Win8 Strawberry 5.8.9.5 (32)  Sun 11/22/2020  1:34:08
C:\@Work\Perl\monks
>perl
use strict;
use warnings;

use constant ADD_DATA    => qw(add    1);
use constant REMOVE_DATA => qw(remove 2);
use constant MODES       => (\&ADD_DATA, \&REMOVE_DATA);

warn &{(MODES)[0]};
warn &{(MODES)[1]};
^Z
add1 at - line 8.
remove2 at - line 9.