正则表达式迭代器

为了访问正则表达式的匹配结果，使用regex iterator。这些iterator的类型是regex_iterator<>,有针对string和字符序列而预先定义的实例化实现，分别有sregex_iterator,wsregex_iterator,cregex_iterator和wcregex_itreator。如下示例：

 #include <iostream>
#include <regex>
#include <string>
#include <algorithm>
using namespace std;
int main(int argc,char *argv[])
{
    string  data = "<person>\n"
                   "<first>Nano</first>\n"
                   "<second>Nike</second>\n"
                   "</person>\n";
    regex reg("<(.*)>(.*)</(\\1)>");

    //iterate over all matches
    sregex_iterator pos(data.begin(),data.end(),reg);
    sregex_iterator  end;
    auto func = [](const sregex_iterator& pos){cout << " match: " << pos->str() << endl;
        cout << " tag: " << pos->str(1) << endl;
        cout << " value: " << pos->str(2) << endl;};
    for(;pos != end;++pos){
        func(pos);
    }
    // use a regex_iterator to process each matched substring
    sregex_iterator beg(data.begin(),data.end(),reg);
    for_each(beg,end,[](const smatch& pos){
        cout << " match: " << pos.str() << endl;
        cout << " tag: " << pos.str(1) << endl;
        cout << " value: " << pos.str(2) << endl;
    });
    return 0;
}

其中：

赏

谢谢你请我吃糖果