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  • Extend and Overload MS and Point Types

    - by dr d b karron
    Do I have make my own Point and Vector types to overload them ? Why does this not work ? namespace System . windows { public partial struct Point : IFormattable { public static Point operator * ( Point P , double D ) { Point Po = new Point ( ); return Po; } } } namespace SilverlightApplication36 { public partial class MainPage : UserControl { public static void ShrinkingRectangle ( WriteableBitmap wBM , int x1 , int y1 , int x2 , int y2 , Color C ) { wBM . DrawRectangle ( x1 , y1 , x2 , y2 , Colors . Red ); Point Center = Mean ( x1 , y1 , x2 , y2 ); wBM . SetPixel ( Center , Colors.Blue , 3 ); Point P1 = new Point ( x1 , y1 ); Point P2 = new Point ( x1 , y2 ); Point P3 = new Point ( x1 , y2 ); Point P4 = new Point ( x2 , y1 ); const int Steps = 10; for ( int i = 0 ; i < Steps ; i++ ) { double iF = (double)(i+1) / (double)Steps; double jF = ( 1.0 - iF ); Point P11 = **P1 * jF;** } }

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  • Send C++ Structure to MSMQ Message

    - by Gobalakrishnan
    Hi, I am trying to send the below structure through MSMQ Message typedef struct { char cfiller[7]; short MsgCode; char cfiller1[11]; short MsgLength; char cfiller2[2]; } MESSAGECODE; typedef struct { MESSAGECODE Header; char DealerId[16]; char GroupId[16]; long Token; short Periodicity; double Deposit; double GrossExposureLimit; double NetExposureLimit; double NetSaleExposureLimit; double NetPositionLimit; double TurnoverLimit; double PendingOrdersLimit; double MTMLossLimit; double MaxSingleTransValue; long MaxSingleTransQty; double IMLimit; long NetQuantityLimit; } LIMITUPDATE; void main() { // // create queue // open queue // send message // OleInitialize(NULL); // have to init OLE // // declare some variables // IMSMQQueueInfoPtr qinfo("MSMQ.MSMQQueueInfo"); IMSMQQueuePtr qSend; IMSMQMessagePtr m("MSMQ.MSMQMessage"); LIMITUPDATE l1; l1.Header.MsgCode=26001; l1.Header.MsgLength=150; qinfo->PathName = ".\\private$\\q99"; m->Body = l1; qSend = qinfo->Open(MQ_SEND_ACCESS, MQ_DENY_NONE); m->Send(qSend); qSend->Close(); } while compiling i am getting the following error. Error 2 error C2664: 'IMSMQMessage::PutBody' : cannot convert parameter 1 from 'LIMITUPDATE' to 'const _variant_t &' c:\temp\msmq\msmq.cpp 58 msmq thank you.

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  • How to easily map c++ enums to strings

    - by Roddy
    I have a bunch of enum types in some library header files that I'm using, and I want to have a way of converting enum values to user strings - and vice-versa. RTTI won't do it for me, because the 'user strings' need to be a bit more readable than the enumerations. A brute force solution would be a bunch of functions like this, but I feel that's a bit too C-like. enum MyEnum {VAL1, VAL2,VAL3}; String getStringFromEnum(MyEnum e) { switch e { case VAL1: return "Value 1"; case VAL2: return "Value 2"; case VAL1: return "Value 3"; default: throw Exception("Bad MyEnum"); } } I have a gut feeling that there's an elegant solution using templates, but I can't quite get my head round it yet. UPDATE: Thanks for suggestions - I should have made clear that the enums are defined in a third-party library header, so I don't want to have to change the definition of them. My gut feeling now is to avoid templates and do something like this: char * MyGetValue(int v, char *tmp); // implementation is trivial #define ENUM_MAP(type, strings) char * getStringValue(const type &T) \ { \ return MyGetValue((int)T, strings); \ } ; enum eee {AA,BB,CC}; - exists in library header file ; enum fff {DD,GG,HH}; ENUM_MAP(eee,"AA|BB|CC") ENUM_MAP(fff,"DD|GG|HH") // To use... eee e; fff f; std::cout<< getStringValue(e); std::cout<< getStringValue(f);

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  • Storing header and data sections in a CSV file

    - by morpheous
    This should be relatively easy to do, but after several hours straight programming my mind seems a bit frazzled and could do with some help. I have a C++ class which I am currently using to store read/write data to file. I was initially using binary data, but have decided to store the data as CSV in order to let programs written in other languages be able to load the data. The C++ class looks a bit like this: class BinaryData { public: BinaryData(); void serialize(std::ostream& output) const; void deserialize(std::istream& input); private: Header m_hdr; std::vector<Row> m_rows; }; I am simply rewriting the serialize/deserialize methods to write to a CSV file. I am not sure on the "best" way to store a header section and a "data" section in a "flat" CSV file though - any suggestions on the most sensible way to do this?

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  • Inheritance inside a template - public members become invisible?

    - by Juliano
    I'm trying to use inheritance among classes defined inside a class template (inner classes). However, the compiler (GCC) is refusing to give me access to public members in the base class. Example code: template <int D> struct Space { struct Plane { Plane(Space& b); virtual int& at(int y, int z) = 0; Space& space; /* <= this member is public */ }; struct PlaneX: public Plane { /* using Plane::space; */ PlaneX(Space& b, int x); int& at(int y, int z); const int cx; }; int& at(int x, int y, int z); }; template <int D> int& Space<D>::PlaneX::at(int y, int z) { return space.at(cx, y, z); /* <= but it fails here */ }; Space<4> sp4; The compiler says: file.cpp: In member function ‘int& Space::PlaneX::at(int, int)’: file.cpp:21: error: ‘space’ was not declared in this scope If using Plane::space; is added to the definition of class PlaneX, or if the base class member is accessed through the this pointer, or if class Space is changed to a non-template class, then the compiler is fine with it. I don't know if this is either some obscure restriction of C++, or a bug in GCC (GCC versions 4.4.1 and 4.4.3 tested). Does anyone have an idea?

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  • Boost ASIO async_write "Vector iterator not dereferencable"

    - by xeross
    Hey, I've been working on an async boost server program, and so far I've got it to connect. However I'm now getting a "Vector iterator not dereferencable" error. I suspect the vector gets destroyed or dereferenced before he packet gets sent thus causing the error. void start() { Packet packet; packet.setOpcode(SMSG_PING); send(packet); } void send(Packet packet) { cout << "DEBUG> Transferring packet with opcode " << packet.GetOpcode() << endl; async_write(m_socket, buffer(packet.write()), boost::bind(&Session::writeHandler, shared_from_this(), placeholders::error, placeholders::bytes_transferred)); } void writeHandler(const boost::system::error_code& errorCode, size_t bytesTransferred) { cout << "DEBUG> Transfered " << bytesTransferred << " bytes to " << m_socket.remote_endpoint().address().to_string() << endl; } Start gets called once a connection is made. packet.write() returns a uint8_t vector Would it matter if I'd change void send(Packet packet) to void send(Packet& packet) Not in relation to this problem but performance wise.

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  • Identity.Name is disposed in a IIS7 Asp.NET MVC application Thread

    - by vIceBerg
    I have made the smallest demo project to illustrate my problem. You can download the sources Here Visual Studio 2008, .NET 3.5, IIS7, Windows 7 Ultimate 32 bits. The IIS Website is configured ONLY for Windows Authentication in an Integreated pipeline app pool (DefaultAppPool). Here's the problem. I have an Asp.NET MVC 2 application. In an action, I start a thread. The View returns. The thread is doing it's job... but it needs to access Thread.CurrentPrincipal.Identity.Name BANG The worker process of IIS7 stops. I have a window that says: "Visual Studio Just-In-Time Debugger An unhandled exception ('System.Object.DisposedException') occured in w3wp.exe [5524]" I checked with the debugger and the Thread.CurrentPrincipal.Identity is valid, but the Name property is disposed. If I put a long wait in the action before it returns the view, then the Thread can do it's job and the Identity.Name is not disposed. So I think the Name gets disposed when the view is returned. For the sake of the discussion, here's the code that the thread runs (but you can also download the demo project. The link is on top of this post): private void Run() { const int SECTOWAIT = 3; //wait SECTOWAIT seconds long end = DateTime.Now.Ticks + (TimeSpan.TicksPerSecond * SECTOWAIT); while (DateTime.Now.Ticks <= end) continue; //Check the currentprincipal. BANG!!!!!!!!!!!!! var userName = Thread.CurrentPrincipal.Identity.Name; } Here's the code that starts the thread public void Start() { Thread thread = new Thread(new ParameterizedThreadStart(ThreadProc)); thread.SetApartmentState(ApartmentState.MTA); thread.Name = "TestThread"; thread.Start(this); } static void ThreadProc(object o) { try { Builder builder = (Builder)o; builder.Run(); } catch (Exception ex) { throw; } } So... what am i doing wrong? Thanks

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  • How do I break down an NSTimeInterval into year, months, days, hours, minutes and seconds on iPhone?

    - by willc2
    I have a time interval that spans years and I want all the time components from year down to seconds. My first thought is to integer divide the time interval by seconds in a year, subtract that from a running total of seconds, divide that by seconds in a month, subtract that from the running total and so on. That just seems convoluted and I've read that whenever you are doing something that looks convoluted, there is probably a built-in method. Is there? I integrated Alex's 2nd method into my code. It's in a method called by a UIDatePicker in my interface. NSDate *now = [NSDate date]; NSDate *then = self.datePicker.date; NSTimeInterval howLong = [now timeIntervalSinceDate:then]; NSDate *date = [NSDate dateWithTimeIntervalSince1970:howLong]; NSString *dateStr = [date description]; const char *dateStrPtr = [dateStr UTF8String]; int year, month, day, hour, minute, sec; sscanf(dateStrPtr, "%d-%d-%d %d:%d:%d", &year, &month, &day, &hour, &minute, &sec); year -= 1970; NSLog(@"%d years\n%d months\n%d days\n%d hours\n%d minutes\n%d seconds", year, month, day, hour, minute, sec); When I set the date picker to a date 1 year and 1 day in the past, I get: 1 years 1 months 1 days 16 hours 0 minutes 20 seconds which is 1 month and 16 hours off. If I set the date picker to 1 day in the past, I am off by the same amount. Update: I have an app that calculates your age in years, given your birthday (set from a UIDatePicker), yet it was often off. This proves there was an inaccuracy, but I can't figure out where it comes from, can you?

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  • Is it possible to get the parsed text of a SqlCommand with SqlParameters?

    - by Burg
    What I am trying to do is create some arbitrary sql command with parameters, set the values and types of the parameters, and then return the parsed sql command - with parameters included. I will not be directly running this command against a sql database, so no connection should be necessary. So if I ran the example program below, I would hope to see the following text (or something similar): WITH SomeTable (SomeColumn) AS ( SELECT N':)' UNION ALL SELECT N'>:o' UNION ALL SELECT N'^_^' ) SELECT SomeColumn FROM SomeTable And the sample program is: using System; using System.Data; using System.Data.SqlClient; namespace DryEraseConsole { class Program { static void Main(string[] args) { const string COMMAND_TEXT = @" WITH SomeTable (SomeColumn) AS ( SELECT N':)' UNION ALL SELECT N'>:o' UNION ALL SELECT @Value ) SELECT SomeColumn FROM SomeTable "; SqlCommand cmd = new SqlCommand(COMMAND_TEXT); cmd.CommandText = COMMAND_TEXT; cmd.Parameters.Add(new SqlParameter { ParameterName = "@Value", Size = 128, SqlDbType = SqlDbType.NVarChar, Value = "^_^" }); Console.WriteLine(cmd.CommandText); Console.ReadKey(); } } } Is this something that is achievable using the .net standard libraries? Initial searching says no, but I hope I'm wrong.

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  • How can I exclude words with apostrophes when reading into a table of strings?

    - by rearden
    ifstream fin; string temp; fin.open("engldict.txt"); if(fin.is_open()) { bool apos = false; while(!fin.eof()) { getline(fin, temp, '\n'); if(temp.length() > 2 && temp.length() < 7) { for(unsigned int i = 0; i < temp.length(); i++) { if(temp.c_str()[i] == '\'') apos = true; } if(!apos) dictionary.insert(temp); } } } This code gives me a runtime error: Unhandled exception at 0x00A50606 in Word Jumble.exe: 0xC0000005: Access violation reading location 0x00000014. and throws me a break point at: size_type size() const _NOEXCEPT { // return length of sequence return (this->_Mysize); } within the xstring header. This exception is thrown no matter what character I use, so long as it is present within the words I am reading in. I am aware that it is probably a super simple fix, but I just really need another set of eyes to see it. Thanks in advance.

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  • WYSIWYG with Qt - font size woes

    - by Rob
    I am creating a custom Qt widget that mimics an A4 printed page and am having problems getting fonts to render at the correct size. My widget uses QPainter::setViewport and QPainter::setWindow to mimic the A4 page, using units of 10ths of a millimetre which enables me to draw easily. However, attempting to create a font at a specific point size doesn't seem to work and using QFont:setPixelSize isn't accurate. Here is some code: View::View(QWidget *parent) : QWidget(parent), printer(new QPrinter) { printer->setPaperSize(QPrinter::A4); printer->setFullPage(true); } void View::paintEvent(QPaintEvent*) { QPainter painter(this); painter.setWindow(0, 0, 2100, 2970); painter.setViewport(0, 0, printer->width(), printer->height()); // Draw a rect at x = 1cm, y = 1cm, 6cm wide and 1 inch high painter.drawRect(100, 100, 600, 254); // Create a 72pt (1 inch) high font QFont font("Arial"); font.setPixelSize(254); painter.setFont(font); // Draw in the same box // The font is too large painter.drawText(QRect(100, 100, 600, 254), tr("Wg\u0102")); // Ack - the actual font size reported by the metrics is 283 pixels! const QFontMetrics fontMetrics = painter.fontMetrics(); qDebug() << "Font height = " << fontMetrics.height(); } So I'm asking for a 254 high font (1 inch, 72 pts) and it's too big and sure enough when I query for the font height via QFontMetrics it is 283 high. Does anyone else know how to use font sizes in points when using custom mapping modes like this? It must be possible. Note that I cannot see how to convert between logical/device points either (i.e. the Win32 DPtoLP/LPtoDP equivalents.)

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  • C when to allocate and free memory - before function call, after function call...etc

    - by Keith P
    I am working with my first straight C project, and it has been a while since I worked on C++ for that matter. So the whole memory management is a bit fuzzy. I have a function that I created that will validate some input. In the simple sample below, it just ignores spaces: int validate_input(const char *input_line, char* out_value){ int ret_val = 0; /*false*/ int length = strlen(input_line); cout << "length = " << length << "\n"; out_value =(char*) malloc(sizeof(char) * length + 1); if (0 != length){ int number_found = 0; for (int x = 0; x < length; x++){ if (input_line[x] != ' '){ /*ignore space*/ /*get the character*/ out_value[number_found] = input_line[x]; number_found++; /*increment counter*/ } } out_value[number_found + 1] = '\0'; ret_val = 1; } return ret_val; } Instead of allocating memory inside the function for out_value, should I do it before I call the function and always expect the caller to allocate memory before passing into the function? As a rule of thumb, should any memory allocated inside of a function be always freed before the function returns?

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  • How do the operators < and > work with pointers?

    - by Øystein
    Just for fun, I had a std::list of const char*, each element pointing to a null-terminated text string, and ran a std::list::sort() on it. As it happens, it sort of (no pun intended) did not sort the strings. Considering that it was working on pointers, that makes sense. According to the documentation of std::list::sort(), it (by default) uses the operator < between the elements to compare. Forgetting about the list for a moment, my actual question is: How do these (, <, =, <=) operators work on pointers in C++ and C? Do they simply compare the actual memory addresses? char* p1 = (char*) 0xDAB0BC47; char* p2 = (char*) 0xBABEC475; e.g. on a 32-bit, little-endian system, p1 p2 because 0xDAB0BC47 0xBABEC475? Testing seems to confirm this, but I thought it'd be good to put it on StackOverflow for future reference. C and C++ both do some weird things to pointers, so you never really know...

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  • Intel MKL memory management and exceptions

    - by Andrew
    Hello everyone, I am trying out Intel MKL and it appears that they have their own memory management (C-style). They suggest using their MKL_malloc/MKL_free pairs for vectors and matrices and I do not know what is a good way to handle it. One of the reasons for that is that memory-alignment is recommended to be at least 16-byte and with these routines it is specified explicitly. I used to rely on auto_ptr and boost::smart_ptr a lot to forget about memory clean-ups. How can I write an exception-safe program with MKL memory management or should I just use regular auto_ptr's and not bother? Thanks in advance. EDIT http://software.intel.com/sites/products/documentation/hpc/mkl/win/index.htm this link may explain why I brought up the question UPDATE I used an idea from the answer below for allocator. This is what I have now: template <typename T, size_t TALIGN=16, size_t TBLOCK=4> class aligned_allocator : public std::allocator<T> { public: pointer allocate(size_type n, const void *hint) { pointer p = NULL; size_t count = sizeof(T) * n; size_t count_left = count % TBLOCK; if( count_left != 0 ) count += TBLOCK - count_left; if ( !hint ) p = reinterpret_cast<pointer>(MKL_malloc (count,TALIGN)); else p = reinterpret_cast<pointer>(MKL_realloc((void*)hint,count,TALIGN)); return p; } void deallocate(pointer p, size_type n){ MKL_free(p); } }; If anybody has any suggestions, feel free to make it better.

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  • I can't get RedirectToAction to work

    - by DaveDev
    I have the following Action Method that I'm trying to redirect from if the user is valid. But nothing happens. The breakpoint in the redirected-to action method never gets hit. [AcceptVerbs(HttpVerbs.Post)] public ActionResult Login(User user) { try { if (ModelState.IsValid) { if (userRepository.ValidUser(user)) { return RedirectToAction("Index", "Group"); } else { return Json("Invalid"); } } } catch (Exception) { return Json("Invalid"); } } And in another Controller, I have the following Action Method that I'm trying to redirect to: // HttpVerbs.Post doesn't work either [AcceptVerbs(HttpVerbs.Get)] public ActionResult Index(int? page) { const int pageSize = 10; IEnumerable<Group> groups = GetGroups(); var paginatedGroups = new PaginatedList<Group>(groups, page ?? 0, pageSize); return View(paginatedGroups); } private IEnumerable<Group> GetGroups() { return groupRepository.GetGroups(); } Is there anything obviously wrong with what I'm doing? Could somebody suggest a different approach I could take?

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  • Zend Framework Form Element Validators - validate a field even if not required

    - by Jeremy Hicks
    Is there a way to get a validator to fire even if the form element isn't required? I have a form where I want to validate the contents of a texbox (make sure not empty) if the value of another form element, which is a couple of radio buttons, has a specific value selected. Right now I'm doing this by overriding the isValid() function of my form class and it works great. However, I'd like to move this to either its on validator or use the Callback validator. Here's what I have so far, but it never seems to get called unless I change the field to setRequired(true) which I don't want to do at all times, only if the value of the other form element is set to a specific value. // In my form class's init function $budget = new Zend_Form_Element_Radio('budget'); $budget->setLabel('Budget') ->setRequired(true) ->setMultiOptions($options); $budgetAmount = new Zend_Form_Element_Text('budget_amount'); $budgetAmount->setLabel('Budget Amount') ->setRequired(false) ->addFilter('StringTrim') ->addValidator(new App_Validate_BudgetAmount()); //Here is my custom validator (incomplete) but just testing to see if it even gets called. class App_Validate_BudgetAmount extends Zend_Validate_Abstract { const STRING_EMPTY = 'stringEmpty'; protected $_messageTemplates = array( self::STRING_EMPTY => 'please provide a budget amount' ); public function isValid($value) { echo 'validating...'; var_dump($value); return true; } }

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  • [C++][Boost] Acceptor and Problems with Async_Accept

    - by bobber205
    See code. :P I am able to receive new connections before async_accept() has been called. My delegate function is also never called so I can't manage any connections I receive, rendering the new connections useless. ;) So here's my question. Is there a way to prevent the Boost ASIO acceptor from getting new connections on its own and only getting connections from async_accept()? Thanks! bool AlexSocket::StartListening(int port) { bool didStart = false; if (!this->listening) { //try to listen acceptor = new tcp::acceptor(this->myService); boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::tcp::v4(), port); acceptor->open(endpoint.protocol()); acceptor->set_option(boost::asio::ip::tcp::acceptor::reuse_address(true)); acceptor->bind(endpoint); //CAN GET NEW CONNECTIONS HERE (before async_accept is called) acceptor->listen(); didStart = true; //probably change? tcp::socket* tempNewSocket = new tcp::socket(this->myService); acceptor->async_accept(*tempNewSocket, boost::bind(&AlexSocket::NewConnection, this, tempNewSocket, boost::asio::placeholders::error) ); } else //already started! return false; this->listening = didStart; return didStart; } //this function is never called :( void AlexSocket::NewConnection(tcp::socket* s, const boost::system::error_code& error) { cout << "New Connection Made" << endl; //Start new accept async tcp::socket* tempNewSocket = new tcp::socket(this->myService); acceptor->async_accept(*tempNewSocket, boost::bind(&AlexSocket::NewConnection, this, tempNewSocket, boost::asio::placeholders::error) ); }

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  • sqlite3 DELETE problem "Library Routine Called Out Of Sequence"

    - by Michael Bordelon
    Here is my second stupid Noob problem. I am trying to do a simple Delete and I keep blowing up on the prepare step. I already have other Deletes, Inserts, Updates and Selects working. I am sure it is something simple. I appreciate your help. + (void)flushTodaysWorkouts { sqlite3_stmt *statement = nil; //open the database if (sqlite3_open([[BIUtility getDBPath] UTF8String], &database) != SQLITE_OK) { sqlite3_close(database); NSAssert(0, @"Failed to opendatabase"); } NSArray *woList = [self todaysScheduledWorkouts]; for (Workout *wo in woList) { NSInteger woID = wo.woInstanceID; if(statement == nil) { const char *sql = "DELETE FROM IWORKOUT WHERE WOINSTANCEID = ?"; if(sqlite3_prepare_v2(database, sql, -1, &statement, NULL) != SQLITE_OK) NSAssert1(0, @"Error while creating delete statement. '%s'", sqlite3_errmsg(database)); } //When binding parameters, index starts from 1 and not zero. sqlite3_bind_int(statement, 1, woID); if (SQLITE_DONE != sqlite3_step(statement)) NSAssert1(0, @"Error while deleting. '%s'", sqlite3_errmsg(database)); sqlite3_finalize(statement); } if(database) sqlite3_close(database); }

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  • How to use boost::transform_iterator to iterate over modifed std::map values?

    - by Frank
    I have an std::map, and I would like to define an iterator that returns modified values. Typically, a std::map<int,double>::iterator iterates over std::pair<int,double>, and I would like the same behavior, just the double value is multiplied by a constant. I tried it with boost::transform_iterator, but it doesn't compile: #include <map> #include <boost/iterator/transform_iterator.hpp> #include <boost/functional.hpp> typedef std::map<int,double> Map; Map m; m[100] = 2.24; typedef boost::binder2nd< std::multiplies<double> > Function; typedef boost::transform_iterator<Function, Map::value_type*> MultiplyIter; MultiplyIter begin = boost::make_transform_iterator(m.begin(), Function(std::multiplies<double>(), 4)); // now want to similarly create an end iterator // and then iterate over the modified map The error is: error: conversion from 'boost ::transform_iterator< boost::binder2nd<multiplies<double> >, gen_map<int, double>::iterator , boost::use_default, boost::use_default >' to non-scalar type 'boost::transform_iterator< boost::binder2nd<multiplies<double> >, pair<const int, double> * , boost::use_default, boost::use_default >' requested What is gen_map and do I really need it? I adapted the transform_iterator tutorial code from here to write this code ...

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  • C++: Efficiently adding integers to strings

    - by Shinka
    I know how to add integers to strings, but I'm not sure I'm doing it in an efficient matters. I have a class where I often have to return a string plus an integer (a different integer each time), in Java I would do something like public class MyClass { final static String S = "MYSTRING"; private int id = 0; public String getString() { return S + (id++); } } But in C++ I have to do; class MyClass { private: std::string S; // For some reason I can't do const std::string S = "MYSTRING"; int id; public: MyClass() { S = "MYSTRING"; id = 0; } std::string getString() { std::ostringstream oss; oss << S << id++; return oss.str(); } } An additional constraint: I don't want (in fact, in can't) use Boost or any other librairies, I'll have to work with the standard library. So the thing is; the code works, but in C++ I have to create a bunch of ostringstream objects, so it seems inefficient. To be fair, perhaps Java do the same and I just don't notice it, I say it's inefficient mostly because I know very little about strings. Is there a more efficient way to do this ?

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  • Recursive templates: compilation error under g++

    - by Johannes
    Hi, I am trying to use templates recursively to define (at compile-time) a d-tuple of doubles. The code below compiles fine with Visual Studio 2010, but g++ fails and complains that it "cannot call constructor 'point<1::point' directly". Could anyone please shed some light on what is going on here? Many thanks, Jo #include <iostream> #include <utility> using namespace std; template <const int N> class point { private: pair<double, point<N-1> > coordPointPair; public: point() { coordPointPair.first = 0; coordPointPair.second.point<N-1>::point(); } }; template<> class point<1> { private: double coord; public: point() { coord= 0; } }; int main() { point<5> myPoint; return 0; }

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  • iPhone and iPad : Doing a "select * from something" query in a SQLite database

    - by Abramodj
    Hi folks, i'm trying to use the SQLite data base in my iPad app, and here's my function to make a query: - (void)executeQuery:(char*)query { NSString *file = [self getWritableDBPath]; NSFileManager *fileManager = [NSFileManager defaultManager]; BOOL success = [fileManager fileExistsAtPath:file]; // If its not a local copy set it to the bundle copy if(!success) { //file = [[NSBundle mainBundle] pathForResource:DATABASE_TITLE ofType:@"db"]; [self createEditableCopyOfDatabaseIfNeeded]; } dataArray = NULL; dataArray = [NSMutableArray array]; sqlite3 *database = NULL; if (sqlite3_open([file UTF8String], &database) == SQLITE_OK) { sqlite3_exec(database, query, loadTimesCallback, dataArray, NULL); } sqlite3_close(database); [self logResults]; } if I call [self executeQuery:"select name from table1"]; everything is working fine. But if i call [self executeQuery:"select * from cars"]; the app crashes telling me that the NSMutableArray dataArray is not the right kind of variable where to set the query results. So, how can i do a "select * form table1" query, and store the results? Thanks! EDIT: Here's my loadTimesCallback method: static int loadTimesCallback(void *context, int count, char **values, char **columns) { NSMutableArray *times = (NSMutableArray *)context; for (int i=0; i < count; i++) { const char *nameCString = values[i]; [times addObject:[NSString stringWithUTF8String:nameCString]]; } return SQLITE_OK; }

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  • Mysql partitioning: Partitions outside of date range is included

    - by Sturlum
    Hi, I have just tried to configure partitions based on date, but it seems that mysql still includes a partition with no relevant data. It will use the relevant partition but also include the oldest for some reason. Am I doing it wrong? The version is 5.1.44 (MyISAM) I first added a few partitions based on "day", which is of type "date" ALTER TABLE ptest PARTITION BY RANGE(TO_DAYS(day)) ( PARTITION p1 VALUES LESS THAN (TO_DAYS('2009-08-01')), PARTITION p2 VALUES LESS THAN (TO_DAYS('2009-11-01')), PARTITION p3 VALUES LESS THAN (TO_DAYS('2010-02-01')), PARTITION p4 VALUES LESS THAN (TO_DAYS('2010-05-01')) ); After a query, I find that it uses the "old" partition, that should not contain any relevant data. mysql> explain partitions select * from ptest where day between '2010-03-11' and '2010-03-12'; +----+-------------+------------+------------+-------+---------------+------+---------+------+------+-------------+ | id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+------------+-------+---------------+------+---------+------+------+-------------+ | 1 | SIMPLE | ptest | p1,p4 | range | day | day | 3 | NULL | 79 | Using where | +----+-------------+------------+------------+-------+---------------+------+---------+------+------+-------------+ When I select a single day, it works: mysql> explain partitions select * from ptest where day = '2010-03-11'; +----+-------------+------------+------------+------+---------------+------+---------+-------+------+-------+ | id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+------------+------+---------------+------+---------+-------+------+-------+ | 1 | SIMPLE | ptest | p4 | ref | day | day | 3 | const | 39 | | +----+-------------+------------+------------+------+---------------+------+---------+-------+------+-------+

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  • Undefined return value

    - by yynneejj
    what's wrong to my code..where my return value found undefind... var so; var imgid_callback1; const DIV_ID = 'locationsample'; function setup(){ try { so = device.getServiceObject("Service.Location", "ILocation"); } catch (e) { alert('<setup> ' +e); } } function getLocation(imgId) { var updateoptions = new Object(); // Setting PartialUpdates to 'FALSE' ensures that user get atleast // BasicLocationInformation (Longitude, Lattitude, and Altitude.) updateoptions.PartialUpdates = false; var criteria = new Object(); criteria.LocationInformationClass = "BasicLocationInformation"; criteria.Updateoptions = updateoptions; try { var result = so.ILocation.GetLocation(criteria); if(!checkError("ILocation::getLocation",result,DIV_ID,imgId)) { document.getElementById(DIV_ID).innerHTML = showObject(result.ReturnValue); } } catch (e) { alert ("getLocation: " + e); } } function getLocationAsync(imgId) { var updateoptions = new Object(); updateoptions.PartialUpdates = false; var criteria = new Object(); criteria.LocationInformationClass = "BasicLocationInformation"; criteria.Updateoptions = updateoptions; imgid_callback1 = imgId; try { var result = so.ILocation.GetLocation(criteria, callback1); if(!checkError("ILocation::getLocationAsync",result,DIV_ID,imgId)) { showIMG(imgId,""); } } catch (e) { alert ("getLocationAsync: " + e); } } function callback1(transId, eventCode, result){ var latitude = result.ReturnValue.Latitude; //<-----Error: Undefined Value var longitude = result.ReturnValue.Longitude; var req = null; try { req = new XMLHttpRequest(); if (typeof req.overrideMimeType != "undefined") { req.overrideMimeType("text/xml"); } req.onreadystatechange = function() { if (req.readyState == 4) { if (req.status == 200) { } } else { alert("Error"); } } req.open("POST","http://localhost:8080/GPS/location",true); req.setRequestHeader("longitude",+longitude); req.setRequestHeader("latitude",+latitude); req.send(); } catch (ex) { alert(ex); } }

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  • Update multiple progress bar with gtk c++

    - by Yadira Suazo
    I need to output the i progress bars and update them all. But only the last one updates i times. This is the code: static void calculaPi (GtkButton * boton, Datos * dDatos){ const char * threads; GtkWidget * barra, *bot2, *button, *progress, *vbox; threads = gtk_entry_get_text(GTK_ENTRY(dDatos->dthreads )); gint ithreads = 1; ithreads = atoi(threads); barra = gtk_window_new(GTK_WINDOW_TOPLEVEL); gtk_window_set_title((GtkWindow *) barra, "Loteria de Threads"); gtk_window_set_default_size(GTK_WINDOW(barra), 300, ithreads*30); gtk_window_set_position(GTK_WINDOW(barra), GTK_WIN_POS_CENTER); button = gtk_button_new_with_label ("Click me!"); vbox = gtk_vbox_new (FALSE, 5); gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 5); gtk_container_add (GTK_CONTAINER (barra), vbox); for (gint i = 1 ; i <= ithreads; i++) { progress = gtk_progress_bar_new (); gtk_box_pack_start (GTK_BOX (vbox), progress, FALSE, FALSE, 5); g_object_set_data (G_OBJECT (barra), "pbar", (gpointer) progress); g_signal_connect (G_OBJECT (button), "clicked", G_CALLBACK (button_clicked), (gpointer) barra); } bot2 = gtk_button_new_with_label("Salir"); gtk_box_pack_start (GTK_BOX (vbox), bot2, FALSE, FALSE, 5); gtk_widget_set_size_request(bot2, 100, 35); g_signal_connect (G_OBJECT (bot2), "clicked", G_CALLBACK (destroy), G_OBJECT (barra)); gtk_widget_show_all(barra); gtk_main(); } static void button_clicked (GtkButton *button, GtkWidget *barra) { GtkProgressBar *progress; gdouble percent = 0.0; gtk_widget_set_sensitive (GTK_WIDGET (button), FALSE); progress = GTK_PROGRESS_BAR (g_object_get_data (G_OBJECT (barra), "pbar")); while (percent <= 100.0) { gchar *message = g_strdup_printf ("%.0f%% Complete", percent); gtk_progress_bar_set_fraction (progress, percent / 100.0); gtk_progress_bar_set_text (progress, message); while (gtk_events_pending ()) gtk_main_iteration (); g_usleep (500000); percent += 5.0; } }

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