">T</code>, The default definition 
of <code style="white-space: normal">boost::serialization::version&lt;T&gt;::value</code> is 0. 
If we want to assign a value of 2 as the version for class <code style="white-space: normal">my_class</code>
we specialize the version template:
<pre><code>
namespace boost { 
namespace serialization {
struct version&lt;my_class&gt;
{
    BOOST_STATIC_CONSTANT(unsigned int, value = 2);
};
} // namespace serialization
} // namespace boost
</code></pre>
Now whenever the version 