Method get_bson_string

Source/external/json.hpp:9297–9307

	*/
	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.