1.2.7 Abstract Interfaces

   An abstract interface is an entity, which may at runtime represent either a regular interface (see Section 1.2.5, “Interfaces,? on page 1-6) or a value type (see Section 1.2.6, “Value Types,? on page 1-6). Like an abstract value type, it is a pure bundle of operations with no state. Unlike an abstract value type, it does not imply pass-by-value semantics, and unlike a regular interface type, it does not imply pass-byreference semantics. Instead, the entity's runtime type determines which of these semantics are used.