[Caml-list] Magic with fun (type t) ... ?

[Jim Pryor <lists+caml@jimpryor.net>]

I expect this is bad coding style, and should not be relied on. However,
I was surprised at the behavior, and wondered whether it was intended:

# let f = fun (type t) x ->
    let module M = struct exception E of t end in
    M.E x;;
val f : 'a -> exn = <fun>

f is polymorphic, as we expect:

# f 1;;
- : exn = E 1
# f "s";;
- : exn = E "s"

But now notice:

# f ();;
- : exn = E 0
# f None;;
- : exn = E 0

It appears that non-heap values are always getting magicked into ints.

Has this been noted before?

-- 
Jim Pryor
profjimm@jimpryor.net