正则表达式匹配字符串_std::regex如何匹配某个指定的字符串

	/*1 正则表达式 搜索6位数 */
    std::string aa = "072007P44"; 
	std::string bb = "072007 P44";
	std::regex pattern("([0-9]{6})");
	std::smatch matches;
 
	if (std::regex_search(aa, matches, pattern)) {
		std::string result = matches[1].str();
 
		
		std::cout << aa << std::endl;
		std::cout << result << std::endl;/* 072007 */
	}
	else {
		std::cout << "No match found." << std::endl;
	}
 
 
	if (std::regex_search(bb, matches, pattern)) {
		std::string result = matches[1].str();
 
		
		std::cout << bb << std::endl;
		std::cout << result << std::endl;/* 072007 */
	}
	else {
		std::cout << "No match found." << std::endl;
	}
 
 
 
   // 2 
   std::string aa = "CTD220162_1_KSZJ_008-REV01";
	std::regex pattern("[_-]([A-Z]+[_-][0-9]+)[_-]");
	std::smatch matches;
 
	if (std::regex_search(aa, matches, pattern)) {
		std::string result = matches[1].str();
		std::cout << result << std::endl; // KSZJ_008
	}
	else {
		std::cout << "No match found." << std::endl;
	}
 
// 3 找6位字符串
vector<string> GetRegexString(const string& cstr) {
	smatch matches;
	vector<string> cstrs;
	regex x("^.*([_-](([1-9]|[a-z]|[A-Z]){6})[_-]).*$");   // tak2500446_123456_tra
	if (regex_search(cstr, matches, x))
		cstrs.push_back(matches[1]), // _123456_
		cstrs.push_back(matches[2]);//123456
	return cstrs;
}
 
 
// 4 找7位字符串
vector<string> GetRegexString_a(const string& cstr) {
	smatch matches;
	vector<string> cstrs;
	regex x("^.*([_-](([1-9]|[a-z]|[A-Z]){7})[_-]).*$");// tak2500446_123456A_tra
	if (regex_search(cstr, matches, x))
		cstrs.push_back(matches[1]),// _123456A_
		cstrs.push_back(matches[2]);//123456
	return cstrs;
}