use Smart::Comments;    # Enable special comments for debugging

my $data_structure  = {
    a => [ 1, 2, 3 ],
};
my $scalar          = 42;

### This is a comment.
### <now> I'm happy.
### $data_structure
### $scalar

#my $max        = 2**4;     # slow
 my $max        = 2**2;     # fast

for (0..$max) {         ### for1...         done
    sleep(1);
};

for (0..$max) {         ### for2 |===[%]    |
    sleep(1);
};

##</code><code>##

1:    say "var: $var";     # DEBUG
2:    say '$var', $var;    # DEBUG
2:    say $var;            # DEBUG
3:    say $var;

##</code><code>##

my $tmp    = scalar @foobar;
### Elements count: $tmp

##</code><code>##

use Smart::Comments '###', '####';
###   $foo          # $foo will be dumped
####  $foo          # $foo will be dumped
##### $foo          # nothing happens

##</code><code>##

use Smart::Comments;
###   $foo          # $foo will be dumped
no Smart::Comments;
###   $foo          # nothing happens