23:12:32 +0200 > From: Elod G <gyelod(a)gmail.com> > To: boost-users(a)lists.boost.org > Subject: [Boost-users] boost.dll winapi compile error > Message-ID: <569C03BF.9030305(a)gmail.com> > Content-Type: text/plain; charset=utf-8 > > Hello All, > > I cloned origin/master of https://github.com/boostorg/dll and copied > include/ to the 1.60 release of boost to give boost.DLL a go. > > I am getting the following compile error when including: "boost/dll.hpp" > boost\dll\detail\windows\shared_library_impl.hpp:140: error: C2039: > 'get_proc_address' : is not a member of 'boost::detail::winapi' > > I am using VS2013. > > What am I missing? > > -- > ElodG

1 0

boost.dll winapi compile error
by Elod G 17 Jan '16

17 Jan '16

Hello All, I cloned origin/master of https://github.com/boostorg/dll and copied include/ to the 1.60 release of boost to give boost.DLL a go. I am getting the following compile error when including: "boost/dll.hpp" boost\dll\detail\windows\shared_library_impl.hpp:140: error: C2039: 'get_proc_address' : is not a member of 'boost::detail::winapi' I am using VS2013. What am I missing? -- ElodG

1 0

multiprecision thread safety
by Daniel Brake 14 Jan '16

14 Jan '16

Hi Boost, I have a couple of questions regarding thread safety and Boost.Multiprecision. I am writing a library, and would like to be able to use mpfr_float (packed into my own complex class) in differing variable precisions on multiple threads simultaneously. 1. Is this supported? I looked in documentation, but didn't find comments to that end. 2. Must I manually call mpfr_free_cache when terminating threads, as recommended by the mpfr documentation? see http://www.mpfr.org/mpfr-current/mpfr.html, section 4.7 memory handling. If so, since Boost.Multiprecision claims to not change the default precision of mpfr_t, do I need to access the particular back end for the thread, and free its cache? Thanks, Daniel Brake danielthebrake(a)gmail.com

2 1

boost 1.55 asio tcp cpp03 chat_server example memory leaks
by Hung Ruo Han 14 Jan '16

14 Jan '16

Hi all i hope someone could give me a clue where to investigate... i'm running the chat_server example from boost http://www.boost.org/doc/libs/1_55_0/doc/html/boost_asio/example/cpp03/chat… on visual studio 2010, windows 10 and i downloaded boost binaries from : http://sourceforge.net/projects/boost/files/boost-binaries/1.55.0/boost_1_5… i used a script to simulate 30 tcp clients, each thread behavior basically: 1. connect to tcp server 2. start a loop 3. send a message to tcp server 4. receive a message from tcp server 5. sleep 6. back to step 2 the strange fact is when i use windows task manager to monitor the memory consumption. The numbers from columns *private working set* and *shared working set* remains "stable" for almost 18 minutes and after that the values of *private working set* starts to increase almost 5 MB by minute. So my doubts are: 1. Does anyone ever seen anything similar before? 2. What could cause this? Regards -- Hung Ruo Han <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> This email has been sent from a virus-free computer protected by Avast. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> <#DDB4FAA8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

1 0

[phoenix] [clang] error assigning function object
by Nathan Ridge 12 Jan '16

12 Jan '16

Hi there, I'm experiencing a compiler error in code that tries to assign a Boost.Phoenix function object returned by invoking a phoenix::function with a std::string as one of the bound parameters. I've reduced my error to the following minimal code: #include <string> #include <boost/phoenix/core/argument.hpp> #include <boost/phoenix/function.hpp> struct S { void operator()(std::string, int) const; }; boost::phoenix::function<S> lazy; auto func1 = lazy(std::string(), boost::phoenix::placeholders::_1); auto func2 = func1; void foo() { func2 = func1; } My compiler version is clang 3.7; the error does not occur with gcc 5.1. The error also goes away if I change the type of the first argument from std::string to a different type (like int). The compiler error is shown below. Any ideas as to what is going on? Am I doing something wrong, or did I run into a bug in Phoenix? Thanks, Nate In file included from test.cpp:81: In file included from /home/nr/dev/dist/boost/include/boost/phoenix/core/argument.hpp:13: In file included from /home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:25: In file included from /home/nr/dev/dist/boost/include/boost/proto/make_expr.hpp:100: In file included from /home/nr/dev/dist/boost/include/boost/proto/detail/make_expr_.hpp:3: /home/nr/dev/dist/boost/include/boost/proto/detail/preprocessed/make_expr_.hpp:73:88: error: no type named 'type' in 'boost::proto::transform<boost::proto::switch_<boost::phoenix::phoenix_generator, boost::proto::tag_of<boost::proto::_> ()>, void>::result<boost::phoenix::phoenix_generator (boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>)>' typedef typename proto_generator::template result<proto_generator(expr_type)>::type result_type; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~ /home/nr/dev/dist/boost/include/boost/proto/make_expr.hpp:180:34: note: in instantiation of template class 'boost::proto::detail::make_expr_<boost::proto::tagns_::tag::assign, boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, const boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void, void, void, void, void, void, void>' requested here typename detail::make_expr_< ^ /home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:225:36: note: in instantiation of template class 'boost::proto::result_of::make_expr<boost::proto::tagns_::tag::assign, boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, const boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void, void, void, void, void, void, void>' requested here typename proto::result_of::make_expr< ^ /home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:185:12: note: while substituting deduced template arguments into function template 'operator=' [with A0 = const boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>] struct actor ^ /home/nr/dev/dist/boost/include/boost/proto/matches.hpp:830:44: note: in instantiation of template class 'boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>' requested here : Cases::template case_<typename Expr::proto_tag>::template impl<Expr, State, Data> ^ /home/nr/dev/dist/boost/include/boost/proto/transform/impl.hpp:238:13: note: in instantiation of template class 'boost::proto::switch_<boost::phoenix::phoenix_generator, boost::proto::tag_of<boost::proto::_> ()>::impl<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>, int, boost::proto::envns_::empty_env>' requested here : PrimitiveTransform::template impl<Expr, empty_state, empty_env> ^ /home/nr/dev/dist/boost/include/boost/proto/transform/impl.hpp:255:9: note: in instantiation of template class 'boost::proto::detail::apply_transform<boost::phoenix::phoenix_generator (boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>)>' requested here BOOST_PROTO_TRANSFORM_(PrimitiveTransform, X) ^ /home/nr/dev/dist/boost/include/boost/proto/transform/impl.hpp:194:48: note: expanded from macro 'BOOST_PROTO_TRANSFORM_' typedef typename boost::proto::detail::apply_transform<Sig>::result_type type; \ ^ /home/nr/dev/dist/boost/include/boost/proto/detail/preprocessed/make_expr_.hpp:73:43: note: in instantiation of template class 'boost::proto::transform<boost::proto::switch_<boost::phoenix::phoenix_generator, boost::proto::tag_of<boost::proto::_> ()>, void>::result<boost::phoenix::phoenix_generator (boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>)>' requested here typedef typename proto_generator::template result<proto_generator(expr_type)>::type result_type; ^ /home/nr/dev/dist/boost/include/boost/proto/make_expr.hpp:180:34: note: in instantiation of template class 'boost::proto::detail::make_expr_<boost::proto::tagns_::tag::assign, boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void, void, void, void, void, void, void>' requested here typename detail::make_expr_< ^ /home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:213:36: note: in instantiation of template class 'boost::proto::result_of::make_expr<boost::proto::tagns_::tag::assign, boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void, void, void, void, void, void, void>' requested here typename proto::result_of::make_expr< ^ test.cpp:96:8: note: while substituting deduced template arguments into function template 'operator=' [with A0 = boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval, boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>, boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>, boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>] func2 = func1; ^ 1 error generated.

2 3

[Statechart] Implementing an internal timeout in an asynchronous state machine
by John Buonassisi 07 Jan '16

07 Jan '16

Hi there, I am looking for some advice on the best way to implement an internal timeout in an asynchronous state machine using the Boost Statechart library. My project requires an asynchronous state machine that multiple threads can queue events to. The asynchronous state machine will react to events and execute callback functions that are registered on creation of the state machine. So far, this hasn't been a problem, but I have hit a bit of a roadblock when handling timeouts. I need my asynchronous state machine class to start a timer in a certain reaction method, when this timer expires I need the scheduler to queue a timeout event. Basically, the timer will act as an interrupt, when it expires I need a timeout event to be immediately queued to the state machine event queue. Since asynchronous state machines are created and managed by a scheduler class (in my case boost::statechart::fifo_scheduler<>) how can I get the asynchronous state machine to queue a timeout event? If possible, I would like to encapsulate this timeout functionality, so client code that uses my derived asynchronous state machine does not have to deal with managing timeouts. My first thought is to have the asynchronous state machine class create a thread when the timer is started. The thread will continually check if the timer has expired and if it has, will queue a timeout event. The issue with this approach is that I would need to pass the scheduler and state machine handler to the thread function in order to queue the event. Obviously, the state machine does not have access to these objects and I am unsure if this is a safe approach. Any suggestions or help with this matter would be greatly appreciated! This is my first post to the mailing list so I hope this is the right arena for my question. Thanks, John Buonassisi

1 0

*newbie* 'BOOST_INTRUSIVE_HAS_MEMBER_FUNCTION_CALLABLE_WITH_ITERATION' : undeclared identifier
by Gregory Werner 07 Jan '16

07 Jan '16

Hi all new to the list. When trying to build a rather large project which uses boost, I get the following few lines 12 times during the build process: 7>c:\local\boost_1_60_0\boost\intrusive\detail\has_member_function_callable_with.hpp(303): error C2065: 'BOOST_INTRUSIVE_HAS_MEMBER_FUNCTION_CALLABLE_WITH_ITERATION' : undeclared identifier 7>c:\local\boost_1_60_0\boost\intrusive\detail\has_member_function_callable_with.hpp(320): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int 7>c:\local\boost_1_60_0\boost\intrusive\detail\has_member_function_callable_with.hpp(320): error C2143: syntax error : missing ';' before ''template<'' Others can build this same project just fine and I can't find anything on the internet which would indicate others having problems with this file. I am using VS2010 Professional Version with SP1. My compiler and boost libraries are both 32 bit. I tried uninstalling and reinstalling everything but same errors. These are the only errors which prevent my project from successful build. Any ideas as to what could cause this? -Greg

2 1

Feedback boost conan binary packages
by Luis 07 Jan '16

07 Jan '16

Dear Boost Users, Disclaimer: I am founder and developer of conan.io C++ package manager. Please note that it is just a FOSS project, MIT license, fully decentralized, and although I'd like to promote the tool and receive feedback about it, there are already channels for that conversation in the github repos. What I'd really like is to get feedback about the Boost packages I am creating and maintaining in conan. I have generated almost 190 different binary packages for Boost versions 1.57-1.60 ( https://www.conan.io/search?q=Boost%20AND%20user:lasote) for Linux, Win, Mac and different flavours of compilers (gcc 4.7-5.3, VS12-14) and settings (Debug, Release). You can read a quick getting started on such Boost packages in: http://docs.conan.io/en/latest/examples/boost.html If someone has been able to try it, I'd like to know several things: - whether it is interesting to have pre-compiled packages or you always prefer to build from source (i.e. always using the --build option in conan). So far there are about 200 downloads of binary packages, but probably many people prefer to build from source. - It has dependencies to already existing zlib and bzip2 conan packages (can be shared or static). Are you fine with these? Any other Boost dependencies missing that you would like to automate? - It is probably the largest package so far, have you experienced slow downloads? You can report issues and feedback in the conan-boost repo: https://github.com/lasote/conan-boost/issues. Thanks very much, Luis

2 2

boost variant is not a literal type
by Robert Ramey 07 Jan '16

07 Jan '16

I want to use Boost.Variant constexpr function. In order to do this it has to be a literal type - which apparently it isn't. The rule for being a literal type are summarized here: http://en.cppreference.com/w/cpp/concept/LiteralType a boost::variant isn't default constructable so it fails to qualify. Has anyone else had this problem before and managed to solve it in a convenient way? Robert Ramey

3 7

Re: [Boost-users] boost program options
by avib369 . 06 Jan '16

06 Jan '16

With reference to boost 1.59 and program options. The following test passes on boost 1.53, but fails on boost 1.59. I need to able to handle. --arg1 10 and --arg1=10 boost 1.59 now fails on '--arg1 10', with test below with option value being empty. #include <string> #include <iostream> #include <fstream> #include <boost/test/unit_test.hpp> #include <boost/foreach.hpp> #include <boost/program_options.hpp> using namespace std; namespace po = boost::program_options; BOOST_AUTO_TEST_SUITE( BaseTestSuite ) BOOST_AUTO_TEST_CASE( test_program_options_implicit_value ) { cout << "Base:: ...test_program_options_implicit_value\n"; // Declare the supported options. po::options_description desc("Allowed options"); desc.add_options() ("help", "produce help message") ("arg1", po::value<string>()->implicit_value( string("") ), "optional arg1 description") ; { char* argv[] = { const_cast<char*>("test_program_options_implicit_value"), const_cast<char*>("--help"), const_cast<char*>("--arg1") }; po::variables_map vm; po::store(po::parse_command_line(3, argv, desc), vm); po::notify(vm); BOOST_CHECK_MESSAGE(vm.count("help"), "Expected help"); BOOST_CHECK_MESSAGE(vm.count("arg1"), "Expected arg1"); BOOST_CHECK_MESSAGE(vm["arg1"].as<string>() == "", "Expected arg1 to be empty"); } { // ****** This fails on boost 1.59 bit passes in boost 1.53 ******* char* argv[] = { const_cast<char*>("test_program_options_implicit_value"), const_cast<char*>("--arg1"), const_cast<char*>("10") }; po::variables_map vm; po::store(po::command_line_parser(3, argv, desc), vm); po::notify(vm); BOOST_CHECK_MESSAGE(vm.count("arg1"), "Expected arg1"); BOOST_CHECK_MESSAGE(vm["arg1"].as<string>() == "10", "Expected arg1 with value of 10 but found '" << vm["arg1"].as<string>() << "'"); } { char* argv[] = { const_cast<char*>("test_program_options_implicit_value"), const_cast<char*>("--arg1=11") }; po::variables_map vm; po::store(po::parse_command_line(2, argv, desc), vm); po::notify(vm); BOOST_CHECK_MESSAGE(vm.count("arg1"), "Expected arg1"); BOOST_CHECK_MESSAGE(vm["arg1"].as<string>() == "11", "Expected arg1 with value of 11 but found " << vm["arg1"].as<string>()); } } Ta, Avi

2 1

boost program_options
by avib369 . 06 Jan '16

06 Jan '16

There seems to be change/regression in boost program options. In boost/1.53. I used boost::program_options::variables_map vm; po::store( po::parse_command_line( argc, argv, desc_ , po::command_line_style::unix_style ^ po::command_line_style::allow_short), vm ); po::notify( vm ); This could handle arguments like: ./exe --help all ./exe --help summary However from boost 1.59, this no longer works, instead I have to use: ./exe --help=all ./exe --help=summary Is this a known change ? how do i get back to the old functionality ? Ta, Avi

2 1

Boost 1.60.0 breaks Boost.Log formatter on MSVC11
by Robert Rumpf 06 Jan '16

06 Jan '16

I’ve been happily using Boost.Log (and much of the rest of Boost) for years, but on upgrading to 1.60, I find that I get runtime errors on MSVC 11. I’ve tracked the problem back to a simple representative example (as provided with the Boost.Log library): http://www.boost.org/doc/libs/1_60_0/libs/log/example/doc/tutorial_fmt_stre… The problematic portion of the example is the usage of character arrays when setting up the formatter, specifically: << ": <" << "> " The code compiles fine but then throws an exception at runtime, seemingly due to uninitialized data. Removing the strings in the formatter configuration makes the error disappear. I would guess that it has something to do with xvalues going into the formatter unintentionally, but this code has functioned fine on prior versions of Boost 1.59-1.54, and I can find nothing in the release notes that points me at where the problem might be. I am compiling with BOOST_SPIRIT_USE_PHOENIX_V3. Before I start doing lots of diffs, has anyone else experienced this problem, and is there any known solution or workaround? Thanks for all of the excellent work and support, Rob

1 0

[regex] link errors on 1.60 update
by James Walker 06 Jan '16

06 Jan '16

When I tried to convert my project from Boost 1.58.0 to 1.60.0, I got some link errors. This is using Xcode 4.6.3 on Mac OS X 10.7.5. I'm compiling all the sources in libs/regex/src. Help? Undefined symbols for architecture i386: "boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::construct_init(boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags)", referenced from: boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::perl_matcher(char const*, char const*, boost::match_results<char const*, std::allocator<boost::sub_match<char const*> > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, char const*) in BVHJointMap.o boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::perl_matcher(char const*, char const*, boost::match_results<char const*, std::allocator<boost::sub_match<char const*> > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, char const*) in AnimationsManager.o "boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::find()", referenced from: bool boost::regex_search<char const*, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(char const*, char const*, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags) in BVHJointMap.o "boost::re_detail_106000::perl_matcher<char const*, std::allocator<boost::sub_match<char const*> >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::match()", referenced from: bool boost::regex_match<char const*, std::allocator<boost::sub_match<char const*> >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(char const*, char const*, boost::match_results<char const*, std::allocator<boost::sub_match<char const*> > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags) in AnimationsManager.o

3 4

Boost 1.60.0 rc1 is now available
by Marshall Clow 05 Jan '16

05 Jan '16

Release candidate files for 1.60.0 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. The files (and associated md5s) are: MD5 (boost_1_60_0_rc1.7z) = 7ce7f5a4e396484da8da6b60d4ed7661 MD5 (boost_1_60_0_rc1.tar.bz2) = 65a840e1a0b13a558ff19eeb2c4f0cbe MD5 (boost_1_60_0_rc1.tar.gz) = 28f58b9a33469388302110562bdf6188 MD5 (boost_1_60_0_rc1.zip) = 0cc5b9cf9ccdf26945b225c7338b4288 Thanks! -- The release managers P.S. Release notes are here: http://www.boost.org/users/history/version_1_60_0.html

4 8

C++Now 2106 Call for Submission
by Jon Kalb 05 Jan '16

05 Jan '16

Boost Users, The Call for Submissions for C++Now 2016 (AKA BoostCon) has been released: http://cppnow.org/2016-conference/announcements/2015/11/17/call-for-submissi on.html The deadline for submitting is very near and cannot be extended, so don¹t delay your submission. The conference will be held in Aspen the week of May 9th. See you in Aspen! Jon

1 0

[boost][review][qvm] QVM formal review result
by Adam Wulkiewicz 04 Jan '16

04 Jan '16

Dear Boost community, The review period for Emil Dotchevski's QVM library has concluded. I'd like to thank everyone who participated in the discussions, esspecially those who sent formal reviews. Only four votes were casted however more people commented on issues on the mailing list. Comments received during the course of the review were generally positive, with a number of technical issues identified that need to be addressed. The review identified no fundamental problems in the design or implementation of the library that would entail rejection. The final version of the library can be fully accepted once Emil has addressed the issues identified during the review. Therefore I'm happy to say: Emil Dotchevski's Boost.QVM library is CONDITIONALLY ACCEPTED. Full report can be found here: http://lists.boost.org/Archives/boost/2016/01/227027.php Regards, Adam

2 1

[Boost::Python]
by Eugenio Bargiacchi 03 Jan '16

03 Jan '16

Hello everyone, I have a member function with signature const Matrix2D & foo const (); Which returns an internal data structure. Matrix2D is using Matrix2D = Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor | Eigen::AutoAlign>; I have explicitly set a to_python converter for Matrix2D, and I have exported the function with a call policy of return_internal_reference. However, when this function is called from Python I get TypeError: No Python class registered for C++ class Eigen::Matrix<double, -1, -1, 1, -1, -1> This happens also if the reference is not const. At the same time, if I modify the call policy to return_value_policy<copy_const_reference>() Python can decode the matrix just fine. The same holds true if I return the Matrix2D by value. However I really need to have a reference to the matrix in order store it into other classes. How can I make Python see the data structure through the reference? The converter in case it is needed: boost::python::list toPythonList(const double * data, size_t num) { boost::python::list list; for (size_t i = 0; i < num; ++i) list.append(data[i]); return list;} struct Matrix2DToPython{ static PyObject* convert(Matrix2D const & m) { boost::python::list list; for (int i = 0; i < m.rows(); ++i) { list.append(toPythonList(m.row(i).data(), m.cols())); } return boost::python::incref(list.ptr()); }}; Thanks, Eugenio

1 0

[units] Adding two absolute units
by Itzik 03 Jan '16

03 Jan '16

Hello, <obligatory appreciation on first post> I started using Boost just for boost::units and I find new ways boost can help me almost every day. So thanks for the great stuff! </obligatory appreciation on first post> My question to the board is why two absolute quantities (si::temperature (K) in my case) can't be summed in boost::units? I realized that this is a rule enforced by-design (gmane.comp.lib.boost.user/71747), and I understand that it is probably not a very common case, but I wanted my code to solve a simple formula which requires adding up two absolute temperatures (quantity<absolute<temperature>>). Each temperature represents an Inlet temperature in a Heat Exchange system. So even if converting one temperature to a relative type (quantity<temperature>) might be a workaround, it seems like a forced misuse to me. Eventually it turned out that I was mistaken with the formula, and subtraction was required instead, so there's no problem there. Alas, there's also a much simpler use case: What if I want to average the temperature of the last N readouts? Shouldn't boost::units support this simple operation? I have no formal physics education, but intuitively, adding two absolute temperatures doesn't seem really like a mistake to me, even if it's an odd thing to do. Will appreciate your thoughts on the matter.

3 4

Modifying all matching elements in a Boost.MultiIndex Container
by Amit Prakash Ambasta 01 Jan '16

01 Jan '16

Hi, I am trying to modify members of all elements matching value for a given index in a boost.multiindex container index.modify( index.find(value), [](T& element) { ... } ) seems to update a singular element(first match) On the other hand, std::pair<index::iterator, index::iterator> iter = index.equal_range(value); while(iter.first != iter.second) { index.modify( iter.first, [](T& element) { ... } ); iter.first++; } leads to segfaults and unexpected behavior. What would be right way to approach this?

3 4

Pointer to objects in Boost.MultiIndex
by Amit Prakash Ambasta 01 Jan '16

01 Jan '16

Consider the following code snippet: #include <iostream> #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/member.hpp> using namespace std; using namespace boost::multi_index; struct LinkList; struct LinkList { size_t index; LinkList* parent; LinkList(size_t index, LinkList* parent) : index(index), parent(parent) {} }; struct llindex {}; typedef ordered_unique<tag<llindex>, member<LinkList, size_t, &LinkList::index> > LinkListIndex; typedef boost::multi_index_container<LinkList, indexed_by<LinkListIndex> > IndexedLinkList; template <typename T> void show(T& iterable) { for(auto const& element: iterable) { if(element.parent != nullptr) { std::cout << "Index<" << element.index << ">: " << element.parent->index << std::endl; } else { std::cout << "Index<" << element.index << ">: " << "NULL" << std::endl; } } } int main() { IndexedLinkList ill; auto &index_ll = ill.get<0>(); ill.insert(LinkList{0, nullptr}); ill.insert(LinkList{1, (LinkList*)(&(*index_ll.find(0)))}); ill.insert(LinkList{2, (LinkList*)(&(*index_ll.find(0)))}); ill.insert(LinkList{3, (LinkList*)(&(*index_ll.find(2)))}); show(ill); return 0; } Would (LinkList*)(&(*index__ll.find(value))) be the recommended way to fetch the pointer to parent?

2 3

[BGL] Are normal and reverse undirected edges the same or different?
by Ireneusz Szcześniak 01 Jan '16

01 Jan '16

Hi, In an undirected graph, we create an undirected edge: add_edge(a, b, g); We get the reverse of that edge: edge(b, a, g); Now, are these two edges the same or different? vIf I compare them with the == operator, they are equal, but they have different source and target vertexes. Can I count on this behavior? Will it stick? I'm asking because I couldn't find it in the documentation. Please find attached my unit test. On Debian Jessie, I'm compiling it with: g++ test.cc -l boost_test_exec_monitor -l boost_unit_test_framework -o test Thanks & best, Irek

1 0