
Returns the offset (in bytes) of <tt>field</tt> relative to the start
of <tt>ct</tt>, which must be a <tt>struct</tt>. Additionally returns
the position and the field size (in bits) for bit fields.
</p>

<h3 id="ffi_istype"><tt>status = ffi.istype(ct, obj)</tt></h3>
<p>
Returns <tt>true</tt> if <tt>obj</tt> has the C&nbsp;type given by
<tt>ct</tt>. Returns <tt>false</tt> otherwise.
</p>
<p>
C&nbsp;type qualifiers (<tt>const</tt> etc.) are ignored. Pointers are
checked with the standard pointer compatibilit