I know that it doesn't have the elegance of what you're looking for, but why not just build in the default? 
sub push (\@;@) {
    CORE::push ( @{+shift}, @_ ? @_ : $_ )
}

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(Incidentally, this works for me, but is it guaranteed to do so? I seem to remember—but can't find—a discussion here a while back indicating that, while arguments are often evaluated left-to-right, they aren't guaranteed to be. Do we know that the shift will happen before we test the value of @_?)

UPDATE: LanX points out an extremely good answer to “why not?”, namely, “Because it behaves like accessors that get/set based on whether they have/don't have an argument, and passing an empty list leads to surprises.”

In reply to Re^6: why does push not default to $_? (simple) by JadeNB
in thread why does push not default to $_? by LanX

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