c++

Is there any tool to standardize format of C++ code?

Hello, all :) I'm looking for a tool that works on Windows to reformat some C++ code in my codebase. Essentially, I've got some code I wrote a while ago that I'd like to use, but it doesn't match the style I'm using in a more recent project. What's the best way to reformat C++ code in a standard manner? Billy3 ...

How to pause a program for a few milliseconds?

How to pause a program for a few milliseconds using C++ managed code? I tried Sleep() but it didn't work when I included the winbase.h file, I got lots of compile errors! for(int i=0; i<10; i++) { simpleOpenGlControl1->MakeCurrent(); System::Threading::Thread::Sleep(100); theta_rotated += 2.0* 3.141592653/(double)Model->size...

Qt phonon video player example C++ or python

Does anyone have a working example of a video player built using Qt phonon? (in C++ ) See my related question here . I am unable to build one using Python. ...

Operator + for matrices in C++

I suppose the naive implementation of a + operator for matrices (2D for instance) in C++ would be: class Matrix { Matrix operator+ (const Matrix & other) const { Matrix result; // fill result with *this.data plus other.data return result; } } so we could use it like Matrix a; Matrix b; Matrix c; c = a + b; ...

Reading in Russian characters (Unicode) using a basic_ifstream<wchar_t>

Is this even possible? I've been trying to read a simple file that contains Russian, and it's clearly not working. I've called file.imbue(loc) (and at this point, loc is correct, Russian_Russia.1251). And buf is of type basic_string<wchar_t> The reason I'm using basic_ifstream<wchar_t> is because this is a template (so technically, ba...

Is it possible to defer member initialization to the constructor body?

I have a class with an object as a member which doesn't have a default constructor. I'd like to initialize this member in the constructor, but it seems that in C++ I can't do that. Here is the class: #include <boost/asio.hpp> #include <boost/array.hpp> using boost::asio::ip::udp; template<class T> class udp_sock { public: ...

C++ thread safety - exchange data between worker and controller

I still feel a bit unsafe about the topic and hope you folks can help me - For passing data (configuration or results) between a worker thread polling something and a controlling thread interested in the most recent data, I've ended up using more or less the following pattern repeatedly: Mutex m; tData * stage; // temporary, ac...

Possible to distribute or parallel process a sequential program?

In C++, I've written a mathematical program (for diffusion limited aggregation) where each new point calculated is dependent on all of the preceding points. Is it possible to have such a program work in a parallel or distributed manner to increase computing speed? If so, what type of modifications to the code would I need to look into? ...

An interview question on conditional operator

I recently encountered with this question: How to reduce this expression: s>73?61:60;. The hint given was that Instead of using conditional operator we could use a simple comparison which will work fine. I am not sure but I think it is possible with some GCC extension,although I am unable to figure it out myself. EDIT:The whole expre...

How do you process a large data file with size such as 10G?

I found this open question online. How do you process a large data file with size such as 10G? This should be an interview question. Is there a systematic way to answer this type of question? ...

screenshots of covered/minimized windows

Hi, I have the following code to take screenshots of a window: HDC WinDC; HDC CopyDC; HBITMAP hBitmap; RECT rt; GetClientRect (hwnd, &rt); WinDC = GetDC (hwnd); CopyDC = CreateCompatibleDC (WinDC); hBitmap = CreateCompatibleBitmap (WinDC, rt.right - rt.left, //width rt.bottom - rt.top);//height SelectObject (CopyDC, hBitmap); //C...

An "About" message box for a GUI with Qt

QMessageBox::about( this, "About Application", "<h4>Application is a one-paragraph blurb</h4>\n\n" "Copyright 1991-2003 Such-and-such. " "For technical support, call 1234-56789 or see\n" "<a href=\"http://www.such-and-such.com\"&gt;http://www.such-and-such.com&lt;/a&gt;" ); This code is creating the About message box which I wa...

Integer to Character conversion in C

Lets us consider this snippet: int s; scanf("%c",&s); Here I have used int, and not char, for variable s, now for using s for character conversion safely I have to make it char again because when scanf reads a character it only overwrites one byte of the variable it is assigning it to, and not all four that int has. For conversion I ...

Bitmap manipulation in C++ on Windows

Hi, I have myself a handle to a bitmap, in C++, on Windows: HBITMAP hBitmap; On this image I want to do some Image Recognition, pattern analysis, that sort of thing. In my studies at University, I have done this in Matlab, it is quite easy to get at the individual pixels based on their position, but I have no idea how to do this in C...

Sort objects and polymorphism

Suppose I have a class A. And B and C are child of A. Class A has a generic algorithm for sorting arrays of type A, so that I could use it for B and C without writing again the algorithm for each. In the algorithm, sometimes I have to swap. The problem is that I can only see the objects as type A, and if I do: A aux = array[i] array[...

Get current time crossplatform in c++

Hello, How can I get current time (I need hours, minutes, seconds) crossplatform in c++? I saw here make structure of values but there are a lots of another stuff that I don't need. And memory is very important here. ...

C++ help with getline function with ifstream

So I am writing a program that deals with reading in and writing out to a file. I use the getline() function because some of the lines in the text file may contain multiple elements. I've never had a problem with getline until now. Here's what I got. The text file looks like this: John Smith // Client name 123...

How expensive is CreateThread()?

I'm just wondering exactly what factors affect how quickly createthread executes, and how long it has to live to make it "worth it". CONTEXT: Where in my game's loops should I spawn threads? ...

Qt - a QWidget that has a clickable hyperlink

Please tell me how to create a QLabel on the QWidget that has a text that you can click and browser will open the mentioned link. Please bring here a code snippet. Thanks! ...

In C++, where are static, dynamic and local variables stored? How about in C and Java?

In C++, where are static, dynamic and local variables stored? How about in C and Java? ...