Re: [Boost-users] xpressive: sregex_token_iterator assertion

From: Eric Niebler (eric_at_[hidden])
Date: 2008-06-04 23:21:53

Jesse Williamson wrote:
> Hi, folks!
> 
> This program suprises me by causing a runtime assertion:
> 
> =====
> #include <string>
> #include <boost/xpressive/xpressive.hpp>
> 
> using namespace boost::xpressive;
> 
> int main()
> {
>   std::string x("a\tb\tc");
> 
>   sregex_token_iterator   cur(x.begin(), x.end(), as_xpr("\t"), -1),
>                           end;
>   for(; cur != end; ++cur)
>    ;
> }
> =====
<snip>

Interesting. Currently the regex iterators hold a (bare) pointer to the 
regex to be used. If you pass in a temporary regex, it'll obviously not 
live long enough. It wouldn't be hard to make the regex iterators hold a 
reference count to the regex impl, which would make your code work. The 
down-side would be that copying regex iterators (a common operation?) 
would be more expensive.

Thanks for the report. While I ruminate about it, could you could file a 
bug on our bug tracker? (Click the "New Ticket" link at 
http://svn.boost.org/trac/boost/.) Thanks.

-- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com