Add a test to make sure that implicit conversion from error_code to bool will fail

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@292969 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/diagnostics/syserr/syserr.errcode/syserr.errcode.observers/bool.fail.cpp

@@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// XFAIL: c++03
+
+// <system_error>
+
+// class error_code
+
+// explicit operator bool() const;
+
+#include <system_error>
+
+bool test_func(void)
+{
+    const std::error_code ec(0, std::generic_category());
+    return ec;   // conversion to bool is explicit; should fail.
+}
+
+int main()
+{
+    return 0;
+}
+