Queue.swift

import Foundation

class Queue<T: CustomStringConvertible>: CustomStringConvertible {
    
    fileprivate var array: [T] = []
    
    func dequeue() -> T? {
        let dequeueItem = self.array.removeFirst()
        print("DEQUEUE ITEM : \(dequeueItem.description)")
        return dequeueItem
    }
    
    func enqueue(item: T) {
        print("ENQUEUE ITEM : \(item.description)")
        array.append(item)
    }
    
    var isEmpty: Bool {
        return self.array.isEmpty
    }
    
    var count: Int {
        return self.array.count
    }
    
    var description: String {
        let top = "### QUEUE ###\n\n"
        let bottom = "\n\n#############\n"
        let elements = self.array.map { $0.description }.joined(separator: " ")
        return top + elements + bottom
    }
}