The more idiomatic way is to look at API design in a new way. Note these points:
1. `Countable` variant is preferred when you want to deal with integer ranges as it more closely matches the element type.
2. Both countable range variants share a common protocol conformance already: `RandomAccessCollection`
3. Swift API design prefers member functions to free functions.
Hence a more idiomatic (Swifty) API would probably be something like this:
extension RandomAccessCollection {
func random() -> Iterator.Element? {
guard count > 0 else { return nil }
let offset = arc4random_uniform(numericCast(count))
let i = index(startIndex, offsetBy: numericCast(offset))
return self[i]
}
}
Using the above, both cases work and there is no repetition:
(4..<10).random()
(4...9).random()
It also makes a lot more possible:
let people = ["David", "Chris", "Joe", "Jordan", "Tony"]
let winner = people.random()
···
On Oct 12, 2016, at 3:21 AM, Jean-Denis Muys via swift-users <swift-users@swift.org> wrote:
But this is not very DRY.
What would be a more idiomatic way?