April 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

Memory deallocation concerning boost::bind, boost::asio and shared_ptr
by Norman Kradepohl 17 May '16

17 May '16

Hi there, my code is allocating memory and never freeing it, even though it should (at least in my opinion). The header looks like this: typedef boost::asio::ssl::stream<boost::asio::ip::tcp::socket> sslSocket_t; class Object { boost::asio::io_service ioService_; boost::asio::ip::tcp::acceptor acceptor_; boost::asio::ssl::context context_; void functionOne(); void functionTwo(shared_ptr<sslSocket_t>& sslSocket, const boost::system::error_code& error) } And my source like this: void Object::functionOne() { for (int i = 0; i < 10; i++) { shared_ptr<sslSocket_t> sslSocket(new sslSocket_t(ioService_, context_)); acceptor_.async_accept(sslSocket->lowest_layer(), boost::bind(&Object::functionTwo, this, sslSocket, boost::asio::placeholders::error)); } acceptor_.cancel(); boost::asio::io_service::work work(ioService_); ioService_.run(); } void functionTwo(shared_ptr<sslSocket_t>& sslSocket, const boost::system::error_code& err) { // Do nothing } So when i call *Object.functionOne()*, memory is getting allocated to the *Object.ioService_* object, in order to be able to call the bound asynchronous method. Then after the loop, all pending asynchronous actions on the acceptor are getting canceled. The appropriate handler is getting invoked as soon as *Object.ioService_.run()* is called (i've been testing that). BUT for some reason, the allocated memory does not get freed. I'm stuck on this problem for a while now, any hint or help would be really appreciated. Btw.: I'm working on debian and looking at "/proc/self/status" -> "VmRSS" to whatch the used memory.

6 14

FindBoost.cmake does not check for include headers
by j.wuttke 11 May '16

11 May '16

As per cmake 3.5.1, FindBoost.cmake does not check for include headers. Therefore it will give false positives - if a Boost project that only consists of a header file is not installed - if only a libboost* is installed, but not the headers from the corresponding *-dev package. I raised this issue long ago on the cmake bug tracker, and recently again on the cmake mailing list, but got no response. Would perhaps somebody from the Boost community volunteer to look into this issue? Or has already looked into it and could tell us what the problem is?

3 4

boost/multiprecision/float128
by Cooper, Bridgette R D 01 May '16

01 May '16

I'm new to boost. I am trying to use the float128 type for calculating sqrts as a larger part of code, however I am not sure the values obtained are accurate to float128 precision. I have tried running the example for printing log(2) found here, I find the same for sqrt: http://www.boost.org/doc/libs/1_57_0/libs/multiprecision/doc/html/boost_mul… However, the value printed log(2) only agrees to 16 decimal places, i.e. double precision. The value I obtain is 0.693147180559945286226763982995180413 rather than 0.693147180559945309417232121458176575 I'm using: g++ (GCC) 4.8.2 20140120 (Red Hat 4.8.2-15) with boost 1.57.0. Any advice as to what I am doing incorrectly? My compile line is: g++ -I ~/$BOOSTLIB new.cpp -lquadmath -o new Thanks,

3 6

[utility] BOOST_IDENTITY_TYPE drops const-ness of value types
by Nick Stokes 29 Apr '16

29 Apr '16

Looks like const value types, once passed thru BOOST_IDENTITY_TYPE, "becomes" non-const. Like so: // Attempt to implement a multi-argument utility macro, where arguments are // types, parenthesized only when required (by the user, when type has commas) #define ASSERT_EQUAL( t1, t2 ) \ static_assert( std::is_same< \ BOOST_IDENTITY_TYPE((t1)), BOOST_IDENTITY_TYPE((t2)) \ >::value, #t1 " not same as " #t2) // sanity check: static_asserts as expected ASSERT_EQUAL( int, double ); // sanity check: static_assert as expected for types with commas ASSERT_EQUAL( (std::pair<int, double>), (std::pair<double, int>) ); // Here is the failure: this is expected to assert but it doesnt! ASSERT_EQUAL( const int, int ); >From the implementation of BOOST_IDENTITY_TYPE, it is clear why this is happening, as the function signature is independent of const-ness of value type. Is this a bug? Or is this not the way BOOST_IDENTITY_TYPE is supposed to be used? Nick

1 0

linking and including in visual studio
by David Medine 29 Apr '16

29 Apr '16

This is kind of a stupid question, and maybe more of a Windows/Visual Studio question than a boost one, but this has been troubling the back of my mind lately. Having learned to write and compile C++ code on Linux, I am always in the habit of explicitly stating the include and library paths for the compiler to search for, as well as the libraries themselves that need to be linked. However, I am revising some Visual Studio projects that use boost and I realized that the path I gave for 'Additional Library Directories' is $(BOOST_ROOT)/lib, but my version of boost hasn't got this directory (it's actually $(BOOST_ROOT)\libs). I then removed all references to boost from 'Additional Library Directories', and 'Additional Include Directories' and the application builds and runs swimmingly. This leads me to believe, that assigning the BOOST_ROOT environment variable in Windows is the only step that is needed for VS's auto linking magic to link correctly to boost. Am I right here, or is there something I am missing? Cheers, David

7 14

Date and Time with Boost
by Counter Wall 28 Apr '16

28 Apr '16

What I want to do is read a text file containing a text string in ISO 8601 combined date and time in utc format (e.g. 2016-04-26T12:45:05+00:00). I also want to have the freedom to convert this between time zones and have accurate daylight savings time data. Boost::datetime seems to read in the string, but it looks like boost::locale is recommended for time zone conversions and DLS. Is there a way for me to have both?

2 1

Re: [Boost-users] [boost.multiprecision] export_bits throws on a negative number
by Tassilo Glander 28 Apr '16

28 Apr '16

Hi John, thanks for stepping in. I would expect that the export just exports the memory representation of the number - maybe with flipped order via msv_first parameter. Especially, something exported via export_bits and than imported via import_bits should be the same, at least on the same platform. That said, I actually was just looking for a way to implement a hash function and thought it was straightforward to use chunks of char. But I could also compute the hash on the str() output. Tassilo

2 1

[boost.multiprecision] export_bits throws on a negative cpp_int number
by Tassilo Glander 28 Apr '16

28 Apr '16

Dear List, When calling export_bits on a negative boost::multiprecision number based on cpp_int, an exception is thrown from the internal method msb ("testing individual bits in negative values is not supported"). boost::multiprecision::checked_int128_t i (-1); // use negative number std::vector<unsigned char> v; export_bits(i, std::back_inserter(v), 8); // throws How can I extract the content of a boost::multiprecision number? Boost documentation says, export_bits is designed to be used for data exchange, so in my understanding it would be a major flaw, if it cannot export supported values. I learnt that a workaround might be to directly access the backend's limbs, but this way I am accessing internals that may change. http://www.boost.org/doc/libs/master/libs/multiprecision/doc/html/boost_mul… I also asked this on http://stackoverflow.com/questions/36890928/boostmultiprecisionexport-bits-…, but this list is probably the better place. Thanks, Tassilo

2 1

[PBGL] compilation of example/dijkstra_shortest_paths.cpp failed
by Eisuke Kawashima 27 Apr '16

27 Apr '16

Dear all, I tried to compile http://www.boost.org/doc/libs/1_60_0/libs/graph_parallel/example/dijkstra_sh ortest_paths.cpp, an example code of Parallel Boost Graph, resulting in faulure; example/breadth_first_search.cpp has no problem. My environment is: * GCC 4.9.2 * OpenMPI 1.10.2 * boost 1.60.0 * OS: Debian jessie The error, related to template, is long; the summary is: $ mpicxx -std=c++11 -lboost_mpi -lboost_serialization -lboost_system - lboost_graph_parallel dijkstra_shortest_paths.cpp In file included from boost/graph/dijkstra_shortest_paths.hpp:25:0, from dijkstra_shortest_paths.cpp:19: boost/pending/relaxed_heap.hpp: In instantiation of ‘bool boost::relaxed_heap... boost/graph/distributed/crauser_et_al_shortest_paths.hpp:377:54: required from ... boost/graph/distributed/detail/remote_update_set.hpp:148:7: required from ... boost/graph/distributed/crauser_et_al_shortest_paths.hpp:264:37: required from ... boost/graph/breadth_first_search.hpp:76:7: required from ... boost/graph/breadth_first_search.hpp:124:69: required from ... boost/graph/breadth_first_search.hpp:135:64: [ skipping 4 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ] boost/graph/distributed/dijkstra_shortest_paths.hpp:146:50: required from ... boost/graph/distributed/dijkstra_shortest_paths.hpp:200:45: required from ... boost/graph/dijkstra_shortest_paths.hpp:573:16: required from ... boost/graph/dijkstra_shortest_paths.hpp:595:35: required from ... boost/graph/dijkstra_shortest_paths.hpp:614:14: required from ... dijkstra_shortest_paths.cpp:74:64: required from here boost/pending/relaxed_heap.hpp:194:70: error: cannot convert ‘const value_type {aka const boost::optional<boost::detail::parallel::global_descriptor<long unsigned int> >}’ to ‘bool’ in return bool contains(const value_type& x) const { return groups[get(id, x)]; } ^ "-ftemplate-backtrace-limit=0" flag did not work. How to fix this? -- Eisuke Kawashima

2 4

[boost-users][boost graph] edge_descriptor problem when copy from original graph
by Emerson Xu 26 Apr '16

26 Apr '16

Hi all, I have a boost graph copy problem that has been nagging me for a long time. My question is, is there anyway that I can construct a graph once, and reuse it multiple times, each time I may mutate the graph a bit. I have a class, which creates a boost graph with bundled vertex and edge properties (my own properties, vertices are routers in a network, while edges are logical links between routers). When creating the graph, some helper unordered maps are also created, like mapping from an edge_descriptor to a logical link name, from a router name to a vertex_descriptor, etc. Now there are multiple clients calling some method in the class. Current strategy is to construct a new boost graph instance for every client, and run the service on each graph instance. Now I want to improve the performance by avoiding constructing the graph for every client ( >100 clients are calling it simultaneously). So I am thinking that we can initialize only one base graph, and make it a copy for every client. Then the problem comes, since in the method the client needs use those helper unordered maps, but the data inside the maps are from that original base graph. Even if I use a copy constructor(deep copy) for each graph copy, some graph data is still inconsistent, like the edge_descriptor, for example, I can't use the hashmap with edge_descriptor as key, because this edge_descriptor only points to the memory address of base graph. Best, Emerson

2 1

error when copying blocks into a dynamic_bitset
by Diab Jerius 26 Apr '16

26 Apr '16

Hi, I'm trying to initialize a dynamic_bitset<unsigned char> from a vector of blocks. Here's the code: #include <cstdlib> #include <vector> #include <boost/dynamic_bitset.hpp> typedef boost::dynamic_bitset<unsigned char> BitSet; typedef std::vector<BitSet::block_type> Block; int main(int argc, char* argv[]) { int nbits = atoi( argv[1] ); BitSet bits( nbits ); Block buffer; buffer.resize( bits.num_blocks(), 0xff ); boost::from_block_range(buffer.begin(),buffer.end(), bits ); return 0; } If the bitset size isn't a multiple of sizeof(unsigned char) (here 8) , ~dynamic_bitset() throws an exception. For example: % ./a.out 1 a.out: boost-1.60.0/include/boost/dynamic_bitset/dynamic_bitset.hpp:633: boost::dynamic_bitset<Block, Allocator>::~dynamic_bitset() [with Block = unsigned char; Allocator = std::allocator<unsigned char>]: Assertion `m_check_invariants()' failed. Aborted % ./a.out 8 % ./a.out 15 a.out: boost-1.60.0/boost/dynamic_bitset/dynamic_bitset.hpp:633: boost::dynamic_bitset<Block, Allocator>::~dynamic_bitset() [with Block = unsigned char; Allocator = std::allocator<unsigned char>]: Assertion `m_check_invariants()' failed. Aborted % ./a.out 16 % I see this with 1.59 & 1.60 using either g++ 4.7.2 or Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM 3.5svn) I believe that I'm following the rules for the buffer type and size. Is there something I'm missing? Thanks! Diab

1 0

Compiler errors using boost/program_options with Boost v 1.53 and v 1.59
by Christine Peters 26 Apr '16

26 Apr '16

Dear all, I had to reinstall my boost version as the cluster environment I'm working on has switched from Scientific Linux 6 to CentOS 7. When I'm now compiling my code including the header "#include <boost/program_options>", I will receive the following error message: In file included from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/mpl/aux_/arithmetic_op.hpp:34:0, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/mpl/times.hpp:19, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/mpl/multiplies.hpp:17, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/detail/is_subranged.hpp:17, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/detail/conversion_traits.hpp:21, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/conversion_traits.hpp:13, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/converter.hpp:13, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/numeric/conversion/cast.hpp:33, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/lexical_cast/detail/converter_numeric.hpp:37, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/lexical_cast/try_lexical_convert.hpp:34, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/lexical_cast.hpp:32, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/program_options/value_semantic.hpp:14, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/program_options/options_description.hpp:13, from /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/program_options.hpp:15, from /home/cp652127/EclipseWorkspace/AMD-Geant4.10/amd/externals/g4sipm/sample/include/ParticleSourceMessenger.hh:24, from /home/cp652127/EclipseWorkspace/AMD-Geant4.10/amd/externals/g4sipm/sample/include/AsciiPersistencyHandler.hh:20, from /home/cp652127/EclipseWorkspace/AMD-Geant4.10/amd/externals/g4sipm/sample/include/RunAction.hh:16, from /home/cp652127/EclipseWorkspace/AMD-Geant4.10/amd/externals/g4sipm/sample/src/RunAction.cc:9: /home/phys3aauger/tine/ApeInstalled/External/boost/1_59_0/include/boost/mpl/aux_/include_preprocessed.hpp:37:90: fatal error: boost/mpl/aux_/preprocessed/gcc/ostimes.hpp: No such file or directory # include BOOST_PP_STRINGIZE(boost/mpl/aux_/preprocessed/AUX778076_PREPROCESSED_HEADER) ^ compilation terminated. This fatal error occurs with my own boost installation (version 1.59.0) but also with the system default boost (version 1.53.0). It worked properly on Scientific Linux 6. Now, I'm using gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-4), CPU codename Intel Nehalem EX, LINUX, CENTOS 7.2 environment. I would be very glad if someone could help me. It seems that somehow the AUX778076 parameter defined in "boost/1_59_0/include/boost/mpl/times.hpp" is converted to ostimes during the compilation: I've changed, just for testing reasons!, in file "/boost/1_59_0/include/boost/mpl/times.hpp" the line "#define AUX778076_OP_NAME times" to "#define AUX778076_OP_NAME timestest" and then boost is searching for the correct header "timestest.hpp" but in the case of "#define AUX778076_OP_NAME times" it is searching for "ostimes.hpp" instead of "times.hpp". Thanks in advance for your help! Cheers, Christine

2 2

Typo in BGL Subgraph
by Eisuke Kawashima 23 Apr '16

23 Apr '16

Dear all, I submitted the following to boost-docs but have received no response, so also submitting to boost-users. The last part of Boost Graph Library: Subgraph <http://www.boost.org/doc/libs/release/libs/graph/doc/subgraph.html> (since Boost 1.40) > > struct my_vertex { ... }; > typedef property<vertex_index_t, std::size_t, vertex_prop> vertex_prop; > struct my_edge { ... }; > typedef property<edge_index_t, std::size_t, vertex_prop> edge_prop; should be > > struct my_vertex { ... }; > typedef property<vertex_index_t, std::size_t, my_vertex> vertex_prop; > struct my_edge { ... }; > typedef property<edge_index_t, std::size_t, my_edge> edge_prop; Additionally I want you to note how to modify GraphProperties of boost::subgraph (or whether it is not implemented). Regards, -- Eisuke Kawashima email: e.kawaschima(a)gmail.com

2 2

[interprocess] posix_recursive_mutex constructor never called, fails to init mutex
by Adrian Cheater 23 Apr '16

23 Apr '16

This was submitted as a bug (https://svn.boost.org/trac/boost/ticket/12150) but I don't know that this is actually a boost bug, possibly a OSX or clang issue, or maybe I'm just doing something silly, so I'm hoping someone here can shed some light on the issue. I'm trying to use boost's shared memory system to get data from another application, but while it works fine on Ubuntu 15.10 with boost 1.58 and 1.60 on gcc, clang-3.6 and clang-3.7, it throws an exception when it attempts to acquire the mutex lock on OSX because the mutex has not been initialized. Placing a breakpoint in the constructor for the recursive_lock never gets hit, and I'm not sure why. Hopefully someone with more OSX experience can help me sort this out. Thanks very much for your time.

1 0

Compiler does not give error for missing serialize function
by Elizabeta 22 Apr '16

22 Apr '16

Hi I have the following code : class MyClass { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) {} }; class MyClass2 : public MyClass {}; MyClass2* ss = new MyClass2; std::ofstream ofs("C:\\test.xml"); boost::archive::xml_oarchive oa(ofs); oa & boost::serialization::make_nvp("test",ss); I am serializing trough the derived class pointer. The derived class doesnot have serialize function. The Base have. And I was expecting compiler to give me error that MyClass2 doesnot have serialize function. But this code compiles without errors. I am using vs2010. -- View this message in context: http://boost.2283326.n4.nabble.com/Compiler-does-not-give-error-for-missing… Sent from the Boost - Users mailing list archive at Nabble.com.

3 4

[gsoc16] Summer of Code 2016 shall proceed after all
by Niall Douglas 22 Apr '16

22 Apr '16

Dear Boost, We are very glad to announce that non-Google funding has been found to continue the Summer of Code for the following veteran student projects in Summer 2016: A. Boost Document, mentored by Antony Polukhin. Veteran student: Anurag Ghosh https://anuragxel.github.io/boost-document/ B. Boost.Compute, mentored by Kyle Lutz. Veteran student: Jakub Szuppe https://boostorg.github.io/compute/ C. Boost.Http, mentored by Bjorn Reese. Veteran student: Vinícius dos Santos Oliveira https://boostgsoc14.github.io/boost.http/ All three of these projects shall see a Summer of Code as if it were Google Summer of Code following the same timeline, mentor and student stipends, and progress acceptance criteria. Our thanks to the students and mentors for being so patient during the organisation of this funding. This all happened very quickly and much faster than Boost org processes normally happen - it would not have been possible without the efforts of Jon Kalb and Bryce Adelstein Lelbach, the latter of whom wrote up a great funding request worth reading at https://goo.gl/7v3VMK. Thanks are also due to the Boost Steering Committee for moving so quickly to vote on this, and to Boris Schäling for finding sponsorship for this effort. And finally congratulations to the veteran students! Niall and Bryce --- Boost C++ Libraries Google Summer of Code 2016 admin https://svn.boost.org/trac/boost/wiki/SoC2016

3 2

measuring distance between a point and a segment
by Juliette Pera 22 Apr '16

22 Apr '16

Dear all, I am currently trying to use the boost library in order to measure the shortest distance between a point and a list of segments. I am declaring a segment to which I append the two points of my segment and the I calculate the distance from my point P to the segment. xsegment_t segment; geom::append(segment,geom::make_point(A[0],A[1])); geom::append(segment,geom::make_point(B[0],B[1])); double distance2 = geom::distance(segment,geom::make_point(P[0],P[1])); The issue is that I measure every time the same distance even if the segment is different. Does anyone knows from where that issue can come from? Thank you in advance, Juliette Pera

2 8

[units] division with absolute temperature
by João Leal 19 Apr '16

19 Apr '16

Hello, I'm trying to use absolute temperature in some expressions. Unfortunately I'm having some issues with the compilation. For instance, if I divide an absolute temperature by itself I would expect to get 1 dimensionless, however that will cause a compilation error. #include <iostream> #include <boost/units/absolute.hpp> #include <boost/units/io.hpp> #include <boost/units/quantity.hpp> #include <boost/units/systems/si.hpp> #include <boost/units/systems/si/io.hpp> int main(int argc, char** argv) { using namespace boost::units; quantity<si::temperature> rT(273.15 * si::kelvin); // relative temperature quantity<si::dimensionless> v; v = rT / rT; std::cout << v << std::endl; // 1 dimensionless quantity<absolute<si::temperature> > aT(273.15 * absolute<si::temperature>()); // absolute temperature //v = aT / aT; // uncommenting this line will cause compilation errors //std::cout << v << std::endl; // 1 dimensionless return 0; } If I uncomment the line with v = aT / aT, in ubuntu 15.10 with boost 1.58 and gcc 5.2.1, I get the error: (...) /usr/include/boost/units/operators.hpp:81:5: error: no match for ‘operator/’ (operand types are ‘boost::units::absolute<boost::units::unit<boost::units::list<boost::units::dim<boost::units::temperature_base_dimension, boost::units::static_rational<1l> >, boost::units::dimensionless_type>, boost::units::homogeneous_system<boost::units::list<boost::units::si::meter_base_unit, boost::units::list<boost::units::scaled_base_unit<boost::units::cgs::gram_base_unit, boost::units::scale<10l, boost::units::static_rational<3l> > >, boost::units::list<boost::units::si::second_base_unit, boost::units::list<boost::units::si::ampere_base_unit, boost::units::list<boost::units::si::kelvin_base_unit, boost::units::list<boost::units::si::mole_base_unit, boost::units::list<boost::units::si::candela_base_unit, boost::units::list<boost::units::angle::radian_base_unit, boost::units::list<boost::units::angle::steradian_base_unit, boost::units::dimensionless_type> > > > > > > > > > > >’ and ‘boost::units::absolute<boost::units::unit<boost::units::list<boost::units::dim<boost::units::temperature_base_dimension, boost::units::static_rational<1l> >, boost::units::dimensionless_type>, boost::units::homogeneous_system<boost::units::list<boost::units::si::meter_base_unit, boost::units::list<boost::units::scaled_base_unit<boost::units::cgs::gram_base_unit, boost::units::scale<10l, boost::units::static_rational<3l> > >, boost::units::list<boost::units::si::second_base_unit, boost::units::list<boost::units::si::ampere_base_unit, boost::units::list<boost::units::si::kelvin_base_unit, boost::units::list<boost::units::si::mole_base_unit, boost::units::list<boost::units::si::candela_base_unit, boost::units::list<boost::units::angle::radian_base_unit, boost::units::list<boost::units::angle::steradian_base_unit, boost::units::dimensionless_type> > > > > > > > > > > >’) BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, (typeof_::make<X>()/typeof_::make<Y>())) (...) I could add something like namespace boost { namespace units { template<class Unit, class X, class Y> struct divide_typeof_helper<quantity<absolute<Unit>, X>, quantity<absolute<Unit>, Y> > { typedef typename divide_typeof_helper<X, Y>::type value_type; typedef typename divide_typeof_helper<Unit, Unit>::type unit_type; typedef quantity <unit_type, value_type> type; }; } } but that would not work in more complex examples, e.g.: #include <boost/units/systems/si/codata/physico-chemical_constants.hpp> (...) using namespace boost::units::si::constants::codata; typedef boost::mpl::divides<boost::units::energy_dimension, boost::units::amount_dimension>::type Ea_dimension; typedef boost::units::unit<Ea_dimension, boost::units::si::system> Ea; quantity<Ea> ea(0); auto x = ea / (R * aT); Any help would be most appreciated, João Leal

2 2

Boost statechart, how can i transit to previous state using deep_history or shallow history
by juls 16 Apr '16

16 Apr '16

I have a difficulty in understanding the boost statechart history functionality. I have the following state machine. struct InButtonPressed : sc::event<InButtonPressed> {}; struct OutButtonPressed : sc::event<OutButtonPressed> {}; struct InButtonPressed : sc::event<InButtonPressed> {}; struct InputProceed: sc::event<InputProceed> {}; struct OutputProceed: sc::event<OutputProceed> {}; struct CancelEvent: sc::event<CancelEvent> {}; struct Proceed: sc::event<Proceed> {}; struct Revert: sc::event<InputProceed> {}; struct RH_StateMachine : bsc::state_machine< RH_StateMachine, Idle > {}; struct Idle : bsc::state< Idle, RH_StateMachine> { Idle(my_context ctx) : my_base(ctx){ std::cout << "[+] Idle" << std::endl; } ~Idle(){std::cout << "[-] leaving Idle state... \n";} typedef boost::mpl::list< bsc::transition< InButtonPressed, Input>, bsc::transition< OutButtonPressed, Output> >reactions; }; struct Input : bsc::state< Input, RH_StateMachine> { Input(my_context ctx) : my_base(ctx){ std::cout << "[+] Input" << std::endl; } ~Input(){std::cout << "[-] leaving Input state... \n";} typedef boost::bsc::transition< CancelEvent, Cancel> >reactions; }; struct Output : bsc::state< Output, RH_StateMachine> { Output(my_context ctx) : my_base(ctx){ std::cout << "[+] Output" << std::endl; } ~Output(){std::cout << "[-] leaving Output state... \n";} typedef boost::bsc::transition< CancelEvent, Cancel> >reactions; }; struct Cancel::bsc::state<Cancel, RH_StateMAchine>{ Cancel(my_context ctx) : my_base(ctx){ std::cout << "[+] Cancel" << std::endl; } ~Cancel(){std::cout << "[-] leaving Cancel state... \n";} typedef boost::mpl::list< bsc::transition< Proceed, CanceledConfirmed>, bsc::transition< Revert, *"PREVIOUS_STATE"*> >reactions; }; How do i implement transitioning to previous state using deep_history or shallow history, when i can transit to a state from many different states? In the above state machine i want to transit from Cancel state to the previous state when the revert event is triggered, but i have already transited in Cancel state from either Input or Output state... Thank you in advance. -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-statechart-how-can-i-transit-to-pr… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

option to let program_options remove the flags it recognises
by Brice Rebsamen 14 Apr '16

14 Apr '16

I believe it would be good to add an option to program_options to tell it to remove the flags it recognizes. That would allow to make it work with some other parsers such as gflags etc.

1 0

[property_tree] Json parser with invalid JSON string
by Sébastien Gallou 13 Apr '16

13 Apr '16

Hi all, I experience a strange behavior of parsing non-JSON data with JSON parser. I can create a property_tree from a simple non-JSON string, without exception. And serializing back the result throws : boost::property_tree::ptree m_tree; // Non-JSON to ptree using JSON parser std::istringstream is("1"); // Simple value, non-JSON boost::property_tree::json_parser::read_json(is, m_tree); // ==> No exception, I now have a valid ptree object. // ptree back to JSON std::ostringstream buf; boost::property_tree::json_parser::write_json(buf, m_tree, false); // ==> Exception How can I filter input values that will not be serializable later (= verify that input value is well JSON formatted) ? Thanks for your help, S. Gallou

1 0

boost with c++11
by Christian Meesters 13 Apr '16

13 Apr '16

Dear All, Perhaps my question has been covered already, in this case a pointer to the relevant docs / thread would be highly appreciated. However, I have not been able to find the answer on my question: My code makes use of the C++11 standard and the standard libraries. I feel tempted to employ more current features, also beyond C++11, eventually. When downloading the boost 1.60.0 release and compiling with cxxflags='-std=c++11 -march=native' toolset=gcc linkflags=-stdlib=libc++ supplied to b2 compilation of my software (with gcc 5.3.0) leads to a number of warning messages and deprecation messages related to unused variables or redifined symbols, e.g.: - boost_1_60_0/include/boost/system/error_code.hpp:223:36: warning: ‘boost::system::native_ecat’ defined but not used [-Wunused-variable] static const error_category & native_ecat = system_category(); - /boost_1_60_0/include/boost/iostreams/chain.hpp:256:14: warning: ‘template<class> class std::auto_ptr’ is deprecated [-Wdeprecated-declarations] std::auto_ptr<streambuf_t> In file included from /cluster/gcc/5.3.0/include/c++/5.3.0/memory:81:0, from trunk/src/ngs_io.cpp:8: /cluster/gcc/5.3.0/include/c++/5.3.0/bits/unique_ptr.h:49:28: note: declared here template<typename> class auto_ptr; - /usr/include/boost/iostreams/detail/adapter/concept_adapter.hpp:35:7: note: ‘boost::iostreams::detail::concept_adapter<boost::iostreams::basic_gzip_decompressor<> >::concept_adapter(const boost::iostreams::detail::concept_adapter<boost::iostreams::basic_gzip_decompressor<> >&)’ is implicitly deleted because the default definition would be ill-formed: class concept_adapter { ^ etc. And most importantly this error: /usr/include/boost/iostreams/detail/adapter/concept_adapter.hpp:35:7: error: use of deleted function ‘boost::iostreams::basic_gzip_decompressor<>::basic_gzip_decompressor(const boost::iostreams::basic_gzip_decompressor<>&)’ My g++ compiler flags (other than output and source file) are: -c -fopenmp -O3 -march=native -Wall -ansi -pedantic -Wuninitialized -std=c++11 The code compiles fine with a git pull from May last year, yet I do not recall what I have done differently. So, can anybody tell me how to set up boost, such that compilation and linking against C++11 std-libraries works? I understand that Best regards, Christian Meesters

1 0

Boost Log: I can't see syslog messages sent via boost syslog.
by Anatoly G 11 Apr '16

11 Apr '16

Dear members, I have a question about Boost syslog. I"m beginner Boost user. I created attached code and can't understand why it doesn't work. I execute my code on linux Kubuntu 3.13.0 After execution I"m looking for test strings in syslog file: grep "Test" /var/log/syslog But I don't see any line. I tried to execute commands from shell logger "Test from shell" logger -n 127.0.0.1 -t myapp -p user.notice "Test from shell" I see these lines after executing grep on /var/log/syslog I tried to initialize syslog_backend with boost::log::keywords::use_impl = boost::log::sinks::syslog::native instead of boost::log::keywords::use_impl = boost::log::sinks::syslog::udp_socket_based but then I get compile message, native not defined. I found BOOST_LOG_USE_NATIVE_SYSLOG macro which should be defined during Boost build, but I don't understand how to activate this macro in boost build. Can you please suggest what is the problem? Regards, Anatoly.

1 0

[accumulators] nan error of mean
by Ireneusz Szcześniak 08 Apr '16

08 Apr '16

Hi, I'm using Boost.Accumulators to calculate the standard error of a sample mean, and I'm getting a nan (not a number) as a result, while I should be getting a zero or some number close to it. I boiled down the problem to a small sample that I'm attaching. I would appreciate it if someone could help me out here. Thanks, Irek

1 0

[Boost.Container] flat_set constructor with ordered_unique_range
by dariomt＠gmail.com 08 Apr '16

08 Apr '16

Hi list, If I use the flat_set constructor passing ordered_unique_range, does the library assert in debug mode that the passed data range is indeed ordered and unique? I don't seem to find such assert, but I think it would be very useful, to catch programmer errors. Regards

3 2

seekable input filter definition
by Cherotek Music 07 Apr '16

07 Apr '16

Hey, I'm new to boost and need a seekable input filter that will operate on bytes read from an ifstream. This is what I currently have: struct my_filter : boost::iostreams::seekable_filter{ template<typename Source> int get(Source& src) { int byte = boost::iostreams::get(src); if(byte != EOF && byte != boost::iostreams::WOULD_BLOCK) { // Do something with byte } return byte; } template<typename Sink> bool put(Sink&, char) { // No need to actually implement put because this filter is only used with ifstream return true; } template<typename T> std::streampos seek(T& t, boost::iostreams::stream_offset off, std::ios_base::seekdir way, std::ios_base::openmode which = std::ios_base::in | std::ios_base::out) { return boost::iostreams::seek(t, off, way, which); }}; It works but I would like to get rid of the useless put method. The boost documentation here http://www.boost.org/doc/libs/1_60_0/libs/iostreams/doc/concepts/filter.html says there is an InputSeekableFilter refinement of Filter but I can't seem to understand how to use it (there are no input_seekable_filter_tag or input_seekable_filter structs that I could use). Thanks

2 2

[asio] Error code by io_service.run(ec) not the same as in async_read_handler
by Michael Weise 06 Apr '16

06 Apr '16

Hello, my question is about the error code returned by io_service.run_one. I expect the error code returned by run_one to be the same as the one in the handler - but they are not. Inside my handler I check the error code, which is equal to operation aborted: void ConnectionBase::ReadUntilHandler( const boost::system::error_code & ec, std::size_t bytes_transferred) { // ec == boost::asio::error::operation_aborted ... } At some other point I call io_service.run_one, which calls the above handler: ... m_asioService.run_one(ec); assert(ec == boost::asio::error::operation_aborted); ... The assertion fails - for some reason the error code is not the same as in the handler. What's the reason for this? Maybe my assumtion that run_one(ec) returns the error code of the handler is simply wrong? If so, what error does io_service.run(ec) actually report? Thanks for help, Michael PS: boost::asio version is 1.56.0

2 1

Using Boost.ASIO with Boost.Coroutine2
by Carlos Ferreira 06 Apr '16

06 Apr '16

Hello to all! Is it possible to use Boost.ASIO with Boost.Coroutine2? For what I understood upon reading the documentation, using Boost.Corouine2 is preferable, due to issues present in Coroutine that were solved in Coroutine2. The documentation is scarse and I'm having some trouble in making things work. Thank you! -- Carlos Miguel Ferreira Researcher at Telecommunications Institute Aveiro - Portugal Work E-mail - cmf(a)av.it.pt Skype & GTalk -> carlosmf.pt(a)gmail.com LinkedIn -> http://www.linkedin.com/in/carlosmferreira

1 0

[Q] piecewise_construct for boost::container::map::emplace()
by dave m. 05 Apr '16

05 Apr '16

I recently tried (but failed) to use boost::container::map::emplace() with the piecewise_construct tag to forward constructor args as tuples. After some fiddling around, it appears that piecewise_construct is not implemented for boost::container::detail::pair (see boost/container/detail/pair.hpp:151). I couldn't find any discussion in the mailing list archives. Is there a good reason not to use emplace() this way, or unreasonable difficulty in implementing piecewise_construct for pair<U,V>? (I ended up making constructors for my K, V elements that take tuples<>, so emplace() is working for me, but I'm not completely sure that I have avoided all possible copy/move operations. Using gcc-4.9.2, fwiw.) Thanks, dhm

1 0

Re: [Boost-users] [type traits] Using Boost.Geometry with Clang/LLVM & VC14
by degski 05 Apr '16

05 Apr '16

I've successfully compiled Boost 1.61.0 Beta 1 Release Candidate with VC14 (no Clang-Cl.exe) in debug and release. This has exposed the "hacks" I mentioned earlier in this thread. When compiling my test program with Clang-Cl (latest) and VC14, the following errors are reported. (in my hacks I just added std:: to the boost code in the appropriate places, untill Clang stopped complaining. 1>------ Rebuild All started: Project: test, Configuration: Debug x64 ------ 1> In file included from test.cpp:16: 1> In file included from z:\vc\x64\include\boost/geometry.hpp:17: 1> In file included from z:\vc\x64\include\boost/geometry/geometry.hpp:28: 1> In file included from z:\vc\x64\include\boost/geometry/core/coordinate_type.hpp:23: 1> In file included from z:\vc\x64\include\boost/geometry/util/promote_floating_point.hpp:19: 1> In file included from z:\vc\x64\include\boost/type_traits.hpp:62: 1>z:\vc\x64\include\boost/type_traits/has_nothrow_assign.hpp(64,7): error : no template named 'is_assignable'; did you mean 'std::is_assignable'? 1> BOOST_HAS_NOTHROW_ASSIGN(T) 1> ^ 1> z:\vc\x64\include\boost/type_traits/intrinsics.hpp(199,96) : note: expanded from macro 'BOOST_HAS_NOTHROW_ASSIGN' 1> # define BOOST_HAS_NOTHROW_ASSIGN(T) (__has_nothrow_assign(T) && !is_volatile<T>::value && is_assignable<T&, const T&>::value) 1> ^ 1> C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\type_traits(577,9) : note: 'std::is_assignable' declared here 1> struct is_assignable 1> ^ 1> In file included from test.cpp:16: 1> In file included from z:\vc\x64\include\boost/geometry.hpp:17: 1> In file included from z:\vc\x64\include\boost/geometry/geometry.hpp:28: 1> In file included from z:\vc\x64\include\boost/geometry/core/coordinate_type.hpp:23: 1> In file included from z:\vc\x64\include\boost/geometry/util/promote_floating_point.hpp:19: 1> In file included from z:\vc\x64\include\boost/type_traits.hpp:63: 1>z:\vc\x64\include\boost/type_traits/has_nothrow_constructor.hpp(26,84): error : no template named 'is_default_constructible'; did you mean 'std::is_default_constructible'? 1> template <class T> struct has_nothrow_constructor : public integral_constant<bool, BOOST_HAS_NOTHROW_CONSTRUCTOR(T)>{}; 1> ^ 1> z:\vc\x64\include\boost/type_traits/intrinsics.hpp(193,80) : note: expanded from macro 'BOOST_HAS_NOTHROW_CONSTRUCTOR' 1> # define BOOST_HAS_NOTHROW_CONSTRUCTOR(T) (__has_nothrow_constructor(T) && is_default_constructible<T>::value) 1> ^ 1> C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\type_traits(539,9) : note: 'std::is_default_constructible' declared here 1> struct is_default_constructible 1> ^ 1> In file included from test.cpp:16: 1> In file included from z:\vc\x64\include\boost/geometry.hpp:17: 1> In file included from z:\vc\x64\include\boost/geometry/geometry.hpp:28: 1> In file included from z:\vc\x64\include\boost/geometry/core/coordinate_type.hpp:23: 1> In file included from z:\vc\x64\include\boost/geometry/util/promote_floating_point.hpp:19: 1> In file included from z:\vc\x64\include\boost/type_traits.hpp:74: 1>z:\vc\x64\include\boost/type_traits/has_trivial_assign.hpp(28,7): error : no template named 'is_assignable'; did you mean 'std::is_assignable'? 1> BOOST_HAS_TRIVIAL_ASSIGN(T) 1> ^ 1> z:\vc\x64\include\boost/type_traits/intrinsics.hpp(187,96) : note: expanded from macro 'BOOST_HAS_TRIVIAL_ASSIGN' 1> # define BOOST_HAS_TRIVIAL_ASSIGN(T) (__has_trivial_assign(T) && !is_volatile<T>::value && is_assignable<T&, const T&>::value) 1> ^ 1> C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\type_traits(577,9) : note: 'std::is_assignable' declared here 1> struct is_assignable 1> ^ Then there are more errors, but they are either the same as the ones I've reported earlier, or the result of the above errors. Have a good day, degski

4 9

Boost.Fit review Mars 3-20 result
by Vicente J. Botet Escriba 03 Apr '16

03 Apr '16

Hi, I will be out for two weeks and I wanted to at least give the result of the Boost.Fit library review even if I would need more time to have a complete report. Summary ======= The review of the proposed Boost.Fit library ended on Mars 20, 2016. The verdict is: Conditional acceptance (a new review is needed) There were too much concerns about the documentation and what exactly this library is proposing and not enough reviews commenting the design, code and test for each one of the proposed functions. From the review discussion I deduce that there is some interest in the library, and that some people don't understand yet what the library is proposing. Paul has started already to take in account some if the issues raised during the review and a lot of them must be resolved before we re-try a new review. There were some discussion about the name of the library, but there were no consensus. Paul is free to change the name of his library and see how people react. On behalf of the Boost community, I would like to thank Paul Fultz for the work he has put into the Fit library so far. I encourage him to continue to evolve this library and to bring it back for a new review. We had seven 6 formal votes, and 2 more votes without a complete review abbreviated here: Steaven Watanabe: No in his current state Zach Laine : Conditinal acceptance Krzysztof Jusiak: Accepted Artyom Beilis : Rejected Peter Dimov : Accepted (no review) Manuel Sancher : Accepted (no review) Rob Stewart : Conditinal acceptance ??? Louis Dionne : Conditinal acceptance There were other people that participated on the review giving their advice respect to a specific issue. I thank each of these reviewers, and indeed everyone who invested some time participating in the discussions. If you feel that I have misrepresented your position, or have omitted or garbled an important point, please respond: the archived mail thread should accurately reflect the will of the community, even if this message does not. Detailed Report =============== You will need to wait yet for a month before I will be able to do it. On the mean time there are a lot of issues that must be addressed and that are part of the github issues. For more information see: Github:https://github.com/pfultz2/Fit/tree/boost Issues:https://github.com/pfultz2/Fit/issues Documentation:http://pfultz2.github.io/Fit/doc/html/ Hopping this helps, Vicente Botet Escriba

1 0

[Python] exec_file double delete
by Albert Yiamakis 03 Apr '16

03 Apr '16

Hello, Working with Boost 1.58, I am using Boost.Python to interpret python code. eval() and exec() are working as expected, however exec_file results on a double delete upon finishing reading the script. This can be observed in the following minimal: #include <boost/python.hpp> int main() { Py_Initialize(); boost::python::exec_file("foo.py"); } where foo.py contains a single line: print "hello" hello is printed on the screen - i.e. the script is completed before the crash. Valgrind also finds a number of invalid reads in the exec_file line before an invalid free/delete. Is there something I'm missing in exec_file usage, or do you think there might be a mismatch of dependencies? (using boost and python both from my package manager). Thank you, Albert

1 0

Re: [Boost-users] Weird code in lockfree::queue::reserve (compilation error)
by Bjorn Reese 02 Apr '16

02 Apr '16

On 04/02/2016 05:08 PM, Aurelien Regat-Barrel wrote: > I'm trying to use lockfree::queue, and I get a compiler error when calling reserve(). The following code does not compile with VC++ 2015: What error are you getting? Have you checked that the type T you use as the template argument to lockfree::queue<T> fulfills the documented requirements? > void reserve(size_type n) > { > pool.template reserve<true>(n); > } > > And indeed... what does this syntax mean: "pool.template reserve"? You can see it here: The use of the template keyword above is correct. It is used to help the C++ compiler resolve an otherwise ambiguous syntax. See the section "The template disambiguator for dependent names" at: http://en.cppreference.com/w/cpp/language/dependent_name

2 1

Weird code in lockfree::queue::reserve (compilation error)
by Aurelien Regat-Barrel 02 Apr '16

02 Apr '16

Hello, I'm trying to use lockfree::queue, and I get a compiler error when calling reserve(). The following code does not compile with VC++ 2015: void reserve(size_type n) { pool.template reserve<true>(n); } And indeed... what does this syntax mean: "pool.template reserve"? You can see it here: http://www.boost.org/doc/libs/1_60_0/boost/lockfree/queue.hpp Regards, Aurélien Regat-Barrel

1 0

Boost.Spirit's Greedy Fundamental Type Parsers
by Daniel Hofmann 01 Apr '16

01 Apr '16

Suppose I want to parse a list of ";"-separated floating point pairs with "," being the pair separator as in "1,2;3,4". Following this list comes a string literal representing a file extension, such as ".txt". Therefore what I want to successfully parse input like the following: 1,2;3,4.txt (For the record, the input could also be 1.1,2.2;3.3,4.4.txt) The parser I came up with is the 1:1 translation of above's description into the Spirit DSL and shows Spirit's expressive power: ((double_ % ",") % ";") >> ".txt" Unfortunately, the parser fails on the input with the integral values above. Why? Because the fundamental parser for double_ greedily matches on the "4." in "4.txt". Changing the "4" to "4.0" as in 1,2;3,4.0.txt parses successfully (but is not an option as it requires the user to always add a trailing ".0" in case the last digit is integral. I read about Spirit's DSL mapping to Parsing Expression Grammar (PEG) with the choice operator | being evaluated in order. So the next logical step for me was to try making use of it and adapting the parser: (((int_ | double_) % ",") % ";") >> ".txt" which works on 1,2;3,4.txt but no longer on 1,2;3,4.0.txt Is there a way to adapt the parser to handle both cases? I asked this on IRC and got the answer to try a solution based on ((double_ >> ".") | (int_ >> ".")) >> "txt" but when I use use this to parse "4.txt" into a std::vector<double> via parse(first, last, ((double_ >> ".") | (int_ >> ".")) >> "txt", into); the vector contains: {4, 4} and its size() is 2, which I can make no sense of at all (but this may be a different problem). Cheers, Daniel J H

3 4

Is there any ongoing work to support toolset Clang 3.7 with Microsoft CodeGen (v140_clang_3_7)
by forumer＠smartmobili.com 01 Apr '16

01 Apr '16

Hi, Microsoft has released a new toolset mixing clang for the code analysis part and VS2015 for the code generation. https://blogs.msdn.microsoft.com/vcblog/2015/12/04/clang-with-microsoft-cod… https://blogs.msdn.microsoft.com/vcblog/2016/01/20/clang-with-microsoft-cod… Is there any ongoing work to support this new compiler and properly support it ? Thanks

1 0