An annotation that designates that overriding a member is deprecated.

Overriding such a member in a sub-class then generates a warning.

Library authors should state the library's deprecation policy in their documentation to give developers guidance on when a method annotated with@deprecatedOverriding will befinalized.

Library authors should prepend the name of their library to the version number to help developers distinguish deprecations coming from different libraries:

class Foo {  @deprecatedOverriding("this method will be made final", "FooLib 12.0")  def add(x: Int, y: Int) = x + y}

class Bar extends Foo // no deprecation warningclass Baz extends Foo {  override def add(x: Int, y: Int) = x - y}// warning: overriding method add in class Foo is deprecated (since FooLib 12.0): this method will be made final// override def add(x: Int, y: Int) = x - y//              ^