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  • Problems Expanding an Array in C++

    - by dxq
    I'm writing a simulation for class, and part of it involves the reproduction of organisms. My organisms are kept in an array, and I need to increase the size of the array when they reproduce. Because I have multiple classes for multiple organisms, I used a template: template <class orgType> void expandarray(orgType* oldarray, int& numitems, int reproductioncount) { orgType *newarray = new orgType[numitems+reproductioncount]; for (int i=0; i<numitems; i++) { newarray[i] = oldarray[i]; } numitems += reproductioncount; delete[] oldarray; oldarray = newarray; newarray = NULL; } However, this template seems to be somehow corrupting my data. I can run the program fine without reproduction (commenting out the calls to expandarray), but calling this function causes my program to crash. The program does not crash DURING the expandarray function, but crashes on access violation later on. I've written functions to expand an array hundreds of times, and I have no idea what I screwed up this time. Is there something blatantly wrong in my function? Does it look right to you? EDIT: Thanks for everyone's help. I can't believe I missed something so obvious. In response to using std::vector: we haven't discussed it in class yet, and as silly as it seems, I need to write code using the methods we've been taught.

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  • Querying for a unique value based on the aggregate of another value while grouping on a third value

    - by Justin Swartsel
    So I know this problem isn't a new one, but I'm trying to wrap my head around it and understand the best way to deal with scenarios like this. Say I have a hypothetical table 'X' that looks like this: GroupID ID (identity) SomeDateTime -------------------------------------------- 1 1000 1/1/01 1 1001 2/2/02 1 1002 3/3/03 2 1003 4/4/04 2 1004 5/5/05 I want to query it so the result set looks like this: ---------------------------------------- 1 1002 3/3/03 2 1004 5/5/05 Basically what I want is the MAX SomeDateTime value grouped by my GroupID column. The kicker is that I DON'T want to group by the ID column, I just want to know the 'ID' that corresponds to the MAX SomeDateTime. I know one pseudo-solution would be: ;WITH X1 as ( SELECT MAX(SomeDateTime) as SomeDateTime, GroupID FROM X GROUP BY GroupID ) SELECT X1.SomeDateTime, X1.GroupID, X2.ID FROM X1 INNER JOIN X as X2 ON X.DateTime = X2.DateTime But this doesn't solve the fact that a DateTime might not be unique. And it seems sloppy to join on a DateTime like that. Another pseudo-solution could be: SELECT X.GroupID, MAX(X.ID) as ID, MAX(X.SomeDateTime) as SomeDateTime FROM X GROUP BY X.GroupID But there are no guarantees that ID will actually match the row that SomeDateTime comes from. A third less useful option might be: SELECT TOP 1 X.GroupID, X.ID, X.SomeDateTime FROM X WHERE X.GroupID = 1 ORDER BY X.SomeDateTime DESC But obviously that only works with a single, known, GroupID. I want to be able to join this result set on GroupID and/or ID. Does anyone know of any clever solutions? Any good uses of windowing functions? Thanks!

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  • Share variable across site ASP.NET

    - by Anders
    I have a class isSearching with a single boolean property in a 'functions' file in my webapp. On my search page, I have a variable oSearchHandler declared as a Public Shared variable. How can I access the contents of oSearchHandler on other pages in my webapp? Code with Session.... 'search.aspx Public Function oSearchString(ByVal oTextBoxName As String) As String For Each oKey As String In Request.Form.AllKeys If oKey.Contains(oTextBoxName) Then Session.Add("searching", True) Session.Add("search-term", Request.Form(oKey)) Return Request.Form(oKey) End If Next Return "" End Function 'theMaster.master <% If Session("searching") Then %><ul style="float: right;"> <li> <div class="gsSearch"> <asp:TextBox ID="searchbox" runat="server"></asp:TextBox> </div> </li> <li> <div class="gsSearch"> <asp:Button ID="searchbutton" runat="server" Text="search" UseSubmitBehavior="true" PostBackUrl="search.aspx" CssClass="searchBtn" /> </div> </li> </ul> <% End If %> I think that the session will work just fine.

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  • Getting rid of function's argument

    - by Max
    It is better to explain my intention with code. So right now I have the following code: class A, IInterfaceUsedByB { } class B { void func(A someObject) { func2(someObject, 1); func3(someObject, "string"); func4(someObject, new MyObject()); } func2(A someObject, int val); func3(A someObject, string val); func4(A someObject, C val); } Where func2, func3, func4 do need references to someObject. I want to change this to void func() { with(someObject, () => { func2(1); func3("string"); func4(new MyObject()); } ); } Or even better to void func(someObject) { func2(1); func3("string"); func4(new MyObject()); } So that I don't have to drag this someObject around, but I should still be able to use it inside func2,3,4. I can use any of the three languages (C#, F# or IronPython) for this. UPDATE In the ideal solution class B would be independent of A. func* functions only depend on a small interface of A consisting of 2 methods.

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  • Error in value of default parameter [Bug in Visual C++ 2008?]

    - by HellBoy
    I am facing following issue while trying to use template in my code I have some C++ code which i call from C functions. Problem is I am getting different values in the following code for statement 1 and 2. Type id : unsigned int statement 1 : 4 statement 2 : 1 C++ Code : template <typename T> void func(T* value, unsigned int len = sizeof(T)) { cout << "Type id : " << typeid(T).name() << endl; cout << "statement 1 " << sizeof(T) << endl; cout << "statement 2 " << len << endl; } template <typename T> void func1(T data) { T val = data; func(&val); } C Code : void test(void *ptr, unsigned int len) { switch(len) { case 1: func1(*(static_cast<uint32_t *>(ptr)) break; } } This happens only on windows. On Linux it works fine.

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  • Pthread - setting scheduler parameters

    - by Andna
    I wanted to use read-writer locks from pthread library in a way, that writers have priority over readers. I read in my man pages that If the Thread Execution Scheduling option is supported, and the threads involved in the lock are executing with the scheduling policies SCHED_FIFO or SCHED_RR, the calling thread shall not acquire the lock if a writer holds the lock or if writers of higher or equal priority are blocked on the lock; otherwise, the calling thread shall acquire the lock. so I wrote small function that sets up thread scheduling options. void thread_set_up(int _thread) { struct sched_param *_param=malloc(sizeof (struct sched_param)); int *c=malloc(sizeof(int)); *c=sched_get_priority_min(SCHED_FIFO)+1; _param->__sched_priority=*c; long *a=malloc(sizeof(long)); *a=syscall(SYS_gettid); int *b=malloc(sizeof(int)); *b=SCHED_FIFO; if (pthread_setschedparam(*a,*b,_param) == -1) { //depending on which thread calls this functions, few thing can happen if (_thread == MAIN_THREAD) client_cleanup(); else if (_thread==ACCEPT_THREAD) { pthread_kill(params.main_thread_id,SIGINT); pthread_exit(NULL); } } } sorry for those a,b,c but I tried to malloc everything, still I get SIGSEGV on the call to pthread_setschedparam, I am wondering why?

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  • Singleton pattern in C++

    - by skydoor
    I have a question about the singleton pattern. I saw two cases concerning the static member in the singleton class. First it is an object, like this class CMySingleton { public: static CMySingleton& Instance() { static CMySingleton singleton; return singleton; } // Other non-static member functions private: CMySingleton() {} // Private constructor ~CMySingleton() {} CMySingleton(const CMySingleton&); // Prevent copy-construction CMySingleton& operator=(const CMySingleton&); // Prevent assignment }; One is an pointer, like this class GlobalClass { int m_value; static GlobalClass *s_instance; GlobalClass(int v = 0) { m_value = v; } public: int get_value() { return m_value; } void set_value(int v) { m_value = v; } static GlobalClass *instance() { if (!s_instance) s_instance = new GlobalClass; return s_instance; } }; What's the difference between the two cases? Which one is correct?

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  • How can I add file locations to a database after they are uploaded using a Perl CGI script?

    - by Paul K
    I have a CGI program I have written using Perl. One of its functions is to upload pics to the server. All of it is working well, including adding all kinds of info to a MySQL db. My question is: How can I get the uploaded pic files location and names added to the db? I would rather that instead of changing the script to actually upload the pics to the db. I have heard horror stories of uploading binary files to databases. Since I am new to all of this, I am at a loss. Have tried doing some research and web searches for 3 weeks now with no luck. Any suggestions or answers would be greatly appreciated. I would really hate to have to manually add all the locations/names to the db. I am using: a Perl CGI script, MySQL db, Linux server and the files are being uploaded to the server. I AM NOT looking to add the actual files to the db. Just their location(s).

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  • Display error message at top of form

    - by moustafa
    Hello, I'm trying to get the following error to show when some once presses the submit button and has not filled in the required field/s. My PHP code is. <?php require_once("includes/database.php"); require_once("includes/functions.php"); if(isset($_POST['full_name'])) { $required = array('full_name','user_name','email','pwd','pwd2'); $missing = array(); $validation = array( 'full_name' => 'Please provide your full name', 'user_name' => 'Please provide your username', 'email' => 'Please provide your valid email address', 'pwd' => 'Please provide your password', 'pwd2' => 'Please confirm your password', 'userdup' => 'Username already registered', 'emaildup' => 'Email address already registered', 'mismatch' => 'Passwords do not match' ); //Sanitise and clean function $full_name = escape($_POST['full_name']); $user_name = escape($_POST['user_name']); $email = escape($_POST['email']); $pwd = escape($_POST['pwd']); $pwd2 = escape($_POST['pwd2']); foreach($_POST as $key => $value) { $value = trim($value); if(empty($value) && in_array($key,$required)) { array_push($missing,$key); } else { ${$key} = escape($value); } }

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  • PHP Fix Warning: Cannot modify header information - headers already sent...

    - by Storm Kiernan
    Warning: Cannot modify header information - headers already sent by (output started at /home/blocexco/public_html/homepage.php:73) in /home/blocexco/public_html/classes/mysql/mysql.security.php on line 99 This error is repeated a second time for mysql.security.php on line 100. homepage:73 <div class="login"> <?php require_once 'login.php'; ?> </div> mysql.security.php: 99-100 setcookie('username', "", time() - (60 * 60 * 24 * 365)); setcookie('password', "", time() - (60 * 60 * 24 * 365)); I know this isn't a "BOM" issue as I've read about. There is output before and after my calls to header() and setcookie() functions - this is necessary since the homepage includes a php file which then injects the right login or logout form. I've heard about using ob_start() at the beginning of content, but that's not a very specific instruction...I tried placing it at the beginning of homepage.php (just before the html tag) and that didn't fix anything. I'm new to PHP (a few days in, and new to web-app dev in general). To be honest, it blows my mind that I can't just change which page I am on, via php without bending over backwards...

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  • java packets byte

    - by user303289
    Guys, I am implementing a protocol in one of the wireless project. I am stucked at one point. In of the java file i am suppose to receive a packet and that packet is 12 byte packet and I have to write different functions for reading different parts of packets and convert it to diferent type. Like I want first four byte in one of the function and convert it to int, next two bytes in string. and again next two in string, last two hop in string and followed by last two int. I want follwing function to implement: // here is the interface /* FloodingData should use methods defined in this class. */ class FloodingPacket{ public static void main(String arg[]){ byte FloodingPack[]; // just for example to test in code FloodingPack=new byte[12]; interface IFloodingPacket { // Returns the unique sequence number for the packet int getSequenceNumber() ; // Returns the source address for the packet String getSourceAddress(); // Returns the destination address for the packet String getDestinationAddress(); // Returns the last hop address for the packet String getLastHopAddress(); // Sets the last hop address to the address of the node // which the packet was received from void updateLastHopAddress(); // Returns the entire packet in bytes (for sending) byte[] getBytes(); // Sets the bytes of the packet (for receiving) void setBytes(byte[] packet); }

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  • Doing a global count of an object type (like Users), best practice?

    - by user246114
    Hi, I know keeping global counters is frowned upon in app engine. I am interested in getting some stats though, like once every 24 hours. For example, I'd like to count the number of User objects in the system once every 24 hours. So how do we do this? Do we simply keep a set of admin tool functions which do something like: SELECT FROM com.me.project.server.User; and just see what the size of the returned List is? This is kind of a bummer because the datastore would have to deserialize every single User instance to create the returned list, right? I could optimize this possibly by asking for only the keys to be returned, so the whole User object doesn't have to be deserialized. Then again, a global counter for # of users probably would create too much contention, because there probably won't be hundreds of signups a minute for the service I'm creating. How should we go about doing this? Getting my total number of users once a day is probably a pretty typical operation? Thank you

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  • C++ Segmentation Fault when Iterating through a Vector

    - by user1790374
    I have a program that maintains an integer vector. I have three functions that add an integer, remove an integer and check whether an integer is already in the vector. The problem is with the last one. vector<int> children; void CtpTestingApplication::addChild(int child) { for (int i=0; i<children.size(); i++) { //already a child if (children[i]==child) return; } //child not yet recorded children.push_back(child); received.push_back(false); cout<<"added child "<<child; } void CtpTestingApplication::removeChild(int child) { Enter_Method("removeChild"); for (int i=0; i<children.size(); i++) { //already a child, remove it if (children[i]==child) { children.erase(children.begin()+i); received.erase(received.begin()+i); cout<<"removed child "<<child; } } //not recorded, no need to remove } bool CtpTestingApplication::isChild(int child) { Enter_Method("isChild"); vector<int>::iterator ic; bool result = false; for (ic= children.begin(); ic < children.end(); ic++) { cout<<*ic<<" vs "<<child; // if (child==*ic) result = true; } return result; } I always get segmentation fault when I uncomment "if (child==*ic)", even though printouts show that the vector is not empty and contains the expected integers. For example, with the if statements commented, I can see 1 vs 4, 2 vs 4, 4 vs 4, 12 vs 4 I also attempted looping using children[i] and so on, but to no avail. Any help would be appreciated. Thank you.

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  • where is c function attribute set (how to unset) with gcc

    - by cvsdave
    I am working with code from the GNU core utils, and find that the void usage() function is apparently set with the attribute "noreturn". Well, I am modifying the function, and I wish it to return (I removed the call to exit()). The compiler still complains that a "noreturn" function returns, and when using the Eclipse CDT debugger, stepping thorugh the code is anomolous - I skip over lines of code. I do not see the function be set in the .c file, and there is no .h file for this .c file. The file is df.c. I have renamed the file df_call.c. How can the compiler be finding this attribute? How can I unset it? Thanks. ======= Thanks to all contributors for their help! The short answer is "the usage() function found in GNUutils 7.4 is prototyped in system.h as 'void usage (int status) ATTRIBUTE_NORETURN'. Changing to 'void usage (int status); /*ATTRIBUTE_NORETURN;*/' resolved the issue for me, but leaves the problem of a modified system.h. The long answer is: The GNU c compiler supports assigning attributes to functions (see http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html) one of which is "noreturn". The syntax is "attribute ((noreturn))" (see http://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute-Syntax) but is often macro'd to ATTRIBUTE_NORETURN. If the attribute is set, and in this case one tries to return from the function, the executable compiles with a complaint, but compiles and runs. It will, however, behave unexpectedly (skipping over src lines in my case, maybe due to the optimization). The debugger in Eclipse CDT actually jumps past lines of code, leading the developer to doubt his senses.

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  • jQuery, Ajax & PHP submit multiple forms dilemma

    - by user557563
    This is a very simple form that I have found on the web (as I am a jQuery beginner). <!-- this is my jquery --> <script> $(document).ready(function(){ $("form#submit_wall").submit(function() { var message_wall = $('#message_wall').attr('value'); var id = $('#id').attr('value'); $.ajax({ type: "POST", url: "index.php?leht=pildid", data:"message_wall="+ message_wall + "&id="+ id, cache: false, success: function(){ $("ul#wall").prepend(""+message_wall+"", ""+id+""); $("ul#wall li:first").fadeIn(); alert("Thank you for your comment!"); } }); return false; }); }); </script> <!-- this is my HTML+PHP --> some PHP ... while($row_pilt = mysql_fetch_assoc($select_pilt)){ print <form id="submit_wall"> <label for="message_wall">Share your message on the Wall</label> <input type="text" id="message_wall" /> <input type="hidden" id="id" value="'.(int)$row_pilt['id'].'"> <button type="submit">Post to wall</button> </form> and down below is my PHP script that writes to mySQL. It is a pretty straight forward script. However, it is getting little complicated when I submit it. Since I have more than one form on my page (per WHILE PHP LOOP), thus when I submit - only the FIRST form gets submitted. Furthermore, any other subsequent forms that I submit - data is being copied from the first form. Is there any jQuery functions that clear the data? - or is there a better solution. Thanks, Nick

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  • Internal typedef and circular dependency

    - by bcr
    I have two classes whose functions take typedefed pointers to eachother as return values and parameters. I.e.: class Segment; class Location : public Fwk::NamedInterface { public: // ===== Class Typedefs ===== typedef Fwk::Ptr<Location const> PtrConst; typedef Fwk::Ptr<Location> Ptr; // ===== Class Typedefs End ===== void segmentIs(Segment::Ptr seg); /* ... */ } and class Location; class Segment : public Fwk::NamedInterface { public: // ===== Class Typedefs ===== typedef Fwk::Ptr<Segment const> PtrConst; typedef Fwk::Ptr<Segment> Ptr; // ===== Class Typedefs End ===== void locationIs(Location::Ptr seg); /* ... */ } This understandably generated linker errors...which the forward declarations of the respective classes don't fix. How can I forward declare the Ptr and PtrConst typedefs while keeping these typedefs internal to the class (i.e. I would like to write Location::Ptr to refer to the location pointer type)? Thanks folks!

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  • Problem with inherited classes in C#

    - by Unniloct
    I have a class called "Entity," with two child classes: "Creature" and "Item." (I'm making a game.) Creature has two functions called "Attack," one for attacking Creatures, and one for attacking Items. So far, everything works well. Now I'm working on the shooting bit, so I have a function called SelectTarget(). It takes all of the Entities (both Creatures and Items) in the player's view that the player can shoot and lets the player choose one. So here lies the problem: SelectTarget() returns an Entity, but I need some code to figure out whether that Entity is a Creature or an Item, and process it appropriately. Since this question looks kind of empty without any code, and I'm not 100% sure my explanation is good enough, here's where I'm at: if (Input.Check(Key.Fire)) { Entity target = Game.State.SelectTarget.Run(); this.Draw(); if (target != null) { //Player.Attack(target); // This won't work, because I have: // Player.Attack((Creature)Target) // Player.Attack((Item)Target) // but nothing for Entity, the parent class to Creature and Item. return true; } } (If the way the game is laid out seems weird, it's a roguelike.)

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  • More efficient way to update multiple elements in javascript and/or jquery?

    - by Seiverence
    Say I have 6 divs with ID "#first", ""#second" ... "#sixth". Say if I wanted to execute functions on each of those divs, I would set up an array that contains each of the names of the divs I want to update as an element in the array of strings. ["first", "second", "third"] that I want to update. If I wanted to apply I function, I set up a for loop that iterates through each element in the array and say if I wanted to change the background color to red: function updateAllDivsInTheList() { for(var i = 0; i < array.size; i++) $("#"+array[i]).changeCssFunction(); } } Whenever I create a new div, i would add it to the array. The issue is, if I have a large number of divs that need to get updated, say if I wanted to update 1000 out of 1200 divs, it may be a pain/performance tank to have to sequentially iterate through every single element in the array. Is there some alternative more efficient way of updating multiple divs without having to sequentially iterate through every element in an array, maybe with some other more efficient data structure besides array? Or is what I am doing the most efficient way to do it? If can provide some example, that would be great.

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  • Dynamic function arguments in C++, possible?

    - by Jeshwanth Kumar N K
    I am little new to C++, I have one doubt in variable argument passing. As I mentioned in a sample code below ( This code won't work at all, just for others understanding of my question I framed it like this), I have two functions func with 1 parameter and 2 parameters(parameter overloading). I am calling the func from main, before that I am checking whether I needs to call 2 parameter or 1 parameter. Here is the problem, as I know I can call two fuctions in respective if elseif statements, but I am curious to know whether I can manage with only one function. (In below code I am passing string not int, as I mentioned before this is just for others understanding purpose. #include<iostream.h> #include <string> void func(int, int); void func(int); void main() { int a, b,in; cout << "Enter the 2 for 2 arg, 1 for 1 arg\n"; cin << in; if ( in == 2) { string pass = "a,b"; } elseif ( in == 1) { string pass = "a"; } else { return 0; } func(pass); cout<<"In main\n"<<endl; } void func(int iNum1) { cout<<"In func1 "<<iNum1<<endl; } void func(int iNum1, int iNum2) { cout<<"In func2 "<<iNum1<<" "<<iNum2<<endl; }

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  • [Processing/Java]Visibility/Layering Issue

    - by nnash
    I'm working on a small sketch in processing where I am making a "clock" using the time functions and drawing ellipses across the canvas based on milliseconds, seconds and minutes. I'm using a for loop to draw all of the ellipses and each for loop is inside its own method. I'm calling each of these methods in the draw function. However for some reason only the first method that is called is being drawn, when ideally I would like to have them all being visibly rendered. //setup program void setup() { size(800, 600); frameRate(30); background(#eeeeee); smooth(); } void draw(){ milliParticles(); secParticles(); minParticles(); } //time based particles void milliParticles(){ for(int i = int(millis()); i >= 0; i++) { ellipse(random(800), random(600), 5, 5 ); fill(255); } } void secParticles() { for(int i = int(second()); i >= 0; i++) { fill(0); ellipse(random(800), random(600), 10, 10 ); background(#eeeeee); } } void minParticles(){ for(int i = int(minute()); i >= 0; i++) { fill(50); ellipse(random(800), random(600), 20, 20 ); } }

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  • swap! alter and alike

    - by mekka
    Hello, I am having a problem understanding how these functions update the underlying ref, atom etc. The docs say: (apply f current-value-of-identity args) (def one (atom 0)) (swap! one inc) ;; => 1 So I am wondering how it got "expanded" to the apply form. It's not mentioned what exactly 'args' in the apply form is. Is it a sequence of arguments or are these separate values? Was it "expanded" to: (apply inc 0) ; obviously this wouldnt work, so that leaves only one possibility (apply inc 0 '()) (swap! one + 1 2 3) ;; #=> 7 Was it: (apply + 1 1 2 3 '()) ;or (apply + 1 [1 2 3]) (def two (atom [])) (swap! two conj 10 20) ;; #=> [10 20] Was it: (apply conj [] [10 20]) ;or (apply conj [] 10 20 '()) If I swap with a custom function like this: (def three (atom 0)) (swap! three (fn [current elem] (println (class elem))) 10) ;;#=> java.Lang.Integer Which means that the value '10' doesnt magically get changed into a seq '(10) and leads me to the conclusion, that it gets "expanded" to: (apply f current-value-of-identity arg1 arg2 arg3... '()) Is that a correct assumption and the docs are simply lacking a better description?

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  • Yii 'limit' on related model's scope

    - by pethee
    I have a model called Guesses that has_many Comments. I'm making eager queries to this to then pass on as JSON as response to an API call. The relations are obviously set between the two models and they are correct(one2many <= belongs2) I added a scope to Comments called 'api' like this: public function scopes() { return array( 'api' => array( 'select' => 'id, comment, date', 'limit'=>3, 'order'=>'date DESC', 'together'=>true, ), ); } And I'm running the following one-liner query: $data = Guesses::model()->with('comments:api')->findAll(); The issue here is that when calling the 'api' scope using a with('relation'), the limit property simply doesn't apply. I added the 'together'=true there for another type of scope, plus I hear it might help. It doesn't make a difference. I don't need all the comments of all Guesses. I want the top 3 (or 5). I am also trying to keep the one-liner call intact and simple, manage everything through scopes, relations and parameterized functions so that the API call itself is clean and simple. Any advice?

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  • How to increase my "advanced" knowledge of PHP further? (quickly)

    - by Kerry
    I have been working with PHP for years and gotten a very good grasp of the language, created many advanced and not-so-advanced systems that are working very well. The problem I'm running into is that I only learn when I find a need for something that I haven't learned before. This causes me to look up solutions and other code that handles the problem, and so I will learn about a new function or structure that I hadn't seen before. It is in this way that I have learned many of my better techniques (such as studying classes put out by Amazon, Google or other major companies). The main problem with this is the concept of not being able to learn something if you don't know it exists. For instance, it took me several months of programming to learn about the empty() function, and I simply would check the string length using strlen() to check for empty values. I'm now getting into building bigger and bigger systems, and I've started to read blogs like highscalability.com and been researching MySQL replication and server data for scaling. I know that structure of your code is very important to make full systems work. After reading a recent blog about reddit's structure, it made me question if there is some standard or "accepted systems" out there. I have looked into frameworks (I've used Kohana, which I regretted, but decided that PHP frameworks were not for me) and I prefer my own library of functions rather than having a framework. My current structure is a mix between WordPress, Kohana and my own knowledge. The ways I can see as being potentially beneficial are: Read blogs Read tutorials Work with someone else Read a book What would be the best way(s) to "get to the next level" the level of being a very good system developer?

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  • Nullable values in C++

    - by DanDan
    I'm creating a database access layer in native C++, and I'm looking at ways to support NULL values. Here is what I have so far: class CNullValue { public: static CNullValue Null() { static CNullValue nv; return nv; } }; template<class T> class CNullableT { public: CNullableT(CNullValue &v) : m_Value(T()), m_IsNull(true) { } CNullableT(T value) : m_Value(value), m_IsNull(false) { } bool IsNull() { return m_IsNull; } T GetValue() { return m_Value; } private: T m_Value; bool m_IsNull; }; This is how I'll have to define functions: void StoredProc(int i, CNullableT<int> j) { ...connect to database ...if j.IsNull pass null to database etc } And I call it like this: sp.StoredProc(1, 2); or sp.StoredProc(3, CNullValue::Null()); I was just wondering if there was a better way than this. In particular I don't like the singleton-like object of CNullValue with the statics. I'd prefer to just do sp.StoredProc(3, CNullValue); or something similar. How do others solve this problem?

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  • What's up with this reversing bit order function?

    - by MattyW
    I'm rather ashamed to admit that I don't know as much about bits and bit manipulation as I probably should. I tried to fix that this weekend by writing some 'reverse the order of bits' and 'count the ON bits' functions. I took an example from here but when I implemented it as below, I found I had to be looping while < 29. If I loop while < 32 (as in the example) Then when I try to print the integer (using a printBits function i've written) I seem to be missing the first 3 bits. This makes no sense to me, can someone help me out? int reverse(int n) { int r = 0; int i = 0; for(i = 0; i < 29; i++) { r = (r << 1) + (n & 1); n >>=1; } return r; }

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