Created
January 27, 2016 20:39
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Protocol inheritance in Swift
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| //: Playground - noun: a place where people can play | |
| import UIKit | |
| protocol A { } | |
| protocol B: A { } | |
| class MyClass: B { } | |
| let b: [B] = (1...3).map { MyClass(indx: $0) } | |
| // Cannot convert value of type '[B]' to specified type '[A]' | |
| let a: [A] = b |
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Solution: let a: [A] = b.map { $0 as A }
Explanation: http://stackoverflow.com/questions/33090626/swift-upcasting-array-of-protocol-to-array-of-super-protocol-causes-error