That's really an interesting way of getting 1, not 2. Other interesting ways to get 1: 

my $one = !@!;
my $one = !!$];
my $one = /.*/;                # Side-effect: Changes $1, etc
my $one = $$/$$;
my $one = ()=$$;
my $one = @{[$$]};
my $one = 'a'^'P';             # Character set specific.
my $one = ord('b')-ord('a');   # Character set specific.

[download]

And 2: 

my $two = $one+$one;
my $two = $one<<$one;
my $two = ()=qw(a a);
my $two = @{[ qw(a a) ]};
my $two = ()=/(.*)(.*)/;       # Side-effect: Changes $1, etc
my $two = 'a'^'S';             # Character set specific.
my $two = ord('c')-ord('a');   # Character set specific.

[download]

None of these have side effects unless otherwise noted.
All of these run under use strict;.
All of these run silently under use warnings;.

In reply to Re^2: Adding 2 + 2 (digit-less 1) by ikegami
in thread Adding 2 + 2 by merlyn

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