About invalidating iterators
<p>STL containers have the problem that iterators can be invalidated when the container changes.  Would it be possible for the container to announce that it has changed by adding a call has_changed()?  </p>

<p>It is common to query empty() before certain operations.  If the container set a bool on operations that would affect iterators like insert() or erase() then it would be possible to query has_changed() before reusing an iterator.  </p>

<p>Crazy?</p>

<p><strong>EDIT</strong>  Thanks for a bunch of good replies and food for thought. I wish I could award more than one winner.</p>
