sub lowercase {
   wantarray ? (map { lc } @_) : lc(shift);
}

##</code><code>##

sub lowercase {
	( wantarray ? sub{@_} : sub{shift} )->(
		map { lc } @_
	);
}

##</code><code>##

#!/usr/bin/env perl

use v5.14;
use returning { lreturn => sub { wantarray ? @_ : $_[0] } };

sub lowercase {
	lreturn map { lc; } @_;
	warn "this line never executes";
}

say for lowercase('Alice', 'Bob');
say scalar lowercase('Carol', 'Dave');