v class="indent">
Checks function input values.
</div>

<p>
<tt>%typemap(default)</tt>
</p>

<div class="indent">
Set a default value for an argument (making it optional).
</div>

<p>
<tt>%typemap(arginit)</tt>
</p>

<div class="indent">
Initialize an argument to a value before any conversions occur.
</div>

<p>
Examples of these methods will appear shortly.
</p>

<H3><a name="Tcl_nn37">37.7.3 Typemap variables</a></H3>


<p>
Within typemap code, a number of special variables prefaced with a <tt>$</tt> may 