Changing the reserve memory of C++ vector

Question

I have a vector with 1000 \"nodes\"

 if(count + 1 > m_listItems.capacity())
     m_listItems.reserve(count + 100);

The problem is I also

Answer 1

vector(m_listItems).swap(m_listItems);

will shrink m_listItems again: http://www.gotw.ca/gotw/054.htm (Herb Sutter)

If you want to clear it anyway, swap with an empty vector:

vector().swap(m_listItems);

which of course is way more efficient. (Note that swapping vectors basicially means just swapping two pointers. Nothing really time consuming going on)