Question

If I have a simple regex pattern like “ab.” and I have a string that has multiple matches like “abc abd”. If I do the following…

boost::match_flag_type flags = boost::match_default;
boost::cmatch mcMatch;
boost::regex_search("abc abd", mcMatch, "ab.", flags)

Then mcMatch contains just the first “abc” result. How can I get all possible matches?

Answer 1

You can use the boost::sregex_token_iterator like in this short example:

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

int main() {
    std::string text("abc abd");
    boost::regex regex("ab.");

    boost::sregex_token_iterator iter(text.begin(), text.end(), regex, 0);
    boost::sregex_token_iterator end;

    for( ; iter != end; ++iter ) {
        std::cout<<*iter<<'\n';
    }

    return 0;
}

The output from this program is:

abc
abd