RegexPattern.Options.isStrictSubset(of:)

Set *A* is a strict subset of another set *B* if every member of *A* is also a member of *B* and *B* contains at least one element that is not a member of *A*.

let employees: Set = ["Alicia", "Bethany", "Chris", "Diana", "Eric"] let attendees: Set = ["Alicia", "Bethany", "Diana"] print(attendees.isStrictSubset(of: employees)) // Prints "true"

// A set is never a strict subset of itself: print(attendees.isStrictSubset(of: attendees)) // Prints "false"

• Parameter other: A set of the same type as the current set.
• Returns: true if the set is a strict subset of other; otherwise, false.