BEGIN {
  my $constants = (
    FOO => 'foo',
    BAR => 'bar',
    BAZ => 'baz',
  );
  foreach my $name ( keys %constants ) {
    no strict 'refs';
    *{$name} = sub () { $constants{$name} };
  }
  ...
}</blockquote>

##</code><code>##

BEGIN {
    require constant;
    my %constants = (
        FOO => 'foo',
        BAR => 'bar',
        BAZ => 'baz',
    );
    foreach my $name ( keys %constants ) {
        constant->import( $name => $constants{$name} );
    }
}