Function operator<

uspace/lib/cpp/src/system_error.cpp:171–175

    }

    bool operator<(const error_code& lhs, const error_code& rhs) noexcept
    {
        return lhs.category() < rhs.category() ||
            (lhs.category() == rhs.category() && lhs.value() < rhs.value());
    }

    error_condition::error_condition() noexcept
        : val_{}, cat_{&generic_category()}