Search Results

Search found 1632 results on 66 pages for 'cpp'.

Page 44/66 | < Previous Page | 40 41 42 43 44 45 46 47 48 49 50 51  | Next Page >

  • Why is this default template parameter not allowed?

    - by Matt Joiner
    I have the following class: template <typename Type = void> class AlignedMemory { public: AlignedMemory(size_t alignment, size_t size) : memptr_(0) { int iret(posix_memalign((void **)&memptr_, alignment, size)); if (iret) throw system_error("posix_memalign"); } virtual ~AlignedMemory() { free(memptr_); } operator Type *() const { return memptr_; } Type *operator->() const { return memptr_; } //operator Type &() { return *memptr_; } //Type &operator[](size_t index) const; private: Type *memptr_; }; And attempt to instantiate an automatic variable like this: AlignedMemory blah(512, 512); This gives the following error: src/cpfs/entry.cpp:438: error: missing template arguments before ‘buf’ What am I doing wrong? Is void not an allowed default parameter?

    Read the article

  • Memory management in Qt?

    - by Martin
    I'm quite new to Qt and am wondering on some basic stuff with memory management and the life of objects. When do I need to delete / destroy my objects? Is any of this handled automatically? In the example below, which of the objects I create do I need to delete? What happens to the instance variable myOtherClass when myClass is destroyed? What happens if I don't delete / destroy my objects at all, will that be a problem to memory? in MyClass.h: class MyClass { public: MyClass(); ~MyClass(); MyOtherClass *myOtherClass; }; in MyClass.cpp: MyClass::MyClass() { myOtherClass = new MyOtherClass(); MyOtherClass myOtherClass2; QString myString = "Hello"; } As you can see this is quite newbie-easy stuff but where can I learn about this in an easy way? Thanks really much

    Read the article

  • How to change *.ico for button in running mode?

    - by karikari
    I am currently doing visual c++ for an Internet Explorer toolbar button. I have a registration script file (*.rgs) that defines or maybe register the features of my button inside the Windows registry. My objective is, I want my button to change its *.ico image, based on certain conditions process from my *.cpp file. My problem is, I don't understand, how can I somehow change the *.ico file for my button in real time, during my application is running? For example, IF f = 1, ico_file = green.ico; ELSE ico_file = red.ico; Any idea, that you guys can point to me, how can I change the *.ico file for my Internet Explorer toolbar button while the IE is running.

    Read the article

  • Android ndk build mysteriously failing under cygwin with "Error 126"

    - by Jan Hudec
    I have a JNI application built by ndk-build (using Android NDK r5b and cygwin make 3.81). The build usually works, by occasionally fails with: ... Compile++ thumb : components <= Component.cpp make: *** [/c/.hudson/jobs/Nightly/workspace/application/obj/local/armeabi/objs/components/Component.o] Error 126 make: Leaving directory `/c/.hudson/jobs/Nightly/workspace/application/obj/local/armeabi/objs/components' There is no other error. Make than exits with status 2. It happens in different file each time (the name above is anonymized). It seems to happen more often with parallel builds, but sometimes happens with non-parallel builds too. Does anybody have an idea what it might be or at least how to debug it?

    Read the article

  • Documentation concerning platform-specific macros in Linux/POSIX

    - by Nubok
    When compiling a C/C++ program under Windows using Visual Studio (or a compiler that tries to be compatible) there is a predefined macro _WIN32 (Source: http://msdn.microsoft.com/en-us/library/b0084kay.aspx) that you can use for platform-specific #ifdef-s. What I am looking for is an analogon under Linux: a macro which tells me that I am compiling for Linux/an OS that claims to be (more or less) POSIX-compatible. So I looked into gcc documentation and found this: http://gcc.gnu.org/onlinedocs/cpp/System_002dspecific-Predefined-Macros.html Applied to my program, the following macros (gcc 4.4.5 - Ubuntu 10.10) looked promising (I hope that I didn't drop an important macro): #define __USE_BSD 1 #define __unix__ 1 #define __linux 1 #define __unix 1 #define __linux__ 1 #define _POSIX_SOURCE 1 #define __STDC_HOSTED__ 1 #define __STDC_IEC_559__ 1 #define __gnu_linux__ 1 #define __USE_SVID 1 #define __USE_XOPEN2K 1 #define __USE_POSIX199506 1 #define _G_USING_THUNKS 1 #define __USE_XOPEN2K8 1 #define _BSD_SOURCE 1 #define unix 1 #define linux 1 #define __USE_POSIX 1 #define __USE_POSIX199309 1 #define __SSP__ 1 #define _SVID_SOURCE 1 #define _G_HAVE_SYS_CDEFS 1 #define __USE_POSIX_IMPLICITLY 1 Where do I find a detailed documentation of them - as to the mentioned Windows-specific macros above? Additionally I'd be interested in macros normally defined for other POSIX-compliant operating systems as *BSD etc.

    Read the article

  • What is the most efficient way to find missing semicolons in VS with C++?

    - by Dr. Monkey
    What are the best strategies for finding that missing semicolon that's causing the error? Are there automated tools that might help. I'm currently using Visual Studio 2008, but general strategies for any environment would be interesting and more broadly useful. Background: Presently I have a particularly elusive missing semicolon (or brace) in a C++ program that is causing a C2143 error. My header file dependencies are fairly straightforward, but still I can't seem to find the problem. Rather than post my code and play Where's Wally (or Waldo, depending on where you're from) I thought it would be more useful to get some good strategies that can be applied in this and similar situations. As a side-question: the C2143 error is showing up in the first line of the first method declaration (i.e. the method's return type) in a .cpp file that includes only its associated .h file. Would anything other than semicolons or braces lead to this behaviour?

    Read the article

  • wxWidgets errors occur after upgrading gDEBugger

    - by acekiller
    all. Today I upgraded my gDEBugger (though I don't think it involves gDEBugger) to the latest version but problem occurs. When I tried to open gDEBugger, an alert window named "wxWidgets Debug Alert" pop-up, reporting that "....\src\common\xpmdecod.cpp(822):assert "i==colors_cnt" failed in wxXPMDecoder::ReadData(). Call stack: [00]wxConsole....balabala....", like follows. All these words seem just like warnings and didn't affect the following work, however I am wondering why this problem occurs? What's the root cause? I am not familiar with wxWidgets and hopes those guru on it can help me resolve it.

    Read the article

  • I need a simple Example of JNA which can map char * of c dll.

    - by Vikas Sharma
    I have one dll of cpp and i need to call its function which returns char*. Im using String in native Declaration but getting out put like ???? or some crap thing. I just want to knw that do i have to decode the String.i have already set my system property like System.setProperty("jna.encoding","UTF-8"); Im in big mess. Hope to get Some Positive replies from u guys. Thanks in Advance.. Cheers...!

    Read the article

  • how to implement OOP using QT

    - by kaycee
    hi, this is a simple OOP QT question. my app consists of main window (QMainWindow) and a table (QTableWidget). in the main window i have arguments and variables which i would like to pass to the table class, and to access methods in main widnow class from the table class, how should i do it ? mainwindow.h class MainWindow : public QMainWindow { Q_OBJECT private: int a; int b; Spreadsheet *spreadsheet; public: void set_a(int); void set_b(int); spreadsheet.h class Spreadsheet : public QTableWidget { Q_OBJECT public: Spreadsheet(QWidget *parent = 0); atm i define Spreadsheet like this: spreadsheet = new Spreadsheet(this); and i'd like to access set_a() from spreadsheet.cpp...

    Read the article

  • forward declare static function c++

    - by Matthew Scouten
    I want to forward declare a static member function of a class in another file. What I WANT to do looks like this: BigMassiveHeader.h: class foo { static void init_foos(); } Main.cpp: class foo; void init_foos(); int main(char** argv, int argc) { foo::init_foos() } This fails out with "error C2027: use of undefined type 'tt_py_ns::foo'" Is there a way to accomplish what I want to do with out making init_foos a free function, or including BigMassiveHeader.h? (BigMassiveHeader.h is noticeably effecting compile time, and is included everywhere.)

    Read the article

  • No whitespace between a cast and a namespace operator?

    - by Pod
    Hello. Could anyone please explain the following line of code, found on http://docs.openttd.org/ai__cargo_8cpp_source.html return (AICargo::TownEffect)::CargoSpec::Get(cargo_type)->town_effect; If this line was: return (AICargo::TownEffect) ::CargoSpec::Get(cargo_type)->town_effect; (note the space between TownEffect) and the ::) then I would understand it fine. However there is no whitespace in that document*, which would mean (AICargo::TownEffect) is the left operand of the :: operator. How does this code work/compile? Or are the two things equivilent due to some obscure C++ rule? *It's the same in the cpp file as well.

    Read the article

  • Function matching in Qt

    - by Alexander
    Hello, I have some trouble with Qt. I have a class 'Core' class Core { public: static QString get_file_content(QString filename); static void setMainwindow(MainWindow *w); private: static MainWindow *main_window; }; and class 'MainWindow' in namespace Ui: namespace Ui { class MainWindow; } class MainWindow : public QMainWindow { Q_OBJECT public: MainWindow(QWidget *parent = 0); ~MainWindow(); private: Ui::MainWindow *ui; }; In MainWindow constructor I make MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); Core::setMainwindow(this); } and gets error mainwindow.cpp:8: error: no matching function for call to 'Core::setMainwindow(MainWindow* const)' Of cource, i include core.h with declaration of 'Core' class. That's occurs only on setMainwindow method. So the questions is - why Core class method setMainwindow() is invisible in MainWindow class?

    Read the article

  • boost::dynamic_pointer_cast with const pointer not working ?

    - by ereOn
    Hi, Let's say I have two classes, A and B, where B is a child class of A. I also have the following function: void foo(boost::shared_ptr<const A> a) { boost::shared_ptr<const B> b = boost::dynamic_pointer_cast<const B>(a); // Error ! } Compilation with gcc gives me the following errors: C:\Boost\include/boost/smart_ptr/shared_ptr.hpp: In constructor 'boost::shared_ptr< <template-parameter-1-1> >::shared_ptr(const boost::shared_ptr<Y>&, boost::detail::dynamic_cast_tag) [with Y = const A, T = const B]': C:\Boost\include/boost/smart_ptr/shared_ptr.hpp:522: instantiated from 'boost::shared_ptr<X> boost::dynamic_pointer_cast(const boost::shared_ptr<U>&) [with T = const B, U = const A]' src\a.cpp:10: instantiated from here C:\Boost\include/boost/smart_ptr/shared_ptr.hpp:259: error: cannot dynamic_cast 'r->boost::shared_ptr<const A>::px' (of type 'const class A* const') to type 'const class B*' (source type is not polymorphic) What could possibly be wrong ? Thank you.

    Read the article

  • How to override environment variables when running configure?

    - by Sam
    In any major package for Linux, running ./configure --help will output at the end: Some influential environment variables: CC C compiler command CFLAGS C compiler flags LDFLAGS linker flags, e.g. -L<lib dir> if you have libraries in a nonstandard directory <lib dir> CPPFLAGS C/C++ preprocessor flags, e.g. -I<include dir> if you have headers in a nonstandard directory <include dir> CPP C preprocessor Use these variables to override the choices made by `configure' or to help it to find libraries and programs with nonstandard names/locations. How do I use these variables to include a directory? I tried running ./configure --CFLAGS="-I/home/package/custom/" and ./configure CFLAGS="-I/home/package/custom/" however these do not work. Any suggestions?

    Read the article

  • jstring to L_TCHAR* format

    - by Ayusman
    Hi All, I have been trying to call a C function that has the following signature int changeFoo(L_TCHAR* pszFileSrc){....} in my JNI call my method looks like this: JNIEXPORT jint JNICALL Java_com_me_L_AFoo (JNIEnv * env, jclass jclass, jstring pSrc) { jint retValue = -100; retValue = changeFoo(pSrc); return retValue; } I get the following error in visual studio. Error 1 error C2664: 'L_FileConvert' : cannot convert parameter 1 from 'jstring' to 'L_TCHAR *' c:\Ayusman\Work\MyVCpp\LTExampleDll\LTExampleDll\LTExampleMain.cpp 46 LTExampleDll When I looked at the definition of L_TCHAR * here is what I got in the header files (in that sequence): typedef TCHAR L_TCHAR; typedef WCHAR TCHAR,*PTCHAR; typedef wchar_t WCHAR; //wc, 16 bit UNICODE char I work on java, this is a JNI application that I am trying to build. Can any body help as to how can I convert this properly? Thanks, Ayusman

    Read the article

  • Hiding members in a C struct

    - by Marlon
    I've been reading about OOP in C but I never liked how you can't have private data members like you can in C++. But then it came to my mind that you could create 2 structures. One is defined in the header file and the other is defined in the source file. // ========================================= // in somestruct.h typedef struct { int _public_member; } SomeStruct; // ========================================= // in somestruct.cpp #include "somestruct.h" typedef struct { int _public_member; int _private_member; } SomeStructSource; SomeStruct *SomeStruct_Create() { SomeStructSource *p = (SomeStructSource *)malloc(sizeof(SomeStructSource)); p->_private_member = 0xWHATEVER; return (SomeStruct *)p; } From here you can just cast one structure to the other. Is this considered bad practice? Or is it done often? (I think this is done with a lot of the structures when using the Win32 API, but you guys are the experts let me know!)

    Read the article

  • Visual c++ opencv 2.1 contains()

    - by kaushalyjain
    how to check whether a given point is contained in a rectangle using the contains() function in Rect_ construct... Please give me the exact function and its parameters.Like when i type this Point b(2,2); Rect a(10,10,50,50); cout<< Rect_::contains(b); There is a compile error saying 1c:\users\kaushal\documents\visual studio 2008\projects\test1\test1.cpp(23) : error C2352: 'cv::Rect_<Tp::contains' : illegal call of non-static member function 1c:\opencv2.1\include\opencv\cxcore.hpp(385) : see declaration of 'cv::Rect<_Tp::contains'

    Read the article

  • argv[1] loadImage problem xcode 3.2 and snow leopard

    - by ignacionieto
    Hi Im on mac snow leopard and test these code on xcode3.2 of the Learning OpenCV everything works fine but the image doesnt appear and in the windows. I had try to understand searching for two days what does argv[1] means, but Im still no clear. Im a newbie en C++. I had the image in the same directory where the main.cpp is #include <OpenCV/cv.h> #include <OpenCV/highgui.h> int main(int argc, char** argv) { IplImage* interest_img; CvRect interest_rect; if( argc == 7 && ((interest_img= cvLoadImage( argv[1],1) ) != 0 )) { A more easy example is here: http://books.google.cl/books?id=seAgiOfu2EIC&pg=PA17&lpg=PA17&dq=cvLoadImage%28argv[1]&source=bl&ots=hRJ5bhkAOf&sig=gyYAqZBnS6lCCXJz9Fz7vzOsF-U&hl=es&ei=dvdvS-fWG8eWtgePy_WCBg&sa=X&oi=book_result&ct=result&resnum=6&ved=0CBwQ6AEwBTgK#v=onepage&q=cvLoadImage%28argv[1]&f=false both I have test it but they dont work. Please help me

    Read the article

  • Passing user context to from impersonated thread to outproc COM object

    - by Thumbeti
    Hi, I am writing a CPP program on windows 2k3 where i want to achieve the following thing. Pass the user context from the impersonated thread to a outproc COM component. Steps what i m trying in details are: 1) Start an execution of exe with user USR1 2) Impersonate the current thread with USR2 3) Initiate a API on outproc COM object. And this COM object should run with USR2 What is happening: on 3rd step, COM object is getting started with USR1 only. Can anybody help me in passing the user context to COM object. Thanks in advance, Thumbeti

    Read the article

  • StringConverter with StandardValuesSupported and Autocompletion

    - by Marqus
    I want to develop a StringConverter with standard values, which after attaching it to a PropertyGrid will act like comboBox with autocompletion. The example below will give me a comboBox, but without the autocompletion - user have to expand it and choose manually one of the items. Is there a way to allow user to type the beginning of one of the options, so the combobox will automatically select the matching one? public class ConverterSample : System.ComponentModel.StringConverter { public override bool GetStandardValuesSupported(ITypeDescriptorContext context) { //true means show a combobox return true; } public override bool GetStandardValuesExclusive(ITypeDescriptorContext context) { return false; } public override TypeConverter.StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) { return new StandardValuesCollection(new List<string>(){"Stack", "overflow", "rules"); } List returned by GetStandardValues has to be dynamic, so I can't use any enum there. I took above example from: http://www.codeproject.com/KB/cpp/dropdownproperties.aspx

    Read the article

  • How to convert a C++ program that uses CUDA into MEX

    - by Harold Wellington Graves
    For work, I am converting the Image Denoising program that comes with the CUDA SDK into a MATLAB program. As far as I know, I have made all the necessary changes required by MATLAB, but when I try to call mex on it, MATLAB returns a bunch of linkage errors that I have no idea how to fix. If anyone has any suggestions on what I might be doing wrong, I would greatly appreciate it. The command I am giving MATLAB is: mex imageDenoisingGL.cpp -I..\..\common\inc -IC:\CUDA\include -L..\..\common\lib -lglut32 And the output from MATLAB is a bunch of these: imageDenoisingGL.obj : error LNK2019: unresolved external symbol __imp__cutCheckCmdLineFlag@12 referenced in function "void __cdecl __cutilExit(int,char * *)" (?__cutilExit@@YAXHPAPAD@Z) I am running: Windows XP x32 Visual Studio 2005 MATLAB 2007a

    Read the article

  • C++/CLI: CA2123: Requires SecurityCriticalAttribute?

    - by TomTom
    I am a little lost on erros like that: Warning 7 CA2123 : Microsoft.Security : Add the following security attribute to 'RithmicConnector::Connect(String^)' in order to match a LinkDemand on base method 'IConnector::Connect(String^)': 'SecurityCriticalAttribute'. c:\work\nettecture\tradex\source\tradex.connectivity.rithmic\rithmicconnector.cpp 52 Tradex.Connectivity.Rithmic Where do I add the SecurityCriticalAttribute? I tried on the header file - but the error does not disappear. I have one of those pretty much on every exposed method of a (managed C++) interface DLL. And I want CA to run through. How do I fix those? Regards

    Read the article

  • Using MinGW to compile a SFML project

    - by Kyle Martin
    Okay, so I have a C++ project that uses SFML, and I want to be able to compile it from the CMD using MinGW. I have it so I can compile.cpp's, however, I just need to know what more I have to do in order for it to work with SFML. I tried compiling it with CodeBlocks and MinGW, and it works fine, until I try to run it, at which point it tells me that sfml-system.dll is missing from my computer. Does this mean I installed it incorrectly? I followed the CodeBlocks installation down to the letter, from what I could tell... I put the include\SFML in the include\ of MinGW, and I put all the *.a's from lib\ into the \lib of MinGW as well. Thank you for the help you can give! Kyle

    Read the article

  • C++ template class error with operator ==

    - by Tommy
    Error: error C2678: binary '==' : no operator found which takes a left-hand operand of type 'const entry' (or there is no acceptable conversion) The function: template <class T, int maxSize> int indexList<T, maxSize>::search(const T& target) const { for (int i = 0; i < maxSize; i++) if (elements[i] == target) //ERROR??? return i; // target found at position i // target not found return -1; } indexList.h indexList.cpp Is this suppose to be an overloaded operator? Being a template class I am not sure I understand the error? Solution- The overload function in the class now declared const: //Operators bool entry::operator == (const entry& dE) const <-- { return (name ==dE.name); }

    Read the article

  • Visual Studio 2005 - VC++ compiler C1001 on Windows 7

    - by Fritz H
    When I try to build a simple "Hello World" C++ app on Windows 7 Beta, using Visual Studio 2005 (VC++2005) I get a rather generic error C1001 error (Internal compiler error) The compiler seems to just crash, and Windows pops up its (un)helpful This program has stopped working dialog. The file it complains about is mcp1.cpp. Has anyone come across this before? Cheers, Fritz EDIT: The code is: #include <iostream> int main(int argc, char** argv) { std::cout << "Hello!"; return 0; } EDIT 2: I have installed SP1 as well as SP1 for Vista. VS popped up a warning saying it needs SP1 for Vista, but installing it makes no difference. No ideas about what I can possibly do to fix this?

    Read the article

< Previous Page | 40 41 42 43 44 45 46 47 48 49 50 51  | Next Page >