[Bug c++/47412] Output: x = 31 but y = 30

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47412

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-01-22 
14:16:26 UTC ---
(In reply to comment #0)
>     x = 20 + x++;

This is undefined behaviour because there is no sequence point between the
increment and the assignment.

Compiling with -Wall warns you about it