ericdke

let arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]

extension Array {
    func splitBy(subSize: Int) -> [[Element]] {
        return 0.stride(to: self.count, by: subSize).map { startIndex in
            let endIndex = startIndex.advancedBy(subSize, limit: self.count)
            return Array(self[startIndex ..< endIndex])
        }
    }
}