Search Results

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

Page 347/415 | < Previous Page | 343 344 345 346 347 348 349 350 351 352 353 354  | Next Page >

  • Getting bizarre "expected primary-expression" error.

    - by Fecal Brunch
    Hi, I'm getting a really strange error when making a method call: /* input.cpp */ #include <ncurses/ncurses.h> #include "input.h" #include "command.h" Input::Input () { raw (); noecho (); } Command Input::next () { char input = getch (); Command nextCommand; switch (input) { case 'h': nextCommand.setAction (ACTION_MOVELEFT); break; case 'j': nextCommand.setAction (ACTION_MOVEDOWN); break; case 'k': nextCommand.setAction (ACTION_MOVEUP); break; case 'l': nextCommand.setAction (ACTION_MOVERIGHT); break; case 'y': nextCommand.setAction (ACTION_MOVEUPLEFT); break; case 'u': nextCommand.setAction (ACTION_MOVEUPRIGHT); break; case 'n': nextCommand.setAction (ACTION_MOVEDOWNLEFT); break; case 'm': nextCommand.setAction (ACTION_MOVEDOWNRIGHT); break; case '.': nextCommand.setAction (ACTION_WAIT); break; } return nextCommand; } and the error: Administrator@RHYS ~/code/rogue2 $ make g++ -c -Wall -pedantic -g3 -O0 input.cpp input.cpp: In member function `Command Input::next()': input.cpp:21: error: expected primary-expression before '=' token input.cpp:24: error: expected primary-expression before '=' token input.cpp:27: error: expected primary-expression before '=' token input.cpp:30: error: expected primary-expression before '=' token input.cpp:33: error: expected primary-expression before '=' token input.cpp:36: error: expected primary-expression before '=' token input.cpp:39: error: expected primary-expression before '=' token input.cpp:42: error: expected primary-expression before '=' token input.cpp:45: error: expected primary-expression before '=' token make: *** [input.o] Error 1 Sorry about the lack of linenumbers, the errors occur on the lines "nextCommand.setAction(...)", which is totally bizarre considering that they don't contain a '='. Any ideas? Thanks, Rhys

    Read the article

  • Rhino Mocks Partial Mock

    - by dotnet crazy kid
    I am trying to test the logic from some existing classes. It is not possible to re-factor the classes at present as they are very complex and in production. What I want to do is create a mock object and test a method that internally calls another method that is very hard to mock. So I want to just set a behaviour for the secondary method call. But when I setup the behaviour for the method, the code of the method is invoked and fails. Am I missing something or is this just not possible to test without re-factoring the class? I have tried all the different mock types (Strick,Stub,Dynamic,Partial ect.) but they all end up calling the method when I try to set up the behaviour. using System; using MbUnit.Framework; using Rhino.Mocks; namespace MMBusinessObjects.Tests { [TestFixture] public class PartialMockExampleFixture { [Test] public void Simple_Partial_Mock_Test() { const string param = "anything"; //setup mocks MockRepository mocks = new MockRepository(); var mockTestClass = mocks.StrictMock<TestClass>(); //record beahviour *** actualy call into the real method stub *** Expect.Call(mockTestClass.MethodToMock(param)).Return(true); //never get to here mocks.ReplayAll(); //this is what i want to test Assert.IsTrue(mockTestClass.MethodIWantToTest(param)); } public class TestClass { public bool MethodToMock(string param) { //some logic that is very hard to mock throw new NotImplementedException(); } public bool MethodIWantToTest(string param) { //this method calls the if( MethodToMock(param) ) { //some logic i want to test } return true; } } } }

    Read the article

  • bad_alloc occuring when allocating small structs

    - by SalamiArmi
    A bad_alloc has started showing up in some code which looks perfectly valid to me and has worked very well in the past. The bad alloc only occurs once every 50-3000 iterations of the code, which is also confusing. The code itself is from a singly linked list, simply adding a new element to the queue: template<typename T> struct container { inline container() : next(0) {} container *next; T data; }; void push(const T &data) { container<T> *newQueueMember = new container<T>; //... unrelated to crash } Where T is: struct test { int m[256]; }; Changing the size of the array allocated array to anything but very small values (1-8 ints) still results in a bad_alloc occasionally. A few extra notes about my program: - I used Poco::ThreadPool to thread my program. I've only recently added this functionality, before I had it running with Win32 threads. However, only the main thread ever calls push(). - I am also occasionally getting other crashes which could be related. However, when I try to debug with visual studio 2008, I can't navigate back to the call stack, or the crash happens deep within new(). Thanks in advance.

    Read the article

  • the error in the stringbuilder

    - by Kubi
    string rowString = "<tr id=\"row1\" bgcolor=\"#FFFFFF\" onMouseOver=\"this.bgColor='#EEEEEE';\" onMouseOut=\"this.bgColor='#FFFFFF';\" style=\"cursor:pointer;\">" + "<td bgcolor=\"#FFFFFF\"><img src=\"images/"+"-companylogofilename-"+"\" width=\"108\" height=\"32\" alt=\""+"-companyname-"+"\" /></td>" + //turkish.airlines.jpg airlineiconfilename, airline name "<td class=\"table_content\">{0}</td>" + "<td class=\"table_content\">{1}</td>" + "<td class=\"table_content\">{2}</td>" + "<td class=\"table_content\">{3}</td>" + "<td class=\"table_content\">{4}</td>" + "<td class=\"table_content\"><table width=\"98%\" border=\"0\" cellspacing=\"0\" cellpadding=\"0\">" + "<tr><td class=\"table_content\">{5}</td>" + "<td width=\"20\" align=\"right\">" + "<a href=\"default.aspx\" onClick=\"return hs.htmlExpand(this, { headingText: '{6} - {7}', width: 600, height: 215, targetX: 'row1 400px', targetY: 'row1 40px' })\">" + "<img src=\"images/arrow.png\" width=\"13\" height=\"16\" border=\"0\" class=\"tip\" onMouseOver=\"tooltip('Click for Details.');\" onMouseOut=\"exit();\" />" + "</a>"; accordionHTML.Append(String.Format(rowString, flight.Get_AirlineCode(), flight.Get_Clase(), flight.Get_Departure(), flight.Get_DeprtDate(), flight.Get_DeprtTime(), flight.Get_Destination(), flight.Get_Departure(), flight.Get_Destination())); Hi, Can someone please help me to find the mistake above ? I am getting an error as "Input string was not correct !"; Thanks in advance,

    Read the article

  • Weird problem with string function

    - by wrongusername
    I'm having a weird problem with the following function, which returns a string with all the characters in it after a certain point: string after(int after, string word) { char temp[word.size() - after]; cout << word.size() - after << endl; //output here is as expected for(int a = 0; a < (word.size() - after); a++) { cout << word[a + after]; //and so is this temp[a] = word[a + after]; cout << temp[a]; //and this } cout << endl << temp << endl; //but output here does not always match what I want string returnString = temp; return returnString; } The thing is, when the returned string is 7 chars or less, it works just as expected. When the returned string is 8 chars or more, then it starts spewing nonsense at the end of the expected output. For example, the lines cout << after(1, "12345678") << endl; cout << after(1, "123456789") << endl; gives an output of: 7 22334455667788 2345678 2345678 8 2233445566778899 23456789?,?D~ 23456789?,?D~ What can I do to fix this error, and are there any default C++ functions that can do this for me?

    Read the article

  • How to iterate over modifed std::map values?

    - by Frank
    I have an std::map, and I would like to define an iterator that returns modified values. Typically, a std::map<int,double>::iterator iterates over std::pair<int,double>, and I would like the same behavior, just the double value is multiplied by a constant. I tried it with boost::transform_iterator, but it doesn't compile: #include <map> #include <boost/iterator/transform_iterator.hpp> #include <boost/functional.hpp> typedef std::map<int,double> Map; Map m; m[100] = 2.24; typedef boost::binder2nd< std::multiplies<double> > Function; typedef boost::transform_iterator<Function, Map::value_type*> MultiplyIter; MultiplyIter begin = boost::make_transform_iterator(m.begin(), Function(std::multiplies<double>(), 4)); // now want to similarly create an end iterator // and then iterate over the modified map The error is: error: conversion from 'boost ::transform_iterator< boost::binder2nd<multiplies<double> >, gen_map<int, double>::iterator , boost::use_default, boost::use_default >' to non-scalar type 'boost::transform_iterator< boost::binder2nd<multiplies<double> >, pair<const int, double> * , boost::use_default, boost::use_default >' requested What is gen_map and do I really need it? I adapted the transform_iterator tutorial code from here to write this code ...

    Read the article

  • Updating a local sqlite db that is used for local metadata & caching from an service?

    - by Pharaun
    I've searched through the site and haven't found a question/answer that quite answer my question, the closest one I found was: Syncing objects between two disparate systems best approach. Anyway to begun, because there is no RSS feeds available, I'm screen scrapping a webpage, hence it does a fetch then it goes through the webpage to scrap out all of the information that I'm interested in and dumps that information into a sqlite database so that I can query the information at my leisure without doing repeat fetching from the website. However I'm also storing various metadata on the data itself that is stored in the sqlite db, such as: have I looked at the data, is the data new/old, bookmark to a chunk of data (Think of it as a collection of unrelated data, and the bookmark is just a pointer to where I am in processing/reading of the said data). So right now my current problem is trying to figure out how to update the local sqlite database with new data and/or changed data from the website in a manner that is effective and straightforward. Here's my current idea: Download the page itself Create a temporary table for the parsed data to go into Do a comparison between the official and the temporary table and copy updates and/or new information to the official table This process seems kind of complicated because I would have to figure out how to determine if the data in the temporary table is new, updated, or unchanged. So I am wondering if there isn't a better approach or if anyone has any suggestion on how to architecture/structure such system?

    Read the article

  • Reading text files line by line, with exact offset/position reporting

    - by Benjamin Podszun
    Hi. My simple requirement: Reading a huge ( a million) line test file (For this example assume it's a CSV of some sorts) and keeping a reference to the beginning of that line for faster lookup in the future (read a line, starting at X). I tried the naive and easy way first, using a StreamWriter and accessing the underlying BaseStream.Position. Unfortunately that doesn't work as I intended: Given a file containing the following Foo Bar Baz Bla Fasel and this very simple code using (var sr = new StreamReader(@"C:\Temp\LineTest.txt")) { string line; long pos = sr.BaseStream.Position; while ((line = sr.ReadLine()) != null) { Console.Write("{0:d3} ", pos); Console.WriteLine(line); pos = sr.BaseStream.Position; } } the output is: 000 Foo 025 Bar 025 Baz 025 Bla 025 Fasel I can imagine that the stream is trying to be helpful/efficient and probably reads in (big) chunks whenever new data is necessary. For me this is bad.. The question, finally: Any way to get the (byte, char) offset while reading a file line by line without using a basic Stream and messing with \r \n \r\n and string encoding etc. manually? Not a big deal, really, I just don't like to build things that might exist already..

    Read the article

  • What's wrong with my code? (pdcurses/getmaxyx)

    - by flarn2006
    It gives me an access violation on the getmaxyx line (second line in the main function) and also gives me these two warnings: LINK : warning LNK4049: locally defined symbol "_stdscr" imported LINK : warning LNK4049: locally defined symbol "_SP" imported Yes, it's the same code as in another question I asked, it's just that I'm making it more clear. And yes, I have written programs with pdcurses before with no problems. #include <time.h> #include <curses.h> #include "Ball.h" #include "Paddle.h" #include "config.h" int main(int argc, char *argv[]) { int maxY, maxX; getmaxyx(stdscr, maxY, maxX); Paddle *paddleLeft = new Paddle(0, KEY_L_UP, KEY_L_DOWN); Paddle *paddleRight = new Paddle(maxX, KEY_R_UP, KEY_R_DOWN); Ball *ball = new Ball(paddleLeft, paddleRight); int key = 0; initscr(); cbreak(); noecho(); curs_set(0); while (key != KEY_QUIT) { key = getch(); paddleLeft->OnKeyPress(key); paddleRight->OnKeyPress(key); } endwin(); return 0; }

    Read the article

  • css problem - 'post link'

    - by csetzkorn
    Hi, I am no css expert so I am wondering whether someone could help. I have several forms to delete an item like this: <form action="/Items/DeleteItem" class="deleteForm" method="post"> Some text <input id="Id" name="Id" value="14014" type="hidden"> <input value="Delete" class="link_button" type="submit"> </form> This should look like this: Some text Delete Here ‘Some text’ describes the item and Delete is a ‘link’ which performs a post request to delete the item (as virtually all browsers only support the post and get requests). I have started to style things (CSS below) but the ‘Delete’ ‘link’ is still slightly offset in relation to ‘Some text’ (at least in firefox). I would appreciate any help with the css. Thanks! .link_button { background-color:white; border:0; color:#034af3; text-decoration:underline; font-size:1em; font-family:inherit; cursor:pointer; float:left; margin:0; padding:0; } .deleteForm { float:right; margin:0; padding:0; } Christian

    Read the article

  • Using unset member variables within a class or struct

    - by Doug Kavendek
    It's pretty nice to catch some really obvious errors when using unset local variables or when accessing a class or struct's members directly prior to initializing them. In visual studio 2008 you get an "uninitialized local variable used" warning at compile-time and get a run-time check failure at the point of access when debugging. However, if you access an uninitialized struct's member variable through one of its functions, you don't get any warnings or assertions. Obviously the easiest solution is don't do that, but nobody's perfect. For example: struct Test { float GetMember() const { return member; } float member; }; Test test; float f1 = test.member; // Raises warning, asserts in VS debugger at runtime float f2 = test.GetMember(); // No problem, just keeps on going This surprised me, but it makes some sense -- the compiler can't assume calling a function on an unused struct is an error, or how else would you initialize or construct it? And anything fancier just quickly brings up so many other complications that it makes sense that it wouldn't bother classifying which functions are ok to call and when, especially just as a debugging help. I know I can set up my own assertions or error checking within the class itself, but that can complicate some simpler structs. Still, it would seem like within the context of the function call, wouldn't it know insides GetMember() that member wasn't initialized yet? I'm assuming it's not only relying on static compile-time deduction, given the Run-Time Check Failure #3 it raises during execution, so based on my current understanding of it it would seem reasonable for the same checks to apply. Is this just a limitation of this specific compiler/debugger (Visual Studio 2008), or more tied to how C++ works?

    Read the article

  • Can't Display Bitmap of Higher Resolution than CDC area

    - by T. Jones
    Hi there dear gurus and expert coders. i am not gonna start with im a newbie and don't know much about image programming but unfortunately those are the facts :( I am trying to display an image from a bitmap pointer *ImageData which is of resolution 1392x1032. I am trying to draw that at an area of resolution or size 627x474. However, repeated trying doesnt seem to work. It works when I change the bitmap image I created from *ImageData width and height to resolution or size of around 627x474 I really do not know how to solve this after trying all possible solutions from various forums and google. pDC is a CDC* and memDC is a CDC initialized in an earlier method Anything uninitialized here was initialized in other methods. Here is my code dear humble gurus. Do provide me with guidance Yoda and Obi-Wan provided to Luke Skywalker. void DemoControl::ShowImage( void *ImageData ) { int Width; //Width of Image From Camera int Height; //Height of Image From Camera int m_DisplayWidth = 627 ;//width of rectangle area to display int m_DisplayHeight = 474;//height of rectangle area to display GetImageSize( &Width, &Height ) ; //this will return Width = 1392, Height 1032 CBitmap bitmap; bitmap.CreateBitmap(Width,Height,32,1,ImageData); CBitmap* pOldBitmap = memDC.SelectObject((CBitmap*)&bitmap); pDC->BitBlt(22, 24, 627, 474, &memDC, 0, 0, SRCCOPY); memDC.SelectObject((CBitmap*)pOldBitmap); ReleaseDC(pDC); }

    Read the article

  • Unexplained crashs with coregraphic

    - by Ziggy
    Hello there, i'm on this bug for a week now, and i can't solve it. I have some crash with coregraphic calls, it happen randomly (sometimes after 2 mn, or just at the start), but often at the same places in the code. I have a class that just wrap a CGContext, it have a CGContextRef as member. This Object is re-created each time DrawRect() is called, so the CGContextRef is always up-to-date. The draw calls came from the main thread, only After looking for this kind of error, it appear that it should be object Release related. Here is an example of an error : #0 0x90d8a7a7 in ___forwarding___ #1 0x90d8a8b2 in __forwarding_prep_0___ #2 0x90d0d0b6 in CFRetain #3 0x95e54a5d in CGColorRetain #4 0x95e5491d in CGGStateCreateCopy #5 0x95e5486d in CGGStackSave #6 0x95e54846 in CGContextSaveGState #7 0x00073500 in CAutoContextState::CAutoContextState at Context.cpp:47 the AutoContextSave() class look like this : class CAutoContextState { private: CGContextRef m_Hdc; public: CAutoContextState(const CGContextRef& Hdc) { m_Hdc = Hdc; CGContextSaveGState(m_Hdc); } virtual ~CAutoContextState() { CGContextRestoreGState(m_Hdc); } }; It crash at CGContextSaveGState(m_Hdc). Here is what i see into GDB: * -[Not A Type retain]: message sent to deallocated instance 0x16a148b0. When i type malloc-history on the address, i have this : 0: 0x954cf10c in malloc_zone_malloc 1: 0x90d0d201 in _CFRuntimeCreateInstance 2: 0x95e3fe88 in CGTypeCreateInstanceWithAllocator 3: 0x95e44297 in CGTypeCreateInstance 4: 0x95e58f57 in CGColorCreate 5: 0x71fdd in _ZN4Flux4Draw8CContext10DrawStringERKNS_7CStringEPKNS0_5CFontEPKNS0_6CBrushERKNS_5CRectENS0_12tagAlignmentESE_NS0_17tagStringTrimmingEfiPKf at /Volumes/Sources Mac/Flux/Sources/DotFlux/Projects/../Draw/CoreGraphic/Context.cpp:1029 Which point me at this line of code : f32 components[] = {pSolidBrush->GetColor().GetfRed(), pSolidBrush->GetColor().GetfGreen(), pSolidBrush->GetColor().GetfBlue(), pSolidBrush->GetColor().GetfAlpha()}; //{ 1.0, 0.0, 0.0, 0.8 }; CGColorRef TextColor = CGColorCreate(rgbColorSpace, components); Point this func : CGColorCreate(); Any help would be appreciated, i need to finish this task very soon, but i don't know how to resolve this :( Thanks.

    Read the article

  • Why do I get two clicked or released signals when using a custom slot for a QPushButton ?

    - by Chris
    here's the main code at first I thought is was the message box but setting a label instead has the same effect. #include <time.h> #include "ui_mainwindow.h" #include <QMessageBox> class MainWindow : public QWidget, private Ui::MainWindow { Q_OBJECT public: MainWindow(QWidget *parent = 0); void makeSum(void); private: int r1; int r2; private slots: void on_pushButton_released(void); }; MainWindow::MainWindow(QWidget *parent) : QWidget(parent) { setupUi(this); } void MainWindow::on_pushButton_released(void) { bool ok; int a = lineEdit->text().toInt(&ok, 10); if (ok) { if (r1+r2==a) { QMessageBox::information( this, "Sums","Correct!" ); } else { QMessageBox::information( this, "Sums","Wrong!" ); } } else { QMessageBox::information( this, "Sums","You need to enter a number" ); } makeSum(); } void MainWindow::makeSum(void) { r1 = rand() % 10 + 1; r2 = rand() % 10 + 1; label->setText(QString::number(r1)); label_3->setText(QString::number(r2)); } int main(int argc, char *argv[]) { srand ( time(NULL) ); QApplication app(argc, argv); MainWindow mw; mw.makeSum(); mw.show(); return app.exec(); } #include "main.moc"

    Read the article

  • PowerShell PSCX Read-Archive: Cannot bind parameter... problem

    - by Robert
    I'm running across a problem I can't seem to wrap my head around using the Read-Archive cmdlet available via PowerShell Community Extensions (v2.0.3782.38614). Here is a cut down sample used to exhibit the problem I'm running into: $mainPath = "p:\temp" $dest = Join-Path $mainPath "ps\CenCodes.zip" Read-Archive -Path $dest -Format zip Running the above produces the following error: Read-Archive : Cannot bind parameter 'Path'. Cannot convert the "p:\temp\ps\CenCodes.zip" value of type "System.String" to type "Pscx.IO.PscxPathInfo". At line:3 char:19 + Read-Archive -Path <<<< $dest -Format zip + CategoryInfo : InvalidArgument: (:) [Read-Archive], ParameterBindingException + FullyQualifiedErrorId : CannotConvertArgumentNoMessage,Pscx.Commands.IO.Compression.ReadArchiveCommand If I do not use Join-Path to build the path passed to Read-Archive it works, as in this example: $mainPath = "p:\temp" $path = $mainPath + "\ps\CenCodes.zip" Read-Archive -Path $path -Format zip Output from above: ZIP Folder: CenCodes.zip#\ Index LastWriteTime Size Ratio Name ----- ------------- ---- ----- ---- 0 6/17/2010 2:03 AM 3009106 24.53 % CenCodes.xls Even more confusing is if I compare the two variables passed as the Path argument in the two Read-Archive samples above, they seem identical: This... Write-Host "dest=$dest" Write-Host "path=$path" Write-Host ("path -eq dest is " + ($dest -eq $path).ToString()) Outputs... dest=p:\temp\ps\CenCodes.zip path=p:\temp\ps\CenCodes.zip path -eq dest is True Anyone have any ideas as to why the first sample gripes but the second one works fine?

    Read the article

  • Mac OS X and static boost libs -> std::string fail

    - by Ionic
    Hi all, I'm experiencing some very weird problems with static boost libraries under Mac OS X 10.6.6. The error message is main(78485) malloc: *** error for object 0x1000e0b20: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug [1] 78485 abort (core dumped) and a tiny bit of example code which will trigger this problem: #define BOOST_FILESYSTEM_VERSION 3 #include <boost/filesystem.hpp> #include <iostream> int main (int argc, char **argv) { std::cout << boost::filesystem::current_path ().string () << '\n'; } This problem always occurs when linking the static boost libraries into the binary. Linking dynamically will work fine, though. I've seen various reports for quite a similar OS X bug with GCC 4.2 and the _GLIBCXX_DEBUG macro set, but this one seems even more generic, as I'm neither using XCode, nor setting the macro (even undefining it does not help. I tried it just to make sure it's really not related to this problem.) Does anybody have any pointers to why this is happening or even maybe a solution (rather than using the dynamic library workaround)? Best regards, Mihai

    Read the article

  • How to test for existence of a script-scoped variable in PowerShell?

    - by Damian Powell
    Is it possible to test for the existence of a script-scoped variable in PowerShell? I've been using the PowerShell Community Extensions (PSCX) but I've noticed that if you import the module while Set-PSDebug -Strict is set, an error is produced: The variable '$SCRIPT:helpCache' cannot be retrieved because it has not been set. At C:\Users\...\Modules\Pscx\Modules\GetHelp\Pscx.GetHelp.psm1:5 char:24 While investigating how I might fix this, I found this piece of code in Pscx.GetHelp.psm1: #requires -version 2.0 param([string[]]$PreCacheList) if ((!$SCRIPT:helpCache) -or $RefreshCache) { $SCRIPT:helpCache = @{} } This is pretty straight forward code; if the cache doesn't exist or needs to be refreshed, create a new, empty cache. The problem is that calling $SCRIPT:helpCache while Set-PSDebug -Strict is in force casues the error because the variable hasn't been defined yet. Ideally, we could use a Test-Variable cmdlet but such a thing doesn't exist! I thought about looking in the variable: provider but I don't know how to determine the scope of a variable. So my question is: how can I test for the existence of a variable while Set-PSDebug -Strict is in force, without causing an error?

    Read the article

  • Is my method for avoiding dynamic_cast<> faster than dynamic_cast<> itself ?

    - by ereOn
    Hi, I was answering a question a few minutes ago and it raised to me another one: In one of my projects, I do some network message parsing. The messages are in the form of: [1 byte message type][2 bytes payload length][x bytes payload] The format and content of the payload are determined by the message type. I have a class hierarchy, based on a common class Message. To instanciate my messages, i have a static parsing method which gives back a Message* depending on the message type byte. Something like: Message* parse(const char* frame) { // This is sample code, in real life I obviously check that the buffer // is not NULL, and the size, and so on. switch(frame[0]) { case 0x01: return new FooMessage(); case 0x02: return new BarMessage(); } // Throw an exception here because the mesage type is unknown. } I sometimes need to access the methods of the subclasses. Since my network message handling must be fast, I decived to avoid dynamic_cast<> and I added a method to the base Message class that gives back the message type. Depending on this return value, I use a static_cast<> to the right child type instead. I did this mainly because I was told once that dynamic_cast<> was slow. However, I don't know exactly what it really does and how slow it is, thus, my method might be as just as slow (or slower) but far more complicated. What do you guys think of this design ? Is it common ? Is it really faster than using dynamic_cast<> ? Any detailed explanation of what happen under the hood when one use dynamic_cast<> is welcome !

    Read the article

  • Problems Using memset and memcpy

    - by user306557
    So I am trying to create a Memory Management System. In order to do this I have a set amount of space (allocated by malloc) and then I have a function myMalloc which will essentially return a pointer to the space allocated. Since we will then try and free it, we are trying to set a header of the allocated space to be the size of the allocated space, using memset. memset(memPtr,sizeBytes,sizeof(int)); We then need to be able to read this so we can see the size of it. We are attempting to do this by using memcpy and getting the first sizeof(int) bytes into a variable. For testing purposes we are just trying to do memset and then immediately get the size back. I've included the entire method below so that you can see all declarations. Any help would be greatly appreciated! Thanks! void* FirstFit::memMalloc(int sizeBytes){ node* listPtr = freelist; void* memPtr; // Cycle through each node in freelist while(listPtr != NULL) { if(listPtr->size >= sizeBytes) { // We found our space // This is where the new memory allocation begins memPtr = listPtr->head; memset(memPtr,sizeBytes,sizeof(int)); void *size; memcpy(size, memPtr, sizeof(memPtr)); // Now let's shrink freelist listPtr->size = listPtr->size - sizeBytes; int *temp = (int*)listPtr->head + (sizeBytes*sizeof(int)); listPtr->head = (int*) temp; return memPtr; } listPtr = listPtr->next; }

    Read the article

  • Using the Proxy pattern with C++ iterators

    - by Billy ONeal
    Hello everyone :) I've got a moderately complex iterator written which wraps the FindXFile apis on Win32. (See previous question) In order to avoid the overhead of constructing an object that essentially duplicates the work of the WIN32_FIND_DATAW structure, I have a proxy object which simply acts as a sort of const reference to the single WIN32_FIND_DATAW which is declared inside the noncopyable innards of the iterator. This is great because Clients do not pay for construction of irrelevant information they will probably not use (most of the time people are only interested in file names), and Clients can get at all the information provided by the FindXFile APIs if they need or want this information. This becomes an issue though because there is only ever a single copy of the object's actual data. Therefore, when the iterator is incrememnted, all of the proxies are invalidated (set to whatever the next file pointed to by the iterator is). I'm concerned if this is a major problem, because I can think of a case where the proxy object would not behave as somebody would expect: std::vector<MyIterator::value_type> files; std::copy(MyIterator("Hello"), MyIterator(), std::back_inserter(files)); because the vector contains nothing but a bunch of invalid proxies at that point. Instead, clients need to do something like: std::vector<std::wstring> filesToSearch; std::transform( DirectoryIterator<FilesOnly>(L"C:\\Windows\\*"), DirectoryIterator<FilesOnly>(), std::back_inserter(filesToSearch), std::mem_fun_ref(&DirectoryIterator<FilesOnly>::value_type::GetFullFileName) ); Seeing this, I can see why somebody might dislike what the standard library designers did with std::vector<bool>. I'm still wondering though: is this a reasonable trade off in order to achieve (1) and (2) above? If not, is there any way to still achieve (1) and (2) without the proxy?

    Read the article

  • recommended format to save time with MJD + BCD format in database

    - by pierr
    Hi, There is a time represented in MJD and BCD format with 5 bytes .I am wondering what is the recommended format to save this date-time in the sqlite database so that user can search against it ? My first attempt is to save it just as it is, that is a 5 bytes string. The user will use the same format to search and the result will be converted to unix time by the user with following code. However, later, I was suggested to save the time in the integer - the UTC time, for example. But I can not find a standard way to do the conversion. I feel this is a common issue and would like to hear your comments. time_t sidate_to_unixtime(unsigned char sidate[]) { int k = 0; struct tm tm; double mjd; /* check for the undefined value */ if ((sidate[0] == 0xff) && (sidate[1] == 0xff) && (sidate[2] == 0xff) && (sidate[3] == 0xff) && (sidate[4] == 0xff)) { return -1; } memset(&tm, 0, sizeof(tm)); mjd = (sidate[0] << 8) | sidate[1]; tm.tm_year = (int) ((mjd - 15078.2) / 365.25); tm.tm_mon = (int) (((mjd - 14956.1) - (int) (tm.tm_year * 365.25)) / 30.6001); tm.tm_mday = (int) mjd - 14956 - (int) (tm.tm_year * 365.25) - (int) (tm.tm_mon * 30.6001); if ((tm.tm_mon == 14) || (tm.tm_mon == 15)) k = 1; tm.tm_year += k; tm.tm_mon = tm.tm_mon - 2 - k * 12; tm.tm_sec = bcd_to_integer(sidate[4]); tm.tm_min = bcd_to_integer(sidate[3]); tm.tm_hour = bcd_to_integer(sidate[2]); return mktime(&tm); }

    Read the article

  • Multi-dimensional array edge/border conditions

    - by kirbuchi
    Hi, I'm iterating over a 3 dimensional array (which is an image with 3 values for each pixel) to apply a 3x3 filter to each pixel as follows: //For each value on the image for (i=0;i<3*width*height;i++){ //For each filter value for (j=0;j<9;j++){ if (notOutsideEdgesCondition){ *(**(outArray)+i)+= *(**(pixelArray)+i-1+(j%3)) * (*(filter+j)); } } } I'm using pointer arithmetic because if I used array notation I'd have 4 loops and I'm trying to have the least possible number of loops. My problem is my notOutsideEdgesCondition is getting quite out of hands because I have to consider 8 border cases. I have the following handled conditions Left Column: ((i%width)==0) && (j%3==0) Right Column: ((i-1)%width ==0) && (i>1) && (j%3==2) Upper Row: (i<width) && (j<2) Lower Row: (i>(width*height-width)) && (j>5) and still have to consider the 4 corner cases which will have longer expressions. At this point I've stopped and asked myself if this is the best way to go because If I have a 5 line long conditional evaluation it'll not only be truly painful to debug but will slow the inner loop. That's why I come to you to ask if there's a known algorithm to handle this cases or if there's a better approach for my problem. Thanks a lot.

    Read the article

  • How to reuse results with a schema for end of day stock-data

    - by Vishalrix
    I am creating a database schema to be used for technical analysis like top-volume gainers, top-price gainers etc.I have checked answers to questions here, like the design question. Having taken the hint from boe100 's answer there I have a schema modeled pretty much on it, thusly: Symbol - char 6 //primary Date - date //primary Open - decimal 18, 4 High - decimal 18, 4 Low - decimal 18, 4 Close - decimal 18, 4 Volume - int Right now this table containing End Of Day( EOD) data will be about 3 million rows for 3 years. Later when I get/need more data it could be 20 million rows. The front end will be asking requests like "give me the top price gainers on date X over Y days". That request is one of the simpler ones, and as such is not too costly, time wise, I assume. But a request like " give me top volume gainers for the last 10 days, with the previous 100 days acting as baseline", could prove 10-100 times costlier. The result of such a request would be a float which signifies how many times the volume as grown etc. One option I have is adding a column for each such result. And if the user asks for volume gain in 10 days over 20 days, that would require another table. The total such tables could easily cross 100, specially if I start using other results as tables, like MACD-10, MACD-100. each of which will require its own column. Is this a feasible solution? Another option being that I keep the result in cached html files and present them to the user. I dont have much experience in web-development, so to me it looks messy; but I could be wrong ( ofc!) . Is that a option too? Let me add that I am/will be using mod_perl to present the response to the user. With much of the work on mysql database being done using perl. I would like to have a response time of 1-2 seconds.

    Read the article

  • Send Click Message to another application process

    - by Nazar
    Hi Guys I have a scenario, i need to send click events to an independent application. I started that application with the following code. private Process app; app = new Process(); app.StartInfo.FileName = app_path; app.StartInfo.WorkingDirectory = dir_path; app.Start(); Now i want to send Mouse click message to that applicaiton, I have specific coordinates in relative to application window. How can i do it using Windows Messaging or any other technique. I used [DllImport("user32.dll")] private static extern void mouse_event(UInt32 dwFlags, UInt32 dx, UInt32 dy, UInt32 dwData, IntPtr dwExtraInfo); It works well but cause the pointer to move as well. So not fit for my need. Then i use. [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)] static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam); It works well for minimize maximize, but do not work for mouse events. The codes for mousevents i am using are, WM_LBUTTONDOWN = 0x201, //Left mousebutton down WM_LBUTTONUP = 0x202, //Left mousebutton up WM_LBUTTONDBLCLK = 0x203, //Left mousebutton doubleclick WM_RBUTTONDOWN = 0x204, //Right mousebutton down WM_RBUTTONUP = 0x205, //Right mousebutton up WM_RBUTTONDBLCLK = 0x206, //Right mousebutton do Thanks for the help in advance, and waiting for feedback.

    Read the article

  • Communication between parent and child

    - by Pierre
    Hi every one ! I have a little problem. I have to code a simple C application that creat a process and his child (fork()) and I have to do an operation. Parent initialize the values and child calculate. I write this : #include #include #include #include #include typedef struct { int op1; char op; int op2; }Operation; Operation *varOP; void finalResult() { float result = 0; if(varOP-op == '+') result = (varOP-op1 + varOP-op2); if(varOP-op == '-') result = (varOP-op1 - varOP-op2); if(varOP-op == '*') result = (varOP-op1 * varOP-op2); if(varOP-op == '+') result = (varOP-op1 / varOP-op2); printf("%f",result); } int main () { int p; varOP = (Operation *)malloc(sizeof(Operation)); p = fork(); if(p == 0) // If child { signal(SIGUSR1, finalResult ); pause(); } if(p 0) // If parent { varOP-op = '+'; varOP-op1 = 2; varOP-op2 = 3; kill(p, SIGUSR1); wait(NULL); } return 0; } But my child is never called. Is there something wrong with my code? Thanks for your help !

    Read the article

< Previous Page | 343 344 345 346 347 348 349 350 351 352 353 354  | Next Page >