Method parse

docopt_private.h:523–577

	}

	inline Option Option::parse(std::string const& option_description)
	{
		std::string shortOption, longOption;
		int argcount = 0;
		value val { false };

		auto double_space = option_description.find("  ");
		auto options_end = option_description.end();
		if (double_space != std::string::npos) {
			options_end = option_description.begin() + static_cast<std::ptrdiff_t>(double_space);
		}

		static const std::regex pattern {"(-{1,2})?(.*?)([,= ]|$)"};
		for(std::sregex_iterator i {option_description.begin(), options_end, pattern, std::regex_constants::match_not_null},
			   e{};
			i != e;
			++i)
		{
			std::smatch const& match = *i;
			if (match[1].matched) { // [1] is optional.
				if (match[1].length()==1) {
						shortOption = "-" + match[2].str();
				} else {
						longOption =  "--" + match[2].str();
				}
			} else if (match[2].length() > 0) { // [2] always matches.
				std::string m = match[2];
				argcount = 1;
			} else {
				// delimeter
			}

			if (match[3].length() == 0) { // [3] always matches.
				// Hit end of string. For some reason 'match_not_null' will let us match empty
				// at the end, and then we'll spin in an infinite loop. So, if we hit an empty
				// match, we know we must be at the end.
				break;
			}
		}

		if (argcount) {
			std::smatch match;
			if (std::regex_search(options_end, option_description.end(),
						  match,
						  std::regex{"\\[default: (.*)\\]", std::regex::icase}))
			{
				val = match[1].str();
			}
		}

		return {std::move(shortOption),
			std::move(longOption),
			argcount,
			std::move(val)};
	}

	inline std::pair<size_t, std::shared_ptr<LeafPattern>> Option::single_match(PatternList const& left) const
	{