CODEWITHSUNDEEP
scalaimplicit-conversion
Suma
Suma

Reputation: 34423

How to check which implicits are ambiguous?

I have following implicit conversions defined, which helps me porting some Javascript code to Scala:

  case class NullableBoolean(value: Boolean)

  implicit def toNullable(boolean: Boolean) = NullableBoolean(boolean)
  implicit def toBoolean(boolean: NullableBoolean) = boolean != null && boolean.value

The code is then used like this:

class SomeClass {
  var x: NullableBoolean = _

  def set(v: Boolean): Unit = {
    x = v
  }

  def someOtherFunction(): Unit = {
    if (x) println("Yes")
    else print("No")
  }
}

val some = new SomeClass

some.someOtherFunction()
some.set(true)
some.someOtherFunction()

When used in a small sample everything works fine. However when used in the real project, I get error:

Error:(360, 16) type mismatch;

found : xxx.NullableBoolean

required: Boolean

 if (this.someValue) {

I suspect this is because of some other implicit conversion imported which makes the conversion ambiguous, but I am unable to find it. Is there some method or tool which would show me the eligible conversions or otherwise help me determining the ambiguity? I have tried IntelliJ Shift-Ctrl-Q, but it shows me only my conversion to Boolean and some conversions to String, which looks fine.

Upvotes: 0

Views: 57

Answers (1)

Th 00 mÄ s
Th 00 mÄ s

Reputation: 3826

Implicit conversions can not be ambiguous. The compiler would complain if there are multiple conversions in scope matching.

Can you confirm the toBoolean conversion is indeed in scope when calling this.someValue ?

Upvotes: 0

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