Type does not have null as a proper value

Question

For the sample program:

type public MyClass(reasonForLiving:string) =
    member x.ReasonForLiving with get() = reasonForLiving

let classFactory () = MyClas         


        

Answer 1

Use the [] attribute:

[]
type public MyClass(reasonForLiving:string) =
    member x.ReasonForLiving with get() = reasonForLiving

By default, F# types do not allow null (thank heavens!). This attribute is useful for interop with other .NET languages and allows assignment/comparison with null.