[Boost-bugs] [Boost C++ Libraries] #3586: Use of Greedy quantifiers in Quoted Expressions locks up at regex compile

Subject: [Boost-bugs] [Boost C++ Libraries] #3586: Use of Greedy quantifiers in Quoted Expressions locks up at regex compile
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2009-11-03 15:20:39

#3586: Use of Greedy quantifiers in Quoted Expressions locks up at regex compile
------------------------------------+---------------------------------------
 Reporter:  nmaximillian@…          |       Owner:  eric_niebler
     Type:  Bugs                    |      Status:  new         
Milestone:  To Be Determined        |   Component:  xpressive   
  Version:  Boost 1.38.0            |    Severity:  Problem     
 Keywords:                          |  
------------------------------------+---------------------------------------
 The following will not compile: \Q.*\E and causes the program to lockup at
 the compile step. I have attempted other usages: '\Qh*\E', '\Q.+\E',
 '\Q+\E', '\Q*\E' etc. and they all lock-up on compile. Note that escaping
 the quantifier will allow it to compile (but it is a different
 expression): '\Q.\*\E' -- compiles but will only match '.\*' not '.*'


 {{{
 #include <iostream>
 #include <boost/xpressive/xpressive.hpp>

 using namespace boost::xpressive;

 int main()
 {
     std::string hello( "hello .* world!" );

     std::cout << "compile regex" << std::endl;
     sregex rex = sregex::compile( "\\Q.*\\E" );
     smatch what;

     std::cout << "Get Iterator" << std::endl;
     sregex_iterator cur( hello.begin(), hello.end(), rex );
     sregex_iterator end;

     std::cout << "begin search" << std::endl;
     while( cur != end ) {
         smatch const &what = *cur;
         std::cout << "found: " << what[0] << '\n';
         cur++;
     }

     return 0;
 }
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/3586>
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