Vector allocation

[high_flyer]

So what I am asking is there a way I can add data to the middle of the vector before adding real data to the beginning since I have reserved the space for the vector?

You mean so that the vector will increse in size?
Not that I know of.
Sound more as job for a linked list, not a vector.

TIP:
You will notice, that in the main key part of your keybard, on the right side there is a large button, with a "broken" arrow drawn on it - its called the "return" key.
It is there so that you can actually step to a start of a new line, not make your posts so hard to read, so please USE IT!

[marcel]

QVector is a dynamic generic container, therefore its size will grow to fit the contents.
When you use QVector::reserve(N) it does not mean that you actually have N elements in the vector.
It just means that the object just adjusted its backstore to hold N items( without any items actually being there ). So you must populate the vector after calling reserve(). You can do this by hand or you can use QVector::fill(const &T val, int size). This initializes the first "size" elements of the vector to val, BUT it also resizes the vector to size. So you can use this instead reserve.

Then, you can use QVector::insert(int index, const &T).


Regards

[Michiel]

I don't think he's talking about QVector. Just vector.

And I also think a linked list would be better suited for the job.

[wysota]

I don't think he's talking about QVector. Just vector.

reserve() works in a simmilar way for all std::vector-like implementations (including QVector).

And I also think a linked list would be better suited for the job.

It depends. The drawback of using a linked list is that accessing items in a non-sequential order is slower. If you know the size of the data array you need upfront, using vector or an arraylist (like QList) should be better.