loc(nbytes);</PRE><P STYLE="margin-bottom: 0.51cm">
The entire <I>arg_hdr</I> structure must be populated by the
constructor, including the pointers to the appropriate callback
functions, the enclosing <I>arg_xxx</I> structure (<I>void *parent</I>),
and the private data structure (<I>void *priv</I>). 
</P>
<PRE CLASS="western">result-&gt;hdr.flag      = ARG_HASVALUE;                  /* argument accepts a value */
result-&gt;hdr.shortopts = shortopts;                     /* short options */
result-&gt;hdr.l