Method parse_literal_string

src/toml.hpp:13696–13795

		TOML_NODISCARD
		TOML_NEVER_INLINE
		std::string_view parse_literal_string(bool multi_line)
		{
			return_if_error({});
			assert_not_eof();
			TOML_ASSERT_ASSUME(*cp == U'\'');
			push_parse_scope("literal string"sv);

			// skip the delimiter
			advance_and_return_if_error_or_eof({});

			// multi-line strings ignore a single line ending right at the beginning
			if (multi_line)
			{
				consume_line_break();
				return_if_error({});
				set_error_and_return_if_eof({});
			}

			auto& str = string_buffer;
			str.clear();
			do
			{
				return_if_error({});

				// handle closing delimiters
				if (*cp == U'\'')
				{
					if (multi_line)
					{
						size_t lookaheads			  = {};
						size_t consecutive_delimiters = 1;
						do
						{
							advance_and_return_if_error({});
							lookaheads++;
							if (!is_eof() && *cp == U'\'')
								consecutive_delimiters++;
							else
								break;
						}
						while (lookaheads < 4u);

						switch (consecutive_delimiters)
						{
							// ''' ' (one quote somewhere in a ML string)
							case 1: str += '\''; continue;

							// ''' '' (two quotes somewhere in a ML string)
							case 2: str.append("''"sv); continue;

							// ''' ''' (the end of the string)
							case 3: return str;

							// ''' '''' (one at the end of the string)
							case 4: str += '\''; return str;

							// ''' ''''' (two quotes at the end of the string)
							case 5: