Function at

include/behaviortree_cpp/contrib/json.hpp:21240–21254

@brief access specified array element with bounds checking @sa https://json.nlohmann.me/api/basic_json/at/

    /// @brief access specified array element with bounds checking
    /// @sa https://json.nlohmann.me/api/basic_json/at/
    reference at(size_type idx)
    {
        // at only works for arrays
        if (JSON_HEDLEY_LIKELY(is_array()))
        {
            JSON_TRY
            {
                return set_parent(m_data.m_value.array->at(idx));
            }
            JSON_CATCH (std::out_of_range&)
            {
                // create better exception explanation
                JSON_THROW(out_of_range::create(401, detail::concat("array index ", std::to_string(idx), " is out of range"), this));
            }
        }
        else
        {
            JSON_THROW(type_error::create(304, detail::concat("cannot use at() with ", type_name()), this));