Hi, I have a project with two header files mainwindow.h and website.h. I want to access a method from website.cpp from inside mainwindow.cpp. I can access any function from inside mainwindow by doing Window w then doing w->function(); However, when the function finishes from inside the mainwindow the memory for w is erased. How do...
when I write a number to binary file, it won't display. but in case of a character, it does. why? how would you check to see if the file containing character is binary? ...
In Qt, when I use the QPixmap::grabWindow(hwnd,x,y,h,w) function, the coordinates are shifted slightly, when compared to the coordinates using the windows api functions GetCursorPos and GetWindowRect. i.e. (0,0) from the point of view of GetCursorPos and GetWindowRect is at the very top left of the toolbar at the top of the window. But...
I would like to 'shrink-to-fit' an std::vector, to reduce its capacity to its exact size, so that additional memory is freed. The standard trick seems to be the one described here: template< typename T, class Allocator > void shrink_capacity(std::vector<T,Allocator>& v) { std::vector<T,Allocator>(v.begin(),v.end()).swap(v); } The w...
Hi Everyone, I'm just wondering if it is a good idea to make a data structure like std::map< std::pair<int,int>,std::string > Just wondering how the pairs would be ordered internally... :S Thanks! ...
How does the following work? #include <limits> int main() { const int* const foo = &std::numeric_limits<int> ::digits; } I was under the impression that in order to take an address of a static const-ant member we had to physically define it in some translation unit in order to please the linker. That said, after looking at the prep...
My teacher for Advanced C++ has opened the class up for students to suggest whatever topics we want. What are some good advanced C++ topics to know? We've already covered: template metaprogramming the STL (obviously) introduction to the boost libraries Please give reasons for suggestions as well. ...
I am currently working on a project involving external merge-sort using replacement-selection and k-way merge. I have implemented the project in C++[runs on linux]. Its very simple and right now deals with only fixed sized records. For reading & writing I use (i/o)fstream classes. After executing the program for few iterations, I notic...
Greetings, My project structure is as follows: \- base (C static library) callbacks.h callbacks.c paint_node.c . . * libBase.a \-app (C++ application) main.cpp In C library 'base' , I have declared global-function-pointer as: in singleheader file callbacks.h #ifndef CALLBACKS_H_ #define CALLBA...
I'v created a text box and when it gets focus it sets the caret position to 0 rather than the end. I want to set it to the end. Thanks |Text Here -> Text Here| ...
//using namespace std; using std::ifstream; using std::ofstream; using std::cout; class Dog { friend ostream& operator<< (ostream&, const Dog&); public: char* name; char* breed; char* gender; Dog(); ~Dog(); }; im trying to overload the << operator. I'm also trying to practice good...
I want to create a search field that filters the items shown in a QListView. Basically the user could type in "foo" and only items with "foo" in the DisplayRole are shown. I already have a few ideas on how to do this, but thought I'd ask those more experienced than I. My idea would be to use some signals and slots to set a filter in t...
Hi I am learning C++ and at the very beginning used a Command-line... then I started using Xcode (and since then couldn't switch back to command line) and was just wondering some specific reasons/situations to use Command-line instead of IDE... ...
I am working with some code to create a triangle that moves with arrow keys. I want to create a second object that moves independently. This is where I am having trouble, I have created the second actor, but cannot get it to move. There is too much code to post it all so I will just post a little and see if anyone can help at all. ogl_t...
I am using Bode's formuala to calculate distance of nth planet from sun dist = (4 + 3*(2^(n-2)))/10 If I calculate the distance this way, I get the right values: dist[2] = ((4 + 3*1)/10.0) ; dist[3] = ((4 + 3*2)/10.0) ; dist[4] = ((4 + 3*4)/10.0) ; But doing it this way, gives me incorrect values: vector <double> dist(5); f...
I am adding new operator overloads to take advantage of c++0x rvalue references, and I feel like I'm producing a lot of redundant code. I have a class, tree, that holds a tree of algebraic operations on double values. Here is an example use case: tree x = 1.23; tree y = 8.19; tree z = (x + y)/67.31 - 3.15*y; ... std::cout << z; // prin...
Hi all, I have a .lib file, just wondering what compiler it's from: it begins with "!<arch>" ? Thanks ...
I try to inject the exception to thread using signals, but some times the exception is not get caught. For example the following code: void _sigthrow(int sig) { throw runtime_error(strsignal(sig)); } struct sigaction sigthrow = {{&_sigthrow}}; void* thread1(void*) { sigaction(SIGINT,&sigthrow,NULL); try { while(...
I want to open/start my application when a I click on a particular URL from the browser for Symbian OS Series60 5th edition.(So, if I click on a "station" Url, it will start my application & play through my player) Any possible way that I can get it to do this? ...
I have a few simple lines of code (below). [bp] indicates a breakpoint. for(int i=0;i<300;i++){} int i=0; cout<<i; [bp] for (i=0;i<200;i++){} When I debug this in visual studio, it tells me that i is equal to 300 on the breakpoint. Annoyingly, 0 is printed to the console. Is there any way to make it realize that two var...