https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110245
Bug ID: 110245
Summary: constant evaluation fails with uninitialized union and
default constructor
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: danakj at orodu dot net
Target Milestone: ---
```
struct Store {
constexpr Store() {}
union {
int i;
};
bool b = false;
};
struct C {
constexpr C() = default;
Store s;
};
int main() {
constexpr auto c = C(); //
}
```
This should compile but does not, GCC complains that it refers to an
incompletely initialized variable. Union members are not required to be active.
https://godbolt.org/z/G9vcosTG1
Reproduced on GCC trunk and GCC 11.
