This causes an error in clang, but GCC didn't report the error. There is a core language undefined behavior in the constexpr function:



```
struct A {
    constexpr ~A() {}
};

constexpr int foo() {
    A a;
    a.~A();
    return 0;
}

int main() {
    constexpr auto x = foo();
    return x;
}
```

Compiler Explorer link: https://godbolt.org/z/PMfv8G9ev

This code compiles an error with Clang and MSVC.