Search Results

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

Page 49/66 | < Previous Page | 45 46 47 48 49 50 51 52 53 54 55 56  | Next Page >

  • Linkage of namespace functions

    - by user144182
    I have a couple of methods declared at the namespace level within a header for a class: // MyClass.h namespace network { int Method1(double d); int Method2(double d); class MyClass { //... } } then defined in //MyClass.cpp int Method1(double d) { ... } int Method2(double d) { ... } This project compiles cleanly and is a dependency for a ui project which uses MyClass. The functions were previously member functions of MyClass, but were moved to namespace since it was more appropriate. My problem is the ui project complains when it gets to the linker: 1network.lib(MyClass.obj) : error LNK2001: unresolved external symbol "int __cdecl network::Method1(double)" (?INT@ds@sim@@YAHN@Z) 1network.lib(MyClass.obj) : error LNK2001: unresolved external symbol "int __cdecl network::Method2(double)" (?CINT@ds@sim@@YAHN@Z) What am I doing wrong?

    Read the article

  • Oh no, Not another Undefined Reference Question!

    - by roony
    Unfortunately yes. I have my shared library compiled, the linker doesn't complain about not finding it but still I get undefined reference error. Thinking that I might be doing something wrong I did a little research and found this nice, simple walkthrough: http://www.adp-gmbh.ch/cpp/gcc/create_lib.html which I've followed to the letter but still I get: $ gcc -Wall main.c -o dynamically_linked -L.\ -lmean /tmp/ccZjkkkl.o: In function `main': main.c:(.text+0x42): undefined reference to `mean' collect2: ld returned 1 exit status This is pretty simple stuff so what's going wrong?!?!? Can anyone suggest something in my set up that might need checking/tweeking? GCC 4.3.2 Fedora 10 64-bit

    Read the article

  • C++: Where can I define the body for a private function?

    - by Martijn Courteaux
    Hi, I have a header like this (header guards not shown): class GameSystem { public: GameSystem(Game *pcGame); virtual ~GameSystem(); void Setup(); private: void InitGame(); void RunGame(); void ExitGame(); Game *m_pcGame; /* Properties */ int m_nWidth; int m_nHeight; int m_nFps; bool m_bFullscreen; }; Where can I define the body for InitGame(), RunGame() and ExitGame()? Can I define it in my .cpp file? If so, how? Or am I obliged to make their body in my .h file? I'm using Eclipse and I began typing: void GameSystem:: and then he doesn't suggest the private functions.

    Read the article

  • Dynamic-linked DLL needs to share a global variable with its caller.

    - by Fabian Wickborn
    I have a static library libStatic that defines a global variable like this Header file libStatic/globals.h: extern int globvar; Code file libStatic/globals.cpp: int globvar = 42; The DLL libDynamic and the executable runner are using this global variable. Furtheron, libDynamic is linked at run-time into runner (via LoadLibrary(), GetProcAddress(), and the works...) I understand this will lead to globvar being created twice, once in the heap of runner and once in the heap of libDynamic, which is of course very undesirable. Is there a good away around this? How can I ensure that libDynamic and runner are using the same globvar?

    Read the article

  • XCode 5 says I got a duplicate, which I don't

    - by GoodMove
    The point is every time I try to run a C++ code in XCode 5 (the file s "File.cpp") xcode returns this: duplicate symbol _main ld: 1 duplicate symbol for architecture i386 clang: error: linker command failed with exit code 1 (use -v to see invocation) And it only returns the error, when I got the following function whatever it contains: int main() { } I checked the folder, which XCode points to (where it says the duplicates are placed), but didn't find anything though. What am I supposed to do??? #include "File.h" using namespace std; void func (void){ cout << "Hello World!" << endl; }

    Read the article

  • c++ Sorting a vector based on values of other vector, or what's faster?

    - by pollux
    Hi, There are a couple of other posts about sorting a vector A based on values in another vector B. Most of the other answers tell to create a struct or a class to combine the values into one object and use std::sort. Though I'm curious about the performance of such solutions as I need to optimize code which implements bubble sort to sort these two vectors. I'm thinking to use a vector<pair<int,int>> and sort that. I'm working on a blob-tracking application (image analysis) where I try to match previously tracked blobs against newly detected blobs in video frames where I check each of the frames against a couple of previously tracked frames and of course the blobs I found in previous frames. I'm doing this at 60 times per second (speed of my webcam). Any advice on optimizing this is appreciated. The code I'm trying to optimize can be shown here: http://code.google.com/p/projectknave/source/browse/trunk/knaveAddons/ofxBlobTracker/ofCvBlobTracker.cpp?spec=svn313&r=313 Thanks

    Read the article

  • How to call C++ function from C?

    - by claws
    I know this. Calling C function from C++: If my application was in C++ and I had to call functions from a library written in C. Then I would have used //main.cpp extern "C" void C_library_function(int x, int y);//prototype C_library_function(2,4);// directly using it. This wouldn't mangle the name C_library_function and linker would find the same name in its input *.lib files and problem is solved. Calling C++ function from C??? But here I'm extending a large application which is written in C and I need to use a library which is written in C++. Name mangling of C++ is causing trouble here. Linker is complaining about the unresolved symbols. Well I cannot use C++ compiler over my C project because thats breaking lot of other stuff. What is the way out? By the way I'm using MSVC

    Read the article

  • Compiling without setting up a project in NetBeans or Visual Studio

    - by aLostMonkey
    Hi, In short: is there a way to compile and run single file in NetBeans or Visual Studio without having to setup and tinker with projects? I'm currently using code::blocks as my IDE. It's fast and very simple: perfect for my needs as a begginner. I wanted to dive a little deeper and try out a more advanced IDE such as NetBeans or Visual Studio. It appears I have to mess with projects and have a setup that seems overkill for having to compile and run one very simple .c/.cpp source file that contains less than 50-100 lines of code etc. Is there a way around this?

    Read the article

  • aligning extern constants (gcc)

    - by ~buratinas
    I want to make some static constants globally visible. I'm pretty familiar how to do that in C++. The problem is that these constants need to be aligned to some exotic boundary. Do I have to specify the alignment in extern declaration? I'm using GCC4.5 in *.cpp file static const constant_t constant __attribute__((aligned(64))) = {blah,blah,blah}; in *.h file //Which one is correct? extern const constant_t constant; extern const constant_t constant __attribute__((aligned(64)));

    Read the article

  • How should I get Xcode to link an iOS project that uses a C++ static library

    - by user1681572
    Using Xcode, I've written a Cocoa Touch static library, mainly in C++. It exposes a C interface for the benefit of Objective-C client code. I have a client iOS app that uses it, and everything works and runs as expected, except that I found I needed to include a minimal .cpp file in the client project to get the link to succeed. Otherwise I get C++-related unresolved symbols, e.g. operator new(unsigned long). The above hack is easy and effective, and so I guess I'm not breaking any laws, but is there a proper way to eliminate my linker errors?

    Read the article

  • c++ compilation error

    - by clamp
    hello, i got a compile error which i do not understand. i have a h/cpp file combination that does not contain a class but just defines some utility functions. when i try to use a struct that is defined in another class i get the error: error C2027: use of undefined type so, stripped down to the problem, the h file looks like this namespace A { void foo(B::C::SStruct const & Var); } the definition of SStruct is in a class which is in another h-file, that is of course included. namespace B { Class C { struct SStruct { }; } } what am i missing here? thanks!

    Read the article

  • Calling C++ function from C.

    - by claws
    I know this. Calling C function from C++: If my application was in C++ and I had to call functions from a library written in C. Then I would have used //main.cpp extern "C" void C_library_function(int x, int y);//prototype C_library_function(2,4);// directly using it. This wouldn't mangle the name C_library_function and linker would find the same name in its input *.lib files and problem is solved. Calling C++ function from C??? But here I'm extending a large application which is written in C and I need to use a library which is written in C++. Name mangling of C++ is causing trouble here. Well I cannot use C++ compiler over my C project because thats breaking lot of other stuff. What is the way out? By the way I'm using MSVC

    Read the article

  • Compilation failing - no #include - boost

    - by jwoolard
    Hi, I'm trying to compile a third-party library, but g++ is complaining about the following line: typedef boost::shared_ptr<MessageConsumer> MessageConsumerPtr; The strange thing is, there is no #include directive in the file - and it is clearly supposed to be this way; there are about 60 files with the same (or very similar) issues. Clearly if there was an #include directive referencing the relevant boost header this would compile cleanly. My question is: how can I get g++ to somehow automagically find the relevant symbol (in all instances of this issue, it is a namespace that can't be found - usually std:: or boost::) by either automatically processing the relevant header (or some other mechanism). Thanks. Edit My current g++ call looks like: g++ -fPIC -O3 -DUSING_PCH -D_REENTRANT -I/usr/include/boost -I./ -c MessageInterpreter.cpp -o MessageInterpreter.o

    Read the article

  • Call a non member funcion on an instance before is constructed.

    - by Tom
    Hi everyone. I'm writing a class, and this doubt came up. Is this undef. behaviour? On the other hand, I'm not sure its recommended, or if its a good practice. Is it one if I ensure no exceptions to be thrown in the init function? //c.h class C{ float vx,vy; friend void init(C& c); public: C(); ~C(); }; //c.cpp C::C() { init(*this); } void init(C& c) //throws() to ensure no exceptions ? { c.vx = 0; c.vy = 0; } Thanks in advance

    Read the article

  • Call a non member function on an instance before is constructed.

    - by Tom
    Hi everyone. I'm writing a class, and this doubt came up. Is this undef. behaviour? On the other hand, I'm not sure its recommended, or if its a good practice. Is it one if I ensure no exceptions to be thrown in the init function? //c.h class C{ float vx,vy; friend void init(C& c); public: C(); }; //c.cpp C::C() { init(*this); } void init(C& c) //throws() to ensure no exceptions ? { c.vx = 0; c.vy = 0; } Thanks in advance

    Read the article

  • g++: how to specify preference of library path?

    - by Heinrich Schmetterling
    I'm compiling a c++ program using g++ and ld. I have a .so library I want to be used during linking. However, a library of the same name exists in /usr/local/lib, and ld is choosing that library over the one I'm directly specifying. How can I fix this? For the examples below, my library file is /my/dir/libfoo.so.0. Things I've tried that don't work: my g++ command is "g++ -g -Wall -o my_binary -L/my/dir -lfoo bar.cpp" adding /my/dir to the beginning or end of my $PATH env variable adding /my/dir/libfoo.so.0 as an argument to g++ Thanks.

    Read the article

  • How to use a variable inside a _T wrapper?

    - by karikari
    I want to make the hostname part of this string to be variable.. Currently, it is only fix to this URL: _T(" --url=http://www.myurl.com/ --out=c:\\current.png"); I want to make something like this, so the URL is changeable.. _T(" --url=http://www." + myurl + "/ --out=c:\\current.png"); update. Below is my latest attempt: CString one = _T(" --url=http://www."); CString two(url->bstrVal); CString three = _T("/ --out=c:\\current.png"); CString full = one + two + three; ShellExecute(0, _T("open"), // Operation to perform _T("c:\\IECapt"), // Application name _T(full),// Additional parameters 0, // Default directory SW_HIDE); The error is : Error 1 error C2065: 'Lfull' : undeclared identifier c:\test.cpp

    Read the article

  • Two phase Construction in C++

    - by tommieb75
    I have as part of assignment to look into a development kit that uses the "two-phase" construction for C++ classes: // Include Header class someFubar{ public: someFubar(); bool Construction(void); ~someFubar(); private: fooObject _fooObj; } In the source // someFubar.cpp someFubar::someFubar : _fooObj(null){ } bool someFubar::Construction(void){ bool rv = false; this->_fooObj = new fooObject(); if (this->_fooObj != null) rv = true; return rv; } someFubar::~someFubar(){ if (this->_fooObj != null) delete this->_fooObj; } Why would this "two-phase" be used and what benefits are there? Why not just instantiate the object initialization within the actual constructor?

    Read the article

  • C++ Static Array Initialization - Memory Issue

    - by donalmg
    Hi, I have a header file which contains a member variable declaration of a static char array: class ABC { public: static char newArray[4]; // other variables / functions private: void setArray(int i, char * ptr); } In the CPP file, I have the array initialized to NULL: char ABC::newArray[4] = {0}; In the ABC constructor, I need to overwrite this value with a value constructed at runtime, such as the encoding of an integer: ABC::ABC() { int i; //some int value defined at runtime memset(newArray, 0, 4); // not sure if this is necessary setArray(i,newArray); } ... void setArray(int i, char * value) { // encoding i to set value[0] ... value [3] } When I return from this function, and print the modified newArray value, it prints out many more characters than the 4 specified in the array declaration. Any ideas why this is the case. I just want to set the char array to 4 characters and nothing further. Thanks...

    Read the article

  • Hoard allocator not "working"?

    - by Cowboy
    I'm trying to Hoard allocator to work, but it seems it doesn't. I have a benchmark application that does a lot of dynamic memory management. The execution time for Hoard and glibc memory manager is the same. It makes me wonder if I'm doing the right thing. What I do is... export LD_PRELOAD="/path/libhoard.so" g++ main.cpp -O3 -o bm -lpthread -lrt Shouldn't I have to link to Hoard allocator? Does it matter what path (in LD_PRELOAD) is, or can I have whatever path? I'm running Ubuntu 8.04, and g++ 4.2.4 Cheers

    Read the article

  • a macro question for c language (#define)

    - by Daniel
    I am reading source code of hoard memory allocator, and in the file of gnuwrapper.cpp, there are the following code #define CUSTOM_MALLOC(x) CUSTOM_PREFIX(malloc)(x) What's the meaning of CUSTOM_PREFIX(malloc)(x)? is CUSTOM_PREFIX a function? But as a function it didn't defined anywhere. If it's variable, then how can we use variable like var(malloc)(x)? more code: #ifndef __GNUC__ #error "This file requires the GNU compiler." #endif #include <string.h> #include <stdlib.h> #include <stdio.h> #include <malloc.h> #ifndef CUSTOM_PREFIX ==> here looks like it's a variable, so if it doesn't define, then define here. #define CUSTOM_PREFIX #endif #define CUSTOM_MALLOC(x) CUSTOM_PREFIX(malloc)(x) ===> what's the meaning of this? #define CUSTOM_FREE(x) CUSTOM_PREFIX(free)(x) #define CUSTOM_REALLOC(x,y) CUSTOM_PREFIX(realloc)(x,y) #define CUSTOM_MEMALIGN(x,y) CUSTOM_PREFIX(memalign)(x,y)

    Read the article

  • Problem with Initializing Consts

    - by UdiM
    This code, when compiled in xlC 8.0 (on AIX 6.1), produces the wrong result. It should print 12345, but instead prints 804399880. Removing the const in front of result makes the code work correctly. Where is the bug? #include <stdio.h> #include <stdlib.h> #include <string> long int foo(std::string input) { return strtol(input.c_str(), NULL, 0); } void bar() { const long int result = foo("12345"); printf("%u\n", result); } int main() { bar(); return 0; } Compilation command: /usr/vacpp/bin/xlC example.cpp -g

    Read the article

  • C++ Vector of vectors

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

    Read the article

  • QConnect find no such slot on QCombobox by Qt Creater

    - by user2534154
    I create a window inherit from QWidget I set grid layout to that Window I make a function called handleHeroChange(int index) in public slot inside that window I add a Qcombobox to call that function handleHeroChange(int index). Qtcreator keep telling: QObject::connect: No such slot QWidget::handleHeroChange(int) in ../Testing/Window.cpp:92 Why did i do wrong? THE CODE: Window::Window(QWidget *parent) : QWidget(parent) { QGridLayout *grid = new QGridLayout(this); QComboBox *comboHeroClass = new QComboBox(); comboHeroClass->addItem("Witcher"); comboHeroClass->addItem("Maurander"); comboHeroClass->setCurrentIndex(1); grid->addWidget(comboHeroClass, 2,3,1,1); QComboBox::connect(comboHeroClass, SIGNAL(currentIndexChanged(int)),this, SLOT(handleHeroChange(int))); } void Window::handleHeroChange(int index){ QPixmap myImage; if(index == 0){ }else if(index == 1){ } }

    Read the article

  • Are unspecified and undefined behavior required to be consistent between compiles?

    - by sharptooth
    Let's pretend my program contains a specific construct the C++ Standard states to be unspecified behavior. This basically means the implementation has to do something reasonable but is allowed not to document it. But is the implementation required to produce the same behavior every time it compiles a specific construct with unspecified behavior or is it allowed to produce different behavior in different compiles? What about undefined behavior? Let's pretend my program contains a construct that is UB according to the Standard. The implementation is allowed to exhibit any behavior. But can this behavior differ between compiles of the same program on the same compiler with same settings in the same environment? In other words, if I dereference a null pointer on line 78 in file X.cpp and the implementation formats the drive in such case does it mean that it will do the same after the program is recompiled?

    Read the article

< Previous Page | 45 46 47 48 49 50 51 52 53 54 55 56  | Next Page >