Move comparison object in map/set move assignment

	* include/bits/stl_tree.h (_Rb_tree::operator=(_Rb_tree&&)): Move
	comparison object.
	* testsuite/23_containers/set/move_comparison.cc: New test.

From-SVN: r239897

libstdc++-v3/ChangeLog

 2016-08-31  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/bits/stl_tree.h (_Rb_tree::operator=(_Rb_tree&&)): Move
+	comparison object.
+	* testsuite/23_containers/set/move_comparison.cc: New test.
+
 	* testsuite/20_util/enable_shared_from_this/members/weak_from_this.cc:
 	New test.
 

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

@@ -1436,7 +1436,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     noexcept(_Alloc_traits::_S_nothrow_move()
 	     && is_nothrow_move_assignable<_Compare>::value)
     {
-      _M_impl._M_key_compare = __x._M_impl._M_key_compare;
+      _M_impl._M_key_compare = std::move(__x._M_impl._M_key_compare);
       constexpr bool __move_storage =
 	  _Alloc_traits::_S_propagate_on_move_assign()
 	  || _Alloc_traits::_S_always_equal();

libstdc++-v3/testsuite/23_containers/set/move_comparison.cc

+// Copyright (C) 2016 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 <set>
+#include <testsuite_allocator.h>
+#include <testsuite_hooks.h>
+
+struct Cmp
+{
+  Cmp() = default;
+  Cmp(const Cmp&) = default;
+  Cmp(Cmp&&) = default;
+  Cmp& operator=(const Cmp&) = default;
+  Cmp& operator=(Cmp&& c) { c.moved_from = true; return *this; }
+
+  bool moved_from = false;
+
+  bool operator()(int l, int r) const
+  {
+    VERIFY(!moved_from);
+    return l < r;
+  }
+};
+
+void
+test01()
+{
+  using allocator = __gnu_test::uneq_allocator<int>;
+  using test_type = std::set<int, Cmp, allocator>;
+  test_type s1(allocator(1)), s2(allocator(2));
+  s1.insert(1);
+  s1.insert(2);
+  s1.insert(3);
+  s2 = std::move(s1);
+  VERIFY(s1.key_comp().moved_from);
+}
+
+int
+main()
+{
+  test01();
+}