Move test into test/std subdirectory.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@224658 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/strings/basic.string/string.access/back.pass.cpp

@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <string>
+
+// const charT& back() const;
+//       charT& back();
+
+#ifdef _LIBCPP_DEBUG
+#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0))
+#endif
+
+#include <string>
+#include <cassert>
+
+#include "min_allocator.h"
+
+template <class S>
+void
+test(S s)
+{
+    const S& cs = s;
+    assert(&cs.back() == &cs[cs.size()-1]);
+    assert(&s.back() == &s[cs.size()-1]);
+    s.back() = typename S::value_type('z');
+    assert(s.back() == typename S::value_type('z'));
+}
+
+int main()
+{
+    {
+    typedef std::string S;
+    test(S("1"));
+    test(S("1234567890123456789012345678901234567890"));
+    }
+#if __cplusplus >= 201103L
+    {
+    typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
+    test(S("1"));
+    test(S("1234567890123456789012345678901234567890"));
+    }
+#endif
+#ifdef _LIBCPP_DEBUG
+    {
+        std::string s;
+        char c = s.back();
+        assert(false);
+    }
+#endif
+}