Search Results

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

Page 103/144 | < Previous Page | 99 100 101 102 103 104 105 106 107 108 109 110  | Next Page >

  • Can I reproduce Scala's behavior for == ?

    - by JPP
    In Programming in Scala, I can read that the == operator behaves as if it was defined like this: final def == (that: Any): Boolean = if (null eq this) {null eq that} else {this equals that} But there must actually be compiler magic to avoid null pointer exceptions, right? Is there any way for me to replicate this behavior with pure Scala; i.e., have an operator/method return one thing if the receiver is null and another one if it isn't? What I mean is an actual implementation of null eq this. I suppose I can write a "pimp" and then define the method on the wrapper class, but is there a more direct way to do this?

    Read the article

  • jQuery Mobile button js control

    - by David
    I have a button that is not triggering event in jQuery mobile. It was working but I had to remove the css. It was screwing up my all my ul lists. Any help would greatly appreciated Here is the code for the button at the bottom of the form : <div class="next"> <a class="btnNext">Next &gt;&gt;</a> </div> Which is supposed to do this on a separate js file: init: function(){ $('.btnNext').onclick(function(){ if ($('input[type=radio]:checked:visible').length == 0) { return false; } $(this).parents('.questionContainer').fadeOut(500, function(){ Here is the css I removed: a { border: 1px solid #000; padding: 2px 5px; font-weight: bold; font-size: 10px; background: #FFF; cursor: pointer; } a:hover { background: none; }

    Read the article

  • SetWindowLongPtr with DialogBoxParam?

    - by templatetypedef
    Hey all- A while back I was writing a C++ program with the Win32 API that would display a dialog box and then listen to the messages it generated. At one point, I was interested in associating a piece of data with the dialog window. Were I manually creating the window and attaching a window proc, I'd just use SetWindowLongPtr to set the GWLP_USERDATA field to a pointer to the data to associate. However, in this case I was creating and displaying the window with DialogBoxParam, and it wasn't clear whether this function was associating that data with its own internal state. Since the MSDN didn't have a description of what would happen in this case, I ended up using some other approach to solve the problem. My question is this - is it safe to use SetWindowLongPtr to overwrite the GWLP_USERDATA value in a window created by DialogBoxParam? Thanks!

    Read the article

  • ANSI C++: Diferences between delete and delete[]

    - by Sunscreen
    I was looking a snipset of code: int* ip; ip = new int[100]; delete ip; The example above states that: "This code will work with many compilers, but it should instead read:" int* ip; ip = new int[100]; delete [] ip; Is this indeed the case? I use the compiler "Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 11.00.7022 for 80x86" and does not complain (first example) while compiling. At runtime the pointer is set to NULL. Other compilers behave diferrently? Can a compiler not compain and issues can appear at runtime? Thanks, Sun

    Read the article

  • C++ syntax of constructors " 'Object1 a (1, Object1(2))''

    - by osgx
    Hello I have a such syntax in program class Object1 : BaseClass { BaseClass *link; int i; public: Object1(int a){i=a;} Object1(int a, Object1 /*place1*/ o) {i=a; link= &o;} }; int main(){ Object1 a(1, /*place2*/ Object1(2)); ... } What do I need in place1? I want to save a link (pointer) to the second object in the first object. Should I use in place1 reference "&"? What type will have "Object1(2)" in place2? Is it a constructor of the anonymous object? Will it have a "auto" storage type?

    Read the article

  • In PHP can I check a boolean on a function call?

    - by Chris
    I have a function which checks the passed value and returns false or true, if false I want it to add something to an array. The code I've written is below. if(!check_input($_POST['username'])){ $errors[] = "Username"; } Right now it adds to my array anyway, regardless of what is entered in the form. Is the way I've written that the correct way to check if the return from check_input() is false? I've checked the function's logic by altering the returns to echoes and it's returning the correct value, I'm just not sure if I'm checking it wrong. I'd previously attempted to write it as $X=check_input etc, and then if(check_value == false) but that doesn't seem to give me the desired result either. Hmmm a quick pointer please!

    Read the article

  • Extract data from uint8 to double

    - by HADJ AMOR HASSEN
    I have a C function receiving a uint8 pointer with another parameter which is its size (number of bytes). I want to extract double data from this buffer. Here is my code: Write(uint8* data, uint8 size) /* data and size are given by a callback to my function)*/ { double d; for (i = 0; i < size; i++) { d = ((double*)&data)[i]; printf(" d = %d\n"); } } The problem is that I am not receiving what I am sending within an external hardware. I guess that my cast is wrong. I tried other methods but without any good result. I am still not able to get what I send.

    Read the article

  • What is the difference between these two ways of creating NSStrings?

    - by adame
    NSString *myString = @"Hello"; NSString *myString = [NSString stringWithString:@"Hello"]; I understand that using method (1) creates a pointer to a string literal that is defined as static memory (and cannot be deallocated) and that using (2) creates an NSString object that will be autoreleased. Is using method (1) bad? What are the major differences? Is there any instances where you would want to use (1)? Is there a performance difference? P.S. I have searched extensively on Stack Overflow and while there are questions on the same topic, none of them have answers to the questions I have posted above.

    Read the article

  • question abouut string sort

    - by davit-datuashvili
    i have question from programming pearls problem is following show how to use lomuto's partitioning scheme to sort varying length bit strings in time proportional to the sum oof their length and algorithm is following each record in x[0..n-1] has an integer length and pointer to the array bit[0..length-1] code void bsort(l,u,depth){ if (l>=u) return; for (int i=l;i<u;i++) if (x[i].length<depth) swap(i,l++); m=l; if (x[i].bit[depth] ==0) swap(i,m++); bsort(l,m-1,depth+1); bsort(m,u,depth+1); please help me i need following things 1. how this algorith works 2.how implement in java?

    Read the article

  • freeing malloc and checkin it is empty or not

    - by gcc
    char *p; p="kjkjk"; . .//there are codes which are checking another command . if(.....)//i used pointer p in only that area free(p); . . //there are codes which are checking another command . if(p==NULL) //i check whether is empty .... if(p==-1) //can we use "EOF==p " in if statement ... //are there any usage like that EOF==p else .... I think there is big error , but where?

    Read the article

  • C++ Iterators and inheritance

    - by jomnis
    Have a quick question about what would be the best way to implement iterators in the following: Say I have a templated base class 'List' and two subclasses "ListImpl1" and "ListImpl2". The basic requirement of the base class is to be iterable i.e. I can do: for(List<T>::iterator it = list->begin(); it != list->end(); it++){ ... } I also want to allow iterator addition e.g.: for(List<T>::iterator it = list->begin()+5; it != list->end(); it++){ ... } So the problem is that the implementation of the iterator for ListImpl1 will be different to that for ListImpl2. I got around this by using a wrapper ListIterator containing a pointer to a ListIteratorImpl with subclasses ListIteratorImpl2 and ListIteratorImpl2, but it's all getting pretty messy, especially when you need to implement operator+ in the ListIterator. Any thoughts on a better design to get around these issues?

    Read the article

  • How can Java assignment be made to point to an object instead of making a copy?

    - by Matthew Piziak
    In a class, I have: private Foo bar; public Constructor(Foo bar) { this.bar = bar; } Instead of creating a copy of bar from the object provided in the parameter, is it possible to include a pointer to bar in the constructor such that changing the original bar changes the field in this object? Another way of putting it: int x = 7; int y = x; x = 9; System.out.print(y); //Prints 7. It is possible to set it up so that printing y prints 9 instead of 7?

    Read the article

  • Need guidance for my first Android application: how many activities should I use?

    - by jul
    Hi, I'm starting Android doing an application for searching restaurants, and some guidance would be welcome! On the first screen I'd like to have a search field with a submit button (I get the data from a web service), and below a list with the results of the search. When clicking on one of the items of the list it will show a screen with the restaurant details as well as a map showing its location. My questions are: Can I do everything in one single activity or should I do an activity for the search, one for the result list, one for the restaurant description, and another for the map? Would doing one single activity make the application more responsive? How can I use a list and a map within a normal activity (without ListActivity and MapActivity)? Any help, pointer, example application or sample code is very appreciated! Thank you Jul

    Read the article

  • Best way to access nested data structures?

    - by Blackshark
    I would like to know what the best way (performance wise) to access a large data structure is. There are about hundred ways to do it but what is the most accessible for the compiler to optimize? One can access a value by foo[someindex].bar[indexlist[i].subelement[j]].baz[0] or create some pointer aliases like sometype_t* tmpfoo = &foo[someindex]; tmpfoo->bar[indexlist[i].subelement[j]].baz[0] or create reference aliases like sometype_t &tmpfoo = foo[someindex]; tmpfoo.bar[indexlist[i].subelement[j]].baz[0] and so forth...

    Read the article

  • Method to register method to be called when event is raised

    - by zaidwaqi
    I have a Panel which contains 20 PictureBox controls. If a user clicks on any of the controls, I want a method within the Panel to be called. How do I do this? public class MyPanel : Panel { public MyPanel() { for(int i = 0; i < 20; i++) { Controls.Add(new PictureBox()); } } // DOESN'T WORK. // function to register functions to be called if the pictureboxes are clicked. public void RegisterFunction( <function pointer> func ) { foreach ( Control c in Controls ) { c.Click += new EventHandler( func ); } } } How do I implement RegisterFunction()? Also, if there are cool C# features that can make the code more elegant, please share.

    Read the article

  • CUDA Global Memory, Where is it?

    - by gamerx
    I understand that in CUDA's memory hierachy, we have things like shared memory, texture memory, constant memory, registers and of course the global memory which we allocate using cudaMalloc(). I've been searching through whatever documentations I can find but I have yet to come across any that explicitly explains what is the global memory. I believe that the global memory allocated is on the GDDR of graphics card itself and not the RAM that is shared with the CPU since one of the documentations did state that the pointer cannot be dereferenced by the host side. Am I right?

    Read the article

  • Layout of popup components changes while moving

    - by Le_Coeur
    I have designed some popup moving menu with JQuery, it looks perfekt in webkit browsers, but i have one problem in mozilla, when i move my popup window, layout of some components in this window changes! For example button add changes from: to: or to: , and it's absolutly random. What can it be? This image is in span: <span class="sw_link_add"></span> .sw_link_add { background:url("/img/confirm_new.png") no-repeat scroll right center transparent; cursor:pointer; padding-right:30px; padding-top:2px; }

    Read the article

  • How does the stream manipulators work?

    - by Narek
    It is well known that the user can define stream manipulators like this: ostream& tab(ostream & output) { return output<< '\t'; } And this can be used in main() like this: cout<<'a'<<tab<<'b'<<'c'<<endl; Please explain me how does this all work? If operator<< assumes as a second parameter a pointer to the function that takes and returns ostream &, then please explain my why it is necessary? What would be wrong if the function does not take and return ostream & but it was void instead of ostream &? Also it is interesting why “dec”, “hex” manipulators take effect until I don’t change between them, but user defined manipulators should be always used in order to take effect for each streaming?

    Read the article

  • Button border radius and cursor

    - by noober
    CSS border radius does affect button rendering (I see it's round form), but does not affect how it interacts with the user (I still can click button outside its border). How should I fix it? I see the behavior in Chrome. button { cursor: pointer; outline: none; background-size: 100% 100%; background-color: red; /*transparent;*/ /* It's actually red and ROUND. */ background-position: center center; background-repeat: no-repeat; border: 0px; -webkit-border-top-left-radius: 73px; -webkit-border-top-right-radius: 73px; -webkit-border-bottom-left-radius: 73px; -webkit-border-bottom-right-radius: 73px; width: 146px; height: 146px; background-image: url('leftarrow.png'); } Regards,

    Read the article

  • Memory allocated with malloc does not persist outside function scope?

    - by PM
    Hi, I'm a bit new to C's malloc function, but from what I know it should store the value in the heap, so you can reference it with a pointer from outside the original scope. I created a test program that is supposed to do this but I keep getting the value 0, after running the program. What am I doing wrong? int f1(int * b) { b = malloc(sizeof(int)); *b = 5; } int main() { int * a; f1(a); printf("%d\n", a); return 0; }

    Read the article

  • C++ Vector of vectors

    - by xbonez
    I have a class header file called Grid.h that contains the following 2 private data object: vector<int> column; vector<vector<int>> row; And a public method whose prototype in Grid.h is such: int getElement (unsigned int& col, unsigned int& row); The definition of above mentioned function is defined as such in Grid.cpp: int getElement (unsigned int& col, unsigned int& row) { return row[row][col] ; } When I run the program, I get this error: error C2109: subscript requires array or pointer type Whats going wrong?

    Read the article

  • Array-size macro that rejects pointers

    - by nneonneo
    The standard array-size macro that is often taught is #define ARRAYSIZE(arr) (sizeof(arr) / sizeof(arr[0])) or some equivalent formation. However, this kind of thing silently succeeds when a pointer is passed in, and gives results that can seem plausible at runtime until things mysteriously fall apart. It's all-too-easy to make this mistake: a function that has a local array variable is refactored, moving a bit of array manipulation into a new function called with the array as a parameter. So, the question is: is there a "sanitary" macro to detect misuse of the ARRAYSIZE macro in C, preferably at compile-time? In C++ we'd just use a template specialized for array arguments only; in C, it seems we'll need some way to distinguish arrays and pointers. (If I wanted to reject arrays, for instance, I'd just do e.g. (arr=arr, ...) because array assignment is illegal).

    Read the article

  • .NET Regex - need matching string for parsing...

    - by TomTom
    Hello, I am a regex idiot and never found a good tutorial (links welcome, as well as a pointer to an interactive VS2010 integrated editor). I need to parse strings in the following form: [a/b]:c/d a, b: double with "." as possible separator. CAN be empty c: double with "." as separator d: integer, positive I.e. valid strings are: [/]:0.25/2 [-0.5/0.5]:0.05/2 [/0.1]:0.05/2 ;) Anyone can help? Thanks

    Read the article

  • Break the limit of threading, segmentation fault

    - by user353573
    use pthread_create to create limited number of threads running concurrently Successfully compile and run However, after adding function pointer array to run the function, Segmentation fault Where is wrong? workserver number: 0 Segmentation fault void* workserver(void arg) { int status; while(true) { printf("workserver number: %d\n", (int)arg); ( job_queue[(int)arg])(); sleep(3); status = pthread_mutex_lock(&data.mutex); if(status != 0) printf("%d lock mutex", status); data.value = 1; status = pthread_cond_signal(&data.cond); if(status != 0) printf("%d signal condition", status); status = pthread_mutex_unlock(&data.mutex); if(status != 0) printf("%d unlock mutex", status); } }

    Read the article

  • seg violation using pycapsule_new

    - by user1733051
    I am trying some simple c API, where I am using PyCapsule_New to encapsulate a pointer. I am running into segment violation, can some body help me. mystruct *func1(int streamno, char mode,unsigned int options) { char * s; s=malloc(100); return s; } PyObject *Wrapper_func1(PyObject *self, PyObject *args) { int streamno; char mode; unsigned int options; mystruct* result; if (!PyArg_ParseTuple(args,"icI",&streamno,&mode,&options)) return NULL; result = func1(streamno,mode,options); return PyCapsule_New( result,NULL,NULL); }

    Read the article

< Previous Page | 99 100 101 102 103 104 105 106 107 108 109 110  | Next Page >