[boost] [svn][function] missing include is_void.hpp?

The changeset 43884 added some code using is_void, but it seems is_void.hpp is not included somewhere by Boost.Function. I think boost/function/detail/prologue.hpp should include it, right? I post this because today's svn cannot compile (with VC9). Link to changeset 43884: (http://svn.boost.org/trac/boost/changeset/43884/trunk/boost/function/functio...)