Convertto 2d array with raw cout or group by key

Array++.swift

extension Array {

    func convertTo2DArray(rawCount: Int) -> [[Element]] {
        let array = stride(from: 0, to: self.count, by: rawCount).map { (index) -> [Element] in
            if (index + rawCount) > self.count {
                return Array(self[index...])
            } else {
                return Array(self[index..<index + rawCount])
            }
        }
        return array
    }

    func group<GroupingType: Hashable>(by key: (Iterator.Element) -> GroupingType) -> [GroupingType: [Iterator.Element]] {
        var groups: [GroupingType: [Iterator.Element]] = [:]
        forEach { element in
            let key = key(element)
            if case nil = groups[key]?.append(element) {
                groups[key] = [element]
            }
        }
        return groups
    }
    
    func getMax(count: Int) -> Self {
        if self.count < count {
            return self
        } else {
            return Array(self[0..<count])
        }
    }

}