Mercurial > hg > CbC > CbC_gcc
view gcc/testsuite/g++.dg/cpp2a/constexpr-dynamic11.C @ 145:1830386684a0
gcc-9.2.0
author | anatofuz |
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date | Thu, 13 Feb 2020 11:34:05 +0900 |
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// PR c++/88337 - Implement P1327R1: Allow dynamic_cast/typeid in constexpr. // { dg-do compile { target c++2a } } // { dg-additional-options "-fdelete-null-pointer-checks" } // dynamic_cast in a constructor. // [class.cdtor]#6: "If the operand of the dynamic_cast refers to the object // under construction or destruction and the static type of the operand is not // a pointer to or object of the constructor or destructor's own class or one // of its bases, the dynamic_cast results in undefined behavior. struct V { virtual void f(); }; struct A : V { }; struct B : V { constexpr B(V*, A*); }; struct D : A, B { constexpr D() : B((A*)this, this) { } // { dg-message "in 'constexpr' expansion of" } }; constexpr B::B(V* v, A* a) { // well-defined: v of type V*, V base of B results in B* B* b = dynamic_cast<B*>(v); if (b != nullptr) __builtin_abort (); B& br = dynamic_cast<B&>(*v); // { dg-error "reference .dynamic_cast. failed" } // { dg-message "dynamic type .A. of its operand does not have an unambiguous public base class .B." "" { target *-*-* } .-1 } } constexpr D d; // { dg-message "in 'constexpr' expansion of" }