diff -r -u boost_1_38_0/boost/functional/hash/detail/float_functions.hpp boost_1_38_vxworks/boost/functional/hash/detail/float_functions.hpp
--- boost_1_38_0/boost/functional/hash/detail/float_functions.hpp	2008-11-20 16:53:20.000000000 -0500
+++ boost_1_38_vxworks/boost/functional/hash/detail/float_functions.hpp	2009-04-18 16:40:47.867875000 -0400
@@ -59,6 +59,10 @@
 #    define BOOST_HASH_USE_OVERLOAD_FLOAT_FUNCS
 #  endif
 
+// vxWorks. It has its own math library, but uses Dinkumware STL
+#elif defined(__VXWORKS__)
+#  define BOOST_HASH_USE_OVERLOAD_FLOAT_FUNCS
+
 // Dinkumware.
 #elif (defined(_YVALS) && !defined(__IBMCPP__)) || defined(_CPPLIB_VER)
 // Some versions of Visual C++ don't seem to have the C++ overloads but they