Method get_bson_string

deps/json/json.hpp:9301–9311

    */
    template<typename NumberType>
    bool get_bson_string(const NumberType len, string_t& result)
    {
        if (JSON_HEDLEY_UNLIKELY(len < 1))
        {
            auto last_token = get_token_string();
            return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read,
                                    exception_message(input_format_t::bson, concat("string length must be at least 1, is ", std::to_string(len)), "string"), nullptr));
        }

        return get_string(input_format_t::bson, len - static_cast<NumberType>(1), result) && get() != std::char_traits<char_type>::eof();
    }

    /*!
    @brief Parses a byte array input of length @a len from the BSON input.