Swift标准词典是否具有获取或设置功能? [英] Does the Swift standard Dictionary have a get-or-set function?

问题描述

我发现自己开始想要这样的东西:

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
        }
    }
}

但是根据我的经验，Swift忽略了类似的事情，因为它有一种替代的(预期的)方法.我还没有在文档中找到这种方法. 我是否错过了此功能，还是应该创建它?此外，如果他们遗漏了该功能并且我不应该创建它，为什么?

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?

推荐答案

否，它没有这样的功能.在这种情况下，最好创建一个扩展.

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

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