https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89745
Bug ID: 89745
Summary: [[no_unique_address]] has no effect in some cases
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: tower120 at gmail dot com
Target Milestone: ---
[[no_unique_address]] has no effect in the following case:
https://wandbox.org/permlink/pcMbjWGcdKL3aHJS
template<class F, class S>
struct alternative_pair{
[[no_unique_address]] F first;
[[no_unique_address]] S second;
};
int main(){
struct empty{};
using Data = void*;
using P1 = alternative_pair<Data, empty>;
using P2 = alternative_pair<P1, empty>;
std::cout << sizeof(Data) << std::endl;
std::cout << sizeof(P1) << std::endl;
std::cout << sizeof(P2) << std::endl;
return 0;
}
Output: 8 8 16
Expected: 8 8 8
