Optionally bind elements before appending to Arrays

[ArtSabintsev]

This is a bit safer than the force-unwrap solution.

[aciidgh]

how about

if case let e as T = e {
    t.append(e)
} else if case let e as U = e {
    u.append(e)
}

Does the same thing but avoids the ? in as

[ArtSabintsev]

sure - that works!

[kostiakoval]

as for me if case let is to heavy

[ArtSabintsev]

actually, that does not work at all. Still asks to force-downcast. Agree with @kostiakoval.

[aciidgh]

Works for me

extension Array {
    public func partition<T, U>() -> ([T], [U]) {
        var t = [T]()
        var u = [U]()
        for e in self {
            if case let e as T = e {
                t.append(e)
            } else if case let e as U = e {
                u.append(e)
            }
        }
        return (t, u)
    }
}

let a = [1, 2, 3, "2", "3"]
let partition: ([Int], [String]) = a.partition()

agreed though that if case let looks heavier at first but I have grown to like it lol

[aciidgh]

wouldn't say better or worse just different syntactically I guess?

[ArtSabintsev]

@aciidb0mb3r's solution is syntactic sugar (https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Patterns.html#//apple_ref/swift/grammar/optional-pattern). Same solution, different way of implementing, which I would deem non-traditional.

[kostiakoval]

Both solutions works fine and there is no big difference. if let e = e as? T solutions is safe, very clear and it's very often used in Swift community.
I feel there is no need for further discussion.

[aciidgh]

👍

[ArtSabintsev]

Thanks! 👍