From a5183e3460a03df4dc388eb6f7715b25a84a5194 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Thu, 21 Feb 2019 18:06:53 -0600
Subject: [PATCH] include/poll.h and include/nuttx/compiler.h:  Update some
 comments; improved a conditional test.

---
 include/nuttx/compiler.h | 11 +++++++++--
 include/poll.h           |  2 +-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/include/nuttx/compiler.h b/include/nuttx/compiler.h
index c40e3b5cfe..49f9fdbeca 100644
--- a/include/nuttx/compiler.h
+++ b/include/nuttx/compiler.h
@@ -268,16 +268,23 @@
 #  endif
 
 /* ISO C11 supports anonymous (unnamed) structures and unions, added in
- * GCC 4.6 (but might be suppressed with -std= option)
+ * GCC 4.6 (but might be suppressed with -std= option).  ISO C++11 also
+ * adds un-named unions, but NOT unnamed structures (although compilers
+ * may support them).
  *
  * CAREFUL: This can cause issues for shared data structures shared between
  * C and C++ if the two versions do not support the same features.  Structures
  * and unions can lose binary compatibility!
+ *
+ * NOTE: The NuttX coding standard forbids the use of unnamed structures and
+ * unions within the OS.
  */
 
 #  undef CONFIG_HAVE_ANONYMOUS_STRUCT
 #  undef CONFIG_HAVE_ANONYMOUS_UNION
-#  if defined(__cplusplus) || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L)
+
+#  if (defined(__cplusplus) && __cplusplus >= 201103L) || \
+      (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L)
 #    define CONFIG_HAVE_ANONYMOUS_STRUCT 1
 #    define CONFIG_HAVE_ANONYMOUS_UNION 1
 #  endif
diff --git a/include/poll.h b/include/poll.h
index aa23550314..ed97a8f23b 100644
--- a/include/poll.h
+++ b/include/poll.h
@@ -114,7 +114,7 @@ typedef uint8_t pollevent_t;
 
 struct pollfd
 {
-  /* Standard field */
+  /* Standard fields */
 
   int          fd;      /* The descriptor being polled */
   pollevent_t  events;  /* The input event flags */