$ perl -MO=Deparse,-p -e 'my $str = " " x $col%$maxcol;'
(my $str = ((' ' x $col) % $maxcol));
-e syntax OK

##</code><code>##

$ perl -MO=Deparse,-p -e 'my $str = " " x ($col%$maxcol);'
(my $str = (' ' x ($col % $maxcol)));
-e syntax OK

##</code><code>##

$ perl -MO=Deparse,-p -e 'my $str = " " x $col > $maxcol ? $maxcol : $col;'
(my $str = (((' ' x $col) > $maxcol) ? $maxcol : $col));
-e syntax OK

##</code><code>##

$ perl -MO=Deparse,-p -e 'my $str = " " x ($col > $maxcol ? $maxcol : $col);'
(my $str = (' ' x (($col > $maxcol) ? $maxcol : $col)));
-e syntax OK

##</code><code>##

$ perl -MO=Deparse,-p -e 'length "    " x $expr + $margin'
length((('    ' x $expr) + $margin));
-e syntax OK

##</code><code>##

use feature 'diddler_precedence';