ass=syntax-token>c2ml(</span><span class=nonterminal>funct-name</span><span class=syntax-token>)</span> <span class=nonterminal>and</span> <span class=machine><span class=font-tt>ml2c(</span></span>funct-name<span class=machine><span class=font-tt>)</span></span> attributes are
given, the user-provided C functions given as attributes will be
called to perform Caml to C and C to Caml conversions for values of
the typedef-ed type, instead of using the <span class=machine><span class=font-tt>camlidl</span></sp