Open Radar

 
The following code crashes the compiler. Injecting “as DecryptorType?” resolves the crash and successfully compiles.

protocol DataSinkType: class {}

// Removing DataSinkType conformance converts crash to error:
// Function signature '([UInt8]) -> PasswordDecryptorV3?' is not compatible with expected type '([UInt8]) -> DecryptorType?'
// Along with incorrect Fix-it (suggesting I wrap it in a closure)
protocol DecryptorType: DataSinkType {}

final class PasswordDecryptorV3: DecryptorType {
    init?() {}
}

final class Decryptor {
    let decryptors: [() -> DecryptorType?]
    init(password: String) {
        self.decryptors = [
            ( { PasswordDecryptorV3()
//                as DecryptorType? // Uncommenting this line removes crash and successfully compiles
            })
        ]
    }
}