[Qt-interest] How to clear QVector without releasing memory?

[Nikos Chantziaras]

On 06/20/2011 06:16 PM, Atlant Schmidt wrote:
> Nikos:
>
>    (You switched from talking about resize() to reserve();
>    I'll assume that's a typo.)

No, I did mean reserve().  Because that's what you're using to guarantee 
a certain vector capacity and thus memory allocation.


>
>    Here's the description for resize() (from the Qt 4.7.1 docs):
>
>      void QVector::resize ( int size )
>
>      Sets the size of the vector to size. If size is
>      greater than the current size, elements are added
>      to the end; the new elements are initialized with
>      a default-constructed value. If size is less than
>      the current size, elements are removed from the end.
>
>      See also size().
>
>
>    It seems to me that there's no promise that this clears
>    existing elements in the vector (except that elements
>    at the end will be destroyed if you're shortening the
>    vector). In fact, the behaviour when the new size ==
>    the existing size is completely unspecified!

What do you mean with "clears existing elements".  How can you "clear" 
an element?  This is not an operation I'm familiar with.