PR69301 don't assume atomic<T> can default construct T

	PR libstdc++/69301
	* include/std/atomic (atomic<T>::load, atomic<T>::exchange): Use
	aligned buffer instead of default-initialized variable.
	* testsuite/29_atomics/atomic/69301.cc: New test.
	* include/experimental/memory (observer_ptr::release): Use reserved
	name.
	* include/ext/pointer.h (_Pointer_adapter::operator++(int))
	(_Pointer_adapter::operator--(int)): Likewise.

From-SVN: r244588

1 files changed, 56 insertions, 0 deletions

diff --git a/libstdc++-v3/testsuite/29_atomics/atomic/69301.cc b/libstdc++-v3/testsuite/29_atomics/atomic/69301.cc
new file mode 100644
index 0000000..1af3652
--- /dev/null
+++ b/libstdc++-v3/testsuite/29_atomics/atomic/69301.cc
@@ -0,0 +1,56 @@
+// Copyright (C) 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-do run { target c++11 } }
+
+#include <atomic>
+#include <testsuite_hooks.h>
+
+struct NonDefaultConstructible
+{
+  NonDefaultConstructible(int i) : val(i) { }
+  int val;
+};
+
+template class std::atomic<NonDefaultConstructible>;
+
+void
+test01()
+{
+  std::atomic<NonDefaultConstructible> a(1);
+  const auto n1 = a.exchange(2);
+  VERIFY( n1.val == 1 );
+  const auto n2 = a.load();
+  VERIFY( n2.val == 2 );
+}
+
+void
+test02()
+{
+  volatile std::atomic<NonDefaultConstructible> a(1);
+  const auto n1 = a.exchange(2);
+  VERIFY( n1.val == 1 );
+  const auto n2 = a.load();
+  VERIFY( n2.val == 2 );
+}
+
+int
+main()
+{
+  test01();
+  test02();
+}