[Bug c++/56289] Bad unused value warning with comma operator

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56289



--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2013-02-11 
18:32:58 UTC ---

 (void) x, y;

You are only casting x to void and not y.