[Boost-users] assert when using cregex_iterator

I have a very simple test program using the latest 1.33 version of regex library. As soon as I run it, it assert (crash) at the line where std::string s = (*m1)[0]. I am doing something wrong? ============== #include "stdafx.h" #include <boost/regex.hpp> const char matchpattern[] = "\\s+kitty this"; const char astring[] = "hello Kitty this is a test"; using namespace boost; int main(int argc, char* argv[]) { regex header_expr(matchpattern, regex_constants::basic | regex_constants::icase); cregex_iterator m1(astring, astring + strlen(astring), header_expr); std::string s = (*m1)[0]; <==== crash here return 0; }