status changed; resolution set

Eric Niebler — Thu, 20 Nov 2008 08:00:17 GMT

status new → closed
resolution → wontfix

boost::regex goes to some length to present itself as a souped up container of characters. You can assign a character range to it, get begin() and end() iterators for stepping through the characters with which the regex was initialized, etc. Given that, see if you can answer this without checking the docs:

  assert(std::string().empty());    // OK
  assert(std::string("").empty());  // OK
  assert(boost::regex().empty());   // Is this true???
  assert(boost::regex("").empty()); // How about this???

Unsurprisingly, regex::empty() is not part of the standard regex interface in C++0x. I don't like regex::empty() and I'm not inclined to add it. Sorry. You already have a way to get the information you're interested in. If you would like to give it a pretty name, by all means...

template<class Iter>
bool is_invalid(xpressive::basic_regex<Iter> const &rex)
{
  return 0 == rex.regex_id();
}

Boost C++ Libraries: Ticket #2519: Request for an empty function to be added to boost::xpressive::basic_regex

status changed; resolution set