title: std::map: can it copy and move keys after they have been inserted?
body: <p>In other words, is it safe to store pointers to keys from a map? Or is it possible for the map to copy and move keys during its lifetime, thus invalidating existing pointers?</p>
  
  <p>The docs say: "Iterator validity: No changes." Does that mean the answer to my question is "no, they cannot be copied or moved"?</p>