Method at

extern/json/json.hpp:3151–3170

! @brief access specified array element with bounds checking Returns a reference to the element at specified location @a idx, with bounds checking. @param[in] idx index of the element to access @return reference to the element at index @a idx @throw std::domain_error if the JSON value is not an array; example: `"cannot use at() with string"` @throw std::out_of_

    @since version 1.0.0
    */
    reference at(size_type idx)
    {
        // at only works for arrays
        if (is_array())
        {
            try
            {
                return m_value.array->at(idx);
            }
            catch (std::out_of_range&)
            {
                // create better exception explanation
                throw std::out_of_range("array index " + std::to_string(idx) + " is out of range");
            }
        }
        else
        {
            throw std::domain_error("cannot use at() with " + type_name());
        }
    }

    /*!
    @brief access specified array element with bounds checking