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Protocols are your hooks into the Swift core language Swift generics combine abstraction, safety, and performance in new ways Read, experiment, and have fun. There’s plenty to discover!

LogicValue // 重载 if val

Printable // 重载 println

protocol Printable {
    var description: String { get }
}

Sequence // 重载 for-in

protocol Sequence {
  typealias GeneratorType : Generator
  func generate() -> GeneratorType
}

protocol Generator {
  typealias Element
  mutating func next() -> Element?
}

// for .. in { }
var __g = someSequence.generate()
while let x = __g.next() {
    ...
}}

*Convertible

  • IntegerLiteralConvertible
  • FloatLiteralConvertible
  • StringLiteralConvertible
  • ArrayLiteralConvertible
  • DictionaryLiteralConvertible

Equatable

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