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Re: [Boost-users] [multi_index] Problem of scope with the replace in static data structure
by Rodrigo Dias Ferreira 11 Feb '09

11 Feb '09

Hi Joaquim, > > It's hard to know whether you got copy semantics right without knowing > the types > of _rangeBegin, _rangeEnd and the rest of Graph data members, but this > has prompted > me to suspect that maybe there's something wrong with the handler type > Graph_h (which > I assume is some sort of ref-counted reference to Graph, right?). Can > you please > test the following? In your //Test of the commit section, rather than > reuse graph_h please > use a different variable to do the after-commitChanges check: > > //Test of the commit > if (graph_h.commitChanges()) > cout << "Commit was successful!\n"; > else > cout << "Commitretr 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_h2 = Graph_h(it); // WE DON'T REUSE graph_h > //propertystream_h propS; > propS = graph_h2->lookupLocalProp("name"); > p_h = propS.next(); > cout << "DEBUG@main:right after the commit:_git " << p_h.value() <<endl; > nodeIt = graph_h2->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 > > Does this make any difference? Yes, it worked, if I instantiate another object (like graph_h2). After that I have done some more Debug to try to find the reason, but I still don't understand,because inside the constructor it finds the Nodes, when I use the same object (graph_h)... Inside the overloaded operator-> does not work anymore, even I am using the _localGraph in both stretch of codes. So if it was the assignment of the _localGraph, it should not work with the constructor also, isn't true? And the commitChanges, that I told before, it is for replacing this _localGraph in the repository of graphs graphIndex _graphRep; For better explanation, here it is the code: Remark: the Graph_h it will be using referencing count, but since I don't know how yet, it is not implemented. So the Graph_h I use as way of the user handle the Graph, so it has as members: - the iterator of the lookup for the Graph - _localGraph: it is where I can change the Graph, because in the index it is not possible, since their elements are constant - and bool to indicate the creation success /// Graph Handler: Wrapper for manipulating the Graph objects class Graph_h : virtual Handler { private: graphIt _git; Graph _localGraph; bool _createSuccess; public: /// Default Constructor Graph_h() : _createSuccess(false){} /// Constructor with Parameters: for creation of Graphs Graph_h (const pair<graphIt,bool> &creation) : _git(creation.first), _createSuccess(creation.second){ _localGraph = _git->_graph; } ///////////////The below constructor it is where it works,//////////// ///////////////the retrieve of nodes with _localGraph///////////// /// Constructor with Parameters: for lookup of Graphs Graph_h (const graphIt &it) : _git(it), _createSuccess(false){ _localGraph = it->_graph; //#ifndef NDEBUG_DG //Graph_h graph_h; NodeIterator nodeIt; Node_h node_h; //graphIt it = DynamicGraphs::_graphRep.find("COI:0351-123-4555"); //Graph_h //graph_h = Graph_h(it); propertystream_h propS; property_h p_h; propS = _localGraph.lookupLocalProp("name"); p_h = propS.next(); cout << "DEBUG@Graph_hConstructor(it) " << p_h.value() <<endl; nodeIt = _localGraph.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; } //#endif //NDEBUG_DG } /// Copy Constructor Graph_h (const Graph_h &h) : _git(h._git), _createSuccess(h._createSuccess){ _localGraph = h._localGraph; } Graph_h& operator=(const Graph_h &h) { _git = h._git; _createSuccess = h._createSuccess; _localGraph = h._git->_graph; return *this; } bool commitChanges(); bool operator!(){ return !_createSuccess; } ///////////////The below operator-> it is where it does not works,////// ///////////////the retrieve of nodes with _localGraph////////////////// /// Operator-> overloading: allows access to graph members Graph* operator->() { //#ifndef NDEBUG_DG //Graph_h graph_h; NodeIterator nodeIt; Node_h node_h; //graphIt it = DynamicGraphs::_graphRep.find("COI:0351-123-4555"); //Graph_h //graph_h = Graph_h(it); propertystream_h propS; property_h p_h; propS = _localGraph.lookupLocalProp("name"); p_h = propS.next(); cout << "DEBUG@Graph::operator-> " << p_h.value() <<endl; nodeIt = _localGraph.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; } //#endif //NDEBUG_DG return &_localGraph; } }; Output from these strech of code: The node are not being printed because I am changing some stuff in other part of the code... but the important is that it is found the nodes in the constructor, and in the operator-> the node were not found: Constructor Output and operator-> output: DEBUG@Graph_hConstructor(it) COI:0351-123-4555 Found it: Name: Timestamp: -1080916036 Found it: Name: Timestamp: -1080916036 DEBUG@Graph::operator-> COI:0351-123-4555 Node version was not found! Code in the main which generate that: graphIt it = DynamicGraphs::_graphRep.find("COI:0351-123-4555"); graph_h = Graph_h(it); propS = graph_h->lookupLocalProp("name"); As you asked before, Here are the type of the Graph: class Graph { private: /// This variables represent the range of time that one would like to retrieve from the API. time_t _rangeBegin, _rangeEnd; /// Represents the repository of nodes in a graph nodeIndex _nodeRep; /// Represents the Node's name repository in a graph (in order to not have redundant data) uniqueNameTable _nodeNameRep; /// Represents the Node's view with index in the timestamp (in order to filter the data) nodeTimestampView _nodeTimeStampView; /// Represents the properties of a graph propIndex _localPropRep; /// Repository for the properties of the global properties related to the graph; grobalProperties _globalPropRep; The main types here that I think it could be giving me problems it would be the ones related to the nodes, here are the definitions: typedef multi_index_container< nodeMap, indexed_by< hashed_non_unique< tag<nodeName>, key_from_key< BOOST_MULTI_INDEX_MEMBER(uniqueNodeNameStruct,const string,_name), BOOST_MULTI_INDEX_MEMBER(nodeMap, const uniqueNodeNameStruct *,_uniqueName) > >, ordered_non_unique< tag<nodeTimeStamp>,BOOST_MULTI_INDEX_MEMBER(nodeMap,time_t,_timestamp) > > > nodeIndex; /// Defining an iterator for the nodeMapIndex typedef nodeIndex::iterator nodeMapIt; struct nodeMap { const uniqueNodeNameStruct* _uniqueName; time_t _timestamp; Node _node; /// Parameter nodeMap(const uniqueNodeNameStruct* name, time_t t, Node node): _uniqueName(name),_timestamp(t), _node(node) {} /// Copy Constructor nodeMap(const nodeMap &nm): _uniqueName(nm._uniqueName),_timestamp(nm._timestamp), _node(nm._node) {} //TODO: Delete this. /// For debugging friend std::ostream& operator<<(std::ostream& os,const nodeMap& nm) { os<<"Name: " << nm._uniqueName << " Timestamp: " << nm._timestamp << std::endl; return os; } }; struct uniqueNodeNameStruct { string _name; /// Parameter Constructor uniqueNodeNameStruct(const string& name):_name(name){} /// Copy Constructor uniqueNodeNameStruct(const uniqueNodeNameStruct &nodeName): _name(nodeName._name){} uniqueNodeNameStruct* operator=(uniqueNodeNameStruct& st){ _name = st._name; return &st; } friend std::ostream& operator<<(std::ostream& os,const uniqueNodeNameStruct& nodeName) { os<<"uniqueName: " << nodeName._name << endl; return os; } // TODO: Verify the necessity of change a name of the node struct change_name { change_name(const string& new_name):_new_name(new_name){} void operator()(uniqueNodeNameStruct& n) { n._name=_new_name; } private: std::string _new_name; }; }; /** * \brief uniqueNodeNames are store in this table and they are unique. * The uniqueNodeNames will be reference in this table, in order to * associate then with the different versions, in that way it's possible * to maintain just one name for all its versions. */ typedef multi_index_container< uniqueNodeNameStruct, indexed_by< hashed_unique< BOOST_MULTI_INDEX_MEMBER(uniqueNodeNameStruct,string,_name) > > > uniqueNameTable; typedef uniqueNameTable::iterator nameMapIt; I don't know how did you find that could be something in the Graph_h, perhaps you can understand that, because I don't understand what is wrong there... Looking foward for a feedback, and thanks for the help so far... best regards, 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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Re: [Boost-users] for_each_until like algorithm
by Robert Jones 11 Feb '09

11 Feb '09

On Wed, Feb 11, 2009 at 2:24 PM, Marshall Clow <marshall(a)idio.com> wrote: > You might look in the sandbox, specifically in boost/algorithms/all.hpp. > What you call "exists" is called "any" there - which follows the proposal > for TR2. Oh yes, so it is! With your name on the file I see. I prefer exists to any, but OTOH I can see the symetry with none, so maybe your version is best. When is this likely to emerge from the shadows? Also, I see you have range versions too - does this need the RangeEx stuff to be in Boost too? Do you think your algorithms should have Boost concept checks on their template parameters? Cheers, Rob.

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for_each_until like algorithm
by Peter Barker 11 Feb '09

11 Feb '09

Hi, I just wondered if there was already an algorithm (or way to compose one) in Boost that would allow me to iterate over a container of pointers to objects calling a function on each one and completing when one of them returned a particular value? For example, I have a master/child relationship and the master has a method called shouldCalculate(). Whether this returns true is partly dependent on what the children return for their shouldCalculate() method. So I'd like to say something like this: bool Master::shouldCalculate() { // Look at data at the master level to see if it's stale. If it is, return true. // See if any of the children should calculate bool staleChildren = boost::for_each_until(children_.begin(),children_.end(), boost::bind(&Child::shouldCalculate,_1),until_true_returned); return staleChildren; } Regards, Pete

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Boost:Signals and Bind question
by mararual 11 Feb '09

11 Feb '09

Hi Everyone, I have a question on using Signals with a COM server and a client. Is it possible to have a signal on a COM server and a method ConnectSlot(clientMethod) that can be called from a client? I want to have a COM server that when some update is done, notifies all of the slots(subscribers), so that from the clients I can do: helloService->ConnectSlot(boost::bind(&Callback)); where callback is a method in the client. On the server side I have: STDMETHODIMP CHelloService::ConnectSlot(VARIANT aSubscriber) { connect(aSubscriber); //connect(boost::bind(aSubscriber)); return S_OK; } CHelloService::connection_t CHelloService::connect(signal_t::slot_function_type subscriber) { return m_sig.connect(subscriber); } Don't know how to receive the result of Boost::bind from the client. I read Bind supports COM by adding #define BOOST_MEM_FN_ENABLE_STDCALL before the include of bind.hpp. What would you recommend for this approach? Any examples? Thanks in advance, Marcos -- View this message in context: http://www.nabble.com/Boost%3ASignals-and-Bind-question-tp21800004p21800004… Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] [multi_index] Problem of scope with the replace in static data structure
by Rodrigo Dias Ferreira 11 Feb '09

11 Feb '09

Hi Joaquim, > > Hi Rodrigo, > > First of all let me advice you to add the name of the library to the > subject line > of your post (in this case, [multi_index]) so that authors can more easily > track messages of their particular interest. Thanks for the advice. :) > > Rodrigo Dias Ferreira escribi?: > > 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: > > [...] > > 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... > > > > The code is too convoluted for me to detect anything suspicious: the > fact that you check > for the newly replaced element just before commitChanges returns and > just after and > have differing results cannot possibly be related to the fact that > DynamicGraphs::_graphRep > is static, so I'd look somewhere else. Suggestions: > > 1. Can you provide a narrowed down compilable program exhibiting the > problem? I think that will be a little hard to do, let's first try these steps below first, maybe you can figure out what it is, because I'm not understanding what could be, since it seems to work inside the function and outside doesn't, and as it is a static data member... > 2. If the answer to 1 is no, can you post the debug console output of > your program? The output of this part of the code (I will mark the part inside the function commitChanges();: ///////////begin commitChanges();///////////////////////////// DEBUG@commitChanges:before replacing:_git Name: COI:0351-123-4555 Node version was not found! DEBUG@commitChanges:after replacing:_git Name: COI:0351-123-4555 Found it: Name: Node:0351-123-4569 Timestamp: 1234340512 Found it: Name: Node:0351-123-4569 Timestamp: 1234340521 ///////////end commitChanges();///////////////////////////// Commit was successful! Retrieving the graph with commit: Node version was not found! - As you can see, inside before replacing, it did not find the nodes inserted, as expected. - Then after replacing it found the nodes inserted (as expected). - But then after goes out of the function, as you can see, no nodes was found it... they shouldn't be there? I mean because the repository is static, I think it should be no reason for the nodes be there inside the function, and outside no... > 3. You're copying values of the type Graph. How's this type defined? Has > it proper copy semantics? Yes, I think so: class Graph { ... public: // TODO: Really constructors /// Default Constructor Graph() { _rangeBegin = 0; _rangeEnd = 0; } /// Copy constructors Graph(const Graph &g) : _rangeBegin(g._rangeBegin), _rangeEnd(g._rangeEnd), _nodeRep(g._nodeRep), _nodeNameRep(g._nodeNameRep), _nodeTimeStampView(g._nodeTimeStampView), _localPropRep(g._localPropRep), _globalPropRep(g._globalPropRep){} ... } > 4. What happens if you try the after-replace check inside > Graph_h::commitChanges > (that is, the section beginning with cout << "DEBUG@commitChanges:before > replacing:_git Name: ") > *twice* rather than just onec? Still got positive results for both checks? Yes. I've added twice before the replace and after, the result is the same (as expected) and still I don't understand why does not work outside... DEBUG@commitChanges:before replacing:_git Name: COI:0351-123-4555 Node version was not found! DEBUG@commitChanges:before replacing:_git Name: COI:0351-123-4555 Node version was not found! DEBUG@commitChanges:after replacing:_git Name: COI:0351-123-4555 Found it: Name: Node:0351-123-4569 Timestamp: 1234341125 Found it: Name: Node:0351-123-4569 Timestamp: 1234341134 DEBUG@commitChanges:after replacing:_git Name: COI:0351-123-4555 Found it: Name: Node:0351-123-4569 Timestamp: 1234341125 Found it: Name: Node:0351-123-4569 Timestamp: 1234341134 Commit was successful! Retrieving the graph with commit: Node version was not found! thanks a lot for the help, I hope you can figure it out what it is happen... best regards Rodrigo > > I'm sorry I can't be more helpful with the info you provide. Looking fwd > to > having your feedback. > > Joaqu?n M L?pez Mu?oz > Telef?nica, Investigaci?n y Desarrollo > > > > > -- ************************************************* Rodrigo Dias Ferreira Master Student of Computational Engineering Technische Universität Dresden - Germany Mobile Phone:+49 171 3158797 E-mail: rodrigodias(a)gmx.de ************************************************* Psssst! Schon vom neuen GMX MultiMessenger gehört? Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger01

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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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[thread] C++/CLI C# mixed code: linking to libthread yields runtime exception
by Markus Werle 10 Feb '09

10 Feb '09

Hi! I am pretty sure this is an issue beyond boost, rather one of those numerous pitfalls on the way to the M$-promised land called CanUseOldCodeAndCppInDotNet. OTOH I have hope that someone knows about some workaround, OK, here the facts: Win32, XP SP3, using Visual Studio 2008 SP1 with boost_1_37_0 I create a solution containing a C++/CLI project and a C# project, which references the C++/CLI project. Now if the C++/CLI project simply links to libboost_thread*, either via autolink or via explicit configuration, the compiler creates an executable which fails to start in both configurations, Debug and Release. The debugger catches a System.BadImageFormatException. Something went plain wrong. OTOH adding the source files contained in \libs\thread\src\win32 to the project, defining BOOST_ALL_NO_LIB and adding --- #pragma managed(push, off) extern "C" void tss_cleanup_implemented(void) {} #include <boost/thread/thread.hpp> #pragma managed(pop) --- in a cpp file yields a working executable. Scratching my head. Do you have any hint why linking to libboost_thread leads to this weird behaviour? Any idea what I might try? I can provide a stripped down project solution as zip-file on request. regards, Markus [keywords C# C++/CLI CSharp mixed thread boost System.BadImageFormatException]

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[solved] Using Boost in C++/CLI and C# mixed code environment
by Markus Werle 10 Feb '09

10 Feb '09

Hi! With the help of Anthony Williams and Hansi plus a step by step fiddling with the Visual Studio settings I finally managed (sic!) to get C++ and Boost playing nicely in a mixed C++/CLI plus C# code setting. Phew. Went to hell and came back again. Disclaimer: This document was written in order to be useful and published in the hope that it is helpful to others. There is no guarantee that this information really helps in all similar settings. Maybe things are still broken deep inside, but my little demo application at least does not choke on startup or finalization anymore. If you have additional insight, please share this information. Contact me by mail and/or followup to this post. So here is a summary of what I found out: I create a solution containing a C++/CLI project and a C# (Google: CSharp) project, which references the C++/CLI project. The C++/CLI project is a DLL-project which uses the Boost libaries. Without any further settings, the autolink features of Boost are configured such that the Boost libraries are statically linked to the C++ DLL (which IMHO normally is fine and exactly what I want: no extra libraries to ship with my software). Note that some libaries may be used implicitly: Spirit for example includes Boost.Threads when BOOST_SPIRIT_THREADSAFE is defined. Alas, the default compiler settings may lead to trouble: Statically linking to Boost libraries may yield an executable which chokes on startup with a System.BadImageFormatException, even if the compiler and linker run without warning (a bug, IMHO). Explanantion: <cite author="Anthony Williams" date="2009-02-04 15:54:40 GMT"> The problem is that the static boost thread library tries to hook the native win32 PE TLS callbacks in order to ensure that the thread-local data used by boost thread is cleaned up correctly. This is not compatible with a C++/CLI executable. </cite> Solution: In Configuration Properties -> C/C++ -> Preprocessor -> Preprocessor Definitions add BOOST_ALL_DYN_LINK in order to force the usage of the DLLs. In addition copy the necessary DLLs to the directory where the executable resides. E.g. copy boost_thread-vc90-mt-gd-1_XX.dll to MyApp/bin/Debug. It also helps to #define BOOST_LIB_DIAGNOSTIC in the Preprocessor Definitions to find out from the compiler output which libraries are to be included. The .NET framework throws a System.IO.FileNotFoundException on missing libraries without further information about which files are missing (The classical Mirosoft way to handle these things since Windows 98: "An error has occurred.") Setting these compiler flags should yield an application that does not fail on startup. Enters the next bug of Visual Studio: The C++/CLI compiler deliberately chooses to ignore the #pragma managed(push, off) / #pragma managed(pop) PREPRO directives for files which are compiled with /clr command line flag. You obtain a plethora of warnings of the form warning C4793: 'boost::[..]::`vcall'{0}'' : function compiled as native : For the executable this means that on termination another exception is thrown, which adds to the confusion: Unhandled exception at 0x7c812a7b in XXX.exe: 0xC0020001: "Die Zeichenfolgenbindung ist unzulässig." or in english: Error 1700 "The string binding is invalid" or RPC_S_INVALID_STRING_BINDING. Solution: Put managed (CLI) and unmanaged C++ code into different compilation units. For unmanaged code files change the compiler settings this way: In "Configuration Properties -> C/C++ -> General -> Compiler with Common Language" support choose "No Common Language Support". Now things should work fine. best regards, Markus

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Re: [Boost-users] boost and std collisons in c++0x
by Daniel Lidström 10 Feb '09

10 Feb '09

_____ From: Sergey Sadovnikov [mailto:flex_ferrum@artberg.ru] Sent: Thursday, February 05, 2009 10:02 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] boost and std collisons in c++0x MF> If you want to use boost, use boost::. If you want to use the STD MF> library, use std::. Perfectly! What you can say about following pieces of code: std::vector<std::shared_ptr<SomeClass>> vec; std::for_each(vec.begin(), vec.end(), std::bind(&std::shared_ptr<SomeClass>::get, std::placeholders::_1, std::bind(&SomeClass::foo, std::placeholders::_1, 10))); and vector<shared_ptr<SomeClass>> vec; for_each(vec.begin(), vec.end(), bind(&shared_ptr<SomeClass>::get, _1, bind(&SomeClass::foo, _1, 10))); Here's what I do, for every class that's put in shared_ptr's (I'm very disciplined in this way): // SomeClassFwd.h: class SomeClass; typedef std::shared_ptr<SomeClass> SomeClassPtr; typedef std::vector<SomeClassPtr> SomeClassCollection; Now, your code becomes: SomeClassCollection vec; std::for_each(vec.begin(), vec.end(), std::bind(&SomeClassPtr::get, std::placeholders::_1, std::bind(&SomeClass::foo, std::placeholders::_1, 10))); I would agree C++ can be very verbose. Using typedef can limit this a lot though. /Daniel Lidström

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Is bimap swappable?
by Adam Badura 10 Feb '09

10 Feb '09

The documentation for Boost.Bimap does not mention that bimap is swappable (but it does not warn explicitly that it is not - which it should IMHO if it is not). When compiling the code (under VC 2008, Boost 1.38) a.swap(b) compiles for a and b being bimap of the same type. How is it then? Adam Badura

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[proto] problem with templated recursive transform
by Daniel Oberhoff 10 Feb '09

10 Feb '09

Hi, I have gotten my hands pretty dirty with my array expression DSEL, and hove gotten surprisingly far (surprisingly considering the amounts of black template magic involved :) ). Now I am stuck with a templated recursive transform, that I cant seem to get right. Here is a stripped down version: template<typename T, typename IndexSet> struct ExpressionIteratorBuilder : proto::or_< proto::when< cpudata_indexing_grammar< proto::_ > , TerminalIteratorBuilder<T, IndexSet>( proto::_ ) > ,proto::when< proto::unary_plus< cpudata_grammar > , ExpressionIteratorBuilder<T, IndexSet>( proto::_left ) > > {}; so what does work is when I have the first case (i.e. the expression is just an indexed array terminal), but the second case, where it recurses breaks on instantiation. I have tried all the tricks from the proto docs, i.e. adding a dummy callable template parameter, specializing boost::proto:::is_callable, and wrapping the recursion in proto::call, always the same long error. It also works when ExpressionIteratorBuilder is not a template, though that would not make it very useful. Any ideas? Otherwise I am beginning to love proto, and am looking forward to c++0x when the error messages might become readable through concepts :). Best Daniel -- --- Daniel Oberhoff Fraunhofer FIT Schloss Birlinghoven 53754 Sankt Augustin, Germany Tel.: +49-(0)-2241-14-3486 Fax.:+49 (0) 2241/14-2080

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Boost 1.38.0 released
by Beman Dawes 10 Feb '09

10 Feb '09

Boost 1.38.0 has been released and is available from SourceForge. See http://sourceforge.net/projects/boost/ This release includes three new libraries: Flyweight, ScopeExit, and Swap. Updated Libraries: Accumulators, Any, Asio, Config, Date_Time, Exception, Filesystem, Graph, Hash, Interprocess, Intrusive, Lexical Cast, Math, Multi-index Containers, Proto, Regex, Thread, TR1, Type Traits, Unordered, and Xpressive. Other Changes: Experimental CMake build system. You can read the full release announcement here: http://www.boost.org/users/news/version_1_38_0 The release managers were Beman Dawes, Daniel James, Eric Niebler, and Rene Rivera. --Beman Dawes

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Data_Time - Exception: could not convert calendar time to UTC time
by Bruno Dutra 09 Feb '09

09 Feb '09

Hello folks, Today I downloaded the new version of Boost, 1.38, and tried to compile and run the Source listing for Timer.5<http://www.boost.org/doc/libs/1_38_0/doc/html/boost_asio/tutorial/tuttimer5…>example from Asio, but it was throwing the exception: "could not convert calendar time to UTC time" (Note that i'm building it under windows vista using MinGW GCC, which I believe is not on the "tested compilers list of boost 1.38") After some time traking the culprit, I got to the function time_type microsec_clock::create_time(time_converter converter) from the boost\date_time\microsec_time_clock.hpp header in which the variable 'std::time_t t' was strangely assuming a negative value, probably due to an overflow. Then I realized that changing the type of the variable 'micros' from uint64_t to std::time_t on that same function, could solve the problem. I just want to know if that's a known issue and if applying that small fix other issues may appear. Thanks in advance Bruno

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[Proto] implementing an computer algebra system with proto
by Kim Kuen Tang 09 Feb '09

09 Feb '09

Hi all, considering the following expression created with proto: "3 *var_+5=2; .. The tree would be : = / \ + 2 / \ * 5 / \ 3 var_ Here the term "var_" is somewhat a placeholder. I wonder wheter it is possible now to change the structure of the tree. That is i want to define a grammar that is able to produce another expression like this. "var_=(2-5)/3;" In tree: = / \ var_ div / \ - 3 / \ 2 5 With this expression i can now define a context that return the final result of the right hand side. But is this possible in proto with the existing functions? This situation is somewhat different from the examples in the documentation. Here i dont want to replace the child node. The whole structure of the input tree should be transformed in another one. Cheers Kim Tang

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boost accumulators - kth central moments? [and slow compiles]
by Gordon Anderson 09 Feb '09

09 Feb '09

I have a couple Qns about boost accumulators in 1_37_0 - 1) Central moments ? - There are accumulators for simple kth moments - boost/accumulators/statistics/moment.hpp Are central kth moments [relative to the mean] there somewhere? Obviously you can construct one from the other with a weighted sum of the k moments on the same data. 2) Slow build ! - It is a bit slow to compile code using eg. moment<6> accumulators.. It takes around 12 seconds on my machine to build sample code with 'moment<12>' exponential recursive template evaluation?? I'm using gcc 4.2.4 cheers, gord.

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Re: [Boost-users] Cycles of shared_ptr
by Donovan Parks 09 Feb '09

09 Feb '09

Hello Alan, Thanks for the response. I appreciate what you are saying and realize that we need to draw up some diagrams which indicate ownership rules. It turns out my problem was actually unrelated to cycles of shared_ptr, but it is still good to be thinking about this possibility. Cheers, Donovan

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