title: Why does QtCreator complain about missing <algorithm>
body: <p>I can't compile anything in QtCreator - not even a standard QWidget example application. On compilation I get:<code>/usr/include/qt5/QtCore/qglobal.h:82: error: algorithm: No such file or directory</code> and it sets the cursor toline 82 in <code>global.h</code> at <code>#include &lt;algorithm&gt;</code> - why is this, what is missing on this machine?<br>
  <strong>UPDATE:</strong><br>
  What I did: I created a project using QtCreator on another computer which works &amp; compiles fine. I copied it to this one, tried to start it but get an error:<code>: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version</code>GLIBCXX_              3.4.21' not found (required by<code>- hence I then tried to recompiled it with the provided Makefile but I get a whole buch of errors (pages or errors). So My intention was to fire up</code>QtCreator` and see if i can compile it from within but no dough due to the above error....What's going on and how do I get things back in order?</p>