t7290.scala:4: warning: Pattern contains duplicate alternatives: 0
    case 0 | 0 => 0
         ^
t7290.scala:5: warning: Pattern contains duplicate alternatives: 2, 3
    case 2 | 2 | 2 | 3 | 2 | 3 => 0
         ^
t7290.scala:6: warning: Pattern contains duplicate alternatives: 4
    case 4 | (_ @ 4) => 0
         ^
error: No warnings can be incurred under -Xfatal-warnings.
three warnings found
one error found