https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98071
Bug ID: 98071
Summary: no_unique_address and reusing tail padding
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: barry.revzin at gmail dot com
Target Milestone: ---
Simple example:
struct A {
int x;
char y;
};
template <class T>
struct B {
[[no_unique_address]] T t;
bool u;
};
static_assert(sizeof(B<A>) == sizeof(A));
The data member "t" is potentially-overlapping, and its three bytes of padding
could be used to fit the "u" member. But gcc doesn't do this at the moment, and
so sizeof(B<A>) is 12. On clang, sizeof(B<A>) is 8, as desired.
