https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94132
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html "A structure containing a flexible array member, or a union containing such a structure (possibly recursively), may not be a member of a structure or an element of an array. (However, these uses are permitted by GCC as extensions.)" The C++ compiler implements the stricter rule from ISO C, not the extension. (In reply to Amir Ansari from comment #2) > Because I know the flexible array member data isn't dangling. I have > allocated space immediately following the member that I would like to use. That's not how you're supposed to do it. You're supposed to dynamically allocate space for the struct and space after it, not place it inside a larger structute. > It has been working perfectly in previous versions. I'd say it's actually been undefined because G++ allowed pretty much any nonsense in terms of flexible array members.
