c++: a simple boost::regex example

void piMozyAuthUnitTest::testBoostRegex1()
{
    std::string s, sre;
    boost::regex re;
    boost::cmatch matches;

    while(true)
    {
        cout << "Expression: ";
        cin >> sre;
        if (sre == "quit")
            break;
        

        cout << "String:     ";
        cin >> s;

        try
        {
            // Assignment and construction initialize the FSM used
            // for regexp parsing
            re = sre;
        }
        catch (boost::regex_error& e)
        {
            cout << sre << " is not a valid regular expression: \""
            << e.what() << "\"" << endl;
            continue;
        }
        // if (boost::regex_match(s.begin(), s.end(), re))
        if (boost::regex_match(s.c_str(), matches, re))
        {
            // matches[0] contains the original string.  matches[n]
            // contains a sub_match object for each matching
            // subexpression
            for (int i = 1; i < matches.size(); i++)
            {
                // sub_match::first and sub_match::second are iterators that
                // refer to the first and one past the last chars of the
                // matching subexpression
                string match(matches[i].first, matches[i].second);
                cout << "\tmatches[" << i << "] = " << match << endl;
            }
        }
        else
        {
            cout << "The regexp \"" << re << "\" does not match \"" << s << "\"" << endl;
        }
    }

}