$ perl -MO=Deparse,-p junk
sub non_commutative () {
    use warnings;
    return(17);
}
use warnings;
($x = (10 * non_commutative));
($y = (non_commutative * 10));
print("$x\n$y\n\n");
($x = (10 + non_commutative));
($y = (non_commutative + 10));
print("$x\n$y\n");
junk syntax OK