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  1. object Main extends App {
  2.  
  3.   class A(val a: String) { override def toString = s"A: $a"}
  4.  
  5.   object A {
  6.     implicit val default: A = new A("A") //found by default
  7.   }
  8.  
  9.   object B {
  10.     def func(fn: => Int)(implicit a: A) = println(a)
  11.   }
  12.  
  13.   class Broken {
  14.     def doSomething = {
  15.       import Broken._ // or Broken.actual
  16.       B.func { 123 } // Uses A.default, not Broken.actual for implicit
  17.     }
  18.   }
  19.  
  20.   object Broken {
  21.     implicit val actual: A = new A("Broken")
  22.   }
  23.  
  24.   class Fixed {
  25.     def doSomething = {
  26.       import Fixed._
  27.       println(actual) //reference actual
  28.       B.func { 123 } // uses Fixed.actual
  29.     }
  30.   }
  31.  
  32.   object Fixed {
  33.     implicit val actual: A = new A("Fixed")
  34.   }
  35.  
  36.   object WTF {
  37.     implicit val actual: A = new A("WTF")
  38.   }
  39.  
  40.   class WTF {
  41.     def doSomething = {
  42.       import WTF._
  43.       B.func { 123 } // With object definition first this works without referencing actual
  44.     }
  45.   }
  46.  
  47.   (new Broken).doSomething
  48. }
Success #stdin #stdout 0.38s 382016KB
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A: Broken
https://ideone.com/oELulq
language:
Scala (scala 2.12.8)
created:
10 years ago
visibility:
public

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