57 lines
1.4 KiB
C++
57 lines
1.4 KiB
C++
// Copyright (C) 2016-2020 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License along
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// with this library; see the file COPYING3. If not see
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// <http://www.gnu.org/licenses/>.
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// { dg-options "-std=gnu++17" }
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// { dg-do run { target c++17 } }
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#include <new>
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#include <testsuite_hooks.h>
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#include <testsuite_tr1.h>
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void
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test01()
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{
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struct S {
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int i;
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} s;
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auto p = std::launder( &s.i );
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VERIFY( p == &s.i );
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}
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void
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test02()
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{
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// C++17 1.8 [intro.object]
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struct X { const int n; };
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union U { X x; float f; };
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U u = {{ 1 }};
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u.f = 5.f; // OK, creates new subobject of u (9.3)
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X *p = new (&u.x) X {2}; // OK, creates new subobject of u
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VERIFY(p->n == 2); // OK
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VERIFY(*std::launder(&u.x.n) == 2); // OK
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// assert(u.x.n == 2); undefined behavior, u.x does not name new subobject
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}
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int
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main()
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{
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test01();
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test02();
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}
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