re PR libstdc++/64476 (std::uninitialized_copy tests assignability the wrong way, resulting in performance pessimization)

	PR libstdc++/64476
	* include/bits/stl_uninitialized.h (uninitialized_copy): Fix
	is_assignable arguments.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy/64476.cc:
	New.

From-SVN: r219398

3 files changed, 76 insertions, 2 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 83c1add..c27250d 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2015-01-09  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/64476
+	* include/bits/stl_uninitialized.h (uninitialized_copy): Fix
+	is_assignable arguments.
+	* testsuite/20_util/specialized_algorithms/uninitialized_copy/64476.cc:
+	New.
+
 2015-01-09  Andreas Tobler  <andreast@gcc.gnu.org>
 
 	* libsupc++/unwind-cxx.h: Revert previous commit.
diff --git a/libstdc++-v3/include/bits/stl_uninitialized.h b/libstdc++-v3/include/bits/stl_uninitialized.h
index 00659e9..61a1561 100644
--- a/libstdc++-v3/include/bits/stl_uninitialized.h
+++ b/libstdc++-v3/include/bits/stl_uninitialized.h
@@ -115,8 +115,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       const bool __assignable = true;
 #else
       // trivial types can have deleted assignment
-      typedef typename iterator_traits<_InputIterator>::reference _RefType;
-      const bool __assignable = is_assignable<_ValueType1, _RefType>::value;
+      typedef typename iterator_traits<_InputIterator>::reference _RefType1;
+      typedef typename iterator_traits<_ForwardIterator>::reference _RefType2;
+      const bool __assignable = is_assignable<_RefType2, _RefType1>::value;
 #endif
 
       return std::__uninitialized_copy<__is_trivial(_ValueType1)
diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/64476.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/64476.cc
new file mode 100644
index 0000000..6369b17
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/64476.cc
@@ -0,0 +1,65 @@
+// Copyright (C) 2015 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++11" }
+
+#include <memory>
+#include <testsuite_hooks.h>
+
+struct X
+{
+  X() = default;
+  X(X const &) = default;
+  X& operator=(X const&) = delete;
+};
+
+static_assert(__is_trivial(X), "X is trivial");
+
+int constructed = 0;
+int assigned = 0;
+
+struct Y
+{
+  Y() = default;
+  Y(Y const &) = default;
+  Y& operator=(Y const&) = default;
+
+  Y(const X&) { ++constructed; }
+  Y& operator=(const X&)& { ++assigned; return *this; }
+  Y& operator=(const X&)&& = delete;
+  Y& operator=(X&&) = delete;
+};
+
+static_assert(__is_trivial(Y), "Y is trivial");
+
+void
+test01()
+{
+  X a[100];
+  Y b[100];
+
+  std::uninitialized_copy(a, a+10, b);
+
+  VERIFY(constructed == 0);
+  VERIFY(assigned == 10);
+}
+
+int
+main()
+{
+  test01();
+}