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boos::bind class member function
by dirk_griffioen 12 Aug '03

12 Aug '03

Hi, I would like to use a for_each with a class member function. The for_each in myclass::do_print below does not compile. And I simply cant figure it out. I'm using vc7.1. //////////////////////////////// void print2(std::string s) { cout << s << '\n'; } class myclass { public: void print(std::string s); void do_print(); }; void myclass::print(std::string s) { cout << s << '\n'; } void myclass::do_print() { vector<std::string> v; v.push_back("a"); v.push_back("b"); v.push_back("c"); v.push_back("d"); for_each(v.begin(), v.end(), boost::bind(boost::type<void>(), &myclass::print, _1)); } ///////////////////////////////////////// nor will for_each(v.begin(), v.end(), boost::bind(&myclass::print, _1)); for_each(v.begin(), v.end(), boost::bind(print, _1)); whereas for_each(v.begin(), v.end(), boost::bind(print2, _1)); is ok It seems natural to do, but I cant get it. Dirk

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how to convert c++ objects to Python?
by cavok＠filibusta.crema.unimi.it 12 Aug '03

12 Aug '03

hi, i have a c++ function that returns a reference to a c++ object. i want to expose this function to Python making it return the Python version of the object. i'm using Boost.Python. i understood that i have to use to_python_converter but the body of the A_to_Python::convert function is mystery for me. Boost documentation's example solves the problem in a manner i'm not able to apply to my case. my A object is complex and i'd like to somewhat (re)use the class_ object. ---------------- CUT HERE ---------------- #include <boost/python.hpp> using namespace boost::python; struct A { void f() {} }; A a; struct A_to_Python { static PyObject* convert(const A& a) { // documentation says: // return PyObject_New(noddy_NoddyObject, &noddy_NoddyType); } }; A& get_A() { return a; } BOOST_PYTHON_MODULE(hello) { class_<A>("A") .def("f", &A::f) ; to_python_converter<A, A_to_Python>(); def("get_A", get_A, return_value_policy<reference_existing_object>()); } ---------------- CUT HERE ---------------- please, somebody enlighten me. many thanks domenico -----[ Domenico Andreoli, aka cavok --[ http://filibusta.crema.unimi.it/~cavok/gpgkey.asc ---[ 3A0F 2F80 F79C 678A 8936 4FEE 0677 9033 A20E BC50

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BGL write_graphviz and VertexList type
by Solomon Gibbs 12 Aug '03

12 Aug '03

Hello, I've been trying to use the write_graphviz function in BGL, and I've noticed that it appears to be sensitive to the type of VertexList used in the graph. adjacency_lists using a boost::vecS produce vertex indices in integer form like: graph G { 0[label="0"]; 1[label="1"]; 0--1 [label="2.8"]; } but the same code backed by boost::listS seems to not dereference completely: graph G { 0x80545f0[label="10"]; 0x8054608[label="11"]; 0x80545f0--0x8054608 [label="2.8"]; } dot doesn't like this. I notice that write_graphviz dereferences boost::graph_traits<Graph>::vertex_iterator to print the vertex. Are the listS and vecS *operators different somehow? The vector backed adjacency_list also seems to be automagically setting the vertex_index property to the actual index of the vertex in the storage vector instead of the value given in add_vertex(). My question is: Is this the expected behavior for these classes or some problem I've managed to create on my own? Thanks, Solomon

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boost::python - how to expose c++ instancess?
by cavok＠filibusta.crema.unimi.it 11 Aug '03

11 Aug '03

hi, i'd like to do something like this: -------------- CUT HERE -------------- #include <boost/python.hpp> using namespace boost::python; struct A { void f() { /* do something */ } }; A a; BOOST_PYTHON_MODULE(hello) { class_<A>("A") .def("f", &A::f) ; def_readwrite("a", a); } -------------- CUT HERE -------------- i don't see how to do it with boost. any hint for a poor newbie? thanks dom -----[ Domenico Andreoli, aka cavok --[ http://filibusta.crema.unimi.it/~cavok/gpgkey.asc ---[ 3A0F 2F80 F79C 678A 8936 4FEE 0677 9033 A20E BC50

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Boost smart pointers.
by Amit Bhatia 11 Aug '03

11 Aug '03

Hello All, I have been trying to understand the smart pointer library. One thing that I did not understand was in the documentationin quite beginning: "T may be an incomplete type at the point of smart pointer declaration. Unless otherwise specified, it is required that T be a complete type at points of smart pointer instantiation." So what exactly does this incomplete/complete type mean? Does this have anything to do with the class pointed to being abstract /concrete ? thanks, regards, amit.

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FileSystem Link Error
by sarwanaggarwal 10 Aug '03

10 Aug '03

Hi: - managed to build "lib" using bjam tool. - copied that to a conveneient place - tried linking the "ls example" - I get a link error - file name not found. My environment is Borland Builder C++, 6.0. On MSVC++ 6.0, I get too many compile errors. Any hints? Greatly appreciated. Thanks. Sarwan

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How to use wildcards in filesystem::path?
by yxh 10 Aug '03

10 Aug '03

Hello, Can I use "*.*" or "XXX?.???" in filesystem::path? I want to iterate through a directory to get file names such as "*.txt". Can anyone tell how to do this? Thanks in advance.

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shared_ptr and private inheritance
by Jason Winnebeck 10 Aug '03

10 Aug '03

if class B : private A in a method of class B, given a shared_ptr<B>, is it possible to get a shared_ptr<A> that shares ownership without making boost::shared_ptr<A> a friend in class B? Jason Winnebeck

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[BGL] Different types as vertices of a graph
by sashan 10 Aug '03

10 Aug '03

I'd like to use the graph library to support connections between different types of objects. To do this I've created a class GraphNode that forms the base class for various other objects that can become vertices of the graph. I've tried the following. int main(int,char*[]) { //these two classes Translate and Mesh inherit from GraphNode Translate* pT = new Translate; Mesh* pM = new Mesh; // create a typedef for the Graph type typedef adjacency_list<vecS, vecS, bidirectionalS> Graph; const int num_vertices = 2; // writing out the edges in the graph typedef std::pair<GraphNode*, GraphNode*> GraphEdge; GraphEdge edge_array[] = { GraphEdge(pT,pM) }; const int num_edges = sizeof(edge_array)/sizeof(edge_array[0]); // declare a graph object Graph g(num_vertices); // add the edges to the graph object for (int i = 0; i < num_edges; ++i) add_edge(edge_array[i].first, edge_array[i].second, g); return 0; } but get the following error message related to the fact that it can't choose a suitable overloaded add_edge function. If I replace the types in the vertex with an int it compiles happily. I'm using Boost 1.30.0 e:\Code\Edge\Console\Console.cpp(42) : error C2665: 'boost::add_edge' : none of the 2 overloads can convert parameter 1 from type 'GraphNode *' e:\Code\boost\boost\graph\detail\adjacency_list.hpp(1211): could be 'std::pair<_Ty1,_Ty2> boost::add_edge<boost::detail::adj_list_gen<Graph,VertexListS,OutEdgeListS,DirectedS,VertexProperty,EdgeProperty,GraphProperty,EdgeListS>::config>(boost::detail::adj_list_gen<Graph,VertexListS,OutEdgeListS,DirectedS,VertexProperty,EdgeProperty,GraphProperty,EdgeListS>::config::vertex_descriptor,boost::detail::adj_list_gen<Graph,VertexListS,OutEdgeListS,DirectedS,VertexProperty,EdgeProperty,GraphProperty,EdgeListS>::config::vertex_descriptor,boost::bidirectional_graph_helper_with_property<Config> &)' with [ _Ty1=boost::adj_list_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS>,boost::vecS,boost::vecS,boost::bidirectionalS,boost::no_property,boost::no_property,boost::no_property,boost::listS>::config,boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS>,boost::vecS,boost::vecS,boost::bidirectionalS,boost::no_property,boost::no_property,boost::no_property,boost::listS>::DirectedHelper>::edge_descriptor, _Ty2=bool, Graph=boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS>, VertexListS=boost::vecS, OutEdgeListS=boost::vecS, DirectedS=boost::bidirectionalS, VertexProperty=boost::no_property, EdgeProperty=boost::no_property, GraphProperty=boost::no_property, EdgeListS=boost::listS, Config=boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS>,boost::vecS,boost::vecS,boost::bidirectionalS,boost::no_property,boost::no_property,boost::no_property,boost::listS>::config ] e:\Code\boost\boost\graph\detail\adjacency_list.hpp(1941): or 'std::pair<_Ty1,_Ty2> boost::add_edge<Graph,boost::detail::adj_list_gen<Graph,VertexListS,OutEdgeListS,DirectedS,VertexProperty,EdgeProperty,GraphProperty,EdgeListS>::config,boost ::detail::adj_list_gen<Graph,VertexListS,OutEdgeListS,DirectedS,VertexProperty,EdgeProperty,GraphProperty,EdgeListS>::DirectedHelper>(boost::detail::adj_list_gen<Graph,VertexListS,OutEdgeListS,DirectedS,VertexProperty,EdgeProperty,GraphProperty,EdgeListS>::config::vertex_descriptor,boost::detail::adj_list_gen<Graph,VertexListS,OutEdgeListS,DirectedS,VertexProperty,EdgeProperty,GraphProperty,EdgeListS>::config::vertex_descriptor,boost::vec_adj_list_impl<Graph,Config,Base> &)' with [ _Ty1=boost::adj_list_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS>,boost::vecS,boost::vecS,boost::bidirectionalS,boost::no_property,boost::no_property,boost::no_property,boost::listS>::config,boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS>,boost::vecS,boost::vecS,boost::bidirectionalS,boost::no_property,boost::no_property,boost::no_property,boost::listS>::DirectedHelper>::edge_descriptor, _Ty2=bool, Graph=boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS>, VertexListS=boost::vecS, OutEdgeListS=boost::vecS, DirectedS=boost::bidirectionalS, VertexProperty=boost::no_property, EdgeProperty=boost::no_property, GraphProperty=boost::no_property, EdgeListS=boost::listS, Config=boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS>,boost::vecS,boost::vecS,boost::bidirectionalS,boost::no_property,boost::no_property,boost::no_property,boost::listS>::config, Base=boost::detail::adj_list_gen<boost::adjacency_list<boost::vecS,boost::vecS,boost::bidirectionalS>,boost::vecS,boost::vecS,boost::bidirectionalS,boost::no_property,boost::no_property,boost::no_property,boost::listS>::DirectedHelper ] while trying to match the argument list '(GraphNode *, GraphNode *, Graph)' e:\Code\boost\boost\iterator_adaptors.hpp(1409) : see reference to class template instantiation 'boost::filter_iterator_generator<Predicate,Iterator,Value,Reference,Pointer,Category,Distance>' being compiled

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[BGL] build problems
by Angus Leeming 09 Aug '03

09 Aug '03

Dear all, I'm a bjam newbie trying to build the BGL in boost 1.30.0 on a DEC Alpha running linux. However, the build process is failing to generate the graphviz parser and lexer: $ cd libs/graph/build $ bjam "-sTOOLS=gcc" ...found 437 targets... ...using 2 temp targets... ...updating 3 targets... ...using <libs!graph!build/liblibbgl-viz.a/gcc/debug/inlining-on/runtime-link-dynamic>graphviz_graph_lex.o... ...using <libs!graph!build/liblibbgl-viz.a/gcc/debug/inlining-on/runtime-link-dynamic>graphviz_digraph_lex.o... gcc-C++-action ../../../libs/graph/build/bin/liblibbgl-viz.a/gcc/debug/inlining-on/runtime-link-dynamic/graphviz_graph_parser.o graphviz_parser.y:44:2: #error Need to define the GRAPHVIZ_GRAPH macro to either GraphvizGraph or GraphvizDigraph. graphviz_parser.y:61: error: `GRAPHVIZ_GRAPH' was not declared in this scope graphviz_parser.y:61: error: template argument 1 is invalid graphviz_parser.y:61: error: syntax error before `;' token graphviz_parser.y:62: error: `GRAPHVIZ_GRAPH' was not declared in this scope graphviz_parser.y:62: error: template argument 1 is invalid graphviz_parser.y:62: error: syntax error before `;' token graphviz_parser.y:63: error: syntax error before `;' token [snip] This all seems very reasonable, but I do not know how to resolve the problem. I see that Jamfile.v2 has explicit rules to build graphviz_graph_lex.o, graphviz_digraph_lex.o, setting GRAPHVIZ_GRAPH appropriately. However, my version of bjam (3.1.4) does not understand Jamfile.v2 and I lack the knowledge to do the equivalent in Jamfile. I did try to append some rules to the Jamfile(see below), but unsurprisingly without success. Could anyone provide me with pointers on how to proceed? Kind regards, Angus Lex graphviz_graph_lex.cpp : graphviz_lex.l : <define>GRAPHVIZ_DIRECTED=0 <dependency>graphviz_graph_parser ; Yacc graphviz_graph_parser.cpp : graphviz_parser.y : <define>GRAPHVIZ_DIRECTED=0 ; Lex graphviz_digraph_lex.cpp : graphviz_lex.l : <define>GRAPHVIZ_DIRECTED=1 <dependency>graphviz_digraph_parser ; Yacc graphviz_digraph_parser.cpp : graphviz_parser.y : <define>GRAPHVIZ_DIRECTED=1 ; Object graphviz_graph_lex.o : graphviz_graph_lex.cpp ; Object graphviz_graph_parser.o : graphviz_graph_parser.cpp ; Object graphviz_digraph_lex.o : graphviz_digraph_lex.cpp ; Object graphviz_digraph_parser.o : graphviz_digraph_parser.cpp ;

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