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泛型函数中的隐式转换

scala-implicits implicits implicit implicit-conversion scala

0

Álvaro Valencia · 技术社区 · 8 年前

  def convertAny[T](any: Any)(implicit run: Any => Option[T]) = run.apply(any)
  implicit def anyToDouble(any: Any) = Try(any.asInstanceOf[Double]).toOption
  implicit def anyToInt(any: Any) = Try(any.asInstanceOf[Int]).toOption

问题是我需要在像这样的通用函数中进行这些转换:

  def doStuffAndConvert[T](i: Any): Option[T] = {
    // Some pre-processing
    println("Processing data...")

    convertAny[T](i)
  }

doStuffAndConvert 以下内容:

doStuffAndConvert[Double](a)

Error:(40, 18) No implicit view available from Any => Option[T].
    convertAny[T](i)

我试图通过包装int和double类型并绑定 T

我怎么修?

1 回复 | 直到 8 年前

1

2

Alexey Romanov 8 年前

convertAny doStuffAndConvert

def doStuffAndConvert[T](i: Any)(implicit run: Any => Option[T]): Option[T] = {
  // Some pre-processing
  println("Processing data...")

  convertAny[T](i) // or just i, the implicit will be used anyway
}

含蓄的像 anyToDouble/Int