--- boost_1_51_0/libs/thread/src/pthread/once.cpp.orig	2012-05-22 19:03:15.000000000 +0200
+++ boost_1_51_0/libs/thread/src/pthread/once.cpp	2012-08-31 11:32:13.367850688 +0200
@@ -8,6 +8,9 @@
 #include <boost/assert.hpp>
 #include <pthread.h>
 #include <stdlib.h>
+#if defined BOOST_THREAD_PATCH
+#include <string.h> // memcmp.
+#endif
 #include <memory>
 
 namespace boost
--- boost_1_58_0/libs/thread/src/pthread/thread.cpp.orig	2015-03-21 15:44:02.000000000 +0100
+++ boost_1_58_0/libs/thread/src/pthread/thread.cpp	2015-05-14 18:28:41.638216099 +0200
@@ -124,7 +124,8 @@
                 }
                 ~delete_current_thread_tls_key_on_dlclose_t()
                 {
-                    if (current_thread_tls_init_flag.epoch!=BOOST_ONCE_INITIAL_FLAG_VALUE)
+                    const boost::once_flag uninitialized=BOOST_ONCE_INIT;
+                    if (memcmp(&current_thread_tls_init_flag,&uninitialized,sizeof(boost::once_flag)))
                     {
                         pthread_key_delete(current_thread_tls_key);
                     }