Search Results

Search found 21356 results on 855 pages for 'check digit'.

Page 740/855 | < Previous Page | 736 737 738 739 740 741 742 743 744 745 746 747  | Next Page >

  • Use jQuery.post() result in javascript function

    - by Juvlius
    I've got no clue how to do the following, so I wasn't sure what to search for either. For validating my registration form I've a javascript function that checkes the existence of the inserted username in the database onblur of the username textfield. function checkUsername(username){ $.post("checkmail.php", {mail: mailcheck} , function(data){ var $response=$(data); var response = $response.filter('#mail-response').text(); if(response == "taken") { document.getElementById('username').style.borderColor = rood; valid = false; } }); } This works fine, but now I want to validate it again onsubmit of the form in case users decide to submit an existing username. function validateForm() { var valid = true; //checks different fields //now check voor username existence var username = document.getElementById('username').value; checkUsername.call(username); if (!valid) { return false; } else { return true; } } I'm not familiar enough with Javascript to get this working. Probably thinking in the wrong direction...

    Read the article

  • How can I get size in bytes of an object sent using RMI?

    - by Lucas Batistussi
    I'm implementing a cache server with MongoDB and ConcurrentHashMap java class. When there are available space to put object in memory, it will put at. Otherwise, the object will be saved in a mongodb database. Is allowed that user specify a size limit in memory (this should not exceed heap size limit obviously!) for the memory cache. The clients can use the cache service connecting through RMI. I need to know the size of each object to verify if a new incoming object can be put into memory. I searched over internet and i got this solution to get size: public long getObjectSize(Object o){ try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(bos); oos.writeObject(o); oos.close(); return bos.size(); } catch (Exception e) { return Long.MAX_VALUE; } } This solution works very well. But, in terms of memory use doesn't solve my problem. :( If many clients are verifying the object size at same time this will cause stack overflow, right? Well... some people can say: Why you don't get the specific object size and store it in memory and when another object is need to put in memory check the object size? This is not possible because the objects are variable in size. :( Someone can help me? I was thinking in get socket from RMI communication, but I don't know how to do this...

    Read the article

  • What guarantees are there on the run-time complexity (Big-O) of LINQ methods?

    - by tzaman
    I've recently started using LINQ quite a bit, and I haven't really seen any mention of run-time complexity for any of the LINQ methods. Obviously, there are many factors at play here, so let's restrict the discussion to the plain IEnumerable LINQ-to-Objects provider. Further, let's assume that any Func passed in as a selector / mutator / etc. is a cheap O(1) operation. It seems obvious that all the single-pass operations (Select, Where, Count, Take/Skip, Any/All, etc.) will be O(n), since they only need to walk the sequence once; although even this is subject to laziness. Things are murkier for the more complex operations; the set-like operators (Union, Distinct, Except, etc.) work using GetHashCode by default (afaik), so it seems reasonable to assume they're using a hash-table internally, making these operations O(n) as well, in general. What about the versions that use an IEqualityComparer? OrderBy would need a sort, so most likely we're looking at O(n log n). What if it's already sorted? How about if I say OrderBy().ThenBy() and provide the same key to both? I could see GroupBy (and Join) using either sorting, or hashing. Which is it? Contains would be O(n) on a List, but O(1) on a HashSet - does LINQ check the underlying container to see if it can speed things up? And the real question - so far, I've been taking it on faith that the operations are performant. However, can I bank on that? STL containers, for example, clearly specify the complexity of every operation. Are there any similar guarantees on LINQ performance in the .NET library specification?

    Read the article

  • PHP & MySQL - Undefined variable problem?

    - by TaG
    I keep getting the following error Undefined variable: password on line 33 how do I correct this problem? So this error will stop showing. Here is the php code. $first_name = mysqli_real_escape_string($mysqli, $purifier->purify(htmlentities(strip_tags($_POST['first_name'])))); $password1 = mysqli_real_escape_string($mysqli, $purifier->purify(strip_tags($_POST['password1']))); $password2 = mysqli_real_escape_string($mysqli, $purifier->purify(strip_tags($_POST['password2']))); // Check for a password and match against the confirmed password: if ($password1 == $password2) { $sha512 = hash('sha512', $password1); $password = mysqli_real_escape_string($mysqli, $sha512); } else { echo '<p class="error">Your password did not match the confirmed password!</p>'; } //If the table is not found add it to the database if (mysqli_num_rows($dbc) == 0) { $mysqli = mysqli_connect("localhost", "root", "", "sitename"); $dbc = mysqli_query($mysqli,"INSERT INTO users (user_id, first_name, password) VALUES ('$user_id', '$first_name', '$password')"); } //If the table is in the database update each field when needed if ($dbc == TRUE) { $dbc = mysqli_query($mysqli,"UPDATE users SET first_name = '$first_name', password = '$password' WHERE user_id = '$user_id'"); echo '<p class="changes-saved">Your changes have been saved!</p>'; }

    Read the article

  • Jquery Ajax refresh not working in IE.

    - by Probocop
    Hi, I have a <ul> which refreshes every ten seconds to check if there have been any new tweets (its pulling from a twitter feed). This works fine in Firefox and Chrome etc, but it does not work in any version if Internet Explorer. My code is as follows: setInterval(function() { $("#banter .scroll-pane").load(location.href+" #banter .scroll-pane>*",""); }, 10000); My PHP function creating the list is as follows: function showTweets($section, $limit, $class) { $result = mysql_query("SELECT * FROM hash WHERE section = '".$section."' ORDER BY date DESC LIMIT ".$limit); echo '<ul class="scroll-pane '.$class.'">'; while($row = mysql_fetch_array($result)) { echo '<li>'; echo '<p>'.html_entity_decode($row['tweet']).'</p>'; echo '<a href="'.$row['user_url'].'">'.$row['user'].'</a>'; echo '</li>'; } echo '</ul>'; } Any idea what's going wrong? Thanks

    Read the article

  • How should I solve this MySql problem (PHP) ? (Beginner)

    - by Camran
    I have several tables in a MySql database. I have a classifieds website, and at the bottom I display the users last visited classifieds. I do this by storing the ID:s of the ads to an array in the cookie. Now, my db is made up like this kindof: Main Table: // Stores global information, ie these fields have to be filled out in every record, never be blank ID Price category Seller Item Table: // Stores descriptive info about whats for sale ID AD_ID (FK) //This is the same as ID in the MAIN TABLE Color Size Mileage etc My problem is that I need to know what category the ad is in, in order to query mysql for the right information I think. So I need two variables, but the cookie only has one (ID) stored. Offcourse I could make two queries, first one just matching the ID to the main_table and fetch the category from the Main_table. Then make the second query and fetch all other info from the right table. Here is an example if the category was Vehicles: SELECT * FROM main_table, vehicles_table, WHERE main_table.id=$id_from_cookie AND main_table.ad_id=vehicles_table.ad_id As you can see above, I need the category to write in what table to check, right? But I think there must be a smarter way, like fetching them in one single query using only one variable (id from cookie)? How should I do this? Understand? Let me know if you need more input... Thanks

    Read the article

  • Help with string equality in Java

    - by annayena
    The following function accepts 2 strings, the 2nd (not 1st) possibly containing *'s (asterisks). An * is a replacement for a string (empty, 1 char or more), it can appear appear (only in s2) once, twice, more or not at all, it cannot be adjacent to another * (ab**c), no need to check that. public static boolean samePattern(String s1, String s2) It returns true if strings are of the same pattern. It must be recursive, not use any loops, static or global variables. Also it's prohibited to use the method equals in the String class. Can use local variables and method overloading. Can use only these methods: charAt(i), substring(i), substring(i, j), length(). Examples: 1: TheExamIsEasy; 2: "The*xamIs*y" ---> true 1: TheExamIsEasy; 2: "Th*mIsEasy*" ---> true 1: TheExamIsEasy; 2: "*" ---> true 1: TheExamIsEasy; 2: "TheExamIsEasy" ---> true 1: TheExamIsEasy; 2: "The*IsHard" ---> FALSE I am stucked on this question for many hours now! I need the solution in Java please kindly help me.

    Read the article

  • self-destructing objects in php5?

    - by user151841
    I am working on a class in php that is basically an interface to a database row. I wanted to create a delete() method that would 1. delete the database row and 2. destroy the instance of itself so that further attempts to manipulate the row via the object would throw warnings. Doing some googling, it seems that, in php5, it's not possible for an object to unset itself. http://bugs.php.net/bug.php?id=36971 In fact they discuss the very situation I was wanting to do :( So how should I proceed? I could make boolean flag as a class property, for whether the row still exists, and have each operation check that flag and throw an error if the row has been deleted. This maintains the oo structure of code, so I would have $objDbRow->delete(); But then I have to put checks at the beginning of each method. Or, I could implement a __destruct method that deletes the row. But that would seem counter-intuitive to me; if I saw in code unset($objDbRow); All I would suspect that's happening is that the object is being discarded, not that a row is being deleted. So that to me would seem like bad practice.

    Read the article

  • overload == (and != , of course) operator, can I bypass == to determine whether the object is null

    - by LLS
    Hello, when I try to overload operator == and != in C#, and override Equal as recommended, I found I have no way to distinguish a normal object and null. For example, I defined a class Complex. public static bool operator ==(Complex lhs, Complex rhs) { return lhs.Equals(rhs); } public static bool operator !=(Complex lhs, Complex rhs) { return !lhs.Equals(rhs); } public override bool Equals(object obj) { if (obj is Complex) { return (((Complex)obj).Real == this.Real && ((Complex)obj).Imaginary == this.Imaginary); } else { return false; } } But when I want to use if (temp == null) When temp is really null, some exception happens. And I can't use == to determine whether the lhs is null, which will cause infinite loop. What should I do in this situation. One way I can think of is to us some thing like Class.Equal(object, object) (if it exists) to bypass the == when I do the check. What is the normal way to solve the problem?

    Read the article

  • nothrow or exception ?

    - by Muggen
    I am a student and I have small knowledge on C++, which I try to expand. This is more of a philosophical question.. I am not trying to implement something. Since #include <new> //... T * t = new (std::nothrow) T(); if(t) { //... } //... Will hide the Exception, and since dealing with Exceptions is heavier compared to a simple if(t), why isn't the normal new T() not considered less good practice, considering we will have to use try-catch() to check if a simple allocation succeeded (and if we don't, just watch the program die)?? What are the benefits (if any) of the normal new allocation compared to using a nothrow new? Exception's overhead in that case is insignificant ? Also, Assume that an allocation fails (eg. no memory exists in the system). Is there anything the program can do in that situation, or just fail gracefully. There is no way to find free memory on the heap, when all is reserved, is there? Incase an allocation fails, and an std::bad_alloc is thrown, how can we assume that since there is not enough memory to allocate an object (Eg. a new int), there will be enough memory to store an exception ?? Thanks for your time. I hope the question is in line with the rules.

    Read the article

  • Patterns to deal with with functions that can have different kinds of results.

    - by KaptajnKold
    Suppose you have an method on an object that given the some input alters the objects state if the input validates according to some complex logic. Now suppose that when the input doesn't validate, it can be due to several different things, each of which we would like to be able to deal with in different ways. I'm sure many of you are thinking: That's what exceptions are for! I've thought of this also. But my reservation against using exceptions is that in some cases there is nothing exceptional about the input not validating and I really would like to avoid using exceptions to control what is really just in the expected flow of the program. If there were only one interpretation possible, I could simply choose to return a boolean value indicating whether or not the operation resulted in a state change or not and the respond appropriately when it did not. There is of course also the option to return a status code which the client can then choose to interpret or not. I don't like this much either because there is nothing semantic about status codes. The solution I have so far is to always check for each possible situation which I am able to handle before I call the method which then returns a boolean to inform the client if the object changed state. This leaves me the flexibility to handle as few or as many as the possible situations as I wish depending on the context I am in. It also has the benefit of making the method I am calling simpler to write. The drawback is that there is quite a lot of duplication in the client code wherever I call the method. Which of these solutions do you prefer and why? What other patterns do people use for providing meaningful feedback from functions? I know that some languages support multiple return values, and I if I had that option I would surely prefer it.

    Read the article

  • Log4j Logging to the Wrong Directory

    - by John
    I have a relatively complex log4j.xml configuration file with many appenders. Some machines the application runs on need a separate log directory, which is actually a mapped network drive. To get around this, we embed a system property as part of the filename in order to specify the directory. Here is an example: The "${user.dir}" part is set as a system property on each system, and is normally set to the root directory of the application. On some systems, this location is not the root of the application. The problem is that there is always one appender where this is not set, and the file appears not to write to the mapped drive. The rest of the appenders do write to the correct location per the system property. As a unit test, I set up our QA lab to hard-code the values for the appender above, and it worked: however, a different appender will then append to the wrong file. The mis-logged file is always the same for a given configuration: it is not a random file each time. My best educated guess is that there is a HashMap somewhere containing these appenders, and for some reason, the first one retrieved from the map does not have the property set. Our application does have custom system properties loading: the main() method loads a properties file and calls into System.setProperties(). My first instinct was to check the static initialization order, and to ensure the controller class with the main method does not call into log4j (directly or indirectly) before setting the properties just in case this was interfering with log4j's own initialization. Even removing all vestiges of log4j from the initialization logic, this error condition still occurs.

    Read the article

  • Why does java.util.concurrent.ArrayBlockingQueue use 'while' loops instead of 'if' around calls to

    - by theFunkyEngineer
    I have been playing with my own version of this, using 'if', and all seems to be working fine. Of course this will break down horribly if signalAll() is used instead of signal(), but if only one thread at a time is notified, how can this go wrong? Their code here - check out the put() and take() methods; a simpler and more-to-the-point implementation can be seen at the top of the JavaDoc for Condition. Relevant portion of my implementation below. public Object get() { lock.lock(); try { if( items.size() < 1 ) hasItems.await(); Object poppedValue = items.getLast(); items.removeLast(); hasSpace.signal(); return poppedValue; } catch (InterruptedException e) { e.printStackTrace(); return null; } finally { lock.unlock(); } } public void put(Object item) { lock.lock(); try { if( items.size() >= capacity ) hasSpace.await(); items.addFirst(item); hasItems.signal(); return; } catch (InterruptedException e) { e.printStackTrace(); } finally { lock.unlock(); } } P.S. I know that generally, particularly in lib classes like this, one should let the exceptions percolate up.

    Read the article

  • Python - Submit Information on a Website to Extract Data from Resulting Page

    - by bloodstorm17
    So I am trying to figure out how to post on a website that uses a drop down menu which is holding the values like this (based on the page source): <td valign="top" align="right"><span class="emphasis">Select Item Option : </span></td> <td align="left"> <span class="notranslate"> <select name="ItemOption1"> <option value="">Select Item Option</option> <option value="321_cba">Item Option 1</option> <option value="123_abcd">Item Option 2</option> ... Now there are two of these drop down menus on top of each other. I want to be able to select an item from drop down menu 1 and drop down menu 2 and then submit the page. Now based on the code it submits the information using the following code: <td colspan="2" align="center"> <input type="submit" value="View Result" onclick="return check()"> </td> </tr> </table> <input type="hidden" name="ItemOption1" value=""> <input type="hidden" name="ItemOption2" value=""> I have no idea how to select the items in the drop down menu and then submit the page and capture the information on the resulting page into a text file. Can someone please help me with this?

    Read the article

  • Recurrent yearly date alert in Python

    - by coulix
    Hello Hackerz, Here is the idea A user can set a day alert for a birthday. (We do not care about the year of birth) He also picks if he wants to be alerted 0, 1, 2, ou 7 days (Delta) before the D day. Users have a timezone setting. I want the server to send the alerts at 8 am on the the D day - deleta +- user timezone Example: 12 jun, with "alert me 3 days before" will give 9 of Jun. My idea was to have a trigger_datetime extra field saved on the 'recurrent event' object. Like this a cron Job running every hour on my server will just check for all events matching irs current time hour, day and month and send to the alert. The problem from a year to the next the trigger_date could change ! If the alert is set on 1st of March, with a one day delay that could be either 28 or 29 of February .. Maybe i should not use the trigger date trick and use some other kind of scheme. All plans are welcome.

    Read the article

  • What's wrong with this inner query (MySQL)...

    - by stuboo
    ...besides the fact that I am a total amateur? My table is set up like this: CREATE TABLE `messages` ( `id` int(6) unsigned NOT NULL AUTO_INCREMENT, `patient_id` int(6) unsigned NOT NULL, `message` varchar(255) NOT NULL, `savedate` int(10) unsigned NOT NULL, `senddate` int(10) unsigned NOT NULL, `SmsSid` varchar(40) NOT NULL COMMENT 'where we store the cookies from twilio', `sendorder` tinyint(3) unsigned NOT NULL COMMENT 'the order we want the msg sent in', `sent` tinyint(1) NOT NULL COMMENT '0=queued, 1=sent, 2=sent-unqueued,4=rec-unread,5=recd-read', PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=143 ; I need a query that will SELECT * FROM `messages` WHERE `senddate` < $now AND `sent` = 0 (AND LIMIT TO ONLY ONE RECORD PER `patient_id`) I've tried the following: SELECT * FROM `messages` WHERE `senddate` IN (SELECT `patient_id`, max(`senddate`) GROUP by `patient_id`) AND `senddate` < $now AND `sent` = 0 ; But I get this error: MySQL client version: 5.1.37 `#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'GROUP by patient_id) AND senddate < 1270093898 AND sent = 0 LIMIT 0, 30' at line 5

    Read the article

  • Change Default Winform Icon Across Entire App

    - by Kyle Gagnet
    Can I change the default icon used on a Winform? Most of my forms have their icon property set to a custom icon. For the few forms that slip through the cracks, I don't want the generic "hey look, he made this in visual studio" icon. One solution is to tediously check every one of my forms to make sure they either have a custom icon set or have ShowIcon set to False. Another solution is to have every one of my forms inherit from a base class that sets a custom icon in the constructor. Aside from those solutions, what other options do I have? EDIT: I was hoping there would be a way to replace the source of the stock icon with my own. Is it in a resource file somewhere? Or is it embedded in a .NET dll that I can't (or really, really shouldn't) modify? BOUNTY EDIT: Is there a way to accomplish this without editing or writing a single line of code? I don't care how impractical, complicated, waste-of-time the solution is... I just want to know if it's possible. I need to satisfy my curiosity.

    Read the article

  • Accessing global variables in a flash[:notice]

    - by Trip
    This is deals_controller.rb. And it works like this, except two things. Not sure how to call Deal.count to add in my flash[:notice] . I get the hunch that its not calling something global. I need that contional statement back, as I'm pretty sure its responsible for actually adding the new @deal . So I assume my syntax is off. Do note, I added an extra 'end' when I uncomment this block. def create -# This will use the disclaimer_ids submitted from the check boxes in the view -# to add/delete deal.disclaimers entries to matched the list of checked boxes. @deal = Deal.new(params[:deal]) -# <------I Need this commented out IF statement back ------- -#if @deal.valid? && @organization.deals << @deal flash[:notice] = 'Your promotion is published! You may find it in the number 1 position of our #{deal.count} previously posted promotions. To see your promotion, click here."' respond_to do |format| format.html { redirect_to organization_deals_path(@organization) } format.js -# I Need this IF Statement Back! -#else -#@disclaimers = Disclaimer.all -#render :action = 'new' end end Thanks!

    Read the article

  • Zend Framework How can I print a logged in user name from a Zend_Session_Namespace

    - by IrishStudent76
    Hi all I have created the following login controller for my site and it works fine in relation to logging users in a logging them out. The thing I want to do is echo the logged in users name into the FlashMessenger for the success page how ever as my code stands I only get the following message when redirected to the success page, "you have been successfully logged in as Array". Can I also ask the following does the line $session-user =$adaptergetResultArray('Password'); create an array of user information less the password value from the database. Many Thanks in advance, IrishStudent76 <?php class LoginController extends Zend_Controller_Action { public function init(){ $this->view->doctype('XHTML1_STRICT'); } // login action public function loginAction() { $form = new PetManager_Form_Login; $this->view->form = $form; /* check for valid input from the form and authenticate using adapter Add user record to session and redirect to the original request URL if present */ if ($this->getRequest()->isPost()) { if ($form->isValid($this->getRequest()->getPost())) { $values = $form->getValues(); $adapter = new PetManager_Auth_Adapter_Doctrine( $values['username'], $values['password'] ); $auth = Zend_Auth::getInstance(); $result = $auth->authenticate($adapter); if ($result->isValid()) { $session = new Zend_Session_Namespace('petmanager.auth'); $session->user = $adapter->getResultArray('Password'); if (isset($session->requestURL)) { $url = $session->requestURL; unset($session->requestURL); $this->_redirect($url); } else { $this->_helper->getHelper('FlashMessenger') ->addMessage('You have been successfully logged in as '.$session- >user); $this->_redirect('/login/success'); } } else { $this->view->message = 'You could not be logged in. Please try again.'; } } } } public function successAction() { if ($this->_helper->getHelper('FlashMessenger')->getMessages()) { $this->view->messages = $this->_helper ->getHelper('FlashMessenger') ->getMessages(); } else { $this->_redirect('/login'); } } public function logoutAction() { Zend_Auth::getInstance()->clearIdentity(); Zend_Session::destroy(); $this->_redirect('/'); } }

    Read the article

  • JQuery validation using is() and multiple CSS classes

    - by Alex
    Hi Folks, Trying to debug something that basically .trim()'s, .val()'s and .length's a textarea input as HTML below (truncated): <form id="Kontaktanfrage" method="post" action="tests/testform/"> ... <textarea cols="50" rows="8" id="el_12" name="FORM[Kontaktanfrage][el_12]" title="Ihre Nachricht: *" class="textarea required"></textarea> ... </form> JavaScript: function validateField(formId, fieldId) { if (fieldId) { var element = "form#"+formId+" input#"+fieldId; var fieldValue = jQuery.trim(jQuery(element).val()); var fieldLength = fieldValue.length; var fieldError = ""; if ($(element).is('.textarea.required') && fieldLength == 0) { fieldError = "error message"; } } } The above if check is never true. Using JQuery: 1.4.1. Having seen other examples online, I can't see what the difference should be. Feel free to test it in FireBug at (http://www.initiat.de/tests/testform/). Any help appreciated, can't see what I'm doing wrong.

    Read the article

  • Authentication system - Return information that have to change every time

    - by paulohr
    I have a application (made in Delphi) that contains a Authentication system (login & password). This system is in PHP, and the application get results from PHP using HTTP GET method. The system returns 'OK' if login and password are correct, and 'NO' if not correct. Like this... procedure Check; var x: string; begin x:=Get('www.mywebsite.com/auth.php?user=xxxxxx&pass=zzzzzz'); if x='OK' then UnlockFeatures else MessageBox(0,'You're not VIP','Error',0); end; Well, it works fine, but it is very easy to circumvent this system with sniffers, packet editor or proxy. So, I want to get some information (in PHP) that changes every time, and that could be possible get the same information by my application. What can I do? I don't need codes. Just tips, suggestions, please... Thanks...

    Read the article

  • CakePHP "down for maintenance" page

    - by user1852176
    I found this post about how to create a "down for maintenance" page but I'm having some trouble getting it to work properly. define('MAINTENANCE', 1); if(MAINTENANCE > 0){ require('maintenance.php'); die(); } When I place this code in /webroot.index.php it works. However, the answer suggests adding an IP address check so that if it's down, I would still be able to view it and make sure any updates went through smoothly. So, it would look something like this define('MAINTENANCE', 0); if(MAINTENANCE > 0 && $_SERVER['REMOTE_ADDR'] !='188.YOUR.IP.HERE'){ require('maintenance.php'); die(); } The issue is, my IP address will NOT be detected by cake. I've typed echo $_SERVER['REMOTE_ADDR'] and it just shows ::1. I also tried using my user_id but I got the following error Class 'AuthComponent' not found in.... I tried /index.php and /App/index.php but the maintenance page wasn't triggered and the page loads normally.

    Read the article

  • Checking if a function has C-linkage at compile-time [unsolvable]

    - by scjohnno
    Is there any way to check if a given function is declared with C-linkage (that is, with extern "C") at compile-time? I am developing a plugin system. Each plugin can supply factory functions to the plugin-loading code. However, this has to be done via name (and subsequent use of GetProcAddress or dlsym). This requires that the functions be declared with C-linkage so as to prevent name-mangling. It would be nice to be able to throw a compiler error if the referred-to function is declared with C++-linkage (as opposed to finding out at runtime when a function with that name does not exist). Here's a simplified example of what I mean: extern "C" void my_func() { } void my_other_func() { } // Replace this struct with one that actually works template<typename T> struct is_c_linkage { static const bool value = true; }; template<typename T> void assertCLinkage(T *func) { static_assert(is_c_linkage<T>::value, "Supplied function does not have C-linkage"); } int main() { assertCLinkage(my_func); // Should compile assertCLinkage(my_other_func); // Should NOT compile } Is there a possible implementation of is_c_linkage that would throw a compiler error for the second function, but not the first? I'm not sure that it's possible (though it may exist as a compiler extension, which I'd still like to know of). Thanks.

    Read the article

  • Strange PHP array behavior overwriting values with all the same values

    - by dasdas
    Im doing a simple mysqli query with code ive used many times before but have never had this problem happen to me. I am grabbing an entire table with an unknown number of columns (it changes often so i dont know the exact value, nor the column names). I have some code that uses metadata to grab everything and stick it in an array. This all works fine, but the output is messed up: $stmt -> execute(); //the query is legit, no problems there $meta = $stmt->result_metadata(); while ($field = $meta->fetch_field()) { $params[] = &$row[$field->name]; } call_user_func_array(array($stmt, 'bind_result'), $params); while ($stmt->fetch()) { $pvalues[++$i] = $row; //$pvalues is an array of arrays. row is an array //print_r($row); print_r($pvalues[$i-1]); } $stmt -> close(); I would assume that $pvalues has the results that I am looking for. My table currently has 2 rows. $pvalues has array length 2. Both rows in $pvalues are exactly the same. If i use the: print_r($row) it prints out the correct values for both rows, but if later on i check what is in $pvalues it is incorrect (1 row is assigned to both indices of $pvalues). If i use the print_r($pvalues[$i-1]) it prints exactly as I expect, the same row in the table twice. Why isnt the data getting assigned to $pvalues? I know $row holds the right information at one point, but it is getting overwritten or lost.

    Read the article

  • SQL Table design question

    - by Projapati
    Please ignore this question if it sounds stupid to you. I have SQL table (SQL Server) for photo albums and it has 20+ columns & it will hold millions of albums. I need to designate some albums as Promoted and some as Featured every week. I also need a very efficient way to get these albums (page by page) when I show it to users. How should I design this? option 1: I can create another table just to store the ids of the promoted and featured albums like this and then join the main albums table to get the set of columns I need. table designated_albums: album_id promoted_featured 1 1 5 0 7 1 15 0 The query for promoted will return 1, 7 The query for featured will return 5, 15 Option 2: I can add 1 column store 1 if promoted and 0 if featured. Otherwise it is null I can then query to check for 1 in that column for promoted albums & 0 for featured. Option 3: I can add 2 bit columns: one for promoted (0/1) and one for featured(0/1) Which way would perform better? EDIT: The design should be efficient in SQL 2008 as well. Right now I have SQL 2005.

    Read the article

< Previous Page | 736 737 738 739 740 741 742 743 744 745 746 747  | Next Page >