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// PR c++/88337 - Implement P1327R1: Allow dynamic_cast/typeid in constexpr.
// { dg-do compile { target c++20 } }
#if __cpp_constexpr_exceptions >= 202411L
namespace std {
struct exception {
constexpr exception () noexcept {}
constexpr virtual ~exception () noexcept {}
constexpr exception (const exception &) = default;
constexpr exception &operator= (const exception &) = default;
constexpr virtual const char *what () const noexcept { return "std::exception"; }
};
struct bad_cast : public exception {
constexpr virtual ~bad_cast () noexcept {}
constexpr virtual const char *what () const noexcept { return "std::bad_cast"; }
};
}
#endif
// Private base.
struct P1 { virtual void p1(); };
struct P2 { virtual void p2(); };
struct B : private P1 { virtual void b(); };
struct C { virtual void c(); };
struct A : B, C, private P2 { virtual void a(); };
constexpr A a;
// P1 is a non-public base of A.
constexpr bool b1 = (dynamic_cast<B&>((P1&)a), false); // { dg-error "reference .dynamic_cast. failed" "" { target c++23_down } }
// { dg-message "static type .const P1. of its operand is a non-public base class of dynamic type .A." "" { target c++23_down } .-1 }
// { dg-error "uncaught exception" "" { target c++26 } .-2 }
// Don't error here.
static_assert (dynamic_cast<B*>((P1*)&a) == nullptr);
constexpr bool b2 = (dynamic_cast<C&>((P2&)a), false); // { dg-error "reference .dynamic_cast. failed" "" { target c++23_down } }
// { dg-message "static type .const P2. of its operand is a non-public base class of dynamic type .A." "" { target c++23_down } .-1 }
// { dg-error "uncaught exception" "" { target c++26 } .-2 }
static_assert (dynamic_cast<C*>((P1*)&a) == nullptr);
static_assert (dynamic_cast<C*>((P2*)&a) == nullptr);
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