c++ - boost 正则表达式 : Getting the Named Group

Question

如何使用Boost正则表达式获取模式匹配对应的组名？

下面将匹配的表达式输出到给定的模式。但是如何才能得到对应的命名组呢？

boost::regex pattern("(?<alpha>[0-9]*\\.?[0-9]+)|(?<beta>[a-zA-Z_]+)");

string s = "67.2 x  7 I am";

string::const_iterator start = s.begin();
string::const_iterator end   = s.end();
boost::sregex_token_iterator i(start, end, pattern);
boost::sregex_token_iterator j;

for ( ;i != j; ++i)
{
    cout << *i << endl;
        // '67.2' and '7' belongs to "alpha"
        // 'x', 'I', 'am' belongs to "beta"
}

Answer 1

You can get it from match_result它适用于xpressive，但同样适用于Boost.Regex。