Look at the following method

def toOption[T <: AnyRef](value: T | Null): Option[T] = 
    value match {
        case null => None
        case content: T => Some(content)
    }

If you inspect the content pattern variable, the type is T | T & Null, which I guess is the result of the the intersection of the type of the scrutinee value: T | Null and the type of the matched pattern element: T.

Shouldn’t the type T & Null be simplified to Null by the compiler when T<:AnyRef? What is the difference between the types Null and T & Null?

If the definition of the intersection A & B was that it represents values that are members of both A and B then:

• if the values represented by T included null then the values that are members of both T and Null would be only the null value;
• if the values represented by T did not include the null then the values that are members of both T and Null would be none (Nothing)
• List item

Therefore T & Null = Null | Nothing = Null

If the definition of the intersection A & B was that a value conforms to A & B implies that it conforms to both A and B then:

• if null conforms to T then only null would conform to both T and Null;
• if null does not conform to T then no value would conform to both T and Null.
• List item

Therefore T & Null = Null | Nothing = Null

Am I missing something or the compiler has a bug?