IntegerTypeArrayExtension.swift

import Foundation

extension Array where Element : IntegerType {
    var sum: Element {
        return reduce(0, combine: +)
    }

    var odds: [Element] {
        return filter { $0 % 2 != 0 }
    }

    var evens: [Element] {
        return filter { $0 % 2 == 0 }
    }

    func every(n: Element) -> [Element] {
        var count : Element = 0
        return filter { _ in count++ % n == 0 }
    }
}