Retro68/gcc/libstdc++-v3/testsuite/18_support/launder/1.cc
2017-10-07 02:16:47 +02:00

57 lines
1.4 KiB
C++

// Copyright (C) 2016-2017 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
// { dg-options "-std=gnu++17" }
// { dg-do run { target c++1z } }
#include <new>
#include <testsuite_hooks.h>
#include <testsuite_tr1.h>
void
test01()
{
struct S {
int i;
} s;
auto p = std::launder( &s.i );
VERIFY( p == &s.i );
}
void
test02()
{
// C++1z 1.8 [intro.object]
struct X { const int n; };
union U { X x; float f; };
U u = {{ 1 }};
u.f = 5.f; // OK, creates new subobject of u (9.3)
X *p = new (&u.x) X {2}; // OK, creates new subobject of u
VERIFY(p->n == 2); // OK
VERIFY(*std::launder(&u.x.n) == 2); // OK
// assert(u.x.n == 2); undefined behavior, u.x does not name new subobject
}
int
main()
{
test01();
test02();
}