$ perl -v | head -2 | tail -1
This is perl 5, version 18, subversion 2 (v5.18.2) built for x86_64-linux-thread-multi
$ alias perle
alias perle='perl -Mstrict -Mwarnings -Mautodie=:all -E'

##</code><code>##

$ perle 'use constant X => (1,3); my @y = "a".."z"; say for @y[X]'
Scalar value @y[X] better written as $y[X] at -e line 1.
b
d
$ perle 'use constant X => (1,3); my @y = "a".."z"; say for @y[+X]'
Scalar value @y[+X] better written as $y[+X] at -e line 1.
b
d
$ perle 'use constant X => (1,3); my @y = "a".."z"; say for @y[X()]'
b
d

##</code><code>##

$ perle 'use constant X => 1,3; my @y = "a".."z"; say for @y[(X)]'
b
d