Search Results

Search found 3592 results on 144 pages for 'pointer'.

Page 97/144 | < Previous Page | 93 94 95 96 97 98 99 100 101 102 103 104  | Next Page >

  • Why does a delegate with no parameters compile?

    - by Ryan
    I'm confused why this compiles: private delegate int MyDelegate(int p1, int p2); private void testDelegate() { MyDelegate imp = delegate { return 1; }; } MyDelegate should be a pointer to a method that takes two int parameters and returns another int, right? Why am I allowed to assign a method that takes no parameters? Interestingly, these doesn't compile (it complains about the signature mismatches, as I'd expect) private void testDelegate() { // Missing param MyDelegate imp = delegate(int p1) { return 1; }; // Wrong return type MyDelegate imp2 = delegate(int p1, int p2) { return "String"; }; } Thanks for any help! Ryan

    Read the article

  • SWIG-Lua question on class returning another class

    - by John Smith
    I am concreting a question I had earlier. I have two classes in C++ and I use SWIG to wrap them. A method in one class can return a pointer to the other class. How can I get Lua to see it as more than just a userdata? More concretely: I have class fruit { int numberofseeds; //some other stuff about fruit constructors etc... public: getseedcount() { return numberofseeds; } } class tree { fruit * apple; public: //constructors and whatnot fruit * getfruit() { return apple; } } I wrap these two class with SWIG so I can access them in Lua So I can get in Lua the object x=pomona.tree(grannysmith). My question now is: How can I arrange for things so that when I type y=x:getfruit() I will get a pomona:fruit type object? Where I can write something line y:getseedcount()? At the moment all I get is userdata which not edible.

    Read the article

  • Why does accessing a member of a malloced array of structs seg fault?

    - by WSkinner
    I am working through Learn C The Hard Way and am stumped on something. I've written a simplified version of the problem I am running into to make it easier to get down to it. Here is the code: #include <stdlib.h> #define GROUP_SIZE 10 #define DATA_SIZE 64 struct Dummy { char *name; }; struct Group { struct Dummy **dummies; }; int main() { struct Group *group1 = malloc(sizeof(struct Group)); group1->dummies = malloc(sizeof(struct Dummy) * GROUP_SIZE); struct Dummy *dummy1 = group1->dummies[3]; // Why does this seg fault? dummy1->name = (char *) malloc(DATA_SIZE); return 0; } when I try to set the name pointer on one of my dummies I get a seg fault. Using valgrind it tells me this is uninitialized space. Why is this?

    Read the article

  • Removing a UIView from its superView and expanding its frame to full screen

    - by Magic Bullet Dave
    I have an object that is a subclass of UIView that can be added to a view hierarchy as a subView. I want to be able to remove the UIView from its superView and add it as a subView of the main window and then expand to full screen. Something along the lines of: // Remove from superView and add to mainWindow [self retain]; [self removeFromSuperView]; [self addSubView:mainWindow]; // Animate to full screen [UIView beginAnimations:@"expandToFullScreen" context:nil]; [UIView setAnimationDuration:1.0]; self.frame = [[UIScreen mainScreen] applicationFrame]; [UIView commitAnimations]; [self release]; Firstly am I on the right lines? Secondly, is there an easily way for the object to get a pointer to the mainWindow? Thanks Dave

    Read the article

  • How to make an NSURL that contains a | (pipe character)?

    - by aks
    Hi all, I am trying to access google maps' forward geocoding service from my iphone app. When i try to make an NSURL from a string with a pipe in it I just get a nil pointer. NSURL *searchURL = [NSURL URLWithString:@"http://maps.google.com/maps/api/geocode/json?address=6th+and+pine&bounds=37.331689,-122.030731|37.331689,-122.030731&sensor=false"]; I dont see any other way in the google api to send bounds coordinates with out a pipe. Any ideas about how I can do this?

    Read the article

  • If free() knows the length of my array, why can't I ask for it in my own code?

    - by Chris Cooper
    I know that it's a common convention to pass the length of dynamically allocated arrays to functions that manipulate them: void initializeAndFree(int* anArray, int length); int main(){ int arrayLength = 0; scanf("%d", &arrayLength); int* myArray = (int*)malloc(sizeof(int)*arrayLength); initializeAndFree(myArray, arrayLength); } void initializeAndFree(int* anArray, int length){ int i = 0; for (i = 0; i < length; i++) { anArray[i] = 0; } free(anArray); } but if there's no way for me to get the length of the allocated memory from a pointer, how does free() "automagically" know what to deallocate? Why can't I get in on the magic, as a C programmer? Where does free() get its free (har-har) knowledge from?

    Read the article

  • I have an error when I escaping string

    - by Sudip Rooj
    I am trying to write a string in my php code in my panel. This is given bellow <?php $str.="$('#layerList ul').prepend('<li data-refInd=\''+arr_ind+'\'><img src=\''tmp_card_imgs/\'+temp".$k.".name+'\' width='20px' /> Layer '+temp".$k.".zindex+':Image <span class=\'del_layer\' style=\'cursor:pointer;float:right;display:block;\'>X</span></li>');"; ?> but the error showing in console is given bellow SyntaxError: missing ) after argument list [Break On This Error] ...data-refInd=\''+arr_ind+'\'><img src=\''tmp_card_imgs/\'+temp0.name+'\' width='2... -----------------------------------------| editor.php?id=129 (line 837, col 60) What is the problem in my string escaping?

    Read the article

  • trying to make an accordion menu from a list - jquery indexhibit

    - by orionrush
    Hello - Im teaching my self javascript & jquery so this might be a bit of a low brow question or entirely too much code for anyone to wade through, but Im hoping for some feedback. I have looked around and haven't found a thread that looks like it will deals neatly with my question. Im using the cms indexhibit (cant create a new tag!) and trying to create an accordion style menu from the menu list it generates. I basically have the behaviour Im after, modifying an existing bit of work but there are quite a few foibles, which are no doubt a conflict between the .click and .toggle and a confused use if statements. I basically want to start from scratch and redo this so I can a) learn from my mistakes b) understand what's happening. Im having trouble now because I dont know where to go from here, or how to trouble shoot it. Can anyone give me a quick analysis how the the script in the head of the document work together? Also any insight into the nature of the conflicts Im seeing and what approach might take to remedy them? If you were going to start afresh what would be your approach? Here is a test to see it in action (warts and all): http://stillstatic.nfshost.com/ This script goes into the document head: <script type='text/javascript'> //im not entirely clear as to what this achieves path = 'path/to/script/'; $(document).ready(function() { setTimeout('move_up()', 1); expandingMenu(0); expandingMenu(1); expandingMenu(2); expandingMenu(3); expandingMenu(4); //etc }); </script> the generated list: <ul> <li class='section-title active_menu'>blogs</li> <li><a class="active" href='#' onclick="do_click();">3</a></li> </ul> <ul> //this menu section dose not have a label: class .section-title <li><a href='#' onclick="do_click();">1</a></li> <li><a href='#' onclick="do_click();">2</a></li> </ul> <ul> //this menu section is not the 'active menu' this is achieved by the jquery script <li class='section-title'>writing</li> <li><a href='#' onclick="do_click();">4</a></li> <li><a href='#' onclick="do_click();">5</a></li> </ul> The meat of in an external script: function expandingMenu(num) { var speed = 500; var menu_title = $("#menu ul").eq(num).children(":first"); // ie. first child be the title with the class .section-title unless the user turned it off var menu_items = $("#menu ul").eq(num).children().filter(function (index) { return index 0; }); // ie. any li NOT in position 0, below li.section-title if (menu_items.is(".active") == true) { menu_title.addClass("active_menu"); //Add a class to the active list so we can style it. } if (menu_title.is(".section-title") == true){ // this if prevents interference with users who turn off the section titling if ((menu_items.is(".active") == false) && (menu_items.is(":visible")) ) { menu_items.hide(0);// first we hide the inactive exhibits } $('li').click(function (){ if ( (menu_title.is(":visible") == true) ){ menu_items.hide(speed); } if ( (menu_items.is(":hidden") == true ) && (('')) ){// ?! without this second condition things break down. . . menu_items.show(speed); } }) menu_title.css({cursor:"pointer"}).toggle( // add click functions + pointer to menu_title function () { menu_items.show(speed);//Open it up }, function () { // this function could even be empty but without the if things get weird if (menu_items.is(".xx")) menu_items.hide(speed); //Take the menu item off of active duty! } ) } }

    Read the article

  • Compatible types and structures in C

    - by Oli Charlesworth
    I have the following code: int main(void) { struct { int x; } a, b; struct { int x; } c; struct { int x; } *p; b = a; /* OK */ c = a; /* Doesn't work */ p = &a; /* Doesn't work */ return 0; } which fails to compile under GCC (3.4.6), with the following error: test.c:8: error: incompatible types in assignment test.c:9: warning: assignment from incompatible pointer type Now, from what I understand (admittedly from the C99 standard), is that a and c should be compatible types, as they fulfill all the criteria in section 6.2.7, paragraph 1. I've tried compiling with std=c99, to no avail. Presumably my interpretation of the standard is wrong?

    Read the article

  • Android internet connectivity check problem

    - by Chaoz
    Hello, I'm new to Android development and working on an Android application that requires the phone to be connected to the internet, through either Wifi, EDGE or 3G. This is the code that I'm using: public static boolean isConnected() { ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); return cm.getActiveNetworkInfo().isConnectedOrConnecting(); } I've also set these permissions in the manifest file: <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> This works fine in the emulator running version 1.5 of Android when 3G is enabled, but it crashes when I disable the 3G connection. My application throws a null pointer exception when I call isConnectedOrConnecting(). Hope that anyone knows the solution to this. Thanks in advance!

    Read the article

  • typedef resolution rule

    - by kumar_m_kiran
    Hi All, Can you Please tell me the resolution rule involved in resolving the meaning of the variable in a typedef. Any link related to the same will be very useful. Example #typedef string* pstring; const pstring parr; Here confusion arises whether const'ness is for pointer or the content. Now based on what thumb rule do can we start resolving the above interpretation of the pstring?. Smilarly, If I have a very complex typedef'ed variable, like #typedef void (func*)()(int), I should be able to resolve it using the thumb rule. Thanks in advance for your suggestions

    Read the article

  • Efficiently remove points with same slope

    - by Ram
    Hi, In one of mine applications I am dealing with graphics objects. I am using open source GPC library to clip/merge two shapes. To improve accuracy I am sampling (adding multiple points between two edges) existing shapes. But before displaying back the merged shape I need to remove all the points between two edges. But I am not able to find an efficient algorithm that will remove all points between two edges which has same slope with minimum CPU utilization. Currently all points are of type PointF Any pointer on this will be a great help.

    Read the article

  • C optimization breaks algorithm

    - by Halpo
    I am programming an algorithm that contains 4 nested for loops. The problem is at at each level a pointer is updated. The innermost loop only uses 1 of the pointers. The algorithm does a complicated count. When I include a debugging statement that logs the combination of the indexes and the results of the count I get the correct answer. When the debugging statement is omitted, the count is incorrect. The program is compiled with the -O3 option on gcc. Why would this happen?

    Read the article

  • Performing time consuming operation on STL container within a lock

    - by Ashley
    I have an unordered_map of an unordered_map which stores a pointer of objects. The unordered map is being shared by multiple threads. I need to iterate through each object and perform some time consuming operation (like sending it through network etc) . How could I lock the multiple unordered_map so that it won't blocked for too long? typedef std::unordered_map<string, classA*>MAP1; typedef std::unordered_map<int, MAP1*>MAP2; MAP2 map2; pthread_mutex_lock(&mutexA) //how could I lock the maps? Could I reduce the lock granularity? for(MAP2::iterator it2 = map2.begin; it2 != map2.end; it2++) { for(MAP1::iterator it1 = *(it2->second).begin(); it1 != *(it2->second).end(); it1++) { //perform some time consuming operation on it1->second eg sendToNetwork(*(it1->second)); } } pthread_mutex_unlock(&mutexA)

    Read the article

  • Is there a leak in this copy code?

    - by Don Wilson
    Is there a leak in this code? // Move the group Group *movedGroup = [[Group alloc] init]; movedGroup = [[[[GroupList sharedGroupList] groups] objectAtIndex:fromIndex] copy]; [[GroupList sharedGroupList] deleteGroup:fromIndex]; [[GroupList sharedGroupList] insertGroup:movedGroup atIndex:toIndex]; // Update the loadedGroupIndex pointer if (loadedGroupIndex < fromIndex & loadedGroupIndex >= toIndex) { loadedGroupIndex = loadedGroupIndex + 1; } else if (loadedGroupIndex > fromIndex & loadedGroupIndex < toIndex) { loadedGroupIndex = loadedGroupIndex - 1; } else if (loadedGroupIndex == fromIndex) { loadedGroupIndex = toIndex; } [movedGroup release]

    Read the article

  • Resources for memory management in embedded application

    - by Elazar Leibovich
    How should I manage memory in my mission critical embedded application? I found some articles with google, but couldn't pinpoint a really useful practical guide. The DO-178b forbids dynamic memory allocations, but how will you manage the memory than? preallocate everything in advance and send a pointer to each function that needs allocation? Allocate it on the stack? Use a global static allocator (but then it's very similar to dynamic allocation)? Answers can be of the form of regular answer, reference to a resource, or reference to good opensource embedded system for example. clarification: The issue here is not whether or not memory management is availible for the embedded system. But what is a good design for an embedded system, to maximize reliability.

    Read the article

  • @OneToyMany property null in Entity after (second) merge

    - by iNPUTmice
    Hi, I'm using JPA (with Hibernate) and Gilead in a GWT project. On the server side I have this method and I'm calling this method twice with the same "campaign". On the second call it throws a null pointer exception in line 4 "campaign.getTextAds()" public List<WrapperTextAd> getTextAds(WrapperCampaign campaign) { campaign = em.merge(campaign); System.out.println("getting textads for "+campaign.getName()); for(WrapperTextAd textad: campaign.getTextAds()) { //do nothing } return new ArrayList<WrapperTextAd>(campaign.getTextAds()); } The code in WrapperCampaign Entity looks like this @OneToMany(mappedBy="campaign") public Set<WrapperTextAd> getTextAds() { return this.textads; }

    Read the article

  • What does this error mean when using OpenAL in the iPhone Simulator?

    - by mystify
    I'm getting this in the console, when creating my OpenAL Sources and Buffers: Cannot find executable for CFBundle/CFPlugIn 0xf530d0 </Library/Audio/Plug-Ins/HAL/Hear.plugin> (not loaded) 2010-05-05 17:11:13.934 Testproj[43173:207] Cannot find function pointer HearCFPlugInFactory for factory 5268FAAB-0147-4272-93FD-4D60A2433C1C in CFBundle/CFPlugIn 0xf430d0 </Library/Audio/Plug-Ins/HAL/Hear.plugin> (not loaded) However, the sounds play nicely. I think HAL is not available on the iPhone, it's just on Mac OS X, right? Do you guys also get that error in the simulator when using OpenAL?

    Read the article

  • Unexpected key-value behavior in a Core Data Context

    - by ????
    If I create an array of strings (via key-value coding) containing the names of a Managed Object entity's attributes which are stored in the App Delegate the first time, I get an array of NSStrings without any problems. If I subsequently make the same call later from the same entry point in code, that same collection becomes an array of NULL objects- even though nothing in the Core Data Context has changed. One unappealing work-around involves re-creating the string array every time, but I'm wondering if anyone has a guess as to what's happening behind the scenes. // Return an array of strings with the names of attributes the Activity entity - (NSArray *)activityAttributeNames { #pragma mark ALWAYS REFRESH THE ENTITY NAMES? //if (activityAttributeNames == nil) { // Create an entity pointer for Activity NSEntityDescription *entity = [NSEntityDescription entityForName:@"Activity" inManagedObjectContext:managedObjectContext]; NSArray *entityAttributeArray = [[NSArray alloc] initWithArray:[[entity attributesByName] allValues]]; // Extract the names of the attributes with Key-Value Coding activityAttributeNames = [entityAttributeArray valueForKeyPath:@"name"]; [entityAttributeArray release]; //} return activityAttributeNames; }

    Read the article

  • The shortest way to convert infix expressions to postfix (RPN) in C

    - by kuszi
    Original formulation is given here (you can try also your program for correctness) . Additional rules: 1. The program should read from standard input and write do standard output. 2. The program should return zero to the calling system/program. 3. The program should compile and run with gcc -O2 -lm -s -fomit-frame-pointer. The challenge has some history: the call for short implementations has been announced at the Polish programming contest blog in September 2009. After the contest, the shortest code was 81 chars long. Later on the second call has been made for even shorter code and after the year matix2267 published his solution in 78 bytes: main(c){read(0,&c,1)?c-41&&main(c-40&&(c%96<27||main(c),putchar(c))):exit(0);} Anyone to make it even shorter or prove this is impossible?

    Read the article

  • Confused about "override" vs. "new" in C#

    - by iTayb
    I'm having the following classes: class Base { public virtual void Print() { Console.WriteLine("Base"); } } class Der1 : Base { public new virtual void Print() { Console.WriteLine("Der1"); } } class Der2 : Der1 { public override void Print() { Console.WriteLine("Der2"); } } This is my main method: Base b = new Der2(); Der1 d1 = new Der2(); Der2 d2 = new Der2(); b.Print(); d1.Print(); d2.Print(); The output is Base, Der2, Der2. As far as I know, Override won't let previous method to run, even if the pointer is pointing to them. So the first line should output Der2 as well. However Base came out. How is it possible? How the override didn't work there?

    Read the article

  • Writing a PHP web crawler using cron

    - by Horse
    Hi all I have written myself a web crawler using simplehtmldom, and have got the crawl process working quite nicely. It crawls the start page, adds all links into a database table, sets a session pointer, and meta refreshes the page to carry onto the next page. That keeps going until it runs out of links That works fine however obviously the crawl time for larger websites is pretty tedious. I wanted to be able to speed things up a bit though, and possibly make it a cron job. Any ideas on making it as quick and efficient as possible other than setting the memory limit / execution time higher?

    Read the article

  • Can I use memcpy in C++ to copy classes that have no pointers or virtual functions

    - by Shane MacLaughlin
    Say I have a class, something like the following; class MyClass { public: MyClass(); int a,b,c; double x,y,z; }; #define PageSize 1000000 MyClass Array1[PageSize],Array2[PageSize]; If my class has not pointers or virtual methods, is it safe to use the following? memcpy(Array1,Array2,PageSize*sizeof(MyClass)); The reason I ask, is that I'm dealing with very large collections of paged data, as decribed here, where performance is critical, and memcpy offers significant performance advantages over iterative assignment. I suspect it should be ok, as the 'this' pointer is an implicit parameter rather than anything stored, but are there any other hidden nasties I should be aware of?

    Read the article

  • c++/cli pass (managed) delegate to unmanaged code

    - by Ron Klein
    How do I pass a function pointer from managed C++ (C++/CLI) to an unmanaged method? I read a few articles, like this one from MSDN, but it describes two different assemblies, while I want only one. Here is my code: 1) Header (MyInterop.ManagedCppLib.h): #pragma once using namespace System; namespace MyInterop { namespace ManagedCppLib { public ref class MyManagedClass { public: void DoSomething(); }; }} 2) CPP Code (MyInterop.ManagedCppLib.cpp) #include "stdafx.h" #include "MyInterop.ManagedCppLib.h" #pragma unmanaged void UnmanagedMethod(int a, int b, void (*sum)(const int)) { int result = a + b; sum(result); } #pragma managed void MyInterop::ManagedCppLib::MyManagedClass::DoSomething() { System::Console::WriteLine("hello from managed C++"); UnmanagedMethod(3, 7, /* ANY IDEA??? */); } I tried creating my managed delegate and then I tried to use Marshal::GetFunctionPointerForDelegate method, but I couldn't compile.

    Read the article

  • A programming language for teaching data structures and algorithms with? [closed]

    - by Andreas Grech
    Possible Duplicate: Choice of programming language for learning data structures and algorithms Teachers have different opinions on what programming language they would choose to teach data structures and algorithms with. Some would prefer a lower level language such as C because it allows the student to learn more about what goes on beyond the abstractions in terms of memory allocation and deallocation and pointers and pointer arithmetic. On the other hand, others would say that they would prefer a higher level language like Java because it allows the student to learn more about the concepts of the structures and the algorithm design rather than 'waste time' and fiddle around with memory segmentation faults and all the blunders that come with languages where memory management is manual. What is your take on this issue? And also, please post any references you may know of that also discuss this argument.

    Read the article

< Previous Page | 93 94 95 96 97 98 99 100 101 102 103 104  | Next Page >