October 2007 - Boost-users - lists.preview.boost.org

Re: [Boost-users] regex_search in std::string
by Troy Alexander 10 Oct '07

10 Oct '07

Thanks. That did it. I was focusing on the string to match not the return type. Makes since that they need to be the same type. Troy -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of John Maddock Sent: Wednesday, October 10, 2007 2:44 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] regex_search in std::string Troy Alexander wrote: > The 1st regex_search looking at input_line char[] works Ok it's the > 2nd one looking at date_and_time_s std::string that gets the error. > If I remark out the 2nd one the program builds and I watch the > input_line doing what it should in the debugger. > > Also this code used to work before I upgraded from Visual C++6 to > Visual C++8 and from bost_1_33_1 to boost_1_34_0. I don't know if it > was the change in compiler or the boost lib that broke this. In VC6 this worked "by accident" because const char* and std::string::const_iterator were the same type. That's not true in general, and you should use boost::smatch as the match_results type for use with std::string's. HTH, John. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[BGL] maximum flow through push_relabel_max_flow
by "Alejandro M. Aragón" 10 Oct '07

10 Oct '07

Hello all, I've been working with the Edmunds & Karp maximum flow algorithm in the BGL for some time without any problems. However, I realized that I could do better in time complexity by moving to the push_relabel_max_flow algorithm so I gave it a try. I've been trying to figure out what the problem with my code is for the entire day without success. I was wondering if someone could tell me what is my mistake. It is a very simple problem, four vertices, four edges, the result from the algorithm should be two: 2--------1 | | | | | | 0--------3 Source is 0, target is 1, all edges have unit capacity. The code is: void compute_max_flow(Graph* g_) { // obtain number of vertices in undirected graph size_t n = num_vertices(*g_); typedef adjacency_list_traits<vecS, vecS, directedS> Traits; typedef adjacency_list<listS, vecS, directedS, property<vertex_index_t, int>, property<edge_capacity_t, int, property<edge_residual_capacity_t, int, property<edge_reverse_t, Traits::edge_descriptor> > > > FlowGraph; typedef graph_traits<FlowGraph>::edge_descriptor EdgeFlow; FlowGraph g(num_vertices(*this->g_)); property_map<FlowGraph, vertex_index_t>::type indexmap = get(vertex_index, g); property_map<FlowGraph, edge_capacity_t>::type capacity = get(edge_capacity, g); property_map<FlowGraph, edge_reverse_t>::type rev = get(edge_reverse, g); property_map<FlowGraph, edge_residual_capacity_t>::type residual_capacity = get(edge_residual_capacity, g); Traits::vertex_descriptor s, t; EdgeFlow e1,e2; bool in1,in2; // add edges, reverse edges and capacities to new graph for flow computation edge_iter ei,ei_end; for (tie(ei,ei_end) = edges(*g_); ei != ei_end; ++ei) { // obtain vertices in the original graph vertex u = source(*ei, *g_); vertex v = target(*ei, *g_); // insert edges in new graph and add unit capacities tie(e1, in1) = add_edge(u,v,g); tie(e2, in2) = add_edge(v,u,g); if(in1 && in2) { // assign reverse edges to property map rev[e1] = e2; rev[e2] = e1; capacity[e1] = 1; capacity[e2] = 0; } } graph_traits<FlowGraph>::vertex_iterator vvi,vvi_end; for(tie(vvi,vvi_end) = vertices(g); vvi!=vvi_end; ++vvi) { cout<<"index -> "<<indexmap[*vvi]<<endl; } graph_traits<FlowGraph>::edge_iterator eei,eei_end; for(tie(eei,eei_end) = edges(g); eei!=eei_end; ++eei) { cout<<"edge -> "<<*eei<<endl; cout<<"capacity -> "<<capacity[*eei]<<endl; cout<<"rev -> "<<rev[*eei]<<endl; } int flow = push_relabel_max_flow(g, 0, 1, capacity, residual_capacity, rev, indexmap); cout<<"flow -> "<<flow<<endl; } Results in: index -> 0 index -> 1 index -> 2 index -> 3 edge -> (0,2) capacity -> 1 rev -> (2,0) edge -> (0,3) capacity -> 1 rev -> (3,0) edge -> (1,2) capacity -> 1 rev -> (2,1) edge -> (1,3) capacity -> 1 rev -> (3,1) edge -> (2,0) capacity -> 0 rev -> (0,2) edge -> (2,1) capacity -> 0 rev -> (1,2) edge -> (3,0) capacity -> 0 rev -> (0,3) edge -> (3,1) capacity -> 0 rev -> (1,3) flow -> 0 I would appreciate any inputs on this. Thank you, a²

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Usage of Transitive_closure().
by Ning Ruan 10 Oct '07

10 Oct '07

my code to use transitive_closure(): Graph tc; VertexIndexMap index_map = get(&VertexProp::id, g); vector<Vertex> to_tc_vec(num_vertices(g)); iterator_property_map<Vertex*, VertexIndexMap, Vertex, Vertex&> g_to_tc_map(&to_tc_vec[0], index_map); transitive_closure(graph, tc, g_to_tc_map, (index_map)); I use print_graph(tc, get(&VertexProp::id, tc) to print the transitive graph, then it shows: 0 --> 0 0 0 0 0 0 0 0 0 --> 0 0 0 --> 0 --> 0 0 0 0 0 0 0 0 0 --> 0 --> 0 --> 0 0 0 0 --> 0 0 0 0 0 0 0 0 the result miss the id of vertex, what 's the problem. my original graph g is correcet: 0 --> 1 2 3 1 --> 4 5 2 --> 3 --> 6 7 4 --> 5 --> 6 --> 1 7 --> 0

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regex_search in std::string
by Troy Alexander 10 Oct '07

10 Oct '07

I am struggling with a regex in some code of mine. I want to use regex_search to look for a match in a std::string, but my code will not build. This is a snippet of what I am trying to do. using namespace std; string in_file_name_s; string date_and_time_s; string day_s; char input_line[5000]; boost::regex re_date_time("(.*-.*-.*:.*:.*),.*,.*,.*,.*,.*,.*,.*,.*,"); boost::regex re_pices_date_time("(.*)\\-(.*)\\-(.*) (.*)"); boost::cmatch match; while (inFile.getline(input_line , 5000)) { if (boost::regex_search(input_line, match , re_date_time )) { date_and_time_s = match[1]; if (boost::regex_search(date_and_time_s , match , re_pices_date_time )) { day_s = match[1]; } } } When I compile I get the following error error C2784: 'bool boost::regex_search(const std::basic_string<charT,ST,SA> &,const boost::basic_regex<charT,traits> &,boost::regex_constants::match_flag_type)' : could not deduce template argument for 'const boost::basic_regex<charT,traits> &' from 'boost::cmatch' The 1st regex_search looking at input_line char[] works Ok it's the 2nd one looking at date_and_time_s std::string that gets the error. If I remark out the 2nd one the program builds and I watch the input_line doing what it should in the debugger. Also this code used to work before I upgraded from Visual C++6 to Visual C++8 and from bost_1_33_1 to boost_1_34_0. I don't know if it was the change in compiler or the boost lib that broke this. Thanks in advance for your help. Troy

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Re: [Boost-users] Boost::regex causes runtime errors with CLR
by Hansi Hansi 10 Oct '07

10 Oct '07

Hello, In VS2005 is a problem with the Initializing of the CRT when you have a .net application. Normally it helps when you use as entry point '?mainCRTStartupStrArray@@$$FYMHP$01AP$AAVString@System@@@Z'. I hope this helps. Best regards Hansjörg _____________________________________________________________________ Der WEB.DE SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! http://smartsurfer.web.de/?mc=100071&distributionid=000000000066

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Boost::regex causes runtime errors with CLR
by Rajib 09 Oct '07

09 Oct '07

Hi, I'm trying to use boost::regex with a "Windows Forms Application" in Visual Studio 2005. Everything works fine with normal C++, and even using a "CLR Console Application." But when I use the "Windows Form Application" template the program crashes while initializing variables. Basically I take code like: #include <boost/regex.hpp> using boost::regex; using boost::regex_search; bool h() { return regex_search("asdfasdf",regex("sd")); } put it in a separate file, turn off precompiled headers for that file, and never actually call h(). The program crashes instantly with a debug assertion failed at dbgheap.c/Line 1414/_CrtIsValidHeapPointer. The call stack looks like: ... msvcr80d.dll!__dllonexit(int (void)* func=0x00446110, void (void)* * * pbegin=0x0012eab8, void (void)* * * pend=0x0012eab0) Line 273 + 0x11 bytes C temp.exe!_onexit(int (void)* func=0x00446110) Line 110 + 0x11 bytes C temp.exe!atexit(void (void)* func=0x00446110) Line 127 + 0x9 bytes C temp.exe!boost::re_detail::`dynamic initializer for 'block_cache''() Line 189 + 0x2b bytes C++ ... It does this whether I compile the file with regex with the /clr flag or not (although the /clr flag gives a lot of errors, one of which isn't about converting fastcall to stdcall: include\boost/shared_ptr.hpp(92) : warning C4793: 'vararg' : causes native code generation for function 'void boost::detail::sp_enable_shared_from_this(const boost::detail::shared_count &,...)' Thanks, Rajib

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Boost Spirit and C++/CLI
by Jason Stewart 09 Oct '07

09 Oct '07

Has anyone tried using boost spirit with C++/CLI? I have a library that uses Spirit internally to parse a file. The library is built as an unmanaged C++ static library. I then link that to a managed C++/CLI application but when I try to parse the file I get heap corruption. The corruption seems to happen near an #ifdef for BOOST_SPIRIT_THREADSAFE so I tried to define that for the build of the library and the application. Unfortunately it now fails to initialize correctly and dies on startup. Has anyone done this before? Thanks, Jason Stewart

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boost::serialization XSD support
by Juhasz, Zoltan (IT) 09 Oct '07

09 Oct '07

Hi, I've got a pretty strange problem. We are using boost::serialization library to serialize arbitrary structs into XML. That is working pretty good. Our problems are: - we also need to generate schema files (XSD) for the archive file, since this XML archive file is going to be used by other programs (e.g. written in Java etc.), and - the unserialization part should be validated through the schema file. Currently, the boost::serialization library can serialize / deserialize our structs to XML just fine, but: How can we add XSD generation support? How can we 'force' boost::serialization to validate the XML file through an schema file (XSD)? PS: Unfortunately, the automatic generation of the XSD file is a strict requirement, that is why we cannot use regular XML <> C++ object mapping tools, where the C++ codes are generated by an external tool from a schema (XSD) file. PS2: If you know other third party tools that can solve the above mentioned problem, please feel free to write. Thank you in advance! Best Regards, Zoltan Juhasz Morgan Stanley | Technology | Budapest Zoltan dot Juhasz at MorganStanley dot com -------------------------------------------------------- NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error.

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how to schedule nodes in graph
by Suresh Gupta 09 Oct '07

09 Oct '07

Hi, I want to do the following: I have a graph in boost. Now I want to schedule the graph nodes in topological order as follows: 1. The nodes which do not have any parents are to be scheduled in first cycle. Record the list of these nodes. 2. Remove already recorded nodes (in step 1) from the graph. 3. Repeat 1 and 2 on the remaining graph and so on. How to do the above? I need functions: 1. Get all nodes which do not have parents. 2. To remove the nodes from graph. Please suggest me about the functions in boost so do the same. Thanks, Suresh

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Boost::Regex question
by Dima Kagan 09 Oct '07

09 Oct '07

Hi, I'm currently evaluating the Regex package and encountered a minor issue. I need to match a string that can contain some special characters (.[{()\*+?|^$) as well. My question is if there is a way to tell Regex to treat this string "as is", including the special characters? I need to do this without escaping the special characters in the string or the match expression. For those of you familiar with Tcl Expect, I'm looking for an option similar to "expect -ex". Thank you! Regards, Dima Kagan

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