pan> or big array,
in which case they are added to the inputs of the function only.
(The reason for this exception is that byte arrays and big arrays are
shared between Caml and C, thus allowing true <span class=machine><span class=font-tt>in,out</span></span> behavior on the
Caml function parameter, while other data types are copied during
Caml/C conversion, thus turning a C <span class=machine><span class=font-tt>in,out</span></span> parameter into a Caml
<span class=machine><span class=font-tt>copy in, c