Does the Swift standard Dictionary have a get-or-set function?

Question

I found myself starting to want something like this:

extension Dictionary {
    mutating func get(_ key: Key, backup: Value) -> Value {
        if let stored = self[key] {
            return stored
        } else {
            self[key] = backup
            return backup
        }
    }
}

but in my experience, Swift leaves out things like this because it has an alternative (intended) way to do it. I haven't found such a way in documentation. Did I miss this function, or should I create it? Also, if they left it out and I shouldn't create it, why?

Similar solutions here: [Swift Dictionary default value](http://stackoverflow.com/questions/32415188/swift-dictionary-default-value). — Martin R, Dec 06 '16 at 17:53
You didn't miss out a function :) It's usually a good idea to create an extension or function of some kind (see my answer). — GJZ, Dec 06 '16 at 18:07

score 2 · Accepted Answer · answered Dec 06 '16 at 17:51

2

No it doesn't have a function like this. It is fine to create an extension in this circumstance.

answered Dec 06 '16 at 17:51

Jeremy Gurr

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Does the Swift standard Dictionary have a get-or-set function?

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