为什么我的Boost.Regex搜索只报告一次匹配迭代？

#include<boost/regex.hpp>
#include<iostream>
#include<string>

int main() {
    std::string s = "Boost.Regex is a powerful library for regular expressions.";
    boost::regex re("\\w+");
    boost::smatch match;

    while (boost::regex_search(s, match, re)) {
        std::cout << "Match found: "<< match.str()<< std::endl;
        s = match.suffix().str();
    }

    return 0;
}