// basic_regex::flags
// note: using regex, a standard alias of basic_regex<char>
#include <iostream>
#include <regex>

int main ()
{
  using namespace std::regex_constants;
  std::regex first ((char *)"[a-z]+");
  //std::regex second ("[a-z]+", ECMAScript | icase );
  std::regex second ("[a-z]+", icase );

  std::cout << "first ";
  std::cout << ( ( first.flags() & icase ) == icase ? "is":"is not");
  std::cout << " case insensitive.\n";

  std::cout << "second ";
  std::cout << ( ( second.flags() & icase ) == icase ? "is":"is not");
  std::cout << " case insensitive.\n";

  return 0;
}