* Goswin von Brederlow:
> - I create a 3 tupple exp
> - fill it with (Val_int(errno), caml_copy_string("MD5.file"), filename)
> - call caml_raise_with_arg(tag, exp)
This raises an exception with a parenthesized tuple ("exception E of
(int * string * string)", IOW a single-argument exception which takes
a triple as argument.