 no way to know where
they came from.  Therefore, the ownership is set to zero.  For example:
</p>

<div class="code">
<pre>
class Foo {
public:
  ...
  Foo *spam();
  ...
};
</pre>
</div>

<br>

<div class="code">
<pre>
% Foo f
% set s [f spam]
% $s cget -thisown
0
% 
</pre>
</div>

<p>
This behavior is especially important for classes that act as
containers.  For example, if a method returns a pointer to an object
that is contained inside another object, you definitely don't want
Tcl to assume ownership a