From 9d3cef6dba2a199ba45f579d9c84c298e85c327c Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Thu, 18 Jan 2018 21:45:06 +0200
Subject: [PATCH] Define BOOST_NO_CXX11_THREAD_LOCAL for libc++ on Linux

---
 include/boost/config/stdlib/libcpp.hpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/boost/config/stdlib/libcpp.hpp b/include/boost/config/stdlib/libcpp.hpp
index 3d3f4ae4..1e77dca3 100644
--- a/include/boost/config/stdlib/libcpp.hpp
+++ b/include/boost/config/stdlib/libcpp.hpp
@@ -113,6 +113,13 @@
 #  define BOOST_NO_CXX11_THREAD_LOCAL
 #endif
 
+#if defined(__linux__) && !defined(BOOST_NO_CXX11_THREAD_LOCAL)
+// After libc++-dev is installed on Trusty, clang++-libc++ almost works,
+// except uses of `thread_local` fail with undefined reference to
+// `__cxa_thread_atexit`.
+#  define BOOST_NO_CXX11_THREAD_LOCAL
+#endif
+
 #if defined(__has_include)
 #if !__has_include(<shared_mutex>)
 #  define BOOST_NO_CXX14_HDR_SHARED_MUTEX