如何覆盖隐式值? [英] How to override an implicit value?

问题描述

假设我有代码:

class A(implicit s:String = "foo"){println(s)}

object X {
   implicit val s1 = "hello"
}
object Y {
   import X._
   // do something with X
   implicit val s2 = "hi"
   val a = new A
}

我得到了错误:

<console>:14: error: ambiguous implicit values:
 both value s2 in object Y of type => String
 and value s1 in object X of type => String
 match expected type String
           val a = new A

有什么办法可以告诉Scala在Y中使用值s2? (如果我将s2重命名为s1，它可以按预期工作，但这不是我想要的.)

Is there any way I can tell Scala to use the value s2 in Y? (if I rename s2 to s1, it works as expected but that is not what I want).

另一种解决方案是不执行import X._，这也是我试图避免的事情.

Another solution is to not do import X._, again something I'm trying to avoid.

推荐答案

您可以做的另一件事是导入除s1:import X.{s1 => _, _}之外的所有内容.

Another thing you can do is to import everything but s1: import X.{s1 => _, _}.

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