F# has guaranteed not-nullables, except when you do default<NotNullableThing> it returns null. That said, it generally works well in well-defined situations bu

F# has guaranteed not-nullables, except when you do default<NotNullableThing> it returns null. That said, it generally works well in well-defined situations but any time there's deserialization it's often a bigger mess than just never assuming not-null. I think it's a problem that needs to be solved in the CLR, not C#, and my guess is it probably never will be.