use strict;
use warnings;
use constant {
  FOO => 0,
  BAR => 1,
  BAZ => 2
};

$var = BAZ;

my @array;
say $array[FOO];  # OK
say $array[BAH];  # Bareword "BAH" not allowed while "strict subs" in use
say $array[$var]; # OK

##</code><code>##

use strict;
use warnings;
use constant {
  FOO => "foo",
  BAR => "bar",
  BAZ => "baz"
};
my %hash;
say $hash{+FOO};  # OK
say $hash{+BAH};  # Bareword "BAH" not allowed while "strict subs" in use
say $hash{+shift} # Bonus