So I'm trying to learn C++ and I've gotten as far as using header files. They really make no sense to me. I've tried many combinations of this but nothing so far has worked: Main.cpp: #include "test.h" int main() { testClass Player1; return 0; } test.h: #ifndef TEST_H_INCLUDED #define TEST_H_INCLUDED class testClass { ...
Let's say I have a loop like this: vector<shared_ptr<someStruct>> vec; int i = 0; while (condition) { i++ shared_ptr<someStruct> sps(new someStruct()); WCHAR wchr[20]; memset(wchr, i, 20); sps->pwsz = wchr; vec.push_back(sps); } At the end of this loop, I see that for each sps element of the vector, sps-...
I use to write code like this: void fun(char *buff, unsigned size) { std::strstream str(buff, size); str << "hello world: " << 5; } so I can use stream output over an arbitrary buffer. I've found this technique both efficient (no allocations) and useful (streams!). Now that std::strstream is deprecated, how can I get the same ...
Hello! I recently started investigating Qt for myself and have the following question: Suppose I have some QTreeWidget* widget. At some moment I want to add some items to it and this is done via the following call: QList<QTreeWidgetItem*> items; // Prepare the items QTreeWidgetItem* item1 = new QTreeWidgetItem(...); QTreeWidgetItem* ...
Alright, I have a question, I veered away from using strings for selection so now I use an integer. When the user enters a number then the game progresses. If they enter a wrong character it SHOULD give the else statement, however if I enter a letter or character the system goes into an endless loop effect then crashes. Is there a way to...
I've got a screen-aligned quad, and I'd like to zoom into an arbitrary rectangle within that quad, but I'm not getting my math right. I think I've got the translate worked out, just not the scaling. Basically, my code is the following: // // render once zoomed in glPushMatrix(); glTranslatef(offX, offY, 0); glScalef(?wtf?, ?wtf?, 1.0f...
I have a struct that contains pointers: struct foo { char* f; int* d; wchar* m; } I have a vector of shared pointers to these structs: vector<shared_ptr<foo>> vec; vec is allocated on the stack. When it passes out of scope at the end of the method, its destructor will be called. (Right?) That will in turn call the destr...
Hello, I am Patrick Niedzielski, a programmer for the Free Software 3D adventure game Humm and Strumm. I'm working on a minimal Unicode character class in C++. I currently have an array of four bytes representing a UTF-8 sequence. On GNU/Linux, I can just convert to UTF-32 with iconv(), but on Windows, I cannot do this. Is it possib...
#include <iostream> using namespace std; int main() { short int enterVal; cout << "enter a number to say: " << endl; cin >> enterVal; system("say "%d"") << enterVal; return 0; } Is what I am currently trying. I want the user to enter a number and the system() function says it basically. The code above has an erro...
Hello, I have a Visual Studio 2003 solution that I've opened with VS2008, and it converted successfully. However, it won't build because the code contains some things that were acceptable under Visual Studio 2003, but simply don't fly under Visual Studio 2008. Changing the code would be really difficult in my particular situation. Is th...
I want to try writing my own BigInt Class so I am wondering what would be the most efficient way to find the last digit of a number in C, especially for an input that would be an extremely large int. ...
I'm trying to create a WCHAR: LONG bufferSize = foo.bar() + 1; WCHAR wszBaz[bufferSize]; The compiler issues an error: error C2057: expected constant expression error C2466: cannot allocate an array of constant size 0 error C2133: 'wszBaz' unknown size What am I doing wrong? UPDATE: I added const but it still gives the same error:...
Is it possible to tell the Qt MOC that I would like to declare the class and implement it in a single file rather than splitting them up into an .h and .cpp file? ...
I want to be able to access the sign bit of a number in C++. My current code looks something like this: int sign bit = number >> 31; That appears to work, giving me 0 for positive numbers and -1 for negative numbers. However, I don't see how I get -1 for negative numbers: if 12 is 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0...
I have a simple program which I have compiled in both MinGW and Visual C++ 2008 Express, and both give an output file larger than 88200. When I set s = 0, both programs work as expected. What am I doing wrong? #include <fstream> using namespace std; int main(int argc, char *argv[]) { int i; short s; fstream f; f.op...
In a lot of C++ API'S (COM-based ones spring to mind) that make something for you, the pointer to the object that is constructed is usually required as a ** pointer (and the function will construct and init it for you) You usually see signatures like: HRESULT createAnObject( int howbig, Object **objectYouWantMeToInitialize ) ; -- bu...
I keep getting an error on visual studio that says list iterator not decrementable: line 256 My program works fine on Linux, but the Visual Studio compiler throws this error. Anyway, do you see what my problem is? #include <iostream> #include <fstream> #include <sstream> #include <list> using namespace std; int main(){ /** crea...
I have some verticies and then I apply a glrotate(). I'd want to now what my verticies became after this transformation. How could I do this? Thanks ...
I'm sure there's not just 1 answer to this but, do game engines actually change the vectors in memory, or use gltransformations? Because pushing and popping the matrix all the time seems inefficient, but if you keep modifying the verticies you cant make use of display lists. So I'm wondering how it's done in general. Thanks ...
Windows provides encoding conversion functions ("MultiByteToWideChar" and "WideCharToMultiByte") which are capable of UTF-8 to/from UTF-16 conversions, among other things. But I've seen people offer home-grown 30 to 40 line functions that claim also to perform UTF-8 / UTF-16 encoding conversions. My question is, how reliable are such t...