
   ... // see above
};

// nvp objects are generally created on the stack and are never tracked
template&lt;class T&gt;
struct tracking_level&lt;nvp&lt;T&gt; &gt;
{
   ... // see above
};
#endif
</code></pre>
This can be problematic when one wants to make his code <strong>and archives</strong>
portable to other platforms.  It means the she objects will be serialized differently
depending on the platform used.  This implies that objects saved from one platform
won't be loaded properly on another.  In other 