Method parse_date_time

src/toml.hpp:14547–14612

		TOML_NODISCARD
		TOML_NEVER_INLINE
		date_time parse_date_time()
		{
			return_if_error({});
			assert_not_eof();
			TOML_ASSERT_ASSUME(is_decimal_digit(*cp));
			push_parse_scope("date-time"sv);

			// "YYYY-MM-DD"
			auto date = parse_date(true);
			set_error_and_return_if_eof({});

			// ' ', 'T' or 't'
			if (!is_match(*cp, U' ', U'T', U't'))
				set_error_and_return_default("expected space, 'T' or 't', saw '"sv, to_sv(*cp), "'"sv);
			advance_and_return_if_error_or_eof({});

			// "HH:MM:SS.FFFFFFFFF"
			auto time = parse_time(true);
			return_if_error({});

			// no offset
			if (is_eof() || is_value_terminator(*cp))
				return { date, time };

			// zero offset ('Z' or 'z')
			time_offset offset{};
			if (is_match(*cp, U'Z', U'z'))
				advance_and_return_if_error({});

			// explicit offset ("+/-HH:MM")
			else if (is_match(*cp, U'+', U'-'))
			{
				push_parse_scope("date-time offset"sv);

				// sign
				int sign = *cp == U'-' ? -1 : 1;
				advance_and_return_if_error_or_eof({});

				// "HH"
				int digits[2];
				if (!consume_digit_sequence(digits, 2u))
					set_error_and_return_default("expected 2-digit hour, saw '"sv, to_sv(cp), "'"sv);
				const auto hour = digits[1] + digits[0] * 10;
				if (hour > 23)
					set_error_and_return_default("expected hour between 0 and 23 (inclusive), saw "sv, hour);
				set_error_and_return_if_eof({});

				// ':'
				if (*cp != U':')
					set_error_and_return_default("expected ':', saw '"sv, to_sv(*cp), "'"sv);
				advance_and_return_if_error_or_eof({});

				// "MM"
				if (!consume_digit_sequence(digits, 2u))
					set_error_and_return_default("expected 2-digit minute, saw '"sv, to_sv(cp), "'"sv);
				const auto minute = digits[1] + digits[0] * 10;
				if (minute > 59)
					set_error_and_return_default("expected minute between 0 and 59 (inclusive), saw "sv, minute);