hite-space: normal">my_class</code> should be serialized along with its version number:
<pre><code>
BOOST_CLASS_IMPLEMENTATION(my_class, boost::serialization::object_class_info)
</code></pre>
If implementation level is not explicitly assigned, the system uses
a default according to the following rules.
<ul>
  <li>if the data type is <code style="white-space: normal">volatile</code> 
assign <code style="white-space: normal">not_serializable</code>
  <li>else if it's an enum or fundamental type assign <code s