Swift map(_:) extension for Set() ?

Question

  let numberSet = Set(1...11)
  let divideSet = numberSet.map({  $0 / 10 }) 
  //Error: Set does not have a member named map   :(

Swift 1.2 support

Answer 1

I made an extension for Set:

extension Set {

    /// Map, but for a `Set`.
    /// - Parameter transform: The transform to apply to each element.
    func map(_ transform: (Element) throws -> T) rethrows -> Set {
        var tempSet = Set()

        try forEach {
            tempSet.insert(try transform($0))
        }

        return tempSet
    }
}

For example:

let someSet: Set = [1, 3, 5, 7]
print(someSet.map { $0 + 1 })

// Prints:  [2, 6, 8, 4]