These conversions may change the representation of <code>x</code>
and incur a run-time cost.
All other conversions only change the type but not the representation
of <code>x</code>.
</p>

<p>
There is no linguistic mechanism to convert between pointers and integers.
The package <a href="#Package_unsafe"><code>unsafe</code></a>
implements this functionality under
restricted circumstances.
</p>