https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80605
--- Comment #5 from lloda at bluewin dot ch --- (In reply to Jonathan Wakely from comment #3) > (In reply to lloda from comment #0) > > gcc 7.1.0 prints False for the following program. gcc 6.3.0 and others print > > True. > > > > // $CXX -std=c++14 -o stdlayout stdlayout.C > > Are you sure about that? I can only reproduce this with -std=c++17 > > (So it's probably due to the changes to the definition of aggregates in > C++17) You're right, I was actually trying with c++1z. Apologies. It does work with c++14.