https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83732
--- Comment #2 from Stas Sergeev <stsp at users dot sourceforge.net> --- (In reply to Jonathan Wakely from comment #1) > The warning might be using the old C++98 definition of POD. Lets specify -std explicitly then: $ g++ -std=c++11 pod.cpp pod.cpp:11:16: warning: ignoring packed attribute because of unpacked non-POD field 'ttt tst::a' struct ttt a;