mapFilterswift

extension Array {

    func mapFilter<U>(transform: (T) -> U?) -> [U] {
        var array: [U] = []

        for element in self {
            if let mapped: U = transform(element) {
                array.append(mapped)
            }
        }

        return array
    }
}

unshift.swift

extension Array {

    mutating func unshift(match: T -> Bool) {

        for index in 0...self.count {
            var item = self[index]

            if match(item) {
                self.removeAtIndex(index)
                self.insert(item, atIndex: 0)
                break
            }
        }
    }
}

This should be called filterNot