Removes the given element and all elements subsumed by it.
In the following example, the .priority shipping option is removed from
the options option set. Attempting to remove the same shipping option
a second time results in nil, because options no longer contains
.priority as a member.
var options: ShippingOptions = [.secondDay, .priority]
let priorityOption = options.remove(.priority)
print(priorityOption == .priority)
// Prints "true"
print(options.remove(.priority))
// Prints "nil"
In the next example, the .express element is passed to remove(_:).
Although .express is not a member of options, .express subsumes
the remaining .secondDay element of the option set. Therefore,
options is emptied and the intersection between .express and
options is returned.
let expressOption = options.remove(.express)
print(expressOption == .express)
// Prints "false"
print(expressOption == .secondDay)
// Prints "true"
- Parameter member: The element of the set to remove.
- Returns: The intersection of [member] and the set, if the
intersection was nonempty; otherwise, nil.
Removes the given element and all elements subsumed by it.
In the following example, the
.priorityshipping option is removed fromthe
optionsoption set. Attempting to remove the same shipping optiona second time results in
nil, becauseoptionsno longer contains.priorityas a member.var options: ShippingOptions = [.secondDay, .priority]
let priorityOption = options.remove(.priority)
print(priorityOption == .priority)
// Prints "true"
print(options.remove(.priority))
// Prints "nil"
In the next example, the
.expresselement is passed toremove(_:).Although
.expressis not a member ofoptions,.expresssubsumesthe remaining
.secondDayelement of the option set. Therefore,optionsis emptied and the intersection between.expressandoptionsis returned.let expressOption = options.remove(.express)
print(expressOption == .express)
// Prints "false"
print(expressOption == .secondDay)
// Prints "true"
- Parameter member: The element of the set to remove.
- Returns: The intersection of
[member]and the set, if theintersection was nonempty; otherwise,
nil.