A new Set data structure

Paul Hudson      @twostraws

Swift 1.2 introduced a new Set type that works similarly to NSSet except with value semantics. Sets work similarly to arrays except they are not ordered and do not store any element more than once. For example:

var starships = Set<String>()
starships.insert("Serenity")
starships.insert("Enterprise")
starships.insert("Executor")
starships.insert("Serenity")
starships.insert("Serenity")

Even though that code tries to insert Serenity three times, it will only be stored in the set once.

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Other changes in Swift 1.2…

• The zip() function joins two sequences
• The flatMap() method transforms optionals and arrays
• Closures can now be marked @noescape
• Classes can now have static methods and properties
• Constants no longer require immediate initialization
• Implicit bridging has been reduced
• Multiple if let bindings
• Typecasting now includes as!

Download all Swift 1.2 changes as a playground Link to Swift 1.2 changes

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