sub trim3a {
    return trim3a $_ if not @_;

    s/^\s+//, s/\s+$// for
                wantarray ? my @c = @_     :
        defined wantarray ? my $c = $_[-1] :
                                    @_;

    @c ? @c : $c ? $c : ();
}

sub trim3b {
    return trim3b $_ if not @_;

    my $w = wantarray;
    s/^\s+//, s/\s+$// for
                $w ? my @c = @_     :
        defined $w ? my $c = $_[-1] :
                             @_;

    @c ? @c : $c ? $c : ();
}