Easier yet. 
delete @hash{(keys %hash)};

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Update: this is, of course, only useful when you want to use delete the keys from one hash in another one, as in 
delete @foo{(keys %bar)};

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Otherwise, only the below solution makes any sense.

Makeshifts last the longest.

In reply to Re: Answer: How do I empty out a hash? by Aristotle
in thread How do I empty out a hash? by vroom

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