[Interest] Small survey on necessary Qt Container size

[A. Pönitz]

Hi all.

In order to base my potential arguments in a certain discussion on a
neighboring list not purely just on my own experience with both Qt and
(independently) large data (a.k.a. "gut feeling") I would appreciate
if /you/ could help me to find a - very rough, readily admitted in
advance to be completely unscientific - estimation for an answer to
the following question:

  How often do people /need/ /Qt/ containers with /more than
  1 billion elements/ ? 

The question is really meant as conjunction, i.e. I'd like to count
only setups meeting both criteria at the same time:

   1. /Some/ relevant data set is really > 1e9 entries,

   2. It really needs to be a /Qt/ container because of some Qt container
      feature (e.g. reference counting or e.g. because of Q(5)List's
      "indirect" storage etc) that a std:: container does not offer
      out-of-the-box and it /needs/ to be like that, i.e. there is no
      simple / straightforward replacement like using std::*, and
      benefits do not exceed drawbacks like more expensive write
      access.

Problems meeting only one of the two criteria won't count, but I'd
accept "Would have needed in the past, but since Qt < 6 didn't offer
it I had to go through big trouble and create a hand-crafted solution"
;-)

In case of proprietary/personal/otherwise non-disclosable examples
I'd be happy enough to get a private mail. In any case: Any feedback
is appreciated.

Andre'