.NET won't allow you to create a Nullable<T> where T is itself a nullable type. (And Nullable<T> is not itself nullable.) I'm not sure about all languages, but

.NET won't allow you to create a Nullable<T> where T is itself a nullable type. (And Nullable<T> is not itself nullable.) I'm not sure about all languages, but in C# code like that won't even compile. I agree, allowing a nullable wrapper around a (already inherently nullable) reference type would be a horrible misfeature. What language was that?