#!/usr/bin/perl

use strict;
use warnings;

use constant ABC => 'abc';
use constant CDE => 'cde';
use Data::Dumper;

# print the constants value before the sub below has been compiled
# results in $VAR1 = 'abc'
BEGIN {
  print Dumper( ABC );
  print Dumper( CDE );
}

# this is in a sub to show that it's not necessary
# to actually call index to change the constants behaviour
sub some1 { index( shift, ABC ) };

# prefixing the constant with an "&" prevents the error
sub some2 { index( shift, &CDE ) };

# print the constants value after sub some has beenn compiled
# results in $VAR1 = *bc;
print Dumper( ABC );
print Dumper( CDE );