c++

boost::shared_ptr<const T> to boost::shared_ptr<T>

I want to cast the const-ness out of a boost::shared_ptr, but I boost::const_pointer_cast is not the answer. boost::const_pointer_cast wants a const boost::shared_ptr, not a boost::shared_ptr. Let's forego the obligitory 'you shouldn't be doing that'. I know... but I need to do it... so what's the best/easiest way to do it? For clari...

need to get computer speaking to a cell phone

i have this super manual: http://www.arib.or.jp/IMT-2000/V710Dec08/5_Appendix/R99/27/27005-320.pdf i dont understand whether it is for every phone or just a certain subset i would like to know what i need to get started to have my computer speak to the phone i am ready to write in c#, c++, or what ever they need has anyone had exper...

C++ std::string and UTF-8

Hello, I just want to write some few simple lines to a text file in C++, but I want them to be encoded in UTF-8. What is the easiest and simple way to do so? Thanks ...

C++: use a #define in printf?

I was wanting to use a constant of some kind for the application ID (so I can use it in printf). I had this: #define _APPID_ "Hello World!" And then the simple printf, calling it into %s (string). It put this out: simple.cpp:32: error: cannot convert ‘_IO_FILE*’ to ‘const char*’ for argument ‘1’ to ‘int printf(const char*, ...)’ Wh...

Why is my slot not being called?

I have this class: class CustomEdit : public QTextEdit { Q_GADGET public: CustomEdit(QWidget* parent); public slots: void onTextChanged (); }; CustomEdit::CustomEdit(QWidget* parent) : QTextEdit(parent) { connect( this, SIGNAL(textChanged()), this, SLOT(onTextChanged())); } void CustomEdit::onTextChanged (...

How to get width and height of directshow webcam video stream

I found a bit of code that gets me access to the raw pixel data from my webcam. However I need to know the image width, height, pixel format and preferably the data stride(pitch, memory padding or whatever you want to call it) if its ever gonna be something other than the width * bytes per pixel #include <windows.h> #include <dshow.h> ...

Antialiasing algorithm?

I have textures that i'm creating and would like to antialias them. I have access to each pixel's color, given this how could I antialias the entire texture? Thanks ...

Replacement compiler for Qt Creator?

I like Qt Creator as an IDE, but the built-in compiler is slower than dirt. Can I replace it, and if so, with what? Developing on Windows but targeting multiple Mac as well. ...

C++ online Role Playing Game (RPG)

So I've been learning C++ and SDL to make some basic 2d games. I want to create a game sort of like World of Warcraft but a 2D version. I want it to be on-line and use a database or something to start data like amount of Gold, HP, etc. I was wondering though, if I do this in SDL, would it still work on-line or would the user have to down...

Sparse constrained linear least-squares solver

This great SO answer points to a good sparse solver for Ax=b, but I've got constraints on x such that each element in x is >=0 an <=N. Also, A is huge (around 2e6x2e6) but very sparse with <=4 elements per row. Any ideas/recommendations? I'm looking for something like MATLAB's lsqlin but with huge sparse matrices. I'm essentially try...

Command prompt print dialog command

Is there any way a C++ commandline program on Windows can produce a graphical GUI print dialog for printing to a printer, just like usual GUI programs? I've combed through this webpage and it seems there are only commands that print files in the background to a pre-determined printer. ...

Qt 101: Why can't I use this class?

I have experience with C++ but I've never really used Qt before. I'm trying to connect to a SQLite database, so I found a tutorial here and am going with that. In the QtCreator IDE, I went to Add New --> C++ Class and in the header file pasted in the header the header from that link and in the .cpp file I pasted the source. My main.cpp l...

Help with GetGlyphOutline function(WinAPI)

I want to use this function to get contours and within these contours, I want to get cubic bezier. I think I have to call it with GGO_BEZIER. What puzzles me is how the return buffer works. "A glyph outline is returned as a series of one or more contours defined by a TTPOLYGONHEADER structure followed by one or more curves. Eac...

Vector iterators in for loops, return statements, warning, c++

Had 3 questions regarding a hw assignment for C++. The goal was to create a simple palindrome method. Here is my template for that: #ifndef PALINDROME_H #define PALINDROME_H #include <vector> #include <iostream> #include <cmath> template <class T> static bool palindrome(const std::vector<T> &input) { std::vector<T>::const_iterat...

How can i list and watch all global variables on watch windows of visual studio (for c++)?

When stopped at a breakpoint on main(), i can manually add name of a global variables to watch windows, but what i want is how to show a list of all global variables, because i'm using an external library, which contains many static things. Is it possible? Thanks in advance! ...

Problem with late binding!

Hi everyone, i was asked this question in an interview. late binding is dynamically identifying the symbol during the runtime as far as my knowledge is concerned.please correct me if i am wrong. i was asked a question like what are some of the problem that we would face when we use late binding in c++. i was actually out of my own ide...

Initialize Pointer Through Function

I was browsing my teacher's code when I stumbled across this: Order* order1 = NULL; then order1 = order(customer1, product2); which calls Order* order(Customer* customer, Product* product) { return new Order(customer, product); } This looks like silly code. I'm not sure why, but the teacher initialized all pointers to NULL in...

Lots of pointer casts in QGraphicsView framework and performance

Since most of the convenience functions of QGraphicsScene and QGraphicsItem (such as items(), collidingItems(), childItems() etc.) return a QList you're forced to do lots of qgraphicsitem_cast or static_cast and QGraphicsItem::Type() checks to get hold of the actual items when you have lots of different type of items in the scene. I thou...

When should we use * , & , . , -> ?

Why are we using * character when we are creating button but we aren't adding it to app instance? #include <QApplication> #include <QPushButton> int main(int argc,char *argv[]) { QApplication app(argc,argv); QPushButton *button = new QPushButton("Button Text"); QObject::connect(button,SIGNAL(clicked()),&app,SLOT(quit())); ...

boost::asio buffer impossible to convert parameter from char to const mutable_buffer&

visual studio tells me "error C2664: 'boost::asio::mutable_buffer::mutable_buffer(const boost::asio::mutable_buffer&)': impossible to convert parameter 1 from 'char' to 'const boost::asio::mutable_buffer&' at line 163 of consuming_buffers.hpp" I am unsure of why this happen nor how to solve it(otherwise I wouldn't ask this ^^') but I th...