Method operator[]

tests/BS_thread_pool_test.cpp:3882–3887

* @brief Check if a specific command line argument has been passed to the program. If no arguments were passed, use the default value instead. * * @param arg The argument to check for. * @return `true` if the argument exists, `false` otherwise. */

     * @return `true` if the argument exists, `false` otherwise.
     */
    [[nodiscard]] bool operator[](const std::string_view arg)
    {
        if (size() > 0)
            return (args.count(arg) == 1);
        return allowed[arg].def;
    }

    /**
     * @brief Add an argument to the list of allowed arguments.