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  • C++ Constructor With Parameters Won't Initialize, Errors C2059 and C2228

    - by Some Girl
    I'm a C# programmer trying to muddle through C++ to create a Windows Forms Application. I have a Windows Form that makes use of a user-created class. Basically I'm trying to use a constructor that takes parameters, but my form won't let me initialize the object with parameter. Here's the code, hopefully somebody can explain the problem to me because I'm completely baffled... Here's my header file: BankAcct.h public ref class BankAcct { private: int money; public: BankAcct(); BankAcct(int); void Deposit(int); void GetBalance(int&); }; And my definition file: BankAcct.cpp #include "StdAfx.h" #include "BankAcct.h" BankAcct::BankAcct() { money = 0; } BankAcct::BankAcct(int startAmt) { money = startAmt; } void BankAcct::Deposit(int depAmt) { money += depAmt; } void BankAcct::GetBalance(int& balance) { balance = money; } And finally my main form. Won't copy the whole thing, of course, but I'm trying to declare the new bank account object, and start it with a balance of say $50. private: BankAcct myAccount(50); //does not work! WHY?? //private: //BankAcct myAccount; //works then in the form constructor my code is this: public: frmBank(void) { InitializeComponent(); int bal; myAccount.GetBalance(bal); lblBankBalance->Text += Convert::ToString(bal); } I've included the BankAcct.h file at the top of my frmBank.h, what else am I doing wrong here? It works great if I use the default constructor (the one that starts the bank balance at zero). I get the following error messages: error C2059: syntax error: 'constant' and error C2228: left of '.GetBalance' must have class/struct/union Thank you for any and all help on this one!!

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  • Controller actions appear to be synchronous though on different requests?

    - by Oded
    I am under the impression that the below code should work asynchronously. However, when I am looking at firebug, I see the requests fired asynchronously, but the results coming back synchronously: Controller: [HandleError] public class HomeController : Controller { public ActionResult Status() { return Content(Session["status"].ToString()); } public ActionResult CreateSite() { Session["status"] += "Starting new site creation"; Thread.Sleep(20000); // Simulate long running task Session["status"] += "<br />New site creation complete"; return Content(string.Empty); } } Javascript/jQuery: $(document).ready(function () { $.ajax({ url: '/home/CreateSite', async: true, success: function () { mynamespace.done = true; } }); setTimeout(mynamespace.getStatus, 2000); }); var mynamespace = { counter: 0, done: false, getStatus: function () { $('#console').append('.'); if (mynamespace.counter == 4) { mynamespace.counter = 0; $.ajax({ url: '/home/Status', success: function (data) { $('#console').html(data); } }); } if (!mynamespace.done) { mynamespace.counter++; setTimeout(mynamespace.getStatus, 500); } } } Addtional information: IIS 7.0 Windows 2008 R2 Server Running in a VMWare virutual machine Can anyone explain this? Shouldn't the Status action be returning practically immediately instead of waiting for CreateSite to finish? Edit: How can I get the long running process to kick off and still get status updates?

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  • MySQL - What is wrong with this query or my database? Terrible performance.

    - by Moss
    SELECT * from `employees` a LEFT JOIN (SELECT phone1 p1, count(*) c, FROM `employees` GROUP BY phone1) b ON a.phone1 = b.p1; I'm not sure if it is this query in particular that has the problem. I have been getting terrible performance in general with this database. The table in question has 120,000 rows. I have tried this particular query remotely and locally with the MyISAM and InnoDB engines, with different types of joins, and with and without an index on phone1. I can get this to complete in about 4 minutes on a 10,000 row table successfully but performance drops exponentially with larger tables. Remotely it will lose connection to the server and locally it brings my system to its knees and seems to go on forever. This query is only a smaller step I was trying to do when a larger query couldn't complete. Maybe I should explain the whole scenario. I have one big flat ugly table that lists a bunch of people and their contact info and the info of the companies they work for. I'm trying to normalize the database and intelligently determine which phone numbers apply to individual people and which apply to an office location. My reasoning is that if a phone number occurs multiple times and the number of occurrence equals the number of times that the street address it is attached to occurs then it must be an office number. So the first step is to count each phone number grouping by phone number. Normally if you just use COUNT()...GROUP BY it will only list the first record it finds in that group so I figured I have to join the full table to the count table where the phone number matches. This does work but as I said I can't successfully complete it on any table much larger than 10,000 rows. This seems pathetic and this doesn't seem like a crazy query to do. Is there a better way to achieve what I want or do I have to break my large table into 12 pieces or is there something wrong with the table or db?

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  • cannot convert from string to system.windows.forms.string iwin32window

    - by Michael Quiles
    This is supposed to show the winner in the xWinner form label but I cant figure it out. xWinnerForm.Show(b1.Text);. I'm new to c# so can you please explain in layman terms thanks. static public bool CheckWinner(Button[] myControls) { bool gameOver = false; for (int i = 0; i < 8; i++) { int a = Winners[i, 0]; int b = Winners[i, 1]; int c = Winners[i, 2]; Button b1 = myControls[a], b2 = myControls[b], b3 = myControls[c]; if (b1.Text == "" || b2.Text == "" || b3.Text == "") continue; if (b1.Text == b2.Text && b2.Text == b3.Text) { gameOver = true; Form xWinnerForm = new xWinnerForm(); xWinnerForm.Show(b1.Text); } public void Show(string text) { this.xWinnerLabel.Text = text; this.Show(); } } return gameOver; }

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  • Simple POSIX threads question

    - by Andy
    Hi, I have this POSIX thread: void subthread(void) { while(!quit_thread) { // do something ... // don't waste cpu cycles if(!quit_thread) usleep(500); } // free resources ... // tell main thread we're done quit_thread = FALSE; } Now I want to terminate subthread() from my main thread. I've tried the following: quit_thread = TRUE; // wait until subthread() has cleaned its resources while(quit_thread); But it does not work! The while() clause does never exit although my subthread clearly sets quit_thread to FALSE after having freed its resources! If I modify my shutdown code like this: quit_thread = TRUE; // wait until subthread() has cleaned its resources while(quit_thread) usleep(10); Then everything is working fine! Could someone explain to me why the first solution does not work and why the version with usleep(10) suddenly works? I know that this is not a pretty solution. I could use semaphores/signals for this but I'd like to learn something about multithreading, so I'd like to know why my first solution doesn't work. Thanks!

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  • C# - Calling ToString() on a Reference Type

    - by nfplee
    Given two object arrays I need to compare the differences between the two (when converted to a string). I've reduced the code to the following and the problem still exists: public void Compare(object[] array1, object[] array2) { for (var i = 0; i < array1.Length; i++) { var value1 = GetStringValue(array1[i]); var value2 = GetStringValue(array2[i]); } } public string GetStringValue(object value) { return value != null && value.ToString() != string.Empty ? value.ToString() : ""; } The code executes fine no matter what object arrays I throw at it. However if one of the items in the array is a reference type then somehow the reference is updated. This causes issues later. It appears that this happens when calling ToString() against the object reference. I have updated the GetStringValue method to the following (which makes sure the object is either a value type or string) and the problem goes away. public string GetStringValue(object value) { return value != null && (value.GetType().IsValueType || value is string) && value.ToString() != string.Empty ? value.ToString() : ""; } However this is just a temporary hack as I'd like to be able to override the ToString() method on my reference types and compare them as well. I'd appreciate it if someone could explain why this is happening and offer a potential solution. Thanks

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  • C# Interface Method calls from a controller

    - by ArjaaAine
    I was just working on some application architecture and this may sound like a stupid question but please explain to me how the following works: Interface: public interface IMatterDAL { IEnumerable<Matter> GetMattersByCode(string input); IEnumerable<Matter> GetMattersBySearch(string input); } Class: public class MatterDAL : IMatterDAL { private readonly Database _db; public MatterDAL(Database db) { _db = db; LoadAll(); //Private Method } public virtual IEnumerable<Matter> GetMattersBySearch(string input) { //CODE return result; } public virtual IEnumerable<Matter> GetMattersByCode(string input) { //CODE return results; } Controller: public class MatterController : ApiController { private readonly IMatterDAL _publishedData; public MatterController(IMatterDAL publishedData) { _publishedData = publishedData; } [ValidateInput(false)] public JsonResult SearchByCode(string id) { var searchText = id; //better name for this var results = _publishedData.GetMattersBySearch(searchText).Select( matter => new { MatterCode = matter.Code, MatterName = matter.Name, matter.ClientCode, matter.ClientName }); return Json(results); } This works, when I call my controller method from jquery and step into it, the call to the _publishedData method, goes into the class MatterDAL. I want to know how does my controller know to go to the MatterDAL implementation of the Interface IMatterDAL. What if I have another class called MatterDAL2 which is based on the interface. How will my controller know then to call the right method? I am sorry if this is a stupid question, this is baffling me.

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  • PHP preg_match: a pattern which satisfies all MySQL field names (including 'table.field' formations)

    - by gsquare567
    i need a pattern which satisfies mysql field names, but also with the option of having a table name before it examples: mytable.myfield myfield my4732894__7289FiEld here's what i tried: $pattern = "/^[a-zA-Z0-9_]*?[\.[a-zA-Z0-9_]]?$/"; this worked for what i needed before, which was just the field name: $pattern = "/^[a-zA-Z0-9_]*$/"; any ideas why my addition isnt working? maybe i'm making up regex, so i'll explain what i added... the first '?' is to say that it isn't greedy, ie. it will stop if the next part, namely "[.[a-zA-Z0-9_]]?" is satisfied. now, that second part is just the same as the first except it is optional (hence the '?' at the end) and it starts with a period (hence the '[.' and ']' wrapping my old clause. and obviously, the "^" and "$" rep the beginning and end of the string so... any ideas? (also, i'm a tad confused as to why i need to put in those "/"s in the begining/end anyways, so if you could tell me why it's required, that'd be awesome) thanks a lot! (and thanks for reading this all if you actually did... it's quite a ramble)

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  • Call to a member function get_segment() error

    - by hogofwar
    I'm having this problem with this piece of PHP code: class Core { public function start() { require("funk/funks/libraries/uri.php"); $this->uri = new uri(); require("funk/core/loader.php"); $this->load = new loader(); if($this->uri->get_segment(1) != "" and file_exists("funk/pages/".$uri->get_segment(1).".php")){ Only a snippet of the code The best way I can explain it is that it is a class calling upon another class (uri.php) and i am getting the error: Fatal error: Call to a member function get_segment() on a non-object in /home/eeeee/public_html/private/funkyphp/funk/core/core.php on line 11 (the if($this-uri-get_segment(1) part) I'm having this problem a lot and it is really bugging me. the library code is: <?php class uri { private $server_path_info = ''; private $segment = array(); private $segments = 0; public function __construct() { $segment_temp = array(); $this->server_path_info = preg_replace("/\?/", "", $_SERVER["PATH_INFO"]); $segment_temp = explode("/", $this->server_path_info); foreach ($segment_temp as $key => $seg) { if (!preg_match("/([a-zA-Z0-9\.\_\-]+)/", $seg) || empty($seg)) unset($segment_temp[$key]); } foreach ($segment_temp as $k => $value) { $this->segment[] = $value; } unset($segment_temp); $this->segments = count($this->segment); } public function segment_exists($id = 0) { $id = (int)$id; if (isset($this->segment[$id])) return true; else return false; } public function get_segment($id = 0) { $id--; $id = (int)$id; if ($this->segment_exists($id) === true) return $this->segment[$id]; else return false; } } ?>

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  • How to catch unintentional function interpositioning?

    - by SiegeX
    Reading through my book Expert C Programming, I came across the chapter on function interpositioning and how it can lead to some serious hard to find bugs if done unintentionally. The example given in the book is the following: my_source.c mktemp() { ... } main() { mktemp(); getwd(); } libc mktemp(){ ... } getwd(){ ...; mktemp(); ... } According to the book, what happens in main() is that mktemp() (a standard C library function) is interposed by the implementation in my_source.c. Although having main() call my implementation of mktemp() is intended behavior, having getwd() (another C library function) also call my implementation of mktemp() is not. Apparently, this example was a real life bug that existed in SunOS 4.0.3's version of lpr. The book goes on to explain the fix was to add the keyword static to the definition of mktemp() in my_source.c; although changing the name altogether should have fixed this problem as well. This chapter leaves me with some unresolved questions that I hope you guys could answer: Does GCC have a way to warn about function interposition? We certainly don't ever intend on this happening and I'd like to know about it if it does. Should our software group adopt the practice of putting the keyword static in front of all functions that we don't want to be exposed? Can interposition happen with functions introduced by static libraries? Thanks for the help. EDIT I should note that my question is not just aimed at interposing over standard C library functions, but also functions contained in other libraries, perhaps 3rd party, perhaps ones created in-house. Essentially, I want to catch any instance of interpositioning regardless of where the interposed function resides.

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  • Eliminate full table scan due to BETWEEN (and GROUP BY)

    - by Dave Jarvis
    Description According to the explain command, there is a range that is causing a query to perform a full table scan (160k rows). How do I keep the range condition and reduce the scanning? I expect the culprit to be: Y.YEAR BETWEEN 1900 AND 2009 AND Code Here is the code that has the range condition (the STATION_DISTRICT is likely superfluous). SELECT COUNT(1) as MEASUREMENTS, AVG(D.AMOUNT) as AMOUNT, Y.YEAR as YEAR, MAKEDATE(Y.YEAR,1) as AMOUNT_DATE FROM CITY C, STATION S, STATION_DISTRICT SD, YEAR_REF Y FORCE INDEX(YEAR_IDX), MONTH_REF M, DAILY D WHERE -- For a specific city ... -- C.ID = 10663 AND -- Find all the stations within a specific unit radius ... -- 6371.009 * SQRT( POW(RADIANS(C.LATITUDE_DECIMAL - S.LATITUDE_DECIMAL), 2) + (COS(RADIANS(C.LATITUDE_DECIMAL + S.LATITUDE_DECIMAL) / 2) * POW(RADIANS(C.LONGITUDE_DECIMAL - S.LONGITUDE_DECIMAL), 2)) ) <= 50 AND -- Get the station district identification for the matching station. -- S.STATION_DISTRICT_ID = SD.ID AND -- Gather all known years for that station ... -- Y.STATION_DISTRICT_ID = SD.ID AND -- The data before 1900 is shaky; insufficient after 2009. -- Y.YEAR BETWEEN 1900 AND 2009 AND -- Filtered by all known months ... -- M.YEAR_REF_ID = Y.ID AND -- Whittled down by category ... -- M.CATEGORY_ID = '003' AND -- Into the valid daily climate data. -- M.ID = D.MONTH_REF_ID AND D.DAILY_FLAG_ID <> 'M' GROUP BY Y.YEAR Update The SQL is performing a full table scan, which results in MySQL performing a "copy to tmp table", as shown here: +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ | 1 | SIMPLE | C | const | PRIMARY | PRIMARY | 4 | const | 1 | | | 1 | SIMPLE | Y | range | YEAR_IDX | YEAR_IDX | 4 | NULL | 160422 | Using where | | 1 | SIMPLE | SD | eq_ref | PRIMARY | PRIMARY | 4 | climate.Y.STATION_DISTRICT_ID | 1 | Using index | | 1 | SIMPLE | S | eq_ref | PRIMARY | PRIMARY | 4 | climate.SD.ID | 1 | Using where | | 1 | SIMPLE | M | ref | PRIMARY,YEAR_REF_IDX,CATEGORY_IDX | YEAR_REF_IDX | 8 | climate.Y.ID | 54 | Using where | | 1 | SIMPLE | D | ref | INDEX | INDEX | 8 | climate.M.ID | 11 | Using where | +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ Related http://dev.mysql.com/doc/refman/5.0/en/how-to-avoid-table-scan.html http://dev.mysql.com/doc/refman/5.0/en/where-optimizations.html http://stackoverflow.com/questions/557425/optimize-sql-that-uses-between-clause Thank you!

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  • Constructor on type: "Namespace.type" not found.

    - by Nick
    Hello, I am using Castle.Windsor as an IOC. So I am trying to resolve a service type in the constructor of an HTTPHandler. I keep receiving this error, "Constructor on type: "Namespace.type" not found." My configuration has the following entries for service type: IDocumentDirectory <component id="restricted.content.directory" service="org.healthwise.foundations.services.content.IDocumentDirectory, org.healthwise.foundations.services" type="org.healthwise.foundations.services.content.RestrictedLocalizationDocumentDirectory, org.healthwise.foundations.services"> <parameters> <contentDirectory>${content.directory}</contentDirectory> <localizations> <array> <item>en-us</item> <item>es-us</item> </array> </localizations> </parameters> </component> <component id="content.directory" service="org.healthwise.foundations.services.content.IDocumentDirectory, org.healthwise.foundations.services" type="org.healthwise.foundations.services.web.client.WebServiceDocumentDirectory, org.healthwise.foundations.services.web.client"> <parameters> <webServiceURL>#{contentDirectoryWebsiteUrl}</webServiceURL> </parameters> </component> In my new handler the constructor looks like this: public HeartBeatHttpHandler(IDocumentDirectory contentDirectory) { _contentDirectory = contentDirectory; } I have never recieved this error using Castle.Windsor. Can someone explain? Thanks!

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  • Does the pointer to free() have to point to beginning of the memory block, or can it point to the interior?

    - by Lambert
    The question is in the title... I searched but couldn't find anything. Edit: I don't really see any need to explain this, but because people think that what I'm saying makes no sense (and that I'm asking the wrong questions), here's the problem: Since people seem to be very interested in the "root" cause of all the problem rather than the actual question asked (since that apparently helps things get solved better, let's see if it does), here's the problem: I'm trying to make a D runtime library based on NTDLL.dll, so that I can use that library for subsystems other than the Win32 subsystem. So that forces me to only link with NTDLL.dll. Yes, I'm aware that the functions are "undocumented" and could change at any time (even though I'd bet a hundred dollars that wcstombs will still do the same exact thing 20 years from now, if it still exists). Yes, I know people (especially Microsoft) don't like developers linking to that library, and that I'll probably get criticized for the right here. And yes, those two points above mean that programs like chkdsk and defragmenters that run before the Win32 subsystem aren't even supposed to be created in the first place, because it's literally impossible to link with anything like kernel32.dll or msvcrt.dll and still have NT-native executables, so we developers should just pretend that those stages are meant to be forever out of our reaches. But no, I doubt that anyone here would like me to paste a few thousand lines of code and help me look through them and try to figure out why memory allocations that aren't failing are being rejected by the source code I'm modifying. So that's why I asked about a different problem than the "root" cause, even though that's supposedly known to be the best practice by the community. If things still don't make sense, feel free to post comments below! :)

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  • ASP.NET: I'm getting strange output when styling a Label control...

    - by pkiyan
    .labelOne { border-width:thin; border-style:solid; border-color:Red; background-color:Silver; } <asp:Label ID="Label1" runat="server" CssClass="labelOne"> <h1>Hello world</h1> </asp:Label> <br /><br /> <asp:Label ID="Label2" runat="server" BorderColor="Black" BorderStyle="Solid" BorderWidth="1px" BackColor="Silver"> <h1>Hello world</h1> </asp:Label> Hello. In the code sample above I have 2 Label controls with their contents set to an h1 header tag. The first Label is styled using css, and the second with the Label's inline properties (both Labels have identical styling). But the first Label doesn't output properly, it's border is broken. If I replace the first Label's markup with plain "Hello world" text it renders properly, but it breaks again when I use markup. Can someone explain why this is happening?

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  • Simple matrix example using C++ template class

    - by skyeagle
    I am trying to write a trivial Matrix class, using C++ templates in an attempt to brush up my C++, and also to explain something to a fellow coder. This is what I have som far: template class<T> class Matrix { public: Matrix(const unsigned int rows, const unsigned int cols); Matrix(const Matrix& m); Matrix& operator=(const Matrix& m); ~Matrix(); unsigned int getNumRows() const; unsigned int getNumCols() const; template <class T> T getCellValue(unsigned int row, unsigned col) const; template <class T> void setCellValue(unsigned int row, unsigned col, T value) const; private: // Note: intentionally NOT using smart pointers here ... T * m_values; }; template<class T> inline T Matrix::getCellValue(unsigned int row, unsigned col) const { } template<class T> inline void Matrix::setCellValue(unsigned int row, unsigned col, T value) { } I'm stuck on the ctor, since I need to allocate a new[] T, it seems like it needs to be a template method - however, I'm not sure I have come accross a templated ctor before. How can I implemnt the ctor?

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  • RequestBuilder timeouts and browser connection limits per domain.

    - by WesleyJohnson
    This is specifically about GWT's RequestBuilder, but should apply to general XHR as well. My company is having me build a near realtime chat application over HTTP. Yes, I do realize there are better ways to do chat aplications, but this is what they want. Eventually we want it working on the iPad/iPhone as well so flash is out, which rules out websockets and comet as well, I think? Anyway, I'm running into issues were I've set GWT's RequestBuilder timeout to 10 seconds and we get very random and sporadic timeouts. We've got error handling and emailing on the server side and never get any errors, which suggests the underlying XHR request that RequestBuilder is built on, never gets to the server and times out after 10 seconds. We're using these request to poll the server for new messages rather often and also for sending new messages to the server and also polling (less frequently) for other parts of application. What I'm afraid of is that we're running into the browsers limit on concurrent connections to the same domain (2 for IE by default?). Now my question is - If I construct a RequestBuilder and call it's send() method and the browser blocks it from sending until one of the 2 connections per domain is free, does the timeout still start while the request is being blocked or will it not start until the browser actually releases the underlying XHR? I hope that's clear, if not please let me know and I'll try to explain more.

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  • Why does PEAR get installed to my user directory?

    - by webworm
    I am new to Linux and I am attempting to install the PHP PEAR library on a virtual server which is running Ubuntu. I am following a tutorial that covers installing PEAR but have run up against an area where I am confused. When running the PEAR installation program I am prompted as to what I want the INSTALL_PREFIX to be. Evidently the INSTALL_PREFIX, among other things, determines where PEAR will be installed. The tutorial suggest the value of INSTALL_PREFIX be the following path ... "/home/MY_USER_NAME/pear" where MY_USER_NAME = my user account Having come from a Windows world, applications are installed on the system where everyone can use them. If I install PEAR underneath my user directory will other developers on the system be able to make use of PEAR in their PHP scripts? I want to make PEAR available to all users and not just myself. Could someone explain to me the difference between installing for all users and installing just for myself? Does the install location matter? Should I be installing PEAR in a different location? Thanks for any suggestions. P.S. The tutorial I am following is located at the following URL ... http://articles.sitepoint.com/article/getting-started-with-pear/2

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  • Deleting elements from stl set while iterating through it does not invalidate the iterators.

    - by pedromanoel
    I need to go through a set and remove elements that meet a predefined criteria. This is the test code I wrote: #include <set> #include <algorithm> void printElement(int value) { std::cout << value << " "; } int main() { int initNum[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; std::set<int> numbers(initNum, initNum + 10); // print '0 1 2 3 4 5 6 7 8 9' std::for_each(numbers.begin(), numbers.end(), printElement); std::set<int>::iterator it = numbers.begin(); // iterate through the set and erase all even numbers for (; it != numbers.end(); ++it) { int n = *it; if (n % 2 == 0) { // wouldn't invalidate the iterator? numbers.erase(it); } } // print '1 3 5 7 9' std::for_each(numbers.begin(), numbers.end(), printElement); return 0; } At first, I thought that erasing an element from the set while iterating through it would invalidate the iterator, and the increment at the for loop would have undefined behavior. Even though, I executed this test code and all went well, and I can't explain why. My question: Is this the defined behavior for std sets or is this implementation specific? I am using gcc 4.3.3 on ubuntu 10.04 (32-bit version), by the way. Thanks!

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  • Currently using View, Should I use a hard table instead?

    - by 1001010101
    I am currently debating whether my table, mapping_uGroups_uProducts, which is a view formed by the following table: CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `db`.`mapping_uGroups_uProducts` AS select distinct `X`.`upID` AS `upID`,`Z`.`ugID` AS `ugID` from ((`db`.`mapping_uProducts_Products` `X` join `db`.`productsInfo` `Y` on((`X`.`pID` = `Y`.`pID`))) join `db`.`mapping_uGroups_Groups` `Z` on((`Y`.`gID` = `Z`.`gID`))); My current query is: SELECT upID FROM uProductsInfo \ JOIN fs_uProducts USING (upID) column \ JOIN mapping_uGroups_uProducts USING (upID) -- could be faster if we use hard table and index \ JOIN mapping_fs_key USING (fsKeyID) \ WHERE fsName="OVERALL" \ AND ugID=1 \ ORDER BY score DESC \ LIMIT 0,30; which is pretty slow. (for 30 results, it requires about 10 secondes). I think the reason for my query being so slow is definitely due to the fact that that particular query relies on a VIEW which has no index to speed things up. +----+-------------+----------------+--------+----------------+---------+---------+---------------------------------------+-------+---------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+----------------+--------+----------------+---------+---------+---------------------------------------+-------+---------------------------------+ | 1 | PRIMARY | mapping_fs_key | const | PRIMARY,fsName | fsName | 386 | const | 1 | Using temporary; Using filesort | | 1 | PRIMARY | <derived2> | ALL | NULL | NULL | NULL | NULL | 19706 | Using where | | 1 | PRIMARY | uProductsInfo | eq_ref | PRIMARY | PRIMARY | 4 | mapping_uGroups_uProducts.upID | 1 | Using index | | 1 | PRIMARY | fs_uProducts | ref | upID | upID | 4 | db.uProductsInfo.upID | 221 | Using where | | 2 | DERIVED | X | ALL | PRIMARY | NULL | NULL | NULL | 40772 | Using temporary | | 2 | DERIVED | Y | eq_ref | PRIMARY | PRIMARY | 4 | db.X.pID | 1 | Distinct | | 2 | DERIVED | Z | ref | PRIMARY | PRIMARY | 4 | db.Y.gID | 2 | Using index; Distinct | +----+-------------+----------------+--------+----------------+---------+---------+---------------------------------------+-------+---------------------------------+ 7 rows in set (0.48 sec) The explain here looks pretty cryptic, and I don't know whether I should drop view and write a script to just insert everything in the view to a hard table. ( obviously, it will lose the flexibility of the view since the mapping changes quite frequently). Does anyone have any idea to how I can optimize my schema better?

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  • Querying calender events even if they do not have any for the day

    - by StealthRT
    Hey everyone, i am trying to figure out a way of query my mysql server so that even if a company does not have anything posted for the day the user clicks on their logo, it still adds them to the list. That sounds a little confusing so let me try to explain it another way. Say i have 3 company's in my database: Comp1 Comp2 Comp3 And Comp1 & Comp3 have something for today on the calender but Comp2 does not. I still need it to populate and place that company on the page but have something along the lines of "nothing on the calender for today". The other 2 companys (Comp1 & Comp3) would show the calender posting for that day. This is the code i have right now: SELECT clientinfo.id, clientinfo.theCompName, clientinfo.theURL, clientinfo.picURL, clientinfo.idNumber, clientoffers.idNumber, clientoffers.theDateStart, clientoffers.theDateEnd FROM clientinfo, clientoffers WHERE clientinfo.accountStats = 'OPEN' AND clientinfo.idNumber = clientinfo.idNumber AND '2010-05-08' BETWEEN clientoffers.theDateStart AND clientoffers.theDateEnd GROUP BY clientinfo.idNumber ORDER BY clientinfo.theCompName ASC That executes just fine but for Comp2, it just places the calender info from Comp1 into it when it really doesn't have anything. The output looks like this: Comp1 | 2010-05-08 | this is the calender event 1 | etc etc Comp2 | 2010-05-08 | this is the calender event 1 | etc etc comp3 | 2010-05-09 | this is the calender event 2 | etc etc Any help would be great :o) David

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  • How can I store this kind of graph in neo4j for fast traversal?

    - by James
    This is a graph whose nodes exist in many connected components at once because a node's relationships are a collection of edge groups such that only one edge per edge group can be present at once. I need to be able to find all of the connected components that a node exists in. What would be the best way to store this graph in neo4j to quickly find all of the connected components that a node exists in? Is there a way to use the built in traversals to do this? Also: is there a name for this kind of graph? I'd appreciate any help/ideas. Update: Sorry for not being clear. All nodes are of the same type. Nodes have a variable number of edge groups. Exactly one edge from each edge group needs to be chosen for a particular connected component. I'm going to try to explain through example: Node x1 is related to: (x2 or x3 or x4) AND (x5 or x6) AND (x7) Node x2 is related to: (x8) AND (x9 or x10) So x1's first edge group is (x2, x3, x4), its second edge group is (x5, x6), and its third edge group is (x7). So here are a few connected components that x1 exists in: CC1: x1 is related to: x2, x5, x7 x2 is related to: x8 x9 CC2: x1 is related to: x2, x6, x7 x2 is related to: x8, x9 CC3: x1 is related to: x3, x5, x7 CC4: x1 is related to: x3, x6, x7 etc. I'm grateful for your help in this.

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  • PHP Magic faster than simply setting the class attribute?

    - by Marc Trudel
    Well, not exactly that, but here is an example. Can anyone explain the difference between B and C? How can it be faster to use a magic function to dynamically set a value instead of simply setting the value in the attribute definition? Here is some code: [root@vm-202-167-238-17 ~]# cat test.php; for d in A B C; do echo "------"; ./test.php $d; done; #!/usr/bin/php <?php $className = $argv[1]; class A { public function __get($a) { return 5; } } class B { public $a = 5; } class C { public function __get($a) { $this->a = 5; return 5; } } $a = new $className; $start = microtime(true); for ($i=0; $i < 1000000; $i++) $b = $a->a; $end = microtime(true); echo (($end - $start) * 1000) ." msec\n"; ------ 598.90794754028 msec ------ 205.48391342163 msec ------ 189.7759437561 msec

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  • which one of these is an example of coercion

    - by user1890210
    I have been pondering a multiple choice question on coercion. One of the 4 examples a,b,c or d is an example of coercion. I narrowed it down to A or B. But I am having a problem choosing between the two. Cane someone please explain why one is coercion and one isn't. A) string s="tomat"; char c='o'; s=s+c; I thought A could be correct because we have two different types, character and string, being added. Meaning that c is promoted to string, hence coercion. B) double x=1.0; double y=2.0; int i=(int)(x+y); I also thought B was the correct answer because the double (x+y) is being turned into a int to be placed in i. But I thought this could be wrong because its being done actively through use of (int) rather than passively such as "int i = x + y" I'll list the other two options, even though I believe that neither one is the correct answer C) char A=0x20; A = A << 1 | 0x01; cout << A << endl; D) double x=1.0; double y=x+1; return 0; I'm not just looking for an answer, but an explanation. I have read tons of things on coercion and A and B both look like the right answer. So why is one correct and the other not.

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  • How to map a 0..1 to 1 relationship in Entity Framework 3

    - by sako73
    I have two tables, Users, and Address. A the user table has a field that maps to the primary key of the address table. This field can be null. In plain english, Address exist independent of other objects. A user may be associated with one address. In the database, I have this set up as a foreign key relationship. I am attempting to map this relationship in the Entity Framework. I am getting errors on the following code: <Association Name="fk_UserAddress"> <End Role="User" Type="GenesisEntityModel.Store.User" Multiplicity="1"/> <End Role="Address" Type="GenesisEntityModel.Store.Address" Multiplicity="0..1" /> <ReferentialConstraint> <Principal Role="Address"> <PropertyRef Name="addressId"/> </Principal> <Dependent Role="User"> <PropertyRef Name="addressId"/> </Dependent> </ReferentialConstraint> </Association> It is giving a "The Lower Bound of the multiplicity must be 0" error. I would appreciate it if anyone could explain the error, and the best way to solve it. Thanks for any help.

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  • Why does my simple event handling example not work?

    - by njreed
    I am trying to make a simple event handler. (Note, I'm not trying to implement a full-blown publish/subscribe model; I'm just interested in why my example doesn't work as I think it should) var myObj = (function () { var private = "X"; function triggerEvent(eventName) { if (this[eventName]) { this[eventName](); } } // Setter / Getter function getProp() { return private; } function setProp(value) { private = value; triggerEvent("onPropChange"); } // Public API return { // Events "onPropChange": null, // Fires when prop value is changed // Methods "getProp": getProp, "setProp": setProp }; })(); // Now set event handler myObj.onPropChange = function () { alert("You changed the property!"); }; myObj.setProp("Z"); // --> Nothing happens. Wrong // Why doesn't my alert show? I set the onPropChange property of my object to a simpler handler function but it is not being fired. I have debugged this and it seems that in triggerEvent the variable this is referencing the global window object. I thought it should reference myObj (which is what I need). Can someone explain the error in my thinking and how I correct this? Help much appreciated. jsFiddle here

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