https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111511
Bug ID: 111511
Summary: Incorrect ADL in std::to_array in GCC 11/12/13
Product: gcc
Version: 13.2.1
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: de34 at live dot cn
Target Milestone: ---
The following program is incorrectly rejected when using libstdc++
(https://godbolt.org/z/x6K6r5svM).
```
#include <array>
#include <utility>
struct incomplete;
template<class T>
struct holder {
T t;
};
using validator = holder<incomplete>*;
int main()
{
validator a[1]{};
(void) std::to_array(a);
(void) std::to_array(std::move(a));
}
```
The error is caused by aunqualified calls to the `__to_array` internal
function, which triggers ADL for `incomplete` and requires it to be complete.
Not sure whether this should be WONTFIX since the implementation is
fundamentally changed in GCC 14 (PR 110167).
