Partition.swift

extension Array {
    func partition(predicate: (Element) -> Bool) -> ([Element],[Element]) {
        var res = (satisfy:[Element](),notSatisfy:[Element]())
        self.forEach { element in
            if predicate(element){
                res.satisfy.append(element)
            } else {
                res.notSatisfy.append(element)
            }
        }
        return res
    }
}