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boost [C++ database development library]
by Sundaram Ramasamy 12 Jul '06

12 Jul '06

Hi, Can someone help me to locate cross-platform (platform independant) and cross-database C++ database development BOOST library? Thanks and regards, Sundaram Ramasamy Sundaram.Ramasamy(a)saama.com

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fs::exists() question
by Simon Lacroix 11 Jul '06

11 Jul '06

Hello all, I started using the file system about a week ago in order to port a Windows application using win API calls to manipulate folders and file on Linux. So far it works great but I am having one issue, the fs::exists() function seems to throw an exception when I try to look for directory containing special characters like ./test[0] ./test<1> etc. Is this normal ? I can create directory with these characters using mkdir in Linux so it should be legal names. Any ideas ? Thanks for your time Simon

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c array parameter in resize method of multi_array
by Manuel.Yguel＠inrialpes.fr 11 Jul '06

11 Jul '06

Hi, is there any reason to refuse a resize method for multi_array that accept a C array as parameter ? As long as the resize method just works if the boost::extents parameter has the same dimension as the array to be resized a call like that: typedef boost::multi_array<double, 3> array_type; array_type A( boost::extents[3][4][2] ); ---> A.resize( {6;5;2} ); could be understood as: A.resize( boost::extents[6][5][2] ); without any ambiguity, am I wrong ?

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[graph] remove_if algorithm
by Loïc Joly 11 Jul '06

11 Jul '06

Hello, I'm new to the graph library, but I'm missing some algorithms that I believe are quite low level, and that I expected to find. For instance, I'd like to be able to remove nodes from a graph that meet some criterion. The closest I could find to remove_if was : - Iterate on each node manually: for (tie(vi, viend) = boost::vertices(myGraph) ; vi != viend; ++vi) { if (criterion(vi) { clear_vertex(*vi, myGraph); remove_vertex(*vi, myGraph); } } But I'm afraid of iterator invalidity - Filter, copy, swap: Graph tempGraph; { filtered_graph<Graph, keep_all, Criterion> fg (myGraph, criterion); copy_graph(fg, tempGraph); } copy_graph(tempGraph, myGraph); Will one of my attempts work ? Is there any other solution I missed ? Best regards, -- Loïc

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Re: [Boost-users] erase and iterators
by David Klein 11 Jul '06

11 Jul '06

boost-users-bounces(a)lists.boost.org wrote: > On 7/11/06, David Klein <d.klein(a)ascaron.com> wrote: >> you can use Boost.Lambda for this >> >> #include <boost/lambda/lambda.hpp> >> >> using namespace boost::lambda; >> >> std::vector<int> v; >> ... >> v.erase(std::remove_if(v.begin(), v.end(), 5 == _1)); >> > Shouldn't it be > v.erase( std::remove_if(v.begin(), v.end(), 5 == _1), v.end() > ); as you want to erase the range, not just the single element? > > ~ SWMc > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users <blush> of course, my bad (... actually i blame the heat in our office ;) ) </> -- dave

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Re: [Boost-users] erase and iterators
by David Klein 11 Jul '06

11 Jul '06

boost-users-bounces(a)lists.boost.org wrote: > On Tue, Jul 11, 2006 at 10:19:05AM +0000, Roman Neuhauser wrote: >> # kneeride(a)gmail.com / 2006-07-11 17:31:23 +1000: >>> On 7/11/06, Michael Nicolella <boost(a)mike-n.com> wrote: >>>> vec.erase( std::remove_if( vec.begin(), vec.end(), >>>> some_condition_functor >>>> ) ); >>> >>> Mike, I do like your remove_if example. >>> >>> i am not familar with this approach, can you please give me an >>> example of defining a some_condition_functor? for example when the >>> value == 5. > > What about this? > > Let's assume the vector contains ints > > class condition_functor { > > public: > > bool operator()(int elem) > { > return elem==5 > } > }; > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users you can use Boost.Lambda for this #include <boost/lambda/lambda.hpp> using namespace boost::lambda; std::vector<int> v; ... v.erase(std::remove_if(v.begin(), v.end(), 5 == _1)); -- HTH dave

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[serialization] skipping data
by Joel de Guzman 11 Jul '06

11 Jul '06

Hi, Here's a use case that I can't seem to find a way to do using boost.serialization. Say with version 1, I want to serialize X Y and Z. These are hierarchical and expensive data structures. Now, with version 2, I do not need to create Y objects anymore. Yet, I still have to open version 1 files for backward compatibility. So, when loading version 1 files, I want to skip reading Y objects. How do I do that without having to create a temporary Y object that will be discarded later? (I'm particularly interested with XML archives. If I had control over the xml parser, that would simply mean ignoring everything from the current tag until the next matching tag is found). Regards, -- Joel de Guzman http://www.boost-consulting.com http://spirit.sf.net

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[BGL] bipartite graphs
by Heiko Bauke 11 Jul '06

11 Jul '06

Hello, how can I deal with bipartite graphs and BGL? In particular I have the problem that my graph has two kinds of nodes with different kinds of vertex properties. Any suggestions? Heiko -- -- Es gibt vielerlei Lärm. Aber es gibt nur eine Stille. -- (Kurt Tucholsky, dt. Schriftsteller, 1890-1935) -- Cluster Computing @ http://www.clustercomputing.de -- Heiko Bauke @ http://www.uni-magdeburg.de/bauke

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Serialization of boost::any
by Sliwa, Przemyslaw (London) 11 Jul '06

11 Jul '06

Does it exist somewhere? Is it planned at all? Thanks for help Kind regards Pshemek Przemyslaw Sliwa Global Foreign Exchange FX Risk Engine Development Merrill Lynch ( +44 (0)20 7995 4182 ) +44 (0)79 6325 2319 * Email: przemyslaw_sliwa(a)ml.com -------------------------------------------------------- If you are not an intended recipient of this e-mail, please notify the sender, delete it and do not read, act upon, print, disclose, copy, retain or redistribute it. Click here for important additional terms relating to this e-mail. http://www.ml.com/email_terms/ --------------------------------------------------------

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[BGL] conflict with call of boost::source
by Lars Monecke 11 Jul '06

11 Jul '06

Hi, i have reduced my problem to the following lines. I want to install a own edge property to a graph. The property as a template argument with then name "source". Here is my try: ---> code starts here <--- #include <boost/graph/adjacency_list.hpp> namespace Foo { class source { }; } namespace Bar { template <class Source> class Edge { }; } typedef Bar::Edge<Foo::source> tMyEdge; struct edge_impl_t { typedef boost::edge_property_tag kind; }; typedef boost::property <edge_impl_t, tMyEdge> edge_property_t; typedef boost::adjacency_list < boost::listS, boost::vecS, boost::undirectedS, boost::no_property, edge_property_t> tGraph; int main(int /* argc */, char* /* argv[] */) { tGraph stGraph1; tGraph stGraph2; stGraph1 = stGraph2; } ----> code ends here <--- When compiling the above code with gcc 4.1.1, i get these errors: main.cpp: In member function 'void boost::vec_adj_list_impl<Graph, Config, Base>::copy_impl(const boost::vec_adj_list_impl<Graph, Config, Base>&) [with Graph = boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>, Config = boost::detail::adj_list_gen<boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>, boost::vecS, boost::listS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>::config, Base = boost::undirected_graph_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>, boost::vecS, boost::listS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>::config>]': /usr/local/gcc-4.1.1/boost-1.33.1/boost/graph/detail/adjacency_list.hpp:1990: instantiated from 'boost::vec_adj_list_impl<Graph, Config, Base>& boost::vec_adj_list_impl<Graph, Config, Base>::operator=(const boost::vec_adj_list_impl<Graph, Config, Base>&) [with Graph = boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>, Config = boost::detail::adj_list_gen<boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>, boost::vecS, boost::listS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>::config, Base = boost::undirected_graph_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>, boost::vecS, boost::listS, boost::undirectedS, boost::no_property, boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, boost::no_property, boost::listS>::config>]' /usr/local/gcc-4.1.1/boost-1.33.1/boost/graph/adjacency_list.hpp:373: instantiated from 'boost::adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>& boost::adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>::operator=(const boost::adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>&) [with OutEdgeListS = boost::listS, VertexListS = boost::vecS, DirectedS = boost::undirectedS, VertexProperty = boost::no_property, EdgeProperty = boost::property<edge_impl_t, Bar::Edge<Foo::source>, boost::no_property>, GraphProperty = boost::no_property, EdgeListS = boost::listS]' main.cpp:42: instantiated from here main.cpp:7: error: 'class Foo::source' is not a function, /usr/local/gcc-4.1.1/boost-1.33.1/boost/graph/adjacency_list.hpp:464: error: conflict with 'template<class Directed, class Vertex, class OutEdgeListS, class VertexListS, class DirectedS, class VertexProperty, class EdgeProperty, class GraphProperty, class EdgeListS> Vertex boost::source(const boost::detail::edge_base<Directed, Vertex>&, const boost::adjacency_list<OutEdgeListS, VertexListS, DirectedS, VertexProperty, EdgeProperty, GraphProperty, EdgeListS>&)' /usr/local/gcc-4.1.1/boost-1.33.1/boost/graph/detail/adjacency_list.hpp:2051: error: in call to 'source' I know the easiest way is to rename Foo::source but this class came from another library. Is there a chance to use this class anyway? Thanks in advance, Lars

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