Регулярные выражения

#include <iostream>
#include <string>
#include <regex>
 
int main()
{
   std::string phone_number = "(012) 345-67-89";
   std::regex reg{ R"re(\(\d(\d{2})\) (\d{3}-\d{2}-\d{2}))re" };
   std::cout << std::regex_replace(phone_number, reg, "+380 $1 $2") << "\n";
}

string test = "name (012) 3456789";
    string regstring = "";  //регулярное выражение 1
    string replacestr = ""; //регулярное выражение 2
    regex rx(regstring);
 
    cmatch matches;
 
    if (regex_search(test.c_str(), matches, rx)) {
 
        for (int i = 0; i<matches.size(); i++) 
        {
            cout << matches[i].first << "\n";
        }
    }
 
    string strResult = regex_replace(test, rx, replacestr);
 
    cout << "\n\n\n" << strResult;

int main()
{
   using namespace std;
 
   string test = "name (012) 3456789";
   string regstring = R"re(\(\d(\d{2})\) (\d{7}))re";
   string replacestr = "+380 $1 $2";
   regex rx(regstring);
 
   string strResult = regex_replace(test, rx, replacestr);
   cout << "\nstrResult: " << strResult << "\n";
}

R"re(\(\d(\d{2})\) (\d{7}))re"

"\\(\\d(\\d{2})\\) (\\d{7})"

"\\(\\d(\\d{2})\\)(?=\\s\\d)"

".*?(\\d{2})[)](?=\\s\\d)"