title: Qt: what class should I use for matrices instead of QMatrix?
body: <p>The documentation for QMatrix says it's obsolete and is strongly unadvised to use. Ok, but what should I use instead to store a matrix?<br>
  I have even posted a bug report on the <a href="https://bugreports.qt-project.org/browse/QTBUG-25430" rel="nofollow">Qt Documentation Bug tracker</a> but they didn't respond.</p>