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// PR c++/88337 - Implement P1327R1: Allow dynamic_cast/typeid in constexpr. // { dg-do compile { target c++20 } }
// Adopted from g++.old-deja/g++.other/dyncast1.C. // But use reference dynamic_cast.
// 1. downcast // 1.1. single inheritance case
struct A { virtual void a(); }; struct AA : A {}; struct B : A {}; struct BB : B {}; class C : B {}; struct D : C {};
struct CC : B {}; class DD : CC {};
class CCC : protected B {}; class DDD : protected CCC {};
constexpr D d; constexpr bool b01 = (dynamic_cast<D&> ((A&)d), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const A. of its operand is a non-public base class of dynamic type .D." "" { target *-*-* } .-1 } constexpr bool b02 = (dynamic_cast<D&> ((B&)d), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const B. of its operand is a non-public base class of dynamic type .D." "" { target *-*-* } .-1 } static_assert (&d == &dynamic_cast<const D&> ((C&)d)); constexpr bool b03 = (dynamic_cast<C&> ((B&)d), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const B. of its operand is a non-public base class of dynamic type .D." "" { target *-*-* } .-1 }
constexpr DD dd; constexpr bool b04 = (dynamic_cast<DD&> ((A&)dd), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const A. of its operand is a non-public base class of dynamic type .DD." "" { target *-*-* } .-1 } constexpr bool b05 = (dynamic_cast<DD&> ((B&)dd), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const B. of its operand is a non-public base class of dynamic type .DD." "" { target *-*-* } .-1 }
constexpr DDD ddd; constexpr bool b06 = (dynamic_cast<DDD&> ((A&)ddd), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const A. of its operand is a non-public base class of dynamic type .DDD." "" { target *-*-* } .-1 } constexpr bool b07 = (dynamic_cast<DDD&> ((B&)ddd), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const B. of its operand is a non-public base class of dynamic type .DDD." "" { target *-*-* } .-1 } constexpr bool b08 = (dynamic_cast<CCC&> ((B&)ddd), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const B. of its operand is a non-public base class of dynamic type .DDD." "" { target *-*-* } .-1 }
// 1.2. multiple inheritance case // 1.2.1. all bases are public struct E : D, CC {}; struct EE : CC, D {}; //Will search in reverse order.
constexpr E e; constexpr bool b09 = (dynamic_cast<E&> ((A&)(D&)e), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .A. of its operand is a non-public base class of dynamic type .E." "" { target *-*-* } .-1 } constexpr bool b10 = (dynamic_cast<E&> ((B&)(D&)e), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .B. of its operand is a non-public base class of dynamic type .E." "" { target *-*-* } .-1 } static_assert (&e == &dynamic_cast<E&> ((C&)(D&)e)); static_assert (&e == &dynamic_cast<E&> ((B&)(CC&)e)); static_assert (&(CC&)e == &dynamic_cast<CC&> ((B&)(CC&)e));
constexpr EE ee; constexpr bool b11 = (dynamic_cast<EE&> ((A&)(D&)ee), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .A. of its operand is a non-public base class of dynamic type .EE." "" { target *-*-* } .-1 } constexpr bool b12 = (dynamic_cast<EE&> ((B&)(D&)ee), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .B. of its operand is a non-public base class of dynamic type .EE." "" { target *-*-* } .-1 } static_assert (&ee == &dynamic_cast<EE&> ((C&)(D&)ee)); static_assert (&ee == &dynamic_cast<EE&> ((B&)(CC&)ee)); static_assert (&(CC&)ee == &dynamic_cast<CC&> ((B&)(CC&)ee));
// 1.2.2 one or more branches are nonpublic
struct X : private BB, E {}; struct Y : AA, private B {};
class XX : BB, E {};
constexpr X x; static_assert (&x == &dynamic_cast<X&>((B&)(CC&)(E&)x));
constexpr XX xx; constexpr bool b13 = (dynamic_cast<XX&>((B&)(CC&)(E&)xx), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .B. of its operand is a non-public base class of dynamic type .XX." "" { target *-*-* } .-1 }
constexpr Y y; constexpr bool b14 = (dynamic_cast<Y&>((B&)y), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const B. of its operand is a non-public base class of dynamic type .Y." "" { target *-*-* } .-1 } constexpr bool b15 = (dynamic_cast<Y&>((A&)(B&)y), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .A. of its operand is a non-public base class of dynamic type .Y." "" { target *-*-* } .-1 }
// 2. crosscast
struct J { virtual void j(); }; struct K : CC, private J {}; class KK : J, CC{}; constexpr bool b16 = (dynamic_cast<CC&> ((B&)(D&)e), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .B. of its operand is a non-public base class of dynamic type .CC." "" { target *-*-* } .-1 } static_assert (&(CC&)e == &dynamic_cast<CC&> ((C&)(D&)e));
constexpr K k; constexpr bool b17 = (dynamic_cast<J&> ((B&)k), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "dynamic type .K. of its operand does not have an unambiguous public base class .J." "" { target *-*-* } .-1 } constexpr KK kk; constexpr bool b18 = (dynamic_cast<J&> ((CC&)kk), true); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "static type .const CC. of its operand is a non-public base class of dynamic type .KK." "" { target *-*-* } .-1 }
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