// Does not compile
type A (a : int option, b : string option) =

    new a = A (a, None)
    new b = A (None, b)

    member __.X = ""


// Compiles
type A (a : int option, b : string option) =

    new (a) = A (a, None)
    new b = A (None, b)

    member __.X = ""