https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102401
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Why do you think GCC is not right? The Item class has 3 bytes of padding, and the Data class doesn't have any. So, when evaluated at runtime, it would be a UB, while during constant evaluation it has to be an error.