Search Results

Search found 10366 results on 415 pages for 'const char pointer'.

Page 301/415 | < Previous Page | 297 298 299 300 301 302 303 304 305 306 307 308  | Next Page >

• Floating point precision nuances.

  - by user247077

  Hi, I found this code in NVIDIA's cuda SDK samples. void computeGold( float* reference, float* idata, const unsigned int len) { reference[0] = 0; double total_sum = 0; unsigned int i; for( i = 1; i < len; ++i) { total_sum += idata[i-1]; reference[i] = idata[i-1] + reference[i-1]; } // Here it should be okay to use != because we have integer values // in a range where float can be exactly represented if (total_sum != reference[i-1]) printf("Warning: exceeding single-precision accuracy. Scan will be inaccurate.\n"); } (C) Nvidia Corp Can somebody please tell me a case where the warning would be printed, and most importantly, why. Thank you very much.

  Read the article

• An easy way to replace fread()'s with reading from a byte array?

  - by Sam Washburn

  I have a piece of code that needs to be run from a restricted environment that doesn't allow stdio (Flash's Alchemy compiler). The code uses standard fopen/fread functions and I need to convert it to read from a char* array. Any ideas on how to best approach this? Does a wrapper exist or some library that would help? Thanks! EDIT: I should also mention that it's reading in structs. Like this: fread(&myStruct, 1, sizeof(myStruct), f);

  Read the article

• C++0x, How do I expand a tuple into variadic template function arguments?

  - by Gustaf

  Consider the case of a templated function with variadic template arguments: template<typename Tret, typename... T> Tret func(const T&... t); Now, I have a tuple t of values. How do I call func() using the tuple values as arguments? I've read about the bind() function object, with call() function, and also the apply() function in different some now-obsolete documents. The GNU GCC 4.4 implementation seems to have a call() function in the bind() class, but there is very little documentation on the subject. Some people suggest hand-written recursive hacks, but the true value of variadic template arguments is to be able to use them in cases like above. Does anyone have a solution to is, or hint on where to read about it?

  Read the article

• Marshalling a C structure to C#

  - by Hilbert

  Hi, I don't know how to marshall this structure in Mono. typedef struct rib_struct { rib_used_t used; rib_status_t status; rib_role_t role; uint8_t conf; rib_dc_t *pending; pthread_mutex_t mutex; pthread_cond_t cond; rib_f_t *props; } rib_t; And for example, rib_dc_t is like: typedef struct rib_dc_struct { uint16_t id; uint8_t min_id; uint8_t conf; struct rib_dc_struct *next; } rib_dc_t; I don't know how to marshall the pthread structures. And the pointers... should I use IntPtr or a managed structures? How to mashall the pointer in the last struct to the struct itself? Thanks in adanvaced

  Read the article

• What will be the setup process for website development?

  - by Vijay Shanker

  Hi, I want to create a simple site for my personal usage. And this only in python based technologies. So I want to get a expert oponian on this topic. What should i used as platform? I did a search for available options and found Django, grok, web2py and many more of these. Which one a novice use should use? If I choose to use only the basic python scripts then what option i have to work on? http://wiki.python.org/moin/WebBrowserProgramming. This link on python site confused me more, instead of solving my curiosity about the topic. Please give some pointer to accurate and easy to understand reading materials. I have got a idea of developing java based web applications using either spring-webmvc and struts. Can I relate Java process to python process for web development?

  Read the article

• undefined reference to static member variable

  - by Max

  Hi. I have this class that has a static member. it is also a base class for several other classes in my program. Here's its header file: #ifndef YARL_OBJECT_HPP #define YARL_OBJECT_HPP namespace yarlObject { class YarlObject { // Member Variables private: static int nextID; // keeps track of the next ID number to be used int ID; // the identifier for a specific object // Member Functions public: YarlObject(): ID(++nextID) {} virtual ~YarlObject() {} int getID() const {return ID;} }; } #endif and here's its implementation file. #include "YarlObject.hpp" namespace yarlObject { int YarlObject::nextID = 0; } I'm using g++, and it returns three undefined reference to 'yarlObject::YarlObject::nextID linker errors. If I change the ++nextID phrase in the constructor to just nextID, then I only get one error, and if I change it to 1, then it links correctly. I imagine it's something simple, but what's going on?

  Read the article

• Send copy of class to view class so it can render him? ( iPhone )

  - by Johannes Jensen

  I'm making a game for the iPhone, and I have a class called Robot. Then I have a class called View, which renders everything. I want to send a copy of my Robot, which I defined in my ViewController, and I send it to gameView (which is View *gameView), like this: robot = [Robot new]; [gameView setRobot: [robot copy]]; I tried to make a copy but that didn't work, I could also do it with a pointer to Robot (&robot) but sometimes it just crashes ? I tried this in my View.h @interface definition: @property (copy) Robot* robot; but I get the error /RobotsAdventure/Classes/View.h:24: error: setter '-robot' argument type does not match property type :/ Help? I'm pretty new at this, heh.

  Read the article

• problem in reading output of dd command using pipe

  - by Ummar

  I am developing an application, in which I want to redirect the output (progress information) of dd command to my C++ program, but it is not actually getting the output, here is the code FILE * progressInfo = popen("gzip -dc backup/backup.img.gz | pv -ptrbe -i 2 -s 2339876653 | dd of=/dev/sdb","r"); if(!progressInfo) { return -1; } char buf[1024]; while(fgets(buff, sizeof(buff),progressInfo)!=NULL) { std::cout << buff << endl; } but the problem is the progress information is not received in buff, and the output is continuously printed on terminal, and above program halts on while(fgets(buff, sizeof(buff),progressInfo)!=NULL), and as soon as the dd operation is completed, the very next line to loop block is executed. if anyone has any idea why the output is not returned to buff, and its continuously retuned on terminal?

  Read the article

• Can't delete a file created by mkstemp() on Mac OS X

  - by splicer

  Apparently, NSFileManager is unable to delete files created by mkstemp(). Here's some test code to demonstrate this: char pathCString[] = "/tmp/temp.XXXXXX"; int fileDescriptor = mkstemp(pathCString); if (fileDescriptor == -1) { NSLog(@"mkstemp failed"); } else { close(fileDescriptor); NSURL *url = [NSURL URLWithString:[NSString stringWithCString:pathCString encoding:NSASCIIStringEncoding]]; NSLog(@"URL: %@", url); NSError *error; if (![[NSFileManager defaultManager] removeItemAtURL:url error:&error]) { NSLog(@"could not delete file: %@", error); } } Here's what I see in the log when I run the above code: URL: /tmp/temp.A7DsLW could not delete file: Error Domain=NSCocoaErrorDomain Code=4 UserInfo=0x1001108a0 "The file “temp.A7DsLW” doesn’t exist." I'm running this on Snow Leopard. Any ideas on why the problem is occurring and/or how to work around it? Thanks!

  Read the article

• Avoiding Nested Blocks

  - by Helium3

  If there is a view controller that wants to execute a number of block based tasks one at a time, how can the control be given back to the view controller after a completion block has executed. Lets say ViewControllerOne wants to execute a number of tasks, each relying on the result of the previous one, how would this control be given back to the viewcontroller after each completion block has been executed? I started thinking about this and I was heading towards a deeply nested block pattern that will surely only cause confusion to whoever else reads or tests it. A task executes and the completion block returns the result or error which is needed by the next task, which has its own completion task, that the next task relies on and so forth. How can the control be managed in one place, the viewcontroller? Would the completion block just call the next function that handles the next task, using a pointer to the view controller?

  Read the article

• C++: Binding to a base class

  - by Helltone

  The following code works, but I'm not sure it is correct/portable. #include <iostream> #include <tr1/functional> class base { public: base(int v) : x(v) {} protected: int x; }; class derived : public base { public: bool test() { return (x == 42); } }; int main(int argc, char* argv[]) { base b(42); if(std::tr1::bind((bool (base::*)()) &derived::test, b)()) { std::cout << "ok\n"; } return 0; }

  Read the article

• iPhone OpenGL Template is cheating?

  - by carrots

  XCode's OpenGL template seems to be cheating to solve this "stretched" viewport problem I've been trying to understand for the last 3 hours. In the iphone "OpenGL ES Application" template, the colorful square that bounces up and down on the screen is not really a square at all! ES1Renderer.m (the ES2 file as well) static const GLfloat squareVertices[] = { -0.5f, -0.33f, 0.5f, -0.33f, -0.5f, 0.33f, 0.5f, 0.33f, }; But it comes out looking square on the device/simulator due to the stretching/squashing effect of a non-square viewport. I tried to fix it by fiddling with glFrustumf() but that doesn't seem to change the aspect ratio. I was able to get things looking good (not-stretched) when I fed glViewport() with a 1:1 widht:height.. But this doesn't seem like the answer because it offsets the viewport placement. What's the right way to correct for this stretching and why doesn't XCode do it that way?

  Read the article

• ASP.NET 3.5 Page character encoding problem

  - by Dorian McHensie

  Hello everyone. I have a problem in my asp.net 3.5 application (C#) when I try to render in my pages characters like 'è' which are shown in a very strange manner (if i'm lucky i get a ? mark in my web page). in fact Expression Web, when i open my web site, substitutes the è char with �... How can I tell asp.net that I want to use a particular charset so that i can write in the html source letters like è without using hexadecimal codes?????? I tried in the web.config this: inside the system.web namespace of the file but nothing works.... Can anyone tell me how to do? THANKS in advance

  Read the article

• one document.createElement, append it twice, only shows once

  - by Sirber

  I have a button I want to use in the beginning and the end of the page: var button_save = document.createElement('button'); $("#compteurs").append(button_save); [...] $("#compteurs").append(button_save); but it only appear at the end of the page. If I remove it from the bottom of the page, it appear at the begining of page. It's a kind of pointer. Is there a way to create the button only once and use it twice? Thanks!

  Read the article

• Are self-described / auto-descriptive services loosely or tightly coupled in a SOA architecture ?

  - by snowflake

  I consider a self-described / auto-descriptive service as a good thing in a SOA architecture, since (almost) everything you know to call the service is present in the service contract (such a WSDL). Sample of a non self-described service for me is Facebook Query Language (FQL http://wiki.developers.facebook.com/index.php/FQL), or any web service exchanging XML flow in a one String parameter for then parsing XML and performing treatments. Last ones seem further more technically decoupled, since technically you can switch implementations without technical impact on the caller, handling compatibility between implementations/versions at a business level. On the other side, having no strong interface (diluted into the service and its version), make the service tightly coupled to the existing implementation (more difficulty to interchange the service and to ensure perfect compatibility). This question is related to http://stackoverflow.com/questions/2503071/how-to-implement-loose-coupling-with-a-soa-architecture So, are self-described / auto-descriptive services loosely or tightly coupled in a SOA architecture ? What are the impacts regarding ESBs ? Any pointer will be appreciated.

  Read the article

• Trouble creating a makefile

  - by catia

  Hi everyone! I'm having some trouble making a Makefile. Write now I just compile everything every time. Although, the professor is ok with that, I do want to get it working faster and to avoid unnecessary compiling. Here's what I have. FILES= p6.cpp SetIter.cpp Node.cpp Set.cpp CFLAGS= -ansi -pendantic -Wall -Wextra CC= g++ MakePg6: p6.cpp SetIter.cpp Node.cpp Set.cpp $(CC) $(CFLAGS) $(FILES) -o pg6 Node.cpp - node class Set.cpp - uses nodes. Friend of Node. SetIter.cpp - gets a set and uses a pointer to iterator through I'm confused with some of the depencies arising from the friends thing and the point of lib.o being included in the Makefile as some sites have. Any help is greatly appreciated. Thanks in advance.

  Read the article

• insert data into several tables

  - by csetzkorn

  Let us say I have a table (everything is very much simplified): create table OriginalData ( bla char(10) not null ) And I would like to insert its data (set based!) into two tables which model inheritance create table Statements ( Id int IDENTITY NOT NULL, ProposalDateTime DATETIME null ) create table Items ( StatementFk INT not null, ItemName NVARCHAR(255) null, primary key (StatementFk) ) Statements is the parent table and Items is the child table. I have no problem doing this with one row which involves the use of IDENT_CURRENT but I have no idea how to do this set based (i.e. enter several rows into both tables). Thanks. Best wishes, Christian

  Read the article

• C++: Template functor cannot deduce reference type

  - by maciekp

  I've got a functor f, which takes a function func and a parameter t of the same type as func. I cannot pass g to f because of compilation error (no matching function for call to f(int&, void (&)(int&)) ). If g would take non-reference parameter g(int s), compilation finishes. Or if I manually specify template parameter f(i, g), compilation also finishes. template<typename T> void f(T t, void (*func)(T)) {} void g(int& s) {} int main(int, char*[]) { int i = 7; f(i, g); // compilation error here return 0; } How can I get deduction to work?

  Read the article

• Regular Expression to match unlimited number of options

  - by Pekka

  I want to be able to parse file paths like this one: /var/www/index.(htm|html|php|shtml) into an ordered array: array("htm", "html", "php", "shtml") and then produce a list of alternatives: /var/www/index.htm /var/www/index.html /var/www/index.php /var/www/index.shtml Right now, I have a preg_match statement that can split two alternatives: preg_match_all ("/\(([^)]*)\|([^)]*)\)/", $path_resource, $matches); Could somebody give me a pointer how to extend this to accept an unlimited number of alternatives (at least two)? Just regarding the regular expression, the rest I can deal with. The rule is: The list needs to start with a ( and close with a ) There must be one | in the list (i.e. at least two alternatives) Any other occurrence(s) of ( or ) are to remain untouched.

  Read the article

• Are macro definitions compatible between MIPS and Intel C compiler?

  - by Derek

  I seem to be having a problem with a macro that I have defined in a C program. I compile this software and run it sucessfully with the MIPS compiler. It builds OK but throws the error "Segmentation fault" at runtime when using icc. I compiled both of these on 64 bit architectures (MIPS on SGI, with -64 flag and icc on an intel platform). Is there some magic switch I need to use to make this work correctly on both system? I turned on warnings for the intel compiler, and EVERY one of the places in my program where a macro is invoked throws a warning. Usually something along the lines of mismatched types on the macro's parameters (int to char *) or some such thing.

  Read the article

• How to print an isosceles triangle

  - by Steve

  Hello, I'm trying to learn programming by myself, I'm working from a book that has the following problem which I can't solve: Allow the user to input two values: a character to be used for printing an isosceles triangle and the size of the peak for the triangle. For example, if the user inputs # for the character and 6 for the peak, you should produce the following display: # ## ### #### ##### ###### ##### #### ### ## # This is the code I've got so far: char character; int peak; InputValues(out character, out peak); for (int row = 1; row < peak * 2; row++) { for (int col = 1; col <= row; col++) { Console.Write(character); } Console.WriteLine(); } Console.Read() // hold console open Thanks in advance.

  Read the article

• 1 bug to kill... Letting PHP Generate The Canonical.

  - by Sam

  Hi folks, for building a clean canonical url, that always returns 1 base URL, im stuck in following case: <?php # every page $extensions = $_SERVER['REQUEST_URI']; # path like: /en/home.ast?ln=ja $qsIndex = strpos($extensions, '?'); # removes the ?ln=de part $pageclean = $qsIndex !== FALSE ? substr($extensions, 0, $qsIndex) : $extensions; $canonical = "http://website.com" . $pageclean; # basic canonical url ?> <html><head><link rel="canonical" href="<?=$canonical?>"></head> when URL : http://website.com/de/home.ext?ln=de canonical: http://website.com/de/home.ext BUT I want to remove the file extension aswell, whether its .php, .ext .inc or whatever two or three char extension .[xx] or .[xxx] so the base url becomes: http://website.com/en/home Aaah much nicer! but How do i achieve that in current code? Any hints are much appreciated +! (other advices for proper canonical usage in this multi-lingual environment are welcome as well)

  Read the article

• Screen capture code produces black bitmap

  - by wadetandy

  I need to add the ability to take a screenshot of the entire screen, not just the current window. The following code produces a bmp file with the correct dimensions, but the image is completely black. What am I doing wrong? void CaptureScreen(LPCTSTR lpszFilePathName) { BITMAPFILEHEADER bmfHeader; BITMAPINFO *pbminfo; HBITMAP hBmp; FILE *oFile; HDC screen; HDC memDC; int sHeight; int sWidth; LPBYTE pBuff; BITMAP bmp; WORD cClrBits; RECT rcClient; screen = GetDC(0); memDC = CreateCompatibleDC(screen); sHeight = GetDeviceCaps(screen, VERTRES); sWidth = GetDeviceCaps(screen, HORZRES); //GetObject(screen, sizeof(BITMAP), &bmp); hBmp = CreateCompatibleBitmap ( screen, sWidth, sHeight ); // Retrieve the bitmap color format, width, and height. GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp) ; // Convert the color format to a count of bits. cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel); if (cClrBits == 1) cClrBits = 1; else if (cClrBits bmiHeader.biSize = sizeof(BITMAPINFOHEADER); pbminfo-bmiHeader.biWidth = bmp.bmWidth; pbminfo-bmiHeader.biHeight = bmp.bmHeight; pbminfo-bmiHeader.biPlanes = bmp.bmPlanes; pbminfo-bmiHeader.biBitCount = bmp.bmBitsPixel; if (cClrBits bmiHeader.biClrUsed = (1bmiHeader.biCompression = BI_RGB; // Compute the number of bytes in the array of color // indices and store the result in biSizeImage. // The width must be DWORD aligned unless the bitmap is RLE // compressed. pbminfo-bmiHeader.biSizeImage = ((pbminfo-bmiHeader.biWidth * cClrBits +31) & ~31) /8 * pbminfo-bmiHeader.biHeight; // Set biClrImportant to 0, indicating that all of the // device colors are important. pbminfo-bmiHeader.biClrImportant = 0; CreateBMPFile(lpszFilePathName, pbminfo, hBmp, memDC); } void CreateBMPFile(LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP, HDC hDC) { HANDLE hf; // file handle BITMAPFILEHEADER hdr; // bitmap file-header PBITMAPINFOHEADER pbih; // bitmap info-header LPBYTE lpBits; // memory pointer DWORD dwTotal; // total count of bytes DWORD cb; // incremental count of bytes BYTE *hp; // byte pointer DWORD dwTmp; int lines; pbih = (PBITMAPINFOHEADER) pbi; lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih-biSizeImage); // Retrieve the color table (RGBQUAD array) and the bits // (array of palette indices) from the DIB. lines = GetDIBits(hDC, hBMP, 0, (WORD) pbih-biHeight, lpBits, pbi, DIB_RGB_COLORS); // Create the .BMP file. hf = CreateFile(pszFile, GENERIC_READ | GENERIC_WRITE, (DWORD) 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, (HANDLE) NULL); hdr.bfType = 0x4d42; // 0x42 = "B" 0x4d = "M" // Compute the size of the entire file. hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih-biSize + pbih-biClrUsed * sizeof(RGBQUAD) + pbih-biSizeImage); hdr.bfReserved1 = 0; hdr.bfReserved2 = 0; // Compute the offset to the array of color indices. hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih-biSize + pbih-biClrUsed * sizeof (RGBQUAD); // Copy the BITMAPFILEHEADER into the .BMP file. WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp, NULL); // Copy the BITMAPINFOHEADER and RGBQUAD array into the file. WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih-biClrUsed * sizeof (RGBQUAD), (LPDWORD) &dwTmp, ( NULL)); // Copy the array of color indices into the .BMP file. dwTotal = cb = pbih-biSizeImage; hp = lpBits; WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL); // Close the .BMP file. CloseHandle(hf); // Free memory. GlobalFree((HGLOBAL)lpBits); }

  Read the article

• Manage bad_alloc exception in C++ construtor

  - by Jimmy zhang

  I have Java experience and recently am doing some C++ coding. My question is that if I have class A, in which I have to instantiate class B and class C as two of the member variables of A. If in the constructor of A, should I assume that allocations of class B and C never fail, and handle the bad allocation exception in the destructor of A? If I don't make that assumption, meaning that I add some try catch block to catch bad_alloc of class B and class C, then if the allocation exception occurs, should I do clean up in the constructor of A? What are the recommended practices? If "new" generates a bad allocation, what value does the pointer carry?

  Read the article

• Reducing template bloat with inheritance

  - by benoitj

  Does anyone have experience reducing template code bloat using inheritance? i hesitate rewriting our containers this way: class vectorBase { public: int size(); void clear(); int m_size; void *m_rawData; //.... }; template< typename T > class vector : public vectorBase { void push_back( const T& ); //... }; I should keep maximum performance while reducing compile time I'm also wondering why stl implementations do not uses this approach Thanks for your feedbacks

  Read the article

< Previous Page | 297 298 299 300 301 302 303 304 305 306 307 308  | Next Page >