Sub signature

#!/usr/bin/env perl

# Pragmas
use 5.020; # Also turns on "use strict" ever since 5.012
use warnings;
no warnings qw(experimental::signatures);
use feature qw(signatures);

# Using a signature means less work to set up arguments
sub main ($utterance) {
  say $utterance;
}

main( "What a re-leaf!" ); # says it!