 support. Therefore, optimal performance
      comes from having both move-support, and expression templates enabled.
    </p>
<p>
      Note that while "moved-from" objects are left in a sane state, they
      have an unspecified value, and the only permitted operations on them are destruction
      or the assignment of a new value. Any other operation should be considered
      a programming error and all of our backends will trigger an assertion if any
      other operation is attempted. This behavior al