b04445d4a8
C++20 isn't final quite yet, but all that remains is formalities, so let's go ahead and change all the references. I think for the next C++ standard we can just call it C++23 rather than C++2b, since the committee has been consistent about time-based releases rather than feature-based. gcc/c-family/ChangeLog 2020-05-13 Jason Merrill <jason@redhat.com> * c.opt (std=c++20): Make c++2a the alias. (std=gnu++20): Likewise. * c-common.h (cxx_dialect): Change cxx2a to cxx20. * c-opts.c: Adjust. * c-cppbuiltin.c: Adjust. * c-ubsan.c: Adjust. * c-warn.c: Adjust. gcc/cp/ChangeLog 2020-05-13 Jason Merrill <jason@redhat.com> * call.c, class.c, constexpr.c, constraint.cc, decl.c, init.c, lambda.c, lex.c, method.c, name-lookup.c, parser.c, pt.c, tree.c, typeck2.c: Change cxx2a to cxx20. libcpp/ChangeLog 2020-05-13 Jason Merrill <jason@redhat.com> * include/cpplib.h (enum c_lang): Change CXX2A to CXX20. * init.c, lex.c: Adjust.
21 lines
704 B
C
21 lines
704 B
C
// PR c++/88337 - Implement P1327R1: Allow dynamic_cast/typeid in constexpr.
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// { dg-do compile { target c++20 } }
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// Here the hint turns out to be wrong: A is a public base of B2, but the
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// dynamic_cast operand is not that subobject, but rather a sibling base of
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// B2.
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struct A { virtual void f(); };
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struct B1: A { };
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struct B2: A { };
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struct C: B1, B2 { };
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constexpr C c;
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constexpr A *ap = (B1*)&c;
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constexpr A &ar = (B1&)c;
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constexpr auto p = dynamic_cast<B2*>(ap);
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static_assert (p != nullptr);
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constexpr auto p2 = dynamic_cast<B2&>(ar);
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static_assert(dynamic_cast<B2*>(ap) == (B2*)&c);
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static_assert(dynamic_cast<B2*>((B1*)&c) == (B2*)&c);
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static_assert(&dynamic_cast<B2&>((B1&)c) == &(B2&)c);
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