A PrefixInclusiveEvent helper type.

prefix_inclusive_event.swift

private enum PrefixInclusiveEvent<Output> {
	/// A signal that upstream should complete successfully after a predicate-failing value.
	case end

	/// A signal that the inner associated value either passed the predicate or is the first not to.
	case predicatePassingValueOrIncluded(Output)

	/// An [enumeration property](https://www.pointfree.co/episodes/ep52-enum-properties)
	/// to check if `self` is a `predicatePassingValueOrIncluded` event.
	var isPredicatePassingValueOrIncluded: Bool {
		guard case .predicatePassingValueOrIncluded = self else { return false }
		return true
	}

	/// An enumeration property for quick access to the output value, if present.
	var output: Output? {
		guard case let .predicatePassingValueOrIncluded(inner) = self else { return nil }
		return inner
	}
}