trait Foo trait Bar { this: Foo => } trait NoBar { this: Foo => }
有没有办法可以欺骗类型系统禁止:
new Foo with Bar with NoBar {}
trait Foo trait Dummy[A] trait Bar extends Dummy[Bar]{ this: Foo => } trait NoBar extends Dummy[NoBar]{ this: Foo => } new Foo with Bar with NoBar {}
这会导致以下错误:
illegal inheritance; anonymous class $anon inherits different type instances of trait Dummy: Dummy[Bar] and Dummy[NoBar]