Suppose you'd write a function like map, its first argument plays a very different role than the rest - which can be any length. Wouldn't it make sense to write: 
    sub my_map {
        my $special_thingy = shift;
        foreach my $item (@_) {
            apply($special_thingy, $item);
        }
    }

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Starting with 
    my ($special_thingy, @list_of_items) = @_;

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is a potentially costly operation, since you are copying everything else in @_ - and it is slightly different as you lose the aliasing. And writing: 
    sub my_map {
        foreach my $item (@_[1 ..$#_]) {
            apply($_[0], $item);
        }
    }

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or 
    sub my_map {
        for (my $i = 1; $i < @_; $i++) {
            apply($_[0], $_[$i]);
        }
    }

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is not something I fancy.

In reply to Re: shift vs @_ by Anonymous Monk
in thread shift vs @_ by Zadeh

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