http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58772
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> --- The syntax would be int main() { Actor *act; ::posix_memalign (&act, 16, sizeof (Actor)); new (*act) Actor; } that is, you have to use a different allocator. Paolo, does libstdc++ provide a custom allocator for aligned memory? Is this issue going to be resolved with C++1y?