use warnings;
use strict;

my $one = 1;

$one += 0 || warn "||\n";
$one += 0 or warn "or\n";

$one += 0 && warn "&&\n";
$one += 0 and warn "and\n";

##</code><code>##

||
and

##</code><code>##

($one += 0) || warn "||\n";