Boost C++ Libraries: Ticket #6444: qi::lit() parses into a '\0' in 1.47 and 1.48

attachment set

mathstuf@… — Tue, 24 Jan 2012 20:16:13 GMT

attachment → qi.cxx

Small example code

attachment set

mathstuf@… — Tue, 24 Jan 2012 20:17:04 GMT

attachment → qi-output

Output from 1.46, 1.47, and 1.48

status changed; resolution set

Joel de Guzman — Wed, 25 Jan 2012 00:36:14 GMT

status new → closed
resolution → wontfix

Use char_ instead (as you hinted):

tok %=

+( qi::alnum

| qi::char_('-') | qi::char_('_') );

lit has an "unused" attribute ( http://tinyurl.com/6lu2stx ) while char gives you the character type of the enclosing character encoding namespace (e.g. ascii, unicode, etc.). The way "unused" attribute is synthesized is undefined.

The behavior you see is an upshot of the optimizations and refinement we did for 1.47 and higher. As such, for alternatives, we only synthesize the advertized attribute in cases like this where the client passed in a non-variant (std::string).

mathstuf@… — Wed, 25 Jan 2012 00:40:44 GMT

Right. That's fine. The bug is that an "unused" attribute should not insert NUL characters in the resulting match.

status changed; resolution deleted

Joel de Guzman — Wed, 25 Jan 2012 08:50:08 GMT

status closed → reopened
resolution wontfix

Fair enough. Let's open this for discussion then. There might be a "fix", but I'd like to discuss this in the Spirit mailing list. I'll re-open this ticket. Could you please post a message to the list here: http://boost-spirit.com/home/feedback-and-support/

Thanks!