Is there any real reason why KO would not work ?
type IBase =
abstract member test : (unit * unit) -> unit
type OK() =
interface IBase with
member x.test ((titi,tata)) = () //OK
type KO() =
interface IBase with
member x.test (titi,tata) = () //fail : This override takes a different number of arguments to the corresponding abstract member
Because the parentheses mean something in F# (it indicates a tuple), so they're not the same.
As given, the test method is defined as a method that takes a tuple of two unit values as arguments. If you use Reflection to get the MethodInfo, the method is defined as:
Void test(System.Tuple`2[Microsoft.FSharp.Core.Unit,Microsoft.FSharp.Core.Unit])
That matches the OK method, but not the KO method.
If you redefine the interface to
type IBase =
abstract member test : unit * unit -> unit
Then OK doesn't compile, but KO does.
This alternative version produces a test method which takes two arguments:
Void test(Microsoft.FSharp.Core.Unit, Microsoft.FSharp.Core.Unit)