When adding a new function object to the kernel you must:

  -- possibly change include/CGAL/Kernel/function_objects.h
     to add a new function object "builder" in namespace internal::
  -- change include/CGAL/Kernel/interface_macros.h
     to add the actual function object class and its corresponding 
     member function that returns an object of this class 
  -- change test/Kernel/include/CGAL/_test_new_2.h and/or
     test/Kernel/include/CGAL/_test_new_3.h to add the test
     for this function object.
  -- in the directory doc_tex/kernel/Ref add a file called
     Kernel_<NewFunctionObject> that describes the requirements for
     this function object type (see the other similarly named files in this
     directory)
      -- This functor should have a SeeAlso entry for the global function(s)
         or class(es) that provide the same functionality in the imperative
         interface
  -- add <New_function_object> to the set of requirements for the Kernel
     concept in the file doc_tex/kernel/Ref/Kernel.tex.  
  -- in the file doc_tex/kernel/Ref/ref_manual.tex add the command
        \input{Ref/Kernel_<New function object>} 
     in the proper place 
  -- in the file doc_tex/kernel/kernel_toc add a ccRefConceptPage command
     for the page in the proper place.