http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47902
--- Comment #3 from Daniel Richard G. <skunk at iskunk dot org> 2011-02-28 20:01:51 UTC --- I played around with this a bit, and found something rather amusing: sizeof(pid_t) ..... compiles just fine sizeof((pid_t)) ... parse error before `)' The extra parens do it in. And this is with (an older version of) GCC: % gcc -v Reading specs from /usr/bin/../lib/gcc-lib/powerpc-ibm-aix4.3.3.0/2.9-aix51-020209/specs gcc version 2.9-aix51-020209 This quirk might also be the cause of bug #47907.