https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80605
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- (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)