Index: boost/interprocess/mem_algo/rbtree_best_fit.hpp
===================================================================
--- boost/interprocess/mem_algo/rbtree_best_fit.hpp	(revision 68413)
+++ boost/interprocess/mem_algo/rbtree_best_fit.hpp	(working copy)
@@ -317,7 +317,7 @@
    public:
    
    static const std::size_t Alignment = !MemAlignment
-      ? detail::alignment_of<detail::max_align>::value
+      ? std::size_t(detail::alignment_of<detail::max_align>::value)
       : MemAlignment
       ;