Method moved_or_copied

3rd/json/include/nlohmann/json.hpp:9396–9403

    ~json_ref() = default;

    value_type moved_or_copied() const
    {
        if (is_rvalue)
        {
            return std::move(*value_ref);
        }
        return *value_ref;
    }

    value_type const& operator*() const
    {