From 743dc92612378063da5a41a252556878bb7b0e0c Mon Sep 17 00:00:00 2001
From: jzmaddock <john@johnmaddock.co.uk>
Date: Wed, 30 Mar 2016 19:36:22 +0100
Subject: [PATCH] Don't use __is_identifier unless it's actually defined.

---
 include/boost/config/compiler/clang.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/boost/config/compiler/clang.hpp b/include/boost/config/compiler/clang.hpp
index a1463a0d..3ba62096 100644
--- a/include/boost/config/compiler/clang.hpp
+++ b/include/boost/config/compiler/clang.hpp
@@ -39,7 +39,7 @@
 #  define BOOST_NO_TYPEID
 #endif
 
-#if !__is_identifier(__int64) && !defined(__GNUC__)
+#if defined(__is_identifier) && !__is_identifier(__int64) && !defined(__GNUC__)
 #  define BOOST_HAS_MS_INT64
 #endif