[Boost-bugs] [Boost C++ Libraries] #2519: Request for an empty function to be added to boost::xpressive::basic_regex

Subject: [Boost-bugs] [Boost C++ Libraries] #2519: Request for an empty function to be added to boost::xpressive::basic_regex
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2008-11-20 03:38:06

#2519: Request for an empty function to be added to boost::xpressive::basic_regex
-------------------------------------+--------------------------------------
 Reporter:  mgoldshteyn_at_[hidden]  |       Owner:  eric_niebler
     Type:  Feature Requests         |      Status:  new         
Milestone:  Boost 1.38.0             |   Component:  xpressive   
  Version:  Boost 1.37.0             |    Severity:  Problem     
 Keywords:  empty xpressive regex    |  
-------------------------------------+--------------------------------------
 Currently the only way to tell if a regex object is empty (i.e., not
 containing a compiled regex) is to compare the result of its regex_id()
 function to zero. This is not intuitive to a reader of such code without
 explicit comments.

 It would be much easier to read said code if basic_regex supplied an empty
 function which internally performed this test. This would transform code
 that looks like:

 if (re.regex_id()!=0)
   do_something(re);

 to code that reads:

 if (!re.empty())
   do_something(re);

 which is much more intuitive. It seems to me to be a trivial change that
 makes xpressive regexes even more similar to the regular boost::regex in
 terms of interface, so it's a win/win.

 Thanks for your consideration,

 Michael Goldshteyn

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/2519>
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