$NetBSD: patch-ad,v 1.4 2006/01/21 09:02:16 jmmv Exp $

--- boost/config/suffix.hpp.orig	2006-01-20 21:59:33.000000000 +0100
+++ boost/config/suffix.hpp
@@ -213,7 +213,7 @@
 // from here then add to the appropriate compiler section):
 //
 #if (defined(__MT__) || defined(_MT) || defined(_REENTRANT) \
-    || defined(_PTHREADS)) && !defined(BOOST_HAS_THREADS)
+    || defined(_PTHREADS) || defined(__DragonFly__) || defined(__APPLE__)) && !defined(BOOST_HAS_THREADS)
 #  define BOOST_HAS_THREADS
 #endif