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Re: [boost] Boost.Local Review (Nov 10, 2011 to Nov 19, 2011)
by Lorenzo Caminiti 14 Nov '11

14 Nov '11

Hello all, I have received a couple of questions on Boost.Local and I will answer them on the ML. On Mon, Nov 14, 2011 at 4:20 AM, Andrzej Krzemienski <akrzemi1(a)gmail.com> wrote: > 1. Can Boost.Local be used to create global functions? No, Boost.Local macros need to be used at local scope. If it were important to use the functionality of Boost.Local at global scope, it _might_ be possible to do so but another set of macros (BOOST_GLOBAL_?) will have to be defined for that. Does anyone see a need to use LOCAL_EXIT, LOCAL_BLOCK, or LOCAL_FUNCTION at global scope? If so, why? > 2. For Local Exits, is it possible not to bind any variable (because I will > only be calling global functions): > > int runCommand() { > ::DisplayWaitCursor(); > BOOST_LOCAL_EXIT( /*nothing*/ ) { > ::DisplayNormalCursor(); > } BOOST_LOCAL_EXIT_END; > > DoALongLastingOperation(); > } Yes, you can do this. However, the most portable syntax is to use void for the empty parameter list: https://svn.boost.org/svn/boost/sandbox/local/libs/local/doc/html/boost_loc… For example: #include <boost/local/exit.hpp> #include <iostream> void f() { std::cout << "f" << std::endl; } int main() { ::f(); BOOST_LOCAL_EXIT(void) { ::f(); } BOOST_LOCAL_EXIT_END return 0; }; This compiles and it prints "f" twice (at main entry and exit). HTH, --Lorenzo

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[1.48][flyweight] regression in release branch
by JOAQUIN M. LOPEZ MUÑOZ 13 Nov '11

13 Nov '11

Hi, Sorry for not having tracked this before. There's a trivial regression in Boost.Flyweight due to a change of namespace name in Boost.Interprocess: https://svn.boost.org/trac/boost/changeset/75464 OK to commit to branch? Joaquín M López Muñoz Telefónica Digital ________________________________ Este mensaje se dirige exclusivamente a su destinatario. Puede consultar nuestra política de envío y recepción de correo electrónico en el enlace situado más abajo. This message is intended exclusively for its addressee. We only send and receive email on the basis of the terms set out at. http://www.tid.es/ES/PAGINAS/disclaimer.aspx

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[iostreams][io_state_savers] Request for interest in some ios_base basic utilities
by Vicente J. Botet Escriba 12 Nov '11

12 Nov '11

Hi, I'm a beginner of the standard IOStream library. While restructuring Boost.Chrono I/O I have find some classes that could be of general use (if the design is correct, of course). The first one is quite simple, is used to define manipulators with parameters. Instead of defining a class and the correspondent stream inserters and extractors the manip template class do all this at once. It can be used as follows class mendl: public manip<mendl> { public: explicit mendl(size_t how_many) : count(how_many) {} template <typename out_stream> void operator()(out_stream &out) const { for (size_t line = 0; line < count; ++line) { out.put(out.widen('\n')); } out.flush(); } private: size_t count; }; Now mendl can be use to insert n new lines at once as follows cout << mendl(3); The second one is an ios specific smart pointer ios_base_state_ptr (based on the use of ios_base::pword and ios_base::xalloc). The class ios_base_state is a ios_base_state_ptr that can not be null. It can be used like struct MyData { std::string time_fmt; std::string duration_fmt; }; std::string get_time_fmt(std::ios_base & ios) { return ios_base_state<MyData>(ios)->time_fmt; } ios_base_state stores a new MyData in the ios if not already stored and provides an smart pointer interface to it. The 3rd one (ios_base_flags) uses the ios_base::iword and xalloc to provide access to specific ios flags. It can be used as follows: class fmt_masks : ios_base_flags<fmt_masks> { typedef ios_base_flags<fmt_masks> base_type; public: fmt_masks(std::ios_base& ios): base_type(ios) {} enum type { uses_symbol = 1 << 0, uses_local = 1 << 1 }; }; Usage of this class can be duration_style::type get_duration_style(std::ios_base& ios) { return (fmt_masks(ios).flags() & fmt_masks::uses_symbol) ? duration_style::symbol : duration_style::prefix; } The interface and the implementation of these classes is attached. Do you see a design flag on these classes? If not, do you think these kind of utilities could be added to boost? If yes, could these be merged with Boost.io_state_savers or Boost.IOStreams to form a larger io utilities libraries? Best, Vicente

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Are some of the trunk regression tests running in C++0x mode when they shouldn't be?
by Richard Webb 11 Nov '11

11 Nov '11

Looking at the Trunk regression tests, it appears that some of the GCC tests are running in C++0x mode when they shouldn't be. for example: Large numbers of the Sandia-gcc-3.4.6 tests are failing with the error: unrecognized command line option "-std=c++0x" If you look at the test results for assign, there are rvalue-reference related errors in toolsets which shouldn't have them. Looks like -std=c++0x is being specified when it shouldn't for some reason? Is something broken, or am i imagining it? Thanks, Richard Webb

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leak in win32 detail::basic_condition_variable
by Kenneth Porter 10 Nov '11

10 Nov '11

I'm finding that an element in the CV's generation_list is left orphaned sometimes when the CV is destroyed. I'm running Visual Leak Detector and it gives this stack dump of the allocation point of the leaked object: c:\devel\boost\boost_1_46_1\boost\thread\win32\condition_variable.hpp (172): boost::detail::basic_condition_variable::get_wait_entry c:\devel\boost\boost_1_46_1\boost\thread\win32\condition_variable.hpp (211): boost::detail::basic_condition_variable::do_wait<boost::unique_lock <boost::mutex> > + 0xC bytes c:\devel\boost\boost_1_46_1\boost\thread\win32\condition_variable.hpp (369): boost::condition_variable_any::wait<boost::unique_lock<boost::mutex> > c:\devel\boost\boost_1_46_1\boost\thread\win32\condition_variable.hpp (374): boost::condition_variable_any::wait<boost::unique_lock <boost::mutex>,boost::_bi::bind_t<bool,boost::_mfi::cmf0 <bool,bounded_buffer<Axis::Report> >,boost::_bi::list1<boost::_bi::value <bounded_buffer<Axis: + 0x1B bytes I compared the source file against trunk and it hasn't changed.

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asio ipv6 anycast
by Julian Faude 10 Nov '11

10 Nov '11

Hi, I am working on a project which depends on IPv6 anycast. In linux IPv6 anycast is available through a socket options called IPV6_JOIN_ANYCAST and IPV6_LEAVE_ANYCAST. Like the multicast option it's based on the ipv6_mreq struct. If I'm not mistaken there is no ipv6 anycast socket option in asio. Am I right? Is anybody working on it? Best, Julian

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[Test] Darwin Intel 11.1
by Belcourt, K. Noel 09 Nov '11

09 Nov '11

Hi, I've attached a patch that appears to fix problems with about 20 Boost libraries on trunk that depend on Boost.Test. This patch simply removes an argument to format_report(). The trunk tests (http://www.boost.org/development/tests/trunk/developer/summary.html ) currently reflect this patch. I've added this patch to the nightly trunk testing patch script until such time as we get this committed to trunk. -- Noel

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Fw: [atomic] review results
by Peter Dimov 08 Nov '11

08 Nov '11

-----Original Message----- From: Peter Dimov Sent: Monday, November 07, 2011 22:38 To: Helge Bahmann Subject: Re: [boost] [atomic] review results Helge Bahmann wrote: > yes makes sense -- there was a concern raised by Andrey Semashev that the > spinlock pool as implemented and used by shared_ptr presently may fail on > Windows due to the pool being non-unique (not had a chance to test this > yet), > and I have found a way to produce a similar failure using dlopen, atomics > private to shared libraries and RTLD_LOCAL -- currently I am therefore > leaning on creating a shared library just for the spinlock pool, but since > you wrote the initial implementation maybe you could comment as well? This is a problem in principle, but requiring all users of shared_ptr to link to a shared library is a non-starter. I wouldn't use such a shared_ptr, and I doubt many others will. And I wouldn't be surprised if this sentiment applies to Boost.Atomic as well.

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[parameter] type requirement compiler error
by lcaminiti 08 Nov '11

08 Nov '11

Hello all, The following parameter type requirement: (required (graph, *) ) (optional (root_vertex, (typename boost::graph_traits<graph_type>::vertex_descriptor), *boost::vertices(graph).first) ) Generates a GCC error: dfs.05.cpp:40: error: ‘graph_type’ was not declared in this scope Detailed code and error below. In fact, if I look at the code after pp, I can see that graph_type is define only after the type requirement is checked... why? What am I doing wrong? Thanks a lot! --Lorenzo #include <boost/graph/adjacency_list.hpp> #include <boost/graph/depth_first_search.hpp> #include <boost/range/irange.hpp> #include <boost/pending/indirect_cmp.hpp> #include <boost/parameter.hpp> #include <iostream> namespace graphs { BOOST_PARAMETER_NAME(graph) BOOST_PARAMETER_NAME(visitor) BOOST_PARAMETER_NAME(root_vertex) BOOST_PARAMETER_NAME(index_map) BOOST_PARAMETER_NAME(color_map) template< typename Size, typename IndexMap > boost::iterator_property_map<boost::default_color_type*, IndexMap, boost::default_color_type, boost::default_color_type&> default_color_map ( Size const& num_vertices, IndexMap const& index_map ) { std::vector<boost::default_color_type> colors(num_vertices); return &colors[0]; } BOOST_PARAMETER_FUNCTION( (void), depth_first_search, tag, (required (graph, *)) (optional (visitor, *, boost::dfs_visitor<>()) (root_vertex, (typename boost::graph_traits<graph_type>::vertex_descriptor), *boost::vertices(graph).first) (index_map, *, boost::get(boost::vertex_index, graph)) (in_out(color_map), *, default_color_map(boost::num_vertices(graph), index_map)) ) ) { std::cout << "here\n"; boost::depth_first_search(graph, boost::visitor(visitor). color_map(color_map).root_vertex(root_vertex). vertex_index_map(index_map)); } } // namespace graphs template< typename TimeMap > class dfs_time_visitor : public boost::default_dfs_visitor { typedef typename boost::property_traits< TimeMap >::value_type T; public: dfs_time_visitor(TimeMap dmap, TimeMap fmap, T& t) : dmap_(dmap), fmap_(fmap), time_(t) {} template< typename V, typename G > void discover_vertex ( V u, G const& g ) const { put(dmap_, u, time_++); } template< typename V, typename G > void finish_vertex ( V u, G const& g ) const { put(fmap_, u, time_++); } TimeMap dmap_; TimeMap fmap_; T& time_; }; using namespace boost; int main ( ) { typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS> G; typedef boost::graph_traits<G>::vertices_size_type size_type; enum {u, v, w, x, y, z, N}; char names[] = {'u', 'v', 'w', 'x', 'y', 'z'}; typedef std::pair<int, int> E; E edges[] = {E(u, v), E(u, x), E(x, v), E(y, x), E(v, y), E(w, y), E(w, z), E(z, z)}; G g(edges, edges + sizeof(edges) / sizeof(E), N); std::vector<size_type> dtime(boost::num_vertices(g)); std::vector<size_type> ftime(boost::num_vertices(g)); size_type t = 0; dfs_time_visitor<size_type*> vis(&dtime[0], &ftime[0], t); graphs::depth_first_search(g, vis); std::vector<size_type> dorder(N); boost::integer_range<size_type> r(0, N); std::copy(r.begin(), r.end(), dorder.begin()); std::sort(dorder.begin(), dorder.end(), boost::indirect_cmp<size_type*, std::less<size_type> >(&dtime[0])); std::cout << "order of discovery: "; for(int i = 0; i < N; ++i) std::cout << names[dorder[i]] << " "; std::cout << std::endl; std::vector<size_type> forder(N); std::copy(r.begin(), r.end(), forder.begin()); std::sort(forder.begin(), forder.end(), boost::indirect_cmp<size_type*, std::less<size_type> >(&ftime[0])); std::cout << "order of finish: "; for(int i = 0; i < N; ++i) std::cout << names[forder[i]] << " "; std::cout << std::endl; return 0; } $ g++ -Wall -I../../../../../boost-trunk.cygwin dfs.05.cpp dfs.05.cpp:40: error: ‘graph_type’ was not declared in this scope dfs.05.cpp:40: error: template argument 1 is invalid dfs.05.cpp:40: error: expected `::' before ‘,’ token dfs.05.cpp:40: error: expected identifier before ‘,’ token dfs.05.cpp:40: error: template argument 3 is invalid dfs.05.cpp:40: error: expected `::' before ‘{’ token dfs.05.cpp:40: error: expected class-name before ‘{’ token ../../../../../boost-trunk.cygwin/boost/parameter/preprocessor.hpp: In instantiation of ‘boost::parameter::aux::argument_pack<graphs::boost_param_params_40depth_first_search<int>, const boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::no_property, boost::no_property, boost::no_property, boost::listS>, const dfs_time_visitor<main::size_type*>, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_>’: dfs.05.cpp:88: instantiated from here ../../../../../boost-trunk.cygwin/boost/parameter/preprocessor.hpp:157: error: no type named ‘parameter_spec0’ in ‘struct graphs::boost_param_params_40depth_first_search<int>’ ../../../../../boost-trunk.cygwin/boost/parameter/preprocessor.hpp:158: error: no type named ‘parameter_spec0’ in ‘struct graphs::boost_param_params_40depth_first_search<int>’ ../../../../../boost-trunk.cygwin/boost/parameter/preprocessor.hpp: In instantiation of ‘boost::parameter::aux::argument_pack<graphs::boost_param_params_40depth_first_search<int>, const boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::no_property, boost::no_property, boost::no_property, boost::listS>, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_>’: dfs.05.cpp:88: instantiated from here ../../../../../boost-trunk.cygwin/boost/parameter/preprocessor.hpp:157: error: no type named ‘parameter_spec0’ in ‘struct graphs::boost_param_params_40depth_first_search<int>’ ../../../../../boost-trunk.cygwin/boost/parameter/preprocessor.hpp:158: error: no type named ‘parameter_spec0’ in ‘struct graphs::boost_param_params_40depth_first_search<int>’ dfs.05.cpp: In function ‘int main()’: dfs.05.cpp:88: error: no matching function for call to ‘depth_first_search(main()::G&, dfs_time_visitor<size_type*>&)’ -- View this message in context: http://boost.2283326.n4.nabble.com/boost-parameter-type-requirement-compile… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[1.48 lexical_cast] Illegal Derefence
by Olaf van der Spek 08 Nov '11

08 Nov '11

Hi, This does an illegal dereference in boost\lexical_cast.hpp(1357): if ( Traits::eq(minus,*start) ) #include <boost/lexical_cast.hpp> #include <boost/range/iterator_range.hpp> int main() { boost::iterator_range<const char*> v; boost::lexical_cast<int>(v); } -- Olaf

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