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howto store vertex-iterators as internal graph property?
by Sebastian Weber 29 Nov '04

29 Nov '04

Hi folks! I got a cyclic type-dependency problem. I am trying to let every vertex store a iterator to a list which stores vertex-iterators. This sounds weired, but I need to keep track of very few vertices within my graph which have a particle located at it. Thus I created a list of vertex-iterators who carry my particle positions in the graph. In order to be able to tell quickly if a vertice is taken by a particle I want each vertice to include a pointer to a null element representing the absence of a particle or a pointer into that list. My non-working code looks like: Definition of my graph: struct Spot { // acutally I need the vertex_iterator to be defined already // in order to define particle, but this is not yet defined // so I am using the knowledge that it is going to be represented // by a vector<std::size_t>::iterator (at least I hope so) // this assumption is WRONG!! typedef std::list< std::vector<std::size_t>::iterator >::iterator \\ particle_t; particle_t particle; }; typedef boost::adjacency_list<boost::vecS, boost::vecS, \\ boost::undirectedS, Spot > graph_t; Here I initialise my particles to be distributed in the graph object bg. m_posA is of type: std::list<RandomGraph::gtraits::vertex_iterator> // first initialise every position to the null-flag for(; vi != vend; ++vi) bg[*vi].particle = Spot::particle_t(); // now place particles at random positions boost::tie(vi, vend) = boost::vertices(bg); for(std::size_t i = 0; i < initialA; i++) { std::size_t pos; //aList_t::iterator iter; // find a random empty vertice do { pos = rand_gen(); } while(bg[pos].particle != m_posA_end); // place particle A there RandomGraph::gtraits::vertex_iterator vref = vi + pos; // put returns an iterator to the list-element where // vref has been stored bg[pos].particle = m_posA.put(vref); } Any help would be great. Thanks in adavance. Greetings, Sebastian Weber

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[OSX] Multiply defined symbols between Function and Signals libs ?
by Alo Sarv 29 Nov '04

29 Nov '04

Hi I'v been compiling boost libraries objects straight into my application binaries on linux and OSX platforms (e.g. not using bjam/stat/dynlibs), and thus far it has worked. However, recently I started getting multiply defined symbols on OSX, namely _1, _2, _3 etc. Most likely they come between Boost.Function and Boost.Signals libraries (latter of which I started using recently). My question is is it inherently bad idea to compile boost objects like this straight into application binary (e.g. should I always use bjam?), or there any other workarounds to avoid those multiple symbols on OSX ? Alo Sarv.

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Re: Re: Graph library - bundled properties for edge
by TC MA 29 Nov '04

29 Nov '04

Thank you for your answer. I don't know '*first' will give an edge_description already. > TC MA wrote: > > > G[source(*first, G)].y << " joins " << > > G[target(*first, G)].x << "," << G[target(*first, > > G)].y << " weight " << G[edge(*first)].weight << endl; > > ++first; > > What's the 'edge' function and why do you call it? What about just '*first', > which gives you an edge_description already? > > - Volodya ===== TingChong Ma ______________________________________________________________________ Post your free ad now! http://personals.yahoo.ca

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Re: Re: Re: Leak when using boost threads under VC .NET using usi ng statically linked CRT
by alansa＠ati-uk.com 29 Nov '04

29 Nov '04

-----Original Message----- From: Alan Saunders Sent: 22 November 2004 17:24 To: 'boost-users(a)lists.boost.org' Subject: >> Hmmm no linker errors or warnings. I've set my main exe to statically >> link. if i use the version of threads that statically links to >> msvcrt71 or dynamically to msvcrt71.dll it doesn't seem to make any >> difference. Our boost libraries where compiled here for msvcrt71 and i >> can confirm this. >> >> As i say if my main exe uses msvcrt71.dll then theres no leak. >Are you using tls code? >TLS currently (as to my knowledge) contains a "intentional" leak which >however is harmless. >Could you post the messages? >Did you track down the leak? Hi Roland In order to clear random influences from other areas of the software i'm working on, I have created a simple program with the code that i listed before. nothing else, no tls code. The intentinal leak would be harmless if it did not keep increasing. If I let the program run for long enough i will run out of memory. Sorry which messages would you like me to post? Haven't tracked down the leak yet. My problem is solved for the time being by using msvcrt71.dll as i said before. However it would be nice to be able to using the static lib. I replace the code in the loop which constantly starts and stop threads with my own code that did the same thing. This code was pretty much the same as the code for boost::thread using the windows api functions. This did not leak. However the big difference between my code and boost::thread is that my code didn't use boost::function. Therefore I suspect the leak could be in there! Looking at function it certainly isn't as trivial as thread. One thing i have noticed is that there is an option to get function to use "new" instead of std::allocator with the macro BOOST_NO_STD_ALLOCATOR. (function_template.hpp). I haven't got round to trying this yet though. Alan

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accessing internal graph properties via vertex-iterators directly?
by Sebastian Weber 29 Nov '04

29 Nov '04

Hello there! First of all thanks a lot for the rapid response of my last question. I got another question concerning the access of internal graph properties: To access a bundeled vertice internal properties of a graph one has to use the following syntax: struct VertStruct { int stuff; }; typedef adjacency_list<vecS, vecS, undirectedS, VertStruct> graph_t; graph_t bg; ... setup graph ... graph_traits<graph_t>::vertex_iterator vi, vend; tie(vi, vend) = vertices(bg); bg[*vi].stuff = 4; This makes it clear, that even though we already have an iterator (vi) pointing to our vertice of interest, the BGL has to spend again some time locating the data ascociated with it. A far more direct and much clearer notion would be: (*vi).stuff = 4; With this, one would save a lookup in the data-structures and the vertice-iterator concept would be far more logic to me, concernig internal property handling. I don't know the BGL internals and how this behaviour is optimally programmed with the BGL. I thought of providing a custom container for the vertex-container which is composed of a vector of a customary struct, which glues vertice properties together with every element of the vertice list and makes the property really internal, allowing a (*vi).myrealinternalstuff = 4 expression. I hope my point is clear. Thanks a lot for any help. Greetings, Sebastian Weber

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Graph library - bundled properties for edge
by TC MA 29 Nov '04

29 Nov '04

I try to add Vertex and Edge data with bundled properties. I am modifying the sample program interior_property_map.cpp to learn how to access the bundled properties, but I don't know how to fix my compile error. What is the right way to access the bundled properties for edge? Source code is: #include <boost/config.hpp> #include <iostream> #include <algorithm> #include <boost/graph/adjacency_list.hpp> #include <boost/property_map.hpp> using namespace std; using namespace boost; struct VertexData { int x; int y; }; struct EdgeData { int weight; }; template <class EdgeIter, class Graph> void who_owes_who(EdgeIter first, EdgeIter last, const Graph& G) { // Access the propety acessor type for this graph while (first != last) { // fail to compile here!!! cout << G[source(*first, G)].x << "," << G[source(*first, G)].y << " joins " << G[target(*first, G)].x << "," << G[target(*first, G)].y << " weight " << G[edge(*first)].weight << endl; ++first; } } int main() { // Create the graph, and specify that we will use store the data. typedef adjacency_list<vecS, vecS, directedS, VertexData, EdgeData> MyGraphType; typedef pair<int, int> Pair; // from <utility> Pair edge_array[11] = { Pair(0,1), Pair(0,2), Pair(0,3), Pair(0,4), Pair(2,0), Pair(3,0), Pair(2,4), Pair(3,1), Pair(3,4), Pair(4,0), Pair(4,1) }; MyGraphType G(5); for (int i=0; i<11; ++i) add_edge(edge_array[i].first, edge_array[i].second, G); G[0].x = 0; G[0].y = 0; G[1].x = 1; G[1].y = 1; G[2].x = 2; G[2].y = 2; G[3].x = 3; G[3].y = 3; G[4].x = 4; G[4].y = 4; // store weights in edges graph_traits <MyGraphType>::edge_iterator ei, eend; int i = 0; for (tie(ei, eend) = edges(G); ei != eend; ++ei) { G[*ei].weight = i++; cout << "G[e] weight " << G[*ei].weight << endl; } who_owes_who(edges(G).first, edges(G).second, G); cout << endl; return 0; } Compile error is: gcc-C++-action /home/tcma/cpp/boosttcma/libs/graph/interior_property_map.test/gcc/debug/inlining-on/interior_property_map.o /home/tcma/cpp/boosttcma/libs/graph/interior_property_map.cpp: In function `void who_owes_who(EdgeIter, EdgeIter, const Graph&) [with EdgeIter = boost::detail::adj_list_edge_iterator<boost::counting_iterator<size_t, boost::use_default, boost::use_default>, boost::detail::out_edge_iter<__gnu_cxx::__normal_iterator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, EdgeData, boost::no_property> >*, std::vector<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, EdgeData, boost::no_property> >, std::allocator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, EdgeData, boost::no_property> > > > >, size_t, boost::detail::edge_desc_impl<boost::directed_tag, size_t>, ptrdiff_t>, boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, VertexData, EdgeData, boost::no_property, boost::listS> >, Graph = main()::MyGraphType]': /home/tcma/cpp/boosttcma/libs/graph/interior_property_map.cpp:113: instantiated from here /home/tcma/cpp/boosttcma/libs/graph/interior_property_map.cpp:64: error: no matching function for call to `edge(boost::detail::edge_desc_impl<boost::directed_tag, size_t>)' set -e "g++" -c -Wall -ftemplate-depth-255 -g -O0 -Wno-inline -I"../../../bin/boost/libs/graph/example" -I "/home/tcma/cpp/boost_1_32_0" -o "/home/tcma/cpp/boosttcma/libs/graph/interior_property_map.test/gcc/debug/inlining-on/interior_property_map.o" "/home/tcma/cpp/boosttcma/libs/graph/interior_property_map.cpp" "/usr/bin/objcopy" --set-section-flags .debug_str=contents,debug "/home/tcma/cpp/boosttcma/libs/graph/interior_property_map.test/gcc/debug/inlining-on/interior_property_map.o" ... ===== TingChong Ma ______________________________________________________________________ Post your free ad now! http://personals.yahoo.ca

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RE: Problem with graph:johnson_all_pairs_shortest_paths
by keith.briggs＠bt.com 29 Nov '04

29 Nov '04

>So, you get a code like: const int V = n; int D[V][V]; In this case, 'V' is not a compile time constant and the second line >is not valid -- array bounds must be compile time constant. I have no idea why you get the error you get, instead of >error right at the point where array is declared. Most likely, this is diagnostic problem in the rather ancient (;-)) version of >gcc that you're using. Ok, so what's the right say to do this kind of dynamically-sized problem? Keith

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Problem with graph:johnson_all_pairs_shortest_paths
by keith.briggs＠bt.com 29 Nov '04

29 Nov '04

I am using g++ 3.2 on a redhat linux system. I took the johnson_all_pairs_shortest_paths example, (http://www.boost.org/libs/graph/example/johnson-eg.cpp) which works fine, but then changed const int V = 5; to const int V = n; where n has been computed at runtime. This should not change the type of V or D, but I now get the error below. Can anyone explain how to fix this? Thanks, Keith > /usr/bin/g++ -I ~/boost_1_32_0/ graph_stats.cc graph_stats.cc: In function `int main()': graph_stats.cc:46: no matching function for call to ` johnson_all_pairs_shortest_paths(main()::Graph&, int[V][V], boost::bgl_named_params<int*, boost::vertex_distance_t, boost::no_property> )'

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Serialization and source code organization
by Malte Clasen 28 Nov '04

28 Nov '04

Hi, I'm currently trying to use the new Boost 1.32 serialization library to save the state of a medium complex program (about 10.000 lines of code). The problem is that the serialization lib seems to require very close source code coupling: The translation unit that contains the load/save functions for the application has to see all serialize() method definitions (as they are templates). That means that I cannot rely on forward declarations, so I always have to include the respective header file. This slows down the compilation noticably and results in errors such as "C1204: compiler limit : internal structure overflow" and "C1055: compiler limit : out of keys" (VC++ 7.1), as more or less all significant headers are included in this translation unit. The documentation is aware of this kind of problem and recommends manual instantiations of the serialize() methods (in the PIMPL section). Do I get something wrong or is this the only solution? I don't really like manual template instantiations, but in this case I can't imagine another way to deal with it, except waiting for the next VC++ release and hoping for the best. Malte

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help needed on random libary
by Deng Kun 28 Nov '04

28 Nov '04

can someone tell me how to seed the random library? I am having some problem with the following code the seed method won't compile on solaris but works fine on windows especially in the "else" part die->engine().seed((unsigned int)(s)); gives me some error. #ifndef RANDOMBITSET_H #define RANDOMBITSET_H #include <stdlib.h> #include <boost/random.hpp> #include <boost/dynamic_bitset.hpp> class RandomBitset { public: typedef boost::mt19937 EngineType; typedef boost::bernoulli_distribution<> DistType; typedef boost::variate_generator<EngineType, DistType> DieType; EngineType rng; DistType dist; DieType *die; RandomBitset(double p=0.5): rng(), dist(p){ die= new DieType(rng, dist); } RandomBitset(const RandomBitset & r){ rng=r.rng; dist=r.dist; if (die!=NULL) { delete die; } die= new DieType(rng,dist); } virtual ~RandomBitset(){ delete die; } //force reseed //input s<0 will use system time to reseed //otherwise use s as seed void seed(int s=-1){ if (s<0) { long rs=time(NULL); srand(rs); die->engine().seed((unsigned int) rand()); }else { die->engine().seed((unsigned int)(s)); } } void randomBitset(boost::dynamic_bitset<> & bs); }; #endif //RANDOMBITSET_H

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