October 2002 - Boost-users - lists.boost.org

boost::shared_ptr and stl algorithms
by Bill Eidson 15 Apr '05

15 Apr '05

std::vector< boost::shared_ptr<T> > TVec; I want to write a function object to run std::for_each. to do somework against members of T and accumulate results in functor. My attempts have failed in VC7 with memory errors in my operator() method. struct fo { bool operator()( boost::shared_ptr<T>& t ) { return true; } }; Thanks in advance bille

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BGL and reversing / moving edges
by joshrose 18 Dec '03

18 Dec '03

G'day, I was hoping someone might be able to tell me if they've run into any situations using BGL where they needed to move (or reverse (i.e. flip the source and target)) an edge within a graph implemented as an adjacency_list. I'm working on an implementation of an algorithm for max. weight bipartite matching ("the assignment problem"), and one of the assumptions in the algorithm is that non-matched edges are directed from one subgraph, A, to the other subgraph, B, and matched edges are directed the other way. Over the course of growing the matching, a simple way to add and remove edges from the candidate set is just to reverse the edge, thus the need for some way to reverse the edge within BGL. I don't think I can just remove and then re-add the edge in the other direction, primarily because doing so will (I believe) invalidate any edge_descriptors referring to that edge. In particular, there are property maps keeping track of the weight of edges, the predecessors of certain nodes, etc. that use edge descriptors as keys. I've spent a fair bit of time reading the documentation and looking through the implementation of adjacency_lists (incl. edge_list_impl), and I'm not really sure of a way to either move an edge directly within a graph, or even to create a new edge from another s.t. they have the same edge_descriptor (in general a bad thing, probably). Anyone have any thoughts on this? Thanks, -Josh

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bjam and windows command line problem.
by Fernando Cacciola 07 May '03

07 May '03

Hi, I'm having a hard time trying to use bjam to build boost 1.29.0. I have Win98 in Spanish, and I use Borland C++ Builder 5.0 (its bcc32.exe corresponds to is BCC5.5.1) I have boost 1.29.0 installed at: "C:\Libraries\boost\Repository\boost" I've downloaded bjam for Microsoft Windows: >bjam -v Boost.Jam Version 3.1.0. OS=NT. Copyright 1993-2002 Christopher Seiwald and Perforce Software, Inc. Copyright 2001 David Turner. Copyright 2001-2002 David Abrahams. I've temporarily modified the root 'jamfile' so that it builds only the Test library. and I've done: subst d: "c:\archivos de programa\borland\cbuilder5" set BCCROOT=d: (you'll see why in a moment) If I try: c:\>cd C:\Libraries\boost\Repository\boost" C:\Libraries\boost\Repository\boost> bjam -sTOOLS=borland I receive messages of the form: borland-C++-action libs\test\build\bin\libpem.lib\borland\debug\runtime-link-static\threading-s ingle\execution_monitor.obj "d:\bin\bcc32" -j5 -q -c -P -w -Ve -Vx -a8 -v -Od -vi- -tWC -WM- -w-8001 -I"libs\test\build" -I"C:\Libraries\boost\Repository\boost" -I"d:\includ e" -o"libs\test\build\bin\libpem.lib\borland\debug\runtime-link-static\thre ading-single\execution_moni Error E2266: No file names given tor.obj" "libs\test\build\../src\execution_monitor.cpp" C:\WINDOWS\TEMP\JAMTMP00.BAT [2] Unknown command "TOR.OBJ" "LIBS\TEST\BUILD\.." "d:\bin\bcc32" -j5 -q -c -P -w -Ve -Vx -a8 -v -Od -vi- -tWC -WM- -w-8001 -I"libs\test\build" -I"C:\Libraries\boost\Repository\boost" -I"d:\includ e" -o"libs\test\build\bin\libpem.lib\borland\debug\runtime-link-static\thre ading-single\execution_monitor.obj" "libs\test\build\../src\execution_monitor.cpp" ...failed borland-C++-action libs\test\build\bin\libpem.lib\borland\debug\runtime-link-static\threading-s ingle\execution_monitor.obj... If I'm interpreting this output correctly, the problem is that the command line feed to bcc32 exceeds 256 characters. What can be done about this? Is there a way for 'borland-tools.jam' to put the bcc32 parameters in a tmp response file and use: bcc32.exe @tmprsp.rsp? Any help will be appreciated. TIA, -- Fernando Cacciola

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VC7 says 'fatal C1067' compiling multi_array?
by Clift Norris 02 Mar '03

02 Mar '03

Greetings: I'm using VC7 and boost_1_29_0 to compile this code that is using multi_array.hpp. typedef boost::multi_array<double, 4> theta4_t; typedef theta4_t::index index; theta4_t Theta_Trun( boost::extents[10000][2][10][256] ); I'm receiving this error: "fatal error C1067: compiler limit: debug information module size exceeded" Of course, the code compiles fine using the "Release" configuration, but I need the "Debug" one also. Is there a workaround for this, other than the 'make your variables shorter' suggested in the VC7 documentation? Thanks, -Clift

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bug report: boost::tokenizer with VC6
by Navi Singh 10 Feb '03

10 Feb '03

The boost release 1.28.0 of the tokenizer library has the following problem: There are 5 examples, namely, simple_example_1.cpp thru simple_example_5.cpp If I change the main() in each of the 5 to to main1() thru main5() and return 0; the vc60 compiler generates an internal compiler error when parsing the file boost\iterator_adapters.hpp on line 869, where it is parsing the following lines: reference operator*() const { return policies().dereference(*this); }

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Q: Graphs. Sorting edges. Possible? How to?
by stas_fomin 08 Nov '02

08 Nov '02

Hello. I a newbie in BGL and I rewrite my LEDA code now... I have to sort (order) edges according to some functor. For example (simplified): typedef adjacency_list<vecS, vecS, bidirectionalS> MyGraph; typedef graph_traits < MyGraph >::edge_descriptor MyGraphEdge; typedef graph_traits < MyGraph >::edge_iterator MyEdgeIter; class MyCompareEdges{ public: bool operator()(MyGraphEdge e1, MyGraphEdge e2) const { return true; } }; .... { MyGraph Gr(10); MyEdgeIter ei_beg, ei_end; MyCompareEdges comp; tie(ei_beg, ei_end) = edges(Gr); std::sort(ei_beg, ei_end, comp); //Error C2676 } And I have error C2676 (below the message...). Questions: 1. Is it possible to sort edges in the graph? 2. How to... Thanks all in advance... Stas Fomin. P.S. vecS, setS, listS for edge container... - C2676. ------------------------------ d:\projects\lib\cpp_libs\libboost\boost\iterator_adaptors.hpp(264) : error C2676: binary '+=' : 'class std::list<struct boost::list_edge<unsigned int,struct boost::no_property>,class std::allocator<struct boost::list_edge<unsigned int,struct boost:: no_property> > >::iterator' does not define this operator or a conversion to a type acceptable to the predefined operator d:\projects\lib\cpp_libs\libboost\boost\iterator_adaptors.hpp (911) : see reference to function template instantiation 'void __thiscall boost::default_iterator_policies::advance(struct boost::iterator_adaptor<class std::list<struct boost::lis t_edge<unsigned int,struct boost::no_property>,class std::allocator<struct boost::list_edge<unsigned int,struct boost::no_property> > >::iterator,struct boost::detail::undirected_edge_iter_policies,class boost::detail::edge_desc_impl<struct boost::b idirectional_tag,unsigned int>,class boost::detail::edge_desc_impl<struct boost::bidirectional_tag,unsigned int>,class boost::detail::edge_desc_impl<struct boost::bidirectional_tag,unsigned int> *,struct boost::multi_pass_input_iterator_tag,int> &,i nt)' being compiled Error executing cl.exe.

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Q: Problems building boost.python under cygwin
by "Schnörr, Claudius Dr." 07 Nov '02

07 Nov '02

Hello, I run into problems building boost under cygwin. It seems to be merely a matter of a wrong configuration or wrong scripts. After running 'bjam -sTOOLS=gcc -n > build.com' in boost/libs/python/build in order to get hands on the statements being executed by bjam, there had to be made a lot of textual replacements to get the statements in build.com run: Just to mention some: - replace '-isystem ' by '-I' - remove '-I""' - change shared library-names from *.so to *.dll - insert '-L <path_to_libpython2.2.dll> -lpython2.2' where shared libs are created In boost/libs/python/test, going the same way, there have in addition this changes to be made: - LD_LIBRARY_PATH=... --> PATH=$PATH:..., because cygwin uses PATH to look for .dlls My question: I think there have to be made more configurations than I did to create the boost.python-stuff under cygwin. Where have they to be done, and what? (I already configured environment variables like GCC_ROOT_DIRECTORY, GXX, PYTHON_ROOT, ...etc...) Any suggestions are welcome! Please send a copy of your answer to schnoerr(a)mailzone.com Thank you in advance, Claudius --------------------------------------------------------- This Mail has been checked for Viruses Attention: Encrypted mails can NOT be checked! ** Diese Mail wurde auf Viren geprueft Hinweis: Verschluesselte mails koennen NICHT auf Viren geprueft werden! ---------------------------------------------------------

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Wrapping a std::list with boost.python
by jefflholle 04 Nov '02

04 Nov '02

I've just started experimenting with version 2 of boost.python. In iterator.cpp, a std::list is wrapped using following code: typedef std::list<int> list_int; void push_back(list_int& x, int y) { x.push_back(y); } int back(list_int& x) { return x.back(); } . . . class_<list_int>("list_int") .def("push_back", push_back) .def("back", back) .def("__iter__", iterator<list_int>()) ; Is it possible to use the container methods instead of user defined functions? I've tried the code: class_<list_int>("list_int") .def("push_back", &list_int::push_back) .def("back", &list_int::back) .def("__iter__", iterator<list_int>()) ; This doesn't work. Am what I'm tried to do possible? If so, how?

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[BGL] How to prune a BFS or exit a BFS
by kweeheong 02 Nov '02

02 Nov '02

I have a custom BFS visitor used to traverse a graph. Is there a built-in way to - prune off a vertex's descendants from the search - exit a BFS These ( pruning and terminating ) are separate situations. I believe the following will work; however, I do not know how to access the relevant data structures. - To prune off a vertex's descendents from the search In the custom BFS visitor's discover_vertex event, set the color of all its adjacent descendants to "black". - To exit a BFS In the custom BFS visitor's discover_vertex event, once the required vertex is found, empty the queue of vertices. How can I access a vertex's color and a BFS's queue? Or is there a better way?

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How to pass result of boost::bind to arg of template function ?
by hugo duncan 01 Nov '02

01 Nov '02

Hi, I want to pass the result of a boost::bind as an argument of a templated function of a class, and am struggling to find a signature that will let me do this. Is this possible? if so what signature should the function have ? Any help much apreciated Hugo #include "boost/function/function1.hpp" #include "boost/bind.hpp" class another_class {}; class my_class { public: typedef another_class ObjectType; //! this works fine passing a boost::function object template <class ReturnType> void add(const boost::function1<ReturnType,ObjectType>& arg) { boost::function1<ReturnType,ObjectType> fn_obj=arg; } //! this should work when passed the result of a boost::bind template <class ReturnType> void add(?what goes here? & arg) { function1<ReturnType,ObjectType> fn_obj(arg); } }; int fn(another_class,int) { return 1; } int main(int, char**) { my_class c; c.add(boost::bind(&fn,_1,1)); }

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