[Scala] Views example from Scala in Depth book

FileWrapper.scala

import FileWrapper.wrap

/**
 * Views example: converting one type to other.
 */
class FileWrapper(val file: java.io.File) {
  def /(next: String) = new FileWrapper(new java.io.File(file, next))
  override def toString = file.getCanonicalPath()
}

object FileWrapper {
  implicit def wrap(file: java.io.File) = new FileWrapper(file)
  implicit def unwrap(wrapper: FileWrapper) = wrapper.file
}

object MainFileWrapper {

  def main(args: Array[String]) {
    val cur = new java.io.File(".")

    val tempFile = cur / "temp.txt" //tempFile will be implicitly converted to FileWrapper
    useFile(tempFile) //tempFile will be implicitly converted to File
  }

  def useFile(file: java.io.File) = file.getCanonicalPath()
}