https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121945
Bug ID: 121945
Summary: g++ rejects constructor with unsatisfied constraint
Product: gcc
Version: 15.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: avi at scylladb dot com
Target Milestone: ---
Consider
```
#include <concepts>
template <typename T>
struct a {
T v;
a(a<int> x) requires (!std::same_as<T, int>) : v(x.v) {}
};
```
g++ 15.2 complains:
```
error: invalid constructor; you probably meant 'a<int> (const a<int>&)
```
But the constructor should be ignored due to the unsatisfied constraint. For
any T that isn't `int`, it's a valid converting constructor.
