#include <string>
#include <iostream>
#include <regex>
using namespace std;

int main() {
	std::vector<std::string> strings;
	std::string s = "1 This is an exampl";
	std::regex re("\\b(?=e)");
	std::regex_token_iterator<std::string::iterator> it(s.begin(), s.end(), re, -1);
	decltype(it) end{};
	while (it != end){
		strings.push_back(*it++);
		std::cout << strings[strings.size()-1] << std::endl; // DEMO!
	}
	return 0;
}