NAME

Data::Swap - Swap referenced variables, type-agnostic

SYNOPSIS

    use Data::Swap;

    my $p = [];
    my $q = {};
    print "$p $q\n";            # ARRAY(0x965cc) HASH(0x966b0)
    swap $p, $q;
    print "$p $q\n";            # HASH(0x965cc) ARRAY(0x966b0)

    my $x = {};
    my $y = $x;                 # $x and $y point to the same thing
    swap $x, [1, 2, 3];         # swap the referent with an array
    print "@$y\n";

DESCRIPTION

Should be fairly self-explanatory. This module allows you to swap two variables by reference. The module doesn't care about their type.

My own application of this function is to change the base type of an object after it has been created, like:

    swap $self, bless $replacement, $newclass;

(for on-demand loading of objects)

FUNCTIONS

This module has only one function, which is exported by default:

swap($ref1, $ref2)

Swaps the variable referenced by $ref1 by the one referenced by $ref2. The two variables may be of different types.

You can't swap an overloaded object with a non-overloaded one.

KNOWN ISSUES

Don't change the type of a directly accessible variable.. that is, don't do stuff like:

    my ($x, @y);
    swap \$x, \@y;
    print "@y";

Unless you enjoy segfaults ofcourse.

Unforunately, there is no good way for me detect this situation during swap.

AUTHOR

Matthijs van Duin <xmath@cpan.org>

Copyright (C) 2003 Matthijs van Duin. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.