p (we cannot write the
    data again). A unique owner may decide to make the data shared
    (giving up mutation rights on it), but shared data may not become
    uniquely-owned again.</p>

<p><code class="code">unsafe_to_string&nbsp;s</code> can only be used when the caller owns the byte
   sequence <code class="code">s</code> -- either uniquely or as shared immutable data. The
   caller gives up ownership of <code class="code">s</code>, and gains ownership of the
   returned string.</p>

<p>There are two