Aladdin - Scala Bugtracking
[#413] project: specification priority: low category: bug
submitter assigned to status date submitted
Iulian Martin _ 2005-04-04 17:05:26.0
subject mixin example doesn't compile
code 
class A { def f: Int = 1 ; def g: Int = 2 ; def h: Int = 3 } 
abstract class B { def f: Int = 4 ; def g: Int } 
abstract class C extends A with B { def h: Int }
what happened 
outer.scala:14: error overriding method f in class A;
 method f in class B needs `override' modifier
abstract class C extends A with B { def h: Int }
                                ^
outer.scala:14: error overriding method h in class A;
 method h in class C needs `override' modifier
abstract class C extends A with B { def h: Int }
                                        ^
what expected Silent compilation

This example appears at page 42 (Example 5.1.2).

The first "override" cannot be solved: adding an override modifier will trigger another error (" method f:scala.Int in class B overrides nothing").
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