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// RUN: %target-run-simple-swift | %FileCheck %s
// REQUIRES: executable_test
struct BoxedError<T: Error> {
var contents: T
}
enum MyError: Error {
case nothingImportant
case reallyImportant(String)
}
// CHECK: start
print("start")
let value = MyError.reallyImportant("hello")
// CHECK-NEXT: reallyImportant("hello")
print(value)
func takeBoxedError<T>(error: BoxedError<T>) -> Error {
return error.contents
}
func makeBoxedError<T: Error>(error: T) -> BoxedError<Error> {
return BoxedError(contents: error)
}
let unboxedValue = takeBoxedError(error: makeBoxedError(error: value))
// CHECK-NEXT: reallyImportant("hello")
print(unboxedValue)
let errorValue: Error = MyError.reallyImportant("goodbye")
func castValueToError<T>(error: T) -> Error? {
return error as? Error
}
// CHECK-NEXT: reallyImportant("goodbye")
print(castValueToError(error: errorValue) ?? value)
struct Carrier<T> {
var name: String
}
protocol ErrorCarrier {}
extension Carrier: ErrorCarrier where T: Error {}
func castValueToErrorCarrier<T>(_ value: T) -> ErrorCarrier? {
return value as? ErrorCarrier
}
// CHECK-NEXT: nil
print(castValueToErrorCarrier(Carrier<Int>(name: "A carrier of numbers")))
// CHECK-NEXT: A carrier of my errors
print(castValueToErrorCarrier(Carrier<MyError>(name: "A carrier of my errors")))
// CHECK-NEXT: A carrier of all errors
print(castValueToErrorCarrier(Carrier<Error>(name: "A carrier of all errors")))
// CHECK-NEXT: nil
protocol ErrorRefinement : Error {}
print(castValueToErrorCarrier(Carrier<ErrorRefinement>(name: "A carrier of refined errors")))
// CHECK-NEXT: nil
protocol OtherProtocol {}
print(castValueToErrorCarrier(Carrier<Error & OtherProtocol>(name: "A carrier of composed errors")))
// CHECK-NEXT: nil
class C {}
print(castValueToErrorCarrier(Carrier<Error & C>(name: "A carrier of classic composed errors")))
// CHECK-NEXT: end
print("end")
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