Implement N3672, optional<T>.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@189772 91177308-0d34-0410-b5e6-96231b3b80d8

test/utilities/optional/optional.bad_optional_access/char_pointer.pass.cpp

@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+// class bad_optional_access;
+// explicit bad_optional_access(const char* what_arg);
+
+#include <optional>
+#include <string>
+#include <cstring>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    const char* s = "message";
+    std::bad_optional_access e(s);
+    assert(std::strcmp(e.what(), s) == 0);
+#endif  // _LIBCPP_STD_VER > 11
+}