Order of evaluation in C++ function parameters
If we have three functions (foo, bar, and baz) that are composed like so... foo(bar(), baz()) Is there any guarantee by the C++ standard that bar will be evaluated before baz? ...
c++
Input system reference trouble
Hello, I'm using SFML for input system in my application. size_t WindowHandle; WindowHandle = ...; // Here I get the handler sf::Window InputWindow(WindowHandle); const sf::Input *InputHandle = &InputWindow.GetInput(); // [x] Error At the last lines I have to get reference for the input system. Here is declaration of GetInput from...
Why can't I add pointers
Having very similiar code like so: LINT_rep::Iterator::difference_type LINT_rep::Iterator::operator+(const Iterator& right)const { return (this + &right);//IN THIS PLACE I'M GETTING AN ERROR } LINT_rep::Iterator::difference_type LINT_rep::Iterator::operator-(const Iterator& right)const {//substracts one iterator from another re...
Window Wrapper Class C++ (G++)
Hi all, I am attempting to learn about creating windows in c++, I have looked at an article about creating a wrapper class but I don't really understand it. So far I know that you can't have a class method WndProc (I dont know why) but honestly, that is all. Can somebody give an explanation, also explaining the reinterpret_cast? Here is ...
What good programming practices will change with C++0x?
For example, "Don't return objects by value if they are expensive to copy" (RVO can't always be used). This advice might change because of rvalue references. The same might be said about storing collections of pointers to objects, because copying them by value into the collection was too expensive; this reason might no longer be valid. ...
Init var without copy constructor
Hello, I have some class(Window) without copy constructor (it's private). I can't understand how to init var of this class in my own class: class MyClass { Window obj; // Hasn't copy constructor public: void init() { obj = Window(/* constructor params */); // [error] obj(/* constructor params */); // ...
how to get vendor id and product id of a plugged usb device on windows
Hello all, I am using Qt on windows platform. i want to get and display vendor id and product id of a plugged usb device from my local system. Below is my full source code to get the vendor id and product id from the usb device. when i run the my qt application it does not throw me any errors . so i plug the usb device into the sys...
Will C++0x support __stdcall or extern "C" capture-nothing lambdas?
Yesterday I was thinking about whether it would be possible to use the convenience of C++0x lambda functions to write callbacks for Windows API functions. For example, what if I wanted to use a lambda as an EnumChildProc with EnumChildWindows? Something like: EnumChildWindows(hTrayWnd, CALLBACK [](HWND hWnd, LPARAM lParam) { //...
C++ Inheritance and Constructors
Hello, trying to work out how to use constructors with an inherited class. I know this is very much wrong, I've been writing C++ for about three days now, but here's my code anyway: clientData.h, two classes, ClientData extends Entity : #pragma once class Entity { public: int x, y, width, height, leftX, rightX, topY, bottomY; Entit...
In C++, what happens when you return a variable?
What happens, step by step, when a variable is returned. I know that if it's a built-in and fits, it's thrown into rax/eax/ax. What happens when it doesn't fit, and/or isn't built-in? More importantly, is there a guaranteed copy constructor call? edit: What about the destructor? Is that called "sometimes", "always", or "never"? ...
Draw OpenGL on the windows desktop without a window
I've seen things like this and I was wondering if this was possible, say I run my application and it will show the render on whatever is below it. So basically, rendering on the screen without a window. Possible or a lie? Note: Want to do this on windows and in c++. ...
Portable way to hide console window in GLUT application?
Hey, I'm creating a little GLUT application and need help with hiding/removing the console window. I am developing on windows and I already know of the various methods to hide the console window on a windows system, however is there no portable method of hiding it? Thanks... ...
Handle complex options with Boost's program_options
I have a program that generates graphs using different multi-level models. Each multi-level model consists of a generation of a smaller seed graph (say, 50 nodes) which can be created from several models (for example - for each possible edge, choose to include it with probability p). After the seed graph generation, the graph is expande...
Qt cross thread call
I have a Qt/C++ application, with the usual GUI thread, and a network thread. The network thread is using an external library, which has its own select() based event loop... so the network thread isn't using Qt's event system. At the moment, the network thread just emit()s signals when various events occur, such as a successful connecti...
Getline and 16h (26d) character
Hi, in VC++ environment Im using (string) getline function to read separate lines in opened file. Problem is that getline takes character 1Ah as end of file and if it is present on the line, whole reading ends prematurely. Is there any solution for this? Code snippet: fstream LogFile (Source,fstream::in); string Line while (getline(L...
Using a member function with QScriptEngine::newFunction
Hey all, Let's take the case of a simple class: QScriptEngine engine; class MyClass { public: QScriptValue foo(QScriptContext*, QScriptEngine*); MyClass(); }; QScriptValue MyClass:foo(QScriptContext* context, QScriptEngine* eng) { //something } MyClass::MyClass() { QScriptValue self = engine.newFunction(this->foo, 0);...
Multi-reader IPC solution?
I'm working on a framework in C++ (just for fun for now), that lets the user write plugins that use a standard API to stream data between each other. There's going to be three basic transport mechanisms for the data: files, sockets, and some kind of IPC piping system. The system is set up so that for the non-file transport, each stream...
C++ meta-splat function
Is there an existing function (in boost mpl or fusion) to splat meta-vector to variadic template arguments? For example: splat<vector<T1, T2, ...>, function>::type // that would be the same as function<T1, T2, ...> My search have not found one, and I do not want to reinvent one if it already exists. Alternatively, is there a solutio...
How to use environment variable in #import c++ command?
Hello, nowadays I have this piece of code: #import "C:\Users\Public\SoundLog\DLLs\ForPython\SoundLogDLL.tlb" named_guids but I want to substitute the C:\Users\Public part by the %PUBLIC% environment variable. How can I do this ? ...
Doing extra initialisations on a MFC Dialog in Visual Studio C++ 2008 Pro
How do I make extra initializations on a modal dialog before calling DoModal(); ? The whole application is created using VS wizards. I have a main Dialog (the one that is created automatically when I select new MFC Application in Visual Studio 2008 Professional). When I click a button on this dialog I want to open another dialog and set...