Boost 1.40 merge from trunk

[SVN r55023]

example/doc_set.cpp

@@ -34,7 +34,7 @@ class MyClass : public set_base_hook<optimize_size<true> >
    friend bool operator> (const MyClass &a, const MyClass &b)
       {  return a.int_ > b.int_;  }
    friend bool operator== (const MyClass &a, const MyClass &b)
-      {  return a.int_ < b.int_;  }
+      {  return a.int_ == b.int_;  }
 };
 
 //Define a set using the base hook that will store values in reverse order