PR libstdc++/82966 fix swapping of node handles

	PR libstdc++/82966
	* include/bits/node_handle.h (_Node_handle_common::_M_swap): Use value
	instead of type.
	* testsuite/23_containers/set/modifiers/node_swap.cc: New.

From-SVN: r260226

libstdc++-v3/ChangeLog

+2018-05-14  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/82966
+	* include/bits/node_handle.h (_Node_handle_common::_M_swap): Use value
+	instead of type.
+	* testsuite/23_containers/set/modifiers/node_swap.cc: New.
+
 2018-05-13  Ville Voutilainen  <ville.voutilainen@gmail.com>
 
 	PR libstdc++/80165

libstdc++-v3/include/bits/node_handle.h

@@ -109,7 +109,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       {
 	using std::swap;
 	swap(_M_ptr, __nh._M_ptr);
-	if (_AllocTraits::propagate_on_container_swap
+	if (_AllocTraits::propagate_on_container_swap::value
 	    || !_M_alloc || !__nh._M_alloc)
 	  _M_alloc.swap(__nh._M_alloc);
 	else

libstdc++-v3/testsuite/23_containers/set/modifiers/node_swap.cc

+// Copyright (C) 2018 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++17 } }
+
+#include <set>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  // PR libstdc++/82966
+  std::set<int>::node_type n1, n2;
+  n1.swap(n2);
+  VERIFY( n1.empty() );
+  VERIFY( n2.empty() );
+}
+
+void
+test02()
+{
+  std::set<int> s{1, 2};
+  std::set<int>::node_type n1 = s.extract(1), n2;
+  swap(n1, n2);
+  VERIFY( n1.empty() );
+  VERIFY( !n2.empty() );
+}
+
+int main()
+{
+  test01();
+  test02();
+}