Search:

Thanks, I'll look into all this!

Thanks, I think I understand this now. So storing a vector of pointers will retain the derived object, rather than slicing it to the base object, which enables me to call the derived function via the...

Hi,

Thanks for the responses. The reason I am writing this code is that I am writing a GUI, which has a set of buttons. But there are several different types of buttons. So, I have a "Button"...

Hello,

I have a simple question about inheritance. Consider the following code:




Class Base
{
int type;

Hello,

I am very new to database with C#, so hopefully this will just be a quick one.

I'm trying to create a new SQL database with Visual Studio 2013, with one table. I am following a tutorial,...

Hello,

When running my code in Visual Studio, there is a particular point in the code where my program is crashing. To debug this, I am adding a break point in Debug mode just before that point,...

Hello,

If I have a one-dimensional array of length 10, vector<int> x, and I want to assign all the elements to value 5, then I can do the following:



vector<int> x(10);
x.assign(10, 5);

Hello,

I am just wondering what the best practice is for when to use static classes (by static class, I mean a class which has only static attributes and functions).

If you are creating more...

Hello,

I have a very general question about object-orientation programming. I have been programming for a few years, but I'm just wondering what the best practice is for this particular situation....

Hello,

I have a Visual Studio 10 Project, and I want to rename both the Project, and the Solution. To do this so far, I have right-clicked on the Project or Solution in the Solution Explorer, then...

Hello,

I want to edit the contents of a file using fstream, but none of the modes in the fstream constructor work for me.

If I use ios::trunc, then the whole file is deleted - but I want to...

Hello,

This is not strictly a C++ question, but I don't know where else to ask!

Anyway, I am writing a program to read and write EXIF data in a JPEG file; specifically, the GPS data.

I have...

Hello,

I'm hoping that there is somebody out there who is familiar with OpenCV, as I have a very simple problem.

I have a linear equation Ax = B which I want to solve. This is done with the...

Hello,

I have a library that I want to link to with Visual Studio 10. It is a dynamic-link library, with a .dll file and a .lib file. I am following what I think is the correct procedure for...

Hello,

I have a fairly basic question about compiling libraries. Suppose that I want to use an open-source library that has been written by somebody else. Typically, when I go to the website to...

But is it possible to write the vector.size() value at the beginning of the file, after I've written the rest of the file?

The reason I need that piece of code is because I need to read the last entry in the data file, before I read the rest of the file. When creating the file, I am adding numbers from an array to the...

Hi,

Thanks for your help. Losing the ios::app worked!

However, I have also come across something else peculiar.

If I use:


in.seekg(-(sizeof(int)), ios::end);

Hello,

I am saving data to a file "myfile.dat". Every time I save new data, I want to eliminate the existing file and start a new file. From what I know, setting the ios::trunc flag should do...

Hi, thanks for your reply. The Wikipedia article states that:

"the Perron–Frobenius theorem ... asserts that a real square matrix with positive entries has a unique largest real eigenvalue and...

Hello,

I am trying to use the GNU Scientific Library (GSL) to compute the leading eigenvector (corresponding to the largest eigenvalue) of a matrix M of size N (N ~ 100). M is square and...

Hello,

I am using a computer vision C++ library called OpenCV, which has a function "int waitKey(int delay)". This function waits for a user input key, for a specified number of milliseconds. It...

Hello,

I am running Windows 7 on a Mac, using Apple's Bootcamp utility, such that the Windows installation is native. However, I am finding some issues when programming the Windows API using...

Hello,

What is the difference between the header files <header.h> and <header>?

I know that the <...> brackets indicate that the header file is located in some standard directory that the...

Hello,

I'd like to ask two different questions on a related topic please...

1. When I am writing float data to a text file, I want to set the precision. I know that with std::cout, you can...