libdata-swap-perl binary package in Ubuntu Xenial amd64

 The Data::Swap module allows you to swap the contents of two referenced
 variables, even if they have different types.
 .
 The main application is to change the base type of an object after it has
 been created, for example for dynamic loading of data structures:
 .
  swap $self, bless $replacement, $newclass;
 .
 This module additionally contain the function "deref" which acts like a
 generic list-dereferencing operator.

Source package