nversion
to Caml big arrays, and does not free them when the Caml bigarrays
become unreachable.</p><p>Finally, the <span class=machine><span class=font-tt>[unique]</span></span> attribute applies to bigarrays as to arrays,
that is, it maps a null C pointer to <span class=machine><span class=font-tt>None</span></span>, and a non-null C pointer
<span class=font-it>p</span> to <span class=machine><span class=font-tt>Some(</span></span><span class=font-it>v</span><span class=machine><span class=font-tt>)</span>