[Jason, can you pontificate on tail-padding and the upcoming C++
standard with regards to bitfields?]
so you wasn't convinced about my worries about tail-padding re-use?
To answer your question, I believe we can't touch past the last field
(into the padding) if the subsequent record will be packed into the
first's padding.
struct A {
int a : 17;
};
struct B : public A {
char c;
};
So here, if <c> gets packed into the tail-padding of A, we can't touch
the padding of A when storing into <a>. These are different structures,
and I assume would be treated as nested structures, which are distinct
memory locations.
Is there a way of distinguishing this particular variant (possible
tail-packing), or will we have to disallow storing into the record tail
padding altogether? That would seriously suck.
Aldy
