Merge to upstream r225300.

Change-Id: I2b23715db9ac129ff80aa78ad5824db0a4d6fbb3

test/std/utilities/tuple/tuple.tuple/tuple.assign/copy.pass.cpp

@@ -0,0 +1,52 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <tuple>
+
+// template <class... Types> class tuple;
+
+// tuple& operator=(const tuple& u);
+
+#include <tuple>
+#include <string>
+#include <cassert>
+
+int main()
+{
+    {
+        typedef std::tuple<> T;
+        T t0;
+        T t;
+        t = t0;
+    }
+    {
+        typedef std::tuple<int> T;
+        T t0(2);
+        T t;
+        t = t0;
+        assert(std::get<0>(t) == 2);
+    }
+    {
+        typedef std::tuple<int, char> T;
+        T t0(2, 'a');
+        T t;
+        t = t0;
+        assert(std::get<0>(t) == 2);
+        assert(std::get<1>(t) == 'a');
+    }
+    {
+        typedef std::tuple<int, char, std::string> T;
+        const T t0(2, 'a', "some text");
+        T t;
+        t = t0;
+        assert(std::get<0>(t) == 2);
+        assert(std::get<1>(t) == 'a');
+        assert(std::get<2>(t) == "some text");
+    }
+}