sub localised {
    package localised;
    use Scalar::Util 'reftype';

    my $ref = shift;
    my $reftype = reftype $ref or die "$ref is not a reference";
    my @old = $reftype eq 'SCALAR' ? $$ref
            : $reftype eq 'ARRAY'  ? @$ref
            : $reftype eq 'HASH'   ? %$ref
            : die sprintf "Unsupported reftype %s", reftype $ref;
    return bless [$ref, @old];
    
    sub DESTROY {
        my ($ref, @old) = @{+shift};
        my $reftype = reftype $ref;
        $reftype eq 'SCALAR' ? ($$ref)
      : $reftype eq 'ARRAY'  ?  @$ref
      :                         %$ref  = @old;
    }
}