Merge to upstream r225300.

Change-Id: I2b23715db9ac129ff80aa78ad5824db0a4d6fbb3

test/std/input.output/file.streams/fstreams/fstream.cons/string.pass.cpp

@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <fstream>
+
+// template <class charT, class traits = char_traits<charT> >
+// class basic_fstream
+
+// explicit basic_fstream(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
+
+#include <fstream>
+#include <cassert>
+#include "platform_support.h"
+
+int main()
+{
+    std::string temp = get_temp_file_name();
+    {
+        std::fstream fs(temp,
+                        std::ios_base::in | std::ios_base::out
+                                          | std::ios_base::trunc);
+        double x = 0;
+        fs << 3.25;
+        fs.seekg(0);
+        fs >> x;
+        assert(x == 3.25);
+    }
+    std::remove(temp.c_str());
+    {
+        std::wfstream fs(temp,
+                         std::ios_base::in | std::ios_base::out
+                                           | std::ios_base::trunc);
+        double x = 0;
+        fs << 3.25;
+        fs.seekg(0);
+        fs >> x;
+        assert(x == 3.25);
+    }
+    std::remove(temp.c_str());
+}