An alternative approach is to use objects, and bless.

Imagine an Account class (an abstract base). Create two subclasses: ActiveAccount and DisabledAccount. You can now create

  ActiveAccount::disable
  {
    my ($self) = @_;
    bless $self, "DisabledAccount";
  }
[download]

The reblessed object will no longer have access to the methods in ActiveAccount. --Dave