Method position_string

src/nlohmann/json.hpp:4513–4517

        : exception(id_, what_arg), byte(byte_) {}

    static std::string position_string(const position_t& pos)
    {
        return concat(" at line ", std::to_string(pos.lines_read + 1),
                      ", column ", std::to_string(pos.chars_read_current_line));
    }
};

/// @brief exception indicating errors with iterators