int main()
{
    {
        const std::error_code ec(6, std::generic_category());
        std::error_condition e_cond = ec.default_error_condition();
        assert(e_cond == ec);
    }
    {
        const std::error_code ec(6, std::system_category());
        std::error_condition e_cond = ec.default_error_condition();
        assert(e_cond == ec);
    }
}