编译器构造 – Scala：比较新鲜对象

这是测试’输出：
http://lampsvn.epfl.ch/trac/scala/browser/scala/trunk/test/files/neg/checksensible.check

例：

checksensible.scala:12: warning: comparing a fresh object using `!=' will always yield true
println(new Exception() != new Exception())
                        ^

如果我编写一个实现==方法的类,它也会产生这个警告：

class Foo(val bar: Int) {
    def ==(other: Foo) : Boolean = this.bar == other.bar
}

new Foo(1) == new Foo(1)

warning: comparing a fresh object using `==' will always yield false

编辑：谢谢oxbow_lakes,我必须覆盖equals方法,而不是==

class Foo(val bar: Int) {
    override def equals(other: Any) : Boolean = other match { 
        case other: Foo => this.bar == other.bar
        case _ => false
    }
}