Search Results

Search found 34893 results on 1396 pages for 'const method'.

Page 515/1396 | < Previous Page | 511 512 513 514 515 516 517 518 519 520 521 522  | Next Page >

• staying within boundaries of image?

  - by codefail

  So I am to loop through copyFrom.pixelData and copy it into pixelData. I realize that I need to check the conditions of i and j, and have them not copy past the boundaries of pixelData[x][y], I need another 2 loops for that? I tried this, but was getting segmentation fault.. Is this the right approach? void Image::insert(int xoff, int yoff, const Image& copyFrom, Color notCopy) { for (int x = xoff; x < xoff+copyFrom.width; x++) { for (int y = yoff; y < yoff+copyFrom.height; y++) { for (int i = 0; i<width; i++){ for (int j = 0; j<height; j++){ if (copyFrom.pixelData[i][j].colorDistance(notCopy)>20 ) pixelData[x][y]=copyFrom.pixelData[i][j]; } } } } }

  Read the article

• Quick, Beginner C++ Overloading Question - Getting the compiler to perceive << is defined for a spec

  - by Francisco P.

  Hello everyone. I edited a post of mine so I coul I overloaded << for a class, Score (defined in score.h), in score.cpp. ostream& operator<< (ostream & os, const Score & right) { os << right.getPoints() << " " << right.scoreGetName(); return os; } (getPoints fetches an int attribute, getName a string one) I get this compiling error for a test in main(), contained in main.cpp binary '<<' : no operator found which takes a right-hand operand of type 'Score' (or there is no acceptable conversion) How come the compiler doesn't 'recognize' that overload as valid? (includes are proper) Thanks for your time.

  Read the article

• Is there any way to pass an anonymous array as an argument in C++?

  - by Jeremy Friesner

  Hi all, I'd like to be able to declare an array as a function argument in C++, as shown in the example code below (which doesn't compile). Is there any way to do this (other than declaring the array separately beforehand)? #include <stdio.h> static void PrintArray(int arrayLen, const int * array) { for (int i=0; i<arrayLen; i++) printf("%i -> %i\n", i, array[i]); } int main(int, char **) { PrintArray(5, {5,6,7,8,9} ); // doesn't compile return 0; }

  Read the article

• Python extension building with boost

  - by user1544053

  Hey guys I'm fairly new to boost c/c++ library. I downloaded boost library and build the library. I created a very simple python library in c++ using boost interface (actually it is example code given in the documentation). I built it into a dll file. In the documentation it reads that this dll is exposed to python and they just show the import function in python and include the created library. I don't understand how to expose that dll to python and load the library inside in tradition ('import') manner. In case if you wanna look at the code then here it is: #include <boost/python.hpp> char const* greet() { return "hello, world"; } BOOST_PYTHON_MODULE(hello_ext) { using namespace boost::python; def("greet", greet); } Please help I really want to build applications with c/c++ and python. I simply want to use hello_ext as: >>>import hello_ext >>>print hello_ext.greet() Thank you.

  Read the article

• Call a C++ constructor from an Objective C class

  - by syvex

  How can I call a C++ constructor from inside an Objective C class? class CppClass { public: CppClass(int arg1, const std::string& arg2): _arg1(arg1), _arg2(arg2) { } // ... private: int _arg1; std::string _arg2; }; @interface ObjC: NSObject { CppClass _cppClass; } @end @implementation ObjC - (id)init { self = [super init]; if ( self ) { // what is the syntax to call CppClass::CppClass(5, "hello") on _cppClass? } return self; } @end

  Read the article

• class which cannot be derived

  - by benjamin button

  I found this code here class Usable; class Usable_lock { friend class Usable; private: Usable_lock() {} Usable_lock(const Usable_lock&) {} }; class Usable : public virtual Usable_lock { // ... public: Usable(); Usable(char*); // ... }; Usable a; class DD : public Usable { }; DD dd; // error: DD::DD() cannot access // Usable_lock::Usable_lock(): private member Could anybody explain me this code?

  Read the article

• C# (ASP.Net) Linking selection values to constants in Codebehind

  - by jasonvogel

  ASPX Code <asp:RadioButtonList ID="rbServer" runat="server" > <asp:ListItem Value=<%=ServerDeveloper%>> Developer </asp:ListItemv <asp:ListItem Value="dev.ahsvendor.com"> dev.test.com</asp:ListItem> <asp:ListItem Value="staging.ahsvendor.com"> staging.test.com</asp:ListItem> </asp:RadioButtonList> ASPX.CS - Codebehind const string ServerDeveloper = "developer"; ASPX Error: Code blocks are not supported in this context. Question: So what is the correct way to tie an dropdown/radio buttion/... ASPX value to a constant that is shared with the CodeBehind code? I know that I could do rbServer.Add.Item("developer") [from the CodeBehind], but is there a way to achieve it from the Presentation side of things?

  Read the article

• C++ iterators & loop optimization

  - by Quantum7

  I see a lot of c++ code that looks like this: for( const_iterator it = list.begin(), const_iterator ite = list.end(); it != ite; ++it) As opposed to the more concise version: for( const_iterator it = list.begin(); it != list.end(); ++it) Will there be any difference in speed between these two conventions? Naively the first will be slightly faster since list.end() is only called once. But since the iterator is const, it seems like the compiler will pull this test out of the loop, generating equivalent assembly for both.

  Read the article

• How to I count key collisions when using boost::unordered_map?

  - by Nikhil

  I have a data structure with 15 unsigned longs, I have defined a hash function using hash_combine as follows: friend std::size_t hash_value(const TUPLE15& given) { std::size_t seed = 0; boost::hash_combine(seed, val1); boost::hash_combine(seed, val2); ... return seed; } I insert a large number of values into a boost::unordered_map but the performance is not good enough. Probably, I could do better with an alternative hashing function. To confirm this, I need to check how many collisions I am getting. How do I do this?

  Read the article

• How to use the boost lexical_cast library for just for checking input

  - by Inverse

  I use the boost lexical_cast library for parsing text data into numeric values quite often. In several situations however, I only need to check if values are numeric; I don't actually need or use the conversion. So, I was thinking about writing a simple function to test if a string is a double: template<typename T> bool is_double(const T& s) { try { boost::lexical_cast<double>(s); return true; } catch (...) { return false; } } My question is, are there any optimizing compilers that would drop out the lexical_cast here since I never actually use the value? Is there a better technique to use the lexical_cast library to perform input checking?

  Read the article

• array loop not working correctly? c++

  - by igor

  Trying to count how many elements within the array are not equal to 0, is something set up wrong? I'd like to check all values in the array (it's a sudoku board) and then when all elements are "full" I need to return true. Is something off? bool boardFull(const Square board[BOARD_SIZE][BOARD_SIZE]) { int totalCount=0; for (int index1 = 0; index1 < BOARD_SIZE; index1++) for (int index2 = 0; index2 < BOARD_SIZE; index2++){ if(board[index1][index2].number!=0) totalCount++; } if(totalCount=81) return true; else return false;

  Read the article

• How can I (is there a way to) convert an HRESULT into a system specific error message?

  - by Billy ONeal

  According to this, there's no way to convert a HRESULT error code into a Win32 error code. Therefore (at least to my understanding), my use of FormatMessage in order to generate error messages (i.e. std::wstring Exception::GetWideMessage() const { using std::tr1::shared_ptr; shared_ptr<void> buff; LPWSTR buffPtr; DWORD bufferLength = FormatMessageW( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetErrorCode(), 0, reinterpret_cast<LPWSTR>(&buffPtr), 0, NULL); buff.reset(buffPtr, LocalFreeHelper()); return std::wstring(buffPtr, bufferLength); } ) does not work for HRESULTs. How do I generate these kinds of system-specific error strings for HRESULTs?

  Read the article

• Any side effect of not using USES_CONVERSION

  - by Yan Cheng CHEOK

  Recently, I have a utilities function of // T2CA #include "ATLCONV.H" std::string Utils::CString2String(const CString& cString) { #if _MSC_VER > 1200 // Convert a TCHAR string to a LPCSTR // construct a std::string using the LPCSTR input CT2CA tmp(cString); std::string strStd (tmp); #else // Deprecated in VC2008. // construct a std::string using the LPCSTR input std::string strStd (T2CA (cString)); #endif return strStd; } I do several simple test it seems work fine. However, when I google around, I see most usage of T2CA in VC6, before they call, they will invoke USES_CONVERSION; Is there any thing I had missed out? Shall I invoke my function by : #else // Deprecated in VC2008. // construct a std::string using the LPCSTR input USES_CONVERSION; std::string strStd (T2CA (cString)); #endif

  Read the article

• In a C++ template, is it allowed to return an object with spesific type parameters?

  - by nieldw

  When I've got a template with certain type parameters, is it allowed for a function to return an object of this same template, but with different types? In other words, is the following allowed? template<class edgeDecor, class vertexDecor, bool dir> Graph<edgeDecor,int,dir> Graph<edgeDecor,vertexDecor,dir>::Dijkstra(vertex s, bool print = false) const { /* Construct new Graph with apropriate decorators */ Graph<edgeDecor,int,dir> span = new Graph<edgeDecor,int,dir>(); /* ... */ return span; }; If this is not allowed, how can I accomplish the same kind of thing?

  Read the article

• parsing Two-dimensional array in c

  - by gitter78

  I'm trying to parse an array that looks like the one below: char *arr[][2] = { { "1", "Purple" }, { "2", "Blue" }, { "22", "Red" }, ... }; I was thinking having a loop as: char *func(char *a){ for(i = 0; i<sizeof(arr)/sizeof(arr[0]);i++){ if(strstr(a,arr[i][0])!=NULL) return arr[i][1]; } } char *out; const char *hello = "this is my 2 string"; out = func(hello); In this case, I'm trying to get the second value based on the first one: Purple, Blue Red, etc.. The question is how would go in parsing this and instead of printing out the value, return the value. UPDATE/FIXED: It has been fixed above. Thanks

  Read the article

• Statically initialize anonymous union in C++

  - by wpfwannabe

  I am trying to statically initialize the following structure in Visual Studio 2010: struct Data { int x; union { char ch; const Data* data; }; }; The following is fails with error C2440: 'initializing' : cannot convert from 'Data *' to 'char'. static Data d1; static Data d = {1, &d1}; I have found references to some ways this can be initialized properly but none of them work in VS2010. Any ideas?

  Read the article

• Can anyone tell me were I am making mistake in the snippet

  - by Solitaire

  public partial class Form1 : Form { [DllImport("coredll.dll")] static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong); const int GWL_WNDPROC = -4; public delegate int WindProc(IntPtr hWnd, uint msg, long Wparam, long lparam); public Form1() { InitializeComponent(); WindProc SampleProc = new WindProc (SubclassWndProc); SetWindowLong(this .Handle , GWL_WNDPROC, SampleProc.Method .MethodHandle.Value.ToInt32()); } public int SubclassWndProc(IntPtr hwnd, uint msg, long Wparam, long lparam) { return 1; } Here is the sample which i was trying to take the window procedure of a form, this is how i do in C++ i get the windwproc easlily if i try the same in C# .net 3.5 i am unable to get the window proc,, after calling SetWindowLong API application hangs and it pops up some dont send report... i have read this is the way to get the window proc.. please let me know were i am making mistake...

  Read the article

• How to use #ifdef entities as part of functions in header files

  - by Crazyjavahacking

  I would like to ask if it is possible to use the entities defined in #ifdef block in header files. To be clear, I have following code: #ifdef #include <winsock2.h> #define SOCKET_HANDLE SOCKET #define CONNECTION_HANDLE SOCKET #endif SOCKET_HANDLE createServerSocket(const char* hostAddress, short port); I am Java developer and this seems completely fine for me. However compiler has a problem with this. Can you explain why is that code a problem? Also how can I force to compile it. (The idea is to have generic interface and conditional compilation to determine real types according to running platform at compile time.) Thanks

  Read the article

• Objective C: App freezes when using a timer

  - by Chris

  It took me hours to figure out how to implement a timer into my program, but when it runs, the app doesn't load completely as it did before the timer. In my main.m: int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; OutLauncher *theLauncher = [[OutLauncher alloc] init]; NSTimer *theTimer = [theLauncher getTimer]; [theTimer retain]; [[NSRunLoop currentRunLoop] addTimer: theTimer forMode: NSDefaultRunLoopMode]; [[NSRunLoop currentRunLoop] run]; [pool release]; return 0; } The file OutLauncher is being imported into that, which looks like this: - (void)doStuff { NSLog( @"Doing Stuff"); } - (NSTimer *)getTimer{ NSTimer *theTimer; theTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector: @selector(doStuff) userInfo:nil repeats:YES]; return [theTimer autorelease]; } The timer works, the console updates every second with the phrase "doing stuff" but the rest of the program just won't load. It will if I comment out the code I added to int main though

  Read the article

• strcat() won't exit

  - by Tristan Sebens

  I'm trying to implement a very basic server in C, one part of which is constructing HTTP headers. To do this I have written a class called header_builder, which basically constructs the headers for me. One of the most basic methods of this class is append_header_line, shown below: void append_header_line( const char *line, char *hdr ) { printf("Adding header line\n"); strcat( hdr, line ); printf("Line added. Adding ending.\n"); strcat( hdr, "\r\n" ); printf("Success\n"); } All it's supposed to do is tack the "line" parameter onto the end of the "hdr" parameter, and then add "\r\n" to the end of it all. The problem is that the first strcat call never exits. When I run this code, all it does is say: Adding header line Which means that the following lines never execute, and I can't figure out why. Any thoughts?

  Read the article

• C++, constructor restrictions

  - by Pie86

  Hi everybaody, I'm studing C++ and I can't understand the meaning of the boldface sentence below: From IBM manual: The following restrictions apply to constructors and destructors: Constructors and destructors do not have return types nor can they return values. References and pointers cannot be used on constructors and destructors because their addresses cannot be taken. Constructors cannot be declared with the keyword virtual. Constructors and destructors cannot be declared static, const, or volatile. Unions cannot contain class objects that have constructors or destructors. Could you please provide me an example? Thank you!

  Read the article

• int[] to string c#

  - by Robin Webdev

  Hi I'm developing an client application in C# and the server is written in c++ the server uses: inline void StrToInts(int *pInts, int Num, const char *pStr) { int Index = 0; while(Num) { char aBuf[4] = {0,0,0,0}; for(int c = 0; c < 4 && pStr[Index]; c++, Index++) aBuf[c] = pStr[Index]; *pInts = ((aBuf[0]+128)<<24)|((aBuf[1]+128)<<16)|((aBuf[2]+128)<<8)|(aBuf[3]+128); pInts++; Num--; } // null terminate pInts[-1] &= 0xffffff00; } to convert an string to int[] in my c# client i recieve: int[4] { -14240, -12938, -16988, -8832 } How do I convert the array back to an string? I don't want to use unsafe code (e.g. pointers) Any of my tries resulted in unreadable strings.

  Read the article

• View is moved 3 pixels

  - by Jakub

  Hello, In my app I move the table view (in order to make the text fields visible when the keyboard appears). The view is looks following: This is the code I use for resizing the view and moving it up: static const NSUInteger navBarHeight = 44; CGRect appFrame = [[UIScreen mainScreen] applicationFrame]; tableView.frame = CGRectMake(0, navBarHeight, appFrame.size.width, appFrame.size.height-navBarHeight-216); //216 for the keyboard NSIndexPath *indPath = [self getIndexPathForTextField:textField]; //get the field the view should scroll to [tableView scrollToRowAtIndexPath:indPath atScrollPosition:UITableViewScrollPositionMiddle animated:YES]; The problem is that when the view is moved up it also moves 3 pixels into right direction (it is hard to see the difference in the screenshot, but it is visible when the animation is on and I measured the difference with PixelStick tool). Here it is how it looks after the move: My analysis shows that scrolling the table does not influence the move to the right. Any ideas what is wrong in the code above that makes the view move to the right?

  Read the article

• Is call to function object inlined?

  - by dehmann

  In the following code, Foo::add calls a function via a function object: struct Plus { inline int operator()(int x, int y) const { return x + y; } }; template<class Fct> struct Foo { Fct fct; Foo(Fct f) : fct(f) {} inline int add(int x, int y) { return fct(x,y); // same efficiency adding directly? } }; Is this the same efficiency as calling x+y directly in Foo::add? In other words, does the compiler typically directly replace fct(x,y) with the actual call, inlining the code, when compiling with optimizations enabled?

  Read the article

• Possible to convert list of #defines into strings (C++)

  - by brandonC

  Suppose I have a list of #defines in a header file for an external library. These #defines represent error codes returned from functions. I want to write a conversion function that can take as an input an error code and return as an output a string literal representing the actual #define name. As an example, if I have #define NO_ERROR 0 #define ONE_KIND_OF_ERROR 1 #define ANOTHER_KIND_OF_ERROR 2 I would like a function to be able to called like int errorCode = doSomeLibraryFunction(); if (errorCode) writeToLog(convertToString(errorCode)); And have convertToString() be able to auto-convert that error code without being a giant switch-case looking like const char* convertToString(int errorCode) { switch (errorCode) { case NO_ERROR: return "NO_ERROR"; case ONE_KIND_OF_ERROR: return "ONE_KIND_OF_ERROR"; ... ... ... I have a feeling that if this is possible, it would be possible using templates and metaprogramming, but that would only work the error codes were actually a type and not a bunch of processor macros. Thanks

  Read the article

< Previous Page | 511 512 513 514 515 516 517 518 519 520 521 522  | Next Page >