I can't help but wonder why you would require the caller to pass a parameter you're never going to use?

If there is a good reason, (and I cannot think of one), then given the not insignificant difference in performance:

$a='a'x1e6; $b=12345; 
cmpthese -1,{
    a=>q[ sub{ my( undef, $x ) = @_ }->( $a, $b ) ],
    b=>q[ sub{ my $x = $_[1]        }->( $a, $b ) ],
    c=>q[ sub{ my( $unused, $x );   }->( $a, $b ) ],
};;
       Rate    a    b    c
a 1703708/s   -- -19% -20%
b 2107186/s  24%   --  -1%
c 2129207/s  25%   1%   --

[download]

I'd be asking myself if I thought that assignment to undef was any clearer than assignment to a variable called $unused?

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re: Is undef list assignment a no-op? by BrowserUk
in thread Is undef list assignment a no-op? by repellent

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