https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105864
--- Comment #5 from Ivan Sorokin <vanyacpp at gmail dot com> --- I would suggest (In reply to Andrew Pinski from comment #4) > nullptr_t t, t1 = nullptr; > __builtin_memcpy(&a[0], &t, sizeof(t)); > So I suspect this should be marked as invalid. The questions is how GCC defines memcpy'ing from nullptr_t. Should it be required to read zero bytes? Or null pointer value? What about systems where the value of null pointer is not zero? In any case I don't think memcpy'ing nullptr_t into a different type is particularly useful or used anywhere (I might be wrong). So I suggest defining nullptr_t as an empty type containing only padding bytes. In this case memcpy should just read the padding bytes.
