scala Weak Conformance

Weak Conformance

In some situations Scala uses a more general conformance relation. A type S weakly conforms to a type T, written S<:wT, if S<:T or both S and T are primitive number types and S precedes T in the following ordering.

Byte  <:w Short

Short <:w Int

Char  <:w Int

Int   <:w Long

Long  <:w Float

Float <:w Double

A weak least upper bound is a least upper bound with respect to weak conformance.

SCALA-DOC-TYPES