@internal class Double {
  @internal fun toInt() -> Int;
  @internal fun toLong() -> Long;
  @internal fun toFloat() -> Float;
  @internal fun toString() -> String;

  @internal fun asLong() -> Long;

  @internal fun equals(rhs: Double) -> Bool;
  @internal fun compareTo(rhs: Double) -> Int;

  @internal fun plus(rhs: Double) -> Double;
  @internal fun minus(rhs: Double) -> Double;
  @internal fun times(rhs: Double) -> Double;
  @internal fun div(rhs: Double) -> Double;

  @internal fun unaryPlus() -> Double;
  @internal fun unaryMinus() -> Double;

  @internal fun isNan() -> Bool;
  @internal fun sqrt() -> Double;

  fun hash() -> Int = self.asLong().toInt();
}