CaseIterable RawRepresentable enum: when using index in allCases as raw representation, rawValue property gets stuck in infinite loop.

[kr1sc]

Description

Below code does not work.

enum TestEnum: CaseIterable {
    case one, two, three
}

extension TestEnum: RawRepresentable {

    init?(rawValue: Int) {
        guard rawValue >= 0 && rawValue < TestEnum.allCases.count else { return nil }
        self = TestEnum.allCases[rawValue]
    }

    var rawValue: Int {
        TestEnum.allCases.firstIndex(of: self)!
    }

}

TestEnum.one.rawValue

TestEnum.one.rawValue will cause recursive cascade of rawValue invocations resulting in EXC_BAD_ACCESS. For me it looks like invalid behavior.

Steps to reproduce

Run above code.

Expected behavior

TestEnum.one.rawValue correctly evaluates to value 0 in this case.

Environment

• Swift compiler version info

  swift-driver version: 1.87.1 Apple Swift version 5.9 (swiftlang-5.9.0.128.108 clang-1500.0.40.1)
  Target: arm64-apple-macosx14.0

• Xcode version info

  Version 15.0 (15A240d)

• Deployment target:

  iOS 17.0

[aniket-singh-01]

Hi,kr1sc.
Can I take the issue?.

[kr1sc]

Hi Aniket, I just report what I suspect is incorrect behavior, but I do not decide how it is handled or by whom.