Let's suppose you have this class: class A { public: A () {} A (double val) : m_val(val) {} ~A () {} private: double m_val; }; Once I create an instance of A, how can I check if m_val has been initialized/defined? Put it in other words, is there a way to know if m_val has been initialized/defined or not? Something along the li...
Hello! I can't understand why does the following code produce memory leaks (I am using boost::shared_ptr with static class instance). Could someone help me? #include <crtdbg.h> #include <boost/shared_ptr.hpp> using boost::shared_ptr; #define _CRTDBG_MAP_ALLOC #define NEW new(_NORMAL_BLOCK, __FILE__, __LINE__) static struct myclass { ...
Hi, I am writing application to monitor a file and then match some pattern in that file. I want to know what is the fastest way to read a file in C++ Is reading line by line is faster of reading chunk of the file is faster. ...
I want to have something like that class A { public: Array& operator()() { . . . } }; class B { public: Element& operator[](int i) { ... } }; template<class T> class execute { public: output_type = operator()(T& t) { if(T == A) Array out = T()(); else { Array res;...
I'm designing a custom VM and am curious about how many registers I should use. Initially, I had 255, but I'm a little concerned about backing 255 pointers (a whole KB) on to the stack or heap every time I call a function, when most of them won't even be used. How many registers should I use? ...
Hi All, What is the CodecData field at the end of the WAVEFORMATEX struct used for? What format is it in? How can I write an integer into it and read it somewhere else? Thanks Roey ...
I have a project in VC++ 6.0 where there is an exe and a InProc COM Dll. I want to be able to place a breakpoint somewhere in the InProc COM DLL, but VC++ won't allow me to set a breakpoint. I have the source code for this DLL, however I cannot figure out how I can place a breakpoint in the code and the debug it? Can someone help me. ...
I'm in the process of creating an Excel addIn package to work with a web service. I have a C++ .xll addIn that uses MSXML to communicate with the web service, and registers worksheet functions, but otherwise provides no UI. I am developing a c# .net addIn to provide the GUI using the Office 2007 ribbon, and a VBA addIn for earlier versi...
I have an file that is a long list of weighted edges, in the following form node1_id node2_id weight node1_id node3_id weight and so on. So one weighted edge per line. I want to load this file into boost graph and find the connected components in the graph. Each of these connected components is a subgraph. For each of these compon...
I was trying to compile our project in Visual Studio 2010 using the 2005 compiler and I stumbled upon this strange bug. There's this particular file that crashes the compiler whenever I try to compile it from VS2010 with a "Microsoft (R) C/C++ Optimizing Compiler" error dialog with "don't send" buttons. I looked at the way VS2010 invok...
Consider the following macro definitions and invocation: #define x x[0] #define y(arg) arg y(x) This invocation expands to x[0] (tested on Visual C++ 2010, g++ 4.1, mcpp 2.7.2, and Wave). Why? Specifically, why does it not expand to x[0][0]? During macro replacement, A parameter in the replacement list...is replaced by the cor...
Hello, I'm using boost::function for making references to the functions. Can I make a list of references? For example: boost::function<bool (Entity &handle)> behaviorRef; And I need in a list of such pointers. For example: std::vector<behaviorRef> listPointers; Of course it's wrong code due to behaviorRef isn't a type. So the ques...
In C# (.Net) you can create a panel and set autoscroll to true. you can then add controls into it, including beyond it's size, then it will scroll. I was wondering if when using the real WinAPI in c++ (not .net) how one could acheive the same result. Must I keep track of the controls inside and move them all when I scroll or is there a...
Just curious on why a param has to be a const in operation overloading CVector& CVector::operator= (const CVector& param) { x=param.x; y=param.y; return *this; } couldn't you have easily done something like this ?? CVector& CVector::operator= (CVector& param) //no const { x=param.x; y=param.y; return *this; } Isn't when...
Hi, I'm trying to map a C structure to Java using JNA. I came across something that I've never seen. The struct definition is as follow, struct op { unsigned op_type:9; //---> what does this means? unsigned op_opt:1; unsigned op_latefree:1; unsigned op_latefreed:1; unsigned op_attached:1; unsigned op_spa...
Hello, I have another one question about functions reference. For example, I have such definition: typedef boost::function<bool (Entity &handle)> behaviorRef; std::map< std::string, ptr_vector<behaviorRef> > eventAssociation; The first question is: how to insert values into such map object? I tried: eventAssociation.insert(std::pair...
I want to change text color inside a rectangle periyodically Here is my trial: TrainIdBox::TrainIdBox() { boxRect = QRectF(0,0,40,15); testPen = QPen(Qt:red); i=0; startTimer(500); } QRectF TrainIdBox::boundingRect() const { return boxRect; } void TrainIdBox::paint(QPainter *painter, const QStyleOptionGraphicsItem *opt...
I'm writing a reactive software, which repeatedly recieves input, processes it and emits relevant output. The main loop looks something like: initialize(); while (true) { Message msg,out; recieve(msg); process(msg,out); //no global state is saved between loop iterations! send(out); } I want that whatever error occu...
I'm trying to compile some code on one of our systems for our DBA...I've edited the makefiles to include the pertinent libraries listed in the documentation, but I keep getting these errors... Can you discern any obvious problems from my command lines in reference to the errors listed? Thank you! make -f /u01/app/banner/ban8/TEST3/link...
Hi, I'm trying to use BOOST_FOREACH for iterating through the std::queue. But there isn't iterators in that class cause I have an error: std::queue<std::string> someList; BOOST_FOREACH(std::string temp, someList) { std::cout << temp; } >no matching function for call to begin(...) >no type named ‘iterator’ in ‘class std::queue<std::b...