title: Boost C++ regex - how to get multiple matches
body: <p>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...</p>
  
  <pre><code>boost::match_flag_type flags = boost::match_default;
  boost::cmatch mcMatch;
  boost::regex_search("abc abd", mcMatch, "ab.", flags)
  </code></pre>
  
  <p>Then mcMatch contains just the first "abc" result.  How can I get all possible matches?</p>