Cut out the middle of an array in Swift

drop-start-quantity.swift

extension Sequence {
    func drop(start at: Int, quantity: Int) -> [Element] {
        return Array(self.dropFirst(at).prefix(quantity))
    }
}

let array = [0, 1, 2, 3, 4, 5]
let actual = array.drop(start: 2, quantity: 3)

print(actual == [2, 3, 4])
// true