Re: [boost] [xpressive] Is there a way to test for an empty regex?

Michael Goldshteyn wrote:

What is the best way to test for an empty boost::xpressive::regex object?

That is, if I have code like:

boost::xpressive::sregex re;

...

// Test if re is empty and should not be used to perform a regex_search if (?????)

There is, although it's not obvious from the documentation that it's possible. You can see from the postcondition on the default constructor of basic_regex that this->regex_id() == 0 for default-constructed regex objects and != 0 for non-default constructed regex objects. So your test above can be: if( 0 != re.regex_id() ) HTH, -- Eric Niebler BoostPro Computing http://www.boostpro.com