clang-3.5 compatibility

diff --git a/cds/compiler/cxx11_atomic.h b/cds/compiler/cxx11_atomic.h
index 08cdd3a39a8cbb7b289e6c420de02dd2f44a99ff..e83195611639fdaa70857c62aa450dceeb920872 100644 (file)
--- a/cds/compiler/cxx11_atomic.h
+++ b/cds/compiler/cxx11_atomic.h
@@ -4,6 +4,7 @@
 #define __CDS_COMPILER_CXX11_ATOMIC_H
 //@cond
 
+#include <stddef.h>     // ptrdiff_t
 #include <type_traits>  // make_unsigned
 #include <cds/details/defs.h>
 #include <cds/details/aligned_type.h>