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@tomlokhorst
Created March 4, 2015 18:29
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Invalid cast causing runtime crash in Swift <= 1.2
import Foundation
let obj = NSNumber(int: 2)
func correct<T>() -> T? {
if let val = obj as? T {
println("matching types")
return val
}
else {
println("not matching")
}
return nil
}
func incorrect<T : NSObject>() -> T? {
if let val = obj as? T {
println("matching types")
return val
}
else {
println("not matching")
}
return nil
}
correct() as NSString? // prints "not matching"
incorrect() as NSString? // prints "matching types"
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