如何在Swift中返回自定义错误？

enum CustomError: Error {
    case invalidInput
    case networkError
    case fileNotFound
}

func doSomething() throws {
    // 可能会抛出错误的代码
}

func divide(_ number: Int, by divisor: Int) throws -> Int {
    guard divisor != 0 else {
        throw CustomError.invalidInput
    }
    return number / divisor
}

do {
    let result = try divide(10, by: 2)
    // 处理函数返回的结果
} catch CustomError.invalidInput {
    // 处理无效输入错误
} catch CustomError.networkError {
    // 处理网络错误
} catch CustomError.fileNotFound {
    // 处理文件未找到错误
} catch {
    // 处理其他未知错误
}