def wrap( obj )
      ptr = FFI::MemoryPointer.new( :uint64 )
      ptr.write_uint64( obj.object_id )
      ptr
    end
def wrap( obj )
      ptr = FFI::MemoryPointer.new( :uint64 )
      ptr.write_uint64( obj.object_id )
      ptr
    end
Returns a pointer to the object_id of +obj+