dot/trpl17-08.dot

digraph {
   rankdir = LR;
   overlap = false;
   dpi = 300.0;
   splines = false;
   cluster = true;
   newrank = true;
   outputorder = in;
   compound = true;
   labelloc = "c";
   
   node [shape = "plaintext";];
   
   pinned_box [label = <<table border="0" cellborder="1" cellspacing="0">
      <tr><td sides="B">Pin</td></tr>
      <tr><td port="source"> </td></tr>
      </table>>;];
   
   
   subgraph cluster_deref {
      style = dashed;
      label = "String";
      
      pin [shape = "point";];
      
      fut [label = <<table border="0" cellborder="1" cellspacing="0">
         <tr><td port="target">5usize</td>
         <td>h</td>
         <td>e</td>
         <td>l</td>
         <td>l</td>
         <td>o</td></tr>
         </table>>;];
   }
   
   edge [tailclip = false;];
   pinned_box -> pin [tailport = "source:c"; arrowhead = "none";];
   pin -> fut [headport = "target";];
}