sub some_func {
  my $saveDir = new PreserveWD;
  # Do stuff
}

##</code><code>##

package PreserveWD;

use strict 'vars';
use Carp;
use Cwd;


sub back {
  my $self = shift;
  chdir($$self) or confess("Cannot chdir to $$self: $!");
}

sub new {
  my $cwd;
  return tie $cwd, 'PreserveWD';
}

sub TIESCALAR {
  my ($type, $dir) = @_;
  $dir ||= cwd();
  return bless \$dir, $type;
}

*DESTROY = *back;

1;