August 2003 - Boost-users - lists.preview.boost.org

BUG: _DLL used to define BOOST_SIGNALS_STATIC_LINK
by kaineumann2001 12 Aug '03

12 Aug '03

Under cl(MS)/icl(Intel) compiler hash-def '_DLL' denotes dynamic linking of the C runtime library. Therefore, signals library should not use this to determine linkage (I may wish to statically link the signals library, while dynamically linking c-runtime.) see file boost/signals/detail/signals_common.hpp where the following snippet is invalid: #if defined(_MSC_VER) && defined(_DLL) # define BOOST_SIGNALS_HAS_DLL_RUNTIME #endif #if defined(BOOST_SIGNALS_HAS_DLL_RUNTIME) && !defined (BOOST_SIGNALS_STATIC_LINK) # if defined(BOOST_SIGNALS_IN_LIBRARY_SOURCE) # define BOOST_SIGNALS_DECL __declspec(dllexport) # define BOOST_SIGNALS_BUILD_DLL # else # define BOOST_SIGNALS_DECL __declspec(dllimport) # endif #endif here BOOST_SIGNALS_DECL is defined as __declspec(dllimport) as a consequence of linking the c-runtime dynamically under cl/icl compilers. But that's not what I wanted - I wanted to link signals.lib statically. This same bug is in the regex library. In fact, anyone able to fix this, should search for _DLL in the BOOST headers. Cheers, Kai

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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 10 Aug '03

10 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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what is wrong with boost::bind?
by yxh 08 Aug '03

08 Aug '03

Hi, I am using boost::bind from boost 1.30.0. When I type "boost::bind(", the VS.NET 20003 IDE stopped responding. What is wrong? #include <boost/bind.hpp> int main(void) { boost::bind( // IDE dies here }

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use of REGEX_SEARCH to match lookahed subexpression.
by yanbelinky 08 Aug '03

08 Aug '03

Dear Regex Guru, I am trying to use REGEX_SEARCH algorithm to match lookahed subexpression. Search in the folowing strings (see below) using expression like: /exchange/test/(?!Drafts)/a.EML/b.png fails /exchange/test/Drafts/a.EML/b.gif /exchange/test/Inbox/a.EML/b.png /exchange/test/Inbox/a.EML/b.gif /exchange/test/Drafts/a.EML/b.png At the same moment I can suceesfully search using the expression: /exchange/test/Inbox/a.EML/b.(?!png). >From online documentation I realize that regex supports lookahed search. Please help me understand what I am doing wrong. P.S. It is tested with the program closely modeled from example provided for regex_search. Thank you for your help. Yan Belinky Senior Software Engineer. Whale Communications, LTD.

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RE: [Boost-Users] shared_ptr memory leak (newb)
by Mark Storer 07 Aug '03

07 Aug '03

*string allocates it's own copy of the string, so your pmem pointer is leaked. STL's string templates manage their own memory, you never need to use new or delete to [de]allocate for them. --Mark Storer Software Engineer Cardiff Software #include <disclaimer> typdef std::disclaimer<Cardiff> Discard; > -----Original Message----- > From: Aaron Campbell [mailto:yg-boost-users@m.gmane.org] > Sent: Thursday, August 07, 2003 1:22 PM > To: boost-users(a)yahoogroups.com > Subject: [Boost-Users] shared_ptr memory leak (newb) > > > why does this leak memory from the first call to "new"? > how can I prevent the leak? > > wchar_t* pmem = new wchar_t[10]; > boost::shared_ptr<std::wstring> cp ( new std::wstring(pmem) ); > > thanks for the help, > .Aaron > > > > > > ------------------------ Yahoo! Groups Sponsor > ---------------------~--> > Buy Ink Cartridges or Refill Kits for Your HP, Epson, Canon or Lexmark > Printer at Myinks.com. Free s/h on orders $50 or more to the > US & Canada. http://www.c1tracking.com/l.asp?cid=5511 > http://us.click.yahoo.com/l.m7sD/LIdGAA/qnsNAA/EbFolB/TM > -------------------------------------------------------------- > -------~-> > > Info: <http://www.boost.org> > Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> > Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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shared_ptr memory leak (newb)
by Aaron Campbell 07 Aug '03

07 Aug '03

why does this leak memory from the first call to "new"? how can I prevent the leak? wchar_t* pmem = new wchar_t[10]; boost::shared_ptr<std::wstring> cp ( new std::wstring(pmem) ); thanks for the help, .Aaron

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Problems with if_then_else_return in boost::lambda library
by Ioffe, Robert 07 Aug '03

07 Aug '03

Hi, If I have a vector of strings vector<string> v; v.push_back("One"); v.push_back("Two"); v.push_back("Three"); v.push_back("Four"); v.push_back("Five"); and define arithmetic action plus like this: namespace boost { namespace lambda { struct plain_return_type_2<arithmetic_action<plus_action>, std::string, std::string> { typedef std::string type; }; } } then the following code works just fine: cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + string(", ") + _2) << endl; and the following also works wonderfully: int i = 1; cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + bind(constructor<string>(), var(i)++, ' ') + _2) << endl; Now, if I want to use if_then_else_return as shown below, it fails miserably, producing a huge error message: cout << accumulate(v.begin(), v.end(), string(), if_then_else_return(_1 == string(), _1, _1 + bind(constructor<string>(), var(i)++, ' ') + _2)) << endl; Now for the questions: What is the proper way to use if_then_else_return? Why do I need to define a separate arithmetic action for strings, even though they are a common library type? Is there a way to say the most intuitive: cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + ", " + _2) << endl; Is there way to do more intuitive: cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + string(i++, ' ') + _2) << endl; Thank you for your help. Robert Ioffe [Non-text portions of this message have been removed]

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[function] How to extract a tuple<A0,A1> of arguments from a boost::function<>?
by Fernando Cacciola 07 Aug '03

07 Aug '03

Short question: As the Subject says, given a boost::function{1..N}<>, how can I extract a tuple of all its arguments? Long question: Anyway, what I'm really trying to do is this: Given some classes with different methods: struct X { void f(int n ) ; } ; struct Y { void g(char c, double d ) ; } ; I want to easly create _polymorphic_ closures binding member functions of X /Y with instances of X/Y and function arguments. The goal is the have a deferred 'action' list for easy backtracing of an algorithm. That is, instead of directly calling: X x ; Y y ; x.f(1); y.g('a',1.2); I want to do something that would look like: X x; Y y; ActionList actions; actions.push_back( make_closure(&X::f, x,1) ); actions.push_back( make_closure(&Y::g, y,'a',1.2) ); std::for_each(actions.begin(),actions.end(),execute_action()); TIA Fernando Cacciola

2 2

filesystem compilation on tru64 unix
by allysonlurena 07 Aug '03

07 Aug '03

Hi all, I have been trying to build the filesystem library for one of our alpha servers running tru64 unix. I have managed to compile bjam using the tru64cxx toolset. Then, I went into the filesystem build directory and ran the following, but it has been hanging for over 30 minutes now on the last command you see below. Can anyone help? It could just be our machines, but I am at a loss. Does anyone have any ideas? Any help would be appreciated! Thanks Allyson $ cxx -V Compaq C++ V6.5-014 for Compaq Tru64 UNIX V5.1A (Rev. 1885) Compiler Driver V6.5-014 (cxx) cxx Driver rum:/.../boost_1_30_0/libs/filesystem/build $ bjam "-sTOOLS=tru64cxx65" ...found 432 targets... ...using 1 temp target... ...updating 9 targets... tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/exception.o tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/operations_posix_windows.o cxx: Warning: ../src/operations_posix_windows.cpp, line 236: #767-D conversion from pointer to smaller integer assert( m_imp.get() ); // fails if dereference end iterator ------^ cxx: Warning: ../src/operations_posix_windows.cpp, line 242: #767-D conversion from pointer to smaller integer assert( m_imp.get() ); // fails on increment end iterator ------^ tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/path_posix_windows.o tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/convenience.o tru64cxx65-Archive-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/libboost_filesystem.a ar: Warning: creating ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/libboost_filesystem.a Ranlib ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/debug/libboost_filesystem.a ...using <libs!filesystem!build/libboost_filesystem.a/tru64cxx65/release>exception.o... tru64cxx65-C++-action ../../../libs/filesystem/build/bin/libboost_filesystem.a/tru64cxx65/release/operations_posix_windows.o So, it seems to hang at the last command above. Thanks again! Allyson

3 2

cvs checkout probs
by Angus Leeming 07 Aug '03

07 Aug '03

Hi, I have just tried to checkout the boost cvs tree from sourceforge, but get stuck at cvs server: Updating boost/libs/numeric/mtl/test cvs server: [05:07:19] waiting for anoncvs_boost's lock in /cvsroot/boost/boost/libs/numeric/mtl/test I can subsequently check out the remaining stuff with $ cat tmp pool preprocessor property_map python random rational regex signals smart_ptr spirit static_assert test thread timer tokenizer tuple type_traits utility $ for dir in `cat tmp`; do cvs -z3 co boost/libs/$dir; done so it appears that the problem is specific to the boost/libs/numeric/mtl/test directory. Kind regards, Angus

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[boost] filesystem lib & linking (MSVC.NET)
by Jonathan Roewen 07 Aug '03

07 Aug '03

Hi All, I'm trying to use the filesystem lib, but I'm having some problems figuring out how to build it properly. I'm using MSVC.NET on WindowsXP, and I ran the bjam tool like in the docs for the whole set of libraries. It took me a while to figure out where it had put everything, and finally found a file called libboost_filesystem.lib. I copied it to a convenient location, added the library path and lib file to my project settings, and then tried to link my app. MSVC then gave a bunch of linker errors, and suggested to add MSVCRT to the nodefaultlib setting, so I did that, and got less linker errors. All that is left is some thing to do with exception & string classes. Linker errors are all about multiply defined symbols. I suppose I'm doing something wrong somewhere along the line, but not sure what. I can't tell if bjam is actually doing what it's supposed to, and the documentation around the place can be pretty sparse in places, so I hope someone can point out what I can do to get things working. Regards, Jonathan Roewen

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Re: what is wrong with boost::bind?
by Jason Shirk 06 Aug '03

06 Aug '03

"yxh" <yg-boost-users(a)m.gmane.org> wrote in message news:<bgqfkv$eeu$1(a)main.gmane.org>... > I solved it by using Visual Assistant .NET I can't seem to reproduce the problem you have reported. If you could send me (jasonsh(a)microsoft.com) a project that reproduces the problem, I'd appreciate it. You might consider trying Intellisense a bit more. Because we use a variant of our C++ compiler for Intellisense, it has capabilities that are beyond many other editors. It's far from perfect, as you've found, but as far as we are aware, the template support for auto completion is much better than with any other similar tool. -- Jason Shirk VC++ Compiler Team

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Problems with if_then_else_return in boost::lambda library
by Ioffe, Robert 06 Aug '03

06 Aug '03

Hi, If I have a vector of strings vector<string> v; v.push_back("One"); v.push_back("Two"); v.push_back("Three"); v.push_back("Four"); v.push_back("Five"); and define arithmetic action plus like this: namespace boost { namespace lambda { struct plain_return_type_2<arithmetic_action<plus_action>, std::string, std::string> { typedef std::string type; }; } } then the following code works just fine: cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + string(", ") + _2) << endl; and the following also works wonderfully: int i = 1; cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + bind(constructor<string>(), var(i)++, ' ') + _2) << endl; Now, if I want to use if_then_else_return as shown below, it fails miserably, producing a huge error message: cout << accumulate(v.begin(), v.end(), string(), if_then_else_return(_1 == string(), _1, _1 + bind(constructor<string>(), var(i)++, ' ') + _2)) << endl; Now for the questions: What is the proper way to use if_then_else_return? Why do I need to define a separate arithmetic action for strings, even though they are a common library type? Is there a way to say the most intuitive: cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + ", " + _2) << endl; Is there way to do more intuitive: cout << accumulate(v.begin()+1, v.end(), v.front(), _1 + string(i++, ' ') + _2) << endl; Thank you for your help. Robert Ioffe [Non-text portions of this message have been removed]

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prim_minimum_spanning_tree crashes
by Stephan Höfer 06 Aug '03

06 Aug '03

Hello, I try to use prim_minimum_spanning_tree to find rings in subgraphs doing the following: typedef subgraph< adjacency_list<vecS, vecS, undirectedS, VertexProperty, EdgeProperty> > Graph; /... building Graph g with some vertices and edges for(int i=0; i<7; ++i) { add_vertex(g); LAMath::Vec3_f tVec((float)i, (float)(6-i), .0); put(vertex_point_t(), g, i, tVec); } property_map<Graph, edge_weight_t>::type weightmap = get(edge_weight, g); Edge e; bool inserted; tie(e, inserted) = add_edge(0, 1, g); weightmap[e] = 1; tie(e, inserted) = add_edge(1, 2, g); weightmap[e] = 1; tie(e, inserted) = add_edge(2, 3, g); .../ Graph tSubGraph = g.create_subgraph(); add_vertex(1, tSubGraph); add_vertex(3, tSubGraph); add_vertex(4, tSubGraph); add_vertex(6, tSubGraph); std::vector < graph_traits < Graph >::vertex_descriptor > p(num_vertices(tSubGraph)); prim_minimum_spanning_tree(tSubGraph, &p[0]); After having created the graph g, I call the create_subgraph member function to get an induced subgraph of it. Trying to use the prim_minimum_spanning_tree function it crashes in dijkstra_dispatch1 by trying to delete the local variable std::vector<D> distance_map(n). Is there something missing in my code which leads to that crash? It works for the root graph but not for any new created subgraph. Help would be appreciated. Thanks in advance Stephan

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boost and vxWorks?
by Alexander Nasonov 06 Aug '03

06 Aug '03

Does anybody use boost libraries under Vxworks? I'm especially interested in pool and threads libraries. Thankin advance -- Alexander Nasonov Remove minus and all between minus and at from my e-mail for timely response

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How to avoid warning C4275 in MSVC 7.1
by yxh 06 Aug '03

06 Aug '03

Hello, when I build /libs/thread/examples/thread.cpp, I got warning C4275. I think it is because std::logic_error is not defined as dllexport/dllimport. Can anyone tell me how to correct this? TIA.

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