ad pointer, you may get a segmentation
fault or access violation.
</p>

<p>
When a member of a structure is itself a structure, it is handled as a
pointer.  For example, suppose you have two structures like this:
</p>

<div class="code">
<pre>
struct Foo {
  int a;
};

struct Bar {
  Foo f;
};
</pre>
</div>

<p>
Now, suppose that you access the <tt>f</tt> attribute of <tt>Bar</tt> like this:
</p>

<div class="code">
<pre>
% Bar b
% set x [b cget -f]
</pre>
</div>

<p>
In this case, <tt>x</tt> is a pointer t