https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99495
Bug ID: 99495
Summary: constexpr virtual destructor is used before its
definition
Product: gcc
Version: 11.0
URL: https://godbolt.org/z/GGY6aa
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: oleksandr.koval.dev at gmail dot com
Target Milestone: ---
I found this while playing with constexpr virtual functions. This code gives
"error: 'virtual constexpr Derived2::~Derived2()' used before its definition".
Error always refers to the last variable, e.g. if we swap d1 and d2
declarations, it will complain about d1. If x is decalred without constexpr it
works fine.
struct Base{
constexpr virtual ~Base() = default;
virtual int Get() const = 0; // non-constexpr
};
struct Derived1 : Base{
constexpr int Get() const override {
return 1;
}
};
struct Derived2 : Base{
constexpr int Get() const override {
return 2;
}
};
constexpr auto GetSum(){
const Derived1 d1;
const Derived2 d2;
const Base* pb1 = &d1;
const Base* pb2 = &d2;
return pb1->Get() + pb2->Get();
}
constexpr // error
int x = GetSum(); // OK if not in constexpr context
