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Generating Numbers With Certain Distribution with Boost
by Gundala Viswanath 11 Feb '09

11 Feb '09

Dear all, Is there a way to generate K numbers of integer (K = 10^6). The maximum value of the integer is 200,000 and minimum is 1. And the occurrences of this integer follows a lognormal distribution. - Gundala Viswanath

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Constructing an error code based on the last error?
by Zachary Turner 10 Feb '09

10 Feb '09

Does boost provide a portable way to create a system::error_code object based on the last error? I don't see an obvious way to do this via the documentation unless I'm just overlooking it. There's lots of ways to create uninitialized error code objects, or error code objects initialized to a specific value, but I don't see an obvious portable way of determining "why the last operation failed". Anyone encountered this before?

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[asio] Clients (try to) connect only once
by Jens Weller 10 Feb '09

10 Feb '09

Hi I am writing on a an app, that has clients, which connect, and get events/updates send. Now, it works almost, but still, I got one problem I couldn't solve sofar: My Client only connects or tries to connect once. If the server isn't running, I have to restart the app, to be able to try again. I do get a connection event at the server, but the client seems not to respond to the send data afterwards. I am not sure, if it might be a threading issue, but i think that calling join() should do the job. My Code: void ZMSRClientFrame::OnConnect(wxCommandEvent& event) { // the behavoir happens also with out those 2 ifs (just tried to check that) if(inputhandler) { inputhandler->close(); } if(t) { t->join(); t.reset(); } try{ boost::asio::ip::tcp::resolver resolver(ios); boost::asio::ip::tcp::resolver::query query("127.0.0.1", "3210"); boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query); //InputHandler in(ios,iterator); inputhandler = boost::shared_ptr<InputHandler>(new InputHandler(this,ios,iterator)); //ios.run(); //starting ioservice thread t = boost::shared_ptr<boost::thread>(new boost::thread(boost::bind(&boost::asio::io_service::run, &ios))); } catch(std::exception& e) { wxMessageBox(e.what()); //inputhandler.reset(); } catch(...) {wxMessageBox("could not connect"); //inputhandler.reset(); } } Inputhandler calls async_connect which returns to one of its members. Which works through the first run. How to solve this? regards Jens Weller -- Jetzt 1 Monat kostenlos! GMX FreeDSL - Telefonanschluss + DSL für nur 17,95 Euro/mtl.!* http://dsl.gmx.de/?ac=OM.AD.PD003K11308T4569a

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[boost-users][asio] timeout - is io_service.reset() safe with pool of threads?
by tomasz jankowski 10 Feb '09

10 Feb '09

hello, I'm implementing timeouts according to suggestion placed here http://lists.boost.org/Archives/boost/2007/04/120339.php because I still don't understand fully how io_service work I have question: is this way of implementation of timeout safe when I'm using pool of threads for one io_service? tom ---------------------------------------------------- Kate Winslet i Leonardo DiCaprio znowu razem na ekranie! DROGA DO SZCZĘŚCIA - w kinach od 30 stycznia. Zobacz zwiastun: http://klik.wp.pl/?adr=http%3A%2F%2Fcorto.www.wp.pl%2Fas%2Fszczescie.html&s…

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Re: [Boost-users] [filesystem] windows program crashes in debug mode ( DbgUiConnectToDbg )
by Everton Patitucci 10 Feb '09

10 Feb '09

Stephen Lavelle-2 wrote: > > It appears to run > fine in release mode*, but crashes when debugged. > I don't know if you alredy figured it out, but I was having EXACTLY the same problem using boost::filesystem-1.37-mingw under Windows XP SP2 - Code::Blocks 8.02. After searching a lot I hit a forum post where another guy was having that problem and it resolved to a mix of debug/release libraries being used together. So I solved the problem in the following way: built boost again (as I'm using only filesystem I built filesystem and system libraries only, you can run a "bjam --show-libraries" so you get their name): bjam --with-system --with-filesystem debug and yet again: bjam --with-system --with-filesystem release this will output the libraries in the following path: ./bin.v2/libs/debug|release/link-static|threading-multi linked my project's debug target to the debug library created (i.e. libboost_filesystem-mgw34-mt-d-1_37.lib and libboost_system-mgw34-mt-d-1_37.lib)... same for release target... (libboost_system-mgw34-mt-1_37.lib and libboost_filesystem-mgw34-mt-1_37.lib) I hope it helps you or someone with the same problem. If you or someone else need further explanation, I'll be glad to help. Patuti

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Problem of scope with the replace in static data structure
by Rodrigo Dias Ferreira 10 Feb '09

10 Feb '09

Hi there, I am having a problem with Boost.MultiIndex (I'm using Boost 1.37). So the problem is the following: I am using a static data structure, an index which I use as my graph repository: /// Data member to represent the graph repository (using ordered_unique index) static graphIndex _graphRep; which is from the type graphIndex: ///ordered_unique Index in the data structure graph_hm typedef multi_index_container< graphMap, indexed_by< ordered_unique< BOOST_MULTI_INDEX_MEMBER(graphMap,string,_name) > > > graphIndex; Here is the graphMap: /// GraphMap: Data Structure for setting an index in the uniqueGraphName and retrieving handler Graph_h struct graphMap { string _name; Graph _graph; /// Default Constructor graphMap(){} /// Constructor with parameters: initialize the name and graph graphMap(string uniqueGraphName, Graph graph) : _name(uniqueGraphName), _graph (graph) {} /// Constructor with parameters: initialize the name and graph graphMap(const graphMap &gm) : _name(gm._name), _graph (gm._graph) {} }; For manipulating the graphs, I use a Graph_h (handler), which does a copy from the graph from this repository, does the changes in the local copy, and then the user has to call commitChanges(); to apply it in the repository (which I am using the replace function from the MultiIndex to commit it). The problem it is that inside the commitChanges(); I can retrieve from the repository through the find function (from MultiIndex). But when I the main program, it does not work (remark: I am trying right after calling the commitChanges(); It founds the graph, but it seems to be the old one, and I cannot retrieve the nodes... Why is that happening? Here it is a stretch of code from the main: //Test of the commit if (graph_h.commitChanges()) cout << "Commit was successful!\n"; else cout << "Commit was unsuccessful!\n"; // Debug //Graph_h graph_h; //NodeIterator nodeIt; //Node_h node_h; graphIt it = DynamicGraphs::_graphRep.find("COI:0351-123-4555"); graph_h = Graph_h(it); //propertystream_h propS; propS = graph_h->lookupLocalProp("name"); p_h = propS.next(); cout << "DEBUG@main:right after the commit:_git " << p_h.value() <<endl; nodeIt = graph_h->nodeIterator("Node:0351-123-4569"); if (!nodeIt) cout << "Node version was not found!"<<endl; else //Works for both: one match and range lookup while (!nodeIt.end()){ node_h = nodeIt.next(); cout << "Found it: " << *node_h; } //Debug And here it is the code from inside the commit, which it works!!! bool Graph_h::commitChanges(){ bool success; propertystream_h ps_h = _localGraph.lookupLocalProp("name"); //Exception handling in the case does not find the name property property_h p_h = ps_h.next(); //TODO: Revise about the setting of the time in the graph... too stable _localGraph.resetTimeRange(); // Debug cout << "DEBUG@commitChanges:before replacing:_git Name: " << p_h.value() <<endl; Graph_h graph_h; NodeIterator nodeIt; Node_h node_h; graphIt it = DynamicGraphs::_graphRep.find("COI:0351-123-4555"); graph_h = Graph_h(it); nodeIt = graph_h->nodeIterator("Node:0351-123-4569"); if (!nodeIt) cout << "Node version was not found!"<<endl; else //Works for both: one match and range lookup while (!nodeIt.end()){ node_h = nodeIt.next(); cout << "Found it: " << *node_h; } //Debug success = DynamicGraphs::_graphRep.replace(_git, graphMap(p_h.value(),_localGraph)); // Debug cout << "DEBUG@commitChanges:after replacing:_git Name: " << p_h.value() <<endl; it = DynamicGraphs::_graphRep.find("COI:0351-123-4555"); graph_h = Graph_h(it); nodeIt = graph_h->nodeIterator("Node:0351-123-4569"); if (!nodeIt) cout << "Node version was not found!"<<endl; else //Works for both: one match and range lookup while (!nodeIt.end()){ node_h = nodeIt.next(); cout << "Found it: " << *node_h; } //Debug return success; } I hope someone can help me.. thanks in advance, Rodrigo -- ************************************************* Rodrigo Dias Ferreira Master Student of Computational Engineering Technische Universität Dresden - Germany Mobile Phone:+49 171 3158797 E-mail: rodrigodias(a)gmx.de ************************************************* Jetzt 1 Monat kostenlos! GMX FreeDSL - Telefonanschluss + DSL für nur 17,95 Euro/mtl.!* http://dsl.gmx.de/?ac=OM.AD.PD003K11308T4569a

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Which singleton to use?
by Leandro T. C. Melo 10 Feb '09

10 Feb '09

Hi all. Apparently, there's a possibility of a singleton library in a future release, right? However, in the meanwhile, if I need a basic singleton that provides thread-safe initialization/destruction, which one would you recommend? I ask this because there's more than one Boost library with its own singleton mechanism. Thanks, Leandro.

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Hi
by Can T. Oguz 10 Feb '09

10 Feb '09

Hi, New to boost, glad to get here. Any book recommendations? Can

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[phoenix] compile error using arg1
by Paul Heil 10 Feb '09

10 Feb '09

While expanding my horizons to include functional programming, I've run in to a problem with boost::phoneix lambda functions. I'm trying to use a for_each() command with an overloaded<< operator, but I can't seem to get they types right, and I get a compile error: test.cpp(147) : error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'const boost::phoenix::actor<Eval>' (or there is no acceptable conversion) I've seen example code that's very similiar to this using "cout" instead of the overloaded << operator I have, so I tend to think this is possible. My code is below, can anybody suggest what I could do to fix this? using namespace boost::phoenix; using namespace boost::phoenix::arg_names; class A { public: friend MSXML2::IXMLDOMNode* operator <<( MSXML2::IXMLDOMNode* node, const A& a ); private: // ... }; MSXML2::IXMLDOMNode* operator <<( MSXML2::IXMLDOMNode* node, const A& a ) { // Add stuff from A to 'node' return node; } int main() { MSXML2::IXMLDOMElementPtr pElem; // MSXML2 DOM doc creation removed for brevity std::list< A > theList; // add items to the list... // copy items from the list to the XML element // This does not compile (C2679) std::for_each( theList.begin(), theList.end(), pElem << arg1 ); return 0; } I realize I could write a proxy function like: void A::Print( MSXML2::IXMLDOMNode* t ) const { t << *this; }; and use the bind() within the for_each() std::for_each( theList.begin(), theList.end(), bind( &A::Print, arg1, pElem ) ); but, I'd like to avoid that if possible. If anybody can suggest how to get this done, I would appreciate it. Thanks, PaulH

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[serialization] removing excess XML tags
by Paul Heil 10 Feb '09

10 Feb '09

I'd like to use the boost::serialization library to generate XML that must be read by a third party application. Unfortunately, this application does not like the extra stuff that the serialization library generates. The code below generates XML that looks like this: <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <!DOCTYPE boost_serialization> <boost_serialization signature="serialization::archive" version="5"> <MYTAG class_id="0" tracking_level="0" version="0"></MYTAG> </boost_serialization> What I need is XML that looks more like this: <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <MYTAG></MYTAG> What can I do to eliminate the extra stuff? Thanks, PaulH class MyClass { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version){}; public: MyClass(){}; friend std::ostream & operator<<(std::ostream &os, const MyClass &gp); virtual ~MyClass(){}; }; int main( int argc, _TCHAR* argv[] ) { MyClass mc; std::ofstream ofs("MyFile.xml"); boost::archive::xml_oarchive oa(ofs); oa << boost::serialization::make_nvp( "MYTAG", mc ); return 0; }

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