Page729_regex.cpp

#include <iostream>
#include <string>
#include <regex>
using std::cout;
using std::endl;
using std::string;
using std::regex;
using std::smatch;
int main()
{
    // find the characters ei that follow a character other than c
    string pattern("[^c]ei");
    // we want the whole word in which our pattern appears
    pattern = "[[:alpha:]]*" + pattern + "[[:alpha:]]*";
    regex r(pattern); // construct an object to find pattern
    smatch results;   // define an object to hold the results of a search
    // define a string that has text that does and doesn't match pattern
    string test_str = "receipt freind theif receive";
    // use r to find a match to pattern in test_str
    if(regex_search(test_str, results, r)) // if there is a match
        cout << results.str() << endl;     // print the matching word
    return 0;
}