Original bug ID: 1582
Reporter: administrator
Status: closed
Resolution: not a bug
Priority: normal
Severity: minor
Category: ~DO NOT USE (was: OCaml general)

Bug description

Full_Name: Virgile Prevosto
Version: 3.06
OS: Linux (RH 7.2)
Submission from: 132.227.83.215 (132.227.83.215)

I don't know if it's really a bug or a feature of initializer (the explanation
given in the manual is quite short), but it has a weird behavior when combined
with multiple inheritance, especially when the inheritance graph has a 'diamond'
shape, as in the following example:

class root =
object
val mutable n = 1
initializer print_string "Initialization, pass "; print_int n;
print_newline(); n <- n+1
method get_n () = n
end

class foo =
object
inherit root
end

class bar =
object
inherit root
end

class foobar =
object
inherit bar
inherit foo
val mutable n = 3
method get_my_n ()= n
end

let y = new foobar;;
let x = y#get_n ();;
let z = y#get_my_n ();;

the output is the following:
Initialization, pass 1
Initialization, pass 1

val x : int = 2

val z : int = 3

It seems like
initializer is called twice, and each call uses a different instance variable
'n', whose initial value is 1 and which gets incremented (get_n returns 2).
Moreover, while get_n uses the same instance variable as one of the two
initializer, get_my_n uses the correct value, '3' which neither of the
initializer call seems to take into account.

E tutto per oggi, a la prossima volta
Virgile