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.
41 lines
732 B
C
41 lines
732 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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// Downcast.
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struct B {
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virtual void baz () {}
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};
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struct D : B { };
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constexpr bool
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fn ()
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{
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bool ok = true;
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B b;
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B *b1 = &b;
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if (D *pd = dynamic_cast<D*>(b1))
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ok = false;
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D d;
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B *b2 = &d;
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if (D *pd = dynamic_cast<D*>(b2))
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/*OK*/;
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else
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ok = false;
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return ok;
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}
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static_assert(fn ());
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constexpr D d;
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constexpr B b;
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constexpr B *b1 = const_cast<B*>(&b);
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constexpr B *b2 = const_cast<D*>(&d);
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static_assert(dynamic_cast<D*>(b2) == &d);
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static_assert(&dynamic_cast<D&>(*b2) == &d);
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static_assert(dynamic_cast<const B*>(&d) == &d);
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static_assert(&dynamic_cast<const B&>(d) == &d);
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