func isDigit(c: char): bool {.inline, ...raises: [], tags: [], forbids: [].}

func isNormalizedWindowsDriveLetter(input: string | StringView): bool {.inline,
    ...raises: [].}

func isWindowsDriveLetter(input: StringView): bool {.inline, ...raises: [],
    tags: [], forbids: [].}

func pathSignature(input: StringView): uint8 {.inline, ...raises: [], tags: [],
    forbids: [].}