SafetyTier...<(_:)

Use the prefix half-open range operator (prefix `..<) to create a partial range of any type that conforms to theComparableprotocol. This example creates aPartialRangeUpTo<Double>instance that includes any value less than5.0`.

let upToFive = ..<5.0

upToFive.contains(3.14) // true upToFive.contains(6.28) // false upToFive.contains(5.0) // false

You can use this type of partial range of a collection's indices to represent the range from the start of the collection up to, but not including, the partial range's upper bound.

let numbers = [10, 20, 30, 40, 50, 60, 70] print(numbers[..<3]) // Prints "[10, 20, 30]"

• Parameter maximum: The upper bound for the range.
• Precondition: maximum must compare equal to itself (i.e. cannot be NaN).