February 2006 - Boost-users

[Boost][Tuples] Compilation error VC7.1 w/ enum in namespace
by Marc Viala 07 Feb '06

07 Feb '06

Hi, I've just tried to define a boost::tuples::tuple with an enum in a namespace, see code hereafter: \code namespace adv { namespace rbt { enum MyType { Type_1, Type_2 } ; } } boost::tuples::tuple<size_t, adv::rbt::MyType> t ; \endcode But during the compilation step, I've got an error w/ BOOST 1.33.1 and VC7.1 like that: "error MyType not defined". Remark: If the enum is not defined in a namespace, there are no compilation errors. Is there any workaround to deals with this compilation error? Thanks in advance Marc Viala mailto:mviala@acticm.com <mailto:mviala@acticm.com>

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iostreams::indirect_streambuf -> sync_impl returning integer?
by Oliver.Kowalke＠infineon.com 07 Feb '06

07 Feb '06

Hello, wouldn't it be better if indirect_streambuf::sync_impl returns a integer? In device::write I want to indicate that no character can be written to the external source via returning EOF (external device == socket -> peer has closed socket) instead throwing an exception. Regards, Oliver

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[BGL] Problem implementing dijkstra
by Thomas Gelzhaeuser 07 Feb '06

07 Feb '06

Hello everyone. I've got a small problem when trying to use the dijkstra-shortest-path algorithm. The error reported by the compiler is: 'void put<void*,void*>(T *,ptrdiff_t,const V &)' : cannot convert parameter 2 from 'void *' to 'ptrdiff_t' Can anyone give me a hint what I am missing? Thanks. Thomas. I made up a small example with the compiler error I receive (VS2005) >>>>>>>>> problem.cpp #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graph_traits.hpp> #include <boost/graph/dijkstra_shortest_paths.hpp> #include <boost/graph/properties.hpp> #include <vector> //defining vertex properties typedef boost::property<boost::vertex_name_t, std::string> VName; typedef boost::property<boost::vertex_index_t, int, VName> VIndex; typedef boost::property<boost::vertex_index_t, int, VIndex> VertexProperties; //defining edge properties typedef boost::property<boost::edge_weight_t, int> EdgeProperties; typedef boost::adjacency_list <boost::listS, boost::listS, boost::directedS, VertexProperties, EdgeProperties> PespGraph_t; typedef boost::graph_traits < PespGraph_t >::vertex_descriptor Pesp_Vertex; typedef boost::graph_traits < PespGraph_t >::edge_descriptor Pesp_Edge; int main(int argc, char* argv[]) { PespGraph_t g; Pesp_Vertex v1, v2; v1 = boost::add_vertex(g); boost::put(boost::vertex_name, g, v1, "Vertex 1"); boost::put(boost::vertex_index, g, v1, 1); v2 = boost::add_vertex(g); boost::put(boost::vertex_name, g, v2, "Vertex 2"); boost::put(boost::vertex_index, g, v2, 2); Pesp_Edge e; bool inserted; tie(e,inserted) = boost::add_edge(v1, v2, g); boost::put(boost::edge_weight, g, e, 10); std::vector<Pesp_Vertex> pred(boost::num_vertices(g)); std::vector<int> dist(boost::num_vertices(g)); dijkstra_shortest_paths(g, v1, boost::predecessor_map(&pred[0])); return 0; } >>>>>>>>> compiler output 1>------ Build started: Project: playground, Configuration: Debug Win32 ------ 1>Compiling... 1>problem.cpp 1>c:\boost\include\boost-1_33_1\boost\graph\dijkstra_shortest_paths.hpp(251) : error C2664: 'void put<void*,void*>(T *,ptrdiff_t,const V &)' : cannot convert parameter 2 from 'void *' to 'ptrdiff_t' 1> with 1> [ 1> T=void *, 1> V=void * 1> ] 1> There is no context in which this conversion is possible 1> c:\boost\include\boost-1_33_1\boost\graph\dijkstra_shortest_paths.hpp(291) : see reference to function template instantiation 'void boost::dijkstra_shortest_paths<VertexListGraph,boost::dijkstra_visitor<>,void**__w64 ,DistanceMap,WeightMap,IndexMap,std::less<_Ty>,boost::closed_plus<T>,int,int,ColorMap>(const VertexListGraph &,void *,PredecessorMap,DistanceMap,WeightMap,IndexMap,Compare,Combine,DistInf,DistZero,DijkstraVisitor,ColorMap)' being compiled 1> with 1> [ 1> VertexListGraph=PespGraph_t, 1> DistanceMap=boost::iterator_property_map<std::_Vector_iterator<int,std::allocator<int>>,boost::adj_list_vertex_property_map<Graph,int,const int &,boost::vertex_index_t>,int,int &>, 1> WeightMap=boost::adj_list_edge_property_map<boost::directed_tag,int,const int &,void *,const boost::property<boost::edge_weight_t,int>,boost::edge_weight_t>, 1> IndexMap=boost::adj_list_vertex_property_map<Graph,int,const int &,boost::vertex_index_t>, 1> _Ty=D, 1> T=D, 1> ColorMap=boost::iterator_property_map<std::_Vector_iterator<boost::default_color_type,std::allocator<boost::default_color_type>>,boost::adj_list_vertex_property_map<Graph,int,const int &,boost::vertex_index_t>,boost::default_color_type,boost::default_color_type &>, 1> PredecessorMap=void **__w64 , 1> Compare=std::less<D>, 1> Combine=boost::closed_plus<D>, 1> DistInf=int, 1> DistZero=int, 1> DijkstraVisitor=boost::dijkstra_visitor<> 1> ] 1> c:\boost\include\boost-1_33_1\boost\graph\dijkstra_shortest_paths.hpp(321) : see reference to function template instantiation 'void boost::detail::dijkstra_dispatch2<VertexListGraph,boost::iterator_property_map<RandomAccessIterator,IndexMap,T,R>,WeightMap,IndexMap,Params,boost::iterator_property_map<std::_Vector _iterator<_Ty,_Alloc>,IndexMap,boost::default_color_type,boost::default_color_type &>>(const VertexListGraph &,void *,DistanceMap,WeightMap,IndexMap,const Params &,ColorMap)' being compiled 1> with 1> [ 1> VertexListGraph=PespGraph_t, 1> RandomAccessIterator=std::_Vector_iterator<int,std::allocator<int>>, 1> IndexMap=boost::adj_list_vertex_property_map<Graph,int,const int &,boost::vertex_index_t>, 1> T=int, 1> R=int &, 1> WeightMap=boost::adj_list_edge_property_map<boost::directed_tag,int,const int &,void *,const boost::property<boost::edge_weight_t,int>,boost::edge_weight_t>, 1> Params=boost::bgl_named_params<void **__w64 ,boost::vertex_predecessor_t,boost::no_property>, 1> _Ty=boost::default_color_type, 1> _Alloc=std::allocator<boost::default_color_type>, 1> DistanceMap=boost::iterator_property_map<std::_Vector_iterator<int,std::allocator<int>>,boost::adj_list_vertex_property_map<Graph,int,const int &,boost::vertex_index_t>,int,int &>, 1> ColorMap=boost::iterator_property_map<std::_Vector_iterator<boost::default_color_type,std::allocator<boost::default_color_type>>,boost::adj_list_vertex_property_map<Graph,int,const int &,boost::vertex_index_t>,boost::default_color_type,boost::default_color_type &> 1> ] 1> c:\boost\include\boost-1_33_1\boost\graph\dijkstra_shortest_paths.hpp(341) : see reference to function template instantiation 'void boost::detail::dijkstra_dispatch1<VertexListGraph,boost::detail::error_property_not_found,boost::adj_list_edge_property_map<Directed,Value,Ref,Vertex,Property,Tag>,boost::adj_list_vertex_property_map<Graph,ValueType,Reference,boost::vertex_index_t>,boost::bgl_named_params<T,boost::vertex_predecessor_t,Base>,boost::detail::error_property_not_found>(const VertexListGraph &,void *,DistanceMap,WeightMap,IndexMap,const Params &,ColorMap)' being compiled 1> with 1> [ 1> VertexListGraph=PespGraph_t, 1> Directed=boost::directed_tag, 1> Value=int, 1> Ref=const int &, 1> Vertex=void *, 1> Property=const boost::property<boost::edge_weight_t,int>, 1> Tag=boost::edge_weight_t, 1> Graph=Graph, 1> ValueType=int, 1> Reference=const int &, 1> T=void **__w64 , 1> Base=boost::no_property, 1> DistanceMap=boost::detail::error_property_not_found, 1> WeightMap=boost::adj_list_edge_property_map<boost::directed_tag,int,const int &,void *,const boost::property<boost::edge_weight_t,int>,boost::edge_weight_t>, 1> IndexMap=boost::adj_list_vertex_property_map<Graph,int,const int &,boost::vertex_index_t>, 1> Params=boost::bgl_named_params<void **__w64 ,boost::vertex_predecessor_t,boost::no_property>, 1> ColorMap=boost::detail::error_property_not_found 1> ] 1> c:\dokumente und einstellungen\gelzi.mediber\eigene dateien\visual studio 2005\projects\playground\playground.cpp(43) : see reference to function template instantiation 'void boost::dijkstra_shortest_paths<PespGraph_t,void**__w64 ,boost::vertex_predecessor_t,boost::no_property>(const VertexListGraph &,void *,const boost::bgl_named_params<T,Tag,Base> &)' being compiled 1> with 1> [ 1> VertexListGraph=PespGraph_t, 1> T=void **__w64 , 1> Tag=boost::vertex_predecessor_t, 1> Base=boost::no_property 1> ] 1>playground - 1 error(s), 0 warning(s) ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

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Boost.MultiArray bounds checking
by Frank Hess 07 Feb '06

07 Feb '06

I'm using boost 1.32, and boost::multi_array doesn't seem to provide any bounds-checked access. I'm curious if there are any plans to add a bounds-checked at() member function to complement the [] operator? Or, is there some reason it is impractical? -- Frank

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Re: [Boost-users] [Review] Shmem Library
by Fred Bertsch 06 Feb '06

06 Feb '06

shmemdoc-0.9.zip and shmemlib-0.9.zip are the most recent versions of the library and documentation. They are the ones getting reviewed. -Fred > > Both documentation and the library itself can be downloaded here: > > http://tinyurl.com/9t5qy > > Which file needs to be dounloaded. There are lots of'em there. > > Gennadiy

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[BGL] there is no in_edges() function for adjacency_matrix<>
by Dmitry Bufistov 06 Feb '06

06 Feb '06

Hi, A huge disappointment again came to me today. I used boost::adjacency<boost::directedS> class for representation of simple Petri net. I was trying to define the following function ////////////////////////////////////////// bool if_enabled(transition_descriptor_t tr, graph_t net) { assert((net[tr].m_node_type == TRANSITION) && "if_enabled called with non transition node"); BGL_FORALL_INEDGES_T(tr, ed, net, graph_t) { if (net[boost::source(ed, net)].m_tokens_number < net[ed].m_weight) return false; } return true; } ////////////////////////////////////////////////////////// But I failed because of lack of boost::in_edges() function specialization for type that I've chosen. Am I doing something wrong? Any ideas how to implement my function in resonable way would be greatly appreciated. Note: all works fine with "adjacency_list<vecS, vecS, bidirecrionalS>" Many thanks in advance, --dima

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Boost thread library wrapper
by boostguy＠kapiladhanvi.com 06 Feb '06

06 Feb '06

Hi all, I am trying to write a generalized object oriented wrapper for thread library implementation of Boost. Boost threads take a function name as an argument when creting a thread. I would like create a warpper in C++ which would in some respects mimic JAVA and have a runnable interface which an threaded application would implement. This code would explain what I want to do.. but my question is how can I do it or if there are already some wrappers out there that I can use for boost threads? Sample code : ----- MyThread.h ----- #include "myRunnable.h" #include <boost/thread/thread.hpp> class MyThread { private: Runnable& task; boost::thread thr; public: MyThread( Runnable& threadTask ) : task( threadTask ), thr( &task.run) // how do I do this ? { } }; --------------------------- Thanks, Dhanvi

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stopping a boost::thread
by xargon 06 Feb '06

06 Feb '06

Hi everyone, I am trying to use the boost multithreading library. I am having a problem as the join() function for the thread never returns. I am using a boolean variable to indicate when the thread should stop running. Here is basically a stub of what I am doing: //........................................ bool m_RunThread = false; scoped_ptr myThread; //....................................... void MyObject::StartThread() { m_RunThread = true; myThread.reset(new boost::thread(boost::bind (&MyObject::MyThreadFunc, this))); } void MyObject::StopThread() { m_RunThread = false; myThread.join(); // this function never returns! ... Never gets here.... } void MyObject::MyThreadFunc() { while (m_RunThread) { // do something } } However, the join() function in StopThread never returns. I think that using a variable to synchronize this is probably not a good idea. Any thoughts and suggestions? Cheers, K

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[Review] Shmem Library
by Fred Bertsch 06 Feb '06

06 Feb '06

Hello everyone, The review of the proposed Boost Shmem library written by Ion Gaztañaga starts today (February 6th, 2006) and ends after 10 days (February 16, 2006). Documentation for the library can be found online here: http://tinyurl.com/e2os3 Both documentation and the library itself can be downloaded here: http://tinyurl.com/9t5qy --------------------------------------------------- About the library: The Shmem Library simplifies the use of shared memory and provides some STL compatible allocators that allow shared memory STL container placement. It also offers helper classes, such as offset pointers, process shared mutexes, condition variables, and named semaphores. Library users can apply all STL algorithms and utilities with created shared memory objects. Shmem also wants to present a portable implementation, unifying UNIX and Windows shared memory object creation, providing simple wrapper classes. Shmem offers the following to the user: - Portable synchronization primitives for shared memory, including shared mutexes and shared condition variables. - Dynamic allocation of portions of a shared memory segment. - Named allocation in shared memory. Shmem can create objects in shared memory and associate it with a c-string offering a similar mechanism to a named new/delete. Created object can be found by other processes using Shmem framework. - Offset pointers that can be safely placed in shared memory to point to another object of the same shared memory segment even if the memory is mapped to a different address. - STL compatible shared memory allocators so that STL containers can be placed in shared memory. Shmem also offers a pooled node allocator to save and optimize shared memory allocation in node containers. - STL compatible containers for systems with STL implementations that cannot deal with shared memory. The user can map shared memory to different addresses and use STL compatible containers and algorithms. Useful to store common data or implement shared memory databases. These containers also show how STL compatible containers can make use of shared memory STL compatible allocators to place such containers in the shared memory. Shmem also offers the basic_string pseudo-container to use full-powered C++ strings in shared memory. --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Fred Bertsch Review Manager

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[BGL] Converting my graph to BGL.
by Robert Bigaignon 06 Feb '06

06 Feb '06

Hi all, I have been trying to convert an existing graph implementation to BGL. I have followed this example http://www.boost.org/libs/graph/doc/leda_conversion.html and implemented the incidence_graph, adjacency_graph and vertex_list_graph concepts. The following concept check compiles : boost::function_requires< boost::GraphConcept<graph_t> >(); boost::function_requires< boost::IncidenceGraphConcept<graph_t> >(); boost::function_requires< boost::AdjacencyGraphConcept<graph_t> >(); boost::function_requires< boost::VertexListGraphConcept<graph_t> >(); and the basic functions for these concepts seems to work properly (out_degree(), num_vertices(), etc..). But when I try to call an algorithm, like for instance articulation_points() (which takes a graph which model must be of Vertex List Graph and Incidence Graph), compilation fails: /usr/include/boost/graph/biconnected_components.hpp: In function 'OutputIterator boost::articulation_points(const Graph&, OutputIterator) [with Graph = vcsn::Graph<vcsn::labels_are_series, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, vcsn::algebra::polynom<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool>, char, vcsn::NoTag, vcsn::geometry>, OutputIterator = std::back_insert_iterator<std::vector<vcsn::handler<vcsn::state_h>, std::allocator<vcsn::handler<vcsn::state_h> > > >]': test2.cc:77: instantiated from here /usr/include/boost/graph/biconnected_components.hpp:246: error: no matching function for call to 'get(boost::vertex_index_t, const vcsn::Graph<vcsn::labels_are_series, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, vcsn::algebra::polynom<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool>, char, vcsn::NoTag, vcsn::geometry>&)' Compilation exited abnormally with code 1 at Fri Feb 3 17:38:31 What did I forgot to do ? -- Robert

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