ベタなLoanパターン

Loan.scala

object Loan {

  def using[A <: { def close() }, B](resource: A)(func: A => B): B =
    try {
      func(resource)
    } finally {
      if (resource != null) resource.close()
    }

}

using(new FileInputStream("hoge.txt")){ fis =>
  fis.read(...)
}