diff -Naur boost_1_51_0/boost/interprocess/smart_ptr/unique_ptr.hpp boost_1_51_0_patched/boost/interprocess/smart_ptr/unique_ptr.hpp
--- boost_1_51_0/boost/interprocess/smart_ptr/unique_ptr.hpp	2012-05-24 18:43:57.000000000 +0200
+++ boost_1_51_0_patched/boost/interprocess/smart_ptr/unique_ptr.hpp	2012-10-29 09:16:58.126024323 +0100
@@ -281,12 +281,11 @@
    deleter_const_reference get_deleter() const
    {  return ptr_.second();   }
 
-   //!Returns: An unspecified value that, when used in boolean
-   //!contexts, is equivalent to get() != 0.
+   //!Returns: A boolean value that is equivalent to get() != 0.
    //!
    //!Throws: nothing.
-   operator int nat::*() const
-   {  return ptr_.first() ? &nat::for_bool_ : 0;   }
+   operator bool () const
+   {  return ptr_.first();   }
 
    //!Postcondition: get() == 0.
    //!