spacepaste

compiles.ml

class c1 =
object
method m1 = 1
end
class c2 =
object
inherit c1
method m2 = 2
end
class c3 =
object
method m3 (x: c1) = x#m1
end
let () =
let i1 = new c1
and i2 = new c2
and i3 = new c3 in
let _ = i3#m3 i1, i3#m3 (i2 :> c1)
in ()

doesnt-compile.ml

class c1 =
object
method m1 = 1
end
class c2 =
object
inherit c1
method m2 = 2
end
class c3 =
object
method m3 (x: c1) = x#m1
end
let () =
let i1 = new c1
and i2 = new c2
and i3 = new c3 in
let _ = i3#m3 i1, i3#m3 i2
in ()