#include <algorithm>    #include <vector>    #include <string>    #include <iostream>    #include <cassert>    #include <boost/regex.hpp>    using namespace std;    using namespace boost;    //写一个程序，提取<p></p>之间的内容    int main()    {            //  regex reg("(<p.*>(.*)</p>)?");        regex reg("<p.*?>(.*?)</p>");        vector<string> vec;        string s= "<p>i‘m here!</p> and of course <pasda>you‘re here too,ok?</p>";        sregex_iterator it(s.begin(),s.end(),reg);        sregex_iterator end;        while (it!=end)        {            vec.push_back((*it).str().c_str());            it++;        }        copy(vec.begin(),vec.end(),ostream_iterator<string>(cout,"/n"));        //在得到iterator或者子字符串后，再用regex_replace进行替换就行了。        vector<string>   vec2;        regex reg2("(<p.*?>)(.*?)(</p>)");        for (vector<string>::iterator it3 = vec.begin();it3!=vec.end();it3++)        {            string s= *it3;            s=regex_replace(s,reg2,"$2");            vec2.push_back(s);        }        copy(vec2.begin(),vec2.end(),ostream_iterator<string>(cout,"/t"));        return 0;    }