/// <summary>
/// Indicates whether some other object is "equal to" this OptionalDouble. The
/// other object is considered equal if:
/// <ul>
/// <li>it is also an {@code OptionalDouble} and;
/// <li>both instances have no value present or;
/// <li>the present values are "equal to" each other via {@code Double.compare() == 0}.
/// </ul>
/// </summary>
/// <param name="obj"> an object to be tested for equality </param>
/// <returns> {code true} if the other object is "equal to" this object
/// otherwise {@code false} </returns>
public override bool Equals(Object obj)
{
if (this == obj)
{
return(true);
}
if (!(obj is OptionalDouble))
{
return(false);
}
OptionalDouble other = (OptionalDouble)obj;
return((IsPresent && other.IsPresent) ? Value.CompareTo(other.Value) == 0 : IsPresent == other.IsPresent);
}
/// <summary>
/// Constructs a {@code FindOp} for streams of doubles.
/// </summary>
/// <param name="mustFindFirst"> whether the {@code TerminalOp} must produce the
/// first element in the encounter order </param>
/// <returns> a {@code TerminalOp} implementing the find operation </returns>
public static TerminalOp <Double, OptionalDouble> MakeDouble(bool mustFindFirst)
{
return(new FindOp <>(mustFindFirst, StreamShape.DOUBLE_VALUE, OptionalDouble.Empty(), OptionalDouble::isPresent, FindSink.OfDouble::new));
}
